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Commit | Line | Data |
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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); |
93407472 | 60 | memset(kaddr + bh_offset(bh), 0, i_blocksize(inode)); |
5eb563f5 RK |
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; | |
39a9dcca RK |
210 | if (!buffer_uptodate(first_bh)) { |
211 | nilfs_msg(inode->i_sb, KERN_ERR, | |
212 | "I/O error reading meta-data file (ino=%lu, block-offset=%lu)", | |
213 | inode->i_ino, block); | |
5eb563f5 | 214 | goto failed_bh; |
39a9dcca | 215 | } |
5eb563f5 RK |
216 | out: |
217 | *out_bh = first_bh; | |
218 | return 0; | |
219 | ||
220 | failed_bh: | |
221 | brelse(first_bh); | |
222 | failed: | |
223 | return err; | |
224 | } | |
225 | ||
226 | /** | |
227 | * nilfs_mdt_get_block - read or create a buffer on meta data file. | |
228 | * @inode: inode of the meta data file | |
229 | * @blkoff: block offset | |
230 | * @create: create flag | |
231 | * @init_block: initializer used for newly allocated block | |
232 | * @out_bh: output of a pointer to the buffer_head | |
233 | * | |
234 | * nilfs_mdt_get_block() looks up the specified buffer and tries to create | |
235 | * a new buffer if @create is not zero. On success, the returned buffer is | |
236 | * assured to be either existing or formatted using a buffer lock on success. | |
237 | * @out_bh is substituted only when zero is returned. | |
238 | * | |
239 | * Return Value: On success, it returns 0. On error, the following negative | |
240 | * error code is returned. | |
241 | * | |
242 | * %-ENOMEM - Insufficient memory available. | |
243 | * | |
244 | * %-EIO - I/O error | |
245 | * | |
246 | * %-ENOENT - the specified block does not exist (hole block) | |
247 | * | |
5eb563f5 RK |
248 | * %-EROFS - Read only filesystem (for create mode) |
249 | */ | |
250 | int nilfs_mdt_get_block(struct inode *inode, unsigned long blkoff, int create, | |
251 | void (*init_block)(struct inode *, | |
252 | struct buffer_head *, void *), | |
253 | struct buffer_head **out_bh) | |
254 | { | |
255 | int ret; | |
256 | ||
257 | /* Should be rewritten with merging nilfs_mdt_read_block() */ | |
258 | retry: | |
b34a6506 | 259 | ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh); |
5eb563f5 RK |
260 | if (!create || ret != -ENOENT) |
261 | return ret; | |
262 | ||
263 | ret = nilfs_mdt_create_block(inode, blkoff, out_bh, init_block); | |
264 | if (unlikely(ret == -EEXIST)) { | |
265 | /* create = 0; */ /* limit read-create loop retries */ | |
266 | goto retry; | |
267 | } | |
268 | return ret; | |
269 | } | |
270 | ||
fa33915c RK |
271 | /** |
272 | * nilfs_mdt_find_block - find and get a buffer on meta data file. | |
273 | * @inode: inode of the meta data file | |
274 | * @start: start block offset (inclusive) | |
275 | * @end: end block offset (inclusive) | |
276 | * @blkoff: block offset | |
277 | * @out_bh: place to store a pointer to buffer_head struct | |
278 | * | |
279 | * nilfs_mdt_find_block() looks up an existing block in range of | |
280 | * [@start, @end] and stores pointer to a buffer head of the block to | |
281 | * @out_bh, and block offset to @blkoff, respectively. @out_bh and | |
282 | * @blkoff are substituted only when zero is returned. | |
283 | * | |
284 | * Return Value: On success, it returns 0. On error, the following negative | |
285 | * error code is returned. | |
286 | * | |
287 | * %-ENOMEM - Insufficient memory available. | |
288 | * | |
289 | * %-EIO - I/O error | |
290 | * | |
291 | * %-ENOENT - no block was found in the range | |
292 | */ | |
293 | int nilfs_mdt_find_block(struct inode *inode, unsigned long start, | |
294 | unsigned long end, unsigned long *blkoff, | |
295 | struct buffer_head **out_bh) | |
296 | { | |
297 | __u64 next; | |
298 | int ret; | |
299 | ||
300 | if (unlikely(start > end)) | |
301 | return -ENOENT; | |
302 | ||
303 | ret = nilfs_mdt_read_block(inode, start, true, out_bh); | |
304 | if (!ret) { | |
305 | *blkoff = start; | |
306 | goto out; | |
307 | } | |
308 | if (unlikely(ret != -ENOENT || start == ULONG_MAX)) | |
309 | goto out; | |
310 | ||
311 | ret = nilfs_bmap_seek_key(NILFS_I(inode)->i_bmap, start + 1, &next); | |
312 | if (!ret) { | |
313 | if (next <= end) { | |
314 | ret = nilfs_mdt_read_block(inode, next, true, out_bh); | |
315 | if (!ret) | |
316 | *blkoff = next; | |
317 | } else { | |
318 | ret = -ENOENT; | |
319 | } | |
320 | } | |
321 | out: | |
322 | return ret; | |
323 | } | |
324 | ||
5eb563f5 RK |
325 | /** |
326 | * nilfs_mdt_delete_block - make a hole on the meta data file. | |
327 | * @inode: inode of the meta data file | |
328 | * @block: block offset | |
329 | * | |
330 | * Return Value: On success, zero is returned. | |
331 | * On error, one of the following negative error code is returned. | |
332 | * | |
333 | * %-ENOMEM - Insufficient memory available. | |
334 | * | |
335 | * %-EIO - I/O error | |
5eb563f5 RK |
336 | */ |
337 | int nilfs_mdt_delete_block(struct inode *inode, unsigned long block) | |
338 | { | |
339 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
340 | int err; | |
341 | ||
342 | err = nilfs_bmap_delete(ii->i_bmap, block); | |
84338237 | 343 | if (!err || err == -ENOENT) { |
5eb563f5 RK |
344 | nilfs_mdt_mark_dirty(inode); |
345 | nilfs_mdt_forget_block(inode, block); | |
346 | } | |
347 | return err; | |
348 | } | |
349 | ||
350 | /** | |
351 | * nilfs_mdt_forget_block - discard dirty state and try to remove the page | |
352 | * @inode: inode of the meta data file | |
353 | * @block: block offset | |
354 | * | |
355 | * nilfs_mdt_forget_block() clears a dirty flag of the specified buffer, and | |
356 | * tries to release the page including the buffer from a page cache. | |
357 | * | |
358 | * Return Value: On success, 0 is returned. On error, one of the following | |
359 | * negative error code is returned. | |
360 | * | |
361 | * %-EBUSY - page has an active buffer. | |
362 | * | |
363 | * %-ENOENT - page cache has no page addressed by the offset. | |
364 | */ | |
365 | int nilfs_mdt_forget_block(struct inode *inode, unsigned long block) | |
366 | { | |
367 | pgoff_t index = (pgoff_t)block >> | |
09cbfeaf | 368 | (PAGE_SHIFT - inode->i_blkbits); |
5eb563f5 RK |
369 | struct page *page; |
370 | unsigned long first_block; | |
371 | int ret = 0; | |
372 | int still_dirty; | |
373 | ||
374 | page = find_lock_page(inode->i_mapping, index); | |
375 | if (!page) | |
376 | return -ENOENT; | |
377 | ||
378 | wait_on_page_writeback(page); | |
379 | ||
380 | first_block = (unsigned long)index << | |
09cbfeaf | 381 | (PAGE_SHIFT - inode->i_blkbits); |
5eb563f5 RK |
382 | if (page_has_buffers(page)) { |
383 | struct buffer_head *bh; | |
384 | ||
385 | bh = nilfs_page_get_nth_block(page, block - first_block); | |
386 | nilfs_forget_buffer(bh); | |
387 | } | |
388 | still_dirty = PageDirty(page); | |
389 | unlock_page(page); | |
09cbfeaf | 390 | put_page(page); |
5eb563f5 RK |
391 | |
392 | if (still_dirty || | |
393 | invalidate_inode_pages2_range(inode->i_mapping, index, index) != 0) | |
394 | ret = -EBUSY; | |
395 | return ret; | |
396 | } | |
397 | ||
5eb563f5 RK |
398 | int nilfs_mdt_fetch_dirty(struct inode *inode) |
399 | { | |
400 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
401 | ||
402 | if (nilfs_bmap_test_and_clear_dirty(ii->i_bmap)) { | |
403 | set_bit(NILFS_I_DIRTY, &ii->i_state); | |
404 | return 1; | |
405 | } | |
406 | return test_bit(NILFS_I_DIRTY, &ii->i_state); | |
407 | } | |
408 | ||
409 | static int | |
410 | nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc) | |
411 | { | |
8c26c4e2 | 412 | struct inode *inode = page->mapping->host; |
ebdfed4d | 413 | struct super_block *sb; |
5eb563f5 RK |
414 | int err = 0; |
415 | ||
8c26c4e2 VD |
416 | if (inode && (inode->i_sb->s_flags & MS_RDONLY)) { |
417 | /* | |
418 | * It means that filesystem was remounted in read-only | |
419 | * mode because of error or metadata corruption. But we | |
420 | * have dirty pages that try to be flushed in background. | |
421 | * So, here we simply discard this dirty page. | |
422 | */ | |
423 | nilfs_clear_dirty_page(page, false); | |
424 | unlock_page(page); | |
425 | return -EROFS; | |
426 | } | |
427 | ||
5eb563f5 RK |
428 | redirty_page_for_writepage(wbc, page); |
429 | unlock_page(page); | |
430 | ||
ebdfed4d RK |
431 | if (!inode) |
432 | return 0; | |
433 | ||
434 | sb = inode->i_sb; | |
5eb563f5 RK |
435 | |
436 | if (wbc->sync_mode == WB_SYNC_ALL) | |
437 | err = nilfs_construct_segment(sb); | |
438 | else if (wbc->for_reclaim) | |
439 | nilfs_flush_segment(sb, inode->i_ino); | |
440 | ||
5eb563f5 RK |
441 | return err; |
442 | } | |
443 | ||
444 | ||
7f09410b | 445 | static const struct address_space_operations def_mdt_aops = { |
5eb563f5 RK |
446 | .writepage = nilfs_mdt_write_page, |
447 | }; | |
448 | ||
6e1d5dcc | 449 | static const struct inode_operations def_mdt_iops; |
828c0950 | 450 | static const struct file_operations def_mdt_fops; |
5eb563f5 | 451 | |
5e19a995 | 452 | |
f1e89c86 | 453 | int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz) |
5e19a995 RK |
454 | { |
455 | struct nilfs_mdt_info *mi; | |
456 | ||
457 | mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS); | |
458 | if (!mi) | |
459 | return -ENOMEM; | |
460 | ||
5e19a995 RK |
461 | init_rwsem(&mi->mi_sem); |
462 | inode->i_private = mi; | |
463 | ||
464 | inode->i_mode = S_IFREG; | |
465 | mapping_set_gfp_mask(inode->i_mapping, gfp_mask); | |
f1e89c86 RK |
466 | |
467 | inode->i_op = &def_mdt_iops; | |
468 | inode->i_fop = &def_mdt_fops; | |
469 | inode->i_mapping->a_ops = &def_mdt_aops; | |
5e19a995 RK |
470 | |
471 | return 0; | |
472 | } | |
473 | ||
2d19961d RK |
474 | /** |
475 | * nilfs_mdt_clear - do cleanup for the metadata file | |
476 | * @inode: inode of the metadata file | |
477 | */ | |
478 | void nilfs_mdt_clear(struct inode *inode) | |
479 | { | |
480 | struct nilfs_mdt_info *mdi = NILFS_MDT(inode); | |
481 | ||
482 | if (mdi->mi_palloc_cache) | |
483 | nilfs_palloc_destroy_cache(inode); | |
484 | } | |
485 | ||
486 | /** | |
487 | * nilfs_mdt_destroy - release resources used by the metadata file | |
488 | * @inode: inode of the metadata file | |
489 | */ | |
490 | void nilfs_mdt_destroy(struct inode *inode) | |
491 | { | |
492 | struct nilfs_mdt_info *mdi = NILFS_MDT(inode); | |
493 | ||
494 | kfree(mdi->mi_bgl); /* kfree(NULL) is safe */ | |
495 | kfree(mdi); | |
496 | } | |
497 | ||
0c6c44cb RK |
498 | void nilfs_mdt_set_entry_size(struct inode *inode, unsigned int entry_size, |
499 | unsigned int header_size) | |
5eb563f5 RK |
500 | { |
501 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
502 | ||
503 | mi->mi_entry_size = entry_size; | |
93407472 | 504 | mi->mi_entries_per_block = i_blocksize(inode) / entry_size; |
5eb563f5 RK |
505 | mi->mi_first_entry_offset = DIV_ROUND_UP(header_size, entry_size); |
506 | } | |
507 | ||
ebdfed4d RK |
508 | /** |
509 | * nilfs_mdt_setup_shadow_map - setup shadow map and bind it to metadata file | |
510 | * @inode: inode of the metadata file | |
511 | * @shadow: shadow mapping | |
512 | */ | |
513 | int nilfs_mdt_setup_shadow_map(struct inode *inode, | |
514 | struct nilfs_shadow_map *shadow) | |
515 | { | |
516 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
ebdfed4d RK |
517 | |
518 | INIT_LIST_HEAD(&shadow->frozen_buffers); | |
2aa15890 | 519 | address_space_init_once(&shadow->frozen_data); |
b83ae6d4 | 520 | nilfs_mapping_init(&shadow->frozen_data, inode); |
2aa15890 | 521 | address_space_init_once(&shadow->frozen_btnodes); |
b83ae6d4 | 522 | nilfs_mapping_init(&shadow->frozen_btnodes, inode); |
ebdfed4d RK |
523 | mi->mi_shadow = shadow; |
524 | return 0; | |
525 | } | |
526 | ||
527 | /** | |
528 | * nilfs_mdt_save_to_shadow_map - copy bmap and dirty pages to shadow map | |
529 | * @inode: inode of the metadata file | |
530 | */ | |
531 | int nilfs_mdt_save_to_shadow_map(struct inode *inode) | |
532 | { | |
533 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
534 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
535 | struct nilfs_shadow_map *shadow = mi->mi_shadow; | |
536 | int ret; | |
537 | ||
538 | ret = nilfs_copy_dirty_pages(&shadow->frozen_data, inode->i_mapping); | |
539 | if (ret) | |
540 | goto out; | |
541 | ||
542 | ret = nilfs_copy_dirty_pages(&shadow->frozen_btnodes, | |
543 | &ii->i_btnode_cache); | |
544 | if (ret) | |
545 | goto out; | |
546 | ||
547 | nilfs_bmap_save(ii->i_bmap, &shadow->bmap_store); | |
548 | out: | |
549 | return ret; | |
550 | } | |
551 | ||
b1f6a4f2 RK |
552 | int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh) |
553 | { | |
554 | struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow; | |
555 | struct buffer_head *bh_frozen; | |
556 | struct page *page; | |
557 | int blkbits = inode->i_blkbits; | |
b1f6a4f2 RK |
558 | |
559 | page = grab_cache_page(&shadow->frozen_data, bh->b_page->index); | |
560 | if (!page) | |
a7a8447e | 561 | return -ENOMEM; |
b1f6a4f2 RK |
562 | |
563 | if (!page_has_buffers(page)) | |
564 | create_empty_buffers(page, 1 << blkbits, 0); | |
565 | ||
566 | bh_frozen = nilfs_page_get_nth_block(page, bh_offset(bh) >> blkbits); | |
a7a8447e RK |
567 | |
568 | if (!buffer_uptodate(bh_frozen)) | |
569 | nilfs_copy_buffer(bh_frozen, bh); | |
570 | if (list_empty(&bh_frozen->b_assoc_buffers)) { | |
571 | list_add_tail(&bh_frozen->b_assoc_buffers, | |
572 | &shadow->frozen_buffers); | |
573 | set_buffer_nilfs_redirected(bh); | |
574 | } else { | |
575 | brelse(bh_frozen); /* already frozen */ | |
b1f6a4f2 | 576 | } |
a7a8447e | 577 | |
b1f6a4f2 | 578 | unlock_page(page); |
09cbfeaf | 579 | put_page(page); |
a7a8447e | 580 | return 0; |
b1f6a4f2 RK |
581 | } |
582 | ||
583 | struct buffer_head * | |
584 | nilfs_mdt_get_frozen_buffer(struct inode *inode, struct buffer_head *bh) | |
585 | { | |
586 | struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow; | |
587 | struct buffer_head *bh_frozen = NULL; | |
588 | struct page *page; | |
589 | int n; | |
590 | ||
591 | page = find_lock_page(&shadow->frozen_data, bh->b_page->index); | |
592 | if (page) { | |
593 | if (page_has_buffers(page)) { | |
594 | n = bh_offset(bh) >> inode->i_blkbits; | |
595 | bh_frozen = nilfs_page_get_nth_block(page, n); | |
596 | } | |
597 | unlock_page(page); | |
09cbfeaf | 598 | put_page(page); |
b1f6a4f2 RK |
599 | } |
600 | return bh_frozen; | |
601 | } | |
602 | ||
603 | static void nilfs_release_frozen_buffers(struct nilfs_shadow_map *shadow) | |
604 | { | |
605 | struct list_head *head = &shadow->frozen_buffers; | |
606 | struct buffer_head *bh; | |
607 | ||
608 | while (!list_empty(head)) { | |
609 | bh = list_first_entry(head, struct buffer_head, | |
610 | b_assoc_buffers); | |
611 | list_del_init(&bh->b_assoc_buffers); | |
612 | brelse(bh); /* drop ref-count to make it releasable */ | |
613 | } | |
614 | } | |
615 | ||
ebdfed4d RK |
616 | /** |
617 | * nilfs_mdt_restore_from_shadow_map - restore dirty pages and bmap state | |
618 | * @inode: inode of the metadata file | |
619 | */ | |
620 | void nilfs_mdt_restore_from_shadow_map(struct inode *inode) | |
621 | { | |
622 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
623 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
624 | struct nilfs_shadow_map *shadow = mi->mi_shadow; | |
625 | ||
626 | down_write(&mi->mi_sem); | |
627 | ||
628 | if (mi->mi_palloc_cache) | |
629 | nilfs_palloc_clear_cache(inode); | |
630 | ||
8c26c4e2 | 631 | nilfs_clear_dirty_pages(inode->i_mapping, true); |
ebdfed4d RK |
632 | nilfs_copy_back_pages(inode->i_mapping, &shadow->frozen_data); |
633 | ||
8c26c4e2 | 634 | nilfs_clear_dirty_pages(&ii->i_btnode_cache, true); |
ebdfed4d RK |
635 | nilfs_copy_back_pages(&ii->i_btnode_cache, &shadow->frozen_btnodes); |
636 | ||
637 | nilfs_bmap_restore(ii->i_bmap, &shadow->bmap_store); | |
638 | ||
639 | up_write(&mi->mi_sem); | |
640 | } | |
641 | ||
642 | /** | |
643 | * nilfs_mdt_clear_shadow_map - truncate pages in shadow map caches | |
644 | * @inode: inode of the metadata file | |
645 | */ | |
646 | void nilfs_mdt_clear_shadow_map(struct inode *inode) | |
647 | { | |
648 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
649 | struct nilfs_shadow_map *shadow = mi->mi_shadow; | |
650 | ||
651 | down_write(&mi->mi_sem); | |
b1f6a4f2 | 652 | nilfs_release_frozen_buffers(shadow); |
ebdfed4d RK |
653 | truncate_inode_pages(&shadow->frozen_data, 0); |
654 | truncate_inode_pages(&shadow->frozen_btnodes, 0); | |
655 | up_write(&mi->mi_sem); | |
656 | } |