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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 | * | |
4b420ab4 | 16 | * Written by Ryusuke Konishi. |
5eb563f5 RK |
17 | */ |
18 | ||
19 | #include <linux/buffer_head.h> | |
20 | #include <linux/mpage.h> | |
21 | #include <linux/mm.h> | |
22 | #include <linux/writeback.h> | |
23 | #include <linux/backing-dev.h> | |
24 | #include <linux/swap.h> | |
5a0e3ad6 | 25 | #include <linux/slab.h> |
5eb563f5 | 26 | #include "nilfs.h" |
05d0e94b | 27 | #include "btnode.h" |
5eb563f5 RK |
28 | #include "segment.h" |
29 | #include "page.h" | |
30 | #include "mdt.h" | |
2d19961d | 31 | #include "alloc.h" /* nilfs_palloc_destroy_cache() */ |
5eb563f5 | 32 | |
a9cd207c | 33 | #include <trace/events/nilfs2.h> |
5eb563f5 RK |
34 | |
35 | #define NILFS_MDT_MAX_RA_BLOCKS (16 - 1) | |
36 | ||
5eb563f5 RK |
37 | |
38 | static int | |
39 | nilfs_mdt_insert_new_block(struct inode *inode, unsigned long block, | |
40 | struct buffer_head *bh, | |
41 | void (*init_block)(struct inode *, | |
42 | struct buffer_head *, void *)) | |
43 | { | |
44 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
45 | void *kaddr; | |
46 | int ret; | |
47 | ||
48 | /* Caller exclude read accesses using page lock */ | |
49 | ||
50 | /* set_buffer_new(bh); */ | |
51 | bh->b_blocknr = 0; | |
52 | ||
53 | ret = nilfs_bmap_insert(ii->i_bmap, block, (unsigned long)bh); | |
54 | if (unlikely(ret)) | |
55 | return ret; | |
56 | ||
57 | set_buffer_mapped(bh); | |
58 | ||
7b9c0976 | 59 | kaddr = kmap_atomic(bh->b_page); |
5eb563f5 RK |
60 | memset(kaddr + bh_offset(bh), 0, 1 << inode->i_blkbits); |
61 | if (init_block) | |
62 | init_block(inode, bh, kaddr); | |
63 | flush_dcache_page(bh->b_page); | |
7b9c0976 | 64 | kunmap_atomic(kaddr); |
5eb563f5 RK |
65 | |
66 | set_buffer_uptodate(bh); | |
5fc7b141 | 67 | mark_buffer_dirty(bh); |
5eb563f5 | 68 | nilfs_mdt_mark_dirty(inode); |
a9cd207c HM |
69 | |
70 | trace_nilfs2_mdt_insert_new_block(inode, inode->i_ino, block); | |
71 | ||
5eb563f5 RK |
72 | return 0; |
73 | } | |
74 | ||
75 | static int nilfs_mdt_create_block(struct inode *inode, unsigned long block, | |
76 | struct buffer_head **out_bh, | |
77 | void (*init_block)(struct inode *, | |
78 | struct buffer_head *, | |
79 | void *)) | |
80 | { | |
5eb563f5 RK |
81 | struct super_block *sb = inode->i_sb; |
82 | struct nilfs_transaction_info ti; | |
83 | struct buffer_head *bh; | |
84 | int err; | |
85 | ||
5eb563f5 RK |
86 | nilfs_transaction_begin(sb, &ti, 0); |
87 | ||
88 | err = -ENOMEM; | |
89 | bh = nilfs_grab_buffer(inode, inode->i_mapping, block, 0); | |
90 | if (unlikely(!bh)) | |
91 | goto failed_unlock; | |
92 | ||
93 | err = -EEXIST; | |
14351104 | 94 | if (buffer_uptodate(bh)) |
5eb563f5 | 95 | goto failed_bh; |
14351104 | 96 | |
5eb563f5 RK |
97 | wait_on_buffer(bh); |
98 | if (buffer_uptodate(bh)) | |
99 | goto failed_bh; | |
5eb563f5 | 100 | |
090fd5b1 | 101 | bh->b_bdev = sb->s_bdev; |
5eb563f5 RK |
102 | err = nilfs_mdt_insert_new_block(inode, block, bh, init_block); |
103 | if (likely(!err)) { | |
104 | get_bh(bh); | |
105 | *out_bh = bh; | |
106 | } | |
107 | ||
108 | failed_bh: | |
109 | unlock_page(bh->b_page); | |
09cbfeaf | 110 | put_page(bh->b_page); |
5eb563f5 RK |
111 | brelse(bh); |
112 | ||
113 | failed_unlock: | |
47420c79 RK |
114 | if (likely(!err)) |
115 | err = nilfs_transaction_commit(sb); | |
116 | else | |
117 | nilfs_transaction_abort(sb); | |
090fd5b1 | 118 | |
5eb563f5 RK |
119 | return err; |
120 | } | |
121 | ||
122 | static int | |
123 | nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff, | |
2a222ca9 | 124 | int mode, int mode_flags, struct buffer_head **out_bh) |
5eb563f5 RK |
125 | { |
126 | struct buffer_head *bh; | |
0f3fe33b | 127 | __u64 blknum = 0; |
5eb563f5 RK |
128 | int ret = -ENOMEM; |
129 | ||
130 | bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0); | |
131 | if (unlikely(!bh)) | |
132 | goto failed; | |
133 | ||
134 | ret = -EEXIST; /* internal code */ | |
135 | if (buffer_uptodate(bh)) | |
136 | goto out; | |
137 | ||
2a222ca9 | 138 | if (mode_flags & REQ_RAHEAD) { |
5eb563f5 RK |
139 | if (!trylock_buffer(bh)) { |
140 | ret = -EBUSY; | |
141 | goto failed_bh; | |
142 | } | |
1f5abe7e | 143 | } else /* mode == READ */ |
5eb563f5 | 144 | lock_buffer(bh); |
5eb563f5 RK |
145 | |
146 | if (buffer_uptodate(bh)) { | |
147 | unlock_buffer(bh); | |
148 | goto out; | |
149 | } | |
14351104 RK |
150 | |
151 | ret = nilfs_bmap_lookup(NILFS_I(inode)->i_bmap, blkoff, &blknum); | |
152 | if (unlikely(ret)) { | |
153 | unlock_buffer(bh); | |
154 | goto failed_bh; | |
5eb563f5 | 155 | } |
c6e07188 | 156 | map_bh(bh, inode->i_sb, (sector_t)blknum); |
5eb563f5 RK |
157 | |
158 | bh->b_end_io = end_buffer_read_sync; | |
159 | get_bh(bh); | |
2a222ca9 | 160 | submit_bh(mode, mode_flags, bh); |
5eb563f5 | 161 | ret = 0; |
a9cd207c HM |
162 | |
163 | trace_nilfs2_mdt_submit_block(inode, inode->i_ino, blkoff, mode); | |
5eb563f5 RK |
164 | out: |
165 | get_bh(bh); | |
166 | *out_bh = bh; | |
167 | ||
168 | failed_bh: | |
169 | unlock_page(bh->b_page); | |
09cbfeaf | 170 | put_page(bh->b_page); |
5eb563f5 RK |
171 | brelse(bh); |
172 | failed: | |
173 | return ret; | |
174 | } | |
175 | ||
176 | static int nilfs_mdt_read_block(struct inode *inode, unsigned long block, | |
b34a6506 | 177 | int readahead, struct buffer_head **out_bh) |
5eb563f5 RK |
178 | { |
179 | struct buffer_head *first_bh, *bh; | |
180 | unsigned long blkoff; | |
181 | int i, nr_ra_blocks = NILFS_MDT_MAX_RA_BLOCKS; | |
182 | int err; | |
183 | ||
2a222ca9 | 184 | err = nilfs_mdt_submit_block(inode, block, REQ_OP_READ, 0, &first_bh); |
5eb563f5 RK |
185 | if (err == -EEXIST) /* internal code */ |
186 | goto out; | |
187 | ||
188 | if (unlikely(err)) | |
189 | goto failed; | |
190 | ||
b34a6506 RK |
191 | if (readahead) { |
192 | blkoff = block + 1; | |
193 | for (i = 0; i < nr_ra_blocks; i++, blkoff++) { | |
2a222ca9 MC |
194 | err = nilfs_mdt_submit_block(inode, blkoff, REQ_OP_READ, |
195 | REQ_RAHEAD, &bh); | |
b34a6506 RK |
196 | if (likely(!err || err == -EEXIST)) |
197 | brelse(bh); | |
198 | else if (err != -EBUSY) | |
199 | break; | |
200 | /* abort readahead if bmap lookup failed */ | |
201 | if (!buffer_locked(first_bh)) | |
202 | goto out_no_wait; | |
203 | } | |
5eb563f5 RK |
204 | } |
205 | ||
206 | wait_on_buffer(first_bh); | |
207 | ||
208 | out_no_wait: | |
209 | err = -EIO; | |
210 | if (!buffer_uptodate(first_bh)) | |
211 | goto failed_bh; | |
212 | out: | |
213 | *out_bh = first_bh; | |
214 | return 0; | |
215 | ||
216 | failed_bh: | |
217 | brelse(first_bh); | |
218 | failed: | |
219 | return err; | |
220 | } | |
221 | ||
222 | /** | |
223 | * nilfs_mdt_get_block - read or create a buffer on meta data file. | |
224 | * @inode: inode of the meta data file | |
225 | * @blkoff: block offset | |
226 | * @create: create flag | |
227 | * @init_block: initializer used for newly allocated block | |
228 | * @out_bh: output of a pointer to the buffer_head | |
229 | * | |
230 | * nilfs_mdt_get_block() looks up the specified buffer and tries to create | |
231 | * a new buffer if @create is not zero. On success, the returned buffer is | |
232 | * assured to be either existing or formatted using a buffer lock on success. | |
233 | * @out_bh is substituted only when zero is returned. | |
234 | * | |
235 | * Return Value: On success, it returns 0. On error, the following negative | |
236 | * error code is returned. | |
237 | * | |
238 | * %-ENOMEM - Insufficient memory available. | |
239 | * | |
240 | * %-EIO - I/O error | |
241 | * | |
242 | * %-ENOENT - the specified block does not exist (hole block) | |
243 | * | |
5eb563f5 RK |
244 | * %-EROFS - Read only filesystem (for create mode) |
245 | */ | |
246 | int nilfs_mdt_get_block(struct inode *inode, unsigned long blkoff, int create, | |
247 | void (*init_block)(struct inode *, | |
248 | struct buffer_head *, void *), | |
249 | struct buffer_head **out_bh) | |
250 | { | |
251 | int ret; | |
252 | ||
253 | /* Should be rewritten with merging nilfs_mdt_read_block() */ | |
254 | retry: | |
b34a6506 | 255 | ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh); |
5eb563f5 RK |
256 | if (!create || ret != -ENOENT) |
257 | return ret; | |
258 | ||
259 | ret = nilfs_mdt_create_block(inode, blkoff, out_bh, init_block); | |
260 | if (unlikely(ret == -EEXIST)) { | |
261 | /* create = 0; */ /* limit read-create loop retries */ | |
262 | goto retry; | |
263 | } | |
264 | return ret; | |
265 | } | |
266 | ||
fa33915c RK |
267 | /** |
268 | * nilfs_mdt_find_block - find and get a buffer on meta data file. | |
269 | * @inode: inode of the meta data file | |
270 | * @start: start block offset (inclusive) | |
271 | * @end: end block offset (inclusive) | |
272 | * @blkoff: block offset | |
273 | * @out_bh: place to store a pointer to buffer_head struct | |
274 | * | |
275 | * nilfs_mdt_find_block() looks up an existing block in range of | |
276 | * [@start, @end] and stores pointer to a buffer head of the block to | |
277 | * @out_bh, and block offset to @blkoff, respectively. @out_bh and | |
278 | * @blkoff are substituted only when zero is returned. | |
279 | * | |
280 | * Return Value: On success, it returns 0. On error, the following negative | |
281 | * error code is returned. | |
282 | * | |
283 | * %-ENOMEM - Insufficient memory available. | |
284 | * | |
285 | * %-EIO - I/O error | |
286 | * | |
287 | * %-ENOENT - no block was found in the range | |
288 | */ | |
289 | int nilfs_mdt_find_block(struct inode *inode, unsigned long start, | |
290 | unsigned long end, unsigned long *blkoff, | |
291 | struct buffer_head **out_bh) | |
292 | { | |
293 | __u64 next; | |
294 | int ret; | |
295 | ||
296 | if (unlikely(start > end)) | |
297 | return -ENOENT; | |
298 | ||
299 | ret = nilfs_mdt_read_block(inode, start, true, out_bh); | |
300 | if (!ret) { | |
301 | *blkoff = start; | |
302 | goto out; | |
303 | } | |
304 | if (unlikely(ret != -ENOENT || start == ULONG_MAX)) | |
305 | goto out; | |
306 | ||
307 | ret = nilfs_bmap_seek_key(NILFS_I(inode)->i_bmap, start + 1, &next); | |
308 | if (!ret) { | |
309 | if (next <= end) { | |
310 | ret = nilfs_mdt_read_block(inode, next, true, out_bh); | |
311 | if (!ret) | |
312 | *blkoff = next; | |
313 | } else { | |
314 | ret = -ENOENT; | |
315 | } | |
316 | } | |
317 | out: | |
318 | return ret; | |
319 | } | |
320 | ||
5eb563f5 RK |
321 | /** |
322 | * nilfs_mdt_delete_block - make a hole on the meta data file. | |
323 | * @inode: inode of the meta data file | |
324 | * @block: block offset | |
325 | * | |
326 | * Return Value: On success, zero is returned. | |
327 | * On error, one of the following negative error code is returned. | |
328 | * | |
329 | * %-ENOMEM - Insufficient memory available. | |
330 | * | |
331 | * %-EIO - I/O error | |
5eb563f5 RK |
332 | */ |
333 | int nilfs_mdt_delete_block(struct inode *inode, unsigned long block) | |
334 | { | |
335 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
336 | int err; | |
337 | ||
338 | err = nilfs_bmap_delete(ii->i_bmap, block); | |
84338237 | 339 | if (!err || err == -ENOENT) { |
5eb563f5 RK |
340 | nilfs_mdt_mark_dirty(inode); |
341 | nilfs_mdt_forget_block(inode, block); | |
342 | } | |
343 | return err; | |
344 | } | |
345 | ||
346 | /** | |
347 | * nilfs_mdt_forget_block - discard dirty state and try to remove the page | |
348 | * @inode: inode of the meta data file | |
349 | * @block: block offset | |
350 | * | |
351 | * nilfs_mdt_forget_block() clears a dirty flag of the specified buffer, and | |
352 | * tries to release the page including the buffer from a page cache. | |
353 | * | |
354 | * Return Value: On success, 0 is returned. On error, one of the following | |
355 | * negative error code is returned. | |
356 | * | |
357 | * %-EBUSY - page has an active buffer. | |
358 | * | |
359 | * %-ENOENT - page cache has no page addressed by the offset. | |
360 | */ | |
361 | int nilfs_mdt_forget_block(struct inode *inode, unsigned long block) | |
362 | { | |
363 | pgoff_t index = (pgoff_t)block >> | |
09cbfeaf | 364 | (PAGE_SHIFT - inode->i_blkbits); |
5eb563f5 RK |
365 | struct page *page; |
366 | unsigned long first_block; | |
367 | int ret = 0; | |
368 | int still_dirty; | |
369 | ||
370 | page = find_lock_page(inode->i_mapping, index); | |
371 | if (!page) | |
372 | return -ENOENT; | |
373 | ||
374 | wait_on_page_writeback(page); | |
375 | ||
376 | first_block = (unsigned long)index << | |
09cbfeaf | 377 | (PAGE_SHIFT - inode->i_blkbits); |
5eb563f5 RK |
378 | if (page_has_buffers(page)) { |
379 | struct buffer_head *bh; | |
380 | ||
381 | bh = nilfs_page_get_nth_block(page, block - first_block); | |
382 | nilfs_forget_buffer(bh); | |
383 | } | |
384 | still_dirty = PageDirty(page); | |
385 | unlock_page(page); | |
09cbfeaf | 386 | put_page(page); |
5eb563f5 RK |
387 | |
388 | if (still_dirty || | |
389 | invalidate_inode_pages2_range(inode->i_mapping, index, index) != 0) | |
390 | ret = -EBUSY; | |
391 | return ret; | |
392 | } | |
393 | ||
5eb563f5 RK |
394 | int nilfs_mdt_fetch_dirty(struct inode *inode) |
395 | { | |
396 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
397 | ||
398 | if (nilfs_bmap_test_and_clear_dirty(ii->i_bmap)) { | |
399 | set_bit(NILFS_I_DIRTY, &ii->i_state); | |
400 | return 1; | |
401 | } | |
402 | return test_bit(NILFS_I_DIRTY, &ii->i_state); | |
403 | } | |
404 | ||
405 | static int | |
406 | nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc) | |
407 | { | |
8c26c4e2 | 408 | struct inode *inode = page->mapping->host; |
ebdfed4d | 409 | struct super_block *sb; |
5eb563f5 RK |
410 | int err = 0; |
411 | ||
8c26c4e2 VD |
412 | if (inode && (inode->i_sb->s_flags & MS_RDONLY)) { |
413 | /* | |
414 | * It means that filesystem was remounted in read-only | |
415 | * mode because of error or metadata corruption. But we | |
416 | * have dirty pages that try to be flushed in background. | |
417 | * So, here we simply discard this dirty page. | |
418 | */ | |
419 | nilfs_clear_dirty_page(page, false); | |
420 | unlock_page(page); | |
421 | return -EROFS; | |
422 | } | |
423 | ||
5eb563f5 RK |
424 | redirty_page_for_writepage(wbc, page); |
425 | unlock_page(page); | |
426 | ||
ebdfed4d RK |
427 | if (!inode) |
428 | return 0; | |
429 | ||
430 | sb = inode->i_sb; | |
5eb563f5 RK |
431 | |
432 | if (wbc->sync_mode == WB_SYNC_ALL) | |
433 | err = nilfs_construct_segment(sb); | |
434 | else if (wbc->for_reclaim) | |
435 | nilfs_flush_segment(sb, inode->i_ino); | |
436 | ||
5eb563f5 RK |
437 | return err; |
438 | } | |
439 | ||
440 | ||
7f09410b | 441 | static const struct address_space_operations def_mdt_aops = { |
5eb563f5 RK |
442 | .writepage = nilfs_mdt_write_page, |
443 | }; | |
444 | ||
6e1d5dcc | 445 | static const struct inode_operations def_mdt_iops; |
828c0950 | 446 | static const struct file_operations def_mdt_fops; |
5eb563f5 | 447 | |
5e19a995 | 448 | |
f1e89c86 | 449 | int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz) |
5e19a995 RK |
450 | { |
451 | struct nilfs_mdt_info *mi; | |
452 | ||
453 | mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS); | |
454 | if (!mi) | |
455 | return -ENOMEM; | |
456 | ||
5e19a995 RK |
457 | init_rwsem(&mi->mi_sem); |
458 | inode->i_private = mi; | |
459 | ||
460 | inode->i_mode = S_IFREG; | |
461 | mapping_set_gfp_mask(inode->i_mapping, gfp_mask); | |
f1e89c86 RK |
462 | |
463 | inode->i_op = &def_mdt_iops; | |
464 | inode->i_fop = &def_mdt_fops; | |
465 | inode->i_mapping->a_ops = &def_mdt_aops; | |
5e19a995 RK |
466 | |
467 | return 0; | |
468 | } | |
469 | ||
2d19961d RK |
470 | /** |
471 | * nilfs_mdt_clear - do cleanup for the metadata file | |
472 | * @inode: inode of the metadata file | |
473 | */ | |
474 | void nilfs_mdt_clear(struct inode *inode) | |
475 | { | |
476 | struct nilfs_mdt_info *mdi = NILFS_MDT(inode); | |
477 | ||
478 | if (mdi->mi_palloc_cache) | |
479 | nilfs_palloc_destroy_cache(inode); | |
480 | } | |
481 | ||
482 | /** | |
483 | * nilfs_mdt_destroy - release resources used by the metadata file | |
484 | * @inode: inode of the metadata file | |
485 | */ | |
486 | void nilfs_mdt_destroy(struct inode *inode) | |
487 | { | |
488 | struct nilfs_mdt_info *mdi = NILFS_MDT(inode); | |
489 | ||
490 | kfree(mdi->mi_bgl); /* kfree(NULL) is safe */ | |
491 | kfree(mdi); | |
492 | } | |
493 | ||
0c6c44cb RK |
494 | void nilfs_mdt_set_entry_size(struct inode *inode, unsigned int entry_size, |
495 | unsigned int header_size) | |
5eb563f5 RK |
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 | 574 | unlock_page(page); |
09cbfeaf | 575 | put_page(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); | |
09cbfeaf | 594 | put_page(page); |
b1f6a4f2 RK |
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 | } |