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1/*
2 * linux/fs/ext4/inode.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/inode.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * 64-bit file support on 64-bit platforms by Jakub Jelinek
16 * (jj@sunsite.ms.mff.cuni.cz)
17 *
18 * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
19 */
20
21#include <linux/fs.h>
22#include <linux/time.h>
23#include <linux/jbd2.h>
24#include <linux/highuid.h>
25#include <linux/pagemap.h>
26#include <linux/quotaops.h>
27#include <linux/string.h>
28#include <linux/buffer_head.h>
29#include <linux/writeback.h>
30#include <linux/pagevec.h>
31#include <linux/mpage.h>
32#include <linux/namei.h>
33#include <linux/uio.h>
34#include <linux/bio.h>
35#include <linux/workqueue.h>
36#include <linux/kernel.h>
37#include <linux/printk.h>
38#include <linux/slab.h>
39#include <linux/ratelimit.h>
40
41#include "ext4_jbd2.h"
42#include "xattr.h"
43#include "acl.h"
44#include "truncate.h"
45
46#include <trace/events/ext4.h>
47
48#define MPAGE_DA_EXTENT_TAIL 0x01
49
50static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw,
51 struct ext4_inode_info *ei)
52{
53 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
54 __u16 csum_lo;
55 __u16 csum_hi = 0;
56 __u32 csum;
57
58 csum_lo = raw->i_checksum_lo;
59 raw->i_checksum_lo = 0;
60 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
61 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) {
62 csum_hi = raw->i_checksum_hi;
63 raw->i_checksum_hi = 0;
64 }
65
66 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw,
67 EXT4_INODE_SIZE(inode->i_sb));
68
69 raw->i_checksum_lo = csum_lo;
70 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
71 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
72 raw->i_checksum_hi = csum_hi;
73
74 return csum;
75}
76
77static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw,
78 struct ext4_inode_info *ei)
79{
80 __u32 provided, calculated;
81
82 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
83 cpu_to_le32(EXT4_OS_LINUX) ||
84 !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
85 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
86 return 1;
87
88 provided = le16_to_cpu(raw->i_checksum_lo);
89 calculated = ext4_inode_csum(inode, raw, ei);
90 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
91 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
92 provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16;
93 else
94 calculated &= 0xFFFF;
95
96 return provided == calculated;
97}
98
99static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
100 struct ext4_inode_info *ei)
101{
102 __u32 csum;
103
104 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
105 cpu_to_le32(EXT4_OS_LINUX) ||
106 !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
107 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
108 return;
109
110 csum = ext4_inode_csum(inode, raw, ei);
111 raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF);
112 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
113 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
114 raw->i_checksum_hi = cpu_to_le16(csum >> 16);
115}
116
117static inline int ext4_begin_ordered_truncate(struct inode *inode,
118 loff_t new_size)
119{
120 trace_ext4_begin_ordered_truncate(inode, new_size);
121 /*
122 * If jinode is zero, then we never opened the file for
123 * writing, so there's no need to call
124 * jbd2_journal_begin_ordered_truncate() since there's no
125 * outstanding writes we need to flush.
126 */
127 if (!EXT4_I(inode)->jinode)
128 return 0;
129 return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode),
130 EXT4_I(inode)->jinode,
131 new_size);
132}
133
134static void ext4_invalidatepage(struct page *page, unsigned long offset);
135static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
136 struct buffer_head *bh_result, int create);
137static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
138static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
139static int __ext4_journalled_writepage(struct page *page, unsigned int len);
140static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
141static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
142 struct inode *inode, struct page *page, loff_t from,
143 loff_t length, int flags);
144
145/*
146 * Test whether an inode is a fast symlink.
147 */
148static int ext4_inode_is_fast_symlink(struct inode *inode)
149{
150 int ea_blocks = EXT4_I(inode)->i_file_acl ?
151 (inode->i_sb->s_blocksize >> 9) : 0;
152
153 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
154}
155
156/*
157 * Restart the transaction associated with *handle. This does a commit,
158 * so before we call here everything must be consistently dirtied against
159 * this transaction.
160 */
161int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
162 int nblocks)
163{
164 int ret;
165
166 /*
167 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
168 * moment, get_block can be called only for blocks inside i_size since
169 * page cache has been already dropped and writes are blocked by
170 * i_mutex. So we can safely drop the i_data_sem here.
171 */
172 BUG_ON(EXT4_JOURNAL(inode) == NULL);
173 jbd_debug(2, "restarting handle %p\n", handle);
174 up_write(&EXT4_I(inode)->i_data_sem);
175 ret = ext4_journal_restart(handle, nblocks);
176 down_write(&EXT4_I(inode)->i_data_sem);
177 ext4_discard_preallocations(inode);
178
179 return ret;
180}
181
182/*
183 * Called at the last iput() if i_nlink is zero.
184 */
185void ext4_evict_inode(struct inode *inode)
186{
187 handle_t *handle;
188 int err;
189
190 trace_ext4_evict_inode(inode);
191
192 ext4_ioend_wait(inode);
193
194 if (inode->i_nlink) {
195 /*
196 * When journalling data dirty buffers are tracked only in the
197 * journal. So although mm thinks everything is clean and
198 * ready for reaping the inode might still have some pages to
199 * write in the running transaction or waiting to be
200 * checkpointed. Thus calling jbd2_journal_invalidatepage()
201 * (via truncate_inode_pages()) to discard these buffers can
202 * cause data loss. Also even if we did not discard these
203 * buffers, we would have no way to find them after the inode
204 * is reaped and thus user could see stale data if he tries to
205 * read them before the transaction is checkpointed. So be
206 * careful and force everything to disk here... We use
207 * ei->i_datasync_tid to store the newest transaction
208 * containing inode's data.
209 *
210 * Note that directories do not have this problem because they
211 * don't use page cache.
212 */
213 if (ext4_should_journal_data(inode) &&
214 (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode))) {
215 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
216 tid_t commit_tid = EXT4_I(inode)->i_datasync_tid;
217
218 jbd2_log_start_commit(journal, commit_tid);
219 jbd2_log_wait_commit(journal, commit_tid);
220 filemap_write_and_wait(&inode->i_data);
221 }
222 truncate_inode_pages(&inode->i_data, 0);
223 goto no_delete;
224 }
225
226 if (!is_bad_inode(inode))
227 dquot_initialize(inode);
228
229 if (ext4_should_order_data(inode))
230 ext4_begin_ordered_truncate(inode, 0);
231 truncate_inode_pages(&inode->i_data, 0);
232
233 if (is_bad_inode(inode))
234 goto no_delete;
235
236 handle = ext4_journal_start(inode, ext4_blocks_for_truncate(inode)+3);
237 if (IS_ERR(handle)) {
238 ext4_std_error(inode->i_sb, PTR_ERR(handle));
239 /*
240 * If we're going to skip the normal cleanup, we still need to
241 * make sure that the in-core orphan linked list is properly
242 * cleaned up.
243 */
244 ext4_orphan_del(NULL, inode);
245 goto no_delete;
246 }
247
248 if (IS_SYNC(inode))
249 ext4_handle_sync(handle);
250 inode->i_size = 0;
251 err = ext4_mark_inode_dirty(handle, inode);
252 if (err) {
253 ext4_warning(inode->i_sb,
254 "couldn't mark inode dirty (err %d)", err);
255 goto stop_handle;
256 }
257 if (inode->i_blocks)
258 ext4_truncate(inode);
259
260 /*
261 * ext4_ext_truncate() doesn't reserve any slop when it
262 * restarts journal transactions; therefore there may not be
263 * enough credits left in the handle to remove the inode from
264 * the orphan list and set the dtime field.
265 */
266 if (!ext4_handle_has_enough_credits(handle, 3)) {
267 err = ext4_journal_extend(handle, 3);
268 if (err > 0)
269 err = ext4_journal_restart(handle, 3);
270 if (err != 0) {
271 ext4_warning(inode->i_sb,
272 "couldn't extend journal (err %d)", err);
273 stop_handle:
274 ext4_journal_stop(handle);
275 ext4_orphan_del(NULL, inode);
276 goto no_delete;
277 }
278 }
279
280 /*
281 * Kill off the orphan record which ext4_truncate created.
282 * AKPM: I think this can be inside the above `if'.
283 * Note that ext4_orphan_del() has to be able to cope with the
284 * deletion of a non-existent orphan - this is because we don't
285 * know if ext4_truncate() actually created an orphan record.
286 * (Well, we could do this if we need to, but heck - it works)
287 */
288 ext4_orphan_del(handle, inode);
289 EXT4_I(inode)->i_dtime = get_seconds();
290
291 /*
292 * One subtle ordering requirement: if anything has gone wrong
293 * (transaction abort, IO errors, whatever), then we can still
294 * do these next steps (the fs will already have been marked as
295 * having errors), but we can't free the inode if the mark_dirty
296 * fails.
297 */
298 if (ext4_mark_inode_dirty(handle, inode))
299 /* If that failed, just do the required in-core inode clear. */
300 ext4_clear_inode(inode);
301 else
302 ext4_free_inode(handle, inode);
303 ext4_journal_stop(handle);
304 return;
305no_delete:
306 ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
307}
308
309#ifdef CONFIG_QUOTA
310qsize_t *ext4_get_reserved_space(struct inode *inode)
311{
312 return &EXT4_I(inode)->i_reserved_quota;
313}
314#endif
315
316/*
317 * Calculate the number of metadata blocks need to reserve
318 * to allocate a block located at @lblock
319 */
320static int ext4_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
321{
322 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
323 return ext4_ext_calc_metadata_amount(inode, lblock);
324
325 return ext4_ind_calc_metadata_amount(inode, lblock);
326}
327
328/*
329 * Called with i_data_sem down, which is important since we can call
330 * ext4_discard_preallocations() from here.
331 */
332void ext4_da_update_reserve_space(struct inode *inode,
333 int used, int quota_claim)
334{
335 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
336 struct ext4_inode_info *ei = EXT4_I(inode);
337
338 spin_lock(&ei->i_block_reservation_lock);
339 trace_ext4_da_update_reserve_space(inode, used, quota_claim);
340 if (unlikely(used > ei->i_reserved_data_blocks)) {
341 ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, used %d "
342 "with only %d reserved data blocks",
343 __func__, inode->i_ino, used,
344 ei->i_reserved_data_blocks);
345 WARN_ON(1);
346 used = ei->i_reserved_data_blocks;
347 }
348
349 if (unlikely(ei->i_allocated_meta_blocks > ei->i_reserved_meta_blocks)) {
350 ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, allocated %d "
351 "with only %d reserved metadata blocks\n", __func__,
352 inode->i_ino, ei->i_allocated_meta_blocks,
353 ei->i_reserved_meta_blocks);
354 WARN_ON(1);
355 ei->i_allocated_meta_blocks = ei->i_reserved_meta_blocks;
356 }
357
358 /* Update per-inode reservations */
359 ei->i_reserved_data_blocks -= used;
360 ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks;
361 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
362 used + ei->i_allocated_meta_blocks);
363 ei->i_allocated_meta_blocks = 0;
364
365 if (ei->i_reserved_data_blocks == 0) {
366 /*
367 * We can release all of the reserved metadata blocks
368 * only when we have written all of the delayed
369 * allocation blocks.
370 */
371 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
372 ei->i_reserved_meta_blocks);
373 ei->i_reserved_meta_blocks = 0;
374 ei->i_da_metadata_calc_len = 0;
375 }
376 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
377
378 /* Update quota subsystem for data blocks */
379 if (quota_claim)
380 dquot_claim_block(inode, EXT4_C2B(sbi, used));
381 else {
382 /*
383 * We did fallocate with an offset that is already delayed
384 * allocated. So on delayed allocated writeback we should
385 * not re-claim the quota for fallocated blocks.
386 */
387 dquot_release_reservation_block(inode, EXT4_C2B(sbi, used));
388 }
389
390 /*
391 * If we have done all the pending block allocations and if
392 * there aren't any writers on the inode, we can discard the
393 * inode's preallocations.
394 */
395 if ((ei->i_reserved_data_blocks == 0) &&
396 (atomic_read(&inode->i_writecount) == 0))
397 ext4_discard_preallocations(inode);
398}
399
400static int __check_block_validity(struct inode *inode, const char *func,
401 unsigned int line,
402 struct ext4_map_blocks *map)
403{
404 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
405 map->m_len)) {
406 ext4_error_inode(inode, func, line, map->m_pblk,
407 "lblock %lu mapped to illegal pblock "
408 "(length %d)", (unsigned long) map->m_lblk,
409 map->m_len);
410 return -EIO;
411 }
412 return 0;
413}
414
415#define check_block_validity(inode, map) \
416 __check_block_validity((inode), __func__, __LINE__, (map))
417
418/*
419 * Return the number of contiguous dirty pages in a given inode
420 * starting at page frame idx.
421 */
422static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
423 unsigned int max_pages)
424{
425 struct address_space *mapping = inode->i_mapping;
426 pgoff_t index;
427 struct pagevec pvec;
428 pgoff_t num = 0;
429 int i, nr_pages, done = 0;
430
431 if (max_pages == 0)
432 return 0;
433 pagevec_init(&pvec, 0);
434 while (!done) {
435 index = idx;
436 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
437 PAGECACHE_TAG_DIRTY,
438 (pgoff_t)PAGEVEC_SIZE);
439 if (nr_pages == 0)
440 break;
441 for (i = 0; i < nr_pages; i++) {
442 struct page *page = pvec.pages[i];
443 struct buffer_head *bh, *head;
444
445 lock_page(page);
446 if (unlikely(page->mapping != mapping) ||
447 !PageDirty(page) ||
448 PageWriteback(page) ||
449 page->index != idx) {
450 done = 1;
451 unlock_page(page);
452 break;
453 }
454 if (page_has_buffers(page)) {
455 bh = head = page_buffers(page);
456 do {
457 if (!buffer_delay(bh) &&
458 !buffer_unwritten(bh))
459 done = 1;
460 bh = bh->b_this_page;
461 } while (!done && (bh != head));
462 }
463 unlock_page(page);
464 if (done)
465 break;
466 idx++;
467 num++;
468 if (num >= max_pages) {
469 done = 1;
470 break;
471 }
472 }
473 pagevec_release(&pvec);
474 }
475 return num;
476}
477
478/*
479 * Sets the BH_Da_Mapped bit on the buffer heads corresponding to the given map.
480 */
481static void set_buffers_da_mapped(struct inode *inode,
482 struct ext4_map_blocks *map)
483{
484 struct address_space *mapping = inode->i_mapping;
485 struct pagevec pvec;
486 int i, nr_pages;
487 pgoff_t index, end;
488
489 index = map->m_lblk >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
490 end = (map->m_lblk + map->m_len - 1) >>
491 (PAGE_CACHE_SHIFT - inode->i_blkbits);
492
493 pagevec_init(&pvec, 0);
494 while (index <= end) {
495 nr_pages = pagevec_lookup(&pvec, mapping, index,
496 min(end - index + 1,
497 (pgoff_t)PAGEVEC_SIZE));
498 if (nr_pages == 0)
499 break;
500 for (i = 0; i < nr_pages; i++) {
501 struct page *page = pvec.pages[i];
502 struct buffer_head *bh, *head;
503
504 if (unlikely(page->mapping != mapping) ||
505 !PageDirty(page))
506 break;
507
508 if (page_has_buffers(page)) {
509 bh = head = page_buffers(page);
510 do {
511 set_buffer_da_mapped(bh);
512 bh = bh->b_this_page;
513 } while (bh != head);
514 }
515 index++;
516 }
517 pagevec_release(&pvec);
518 }
519}
520
521/*
522 * The ext4_map_blocks() function tries to look up the requested blocks,
523 * and returns if the blocks are already mapped.
524 *
525 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
526 * and store the allocated blocks in the result buffer head and mark it
527 * mapped.
528 *
529 * If file type is extents based, it will call ext4_ext_map_blocks(),
530 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
531 * based files
532 *
533 * On success, it returns the number of blocks being mapped or allocate.
534 * if create==0 and the blocks are pre-allocated and uninitialized block,
535 * the result buffer head is unmapped. If the create ==1, it will make sure
536 * the buffer head is mapped.
537 *
538 * It returns 0 if plain look up failed (blocks have not been allocated), in
539 * that case, buffer head is unmapped
540 *
541 * It returns the error in case of allocation failure.
542 */
543int ext4_map_blocks(handle_t *handle, struct inode *inode,
544 struct ext4_map_blocks *map, int flags)
545{
546 int retval;
547
548 map->m_flags = 0;
549 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
550 "logical block %lu\n", inode->i_ino, flags, map->m_len,
551 (unsigned long) map->m_lblk);
552 /*
553 * Try to see if we can get the block without requesting a new
554 * file system block.
555 */
556 down_read((&EXT4_I(inode)->i_data_sem));
557 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
558 retval = ext4_ext_map_blocks(handle, inode, map, flags &
559 EXT4_GET_BLOCKS_KEEP_SIZE);
560 } else {
561 retval = ext4_ind_map_blocks(handle, inode, map, flags &
562 EXT4_GET_BLOCKS_KEEP_SIZE);
563 }
564 up_read((&EXT4_I(inode)->i_data_sem));
565
566 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
567 int ret = check_block_validity(inode, map);
568 if (ret != 0)
569 return ret;
570 }
571
572 /* If it is only a block(s) look up */
573 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
574 return retval;
575
576 /*
577 * Returns if the blocks have already allocated
578 *
579 * Note that if blocks have been preallocated
580 * ext4_ext_get_block() returns the create = 0
581 * with buffer head unmapped.
582 */
583 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
584 return retval;
585
586 /*
587 * When we call get_blocks without the create flag, the
588 * BH_Unwritten flag could have gotten set if the blocks
589 * requested were part of a uninitialized extent. We need to
590 * clear this flag now that we are committed to convert all or
591 * part of the uninitialized extent to be an initialized
592 * extent. This is because we need to avoid the combination
593 * of BH_Unwritten and BH_Mapped flags being simultaneously
594 * set on the buffer_head.
595 */
596 map->m_flags &= ~EXT4_MAP_UNWRITTEN;
597
598 /*
599 * New blocks allocate and/or writing to uninitialized extent
600 * will possibly result in updating i_data, so we take
601 * the write lock of i_data_sem, and call get_blocks()
602 * with create == 1 flag.
603 */
604 down_write((&EXT4_I(inode)->i_data_sem));
605
606 /*
607 * if the caller is from delayed allocation writeout path
608 * we have already reserved fs blocks for allocation
609 * let the underlying get_block() function know to
610 * avoid double accounting
611 */
612 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
613 ext4_set_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
614 /*
615 * We need to check for EXT4 here because migrate
616 * could have changed the inode type in between
617 */
618 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
619 retval = ext4_ext_map_blocks(handle, inode, map, flags);
620 } else {
621 retval = ext4_ind_map_blocks(handle, inode, map, flags);
622
623 if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
624 /*
625 * We allocated new blocks which will result in
626 * i_data's format changing. Force the migrate
627 * to fail by clearing migrate flags
628 */
629 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
630 }
631
632 /*
633 * Update reserved blocks/metadata blocks after successful
634 * block allocation which had been deferred till now. We don't
635 * support fallocate for non extent files. So we can update
636 * reserve space here.
637 */
638 if ((retval > 0) &&
639 (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
640 ext4_da_update_reserve_space(inode, retval, 1);
641 }
642 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
643 ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
644
645 /* If we have successfully mapped the delayed allocated blocks,
646 * set the BH_Da_Mapped bit on them. Its important to do this
647 * under the protection of i_data_sem.
648 */
649 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
650 set_buffers_da_mapped(inode, map);
651 }
652
653 up_write((&EXT4_I(inode)->i_data_sem));
654 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
655 int ret = check_block_validity(inode, map);
656 if (ret != 0)
657 return ret;
658 }
659 return retval;
660}
661
662/* Maximum number of blocks we map for direct IO at once. */
663#define DIO_MAX_BLOCKS 4096
664
665static int _ext4_get_block(struct inode *inode, sector_t iblock,
666 struct buffer_head *bh, int flags)
667{
668 handle_t *handle = ext4_journal_current_handle();
669 struct ext4_map_blocks map;
670 int ret = 0, started = 0;
671 int dio_credits;
672
673 map.m_lblk = iblock;
674 map.m_len = bh->b_size >> inode->i_blkbits;
675
676 if (flags && !handle) {
677 /* Direct IO write... */
678 if (map.m_len > DIO_MAX_BLOCKS)
679 map.m_len = DIO_MAX_BLOCKS;
680 dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
681 handle = ext4_journal_start(inode, dio_credits);
682 if (IS_ERR(handle)) {
683 ret = PTR_ERR(handle);
684 return ret;
685 }
686 started = 1;
687 }
688
689 ret = ext4_map_blocks(handle, inode, &map, flags);
690 if (ret > 0) {
691 map_bh(bh, inode->i_sb, map.m_pblk);
692 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
693 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
694 ret = 0;
695 }
696 if (started)
697 ext4_journal_stop(handle);
698 return ret;
699}
700
701int ext4_get_block(struct inode *inode, sector_t iblock,
702 struct buffer_head *bh, int create)
703{
704 return _ext4_get_block(inode, iblock, bh,
705 create ? EXT4_GET_BLOCKS_CREATE : 0);
706}
707
708/*
709 * `handle' can be NULL if create is zero
710 */
711struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
712 ext4_lblk_t block, int create, int *errp)
713{
714 struct ext4_map_blocks map;
715 struct buffer_head *bh;
716 int fatal = 0, err;
717
718 J_ASSERT(handle != NULL || create == 0);
719
720 map.m_lblk = block;
721 map.m_len = 1;
722 err = ext4_map_blocks(handle, inode, &map,
723 create ? EXT4_GET_BLOCKS_CREATE : 0);
724
725 if (err < 0)
726 *errp = err;
727 if (err <= 0)
728 return NULL;
729 *errp = 0;
730
731 bh = sb_getblk(inode->i_sb, map.m_pblk);
732 if (!bh) {
733 *errp = -EIO;
734 return NULL;
735 }
736 if (map.m_flags & EXT4_MAP_NEW) {
737 J_ASSERT(create != 0);
738 J_ASSERT(handle != NULL);
739
740 /*
741 * Now that we do not always journal data, we should
742 * keep in mind whether this should always journal the
743 * new buffer as metadata. For now, regular file
744 * writes use ext4_get_block instead, so it's not a
745 * problem.
746 */
747 lock_buffer(bh);
748 BUFFER_TRACE(bh, "call get_create_access");
749 fatal = ext4_journal_get_create_access(handle, bh);
750 if (!fatal && !buffer_uptodate(bh)) {
751 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
752 set_buffer_uptodate(bh);
753 }
754 unlock_buffer(bh);
755 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
756 err = ext4_handle_dirty_metadata(handle, inode, bh);
757 if (!fatal)
758 fatal = err;
759 } else {
760 BUFFER_TRACE(bh, "not a new buffer");
761 }
762 if (fatal) {
763 *errp = fatal;
764 brelse(bh);
765 bh = NULL;
766 }
767 return bh;
768}
769
770struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
771 ext4_lblk_t block, int create, int *err)
772{
773 struct buffer_head *bh;
774
775 bh = ext4_getblk(handle, inode, block, create, err);
776 if (!bh)
777 return bh;
778 if (buffer_uptodate(bh))
779 return bh;
780 ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);
781 wait_on_buffer(bh);
782 if (buffer_uptodate(bh))
783 return bh;
784 put_bh(bh);
785 *err = -EIO;
786 return NULL;
787}
788
789static int walk_page_buffers(handle_t *handle,
790 struct buffer_head *head,
791 unsigned from,
792 unsigned to,
793 int *partial,
794 int (*fn)(handle_t *handle,
795 struct buffer_head *bh))
796{
797 struct buffer_head *bh;
798 unsigned block_start, block_end;
799 unsigned blocksize = head->b_size;
800 int err, ret = 0;
801 struct buffer_head *next;
802
803 for (bh = head, block_start = 0;
804 ret == 0 && (bh != head || !block_start);
805 block_start = block_end, bh = next) {
806 next = bh->b_this_page;
807 block_end = block_start + blocksize;
808 if (block_end <= from || block_start >= to) {
809 if (partial && !buffer_uptodate(bh))
810 *partial = 1;
811 continue;
812 }
813 err = (*fn)(handle, bh);
814 if (!ret)
815 ret = err;
816 }
817 return ret;
818}
819
820/*
821 * To preserve ordering, it is essential that the hole instantiation and
822 * the data write be encapsulated in a single transaction. We cannot
823 * close off a transaction and start a new one between the ext4_get_block()
824 * and the commit_write(). So doing the jbd2_journal_start at the start of
825 * prepare_write() is the right place.
826 *
827 * Also, this function can nest inside ext4_writepage() ->
828 * block_write_full_page(). In that case, we *know* that ext4_writepage()
829 * has generated enough buffer credits to do the whole page. So we won't
830 * block on the journal in that case, which is good, because the caller may
831 * be PF_MEMALLOC.
832 *
833 * By accident, ext4 can be reentered when a transaction is open via
834 * quota file writes. If we were to commit the transaction while thus
835 * reentered, there can be a deadlock - we would be holding a quota
836 * lock, and the commit would never complete if another thread had a
837 * transaction open and was blocking on the quota lock - a ranking
838 * violation.
839 *
840 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
841 * will _not_ run commit under these circumstances because handle->h_ref
842 * is elevated. We'll still have enough credits for the tiny quotafile
843 * write.
844 */
845static int do_journal_get_write_access(handle_t *handle,
846 struct buffer_head *bh)
847{
848 int dirty = buffer_dirty(bh);
849 int ret;
850
851 if (!buffer_mapped(bh) || buffer_freed(bh))
852 return 0;
853 /*
854 * __block_write_begin() could have dirtied some buffers. Clean
855 * the dirty bit as jbd2_journal_get_write_access() could complain
856 * otherwise about fs integrity issues. Setting of the dirty bit
857 * by __block_write_begin() isn't a real problem here as we clear
858 * the bit before releasing a page lock and thus writeback cannot
859 * ever write the buffer.
860 */
861 if (dirty)
862 clear_buffer_dirty(bh);
863 ret = ext4_journal_get_write_access(handle, bh);
864 if (!ret && dirty)
865 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
866 return ret;
867}
868
869static int ext4_get_block_write(struct inode *inode, sector_t iblock,
870 struct buffer_head *bh_result, int create);
871static int ext4_write_begin(struct file *file, struct address_space *mapping,
872 loff_t pos, unsigned len, unsigned flags,
873 struct page **pagep, void **fsdata)
874{
875 struct inode *inode = mapping->host;
876 int ret, needed_blocks;
877 handle_t *handle;
878 int retries = 0;
879 struct page *page;
880 pgoff_t index;
881 unsigned from, to;
882
883 trace_ext4_write_begin(inode, pos, len, flags);
884 /*
885 * Reserve one block more for addition to orphan list in case
886 * we allocate blocks but write fails for some reason
887 */
888 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
889 index = pos >> PAGE_CACHE_SHIFT;
890 from = pos & (PAGE_CACHE_SIZE - 1);
891 to = from + len;
892
893retry:
894 handle = ext4_journal_start(inode, needed_blocks);
895 if (IS_ERR(handle)) {
896 ret = PTR_ERR(handle);
897 goto out;
898 }
899
900 /* We cannot recurse into the filesystem as the transaction is already
901 * started */
902 flags |= AOP_FLAG_NOFS;
903
904 page = grab_cache_page_write_begin(mapping, index, flags);
905 if (!page) {
906 ext4_journal_stop(handle);
907 ret = -ENOMEM;
908 goto out;
909 }
910 *pagep = page;
911
912 if (ext4_should_dioread_nolock(inode))
913 ret = __block_write_begin(page, pos, len, ext4_get_block_write);
914 else
915 ret = __block_write_begin(page, pos, len, ext4_get_block);
916
917 if (!ret && ext4_should_journal_data(inode)) {
918 ret = walk_page_buffers(handle, page_buffers(page),
919 from, to, NULL, do_journal_get_write_access);
920 }
921
922 if (ret) {
923 unlock_page(page);
924 page_cache_release(page);
925 /*
926 * __block_write_begin may have instantiated a few blocks
927 * outside i_size. Trim these off again. Don't need
928 * i_size_read because we hold i_mutex.
929 *
930 * Add inode to orphan list in case we crash before
931 * truncate finishes
932 */
933 if (pos + len > inode->i_size && ext4_can_truncate(inode))
934 ext4_orphan_add(handle, inode);
935
936 ext4_journal_stop(handle);
937 if (pos + len > inode->i_size) {
938 ext4_truncate_failed_write(inode);
939 /*
940 * If truncate failed early the inode might
941 * still be on the orphan list; we need to
942 * make sure the inode is removed from the
943 * orphan list in that case.
944 */
945 if (inode->i_nlink)
946 ext4_orphan_del(NULL, inode);
947 }
948 }
949
950 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
951 goto retry;
952out:
953 return ret;
954}
955
956/* For write_end() in data=journal mode */
957static int write_end_fn(handle_t *handle, struct buffer_head *bh)
958{
959 if (!buffer_mapped(bh) || buffer_freed(bh))
960 return 0;
961 set_buffer_uptodate(bh);
962 return ext4_handle_dirty_metadata(handle, NULL, bh);
963}
964
965static int ext4_generic_write_end(struct file *file,
966 struct address_space *mapping,
967 loff_t pos, unsigned len, unsigned copied,
968 struct page *page, void *fsdata)
969{
970 int i_size_changed = 0;
971 struct inode *inode = mapping->host;
972 handle_t *handle = ext4_journal_current_handle();
973
974 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
975
976 /*
977 * No need to use i_size_read() here, the i_size
978 * cannot change under us because we hold i_mutex.
979 *
980 * But it's important to update i_size while still holding page lock:
981 * page writeout could otherwise come in and zero beyond i_size.
982 */
983 if (pos + copied > inode->i_size) {
984 i_size_write(inode, pos + copied);
985 i_size_changed = 1;
986 }
987
988 if (pos + copied > EXT4_I(inode)->i_disksize) {
989 /* We need to mark inode dirty even if
990 * new_i_size is less that inode->i_size
991 * bu greater than i_disksize.(hint delalloc)
992 */
993 ext4_update_i_disksize(inode, (pos + copied));
994 i_size_changed = 1;
995 }
996 unlock_page(page);
997 page_cache_release(page);
998
999 /*
1000 * Don't mark the inode dirty under page lock. First, it unnecessarily
1001 * makes the holding time of page lock longer. Second, it forces lock
1002 * ordering of page lock and transaction start for journaling
1003 * filesystems.
1004 */
1005 if (i_size_changed)
1006 ext4_mark_inode_dirty(handle, inode);
1007
1008 return copied;
1009}
1010
1011/*
1012 * We need to pick up the new inode size which generic_commit_write gave us
1013 * `file' can be NULL - eg, when called from page_symlink().
1014 *
1015 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1016 * buffers are managed internally.
1017 */
1018static int ext4_ordered_write_end(struct file *file,
1019 struct address_space *mapping,
1020 loff_t pos, unsigned len, unsigned copied,
1021 struct page *page, void *fsdata)
1022{
1023 handle_t *handle = ext4_journal_current_handle();
1024 struct inode *inode = mapping->host;
1025 int ret = 0, ret2;
1026
1027 trace_ext4_ordered_write_end(inode, pos, len, copied);
1028 ret = ext4_jbd2_file_inode(handle, inode);
1029
1030 if (ret == 0) {
1031 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
1032 page, fsdata);
1033 copied = ret2;
1034 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1035 /* if we have allocated more blocks and copied
1036 * less. We will have blocks allocated outside
1037 * inode->i_size. So truncate them
1038 */
1039 ext4_orphan_add(handle, inode);
1040 if (ret2 < 0)
1041 ret = ret2;
1042 } else {
1043 unlock_page(page);
1044 page_cache_release(page);
1045 }
1046
1047 ret2 = ext4_journal_stop(handle);
1048 if (!ret)
1049 ret = ret2;
1050
1051 if (pos + len > inode->i_size) {
1052 ext4_truncate_failed_write(inode);
1053 /*
1054 * If truncate failed early the inode might still be
1055 * on the orphan list; we need to make sure the inode
1056 * is removed from the orphan list in that case.
1057 */
1058 if (inode->i_nlink)
1059 ext4_orphan_del(NULL, inode);
1060 }
1061
1062
1063 return ret ? ret : copied;
1064}
1065
1066static int ext4_writeback_write_end(struct file *file,
1067 struct address_space *mapping,
1068 loff_t pos, unsigned len, unsigned copied,
1069 struct page *page, void *fsdata)
1070{
1071 handle_t *handle = ext4_journal_current_handle();
1072 struct inode *inode = mapping->host;
1073 int ret = 0, ret2;
1074
1075 trace_ext4_writeback_write_end(inode, pos, len, copied);
1076 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
1077 page, fsdata);
1078 copied = ret2;
1079 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1080 /* if we have allocated more blocks and copied
1081 * less. We will have blocks allocated outside
1082 * inode->i_size. So truncate them
1083 */
1084 ext4_orphan_add(handle, inode);
1085
1086 if (ret2 < 0)
1087 ret = ret2;
1088
1089 ret2 = ext4_journal_stop(handle);
1090 if (!ret)
1091 ret = ret2;
1092
1093 if (pos + len > inode->i_size) {
1094 ext4_truncate_failed_write(inode);
1095 /*
1096 * If truncate failed early the inode might still be
1097 * on the orphan list; we need to make sure the inode
1098 * is removed from the orphan list in that case.
1099 */
1100 if (inode->i_nlink)
1101 ext4_orphan_del(NULL, inode);
1102 }
1103
1104 return ret ? ret : copied;
1105}
1106
1107static int ext4_journalled_write_end(struct file *file,
1108 struct address_space *mapping,
1109 loff_t pos, unsigned len, unsigned copied,
1110 struct page *page, void *fsdata)
1111{
1112 handle_t *handle = ext4_journal_current_handle();
1113 struct inode *inode = mapping->host;
1114 int ret = 0, ret2;
1115 int partial = 0;
1116 unsigned from, to;
1117 loff_t new_i_size;
1118
1119 trace_ext4_journalled_write_end(inode, pos, len, copied);
1120 from = pos & (PAGE_CACHE_SIZE - 1);
1121 to = from + len;
1122
1123 BUG_ON(!ext4_handle_valid(handle));
1124
1125 if (copied < len) {
1126 if (!PageUptodate(page))
1127 copied = 0;
1128 page_zero_new_buffers(page, from+copied, to);
1129 }
1130
1131 ret = walk_page_buffers(handle, page_buffers(page), from,
1132 to, &partial, write_end_fn);
1133 if (!partial)
1134 SetPageUptodate(page);
1135 new_i_size = pos + copied;
1136 if (new_i_size > inode->i_size)
1137 i_size_write(inode, pos+copied);
1138 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1139 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1140 if (new_i_size > EXT4_I(inode)->i_disksize) {
1141 ext4_update_i_disksize(inode, new_i_size);
1142 ret2 = ext4_mark_inode_dirty(handle, inode);
1143 if (!ret)
1144 ret = ret2;
1145 }
1146
1147 unlock_page(page);
1148 page_cache_release(page);
1149 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1150 /* if we have allocated more blocks and copied
1151 * less. We will have blocks allocated outside
1152 * inode->i_size. So truncate them
1153 */
1154 ext4_orphan_add(handle, inode);
1155
1156 ret2 = ext4_journal_stop(handle);
1157 if (!ret)
1158 ret = ret2;
1159 if (pos + len > inode->i_size) {
1160 ext4_truncate_failed_write(inode);
1161 /*
1162 * If truncate failed early the inode might still be
1163 * on the orphan list; we need to make sure the inode
1164 * is removed from the orphan list in that case.
1165 */
1166 if (inode->i_nlink)
1167 ext4_orphan_del(NULL, inode);
1168 }
1169
1170 return ret ? ret : copied;
1171}
1172
1173/*
1174 * Reserve a single cluster located at lblock
1175 */
1176static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock)
1177{
1178 int retries = 0;
1179 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1180 struct ext4_inode_info *ei = EXT4_I(inode);
1181 unsigned int md_needed;
1182 int ret;
1183 ext4_lblk_t save_last_lblock;
1184 int save_len;
1185
1186 /*
1187 * We will charge metadata quota at writeout time; this saves
1188 * us from metadata over-estimation, though we may go over by
1189 * a small amount in the end. Here we just reserve for data.
1190 */
1191 ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
1192 if (ret)
1193 return ret;
1194
1195 /*
1196 * recalculate the amount of metadata blocks to reserve
1197 * in order to allocate nrblocks
1198 * worse case is one extent per block
1199 */
1200repeat:
1201 spin_lock(&ei->i_block_reservation_lock);
1202 /*
1203 * ext4_calc_metadata_amount() has side effects, which we have
1204 * to be prepared undo if we fail to claim space.
1205 */
1206 save_len = ei->i_da_metadata_calc_len;
1207 save_last_lblock = ei->i_da_metadata_calc_last_lblock;
1208 md_needed = EXT4_NUM_B2C(sbi,
1209 ext4_calc_metadata_amount(inode, lblock));
1210 trace_ext4_da_reserve_space(inode, md_needed);
1211
1212 /*
1213 * We do still charge estimated metadata to the sb though;
1214 * we cannot afford to run out of free blocks.
1215 */
1216 if (ext4_claim_free_clusters(sbi, md_needed + 1, 0)) {
1217 ei->i_da_metadata_calc_len = save_len;
1218 ei->i_da_metadata_calc_last_lblock = save_last_lblock;
1219 spin_unlock(&ei->i_block_reservation_lock);
1220 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
1221 yield();
1222 goto repeat;
1223 }
1224 dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
1225 return -ENOSPC;
1226 }
1227 ei->i_reserved_data_blocks++;
1228 ei->i_reserved_meta_blocks += md_needed;
1229 spin_unlock(&ei->i_block_reservation_lock);
1230
1231 return 0; /* success */
1232}
1233
1234static void ext4_da_release_space(struct inode *inode, int to_free)
1235{
1236 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1237 struct ext4_inode_info *ei = EXT4_I(inode);
1238
1239 if (!to_free)
1240 return; /* Nothing to release, exit */
1241
1242 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1243
1244 trace_ext4_da_release_space(inode, to_free);
1245 if (unlikely(to_free > ei->i_reserved_data_blocks)) {
1246 /*
1247 * if there aren't enough reserved blocks, then the
1248 * counter is messed up somewhere. Since this
1249 * function is called from invalidate page, it's
1250 * harmless to return without any action.
1251 */
1252 ext4_msg(inode->i_sb, KERN_NOTICE, "ext4_da_release_space: "
1253 "ino %lu, to_free %d with only %d reserved "
1254 "data blocks", inode->i_ino, to_free,
1255 ei->i_reserved_data_blocks);
1256 WARN_ON(1);
1257 to_free = ei->i_reserved_data_blocks;
1258 }
1259 ei->i_reserved_data_blocks -= to_free;
1260
1261 if (ei->i_reserved_data_blocks == 0) {
1262 /*
1263 * We can release all of the reserved metadata blocks
1264 * only when we have written all of the delayed
1265 * allocation blocks.
1266 * Note that in case of bigalloc, i_reserved_meta_blocks,
1267 * i_reserved_data_blocks, etc. refer to number of clusters.
1268 */
1269 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
1270 ei->i_reserved_meta_blocks);
1271 ei->i_reserved_meta_blocks = 0;
1272 ei->i_da_metadata_calc_len = 0;
1273 }
1274
1275 /* update fs dirty data blocks counter */
1276 percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free);
1277
1278 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1279
1280 dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
1281}
1282
1283static void ext4_da_page_release_reservation(struct page *page,
1284 unsigned long offset)
1285{
1286 int to_release = 0;
1287 struct buffer_head *head, *bh;
1288 unsigned int curr_off = 0;
1289 struct inode *inode = page->mapping->host;
1290 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1291 int num_clusters;
1292
1293 head = page_buffers(page);
1294 bh = head;
1295 do {
1296 unsigned int next_off = curr_off + bh->b_size;
1297
1298 if ((offset <= curr_off) && (buffer_delay(bh))) {
1299 to_release++;
1300 clear_buffer_delay(bh);
1301 clear_buffer_da_mapped(bh);
1302 }
1303 curr_off = next_off;
1304 } while ((bh = bh->b_this_page) != head);
1305
1306 /* If we have released all the blocks belonging to a cluster, then we
1307 * need to release the reserved space for that cluster. */
1308 num_clusters = EXT4_NUM_B2C(sbi, to_release);
1309 while (num_clusters > 0) {
1310 ext4_fsblk_t lblk;
1311 lblk = (page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits)) +
1312 ((num_clusters - 1) << sbi->s_cluster_bits);
1313 if (sbi->s_cluster_ratio == 1 ||
1314 !ext4_find_delalloc_cluster(inode, lblk, 1))
1315 ext4_da_release_space(inode, 1);
1316
1317 num_clusters--;
1318 }
1319}
1320
1321/*
1322 * Delayed allocation stuff
1323 */
1324
1325/*
1326 * mpage_da_submit_io - walks through extent of pages and try to write
1327 * them with writepage() call back
1328 *
1329 * @mpd->inode: inode
1330 * @mpd->first_page: first page of the extent
1331 * @mpd->next_page: page after the last page of the extent
1332 *
1333 * By the time mpage_da_submit_io() is called we expect all blocks
1334 * to be allocated. this may be wrong if allocation failed.
1335 *
1336 * As pages are already locked by write_cache_pages(), we can't use it
1337 */
1338static int mpage_da_submit_io(struct mpage_da_data *mpd,
1339 struct ext4_map_blocks *map)
1340{
1341 struct pagevec pvec;
1342 unsigned long index, end;
1343 int ret = 0, err, nr_pages, i;
1344 struct inode *inode = mpd->inode;
1345 struct address_space *mapping = inode->i_mapping;
1346 loff_t size = i_size_read(inode);
1347 unsigned int len, block_start;
1348 struct buffer_head *bh, *page_bufs = NULL;
1349 int journal_data = ext4_should_journal_data(inode);
1350 sector_t pblock = 0, cur_logical = 0;
1351 struct ext4_io_submit io_submit;
1352
1353 BUG_ON(mpd->next_page <= mpd->first_page);
1354 memset(&io_submit, 0, sizeof(io_submit));
1355 /*
1356 * We need to start from the first_page to the next_page - 1
1357 * to make sure we also write the mapped dirty buffer_heads.
1358 * If we look at mpd->b_blocknr we would only be looking
1359 * at the currently mapped buffer_heads.
1360 */
1361 index = mpd->first_page;
1362 end = mpd->next_page - 1;
1363
1364 pagevec_init(&pvec, 0);
1365 while (index <= end) {
1366 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1367 if (nr_pages == 0)
1368 break;
1369 for (i = 0; i < nr_pages; i++) {
1370 int commit_write = 0, skip_page = 0;
1371 struct page *page = pvec.pages[i];
1372
1373 index = page->index;
1374 if (index > end)
1375 break;
1376
1377 if (index == size >> PAGE_CACHE_SHIFT)
1378 len = size & ~PAGE_CACHE_MASK;
1379 else
1380 len = PAGE_CACHE_SIZE;
1381 if (map) {
1382 cur_logical = index << (PAGE_CACHE_SHIFT -
1383 inode->i_blkbits);
1384 pblock = map->m_pblk + (cur_logical -
1385 map->m_lblk);
1386 }
1387 index++;
1388
1389 BUG_ON(!PageLocked(page));
1390 BUG_ON(PageWriteback(page));
1391
1392 /*
1393 * If the page does not have buffers (for
1394 * whatever reason), try to create them using
1395 * __block_write_begin. If this fails,
1396 * skip the page and move on.
1397 */
1398 if (!page_has_buffers(page)) {
1399 if (__block_write_begin(page, 0, len,
1400 noalloc_get_block_write)) {
1401 skip_page:
1402 unlock_page(page);
1403 continue;
1404 }
1405 commit_write = 1;
1406 }
1407
1408 bh = page_bufs = page_buffers(page);
1409 block_start = 0;
1410 do {
1411 if (!bh)
1412 goto skip_page;
1413 if (map && (cur_logical >= map->m_lblk) &&
1414 (cur_logical <= (map->m_lblk +
1415 (map->m_len - 1)))) {
1416 if (buffer_delay(bh)) {
1417 clear_buffer_delay(bh);
1418 bh->b_blocknr = pblock;
1419 }
1420 if (buffer_da_mapped(bh))
1421 clear_buffer_da_mapped(bh);
1422 if (buffer_unwritten(bh) ||
1423 buffer_mapped(bh))
1424 BUG_ON(bh->b_blocknr != pblock);
1425 if (map->m_flags & EXT4_MAP_UNINIT)
1426 set_buffer_uninit(bh);
1427 clear_buffer_unwritten(bh);
1428 }
1429
1430 /*
1431 * skip page if block allocation undone and
1432 * block is dirty
1433 */
1434 if (ext4_bh_delay_or_unwritten(NULL, bh))
1435 skip_page = 1;
1436 bh = bh->b_this_page;
1437 block_start += bh->b_size;
1438 cur_logical++;
1439 pblock++;
1440 } while (bh != page_bufs);
1441
1442 if (skip_page)
1443 goto skip_page;
1444
1445 if (commit_write)
1446 /* mark the buffer_heads as dirty & uptodate */
1447 block_commit_write(page, 0, len);
1448
1449 clear_page_dirty_for_io(page);
1450 /*
1451 * Delalloc doesn't support data journalling,
1452 * but eventually maybe we'll lift this
1453 * restriction.
1454 */
1455 if (unlikely(journal_data && PageChecked(page)))
1456 err = __ext4_journalled_writepage(page, len);
1457 else if (test_opt(inode->i_sb, MBLK_IO_SUBMIT))
1458 err = ext4_bio_write_page(&io_submit, page,
1459 len, mpd->wbc);
1460 else if (buffer_uninit(page_bufs)) {
1461 ext4_set_bh_endio(page_bufs, inode);
1462 err = block_write_full_page_endio(page,
1463 noalloc_get_block_write,
1464 mpd->wbc, ext4_end_io_buffer_write);
1465 } else
1466 err = block_write_full_page(page,
1467 noalloc_get_block_write, mpd->wbc);
1468
1469 if (!err)
1470 mpd->pages_written++;
1471 /*
1472 * In error case, we have to continue because
1473 * remaining pages are still locked
1474 */
1475 if (ret == 0)
1476 ret = err;
1477 }
1478 pagevec_release(&pvec);
1479 }
1480 ext4_io_submit(&io_submit);
1481 return ret;
1482}
1483
1484static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd)
1485{
1486 int nr_pages, i;
1487 pgoff_t index, end;
1488 struct pagevec pvec;
1489 struct inode *inode = mpd->inode;
1490 struct address_space *mapping = inode->i_mapping;
1491
1492 index = mpd->first_page;
1493 end = mpd->next_page - 1;
1494 while (index <= end) {
1495 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1496 if (nr_pages == 0)
1497 break;
1498 for (i = 0; i < nr_pages; i++) {
1499 struct page *page = pvec.pages[i];
1500 if (page->index > end)
1501 break;
1502 BUG_ON(!PageLocked(page));
1503 BUG_ON(PageWriteback(page));
1504 block_invalidatepage(page, 0);
1505 ClearPageUptodate(page);
1506 unlock_page(page);
1507 }
1508 index = pvec.pages[nr_pages - 1]->index + 1;
1509 pagevec_release(&pvec);
1510 }
1511 return;
1512}
1513
1514static void ext4_print_free_blocks(struct inode *inode)
1515{
1516 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1517 struct super_block *sb = inode->i_sb;
1518
1519 ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld",
1520 EXT4_C2B(EXT4_SB(inode->i_sb),
1521 ext4_count_free_clusters(inode->i_sb)));
1522 ext4_msg(sb, KERN_CRIT, "Free/Dirty block details");
1523 ext4_msg(sb, KERN_CRIT, "free_blocks=%lld",
1524 (long long) EXT4_C2B(EXT4_SB(inode->i_sb),
1525 percpu_counter_sum(&sbi->s_freeclusters_counter)));
1526 ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld",
1527 (long long) EXT4_C2B(EXT4_SB(inode->i_sb),
1528 percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
1529 ext4_msg(sb, KERN_CRIT, "Block reservation details");
1530 ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u",
1531 EXT4_I(inode)->i_reserved_data_blocks);
1532 ext4_msg(sb, KERN_CRIT, "i_reserved_meta_blocks=%u",
1533 EXT4_I(inode)->i_reserved_meta_blocks);
1534 return;
1535}
1536
1537/*
1538 * mpage_da_map_and_submit - go through given space, map them
1539 * if necessary, and then submit them for I/O
1540 *
1541 * @mpd - bh describing space
1542 *
1543 * The function skips space we know is already mapped to disk blocks.
1544 *
1545 */
1546static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
1547{
1548 int err, blks, get_blocks_flags;
1549 struct ext4_map_blocks map, *mapp = NULL;
1550 sector_t next = mpd->b_blocknr;
1551 unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
1552 loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
1553 handle_t *handle = NULL;
1554
1555 /*
1556 * If the blocks are mapped already, or we couldn't accumulate
1557 * any blocks, then proceed immediately to the submission stage.
1558 */
1559 if ((mpd->b_size == 0) ||
1560 ((mpd->b_state & (1 << BH_Mapped)) &&
1561 !(mpd->b_state & (1 << BH_Delay)) &&
1562 !(mpd->b_state & (1 << BH_Unwritten))))
1563 goto submit_io;
1564
1565 handle = ext4_journal_current_handle();
1566 BUG_ON(!handle);
1567
1568 /*
1569 * Call ext4_map_blocks() to allocate any delayed allocation
1570 * blocks, or to convert an uninitialized extent to be
1571 * initialized (in the case where we have written into
1572 * one or more preallocated blocks).
1573 *
1574 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
1575 * indicate that we are on the delayed allocation path. This
1576 * affects functions in many different parts of the allocation
1577 * call path. This flag exists primarily because we don't
1578 * want to change *many* call functions, so ext4_map_blocks()
1579 * will set the EXT4_STATE_DELALLOC_RESERVED flag once the
1580 * inode's allocation semaphore is taken.
1581 *
1582 * If the blocks in questions were delalloc blocks, set
1583 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
1584 * variables are updated after the blocks have been allocated.
1585 */
1586 map.m_lblk = next;
1587 map.m_len = max_blocks;
1588 get_blocks_flags = EXT4_GET_BLOCKS_CREATE;
1589 if (ext4_should_dioread_nolock(mpd->inode))
1590 get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
1591 if (mpd->b_state & (1 << BH_Delay))
1592 get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
1593
1594 blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags);
1595 if (blks < 0) {
1596 struct super_block *sb = mpd->inode->i_sb;
1597
1598 err = blks;
1599 /*
1600 * If get block returns EAGAIN or ENOSPC and there
1601 * appears to be free blocks we will just let
1602 * mpage_da_submit_io() unlock all of the pages.
1603 */
1604 if (err == -EAGAIN)
1605 goto submit_io;
1606
1607 if (err == -ENOSPC && ext4_count_free_clusters(sb)) {
1608 mpd->retval = err;
1609 goto submit_io;
1610 }
1611
1612 /*
1613 * get block failure will cause us to loop in
1614 * writepages, because a_ops->writepage won't be able
1615 * to make progress. The page will be redirtied by
1616 * writepage and writepages will again try to write
1617 * the same.
1618 */
1619 if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
1620 ext4_msg(sb, KERN_CRIT,
1621 "delayed block allocation failed for inode %lu "
1622 "at logical offset %llu with max blocks %zd "
1623 "with error %d", mpd->inode->i_ino,
1624 (unsigned long long) next,
1625 mpd->b_size >> mpd->inode->i_blkbits, err);
1626 ext4_msg(sb, KERN_CRIT,
1627 "This should not happen!! Data will be lost\n");
1628 if (err == -ENOSPC)
1629 ext4_print_free_blocks(mpd->inode);
1630 }
1631 /* invalidate all the pages */
1632 ext4_da_block_invalidatepages(mpd);
1633
1634 /* Mark this page range as having been completed */
1635 mpd->io_done = 1;
1636 return;
1637 }
1638 BUG_ON(blks == 0);
1639
1640 mapp = ↦
1641 if (map.m_flags & EXT4_MAP_NEW) {
1642 struct block_device *bdev = mpd->inode->i_sb->s_bdev;
1643 int i;
1644
1645 for (i = 0; i < map.m_len; i++)
1646 unmap_underlying_metadata(bdev, map.m_pblk + i);
1647
1648 if (ext4_should_order_data(mpd->inode)) {
1649 err = ext4_jbd2_file_inode(handle, mpd->inode);
1650 if (err) {
1651 /* Only if the journal is aborted */
1652 mpd->retval = err;
1653 goto submit_io;
1654 }
1655 }
1656 }
1657
1658 /*
1659 * Update on-disk size along with block allocation.
1660 */
1661 disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
1662 if (disksize > i_size_read(mpd->inode))
1663 disksize = i_size_read(mpd->inode);
1664 if (disksize > EXT4_I(mpd->inode)->i_disksize) {
1665 ext4_update_i_disksize(mpd->inode, disksize);
1666 err = ext4_mark_inode_dirty(handle, mpd->inode);
1667 if (err)
1668 ext4_error(mpd->inode->i_sb,
1669 "Failed to mark inode %lu dirty",
1670 mpd->inode->i_ino);
1671 }
1672
1673submit_io:
1674 mpage_da_submit_io(mpd, mapp);
1675 mpd->io_done = 1;
1676}
1677
1678#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
1679 (1 << BH_Delay) | (1 << BH_Unwritten))
1680
1681/*
1682 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
1683 *
1684 * @mpd->lbh - extent of blocks
1685 * @logical - logical number of the block in the file
1686 * @bh - bh of the block (used to access block's state)
1687 *
1688 * the function is used to collect contig. blocks in same state
1689 */
1690static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
1691 sector_t logical, size_t b_size,
1692 unsigned long b_state)
1693{
1694 sector_t next;
1695 int nrblocks = mpd->b_size >> mpd->inode->i_blkbits;
1696
1697 /*
1698 * XXX Don't go larger than mballoc is willing to allocate
1699 * This is a stopgap solution. We eventually need to fold
1700 * mpage_da_submit_io() into this function and then call
1701 * ext4_map_blocks() multiple times in a loop
1702 */
1703 if (nrblocks >= 8*1024*1024/mpd->inode->i_sb->s_blocksize)
1704 goto flush_it;
1705
1706 /* check if thereserved journal credits might overflow */
1707 if (!(ext4_test_inode_flag(mpd->inode, EXT4_INODE_EXTENTS))) {
1708 if (nrblocks >= EXT4_MAX_TRANS_DATA) {
1709 /*
1710 * With non-extent format we are limited by the journal
1711 * credit available. Total credit needed to insert
1712 * nrblocks contiguous blocks is dependent on the
1713 * nrblocks. So limit nrblocks.
1714 */
1715 goto flush_it;
1716 } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
1717 EXT4_MAX_TRANS_DATA) {
1718 /*
1719 * Adding the new buffer_head would make it cross the
1720 * allowed limit for which we have journal credit
1721 * reserved. So limit the new bh->b_size
1722 */
1723 b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
1724 mpd->inode->i_blkbits;
1725 /* we will do mpage_da_submit_io in the next loop */
1726 }
1727 }
1728 /*
1729 * First block in the extent
1730 */
1731 if (mpd->b_size == 0) {
1732 mpd->b_blocknr = logical;
1733 mpd->b_size = b_size;
1734 mpd->b_state = b_state & BH_FLAGS;
1735 return;
1736 }
1737
1738 next = mpd->b_blocknr + nrblocks;
1739 /*
1740 * Can we merge the block to our big extent?
1741 */
1742 if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
1743 mpd->b_size += b_size;
1744 return;
1745 }
1746
1747flush_it:
1748 /*
1749 * We couldn't merge the block to our extent, so we
1750 * need to flush current extent and start new one
1751 */
1752 mpage_da_map_and_submit(mpd);
1753 return;
1754}
1755
1756static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
1757{
1758 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
1759}
1760
1761/*
1762 * This function is grabs code from the very beginning of
1763 * ext4_map_blocks, but assumes that the caller is from delayed write
1764 * time. This function looks up the requested blocks and sets the
1765 * buffer delay bit under the protection of i_data_sem.
1766 */
1767static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
1768 struct ext4_map_blocks *map,
1769 struct buffer_head *bh)
1770{
1771 int retval;
1772 sector_t invalid_block = ~((sector_t) 0xffff);
1773
1774 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
1775 invalid_block = ~0;
1776
1777 map->m_flags = 0;
1778 ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u,"
1779 "logical block %lu\n", inode->i_ino, map->m_len,
1780 (unsigned long) map->m_lblk);
1781 /*
1782 * Try to see if we can get the block without requesting a new
1783 * file system block.
1784 */
1785 down_read((&EXT4_I(inode)->i_data_sem));
1786 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
1787 retval = ext4_ext_map_blocks(NULL, inode, map, 0);
1788 else
1789 retval = ext4_ind_map_blocks(NULL, inode, map, 0);
1790
1791 if (retval == 0) {
1792 /*
1793 * XXX: __block_prepare_write() unmaps passed block,
1794 * is it OK?
1795 */
1796 /* If the block was allocated from previously allocated cluster,
1797 * then we dont need to reserve it again. */
1798 if (!(map->m_flags & EXT4_MAP_FROM_CLUSTER)) {
1799 retval = ext4_da_reserve_space(inode, iblock);
1800 if (retval)
1801 /* not enough space to reserve */
1802 goto out_unlock;
1803 }
1804
1805 /* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served
1806 * and it should not appear on the bh->b_state.
1807 */
1808 map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
1809
1810 map_bh(bh, inode->i_sb, invalid_block);
1811 set_buffer_new(bh);
1812 set_buffer_delay(bh);
1813 }
1814
1815out_unlock:
1816 up_read((&EXT4_I(inode)->i_data_sem));
1817
1818 return retval;
1819}
1820
1821/*
1822 * This is a special get_blocks_t callback which is used by
1823 * ext4_da_write_begin(). It will either return mapped block or
1824 * reserve space for a single block.
1825 *
1826 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
1827 * We also have b_blocknr = -1 and b_bdev initialized properly
1828 *
1829 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
1830 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
1831 * initialized properly.
1832 */
1833static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
1834 struct buffer_head *bh, int create)
1835{
1836 struct ext4_map_blocks map;
1837 int ret = 0;
1838
1839 BUG_ON(create == 0);
1840 BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
1841
1842 map.m_lblk = iblock;
1843 map.m_len = 1;
1844
1845 /*
1846 * first, we need to know whether the block is allocated already
1847 * preallocated blocks are unmapped but should treated
1848 * the same as allocated blocks.
1849 */
1850 ret = ext4_da_map_blocks(inode, iblock, &map, bh);
1851 if (ret <= 0)
1852 return ret;
1853
1854 map_bh(bh, inode->i_sb, map.m_pblk);
1855 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
1856
1857 if (buffer_unwritten(bh)) {
1858 /* A delayed write to unwritten bh should be marked
1859 * new and mapped. Mapped ensures that we don't do
1860 * get_block multiple times when we write to the same
1861 * offset and new ensures that we do proper zero out
1862 * for partial write.
1863 */
1864 set_buffer_new(bh);
1865 set_buffer_mapped(bh);
1866 }
1867 return 0;
1868}
1869
1870/*
1871 * This function is used as a standard get_block_t calback function
1872 * when there is no desire to allocate any blocks. It is used as a
1873 * callback function for block_write_begin() and block_write_full_page().
1874 * These functions should only try to map a single block at a time.
1875 *
1876 * Since this function doesn't do block allocations even if the caller
1877 * requests it by passing in create=1, it is critically important that
1878 * any caller checks to make sure that any buffer heads are returned
1879 * by this function are either all already mapped or marked for
1880 * delayed allocation before calling block_write_full_page(). Otherwise,
1881 * b_blocknr could be left unitialized, and the page write functions will
1882 * be taken by surprise.
1883 */
1884static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
1885 struct buffer_head *bh_result, int create)
1886{
1887 BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
1888 return _ext4_get_block(inode, iblock, bh_result, 0);
1889}
1890
1891static int bget_one(handle_t *handle, struct buffer_head *bh)
1892{
1893 get_bh(bh);
1894 return 0;
1895}
1896
1897static int bput_one(handle_t *handle, struct buffer_head *bh)
1898{
1899 put_bh(bh);
1900 return 0;
1901}
1902
1903static int __ext4_journalled_writepage(struct page *page,
1904 unsigned int len)
1905{
1906 struct address_space *mapping = page->mapping;
1907 struct inode *inode = mapping->host;
1908 struct buffer_head *page_bufs;
1909 handle_t *handle = NULL;
1910 int ret = 0;
1911 int err;
1912
1913 ClearPageChecked(page);
1914 page_bufs = page_buffers(page);
1915 BUG_ON(!page_bufs);
1916 walk_page_buffers(handle, page_bufs, 0, len, NULL, bget_one);
1917 /* As soon as we unlock the page, it can go away, but we have
1918 * references to buffers so we are safe */
1919 unlock_page(page);
1920
1921 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
1922 if (IS_ERR(handle)) {
1923 ret = PTR_ERR(handle);
1924 goto out;
1925 }
1926
1927 BUG_ON(!ext4_handle_valid(handle));
1928
1929 ret = walk_page_buffers(handle, page_bufs, 0, len, NULL,
1930 do_journal_get_write_access);
1931
1932 err = walk_page_buffers(handle, page_bufs, 0, len, NULL,
1933 write_end_fn);
1934 if (ret == 0)
1935 ret = err;
1936 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1937 err = ext4_journal_stop(handle);
1938 if (!ret)
1939 ret = err;
1940
1941 walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one);
1942 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1943out:
1944 return ret;
1945}
1946
1947static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
1948static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
1949
1950/*
1951 * Note that we don't need to start a transaction unless we're journaling data
1952 * because we should have holes filled from ext4_page_mkwrite(). We even don't
1953 * need to file the inode to the transaction's list in ordered mode because if
1954 * we are writing back data added by write(), the inode is already there and if
1955 * we are writing back data modified via mmap(), no one guarantees in which
1956 * transaction the data will hit the disk. In case we are journaling data, we
1957 * cannot start transaction directly because transaction start ranks above page
1958 * lock so we have to do some magic.
1959 *
1960 * This function can get called via...
1961 * - ext4_da_writepages after taking page lock (have journal handle)
1962 * - journal_submit_inode_data_buffers (no journal handle)
1963 * - shrink_page_list via pdflush (no journal handle)
1964 * - grab_page_cache when doing write_begin (have journal handle)
1965 *
1966 * We don't do any block allocation in this function. If we have page with
1967 * multiple blocks we need to write those buffer_heads that are mapped. This
1968 * is important for mmaped based write. So if we do with blocksize 1K
1969 * truncate(f, 1024);
1970 * a = mmap(f, 0, 4096);
1971 * a[0] = 'a';
1972 * truncate(f, 4096);
1973 * we have in the page first buffer_head mapped via page_mkwrite call back
1974 * but other buffer_heads would be unmapped but dirty (dirty done via the
1975 * do_wp_page). So writepage should write the first block. If we modify
1976 * the mmap area beyond 1024 we will again get a page_fault and the
1977 * page_mkwrite callback will do the block allocation and mark the
1978 * buffer_heads mapped.
1979 *
1980 * We redirty the page if we have any buffer_heads that is either delay or
1981 * unwritten in the page.
1982 *
1983 * We can get recursively called as show below.
1984 *
1985 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1986 * ext4_writepage()
1987 *
1988 * But since we don't do any block allocation we should not deadlock.
1989 * Page also have the dirty flag cleared so we don't get recurive page_lock.
1990 */
1991static int ext4_writepage(struct page *page,
1992 struct writeback_control *wbc)
1993{
1994 int ret = 0, commit_write = 0;
1995 loff_t size;
1996 unsigned int len;
1997 struct buffer_head *page_bufs = NULL;
1998 struct inode *inode = page->mapping->host;
1999
2000 trace_ext4_writepage(page);
2001 size = i_size_read(inode);
2002 if (page->index == size >> PAGE_CACHE_SHIFT)
2003 len = size & ~PAGE_CACHE_MASK;
2004 else
2005 len = PAGE_CACHE_SIZE;
2006
2007 /*
2008 * If the page does not have buffers (for whatever reason),
2009 * try to create them using __block_write_begin. If this
2010 * fails, redirty the page and move on.
2011 */
2012 if (!page_has_buffers(page)) {
2013 if (__block_write_begin(page, 0, len,
2014 noalloc_get_block_write)) {
2015 redirty_page:
2016 redirty_page_for_writepage(wbc, page);
2017 unlock_page(page);
2018 return 0;
2019 }
2020 commit_write = 1;
2021 }
2022 page_bufs = page_buffers(page);
2023 if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2024 ext4_bh_delay_or_unwritten)) {
2025 /*
2026 * We don't want to do block allocation, so redirty
2027 * the page and return. We may reach here when we do
2028 * a journal commit via journal_submit_inode_data_buffers.
2029 * We can also reach here via shrink_page_list but it
2030 * should never be for direct reclaim so warn if that
2031 * happens
2032 */
2033 WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) ==
2034 PF_MEMALLOC);
2035 goto redirty_page;
2036 }
2037 if (commit_write)
2038 /* now mark the buffer_heads as dirty and uptodate */
2039 block_commit_write(page, 0, len);
2040
2041 if (PageChecked(page) && ext4_should_journal_data(inode))
2042 /*
2043 * It's mmapped pagecache. Add buffers and journal it. There
2044 * doesn't seem much point in redirtying the page here.
2045 */
2046 return __ext4_journalled_writepage(page, len);
2047
2048 if (buffer_uninit(page_bufs)) {
2049 ext4_set_bh_endio(page_bufs, inode);
2050 ret = block_write_full_page_endio(page, noalloc_get_block_write,
2051 wbc, ext4_end_io_buffer_write);
2052 } else
2053 ret = block_write_full_page(page, noalloc_get_block_write,
2054 wbc);
2055
2056 return ret;
2057}
2058
2059/*
2060 * This is called via ext4_da_writepages() to
2061 * calculate the total number of credits to reserve to fit
2062 * a single extent allocation into a single transaction,
2063 * ext4_da_writpeages() will loop calling this before
2064 * the block allocation.
2065 */
2066
2067static int ext4_da_writepages_trans_blocks(struct inode *inode)
2068{
2069 int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
2070
2071 /*
2072 * With non-extent format the journal credit needed to
2073 * insert nrblocks contiguous block is dependent on
2074 * number of contiguous block. So we will limit
2075 * number of contiguous block to a sane value
2076 */
2077 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) &&
2078 (max_blocks > EXT4_MAX_TRANS_DATA))
2079 max_blocks = EXT4_MAX_TRANS_DATA;
2080
2081 return ext4_chunk_trans_blocks(inode, max_blocks);
2082}
2083
2084/*
2085 * write_cache_pages_da - walk the list of dirty pages of the given
2086 * address space and accumulate pages that need writing, and call
2087 * mpage_da_map_and_submit to map a single contiguous memory region
2088 * and then write them.
2089 */
2090static int write_cache_pages_da(struct address_space *mapping,
2091 struct writeback_control *wbc,
2092 struct mpage_da_data *mpd,
2093 pgoff_t *done_index)
2094{
2095 struct buffer_head *bh, *head;
2096 struct inode *inode = mapping->host;
2097 struct pagevec pvec;
2098 unsigned int nr_pages;
2099 sector_t logical;
2100 pgoff_t index, end;
2101 long nr_to_write = wbc->nr_to_write;
2102 int i, tag, ret = 0;
2103
2104 memset(mpd, 0, sizeof(struct mpage_da_data));
2105 mpd->wbc = wbc;
2106 mpd->inode = inode;
2107 pagevec_init(&pvec, 0);
2108 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2109 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2110
2111 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2112 tag = PAGECACHE_TAG_TOWRITE;
2113 else
2114 tag = PAGECACHE_TAG_DIRTY;
2115
2116 *done_index = index;
2117 while (index <= end) {
2118 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
2119 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
2120 if (nr_pages == 0)
2121 return 0;
2122
2123 for (i = 0; i < nr_pages; i++) {
2124 struct page *page = pvec.pages[i];
2125
2126 /*
2127 * At this point, the page may be truncated or
2128 * invalidated (changing page->mapping to NULL), or
2129 * even swizzled back from swapper_space to tmpfs file
2130 * mapping. However, page->index will not change
2131 * because we have a reference on the page.
2132 */
2133 if (page->index > end)
2134 goto out;
2135
2136 *done_index = page->index + 1;
2137
2138 /*
2139 * If we can't merge this page, and we have
2140 * accumulated an contiguous region, write it
2141 */
2142 if ((mpd->next_page != page->index) &&
2143 (mpd->next_page != mpd->first_page)) {
2144 mpage_da_map_and_submit(mpd);
2145 goto ret_extent_tail;
2146 }
2147
2148 lock_page(page);
2149
2150 /*
2151 * If the page is no longer dirty, or its
2152 * mapping no longer corresponds to inode we
2153 * are writing (which means it has been
2154 * truncated or invalidated), or the page is
2155 * already under writeback and we are not
2156 * doing a data integrity writeback, skip the page
2157 */
2158 if (!PageDirty(page) ||
2159 (PageWriteback(page) &&
2160 (wbc->sync_mode == WB_SYNC_NONE)) ||
2161 unlikely(page->mapping != mapping)) {
2162 unlock_page(page);
2163 continue;
2164 }
2165
2166 wait_on_page_writeback(page);
2167 BUG_ON(PageWriteback(page));
2168
2169 if (mpd->next_page != page->index)
2170 mpd->first_page = page->index;
2171 mpd->next_page = page->index + 1;
2172 logical = (sector_t) page->index <<
2173 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2174
2175 if (!page_has_buffers(page)) {
2176 mpage_add_bh_to_extent(mpd, logical,
2177 PAGE_CACHE_SIZE,
2178 (1 << BH_Dirty) | (1 << BH_Uptodate));
2179 if (mpd->io_done)
2180 goto ret_extent_tail;
2181 } else {
2182 /*
2183 * Page with regular buffer heads,
2184 * just add all dirty ones
2185 */
2186 head = page_buffers(page);
2187 bh = head;
2188 do {
2189 BUG_ON(buffer_locked(bh));
2190 /*
2191 * We need to try to allocate
2192 * unmapped blocks in the same page.
2193 * Otherwise we won't make progress
2194 * with the page in ext4_writepage
2195 */
2196 if (ext4_bh_delay_or_unwritten(NULL, bh)) {
2197 mpage_add_bh_to_extent(mpd, logical,
2198 bh->b_size,
2199 bh->b_state);
2200 if (mpd->io_done)
2201 goto ret_extent_tail;
2202 } else if (buffer_dirty(bh) && (buffer_mapped(bh))) {
2203 /*
2204 * mapped dirty buffer. We need
2205 * to update the b_state
2206 * because we look at b_state
2207 * in mpage_da_map_blocks. We
2208 * don't update b_size because
2209 * if we find an unmapped
2210 * buffer_head later we need to
2211 * use the b_state flag of that
2212 * buffer_head.
2213 */
2214 if (mpd->b_size == 0)
2215 mpd->b_state = bh->b_state & BH_FLAGS;
2216 }
2217 logical++;
2218 } while ((bh = bh->b_this_page) != head);
2219 }
2220
2221 if (nr_to_write > 0) {
2222 nr_to_write--;
2223 if (nr_to_write == 0 &&
2224 wbc->sync_mode == WB_SYNC_NONE)
2225 /*
2226 * We stop writing back only if we are
2227 * not doing integrity sync. In case of
2228 * integrity sync we have to keep going
2229 * because someone may be concurrently
2230 * dirtying pages, and we might have
2231 * synced a lot of newly appeared dirty
2232 * pages, but have not synced all of the
2233 * old dirty pages.
2234 */
2235 goto out;
2236 }
2237 }
2238 pagevec_release(&pvec);
2239 cond_resched();
2240 }
2241 return 0;
2242ret_extent_tail:
2243 ret = MPAGE_DA_EXTENT_TAIL;
2244out:
2245 pagevec_release(&pvec);
2246 cond_resched();
2247 return ret;
2248}
2249
2250
2251static int ext4_da_writepages(struct address_space *mapping,
2252 struct writeback_control *wbc)
2253{
2254 pgoff_t index;
2255 int range_whole = 0;
2256 handle_t *handle = NULL;
2257 struct mpage_da_data mpd;
2258 struct inode *inode = mapping->host;
2259 int pages_written = 0;
2260 unsigned int max_pages;
2261 int range_cyclic, cycled = 1, io_done = 0;
2262 int needed_blocks, ret = 0;
2263 long desired_nr_to_write, nr_to_writebump = 0;
2264 loff_t range_start = wbc->range_start;
2265 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
2266 pgoff_t done_index = 0;
2267 pgoff_t end;
2268 struct blk_plug plug;
2269
2270 trace_ext4_da_writepages(inode, wbc);
2271
2272 /*
2273 * No pages to write? This is mainly a kludge to avoid starting
2274 * a transaction for special inodes like journal inode on last iput()
2275 * because that could violate lock ordering on umount
2276 */
2277 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2278 return 0;
2279
2280 /*
2281 * If the filesystem has aborted, it is read-only, so return
2282 * right away instead of dumping stack traces later on that
2283 * will obscure the real source of the problem. We test
2284 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2285 * the latter could be true if the filesystem is mounted
2286 * read-only, and in that case, ext4_da_writepages should
2287 * *never* be called, so if that ever happens, we would want
2288 * the stack trace.
2289 */
2290 if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
2291 return -EROFS;
2292
2293 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2294 range_whole = 1;
2295
2296 range_cyclic = wbc->range_cyclic;
2297 if (wbc->range_cyclic) {
2298 index = mapping->writeback_index;
2299 if (index)
2300 cycled = 0;
2301 wbc->range_start = index << PAGE_CACHE_SHIFT;
2302 wbc->range_end = LLONG_MAX;
2303 wbc->range_cyclic = 0;
2304 end = -1;
2305 } else {
2306 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2307 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2308 }
2309
2310 /*
2311 * This works around two forms of stupidity. The first is in
2312 * the writeback code, which caps the maximum number of pages
2313 * written to be 1024 pages. This is wrong on multiple
2314 * levels; different architectues have a different page size,
2315 * which changes the maximum amount of data which gets
2316 * written. Secondly, 4 megabytes is way too small. XFS
2317 * forces this value to be 16 megabytes by multiplying
2318 * nr_to_write parameter by four, and then relies on its
2319 * allocator to allocate larger extents to make them
2320 * contiguous. Unfortunately this brings us to the second
2321 * stupidity, which is that ext4's mballoc code only allocates
2322 * at most 2048 blocks. So we force contiguous writes up to
2323 * the number of dirty blocks in the inode, or
2324 * sbi->max_writeback_mb_bump whichever is smaller.
2325 */
2326 max_pages = sbi->s_max_writeback_mb_bump << (20 - PAGE_CACHE_SHIFT);
2327 if (!range_cyclic && range_whole) {
2328 if (wbc->nr_to_write == LONG_MAX)
2329 desired_nr_to_write = wbc->nr_to_write;
2330 else
2331 desired_nr_to_write = wbc->nr_to_write * 8;
2332 } else
2333 desired_nr_to_write = ext4_num_dirty_pages(inode, index,
2334 max_pages);
2335 if (desired_nr_to_write > max_pages)
2336 desired_nr_to_write = max_pages;
2337
2338 if (wbc->nr_to_write < desired_nr_to_write) {
2339 nr_to_writebump = desired_nr_to_write - wbc->nr_to_write;
2340 wbc->nr_to_write = desired_nr_to_write;
2341 }
2342
2343retry:
2344 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2345 tag_pages_for_writeback(mapping, index, end);
2346
2347 blk_start_plug(&plug);
2348 while (!ret && wbc->nr_to_write > 0) {
2349
2350 /*
2351 * we insert one extent at a time. So we need
2352 * credit needed for single extent allocation.
2353 * journalled mode is currently not supported
2354 * by delalloc
2355 */
2356 BUG_ON(ext4_should_journal_data(inode));
2357 needed_blocks = ext4_da_writepages_trans_blocks(inode);
2358
2359 /* start a new transaction*/
2360 handle = ext4_journal_start(inode, needed_blocks);
2361 if (IS_ERR(handle)) {
2362 ret = PTR_ERR(handle);
2363 ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
2364 "%ld pages, ino %lu; err %d", __func__,
2365 wbc->nr_to_write, inode->i_ino, ret);
2366 blk_finish_plug(&plug);
2367 goto out_writepages;
2368 }
2369
2370 /*
2371 * Now call write_cache_pages_da() to find the next
2372 * contiguous region of logical blocks that need
2373 * blocks to be allocated by ext4 and submit them.
2374 */
2375 ret = write_cache_pages_da(mapping, wbc, &mpd, &done_index);
2376 /*
2377 * If we have a contiguous extent of pages and we
2378 * haven't done the I/O yet, map the blocks and submit
2379 * them for I/O.
2380 */
2381 if (!mpd.io_done && mpd.next_page != mpd.first_page) {
2382 mpage_da_map_and_submit(&mpd);
2383 ret = MPAGE_DA_EXTENT_TAIL;
2384 }
2385 trace_ext4_da_write_pages(inode, &mpd);
2386 wbc->nr_to_write -= mpd.pages_written;
2387
2388 ext4_journal_stop(handle);
2389
2390 if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
2391 /* commit the transaction which would
2392 * free blocks released in the transaction
2393 * and try again
2394 */
2395 jbd2_journal_force_commit_nested(sbi->s_journal);
2396 ret = 0;
2397 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
2398 /*
2399 * Got one extent now try with rest of the pages.
2400 * If mpd.retval is set -EIO, journal is aborted.
2401 * So we don't need to write any more.
2402 */
2403 pages_written += mpd.pages_written;
2404 ret = mpd.retval;
2405 io_done = 1;
2406 } else if (wbc->nr_to_write)
2407 /*
2408 * There is no more writeout needed
2409 * or we requested for a noblocking writeout
2410 * and we found the device congested
2411 */
2412 break;
2413 }
2414 blk_finish_plug(&plug);
2415 if (!io_done && !cycled) {
2416 cycled = 1;
2417 index = 0;
2418 wbc->range_start = index << PAGE_CACHE_SHIFT;
2419 wbc->range_end = mapping->writeback_index - 1;
2420 goto retry;
2421 }
2422
2423 /* Update index */
2424 wbc->range_cyclic = range_cyclic;
2425 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2426 /*
2427 * set the writeback_index so that range_cyclic
2428 * mode will write it back later
2429 */
2430 mapping->writeback_index = done_index;
2431
2432out_writepages:
2433 wbc->nr_to_write -= nr_to_writebump;
2434 wbc->range_start = range_start;
2435 trace_ext4_da_writepages_result(inode, wbc, ret, pages_written);
2436 return ret;
2437}
2438
2439#define FALL_BACK_TO_NONDELALLOC 1
2440static int ext4_nonda_switch(struct super_block *sb)
2441{
2442 s64 free_blocks, dirty_blocks;
2443 struct ext4_sb_info *sbi = EXT4_SB(sb);
2444
2445 /*
2446 * switch to non delalloc mode if we are running low
2447 * on free block. The free block accounting via percpu
2448 * counters can get slightly wrong with percpu_counter_batch getting
2449 * accumulated on each CPU without updating global counters
2450 * Delalloc need an accurate free block accounting. So switch
2451 * to non delalloc when we are near to error range.
2452 */
2453 free_blocks = EXT4_C2B(sbi,
2454 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
2455 dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyclusters_counter);
2456 if (2 * free_blocks < 3 * dirty_blocks ||
2457 free_blocks < (dirty_blocks + EXT4_FREECLUSTERS_WATERMARK)) {
2458 /*
2459 * free block count is less than 150% of dirty blocks
2460 * or free blocks is less than watermark
2461 */
2462 return 1;
2463 }
2464 /*
2465 * Even if we don't switch but are nearing capacity,
2466 * start pushing delalloc when 1/2 of free blocks are dirty.
2467 */
2468 if (free_blocks < 2 * dirty_blocks)
2469 writeback_inodes_sb_if_idle(sb, WB_REASON_FS_FREE_SPACE);
2470
2471 return 0;
2472}
2473
2474static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
2475 loff_t pos, unsigned len, unsigned flags,
2476 struct page **pagep, void **fsdata)
2477{
2478 int ret, retries = 0;
2479 struct page *page;
2480 pgoff_t index;
2481 struct inode *inode = mapping->host;
2482 handle_t *handle;
2483
2484 index = pos >> PAGE_CACHE_SHIFT;
2485
2486 if (ext4_nonda_switch(inode->i_sb)) {
2487 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
2488 return ext4_write_begin(file, mapping, pos,
2489 len, flags, pagep, fsdata);
2490 }
2491 *fsdata = (void *)0;
2492 trace_ext4_da_write_begin(inode, pos, len, flags);
2493retry:
2494 /*
2495 * With delayed allocation, we don't log the i_disksize update
2496 * if there is delayed block allocation. But we still need
2497 * to journalling the i_disksize update if writes to the end
2498 * of file which has an already mapped buffer.
2499 */
2500 handle = ext4_journal_start(inode, 1);
2501 if (IS_ERR(handle)) {
2502 ret = PTR_ERR(handle);
2503 goto out;
2504 }
2505 /* We cannot recurse into the filesystem as the transaction is already
2506 * started */
2507 flags |= AOP_FLAG_NOFS;
2508
2509 page = grab_cache_page_write_begin(mapping, index, flags);
2510 if (!page) {
2511 ext4_journal_stop(handle);
2512 ret = -ENOMEM;
2513 goto out;
2514 }
2515 *pagep = page;
2516
2517 ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
2518 if (ret < 0) {
2519 unlock_page(page);
2520 ext4_journal_stop(handle);
2521 page_cache_release(page);
2522 /*
2523 * block_write_begin may have instantiated a few blocks
2524 * outside i_size. Trim these off again. Don't need
2525 * i_size_read because we hold i_mutex.
2526 */
2527 if (pos + len > inode->i_size)
2528 ext4_truncate_failed_write(inode);
2529 }
2530
2531 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
2532 goto retry;
2533out:
2534 return ret;
2535}
2536
2537/*
2538 * Check if we should update i_disksize
2539 * when write to the end of file but not require block allocation
2540 */
2541static int ext4_da_should_update_i_disksize(struct page *page,
2542 unsigned long offset)
2543{
2544 struct buffer_head *bh;
2545 struct inode *inode = page->mapping->host;
2546 unsigned int idx;
2547 int i;
2548
2549 bh = page_buffers(page);
2550 idx = offset >> inode->i_blkbits;
2551
2552 for (i = 0; i < idx; i++)
2553 bh = bh->b_this_page;
2554
2555 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
2556 return 0;
2557 return 1;
2558}
2559
2560static int ext4_da_write_end(struct file *file,
2561 struct address_space *mapping,
2562 loff_t pos, unsigned len, unsigned copied,
2563 struct page *page, void *fsdata)
2564{
2565 struct inode *inode = mapping->host;
2566 int ret = 0, ret2;
2567 handle_t *handle = ext4_journal_current_handle();
2568 loff_t new_i_size;
2569 unsigned long start, end;
2570 int write_mode = (int)(unsigned long)fsdata;
2571
2572 if (write_mode == FALL_BACK_TO_NONDELALLOC) {
2573 switch (ext4_inode_journal_mode(inode)) {
2574 case EXT4_INODE_ORDERED_DATA_MODE:
2575 return ext4_ordered_write_end(file, mapping, pos,
2576 len, copied, page, fsdata);
2577 case EXT4_INODE_WRITEBACK_DATA_MODE:
2578 return ext4_writeback_write_end(file, mapping, pos,
2579 len, copied, page, fsdata);
2580 default:
2581 BUG();
2582 }
2583 }
2584
2585 trace_ext4_da_write_end(inode, pos, len, copied);
2586 start = pos & (PAGE_CACHE_SIZE - 1);
2587 end = start + copied - 1;
2588
2589 /*
2590 * generic_write_end() will run mark_inode_dirty() if i_size
2591 * changes. So let's piggyback the i_disksize mark_inode_dirty
2592 * into that.
2593 */
2594
2595 new_i_size = pos + copied;
2596 if (copied && new_i_size > EXT4_I(inode)->i_disksize) {
2597 if (ext4_da_should_update_i_disksize(page, end)) {
2598 down_write(&EXT4_I(inode)->i_data_sem);
2599 if (new_i_size > EXT4_I(inode)->i_disksize) {
2600 /*
2601 * Updating i_disksize when extending file
2602 * without needing block allocation
2603 */
2604 if (ext4_should_order_data(inode))
2605 ret = ext4_jbd2_file_inode(handle,
2606 inode);
2607
2608 EXT4_I(inode)->i_disksize = new_i_size;
2609 }
2610 up_write(&EXT4_I(inode)->i_data_sem);
2611 /* We need to mark inode dirty even if
2612 * new_i_size is less that inode->i_size
2613 * bu greater than i_disksize.(hint delalloc)
2614 */
2615 ext4_mark_inode_dirty(handle, inode);
2616 }
2617 }
2618 ret2 = generic_write_end(file, mapping, pos, len, copied,
2619 page, fsdata);
2620 copied = ret2;
2621 if (ret2 < 0)
2622 ret = ret2;
2623 ret2 = ext4_journal_stop(handle);
2624 if (!ret)
2625 ret = ret2;
2626
2627 return ret ? ret : copied;
2628}
2629
2630static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
2631{
2632 /*
2633 * Drop reserved blocks
2634 */
2635 BUG_ON(!PageLocked(page));
2636 if (!page_has_buffers(page))
2637 goto out;
2638
2639 ext4_da_page_release_reservation(page, offset);
2640
2641out:
2642 ext4_invalidatepage(page, offset);
2643
2644 return;
2645}
2646
2647/*
2648 * Force all delayed allocation blocks to be allocated for a given inode.
2649 */
2650int ext4_alloc_da_blocks(struct inode *inode)
2651{
2652 trace_ext4_alloc_da_blocks(inode);
2653
2654 if (!EXT4_I(inode)->i_reserved_data_blocks &&
2655 !EXT4_I(inode)->i_reserved_meta_blocks)
2656 return 0;
2657
2658 /*
2659 * We do something simple for now. The filemap_flush() will
2660 * also start triggering a write of the data blocks, which is
2661 * not strictly speaking necessary (and for users of
2662 * laptop_mode, not even desirable). However, to do otherwise
2663 * would require replicating code paths in:
2664 *
2665 * ext4_da_writepages() ->
2666 * write_cache_pages() ---> (via passed in callback function)
2667 * __mpage_da_writepage() -->
2668 * mpage_add_bh_to_extent()
2669 * mpage_da_map_blocks()
2670 *
2671 * The problem is that write_cache_pages(), located in
2672 * mm/page-writeback.c, marks pages clean in preparation for
2673 * doing I/O, which is not desirable if we're not planning on
2674 * doing I/O at all.
2675 *
2676 * We could call write_cache_pages(), and then redirty all of
2677 * the pages by calling redirty_page_for_writepage() but that
2678 * would be ugly in the extreme. So instead we would need to
2679 * replicate parts of the code in the above functions,
2680 * simplifying them because we wouldn't actually intend to
2681 * write out the pages, but rather only collect contiguous
2682 * logical block extents, call the multi-block allocator, and
2683 * then update the buffer heads with the block allocations.
2684 *
2685 * For now, though, we'll cheat by calling filemap_flush(),
2686 * which will map the blocks, and start the I/O, but not
2687 * actually wait for the I/O to complete.
2688 */
2689 return filemap_flush(inode->i_mapping);
2690}
2691
2692/*
2693 * bmap() is special. It gets used by applications such as lilo and by
2694 * the swapper to find the on-disk block of a specific piece of data.
2695 *
2696 * Naturally, this is dangerous if the block concerned is still in the
2697 * journal. If somebody makes a swapfile on an ext4 data-journaling
2698 * filesystem and enables swap, then they may get a nasty shock when the
2699 * data getting swapped to that swapfile suddenly gets overwritten by
2700 * the original zero's written out previously to the journal and
2701 * awaiting writeback in the kernel's buffer cache.
2702 *
2703 * So, if we see any bmap calls here on a modified, data-journaled file,
2704 * take extra steps to flush any blocks which might be in the cache.
2705 */
2706static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
2707{
2708 struct inode *inode = mapping->host;
2709 journal_t *journal;
2710 int err;
2711
2712 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
2713 test_opt(inode->i_sb, DELALLOC)) {
2714 /*
2715 * With delalloc we want to sync the file
2716 * so that we can make sure we allocate
2717 * blocks for file
2718 */
2719 filemap_write_and_wait(mapping);
2720 }
2721
2722 if (EXT4_JOURNAL(inode) &&
2723 ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
2724 /*
2725 * This is a REALLY heavyweight approach, but the use of
2726 * bmap on dirty files is expected to be extremely rare:
2727 * only if we run lilo or swapon on a freshly made file
2728 * do we expect this to happen.
2729 *
2730 * (bmap requires CAP_SYS_RAWIO so this does not
2731 * represent an unprivileged user DOS attack --- we'd be
2732 * in trouble if mortal users could trigger this path at
2733 * will.)
2734 *
2735 * NB. EXT4_STATE_JDATA is not set on files other than
2736 * regular files. If somebody wants to bmap a directory
2737 * or symlink and gets confused because the buffer
2738 * hasn't yet been flushed to disk, they deserve
2739 * everything they get.
2740 */
2741
2742 ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
2743 journal = EXT4_JOURNAL(inode);
2744 jbd2_journal_lock_updates(journal);
2745 err = jbd2_journal_flush(journal);
2746 jbd2_journal_unlock_updates(journal);
2747
2748 if (err)
2749 return 0;
2750 }
2751
2752 return generic_block_bmap(mapping, block, ext4_get_block);
2753}
2754
2755static int ext4_readpage(struct file *file, struct page *page)
2756{
2757 trace_ext4_readpage(page);
2758 return mpage_readpage(page, ext4_get_block);
2759}
2760
2761static int
2762ext4_readpages(struct file *file, struct address_space *mapping,
2763 struct list_head *pages, unsigned nr_pages)
2764{
2765 return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
2766}
2767
2768static void ext4_invalidatepage_free_endio(struct page *page, unsigned long offset)
2769{
2770 struct buffer_head *head, *bh;
2771 unsigned int curr_off = 0;
2772
2773 if (!page_has_buffers(page))
2774 return;
2775 head = bh = page_buffers(page);
2776 do {
2777 if (offset <= curr_off && test_clear_buffer_uninit(bh)
2778 && bh->b_private) {
2779 ext4_free_io_end(bh->b_private);
2780 bh->b_private = NULL;
2781 bh->b_end_io = NULL;
2782 }
2783 curr_off = curr_off + bh->b_size;
2784 bh = bh->b_this_page;
2785 } while (bh != head);
2786}
2787
2788static void ext4_invalidatepage(struct page *page, unsigned long offset)
2789{
2790 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
2791
2792 trace_ext4_invalidatepage(page, offset);
2793
2794 /*
2795 * free any io_end structure allocated for buffers to be discarded
2796 */
2797 if (ext4_should_dioread_nolock(page->mapping->host))
2798 ext4_invalidatepage_free_endio(page, offset);
2799 /*
2800 * If it's a full truncate we just forget about the pending dirtying
2801 */
2802 if (offset == 0)
2803 ClearPageChecked(page);
2804
2805 if (journal)
2806 jbd2_journal_invalidatepage(journal, page, offset);
2807 else
2808 block_invalidatepage(page, offset);
2809}
2810
2811static int ext4_releasepage(struct page *page, gfp_t wait)
2812{
2813 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
2814
2815 trace_ext4_releasepage(page);
2816
2817 WARN_ON(PageChecked(page));
2818 if (!page_has_buffers(page))
2819 return 0;
2820 if (journal)
2821 return jbd2_journal_try_to_free_buffers(journal, page, wait);
2822 else
2823 return try_to_free_buffers(page);
2824}
2825
2826/*
2827 * ext4_get_block used when preparing for a DIO write or buffer write.
2828 * We allocate an uinitialized extent if blocks haven't been allocated.
2829 * The extent will be converted to initialized after the IO is complete.
2830 */
2831static int ext4_get_block_write(struct inode *inode, sector_t iblock,
2832 struct buffer_head *bh_result, int create)
2833{
2834 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
2835 inode->i_ino, create);
2836 return _ext4_get_block(inode, iblock, bh_result,
2837 EXT4_GET_BLOCKS_IO_CREATE_EXT);
2838}
2839
2840static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
2841 ssize_t size, void *private, int ret,
2842 bool is_async)
2843{
2844 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
2845 ext4_io_end_t *io_end = iocb->private;
2846 struct workqueue_struct *wq;
2847 unsigned long flags;
2848 struct ext4_inode_info *ei;
2849
2850 /* if not async direct IO or dio with 0 bytes write, just return */
2851 if (!io_end || !size)
2852 goto out;
2853
2854 ext_debug("ext4_end_io_dio(): io_end 0x%p "
2855 "for inode %lu, iocb 0x%p, offset %llu, size %zd\n",
2856 iocb->private, io_end->inode->i_ino, iocb, offset,
2857 size);
2858
2859 iocb->private = NULL;
2860
2861 /* if not aio dio with unwritten extents, just free io and return */
2862 if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
2863 ext4_free_io_end(io_end);
2864out:
2865 if (is_async)
2866 aio_complete(iocb, ret, 0);
2867 inode_dio_done(inode);
2868 return;
2869 }
2870
2871 io_end->offset = offset;
2872 io_end->size = size;
2873 if (is_async) {
2874 io_end->iocb = iocb;
2875 io_end->result = ret;
2876 }
2877 wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;
2878
2879 /* Add the io_end to per-inode completed aio dio list*/
2880 ei = EXT4_I(io_end->inode);
2881 spin_lock_irqsave(&ei->i_completed_io_lock, flags);
2882 list_add_tail(&io_end->list, &ei->i_completed_io_list);
2883 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
2884
2885 /* queue the work to convert unwritten extents to written */
2886 queue_work(wq, &io_end->work);
2887}
2888
2889static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate)
2890{
2891 ext4_io_end_t *io_end = bh->b_private;
2892 struct workqueue_struct *wq;
2893 struct inode *inode;
2894 unsigned long flags;
2895
2896 if (!test_clear_buffer_uninit(bh) || !io_end)
2897 goto out;
2898
2899 if (!(io_end->inode->i_sb->s_flags & MS_ACTIVE)) {
2900 ext4_msg(io_end->inode->i_sb, KERN_INFO,
2901 "sb umounted, discard end_io request for inode %lu",
2902 io_end->inode->i_ino);
2903 ext4_free_io_end(io_end);
2904 goto out;
2905 }
2906
2907 /*
2908 * It may be over-defensive here to check EXT4_IO_END_UNWRITTEN now,
2909 * but being more careful is always safe for the future change.
2910 */
2911 inode = io_end->inode;
2912 ext4_set_io_unwritten_flag(inode, io_end);
2913
2914 /* Add the io_end to per-inode completed io list*/
2915 spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
2916 list_add_tail(&io_end->list, &EXT4_I(inode)->i_completed_io_list);
2917 spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags);
2918
2919 wq = EXT4_SB(inode->i_sb)->dio_unwritten_wq;
2920 /* queue the work to convert unwritten extents to written */
2921 queue_work(wq, &io_end->work);
2922out:
2923 bh->b_private = NULL;
2924 bh->b_end_io = NULL;
2925 clear_buffer_uninit(bh);
2926 end_buffer_async_write(bh, uptodate);
2927}
2928
2929static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode)
2930{
2931 ext4_io_end_t *io_end;
2932 struct page *page = bh->b_page;
2933 loff_t offset = (sector_t)page->index << PAGE_CACHE_SHIFT;
2934 size_t size = bh->b_size;
2935
2936retry:
2937 io_end = ext4_init_io_end(inode, GFP_ATOMIC);
2938 if (!io_end) {
2939 pr_warn_ratelimited("%s: allocation fail\n", __func__);
2940 schedule();
2941 goto retry;
2942 }
2943 io_end->offset = offset;
2944 io_end->size = size;
2945 /*
2946 * We need to hold a reference to the page to make sure it
2947 * doesn't get evicted before ext4_end_io_work() has a chance
2948 * to convert the extent from written to unwritten.
2949 */
2950 io_end->page = page;
2951 get_page(io_end->page);
2952
2953 bh->b_private = io_end;
2954 bh->b_end_io = ext4_end_io_buffer_write;
2955 return 0;
2956}
2957
2958/*
2959 * For ext4 extent files, ext4 will do direct-io write to holes,
2960 * preallocated extents, and those write extend the file, no need to
2961 * fall back to buffered IO.
2962 *
2963 * For holes, we fallocate those blocks, mark them as uninitialized
2964 * If those blocks were preallocated, we mark sure they are splited, but
2965 * still keep the range to write as uninitialized.
2966 *
2967 * The unwrritten extents will be converted to written when DIO is completed.
2968 * For async direct IO, since the IO may still pending when return, we
2969 * set up an end_io call back function, which will do the conversion
2970 * when async direct IO completed.
2971 *
2972 * If the O_DIRECT write will extend the file then add this inode to the
2973 * orphan list. So recovery will truncate it back to the original size
2974 * if the machine crashes during the write.
2975 *
2976 */
2977static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
2978 const struct iovec *iov, loff_t offset,
2979 unsigned long nr_segs)
2980{
2981 struct file *file = iocb->ki_filp;
2982 struct inode *inode = file->f_mapping->host;
2983 ssize_t ret;
2984 size_t count = iov_length(iov, nr_segs);
2985
2986 loff_t final_size = offset + count;
2987 if (rw == WRITE && final_size <= inode->i_size) {
2988 /*
2989 * We could direct write to holes and fallocate.
2990 *
2991 * Allocated blocks to fill the hole are marked as uninitialized
2992 * to prevent parallel buffered read to expose the stale data
2993 * before DIO complete the data IO.
2994 *
2995 * As to previously fallocated extents, ext4 get_block
2996 * will just simply mark the buffer mapped but still
2997 * keep the extents uninitialized.
2998 *
2999 * for non AIO case, we will convert those unwritten extents
3000 * to written after return back from blockdev_direct_IO.
3001 *
3002 * for async DIO, the conversion needs to be defered when
3003 * the IO is completed. The ext4 end_io callback function
3004 * will be called to take care of the conversion work.
3005 * Here for async case, we allocate an io_end structure to
3006 * hook to the iocb.
3007 */
3008 iocb->private = NULL;
3009 EXT4_I(inode)->cur_aio_dio = NULL;
3010 if (!is_sync_kiocb(iocb)) {
3011 ext4_io_end_t *io_end =
3012 ext4_init_io_end(inode, GFP_NOFS);
3013 if (!io_end)
3014 return -ENOMEM;
3015 io_end->flag |= EXT4_IO_END_DIRECT;
3016 iocb->private = io_end;
3017 /*
3018 * we save the io structure for current async
3019 * direct IO, so that later ext4_map_blocks()
3020 * could flag the io structure whether there
3021 * is a unwritten extents needs to be converted
3022 * when IO is completed.
3023 */
3024 EXT4_I(inode)->cur_aio_dio = iocb->private;
3025 }
3026
3027 ret = __blockdev_direct_IO(rw, iocb, inode,
3028 inode->i_sb->s_bdev, iov,
3029 offset, nr_segs,
3030 ext4_get_block_write,
3031 ext4_end_io_dio,
3032 NULL,
3033 DIO_LOCKING);
3034 if (iocb->private)
3035 EXT4_I(inode)->cur_aio_dio = NULL;
3036 /*
3037 * The io_end structure takes a reference to the inode,
3038 * that structure needs to be destroyed and the
3039 * reference to the inode need to be dropped, when IO is
3040 * complete, even with 0 byte write, or failed.
3041 *
3042 * In the successful AIO DIO case, the io_end structure will be
3043 * desctroyed and the reference to the inode will be dropped
3044 * after the end_io call back function is called.
3045 *
3046 * In the case there is 0 byte write, or error case, since
3047 * VFS direct IO won't invoke the end_io call back function,
3048 * we need to free the end_io structure here.
3049 */
3050 if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
3051 ext4_free_io_end(iocb->private);
3052 iocb->private = NULL;
3053 } else if (ret > 0 && ext4_test_inode_state(inode,
3054 EXT4_STATE_DIO_UNWRITTEN)) {
3055 int err;
3056 /*
3057 * for non AIO case, since the IO is already
3058 * completed, we could do the conversion right here
3059 */
3060 err = ext4_convert_unwritten_extents(inode,
3061 offset, ret);
3062 if (err < 0)
3063 ret = err;
3064 ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3065 }
3066 return ret;
3067 }
3068
3069 /* for write the the end of file case, we fall back to old way */
3070 return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3071}
3072
3073static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
3074 const struct iovec *iov, loff_t offset,
3075 unsigned long nr_segs)
3076{
3077 struct file *file = iocb->ki_filp;
3078 struct inode *inode = file->f_mapping->host;
3079 ssize_t ret;
3080
3081 /*
3082 * If we are doing data journalling we don't support O_DIRECT
3083 */
3084 if (ext4_should_journal_data(inode))
3085 return 0;
3086
3087 trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
3088 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3089 ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
3090 else
3091 ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3092 trace_ext4_direct_IO_exit(inode, offset,
3093 iov_length(iov, nr_segs), rw, ret);
3094 return ret;
3095}
3096
3097/*
3098 * Pages can be marked dirty completely asynchronously from ext4's journalling
3099 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3100 * much here because ->set_page_dirty is called under VFS locks. The page is
3101 * not necessarily locked.
3102 *
3103 * We cannot just dirty the page and leave attached buffers clean, because the
3104 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3105 * or jbddirty because all the journalling code will explode.
3106 *
3107 * So what we do is to mark the page "pending dirty" and next time writepage
3108 * is called, propagate that into the buffers appropriately.
3109 */
3110static int ext4_journalled_set_page_dirty(struct page *page)
3111{
3112 SetPageChecked(page);
3113 return __set_page_dirty_nobuffers(page);
3114}
3115
3116static const struct address_space_operations ext4_ordered_aops = {
3117 .readpage = ext4_readpage,
3118 .readpages = ext4_readpages,
3119 .writepage = ext4_writepage,
3120 .write_begin = ext4_write_begin,
3121 .write_end = ext4_ordered_write_end,
3122 .bmap = ext4_bmap,
3123 .invalidatepage = ext4_invalidatepage,
3124 .releasepage = ext4_releasepage,
3125 .direct_IO = ext4_direct_IO,
3126 .migratepage = buffer_migrate_page,
3127 .is_partially_uptodate = block_is_partially_uptodate,
3128 .error_remove_page = generic_error_remove_page,
3129};
3130
3131static const struct address_space_operations ext4_writeback_aops = {
3132 .readpage = ext4_readpage,
3133 .readpages = ext4_readpages,
3134 .writepage = ext4_writepage,
3135 .write_begin = ext4_write_begin,
3136 .write_end = ext4_writeback_write_end,
3137 .bmap = ext4_bmap,
3138 .invalidatepage = ext4_invalidatepage,
3139 .releasepage = ext4_releasepage,
3140 .direct_IO = ext4_direct_IO,
3141 .migratepage = buffer_migrate_page,
3142 .is_partially_uptodate = block_is_partially_uptodate,
3143 .error_remove_page = generic_error_remove_page,
3144};
3145
3146static const struct address_space_operations ext4_journalled_aops = {
3147 .readpage = ext4_readpage,
3148 .readpages = ext4_readpages,
3149 .writepage = ext4_writepage,
3150 .write_begin = ext4_write_begin,
3151 .write_end = ext4_journalled_write_end,
3152 .set_page_dirty = ext4_journalled_set_page_dirty,
3153 .bmap = ext4_bmap,
3154 .invalidatepage = ext4_invalidatepage,
3155 .releasepage = ext4_releasepage,
3156 .direct_IO = ext4_direct_IO,
3157 .is_partially_uptodate = block_is_partially_uptodate,
3158 .error_remove_page = generic_error_remove_page,
3159};
3160
3161static const struct address_space_operations ext4_da_aops = {
3162 .readpage = ext4_readpage,
3163 .readpages = ext4_readpages,
3164 .writepage = ext4_writepage,
3165 .writepages = ext4_da_writepages,
3166 .write_begin = ext4_da_write_begin,
3167 .write_end = ext4_da_write_end,
3168 .bmap = ext4_bmap,
3169 .invalidatepage = ext4_da_invalidatepage,
3170 .releasepage = ext4_releasepage,
3171 .direct_IO = ext4_direct_IO,
3172 .migratepage = buffer_migrate_page,
3173 .is_partially_uptodate = block_is_partially_uptodate,
3174 .error_remove_page = generic_error_remove_page,
3175};
3176
3177void ext4_set_aops(struct inode *inode)
3178{
3179 switch (ext4_inode_journal_mode(inode)) {
3180 case EXT4_INODE_ORDERED_DATA_MODE:
3181 if (test_opt(inode->i_sb, DELALLOC))
3182 inode->i_mapping->a_ops = &ext4_da_aops;
3183 else
3184 inode->i_mapping->a_ops = &ext4_ordered_aops;
3185 break;
3186 case EXT4_INODE_WRITEBACK_DATA_MODE:
3187 if (test_opt(inode->i_sb, DELALLOC))
3188 inode->i_mapping->a_ops = &ext4_da_aops;
3189 else
3190 inode->i_mapping->a_ops = &ext4_writeback_aops;
3191 break;
3192 case EXT4_INODE_JOURNAL_DATA_MODE:
3193 inode->i_mapping->a_ops = &ext4_journalled_aops;
3194 break;
3195 default:
3196 BUG();
3197 }
3198}
3199
3200
3201/*
3202 * ext4_discard_partial_page_buffers()
3203 * Wrapper function for ext4_discard_partial_page_buffers_no_lock.
3204 * This function finds and locks the page containing the offset
3205 * "from" and passes it to ext4_discard_partial_page_buffers_no_lock.
3206 * Calling functions that already have the page locked should call
3207 * ext4_discard_partial_page_buffers_no_lock directly.
3208 */
3209int ext4_discard_partial_page_buffers(handle_t *handle,
3210 struct address_space *mapping, loff_t from,
3211 loff_t length, int flags)
3212{
3213 struct inode *inode = mapping->host;
3214 struct page *page;
3215 int err = 0;
3216
3217 page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
3218 mapping_gfp_mask(mapping) & ~__GFP_FS);
3219 if (!page)
3220 return -ENOMEM;
3221
3222 err = ext4_discard_partial_page_buffers_no_lock(handle, inode, page,
3223 from, length, flags);
3224
3225 unlock_page(page);
3226 page_cache_release(page);
3227 return err;
3228}
3229
3230/*
3231 * ext4_discard_partial_page_buffers_no_lock()
3232 * Zeros a page range of length 'length' starting from offset 'from'.
3233 * Buffer heads that correspond to the block aligned regions of the
3234 * zeroed range will be unmapped. Unblock aligned regions
3235 * will have the corresponding buffer head mapped if needed so that
3236 * that region of the page can be updated with the partial zero out.
3237 *
3238 * This function assumes that the page has already been locked. The
3239 * The range to be discarded must be contained with in the given page.
3240 * If the specified range exceeds the end of the page it will be shortened
3241 * to the end of the page that corresponds to 'from'. This function is
3242 * appropriate for updating a page and it buffer heads to be unmapped and
3243 * zeroed for blocks that have been either released, or are going to be
3244 * released.
3245 *
3246 * handle: The journal handle
3247 * inode: The files inode
3248 * page: A locked page that contains the offset "from"
3249 * from: The starting byte offset (from the begining of the file)
3250 * to begin discarding
3251 * len: The length of bytes to discard
3252 * flags: Optional flags that may be used:
3253 *
3254 * EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED
3255 * Only zero the regions of the page whose buffer heads
3256 * have already been unmapped. This flag is appropriate
3257 * for updateing the contents of a page whose blocks may
3258 * have already been released, and we only want to zero
3259 * out the regions that correspond to those released blocks.
3260 *
3261 * Returns zero on sucess or negative on failure.
3262 */
3263static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
3264 struct inode *inode, struct page *page, loff_t from,
3265 loff_t length, int flags)
3266{
3267 ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
3268 unsigned int offset = from & (PAGE_CACHE_SIZE-1);
3269 unsigned int blocksize, max, pos;
3270 ext4_lblk_t iblock;
3271 struct buffer_head *bh;
3272 int err = 0;
3273
3274 blocksize = inode->i_sb->s_blocksize;
3275 max = PAGE_CACHE_SIZE - offset;
3276
3277 if (index != page->index)
3278 return -EINVAL;
3279
3280 /*
3281 * correct length if it does not fall between
3282 * 'from' and the end of the page
3283 */
3284 if (length > max || length < 0)
3285 length = max;
3286
3287 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
3288
3289 if (!page_has_buffers(page))
3290 create_empty_buffers(page, blocksize, 0);
3291
3292 /* Find the buffer that contains "offset" */
3293 bh = page_buffers(page);
3294 pos = blocksize;
3295 while (offset >= pos) {
3296 bh = bh->b_this_page;
3297 iblock++;
3298 pos += blocksize;
3299 }
3300
3301 pos = offset;
3302 while (pos < offset + length) {
3303 unsigned int end_of_block, range_to_discard;
3304
3305 err = 0;
3306
3307 /* The length of space left to zero and unmap */
3308 range_to_discard = offset + length - pos;
3309
3310 /* The length of space until the end of the block */
3311 end_of_block = blocksize - (pos & (blocksize-1));
3312
3313 /*
3314 * Do not unmap or zero past end of block
3315 * for this buffer head
3316 */
3317 if (range_to_discard > end_of_block)
3318 range_to_discard = end_of_block;
3319
3320
3321 /*
3322 * Skip this buffer head if we are only zeroing unampped
3323 * regions of the page
3324 */
3325 if (flags & EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED &&
3326 buffer_mapped(bh))
3327 goto next;
3328
3329 /* If the range is block aligned, unmap */
3330 if (range_to_discard == blocksize) {
3331 clear_buffer_dirty(bh);
3332 bh->b_bdev = NULL;
3333 clear_buffer_mapped(bh);
3334 clear_buffer_req(bh);
3335 clear_buffer_new(bh);
3336 clear_buffer_delay(bh);
3337 clear_buffer_unwritten(bh);
3338 clear_buffer_uptodate(bh);
3339 zero_user(page, pos, range_to_discard);
3340 BUFFER_TRACE(bh, "Buffer discarded");
3341 goto next;
3342 }
3343
3344 /*
3345 * If this block is not completely contained in the range
3346 * to be discarded, then it is not going to be released. Because
3347 * we need to keep this block, we need to make sure this part
3348 * of the page is uptodate before we modify it by writeing
3349 * partial zeros on it.
3350 */
3351 if (!buffer_mapped(bh)) {
3352 /*
3353 * Buffer head must be mapped before we can read
3354 * from the block
3355 */
3356 BUFFER_TRACE(bh, "unmapped");
3357 ext4_get_block(inode, iblock, bh, 0);
3358 /* unmapped? It's a hole - nothing to do */
3359 if (!buffer_mapped(bh)) {
3360 BUFFER_TRACE(bh, "still unmapped");
3361 goto next;
3362 }
3363 }
3364
3365 /* Ok, it's mapped. Make sure it's up-to-date */
3366 if (PageUptodate(page))
3367 set_buffer_uptodate(bh);
3368
3369 if (!buffer_uptodate(bh)) {
3370 err = -EIO;
3371 ll_rw_block(READ, 1, &bh);
3372 wait_on_buffer(bh);
3373 /* Uhhuh. Read error. Complain and punt.*/
3374 if (!buffer_uptodate(bh))
3375 goto next;
3376 }
3377
3378 if (ext4_should_journal_data(inode)) {
3379 BUFFER_TRACE(bh, "get write access");
3380 err = ext4_journal_get_write_access(handle, bh);
3381 if (err)
3382 goto next;
3383 }
3384
3385 zero_user(page, pos, range_to_discard);
3386
3387 err = 0;
3388 if (ext4_should_journal_data(inode)) {
3389 err = ext4_handle_dirty_metadata(handle, inode, bh);
3390 } else
3391 mark_buffer_dirty(bh);
3392
3393 BUFFER_TRACE(bh, "Partial buffer zeroed");
3394next:
3395 bh = bh->b_this_page;
3396 iblock++;
3397 pos += range_to_discard;
3398 }
3399
3400 return err;
3401}
3402
3403int ext4_can_truncate(struct inode *inode)
3404{
3405 if (S_ISREG(inode->i_mode))
3406 return 1;
3407 if (S_ISDIR(inode->i_mode))
3408 return 1;
3409 if (S_ISLNK(inode->i_mode))
3410 return !ext4_inode_is_fast_symlink(inode);
3411 return 0;
3412}
3413
3414/*
3415 * ext4_punch_hole: punches a hole in a file by releaseing the blocks
3416 * associated with the given offset and length
3417 *
3418 * @inode: File inode
3419 * @offset: The offset where the hole will begin
3420 * @len: The length of the hole
3421 *
3422 * Returns: 0 on sucess or negative on failure
3423 */
3424
3425int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
3426{
3427 struct inode *inode = file->f_path.dentry->d_inode;
3428 if (!S_ISREG(inode->i_mode))
3429 return -EOPNOTSUPP;
3430
3431 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
3432 /* TODO: Add support for non extent hole punching */
3433 return -EOPNOTSUPP;
3434 }
3435
3436 if (EXT4_SB(inode->i_sb)->s_cluster_ratio > 1) {
3437 /* TODO: Add support for bigalloc file systems */
3438 return -EOPNOTSUPP;
3439 }
3440
3441 return ext4_ext_punch_hole(file, offset, length);
3442}
3443
3444/*
3445 * ext4_truncate()
3446 *
3447 * We block out ext4_get_block() block instantiations across the entire
3448 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
3449 * simultaneously on behalf of the same inode.
3450 *
3451 * As we work through the truncate and commit bits of it to the journal there
3452 * is one core, guiding principle: the file's tree must always be consistent on
3453 * disk. We must be able to restart the truncate after a crash.
3454 *
3455 * The file's tree may be transiently inconsistent in memory (although it
3456 * probably isn't), but whenever we close off and commit a journal transaction,
3457 * the contents of (the filesystem + the journal) must be consistent and
3458 * restartable. It's pretty simple, really: bottom up, right to left (although
3459 * left-to-right works OK too).
3460 *
3461 * Note that at recovery time, journal replay occurs *before* the restart of
3462 * truncate against the orphan inode list.
3463 *
3464 * The committed inode has the new, desired i_size (which is the same as
3465 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
3466 * that this inode's truncate did not complete and it will again call
3467 * ext4_truncate() to have another go. So there will be instantiated blocks
3468 * to the right of the truncation point in a crashed ext4 filesystem. But
3469 * that's fine - as long as they are linked from the inode, the post-crash
3470 * ext4_truncate() run will find them and release them.
3471 */
3472void ext4_truncate(struct inode *inode)
3473{
3474 trace_ext4_truncate_enter(inode);
3475
3476 if (!ext4_can_truncate(inode))
3477 return;
3478
3479 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3480
3481 if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
3482 ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
3483
3484 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3485 ext4_ext_truncate(inode);
3486 else
3487 ext4_ind_truncate(inode);
3488
3489 trace_ext4_truncate_exit(inode);
3490}
3491
3492/*
3493 * ext4_get_inode_loc returns with an extra refcount against the inode's
3494 * underlying buffer_head on success. If 'in_mem' is true, we have all
3495 * data in memory that is needed to recreate the on-disk version of this
3496 * inode.
3497 */
3498static int __ext4_get_inode_loc(struct inode *inode,
3499 struct ext4_iloc *iloc, int in_mem)
3500{
3501 struct ext4_group_desc *gdp;
3502 struct buffer_head *bh;
3503 struct super_block *sb = inode->i_sb;
3504 ext4_fsblk_t block;
3505 int inodes_per_block, inode_offset;
3506
3507 iloc->bh = NULL;
3508 if (!ext4_valid_inum(sb, inode->i_ino))
3509 return -EIO;
3510
3511 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
3512 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
3513 if (!gdp)
3514 return -EIO;
3515
3516 /*
3517 * Figure out the offset within the block group inode table
3518 */
3519 inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
3520 inode_offset = ((inode->i_ino - 1) %
3521 EXT4_INODES_PER_GROUP(sb));
3522 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
3523 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
3524
3525 bh = sb_getblk(sb, block);
3526 if (!bh) {
3527 EXT4_ERROR_INODE_BLOCK(inode, block,
3528 "unable to read itable block");
3529 return -EIO;
3530 }
3531 if (!buffer_uptodate(bh)) {
3532 lock_buffer(bh);
3533
3534 /*
3535 * If the buffer has the write error flag, we have failed
3536 * to write out another inode in the same block. In this
3537 * case, we don't have to read the block because we may
3538 * read the old inode data successfully.
3539 */
3540 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
3541 set_buffer_uptodate(bh);
3542
3543 if (buffer_uptodate(bh)) {
3544 /* someone brought it uptodate while we waited */
3545 unlock_buffer(bh);
3546 goto has_buffer;
3547 }
3548
3549 /*
3550 * If we have all information of the inode in memory and this
3551 * is the only valid inode in the block, we need not read the
3552 * block.
3553 */
3554 if (in_mem) {
3555 struct buffer_head *bitmap_bh;
3556 int i, start;
3557
3558 start = inode_offset & ~(inodes_per_block - 1);
3559
3560 /* Is the inode bitmap in cache? */
3561 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
3562 if (!bitmap_bh)
3563 goto make_io;
3564
3565 /*
3566 * If the inode bitmap isn't in cache then the
3567 * optimisation may end up performing two reads instead
3568 * of one, so skip it.
3569 */
3570 if (!buffer_uptodate(bitmap_bh)) {
3571 brelse(bitmap_bh);
3572 goto make_io;
3573 }
3574 for (i = start; i < start + inodes_per_block; i++) {
3575 if (i == inode_offset)
3576 continue;
3577 if (ext4_test_bit(i, bitmap_bh->b_data))
3578 break;
3579 }
3580 brelse(bitmap_bh);
3581 if (i == start + inodes_per_block) {
3582 /* all other inodes are free, so skip I/O */
3583 memset(bh->b_data, 0, bh->b_size);
3584 set_buffer_uptodate(bh);
3585 unlock_buffer(bh);
3586 goto has_buffer;
3587 }
3588 }
3589
3590make_io:
3591 /*
3592 * If we need to do any I/O, try to pre-readahead extra
3593 * blocks from the inode table.
3594 */
3595 if (EXT4_SB(sb)->s_inode_readahead_blks) {
3596 ext4_fsblk_t b, end, table;
3597 unsigned num;
3598
3599 table = ext4_inode_table(sb, gdp);
3600 /* s_inode_readahead_blks is always a power of 2 */
3601 b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
3602 if (table > b)
3603 b = table;
3604 end = b + EXT4_SB(sb)->s_inode_readahead_blks;
3605 num = EXT4_INODES_PER_GROUP(sb);
3606 if (ext4_has_group_desc_csum(sb))
3607 num -= ext4_itable_unused_count(sb, gdp);
3608 table += num / inodes_per_block;
3609 if (end > table)
3610 end = table;
3611 while (b <= end)
3612 sb_breadahead(sb, b++);
3613 }
3614
3615 /*
3616 * There are other valid inodes in the buffer, this inode
3617 * has in-inode xattrs, or we don't have this inode in memory.
3618 * Read the block from disk.
3619 */
3620 trace_ext4_load_inode(inode);
3621 get_bh(bh);
3622 bh->b_end_io = end_buffer_read_sync;
3623 submit_bh(READ | REQ_META | REQ_PRIO, bh);
3624 wait_on_buffer(bh);
3625 if (!buffer_uptodate(bh)) {
3626 EXT4_ERROR_INODE_BLOCK(inode, block,
3627 "unable to read itable block");
3628 brelse(bh);
3629 return -EIO;
3630 }
3631 }
3632has_buffer:
3633 iloc->bh = bh;
3634 return 0;
3635}
3636
3637int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
3638{
3639 /* We have all inode data except xattrs in memory here. */
3640 return __ext4_get_inode_loc(inode, iloc,
3641 !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
3642}
3643
3644void ext4_set_inode_flags(struct inode *inode)
3645{
3646 unsigned int flags = EXT4_I(inode)->i_flags;
3647
3648 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
3649 if (flags & EXT4_SYNC_FL)
3650 inode->i_flags |= S_SYNC;
3651 if (flags & EXT4_APPEND_FL)
3652 inode->i_flags |= S_APPEND;
3653 if (flags & EXT4_IMMUTABLE_FL)
3654 inode->i_flags |= S_IMMUTABLE;
3655 if (flags & EXT4_NOATIME_FL)
3656 inode->i_flags |= S_NOATIME;
3657 if (flags & EXT4_DIRSYNC_FL)
3658 inode->i_flags |= S_DIRSYNC;
3659}
3660
3661/* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
3662void ext4_get_inode_flags(struct ext4_inode_info *ei)
3663{
3664 unsigned int vfs_fl;
3665 unsigned long old_fl, new_fl;
3666
3667 do {
3668 vfs_fl = ei->vfs_inode.i_flags;
3669 old_fl = ei->i_flags;
3670 new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
3671 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|
3672 EXT4_DIRSYNC_FL);
3673 if (vfs_fl & S_SYNC)
3674 new_fl |= EXT4_SYNC_FL;
3675 if (vfs_fl & S_APPEND)
3676 new_fl |= EXT4_APPEND_FL;
3677 if (vfs_fl & S_IMMUTABLE)
3678 new_fl |= EXT4_IMMUTABLE_FL;
3679 if (vfs_fl & S_NOATIME)
3680 new_fl |= EXT4_NOATIME_FL;
3681 if (vfs_fl & S_DIRSYNC)
3682 new_fl |= EXT4_DIRSYNC_FL;
3683 } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl);
3684}
3685
3686static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
3687 struct ext4_inode_info *ei)
3688{
3689 blkcnt_t i_blocks ;
3690 struct inode *inode = &(ei->vfs_inode);
3691 struct super_block *sb = inode->i_sb;
3692
3693 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3694 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
3695 /* we are using combined 48 bit field */
3696 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
3697 le32_to_cpu(raw_inode->i_blocks_lo);
3698 if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
3699 /* i_blocks represent file system block size */
3700 return i_blocks << (inode->i_blkbits - 9);
3701 } else {
3702 return i_blocks;
3703 }
3704 } else {
3705 return le32_to_cpu(raw_inode->i_blocks_lo);
3706 }
3707}
3708
3709struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
3710{
3711 struct ext4_iloc iloc;
3712 struct ext4_inode *raw_inode;
3713 struct ext4_inode_info *ei;
3714 struct inode *inode;
3715 journal_t *journal = EXT4_SB(sb)->s_journal;
3716 long ret;
3717 int block;
3718 uid_t i_uid;
3719 gid_t i_gid;
3720
3721 inode = iget_locked(sb, ino);
3722 if (!inode)
3723 return ERR_PTR(-ENOMEM);
3724 if (!(inode->i_state & I_NEW))
3725 return inode;
3726
3727 ei = EXT4_I(inode);
3728 iloc.bh = NULL;
3729
3730 ret = __ext4_get_inode_loc(inode, &iloc, 0);
3731 if (ret < 0)
3732 goto bad_inode;
3733 raw_inode = ext4_raw_inode(&iloc);
3734
3735 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
3736 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
3737 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
3738 EXT4_INODE_SIZE(inode->i_sb)) {
3739 EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)",
3740 EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize,
3741 EXT4_INODE_SIZE(inode->i_sb));
3742 ret = -EIO;
3743 goto bad_inode;
3744 }
3745 } else
3746 ei->i_extra_isize = 0;
3747
3748 /* Precompute checksum seed for inode metadata */
3749 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3750 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3751 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3752 __u32 csum;
3753 __le32 inum = cpu_to_le32(inode->i_ino);
3754 __le32 gen = raw_inode->i_generation;
3755 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
3756 sizeof(inum));
3757 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
3758 sizeof(gen));
3759 }
3760
3761 if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
3762 EXT4_ERROR_INODE(inode, "checksum invalid");
3763 ret = -EIO;
3764 goto bad_inode;
3765 }
3766
3767 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
3768 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
3769 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
3770 if (!(test_opt(inode->i_sb, NO_UID32))) {
3771 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
3772 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
3773 }
3774 i_uid_write(inode, i_uid);
3775 i_gid_write(inode, i_gid);
3776 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
3777
3778 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
3779 ei->i_dir_start_lookup = 0;
3780 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
3781 /* We now have enough fields to check if the inode was active or not.
3782 * This is needed because nfsd might try to access dead inodes
3783 * the test is that same one that e2fsck uses
3784 * NeilBrown 1999oct15
3785 */
3786 if (inode->i_nlink == 0) {
3787 if (inode->i_mode == 0 ||
3788 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
3789 /* this inode is deleted */
3790 ret = -ESTALE;
3791 goto bad_inode;
3792 }
3793 /* The only unlinked inodes we let through here have
3794 * valid i_mode and are being read by the orphan
3795 * recovery code: that's fine, we're about to complete
3796 * the process of deleting those. */
3797 }
3798 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
3799 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
3800 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
3801 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
3802 ei->i_file_acl |=
3803 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
3804 inode->i_size = ext4_isize(raw_inode);
3805 ei->i_disksize = inode->i_size;
3806#ifdef CONFIG_QUOTA
3807 ei->i_reserved_quota = 0;
3808#endif
3809 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
3810 ei->i_block_group = iloc.block_group;
3811 ei->i_last_alloc_group = ~0;
3812 /*
3813 * NOTE! The in-memory inode i_data array is in little-endian order
3814 * even on big-endian machines: we do NOT byteswap the block numbers!
3815 */
3816 for (block = 0; block < EXT4_N_BLOCKS; block++)
3817 ei->i_data[block] = raw_inode->i_block[block];
3818 INIT_LIST_HEAD(&ei->i_orphan);
3819
3820 /*
3821 * Set transaction id's of transactions that have to be committed
3822 * to finish f[data]sync. We set them to currently running transaction
3823 * as we cannot be sure that the inode or some of its metadata isn't
3824 * part of the transaction - the inode could have been reclaimed and
3825 * now it is reread from disk.
3826 */
3827 if (journal) {
3828 transaction_t *transaction;
3829 tid_t tid;
3830
3831 read_lock(&journal->j_state_lock);
3832 if (journal->j_running_transaction)
3833 transaction = journal->j_running_transaction;
3834 else
3835 transaction = journal->j_committing_transaction;
3836 if (transaction)
3837 tid = transaction->t_tid;
3838 else
3839 tid = journal->j_commit_sequence;
3840 read_unlock(&journal->j_state_lock);
3841 ei->i_sync_tid = tid;
3842 ei->i_datasync_tid = tid;
3843 }
3844
3845 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
3846 if (ei->i_extra_isize == 0) {
3847 /* The extra space is currently unused. Use it. */
3848 ei->i_extra_isize = sizeof(struct ext4_inode) -
3849 EXT4_GOOD_OLD_INODE_SIZE;
3850 } else {
3851 __le32 *magic = (void *)raw_inode +
3852 EXT4_GOOD_OLD_INODE_SIZE +
3853 ei->i_extra_isize;
3854 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))
3855 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
3856 }
3857 }
3858
3859 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
3860 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
3861 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
3862 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
3863
3864 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
3865 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
3866 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
3867 inode->i_version |=
3868 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
3869 }
3870
3871 ret = 0;
3872 if (ei->i_file_acl &&
3873 !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
3874 EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
3875 ei->i_file_acl);
3876 ret = -EIO;
3877 goto bad_inode;
3878 } else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
3879 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
3880 (S_ISLNK(inode->i_mode) &&
3881 !ext4_inode_is_fast_symlink(inode)))
3882 /* Validate extent which is part of inode */
3883 ret = ext4_ext_check_inode(inode);
3884 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
3885 (S_ISLNK(inode->i_mode) &&
3886 !ext4_inode_is_fast_symlink(inode))) {
3887 /* Validate block references which are part of inode */
3888 ret = ext4_ind_check_inode(inode);
3889 }
3890 if (ret)
3891 goto bad_inode;
3892
3893 if (S_ISREG(inode->i_mode)) {
3894 inode->i_op = &ext4_file_inode_operations;
3895 inode->i_fop = &ext4_file_operations;
3896 ext4_set_aops(inode);
3897 } else if (S_ISDIR(inode->i_mode)) {
3898 inode->i_op = &ext4_dir_inode_operations;
3899 inode->i_fop = &ext4_dir_operations;
3900 } else if (S_ISLNK(inode->i_mode)) {
3901 if (ext4_inode_is_fast_symlink(inode)) {
3902 inode->i_op = &ext4_fast_symlink_inode_operations;
3903 nd_terminate_link(ei->i_data, inode->i_size,
3904 sizeof(ei->i_data) - 1);
3905 } else {
3906 inode->i_op = &ext4_symlink_inode_operations;
3907 ext4_set_aops(inode);
3908 }
3909 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
3910 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
3911 inode->i_op = &ext4_special_inode_operations;
3912 if (raw_inode->i_block[0])
3913 init_special_inode(inode, inode->i_mode,
3914 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
3915 else
3916 init_special_inode(inode, inode->i_mode,
3917 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
3918 } else {
3919 ret = -EIO;
3920 EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
3921 goto bad_inode;
3922 }
3923 brelse(iloc.bh);
3924 ext4_set_inode_flags(inode);
3925 unlock_new_inode(inode);
3926 return inode;
3927
3928bad_inode:
3929 brelse(iloc.bh);
3930 iget_failed(inode);
3931 return ERR_PTR(ret);
3932}
3933
3934static int ext4_inode_blocks_set(handle_t *handle,
3935 struct ext4_inode *raw_inode,
3936 struct ext4_inode_info *ei)
3937{
3938 struct inode *inode = &(ei->vfs_inode);
3939 u64 i_blocks = inode->i_blocks;
3940 struct super_block *sb = inode->i_sb;
3941
3942 if (i_blocks <= ~0U) {
3943 /*
3944 * i_blocks can be represnted in a 32 bit variable
3945 * as multiple of 512 bytes
3946 */
3947 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
3948 raw_inode->i_blocks_high = 0;
3949 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
3950 return 0;
3951 }
3952 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
3953 return -EFBIG;
3954
3955 if (i_blocks <= 0xffffffffffffULL) {
3956 /*
3957 * i_blocks can be represented in a 48 bit variable
3958 * as multiple of 512 bytes
3959 */
3960 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
3961 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
3962 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
3963 } else {
3964 ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
3965 /* i_block is stored in file system block size */
3966 i_blocks = i_blocks >> (inode->i_blkbits - 9);
3967 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
3968 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
3969 }
3970 return 0;
3971}
3972
3973/*
3974 * Post the struct inode info into an on-disk inode location in the
3975 * buffer-cache. This gobbles the caller's reference to the
3976 * buffer_head in the inode location struct.
3977 *
3978 * The caller must have write access to iloc->bh.
3979 */
3980static int ext4_do_update_inode(handle_t *handle,
3981 struct inode *inode,
3982 struct ext4_iloc *iloc)
3983{
3984 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
3985 struct ext4_inode_info *ei = EXT4_I(inode);
3986 struct buffer_head *bh = iloc->bh;
3987 int err = 0, rc, block;
3988 uid_t i_uid;
3989 gid_t i_gid;
3990
3991 /* For fields not not tracking in the in-memory inode,
3992 * initialise them to zero for new inodes. */
3993 if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
3994 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
3995
3996 ext4_get_inode_flags(ei);
3997 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
3998 i_uid = i_uid_read(inode);
3999 i_gid = i_gid_read(inode);
4000 if (!(test_opt(inode->i_sb, NO_UID32))) {
4001 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
4002 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
4003/*
4004 * Fix up interoperability with old kernels. Otherwise, old inodes get
4005 * re-used with the upper 16 bits of the uid/gid intact
4006 */
4007 if (!ei->i_dtime) {
4008 raw_inode->i_uid_high =
4009 cpu_to_le16(high_16_bits(i_uid));
4010 raw_inode->i_gid_high =
4011 cpu_to_le16(high_16_bits(i_gid));
4012 } else {
4013 raw_inode->i_uid_high = 0;
4014 raw_inode->i_gid_high = 0;
4015 }
4016 } else {
4017 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
4018 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
4019 raw_inode->i_uid_high = 0;
4020 raw_inode->i_gid_high = 0;
4021 }
4022 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
4023
4024 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
4025 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
4026 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
4027 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
4028
4029 if (ext4_inode_blocks_set(handle, raw_inode, ei))
4030 goto out_brelse;
4031 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
4032 raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
4033 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
4034 cpu_to_le32(EXT4_OS_HURD))
4035 raw_inode->i_file_acl_high =
4036 cpu_to_le16(ei->i_file_acl >> 32);
4037 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
4038 ext4_isize_set(raw_inode, ei->i_disksize);
4039 if (ei->i_disksize > 0x7fffffffULL) {
4040 struct super_block *sb = inode->i_sb;
4041 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
4042 EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
4043 EXT4_SB(sb)->s_es->s_rev_level ==
4044 cpu_to_le32(EXT4_GOOD_OLD_REV)) {
4045 /* If this is the first large file
4046 * created, add a flag to the superblock.
4047 */
4048 err = ext4_journal_get_write_access(handle,
4049 EXT4_SB(sb)->s_sbh);
4050 if (err)
4051 goto out_brelse;
4052 ext4_update_dynamic_rev(sb);
4053 EXT4_SET_RO_COMPAT_FEATURE(sb,
4054 EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
4055 ext4_handle_sync(handle);
4056 err = ext4_handle_dirty_super_now(handle, sb);
4057 }
4058 }
4059 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
4060 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
4061 if (old_valid_dev(inode->i_rdev)) {
4062 raw_inode->i_block[0] =
4063 cpu_to_le32(old_encode_dev(inode->i_rdev));
4064 raw_inode->i_block[1] = 0;
4065 } else {
4066 raw_inode->i_block[0] = 0;
4067 raw_inode->i_block[1] =
4068 cpu_to_le32(new_encode_dev(inode->i_rdev));
4069 raw_inode->i_block[2] = 0;
4070 }
4071 } else
4072 for (block = 0; block < EXT4_N_BLOCKS; block++)
4073 raw_inode->i_block[block] = ei->i_data[block];
4074
4075 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
4076 if (ei->i_extra_isize) {
4077 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4078 raw_inode->i_version_hi =
4079 cpu_to_le32(inode->i_version >> 32);
4080 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
4081 }
4082
4083 ext4_inode_csum_set(inode, raw_inode, ei);
4084
4085 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
4086 rc = ext4_handle_dirty_metadata(handle, NULL, bh);
4087 if (!err)
4088 err = rc;
4089 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
4090
4091 ext4_update_inode_fsync_trans(handle, inode, 0);
4092out_brelse:
4093 brelse(bh);
4094 ext4_std_error(inode->i_sb, err);
4095 return err;
4096}
4097
4098/*
4099 * ext4_write_inode()
4100 *
4101 * We are called from a few places:
4102 *
4103 * - Within generic_file_write() for O_SYNC files.
4104 * Here, there will be no transaction running. We wait for any running
4105 * trasnaction to commit.
4106 *
4107 * - Within sys_sync(), kupdate and such.
4108 * We wait on commit, if tol to.
4109 *
4110 * - Within prune_icache() (PF_MEMALLOC == true)
4111 * Here we simply return. We can't afford to block kswapd on the
4112 * journal commit.
4113 *
4114 * In all cases it is actually safe for us to return without doing anything,
4115 * because the inode has been copied into a raw inode buffer in
4116 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
4117 * knfsd.
4118 *
4119 * Note that we are absolutely dependent upon all inode dirtiers doing the
4120 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4121 * which we are interested.
4122 *
4123 * It would be a bug for them to not do this. The code:
4124 *
4125 * mark_inode_dirty(inode)
4126 * stuff();
4127 * inode->i_size = expr;
4128 *
4129 * is in error because a kswapd-driven write_inode() could occur while
4130 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4131 * will no longer be on the superblock's dirty inode list.
4132 */
4133int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
4134{
4135 int err;
4136
4137 if (current->flags & PF_MEMALLOC)
4138 return 0;
4139
4140 if (EXT4_SB(inode->i_sb)->s_journal) {
4141 if (ext4_journal_current_handle()) {
4142 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4143 dump_stack();
4144 return -EIO;
4145 }
4146
4147 if (wbc->sync_mode != WB_SYNC_ALL)
4148 return 0;
4149
4150 err = ext4_force_commit(inode->i_sb);
4151 } else {
4152 struct ext4_iloc iloc;
4153
4154 err = __ext4_get_inode_loc(inode, &iloc, 0);
4155 if (err)
4156 return err;
4157 if (wbc->sync_mode == WB_SYNC_ALL)
4158 sync_dirty_buffer(iloc.bh);
4159 if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
4160 EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
4161 "IO error syncing inode");
4162 err = -EIO;
4163 }
4164 brelse(iloc.bh);
4165 }
4166 return err;
4167}
4168
4169/*
4170 * ext4_setattr()
4171 *
4172 * Called from notify_change.
4173 *
4174 * We want to trap VFS attempts to truncate the file as soon as
4175 * possible. In particular, we want to make sure that when the VFS
4176 * shrinks i_size, we put the inode on the orphan list and modify
4177 * i_disksize immediately, so that during the subsequent flushing of
4178 * dirty pages and freeing of disk blocks, we can guarantee that any
4179 * commit will leave the blocks being flushed in an unused state on
4180 * disk. (On recovery, the inode will get truncated and the blocks will
4181 * be freed, so we have a strong guarantee that no future commit will
4182 * leave these blocks visible to the user.)
4183 *
4184 * Another thing we have to assure is that if we are in ordered mode
4185 * and inode is still attached to the committing transaction, we must
4186 * we start writeout of all the dirty pages which are being truncated.
4187 * This way we are sure that all the data written in the previous
4188 * transaction are already on disk (truncate waits for pages under
4189 * writeback).
4190 *
4191 * Called with inode->i_mutex down.
4192 */
4193int ext4_setattr(struct dentry *dentry, struct iattr *attr)
4194{
4195 struct inode *inode = dentry->d_inode;
4196 int error, rc = 0;
4197 int orphan = 0;
4198 const unsigned int ia_valid = attr->ia_valid;
4199
4200 error = inode_change_ok(inode, attr);
4201 if (error)
4202 return error;
4203
4204 if (is_quota_modification(inode, attr))
4205 dquot_initialize(inode);
4206 if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) ||
4207 (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) {
4208 handle_t *handle;
4209
4210 /* (user+group)*(old+new) structure, inode write (sb,
4211 * inode block, ? - but truncate inode update has it) */
4212 handle = ext4_journal_start(inode, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)+
4213 EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb))+3);
4214 if (IS_ERR(handle)) {
4215 error = PTR_ERR(handle);
4216 goto err_out;
4217 }
4218 error = dquot_transfer(inode, attr);
4219 if (error) {
4220 ext4_journal_stop(handle);
4221 return error;
4222 }
4223 /* Update corresponding info in inode so that everything is in
4224 * one transaction */
4225 if (attr->ia_valid & ATTR_UID)
4226 inode->i_uid = attr->ia_uid;
4227 if (attr->ia_valid & ATTR_GID)
4228 inode->i_gid = attr->ia_gid;
4229 error = ext4_mark_inode_dirty(handle, inode);
4230 ext4_journal_stop(handle);
4231 }
4232
4233 if (attr->ia_valid & ATTR_SIZE) {
4234 inode_dio_wait(inode);
4235
4236 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4237 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4238
4239 if (attr->ia_size > sbi->s_bitmap_maxbytes)
4240 return -EFBIG;
4241 }
4242 }
4243
4244 if (S_ISREG(inode->i_mode) &&
4245 attr->ia_valid & ATTR_SIZE &&
4246 (attr->ia_size < inode->i_size)) {
4247 handle_t *handle;
4248
4249 handle = ext4_journal_start(inode, 3);
4250 if (IS_ERR(handle)) {
4251 error = PTR_ERR(handle);
4252 goto err_out;
4253 }
4254 if (ext4_handle_valid(handle)) {
4255 error = ext4_orphan_add(handle, inode);
4256 orphan = 1;
4257 }
4258 EXT4_I(inode)->i_disksize = attr->ia_size;
4259 rc = ext4_mark_inode_dirty(handle, inode);
4260 if (!error)
4261 error = rc;
4262 ext4_journal_stop(handle);
4263
4264 if (ext4_should_order_data(inode)) {
4265 error = ext4_begin_ordered_truncate(inode,
4266 attr->ia_size);
4267 if (error) {
4268 /* Do as much error cleanup as possible */
4269 handle = ext4_journal_start(inode, 3);
4270 if (IS_ERR(handle)) {
4271 ext4_orphan_del(NULL, inode);
4272 goto err_out;
4273 }
4274 ext4_orphan_del(handle, inode);
4275 orphan = 0;
4276 ext4_journal_stop(handle);
4277 goto err_out;
4278 }
4279 }
4280 }
4281
4282 if (attr->ia_valid & ATTR_SIZE) {
4283 if (attr->ia_size != i_size_read(inode))
4284 truncate_setsize(inode, attr->ia_size);
4285 ext4_truncate(inode);
4286 }
4287
4288 if (!rc) {
4289 setattr_copy(inode, attr);
4290 mark_inode_dirty(inode);
4291 }
4292
4293 /*
4294 * If the call to ext4_truncate failed to get a transaction handle at
4295 * all, we need to clean up the in-core orphan list manually.
4296 */
4297 if (orphan && inode->i_nlink)
4298 ext4_orphan_del(NULL, inode);
4299
4300 if (!rc && (ia_valid & ATTR_MODE))
4301 rc = ext4_acl_chmod(inode);
4302
4303err_out:
4304 ext4_std_error(inode->i_sb, error);
4305 if (!error)
4306 error = rc;
4307 return error;
4308}
4309
4310int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
4311 struct kstat *stat)
4312{
4313 struct inode *inode;
4314 unsigned long delalloc_blocks;
4315
4316 inode = dentry->d_inode;
4317 generic_fillattr(inode, stat);
4318
4319 /*
4320 * We can't update i_blocks if the block allocation is delayed
4321 * otherwise in the case of system crash before the real block
4322 * allocation is done, we will have i_blocks inconsistent with
4323 * on-disk file blocks.
4324 * We always keep i_blocks updated together with real
4325 * allocation. But to not confuse with user, stat
4326 * will return the blocks that include the delayed allocation
4327 * blocks for this file.
4328 */
4329 delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
4330 EXT4_I(inode)->i_reserved_data_blocks);
4331
4332 stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
4333 return 0;
4334}
4335
4336static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
4337{
4338 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4339 return ext4_ind_trans_blocks(inode, nrblocks, chunk);
4340 return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
4341}
4342
4343/*
4344 * Account for index blocks, block groups bitmaps and block group
4345 * descriptor blocks if modify datablocks and index blocks
4346 * worse case, the indexs blocks spread over different block groups
4347 *
4348 * If datablocks are discontiguous, they are possible to spread over
4349 * different block groups too. If they are contiuguous, with flexbg,
4350 * they could still across block group boundary.
4351 *
4352 * Also account for superblock, inode, quota and xattr blocks
4353 */
4354static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
4355{
4356 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
4357 int gdpblocks;
4358 int idxblocks;
4359 int ret = 0;
4360
4361 /*
4362 * How many index blocks need to touch to modify nrblocks?
4363 * The "Chunk" flag indicating whether the nrblocks is
4364 * physically contiguous on disk
4365 *
4366 * For Direct IO and fallocate, they calls get_block to allocate
4367 * one single extent at a time, so they could set the "Chunk" flag
4368 */
4369 idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
4370
4371 ret = idxblocks;
4372
4373 /*
4374 * Now let's see how many group bitmaps and group descriptors need
4375 * to account
4376 */
4377 groups = idxblocks;
4378 if (chunk)
4379 groups += 1;
4380 else
4381 groups += nrblocks;
4382
4383 gdpblocks = groups;
4384 if (groups > ngroups)
4385 groups = ngroups;
4386 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
4387 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
4388
4389 /* bitmaps and block group descriptor blocks */
4390 ret += groups + gdpblocks;
4391
4392 /* Blocks for super block, inode, quota and xattr blocks */
4393 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
4394
4395 return ret;
4396}
4397
4398/*
4399 * Calculate the total number of credits to reserve to fit
4400 * the modification of a single pages into a single transaction,
4401 * which may include multiple chunks of block allocations.
4402 *
4403 * This could be called via ext4_write_begin()
4404 *
4405 * We need to consider the worse case, when
4406 * one new block per extent.
4407 */
4408int ext4_writepage_trans_blocks(struct inode *inode)
4409{
4410 int bpp = ext4_journal_blocks_per_page(inode);
4411 int ret;
4412
4413 ret = ext4_meta_trans_blocks(inode, bpp, 0);
4414
4415 /* Account for data blocks for journalled mode */
4416 if (ext4_should_journal_data(inode))
4417 ret += bpp;
4418 return ret;
4419}
4420
4421/*
4422 * Calculate the journal credits for a chunk of data modification.
4423 *
4424 * This is called from DIO, fallocate or whoever calling
4425 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
4426 *
4427 * journal buffers for data blocks are not included here, as DIO
4428 * and fallocate do no need to journal data buffers.
4429 */
4430int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
4431{
4432 return ext4_meta_trans_blocks(inode, nrblocks, 1);
4433}
4434
4435/*
4436 * The caller must have previously called ext4_reserve_inode_write().
4437 * Give this, we know that the caller already has write access to iloc->bh.
4438 */
4439int ext4_mark_iloc_dirty(handle_t *handle,
4440 struct inode *inode, struct ext4_iloc *iloc)
4441{
4442 int err = 0;
4443
4444 if (IS_I_VERSION(inode))
4445 inode_inc_iversion(inode);
4446
4447 /* the do_update_inode consumes one bh->b_count */
4448 get_bh(iloc->bh);
4449
4450 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
4451 err = ext4_do_update_inode(handle, inode, iloc);
4452 put_bh(iloc->bh);
4453 return err;
4454}
4455
4456/*
4457 * On success, We end up with an outstanding reference count against
4458 * iloc->bh. This _must_ be cleaned up later.
4459 */
4460
4461int
4462ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
4463 struct ext4_iloc *iloc)
4464{
4465 int err;
4466
4467 err = ext4_get_inode_loc(inode, iloc);
4468 if (!err) {
4469 BUFFER_TRACE(iloc->bh, "get_write_access");
4470 err = ext4_journal_get_write_access(handle, iloc->bh);
4471 if (err) {
4472 brelse(iloc->bh);
4473 iloc->bh = NULL;
4474 }
4475 }
4476 ext4_std_error(inode->i_sb, err);
4477 return err;
4478}
4479
4480/*
4481 * Expand an inode by new_extra_isize bytes.
4482 * Returns 0 on success or negative error number on failure.
4483 */
4484static int ext4_expand_extra_isize(struct inode *inode,
4485 unsigned int new_extra_isize,
4486 struct ext4_iloc iloc,
4487 handle_t *handle)
4488{
4489 struct ext4_inode *raw_inode;
4490 struct ext4_xattr_ibody_header *header;
4491
4492 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
4493 return 0;
4494
4495 raw_inode = ext4_raw_inode(&iloc);
4496
4497 header = IHDR(inode, raw_inode);
4498
4499 /* No extended attributes present */
4500 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
4501 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
4502 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
4503 new_extra_isize);
4504 EXT4_I(inode)->i_extra_isize = new_extra_isize;
4505 return 0;
4506 }
4507
4508 /* try to expand with EAs present */
4509 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
4510 raw_inode, handle);
4511}
4512
4513/*
4514 * What we do here is to mark the in-core inode as clean with respect to inode
4515 * dirtiness (it may still be data-dirty).
4516 * This means that the in-core inode may be reaped by prune_icache
4517 * without having to perform any I/O. This is a very good thing,
4518 * because *any* task may call prune_icache - even ones which
4519 * have a transaction open against a different journal.
4520 *
4521 * Is this cheating? Not really. Sure, we haven't written the
4522 * inode out, but prune_icache isn't a user-visible syncing function.
4523 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
4524 * we start and wait on commits.
4525 *
4526 * Is this efficient/effective? Well, we're being nice to the system
4527 * by cleaning up our inodes proactively so they can be reaped
4528 * without I/O. But we are potentially leaving up to five seconds'
4529 * worth of inodes floating about which prune_icache wants us to
4530 * write out. One way to fix that would be to get prune_icache()
4531 * to do a write_super() to free up some memory. It has the desired
4532 * effect.
4533 */
4534int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
4535{
4536 struct ext4_iloc iloc;
4537 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4538 static unsigned int mnt_count;
4539 int err, ret;
4540
4541 might_sleep();
4542 trace_ext4_mark_inode_dirty(inode, _RET_IP_);
4543 err = ext4_reserve_inode_write(handle, inode, &iloc);
4544 if (ext4_handle_valid(handle) &&
4545 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
4546 !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
4547 /*
4548 * We need extra buffer credits since we may write into EA block
4549 * with this same handle. If journal_extend fails, then it will
4550 * only result in a minor loss of functionality for that inode.
4551 * If this is felt to be critical, then e2fsck should be run to
4552 * force a large enough s_min_extra_isize.
4553 */
4554 if ((jbd2_journal_extend(handle,
4555 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
4556 ret = ext4_expand_extra_isize(inode,
4557 sbi->s_want_extra_isize,
4558 iloc, handle);
4559 if (ret) {
4560 ext4_set_inode_state(inode,
4561 EXT4_STATE_NO_EXPAND);
4562 if (mnt_count !=
4563 le16_to_cpu(sbi->s_es->s_mnt_count)) {
4564 ext4_warning(inode->i_sb,
4565 "Unable to expand inode %lu. Delete"
4566 " some EAs or run e2fsck.",
4567 inode->i_ino);
4568 mnt_count =
4569 le16_to_cpu(sbi->s_es->s_mnt_count);
4570 }
4571 }
4572 }
4573 }
4574 if (!err)
4575 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
4576 return err;
4577}
4578
4579/*
4580 * ext4_dirty_inode() is called from __mark_inode_dirty()
4581 *
4582 * We're really interested in the case where a file is being extended.
4583 * i_size has been changed by generic_commit_write() and we thus need
4584 * to include the updated inode in the current transaction.
4585 *
4586 * Also, dquot_alloc_block() will always dirty the inode when blocks
4587 * are allocated to the file.
4588 *
4589 * If the inode is marked synchronous, we don't honour that here - doing
4590 * so would cause a commit on atime updates, which we don't bother doing.
4591 * We handle synchronous inodes at the highest possible level.
4592 */
4593void ext4_dirty_inode(struct inode *inode, int flags)
4594{
4595 handle_t *handle;
4596
4597 handle = ext4_journal_start(inode, 2);
4598 if (IS_ERR(handle))
4599 goto out;
4600
4601 ext4_mark_inode_dirty(handle, inode);
4602
4603 ext4_journal_stop(handle);
4604out:
4605 return;
4606}
4607
4608#if 0
4609/*
4610 * Bind an inode's backing buffer_head into this transaction, to prevent
4611 * it from being flushed to disk early. Unlike
4612 * ext4_reserve_inode_write, this leaves behind no bh reference and
4613 * returns no iloc structure, so the caller needs to repeat the iloc
4614 * lookup to mark the inode dirty later.
4615 */
4616static int ext4_pin_inode(handle_t *handle, struct inode *inode)
4617{
4618 struct ext4_iloc iloc;
4619
4620 int err = 0;
4621 if (handle) {
4622 err = ext4_get_inode_loc(inode, &iloc);
4623 if (!err) {
4624 BUFFER_TRACE(iloc.bh, "get_write_access");
4625 err = jbd2_journal_get_write_access(handle, iloc.bh);
4626 if (!err)
4627 err = ext4_handle_dirty_metadata(handle,
4628 NULL,
4629 iloc.bh);
4630 brelse(iloc.bh);
4631 }
4632 }
4633 ext4_std_error(inode->i_sb, err);
4634 return err;
4635}
4636#endif
4637
4638int ext4_change_inode_journal_flag(struct inode *inode, int val)
4639{
4640 journal_t *journal;
4641 handle_t *handle;
4642 int err;
4643
4644 /*
4645 * We have to be very careful here: changing a data block's
4646 * journaling status dynamically is dangerous. If we write a
4647 * data block to the journal, change the status and then delete
4648 * that block, we risk forgetting to revoke the old log record
4649 * from the journal and so a subsequent replay can corrupt data.
4650 * So, first we make sure that the journal is empty and that
4651 * nobody is changing anything.
4652 */
4653
4654 journal = EXT4_JOURNAL(inode);
4655 if (!journal)
4656 return 0;
4657 if (is_journal_aborted(journal))
4658 return -EROFS;
4659 /* We have to allocate physical blocks for delalloc blocks
4660 * before flushing journal. otherwise delalloc blocks can not
4661 * be allocated any more. even more truncate on delalloc blocks
4662 * could trigger BUG by flushing delalloc blocks in journal.
4663 * There is no delalloc block in non-journal data mode.
4664 */
4665 if (val && test_opt(inode->i_sb, DELALLOC)) {
4666 err = ext4_alloc_da_blocks(inode);
4667 if (err < 0)
4668 return err;
4669 }
4670
4671 jbd2_journal_lock_updates(journal);
4672
4673 /*
4674 * OK, there are no updates running now, and all cached data is
4675 * synced to disk. We are now in a completely consistent state
4676 * which doesn't have anything in the journal, and we know that
4677 * no filesystem updates are running, so it is safe to modify
4678 * the inode's in-core data-journaling state flag now.
4679 */
4680
4681 if (val)
4682 ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
4683 else {
4684 jbd2_journal_flush(journal);
4685 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
4686 }
4687 ext4_set_aops(inode);
4688
4689 jbd2_journal_unlock_updates(journal);
4690
4691 /* Finally we can mark the inode as dirty. */
4692
4693 handle = ext4_journal_start(inode, 1);
4694 if (IS_ERR(handle))
4695 return PTR_ERR(handle);
4696
4697 err = ext4_mark_inode_dirty(handle, inode);
4698 ext4_handle_sync(handle);
4699 ext4_journal_stop(handle);
4700 ext4_std_error(inode->i_sb, err);
4701
4702 return err;
4703}
4704
4705static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
4706{
4707 return !buffer_mapped(bh);
4708}
4709
4710int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
4711{
4712 struct page *page = vmf->page;
4713 loff_t size;
4714 unsigned long len;
4715 int ret;
4716 struct file *file = vma->vm_file;
4717 struct inode *inode = file->f_path.dentry->d_inode;
4718 struct address_space *mapping = inode->i_mapping;
4719 handle_t *handle;
4720 get_block_t *get_block;
4721 int retries = 0;
4722
4723 /*
4724 * This check is racy but catches the common case. We rely on
4725 * __block_page_mkwrite() to do a reliable check.
4726 */
4727 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
4728 /* Delalloc case is easy... */
4729 if (test_opt(inode->i_sb, DELALLOC) &&
4730 !ext4_should_journal_data(inode) &&
4731 !ext4_nonda_switch(inode->i_sb)) {
4732 do {
4733 ret = __block_page_mkwrite(vma, vmf,
4734 ext4_da_get_block_prep);
4735 } while (ret == -ENOSPC &&
4736 ext4_should_retry_alloc(inode->i_sb, &retries));
4737 goto out_ret;
4738 }
4739
4740 lock_page(page);
4741 size = i_size_read(inode);
4742 /* Page got truncated from under us? */
4743 if (page->mapping != mapping || page_offset(page) > size) {
4744 unlock_page(page);
4745 ret = VM_FAULT_NOPAGE;
4746 goto out;
4747 }
4748
4749 if (page->index == size >> PAGE_CACHE_SHIFT)
4750 len = size & ~PAGE_CACHE_MASK;
4751 else
4752 len = PAGE_CACHE_SIZE;
4753 /*
4754 * Return if we have all the buffers mapped. This avoids the need to do
4755 * journal_start/journal_stop which can block and take a long time
4756 */
4757 if (page_has_buffers(page)) {
4758 if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
4759 ext4_bh_unmapped)) {
4760 /* Wait so that we don't change page under IO */
4761 wait_on_page_writeback(page);
4762 ret = VM_FAULT_LOCKED;
4763 goto out;
4764 }
4765 }
4766 unlock_page(page);
4767 /* OK, we need to fill the hole... */
4768 if (ext4_should_dioread_nolock(inode))
4769 get_block = ext4_get_block_write;
4770 else
4771 get_block = ext4_get_block;
4772retry_alloc:
4773 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
4774 if (IS_ERR(handle)) {
4775 ret = VM_FAULT_SIGBUS;
4776 goto out;
4777 }
4778 ret = __block_page_mkwrite(vma, vmf, get_block);
4779 if (!ret && ext4_should_journal_data(inode)) {
4780 if (walk_page_buffers(handle, page_buffers(page), 0,
4781 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access)) {
4782 unlock_page(page);
4783 ret = VM_FAULT_SIGBUS;
4784 ext4_journal_stop(handle);
4785 goto out;
4786 }
4787 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
4788 }
4789 ext4_journal_stop(handle);
4790 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
4791 goto retry_alloc;
4792out_ret:
4793 ret = block_page_mkwrite_return(ret);
4794out:
4795 return ret;
4796}
1/*
2 * linux/fs/ext4/inode.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/inode.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * 64-bit file support on 64-bit platforms by Jakub Jelinek
16 * (jj@sunsite.ms.mff.cuni.cz)
17 *
18 * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
19 */
20
21#include <linux/fs.h>
22#include <linux/time.h>
23#include <linux/highuid.h>
24#include <linux/pagemap.h>
25#include <linux/dax.h>
26#include <linux/quotaops.h>
27#include <linux/string.h>
28#include <linux/buffer_head.h>
29#include <linux/writeback.h>
30#include <linux/pagevec.h>
31#include <linux/mpage.h>
32#include <linux/namei.h>
33#include <linux/uio.h>
34#include <linux/bio.h>
35#include <linux/workqueue.h>
36#include <linux/kernel.h>
37#include <linux/printk.h>
38#include <linux/slab.h>
39#include <linux/bitops.h>
40
41#include "ext4_jbd2.h"
42#include "xattr.h"
43#include "acl.h"
44#include "truncate.h"
45
46#include <trace/events/ext4.h>
47
48#define MPAGE_DA_EXTENT_TAIL 0x01
49
50static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw,
51 struct ext4_inode_info *ei)
52{
53 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
54 __u16 csum_lo;
55 __u16 csum_hi = 0;
56 __u32 csum;
57
58 csum_lo = le16_to_cpu(raw->i_checksum_lo);
59 raw->i_checksum_lo = 0;
60 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
61 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) {
62 csum_hi = le16_to_cpu(raw->i_checksum_hi);
63 raw->i_checksum_hi = 0;
64 }
65
66 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw,
67 EXT4_INODE_SIZE(inode->i_sb));
68
69 raw->i_checksum_lo = cpu_to_le16(csum_lo);
70 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
71 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
72 raw->i_checksum_hi = cpu_to_le16(csum_hi);
73
74 return csum;
75}
76
77static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw,
78 struct ext4_inode_info *ei)
79{
80 __u32 provided, calculated;
81
82 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
83 cpu_to_le32(EXT4_OS_LINUX) ||
84 !ext4_has_metadata_csum(inode->i_sb))
85 return 1;
86
87 provided = le16_to_cpu(raw->i_checksum_lo);
88 calculated = ext4_inode_csum(inode, raw, ei);
89 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
90 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
91 provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16;
92 else
93 calculated &= 0xFFFF;
94
95 return provided == calculated;
96}
97
98static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
99 struct ext4_inode_info *ei)
100{
101 __u32 csum;
102
103 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
104 cpu_to_le32(EXT4_OS_LINUX) ||
105 !ext4_has_metadata_csum(inode->i_sb))
106 return;
107
108 csum = ext4_inode_csum(inode, raw, ei);
109 raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF);
110 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
111 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
112 raw->i_checksum_hi = cpu_to_le16(csum >> 16);
113}
114
115static inline int ext4_begin_ordered_truncate(struct inode *inode,
116 loff_t new_size)
117{
118 trace_ext4_begin_ordered_truncate(inode, new_size);
119 /*
120 * If jinode is zero, then we never opened the file for
121 * writing, so there's no need to call
122 * jbd2_journal_begin_ordered_truncate() since there's no
123 * outstanding writes we need to flush.
124 */
125 if (!EXT4_I(inode)->jinode)
126 return 0;
127 return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode),
128 EXT4_I(inode)->jinode,
129 new_size);
130}
131
132static void ext4_invalidatepage(struct page *page, unsigned int offset,
133 unsigned int length);
134static int __ext4_journalled_writepage(struct page *page, unsigned int len);
135static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
136static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
137 int pextents);
138
139/*
140 * Test whether an inode is a fast symlink.
141 */
142int ext4_inode_is_fast_symlink(struct inode *inode)
143{
144 int ea_blocks = EXT4_I(inode)->i_file_acl ?
145 EXT4_CLUSTER_SIZE(inode->i_sb) >> 9 : 0;
146
147 if (ext4_has_inline_data(inode))
148 return 0;
149
150 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
151}
152
153/*
154 * Restart the transaction associated with *handle. This does a commit,
155 * so before we call here everything must be consistently dirtied against
156 * this transaction.
157 */
158int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
159 int nblocks)
160{
161 int ret;
162
163 /*
164 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
165 * moment, get_block can be called only for blocks inside i_size since
166 * page cache has been already dropped and writes are blocked by
167 * i_mutex. So we can safely drop the i_data_sem here.
168 */
169 BUG_ON(EXT4_JOURNAL(inode) == NULL);
170 jbd_debug(2, "restarting handle %p\n", handle);
171 up_write(&EXT4_I(inode)->i_data_sem);
172 ret = ext4_journal_restart(handle, nblocks);
173 down_write(&EXT4_I(inode)->i_data_sem);
174 ext4_discard_preallocations(inode);
175
176 return ret;
177}
178
179/*
180 * Called at the last iput() if i_nlink is zero.
181 */
182void ext4_evict_inode(struct inode *inode)
183{
184 handle_t *handle;
185 int err;
186
187 trace_ext4_evict_inode(inode);
188
189 if (inode->i_nlink) {
190 /*
191 * When journalling data dirty buffers are tracked only in the
192 * journal. So although mm thinks everything is clean and
193 * ready for reaping the inode might still have some pages to
194 * write in the running transaction or waiting to be
195 * checkpointed. Thus calling jbd2_journal_invalidatepage()
196 * (via truncate_inode_pages()) to discard these buffers can
197 * cause data loss. Also even if we did not discard these
198 * buffers, we would have no way to find them after the inode
199 * is reaped and thus user could see stale data if he tries to
200 * read them before the transaction is checkpointed. So be
201 * careful and force everything to disk here... We use
202 * ei->i_datasync_tid to store the newest transaction
203 * containing inode's data.
204 *
205 * Note that directories do not have this problem because they
206 * don't use page cache.
207 */
208 if (ext4_should_journal_data(inode) &&
209 (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) &&
210 inode->i_ino != EXT4_JOURNAL_INO) {
211 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
212 tid_t commit_tid = EXT4_I(inode)->i_datasync_tid;
213
214 jbd2_complete_transaction(journal, commit_tid);
215 filemap_write_and_wait(&inode->i_data);
216 }
217 truncate_inode_pages_final(&inode->i_data);
218
219 goto no_delete;
220 }
221
222 if (is_bad_inode(inode))
223 goto no_delete;
224 dquot_initialize(inode);
225
226 if (ext4_should_order_data(inode))
227 ext4_begin_ordered_truncate(inode, 0);
228 truncate_inode_pages_final(&inode->i_data);
229
230 /*
231 * Protect us against freezing - iput() caller didn't have to have any
232 * protection against it
233 */
234 sb_start_intwrite(inode->i_sb);
235 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE,
236 ext4_blocks_for_truncate(inode)+3);
237 if (IS_ERR(handle)) {
238 ext4_std_error(inode->i_sb, PTR_ERR(handle));
239 /*
240 * If we're going to skip the normal cleanup, we still need to
241 * make sure that the in-core orphan linked list is properly
242 * cleaned up.
243 */
244 ext4_orphan_del(NULL, inode);
245 sb_end_intwrite(inode->i_sb);
246 goto no_delete;
247 }
248
249 if (IS_SYNC(inode))
250 ext4_handle_sync(handle);
251 inode->i_size = 0;
252 err = ext4_mark_inode_dirty(handle, inode);
253 if (err) {
254 ext4_warning(inode->i_sb,
255 "couldn't mark inode dirty (err %d)", err);
256 goto stop_handle;
257 }
258 if (inode->i_blocks)
259 ext4_truncate(inode);
260
261 /*
262 * ext4_ext_truncate() doesn't reserve any slop when it
263 * restarts journal transactions; therefore there may not be
264 * enough credits left in the handle to remove the inode from
265 * the orphan list and set the dtime field.
266 */
267 if (!ext4_handle_has_enough_credits(handle, 3)) {
268 err = ext4_journal_extend(handle, 3);
269 if (err > 0)
270 err = ext4_journal_restart(handle, 3);
271 if (err != 0) {
272 ext4_warning(inode->i_sb,
273 "couldn't extend journal (err %d)", err);
274 stop_handle:
275 ext4_journal_stop(handle);
276 ext4_orphan_del(NULL, inode);
277 sb_end_intwrite(inode->i_sb);
278 goto no_delete;
279 }
280 }
281
282 /*
283 * Kill off the orphan record which ext4_truncate created.
284 * AKPM: I think this can be inside the above `if'.
285 * Note that ext4_orphan_del() has to be able to cope with the
286 * deletion of a non-existent orphan - this is because we don't
287 * know if ext4_truncate() actually created an orphan record.
288 * (Well, we could do this if we need to, but heck - it works)
289 */
290 ext4_orphan_del(handle, inode);
291 EXT4_I(inode)->i_dtime = get_seconds();
292
293 /*
294 * One subtle ordering requirement: if anything has gone wrong
295 * (transaction abort, IO errors, whatever), then we can still
296 * do these next steps (the fs will already have been marked as
297 * having errors), but we can't free the inode if the mark_dirty
298 * fails.
299 */
300 if (ext4_mark_inode_dirty(handle, inode))
301 /* If that failed, just do the required in-core inode clear. */
302 ext4_clear_inode(inode);
303 else
304 ext4_free_inode(handle, inode);
305 ext4_journal_stop(handle);
306 sb_end_intwrite(inode->i_sb);
307 return;
308no_delete:
309 ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
310}
311
312#ifdef CONFIG_QUOTA
313qsize_t *ext4_get_reserved_space(struct inode *inode)
314{
315 return &EXT4_I(inode)->i_reserved_quota;
316}
317#endif
318
319/*
320 * Called with i_data_sem down, which is important since we can call
321 * ext4_discard_preallocations() from here.
322 */
323void ext4_da_update_reserve_space(struct inode *inode,
324 int used, int quota_claim)
325{
326 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
327 struct ext4_inode_info *ei = EXT4_I(inode);
328
329 spin_lock(&ei->i_block_reservation_lock);
330 trace_ext4_da_update_reserve_space(inode, used, quota_claim);
331 if (unlikely(used > ei->i_reserved_data_blocks)) {
332 ext4_warning(inode->i_sb, "%s: ino %lu, used %d "
333 "with only %d reserved data blocks",
334 __func__, inode->i_ino, used,
335 ei->i_reserved_data_blocks);
336 WARN_ON(1);
337 used = ei->i_reserved_data_blocks;
338 }
339
340 /* Update per-inode reservations */
341 ei->i_reserved_data_blocks -= used;
342 percpu_counter_sub(&sbi->s_dirtyclusters_counter, used);
343
344 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
345
346 /* Update quota subsystem for data blocks */
347 if (quota_claim)
348 dquot_claim_block(inode, EXT4_C2B(sbi, used));
349 else {
350 /*
351 * We did fallocate with an offset that is already delayed
352 * allocated. So on delayed allocated writeback we should
353 * not re-claim the quota for fallocated blocks.
354 */
355 dquot_release_reservation_block(inode, EXT4_C2B(sbi, used));
356 }
357
358 /*
359 * If we have done all the pending block allocations and if
360 * there aren't any writers on the inode, we can discard the
361 * inode's preallocations.
362 */
363 if ((ei->i_reserved_data_blocks == 0) &&
364 (atomic_read(&inode->i_writecount) == 0))
365 ext4_discard_preallocations(inode);
366}
367
368static int __check_block_validity(struct inode *inode, const char *func,
369 unsigned int line,
370 struct ext4_map_blocks *map)
371{
372 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
373 map->m_len)) {
374 ext4_error_inode(inode, func, line, map->m_pblk,
375 "lblock %lu mapped to illegal pblock "
376 "(length %d)", (unsigned long) map->m_lblk,
377 map->m_len);
378 return -EFSCORRUPTED;
379 }
380 return 0;
381}
382
383int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk, ext4_fsblk_t pblk,
384 ext4_lblk_t len)
385{
386 int ret;
387
388 if (ext4_encrypted_inode(inode))
389 return ext4_encrypted_zeroout(inode, lblk, pblk, len);
390
391 ret = sb_issue_zeroout(inode->i_sb, pblk, len, GFP_NOFS);
392 if (ret > 0)
393 ret = 0;
394
395 return ret;
396}
397
398#define check_block_validity(inode, map) \
399 __check_block_validity((inode), __func__, __LINE__, (map))
400
401#ifdef ES_AGGRESSIVE_TEST
402static void ext4_map_blocks_es_recheck(handle_t *handle,
403 struct inode *inode,
404 struct ext4_map_blocks *es_map,
405 struct ext4_map_blocks *map,
406 int flags)
407{
408 int retval;
409
410 map->m_flags = 0;
411 /*
412 * There is a race window that the result is not the same.
413 * e.g. xfstests #223 when dioread_nolock enables. The reason
414 * is that we lookup a block mapping in extent status tree with
415 * out taking i_data_sem. So at the time the unwritten extent
416 * could be converted.
417 */
418 down_read(&EXT4_I(inode)->i_data_sem);
419 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
420 retval = ext4_ext_map_blocks(handle, inode, map, flags &
421 EXT4_GET_BLOCKS_KEEP_SIZE);
422 } else {
423 retval = ext4_ind_map_blocks(handle, inode, map, flags &
424 EXT4_GET_BLOCKS_KEEP_SIZE);
425 }
426 up_read((&EXT4_I(inode)->i_data_sem));
427
428 /*
429 * We don't check m_len because extent will be collpased in status
430 * tree. So the m_len might not equal.
431 */
432 if (es_map->m_lblk != map->m_lblk ||
433 es_map->m_flags != map->m_flags ||
434 es_map->m_pblk != map->m_pblk) {
435 printk("ES cache assertion failed for inode: %lu "
436 "es_cached ex [%d/%d/%llu/%x] != "
437 "found ex [%d/%d/%llu/%x] retval %d flags %x\n",
438 inode->i_ino, es_map->m_lblk, es_map->m_len,
439 es_map->m_pblk, es_map->m_flags, map->m_lblk,
440 map->m_len, map->m_pblk, map->m_flags,
441 retval, flags);
442 }
443}
444#endif /* ES_AGGRESSIVE_TEST */
445
446/*
447 * The ext4_map_blocks() function tries to look up the requested blocks,
448 * and returns if the blocks are already mapped.
449 *
450 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
451 * and store the allocated blocks in the result buffer head and mark it
452 * mapped.
453 *
454 * If file type is extents based, it will call ext4_ext_map_blocks(),
455 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
456 * based files
457 *
458 * On success, it returns the number of blocks being mapped or allocated. if
459 * create==0 and the blocks are pre-allocated and unwritten, the resulting @map
460 * is marked as unwritten. If the create == 1, it will mark @map as mapped.
461 *
462 * It returns 0 if plain look up failed (blocks have not been allocated), in
463 * that case, @map is returned as unmapped but we still do fill map->m_len to
464 * indicate the length of a hole starting at map->m_lblk.
465 *
466 * It returns the error in case of allocation failure.
467 */
468int ext4_map_blocks(handle_t *handle, struct inode *inode,
469 struct ext4_map_blocks *map, int flags)
470{
471 struct extent_status es;
472 int retval;
473 int ret = 0;
474#ifdef ES_AGGRESSIVE_TEST
475 struct ext4_map_blocks orig_map;
476
477 memcpy(&orig_map, map, sizeof(*map));
478#endif
479
480 map->m_flags = 0;
481 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
482 "logical block %lu\n", inode->i_ino, flags, map->m_len,
483 (unsigned long) map->m_lblk);
484
485 /*
486 * ext4_map_blocks returns an int, and m_len is an unsigned int
487 */
488 if (unlikely(map->m_len > INT_MAX))
489 map->m_len = INT_MAX;
490
491 /* We can handle the block number less than EXT_MAX_BLOCKS */
492 if (unlikely(map->m_lblk >= EXT_MAX_BLOCKS))
493 return -EFSCORRUPTED;
494
495 /* Lookup extent status tree firstly */
496 if (ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
497 if (ext4_es_is_written(&es) || ext4_es_is_unwritten(&es)) {
498 map->m_pblk = ext4_es_pblock(&es) +
499 map->m_lblk - es.es_lblk;
500 map->m_flags |= ext4_es_is_written(&es) ?
501 EXT4_MAP_MAPPED : EXT4_MAP_UNWRITTEN;
502 retval = es.es_len - (map->m_lblk - es.es_lblk);
503 if (retval > map->m_len)
504 retval = map->m_len;
505 map->m_len = retval;
506 } else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) {
507 map->m_pblk = 0;
508 retval = es.es_len - (map->m_lblk - es.es_lblk);
509 if (retval > map->m_len)
510 retval = map->m_len;
511 map->m_len = retval;
512 retval = 0;
513 } else {
514 BUG_ON(1);
515 }
516#ifdef ES_AGGRESSIVE_TEST
517 ext4_map_blocks_es_recheck(handle, inode, map,
518 &orig_map, flags);
519#endif
520 goto found;
521 }
522
523 /*
524 * Try to see if we can get the block without requesting a new
525 * file system block.
526 */
527 down_read(&EXT4_I(inode)->i_data_sem);
528 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
529 retval = ext4_ext_map_blocks(handle, inode, map, flags &
530 EXT4_GET_BLOCKS_KEEP_SIZE);
531 } else {
532 retval = ext4_ind_map_blocks(handle, inode, map, flags &
533 EXT4_GET_BLOCKS_KEEP_SIZE);
534 }
535 if (retval > 0) {
536 unsigned int status;
537
538 if (unlikely(retval != map->m_len)) {
539 ext4_warning(inode->i_sb,
540 "ES len assertion failed for inode "
541 "%lu: retval %d != map->m_len %d",
542 inode->i_ino, retval, map->m_len);
543 WARN_ON(1);
544 }
545
546 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
547 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
548 if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
549 !(status & EXTENT_STATUS_WRITTEN) &&
550 ext4_find_delalloc_range(inode, map->m_lblk,
551 map->m_lblk + map->m_len - 1))
552 status |= EXTENT_STATUS_DELAYED;
553 ret = ext4_es_insert_extent(inode, map->m_lblk,
554 map->m_len, map->m_pblk, status);
555 if (ret < 0)
556 retval = ret;
557 }
558 up_read((&EXT4_I(inode)->i_data_sem));
559
560found:
561 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
562 ret = check_block_validity(inode, map);
563 if (ret != 0)
564 return ret;
565 }
566
567 /* If it is only a block(s) look up */
568 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
569 return retval;
570
571 /*
572 * Returns if the blocks have already allocated
573 *
574 * Note that if blocks have been preallocated
575 * ext4_ext_get_block() returns the create = 0
576 * with buffer head unmapped.
577 */
578 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
579 /*
580 * If we need to convert extent to unwritten
581 * we continue and do the actual work in
582 * ext4_ext_map_blocks()
583 */
584 if (!(flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN))
585 return retval;
586
587 /*
588 * Here we clear m_flags because after allocating an new extent,
589 * it will be set again.
590 */
591 map->m_flags &= ~EXT4_MAP_FLAGS;
592
593 /*
594 * New blocks allocate and/or writing to unwritten extent
595 * will possibly result in updating i_data, so we take
596 * the write lock of i_data_sem, and call get_block()
597 * with create == 1 flag.
598 */
599 down_write(&EXT4_I(inode)->i_data_sem);
600
601 /*
602 * We need to check for EXT4 here because migrate
603 * could have changed the inode type in between
604 */
605 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
606 retval = ext4_ext_map_blocks(handle, inode, map, flags);
607 } else {
608 retval = ext4_ind_map_blocks(handle, inode, map, flags);
609
610 if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
611 /*
612 * We allocated new blocks which will result in
613 * i_data's format changing. Force the migrate
614 * to fail by clearing migrate flags
615 */
616 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
617 }
618
619 /*
620 * Update reserved blocks/metadata blocks after successful
621 * block allocation which had been deferred till now. We don't
622 * support fallocate for non extent files. So we can update
623 * reserve space here.
624 */
625 if ((retval > 0) &&
626 (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
627 ext4_da_update_reserve_space(inode, retval, 1);
628 }
629
630 if (retval > 0) {
631 unsigned int status;
632
633 if (unlikely(retval != map->m_len)) {
634 ext4_warning(inode->i_sb,
635 "ES len assertion failed for inode "
636 "%lu: retval %d != map->m_len %d",
637 inode->i_ino, retval, map->m_len);
638 WARN_ON(1);
639 }
640
641 /*
642 * We have to zeroout blocks before inserting them into extent
643 * status tree. Otherwise someone could look them up there and
644 * use them before they are really zeroed.
645 */
646 if (flags & EXT4_GET_BLOCKS_ZERO &&
647 map->m_flags & EXT4_MAP_MAPPED &&
648 map->m_flags & EXT4_MAP_NEW) {
649 ret = ext4_issue_zeroout(inode, map->m_lblk,
650 map->m_pblk, map->m_len);
651 if (ret) {
652 retval = ret;
653 goto out_sem;
654 }
655 }
656
657 /*
658 * If the extent has been zeroed out, we don't need to update
659 * extent status tree.
660 */
661 if ((flags & EXT4_GET_BLOCKS_PRE_IO) &&
662 ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
663 if (ext4_es_is_written(&es))
664 goto out_sem;
665 }
666 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
667 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
668 if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
669 !(status & EXTENT_STATUS_WRITTEN) &&
670 ext4_find_delalloc_range(inode, map->m_lblk,
671 map->m_lblk + map->m_len - 1))
672 status |= EXTENT_STATUS_DELAYED;
673 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
674 map->m_pblk, status);
675 if (ret < 0) {
676 retval = ret;
677 goto out_sem;
678 }
679 }
680
681out_sem:
682 up_write((&EXT4_I(inode)->i_data_sem));
683 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
684 ret = check_block_validity(inode, map);
685 if (ret != 0)
686 return ret;
687 }
688 return retval;
689}
690
691/*
692 * Update EXT4_MAP_FLAGS in bh->b_state. For buffer heads attached to pages
693 * we have to be careful as someone else may be manipulating b_state as well.
694 */
695static void ext4_update_bh_state(struct buffer_head *bh, unsigned long flags)
696{
697 unsigned long old_state;
698 unsigned long new_state;
699
700 flags &= EXT4_MAP_FLAGS;
701
702 /* Dummy buffer_head? Set non-atomically. */
703 if (!bh->b_page) {
704 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | flags;
705 return;
706 }
707 /*
708 * Someone else may be modifying b_state. Be careful! This is ugly but
709 * once we get rid of using bh as a container for mapping information
710 * to pass to / from get_block functions, this can go away.
711 */
712 do {
713 old_state = READ_ONCE(bh->b_state);
714 new_state = (old_state & ~EXT4_MAP_FLAGS) | flags;
715 } while (unlikely(
716 cmpxchg(&bh->b_state, old_state, new_state) != old_state));
717}
718
719static int _ext4_get_block(struct inode *inode, sector_t iblock,
720 struct buffer_head *bh, int flags)
721{
722 struct ext4_map_blocks map;
723 int ret = 0;
724
725 if (ext4_has_inline_data(inode))
726 return -ERANGE;
727
728 map.m_lblk = iblock;
729 map.m_len = bh->b_size >> inode->i_blkbits;
730
731 ret = ext4_map_blocks(ext4_journal_current_handle(), inode, &map,
732 flags);
733 if (ret > 0) {
734 map_bh(bh, inode->i_sb, map.m_pblk);
735 ext4_update_bh_state(bh, map.m_flags);
736 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
737 ret = 0;
738 }
739 return ret;
740}
741
742int ext4_get_block(struct inode *inode, sector_t iblock,
743 struct buffer_head *bh, int create)
744{
745 return _ext4_get_block(inode, iblock, bh,
746 create ? EXT4_GET_BLOCKS_CREATE : 0);
747}
748
749/*
750 * Get block function used when preparing for buffered write if we require
751 * creating an unwritten extent if blocks haven't been allocated. The extent
752 * will be converted to written after the IO is complete.
753 */
754int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
755 struct buffer_head *bh_result, int create)
756{
757 ext4_debug("ext4_get_block_unwritten: inode %lu, create flag %d\n",
758 inode->i_ino, create);
759 return _ext4_get_block(inode, iblock, bh_result,
760 EXT4_GET_BLOCKS_IO_CREATE_EXT);
761}
762
763/* Maximum number of blocks we map for direct IO at once. */
764#define DIO_MAX_BLOCKS 4096
765
766/*
767 * Get blocks function for the cases that need to start a transaction -
768 * generally difference cases of direct IO and DAX IO. It also handles retries
769 * in case of ENOSPC.
770 */
771static int ext4_get_block_trans(struct inode *inode, sector_t iblock,
772 struct buffer_head *bh_result, int flags)
773{
774 int dio_credits;
775 handle_t *handle;
776 int retries = 0;
777 int ret;
778
779 /* Trim mapping request to maximum we can map at once for DIO */
780 if (bh_result->b_size >> inode->i_blkbits > DIO_MAX_BLOCKS)
781 bh_result->b_size = DIO_MAX_BLOCKS << inode->i_blkbits;
782 dio_credits = ext4_chunk_trans_blocks(inode,
783 bh_result->b_size >> inode->i_blkbits);
784retry:
785 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits);
786 if (IS_ERR(handle))
787 return PTR_ERR(handle);
788
789 ret = _ext4_get_block(inode, iblock, bh_result, flags);
790 ext4_journal_stop(handle);
791
792 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
793 goto retry;
794 return ret;
795}
796
797/* Get block function for DIO reads and writes to inodes without extents */
798int ext4_dio_get_block(struct inode *inode, sector_t iblock,
799 struct buffer_head *bh, int create)
800{
801 /* We don't expect handle for direct IO */
802 WARN_ON_ONCE(ext4_journal_current_handle());
803
804 if (!create)
805 return _ext4_get_block(inode, iblock, bh, 0);
806 return ext4_get_block_trans(inode, iblock, bh, EXT4_GET_BLOCKS_CREATE);
807}
808
809/*
810 * Get block function for AIO DIO writes when we create unwritten extent if
811 * blocks are not allocated yet. The extent will be converted to written
812 * after IO is complete.
813 */
814static int ext4_dio_get_block_unwritten_async(struct inode *inode,
815 sector_t iblock, struct buffer_head *bh_result, int create)
816{
817 int ret;
818
819 /* We don't expect handle for direct IO */
820 WARN_ON_ONCE(ext4_journal_current_handle());
821
822 ret = ext4_get_block_trans(inode, iblock, bh_result,
823 EXT4_GET_BLOCKS_IO_CREATE_EXT);
824
825 /*
826 * When doing DIO using unwritten extents, we need io_end to convert
827 * unwritten extents to written on IO completion. We allocate io_end
828 * once we spot unwritten extent and store it in b_private. Generic
829 * DIO code keeps b_private set and furthermore passes the value to
830 * our completion callback in 'private' argument.
831 */
832 if (!ret && buffer_unwritten(bh_result)) {
833 if (!bh_result->b_private) {
834 ext4_io_end_t *io_end;
835
836 io_end = ext4_init_io_end(inode, GFP_KERNEL);
837 if (!io_end)
838 return -ENOMEM;
839 bh_result->b_private = io_end;
840 ext4_set_io_unwritten_flag(inode, io_end);
841 }
842 set_buffer_defer_completion(bh_result);
843 }
844
845 return ret;
846}
847
848/*
849 * Get block function for non-AIO DIO writes when we create unwritten extent if
850 * blocks are not allocated yet. The extent will be converted to written
851 * after IO is complete from ext4_ext_direct_IO() function.
852 */
853static int ext4_dio_get_block_unwritten_sync(struct inode *inode,
854 sector_t iblock, struct buffer_head *bh_result, int create)
855{
856 int ret;
857
858 /* We don't expect handle for direct IO */
859 WARN_ON_ONCE(ext4_journal_current_handle());
860
861 ret = ext4_get_block_trans(inode, iblock, bh_result,
862 EXT4_GET_BLOCKS_IO_CREATE_EXT);
863
864 /*
865 * Mark inode as having pending DIO writes to unwritten extents.
866 * ext4_ext_direct_IO() checks this flag and converts extents to
867 * written.
868 */
869 if (!ret && buffer_unwritten(bh_result))
870 ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
871
872 return ret;
873}
874
875static int ext4_dio_get_block_overwrite(struct inode *inode, sector_t iblock,
876 struct buffer_head *bh_result, int create)
877{
878 int ret;
879
880 ext4_debug("ext4_dio_get_block_overwrite: inode %lu, create flag %d\n",
881 inode->i_ino, create);
882 /* We don't expect handle for direct IO */
883 WARN_ON_ONCE(ext4_journal_current_handle());
884
885 ret = _ext4_get_block(inode, iblock, bh_result, 0);
886 /*
887 * Blocks should have been preallocated! ext4_file_write_iter() checks
888 * that.
889 */
890 WARN_ON_ONCE(!buffer_mapped(bh_result) || buffer_unwritten(bh_result));
891
892 return ret;
893}
894
895
896/*
897 * `handle' can be NULL if create is zero
898 */
899struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
900 ext4_lblk_t block, int map_flags)
901{
902 struct ext4_map_blocks map;
903 struct buffer_head *bh;
904 int create = map_flags & EXT4_GET_BLOCKS_CREATE;
905 int err;
906
907 J_ASSERT(handle != NULL || create == 0);
908
909 map.m_lblk = block;
910 map.m_len = 1;
911 err = ext4_map_blocks(handle, inode, &map, map_flags);
912
913 if (err == 0)
914 return create ? ERR_PTR(-ENOSPC) : NULL;
915 if (err < 0)
916 return ERR_PTR(err);
917
918 bh = sb_getblk(inode->i_sb, map.m_pblk);
919 if (unlikely(!bh))
920 return ERR_PTR(-ENOMEM);
921 if (map.m_flags & EXT4_MAP_NEW) {
922 J_ASSERT(create != 0);
923 J_ASSERT(handle != NULL);
924
925 /*
926 * Now that we do not always journal data, we should
927 * keep in mind whether this should always journal the
928 * new buffer as metadata. For now, regular file
929 * writes use ext4_get_block instead, so it's not a
930 * problem.
931 */
932 lock_buffer(bh);
933 BUFFER_TRACE(bh, "call get_create_access");
934 err = ext4_journal_get_create_access(handle, bh);
935 if (unlikely(err)) {
936 unlock_buffer(bh);
937 goto errout;
938 }
939 if (!buffer_uptodate(bh)) {
940 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
941 set_buffer_uptodate(bh);
942 }
943 unlock_buffer(bh);
944 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
945 err = ext4_handle_dirty_metadata(handle, inode, bh);
946 if (unlikely(err))
947 goto errout;
948 } else
949 BUFFER_TRACE(bh, "not a new buffer");
950 return bh;
951errout:
952 brelse(bh);
953 return ERR_PTR(err);
954}
955
956struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
957 ext4_lblk_t block, int map_flags)
958{
959 struct buffer_head *bh;
960
961 bh = ext4_getblk(handle, inode, block, map_flags);
962 if (IS_ERR(bh))
963 return bh;
964 if (!bh || buffer_uptodate(bh))
965 return bh;
966 ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);
967 wait_on_buffer(bh);
968 if (buffer_uptodate(bh))
969 return bh;
970 put_bh(bh);
971 return ERR_PTR(-EIO);
972}
973
974int ext4_walk_page_buffers(handle_t *handle,
975 struct buffer_head *head,
976 unsigned from,
977 unsigned to,
978 int *partial,
979 int (*fn)(handle_t *handle,
980 struct buffer_head *bh))
981{
982 struct buffer_head *bh;
983 unsigned block_start, block_end;
984 unsigned blocksize = head->b_size;
985 int err, ret = 0;
986 struct buffer_head *next;
987
988 for (bh = head, block_start = 0;
989 ret == 0 && (bh != head || !block_start);
990 block_start = block_end, bh = next) {
991 next = bh->b_this_page;
992 block_end = block_start + blocksize;
993 if (block_end <= from || block_start >= to) {
994 if (partial && !buffer_uptodate(bh))
995 *partial = 1;
996 continue;
997 }
998 err = (*fn)(handle, bh);
999 if (!ret)
1000 ret = err;
1001 }
1002 return ret;
1003}
1004
1005/*
1006 * To preserve ordering, it is essential that the hole instantiation and
1007 * the data write be encapsulated in a single transaction. We cannot
1008 * close off a transaction and start a new one between the ext4_get_block()
1009 * and the commit_write(). So doing the jbd2_journal_start at the start of
1010 * prepare_write() is the right place.
1011 *
1012 * Also, this function can nest inside ext4_writepage(). In that case, we
1013 * *know* that ext4_writepage() has generated enough buffer credits to do the
1014 * whole page. So we won't block on the journal in that case, which is good,
1015 * because the caller may be PF_MEMALLOC.
1016 *
1017 * By accident, ext4 can be reentered when a transaction is open via
1018 * quota file writes. If we were to commit the transaction while thus
1019 * reentered, there can be a deadlock - we would be holding a quota
1020 * lock, and the commit would never complete if another thread had a
1021 * transaction open and was blocking on the quota lock - a ranking
1022 * violation.
1023 *
1024 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1025 * will _not_ run commit under these circumstances because handle->h_ref
1026 * is elevated. We'll still have enough credits for the tiny quotafile
1027 * write.
1028 */
1029int do_journal_get_write_access(handle_t *handle,
1030 struct buffer_head *bh)
1031{
1032 int dirty = buffer_dirty(bh);
1033 int ret;
1034
1035 if (!buffer_mapped(bh) || buffer_freed(bh))
1036 return 0;
1037 /*
1038 * __block_write_begin() could have dirtied some buffers. Clean
1039 * the dirty bit as jbd2_journal_get_write_access() could complain
1040 * otherwise about fs integrity issues. Setting of the dirty bit
1041 * by __block_write_begin() isn't a real problem here as we clear
1042 * the bit before releasing a page lock and thus writeback cannot
1043 * ever write the buffer.
1044 */
1045 if (dirty)
1046 clear_buffer_dirty(bh);
1047 BUFFER_TRACE(bh, "get write access");
1048 ret = ext4_journal_get_write_access(handle, bh);
1049 if (!ret && dirty)
1050 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
1051 return ret;
1052}
1053
1054#ifdef CONFIG_EXT4_FS_ENCRYPTION
1055static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
1056 get_block_t *get_block)
1057{
1058 unsigned from = pos & (PAGE_SIZE - 1);
1059 unsigned to = from + len;
1060 struct inode *inode = page->mapping->host;
1061 unsigned block_start, block_end;
1062 sector_t block;
1063 int err = 0;
1064 unsigned blocksize = inode->i_sb->s_blocksize;
1065 unsigned bbits;
1066 struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
1067 bool decrypt = false;
1068
1069 BUG_ON(!PageLocked(page));
1070 BUG_ON(from > PAGE_SIZE);
1071 BUG_ON(to > PAGE_SIZE);
1072 BUG_ON(from > to);
1073
1074 if (!page_has_buffers(page))
1075 create_empty_buffers(page, blocksize, 0);
1076 head = page_buffers(page);
1077 bbits = ilog2(blocksize);
1078 block = (sector_t)page->index << (PAGE_SHIFT - bbits);
1079
1080 for (bh = head, block_start = 0; bh != head || !block_start;
1081 block++, block_start = block_end, bh = bh->b_this_page) {
1082 block_end = block_start + blocksize;
1083 if (block_end <= from || block_start >= to) {
1084 if (PageUptodate(page)) {
1085 if (!buffer_uptodate(bh))
1086 set_buffer_uptodate(bh);
1087 }
1088 continue;
1089 }
1090 if (buffer_new(bh))
1091 clear_buffer_new(bh);
1092 if (!buffer_mapped(bh)) {
1093 WARN_ON(bh->b_size != blocksize);
1094 err = get_block(inode, block, bh, 1);
1095 if (err)
1096 break;
1097 if (buffer_new(bh)) {
1098 unmap_underlying_metadata(bh->b_bdev,
1099 bh->b_blocknr);
1100 if (PageUptodate(page)) {
1101 clear_buffer_new(bh);
1102 set_buffer_uptodate(bh);
1103 mark_buffer_dirty(bh);
1104 continue;
1105 }
1106 if (block_end > to || block_start < from)
1107 zero_user_segments(page, to, block_end,
1108 block_start, from);
1109 continue;
1110 }
1111 }
1112 if (PageUptodate(page)) {
1113 if (!buffer_uptodate(bh))
1114 set_buffer_uptodate(bh);
1115 continue;
1116 }
1117 if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
1118 !buffer_unwritten(bh) &&
1119 (block_start < from || block_end > to)) {
1120 ll_rw_block(READ, 1, &bh);
1121 *wait_bh++ = bh;
1122 decrypt = ext4_encrypted_inode(inode) &&
1123 S_ISREG(inode->i_mode);
1124 }
1125 }
1126 /*
1127 * If we issued read requests, let them complete.
1128 */
1129 while (wait_bh > wait) {
1130 wait_on_buffer(*--wait_bh);
1131 if (!buffer_uptodate(*wait_bh))
1132 err = -EIO;
1133 }
1134 if (unlikely(err))
1135 page_zero_new_buffers(page, from, to);
1136 else if (decrypt)
1137 err = ext4_decrypt(page);
1138 return err;
1139}
1140#endif
1141
1142static int ext4_write_begin(struct file *file, struct address_space *mapping,
1143 loff_t pos, unsigned len, unsigned flags,
1144 struct page **pagep, void **fsdata)
1145{
1146 struct inode *inode = mapping->host;
1147 int ret, needed_blocks;
1148 handle_t *handle;
1149 int retries = 0;
1150 struct page *page;
1151 pgoff_t index;
1152 unsigned from, to;
1153
1154 trace_ext4_write_begin(inode, pos, len, flags);
1155 /*
1156 * Reserve one block more for addition to orphan list in case
1157 * we allocate blocks but write fails for some reason
1158 */
1159 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
1160 index = pos >> PAGE_SHIFT;
1161 from = pos & (PAGE_SIZE - 1);
1162 to = from + len;
1163
1164 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
1165 ret = ext4_try_to_write_inline_data(mapping, inode, pos, len,
1166 flags, pagep);
1167 if (ret < 0)
1168 return ret;
1169 if (ret == 1)
1170 return 0;
1171 }
1172
1173 /*
1174 * grab_cache_page_write_begin() can take a long time if the
1175 * system is thrashing due to memory pressure, or if the page
1176 * is being written back. So grab it first before we start
1177 * the transaction handle. This also allows us to allocate
1178 * the page (if needed) without using GFP_NOFS.
1179 */
1180retry_grab:
1181 page = grab_cache_page_write_begin(mapping, index, flags);
1182 if (!page)
1183 return -ENOMEM;
1184 unlock_page(page);
1185
1186retry_journal:
1187 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks);
1188 if (IS_ERR(handle)) {
1189 put_page(page);
1190 return PTR_ERR(handle);
1191 }
1192
1193 lock_page(page);
1194 if (page->mapping != mapping) {
1195 /* The page got truncated from under us */
1196 unlock_page(page);
1197 put_page(page);
1198 ext4_journal_stop(handle);
1199 goto retry_grab;
1200 }
1201 /* In case writeback began while the page was unlocked */
1202 wait_for_stable_page(page);
1203
1204#ifdef CONFIG_EXT4_FS_ENCRYPTION
1205 if (ext4_should_dioread_nolock(inode))
1206 ret = ext4_block_write_begin(page, pos, len,
1207 ext4_get_block_unwritten);
1208 else
1209 ret = ext4_block_write_begin(page, pos, len,
1210 ext4_get_block);
1211#else
1212 if (ext4_should_dioread_nolock(inode))
1213 ret = __block_write_begin(page, pos, len,
1214 ext4_get_block_unwritten);
1215 else
1216 ret = __block_write_begin(page, pos, len, ext4_get_block);
1217#endif
1218 if (!ret && ext4_should_journal_data(inode)) {
1219 ret = ext4_walk_page_buffers(handle, page_buffers(page),
1220 from, to, NULL,
1221 do_journal_get_write_access);
1222 }
1223
1224 if (ret) {
1225 unlock_page(page);
1226 /*
1227 * __block_write_begin may have instantiated a few blocks
1228 * outside i_size. Trim these off again. Don't need
1229 * i_size_read because we hold i_mutex.
1230 *
1231 * Add inode to orphan list in case we crash before
1232 * truncate finishes
1233 */
1234 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1235 ext4_orphan_add(handle, inode);
1236
1237 ext4_journal_stop(handle);
1238 if (pos + len > inode->i_size) {
1239 ext4_truncate_failed_write(inode);
1240 /*
1241 * If truncate failed early the inode might
1242 * still be on the orphan list; we need to
1243 * make sure the inode is removed from the
1244 * orphan list in that case.
1245 */
1246 if (inode->i_nlink)
1247 ext4_orphan_del(NULL, inode);
1248 }
1249
1250 if (ret == -ENOSPC &&
1251 ext4_should_retry_alloc(inode->i_sb, &retries))
1252 goto retry_journal;
1253 put_page(page);
1254 return ret;
1255 }
1256 *pagep = page;
1257 return ret;
1258}
1259
1260/* For write_end() in data=journal mode */
1261static int write_end_fn(handle_t *handle, struct buffer_head *bh)
1262{
1263 int ret;
1264 if (!buffer_mapped(bh) || buffer_freed(bh))
1265 return 0;
1266 set_buffer_uptodate(bh);
1267 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
1268 clear_buffer_meta(bh);
1269 clear_buffer_prio(bh);
1270 return ret;
1271}
1272
1273/*
1274 * We need to pick up the new inode size which generic_commit_write gave us
1275 * `file' can be NULL - eg, when called from page_symlink().
1276 *
1277 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1278 * buffers are managed internally.
1279 */
1280static int ext4_write_end(struct file *file,
1281 struct address_space *mapping,
1282 loff_t pos, unsigned len, unsigned copied,
1283 struct page *page, void *fsdata)
1284{
1285 handle_t *handle = ext4_journal_current_handle();
1286 struct inode *inode = mapping->host;
1287 loff_t old_size = inode->i_size;
1288 int ret = 0, ret2;
1289 int i_size_changed = 0;
1290
1291 trace_ext4_write_end(inode, pos, len, copied);
1292 if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE)) {
1293 ret = ext4_jbd2_file_inode(handle, inode);
1294 if (ret) {
1295 unlock_page(page);
1296 put_page(page);
1297 goto errout;
1298 }
1299 }
1300
1301 if (ext4_has_inline_data(inode)) {
1302 ret = ext4_write_inline_data_end(inode, pos, len,
1303 copied, page);
1304 if (ret < 0)
1305 goto errout;
1306 copied = ret;
1307 } else
1308 copied = block_write_end(file, mapping, pos,
1309 len, copied, page, fsdata);
1310 /*
1311 * it's important to update i_size while still holding page lock:
1312 * page writeout could otherwise come in and zero beyond i_size.
1313 */
1314 i_size_changed = ext4_update_inode_size(inode, pos + copied);
1315 unlock_page(page);
1316 put_page(page);
1317
1318 if (old_size < pos)
1319 pagecache_isize_extended(inode, old_size, pos);
1320 /*
1321 * Don't mark the inode dirty under page lock. First, it unnecessarily
1322 * makes the holding time of page lock longer. Second, it forces lock
1323 * ordering of page lock and transaction start for journaling
1324 * filesystems.
1325 */
1326 if (i_size_changed)
1327 ext4_mark_inode_dirty(handle, inode);
1328
1329 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1330 /* if we have allocated more blocks and copied
1331 * less. We will have blocks allocated outside
1332 * inode->i_size. So truncate them
1333 */
1334 ext4_orphan_add(handle, inode);
1335errout:
1336 ret2 = ext4_journal_stop(handle);
1337 if (!ret)
1338 ret = ret2;
1339
1340 if (pos + len > inode->i_size) {
1341 ext4_truncate_failed_write(inode);
1342 /*
1343 * If truncate failed early the inode might still be
1344 * on the orphan list; we need to make sure the inode
1345 * is removed from the orphan list in that case.
1346 */
1347 if (inode->i_nlink)
1348 ext4_orphan_del(NULL, inode);
1349 }
1350
1351 return ret ? ret : copied;
1352}
1353
1354/*
1355 * This is a private version of page_zero_new_buffers() which doesn't
1356 * set the buffer to be dirty, since in data=journalled mode we need
1357 * to call ext4_handle_dirty_metadata() instead.
1358 */
1359static void zero_new_buffers(struct page *page, unsigned from, unsigned to)
1360{
1361 unsigned int block_start = 0, block_end;
1362 struct buffer_head *head, *bh;
1363
1364 bh = head = page_buffers(page);
1365 do {
1366 block_end = block_start + bh->b_size;
1367 if (buffer_new(bh)) {
1368 if (block_end > from && block_start < to) {
1369 if (!PageUptodate(page)) {
1370 unsigned start, size;
1371
1372 start = max(from, block_start);
1373 size = min(to, block_end) - start;
1374
1375 zero_user(page, start, size);
1376 set_buffer_uptodate(bh);
1377 }
1378 clear_buffer_new(bh);
1379 }
1380 }
1381 block_start = block_end;
1382 bh = bh->b_this_page;
1383 } while (bh != head);
1384}
1385
1386static int ext4_journalled_write_end(struct file *file,
1387 struct address_space *mapping,
1388 loff_t pos, unsigned len, unsigned copied,
1389 struct page *page, void *fsdata)
1390{
1391 handle_t *handle = ext4_journal_current_handle();
1392 struct inode *inode = mapping->host;
1393 loff_t old_size = inode->i_size;
1394 int ret = 0, ret2;
1395 int partial = 0;
1396 unsigned from, to;
1397 int size_changed = 0;
1398
1399 trace_ext4_journalled_write_end(inode, pos, len, copied);
1400 from = pos & (PAGE_SIZE - 1);
1401 to = from + len;
1402
1403 BUG_ON(!ext4_handle_valid(handle));
1404
1405 if (ext4_has_inline_data(inode))
1406 copied = ext4_write_inline_data_end(inode, pos, len,
1407 copied, page);
1408 else {
1409 if (copied < len) {
1410 if (!PageUptodate(page))
1411 copied = 0;
1412 zero_new_buffers(page, from+copied, to);
1413 }
1414
1415 ret = ext4_walk_page_buffers(handle, page_buffers(page), from,
1416 to, &partial, write_end_fn);
1417 if (!partial)
1418 SetPageUptodate(page);
1419 }
1420 size_changed = ext4_update_inode_size(inode, pos + copied);
1421 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1422 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1423 unlock_page(page);
1424 put_page(page);
1425
1426 if (old_size < pos)
1427 pagecache_isize_extended(inode, old_size, pos);
1428
1429 if (size_changed) {
1430 ret2 = ext4_mark_inode_dirty(handle, inode);
1431 if (!ret)
1432 ret = ret2;
1433 }
1434
1435 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1436 /* if we have allocated more blocks and copied
1437 * less. We will have blocks allocated outside
1438 * inode->i_size. So truncate them
1439 */
1440 ext4_orphan_add(handle, inode);
1441
1442 ret2 = ext4_journal_stop(handle);
1443 if (!ret)
1444 ret = ret2;
1445 if (pos + len > inode->i_size) {
1446 ext4_truncate_failed_write(inode);
1447 /*
1448 * If truncate failed early the inode might still be
1449 * on the orphan list; we need to make sure the inode
1450 * is removed from the orphan list in that case.
1451 */
1452 if (inode->i_nlink)
1453 ext4_orphan_del(NULL, inode);
1454 }
1455
1456 return ret ? ret : copied;
1457}
1458
1459/*
1460 * Reserve space for a single cluster
1461 */
1462static int ext4_da_reserve_space(struct inode *inode)
1463{
1464 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1465 struct ext4_inode_info *ei = EXT4_I(inode);
1466 int ret;
1467
1468 /*
1469 * We will charge metadata quota at writeout time; this saves
1470 * us from metadata over-estimation, though we may go over by
1471 * a small amount in the end. Here we just reserve for data.
1472 */
1473 ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
1474 if (ret)
1475 return ret;
1476
1477 spin_lock(&ei->i_block_reservation_lock);
1478 if (ext4_claim_free_clusters(sbi, 1, 0)) {
1479 spin_unlock(&ei->i_block_reservation_lock);
1480 dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
1481 return -ENOSPC;
1482 }
1483 ei->i_reserved_data_blocks++;
1484 trace_ext4_da_reserve_space(inode);
1485 spin_unlock(&ei->i_block_reservation_lock);
1486
1487 return 0; /* success */
1488}
1489
1490static void ext4_da_release_space(struct inode *inode, int to_free)
1491{
1492 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1493 struct ext4_inode_info *ei = EXT4_I(inode);
1494
1495 if (!to_free)
1496 return; /* Nothing to release, exit */
1497
1498 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1499
1500 trace_ext4_da_release_space(inode, to_free);
1501 if (unlikely(to_free > ei->i_reserved_data_blocks)) {
1502 /*
1503 * if there aren't enough reserved blocks, then the
1504 * counter is messed up somewhere. Since this
1505 * function is called from invalidate page, it's
1506 * harmless to return without any action.
1507 */
1508 ext4_warning(inode->i_sb, "ext4_da_release_space: "
1509 "ino %lu, to_free %d with only %d reserved "
1510 "data blocks", inode->i_ino, to_free,
1511 ei->i_reserved_data_blocks);
1512 WARN_ON(1);
1513 to_free = ei->i_reserved_data_blocks;
1514 }
1515 ei->i_reserved_data_blocks -= to_free;
1516
1517 /* update fs dirty data blocks counter */
1518 percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free);
1519
1520 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1521
1522 dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
1523}
1524
1525static void ext4_da_page_release_reservation(struct page *page,
1526 unsigned int offset,
1527 unsigned int length)
1528{
1529 int to_release = 0, contiguous_blks = 0;
1530 struct buffer_head *head, *bh;
1531 unsigned int curr_off = 0;
1532 struct inode *inode = page->mapping->host;
1533 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1534 unsigned int stop = offset + length;
1535 int num_clusters;
1536 ext4_fsblk_t lblk;
1537
1538 BUG_ON(stop > PAGE_SIZE || stop < length);
1539
1540 head = page_buffers(page);
1541 bh = head;
1542 do {
1543 unsigned int next_off = curr_off + bh->b_size;
1544
1545 if (next_off > stop)
1546 break;
1547
1548 if ((offset <= curr_off) && (buffer_delay(bh))) {
1549 to_release++;
1550 contiguous_blks++;
1551 clear_buffer_delay(bh);
1552 } else if (contiguous_blks) {
1553 lblk = page->index <<
1554 (PAGE_SHIFT - inode->i_blkbits);
1555 lblk += (curr_off >> inode->i_blkbits) -
1556 contiguous_blks;
1557 ext4_es_remove_extent(inode, lblk, contiguous_blks);
1558 contiguous_blks = 0;
1559 }
1560 curr_off = next_off;
1561 } while ((bh = bh->b_this_page) != head);
1562
1563 if (contiguous_blks) {
1564 lblk = page->index << (PAGE_SHIFT - inode->i_blkbits);
1565 lblk += (curr_off >> inode->i_blkbits) - contiguous_blks;
1566 ext4_es_remove_extent(inode, lblk, contiguous_blks);
1567 }
1568
1569 /* If we have released all the blocks belonging to a cluster, then we
1570 * need to release the reserved space for that cluster. */
1571 num_clusters = EXT4_NUM_B2C(sbi, to_release);
1572 while (num_clusters > 0) {
1573 lblk = (page->index << (PAGE_SHIFT - inode->i_blkbits)) +
1574 ((num_clusters - 1) << sbi->s_cluster_bits);
1575 if (sbi->s_cluster_ratio == 1 ||
1576 !ext4_find_delalloc_cluster(inode, lblk))
1577 ext4_da_release_space(inode, 1);
1578
1579 num_clusters--;
1580 }
1581}
1582
1583/*
1584 * Delayed allocation stuff
1585 */
1586
1587struct mpage_da_data {
1588 struct inode *inode;
1589 struct writeback_control *wbc;
1590
1591 pgoff_t first_page; /* The first page to write */
1592 pgoff_t next_page; /* Current page to examine */
1593 pgoff_t last_page; /* Last page to examine */
1594 /*
1595 * Extent to map - this can be after first_page because that can be
1596 * fully mapped. We somewhat abuse m_flags to store whether the extent
1597 * is delalloc or unwritten.
1598 */
1599 struct ext4_map_blocks map;
1600 struct ext4_io_submit io_submit; /* IO submission data */
1601};
1602
1603static void mpage_release_unused_pages(struct mpage_da_data *mpd,
1604 bool invalidate)
1605{
1606 int nr_pages, i;
1607 pgoff_t index, end;
1608 struct pagevec pvec;
1609 struct inode *inode = mpd->inode;
1610 struct address_space *mapping = inode->i_mapping;
1611
1612 /* This is necessary when next_page == 0. */
1613 if (mpd->first_page >= mpd->next_page)
1614 return;
1615
1616 index = mpd->first_page;
1617 end = mpd->next_page - 1;
1618 if (invalidate) {
1619 ext4_lblk_t start, last;
1620 start = index << (PAGE_SHIFT - inode->i_blkbits);
1621 last = end << (PAGE_SHIFT - inode->i_blkbits);
1622 ext4_es_remove_extent(inode, start, last - start + 1);
1623 }
1624
1625 pagevec_init(&pvec, 0);
1626 while (index <= end) {
1627 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1628 if (nr_pages == 0)
1629 break;
1630 for (i = 0; i < nr_pages; i++) {
1631 struct page *page = pvec.pages[i];
1632 if (page->index > end)
1633 break;
1634 BUG_ON(!PageLocked(page));
1635 BUG_ON(PageWriteback(page));
1636 if (invalidate) {
1637 block_invalidatepage(page, 0, PAGE_SIZE);
1638 ClearPageUptodate(page);
1639 }
1640 unlock_page(page);
1641 }
1642 index = pvec.pages[nr_pages - 1]->index + 1;
1643 pagevec_release(&pvec);
1644 }
1645}
1646
1647static void ext4_print_free_blocks(struct inode *inode)
1648{
1649 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1650 struct super_block *sb = inode->i_sb;
1651 struct ext4_inode_info *ei = EXT4_I(inode);
1652
1653 ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld",
1654 EXT4_C2B(EXT4_SB(inode->i_sb),
1655 ext4_count_free_clusters(sb)));
1656 ext4_msg(sb, KERN_CRIT, "Free/Dirty block details");
1657 ext4_msg(sb, KERN_CRIT, "free_blocks=%lld",
1658 (long long) EXT4_C2B(EXT4_SB(sb),
1659 percpu_counter_sum(&sbi->s_freeclusters_counter)));
1660 ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld",
1661 (long long) EXT4_C2B(EXT4_SB(sb),
1662 percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
1663 ext4_msg(sb, KERN_CRIT, "Block reservation details");
1664 ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u",
1665 ei->i_reserved_data_blocks);
1666 return;
1667}
1668
1669static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
1670{
1671 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
1672}
1673
1674/*
1675 * This function is grabs code from the very beginning of
1676 * ext4_map_blocks, but assumes that the caller is from delayed write
1677 * time. This function looks up the requested blocks and sets the
1678 * buffer delay bit under the protection of i_data_sem.
1679 */
1680static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
1681 struct ext4_map_blocks *map,
1682 struct buffer_head *bh)
1683{
1684 struct extent_status es;
1685 int retval;
1686 sector_t invalid_block = ~((sector_t) 0xffff);
1687#ifdef ES_AGGRESSIVE_TEST
1688 struct ext4_map_blocks orig_map;
1689
1690 memcpy(&orig_map, map, sizeof(*map));
1691#endif
1692
1693 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
1694 invalid_block = ~0;
1695
1696 map->m_flags = 0;
1697 ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u,"
1698 "logical block %lu\n", inode->i_ino, map->m_len,
1699 (unsigned long) map->m_lblk);
1700
1701 /* Lookup extent status tree firstly */
1702 if (ext4_es_lookup_extent(inode, iblock, &es)) {
1703 if (ext4_es_is_hole(&es)) {
1704 retval = 0;
1705 down_read(&EXT4_I(inode)->i_data_sem);
1706 goto add_delayed;
1707 }
1708
1709 /*
1710 * Delayed extent could be allocated by fallocate.
1711 * So we need to check it.
1712 */
1713 if (ext4_es_is_delayed(&es) && !ext4_es_is_unwritten(&es)) {
1714 map_bh(bh, inode->i_sb, invalid_block);
1715 set_buffer_new(bh);
1716 set_buffer_delay(bh);
1717 return 0;
1718 }
1719
1720 map->m_pblk = ext4_es_pblock(&es) + iblock - es.es_lblk;
1721 retval = es.es_len - (iblock - es.es_lblk);
1722 if (retval > map->m_len)
1723 retval = map->m_len;
1724 map->m_len = retval;
1725 if (ext4_es_is_written(&es))
1726 map->m_flags |= EXT4_MAP_MAPPED;
1727 else if (ext4_es_is_unwritten(&es))
1728 map->m_flags |= EXT4_MAP_UNWRITTEN;
1729 else
1730 BUG_ON(1);
1731
1732#ifdef ES_AGGRESSIVE_TEST
1733 ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0);
1734#endif
1735 return retval;
1736 }
1737
1738 /*
1739 * Try to see if we can get the block without requesting a new
1740 * file system block.
1741 */
1742 down_read(&EXT4_I(inode)->i_data_sem);
1743 if (ext4_has_inline_data(inode))
1744 retval = 0;
1745 else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
1746 retval = ext4_ext_map_blocks(NULL, inode, map, 0);
1747 else
1748 retval = ext4_ind_map_blocks(NULL, inode, map, 0);
1749
1750add_delayed:
1751 if (retval == 0) {
1752 int ret;
1753 /*
1754 * XXX: __block_prepare_write() unmaps passed block,
1755 * is it OK?
1756 */
1757 /*
1758 * If the block was allocated from previously allocated cluster,
1759 * then we don't need to reserve it again. However we still need
1760 * to reserve metadata for every block we're going to write.
1761 */
1762 if (EXT4_SB(inode->i_sb)->s_cluster_ratio == 1 ||
1763 !ext4_find_delalloc_cluster(inode, map->m_lblk)) {
1764 ret = ext4_da_reserve_space(inode);
1765 if (ret) {
1766 /* not enough space to reserve */
1767 retval = ret;
1768 goto out_unlock;
1769 }
1770 }
1771
1772 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
1773 ~0, EXTENT_STATUS_DELAYED);
1774 if (ret) {
1775 retval = ret;
1776 goto out_unlock;
1777 }
1778
1779 map_bh(bh, inode->i_sb, invalid_block);
1780 set_buffer_new(bh);
1781 set_buffer_delay(bh);
1782 } else if (retval > 0) {
1783 int ret;
1784 unsigned int status;
1785
1786 if (unlikely(retval != map->m_len)) {
1787 ext4_warning(inode->i_sb,
1788 "ES len assertion failed for inode "
1789 "%lu: retval %d != map->m_len %d",
1790 inode->i_ino, retval, map->m_len);
1791 WARN_ON(1);
1792 }
1793
1794 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
1795 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
1796 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
1797 map->m_pblk, status);
1798 if (ret != 0)
1799 retval = ret;
1800 }
1801
1802out_unlock:
1803 up_read((&EXT4_I(inode)->i_data_sem));
1804
1805 return retval;
1806}
1807
1808/*
1809 * This is a special get_block_t callback which is used by
1810 * ext4_da_write_begin(). It will either return mapped block or
1811 * reserve space for a single block.
1812 *
1813 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
1814 * We also have b_blocknr = -1 and b_bdev initialized properly
1815 *
1816 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
1817 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
1818 * initialized properly.
1819 */
1820int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
1821 struct buffer_head *bh, int create)
1822{
1823 struct ext4_map_blocks map;
1824 int ret = 0;
1825
1826 BUG_ON(create == 0);
1827 BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
1828
1829 map.m_lblk = iblock;
1830 map.m_len = 1;
1831
1832 /*
1833 * first, we need to know whether the block is allocated already
1834 * preallocated blocks are unmapped but should treated
1835 * the same as allocated blocks.
1836 */
1837 ret = ext4_da_map_blocks(inode, iblock, &map, bh);
1838 if (ret <= 0)
1839 return ret;
1840
1841 map_bh(bh, inode->i_sb, map.m_pblk);
1842 ext4_update_bh_state(bh, map.m_flags);
1843
1844 if (buffer_unwritten(bh)) {
1845 /* A delayed write to unwritten bh should be marked
1846 * new and mapped. Mapped ensures that we don't do
1847 * get_block multiple times when we write to the same
1848 * offset and new ensures that we do proper zero out
1849 * for partial write.
1850 */
1851 set_buffer_new(bh);
1852 set_buffer_mapped(bh);
1853 }
1854 return 0;
1855}
1856
1857static int bget_one(handle_t *handle, struct buffer_head *bh)
1858{
1859 get_bh(bh);
1860 return 0;
1861}
1862
1863static int bput_one(handle_t *handle, struct buffer_head *bh)
1864{
1865 put_bh(bh);
1866 return 0;
1867}
1868
1869static int __ext4_journalled_writepage(struct page *page,
1870 unsigned int len)
1871{
1872 struct address_space *mapping = page->mapping;
1873 struct inode *inode = mapping->host;
1874 struct buffer_head *page_bufs = NULL;
1875 handle_t *handle = NULL;
1876 int ret = 0, err = 0;
1877 int inline_data = ext4_has_inline_data(inode);
1878 struct buffer_head *inode_bh = NULL;
1879
1880 ClearPageChecked(page);
1881
1882 if (inline_data) {
1883 BUG_ON(page->index != 0);
1884 BUG_ON(len > ext4_get_max_inline_size(inode));
1885 inode_bh = ext4_journalled_write_inline_data(inode, len, page);
1886 if (inode_bh == NULL)
1887 goto out;
1888 } else {
1889 page_bufs = page_buffers(page);
1890 if (!page_bufs) {
1891 BUG();
1892 goto out;
1893 }
1894 ext4_walk_page_buffers(handle, page_bufs, 0, len,
1895 NULL, bget_one);
1896 }
1897 /*
1898 * We need to release the page lock before we start the
1899 * journal, so grab a reference so the page won't disappear
1900 * out from under us.
1901 */
1902 get_page(page);
1903 unlock_page(page);
1904
1905 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
1906 ext4_writepage_trans_blocks(inode));
1907 if (IS_ERR(handle)) {
1908 ret = PTR_ERR(handle);
1909 put_page(page);
1910 goto out_no_pagelock;
1911 }
1912 BUG_ON(!ext4_handle_valid(handle));
1913
1914 lock_page(page);
1915 put_page(page);
1916 if (page->mapping != mapping) {
1917 /* The page got truncated from under us */
1918 ext4_journal_stop(handle);
1919 ret = 0;
1920 goto out;
1921 }
1922
1923 if (inline_data) {
1924 BUFFER_TRACE(inode_bh, "get write access");
1925 ret = ext4_journal_get_write_access(handle, inode_bh);
1926
1927 err = ext4_handle_dirty_metadata(handle, inode, inode_bh);
1928
1929 } else {
1930 ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
1931 do_journal_get_write_access);
1932
1933 err = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
1934 write_end_fn);
1935 }
1936 if (ret == 0)
1937 ret = err;
1938 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1939 err = ext4_journal_stop(handle);
1940 if (!ret)
1941 ret = err;
1942
1943 if (!ext4_has_inline_data(inode))
1944 ext4_walk_page_buffers(NULL, page_bufs, 0, len,
1945 NULL, bput_one);
1946 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1947out:
1948 unlock_page(page);
1949out_no_pagelock:
1950 brelse(inode_bh);
1951 return ret;
1952}
1953
1954/*
1955 * Note that we don't need to start a transaction unless we're journaling data
1956 * because we should have holes filled from ext4_page_mkwrite(). We even don't
1957 * need to file the inode to the transaction's list in ordered mode because if
1958 * we are writing back data added by write(), the inode is already there and if
1959 * we are writing back data modified via mmap(), no one guarantees in which
1960 * transaction the data will hit the disk. In case we are journaling data, we
1961 * cannot start transaction directly because transaction start ranks above page
1962 * lock so we have to do some magic.
1963 *
1964 * This function can get called via...
1965 * - ext4_writepages after taking page lock (have journal handle)
1966 * - journal_submit_inode_data_buffers (no journal handle)
1967 * - shrink_page_list via the kswapd/direct reclaim (no journal handle)
1968 * - grab_page_cache when doing write_begin (have journal handle)
1969 *
1970 * We don't do any block allocation in this function. If we have page with
1971 * multiple blocks we need to write those buffer_heads that are mapped. This
1972 * is important for mmaped based write. So if we do with blocksize 1K
1973 * truncate(f, 1024);
1974 * a = mmap(f, 0, 4096);
1975 * a[0] = 'a';
1976 * truncate(f, 4096);
1977 * we have in the page first buffer_head mapped via page_mkwrite call back
1978 * but other buffer_heads would be unmapped but dirty (dirty done via the
1979 * do_wp_page). So writepage should write the first block. If we modify
1980 * the mmap area beyond 1024 we will again get a page_fault and the
1981 * page_mkwrite callback will do the block allocation and mark the
1982 * buffer_heads mapped.
1983 *
1984 * We redirty the page if we have any buffer_heads that is either delay or
1985 * unwritten in the page.
1986 *
1987 * We can get recursively called as show below.
1988 *
1989 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1990 * ext4_writepage()
1991 *
1992 * But since we don't do any block allocation we should not deadlock.
1993 * Page also have the dirty flag cleared so we don't get recurive page_lock.
1994 */
1995static int ext4_writepage(struct page *page,
1996 struct writeback_control *wbc)
1997{
1998 int ret = 0;
1999 loff_t size;
2000 unsigned int len;
2001 struct buffer_head *page_bufs = NULL;
2002 struct inode *inode = page->mapping->host;
2003 struct ext4_io_submit io_submit;
2004 bool keep_towrite = false;
2005
2006 trace_ext4_writepage(page);
2007 size = i_size_read(inode);
2008 if (page->index == size >> PAGE_SHIFT)
2009 len = size & ~PAGE_MASK;
2010 else
2011 len = PAGE_SIZE;
2012
2013 page_bufs = page_buffers(page);
2014 /*
2015 * We cannot do block allocation or other extent handling in this
2016 * function. If there are buffers needing that, we have to redirty
2017 * the page. But we may reach here when we do a journal commit via
2018 * journal_submit_inode_data_buffers() and in that case we must write
2019 * allocated buffers to achieve data=ordered mode guarantees.
2020 *
2021 * Also, if there is only one buffer per page (the fs block
2022 * size == the page size), if one buffer needs block
2023 * allocation or needs to modify the extent tree to clear the
2024 * unwritten flag, we know that the page can't be written at
2025 * all, so we might as well refuse the write immediately.
2026 * Unfortunately if the block size != page size, we can't as
2027 * easily detect this case using ext4_walk_page_buffers(), but
2028 * for the extremely common case, this is an optimization that
2029 * skips a useless round trip through ext4_bio_write_page().
2030 */
2031 if (ext4_walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2032 ext4_bh_delay_or_unwritten)) {
2033 redirty_page_for_writepage(wbc, page);
2034 if ((current->flags & PF_MEMALLOC) ||
2035 (inode->i_sb->s_blocksize == PAGE_SIZE)) {
2036 /*
2037 * For memory cleaning there's no point in writing only
2038 * some buffers. So just bail out. Warn if we came here
2039 * from direct reclaim.
2040 */
2041 WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD))
2042 == PF_MEMALLOC);
2043 unlock_page(page);
2044 return 0;
2045 }
2046 keep_towrite = true;
2047 }
2048
2049 if (PageChecked(page) && ext4_should_journal_data(inode))
2050 /*
2051 * It's mmapped pagecache. Add buffers and journal it. There
2052 * doesn't seem much point in redirtying the page here.
2053 */
2054 return __ext4_journalled_writepage(page, len);
2055
2056 ext4_io_submit_init(&io_submit, wbc);
2057 io_submit.io_end = ext4_init_io_end(inode, GFP_NOFS);
2058 if (!io_submit.io_end) {
2059 redirty_page_for_writepage(wbc, page);
2060 unlock_page(page);
2061 return -ENOMEM;
2062 }
2063 ret = ext4_bio_write_page(&io_submit, page, len, wbc, keep_towrite);
2064 ext4_io_submit(&io_submit);
2065 /* Drop io_end reference we got from init */
2066 ext4_put_io_end_defer(io_submit.io_end);
2067 return ret;
2068}
2069
2070static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page)
2071{
2072 int len;
2073 loff_t size = i_size_read(mpd->inode);
2074 int err;
2075
2076 BUG_ON(page->index != mpd->first_page);
2077 if (page->index == size >> PAGE_SHIFT)
2078 len = size & ~PAGE_MASK;
2079 else
2080 len = PAGE_SIZE;
2081 clear_page_dirty_for_io(page);
2082 err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc, false);
2083 if (!err)
2084 mpd->wbc->nr_to_write--;
2085 mpd->first_page++;
2086
2087 return err;
2088}
2089
2090#define BH_FLAGS ((1 << BH_Unwritten) | (1 << BH_Delay))
2091
2092/*
2093 * mballoc gives us at most this number of blocks...
2094 * XXX: That seems to be only a limitation of ext4_mb_normalize_request().
2095 * The rest of mballoc seems to handle chunks up to full group size.
2096 */
2097#define MAX_WRITEPAGES_EXTENT_LEN 2048
2098
2099/*
2100 * mpage_add_bh_to_extent - try to add bh to extent of blocks to map
2101 *
2102 * @mpd - extent of blocks
2103 * @lblk - logical number of the block in the file
2104 * @bh - buffer head we want to add to the extent
2105 *
2106 * The function is used to collect contig. blocks in the same state. If the
2107 * buffer doesn't require mapping for writeback and we haven't started the
2108 * extent of buffers to map yet, the function returns 'true' immediately - the
2109 * caller can write the buffer right away. Otherwise the function returns true
2110 * if the block has been added to the extent, false if the block couldn't be
2111 * added.
2112 */
2113static bool mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk,
2114 struct buffer_head *bh)
2115{
2116 struct ext4_map_blocks *map = &mpd->map;
2117
2118 /* Buffer that doesn't need mapping for writeback? */
2119 if (!buffer_dirty(bh) || !buffer_mapped(bh) ||
2120 (!buffer_delay(bh) && !buffer_unwritten(bh))) {
2121 /* So far no extent to map => we write the buffer right away */
2122 if (map->m_len == 0)
2123 return true;
2124 return false;
2125 }
2126
2127 /* First block in the extent? */
2128 if (map->m_len == 0) {
2129 map->m_lblk = lblk;
2130 map->m_len = 1;
2131 map->m_flags = bh->b_state & BH_FLAGS;
2132 return true;
2133 }
2134
2135 /* Don't go larger than mballoc is willing to allocate */
2136 if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN)
2137 return false;
2138
2139 /* Can we merge the block to our big extent? */
2140 if (lblk == map->m_lblk + map->m_len &&
2141 (bh->b_state & BH_FLAGS) == map->m_flags) {
2142 map->m_len++;
2143 return true;
2144 }
2145 return false;
2146}
2147
2148/*
2149 * mpage_process_page_bufs - submit page buffers for IO or add them to extent
2150 *
2151 * @mpd - extent of blocks for mapping
2152 * @head - the first buffer in the page
2153 * @bh - buffer we should start processing from
2154 * @lblk - logical number of the block in the file corresponding to @bh
2155 *
2156 * Walk through page buffers from @bh upto @head (exclusive) and either submit
2157 * the page for IO if all buffers in this page were mapped and there's no
2158 * accumulated extent of buffers to map or add buffers in the page to the
2159 * extent of buffers to map. The function returns 1 if the caller can continue
2160 * by processing the next page, 0 if it should stop adding buffers to the
2161 * extent to map because we cannot extend it anymore. It can also return value
2162 * < 0 in case of error during IO submission.
2163 */
2164static int mpage_process_page_bufs(struct mpage_da_data *mpd,
2165 struct buffer_head *head,
2166 struct buffer_head *bh,
2167 ext4_lblk_t lblk)
2168{
2169 struct inode *inode = mpd->inode;
2170 int err;
2171 ext4_lblk_t blocks = (i_size_read(inode) + (1 << inode->i_blkbits) - 1)
2172 >> inode->i_blkbits;
2173
2174 do {
2175 BUG_ON(buffer_locked(bh));
2176
2177 if (lblk >= blocks || !mpage_add_bh_to_extent(mpd, lblk, bh)) {
2178 /* Found extent to map? */
2179 if (mpd->map.m_len)
2180 return 0;
2181 /* Everything mapped so far and we hit EOF */
2182 break;
2183 }
2184 } while (lblk++, (bh = bh->b_this_page) != head);
2185 /* So far everything mapped? Submit the page for IO. */
2186 if (mpd->map.m_len == 0) {
2187 err = mpage_submit_page(mpd, head->b_page);
2188 if (err < 0)
2189 return err;
2190 }
2191 return lblk < blocks;
2192}
2193
2194/*
2195 * mpage_map_buffers - update buffers corresponding to changed extent and
2196 * submit fully mapped pages for IO
2197 *
2198 * @mpd - description of extent to map, on return next extent to map
2199 *
2200 * Scan buffers corresponding to changed extent (we expect corresponding pages
2201 * to be already locked) and update buffer state according to new extent state.
2202 * We map delalloc buffers to their physical location, clear unwritten bits,
2203 * and mark buffers as uninit when we perform writes to unwritten extents
2204 * and do extent conversion after IO is finished. If the last page is not fully
2205 * mapped, we update @map to the next extent in the last page that needs
2206 * mapping. Otherwise we submit the page for IO.
2207 */
2208static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd)
2209{
2210 struct pagevec pvec;
2211 int nr_pages, i;
2212 struct inode *inode = mpd->inode;
2213 struct buffer_head *head, *bh;
2214 int bpp_bits = PAGE_SHIFT - inode->i_blkbits;
2215 pgoff_t start, end;
2216 ext4_lblk_t lblk;
2217 sector_t pblock;
2218 int err;
2219
2220 start = mpd->map.m_lblk >> bpp_bits;
2221 end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits;
2222 lblk = start << bpp_bits;
2223 pblock = mpd->map.m_pblk;
2224
2225 pagevec_init(&pvec, 0);
2226 while (start <= end) {
2227 nr_pages = pagevec_lookup(&pvec, inode->i_mapping, start,
2228 PAGEVEC_SIZE);
2229 if (nr_pages == 0)
2230 break;
2231 for (i = 0; i < nr_pages; i++) {
2232 struct page *page = pvec.pages[i];
2233
2234 if (page->index > end)
2235 break;
2236 /* Up to 'end' pages must be contiguous */
2237 BUG_ON(page->index != start);
2238 bh = head = page_buffers(page);
2239 do {
2240 if (lblk < mpd->map.m_lblk)
2241 continue;
2242 if (lblk >= mpd->map.m_lblk + mpd->map.m_len) {
2243 /*
2244 * Buffer after end of mapped extent.
2245 * Find next buffer in the page to map.
2246 */
2247 mpd->map.m_len = 0;
2248 mpd->map.m_flags = 0;
2249 /*
2250 * FIXME: If dioread_nolock supports
2251 * blocksize < pagesize, we need to make
2252 * sure we add size mapped so far to
2253 * io_end->size as the following call
2254 * can submit the page for IO.
2255 */
2256 err = mpage_process_page_bufs(mpd, head,
2257 bh, lblk);
2258 pagevec_release(&pvec);
2259 if (err > 0)
2260 err = 0;
2261 return err;
2262 }
2263 if (buffer_delay(bh)) {
2264 clear_buffer_delay(bh);
2265 bh->b_blocknr = pblock++;
2266 }
2267 clear_buffer_unwritten(bh);
2268 } while (lblk++, (bh = bh->b_this_page) != head);
2269
2270 /*
2271 * FIXME: This is going to break if dioread_nolock
2272 * supports blocksize < pagesize as we will try to
2273 * convert potentially unmapped parts of inode.
2274 */
2275 mpd->io_submit.io_end->size += PAGE_SIZE;
2276 /* Page fully mapped - let IO run! */
2277 err = mpage_submit_page(mpd, page);
2278 if (err < 0) {
2279 pagevec_release(&pvec);
2280 return err;
2281 }
2282 start++;
2283 }
2284 pagevec_release(&pvec);
2285 }
2286 /* Extent fully mapped and matches with page boundary. We are done. */
2287 mpd->map.m_len = 0;
2288 mpd->map.m_flags = 0;
2289 return 0;
2290}
2291
2292static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd)
2293{
2294 struct inode *inode = mpd->inode;
2295 struct ext4_map_blocks *map = &mpd->map;
2296 int get_blocks_flags;
2297 int err, dioread_nolock;
2298
2299 trace_ext4_da_write_pages_extent(inode, map);
2300 /*
2301 * Call ext4_map_blocks() to allocate any delayed allocation blocks, or
2302 * to convert an unwritten extent to be initialized (in the case
2303 * where we have written into one or more preallocated blocks). It is
2304 * possible that we're going to need more metadata blocks than
2305 * previously reserved. However we must not fail because we're in
2306 * writeback and there is nothing we can do about it so it might result
2307 * in data loss. So use reserved blocks to allocate metadata if
2308 * possible.
2309 *
2310 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE if
2311 * the blocks in question are delalloc blocks. This indicates
2312 * that the blocks and quotas has already been checked when
2313 * the data was copied into the page cache.
2314 */
2315 get_blocks_flags = EXT4_GET_BLOCKS_CREATE |
2316 EXT4_GET_BLOCKS_METADATA_NOFAIL;
2317 dioread_nolock = ext4_should_dioread_nolock(inode);
2318 if (dioread_nolock)
2319 get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
2320 if (map->m_flags & (1 << BH_Delay))
2321 get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
2322
2323 err = ext4_map_blocks(handle, inode, map, get_blocks_flags);
2324 if (err < 0)
2325 return err;
2326 if (dioread_nolock && (map->m_flags & EXT4_MAP_UNWRITTEN)) {
2327 if (!mpd->io_submit.io_end->handle &&
2328 ext4_handle_valid(handle)) {
2329 mpd->io_submit.io_end->handle = handle->h_rsv_handle;
2330 handle->h_rsv_handle = NULL;
2331 }
2332 ext4_set_io_unwritten_flag(inode, mpd->io_submit.io_end);
2333 }
2334
2335 BUG_ON(map->m_len == 0);
2336 if (map->m_flags & EXT4_MAP_NEW) {
2337 struct block_device *bdev = inode->i_sb->s_bdev;
2338 int i;
2339
2340 for (i = 0; i < map->m_len; i++)
2341 unmap_underlying_metadata(bdev, map->m_pblk + i);
2342 }
2343 return 0;
2344}
2345
2346/*
2347 * mpage_map_and_submit_extent - map extent starting at mpd->lblk of length
2348 * mpd->len and submit pages underlying it for IO
2349 *
2350 * @handle - handle for journal operations
2351 * @mpd - extent to map
2352 * @give_up_on_write - we set this to true iff there is a fatal error and there
2353 * is no hope of writing the data. The caller should discard
2354 * dirty pages to avoid infinite loops.
2355 *
2356 * The function maps extent starting at mpd->lblk of length mpd->len. If it is
2357 * delayed, blocks are allocated, if it is unwritten, we may need to convert
2358 * them to initialized or split the described range from larger unwritten
2359 * extent. Note that we need not map all the described range since allocation
2360 * can return less blocks or the range is covered by more unwritten extents. We
2361 * cannot map more because we are limited by reserved transaction credits. On
2362 * the other hand we always make sure that the last touched page is fully
2363 * mapped so that it can be written out (and thus forward progress is
2364 * guaranteed). After mapping we submit all mapped pages for IO.
2365 */
2366static int mpage_map_and_submit_extent(handle_t *handle,
2367 struct mpage_da_data *mpd,
2368 bool *give_up_on_write)
2369{
2370 struct inode *inode = mpd->inode;
2371 struct ext4_map_blocks *map = &mpd->map;
2372 int err;
2373 loff_t disksize;
2374 int progress = 0;
2375
2376 mpd->io_submit.io_end->offset =
2377 ((loff_t)map->m_lblk) << inode->i_blkbits;
2378 do {
2379 err = mpage_map_one_extent(handle, mpd);
2380 if (err < 0) {
2381 struct super_block *sb = inode->i_sb;
2382
2383 if (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
2384 goto invalidate_dirty_pages;
2385 /*
2386 * Let the uper layers retry transient errors.
2387 * In the case of ENOSPC, if ext4_count_free_blocks()
2388 * is non-zero, a commit should free up blocks.
2389 */
2390 if ((err == -ENOMEM) ||
2391 (err == -ENOSPC && ext4_count_free_clusters(sb))) {
2392 if (progress)
2393 goto update_disksize;
2394 return err;
2395 }
2396 ext4_msg(sb, KERN_CRIT,
2397 "Delayed block allocation failed for "
2398 "inode %lu at logical offset %llu with"
2399 " max blocks %u with error %d",
2400 inode->i_ino,
2401 (unsigned long long)map->m_lblk,
2402 (unsigned)map->m_len, -err);
2403 ext4_msg(sb, KERN_CRIT,
2404 "This should not happen!! Data will "
2405 "be lost\n");
2406 if (err == -ENOSPC)
2407 ext4_print_free_blocks(inode);
2408 invalidate_dirty_pages:
2409 *give_up_on_write = true;
2410 return err;
2411 }
2412 progress = 1;
2413 /*
2414 * Update buffer state, submit mapped pages, and get us new
2415 * extent to map
2416 */
2417 err = mpage_map_and_submit_buffers(mpd);
2418 if (err < 0)
2419 goto update_disksize;
2420 } while (map->m_len);
2421
2422update_disksize:
2423 /*
2424 * Update on-disk size after IO is submitted. Races with
2425 * truncate are avoided by checking i_size under i_data_sem.
2426 */
2427 disksize = ((loff_t)mpd->first_page) << PAGE_SHIFT;
2428 if (disksize > EXT4_I(inode)->i_disksize) {
2429 int err2;
2430 loff_t i_size;
2431
2432 down_write(&EXT4_I(inode)->i_data_sem);
2433 i_size = i_size_read(inode);
2434 if (disksize > i_size)
2435 disksize = i_size;
2436 if (disksize > EXT4_I(inode)->i_disksize)
2437 EXT4_I(inode)->i_disksize = disksize;
2438 err2 = ext4_mark_inode_dirty(handle, inode);
2439 up_write(&EXT4_I(inode)->i_data_sem);
2440 if (err2)
2441 ext4_error(inode->i_sb,
2442 "Failed to mark inode %lu dirty",
2443 inode->i_ino);
2444 if (!err)
2445 err = err2;
2446 }
2447 return err;
2448}
2449
2450/*
2451 * Calculate the total number of credits to reserve for one writepages
2452 * iteration. This is called from ext4_writepages(). We map an extent of
2453 * up to MAX_WRITEPAGES_EXTENT_LEN blocks and then we go on and finish mapping
2454 * the last partial page. So in total we can map MAX_WRITEPAGES_EXTENT_LEN +
2455 * bpp - 1 blocks in bpp different extents.
2456 */
2457static int ext4_da_writepages_trans_blocks(struct inode *inode)
2458{
2459 int bpp = ext4_journal_blocks_per_page(inode);
2460
2461 return ext4_meta_trans_blocks(inode,
2462 MAX_WRITEPAGES_EXTENT_LEN + bpp - 1, bpp);
2463}
2464
2465/*
2466 * mpage_prepare_extent_to_map - find & lock contiguous range of dirty pages
2467 * and underlying extent to map
2468 *
2469 * @mpd - where to look for pages
2470 *
2471 * Walk dirty pages in the mapping. If they are fully mapped, submit them for
2472 * IO immediately. When we find a page which isn't mapped we start accumulating
2473 * extent of buffers underlying these pages that needs mapping (formed by
2474 * either delayed or unwritten buffers). We also lock the pages containing
2475 * these buffers. The extent found is returned in @mpd structure (starting at
2476 * mpd->lblk with length mpd->len blocks).
2477 *
2478 * Note that this function can attach bios to one io_end structure which are
2479 * neither logically nor physically contiguous. Although it may seem as an
2480 * unnecessary complication, it is actually inevitable in blocksize < pagesize
2481 * case as we need to track IO to all buffers underlying a page in one io_end.
2482 */
2483static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
2484{
2485 struct address_space *mapping = mpd->inode->i_mapping;
2486 struct pagevec pvec;
2487 unsigned int nr_pages;
2488 long left = mpd->wbc->nr_to_write;
2489 pgoff_t index = mpd->first_page;
2490 pgoff_t end = mpd->last_page;
2491 int tag;
2492 int i, err = 0;
2493 int blkbits = mpd->inode->i_blkbits;
2494 ext4_lblk_t lblk;
2495 struct buffer_head *head;
2496
2497 if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages)
2498 tag = PAGECACHE_TAG_TOWRITE;
2499 else
2500 tag = PAGECACHE_TAG_DIRTY;
2501
2502 pagevec_init(&pvec, 0);
2503 mpd->map.m_len = 0;
2504 mpd->next_page = index;
2505 while (index <= end) {
2506 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
2507 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
2508 if (nr_pages == 0)
2509 goto out;
2510
2511 for (i = 0; i < nr_pages; i++) {
2512 struct page *page = pvec.pages[i];
2513
2514 /*
2515 * At this point, the page may be truncated or
2516 * invalidated (changing page->mapping to NULL), or
2517 * even swizzled back from swapper_space to tmpfs file
2518 * mapping. However, page->index will not change
2519 * because we have a reference on the page.
2520 */
2521 if (page->index > end)
2522 goto out;
2523
2524 /*
2525 * Accumulated enough dirty pages? This doesn't apply
2526 * to WB_SYNC_ALL mode. For integrity sync we have to
2527 * keep going because someone may be concurrently
2528 * dirtying pages, and we might have synced a lot of
2529 * newly appeared dirty pages, but have not synced all
2530 * of the old dirty pages.
2531 */
2532 if (mpd->wbc->sync_mode == WB_SYNC_NONE && left <= 0)
2533 goto out;
2534
2535 /* If we can't merge this page, we are done. */
2536 if (mpd->map.m_len > 0 && mpd->next_page != page->index)
2537 goto out;
2538
2539 lock_page(page);
2540 /*
2541 * If the page is no longer dirty, or its mapping no
2542 * longer corresponds to inode we are writing (which
2543 * means it has been truncated or invalidated), or the
2544 * page is already under writeback and we are not doing
2545 * a data integrity writeback, skip the page
2546 */
2547 if (!PageDirty(page) ||
2548 (PageWriteback(page) &&
2549 (mpd->wbc->sync_mode == WB_SYNC_NONE)) ||
2550 unlikely(page->mapping != mapping)) {
2551 unlock_page(page);
2552 continue;
2553 }
2554
2555 wait_on_page_writeback(page);
2556 BUG_ON(PageWriteback(page));
2557
2558 if (mpd->map.m_len == 0)
2559 mpd->first_page = page->index;
2560 mpd->next_page = page->index + 1;
2561 /* Add all dirty buffers to mpd */
2562 lblk = ((ext4_lblk_t)page->index) <<
2563 (PAGE_SHIFT - blkbits);
2564 head = page_buffers(page);
2565 err = mpage_process_page_bufs(mpd, head, head, lblk);
2566 if (err <= 0)
2567 goto out;
2568 err = 0;
2569 left--;
2570 }
2571 pagevec_release(&pvec);
2572 cond_resched();
2573 }
2574 return 0;
2575out:
2576 pagevec_release(&pvec);
2577 return err;
2578}
2579
2580static int __writepage(struct page *page, struct writeback_control *wbc,
2581 void *data)
2582{
2583 struct address_space *mapping = data;
2584 int ret = ext4_writepage(page, wbc);
2585 mapping_set_error(mapping, ret);
2586 return ret;
2587}
2588
2589static int ext4_writepages(struct address_space *mapping,
2590 struct writeback_control *wbc)
2591{
2592 pgoff_t writeback_index = 0;
2593 long nr_to_write = wbc->nr_to_write;
2594 int range_whole = 0;
2595 int cycled = 1;
2596 handle_t *handle = NULL;
2597 struct mpage_da_data mpd;
2598 struct inode *inode = mapping->host;
2599 int needed_blocks, rsv_blocks = 0, ret = 0;
2600 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
2601 bool done;
2602 struct blk_plug plug;
2603 bool give_up_on_write = false;
2604
2605 trace_ext4_writepages(inode, wbc);
2606
2607 if (dax_mapping(mapping))
2608 return dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev,
2609 wbc);
2610
2611 /*
2612 * No pages to write? This is mainly a kludge to avoid starting
2613 * a transaction for special inodes like journal inode on last iput()
2614 * because that could violate lock ordering on umount
2615 */
2616 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2617 goto out_writepages;
2618
2619 if (ext4_should_journal_data(inode)) {
2620 struct blk_plug plug;
2621
2622 blk_start_plug(&plug);
2623 ret = write_cache_pages(mapping, wbc, __writepage, mapping);
2624 blk_finish_plug(&plug);
2625 goto out_writepages;
2626 }
2627
2628 /*
2629 * If the filesystem has aborted, it is read-only, so return
2630 * right away instead of dumping stack traces later on that
2631 * will obscure the real source of the problem. We test
2632 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2633 * the latter could be true if the filesystem is mounted
2634 * read-only, and in that case, ext4_writepages should
2635 * *never* be called, so if that ever happens, we would want
2636 * the stack trace.
2637 */
2638 if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED)) {
2639 ret = -EROFS;
2640 goto out_writepages;
2641 }
2642
2643 if (ext4_should_dioread_nolock(inode)) {
2644 /*
2645 * We may need to convert up to one extent per block in
2646 * the page and we may dirty the inode.
2647 */
2648 rsv_blocks = 1 + (PAGE_SIZE >> inode->i_blkbits);
2649 }
2650
2651 /*
2652 * If we have inline data and arrive here, it means that
2653 * we will soon create the block for the 1st page, so
2654 * we'd better clear the inline data here.
2655 */
2656 if (ext4_has_inline_data(inode)) {
2657 /* Just inode will be modified... */
2658 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
2659 if (IS_ERR(handle)) {
2660 ret = PTR_ERR(handle);
2661 goto out_writepages;
2662 }
2663 BUG_ON(ext4_test_inode_state(inode,
2664 EXT4_STATE_MAY_INLINE_DATA));
2665 ext4_destroy_inline_data(handle, inode);
2666 ext4_journal_stop(handle);
2667 }
2668
2669 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2670 range_whole = 1;
2671
2672 if (wbc->range_cyclic) {
2673 writeback_index = mapping->writeback_index;
2674 if (writeback_index)
2675 cycled = 0;
2676 mpd.first_page = writeback_index;
2677 mpd.last_page = -1;
2678 } else {
2679 mpd.first_page = wbc->range_start >> PAGE_SHIFT;
2680 mpd.last_page = wbc->range_end >> PAGE_SHIFT;
2681 }
2682
2683 mpd.inode = inode;
2684 mpd.wbc = wbc;
2685 ext4_io_submit_init(&mpd.io_submit, wbc);
2686retry:
2687 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2688 tag_pages_for_writeback(mapping, mpd.first_page, mpd.last_page);
2689 done = false;
2690 blk_start_plug(&plug);
2691 while (!done && mpd.first_page <= mpd.last_page) {
2692 /* For each extent of pages we use new io_end */
2693 mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
2694 if (!mpd.io_submit.io_end) {
2695 ret = -ENOMEM;
2696 break;
2697 }
2698
2699 /*
2700 * We have two constraints: We find one extent to map and we
2701 * must always write out whole page (makes a difference when
2702 * blocksize < pagesize) so that we don't block on IO when we
2703 * try to write out the rest of the page. Journalled mode is
2704 * not supported by delalloc.
2705 */
2706 BUG_ON(ext4_should_journal_data(inode));
2707 needed_blocks = ext4_da_writepages_trans_blocks(inode);
2708
2709 /* start a new transaction */
2710 handle = ext4_journal_start_with_reserve(inode,
2711 EXT4_HT_WRITE_PAGE, needed_blocks, rsv_blocks);
2712 if (IS_ERR(handle)) {
2713 ret = PTR_ERR(handle);
2714 ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
2715 "%ld pages, ino %lu; err %d", __func__,
2716 wbc->nr_to_write, inode->i_ino, ret);
2717 /* Release allocated io_end */
2718 ext4_put_io_end(mpd.io_submit.io_end);
2719 break;
2720 }
2721
2722 trace_ext4_da_write_pages(inode, mpd.first_page, mpd.wbc);
2723 ret = mpage_prepare_extent_to_map(&mpd);
2724 if (!ret) {
2725 if (mpd.map.m_len)
2726 ret = mpage_map_and_submit_extent(handle, &mpd,
2727 &give_up_on_write);
2728 else {
2729 /*
2730 * We scanned the whole range (or exhausted
2731 * nr_to_write), submitted what was mapped and
2732 * didn't find anything needing mapping. We are
2733 * done.
2734 */
2735 done = true;
2736 }
2737 }
2738 ext4_journal_stop(handle);
2739 /* Submit prepared bio */
2740 ext4_io_submit(&mpd.io_submit);
2741 /* Unlock pages we didn't use */
2742 mpage_release_unused_pages(&mpd, give_up_on_write);
2743 /* Drop our io_end reference we got from init */
2744 ext4_put_io_end(mpd.io_submit.io_end);
2745
2746 if (ret == -ENOSPC && sbi->s_journal) {
2747 /*
2748 * Commit the transaction which would
2749 * free blocks released in the transaction
2750 * and try again
2751 */
2752 jbd2_journal_force_commit_nested(sbi->s_journal);
2753 ret = 0;
2754 continue;
2755 }
2756 /* Fatal error - ENOMEM, EIO... */
2757 if (ret)
2758 break;
2759 }
2760 blk_finish_plug(&plug);
2761 if (!ret && !cycled && wbc->nr_to_write > 0) {
2762 cycled = 1;
2763 mpd.last_page = writeback_index - 1;
2764 mpd.first_page = 0;
2765 goto retry;
2766 }
2767
2768 /* Update index */
2769 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2770 /*
2771 * Set the writeback_index so that range_cyclic
2772 * mode will write it back later
2773 */
2774 mapping->writeback_index = mpd.first_page;
2775
2776out_writepages:
2777 trace_ext4_writepages_result(inode, wbc, ret,
2778 nr_to_write - wbc->nr_to_write);
2779 return ret;
2780}
2781
2782static int ext4_nonda_switch(struct super_block *sb)
2783{
2784 s64 free_clusters, dirty_clusters;
2785 struct ext4_sb_info *sbi = EXT4_SB(sb);
2786
2787 /*
2788 * switch to non delalloc mode if we are running low
2789 * on free block. The free block accounting via percpu
2790 * counters can get slightly wrong with percpu_counter_batch getting
2791 * accumulated on each CPU without updating global counters
2792 * Delalloc need an accurate free block accounting. So switch
2793 * to non delalloc when we are near to error range.
2794 */
2795 free_clusters =
2796 percpu_counter_read_positive(&sbi->s_freeclusters_counter);
2797 dirty_clusters =
2798 percpu_counter_read_positive(&sbi->s_dirtyclusters_counter);
2799 /*
2800 * Start pushing delalloc when 1/2 of free blocks are dirty.
2801 */
2802 if (dirty_clusters && (free_clusters < 2 * dirty_clusters))
2803 try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
2804
2805 if (2 * free_clusters < 3 * dirty_clusters ||
2806 free_clusters < (dirty_clusters + EXT4_FREECLUSTERS_WATERMARK)) {
2807 /*
2808 * free block count is less than 150% of dirty blocks
2809 * or free blocks is less than watermark
2810 */
2811 return 1;
2812 }
2813 return 0;
2814}
2815
2816/* We always reserve for an inode update; the superblock could be there too */
2817static int ext4_da_write_credits(struct inode *inode, loff_t pos, unsigned len)
2818{
2819 if (likely(ext4_has_feature_large_file(inode->i_sb)))
2820 return 1;
2821
2822 if (pos + len <= 0x7fffffffULL)
2823 return 1;
2824
2825 /* We might need to update the superblock to set LARGE_FILE */
2826 return 2;
2827}
2828
2829static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
2830 loff_t pos, unsigned len, unsigned flags,
2831 struct page **pagep, void **fsdata)
2832{
2833 int ret, retries = 0;
2834 struct page *page;
2835 pgoff_t index;
2836 struct inode *inode = mapping->host;
2837 handle_t *handle;
2838
2839 index = pos >> PAGE_SHIFT;
2840
2841 if (ext4_nonda_switch(inode->i_sb)) {
2842 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
2843 return ext4_write_begin(file, mapping, pos,
2844 len, flags, pagep, fsdata);
2845 }
2846 *fsdata = (void *)0;
2847 trace_ext4_da_write_begin(inode, pos, len, flags);
2848
2849 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2850 ret = ext4_da_write_inline_data_begin(mapping, inode,
2851 pos, len, flags,
2852 pagep, fsdata);
2853 if (ret < 0)
2854 return ret;
2855 if (ret == 1)
2856 return 0;
2857 }
2858
2859 /*
2860 * grab_cache_page_write_begin() can take a long time if the
2861 * system is thrashing due to memory pressure, or if the page
2862 * is being written back. So grab it first before we start
2863 * the transaction handle. This also allows us to allocate
2864 * the page (if needed) without using GFP_NOFS.
2865 */
2866retry_grab:
2867 page = grab_cache_page_write_begin(mapping, index, flags);
2868 if (!page)
2869 return -ENOMEM;
2870 unlock_page(page);
2871
2872 /*
2873 * With delayed allocation, we don't log the i_disksize update
2874 * if there is delayed block allocation. But we still need
2875 * to journalling the i_disksize update if writes to the end
2876 * of file which has an already mapped buffer.
2877 */
2878retry_journal:
2879 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
2880 ext4_da_write_credits(inode, pos, len));
2881 if (IS_ERR(handle)) {
2882 put_page(page);
2883 return PTR_ERR(handle);
2884 }
2885
2886 lock_page(page);
2887 if (page->mapping != mapping) {
2888 /* The page got truncated from under us */
2889 unlock_page(page);
2890 put_page(page);
2891 ext4_journal_stop(handle);
2892 goto retry_grab;
2893 }
2894 /* In case writeback began while the page was unlocked */
2895 wait_for_stable_page(page);
2896
2897#ifdef CONFIG_EXT4_FS_ENCRYPTION
2898 ret = ext4_block_write_begin(page, pos, len,
2899 ext4_da_get_block_prep);
2900#else
2901 ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
2902#endif
2903 if (ret < 0) {
2904 unlock_page(page);
2905 ext4_journal_stop(handle);
2906 /*
2907 * block_write_begin may have instantiated a few blocks
2908 * outside i_size. Trim these off again. Don't need
2909 * i_size_read because we hold i_mutex.
2910 */
2911 if (pos + len > inode->i_size)
2912 ext4_truncate_failed_write(inode);
2913
2914 if (ret == -ENOSPC &&
2915 ext4_should_retry_alloc(inode->i_sb, &retries))
2916 goto retry_journal;
2917
2918 put_page(page);
2919 return ret;
2920 }
2921
2922 *pagep = page;
2923 return ret;
2924}
2925
2926/*
2927 * Check if we should update i_disksize
2928 * when write to the end of file but not require block allocation
2929 */
2930static int ext4_da_should_update_i_disksize(struct page *page,
2931 unsigned long offset)
2932{
2933 struct buffer_head *bh;
2934 struct inode *inode = page->mapping->host;
2935 unsigned int idx;
2936 int i;
2937
2938 bh = page_buffers(page);
2939 idx = offset >> inode->i_blkbits;
2940
2941 for (i = 0; i < idx; i++)
2942 bh = bh->b_this_page;
2943
2944 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
2945 return 0;
2946 return 1;
2947}
2948
2949static int ext4_da_write_end(struct file *file,
2950 struct address_space *mapping,
2951 loff_t pos, unsigned len, unsigned copied,
2952 struct page *page, void *fsdata)
2953{
2954 struct inode *inode = mapping->host;
2955 int ret = 0, ret2;
2956 handle_t *handle = ext4_journal_current_handle();
2957 loff_t new_i_size;
2958 unsigned long start, end;
2959 int write_mode = (int)(unsigned long)fsdata;
2960
2961 if (write_mode == FALL_BACK_TO_NONDELALLOC)
2962 return ext4_write_end(file, mapping, pos,
2963 len, copied, page, fsdata);
2964
2965 trace_ext4_da_write_end(inode, pos, len, copied);
2966 start = pos & (PAGE_SIZE - 1);
2967 end = start + copied - 1;
2968
2969 /*
2970 * generic_write_end() will run mark_inode_dirty() if i_size
2971 * changes. So let's piggyback the i_disksize mark_inode_dirty
2972 * into that.
2973 */
2974 new_i_size = pos + copied;
2975 if (copied && new_i_size > EXT4_I(inode)->i_disksize) {
2976 if (ext4_has_inline_data(inode) ||
2977 ext4_da_should_update_i_disksize(page, end)) {
2978 ext4_update_i_disksize(inode, new_i_size);
2979 /* We need to mark inode dirty even if
2980 * new_i_size is less that inode->i_size
2981 * bu greater than i_disksize.(hint delalloc)
2982 */
2983 ext4_mark_inode_dirty(handle, inode);
2984 }
2985 }
2986
2987 if (write_mode != CONVERT_INLINE_DATA &&
2988 ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) &&
2989 ext4_has_inline_data(inode))
2990 ret2 = ext4_da_write_inline_data_end(inode, pos, len, copied,
2991 page);
2992 else
2993 ret2 = generic_write_end(file, mapping, pos, len, copied,
2994 page, fsdata);
2995
2996 copied = ret2;
2997 if (ret2 < 0)
2998 ret = ret2;
2999 ret2 = ext4_journal_stop(handle);
3000 if (!ret)
3001 ret = ret2;
3002
3003 return ret ? ret : copied;
3004}
3005
3006static void ext4_da_invalidatepage(struct page *page, unsigned int offset,
3007 unsigned int length)
3008{
3009 /*
3010 * Drop reserved blocks
3011 */
3012 BUG_ON(!PageLocked(page));
3013 if (!page_has_buffers(page))
3014 goto out;
3015
3016 ext4_da_page_release_reservation(page, offset, length);
3017
3018out:
3019 ext4_invalidatepage(page, offset, length);
3020
3021 return;
3022}
3023
3024/*
3025 * Force all delayed allocation blocks to be allocated for a given inode.
3026 */
3027int ext4_alloc_da_blocks(struct inode *inode)
3028{
3029 trace_ext4_alloc_da_blocks(inode);
3030
3031 if (!EXT4_I(inode)->i_reserved_data_blocks)
3032 return 0;
3033
3034 /*
3035 * We do something simple for now. The filemap_flush() will
3036 * also start triggering a write of the data blocks, which is
3037 * not strictly speaking necessary (and for users of
3038 * laptop_mode, not even desirable). However, to do otherwise
3039 * would require replicating code paths in:
3040 *
3041 * ext4_writepages() ->
3042 * write_cache_pages() ---> (via passed in callback function)
3043 * __mpage_da_writepage() -->
3044 * mpage_add_bh_to_extent()
3045 * mpage_da_map_blocks()
3046 *
3047 * The problem is that write_cache_pages(), located in
3048 * mm/page-writeback.c, marks pages clean in preparation for
3049 * doing I/O, which is not desirable if we're not planning on
3050 * doing I/O at all.
3051 *
3052 * We could call write_cache_pages(), and then redirty all of
3053 * the pages by calling redirty_page_for_writepage() but that
3054 * would be ugly in the extreme. So instead we would need to
3055 * replicate parts of the code in the above functions,
3056 * simplifying them because we wouldn't actually intend to
3057 * write out the pages, but rather only collect contiguous
3058 * logical block extents, call the multi-block allocator, and
3059 * then update the buffer heads with the block allocations.
3060 *
3061 * For now, though, we'll cheat by calling filemap_flush(),
3062 * which will map the blocks, and start the I/O, but not
3063 * actually wait for the I/O to complete.
3064 */
3065 return filemap_flush(inode->i_mapping);
3066}
3067
3068/*
3069 * bmap() is special. It gets used by applications such as lilo and by
3070 * the swapper to find the on-disk block of a specific piece of data.
3071 *
3072 * Naturally, this is dangerous if the block concerned is still in the
3073 * journal. If somebody makes a swapfile on an ext4 data-journaling
3074 * filesystem and enables swap, then they may get a nasty shock when the
3075 * data getting swapped to that swapfile suddenly gets overwritten by
3076 * the original zero's written out previously to the journal and
3077 * awaiting writeback in the kernel's buffer cache.
3078 *
3079 * So, if we see any bmap calls here on a modified, data-journaled file,
3080 * take extra steps to flush any blocks which might be in the cache.
3081 */
3082static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
3083{
3084 struct inode *inode = mapping->host;
3085 journal_t *journal;
3086 int err;
3087
3088 /*
3089 * We can get here for an inline file via the FIBMAP ioctl
3090 */
3091 if (ext4_has_inline_data(inode))
3092 return 0;
3093
3094 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
3095 test_opt(inode->i_sb, DELALLOC)) {
3096 /*
3097 * With delalloc we want to sync the file
3098 * so that we can make sure we allocate
3099 * blocks for file
3100 */
3101 filemap_write_and_wait(mapping);
3102 }
3103
3104 if (EXT4_JOURNAL(inode) &&
3105 ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
3106 /*
3107 * This is a REALLY heavyweight approach, but the use of
3108 * bmap on dirty files is expected to be extremely rare:
3109 * only if we run lilo or swapon on a freshly made file
3110 * do we expect this to happen.
3111 *
3112 * (bmap requires CAP_SYS_RAWIO so this does not
3113 * represent an unprivileged user DOS attack --- we'd be
3114 * in trouble if mortal users could trigger this path at
3115 * will.)
3116 *
3117 * NB. EXT4_STATE_JDATA is not set on files other than
3118 * regular files. If somebody wants to bmap a directory
3119 * or symlink and gets confused because the buffer
3120 * hasn't yet been flushed to disk, they deserve
3121 * everything they get.
3122 */
3123
3124 ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
3125 journal = EXT4_JOURNAL(inode);
3126 jbd2_journal_lock_updates(journal);
3127 err = jbd2_journal_flush(journal);
3128 jbd2_journal_unlock_updates(journal);
3129
3130 if (err)
3131 return 0;
3132 }
3133
3134 return generic_block_bmap(mapping, block, ext4_get_block);
3135}
3136
3137static int ext4_readpage(struct file *file, struct page *page)
3138{
3139 int ret = -EAGAIN;
3140 struct inode *inode = page->mapping->host;
3141
3142 trace_ext4_readpage(page);
3143
3144 if (ext4_has_inline_data(inode))
3145 ret = ext4_readpage_inline(inode, page);
3146
3147 if (ret == -EAGAIN)
3148 return ext4_mpage_readpages(page->mapping, NULL, page, 1);
3149
3150 return ret;
3151}
3152
3153static int
3154ext4_readpages(struct file *file, struct address_space *mapping,
3155 struct list_head *pages, unsigned nr_pages)
3156{
3157 struct inode *inode = mapping->host;
3158
3159 /* If the file has inline data, no need to do readpages. */
3160 if (ext4_has_inline_data(inode))
3161 return 0;
3162
3163 return ext4_mpage_readpages(mapping, pages, NULL, nr_pages);
3164}
3165
3166static void ext4_invalidatepage(struct page *page, unsigned int offset,
3167 unsigned int length)
3168{
3169 trace_ext4_invalidatepage(page, offset, length);
3170
3171 /* No journalling happens on data buffers when this function is used */
3172 WARN_ON(page_has_buffers(page) && buffer_jbd(page_buffers(page)));
3173
3174 block_invalidatepage(page, offset, length);
3175}
3176
3177static int __ext4_journalled_invalidatepage(struct page *page,
3178 unsigned int offset,
3179 unsigned int length)
3180{
3181 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
3182
3183 trace_ext4_journalled_invalidatepage(page, offset, length);
3184
3185 /*
3186 * If it's a full truncate we just forget about the pending dirtying
3187 */
3188 if (offset == 0 && length == PAGE_SIZE)
3189 ClearPageChecked(page);
3190
3191 return jbd2_journal_invalidatepage(journal, page, offset, length);
3192}
3193
3194/* Wrapper for aops... */
3195static void ext4_journalled_invalidatepage(struct page *page,
3196 unsigned int offset,
3197 unsigned int length)
3198{
3199 WARN_ON(__ext4_journalled_invalidatepage(page, offset, length) < 0);
3200}
3201
3202static int ext4_releasepage(struct page *page, gfp_t wait)
3203{
3204 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
3205
3206 trace_ext4_releasepage(page);
3207
3208 /* Page has dirty journalled data -> cannot release */
3209 if (PageChecked(page))
3210 return 0;
3211 if (journal)
3212 return jbd2_journal_try_to_free_buffers(journal, page, wait);
3213 else
3214 return try_to_free_buffers(page);
3215}
3216
3217#ifdef CONFIG_FS_DAX
3218int ext4_dax_mmap_get_block(struct inode *inode, sector_t iblock,
3219 struct buffer_head *bh_result, int create)
3220{
3221 int ret, err;
3222 int credits;
3223 struct ext4_map_blocks map;
3224 handle_t *handle = NULL;
3225 int flags = 0;
3226
3227 ext4_debug("ext4_dax_mmap_get_block: inode %lu, create flag %d\n",
3228 inode->i_ino, create);
3229 map.m_lblk = iblock;
3230 map.m_len = bh_result->b_size >> inode->i_blkbits;
3231 credits = ext4_chunk_trans_blocks(inode, map.m_len);
3232 if (create) {
3233 flags |= EXT4_GET_BLOCKS_PRE_IO | EXT4_GET_BLOCKS_CREATE_ZERO;
3234 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, credits);
3235 if (IS_ERR(handle)) {
3236 ret = PTR_ERR(handle);
3237 return ret;
3238 }
3239 }
3240
3241 ret = ext4_map_blocks(handle, inode, &map, flags);
3242 if (create) {
3243 err = ext4_journal_stop(handle);
3244 if (ret >= 0 && err < 0)
3245 ret = err;
3246 }
3247 if (ret <= 0)
3248 goto out;
3249 if (map.m_flags & EXT4_MAP_UNWRITTEN) {
3250 int err2;
3251
3252 /*
3253 * We are protected by i_mmap_sem so we know block cannot go
3254 * away from under us even though we dropped i_data_sem.
3255 * Convert extent to written and write zeros there.
3256 *
3257 * Note: We may get here even when create == 0.
3258 */
3259 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, credits);
3260 if (IS_ERR(handle)) {
3261 ret = PTR_ERR(handle);
3262 goto out;
3263 }
3264
3265 err = ext4_map_blocks(handle, inode, &map,
3266 EXT4_GET_BLOCKS_CONVERT | EXT4_GET_BLOCKS_CREATE_ZERO);
3267 if (err < 0)
3268 ret = err;
3269 err2 = ext4_journal_stop(handle);
3270 if (err2 < 0 && ret > 0)
3271 ret = err2;
3272 }
3273out:
3274 WARN_ON_ONCE(ret == 0 && create);
3275 if (ret > 0) {
3276 map_bh(bh_result, inode->i_sb, map.m_pblk);
3277 /*
3278 * At least for now we have to clear BH_New so that DAX code
3279 * doesn't attempt to zero blocks again in a racy way.
3280 */
3281 map.m_flags &= ~EXT4_MAP_NEW;
3282 ext4_update_bh_state(bh_result, map.m_flags);
3283 bh_result->b_size = map.m_len << inode->i_blkbits;
3284 ret = 0;
3285 }
3286 return ret;
3287}
3288#endif
3289
3290static int ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
3291 ssize_t size, void *private)
3292{
3293 ext4_io_end_t *io_end = private;
3294
3295 /* if not async direct IO just return */
3296 if (!io_end)
3297 return 0;
3298
3299 ext_debug("ext4_end_io_dio(): io_end 0x%p "
3300 "for inode %lu, iocb 0x%p, offset %llu, size %zd\n",
3301 io_end, io_end->inode->i_ino, iocb, offset, size);
3302
3303 /*
3304 * Error during AIO DIO. We cannot convert unwritten extents as the
3305 * data was not written. Just clear the unwritten flag and drop io_end.
3306 */
3307 if (size <= 0) {
3308 ext4_clear_io_unwritten_flag(io_end);
3309 size = 0;
3310 }
3311 io_end->offset = offset;
3312 io_end->size = size;
3313 ext4_put_io_end(io_end);
3314
3315 return 0;
3316}
3317
3318/*
3319 * For ext4 extent files, ext4 will do direct-io write to holes,
3320 * preallocated extents, and those write extend the file, no need to
3321 * fall back to buffered IO.
3322 *
3323 * For holes, we fallocate those blocks, mark them as unwritten
3324 * If those blocks were preallocated, we mark sure they are split, but
3325 * still keep the range to write as unwritten.
3326 *
3327 * The unwritten extents will be converted to written when DIO is completed.
3328 * For async direct IO, since the IO may still pending when return, we
3329 * set up an end_io call back function, which will do the conversion
3330 * when async direct IO completed.
3331 *
3332 * If the O_DIRECT write will extend the file then add this inode to the
3333 * orphan list. So recovery will truncate it back to the original size
3334 * if the machine crashes during the write.
3335 *
3336 */
3337static ssize_t ext4_ext_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
3338 loff_t offset)
3339{
3340 struct file *file = iocb->ki_filp;
3341 struct inode *inode = file->f_mapping->host;
3342 ssize_t ret;
3343 size_t count = iov_iter_count(iter);
3344 int overwrite = 0;
3345 get_block_t *get_block_func = NULL;
3346 int dio_flags = 0;
3347 loff_t final_size = offset + count;
3348
3349 /* Use the old path for reads and writes beyond i_size. */
3350 if (iov_iter_rw(iter) != WRITE || final_size > inode->i_size)
3351 return ext4_ind_direct_IO(iocb, iter, offset);
3352
3353 BUG_ON(iocb->private == NULL);
3354
3355 /*
3356 * Make all waiters for direct IO properly wait also for extent
3357 * conversion. This also disallows race between truncate() and
3358 * overwrite DIO as i_dio_count needs to be incremented under i_mutex.
3359 */
3360 if (iov_iter_rw(iter) == WRITE)
3361 inode_dio_begin(inode);
3362
3363 /* If we do a overwrite dio, i_mutex locking can be released */
3364 overwrite = *((int *)iocb->private);
3365
3366 if (overwrite)
3367 inode_unlock(inode);
3368
3369 /*
3370 * We could direct write to holes and fallocate.
3371 *
3372 * Allocated blocks to fill the hole are marked as unwritten to prevent
3373 * parallel buffered read to expose the stale data before DIO complete
3374 * the data IO.
3375 *
3376 * As to previously fallocated extents, ext4 get_block will just simply
3377 * mark the buffer mapped but still keep the extents unwritten.
3378 *
3379 * For non AIO case, we will convert those unwritten extents to written
3380 * after return back from blockdev_direct_IO. That way we save us from
3381 * allocating io_end structure and also the overhead of offloading
3382 * the extent convertion to a workqueue.
3383 *
3384 * For async DIO, the conversion needs to be deferred when the
3385 * IO is completed. The ext4 end_io callback function will be
3386 * called to take care of the conversion work. Here for async
3387 * case, we allocate an io_end structure to hook to the iocb.
3388 */
3389 iocb->private = NULL;
3390 if (overwrite)
3391 get_block_func = ext4_dio_get_block_overwrite;
3392 else if (is_sync_kiocb(iocb)) {
3393 get_block_func = ext4_dio_get_block_unwritten_sync;
3394 dio_flags = DIO_LOCKING;
3395 } else {
3396 get_block_func = ext4_dio_get_block_unwritten_async;
3397 dio_flags = DIO_LOCKING;
3398 }
3399#ifdef CONFIG_EXT4_FS_ENCRYPTION
3400 BUG_ON(ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode));
3401#endif
3402 if (IS_DAX(inode))
3403 ret = dax_do_io(iocb, inode, iter, offset, get_block_func,
3404 ext4_end_io_dio, dio_flags);
3405 else
3406 ret = __blockdev_direct_IO(iocb, inode,
3407 inode->i_sb->s_bdev, iter, offset,
3408 get_block_func,
3409 ext4_end_io_dio, NULL, dio_flags);
3410
3411 if (ret > 0 && !overwrite && ext4_test_inode_state(inode,
3412 EXT4_STATE_DIO_UNWRITTEN)) {
3413 int err;
3414 /*
3415 * for non AIO case, since the IO is already
3416 * completed, we could do the conversion right here
3417 */
3418 err = ext4_convert_unwritten_extents(NULL, inode,
3419 offset, ret);
3420 if (err < 0)
3421 ret = err;
3422 ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3423 }
3424
3425 if (iov_iter_rw(iter) == WRITE)
3426 inode_dio_end(inode);
3427 /* take i_mutex locking again if we do a ovewrite dio */
3428 if (overwrite)
3429 inode_lock(inode);
3430
3431 return ret;
3432}
3433
3434static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
3435 loff_t offset)
3436{
3437 struct file *file = iocb->ki_filp;
3438 struct inode *inode = file->f_mapping->host;
3439 size_t count = iov_iter_count(iter);
3440 ssize_t ret;
3441
3442#ifdef CONFIG_EXT4_FS_ENCRYPTION
3443 if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode))
3444 return 0;
3445#endif
3446
3447 /*
3448 * If we are doing data journalling we don't support O_DIRECT
3449 */
3450 if (ext4_should_journal_data(inode))
3451 return 0;
3452
3453 /* Let buffer I/O handle the inline data case. */
3454 if (ext4_has_inline_data(inode))
3455 return 0;
3456
3457 trace_ext4_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
3458 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3459 ret = ext4_ext_direct_IO(iocb, iter, offset);
3460 else
3461 ret = ext4_ind_direct_IO(iocb, iter, offset);
3462 trace_ext4_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), ret);
3463 return ret;
3464}
3465
3466/*
3467 * Pages can be marked dirty completely asynchronously from ext4's journalling
3468 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3469 * much here because ->set_page_dirty is called under VFS locks. The page is
3470 * not necessarily locked.
3471 *
3472 * We cannot just dirty the page and leave attached buffers clean, because the
3473 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3474 * or jbddirty because all the journalling code will explode.
3475 *
3476 * So what we do is to mark the page "pending dirty" and next time writepage
3477 * is called, propagate that into the buffers appropriately.
3478 */
3479static int ext4_journalled_set_page_dirty(struct page *page)
3480{
3481 SetPageChecked(page);
3482 return __set_page_dirty_nobuffers(page);
3483}
3484
3485static const struct address_space_operations ext4_aops = {
3486 .readpage = ext4_readpage,
3487 .readpages = ext4_readpages,
3488 .writepage = ext4_writepage,
3489 .writepages = ext4_writepages,
3490 .write_begin = ext4_write_begin,
3491 .write_end = ext4_write_end,
3492 .bmap = ext4_bmap,
3493 .invalidatepage = ext4_invalidatepage,
3494 .releasepage = ext4_releasepage,
3495 .direct_IO = ext4_direct_IO,
3496 .migratepage = buffer_migrate_page,
3497 .is_partially_uptodate = block_is_partially_uptodate,
3498 .error_remove_page = generic_error_remove_page,
3499};
3500
3501static const struct address_space_operations ext4_journalled_aops = {
3502 .readpage = ext4_readpage,
3503 .readpages = ext4_readpages,
3504 .writepage = ext4_writepage,
3505 .writepages = ext4_writepages,
3506 .write_begin = ext4_write_begin,
3507 .write_end = ext4_journalled_write_end,
3508 .set_page_dirty = ext4_journalled_set_page_dirty,
3509 .bmap = ext4_bmap,
3510 .invalidatepage = ext4_journalled_invalidatepage,
3511 .releasepage = ext4_releasepage,
3512 .direct_IO = ext4_direct_IO,
3513 .is_partially_uptodate = block_is_partially_uptodate,
3514 .error_remove_page = generic_error_remove_page,
3515};
3516
3517static const struct address_space_operations ext4_da_aops = {
3518 .readpage = ext4_readpage,
3519 .readpages = ext4_readpages,
3520 .writepage = ext4_writepage,
3521 .writepages = ext4_writepages,
3522 .write_begin = ext4_da_write_begin,
3523 .write_end = ext4_da_write_end,
3524 .bmap = ext4_bmap,
3525 .invalidatepage = ext4_da_invalidatepage,
3526 .releasepage = ext4_releasepage,
3527 .direct_IO = ext4_direct_IO,
3528 .migratepage = buffer_migrate_page,
3529 .is_partially_uptodate = block_is_partially_uptodate,
3530 .error_remove_page = generic_error_remove_page,
3531};
3532
3533void ext4_set_aops(struct inode *inode)
3534{
3535 switch (ext4_inode_journal_mode(inode)) {
3536 case EXT4_INODE_ORDERED_DATA_MODE:
3537 ext4_set_inode_state(inode, EXT4_STATE_ORDERED_MODE);
3538 break;
3539 case EXT4_INODE_WRITEBACK_DATA_MODE:
3540 ext4_clear_inode_state(inode, EXT4_STATE_ORDERED_MODE);
3541 break;
3542 case EXT4_INODE_JOURNAL_DATA_MODE:
3543 inode->i_mapping->a_ops = &ext4_journalled_aops;
3544 return;
3545 default:
3546 BUG();
3547 }
3548 if (test_opt(inode->i_sb, DELALLOC))
3549 inode->i_mapping->a_ops = &ext4_da_aops;
3550 else
3551 inode->i_mapping->a_ops = &ext4_aops;
3552}
3553
3554static int __ext4_block_zero_page_range(handle_t *handle,
3555 struct address_space *mapping, loff_t from, loff_t length)
3556{
3557 ext4_fsblk_t index = from >> PAGE_SHIFT;
3558 unsigned offset = from & (PAGE_SIZE-1);
3559 unsigned blocksize, pos;
3560 ext4_lblk_t iblock;
3561 struct inode *inode = mapping->host;
3562 struct buffer_head *bh;
3563 struct page *page;
3564 int err = 0;
3565
3566 page = find_or_create_page(mapping, from >> PAGE_SHIFT,
3567 mapping_gfp_constraint(mapping, ~__GFP_FS));
3568 if (!page)
3569 return -ENOMEM;
3570
3571 blocksize = inode->i_sb->s_blocksize;
3572
3573 iblock = index << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
3574
3575 if (!page_has_buffers(page))
3576 create_empty_buffers(page, blocksize, 0);
3577
3578 /* Find the buffer that contains "offset" */
3579 bh = page_buffers(page);
3580 pos = blocksize;
3581 while (offset >= pos) {
3582 bh = bh->b_this_page;
3583 iblock++;
3584 pos += blocksize;
3585 }
3586 if (buffer_freed(bh)) {
3587 BUFFER_TRACE(bh, "freed: skip");
3588 goto unlock;
3589 }
3590 if (!buffer_mapped(bh)) {
3591 BUFFER_TRACE(bh, "unmapped");
3592 ext4_get_block(inode, iblock, bh, 0);
3593 /* unmapped? It's a hole - nothing to do */
3594 if (!buffer_mapped(bh)) {
3595 BUFFER_TRACE(bh, "still unmapped");
3596 goto unlock;
3597 }
3598 }
3599
3600 /* Ok, it's mapped. Make sure it's up-to-date */
3601 if (PageUptodate(page))
3602 set_buffer_uptodate(bh);
3603
3604 if (!buffer_uptodate(bh)) {
3605 err = -EIO;
3606 ll_rw_block(READ, 1, &bh);
3607 wait_on_buffer(bh);
3608 /* Uhhuh. Read error. Complain and punt. */
3609 if (!buffer_uptodate(bh))
3610 goto unlock;
3611 if (S_ISREG(inode->i_mode) &&
3612 ext4_encrypted_inode(inode)) {
3613 /* We expect the key to be set. */
3614 BUG_ON(!ext4_has_encryption_key(inode));
3615 BUG_ON(blocksize != PAGE_SIZE);
3616 WARN_ON_ONCE(ext4_decrypt(page));
3617 }
3618 }
3619 if (ext4_should_journal_data(inode)) {
3620 BUFFER_TRACE(bh, "get write access");
3621 err = ext4_journal_get_write_access(handle, bh);
3622 if (err)
3623 goto unlock;
3624 }
3625 zero_user(page, offset, length);
3626 BUFFER_TRACE(bh, "zeroed end of block");
3627
3628 if (ext4_should_journal_data(inode)) {
3629 err = ext4_handle_dirty_metadata(handle, inode, bh);
3630 } else {
3631 err = 0;
3632 mark_buffer_dirty(bh);
3633 if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE))
3634 err = ext4_jbd2_file_inode(handle, inode);
3635 }
3636
3637unlock:
3638 unlock_page(page);
3639 put_page(page);
3640 return err;
3641}
3642
3643/*
3644 * ext4_block_zero_page_range() zeros out a mapping of length 'length'
3645 * starting from file offset 'from'. The range to be zero'd must
3646 * be contained with in one block. If the specified range exceeds
3647 * the end of the block it will be shortened to end of the block
3648 * that cooresponds to 'from'
3649 */
3650static int ext4_block_zero_page_range(handle_t *handle,
3651 struct address_space *mapping, loff_t from, loff_t length)
3652{
3653 struct inode *inode = mapping->host;
3654 unsigned offset = from & (PAGE_SIZE-1);
3655 unsigned blocksize = inode->i_sb->s_blocksize;
3656 unsigned max = blocksize - (offset & (blocksize - 1));
3657
3658 /*
3659 * correct length if it does not fall between
3660 * 'from' and the end of the block
3661 */
3662 if (length > max || length < 0)
3663 length = max;
3664
3665 if (IS_DAX(inode))
3666 return dax_zero_page_range(inode, from, length, ext4_get_block);
3667 return __ext4_block_zero_page_range(handle, mapping, from, length);
3668}
3669
3670/*
3671 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3672 * up to the end of the block which corresponds to `from'.
3673 * This required during truncate. We need to physically zero the tail end
3674 * of that block so it doesn't yield old data if the file is later grown.
3675 */
3676static int ext4_block_truncate_page(handle_t *handle,
3677 struct address_space *mapping, loff_t from)
3678{
3679 unsigned offset = from & (PAGE_SIZE-1);
3680 unsigned length;
3681 unsigned blocksize;
3682 struct inode *inode = mapping->host;
3683
3684 blocksize = inode->i_sb->s_blocksize;
3685 length = blocksize - (offset & (blocksize - 1));
3686
3687 return ext4_block_zero_page_range(handle, mapping, from, length);
3688}
3689
3690int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
3691 loff_t lstart, loff_t length)
3692{
3693 struct super_block *sb = inode->i_sb;
3694 struct address_space *mapping = inode->i_mapping;
3695 unsigned partial_start, partial_end;
3696 ext4_fsblk_t start, end;
3697 loff_t byte_end = (lstart + length - 1);
3698 int err = 0;
3699
3700 partial_start = lstart & (sb->s_blocksize - 1);
3701 partial_end = byte_end & (sb->s_blocksize - 1);
3702
3703 start = lstart >> sb->s_blocksize_bits;
3704 end = byte_end >> sb->s_blocksize_bits;
3705
3706 /* Handle partial zero within the single block */
3707 if (start == end &&
3708 (partial_start || (partial_end != sb->s_blocksize - 1))) {
3709 err = ext4_block_zero_page_range(handle, mapping,
3710 lstart, length);
3711 return err;
3712 }
3713 /* Handle partial zero out on the start of the range */
3714 if (partial_start) {
3715 err = ext4_block_zero_page_range(handle, mapping,
3716 lstart, sb->s_blocksize);
3717 if (err)
3718 return err;
3719 }
3720 /* Handle partial zero out on the end of the range */
3721 if (partial_end != sb->s_blocksize - 1)
3722 err = ext4_block_zero_page_range(handle, mapping,
3723 byte_end - partial_end,
3724 partial_end + 1);
3725 return err;
3726}
3727
3728int ext4_can_truncate(struct inode *inode)
3729{
3730 if (S_ISREG(inode->i_mode))
3731 return 1;
3732 if (S_ISDIR(inode->i_mode))
3733 return 1;
3734 if (S_ISLNK(inode->i_mode))
3735 return !ext4_inode_is_fast_symlink(inode);
3736 return 0;
3737}
3738
3739/*
3740 * We have to make sure i_disksize gets properly updated before we truncate
3741 * page cache due to hole punching or zero range. Otherwise i_disksize update
3742 * can get lost as it may have been postponed to submission of writeback but
3743 * that will never happen after we truncate page cache.
3744 */
3745int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset,
3746 loff_t len)
3747{
3748 handle_t *handle;
3749 loff_t size = i_size_read(inode);
3750
3751 WARN_ON(!inode_is_locked(inode));
3752 if (offset > size || offset + len < size)
3753 return 0;
3754
3755 if (EXT4_I(inode)->i_disksize >= size)
3756 return 0;
3757
3758 handle = ext4_journal_start(inode, EXT4_HT_MISC, 1);
3759 if (IS_ERR(handle))
3760 return PTR_ERR(handle);
3761 ext4_update_i_disksize(inode, size);
3762 ext4_mark_inode_dirty(handle, inode);
3763 ext4_journal_stop(handle);
3764
3765 return 0;
3766}
3767
3768/*
3769 * ext4_punch_hole: punches a hole in a file by releaseing the blocks
3770 * associated with the given offset and length
3771 *
3772 * @inode: File inode
3773 * @offset: The offset where the hole will begin
3774 * @len: The length of the hole
3775 *
3776 * Returns: 0 on success or negative on failure
3777 */
3778
3779int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
3780{
3781 struct super_block *sb = inode->i_sb;
3782 ext4_lblk_t first_block, stop_block;
3783 struct address_space *mapping = inode->i_mapping;
3784 loff_t first_block_offset, last_block_offset;
3785 handle_t *handle;
3786 unsigned int credits;
3787 int ret = 0;
3788
3789 if (!S_ISREG(inode->i_mode))
3790 return -EOPNOTSUPP;
3791
3792 trace_ext4_punch_hole(inode, offset, length, 0);
3793
3794 /*
3795 * Write out all dirty pages to avoid race conditions
3796 * Then release them.
3797 */
3798 if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
3799 ret = filemap_write_and_wait_range(mapping, offset,
3800 offset + length - 1);
3801 if (ret)
3802 return ret;
3803 }
3804
3805 inode_lock(inode);
3806
3807 /* No need to punch hole beyond i_size */
3808 if (offset >= inode->i_size)
3809 goto out_mutex;
3810
3811 /*
3812 * If the hole extends beyond i_size, set the hole
3813 * to end after the page that contains i_size
3814 */
3815 if (offset + length > inode->i_size) {
3816 length = inode->i_size +
3817 PAGE_SIZE - (inode->i_size & (PAGE_SIZE - 1)) -
3818 offset;
3819 }
3820
3821 if (offset & (sb->s_blocksize - 1) ||
3822 (offset + length) & (sb->s_blocksize - 1)) {
3823 /*
3824 * Attach jinode to inode for jbd2 if we do any zeroing of
3825 * partial block
3826 */
3827 ret = ext4_inode_attach_jinode(inode);
3828 if (ret < 0)
3829 goto out_mutex;
3830
3831 }
3832
3833 /* Wait all existing dio workers, newcomers will block on i_mutex */
3834 ext4_inode_block_unlocked_dio(inode);
3835 inode_dio_wait(inode);
3836
3837 /*
3838 * Prevent page faults from reinstantiating pages we have released from
3839 * page cache.
3840 */
3841 down_write(&EXT4_I(inode)->i_mmap_sem);
3842 first_block_offset = round_up(offset, sb->s_blocksize);
3843 last_block_offset = round_down((offset + length), sb->s_blocksize) - 1;
3844
3845 /* Now release the pages and zero block aligned part of pages*/
3846 if (last_block_offset > first_block_offset) {
3847 ret = ext4_update_disksize_before_punch(inode, offset, length);
3848 if (ret)
3849 goto out_dio;
3850 truncate_pagecache_range(inode, first_block_offset,
3851 last_block_offset);
3852 }
3853
3854 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3855 credits = ext4_writepage_trans_blocks(inode);
3856 else
3857 credits = ext4_blocks_for_truncate(inode);
3858 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
3859 if (IS_ERR(handle)) {
3860 ret = PTR_ERR(handle);
3861 ext4_std_error(sb, ret);
3862 goto out_dio;
3863 }
3864
3865 ret = ext4_zero_partial_blocks(handle, inode, offset,
3866 length);
3867 if (ret)
3868 goto out_stop;
3869
3870 first_block = (offset + sb->s_blocksize - 1) >>
3871 EXT4_BLOCK_SIZE_BITS(sb);
3872 stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
3873
3874 /* If there are no blocks to remove, return now */
3875 if (first_block >= stop_block)
3876 goto out_stop;
3877
3878 down_write(&EXT4_I(inode)->i_data_sem);
3879 ext4_discard_preallocations(inode);
3880
3881 ret = ext4_es_remove_extent(inode, first_block,
3882 stop_block - first_block);
3883 if (ret) {
3884 up_write(&EXT4_I(inode)->i_data_sem);
3885 goto out_stop;
3886 }
3887
3888 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3889 ret = ext4_ext_remove_space(inode, first_block,
3890 stop_block - 1);
3891 else
3892 ret = ext4_ind_remove_space(handle, inode, first_block,
3893 stop_block);
3894
3895 up_write(&EXT4_I(inode)->i_data_sem);
3896 if (IS_SYNC(inode))
3897 ext4_handle_sync(handle);
3898
3899 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
3900 ext4_mark_inode_dirty(handle, inode);
3901out_stop:
3902 ext4_journal_stop(handle);
3903out_dio:
3904 up_write(&EXT4_I(inode)->i_mmap_sem);
3905 ext4_inode_resume_unlocked_dio(inode);
3906out_mutex:
3907 inode_unlock(inode);
3908 return ret;
3909}
3910
3911int ext4_inode_attach_jinode(struct inode *inode)
3912{
3913 struct ext4_inode_info *ei = EXT4_I(inode);
3914 struct jbd2_inode *jinode;
3915
3916 if (ei->jinode || !EXT4_SB(inode->i_sb)->s_journal)
3917 return 0;
3918
3919 jinode = jbd2_alloc_inode(GFP_KERNEL);
3920 spin_lock(&inode->i_lock);
3921 if (!ei->jinode) {
3922 if (!jinode) {
3923 spin_unlock(&inode->i_lock);
3924 return -ENOMEM;
3925 }
3926 ei->jinode = jinode;
3927 jbd2_journal_init_jbd_inode(ei->jinode, inode);
3928 jinode = NULL;
3929 }
3930 spin_unlock(&inode->i_lock);
3931 if (unlikely(jinode != NULL))
3932 jbd2_free_inode(jinode);
3933 return 0;
3934}
3935
3936/*
3937 * ext4_truncate()
3938 *
3939 * We block out ext4_get_block() block instantiations across the entire
3940 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
3941 * simultaneously on behalf of the same inode.
3942 *
3943 * As we work through the truncate and commit bits of it to the journal there
3944 * is one core, guiding principle: the file's tree must always be consistent on
3945 * disk. We must be able to restart the truncate after a crash.
3946 *
3947 * The file's tree may be transiently inconsistent in memory (although it
3948 * probably isn't), but whenever we close off and commit a journal transaction,
3949 * the contents of (the filesystem + the journal) must be consistent and
3950 * restartable. It's pretty simple, really: bottom up, right to left (although
3951 * left-to-right works OK too).
3952 *
3953 * Note that at recovery time, journal replay occurs *before* the restart of
3954 * truncate against the orphan inode list.
3955 *
3956 * The committed inode has the new, desired i_size (which is the same as
3957 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
3958 * that this inode's truncate did not complete and it will again call
3959 * ext4_truncate() to have another go. So there will be instantiated blocks
3960 * to the right of the truncation point in a crashed ext4 filesystem. But
3961 * that's fine - as long as they are linked from the inode, the post-crash
3962 * ext4_truncate() run will find them and release them.
3963 */
3964void ext4_truncate(struct inode *inode)
3965{
3966 struct ext4_inode_info *ei = EXT4_I(inode);
3967 unsigned int credits;
3968 handle_t *handle;
3969 struct address_space *mapping = inode->i_mapping;
3970
3971 /*
3972 * There is a possibility that we're either freeing the inode
3973 * or it's a completely new inode. In those cases we might not
3974 * have i_mutex locked because it's not necessary.
3975 */
3976 if (!(inode->i_state & (I_NEW|I_FREEING)))
3977 WARN_ON(!inode_is_locked(inode));
3978 trace_ext4_truncate_enter(inode);
3979
3980 if (!ext4_can_truncate(inode))
3981 return;
3982
3983 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3984
3985 if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
3986 ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
3987
3988 if (ext4_has_inline_data(inode)) {
3989 int has_inline = 1;
3990
3991 ext4_inline_data_truncate(inode, &has_inline);
3992 if (has_inline)
3993 return;
3994 }
3995
3996 /* If we zero-out tail of the page, we have to create jinode for jbd2 */
3997 if (inode->i_size & (inode->i_sb->s_blocksize - 1)) {
3998 if (ext4_inode_attach_jinode(inode) < 0)
3999 return;
4000 }
4001
4002 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
4003 credits = ext4_writepage_trans_blocks(inode);
4004 else
4005 credits = ext4_blocks_for_truncate(inode);
4006
4007 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
4008 if (IS_ERR(handle)) {
4009 ext4_std_error(inode->i_sb, PTR_ERR(handle));
4010 return;
4011 }
4012
4013 if (inode->i_size & (inode->i_sb->s_blocksize - 1))
4014 ext4_block_truncate_page(handle, mapping, inode->i_size);
4015
4016 /*
4017 * We add the inode to the orphan list, so that if this
4018 * truncate spans multiple transactions, and we crash, we will
4019 * resume the truncate when the filesystem recovers. It also
4020 * marks the inode dirty, to catch the new size.
4021 *
4022 * Implication: the file must always be in a sane, consistent
4023 * truncatable state while each transaction commits.
4024 */
4025 if (ext4_orphan_add(handle, inode))
4026 goto out_stop;
4027
4028 down_write(&EXT4_I(inode)->i_data_sem);
4029
4030 ext4_discard_preallocations(inode);
4031
4032 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
4033 ext4_ext_truncate(handle, inode);
4034 else
4035 ext4_ind_truncate(handle, inode);
4036
4037 up_write(&ei->i_data_sem);
4038
4039 if (IS_SYNC(inode))
4040 ext4_handle_sync(handle);
4041
4042out_stop:
4043 /*
4044 * If this was a simple ftruncate() and the file will remain alive,
4045 * then we need to clear up the orphan record which we created above.
4046 * However, if this was a real unlink then we were called by
4047 * ext4_evict_inode(), and we allow that function to clean up the
4048 * orphan info for us.
4049 */
4050 if (inode->i_nlink)
4051 ext4_orphan_del(handle, inode);
4052
4053 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4054 ext4_mark_inode_dirty(handle, inode);
4055 ext4_journal_stop(handle);
4056
4057 trace_ext4_truncate_exit(inode);
4058}
4059
4060/*
4061 * ext4_get_inode_loc returns with an extra refcount against the inode's
4062 * underlying buffer_head on success. If 'in_mem' is true, we have all
4063 * data in memory that is needed to recreate the on-disk version of this
4064 * inode.
4065 */
4066static int __ext4_get_inode_loc(struct inode *inode,
4067 struct ext4_iloc *iloc, int in_mem)
4068{
4069 struct ext4_group_desc *gdp;
4070 struct buffer_head *bh;
4071 struct super_block *sb = inode->i_sb;
4072 ext4_fsblk_t block;
4073 int inodes_per_block, inode_offset;
4074
4075 iloc->bh = NULL;
4076 if (!ext4_valid_inum(sb, inode->i_ino))
4077 return -EFSCORRUPTED;
4078
4079 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
4080 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
4081 if (!gdp)
4082 return -EIO;
4083
4084 /*
4085 * Figure out the offset within the block group inode table
4086 */
4087 inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
4088 inode_offset = ((inode->i_ino - 1) %
4089 EXT4_INODES_PER_GROUP(sb));
4090 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
4091 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
4092
4093 bh = sb_getblk(sb, block);
4094 if (unlikely(!bh))
4095 return -ENOMEM;
4096 if (!buffer_uptodate(bh)) {
4097 lock_buffer(bh);
4098
4099 /*
4100 * If the buffer has the write error flag, we have failed
4101 * to write out another inode in the same block. In this
4102 * case, we don't have to read the block because we may
4103 * read the old inode data successfully.
4104 */
4105 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
4106 set_buffer_uptodate(bh);
4107
4108 if (buffer_uptodate(bh)) {
4109 /* someone brought it uptodate while we waited */
4110 unlock_buffer(bh);
4111 goto has_buffer;
4112 }
4113
4114 /*
4115 * If we have all information of the inode in memory and this
4116 * is the only valid inode in the block, we need not read the
4117 * block.
4118 */
4119 if (in_mem) {
4120 struct buffer_head *bitmap_bh;
4121 int i, start;
4122
4123 start = inode_offset & ~(inodes_per_block - 1);
4124
4125 /* Is the inode bitmap in cache? */
4126 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
4127 if (unlikely(!bitmap_bh))
4128 goto make_io;
4129
4130 /*
4131 * If the inode bitmap isn't in cache then the
4132 * optimisation may end up performing two reads instead
4133 * of one, so skip it.
4134 */
4135 if (!buffer_uptodate(bitmap_bh)) {
4136 brelse(bitmap_bh);
4137 goto make_io;
4138 }
4139 for (i = start; i < start + inodes_per_block; i++) {
4140 if (i == inode_offset)
4141 continue;
4142 if (ext4_test_bit(i, bitmap_bh->b_data))
4143 break;
4144 }
4145 brelse(bitmap_bh);
4146 if (i == start + inodes_per_block) {
4147 /* all other inodes are free, so skip I/O */
4148 memset(bh->b_data, 0, bh->b_size);
4149 set_buffer_uptodate(bh);
4150 unlock_buffer(bh);
4151 goto has_buffer;
4152 }
4153 }
4154
4155make_io:
4156 /*
4157 * If we need to do any I/O, try to pre-readahead extra
4158 * blocks from the inode table.
4159 */
4160 if (EXT4_SB(sb)->s_inode_readahead_blks) {
4161 ext4_fsblk_t b, end, table;
4162 unsigned num;
4163 __u32 ra_blks = EXT4_SB(sb)->s_inode_readahead_blks;
4164
4165 table = ext4_inode_table(sb, gdp);
4166 /* s_inode_readahead_blks is always a power of 2 */
4167 b = block & ~((ext4_fsblk_t) ra_blks - 1);
4168 if (table > b)
4169 b = table;
4170 end = b + ra_blks;
4171 num = EXT4_INODES_PER_GROUP(sb);
4172 if (ext4_has_group_desc_csum(sb))
4173 num -= ext4_itable_unused_count(sb, gdp);
4174 table += num / inodes_per_block;
4175 if (end > table)
4176 end = table;
4177 while (b <= end)
4178 sb_breadahead(sb, b++);
4179 }
4180
4181 /*
4182 * There are other valid inodes in the buffer, this inode
4183 * has in-inode xattrs, or we don't have this inode in memory.
4184 * Read the block from disk.
4185 */
4186 trace_ext4_load_inode(inode);
4187 get_bh(bh);
4188 bh->b_end_io = end_buffer_read_sync;
4189 submit_bh(READ | REQ_META | REQ_PRIO, bh);
4190 wait_on_buffer(bh);
4191 if (!buffer_uptodate(bh)) {
4192 EXT4_ERROR_INODE_BLOCK(inode, block,
4193 "unable to read itable block");
4194 brelse(bh);
4195 return -EIO;
4196 }
4197 }
4198has_buffer:
4199 iloc->bh = bh;
4200 return 0;
4201}
4202
4203int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
4204{
4205 /* We have all inode data except xattrs in memory here. */
4206 return __ext4_get_inode_loc(inode, iloc,
4207 !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
4208}
4209
4210void ext4_set_inode_flags(struct inode *inode)
4211{
4212 unsigned int flags = EXT4_I(inode)->i_flags;
4213 unsigned int new_fl = 0;
4214
4215 if (flags & EXT4_SYNC_FL)
4216 new_fl |= S_SYNC;
4217 if (flags & EXT4_APPEND_FL)
4218 new_fl |= S_APPEND;
4219 if (flags & EXT4_IMMUTABLE_FL)
4220 new_fl |= S_IMMUTABLE;
4221 if (flags & EXT4_NOATIME_FL)
4222 new_fl |= S_NOATIME;
4223 if (flags & EXT4_DIRSYNC_FL)
4224 new_fl |= S_DIRSYNC;
4225 if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode))
4226 new_fl |= S_DAX;
4227 inode_set_flags(inode, new_fl,
4228 S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX);
4229}
4230
4231/* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4232void ext4_get_inode_flags(struct ext4_inode_info *ei)
4233{
4234 unsigned int vfs_fl;
4235 unsigned long old_fl, new_fl;
4236
4237 do {
4238 vfs_fl = ei->vfs_inode.i_flags;
4239 old_fl = ei->i_flags;
4240 new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
4241 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|
4242 EXT4_DIRSYNC_FL);
4243 if (vfs_fl & S_SYNC)
4244 new_fl |= EXT4_SYNC_FL;
4245 if (vfs_fl & S_APPEND)
4246 new_fl |= EXT4_APPEND_FL;
4247 if (vfs_fl & S_IMMUTABLE)
4248 new_fl |= EXT4_IMMUTABLE_FL;
4249 if (vfs_fl & S_NOATIME)
4250 new_fl |= EXT4_NOATIME_FL;
4251 if (vfs_fl & S_DIRSYNC)
4252 new_fl |= EXT4_DIRSYNC_FL;
4253 } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl);
4254}
4255
4256static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
4257 struct ext4_inode_info *ei)
4258{
4259 blkcnt_t i_blocks ;
4260 struct inode *inode = &(ei->vfs_inode);
4261 struct super_block *sb = inode->i_sb;
4262
4263 if (ext4_has_feature_huge_file(sb)) {
4264 /* we are using combined 48 bit field */
4265 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
4266 le32_to_cpu(raw_inode->i_blocks_lo);
4267 if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
4268 /* i_blocks represent file system block size */
4269 return i_blocks << (inode->i_blkbits - 9);
4270 } else {
4271 return i_blocks;
4272 }
4273 } else {
4274 return le32_to_cpu(raw_inode->i_blocks_lo);
4275 }
4276}
4277
4278static inline void ext4_iget_extra_inode(struct inode *inode,
4279 struct ext4_inode *raw_inode,
4280 struct ext4_inode_info *ei)
4281{
4282 __le32 *magic = (void *)raw_inode +
4283 EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize;
4284 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC)) {
4285 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
4286 ext4_find_inline_data_nolock(inode);
4287 } else
4288 EXT4_I(inode)->i_inline_off = 0;
4289}
4290
4291int ext4_get_projid(struct inode *inode, kprojid_t *projid)
4292{
4293 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_PROJECT))
4294 return -EOPNOTSUPP;
4295 *projid = EXT4_I(inode)->i_projid;
4296 return 0;
4297}
4298
4299struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
4300{
4301 struct ext4_iloc iloc;
4302 struct ext4_inode *raw_inode;
4303 struct ext4_inode_info *ei;
4304 struct inode *inode;
4305 journal_t *journal = EXT4_SB(sb)->s_journal;
4306 long ret;
4307 int block;
4308 uid_t i_uid;
4309 gid_t i_gid;
4310 projid_t i_projid;
4311
4312 inode = iget_locked(sb, ino);
4313 if (!inode)
4314 return ERR_PTR(-ENOMEM);
4315 if (!(inode->i_state & I_NEW))
4316 return inode;
4317
4318 ei = EXT4_I(inode);
4319 iloc.bh = NULL;
4320
4321 ret = __ext4_get_inode_loc(inode, &iloc, 0);
4322 if (ret < 0)
4323 goto bad_inode;
4324 raw_inode = ext4_raw_inode(&iloc);
4325
4326 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4327 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
4328 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
4329 EXT4_INODE_SIZE(inode->i_sb)) {
4330 EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)",
4331 EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize,
4332 EXT4_INODE_SIZE(inode->i_sb));
4333 ret = -EFSCORRUPTED;
4334 goto bad_inode;
4335 }
4336 } else
4337 ei->i_extra_isize = 0;
4338
4339 /* Precompute checksum seed for inode metadata */
4340 if (ext4_has_metadata_csum(sb)) {
4341 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4342 __u32 csum;
4343 __le32 inum = cpu_to_le32(inode->i_ino);
4344 __le32 gen = raw_inode->i_generation;
4345 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
4346 sizeof(inum));
4347 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
4348 sizeof(gen));
4349 }
4350
4351 if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
4352 EXT4_ERROR_INODE(inode, "checksum invalid");
4353 ret = -EFSBADCRC;
4354 goto bad_inode;
4355 }
4356
4357 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
4358 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
4359 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
4360 if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_PROJECT) &&
4361 EXT4_INODE_SIZE(sb) > EXT4_GOOD_OLD_INODE_SIZE &&
4362 EXT4_FITS_IN_INODE(raw_inode, ei, i_projid))
4363 i_projid = (projid_t)le32_to_cpu(raw_inode->i_projid);
4364 else
4365 i_projid = EXT4_DEF_PROJID;
4366
4367 if (!(test_opt(inode->i_sb, NO_UID32))) {
4368 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
4369 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
4370 }
4371 i_uid_write(inode, i_uid);
4372 i_gid_write(inode, i_gid);
4373 ei->i_projid = make_kprojid(&init_user_ns, i_projid);
4374 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
4375
4376 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
4377 ei->i_inline_off = 0;
4378 ei->i_dir_start_lookup = 0;
4379 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
4380 /* We now have enough fields to check if the inode was active or not.
4381 * This is needed because nfsd might try to access dead inodes
4382 * the test is that same one that e2fsck uses
4383 * NeilBrown 1999oct15
4384 */
4385 if (inode->i_nlink == 0) {
4386 if ((inode->i_mode == 0 ||
4387 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) &&
4388 ino != EXT4_BOOT_LOADER_INO) {
4389 /* this inode is deleted */
4390 ret = -ESTALE;
4391 goto bad_inode;
4392 }
4393 /* The only unlinked inodes we let through here have
4394 * valid i_mode and are being read by the orphan
4395 * recovery code: that's fine, we're about to complete
4396 * the process of deleting those.
4397 * OR it is the EXT4_BOOT_LOADER_INO which is
4398 * not initialized on a new filesystem. */
4399 }
4400 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
4401 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
4402 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
4403 if (ext4_has_feature_64bit(sb))
4404 ei->i_file_acl |=
4405 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
4406 inode->i_size = ext4_isize(raw_inode);
4407 ei->i_disksize = inode->i_size;
4408#ifdef CONFIG_QUOTA
4409 ei->i_reserved_quota = 0;
4410#endif
4411 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
4412 ei->i_block_group = iloc.block_group;
4413 ei->i_last_alloc_group = ~0;
4414 /*
4415 * NOTE! The in-memory inode i_data array is in little-endian order
4416 * even on big-endian machines: we do NOT byteswap the block numbers!
4417 */
4418 for (block = 0; block < EXT4_N_BLOCKS; block++)
4419 ei->i_data[block] = raw_inode->i_block[block];
4420 INIT_LIST_HEAD(&ei->i_orphan);
4421
4422 /*
4423 * Set transaction id's of transactions that have to be committed
4424 * to finish f[data]sync. We set them to currently running transaction
4425 * as we cannot be sure that the inode or some of its metadata isn't
4426 * part of the transaction - the inode could have been reclaimed and
4427 * now it is reread from disk.
4428 */
4429 if (journal) {
4430 transaction_t *transaction;
4431 tid_t tid;
4432
4433 read_lock(&journal->j_state_lock);
4434 if (journal->j_running_transaction)
4435 transaction = journal->j_running_transaction;
4436 else
4437 transaction = journal->j_committing_transaction;
4438 if (transaction)
4439 tid = transaction->t_tid;
4440 else
4441 tid = journal->j_commit_sequence;
4442 read_unlock(&journal->j_state_lock);
4443 ei->i_sync_tid = tid;
4444 ei->i_datasync_tid = tid;
4445 }
4446
4447 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4448 if (ei->i_extra_isize == 0) {
4449 /* The extra space is currently unused. Use it. */
4450 ei->i_extra_isize = sizeof(struct ext4_inode) -
4451 EXT4_GOOD_OLD_INODE_SIZE;
4452 } else {
4453 ext4_iget_extra_inode(inode, raw_inode, ei);
4454 }
4455 }
4456
4457 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
4458 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
4459 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
4460 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
4461
4462 if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
4463 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
4464 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4465 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4466 inode->i_version |=
4467 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
4468 }
4469 }
4470
4471 ret = 0;
4472 if (ei->i_file_acl &&
4473 !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
4474 EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
4475 ei->i_file_acl);
4476 ret = -EFSCORRUPTED;
4477 goto bad_inode;
4478 } else if (!ext4_has_inline_data(inode)) {
4479 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
4480 if ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4481 (S_ISLNK(inode->i_mode) &&
4482 !ext4_inode_is_fast_symlink(inode))))
4483 /* Validate extent which is part of inode */
4484 ret = ext4_ext_check_inode(inode);
4485 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4486 (S_ISLNK(inode->i_mode) &&
4487 !ext4_inode_is_fast_symlink(inode))) {
4488 /* Validate block references which are part of inode */
4489 ret = ext4_ind_check_inode(inode);
4490 }
4491 }
4492 if (ret)
4493 goto bad_inode;
4494
4495 if (S_ISREG(inode->i_mode)) {
4496 inode->i_op = &ext4_file_inode_operations;
4497 inode->i_fop = &ext4_file_operations;
4498 ext4_set_aops(inode);
4499 } else if (S_ISDIR(inode->i_mode)) {
4500 inode->i_op = &ext4_dir_inode_operations;
4501 inode->i_fop = &ext4_dir_operations;
4502 } else if (S_ISLNK(inode->i_mode)) {
4503 if (ext4_encrypted_inode(inode)) {
4504 inode->i_op = &ext4_encrypted_symlink_inode_operations;
4505 ext4_set_aops(inode);
4506 } else if (ext4_inode_is_fast_symlink(inode)) {
4507 inode->i_link = (char *)ei->i_data;
4508 inode->i_op = &ext4_fast_symlink_inode_operations;
4509 nd_terminate_link(ei->i_data, inode->i_size,
4510 sizeof(ei->i_data) - 1);
4511 } else {
4512 inode->i_op = &ext4_symlink_inode_operations;
4513 ext4_set_aops(inode);
4514 }
4515 inode_nohighmem(inode);
4516 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
4517 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
4518 inode->i_op = &ext4_special_inode_operations;
4519 if (raw_inode->i_block[0])
4520 init_special_inode(inode, inode->i_mode,
4521 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
4522 else
4523 init_special_inode(inode, inode->i_mode,
4524 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
4525 } else if (ino == EXT4_BOOT_LOADER_INO) {
4526 make_bad_inode(inode);
4527 } else {
4528 ret = -EFSCORRUPTED;
4529 EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
4530 goto bad_inode;
4531 }
4532 brelse(iloc.bh);
4533 ext4_set_inode_flags(inode);
4534 unlock_new_inode(inode);
4535 return inode;
4536
4537bad_inode:
4538 brelse(iloc.bh);
4539 iget_failed(inode);
4540 return ERR_PTR(ret);
4541}
4542
4543struct inode *ext4_iget_normal(struct super_block *sb, unsigned long ino)
4544{
4545 if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
4546 return ERR_PTR(-EFSCORRUPTED);
4547 return ext4_iget(sb, ino);
4548}
4549
4550static int ext4_inode_blocks_set(handle_t *handle,
4551 struct ext4_inode *raw_inode,
4552 struct ext4_inode_info *ei)
4553{
4554 struct inode *inode = &(ei->vfs_inode);
4555 u64 i_blocks = inode->i_blocks;
4556 struct super_block *sb = inode->i_sb;
4557
4558 if (i_blocks <= ~0U) {
4559 /*
4560 * i_blocks can be represented in a 32 bit variable
4561 * as multiple of 512 bytes
4562 */
4563 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4564 raw_inode->i_blocks_high = 0;
4565 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4566 return 0;
4567 }
4568 if (!ext4_has_feature_huge_file(sb))
4569 return -EFBIG;
4570
4571 if (i_blocks <= 0xffffffffffffULL) {
4572 /*
4573 * i_blocks can be represented in a 48 bit variable
4574 * as multiple of 512 bytes
4575 */
4576 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4577 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4578 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4579 } else {
4580 ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4581 /* i_block is stored in file system block size */
4582 i_blocks = i_blocks >> (inode->i_blkbits - 9);
4583 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4584 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4585 }
4586 return 0;
4587}
4588
4589struct other_inode {
4590 unsigned long orig_ino;
4591 struct ext4_inode *raw_inode;
4592};
4593
4594static int other_inode_match(struct inode * inode, unsigned long ino,
4595 void *data)
4596{
4597 struct other_inode *oi = (struct other_inode *) data;
4598
4599 if ((inode->i_ino != ino) ||
4600 (inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW |
4601 I_DIRTY_SYNC | I_DIRTY_DATASYNC)) ||
4602 ((inode->i_state & I_DIRTY_TIME) == 0))
4603 return 0;
4604 spin_lock(&inode->i_lock);
4605 if (((inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW |
4606 I_DIRTY_SYNC | I_DIRTY_DATASYNC)) == 0) &&
4607 (inode->i_state & I_DIRTY_TIME)) {
4608 struct ext4_inode_info *ei = EXT4_I(inode);
4609
4610 inode->i_state &= ~(I_DIRTY_TIME | I_DIRTY_TIME_EXPIRED);
4611 spin_unlock(&inode->i_lock);
4612
4613 spin_lock(&ei->i_raw_lock);
4614 EXT4_INODE_SET_XTIME(i_ctime, inode, oi->raw_inode);
4615 EXT4_INODE_SET_XTIME(i_mtime, inode, oi->raw_inode);
4616 EXT4_INODE_SET_XTIME(i_atime, inode, oi->raw_inode);
4617 ext4_inode_csum_set(inode, oi->raw_inode, ei);
4618 spin_unlock(&ei->i_raw_lock);
4619 trace_ext4_other_inode_update_time(inode, oi->orig_ino);
4620 return -1;
4621 }
4622 spin_unlock(&inode->i_lock);
4623 return -1;
4624}
4625
4626/*
4627 * Opportunistically update the other time fields for other inodes in
4628 * the same inode table block.
4629 */
4630static void ext4_update_other_inodes_time(struct super_block *sb,
4631 unsigned long orig_ino, char *buf)
4632{
4633 struct other_inode oi;
4634 unsigned long ino;
4635 int i, inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
4636 int inode_size = EXT4_INODE_SIZE(sb);
4637
4638 oi.orig_ino = orig_ino;
4639 /*
4640 * Calculate the first inode in the inode table block. Inode
4641 * numbers are one-based. That is, the first inode in a block
4642 * (assuming 4k blocks and 256 byte inodes) is (n*16 + 1).
4643 */
4644 ino = ((orig_ino - 1) & ~(inodes_per_block - 1)) + 1;
4645 for (i = 0; i < inodes_per_block; i++, ino++, buf += inode_size) {
4646 if (ino == orig_ino)
4647 continue;
4648 oi.raw_inode = (struct ext4_inode *) buf;
4649 (void) find_inode_nowait(sb, ino, other_inode_match, &oi);
4650 }
4651}
4652
4653/*
4654 * Post the struct inode info into an on-disk inode location in the
4655 * buffer-cache. This gobbles the caller's reference to the
4656 * buffer_head in the inode location struct.
4657 *
4658 * The caller must have write access to iloc->bh.
4659 */
4660static int ext4_do_update_inode(handle_t *handle,
4661 struct inode *inode,
4662 struct ext4_iloc *iloc)
4663{
4664 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
4665 struct ext4_inode_info *ei = EXT4_I(inode);
4666 struct buffer_head *bh = iloc->bh;
4667 struct super_block *sb = inode->i_sb;
4668 int err = 0, rc, block;
4669 int need_datasync = 0, set_large_file = 0;
4670 uid_t i_uid;
4671 gid_t i_gid;
4672 projid_t i_projid;
4673
4674 spin_lock(&ei->i_raw_lock);
4675
4676 /* For fields not tracked in the in-memory inode,
4677 * initialise them to zero for new inodes. */
4678 if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
4679 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
4680
4681 ext4_get_inode_flags(ei);
4682 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
4683 i_uid = i_uid_read(inode);
4684 i_gid = i_gid_read(inode);
4685 i_projid = from_kprojid(&init_user_ns, ei->i_projid);
4686 if (!(test_opt(inode->i_sb, NO_UID32))) {
4687 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
4688 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
4689/*
4690 * Fix up interoperability with old kernels. Otherwise, old inodes get
4691 * re-used with the upper 16 bits of the uid/gid intact
4692 */
4693 if (!ei->i_dtime) {
4694 raw_inode->i_uid_high =
4695 cpu_to_le16(high_16_bits(i_uid));
4696 raw_inode->i_gid_high =
4697 cpu_to_le16(high_16_bits(i_gid));
4698 } else {
4699 raw_inode->i_uid_high = 0;
4700 raw_inode->i_gid_high = 0;
4701 }
4702 } else {
4703 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
4704 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
4705 raw_inode->i_uid_high = 0;
4706 raw_inode->i_gid_high = 0;
4707 }
4708 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
4709
4710 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
4711 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
4712 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
4713 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
4714
4715 err = ext4_inode_blocks_set(handle, raw_inode, ei);
4716 if (err) {
4717 spin_unlock(&ei->i_raw_lock);
4718 goto out_brelse;
4719 }
4720 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
4721 raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
4722 if (likely(!test_opt2(inode->i_sb, HURD_COMPAT)))
4723 raw_inode->i_file_acl_high =
4724 cpu_to_le16(ei->i_file_acl >> 32);
4725 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
4726 if (ei->i_disksize != ext4_isize(raw_inode)) {
4727 ext4_isize_set(raw_inode, ei->i_disksize);
4728 need_datasync = 1;
4729 }
4730 if (ei->i_disksize > 0x7fffffffULL) {
4731 if (!ext4_has_feature_large_file(sb) ||
4732 EXT4_SB(sb)->s_es->s_rev_level ==
4733 cpu_to_le32(EXT4_GOOD_OLD_REV))
4734 set_large_file = 1;
4735 }
4736 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
4737 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
4738 if (old_valid_dev(inode->i_rdev)) {
4739 raw_inode->i_block[0] =
4740 cpu_to_le32(old_encode_dev(inode->i_rdev));
4741 raw_inode->i_block[1] = 0;
4742 } else {
4743 raw_inode->i_block[0] = 0;
4744 raw_inode->i_block[1] =
4745 cpu_to_le32(new_encode_dev(inode->i_rdev));
4746 raw_inode->i_block[2] = 0;
4747 }
4748 } else if (!ext4_has_inline_data(inode)) {
4749 for (block = 0; block < EXT4_N_BLOCKS; block++)
4750 raw_inode->i_block[block] = ei->i_data[block];
4751 }
4752
4753 if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
4754 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
4755 if (ei->i_extra_isize) {
4756 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4757 raw_inode->i_version_hi =
4758 cpu_to_le32(inode->i_version >> 32);
4759 raw_inode->i_extra_isize =
4760 cpu_to_le16(ei->i_extra_isize);
4761 }
4762 }
4763
4764 BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
4765 EXT4_FEATURE_RO_COMPAT_PROJECT) &&
4766 i_projid != EXT4_DEF_PROJID);
4767
4768 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
4769 EXT4_FITS_IN_INODE(raw_inode, ei, i_projid))
4770 raw_inode->i_projid = cpu_to_le32(i_projid);
4771
4772 ext4_inode_csum_set(inode, raw_inode, ei);
4773 spin_unlock(&ei->i_raw_lock);
4774 if (inode->i_sb->s_flags & MS_LAZYTIME)
4775 ext4_update_other_inodes_time(inode->i_sb, inode->i_ino,
4776 bh->b_data);
4777
4778 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
4779 rc = ext4_handle_dirty_metadata(handle, NULL, bh);
4780 if (!err)
4781 err = rc;
4782 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
4783 if (set_large_file) {
4784 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get write access");
4785 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
4786 if (err)
4787 goto out_brelse;
4788 ext4_update_dynamic_rev(sb);
4789 ext4_set_feature_large_file(sb);
4790 ext4_handle_sync(handle);
4791 err = ext4_handle_dirty_super(handle, sb);
4792 }
4793 ext4_update_inode_fsync_trans(handle, inode, need_datasync);
4794out_brelse:
4795 brelse(bh);
4796 ext4_std_error(inode->i_sb, err);
4797 return err;
4798}
4799
4800/*
4801 * ext4_write_inode()
4802 *
4803 * We are called from a few places:
4804 *
4805 * - Within generic_file_aio_write() -> generic_write_sync() for O_SYNC files.
4806 * Here, there will be no transaction running. We wait for any running
4807 * transaction to commit.
4808 *
4809 * - Within flush work (sys_sync(), kupdate and such).
4810 * We wait on commit, if told to.
4811 *
4812 * - Within iput_final() -> write_inode_now()
4813 * We wait on commit, if told to.
4814 *
4815 * In all cases it is actually safe for us to return without doing anything,
4816 * because the inode has been copied into a raw inode buffer in
4817 * ext4_mark_inode_dirty(). This is a correctness thing for WB_SYNC_ALL
4818 * writeback.
4819 *
4820 * Note that we are absolutely dependent upon all inode dirtiers doing the
4821 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4822 * which we are interested.
4823 *
4824 * It would be a bug for them to not do this. The code:
4825 *
4826 * mark_inode_dirty(inode)
4827 * stuff();
4828 * inode->i_size = expr;
4829 *
4830 * is in error because write_inode() could occur while `stuff()' is running,
4831 * and the new i_size will be lost. Plus the inode will no longer be on the
4832 * superblock's dirty inode list.
4833 */
4834int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
4835{
4836 int err;
4837
4838 if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
4839 return 0;
4840
4841 if (EXT4_SB(inode->i_sb)->s_journal) {
4842 if (ext4_journal_current_handle()) {
4843 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4844 dump_stack();
4845 return -EIO;
4846 }
4847
4848 /*
4849 * No need to force transaction in WB_SYNC_NONE mode. Also
4850 * ext4_sync_fs() will force the commit after everything is
4851 * written.
4852 */
4853 if (wbc->sync_mode != WB_SYNC_ALL || wbc->for_sync)
4854 return 0;
4855
4856 err = ext4_force_commit(inode->i_sb);
4857 } else {
4858 struct ext4_iloc iloc;
4859
4860 err = __ext4_get_inode_loc(inode, &iloc, 0);
4861 if (err)
4862 return err;
4863 /*
4864 * sync(2) will flush the whole buffer cache. No need to do
4865 * it here separately for each inode.
4866 */
4867 if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync)
4868 sync_dirty_buffer(iloc.bh);
4869 if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
4870 EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
4871 "IO error syncing inode");
4872 err = -EIO;
4873 }
4874 brelse(iloc.bh);
4875 }
4876 return err;
4877}
4878
4879/*
4880 * In data=journal mode ext4_journalled_invalidatepage() may fail to invalidate
4881 * buffers that are attached to a page stradding i_size and are undergoing
4882 * commit. In that case we have to wait for commit to finish and try again.
4883 */
4884static void ext4_wait_for_tail_page_commit(struct inode *inode)
4885{
4886 struct page *page;
4887 unsigned offset;
4888 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
4889 tid_t commit_tid = 0;
4890 int ret;
4891
4892 offset = inode->i_size & (PAGE_SIZE - 1);
4893 /*
4894 * All buffers in the last page remain valid? Then there's nothing to
4895 * do. We do the check mainly to optimize the common PAGE_SIZE ==
4896 * blocksize case
4897 */
4898 if (offset > PAGE_SIZE - (1 << inode->i_blkbits))
4899 return;
4900 while (1) {
4901 page = find_lock_page(inode->i_mapping,
4902 inode->i_size >> PAGE_SHIFT);
4903 if (!page)
4904 return;
4905 ret = __ext4_journalled_invalidatepage(page, offset,
4906 PAGE_SIZE - offset);
4907 unlock_page(page);
4908 put_page(page);
4909 if (ret != -EBUSY)
4910 return;
4911 commit_tid = 0;
4912 read_lock(&journal->j_state_lock);
4913 if (journal->j_committing_transaction)
4914 commit_tid = journal->j_committing_transaction->t_tid;
4915 read_unlock(&journal->j_state_lock);
4916 if (commit_tid)
4917 jbd2_log_wait_commit(journal, commit_tid);
4918 }
4919}
4920
4921/*
4922 * ext4_setattr()
4923 *
4924 * Called from notify_change.
4925 *
4926 * We want to trap VFS attempts to truncate the file as soon as
4927 * possible. In particular, we want to make sure that when the VFS
4928 * shrinks i_size, we put the inode on the orphan list and modify
4929 * i_disksize immediately, so that during the subsequent flushing of
4930 * dirty pages and freeing of disk blocks, we can guarantee that any
4931 * commit will leave the blocks being flushed in an unused state on
4932 * disk. (On recovery, the inode will get truncated and the blocks will
4933 * be freed, so we have a strong guarantee that no future commit will
4934 * leave these blocks visible to the user.)
4935 *
4936 * Another thing we have to assure is that if we are in ordered mode
4937 * and inode is still attached to the committing transaction, we must
4938 * we start writeout of all the dirty pages which are being truncated.
4939 * This way we are sure that all the data written in the previous
4940 * transaction are already on disk (truncate waits for pages under
4941 * writeback).
4942 *
4943 * Called with inode->i_mutex down.
4944 */
4945int ext4_setattr(struct dentry *dentry, struct iattr *attr)
4946{
4947 struct inode *inode = d_inode(dentry);
4948 int error, rc = 0;
4949 int orphan = 0;
4950 const unsigned int ia_valid = attr->ia_valid;
4951
4952 error = inode_change_ok(inode, attr);
4953 if (error)
4954 return error;
4955
4956 if (is_quota_modification(inode, attr)) {
4957 error = dquot_initialize(inode);
4958 if (error)
4959 return error;
4960 }
4961 if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) ||
4962 (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) {
4963 handle_t *handle;
4964
4965 /* (user+group)*(old+new) structure, inode write (sb,
4966 * inode block, ? - but truncate inode update has it) */
4967 handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4968 (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb) +
4969 EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)) + 3);
4970 if (IS_ERR(handle)) {
4971 error = PTR_ERR(handle);
4972 goto err_out;
4973 }
4974 error = dquot_transfer(inode, attr);
4975 if (error) {
4976 ext4_journal_stop(handle);
4977 return error;
4978 }
4979 /* Update corresponding info in inode so that everything is in
4980 * one transaction */
4981 if (attr->ia_valid & ATTR_UID)
4982 inode->i_uid = attr->ia_uid;
4983 if (attr->ia_valid & ATTR_GID)
4984 inode->i_gid = attr->ia_gid;
4985 error = ext4_mark_inode_dirty(handle, inode);
4986 ext4_journal_stop(handle);
4987 }
4988
4989 if (attr->ia_valid & ATTR_SIZE) {
4990 handle_t *handle;
4991 loff_t oldsize = inode->i_size;
4992 int shrink = (attr->ia_size <= inode->i_size);
4993
4994 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4995 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4996
4997 if (attr->ia_size > sbi->s_bitmap_maxbytes)
4998 return -EFBIG;
4999 }
5000 if (!S_ISREG(inode->i_mode))
5001 return -EINVAL;
5002
5003 if (IS_I_VERSION(inode) && attr->ia_size != inode->i_size)
5004 inode_inc_iversion(inode);
5005
5006 if (ext4_should_order_data(inode) &&
5007 (attr->ia_size < inode->i_size)) {
5008 error = ext4_begin_ordered_truncate(inode,
5009 attr->ia_size);
5010 if (error)
5011 goto err_out;
5012 }
5013 if (attr->ia_size != inode->i_size) {
5014 handle = ext4_journal_start(inode, EXT4_HT_INODE, 3);
5015 if (IS_ERR(handle)) {
5016 error = PTR_ERR(handle);
5017 goto err_out;
5018 }
5019 if (ext4_handle_valid(handle) && shrink) {
5020 error = ext4_orphan_add(handle, inode);
5021 orphan = 1;
5022 }
5023 /*
5024 * Update c/mtime on truncate up, ext4_truncate() will
5025 * update c/mtime in shrink case below
5026 */
5027 if (!shrink) {
5028 inode->i_mtime = ext4_current_time(inode);
5029 inode->i_ctime = inode->i_mtime;
5030 }
5031 down_write(&EXT4_I(inode)->i_data_sem);
5032 EXT4_I(inode)->i_disksize = attr->ia_size;
5033 rc = ext4_mark_inode_dirty(handle, inode);
5034 if (!error)
5035 error = rc;
5036 /*
5037 * We have to update i_size under i_data_sem together
5038 * with i_disksize to avoid races with writeback code
5039 * running ext4_wb_update_i_disksize().
5040 */
5041 if (!error)
5042 i_size_write(inode, attr->ia_size);
5043 up_write(&EXT4_I(inode)->i_data_sem);
5044 ext4_journal_stop(handle);
5045 if (error) {
5046 if (orphan)
5047 ext4_orphan_del(NULL, inode);
5048 goto err_out;
5049 }
5050 }
5051 if (!shrink)
5052 pagecache_isize_extended(inode, oldsize, inode->i_size);
5053
5054 /*
5055 * Blocks are going to be removed from the inode. Wait
5056 * for dio in flight. Temporarily disable
5057 * dioread_nolock to prevent livelock.
5058 */
5059 if (orphan) {
5060 if (!ext4_should_journal_data(inode)) {
5061 ext4_inode_block_unlocked_dio(inode);
5062 inode_dio_wait(inode);
5063 ext4_inode_resume_unlocked_dio(inode);
5064 } else
5065 ext4_wait_for_tail_page_commit(inode);
5066 }
5067 down_write(&EXT4_I(inode)->i_mmap_sem);
5068 /*
5069 * Truncate pagecache after we've waited for commit
5070 * in data=journal mode to make pages freeable.
5071 */
5072 truncate_pagecache(inode, inode->i_size);
5073 if (shrink)
5074 ext4_truncate(inode);
5075 up_write(&EXT4_I(inode)->i_mmap_sem);
5076 }
5077
5078 if (!rc) {
5079 setattr_copy(inode, attr);
5080 mark_inode_dirty(inode);
5081 }
5082
5083 /*
5084 * If the call to ext4_truncate failed to get a transaction handle at
5085 * all, we need to clean up the in-core orphan list manually.
5086 */
5087 if (orphan && inode->i_nlink)
5088 ext4_orphan_del(NULL, inode);
5089
5090 if (!rc && (ia_valid & ATTR_MODE))
5091 rc = posix_acl_chmod(inode, inode->i_mode);
5092
5093err_out:
5094 ext4_std_error(inode->i_sb, error);
5095 if (!error)
5096 error = rc;
5097 return error;
5098}
5099
5100int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
5101 struct kstat *stat)
5102{
5103 struct inode *inode;
5104 unsigned long long delalloc_blocks;
5105
5106 inode = d_inode(dentry);
5107 generic_fillattr(inode, stat);
5108
5109 /*
5110 * If there is inline data in the inode, the inode will normally not
5111 * have data blocks allocated (it may have an external xattr block).
5112 * Report at least one sector for such files, so tools like tar, rsync,
5113 * others doen't incorrectly think the file is completely sparse.
5114 */
5115 if (unlikely(ext4_has_inline_data(inode)))
5116 stat->blocks += (stat->size + 511) >> 9;
5117
5118 /*
5119 * We can't update i_blocks if the block allocation is delayed
5120 * otherwise in the case of system crash before the real block
5121 * allocation is done, we will have i_blocks inconsistent with
5122 * on-disk file blocks.
5123 * We always keep i_blocks updated together with real
5124 * allocation. But to not confuse with user, stat
5125 * will return the blocks that include the delayed allocation
5126 * blocks for this file.
5127 */
5128 delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
5129 EXT4_I(inode)->i_reserved_data_blocks);
5130 stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits - 9);
5131 return 0;
5132}
5133
5134static int ext4_index_trans_blocks(struct inode *inode, int lblocks,
5135 int pextents)
5136{
5137 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
5138 return ext4_ind_trans_blocks(inode, lblocks);
5139 return ext4_ext_index_trans_blocks(inode, pextents);
5140}
5141
5142/*
5143 * Account for index blocks, block groups bitmaps and block group
5144 * descriptor blocks if modify datablocks and index blocks
5145 * worse case, the indexs blocks spread over different block groups
5146 *
5147 * If datablocks are discontiguous, they are possible to spread over
5148 * different block groups too. If they are contiguous, with flexbg,
5149 * they could still across block group boundary.
5150 *
5151 * Also account for superblock, inode, quota and xattr blocks
5152 */
5153static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
5154 int pextents)
5155{
5156 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
5157 int gdpblocks;
5158 int idxblocks;
5159 int ret = 0;
5160
5161 /*
5162 * How many index blocks need to touch to map @lblocks logical blocks
5163 * to @pextents physical extents?
5164 */
5165 idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents);
5166
5167 ret = idxblocks;
5168
5169 /*
5170 * Now let's see how many group bitmaps and group descriptors need
5171 * to account
5172 */
5173 groups = idxblocks + pextents;
5174 gdpblocks = groups;
5175 if (groups > ngroups)
5176 groups = ngroups;
5177 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
5178 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
5179
5180 /* bitmaps and block group descriptor blocks */
5181 ret += groups + gdpblocks;
5182
5183 /* Blocks for super block, inode, quota and xattr blocks */
5184 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
5185
5186 return ret;
5187}
5188
5189/*
5190 * Calculate the total number of credits to reserve to fit
5191 * the modification of a single pages into a single transaction,
5192 * which may include multiple chunks of block allocations.
5193 *
5194 * This could be called via ext4_write_begin()
5195 *
5196 * We need to consider the worse case, when
5197 * one new block per extent.
5198 */
5199int ext4_writepage_trans_blocks(struct inode *inode)
5200{
5201 int bpp = ext4_journal_blocks_per_page(inode);
5202 int ret;
5203
5204 ret = ext4_meta_trans_blocks(inode, bpp, bpp);
5205
5206 /* Account for data blocks for journalled mode */
5207 if (ext4_should_journal_data(inode))
5208 ret += bpp;
5209 return ret;
5210}
5211
5212/*
5213 * Calculate the journal credits for a chunk of data modification.
5214 *
5215 * This is called from DIO, fallocate or whoever calling
5216 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
5217 *
5218 * journal buffers for data blocks are not included here, as DIO
5219 * and fallocate do no need to journal data buffers.
5220 */
5221int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
5222{
5223 return ext4_meta_trans_blocks(inode, nrblocks, 1);
5224}
5225
5226/*
5227 * The caller must have previously called ext4_reserve_inode_write().
5228 * Give this, we know that the caller already has write access to iloc->bh.
5229 */
5230int ext4_mark_iloc_dirty(handle_t *handle,
5231 struct inode *inode, struct ext4_iloc *iloc)
5232{
5233 int err = 0;
5234
5235 if (IS_I_VERSION(inode))
5236 inode_inc_iversion(inode);
5237
5238 /* the do_update_inode consumes one bh->b_count */
5239 get_bh(iloc->bh);
5240
5241 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5242 err = ext4_do_update_inode(handle, inode, iloc);
5243 put_bh(iloc->bh);
5244 return err;
5245}
5246
5247/*
5248 * On success, We end up with an outstanding reference count against
5249 * iloc->bh. This _must_ be cleaned up later.
5250 */
5251
5252int
5253ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
5254 struct ext4_iloc *iloc)
5255{
5256 int err;
5257
5258 err = ext4_get_inode_loc(inode, iloc);
5259 if (!err) {
5260 BUFFER_TRACE(iloc->bh, "get_write_access");
5261 err = ext4_journal_get_write_access(handle, iloc->bh);
5262 if (err) {
5263 brelse(iloc->bh);
5264 iloc->bh = NULL;
5265 }
5266 }
5267 ext4_std_error(inode->i_sb, err);
5268 return err;
5269}
5270
5271/*
5272 * Expand an inode by new_extra_isize bytes.
5273 * Returns 0 on success or negative error number on failure.
5274 */
5275static int ext4_expand_extra_isize(struct inode *inode,
5276 unsigned int new_extra_isize,
5277 struct ext4_iloc iloc,
5278 handle_t *handle)
5279{
5280 struct ext4_inode *raw_inode;
5281 struct ext4_xattr_ibody_header *header;
5282
5283 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
5284 return 0;
5285
5286 raw_inode = ext4_raw_inode(&iloc);
5287
5288 header = IHDR(inode, raw_inode);
5289
5290 /* No extended attributes present */
5291 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
5292 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
5293 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
5294 new_extra_isize);
5295 EXT4_I(inode)->i_extra_isize = new_extra_isize;
5296 return 0;
5297 }
5298
5299 /* try to expand with EAs present */
5300 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
5301 raw_inode, handle);
5302}
5303
5304/*
5305 * What we do here is to mark the in-core inode as clean with respect to inode
5306 * dirtiness (it may still be data-dirty).
5307 * This means that the in-core inode may be reaped by prune_icache
5308 * without having to perform any I/O. This is a very good thing,
5309 * because *any* task may call prune_icache - even ones which
5310 * have a transaction open against a different journal.
5311 *
5312 * Is this cheating? Not really. Sure, we haven't written the
5313 * inode out, but prune_icache isn't a user-visible syncing function.
5314 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5315 * we start and wait on commits.
5316 */
5317int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
5318{
5319 struct ext4_iloc iloc;
5320 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5321 static unsigned int mnt_count;
5322 int err, ret;
5323
5324 might_sleep();
5325 trace_ext4_mark_inode_dirty(inode, _RET_IP_);
5326 err = ext4_reserve_inode_write(handle, inode, &iloc);
5327 if (err)
5328 return err;
5329 if (ext4_handle_valid(handle) &&
5330 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
5331 !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
5332 /*
5333 * We need extra buffer credits since we may write into EA block
5334 * with this same handle. If journal_extend fails, then it will
5335 * only result in a minor loss of functionality for that inode.
5336 * If this is felt to be critical, then e2fsck should be run to
5337 * force a large enough s_min_extra_isize.
5338 */
5339 if ((jbd2_journal_extend(handle,
5340 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
5341 ret = ext4_expand_extra_isize(inode,
5342 sbi->s_want_extra_isize,
5343 iloc, handle);
5344 if (ret) {
5345 ext4_set_inode_state(inode,
5346 EXT4_STATE_NO_EXPAND);
5347 if (mnt_count !=
5348 le16_to_cpu(sbi->s_es->s_mnt_count)) {
5349 ext4_warning(inode->i_sb,
5350 "Unable to expand inode %lu. Delete"
5351 " some EAs or run e2fsck.",
5352 inode->i_ino);
5353 mnt_count =
5354 le16_to_cpu(sbi->s_es->s_mnt_count);
5355 }
5356 }
5357 }
5358 }
5359 return ext4_mark_iloc_dirty(handle, inode, &iloc);
5360}
5361
5362/*
5363 * ext4_dirty_inode() is called from __mark_inode_dirty()
5364 *
5365 * We're really interested in the case where a file is being extended.
5366 * i_size has been changed by generic_commit_write() and we thus need
5367 * to include the updated inode in the current transaction.
5368 *
5369 * Also, dquot_alloc_block() will always dirty the inode when blocks
5370 * are allocated to the file.
5371 *
5372 * If the inode is marked synchronous, we don't honour that here - doing
5373 * so would cause a commit on atime updates, which we don't bother doing.
5374 * We handle synchronous inodes at the highest possible level.
5375 *
5376 * If only the I_DIRTY_TIME flag is set, we can skip everything. If
5377 * I_DIRTY_TIME and I_DIRTY_SYNC is set, the only inode fields we need
5378 * to copy into the on-disk inode structure are the timestamp files.
5379 */
5380void ext4_dirty_inode(struct inode *inode, int flags)
5381{
5382 handle_t *handle;
5383
5384 if (flags == I_DIRTY_TIME)
5385 return;
5386 handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
5387 if (IS_ERR(handle))
5388 goto out;
5389
5390 ext4_mark_inode_dirty(handle, inode);
5391
5392 ext4_journal_stop(handle);
5393out:
5394 return;
5395}
5396
5397#if 0
5398/*
5399 * Bind an inode's backing buffer_head into this transaction, to prevent
5400 * it from being flushed to disk early. Unlike
5401 * ext4_reserve_inode_write, this leaves behind no bh reference and
5402 * returns no iloc structure, so the caller needs to repeat the iloc
5403 * lookup to mark the inode dirty later.
5404 */
5405static int ext4_pin_inode(handle_t *handle, struct inode *inode)
5406{
5407 struct ext4_iloc iloc;
5408
5409 int err = 0;
5410 if (handle) {
5411 err = ext4_get_inode_loc(inode, &iloc);
5412 if (!err) {
5413 BUFFER_TRACE(iloc.bh, "get_write_access");
5414 err = jbd2_journal_get_write_access(handle, iloc.bh);
5415 if (!err)
5416 err = ext4_handle_dirty_metadata(handle,
5417 NULL,
5418 iloc.bh);
5419 brelse(iloc.bh);
5420 }
5421 }
5422 ext4_std_error(inode->i_sb, err);
5423 return err;
5424}
5425#endif
5426
5427int ext4_change_inode_journal_flag(struct inode *inode, int val)
5428{
5429 journal_t *journal;
5430 handle_t *handle;
5431 int err;
5432
5433 /*
5434 * We have to be very careful here: changing a data block's
5435 * journaling status dynamically is dangerous. If we write a
5436 * data block to the journal, change the status and then delete
5437 * that block, we risk forgetting to revoke the old log record
5438 * from the journal and so a subsequent replay can corrupt data.
5439 * So, first we make sure that the journal is empty and that
5440 * nobody is changing anything.
5441 */
5442
5443 journal = EXT4_JOURNAL(inode);
5444 if (!journal)
5445 return 0;
5446 if (is_journal_aborted(journal))
5447 return -EROFS;
5448 /* We have to allocate physical blocks for delalloc blocks
5449 * before flushing journal. otherwise delalloc blocks can not
5450 * be allocated any more. even more truncate on delalloc blocks
5451 * could trigger BUG by flushing delalloc blocks in journal.
5452 * There is no delalloc block in non-journal data mode.
5453 */
5454 if (val && test_opt(inode->i_sb, DELALLOC)) {
5455 err = ext4_alloc_da_blocks(inode);
5456 if (err < 0)
5457 return err;
5458 }
5459
5460 /* Wait for all existing dio workers */
5461 ext4_inode_block_unlocked_dio(inode);
5462 inode_dio_wait(inode);
5463
5464 jbd2_journal_lock_updates(journal);
5465
5466 /*
5467 * OK, there are no updates running now, and all cached data is
5468 * synced to disk. We are now in a completely consistent state
5469 * which doesn't have anything in the journal, and we know that
5470 * no filesystem updates are running, so it is safe to modify
5471 * the inode's in-core data-journaling state flag now.
5472 */
5473
5474 if (val)
5475 ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5476 else {
5477 err = jbd2_journal_flush(journal);
5478 if (err < 0) {
5479 jbd2_journal_unlock_updates(journal);
5480 ext4_inode_resume_unlocked_dio(inode);
5481 return err;
5482 }
5483 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5484 }
5485 ext4_set_aops(inode);
5486
5487 jbd2_journal_unlock_updates(journal);
5488 ext4_inode_resume_unlocked_dio(inode);
5489
5490 /* Finally we can mark the inode as dirty. */
5491
5492 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
5493 if (IS_ERR(handle))
5494 return PTR_ERR(handle);
5495
5496 err = ext4_mark_inode_dirty(handle, inode);
5497 ext4_handle_sync(handle);
5498 ext4_journal_stop(handle);
5499 ext4_std_error(inode->i_sb, err);
5500
5501 return err;
5502}
5503
5504static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
5505{
5506 return !buffer_mapped(bh);
5507}
5508
5509int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
5510{
5511 struct page *page = vmf->page;
5512 loff_t size;
5513 unsigned long len;
5514 int ret;
5515 struct file *file = vma->vm_file;
5516 struct inode *inode = file_inode(file);
5517 struct address_space *mapping = inode->i_mapping;
5518 handle_t *handle;
5519 get_block_t *get_block;
5520 int retries = 0;
5521
5522 sb_start_pagefault(inode->i_sb);
5523 file_update_time(vma->vm_file);
5524
5525 down_read(&EXT4_I(inode)->i_mmap_sem);
5526 /* Delalloc case is easy... */
5527 if (test_opt(inode->i_sb, DELALLOC) &&
5528 !ext4_should_journal_data(inode) &&
5529 !ext4_nonda_switch(inode->i_sb)) {
5530 do {
5531 ret = block_page_mkwrite(vma, vmf,
5532 ext4_da_get_block_prep);
5533 } while (ret == -ENOSPC &&
5534 ext4_should_retry_alloc(inode->i_sb, &retries));
5535 goto out_ret;
5536 }
5537
5538 lock_page(page);
5539 size = i_size_read(inode);
5540 /* Page got truncated from under us? */
5541 if (page->mapping != mapping || page_offset(page) > size) {
5542 unlock_page(page);
5543 ret = VM_FAULT_NOPAGE;
5544 goto out;
5545 }
5546
5547 if (page->index == size >> PAGE_SHIFT)
5548 len = size & ~PAGE_MASK;
5549 else
5550 len = PAGE_SIZE;
5551 /*
5552 * Return if we have all the buffers mapped. This avoids the need to do
5553 * journal_start/journal_stop which can block and take a long time
5554 */
5555 if (page_has_buffers(page)) {
5556 if (!ext4_walk_page_buffers(NULL, page_buffers(page),
5557 0, len, NULL,
5558 ext4_bh_unmapped)) {
5559 /* Wait so that we don't change page under IO */
5560 wait_for_stable_page(page);
5561 ret = VM_FAULT_LOCKED;
5562 goto out;
5563 }
5564 }
5565 unlock_page(page);
5566 /* OK, we need to fill the hole... */
5567 if (ext4_should_dioread_nolock(inode))
5568 get_block = ext4_get_block_unwritten;
5569 else
5570 get_block = ext4_get_block;
5571retry_alloc:
5572 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
5573 ext4_writepage_trans_blocks(inode));
5574 if (IS_ERR(handle)) {
5575 ret = VM_FAULT_SIGBUS;
5576 goto out;
5577 }
5578 ret = block_page_mkwrite(vma, vmf, get_block);
5579 if (!ret && ext4_should_journal_data(inode)) {
5580 if (ext4_walk_page_buffers(handle, page_buffers(page), 0,
5581 PAGE_SIZE, NULL, do_journal_get_write_access)) {
5582 unlock_page(page);
5583 ret = VM_FAULT_SIGBUS;
5584 ext4_journal_stop(handle);
5585 goto out;
5586 }
5587 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
5588 }
5589 ext4_journal_stop(handle);
5590 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
5591 goto retry_alloc;
5592out_ret:
5593 ret = block_page_mkwrite_return(ret);
5594out:
5595 up_read(&EXT4_I(inode)->i_mmap_sem);
5596 sb_end_pagefault(inode->i_sb);
5597 return ret;
5598}
5599
5600int ext4_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
5601{
5602 struct inode *inode = file_inode(vma->vm_file);
5603 int err;
5604
5605 down_read(&EXT4_I(inode)->i_mmap_sem);
5606 err = filemap_fault(vma, vmf);
5607 up_read(&EXT4_I(inode)->i_mmap_sem);
5608
5609 return err;
5610}
5611
5612/*
5613 * Find the first extent at or after @lblk in an inode that is not a hole.
5614 * Search for @map_len blocks at most. The extent is returned in @result.
5615 *
5616 * The function returns 1 if we found an extent. The function returns 0 in
5617 * case there is no extent at or after @lblk and in that case also sets
5618 * @result->es_len to 0. In case of error, the error code is returned.
5619 */
5620int ext4_get_next_extent(struct inode *inode, ext4_lblk_t lblk,
5621 unsigned int map_len, struct extent_status *result)
5622{
5623 struct ext4_map_blocks map;
5624 struct extent_status es = {};
5625 int ret;
5626
5627 map.m_lblk = lblk;
5628 map.m_len = map_len;
5629
5630 /*
5631 * For non-extent based files this loop may iterate several times since
5632 * we do not determine full hole size.
5633 */
5634 while (map.m_len > 0) {
5635 ret = ext4_map_blocks(NULL, inode, &map, 0);
5636 if (ret < 0)
5637 return ret;
5638 /* There's extent covering m_lblk? Just return it. */
5639 if (ret > 0) {
5640 int status;
5641
5642 ext4_es_store_pblock(result, map.m_pblk);
5643 result->es_lblk = map.m_lblk;
5644 result->es_len = map.m_len;
5645 if (map.m_flags & EXT4_MAP_UNWRITTEN)
5646 status = EXTENT_STATUS_UNWRITTEN;
5647 else
5648 status = EXTENT_STATUS_WRITTEN;
5649 ext4_es_store_status(result, status);
5650 return 1;
5651 }
5652 ext4_es_find_delayed_extent_range(inode, map.m_lblk,
5653 map.m_lblk + map.m_len - 1,
5654 &es);
5655 /* Is delalloc data before next block in extent tree? */
5656 if (es.es_len && es.es_lblk < map.m_lblk + map.m_len) {
5657 ext4_lblk_t offset = 0;
5658
5659 if (es.es_lblk < lblk)
5660 offset = lblk - es.es_lblk;
5661 result->es_lblk = es.es_lblk + offset;
5662 ext4_es_store_pblock(result,
5663 ext4_es_pblock(&es) + offset);
5664 result->es_len = es.es_len - offset;
5665 ext4_es_store_status(result, ext4_es_status(&es));
5666
5667 return 1;
5668 }
5669 /* There's a hole at m_lblk, advance us after it */
5670 map.m_lblk += map.m_len;
5671 map_len -= map.m_len;
5672 map.m_len = map_len;
5673 cond_resched();
5674 }
5675 result->es_len = 0;
5676 return 0;
5677}