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5eb563f5 RK |
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> | |
5a0e3ad6 | 29 | #include <linux/slab.h> |
5eb563f5 | 30 | #include "nilfs.h" |
05d0e94b | 31 | #include "btnode.h" |
5eb563f5 RK |
32 | #include "segment.h" |
33 | #include "page.h" | |
34 | #include "mdt.h" | |
35 | ||
36 | ||
37 | #define NILFS_MDT_MAX_RA_BLOCKS (16 - 1) | |
38 | ||
5eb563f5 RK |
39 | |
40 | static int | |
41 | nilfs_mdt_insert_new_block(struct inode *inode, unsigned long block, | |
42 | struct buffer_head *bh, | |
43 | void (*init_block)(struct inode *, | |
44 | struct buffer_head *, void *)) | |
45 | { | |
46 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
47 | void *kaddr; | |
48 | int ret; | |
49 | ||
50 | /* Caller exclude read accesses using page lock */ | |
51 | ||
52 | /* set_buffer_new(bh); */ | |
53 | bh->b_blocknr = 0; | |
54 | ||
55 | ret = nilfs_bmap_insert(ii->i_bmap, block, (unsigned long)bh); | |
56 | if (unlikely(ret)) | |
57 | return ret; | |
58 | ||
59 | set_buffer_mapped(bh); | |
60 | ||
7b9c0976 | 61 | kaddr = kmap_atomic(bh->b_page); |
5eb563f5 RK |
62 | memset(kaddr + bh_offset(bh), 0, 1 << inode->i_blkbits); |
63 | if (init_block) | |
64 | init_block(inode, bh, kaddr); | |
65 | flush_dcache_page(bh->b_page); | |
7b9c0976 | 66 | kunmap_atomic(kaddr); |
5eb563f5 RK |
67 | |
68 | set_buffer_uptodate(bh); | |
5fc7b141 | 69 | mark_buffer_dirty(bh); |
5eb563f5 RK |
70 | nilfs_mdt_mark_dirty(inode); |
71 | return 0; | |
72 | } | |
73 | ||
74 | static int nilfs_mdt_create_block(struct inode *inode, unsigned long block, | |
75 | struct buffer_head **out_bh, | |
76 | void (*init_block)(struct inode *, | |
77 | struct buffer_head *, | |
78 | void *)) | |
79 | { | |
5eb563f5 RK |
80 | struct super_block *sb = inode->i_sb; |
81 | struct nilfs_transaction_info ti; | |
82 | struct buffer_head *bh; | |
83 | int err; | |
84 | ||
5eb563f5 RK |
85 | nilfs_transaction_begin(sb, &ti, 0); |
86 | ||
87 | err = -ENOMEM; | |
88 | bh = nilfs_grab_buffer(inode, inode->i_mapping, block, 0); | |
89 | if (unlikely(!bh)) | |
90 | goto failed_unlock; | |
91 | ||
92 | err = -EEXIST; | |
14351104 | 93 | if (buffer_uptodate(bh)) |
5eb563f5 | 94 | goto failed_bh; |
14351104 | 95 | |
5eb563f5 RK |
96 | wait_on_buffer(bh); |
97 | if (buffer_uptodate(bh)) | |
98 | goto failed_bh; | |
5eb563f5 | 99 | |
090fd5b1 | 100 | bh->b_bdev = sb->s_bdev; |
5eb563f5 RK |
101 | err = nilfs_mdt_insert_new_block(inode, block, bh, init_block); |
102 | if (likely(!err)) { | |
103 | get_bh(bh); | |
104 | *out_bh = bh; | |
105 | } | |
106 | ||
107 | failed_bh: | |
108 | unlock_page(bh->b_page); | |
109 | page_cache_release(bh->b_page); | |
110 | brelse(bh); | |
111 | ||
112 | failed_unlock: | |
47420c79 RK |
113 | if (likely(!err)) |
114 | err = nilfs_transaction_commit(sb); | |
115 | else | |
116 | nilfs_transaction_abort(sb); | |
090fd5b1 | 117 | |
5eb563f5 RK |
118 | return err; |
119 | } | |
120 | ||
121 | static int | |
122 | nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff, | |
123 | int mode, struct buffer_head **out_bh) | |
124 | { | |
125 | struct buffer_head *bh; | |
0f3fe33b | 126 | __u64 blknum = 0; |
5eb563f5 RK |
127 | int ret = -ENOMEM; |
128 | ||
129 | bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0); | |
130 | if (unlikely(!bh)) | |
131 | goto failed; | |
132 | ||
133 | ret = -EEXIST; /* internal code */ | |
134 | if (buffer_uptodate(bh)) | |
135 | goto out; | |
136 | ||
137 | if (mode == READA) { | |
138 | if (!trylock_buffer(bh)) { | |
139 | ret = -EBUSY; | |
140 | goto failed_bh; | |
141 | } | |
1f5abe7e | 142 | } else /* mode == READ */ |
5eb563f5 | 143 | lock_buffer(bh); |
5eb563f5 RK |
144 | |
145 | if (buffer_uptodate(bh)) { | |
146 | unlock_buffer(bh); | |
147 | goto out; | |
148 | } | |
14351104 RK |
149 | |
150 | ret = nilfs_bmap_lookup(NILFS_I(inode)->i_bmap, blkoff, &blknum); | |
151 | if (unlikely(ret)) { | |
152 | unlock_buffer(bh); | |
153 | goto failed_bh; | |
5eb563f5 | 154 | } |
c6e07188 | 155 | map_bh(bh, inode->i_sb, (sector_t)blknum); |
5eb563f5 RK |
156 | |
157 | bh->b_end_io = end_buffer_read_sync; | |
158 | get_bh(bh); | |
159 | submit_bh(mode, bh); | |
160 | ret = 0; | |
161 | out: | |
162 | get_bh(bh); | |
163 | *out_bh = bh; | |
164 | ||
165 | failed_bh: | |
166 | unlock_page(bh->b_page); | |
167 | page_cache_release(bh->b_page); | |
168 | brelse(bh); | |
169 | failed: | |
170 | return ret; | |
171 | } | |
172 | ||
173 | static int nilfs_mdt_read_block(struct inode *inode, unsigned long block, | |
b34a6506 | 174 | int readahead, struct buffer_head **out_bh) |
5eb563f5 RK |
175 | { |
176 | struct buffer_head *first_bh, *bh; | |
177 | unsigned long blkoff; | |
178 | int i, nr_ra_blocks = NILFS_MDT_MAX_RA_BLOCKS; | |
179 | int err; | |
180 | ||
181 | err = nilfs_mdt_submit_block(inode, block, READ, &first_bh); | |
182 | if (err == -EEXIST) /* internal code */ | |
183 | goto out; | |
184 | ||
185 | if (unlikely(err)) | |
186 | goto failed; | |
187 | ||
b34a6506 RK |
188 | if (readahead) { |
189 | blkoff = block + 1; | |
190 | for (i = 0; i < nr_ra_blocks; i++, blkoff++) { | |
191 | err = nilfs_mdt_submit_block(inode, blkoff, READA, &bh); | |
192 | if (likely(!err || err == -EEXIST)) | |
193 | brelse(bh); | |
194 | else if (err != -EBUSY) | |
195 | break; | |
196 | /* abort readahead if bmap lookup failed */ | |
197 | if (!buffer_locked(first_bh)) | |
198 | goto out_no_wait; | |
199 | } | |
5eb563f5 RK |
200 | } |
201 | ||
202 | wait_on_buffer(first_bh); | |
203 | ||
204 | out_no_wait: | |
205 | err = -EIO; | |
206 | if (!buffer_uptodate(first_bh)) | |
207 | goto failed_bh; | |
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 | * | |
5eb563f5 RK |
240 | * %-EROFS - Read only filesystem (for create mode) |
241 | */ | |
242 | int 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: | |
b34a6506 | 251 | ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh); |
5eb563f5 RK |
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 | ||
fa33915c RK |
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 | */ | |
285 | int 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 | } | |
313 | out: | |
314 | return ret; | |
315 | } | |
316 | ||
5eb563f5 RK |
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 | |
5eb563f5 RK |
328 | */ |
329 | int 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); | |
84338237 | 335 | if (!err || err == -ENOENT) { |
5eb563f5 RK |
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 | */ | |
357 | int nilfs_mdt_forget_block(struct inode *inode, unsigned long block) | |
358 | { | |
359 | pgoff_t index = (pgoff_t)block >> | |
360 | (PAGE_CACHE_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_CACHE_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 | page_cache_release(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 | ||
390 | /** | |
391 | * nilfs_mdt_mark_block_dirty - mark a block on the meta data file dirty. | |
392 | * @inode: inode of the meta data file | |
393 | * @block: block offset | |
394 | * | |
395 | * Return Value: On success, it returns 0. On error, the following negative | |
396 | * error code is returned. | |
397 | * | |
398 | * %-ENOMEM - Insufficient memory available. | |
399 | * | |
400 | * %-EIO - I/O error | |
401 | * | |
402 | * %-ENOENT - the specified block does not exist (hole block) | |
5eb563f5 RK |
403 | */ |
404 | int nilfs_mdt_mark_block_dirty(struct inode *inode, unsigned long block) | |
405 | { | |
406 | struct buffer_head *bh; | |
407 | int err; | |
408 | ||
b34a6506 | 409 | err = nilfs_mdt_read_block(inode, block, 0, &bh); |
5eb563f5 RK |
410 | if (unlikely(err)) |
411 | return err; | |
5fc7b141 | 412 | mark_buffer_dirty(bh); |
5eb563f5 RK |
413 | nilfs_mdt_mark_dirty(inode); |
414 | brelse(bh); | |
415 | return 0; | |
416 | } | |
417 | ||
418 | int nilfs_mdt_fetch_dirty(struct inode *inode) | |
419 | { | |
420 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
421 | ||
422 | if (nilfs_bmap_test_and_clear_dirty(ii->i_bmap)) { | |
423 | set_bit(NILFS_I_DIRTY, &ii->i_state); | |
424 | return 1; | |
425 | } | |
426 | return test_bit(NILFS_I_DIRTY, &ii->i_state); | |
427 | } | |
428 | ||
429 | static int | |
430 | nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc) | |
431 | { | |
8c26c4e2 | 432 | struct inode *inode = page->mapping->host; |
ebdfed4d | 433 | struct super_block *sb; |
5eb563f5 RK |
434 | int err = 0; |
435 | ||
8c26c4e2 VD |
436 | if (inode && (inode->i_sb->s_flags & MS_RDONLY)) { |
437 | /* | |
438 | * It means that filesystem was remounted in read-only | |
439 | * mode because of error or metadata corruption. But we | |
440 | * have dirty pages that try to be flushed in background. | |
441 | * So, here we simply discard this dirty page. | |
442 | */ | |
443 | nilfs_clear_dirty_page(page, false); | |
444 | unlock_page(page); | |
445 | return -EROFS; | |
446 | } | |
447 | ||
5eb563f5 RK |
448 | redirty_page_for_writepage(wbc, page); |
449 | unlock_page(page); | |
450 | ||
ebdfed4d RK |
451 | if (!inode) |
452 | return 0; | |
453 | ||
454 | sb = inode->i_sb; | |
5eb563f5 RK |
455 | |
456 | if (wbc->sync_mode == WB_SYNC_ALL) | |
457 | err = nilfs_construct_segment(sb); | |
458 | else if (wbc->for_reclaim) | |
459 | nilfs_flush_segment(sb, inode->i_ino); | |
460 | ||
5eb563f5 RK |
461 | return err; |
462 | } | |
463 | ||
464 | ||
7f09410b | 465 | static const struct address_space_operations def_mdt_aops = { |
5eb563f5 RK |
466 | .writepage = nilfs_mdt_write_page, |
467 | }; | |
468 | ||
6e1d5dcc | 469 | static const struct inode_operations def_mdt_iops; |
828c0950 | 470 | static const struct file_operations def_mdt_fops; |
5eb563f5 | 471 | |
5e19a995 | 472 | |
f1e89c86 | 473 | int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz) |
5e19a995 RK |
474 | { |
475 | struct nilfs_mdt_info *mi; | |
476 | ||
477 | mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS); | |
478 | if (!mi) | |
479 | return -ENOMEM; | |
480 | ||
5e19a995 RK |
481 | init_rwsem(&mi->mi_sem); |
482 | inode->i_private = mi; | |
483 | ||
484 | inode->i_mode = S_IFREG; | |
485 | mapping_set_gfp_mask(inode->i_mapping, gfp_mask); | |
f1e89c86 RK |
486 | |
487 | inode->i_op = &def_mdt_iops; | |
488 | inode->i_fop = &def_mdt_fops; | |
489 | inode->i_mapping->a_ops = &def_mdt_aops; | |
5e19a995 RK |
490 | |
491 | return 0; | |
492 | } | |
493 | ||
5eb563f5 RK |
494 | void nilfs_mdt_set_entry_size(struct inode *inode, unsigned entry_size, |
495 | unsigned header_size) | |
496 | { | |
497 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
498 | ||
499 | mi->mi_entry_size = entry_size; | |
500 | mi->mi_entries_per_block = (1 << inode->i_blkbits) / entry_size; | |
501 | mi->mi_first_entry_offset = DIV_ROUND_UP(header_size, entry_size); | |
502 | } | |
503 | ||
ebdfed4d RK |
504 | /** |
505 | * nilfs_mdt_setup_shadow_map - setup shadow map and bind it to metadata file | |
506 | * @inode: inode of the metadata file | |
507 | * @shadow: shadow mapping | |
508 | */ | |
509 | int nilfs_mdt_setup_shadow_map(struct inode *inode, | |
510 | struct nilfs_shadow_map *shadow) | |
511 | { | |
512 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
ebdfed4d RK |
513 | |
514 | INIT_LIST_HEAD(&shadow->frozen_buffers); | |
2aa15890 | 515 | address_space_init_once(&shadow->frozen_data); |
b83ae6d4 | 516 | nilfs_mapping_init(&shadow->frozen_data, inode); |
2aa15890 | 517 | address_space_init_once(&shadow->frozen_btnodes); |
b83ae6d4 | 518 | nilfs_mapping_init(&shadow->frozen_btnodes, inode); |
ebdfed4d RK |
519 | mi->mi_shadow = shadow; |
520 | return 0; | |
521 | } | |
522 | ||
523 | /** | |
524 | * nilfs_mdt_save_to_shadow_map - copy bmap and dirty pages to shadow map | |
525 | * @inode: inode of the metadata file | |
526 | */ | |
527 | int nilfs_mdt_save_to_shadow_map(struct inode *inode) | |
528 | { | |
529 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
530 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
531 | struct nilfs_shadow_map *shadow = mi->mi_shadow; | |
532 | int ret; | |
533 | ||
534 | ret = nilfs_copy_dirty_pages(&shadow->frozen_data, inode->i_mapping); | |
535 | if (ret) | |
536 | goto out; | |
537 | ||
538 | ret = nilfs_copy_dirty_pages(&shadow->frozen_btnodes, | |
539 | &ii->i_btnode_cache); | |
540 | if (ret) | |
541 | goto out; | |
542 | ||
543 | nilfs_bmap_save(ii->i_bmap, &shadow->bmap_store); | |
544 | out: | |
545 | return ret; | |
546 | } | |
547 | ||
b1f6a4f2 RK |
548 | int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh) |
549 | { | |
550 | struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow; | |
551 | struct buffer_head *bh_frozen; | |
552 | struct page *page; | |
553 | int blkbits = inode->i_blkbits; | |
b1f6a4f2 RK |
554 | |
555 | page = grab_cache_page(&shadow->frozen_data, bh->b_page->index); | |
556 | if (!page) | |
a7a8447e | 557 | return -ENOMEM; |
b1f6a4f2 RK |
558 | |
559 | if (!page_has_buffers(page)) | |
560 | create_empty_buffers(page, 1 << blkbits, 0); | |
561 | ||
562 | bh_frozen = nilfs_page_get_nth_block(page, bh_offset(bh) >> blkbits); | |
a7a8447e RK |
563 | |
564 | if (!buffer_uptodate(bh_frozen)) | |
565 | nilfs_copy_buffer(bh_frozen, bh); | |
566 | if (list_empty(&bh_frozen->b_assoc_buffers)) { | |
567 | list_add_tail(&bh_frozen->b_assoc_buffers, | |
568 | &shadow->frozen_buffers); | |
569 | set_buffer_nilfs_redirected(bh); | |
570 | } else { | |
571 | brelse(bh_frozen); /* already frozen */ | |
b1f6a4f2 | 572 | } |
a7a8447e | 573 | |
b1f6a4f2 RK |
574 | unlock_page(page); |
575 | page_cache_release(page); | |
a7a8447e | 576 | return 0; |
b1f6a4f2 RK |
577 | } |
578 | ||
579 | struct buffer_head * | |
580 | nilfs_mdt_get_frozen_buffer(struct inode *inode, struct buffer_head *bh) | |
581 | { | |
582 | struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow; | |
583 | struct buffer_head *bh_frozen = NULL; | |
584 | struct page *page; | |
585 | int n; | |
586 | ||
587 | page = find_lock_page(&shadow->frozen_data, bh->b_page->index); | |
588 | if (page) { | |
589 | if (page_has_buffers(page)) { | |
590 | n = bh_offset(bh) >> inode->i_blkbits; | |
591 | bh_frozen = nilfs_page_get_nth_block(page, n); | |
592 | } | |
593 | unlock_page(page); | |
594 | page_cache_release(page); | |
595 | } | |
596 | return bh_frozen; | |
597 | } | |
598 | ||
599 | static void nilfs_release_frozen_buffers(struct nilfs_shadow_map *shadow) | |
600 | { | |
601 | struct list_head *head = &shadow->frozen_buffers; | |
602 | struct buffer_head *bh; | |
603 | ||
604 | while (!list_empty(head)) { | |
605 | bh = list_first_entry(head, struct buffer_head, | |
606 | b_assoc_buffers); | |
607 | list_del_init(&bh->b_assoc_buffers); | |
608 | brelse(bh); /* drop ref-count to make it releasable */ | |
609 | } | |
610 | } | |
611 | ||
ebdfed4d RK |
612 | /** |
613 | * nilfs_mdt_restore_from_shadow_map - restore dirty pages and bmap state | |
614 | * @inode: inode of the metadata file | |
615 | */ | |
616 | void nilfs_mdt_restore_from_shadow_map(struct inode *inode) | |
617 | { | |
618 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
619 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
620 | struct nilfs_shadow_map *shadow = mi->mi_shadow; | |
621 | ||
622 | down_write(&mi->mi_sem); | |
623 | ||
624 | if (mi->mi_palloc_cache) | |
625 | nilfs_palloc_clear_cache(inode); | |
626 | ||
8c26c4e2 | 627 | nilfs_clear_dirty_pages(inode->i_mapping, true); |
ebdfed4d RK |
628 | nilfs_copy_back_pages(inode->i_mapping, &shadow->frozen_data); |
629 | ||
8c26c4e2 | 630 | nilfs_clear_dirty_pages(&ii->i_btnode_cache, true); |
ebdfed4d RK |
631 | nilfs_copy_back_pages(&ii->i_btnode_cache, &shadow->frozen_btnodes); |
632 | ||
633 | nilfs_bmap_restore(ii->i_bmap, &shadow->bmap_store); | |
634 | ||
635 | up_write(&mi->mi_sem); | |
636 | } | |
637 | ||
638 | /** | |
639 | * nilfs_mdt_clear_shadow_map - truncate pages in shadow map caches | |
640 | * @inode: inode of the metadata file | |
641 | */ | |
642 | void nilfs_mdt_clear_shadow_map(struct inode *inode) | |
643 | { | |
644 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
645 | struct nilfs_shadow_map *shadow = mi->mi_shadow; | |
646 | ||
647 | down_write(&mi->mi_sem); | |
b1f6a4f2 | 648 | nilfs_release_frozen_buffers(shadow); |
ebdfed4d RK |
649 | truncate_inode_pages(&shadow->frozen_data, 0); |
650 | truncate_inode_pages(&shadow->frozen_btnodes, 0); | |
651 | up_write(&mi->mi_sem); | |
652 | } |