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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
4 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 */
6
7#include <linux/sched.h>
8#include <linux/slab.h>
9#include <linux/spinlock.h>
10#include <linux/completion.h>
11#include <linux/buffer_head.h>
12#include <linux/pagemap.h>
13#include <linux/pagevec.h>
14#include <linux/mpage.h>
15#include <linux/fs.h>
16#include <linux/writeback.h>
17#include <linux/swap.h>
18#include <linux/gfs2_ondisk.h>
19#include <linux/backing-dev.h>
20#include <linux/uio.h>
21#include <trace/events/writeback.h>
22#include <linux/sched/signal.h>
23
24#include "gfs2.h"
25#include "incore.h"
26#include "bmap.h"
27#include "glock.h"
28#include "inode.h"
29#include "log.h"
30#include "meta_io.h"
31#include "quota.h"
32#include "trans.h"
33#include "rgrp.h"
34#include "super.h"
35#include "util.h"
36#include "glops.h"
37#include "aops.h"
38
39
40void gfs2_trans_add_databufs(struct gfs2_inode *ip, struct folio *folio,
41 size_t from, size_t len)
42{
43 struct buffer_head *head = folio_buffers(folio);
44 unsigned int bsize = head->b_size;
45 struct buffer_head *bh;
46 size_t to = from + len;
47 size_t start, end;
48
49 for (bh = head, start = 0; bh != head || !start;
50 bh = bh->b_this_page, start = end) {
51 end = start + bsize;
52 if (end <= from)
53 continue;
54 if (start >= to)
55 break;
56 set_buffer_uptodate(bh);
57 gfs2_trans_add_data(ip->i_gl, bh);
58 }
59}
60
61/**
62 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
63 * @inode: The inode
64 * @lblock: The block number to look up
65 * @bh_result: The buffer head to return the result in
66 * @create: Non-zero if we may add block to the file
67 *
68 * Returns: errno
69 */
70
71static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
72 struct buffer_head *bh_result, int create)
73{
74 int error;
75
76 error = gfs2_block_map(inode, lblock, bh_result, 0);
77 if (error)
78 return error;
79 if (!buffer_mapped(bh_result))
80 return -ENODATA;
81 return 0;
82}
83
84/**
85 * gfs2_write_jdata_folio - gfs2 jdata-specific version of block_write_full_folio
86 * @folio: The folio to write
87 * @wbc: The writeback control
88 *
89 * This is the same as calling block_write_full_folio, but it also
90 * writes pages outside of i_size
91 */
92static int gfs2_write_jdata_folio(struct folio *folio,
93 struct writeback_control *wbc)
94{
95 struct inode * const inode = folio->mapping->host;
96 loff_t i_size = i_size_read(inode);
97
98 /*
99 * The folio straddles i_size. It must be zeroed out on each and every
100 * writepage invocation because it may be mmapped. "A file is mapped
101 * in multiples of the page size. For a file that is not a multiple of
102 * the page size, the remaining memory is zeroed when mapped, and
103 * writes to that region are not written out to the file."
104 */
105 if (folio_pos(folio) < i_size &&
106 i_size < folio_pos(folio) + folio_size(folio))
107 folio_zero_segment(folio, offset_in_folio(folio, i_size),
108 folio_size(folio));
109
110 return __block_write_full_folio(inode, folio, gfs2_get_block_noalloc,
111 wbc);
112}
113
114/**
115 * __gfs2_jdata_write_folio - The core of jdata writepage
116 * @folio: The folio to write
117 * @wbc: The writeback control
118 *
119 * This is shared between writepage and writepages and implements the
120 * core of the writepage operation. If a transaction is required then
121 * the checked flag will have been set and the transaction will have
122 * already been started before this is called.
123 */
124static int __gfs2_jdata_write_folio(struct folio *folio,
125 struct writeback_control *wbc)
126{
127 struct inode *inode = folio->mapping->host;
128 struct gfs2_inode *ip = GFS2_I(inode);
129
130 if (folio_test_checked(folio)) {
131 folio_clear_checked(folio);
132 if (!folio_buffers(folio)) {
133 create_empty_buffers(folio,
134 inode->i_sb->s_blocksize,
135 BIT(BH_Dirty)|BIT(BH_Uptodate));
136 }
137 gfs2_trans_add_databufs(ip, folio, 0, folio_size(folio));
138 }
139 return gfs2_write_jdata_folio(folio, wbc);
140}
141
142/**
143 * gfs2_jdata_writepage - Write complete page
144 * @page: Page to write
145 * @wbc: The writeback control
146 *
147 * Returns: errno
148 *
149 */
150
151static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
152{
153 struct folio *folio = page_folio(page);
154 struct inode *inode = page->mapping->host;
155 struct gfs2_inode *ip = GFS2_I(inode);
156 struct gfs2_sbd *sdp = GFS2_SB(inode);
157
158 if (gfs2_assert_withdraw(sdp, ip->i_gl->gl_state == LM_ST_EXCLUSIVE))
159 goto out;
160 if (folio_test_checked(folio) || current->journal_info)
161 goto out_ignore;
162 return __gfs2_jdata_write_folio(folio, wbc);
163
164out_ignore:
165 folio_redirty_for_writepage(wbc, folio);
166out:
167 folio_unlock(folio);
168 return 0;
169}
170
171/**
172 * gfs2_writepages - Write a bunch of dirty pages back to disk
173 * @mapping: The mapping to write
174 * @wbc: Write-back control
175 *
176 * Used for both ordered and writeback modes.
177 */
178static int gfs2_writepages(struct address_space *mapping,
179 struct writeback_control *wbc)
180{
181 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
182 struct iomap_writepage_ctx wpc = { };
183 int ret;
184
185 /*
186 * Even if we didn't write enough pages here, we might still be holding
187 * dirty pages in the ail. We forcibly flush the ail because we don't
188 * want balance_dirty_pages() to loop indefinitely trying to write out
189 * pages held in the ail that it can't find.
190 */
191 ret = iomap_writepages(mapping, wbc, &wpc, &gfs2_writeback_ops);
192 if (ret == 0 && wbc->nr_to_write > 0)
193 set_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
194 return ret;
195}
196
197/**
198 * gfs2_write_jdata_batch - Write back a folio batch's worth of folios
199 * @mapping: The mapping
200 * @wbc: The writeback control
201 * @fbatch: The batch of folios
202 * @done_index: Page index
203 *
204 * Returns: non-zero if loop should terminate, zero otherwise
205 */
206
207static int gfs2_write_jdata_batch(struct address_space *mapping,
208 struct writeback_control *wbc,
209 struct folio_batch *fbatch,
210 pgoff_t *done_index)
211{
212 struct inode *inode = mapping->host;
213 struct gfs2_sbd *sdp = GFS2_SB(inode);
214 unsigned nrblocks;
215 int i;
216 int ret;
217 size_t size = 0;
218 int nr_folios = folio_batch_count(fbatch);
219
220 for (i = 0; i < nr_folios; i++)
221 size += folio_size(fbatch->folios[i]);
222 nrblocks = size >> inode->i_blkbits;
223
224 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
225 if (ret < 0)
226 return ret;
227
228 for (i = 0; i < nr_folios; i++) {
229 struct folio *folio = fbatch->folios[i];
230
231 *done_index = folio->index;
232
233 folio_lock(folio);
234
235 if (unlikely(folio->mapping != mapping)) {
236continue_unlock:
237 folio_unlock(folio);
238 continue;
239 }
240
241 if (!folio_test_dirty(folio)) {
242 /* someone wrote it for us */
243 goto continue_unlock;
244 }
245
246 if (folio_test_writeback(folio)) {
247 if (wbc->sync_mode != WB_SYNC_NONE)
248 folio_wait_writeback(folio);
249 else
250 goto continue_unlock;
251 }
252
253 BUG_ON(folio_test_writeback(folio));
254 if (!folio_clear_dirty_for_io(folio))
255 goto continue_unlock;
256
257 trace_wbc_writepage(wbc, inode_to_bdi(inode));
258
259 ret = __gfs2_jdata_write_folio(folio, wbc);
260 if (unlikely(ret)) {
261 if (ret == AOP_WRITEPAGE_ACTIVATE) {
262 folio_unlock(folio);
263 ret = 0;
264 } else {
265
266 /*
267 * done_index is set past this page,
268 * so media errors will not choke
269 * background writeout for the entire
270 * file. This has consequences for
271 * range_cyclic semantics (ie. it may
272 * not be suitable for data integrity
273 * writeout).
274 */
275 *done_index = folio_next_index(folio);
276 ret = 1;
277 break;
278 }
279 }
280
281 /*
282 * We stop writing back only if we are not doing
283 * integrity sync. In case of integrity sync we have to
284 * keep going until we have written all the pages
285 * we tagged for writeback prior to entering this loop.
286 */
287 if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
288 ret = 1;
289 break;
290 }
291
292 }
293 gfs2_trans_end(sdp);
294 return ret;
295}
296
297/**
298 * gfs2_write_cache_jdata - Like write_cache_pages but different
299 * @mapping: The mapping to write
300 * @wbc: The writeback control
301 *
302 * The reason that we use our own function here is that we need to
303 * start transactions before we grab page locks. This allows us
304 * to get the ordering right.
305 */
306
307static int gfs2_write_cache_jdata(struct address_space *mapping,
308 struct writeback_control *wbc)
309{
310 int ret = 0;
311 int done = 0;
312 struct folio_batch fbatch;
313 int nr_folios;
314 pgoff_t writeback_index;
315 pgoff_t index;
316 pgoff_t end;
317 pgoff_t done_index;
318 int cycled;
319 int range_whole = 0;
320 xa_mark_t tag;
321
322 folio_batch_init(&fbatch);
323 if (wbc->range_cyclic) {
324 writeback_index = mapping->writeback_index; /* prev offset */
325 index = writeback_index;
326 if (index == 0)
327 cycled = 1;
328 else
329 cycled = 0;
330 end = -1;
331 } else {
332 index = wbc->range_start >> PAGE_SHIFT;
333 end = wbc->range_end >> PAGE_SHIFT;
334 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
335 range_whole = 1;
336 cycled = 1; /* ignore range_cyclic tests */
337 }
338 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
339 tag = PAGECACHE_TAG_TOWRITE;
340 else
341 tag = PAGECACHE_TAG_DIRTY;
342
343retry:
344 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
345 tag_pages_for_writeback(mapping, index, end);
346 done_index = index;
347 while (!done && (index <= end)) {
348 nr_folios = filemap_get_folios_tag(mapping, &index, end,
349 tag, &fbatch);
350 if (nr_folios == 0)
351 break;
352
353 ret = gfs2_write_jdata_batch(mapping, wbc, &fbatch,
354 &done_index);
355 if (ret)
356 done = 1;
357 if (ret > 0)
358 ret = 0;
359 folio_batch_release(&fbatch);
360 cond_resched();
361 }
362
363 if (!cycled && !done) {
364 /*
365 * range_cyclic:
366 * We hit the last page and there is more work to be done: wrap
367 * back to the start of the file
368 */
369 cycled = 1;
370 index = 0;
371 end = writeback_index - 1;
372 goto retry;
373 }
374
375 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
376 mapping->writeback_index = done_index;
377
378 return ret;
379}
380
381
382/**
383 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
384 * @mapping: The mapping to write
385 * @wbc: The writeback control
386 *
387 */
388
389static int gfs2_jdata_writepages(struct address_space *mapping,
390 struct writeback_control *wbc)
391{
392 struct gfs2_inode *ip = GFS2_I(mapping->host);
393 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
394 int ret;
395
396 ret = gfs2_write_cache_jdata(mapping, wbc);
397 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
398 gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
399 GFS2_LFC_JDATA_WPAGES);
400 ret = gfs2_write_cache_jdata(mapping, wbc);
401 }
402 return ret;
403}
404
405/**
406 * stuffed_read_folio - Fill in a Linux folio with stuffed file data
407 * @ip: the inode
408 * @folio: the folio
409 *
410 * Returns: errno
411 */
412static int stuffed_read_folio(struct gfs2_inode *ip, struct folio *folio)
413{
414 struct buffer_head *dibh = NULL;
415 size_t dsize = i_size_read(&ip->i_inode);
416 void *from = NULL;
417 int error = 0;
418
419 /*
420 * Due to the order of unstuffing files and ->fault(), we can be
421 * asked for a zero folio in the case of a stuffed file being extended,
422 * so we need to supply one here. It doesn't happen often.
423 */
424 if (unlikely(folio->index)) {
425 dsize = 0;
426 } else {
427 error = gfs2_meta_inode_buffer(ip, &dibh);
428 if (error)
429 goto out;
430 from = dibh->b_data + sizeof(struct gfs2_dinode);
431 }
432
433 folio_fill_tail(folio, 0, from, dsize);
434 brelse(dibh);
435out:
436 folio_end_read(folio, error == 0);
437
438 return error;
439}
440
441/**
442 * gfs2_read_folio - read a folio from a file
443 * @file: The file to read
444 * @folio: The folio in the file
445 */
446static int gfs2_read_folio(struct file *file, struct folio *folio)
447{
448 struct inode *inode = folio->mapping->host;
449 struct gfs2_inode *ip = GFS2_I(inode);
450 struct gfs2_sbd *sdp = GFS2_SB(inode);
451 int error;
452
453 if (!gfs2_is_jdata(ip) ||
454 (i_blocksize(inode) == PAGE_SIZE && !folio_buffers(folio))) {
455 error = iomap_read_folio(folio, &gfs2_iomap_ops);
456 } else if (gfs2_is_stuffed(ip)) {
457 error = stuffed_read_folio(ip, folio);
458 } else {
459 error = mpage_read_folio(folio, gfs2_block_map);
460 }
461
462 if (gfs2_withdrawing_or_withdrawn(sdp))
463 return -EIO;
464
465 return error;
466}
467
468/**
469 * gfs2_internal_read - read an internal file
470 * @ip: The gfs2 inode
471 * @buf: The buffer to fill
472 * @pos: The file position
473 * @size: The amount to read
474 *
475 */
476
477ssize_t gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
478 size_t size)
479{
480 struct address_space *mapping = ip->i_inode.i_mapping;
481 unsigned long index = *pos >> PAGE_SHIFT;
482 size_t copied = 0;
483
484 do {
485 size_t offset, chunk;
486 struct folio *folio;
487
488 folio = read_cache_folio(mapping, index, gfs2_read_folio, NULL);
489 if (IS_ERR(folio)) {
490 if (PTR_ERR(folio) == -EINTR)
491 continue;
492 return PTR_ERR(folio);
493 }
494 offset = *pos + copied - folio_pos(folio);
495 chunk = min(size - copied, folio_size(folio) - offset);
496 memcpy_from_folio(buf + copied, folio, offset, chunk);
497 index = folio_next_index(folio);
498 folio_put(folio);
499 copied += chunk;
500 } while(copied < size);
501 (*pos) += size;
502 return size;
503}
504
505/**
506 * gfs2_readahead - Read a bunch of pages at once
507 * @rac: Read-ahead control structure
508 *
509 * Some notes:
510 * 1. This is only for readahead, so we can simply ignore any things
511 * which are slightly inconvenient (such as locking conflicts between
512 * the page lock and the glock) and return having done no I/O. Its
513 * obviously not something we'd want to do on too regular a basis.
514 * Any I/O we ignore at this time will be done via readpage later.
515 * 2. We don't handle stuffed files here we let readpage do the honours.
516 * 3. mpage_readahead() does most of the heavy lifting in the common case.
517 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
518 */
519
520static void gfs2_readahead(struct readahead_control *rac)
521{
522 struct inode *inode = rac->mapping->host;
523 struct gfs2_inode *ip = GFS2_I(inode);
524
525 if (gfs2_is_stuffed(ip))
526 ;
527 else if (gfs2_is_jdata(ip))
528 mpage_readahead(rac, gfs2_block_map);
529 else
530 iomap_readahead(rac, &gfs2_iomap_ops);
531}
532
533/**
534 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
535 * @inode: the rindex inode
536 */
537void adjust_fs_space(struct inode *inode)
538{
539 struct gfs2_sbd *sdp = GFS2_SB(inode);
540 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
541 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
542 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
543 struct buffer_head *m_bh;
544 u64 fs_total, new_free;
545
546 if (gfs2_trans_begin(sdp, 2 * RES_STATFS, 0) != 0)
547 return;
548
549 /* Total up the file system space, according to the latest rindex. */
550 fs_total = gfs2_ri_total(sdp);
551 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
552 goto out;
553
554 spin_lock(&sdp->sd_statfs_spin);
555 gfs2_statfs_change_in(m_sc, m_bh->b_data +
556 sizeof(struct gfs2_dinode));
557 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
558 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
559 else
560 new_free = 0;
561 spin_unlock(&sdp->sd_statfs_spin);
562 fs_warn(sdp, "File system extended by %llu blocks.\n",
563 (unsigned long long)new_free);
564 gfs2_statfs_change(sdp, new_free, new_free, 0);
565
566 update_statfs(sdp, m_bh);
567 brelse(m_bh);
568out:
569 sdp->sd_rindex_uptodate = 0;
570 gfs2_trans_end(sdp);
571}
572
573static bool jdata_dirty_folio(struct address_space *mapping,
574 struct folio *folio)
575{
576 if (current->journal_info)
577 folio_set_checked(folio);
578 return block_dirty_folio(mapping, folio);
579}
580
581/**
582 * gfs2_bmap - Block map function
583 * @mapping: Address space info
584 * @lblock: The block to map
585 *
586 * Returns: The disk address for the block or 0 on hole or error
587 */
588
589static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
590{
591 struct gfs2_inode *ip = GFS2_I(mapping->host);
592 struct gfs2_holder i_gh;
593 sector_t dblock = 0;
594 int error;
595
596 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
597 if (error)
598 return 0;
599
600 if (!gfs2_is_stuffed(ip))
601 dblock = iomap_bmap(mapping, lblock, &gfs2_iomap_ops);
602
603 gfs2_glock_dq_uninit(&i_gh);
604
605 return dblock;
606}
607
608static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
609{
610 struct gfs2_bufdata *bd;
611
612 lock_buffer(bh);
613 gfs2_log_lock(sdp);
614 clear_buffer_dirty(bh);
615 bd = bh->b_private;
616 if (bd) {
617 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
618 list_del_init(&bd->bd_list);
619 else {
620 spin_lock(&sdp->sd_ail_lock);
621 gfs2_remove_from_journal(bh, REMOVE_JDATA);
622 spin_unlock(&sdp->sd_ail_lock);
623 }
624 }
625 bh->b_bdev = NULL;
626 clear_buffer_mapped(bh);
627 clear_buffer_req(bh);
628 clear_buffer_new(bh);
629 gfs2_log_unlock(sdp);
630 unlock_buffer(bh);
631}
632
633static void gfs2_invalidate_folio(struct folio *folio, size_t offset,
634 size_t length)
635{
636 struct gfs2_sbd *sdp = GFS2_SB(folio->mapping->host);
637 size_t stop = offset + length;
638 int partial_page = (offset || length < folio_size(folio));
639 struct buffer_head *bh, *head;
640 unsigned long pos = 0;
641
642 BUG_ON(!folio_test_locked(folio));
643 if (!partial_page)
644 folio_clear_checked(folio);
645 head = folio_buffers(folio);
646 if (!head)
647 goto out;
648
649 bh = head;
650 do {
651 if (pos + bh->b_size > stop)
652 return;
653
654 if (offset <= pos)
655 gfs2_discard(sdp, bh);
656 pos += bh->b_size;
657 bh = bh->b_this_page;
658 } while (bh != head);
659out:
660 if (!partial_page)
661 filemap_release_folio(folio, 0);
662}
663
664/**
665 * gfs2_release_folio - free the metadata associated with a folio
666 * @folio: the folio that's being released
667 * @gfp_mask: passed from Linux VFS, ignored by us
668 *
669 * Calls try_to_free_buffers() to free the buffers and put the folio if the
670 * buffers can be released.
671 *
672 * Returns: true if the folio was put or else false
673 */
674
675bool gfs2_release_folio(struct folio *folio, gfp_t gfp_mask)
676{
677 struct address_space *mapping = folio->mapping;
678 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
679 struct buffer_head *bh, *head;
680 struct gfs2_bufdata *bd;
681
682 head = folio_buffers(folio);
683 if (!head)
684 return false;
685
686 /*
687 * mm accommodates an old ext3 case where clean folios might
688 * not have had the dirty bit cleared. Thus, it can send actual
689 * dirty folios to ->release_folio() via shrink_active_list().
690 *
691 * As a workaround, we skip folios that contain dirty buffers
692 * below. Once ->release_folio isn't called on dirty folios
693 * anymore, we can warn on dirty buffers like we used to here
694 * again.
695 */
696
697 gfs2_log_lock(sdp);
698 bh = head;
699 do {
700 if (atomic_read(&bh->b_count))
701 goto cannot_release;
702 bd = bh->b_private;
703 if (bd && bd->bd_tr)
704 goto cannot_release;
705 if (buffer_dirty(bh) || WARN_ON(buffer_pinned(bh)))
706 goto cannot_release;
707 bh = bh->b_this_page;
708 } while (bh != head);
709
710 bh = head;
711 do {
712 bd = bh->b_private;
713 if (bd) {
714 gfs2_assert_warn(sdp, bd->bd_bh == bh);
715 bd->bd_bh = NULL;
716 bh->b_private = NULL;
717 /*
718 * The bd may still be queued as a revoke, in which
719 * case we must not dequeue nor free it.
720 */
721 if (!bd->bd_blkno && !list_empty(&bd->bd_list))
722 list_del_init(&bd->bd_list);
723 if (list_empty(&bd->bd_list))
724 kmem_cache_free(gfs2_bufdata_cachep, bd);
725 }
726
727 bh = bh->b_this_page;
728 } while (bh != head);
729 gfs2_log_unlock(sdp);
730
731 return try_to_free_buffers(folio);
732
733cannot_release:
734 gfs2_log_unlock(sdp);
735 return false;
736}
737
738static const struct address_space_operations gfs2_aops = {
739 .writepages = gfs2_writepages,
740 .read_folio = gfs2_read_folio,
741 .readahead = gfs2_readahead,
742 .dirty_folio = iomap_dirty_folio,
743 .release_folio = iomap_release_folio,
744 .invalidate_folio = iomap_invalidate_folio,
745 .bmap = gfs2_bmap,
746 .migrate_folio = filemap_migrate_folio,
747 .is_partially_uptodate = iomap_is_partially_uptodate,
748 .error_remove_folio = generic_error_remove_folio,
749};
750
751static const struct address_space_operations gfs2_jdata_aops = {
752 .writepage = gfs2_jdata_writepage,
753 .writepages = gfs2_jdata_writepages,
754 .read_folio = gfs2_read_folio,
755 .readahead = gfs2_readahead,
756 .dirty_folio = jdata_dirty_folio,
757 .bmap = gfs2_bmap,
758 .invalidate_folio = gfs2_invalidate_folio,
759 .release_folio = gfs2_release_folio,
760 .is_partially_uptodate = block_is_partially_uptodate,
761 .error_remove_folio = generic_error_remove_folio,
762};
763
764void gfs2_set_aops(struct inode *inode)
765{
766 if (gfs2_is_jdata(GFS2_I(inode)))
767 inode->i_mapping->a_ops = &gfs2_jdata_aops;
768 else
769 inode->i_mapping->a_ops = &gfs2_aops;
770}
1/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
4 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
8 */
9
10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/spinlock.h>
13#include <linux/completion.h>
14#include <linux/buffer_head.h>
15#include <linux/pagemap.h>
16#include <linux/pagevec.h>
17#include <linux/mpage.h>
18#include <linux/fs.h>
19#include <linux/writeback.h>
20#include <linux/swap.h>
21#include <linux/gfs2_ondisk.h>
22#include <linux/backing-dev.h>
23#include <linux/uio.h>
24#include <trace/events/writeback.h>
25
26#include "gfs2.h"
27#include "incore.h"
28#include "bmap.h"
29#include "glock.h"
30#include "inode.h"
31#include "log.h"
32#include "meta_io.h"
33#include "quota.h"
34#include "trans.h"
35#include "rgrp.h"
36#include "super.h"
37#include "util.h"
38#include "glops.h"
39
40
41static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
42 unsigned int from, unsigned int len)
43{
44 struct buffer_head *head = page_buffers(page);
45 unsigned int bsize = head->b_size;
46 struct buffer_head *bh;
47 unsigned int to = from + len;
48 unsigned int start, end;
49
50 for (bh = head, start = 0; bh != head || !start;
51 bh = bh->b_this_page, start = end) {
52 end = start + bsize;
53 if (end <= from)
54 continue;
55 if (start >= to)
56 break;
57 if (gfs2_is_jdata(ip))
58 set_buffer_uptodate(bh);
59 gfs2_trans_add_data(ip->i_gl, bh);
60 }
61}
62
63/**
64 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
65 * @inode: The inode
66 * @lblock: The block number to look up
67 * @bh_result: The buffer head to return the result in
68 * @create: Non-zero if we may add block to the file
69 *
70 * Returns: errno
71 */
72
73static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
74 struct buffer_head *bh_result, int create)
75{
76 int error;
77
78 error = gfs2_block_map(inode, lblock, bh_result, 0);
79 if (error)
80 return error;
81 if (!buffer_mapped(bh_result))
82 return -EIO;
83 return 0;
84}
85
86static int gfs2_get_block_direct(struct inode *inode, sector_t lblock,
87 struct buffer_head *bh_result, int create)
88{
89 return gfs2_block_map(inode, lblock, bh_result, 0);
90}
91
92/**
93 * gfs2_writepage_common - Common bits of writepage
94 * @page: The page to be written
95 * @wbc: The writeback control
96 *
97 * Returns: 1 if writepage is ok, otherwise an error code or zero if no error.
98 */
99
100static int gfs2_writepage_common(struct page *page,
101 struct writeback_control *wbc)
102{
103 struct inode *inode = page->mapping->host;
104 struct gfs2_inode *ip = GFS2_I(inode);
105 struct gfs2_sbd *sdp = GFS2_SB(inode);
106 loff_t i_size = i_size_read(inode);
107 pgoff_t end_index = i_size >> PAGE_SHIFT;
108 unsigned offset;
109
110 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
111 goto out;
112 if (current->journal_info)
113 goto redirty;
114 /* Is the page fully outside i_size? (truncate in progress) */
115 offset = i_size & (PAGE_SIZE-1);
116 if (page->index > end_index || (page->index == end_index && !offset)) {
117 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
118 goto out;
119 }
120 return 1;
121redirty:
122 redirty_page_for_writepage(wbc, page);
123out:
124 unlock_page(page);
125 return 0;
126}
127
128/**
129 * gfs2_writepage - Write page for writeback mappings
130 * @page: The page
131 * @wbc: The writeback control
132 *
133 */
134
135static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
136{
137 int ret;
138
139 ret = gfs2_writepage_common(page, wbc);
140 if (ret <= 0)
141 return ret;
142
143 return nobh_writepage(page, gfs2_get_block_noalloc, wbc);
144}
145
146/* This is the same as calling block_write_full_page, but it also
147 * writes pages outside of i_size
148 */
149static int gfs2_write_full_page(struct page *page, get_block_t *get_block,
150 struct writeback_control *wbc)
151{
152 struct inode * const inode = page->mapping->host;
153 loff_t i_size = i_size_read(inode);
154 const pgoff_t end_index = i_size >> PAGE_SHIFT;
155 unsigned offset;
156
157 /*
158 * The page straddles i_size. It must be zeroed out on each and every
159 * writepage invocation because it may be mmapped. "A file is mapped
160 * in multiples of the page size. For a file that is not a multiple of
161 * the page size, the remaining memory is zeroed when mapped, and
162 * writes to that region are not written out to the file."
163 */
164 offset = i_size & (PAGE_SIZE-1);
165 if (page->index == end_index && offset)
166 zero_user_segment(page, offset, PAGE_SIZE);
167
168 return __block_write_full_page(inode, page, get_block, wbc,
169 end_buffer_async_write);
170}
171
172/**
173 * __gfs2_jdata_writepage - The core of jdata writepage
174 * @page: The page to write
175 * @wbc: The writeback control
176 *
177 * This is shared between writepage and writepages and implements the
178 * core of the writepage operation. If a transaction is required then
179 * PageChecked will have been set and the transaction will have
180 * already been started before this is called.
181 */
182
183static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
184{
185 struct inode *inode = page->mapping->host;
186 struct gfs2_inode *ip = GFS2_I(inode);
187 struct gfs2_sbd *sdp = GFS2_SB(inode);
188
189 if (PageChecked(page)) {
190 ClearPageChecked(page);
191 if (!page_has_buffers(page)) {
192 create_empty_buffers(page, inode->i_sb->s_blocksize,
193 BIT(BH_Dirty)|BIT(BH_Uptodate));
194 }
195 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize);
196 }
197 return gfs2_write_full_page(page, gfs2_get_block_noalloc, wbc);
198}
199
200/**
201 * gfs2_jdata_writepage - Write complete page
202 * @page: Page to write
203 * @wbc: The writeback control
204 *
205 * Returns: errno
206 *
207 */
208
209static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
210{
211 struct inode *inode = page->mapping->host;
212 struct gfs2_inode *ip = GFS2_I(inode);
213 struct gfs2_sbd *sdp = GFS2_SB(inode);
214 int ret;
215
216 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
217 goto out;
218 if (PageChecked(page) || current->journal_info)
219 goto out_ignore;
220 ret = __gfs2_jdata_writepage(page, wbc);
221 return ret;
222
223out_ignore:
224 redirty_page_for_writepage(wbc, page);
225out:
226 unlock_page(page);
227 return 0;
228}
229
230/**
231 * gfs2_writepages - Write a bunch of dirty pages back to disk
232 * @mapping: The mapping to write
233 * @wbc: Write-back control
234 *
235 * Used for both ordered and writeback modes.
236 */
237static int gfs2_writepages(struct address_space *mapping,
238 struct writeback_control *wbc)
239{
240 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
241 int ret = mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
242
243 /*
244 * Even if we didn't write any pages here, we might still be holding
245 * dirty pages in the ail. We forcibly flush the ail because we don't
246 * want balance_dirty_pages() to loop indefinitely trying to write out
247 * pages held in the ail that it can't find.
248 */
249 if (ret == 0)
250 set_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
251
252 return ret;
253}
254
255/**
256 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
257 * @mapping: The mapping
258 * @wbc: The writeback control
259 * @pvec: The vector of pages
260 * @nr_pages: The number of pages to write
261 * @done_index: Page index
262 *
263 * Returns: non-zero if loop should terminate, zero otherwise
264 */
265
266static int gfs2_write_jdata_pagevec(struct address_space *mapping,
267 struct writeback_control *wbc,
268 struct pagevec *pvec,
269 int nr_pages,
270 pgoff_t *done_index)
271{
272 struct inode *inode = mapping->host;
273 struct gfs2_sbd *sdp = GFS2_SB(inode);
274 unsigned nrblocks = nr_pages * (PAGE_SIZE/inode->i_sb->s_blocksize);
275 int i;
276 int ret;
277
278 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
279 if (ret < 0)
280 return ret;
281
282 for(i = 0; i < nr_pages; i++) {
283 struct page *page = pvec->pages[i];
284
285 *done_index = page->index;
286
287 lock_page(page);
288
289 if (unlikely(page->mapping != mapping)) {
290continue_unlock:
291 unlock_page(page);
292 continue;
293 }
294
295 if (!PageDirty(page)) {
296 /* someone wrote it for us */
297 goto continue_unlock;
298 }
299
300 if (PageWriteback(page)) {
301 if (wbc->sync_mode != WB_SYNC_NONE)
302 wait_on_page_writeback(page);
303 else
304 goto continue_unlock;
305 }
306
307 BUG_ON(PageWriteback(page));
308 if (!clear_page_dirty_for_io(page))
309 goto continue_unlock;
310
311 trace_wbc_writepage(wbc, inode_to_bdi(inode));
312
313 ret = __gfs2_jdata_writepage(page, wbc);
314 if (unlikely(ret)) {
315 if (ret == AOP_WRITEPAGE_ACTIVATE) {
316 unlock_page(page);
317 ret = 0;
318 } else {
319
320 /*
321 * done_index is set past this page,
322 * so media errors will not choke
323 * background writeout for the entire
324 * file. This has consequences for
325 * range_cyclic semantics (ie. it may
326 * not be suitable for data integrity
327 * writeout).
328 */
329 *done_index = page->index + 1;
330 ret = 1;
331 break;
332 }
333 }
334
335 /*
336 * We stop writing back only if we are not doing
337 * integrity sync. In case of integrity sync we have to
338 * keep going until we have written all the pages
339 * we tagged for writeback prior to entering this loop.
340 */
341 if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
342 ret = 1;
343 break;
344 }
345
346 }
347 gfs2_trans_end(sdp);
348 return ret;
349}
350
351/**
352 * gfs2_write_cache_jdata - Like write_cache_pages but different
353 * @mapping: The mapping to write
354 * @wbc: The writeback control
355 *
356 * The reason that we use our own function here is that we need to
357 * start transactions before we grab page locks. This allows us
358 * to get the ordering right.
359 */
360
361static int gfs2_write_cache_jdata(struct address_space *mapping,
362 struct writeback_control *wbc)
363{
364 int ret = 0;
365 int done = 0;
366 struct pagevec pvec;
367 int nr_pages;
368 pgoff_t uninitialized_var(writeback_index);
369 pgoff_t index;
370 pgoff_t end;
371 pgoff_t done_index;
372 int cycled;
373 int range_whole = 0;
374 int tag;
375
376 pagevec_init(&pvec);
377 if (wbc->range_cyclic) {
378 writeback_index = mapping->writeback_index; /* prev offset */
379 index = writeback_index;
380 if (index == 0)
381 cycled = 1;
382 else
383 cycled = 0;
384 end = -1;
385 } else {
386 index = wbc->range_start >> PAGE_SHIFT;
387 end = wbc->range_end >> PAGE_SHIFT;
388 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
389 range_whole = 1;
390 cycled = 1; /* ignore range_cyclic tests */
391 }
392 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
393 tag = PAGECACHE_TAG_TOWRITE;
394 else
395 tag = PAGECACHE_TAG_DIRTY;
396
397retry:
398 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
399 tag_pages_for_writeback(mapping, index, end);
400 done_index = index;
401 while (!done && (index <= end)) {
402 nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
403 tag);
404 if (nr_pages == 0)
405 break;
406
407 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, &done_index);
408 if (ret)
409 done = 1;
410 if (ret > 0)
411 ret = 0;
412 pagevec_release(&pvec);
413 cond_resched();
414 }
415
416 if (!cycled && !done) {
417 /*
418 * range_cyclic:
419 * We hit the last page and there is more work to be done: wrap
420 * back to the start of the file
421 */
422 cycled = 1;
423 index = 0;
424 end = writeback_index - 1;
425 goto retry;
426 }
427
428 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
429 mapping->writeback_index = done_index;
430
431 return ret;
432}
433
434
435/**
436 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
437 * @mapping: The mapping to write
438 * @wbc: The writeback control
439 *
440 */
441
442static int gfs2_jdata_writepages(struct address_space *mapping,
443 struct writeback_control *wbc)
444{
445 struct gfs2_inode *ip = GFS2_I(mapping->host);
446 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
447 int ret;
448
449 ret = gfs2_write_cache_jdata(mapping, wbc);
450 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
451 gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
452 GFS2_LFC_JDATA_WPAGES);
453 ret = gfs2_write_cache_jdata(mapping, wbc);
454 }
455 return ret;
456}
457
458/**
459 * stuffed_readpage - Fill in a Linux page with stuffed file data
460 * @ip: the inode
461 * @page: the page
462 *
463 * Returns: errno
464 */
465
466static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
467{
468 struct buffer_head *dibh;
469 u64 dsize = i_size_read(&ip->i_inode);
470 void *kaddr;
471 int error;
472
473 /*
474 * Due to the order of unstuffing files and ->fault(), we can be
475 * asked for a zero page in the case of a stuffed file being extended,
476 * so we need to supply one here. It doesn't happen often.
477 */
478 if (unlikely(page->index)) {
479 zero_user(page, 0, PAGE_SIZE);
480 SetPageUptodate(page);
481 return 0;
482 }
483
484 error = gfs2_meta_inode_buffer(ip, &dibh);
485 if (error)
486 return error;
487
488 kaddr = kmap_atomic(page);
489 if (dsize > gfs2_max_stuffed_size(ip))
490 dsize = gfs2_max_stuffed_size(ip);
491 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
492 memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
493 kunmap_atomic(kaddr);
494 flush_dcache_page(page);
495 brelse(dibh);
496 SetPageUptodate(page);
497
498 return 0;
499}
500
501
502/**
503 * __gfs2_readpage - readpage
504 * @file: The file to read a page for
505 * @page: The page to read
506 *
507 * This is the core of gfs2's readpage. It's used by the internal file
508 * reading code as in that case we already hold the glock. Also it's
509 * called by gfs2_readpage() once the required lock has been granted.
510 */
511
512static int __gfs2_readpage(void *file, struct page *page)
513{
514 struct gfs2_inode *ip = GFS2_I(page->mapping->host);
515 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
516 int error;
517
518 if (gfs2_is_stuffed(ip)) {
519 error = stuffed_readpage(ip, page);
520 unlock_page(page);
521 } else {
522 error = mpage_readpage(page, gfs2_block_map);
523 }
524
525 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
526 return -EIO;
527
528 return error;
529}
530
531/**
532 * gfs2_readpage - read a page of a file
533 * @file: The file to read
534 * @page: The page of the file
535 *
536 * This deals with the locking required. We have to unlock and
537 * relock the page in order to get the locking in the right
538 * order.
539 */
540
541static int gfs2_readpage(struct file *file, struct page *page)
542{
543 struct address_space *mapping = page->mapping;
544 struct gfs2_inode *ip = GFS2_I(mapping->host);
545 struct gfs2_holder gh;
546 int error;
547
548 unlock_page(page);
549 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
550 error = gfs2_glock_nq(&gh);
551 if (unlikely(error))
552 goto out;
553 error = AOP_TRUNCATED_PAGE;
554 lock_page(page);
555 if (page->mapping == mapping && !PageUptodate(page))
556 error = __gfs2_readpage(file, page);
557 else
558 unlock_page(page);
559 gfs2_glock_dq(&gh);
560out:
561 gfs2_holder_uninit(&gh);
562 if (error && error != AOP_TRUNCATED_PAGE)
563 lock_page(page);
564 return error;
565}
566
567/**
568 * gfs2_internal_read - read an internal file
569 * @ip: The gfs2 inode
570 * @buf: The buffer to fill
571 * @pos: The file position
572 * @size: The amount to read
573 *
574 */
575
576int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
577 unsigned size)
578{
579 struct address_space *mapping = ip->i_inode.i_mapping;
580 unsigned long index = *pos / PAGE_SIZE;
581 unsigned offset = *pos & (PAGE_SIZE - 1);
582 unsigned copied = 0;
583 unsigned amt;
584 struct page *page;
585 void *p;
586
587 do {
588 amt = size - copied;
589 if (offset + size > PAGE_SIZE)
590 amt = PAGE_SIZE - offset;
591 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
592 if (IS_ERR(page))
593 return PTR_ERR(page);
594 p = kmap_atomic(page);
595 memcpy(buf + copied, p + offset, amt);
596 kunmap_atomic(p);
597 put_page(page);
598 copied += amt;
599 index++;
600 offset = 0;
601 } while(copied < size);
602 (*pos) += size;
603 return size;
604}
605
606/**
607 * gfs2_readpages - Read a bunch of pages at once
608 * @file: The file to read from
609 * @mapping: Address space info
610 * @pages: List of pages to read
611 * @nr_pages: Number of pages to read
612 *
613 * Some notes:
614 * 1. This is only for readahead, so we can simply ignore any things
615 * which are slightly inconvenient (such as locking conflicts between
616 * the page lock and the glock) and return having done no I/O. Its
617 * obviously not something we'd want to do on too regular a basis.
618 * Any I/O we ignore at this time will be done via readpage later.
619 * 2. We don't handle stuffed files here we let readpage do the honours.
620 * 3. mpage_readpages() does most of the heavy lifting in the common case.
621 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
622 */
623
624static int gfs2_readpages(struct file *file, struct address_space *mapping,
625 struct list_head *pages, unsigned nr_pages)
626{
627 struct inode *inode = mapping->host;
628 struct gfs2_inode *ip = GFS2_I(inode);
629 struct gfs2_sbd *sdp = GFS2_SB(inode);
630 struct gfs2_holder gh;
631 int ret;
632
633 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
634 ret = gfs2_glock_nq(&gh);
635 if (unlikely(ret))
636 goto out_uninit;
637 if (!gfs2_is_stuffed(ip))
638 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
639 gfs2_glock_dq(&gh);
640out_uninit:
641 gfs2_holder_uninit(&gh);
642 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
643 ret = -EIO;
644 return ret;
645}
646
647/**
648 * gfs2_write_begin - Begin to write to a file
649 * @file: The file to write to
650 * @mapping: The mapping in which to write
651 * @pos: The file offset at which to start writing
652 * @len: Length of the write
653 * @flags: Various flags
654 * @pagep: Pointer to return the page
655 * @fsdata: Pointer to return fs data (unused by GFS2)
656 *
657 * Returns: errno
658 */
659
660static int gfs2_write_begin(struct file *file, struct address_space *mapping,
661 loff_t pos, unsigned len, unsigned flags,
662 struct page **pagep, void **fsdata)
663{
664 struct gfs2_inode *ip = GFS2_I(mapping->host);
665 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
666 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
667 unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
668 unsigned requested = 0;
669 int alloc_required;
670 int error = 0;
671 pgoff_t index = pos >> PAGE_SHIFT;
672 unsigned from = pos & (PAGE_SIZE - 1);
673 struct page *page;
674
675 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
676 error = gfs2_glock_nq(&ip->i_gh);
677 if (unlikely(error))
678 goto out_uninit;
679 if (&ip->i_inode == sdp->sd_rindex) {
680 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
681 GL_NOCACHE, &m_ip->i_gh);
682 if (unlikely(error)) {
683 gfs2_glock_dq(&ip->i_gh);
684 goto out_uninit;
685 }
686 }
687
688 alloc_required = gfs2_write_alloc_required(ip, pos, len);
689
690 if (alloc_required || gfs2_is_jdata(ip))
691 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
692
693 if (alloc_required) {
694 struct gfs2_alloc_parms ap = { .aflags = 0, };
695 requested = data_blocks + ind_blocks;
696 ap.target = requested;
697 error = gfs2_quota_lock_check(ip, &ap);
698 if (error)
699 goto out_unlock;
700
701 error = gfs2_inplace_reserve(ip, &ap);
702 if (error)
703 goto out_qunlock;
704 }
705
706 rblocks = RES_DINODE + ind_blocks;
707 if (gfs2_is_jdata(ip))
708 rblocks += data_blocks ? data_blocks : 1;
709 if (ind_blocks || data_blocks)
710 rblocks += RES_STATFS + RES_QUOTA;
711 if (&ip->i_inode == sdp->sd_rindex)
712 rblocks += 2 * RES_STATFS;
713 if (alloc_required)
714 rblocks += gfs2_rg_blocks(ip, requested);
715
716 error = gfs2_trans_begin(sdp, rblocks,
717 PAGE_SIZE/sdp->sd_sb.sb_bsize);
718 if (error)
719 goto out_trans_fail;
720
721 error = -ENOMEM;
722 flags |= AOP_FLAG_NOFS;
723 page = grab_cache_page_write_begin(mapping, index, flags);
724 *pagep = page;
725 if (unlikely(!page))
726 goto out_endtrans;
727
728 if (gfs2_is_stuffed(ip)) {
729 error = 0;
730 if (pos + len > gfs2_max_stuffed_size(ip)) {
731 error = gfs2_unstuff_dinode(ip, page);
732 if (error == 0)
733 goto prepare_write;
734 } else if (!PageUptodate(page)) {
735 error = stuffed_readpage(ip, page);
736 }
737 goto out;
738 }
739
740prepare_write:
741 error = __block_write_begin(page, from, len, gfs2_block_map);
742out:
743 if (error == 0)
744 return 0;
745
746 unlock_page(page);
747 put_page(page);
748
749 gfs2_trans_end(sdp);
750 if (pos + len > ip->i_inode.i_size)
751 gfs2_trim_blocks(&ip->i_inode);
752 goto out_trans_fail;
753
754out_endtrans:
755 gfs2_trans_end(sdp);
756out_trans_fail:
757 if (alloc_required) {
758 gfs2_inplace_release(ip);
759out_qunlock:
760 gfs2_quota_unlock(ip);
761 }
762out_unlock:
763 if (&ip->i_inode == sdp->sd_rindex) {
764 gfs2_glock_dq(&m_ip->i_gh);
765 gfs2_holder_uninit(&m_ip->i_gh);
766 }
767 gfs2_glock_dq(&ip->i_gh);
768out_uninit:
769 gfs2_holder_uninit(&ip->i_gh);
770 return error;
771}
772
773/**
774 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
775 * @inode: the rindex inode
776 */
777static void adjust_fs_space(struct inode *inode)
778{
779 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
780 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
781 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
782 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
783 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
784 struct buffer_head *m_bh, *l_bh;
785 u64 fs_total, new_free;
786
787 /* Total up the file system space, according to the latest rindex. */
788 fs_total = gfs2_ri_total(sdp);
789 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
790 return;
791
792 spin_lock(&sdp->sd_statfs_spin);
793 gfs2_statfs_change_in(m_sc, m_bh->b_data +
794 sizeof(struct gfs2_dinode));
795 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
796 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
797 else
798 new_free = 0;
799 spin_unlock(&sdp->sd_statfs_spin);
800 fs_warn(sdp, "File system extended by %llu blocks.\n",
801 (unsigned long long)new_free);
802 gfs2_statfs_change(sdp, new_free, new_free, 0);
803
804 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0)
805 goto out;
806 update_statfs(sdp, m_bh, l_bh);
807 brelse(l_bh);
808out:
809 brelse(m_bh);
810}
811
812/**
813 * gfs2_stuffed_write_end - Write end for stuffed files
814 * @inode: The inode
815 * @dibh: The buffer_head containing the on-disk inode
816 * @pos: The file position
817 * @len: The length of the write
818 * @copied: How much was actually copied by the VFS
819 * @page: The page
820 *
821 * This copies the data from the page into the inode block after
822 * the inode data structure itself.
823 *
824 * Returns: errno
825 */
826static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
827 loff_t pos, unsigned len, unsigned copied,
828 struct page *page)
829{
830 struct gfs2_inode *ip = GFS2_I(inode);
831 struct gfs2_sbd *sdp = GFS2_SB(inode);
832 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
833 u64 to = pos + copied;
834 void *kaddr;
835 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
836
837 BUG_ON(pos + len > gfs2_max_stuffed_size(ip));
838
839 kaddr = kmap_atomic(page);
840 memcpy(buf + pos, kaddr + pos, copied);
841 flush_dcache_page(page);
842 kunmap_atomic(kaddr);
843
844 WARN_ON(!PageUptodate(page));
845 unlock_page(page);
846 put_page(page);
847
848 if (copied) {
849 if (inode->i_size < to)
850 i_size_write(inode, to);
851 mark_inode_dirty(inode);
852 }
853
854 if (inode == sdp->sd_rindex) {
855 adjust_fs_space(inode);
856 sdp->sd_rindex_uptodate = 0;
857 }
858
859 brelse(dibh);
860 gfs2_trans_end(sdp);
861 if (inode == sdp->sd_rindex) {
862 gfs2_glock_dq(&m_ip->i_gh);
863 gfs2_holder_uninit(&m_ip->i_gh);
864 }
865 gfs2_glock_dq(&ip->i_gh);
866 gfs2_holder_uninit(&ip->i_gh);
867 return copied;
868}
869
870/**
871 * gfs2_write_end
872 * @file: The file to write to
873 * @mapping: The address space to write to
874 * @pos: The file position
875 * @len: The length of the data
876 * @copied: How much was actually copied by the VFS
877 * @page: The page that has been written
878 * @fsdata: The fsdata (unused in GFS2)
879 *
880 * The main write_end function for GFS2. We have a separate one for
881 * stuffed files as they are slightly different, otherwise we just
882 * put our locking around the VFS provided functions.
883 *
884 * Returns: errno
885 */
886
887static int gfs2_write_end(struct file *file, struct address_space *mapping,
888 loff_t pos, unsigned len, unsigned copied,
889 struct page *page, void *fsdata)
890{
891 struct inode *inode = page->mapping->host;
892 struct gfs2_inode *ip = GFS2_I(inode);
893 struct gfs2_sbd *sdp = GFS2_SB(inode);
894 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
895 struct buffer_head *dibh;
896 int ret;
897 struct gfs2_trans *tr = current->journal_info;
898 BUG_ON(!tr);
899
900 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);
901
902 ret = gfs2_meta_inode_buffer(ip, &dibh);
903 if (unlikely(ret)) {
904 unlock_page(page);
905 put_page(page);
906 goto failed;
907 }
908
909 if (gfs2_is_stuffed(ip))
910 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
911
912 if (!gfs2_is_writeback(ip))
913 gfs2_page_add_databufs(ip, page, pos & ~PAGE_MASK, len);
914
915 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
916 if (tr->tr_num_buf_new)
917 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
918 else
919 gfs2_trans_add_meta(ip->i_gl, dibh);
920
921
922 if (inode == sdp->sd_rindex) {
923 adjust_fs_space(inode);
924 sdp->sd_rindex_uptodate = 0;
925 }
926
927 brelse(dibh);
928failed:
929 gfs2_trans_end(sdp);
930 gfs2_inplace_release(ip);
931 if (ip->i_qadata && ip->i_qadata->qa_qd_num)
932 gfs2_quota_unlock(ip);
933 if (inode == sdp->sd_rindex) {
934 gfs2_glock_dq(&m_ip->i_gh);
935 gfs2_holder_uninit(&m_ip->i_gh);
936 }
937 gfs2_glock_dq(&ip->i_gh);
938 gfs2_holder_uninit(&ip->i_gh);
939 return ret;
940}
941
942/**
943 * jdata_set_page_dirty - Page dirtying function
944 * @page: The page to dirty
945 *
946 * Returns: 1 if it dirtyed the page, or 0 otherwise
947 */
948
949static int jdata_set_page_dirty(struct page *page)
950{
951 SetPageChecked(page);
952 return __set_page_dirty_buffers(page);
953}
954
955/**
956 * gfs2_bmap - Block map function
957 * @mapping: Address space info
958 * @lblock: The block to map
959 *
960 * Returns: The disk address for the block or 0 on hole or error
961 */
962
963static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
964{
965 struct gfs2_inode *ip = GFS2_I(mapping->host);
966 struct gfs2_holder i_gh;
967 sector_t dblock = 0;
968 int error;
969
970 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
971 if (error)
972 return 0;
973
974 if (!gfs2_is_stuffed(ip))
975 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
976
977 gfs2_glock_dq_uninit(&i_gh);
978
979 return dblock;
980}
981
982static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
983{
984 struct gfs2_bufdata *bd;
985
986 lock_buffer(bh);
987 gfs2_log_lock(sdp);
988 clear_buffer_dirty(bh);
989 bd = bh->b_private;
990 if (bd) {
991 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
992 list_del_init(&bd->bd_list);
993 else
994 gfs2_remove_from_journal(bh, REMOVE_JDATA);
995 }
996 bh->b_bdev = NULL;
997 clear_buffer_mapped(bh);
998 clear_buffer_req(bh);
999 clear_buffer_new(bh);
1000 gfs2_log_unlock(sdp);
1001 unlock_buffer(bh);
1002}
1003
1004static void gfs2_invalidatepage(struct page *page, unsigned int offset,
1005 unsigned int length)
1006{
1007 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
1008 unsigned int stop = offset + length;
1009 int partial_page = (offset || length < PAGE_SIZE);
1010 struct buffer_head *bh, *head;
1011 unsigned long pos = 0;
1012
1013 BUG_ON(!PageLocked(page));
1014 if (!partial_page)
1015 ClearPageChecked(page);
1016 if (!page_has_buffers(page))
1017 goto out;
1018
1019 bh = head = page_buffers(page);
1020 do {
1021 if (pos + bh->b_size > stop)
1022 return;
1023
1024 if (offset <= pos)
1025 gfs2_discard(sdp, bh);
1026 pos += bh->b_size;
1027 bh = bh->b_this_page;
1028 } while (bh != head);
1029out:
1030 if (!partial_page)
1031 try_to_release_page(page, 0);
1032}
1033
1034/**
1035 * gfs2_ok_for_dio - check that dio is valid on this file
1036 * @ip: The inode
1037 * @offset: The offset at which we are reading or writing
1038 *
1039 * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o)
1040 * 1 (to accept the i/o request)
1041 */
1042static int gfs2_ok_for_dio(struct gfs2_inode *ip, loff_t offset)
1043{
1044 /*
1045 * Should we return an error here? I can't see that O_DIRECT for
1046 * a stuffed file makes any sense. For now we'll silently fall
1047 * back to buffered I/O
1048 */
1049 if (gfs2_is_stuffed(ip))
1050 return 0;
1051
1052 if (offset >= i_size_read(&ip->i_inode))
1053 return 0;
1054 return 1;
1055}
1056
1057
1058
1059static ssize_t gfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
1060{
1061 struct file *file = iocb->ki_filp;
1062 struct inode *inode = file->f_mapping->host;
1063 struct address_space *mapping = inode->i_mapping;
1064 struct gfs2_inode *ip = GFS2_I(inode);
1065 loff_t offset = iocb->ki_pos;
1066 struct gfs2_holder gh;
1067 int rv;
1068
1069 /*
1070 * Deferred lock, even if its a write, since we do no allocation
1071 * on this path. All we need change is atime, and this lock mode
1072 * ensures that other nodes have flushed their buffered read caches
1073 * (i.e. their page cache entries for this inode). We do not,
1074 * unfortunately have the option of only flushing a range like
1075 * the VFS does.
1076 */
1077 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
1078 rv = gfs2_glock_nq(&gh);
1079 if (rv)
1080 goto out_uninit;
1081 rv = gfs2_ok_for_dio(ip, offset);
1082 if (rv != 1)
1083 goto out; /* dio not valid, fall back to buffered i/o */
1084
1085 /*
1086 * Now since we are holding a deferred (CW) lock at this point, you
1087 * might be wondering why this is ever needed. There is a case however
1088 * where we've granted a deferred local lock against a cached exclusive
1089 * glock. That is ok provided all granted local locks are deferred, but
1090 * it also means that it is possible to encounter pages which are
1091 * cached and possibly also mapped. So here we check for that and sort
1092 * them out ahead of the dio. The glock state machine will take care of
1093 * everything else.
1094 *
1095 * If in fact the cached glock state (gl->gl_state) is deferred (CW) in
1096 * the first place, mapping->nr_pages will always be zero.
1097 */
1098 if (mapping->nrpages) {
1099 loff_t lstart = offset & ~(PAGE_SIZE - 1);
1100 loff_t len = iov_iter_count(iter);
1101 loff_t end = PAGE_ALIGN(offset + len) - 1;
1102
1103 rv = 0;
1104 if (len == 0)
1105 goto out;
1106 if (test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags))
1107 unmap_shared_mapping_range(ip->i_inode.i_mapping, offset, len);
1108 rv = filemap_write_and_wait_range(mapping, lstart, end);
1109 if (rv)
1110 goto out;
1111 if (iov_iter_rw(iter) == WRITE)
1112 truncate_inode_pages_range(mapping, lstart, end);
1113 }
1114
1115 rv = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
1116 gfs2_get_block_direct, NULL, NULL, 0);
1117out:
1118 gfs2_glock_dq(&gh);
1119out_uninit:
1120 gfs2_holder_uninit(&gh);
1121 return rv;
1122}
1123
1124/**
1125 * gfs2_releasepage - free the metadata associated with a page
1126 * @page: the page that's being released
1127 * @gfp_mask: passed from Linux VFS, ignored by us
1128 *
1129 * Call try_to_free_buffers() if the buffers in this page can be
1130 * released.
1131 *
1132 * Returns: 0
1133 */
1134
1135int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
1136{
1137 struct address_space *mapping = page->mapping;
1138 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
1139 struct buffer_head *bh, *head;
1140 struct gfs2_bufdata *bd;
1141
1142 if (!page_has_buffers(page))
1143 return 0;
1144
1145 /*
1146 * From xfs_vm_releasepage: mm accommodates an old ext3 case where
1147 * clean pages might not have had the dirty bit cleared. Thus, it can
1148 * send actual dirty pages to ->releasepage() via shrink_active_list().
1149 *
1150 * As a workaround, we skip pages that contain dirty buffers below.
1151 * Once ->releasepage isn't called on dirty pages anymore, we can warn
1152 * on dirty buffers like we used to here again.
1153 */
1154
1155 gfs2_log_lock(sdp);
1156 spin_lock(&sdp->sd_ail_lock);
1157 head = bh = page_buffers(page);
1158 do {
1159 if (atomic_read(&bh->b_count))
1160 goto cannot_release;
1161 bd = bh->b_private;
1162 if (bd && bd->bd_tr)
1163 goto cannot_release;
1164 if (buffer_dirty(bh) || WARN_ON(buffer_pinned(bh)))
1165 goto cannot_release;
1166 bh = bh->b_this_page;
1167 } while(bh != head);
1168 spin_unlock(&sdp->sd_ail_lock);
1169
1170 head = bh = page_buffers(page);
1171 do {
1172 bd = bh->b_private;
1173 if (bd) {
1174 gfs2_assert_warn(sdp, bd->bd_bh == bh);
1175 if (!list_empty(&bd->bd_list))
1176 list_del_init(&bd->bd_list);
1177 bd->bd_bh = NULL;
1178 bh->b_private = NULL;
1179 kmem_cache_free(gfs2_bufdata_cachep, bd);
1180 }
1181
1182 bh = bh->b_this_page;
1183 } while (bh != head);
1184 gfs2_log_unlock(sdp);
1185
1186 return try_to_free_buffers(page);
1187
1188cannot_release:
1189 spin_unlock(&sdp->sd_ail_lock);
1190 gfs2_log_unlock(sdp);
1191 return 0;
1192}
1193
1194static const struct address_space_operations gfs2_writeback_aops = {
1195 .writepage = gfs2_writepage,
1196 .writepages = gfs2_writepages,
1197 .readpage = gfs2_readpage,
1198 .readpages = gfs2_readpages,
1199 .write_begin = gfs2_write_begin,
1200 .write_end = gfs2_write_end,
1201 .bmap = gfs2_bmap,
1202 .invalidatepage = gfs2_invalidatepage,
1203 .releasepage = gfs2_releasepage,
1204 .direct_IO = gfs2_direct_IO,
1205 .migratepage = buffer_migrate_page,
1206 .is_partially_uptodate = block_is_partially_uptodate,
1207 .error_remove_page = generic_error_remove_page,
1208};
1209
1210static const struct address_space_operations gfs2_ordered_aops = {
1211 .writepage = gfs2_writepage,
1212 .writepages = gfs2_writepages,
1213 .readpage = gfs2_readpage,
1214 .readpages = gfs2_readpages,
1215 .write_begin = gfs2_write_begin,
1216 .write_end = gfs2_write_end,
1217 .set_page_dirty = __set_page_dirty_buffers,
1218 .bmap = gfs2_bmap,
1219 .invalidatepage = gfs2_invalidatepage,
1220 .releasepage = gfs2_releasepage,
1221 .direct_IO = gfs2_direct_IO,
1222 .migratepage = buffer_migrate_page,
1223 .is_partially_uptodate = block_is_partially_uptodate,
1224 .error_remove_page = generic_error_remove_page,
1225};
1226
1227static const struct address_space_operations gfs2_jdata_aops = {
1228 .writepage = gfs2_jdata_writepage,
1229 .writepages = gfs2_jdata_writepages,
1230 .readpage = gfs2_readpage,
1231 .readpages = gfs2_readpages,
1232 .write_begin = gfs2_write_begin,
1233 .write_end = gfs2_write_end,
1234 .set_page_dirty = jdata_set_page_dirty,
1235 .bmap = gfs2_bmap,
1236 .invalidatepage = gfs2_invalidatepage,
1237 .releasepage = gfs2_releasepage,
1238 .is_partially_uptodate = block_is_partially_uptodate,
1239 .error_remove_page = generic_error_remove_page,
1240};
1241
1242void gfs2_set_aops(struct inode *inode)
1243{
1244 struct gfs2_inode *ip = GFS2_I(inode);
1245
1246 if (gfs2_is_writeback(ip))
1247 inode->i_mapping->a_ops = &gfs2_writeback_aops;
1248 else if (gfs2_is_ordered(ip))
1249 inode->i_mapping->a_ops = &gfs2_ordered_aops;
1250 else if (gfs2_is_jdata(ip))
1251 inode->i_mapping->a_ops = &gfs2_jdata_aops;
1252 else
1253 BUG();
1254}
1255