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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Meta data file for NILFS
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Ryusuke Konishi.
8 */
9
10#include <linux/buffer_head.h>
11#include <linux/mpage.h>
12#include <linux/mm.h>
13#include <linux/writeback.h>
14#include <linux/backing-dev.h>
15#include <linux/swap.h>
16#include <linux/slab.h>
17#include "nilfs.h"
18#include "btnode.h"
19#include "segment.h"
20#include "page.h"
21#include "mdt.h"
22#include "alloc.h" /* nilfs_palloc_destroy_cache() */
23
24#include <trace/events/nilfs2.h>
25
26#define NILFS_MDT_MAX_RA_BLOCKS (16 - 1)
27
28
29static int
30nilfs_mdt_insert_new_block(struct inode *inode, unsigned long block,
31 struct buffer_head *bh,
32 void (*init_block)(struct inode *,
33 struct buffer_head *, void *))
34{
35 struct nilfs_inode_info *ii = NILFS_I(inode);
36 void *kaddr;
37 int ret;
38
39 /* Caller exclude read accesses using page lock */
40
41 /* set_buffer_new(bh); */
42 bh->b_blocknr = 0;
43
44 ret = nilfs_bmap_insert(ii->i_bmap, block, (unsigned long)bh);
45 if (unlikely(ret))
46 return ret;
47
48 set_buffer_mapped(bh);
49
50 kaddr = kmap_atomic(bh->b_page);
51 memset(kaddr + bh_offset(bh), 0, i_blocksize(inode));
52 if (init_block)
53 init_block(inode, bh, kaddr);
54 flush_dcache_page(bh->b_page);
55 kunmap_atomic(kaddr);
56
57 set_buffer_uptodate(bh);
58 mark_buffer_dirty(bh);
59 nilfs_mdt_mark_dirty(inode);
60
61 trace_nilfs2_mdt_insert_new_block(inode, inode->i_ino, block);
62
63 return 0;
64}
65
66static int nilfs_mdt_create_block(struct inode *inode, unsigned long block,
67 struct buffer_head **out_bh,
68 void (*init_block)(struct inode *,
69 struct buffer_head *,
70 void *))
71{
72 struct super_block *sb = inode->i_sb;
73 struct nilfs_transaction_info ti;
74 struct buffer_head *bh;
75 int err;
76
77 nilfs_transaction_begin(sb, &ti, 0);
78
79 err = -ENOMEM;
80 bh = nilfs_grab_buffer(inode, inode->i_mapping, block, 0);
81 if (unlikely(!bh))
82 goto failed_unlock;
83
84 err = -EEXIST;
85 if (buffer_uptodate(bh))
86 goto failed_bh;
87
88 wait_on_buffer(bh);
89 if (buffer_uptodate(bh))
90 goto failed_bh;
91
92 bh->b_bdev = sb->s_bdev;
93 err = nilfs_mdt_insert_new_block(inode, block, bh, init_block);
94 if (likely(!err)) {
95 get_bh(bh);
96 *out_bh = bh;
97 }
98
99 failed_bh:
100 unlock_page(bh->b_page);
101 put_page(bh->b_page);
102 brelse(bh);
103
104 failed_unlock:
105 if (likely(!err))
106 err = nilfs_transaction_commit(sb);
107 else
108 nilfs_transaction_abort(sb);
109
110 return err;
111}
112
113static int
114nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff, blk_opf_t opf,
115 struct buffer_head **out_bh)
116{
117 struct buffer_head *bh;
118 __u64 blknum = 0;
119 int ret = -ENOMEM;
120
121 bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0);
122 if (unlikely(!bh))
123 goto failed;
124
125 ret = -EEXIST; /* internal code */
126 if (buffer_uptodate(bh))
127 goto out;
128
129 if (opf & REQ_RAHEAD) {
130 if (!trylock_buffer(bh)) {
131 ret = -EBUSY;
132 goto failed_bh;
133 }
134 } else /* opf == REQ_OP_READ */
135 lock_buffer(bh);
136
137 if (buffer_uptodate(bh)) {
138 unlock_buffer(bh);
139 goto out;
140 }
141
142 ret = nilfs_bmap_lookup(NILFS_I(inode)->i_bmap, blkoff, &blknum);
143 if (unlikely(ret)) {
144 unlock_buffer(bh);
145 goto failed_bh;
146 }
147 map_bh(bh, inode->i_sb, (sector_t)blknum);
148
149 bh->b_end_io = end_buffer_read_sync;
150 get_bh(bh);
151 submit_bh(opf, bh);
152 ret = 0;
153
154 trace_nilfs2_mdt_submit_block(inode, inode->i_ino, blkoff,
155 opf & REQ_OP_MASK);
156 out:
157 get_bh(bh);
158 *out_bh = bh;
159
160 failed_bh:
161 unlock_page(bh->b_page);
162 put_page(bh->b_page);
163 brelse(bh);
164 failed:
165 return ret;
166}
167
168static int nilfs_mdt_read_block(struct inode *inode, unsigned long block,
169 int readahead, struct buffer_head **out_bh)
170{
171 struct buffer_head *first_bh, *bh;
172 unsigned long blkoff;
173 int i, nr_ra_blocks = NILFS_MDT_MAX_RA_BLOCKS;
174 int err;
175
176 err = nilfs_mdt_submit_block(inode, block, REQ_OP_READ, &first_bh);
177 if (err == -EEXIST) /* internal code */
178 goto out;
179
180 if (unlikely(err))
181 goto failed;
182
183 if (readahead) {
184 blkoff = block + 1;
185 for (i = 0; i < nr_ra_blocks; i++, blkoff++) {
186 err = nilfs_mdt_submit_block(inode, blkoff,
187 REQ_OP_READ | REQ_RAHEAD, &bh);
188 if (likely(!err || err == -EEXIST))
189 brelse(bh);
190 else if (err != -EBUSY)
191 break;
192 /* abort readahead if bmap lookup failed */
193 if (!buffer_locked(first_bh))
194 goto out_no_wait;
195 }
196 }
197
198 wait_on_buffer(first_bh);
199
200 out_no_wait:
201 err = -EIO;
202 if (!buffer_uptodate(first_bh)) {
203 nilfs_err(inode->i_sb,
204 "I/O error reading meta-data file (ino=%lu, block-offset=%lu)",
205 inode->i_ino, block);
206 goto failed_bh;
207 }
208 out:
209 *out_bh = first_bh;
210 return 0;
211
212 failed_bh:
213 brelse(first_bh);
214 failed:
215 return err;
216}
217
218/**
219 * nilfs_mdt_get_block - read or create a buffer on meta data file.
220 * @inode: inode of the meta data file
221 * @blkoff: block offset
222 * @create: create flag
223 * @init_block: initializer used for newly allocated block
224 * @out_bh: output of a pointer to the buffer_head
225 *
226 * nilfs_mdt_get_block() looks up the specified buffer and tries to create
227 * a new buffer if @create is not zero. On success, the returned buffer is
228 * assured to be either existing or formatted using a buffer lock on success.
229 * @out_bh is substituted only when zero is returned.
230 *
231 * Return Value: On success, it returns 0. On error, the following negative
232 * error code is returned.
233 *
234 * %-ENOMEM - Insufficient memory available.
235 *
236 * %-EIO - I/O error
237 *
238 * %-ENOENT - the specified block does not exist (hole block)
239 *
240 * %-EROFS - Read only filesystem (for create mode)
241 */
242int nilfs_mdt_get_block(struct inode *inode, unsigned long blkoff, int create,
243 void (*init_block)(struct inode *,
244 struct buffer_head *, void *),
245 struct buffer_head **out_bh)
246{
247 int ret;
248
249 /* Should be rewritten with merging nilfs_mdt_read_block() */
250 retry:
251 ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh);
252 if (!create || ret != -ENOENT)
253 return ret;
254
255 ret = nilfs_mdt_create_block(inode, blkoff, out_bh, init_block);
256 if (unlikely(ret == -EEXIST)) {
257 /* create = 0; */ /* limit read-create loop retries */
258 goto retry;
259 }
260 return ret;
261}
262
263/**
264 * nilfs_mdt_find_block - find and get a buffer on meta data file.
265 * @inode: inode of the meta data file
266 * @start: start block offset (inclusive)
267 * @end: end block offset (inclusive)
268 * @blkoff: block offset
269 * @out_bh: place to store a pointer to buffer_head struct
270 *
271 * nilfs_mdt_find_block() looks up an existing block in range of
272 * [@start, @end] and stores pointer to a buffer head of the block to
273 * @out_bh, and block offset to @blkoff, respectively. @out_bh and
274 * @blkoff are substituted only when zero is returned.
275 *
276 * Return Value: On success, it returns 0. On error, the following negative
277 * error code is returned.
278 *
279 * %-ENOMEM - Insufficient memory available.
280 *
281 * %-EIO - I/O error
282 *
283 * %-ENOENT - no block was found in the range
284 */
285int nilfs_mdt_find_block(struct inode *inode, unsigned long start,
286 unsigned long end, unsigned long *blkoff,
287 struct buffer_head **out_bh)
288{
289 __u64 next;
290 int ret;
291
292 if (unlikely(start > end))
293 return -ENOENT;
294
295 ret = nilfs_mdt_read_block(inode, start, true, out_bh);
296 if (!ret) {
297 *blkoff = start;
298 goto out;
299 }
300 if (unlikely(ret != -ENOENT || start == ULONG_MAX))
301 goto out;
302
303 ret = nilfs_bmap_seek_key(NILFS_I(inode)->i_bmap, start + 1, &next);
304 if (!ret) {
305 if (next <= end) {
306 ret = nilfs_mdt_read_block(inode, next, true, out_bh);
307 if (!ret)
308 *blkoff = next;
309 } else {
310 ret = -ENOENT;
311 }
312 }
313out:
314 return ret;
315}
316
317/**
318 * nilfs_mdt_delete_block - make a hole on the meta data file.
319 * @inode: inode of the meta data file
320 * @block: block offset
321 *
322 * Return Value: On success, zero is returned.
323 * On error, one of the following negative error code is returned.
324 *
325 * %-ENOMEM - Insufficient memory available.
326 *
327 * %-EIO - I/O error
328 */
329int nilfs_mdt_delete_block(struct inode *inode, unsigned long block)
330{
331 struct nilfs_inode_info *ii = NILFS_I(inode);
332 int err;
333
334 err = nilfs_bmap_delete(ii->i_bmap, block);
335 if (!err || err == -ENOENT) {
336 nilfs_mdt_mark_dirty(inode);
337 nilfs_mdt_forget_block(inode, block);
338 }
339 return err;
340}
341
342/**
343 * nilfs_mdt_forget_block - discard dirty state and try to remove the page
344 * @inode: inode of the meta data file
345 * @block: block offset
346 *
347 * nilfs_mdt_forget_block() clears a dirty flag of the specified buffer, and
348 * tries to release the page including the buffer from a page cache.
349 *
350 * Return Value: On success, 0 is returned. On error, one of the following
351 * negative error code is returned.
352 *
353 * %-EBUSY - page has an active buffer.
354 *
355 * %-ENOENT - page cache has no page addressed by the offset.
356 */
357int nilfs_mdt_forget_block(struct inode *inode, unsigned long block)
358{
359 pgoff_t index = (pgoff_t)block >>
360 (PAGE_SHIFT - inode->i_blkbits);
361 struct page *page;
362 unsigned long first_block;
363 int ret = 0;
364 int still_dirty;
365
366 page = find_lock_page(inode->i_mapping, index);
367 if (!page)
368 return -ENOENT;
369
370 wait_on_page_writeback(page);
371
372 first_block = (unsigned long)index <<
373 (PAGE_SHIFT - inode->i_blkbits);
374 if (page_has_buffers(page)) {
375 struct buffer_head *bh;
376
377 bh = nilfs_page_get_nth_block(page, block - first_block);
378 nilfs_forget_buffer(bh);
379 }
380 still_dirty = PageDirty(page);
381 unlock_page(page);
382 put_page(page);
383
384 if (still_dirty ||
385 invalidate_inode_pages2_range(inode->i_mapping, index, index) != 0)
386 ret = -EBUSY;
387 return ret;
388}
389
390int nilfs_mdt_fetch_dirty(struct inode *inode)
391{
392 struct nilfs_inode_info *ii = NILFS_I(inode);
393
394 if (nilfs_bmap_test_and_clear_dirty(ii->i_bmap)) {
395 set_bit(NILFS_I_DIRTY, &ii->i_state);
396 return 1;
397 }
398 return test_bit(NILFS_I_DIRTY, &ii->i_state);
399}
400
401static int
402nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
403{
404 struct inode *inode = page->mapping->host;
405 struct super_block *sb;
406 int err = 0;
407
408 if (inode && sb_rdonly(inode->i_sb)) {
409 /*
410 * It means that filesystem was remounted in read-only
411 * mode because of error or metadata corruption. But we
412 * have dirty pages that try to be flushed in background.
413 * So, here we simply discard this dirty page.
414 */
415 nilfs_clear_dirty_page(page, false);
416 unlock_page(page);
417 return -EROFS;
418 }
419
420 redirty_page_for_writepage(wbc, page);
421 unlock_page(page);
422
423 if (!inode)
424 return 0;
425
426 sb = inode->i_sb;
427
428 if (wbc->sync_mode == WB_SYNC_ALL)
429 err = nilfs_construct_segment(sb);
430 else if (wbc->for_reclaim)
431 nilfs_flush_segment(sb, inode->i_ino);
432
433 return err;
434}
435
436
437static const struct address_space_operations def_mdt_aops = {
438 .dirty_folio = block_dirty_folio,
439 .invalidate_folio = block_invalidate_folio,
440 .writepage = nilfs_mdt_write_page,
441};
442
443static const struct inode_operations def_mdt_iops;
444static const struct file_operations def_mdt_fops;
445
446
447int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz)
448{
449 struct nilfs_mdt_info *mi;
450
451 mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS);
452 if (!mi)
453 return -ENOMEM;
454
455 init_rwsem(&mi->mi_sem);
456 inode->i_private = mi;
457
458 inode->i_mode = S_IFREG;
459 mapping_set_gfp_mask(inode->i_mapping, gfp_mask);
460
461 inode->i_op = &def_mdt_iops;
462 inode->i_fop = &def_mdt_fops;
463 inode->i_mapping->a_ops = &def_mdt_aops;
464
465 return 0;
466}
467
468/**
469 * nilfs_mdt_clear - do cleanup for the metadata file
470 * @inode: inode of the metadata file
471 */
472void nilfs_mdt_clear(struct inode *inode)
473{
474 struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
475 struct nilfs_shadow_map *shadow = mdi->mi_shadow;
476
477 if (mdi->mi_palloc_cache)
478 nilfs_palloc_destroy_cache(inode);
479
480 if (shadow) {
481 struct inode *s_inode = shadow->inode;
482
483 shadow->inode = NULL;
484 iput(s_inode);
485 mdi->mi_shadow = NULL;
486 }
487}
488
489/**
490 * nilfs_mdt_destroy - release resources used by the metadata file
491 * @inode: inode of the metadata file
492 */
493void nilfs_mdt_destroy(struct inode *inode)
494{
495 struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
496
497 kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
498 kfree(mdi);
499}
500
501void nilfs_mdt_set_entry_size(struct inode *inode, unsigned int entry_size,
502 unsigned int header_size)
503{
504 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
505
506 mi->mi_entry_size = entry_size;
507 mi->mi_entries_per_block = i_blocksize(inode) / entry_size;
508 mi->mi_first_entry_offset = DIV_ROUND_UP(header_size, entry_size);
509}
510
511/**
512 * nilfs_mdt_setup_shadow_map - setup shadow map and bind it to metadata file
513 * @inode: inode of the metadata file
514 * @shadow: shadow mapping
515 */
516int nilfs_mdt_setup_shadow_map(struct inode *inode,
517 struct nilfs_shadow_map *shadow)
518{
519 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
520 struct inode *s_inode;
521
522 INIT_LIST_HEAD(&shadow->frozen_buffers);
523
524 s_inode = nilfs_iget_for_shadow(inode);
525 if (IS_ERR(s_inode))
526 return PTR_ERR(s_inode);
527
528 shadow->inode = s_inode;
529 mi->mi_shadow = shadow;
530 return 0;
531}
532
533/**
534 * nilfs_mdt_save_to_shadow_map - copy bmap and dirty pages to shadow map
535 * @inode: inode of the metadata file
536 */
537int nilfs_mdt_save_to_shadow_map(struct inode *inode)
538{
539 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
540 struct nilfs_inode_info *ii = NILFS_I(inode);
541 struct nilfs_shadow_map *shadow = mi->mi_shadow;
542 struct inode *s_inode = shadow->inode;
543 int ret;
544
545 ret = nilfs_copy_dirty_pages(s_inode->i_mapping, inode->i_mapping);
546 if (ret)
547 goto out;
548
549 ret = nilfs_copy_dirty_pages(NILFS_I(s_inode)->i_assoc_inode->i_mapping,
550 ii->i_assoc_inode->i_mapping);
551 if (ret)
552 goto out;
553
554 nilfs_bmap_save(ii->i_bmap, &shadow->bmap_store);
555 out:
556 return ret;
557}
558
559int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh)
560{
561 struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
562 struct buffer_head *bh_frozen;
563 struct page *page;
564 int blkbits = inode->i_blkbits;
565
566 page = grab_cache_page(shadow->inode->i_mapping, bh->b_page->index);
567 if (!page)
568 return -ENOMEM;
569
570 if (!page_has_buffers(page))
571 create_empty_buffers(page, 1 << blkbits, 0);
572
573 bh_frozen = nilfs_page_get_nth_block(page, bh_offset(bh) >> blkbits);
574
575 if (!buffer_uptodate(bh_frozen))
576 nilfs_copy_buffer(bh_frozen, bh);
577 if (list_empty(&bh_frozen->b_assoc_buffers)) {
578 list_add_tail(&bh_frozen->b_assoc_buffers,
579 &shadow->frozen_buffers);
580 set_buffer_nilfs_redirected(bh);
581 } else {
582 brelse(bh_frozen); /* already frozen */
583 }
584
585 unlock_page(page);
586 put_page(page);
587 return 0;
588}
589
590struct buffer_head *
591nilfs_mdt_get_frozen_buffer(struct inode *inode, struct buffer_head *bh)
592{
593 struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
594 struct buffer_head *bh_frozen = NULL;
595 struct page *page;
596 int n;
597
598 page = find_lock_page(shadow->inode->i_mapping, bh->b_page->index);
599 if (page) {
600 if (page_has_buffers(page)) {
601 n = bh_offset(bh) >> inode->i_blkbits;
602 bh_frozen = nilfs_page_get_nth_block(page, n);
603 }
604 unlock_page(page);
605 put_page(page);
606 }
607 return bh_frozen;
608}
609
610static void nilfs_release_frozen_buffers(struct nilfs_shadow_map *shadow)
611{
612 struct list_head *head = &shadow->frozen_buffers;
613 struct buffer_head *bh;
614
615 while (!list_empty(head)) {
616 bh = list_first_entry(head, struct buffer_head,
617 b_assoc_buffers);
618 list_del_init(&bh->b_assoc_buffers);
619 brelse(bh); /* drop ref-count to make it releasable */
620 }
621}
622
623/**
624 * nilfs_mdt_restore_from_shadow_map - restore dirty pages and bmap state
625 * @inode: inode of the metadata file
626 */
627void nilfs_mdt_restore_from_shadow_map(struct inode *inode)
628{
629 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
630 struct nilfs_inode_info *ii = NILFS_I(inode);
631 struct nilfs_shadow_map *shadow = mi->mi_shadow;
632
633 down_write(&mi->mi_sem);
634
635 if (mi->mi_palloc_cache)
636 nilfs_palloc_clear_cache(inode);
637
638 nilfs_clear_dirty_pages(inode->i_mapping, true);
639 nilfs_copy_back_pages(inode->i_mapping, shadow->inode->i_mapping);
640
641 nilfs_clear_dirty_pages(ii->i_assoc_inode->i_mapping, true);
642 nilfs_copy_back_pages(ii->i_assoc_inode->i_mapping,
643 NILFS_I(shadow->inode)->i_assoc_inode->i_mapping);
644
645 nilfs_bmap_restore(ii->i_bmap, &shadow->bmap_store);
646
647 up_write(&mi->mi_sem);
648}
649
650/**
651 * nilfs_mdt_clear_shadow_map - truncate pages in shadow map caches
652 * @inode: inode of the metadata file
653 */
654void nilfs_mdt_clear_shadow_map(struct inode *inode)
655{
656 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
657 struct nilfs_shadow_map *shadow = mi->mi_shadow;
658 struct inode *shadow_btnc_inode = NILFS_I(shadow->inode)->i_assoc_inode;
659
660 down_write(&mi->mi_sem);
661 nilfs_release_frozen_buffers(shadow);
662 truncate_inode_pages(shadow->inode->i_mapping, 0);
663 truncate_inode_pages(shadow_btnc_inode->i_mapping, 0);
664 up_write(&mi->mi_sem);
665}
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Meta data file for NILFS
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Ryusuke Konishi.
8 */
9
10#include <linux/buffer_head.h>
11#include <linux/mpage.h>
12#include <linux/mm.h>
13#include <linux/writeback.h>
14#include <linux/backing-dev.h>
15#include <linux/swap.h>
16#include <linux/slab.h>
17#include "nilfs.h"
18#include "btnode.h"
19#include "segment.h"
20#include "page.h"
21#include "mdt.h"
22#include "alloc.h" /* nilfs_palloc_destroy_cache() */
23
24#include <trace/events/nilfs2.h>
25
26#define NILFS_MDT_MAX_RA_BLOCKS (16 - 1)
27
28
29static int
30nilfs_mdt_insert_new_block(struct inode *inode, unsigned long block,
31 struct buffer_head *bh,
32 void (*init_block)(struct inode *,
33 struct buffer_head *, void *))
34{
35 struct nilfs_inode_info *ii = NILFS_I(inode);
36 struct folio *folio = bh->b_folio;
37 void *from;
38 int ret;
39
40 /* Caller exclude read accesses using page lock */
41
42 /* set_buffer_new(bh); */
43 bh->b_blocknr = 0;
44
45 ret = nilfs_bmap_insert(ii->i_bmap, block, (unsigned long)bh);
46 if (unlikely(ret))
47 return ret;
48
49 set_buffer_mapped(bh);
50
51 /* Initialize block (block size > PAGE_SIZE not yet supported) */
52 from = kmap_local_folio(folio, offset_in_folio(folio, bh->b_data));
53 memset(from, 0, bh->b_size);
54 if (init_block)
55 init_block(inode, bh, from);
56 kunmap_local(from);
57
58 flush_dcache_folio(folio);
59
60 set_buffer_uptodate(bh);
61 mark_buffer_dirty(bh);
62 nilfs_mdt_mark_dirty(inode);
63
64 trace_nilfs2_mdt_insert_new_block(inode, inode->i_ino, block);
65
66 return 0;
67}
68
69static int nilfs_mdt_create_block(struct inode *inode, unsigned long block,
70 struct buffer_head **out_bh,
71 void (*init_block)(struct inode *,
72 struct buffer_head *,
73 void *))
74{
75 struct super_block *sb = inode->i_sb;
76 struct nilfs_transaction_info ti;
77 struct buffer_head *bh;
78 int err;
79
80 nilfs_transaction_begin(sb, &ti, 0);
81
82 err = -ENOMEM;
83 bh = nilfs_grab_buffer(inode, inode->i_mapping, block, 0);
84 if (unlikely(!bh))
85 goto failed_unlock;
86
87 err = -EEXIST;
88 if (buffer_uptodate(bh))
89 goto failed_bh;
90
91 wait_on_buffer(bh);
92 if (buffer_uptodate(bh))
93 goto failed_bh;
94
95 err = nilfs_mdt_insert_new_block(inode, block, bh, init_block);
96 if (likely(!err)) {
97 get_bh(bh);
98 *out_bh = bh;
99 }
100
101 failed_bh:
102 folio_unlock(bh->b_folio);
103 folio_put(bh->b_folio);
104 brelse(bh);
105
106 failed_unlock:
107 if (likely(!err))
108 err = nilfs_transaction_commit(sb);
109 else
110 nilfs_transaction_abort(sb);
111
112 return err;
113}
114
115static int
116nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff, blk_opf_t opf,
117 struct buffer_head **out_bh)
118{
119 struct buffer_head *bh;
120 __u64 blknum = 0;
121 int ret = -ENOMEM;
122
123 bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0);
124 if (unlikely(!bh))
125 goto failed;
126
127 ret = -EEXIST; /* internal code */
128 if (buffer_uptodate(bh))
129 goto out;
130
131 if (opf & REQ_RAHEAD) {
132 if (!trylock_buffer(bh)) {
133 ret = -EBUSY;
134 goto failed_bh;
135 }
136 } else /* opf == REQ_OP_READ */
137 lock_buffer(bh);
138
139 if (buffer_uptodate(bh)) {
140 unlock_buffer(bh);
141 goto out;
142 }
143
144 ret = nilfs_bmap_lookup(NILFS_I(inode)->i_bmap, blkoff, &blknum);
145 if (unlikely(ret)) {
146 unlock_buffer(bh);
147 goto failed_bh;
148 }
149 map_bh(bh, inode->i_sb, (sector_t)blknum);
150
151 bh->b_end_io = end_buffer_read_sync;
152 get_bh(bh);
153 submit_bh(opf, bh);
154 ret = 0;
155
156 trace_nilfs2_mdt_submit_block(inode, inode->i_ino, blkoff,
157 opf & REQ_OP_MASK);
158 out:
159 get_bh(bh);
160 *out_bh = bh;
161
162 failed_bh:
163 folio_unlock(bh->b_folio);
164 folio_put(bh->b_folio);
165 brelse(bh);
166 failed:
167 return ret;
168}
169
170static int nilfs_mdt_read_block(struct inode *inode, unsigned long block,
171 int readahead, struct buffer_head **out_bh)
172{
173 struct buffer_head *first_bh, *bh;
174 unsigned long blkoff;
175 int i, nr_ra_blocks = NILFS_MDT_MAX_RA_BLOCKS;
176 int err;
177
178 err = nilfs_mdt_submit_block(inode, block, REQ_OP_READ, &first_bh);
179 if (err == -EEXIST) /* internal code */
180 goto out;
181
182 if (unlikely(err))
183 goto failed;
184
185 if (readahead) {
186 blkoff = block + 1;
187 for (i = 0; i < nr_ra_blocks; i++, blkoff++) {
188 err = nilfs_mdt_submit_block(inode, blkoff,
189 REQ_OP_READ | REQ_RAHEAD, &bh);
190 if (likely(!err || err == -EEXIST))
191 brelse(bh);
192 else if (err != -EBUSY)
193 break;
194 /* abort readahead if bmap lookup failed */
195 if (!buffer_locked(first_bh))
196 goto out_no_wait;
197 }
198 }
199
200 wait_on_buffer(first_bh);
201
202 out_no_wait:
203 err = -EIO;
204 if (!buffer_uptodate(first_bh)) {
205 nilfs_err(inode->i_sb,
206 "I/O error reading meta-data file (ino=%lu, block-offset=%lu)",
207 inode->i_ino, block);
208 goto failed_bh;
209 }
210 out:
211 *out_bh = first_bh;
212 return 0;
213
214 failed_bh:
215 brelse(first_bh);
216 failed:
217 return err;
218}
219
220/**
221 * nilfs_mdt_get_block - read or create a buffer on meta data file.
222 * @inode: inode of the meta data file
223 * @blkoff: block offset
224 * @create: create flag
225 * @init_block: initializer used for newly allocated block
226 * @out_bh: output of a pointer to the buffer_head
227 *
228 * nilfs_mdt_get_block() looks up the specified buffer and tries to create
229 * a new buffer if @create is not zero. On success, the returned buffer is
230 * assured to be either existing or formatted using a buffer lock on success.
231 * @out_bh is substituted only when zero is returned.
232 *
233 * Return Value: On success, it returns 0. On error, the following negative
234 * error code is returned.
235 *
236 * %-ENOMEM - Insufficient memory available.
237 *
238 * %-EIO - I/O error
239 *
240 * %-ENOENT - the specified block does not exist (hole block)
241 *
242 * %-EROFS - Read only filesystem (for create mode)
243 */
244int nilfs_mdt_get_block(struct inode *inode, unsigned long blkoff, int create,
245 void (*init_block)(struct inode *,
246 struct buffer_head *, void *),
247 struct buffer_head **out_bh)
248{
249 int ret;
250
251 /* Should be rewritten with merging nilfs_mdt_read_block() */
252 retry:
253 ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh);
254 if (!create || ret != -ENOENT)
255 return ret;
256
257 ret = nilfs_mdt_create_block(inode, blkoff, out_bh, init_block);
258 if (unlikely(ret == -EEXIST)) {
259 /* create = 0; */ /* limit read-create loop retries */
260 goto retry;
261 }
262 return ret;
263}
264
265/**
266 * nilfs_mdt_find_block - find and get a buffer on meta data file.
267 * @inode: inode of the meta data file
268 * @start: start block offset (inclusive)
269 * @end: end block offset (inclusive)
270 * @blkoff: block offset
271 * @out_bh: place to store a pointer to buffer_head struct
272 *
273 * nilfs_mdt_find_block() looks up an existing block in range of
274 * [@start, @end] and stores pointer to a buffer head of the block to
275 * @out_bh, and block offset to @blkoff, respectively. @out_bh and
276 * @blkoff are substituted only when zero is returned.
277 *
278 * Return Value: On success, it returns 0. On error, the following negative
279 * error code is returned.
280 *
281 * %-ENOMEM - Insufficient memory available.
282 *
283 * %-EIO - I/O error
284 *
285 * %-ENOENT - no block was found in the range
286 */
287int nilfs_mdt_find_block(struct inode *inode, unsigned long start,
288 unsigned long end, unsigned long *blkoff,
289 struct buffer_head **out_bh)
290{
291 __u64 next;
292 int ret;
293
294 if (unlikely(start > end))
295 return -ENOENT;
296
297 ret = nilfs_mdt_read_block(inode, start, true, out_bh);
298 if (!ret) {
299 *blkoff = start;
300 goto out;
301 }
302 if (unlikely(ret != -ENOENT || start == ULONG_MAX))
303 goto out;
304
305 ret = nilfs_bmap_seek_key(NILFS_I(inode)->i_bmap, start + 1, &next);
306 if (!ret) {
307 if (next <= end) {
308 ret = nilfs_mdt_read_block(inode, next, true, out_bh);
309 if (!ret)
310 *blkoff = next;
311 } else {
312 ret = -ENOENT;
313 }
314 }
315out:
316 return ret;
317}
318
319/**
320 * nilfs_mdt_delete_block - make a hole on the meta data file.
321 * @inode: inode of the meta data file
322 * @block: block offset
323 *
324 * Return Value: On success, zero is returned.
325 * On error, one of the following negative error code is returned.
326 *
327 * %-ENOMEM - Insufficient memory available.
328 *
329 * %-EIO - I/O error
330 */
331int nilfs_mdt_delete_block(struct inode *inode, unsigned long block)
332{
333 struct nilfs_inode_info *ii = NILFS_I(inode);
334 int err;
335
336 err = nilfs_bmap_delete(ii->i_bmap, block);
337 if (!err || err == -ENOENT) {
338 nilfs_mdt_mark_dirty(inode);
339 nilfs_mdt_forget_block(inode, block);
340 }
341 return err;
342}
343
344/**
345 * nilfs_mdt_forget_block - discard dirty state and try to remove the page
346 * @inode: inode of the meta data file
347 * @block: block offset
348 *
349 * nilfs_mdt_forget_block() clears a dirty flag of the specified buffer, and
350 * tries to release the page including the buffer from a page cache.
351 *
352 * Return Value: On success, 0 is returned. On error, one of the following
353 * negative error code is returned.
354 *
355 * %-EBUSY - page has an active buffer.
356 *
357 * %-ENOENT - page cache has no page addressed by the offset.
358 */
359int nilfs_mdt_forget_block(struct inode *inode, unsigned long block)
360{
361 pgoff_t index = block >> (PAGE_SHIFT - inode->i_blkbits);
362 struct folio *folio;
363 struct buffer_head *bh;
364 int ret = 0;
365 int still_dirty;
366
367 folio = filemap_lock_folio(inode->i_mapping, index);
368 if (IS_ERR(folio))
369 return -ENOENT;
370
371 folio_wait_writeback(folio);
372
373 bh = folio_buffers(folio);
374 if (bh) {
375 unsigned long first_block = index <<
376 (PAGE_SHIFT - inode->i_blkbits);
377 bh = get_nth_bh(bh, block - first_block);
378 nilfs_forget_buffer(bh);
379 }
380 still_dirty = folio_test_dirty(folio);
381 folio_unlock(folio);
382 folio_put(folio);
383
384 if (still_dirty ||
385 invalidate_inode_pages2_range(inode->i_mapping, index, index) != 0)
386 ret = -EBUSY;
387 return ret;
388}
389
390int nilfs_mdt_fetch_dirty(struct inode *inode)
391{
392 struct nilfs_inode_info *ii = NILFS_I(inode);
393
394 if (nilfs_bmap_test_and_clear_dirty(ii->i_bmap)) {
395 set_bit(NILFS_I_DIRTY, &ii->i_state);
396 return 1;
397 }
398 return test_bit(NILFS_I_DIRTY, &ii->i_state);
399}
400
401static int nilfs_mdt_write_folio(struct folio *folio,
402 struct writeback_control *wbc)
403{
404 struct inode *inode = folio->mapping->host;
405 struct super_block *sb;
406 int err = 0;
407
408 if (inode && sb_rdonly(inode->i_sb)) {
409 /*
410 * It means that filesystem was remounted in read-only
411 * mode because of error or metadata corruption. But we
412 * have dirty folios that try to be flushed in background.
413 * So, here we simply discard this dirty folio.
414 */
415 nilfs_clear_folio_dirty(folio);
416 folio_unlock(folio);
417 return -EROFS;
418 }
419
420 folio_redirty_for_writepage(wbc, folio);
421 folio_unlock(folio);
422
423 if (!inode)
424 return 0;
425
426 sb = inode->i_sb;
427
428 if (wbc->sync_mode == WB_SYNC_ALL)
429 err = nilfs_construct_segment(sb);
430 else if (wbc->for_reclaim)
431 nilfs_flush_segment(sb, inode->i_ino);
432
433 return err;
434}
435
436static int nilfs_mdt_writeback(struct address_space *mapping,
437 struct writeback_control *wbc)
438{
439 struct folio *folio = NULL;
440 int error;
441
442 while ((folio = writeback_iter(mapping, wbc, folio, &error)))
443 error = nilfs_mdt_write_folio(folio, wbc);
444
445 return error;
446}
447
448static const struct address_space_operations def_mdt_aops = {
449 .dirty_folio = block_dirty_folio,
450 .invalidate_folio = block_invalidate_folio,
451 .writepages = nilfs_mdt_writeback,
452 .migrate_folio = buffer_migrate_folio_norefs,
453};
454
455static const struct inode_operations def_mdt_iops;
456static const struct file_operations def_mdt_fops;
457
458
459int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz)
460{
461 struct nilfs_mdt_info *mi;
462
463 mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS);
464 if (!mi)
465 return -ENOMEM;
466
467 init_rwsem(&mi->mi_sem);
468 inode->i_private = mi;
469
470 inode->i_mode = S_IFREG;
471 mapping_set_gfp_mask(inode->i_mapping, gfp_mask);
472
473 inode->i_op = &def_mdt_iops;
474 inode->i_fop = &def_mdt_fops;
475 inode->i_mapping->a_ops = &def_mdt_aops;
476
477 return 0;
478}
479
480/**
481 * nilfs_mdt_clear - do cleanup for the metadata file
482 * @inode: inode of the metadata file
483 */
484void nilfs_mdt_clear(struct inode *inode)
485{
486 struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
487 struct nilfs_shadow_map *shadow = mdi->mi_shadow;
488
489 if (mdi->mi_palloc_cache)
490 nilfs_palloc_destroy_cache(inode);
491
492 if (shadow) {
493 struct inode *s_inode = shadow->inode;
494
495 shadow->inode = NULL;
496 iput(s_inode);
497 mdi->mi_shadow = NULL;
498 }
499}
500
501/**
502 * nilfs_mdt_destroy - release resources used by the metadata file
503 * @inode: inode of the metadata file
504 */
505void nilfs_mdt_destroy(struct inode *inode)
506{
507 struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
508
509 kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
510 kfree(mdi);
511}
512
513void nilfs_mdt_set_entry_size(struct inode *inode, unsigned int entry_size,
514 unsigned int header_size)
515{
516 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
517
518 mi->mi_entry_size = entry_size;
519 mi->mi_entries_per_block = i_blocksize(inode) / entry_size;
520 mi->mi_first_entry_offset = DIV_ROUND_UP(header_size, entry_size);
521}
522
523/**
524 * nilfs_mdt_setup_shadow_map - setup shadow map and bind it to metadata file
525 * @inode: inode of the metadata file
526 * @shadow: shadow mapping
527 */
528int nilfs_mdt_setup_shadow_map(struct inode *inode,
529 struct nilfs_shadow_map *shadow)
530{
531 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
532 struct inode *s_inode;
533
534 INIT_LIST_HEAD(&shadow->frozen_buffers);
535
536 s_inode = nilfs_iget_for_shadow(inode);
537 if (IS_ERR(s_inode))
538 return PTR_ERR(s_inode);
539
540 shadow->inode = s_inode;
541 mi->mi_shadow = shadow;
542 return 0;
543}
544
545/**
546 * nilfs_mdt_save_to_shadow_map - copy bmap and dirty pages to shadow map
547 * @inode: inode of the metadata file
548 */
549int nilfs_mdt_save_to_shadow_map(struct inode *inode)
550{
551 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
552 struct nilfs_inode_info *ii = NILFS_I(inode);
553 struct nilfs_shadow_map *shadow = mi->mi_shadow;
554 struct inode *s_inode = shadow->inode;
555 int ret;
556
557 ret = nilfs_copy_dirty_pages(s_inode->i_mapping, inode->i_mapping);
558 if (ret)
559 goto out;
560
561 ret = nilfs_copy_dirty_pages(NILFS_I(s_inode)->i_assoc_inode->i_mapping,
562 ii->i_assoc_inode->i_mapping);
563 if (ret)
564 goto out;
565
566 nilfs_bmap_save(ii->i_bmap, &shadow->bmap_store);
567 out:
568 return ret;
569}
570
571int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh)
572{
573 struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
574 struct buffer_head *bh_frozen;
575 struct folio *folio;
576 int blkbits = inode->i_blkbits;
577
578 folio = filemap_grab_folio(shadow->inode->i_mapping,
579 bh->b_folio->index);
580 if (IS_ERR(folio))
581 return PTR_ERR(folio);
582
583 bh_frozen = folio_buffers(folio);
584 if (!bh_frozen)
585 bh_frozen = create_empty_buffers(folio, 1 << blkbits, 0);
586
587 bh_frozen = get_nth_bh(bh_frozen,
588 offset_in_folio(folio, bh->b_data) >> blkbits);
589
590 if (!buffer_uptodate(bh_frozen))
591 nilfs_copy_buffer(bh_frozen, bh);
592 if (list_empty(&bh_frozen->b_assoc_buffers)) {
593 list_add_tail(&bh_frozen->b_assoc_buffers,
594 &shadow->frozen_buffers);
595 set_buffer_nilfs_redirected(bh);
596 } else {
597 brelse(bh_frozen); /* already frozen */
598 }
599
600 folio_unlock(folio);
601 folio_put(folio);
602 return 0;
603}
604
605struct buffer_head *
606nilfs_mdt_get_frozen_buffer(struct inode *inode, struct buffer_head *bh)
607{
608 struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
609 struct buffer_head *bh_frozen = NULL;
610 struct folio *folio;
611 int n;
612
613 folio = filemap_lock_folio(shadow->inode->i_mapping,
614 bh->b_folio->index);
615 if (!IS_ERR(folio)) {
616 bh_frozen = folio_buffers(folio);
617 if (bh_frozen) {
618 n = offset_in_folio(folio, bh->b_data) >>
619 inode->i_blkbits;
620 bh_frozen = get_nth_bh(bh_frozen, n);
621 }
622 folio_unlock(folio);
623 folio_put(folio);
624 }
625 return bh_frozen;
626}
627
628static void nilfs_release_frozen_buffers(struct nilfs_shadow_map *shadow)
629{
630 struct list_head *head = &shadow->frozen_buffers;
631 struct buffer_head *bh;
632
633 while (!list_empty(head)) {
634 bh = list_first_entry(head, struct buffer_head,
635 b_assoc_buffers);
636 list_del_init(&bh->b_assoc_buffers);
637 brelse(bh); /* drop ref-count to make it releasable */
638 }
639}
640
641/**
642 * nilfs_mdt_restore_from_shadow_map - restore dirty pages and bmap state
643 * @inode: inode of the metadata file
644 */
645void nilfs_mdt_restore_from_shadow_map(struct inode *inode)
646{
647 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
648 struct nilfs_inode_info *ii = NILFS_I(inode);
649 struct nilfs_shadow_map *shadow = mi->mi_shadow;
650
651 down_write(&mi->mi_sem);
652
653 if (mi->mi_palloc_cache)
654 nilfs_palloc_clear_cache(inode);
655
656 nilfs_clear_dirty_pages(inode->i_mapping);
657 nilfs_copy_back_pages(inode->i_mapping, shadow->inode->i_mapping);
658
659 nilfs_clear_dirty_pages(ii->i_assoc_inode->i_mapping);
660 nilfs_copy_back_pages(ii->i_assoc_inode->i_mapping,
661 NILFS_I(shadow->inode)->i_assoc_inode->i_mapping);
662
663 nilfs_bmap_restore(ii->i_bmap, &shadow->bmap_store);
664
665 up_write(&mi->mi_sem);
666}
667
668/**
669 * nilfs_mdt_clear_shadow_map - truncate pages in shadow map caches
670 * @inode: inode of the metadata file
671 */
672void nilfs_mdt_clear_shadow_map(struct inode *inode)
673{
674 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
675 struct nilfs_shadow_map *shadow = mi->mi_shadow;
676 struct inode *shadow_btnc_inode = NILFS_I(shadow->inode)->i_assoc_inode;
677
678 down_write(&mi->mi_sem);
679 nilfs_release_frozen_buffers(shadow);
680 truncate_inode_pages(shadow->inode->i_mapping, 0);
681 truncate_inode_pages(shadow_btnc_inode->i_mapping, 0);
682 up_write(&mi->mi_sem);
683}