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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 | ||
a9cd207c | 36 | #include <trace/events/nilfs2.h> |
5eb563f5 RK |
37 | |
38 | #define NILFS_MDT_MAX_RA_BLOCKS (16 - 1) | |
39 | ||
5eb563f5 RK |
40 | |
41 | static int | |
42 | nilfs_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 | ||
7b9c0976 | 62 | kaddr = kmap_atomic(bh->b_page); |
5eb563f5 RK |
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); | |
7b9c0976 | 67 | kunmap_atomic(kaddr); |
5eb563f5 RK |
68 | |
69 | set_buffer_uptodate(bh); | |
5fc7b141 | 70 | mark_buffer_dirty(bh); |
5eb563f5 | 71 | nilfs_mdt_mark_dirty(inode); |
a9cd207c HM |
72 | |
73 | trace_nilfs2_mdt_insert_new_block(inode, inode->i_ino, block); | |
74 | ||
5eb563f5 RK |
75 | return 0; |
76 | } | |
77 | ||
78 | static 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 | { | |
5eb563f5 RK |
84 | struct super_block *sb = inode->i_sb; |
85 | struct nilfs_transaction_info ti; | |
86 | struct buffer_head *bh; | |
87 | int err; | |
88 | ||
5eb563f5 RK |
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; | |
14351104 | 97 | if (buffer_uptodate(bh)) |
5eb563f5 | 98 | goto failed_bh; |
14351104 | 99 | |
5eb563f5 RK |
100 | wait_on_buffer(bh); |
101 | if (buffer_uptodate(bh)) | |
102 | goto failed_bh; | |
5eb563f5 | 103 | |
090fd5b1 | 104 | bh->b_bdev = sb->s_bdev; |
5eb563f5 RK |
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); | |
09cbfeaf | 113 | put_page(bh->b_page); |
5eb563f5 RK |
114 | brelse(bh); |
115 | ||
116 | failed_unlock: | |
47420c79 RK |
117 | if (likely(!err)) |
118 | err = nilfs_transaction_commit(sb); | |
119 | else | |
120 | nilfs_transaction_abort(sb); | |
090fd5b1 | 121 | |
5eb563f5 RK |
122 | return err; |
123 | } | |
124 | ||
125 | static int | |
126 | nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff, | |
127 | int mode, struct buffer_head **out_bh) | |
128 | { | |
129 | struct buffer_head *bh; | |
0f3fe33b | 130 | __u64 blknum = 0; |
5eb563f5 RK |
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 | } | |
1f5abe7e | 146 | } else /* mode == READ */ |
5eb563f5 | 147 | lock_buffer(bh); |
5eb563f5 RK |
148 | |
149 | if (buffer_uptodate(bh)) { | |
150 | unlock_buffer(bh); | |
151 | goto out; | |
152 | } | |
14351104 RK |
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; | |
5eb563f5 | 158 | } |
c6e07188 | 159 | map_bh(bh, inode->i_sb, (sector_t)blknum); |
5eb563f5 RK |
160 | |
161 | bh->b_end_io = end_buffer_read_sync; | |
162 | get_bh(bh); | |
163 | submit_bh(mode, bh); | |
164 | ret = 0; | |
a9cd207c HM |
165 | |
166 | trace_nilfs2_mdt_submit_block(inode, inode->i_ino, blkoff, mode); | |
5eb563f5 RK |
167 | out: |
168 | get_bh(bh); | |
169 | *out_bh = bh; | |
170 | ||
171 | failed_bh: | |
172 | unlock_page(bh->b_page); | |
09cbfeaf | 173 | put_page(bh->b_page); |
5eb563f5 RK |
174 | brelse(bh); |
175 | failed: | |
176 | return ret; | |
177 | } | |
178 | ||
179 | static int nilfs_mdt_read_block(struct inode *inode, unsigned long block, | |
b34a6506 | 180 | int readahead, struct buffer_head **out_bh) |
5eb563f5 RK |
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 | ||
b34a6506 RK |
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 | } | |
5eb563f5 RK |
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 | * | |
5eb563f5 RK |
246 | * %-EROFS - Read only filesystem (for create mode) |
247 | */ | |
248 | int 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: | |
b34a6506 | 257 | ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh); |
5eb563f5 RK |
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 | ||
fa33915c RK |
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 | */ | |
291 | int 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 | } | |
319 | out: | |
320 | return ret; | |
321 | } | |
322 | ||
5eb563f5 RK |
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 | |
5eb563f5 RK |
334 | */ |
335 | int 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); | |
84338237 | 341 | if (!err || err == -ENOENT) { |
5eb563f5 RK |
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 | */ | |
363 | int nilfs_mdt_forget_block(struct inode *inode, unsigned long block) | |
364 | { | |
365 | pgoff_t index = (pgoff_t)block >> | |
09cbfeaf | 366 | (PAGE_SHIFT - inode->i_blkbits); |
5eb563f5 RK |
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 << | |
09cbfeaf | 379 | (PAGE_SHIFT - inode->i_blkbits); |
5eb563f5 RK |
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); | |
09cbfeaf | 388 | put_page(page); |
5eb563f5 RK |
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) | |
5eb563f5 RK |
409 | */ |
410 | int nilfs_mdt_mark_block_dirty(struct inode *inode, unsigned long block) | |
411 | { | |
412 | struct buffer_head *bh; | |
413 | int err; | |
414 | ||
b34a6506 | 415 | err = nilfs_mdt_read_block(inode, block, 0, &bh); |
5eb563f5 RK |
416 | if (unlikely(err)) |
417 | return err; | |
5fc7b141 | 418 | mark_buffer_dirty(bh); |
5eb563f5 RK |
419 | nilfs_mdt_mark_dirty(inode); |
420 | brelse(bh); | |
421 | return 0; | |
422 | } | |
423 | ||
424 | int 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 | ||
435 | static int | |
436 | nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc) | |
437 | { | |
8c26c4e2 | 438 | struct inode *inode = page->mapping->host; |
ebdfed4d | 439 | struct super_block *sb; |
5eb563f5 RK |
440 | int err = 0; |
441 | ||
8c26c4e2 VD |
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 | ||
5eb563f5 RK |
454 | redirty_page_for_writepage(wbc, page); |
455 | unlock_page(page); | |
456 | ||
ebdfed4d RK |
457 | if (!inode) |
458 | return 0; | |
459 | ||
460 | sb = inode->i_sb; | |
5eb563f5 RK |
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 | ||
5eb563f5 RK |
467 | return err; |
468 | } | |
469 | ||
470 | ||
7f09410b | 471 | static const struct address_space_operations def_mdt_aops = { |
5eb563f5 RK |
472 | .writepage = nilfs_mdt_write_page, |
473 | }; | |
474 | ||
6e1d5dcc | 475 | static const struct inode_operations def_mdt_iops; |
828c0950 | 476 | static const struct file_operations def_mdt_fops; |
5eb563f5 | 477 | |
5e19a995 | 478 | |
f1e89c86 | 479 | int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz) |
5e19a995 RK |
480 | { |
481 | struct nilfs_mdt_info *mi; | |
482 | ||
483 | mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS); | |
484 | if (!mi) | |
485 | return -ENOMEM; | |
486 | ||
5e19a995 RK |
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); | |
f1e89c86 RK |
492 | |
493 | inode->i_op = &def_mdt_iops; | |
494 | inode->i_fop = &def_mdt_fops; | |
495 | inode->i_mapping->a_ops = &def_mdt_aops; | |
5e19a995 RK |
496 | |
497 | return 0; | |
498 | } | |
499 | ||
5eb563f5 RK |
500 | void 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 | ||
ebdfed4d RK |
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 | */ | |
515 | int nilfs_mdt_setup_shadow_map(struct inode *inode, | |
516 | struct nilfs_shadow_map *shadow) | |
517 | { | |
518 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
ebdfed4d RK |
519 | |
520 | INIT_LIST_HEAD(&shadow->frozen_buffers); | |
2aa15890 | 521 | address_space_init_once(&shadow->frozen_data); |
b83ae6d4 | 522 | nilfs_mapping_init(&shadow->frozen_data, inode); |
2aa15890 | 523 | address_space_init_once(&shadow->frozen_btnodes); |
b83ae6d4 | 524 | nilfs_mapping_init(&shadow->frozen_btnodes, inode); |
ebdfed4d RK |
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 | */ | |
533 | int 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 | ||
b1f6a4f2 RK |
554 | int 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; | |
b1f6a4f2 RK |
560 | |
561 | page = grab_cache_page(&shadow->frozen_data, bh->b_page->index); | |
562 | if (!page) | |
a7a8447e | 563 | return -ENOMEM; |
b1f6a4f2 RK |
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); | |
a7a8447e RK |
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 */ | |
b1f6a4f2 | 578 | } |
a7a8447e | 579 | |
b1f6a4f2 | 580 | unlock_page(page); |
09cbfeaf | 581 | put_page(page); |
a7a8447e | 582 | return 0; |
b1f6a4f2 RK |
583 | } |
584 | ||
585 | struct buffer_head * | |
586 | nilfs_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); | |
09cbfeaf | 600 | put_page(page); |
b1f6a4f2 RK |
601 | } |
602 | return bh_frozen; | |
603 | } | |
604 | ||
605 | static 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 | ||
ebdfed4d RK |
618 | /** |
619 | * nilfs_mdt_restore_from_shadow_map - restore dirty pages and bmap state | |
620 | * @inode: inode of the metadata file | |
621 | */ | |
622 | void 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 | ||
8c26c4e2 | 633 | nilfs_clear_dirty_pages(inode->i_mapping, true); |
ebdfed4d RK |
634 | nilfs_copy_back_pages(inode->i_mapping, &shadow->frozen_data); |
635 | ||
8c26c4e2 | 636 | nilfs_clear_dirty_pages(&ii->i_btnode_cache, true); |
ebdfed4d RK |
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 | */ | |
648 | void 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); | |
b1f6a4f2 | 654 | nilfs_release_frozen_buffers(shadow); |
ebdfed4d RK |
655 | truncate_inode_pages(&shadow->frozen_data, 0); |
656 | truncate_inode_pages(&shadow->frozen_btnodes, 0); | |
657 | up_write(&mi->mi_sem); | |
658 | } |