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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/*
2 * mdt.c - meta data file for NILFS
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
21 */
22
23#include <linux/buffer_head.h>
24#include <linux/mpage.h>
25#include <linux/mm.h>
26#include <linux/writeback.h>
27#include <linux/backing-dev.h>
28#include <linux/swap.h>
29#include <linux/slab.h>
30#include "nilfs.h"
31#include "btnode.h"
32#include "segment.h"
33#include "page.h"
34#include "mdt.h"
35
36#include <trace/events/nilfs2.h>
37
38#define NILFS_MDT_MAX_RA_BLOCKS (16 - 1)
39
40
41static int
42nilfs_mdt_insert_new_block(struct inode *inode, unsigned long block,
43 struct buffer_head *bh,
44 void (*init_block)(struct inode *,
45 struct buffer_head *, void *))
46{
47 struct nilfs_inode_info *ii = NILFS_I(inode);
48 void *kaddr;
49 int ret;
50
51 /* Caller exclude read accesses using page lock */
52
53 /* set_buffer_new(bh); */
54 bh->b_blocknr = 0;
55
56 ret = nilfs_bmap_insert(ii->i_bmap, block, (unsigned long)bh);
57 if (unlikely(ret))
58 return ret;
59
60 set_buffer_mapped(bh);
61
62 kaddr = kmap_atomic(bh->b_page);
63 memset(kaddr + bh_offset(bh), 0, 1 << inode->i_blkbits);
64 if (init_block)
65 init_block(inode, bh, kaddr);
66 flush_dcache_page(bh->b_page);
67 kunmap_atomic(kaddr);
68
69 set_buffer_uptodate(bh);
70 mark_buffer_dirty(bh);
71 nilfs_mdt_mark_dirty(inode);
72
73 trace_nilfs2_mdt_insert_new_block(inode, inode->i_ino, block);
74
75 return 0;
76}
77
78static int nilfs_mdt_create_block(struct inode *inode, unsigned long block,
79 struct buffer_head **out_bh,
80 void (*init_block)(struct inode *,
81 struct buffer_head *,
82 void *))
83{
84 struct super_block *sb = inode->i_sb;
85 struct nilfs_transaction_info ti;
86 struct buffer_head *bh;
87 int err;
88
89 nilfs_transaction_begin(sb, &ti, 0);
90
91 err = -ENOMEM;
92 bh = nilfs_grab_buffer(inode, inode->i_mapping, block, 0);
93 if (unlikely(!bh))
94 goto failed_unlock;
95
96 err = -EEXIST;
97 if (buffer_uptodate(bh))
98 goto failed_bh;
99
100 wait_on_buffer(bh);
101 if (buffer_uptodate(bh))
102 goto failed_bh;
103
104 bh->b_bdev = sb->s_bdev;
105 err = nilfs_mdt_insert_new_block(inode, block, bh, init_block);
106 if (likely(!err)) {
107 get_bh(bh);
108 *out_bh = bh;
109 }
110
111 failed_bh:
112 unlock_page(bh->b_page);
113 put_page(bh->b_page);
114 brelse(bh);
115
116 failed_unlock:
117 if (likely(!err))
118 err = nilfs_transaction_commit(sb);
119 else
120 nilfs_transaction_abort(sb);
121
122 return err;
123}
124
125static int
126nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff,
127 int mode, struct buffer_head **out_bh)
128{
129 struct buffer_head *bh;
130 __u64 blknum = 0;
131 int ret = -ENOMEM;
132
133 bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0);
134 if (unlikely(!bh))
135 goto failed;
136
137 ret = -EEXIST; /* internal code */
138 if (buffer_uptodate(bh))
139 goto out;
140
141 if (mode == READA) {
142 if (!trylock_buffer(bh)) {
143 ret = -EBUSY;
144 goto failed_bh;
145 }
146 } else /* mode == READ */
147 lock_buffer(bh);
148
149 if (buffer_uptodate(bh)) {
150 unlock_buffer(bh);
151 goto out;
152 }
153
154 ret = nilfs_bmap_lookup(NILFS_I(inode)->i_bmap, blkoff, &blknum);
155 if (unlikely(ret)) {
156 unlock_buffer(bh);
157 goto failed_bh;
158 }
159 map_bh(bh, inode->i_sb, (sector_t)blknum);
160
161 bh->b_end_io = end_buffer_read_sync;
162 get_bh(bh);
163 submit_bh(mode, bh);
164 ret = 0;
165
166 trace_nilfs2_mdt_submit_block(inode, inode->i_ino, blkoff, mode);
167 out:
168 get_bh(bh);
169 *out_bh = bh;
170
171 failed_bh:
172 unlock_page(bh->b_page);
173 put_page(bh->b_page);
174 brelse(bh);
175 failed:
176 return ret;
177}
178
179static int nilfs_mdt_read_block(struct inode *inode, unsigned long block,
180 int readahead, struct buffer_head **out_bh)
181{
182 struct buffer_head *first_bh, *bh;
183 unsigned long blkoff;
184 int i, nr_ra_blocks = NILFS_MDT_MAX_RA_BLOCKS;
185 int err;
186
187 err = nilfs_mdt_submit_block(inode, block, READ, &first_bh);
188 if (err == -EEXIST) /* internal code */
189 goto out;
190
191 if (unlikely(err))
192 goto failed;
193
194 if (readahead) {
195 blkoff = block + 1;
196 for (i = 0; i < nr_ra_blocks; i++, blkoff++) {
197 err = nilfs_mdt_submit_block(inode, blkoff, READA, &bh);
198 if (likely(!err || err == -EEXIST))
199 brelse(bh);
200 else if (err != -EBUSY)
201 break;
202 /* abort readahead if bmap lookup failed */
203 if (!buffer_locked(first_bh))
204 goto out_no_wait;
205 }
206 }
207
208 wait_on_buffer(first_bh);
209
210 out_no_wait:
211 err = -EIO;
212 if (!buffer_uptodate(first_bh))
213 goto failed_bh;
214 out:
215 *out_bh = first_bh;
216 return 0;
217
218 failed_bh:
219 brelse(first_bh);
220 failed:
221 return err;
222}
223
224/**
225 * nilfs_mdt_get_block - read or create a buffer on meta data file.
226 * @inode: inode of the meta data file
227 * @blkoff: block offset
228 * @create: create flag
229 * @init_block: initializer used for newly allocated block
230 * @out_bh: output of a pointer to the buffer_head
231 *
232 * nilfs_mdt_get_block() looks up the specified buffer and tries to create
233 * a new buffer if @create is not zero. On success, the returned buffer is
234 * assured to be either existing or formatted using a buffer lock on success.
235 * @out_bh is substituted only when zero is returned.
236 *
237 * Return Value: On success, it returns 0. On error, the following negative
238 * error code is returned.
239 *
240 * %-ENOMEM - Insufficient memory available.
241 *
242 * %-EIO - I/O error
243 *
244 * %-ENOENT - the specified block does not exist (hole block)
245 *
246 * %-EROFS - Read only filesystem (for create mode)
247 */
248int nilfs_mdt_get_block(struct inode *inode, unsigned long blkoff, int create,
249 void (*init_block)(struct inode *,
250 struct buffer_head *, void *),
251 struct buffer_head **out_bh)
252{
253 int ret;
254
255 /* Should be rewritten with merging nilfs_mdt_read_block() */
256 retry:
257 ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh);
258 if (!create || ret != -ENOENT)
259 return ret;
260
261 ret = nilfs_mdt_create_block(inode, blkoff, out_bh, init_block);
262 if (unlikely(ret == -EEXIST)) {
263 /* create = 0; */ /* limit read-create loop retries */
264 goto retry;
265 }
266 return ret;
267}
268
269/**
270 * nilfs_mdt_find_block - find and get a buffer on meta data file.
271 * @inode: inode of the meta data file
272 * @start: start block offset (inclusive)
273 * @end: end block offset (inclusive)
274 * @blkoff: block offset
275 * @out_bh: place to store a pointer to buffer_head struct
276 *
277 * nilfs_mdt_find_block() looks up an existing block in range of
278 * [@start, @end] and stores pointer to a buffer head of the block to
279 * @out_bh, and block offset to @blkoff, respectively. @out_bh and
280 * @blkoff are substituted only when zero is returned.
281 *
282 * Return Value: On success, it returns 0. On error, the following negative
283 * error code is returned.
284 *
285 * %-ENOMEM - Insufficient memory available.
286 *
287 * %-EIO - I/O error
288 *
289 * %-ENOENT - no block was found in the range
290 */
291int nilfs_mdt_find_block(struct inode *inode, unsigned long start,
292 unsigned long end, unsigned long *blkoff,
293 struct buffer_head **out_bh)
294{
295 __u64 next;
296 int ret;
297
298 if (unlikely(start > end))
299 return -ENOENT;
300
301 ret = nilfs_mdt_read_block(inode, start, true, out_bh);
302 if (!ret) {
303 *blkoff = start;
304 goto out;
305 }
306 if (unlikely(ret != -ENOENT || start == ULONG_MAX))
307 goto out;
308
309 ret = nilfs_bmap_seek_key(NILFS_I(inode)->i_bmap, start + 1, &next);
310 if (!ret) {
311 if (next <= end) {
312 ret = nilfs_mdt_read_block(inode, next, true, out_bh);
313 if (!ret)
314 *blkoff = next;
315 } else {
316 ret = -ENOENT;
317 }
318 }
319out:
320 return ret;
321}
322
323/**
324 * nilfs_mdt_delete_block - make a hole on the meta data file.
325 * @inode: inode of the meta data file
326 * @block: block offset
327 *
328 * Return Value: On success, zero is returned.
329 * On error, one of the following negative error code is returned.
330 *
331 * %-ENOMEM - Insufficient memory available.
332 *
333 * %-EIO - I/O error
334 */
335int nilfs_mdt_delete_block(struct inode *inode, unsigned long block)
336{
337 struct nilfs_inode_info *ii = NILFS_I(inode);
338 int err;
339
340 err = nilfs_bmap_delete(ii->i_bmap, block);
341 if (!err || err == -ENOENT) {
342 nilfs_mdt_mark_dirty(inode);
343 nilfs_mdt_forget_block(inode, block);
344 }
345 return err;
346}
347
348/**
349 * nilfs_mdt_forget_block - discard dirty state and try to remove the page
350 * @inode: inode of the meta data file
351 * @block: block offset
352 *
353 * nilfs_mdt_forget_block() clears a dirty flag of the specified buffer, and
354 * tries to release the page including the buffer from a page cache.
355 *
356 * Return Value: On success, 0 is returned. On error, one of the following
357 * negative error code is returned.
358 *
359 * %-EBUSY - page has an active buffer.
360 *
361 * %-ENOENT - page cache has no page addressed by the offset.
362 */
363int nilfs_mdt_forget_block(struct inode *inode, unsigned long block)
364{
365 pgoff_t index = (pgoff_t)block >>
366 (PAGE_SHIFT - inode->i_blkbits);
367 struct page *page;
368 unsigned long first_block;
369 int ret = 0;
370 int still_dirty;
371
372 page = find_lock_page(inode->i_mapping, index);
373 if (!page)
374 return -ENOENT;
375
376 wait_on_page_writeback(page);
377
378 first_block = (unsigned long)index <<
379 (PAGE_SHIFT - inode->i_blkbits);
380 if (page_has_buffers(page)) {
381 struct buffer_head *bh;
382
383 bh = nilfs_page_get_nth_block(page, block - first_block);
384 nilfs_forget_buffer(bh);
385 }
386 still_dirty = PageDirty(page);
387 unlock_page(page);
388 put_page(page);
389
390 if (still_dirty ||
391 invalidate_inode_pages2_range(inode->i_mapping, index, index) != 0)
392 ret = -EBUSY;
393 return ret;
394}
395
396/**
397 * nilfs_mdt_mark_block_dirty - mark a block on the meta data file dirty.
398 * @inode: inode of the meta data file
399 * @block: block offset
400 *
401 * Return Value: On success, it returns 0. On error, the following negative
402 * error code is returned.
403 *
404 * %-ENOMEM - Insufficient memory available.
405 *
406 * %-EIO - I/O error
407 *
408 * %-ENOENT - the specified block does not exist (hole block)
409 */
410int nilfs_mdt_mark_block_dirty(struct inode *inode, unsigned long block)
411{
412 struct buffer_head *bh;
413 int err;
414
415 err = nilfs_mdt_read_block(inode, block, 0, &bh);
416 if (unlikely(err))
417 return err;
418 mark_buffer_dirty(bh);
419 nilfs_mdt_mark_dirty(inode);
420 brelse(bh);
421 return 0;
422}
423
424int nilfs_mdt_fetch_dirty(struct inode *inode)
425{
426 struct nilfs_inode_info *ii = NILFS_I(inode);
427
428 if (nilfs_bmap_test_and_clear_dirty(ii->i_bmap)) {
429 set_bit(NILFS_I_DIRTY, &ii->i_state);
430 return 1;
431 }
432 return test_bit(NILFS_I_DIRTY, &ii->i_state);
433}
434
435static int
436nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
437{
438 struct inode *inode = page->mapping->host;
439 struct super_block *sb;
440 int err = 0;
441
442 if (inode && (inode->i_sb->s_flags & MS_RDONLY)) {
443 /*
444 * It means that filesystem was remounted in read-only
445 * mode because of error or metadata corruption. But we
446 * have dirty pages that try to be flushed in background.
447 * So, here we simply discard this dirty page.
448 */
449 nilfs_clear_dirty_page(page, false);
450 unlock_page(page);
451 return -EROFS;
452 }
453
454 redirty_page_for_writepage(wbc, page);
455 unlock_page(page);
456
457 if (!inode)
458 return 0;
459
460 sb = inode->i_sb;
461
462 if (wbc->sync_mode == WB_SYNC_ALL)
463 err = nilfs_construct_segment(sb);
464 else if (wbc->for_reclaim)
465 nilfs_flush_segment(sb, inode->i_ino);
466
467 return err;
468}
469
470
471static const struct address_space_operations def_mdt_aops = {
472 .writepage = nilfs_mdt_write_page,
473};
474
475static const struct inode_operations def_mdt_iops;
476static const struct file_operations def_mdt_fops;
477
478
479int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz)
480{
481 struct nilfs_mdt_info *mi;
482
483 mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS);
484 if (!mi)
485 return -ENOMEM;
486
487 init_rwsem(&mi->mi_sem);
488 inode->i_private = mi;
489
490 inode->i_mode = S_IFREG;
491 mapping_set_gfp_mask(inode->i_mapping, gfp_mask);
492
493 inode->i_op = &def_mdt_iops;
494 inode->i_fop = &def_mdt_fops;
495 inode->i_mapping->a_ops = &def_mdt_aops;
496
497 return 0;
498}
499
500void nilfs_mdt_set_entry_size(struct inode *inode, unsigned entry_size,
501 unsigned header_size)
502{
503 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
504
505 mi->mi_entry_size = entry_size;
506 mi->mi_entries_per_block = (1 << inode->i_blkbits) / entry_size;
507 mi->mi_first_entry_offset = DIV_ROUND_UP(header_size, entry_size);
508}
509
510/**
511 * nilfs_mdt_setup_shadow_map - setup shadow map and bind it to metadata file
512 * @inode: inode of the metadata file
513 * @shadow: shadow mapping
514 */
515int nilfs_mdt_setup_shadow_map(struct inode *inode,
516 struct nilfs_shadow_map *shadow)
517{
518 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
519
520 INIT_LIST_HEAD(&shadow->frozen_buffers);
521 address_space_init_once(&shadow->frozen_data);
522 nilfs_mapping_init(&shadow->frozen_data, inode);
523 address_space_init_once(&shadow->frozen_btnodes);
524 nilfs_mapping_init(&shadow->frozen_btnodes, inode);
525 mi->mi_shadow = shadow;
526 return 0;
527}
528
529/**
530 * nilfs_mdt_save_to_shadow_map - copy bmap and dirty pages to shadow map
531 * @inode: inode of the metadata file
532 */
533int nilfs_mdt_save_to_shadow_map(struct inode *inode)
534{
535 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
536 struct nilfs_inode_info *ii = NILFS_I(inode);
537 struct nilfs_shadow_map *shadow = mi->mi_shadow;
538 int ret;
539
540 ret = nilfs_copy_dirty_pages(&shadow->frozen_data, inode->i_mapping);
541 if (ret)
542 goto out;
543
544 ret = nilfs_copy_dirty_pages(&shadow->frozen_btnodes,
545 &ii->i_btnode_cache);
546 if (ret)
547 goto out;
548
549 nilfs_bmap_save(ii->i_bmap, &shadow->bmap_store);
550 out:
551 return ret;
552}
553
554int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh)
555{
556 struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
557 struct buffer_head *bh_frozen;
558 struct page *page;
559 int blkbits = inode->i_blkbits;
560
561 page = grab_cache_page(&shadow->frozen_data, bh->b_page->index);
562 if (!page)
563 return -ENOMEM;
564
565 if (!page_has_buffers(page))
566 create_empty_buffers(page, 1 << blkbits, 0);
567
568 bh_frozen = nilfs_page_get_nth_block(page, bh_offset(bh) >> blkbits);
569
570 if (!buffer_uptodate(bh_frozen))
571 nilfs_copy_buffer(bh_frozen, bh);
572 if (list_empty(&bh_frozen->b_assoc_buffers)) {
573 list_add_tail(&bh_frozen->b_assoc_buffers,
574 &shadow->frozen_buffers);
575 set_buffer_nilfs_redirected(bh);
576 } else {
577 brelse(bh_frozen); /* already frozen */
578 }
579
580 unlock_page(page);
581 put_page(page);
582 return 0;
583}
584
585struct buffer_head *
586nilfs_mdt_get_frozen_buffer(struct inode *inode, struct buffer_head *bh)
587{
588 struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
589 struct buffer_head *bh_frozen = NULL;
590 struct page *page;
591 int n;
592
593 page = find_lock_page(&shadow->frozen_data, bh->b_page->index);
594 if (page) {
595 if (page_has_buffers(page)) {
596 n = bh_offset(bh) >> inode->i_blkbits;
597 bh_frozen = nilfs_page_get_nth_block(page, n);
598 }
599 unlock_page(page);
600 put_page(page);
601 }
602 return bh_frozen;
603}
604
605static void nilfs_release_frozen_buffers(struct nilfs_shadow_map *shadow)
606{
607 struct list_head *head = &shadow->frozen_buffers;
608 struct buffer_head *bh;
609
610 while (!list_empty(head)) {
611 bh = list_first_entry(head, struct buffer_head,
612 b_assoc_buffers);
613 list_del_init(&bh->b_assoc_buffers);
614 brelse(bh); /* drop ref-count to make it releasable */
615 }
616}
617
618/**
619 * nilfs_mdt_restore_from_shadow_map - restore dirty pages and bmap state
620 * @inode: inode of the metadata file
621 */
622void nilfs_mdt_restore_from_shadow_map(struct inode *inode)
623{
624 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
625 struct nilfs_inode_info *ii = NILFS_I(inode);
626 struct nilfs_shadow_map *shadow = mi->mi_shadow;
627
628 down_write(&mi->mi_sem);
629
630 if (mi->mi_palloc_cache)
631 nilfs_palloc_clear_cache(inode);
632
633 nilfs_clear_dirty_pages(inode->i_mapping, true);
634 nilfs_copy_back_pages(inode->i_mapping, &shadow->frozen_data);
635
636 nilfs_clear_dirty_pages(&ii->i_btnode_cache, true);
637 nilfs_copy_back_pages(&ii->i_btnode_cache, &shadow->frozen_btnodes);
638
639 nilfs_bmap_restore(ii->i_bmap, &shadow->bmap_store);
640
641 up_write(&mi->mi_sem);
642}
643
644/**
645 * nilfs_mdt_clear_shadow_map - truncate pages in shadow map caches
646 * @inode: inode of the metadata file
647 */
648void nilfs_mdt_clear_shadow_map(struct inode *inode)
649{
650 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
651 struct nilfs_shadow_map *shadow = mi->mi_shadow;
652
653 down_write(&mi->mi_sem);
654 nilfs_release_frozen_buffers(shadow);
655 truncate_inode_pages(&shadow->frozen_data, 0);
656 truncate_inode_pages(&shadow->frozen_btnodes, 0);
657 up_write(&mi->mi_sem);
658}