This source file includes following definitions.
- nilfs_mdt_insert_new_block
- nilfs_mdt_create_block
- nilfs_mdt_submit_block
- nilfs_mdt_read_block
- nilfs_mdt_get_block
- nilfs_mdt_find_block
- nilfs_mdt_delete_block
- nilfs_mdt_forget_block
- nilfs_mdt_fetch_dirty
- nilfs_mdt_write_page
- nilfs_mdt_init
- nilfs_mdt_clear
- nilfs_mdt_destroy
- nilfs_mdt_set_entry_size
- nilfs_mdt_setup_shadow_map
- nilfs_mdt_save_to_shadow_map
- nilfs_mdt_freeze_buffer
- nilfs_mdt_get_frozen_buffer
- nilfs_release_frozen_buffers
- nilfs_mdt_restore_from_shadow_map
- nilfs_mdt_clear_shadow_map
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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"
23
24 #include <trace/events/nilfs2.h>
25
26 #define NILFS_MDT_MAX_RA_BLOCKS (16 - 1)
27
28
29 static int
30 nilfs_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
40
41
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
66 static 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
113 static int
114 nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff,
115 int mode, int mode_flags, 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;
126 if (buffer_uptodate(bh))
127 goto out;
128
129 if (mode_flags & REQ_RAHEAD) {
130 if (!trylock_buffer(bh)) {
131 ret = -EBUSY;
132 goto failed_bh;
133 }
134 } else
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(mode, mode_flags, bh);
152 ret = 0;
153
154 trace_nilfs2_mdt_submit_block(inode, inode->i_ino, blkoff, mode);
155 out:
156 get_bh(bh);
157 *out_bh = bh;
158
159 failed_bh:
160 unlock_page(bh->b_page);
161 put_page(bh->b_page);
162 brelse(bh);
163 failed:
164 return ret;
165 }
166
167 static int nilfs_mdt_read_block(struct inode *inode, unsigned long block,
168 int readahead, struct buffer_head **out_bh)
169 {
170 struct buffer_head *first_bh, *bh;
171 unsigned long blkoff;
172 int i, nr_ra_blocks = NILFS_MDT_MAX_RA_BLOCKS;
173 int err;
174
175 err = nilfs_mdt_submit_block(inode, block, REQ_OP_READ, 0, &first_bh);
176 if (err == -EEXIST)
177 goto out;
178
179 if (unlikely(err))
180 goto failed;
181
182 if (readahead) {
183 blkoff = block + 1;
184 for (i = 0; i < nr_ra_blocks; i++, blkoff++) {
185 err = nilfs_mdt_submit_block(inode, blkoff, REQ_OP_READ,
186 REQ_RAHEAD, &bh);
187 if (likely(!err || err == -EEXIST))
188 brelse(bh);
189 else if (err != -EBUSY)
190 break;
191
192 if (!buffer_locked(first_bh))
193 goto out_no_wait;
194 }
195 }
196
197 wait_on_buffer(first_bh);
198
199 out_no_wait:
200 err = -EIO;
201 if (!buffer_uptodate(first_bh)) {
202 nilfs_msg(inode->i_sb, KERN_ERR,
203 "I/O error reading meta-data file (ino=%lu, block-offset=%lu)",
204 inode->i_ino, block);
205 goto failed_bh;
206 }
207 out:
208 *out_bh = first_bh;
209 return 0;
210
211 failed_bh:
212 brelse(first_bh);
213 failed:
214 return err;
215 }
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241 int nilfs_mdt_get_block(struct inode *inode, unsigned long blkoff, int create,
242 void (*init_block)(struct inode *,
243 struct buffer_head *, void *),
244 struct buffer_head **out_bh)
245 {
246 int ret;
247
248
249 retry:
250 ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh);
251 if (!create || ret != -ENOENT)
252 return ret;
253
254 ret = nilfs_mdt_create_block(inode, blkoff, out_bh, init_block);
255 if (unlikely(ret == -EEXIST)) {
256
257 goto retry;
258 }
259 return ret;
260 }
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284 int nilfs_mdt_find_block(struct inode *inode, unsigned long start,
285 unsigned long end, unsigned long *blkoff,
286 struct buffer_head **out_bh)
287 {
288 __u64 next;
289 int ret;
290
291 if (unlikely(start > end))
292 return -ENOENT;
293
294 ret = nilfs_mdt_read_block(inode, start, true, out_bh);
295 if (!ret) {
296 *blkoff = start;
297 goto out;
298 }
299 if (unlikely(ret != -ENOENT || start == ULONG_MAX))
300 goto out;
301
302 ret = nilfs_bmap_seek_key(NILFS_I(inode)->i_bmap, start + 1, &next);
303 if (!ret) {
304 if (next <= end) {
305 ret = nilfs_mdt_read_block(inode, next, true, out_bh);
306 if (!ret)
307 *blkoff = next;
308 } else {
309 ret = -ENOENT;
310 }
311 }
312 out:
313 return ret;
314 }
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328 int nilfs_mdt_delete_block(struct inode *inode, unsigned long block)
329 {
330 struct nilfs_inode_info *ii = NILFS_I(inode);
331 int err;
332
333 err = nilfs_bmap_delete(ii->i_bmap, block);
334 if (!err || err == -ENOENT) {
335 nilfs_mdt_mark_dirty(inode);
336 nilfs_mdt_forget_block(inode, block);
337 }
338 return err;
339 }
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356 int nilfs_mdt_forget_block(struct inode *inode, unsigned long block)
357 {
358 pgoff_t index = (pgoff_t)block >>
359 (PAGE_SHIFT - inode->i_blkbits);
360 struct page *page;
361 unsigned long first_block;
362 int ret = 0;
363 int still_dirty;
364
365 page = find_lock_page(inode->i_mapping, index);
366 if (!page)
367 return -ENOENT;
368
369 wait_on_page_writeback(page);
370
371 first_block = (unsigned long)index <<
372 (PAGE_SHIFT - inode->i_blkbits);
373 if (page_has_buffers(page)) {
374 struct buffer_head *bh;
375
376 bh = nilfs_page_get_nth_block(page, block - first_block);
377 nilfs_forget_buffer(bh);
378 }
379 still_dirty = PageDirty(page);
380 unlock_page(page);
381 put_page(page);
382
383 if (still_dirty ||
384 invalidate_inode_pages2_range(inode->i_mapping, index, index) != 0)
385 ret = -EBUSY;
386 return ret;
387 }
388
389 int nilfs_mdt_fetch_dirty(struct inode *inode)
390 {
391 struct nilfs_inode_info *ii = NILFS_I(inode);
392
393 if (nilfs_bmap_test_and_clear_dirty(ii->i_bmap)) {
394 set_bit(NILFS_I_DIRTY, &ii->i_state);
395 return 1;
396 }
397 return test_bit(NILFS_I_DIRTY, &ii->i_state);
398 }
399
400 static int
401 nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
402 {
403 struct inode *inode = page->mapping->host;
404 struct super_block *sb;
405 int err = 0;
406
407 if (inode && sb_rdonly(inode->i_sb)) {
408
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412
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414 nilfs_clear_dirty_page(page, false);
415 unlock_page(page);
416 return -EROFS;
417 }
418
419 redirty_page_for_writepage(wbc, page);
420 unlock_page(page);
421
422 if (!inode)
423 return 0;
424
425 sb = inode->i_sb;
426
427 if (wbc->sync_mode == WB_SYNC_ALL)
428 err = nilfs_construct_segment(sb);
429 else if (wbc->for_reclaim)
430 nilfs_flush_segment(sb, inode->i_ino);
431
432 return err;
433 }
434
435
436 static const struct address_space_operations def_mdt_aops = {
437 .writepage = nilfs_mdt_write_page,
438 };
439
440 static const struct inode_operations def_mdt_iops;
441 static const struct file_operations def_mdt_fops;
442
443
444 int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz)
445 {
446 struct nilfs_mdt_info *mi;
447
448 mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS);
449 if (!mi)
450 return -ENOMEM;
451
452 init_rwsem(&mi->mi_sem);
453 inode->i_private = mi;
454
455 inode->i_mode = S_IFREG;
456 mapping_set_gfp_mask(inode->i_mapping, gfp_mask);
457
458 inode->i_op = &def_mdt_iops;
459 inode->i_fop = &def_mdt_fops;
460 inode->i_mapping->a_ops = &def_mdt_aops;
461
462 return 0;
463 }
464
465
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467
468
469 void nilfs_mdt_clear(struct inode *inode)
470 {
471 struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
472
473 if (mdi->mi_palloc_cache)
474 nilfs_palloc_destroy_cache(inode);
475 }
476
477
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480
481 void nilfs_mdt_destroy(struct inode *inode)
482 {
483 struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
484
485 kfree(mdi->mi_bgl);
486 kfree(mdi);
487 }
488
489 void nilfs_mdt_set_entry_size(struct inode *inode, unsigned int entry_size,
490 unsigned int header_size)
491 {
492 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
493
494 mi->mi_entry_size = entry_size;
495 mi->mi_entries_per_block = i_blocksize(inode) / entry_size;
496 mi->mi_first_entry_offset = DIV_ROUND_UP(header_size, entry_size);
497 }
498
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503
504 int nilfs_mdt_setup_shadow_map(struct inode *inode,
505 struct nilfs_shadow_map *shadow)
506 {
507 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
508
509 INIT_LIST_HEAD(&shadow->frozen_buffers);
510 address_space_init_once(&shadow->frozen_data);
511 nilfs_mapping_init(&shadow->frozen_data, inode);
512 address_space_init_once(&shadow->frozen_btnodes);
513 nilfs_mapping_init(&shadow->frozen_btnodes, inode);
514 mi->mi_shadow = shadow;
515 return 0;
516 }
517
518
519
520
521
522 int nilfs_mdt_save_to_shadow_map(struct inode *inode)
523 {
524 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
525 struct nilfs_inode_info *ii = NILFS_I(inode);
526 struct nilfs_shadow_map *shadow = mi->mi_shadow;
527 int ret;
528
529 ret = nilfs_copy_dirty_pages(&shadow->frozen_data, inode->i_mapping);
530 if (ret)
531 goto out;
532
533 ret = nilfs_copy_dirty_pages(&shadow->frozen_btnodes,
534 &ii->i_btnode_cache);
535 if (ret)
536 goto out;
537
538 nilfs_bmap_save(ii->i_bmap, &shadow->bmap_store);
539 out:
540 return ret;
541 }
542
543 int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh)
544 {
545 struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
546 struct buffer_head *bh_frozen;
547 struct page *page;
548 int blkbits = inode->i_blkbits;
549
550 page = grab_cache_page(&shadow->frozen_data, bh->b_page->index);
551 if (!page)
552 return -ENOMEM;
553
554 if (!page_has_buffers(page))
555 create_empty_buffers(page, 1 << blkbits, 0);
556
557 bh_frozen = nilfs_page_get_nth_block(page, bh_offset(bh) >> blkbits);
558
559 if (!buffer_uptodate(bh_frozen))
560 nilfs_copy_buffer(bh_frozen, bh);
561 if (list_empty(&bh_frozen->b_assoc_buffers)) {
562 list_add_tail(&bh_frozen->b_assoc_buffers,
563 &shadow->frozen_buffers);
564 set_buffer_nilfs_redirected(bh);
565 } else {
566 brelse(bh_frozen);
567 }
568
569 unlock_page(page);
570 put_page(page);
571 return 0;
572 }
573
574 struct buffer_head *
575 nilfs_mdt_get_frozen_buffer(struct inode *inode, struct buffer_head *bh)
576 {
577 struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
578 struct buffer_head *bh_frozen = NULL;
579 struct page *page;
580 int n;
581
582 page = find_lock_page(&shadow->frozen_data, bh->b_page->index);
583 if (page) {
584 if (page_has_buffers(page)) {
585 n = bh_offset(bh) >> inode->i_blkbits;
586 bh_frozen = nilfs_page_get_nth_block(page, n);
587 }
588 unlock_page(page);
589 put_page(page);
590 }
591 return bh_frozen;
592 }
593
594 static void nilfs_release_frozen_buffers(struct nilfs_shadow_map *shadow)
595 {
596 struct list_head *head = &shadow->frozen_buffers;
597 struct buffer_head *bh;
598
599 while (!list_empty(head)) {
600 bh = list_first_entry(head, struct buffer_head,
601 b_assoc_buffers);
602 list_del_init(&bh->b_assoc_buffers);
603 brelse(bh);
604 }
605 }
606
607
608
609
610
611 void nilfs_mdt_restore_from_shadow_map(struct inode *inode)
612 {
613 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
614 struct nilfs_inode_info *ii = NILFS_I(inode);
615 struct nilfs_shadow_map *shadow = mi->mi_shadow;
616
617 down_write(&mi->mi_sem);
618
619 if (mi->mi_palloc_cache)
620 nilfs_palloc_clear_cache(inode);
621
622 nilfs_clear_dirty_pages(inode->i_mapping, true);
623 nilfs_copy_back_pages(inode->i_mapping, &shadow->frozen_data);
624
625 nilfs_clear_dirty_pages(&ii->i_btnode_cache, true);
626 nilfs_copy_back_pages(&ii->i_btnode_cache, &shadow->frozen_btnodes);
627
628 nilfs_bmap_restore(ii->i_bmap, &shadow->bmap_store);
629
630 up_write(&mi->mi_sem);
631 }
632
633
634
635
636
637 void nilfs_mdt_clear_shadow_map(struct inode *inode)
638 {
639 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
640 struct nilfs_shadow_map *shadow = mi->mi_shadow;
641
642 down_write(&mi->mi_sem);
643 nilfs_release_frozen_buffers(shadow);
644 truncate_inode_pages(&shadow->frozen_data, 0);
645 truncate_inode_pages(&shadow->frozen_btnodes, 0);
646 up_write(&mi->mi_sem);
647 }