Commit | Line | Data |
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ae98043f | 1 | // SPDX-License-Identifier: GPL-2.0+ |
5eb563f5 RK |
2 | /* |
3 | * mdt.c - meta data file for NILFS | |
4 | * | |
5 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. | |
6 | * | |
4b420ab4 | 7 | * Written by Ryusuke Konishi. |
5eb563f5 RK |
8 | */ |
9 | ||
10 | #include <linux/buffer_head.h> | |
11 | #include <linux/mpage.h> | |
12 | #include <linux/mm.h> | |
13 | #include <linux/writeback.h> | |
14 | #include <linux/backing-dev.h> | |
15 | #include <linux/swap.h> | |
5a0e3ad6 | 16 | #include <linux/slab.h> |
5eb563f5 | 17 | #include "nilfs.h" |
05d0e94b | 18 | #include "btnode.h" |
5eb563f5 RK |
19 | #include "segment.h" |
20 | #include "page.h" | |
21 | #include "mdt.h" | |
2d19961d | 22 | #include "alloc.h" /* nilfs_palloc_destroy_cache() */ |
5eb563f5 | 23 | |
a9cd207c | 24 | #include <trace/events/nilfs2.h> |
5eb563f5 RK |
25 | |
26 | #define NILFS_MDT_MAX_RA_BLOCKS (16 - 1) | |
27 | ||
5eb563f5 RK |
28 | |
29 | static int | |
30 | nilfs_mdt_insert_new_block(struct inode *inode, unsigned long block, | |
31 | struct buffer_head *bh, | |
32 | void (*init_block)(struct inode *, | |
33 | struct buffer_head *, void *)) | |
34 | { | |
35 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
36 | void *kaddr; | |
37 | int ret; | |
38 | ||
39 | /* Caller exclude read accesses using page lock */ | |
40 | ||
41 | /* set_buffer_new(bh); */ | |
42 | bh->b_blocknr = 0; | |
43 | ||
44 | ret = nilfs_bmap_insert(ii->i_bmap, block, (unsigned long)bh); | |
45 | if (unlikely(ret)) | |
46 | return ret; | |
47 | ||
48 | set_buffer_mapped(bh); | |
49 | ||
7b9c0976 | 50 | kaddr = kmap_atomic(bh->b_page); |
93407472 | 51 | memset(kaddr + bh_offset(bh), 0, i_blocksize(inode)); |
5eb563f5 RK |
52 | if (init_block) |
53 | init_block(inode, bh, kaddr); | |
54 | flush_dcache_page(bh->b_page); | |
7b9c0976 | 55 | kunmap_atomic(kaddr); |
5eb563f5 RK |
56 | |
57 | set_buffer_uptodate(bh); | |
5fc7b141 | 58 | mark_buffer_dirty(bh); |
5eb563f5 | 59 | nilfs_mdt_mark_dirty(inode); |
a9cd207c HM |
60 | |
61 | trace_nilfs2_mdt_insert_new_block(inode, inode->i_ino, block); | |
62 | ||
5eb563f5 RK |
63 | return 0; |
64 | } | |
65 | ||
66 | static int nilfs_mdt_create_block(struct inode *inode, unsigned long block, | |
67 | struct buffer_head **out_bh, | |
68 | void (*init_block)(struct inode *, | |
69 | struct buffer_head *, | |
70 | void *)) | |
71 | { | |
5eb563f5 RK |
72 | struct super_block *sb = inode->i_sb; |
73 | struct nilfs_transaction_info ti; | |
74 | struct buffer_head *bh; | |
75 | int err; | |
76 | ||
5eb563f5 RK |
77 | nilfs_transaction_begin(sb, &ti, 0); |
78 | ||
79 | err = -ENOMEM; | |
80 | bh = nilfs_grab_buffer(inode, inode->i_mapping, block, 0); | |
81 | if (unlikely(!bh)) | |
82 | goto failed_unlock; | |
83 | ||
84 | err = -EEXIST; | |
14351104 | 85 | if (buffer_uptodate(bh)) |
5eb563f5 | 86 | goto failed_bh; |
14351104 | 87 | |
5eb563f5 RK |
88 | wait_on_buffer(bh); |
89 | if (buffer_uptodate(bh)) | |
90 | goto failed_bh; | |
5eb563f5 | 91 | |
090fd5b1 | 92 | bh->b_bdev = sb->s_bdev; |
5eb563f5 RK |
93 | err = nilfs_mdt_insert_new_block(inode, block, bh, init_block); |
94 | if (likely(!err)) { | |
95 | get_bh(bh); | |
96 | *out_bh = bh; | |
97 | } | |
98 | ||
99 | failed_bh: | |
100 | unlock_page(bh->b_page); | |
09cbfeaf | 101 | put_page(bh->b_page); |
5eb563f5 RK |
102 | brelse(bh); |
103 | ||
104 | failed_unlock: | |
47420c79 RK |
105 | if (likely(!err)) |
106 | err = nilfs_transaction_commit(sb); | |
107 | else | |
108 | nilfs_transaction_abort(sb); | |
090fd5b1 | 109 | |
5eb563f5 RK |
110 | return err; |
111 | } | |
112 | ||
113 | static int | |
114 | nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff, | |
2a222ca9 | 115 | int mode, int mode_flags, struct buffer_head **out_bh) |
5eb563f5 RK |
116 | { |
117 | struct buffer_head *bh; | |
0f3fe33b | 118 | __u64 blknum = 0; |
5eb563f5 RK |
119 | int ret = -ENOMEM; |
120 | ||
121 | bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0); | |
122 | if (unlikely(!bh)) | |
123 | goto failed; | |
124 | ||
125 | ret = -EEXIST; /* internal code */ | |
126 | if (buffer_uptodate(bh)) | |
127 | goto out; | |
128 | ||
2a222ca9 | 129 | if (mode_flags & REQ_RAHEAD) { |
5eb563f5 RK |
130 | if (!trylock_buffer(bh)) { |
131 | ret = -EBUSY; | |
132 | goto failed_bh; | |
133 | } | |
1f5abe7e | 134 | } else /* mode == READ */ |
5eb563f5 | 135 | lock_buffer(bh); |
5eb563f5 RK |
136 | |
137 | if (buffer_uptodate(bh)) { | |
138 | unlock_buffer(bh); | |
139 | goto out; | |
140 | } | |
14351104 RK |
141 | |
142 | ret = nilfs_bmap_lookup(NILFS_I(inode)->i_bmap, blkoff, &blknum); | |
143 | if (unlikely(ret)) { | |
144 | unlock_buffer(bh); | |
145 | goto failed_bh; | |
5eb563f5 | 146 | } |
c6e07188 | 147 | map_bh(bh, inode->i_sb, (sector_t)blknum); |
5eb563f5 RK |
148 | |
149 | bh->b_end_io = end_buffer_read_sync; | |
150 | get_bh(bh); | |
2a222ca9 | 151 | submit_bh(mode, mode_flags, bh); |
5eb563f5 | 152 | ret = 0; |
a9cd207c HM |
153 | |
154 | trace_nilfs2_mdt_submit_block(inode, inode->i_ino, blkoff, mode); | |
5eb563f5 RK |
155 | out: |
156 | get_bh(bh); | |
157 | *out_bh = bh; | |
158 | ||
159 | failed_bh: | |
160 | unlock_page(bh->b_page); | |
09cbfeaf | 161 | put_page(bh->b_page); |
5eb563f5 RK |
162 | brelse(bh); |
163 | failed: | |
164 | return ret; | |
165 | } | |
166 | ||
167 | static int nilfs_mdt_read_block(struct inode *inode, unsigned long block, | |
b34a6506 | 168 | int readahead, struct buffer_head **out_bh) |
5eb563f5 RK |
169 | { |
170 | struct buffer_head *first_bh, *bh; | |
171 | unsigned long blkoff; | |
172 | int i, nr_ra_blocks = NILFS_MDT_MAX_RA_BLOCKS; | |
173 | int err; | |
174 | ||
2a222ca9 | 175 | err = nilfs_mdt_submit_block(inode, block, REQ_OP_READ, 0, &first_bh); |
5eb563f5 RK |
176 | if (err == -EEXIST) /* internal code */ |
177 | goto out; | |
178 | ||
179 | if (unlikely(err)) | |
180 | goto failed; | |
181 | ||
b34a6506 RK |
182 | if (readahead) { |
183 | blkoff = block + 1; | |
184 | for (i = 0; i < nr_ra_blocks; i++, blkoff++) { | |
2a222ca9 MC |
185 | err = nilfs_mdt_submit_block(inode, blkoff, REQ_OP_READ, |
186 | REQ_RAHEAD, &bh); | |
b34a6506 RK |
187 | if (likely(!err || err == -EEXIST)) |
188 | brelse(bh); | |
189 | else if (err != -EBUSY) | |
190 | break; | |
191 | /* abort readahead if bmap lookup failed */ | |
192 | if (!buffer_locked(first_bh)) | |
193 | goto out_no_wait; | |
194 | } | |
5eb563f5 RK |
195 | } |
196 | ||
197 | wait_on_buffer(first_bh); | |
198 | ||
199 | out_no_wait: | |
200 | err = -EIO; | |
39a9dcca RK |
201 | if (!buffer_uptodate(first_bh)) { |
202 | nilfs_msg(inode->i_sb, KERN_ERR, | |
203 | "I/O error reading meta-data file (ino=%lu, block-offset=%lu)", | |
204 | inode->i_ino, block); | |
5eb563f5 | 205 | goto failed_bh; |
39a9dcca | 206 | } |
5eb563f5 RK |
207 | out: |
208 | *out_bh = first_bh; | |
209 | return 0; | |
210 | ||
211 | failed_bh: | |
212 | brelse(first_bh); | |
213 | failed: | |
214 | return err; | |
215 | } | |
216 | ||
217 | /** | |
218 | * nilfs_mdt_get_block - read or create a buffer on meta data file. | |
219 | * @inode: inode of the meta data file | |
220 | * @blkoff: block offset | |
221 | * @create: create flag | |
222 | * @init_block: initializer used for newly allocated block | |
223 | * @out_bh: output of a pointer to the buffer_head | |
224 | * | |
225 | * nilfs_mdt_get_block() looks up the specified buffer and tries to create | |
226 | * a new buffer if @create is not zero. On success, the returned buffer is | |
227 | * assured to be either existing or formatted using a buffer lock on success. | |
228 | * @out_bh is substituted only when zero is returned. | |
229 | * | |
230 | * Return Value: On success, it returns 0. On error, the following negative | |
231 | * error code is returned. | |
232 | * | |
233 | * %-ENOMEM - Insufficient memory available. | |
234 | * | |
235 | * %-EIO - I/O error | |
236 | * | |
237 | * %-ENOENT - the specified block does not exist (hole block) | |
238 | * | |
5eb563f5 RK |
239 | * %-EROFS - Read only filesystem (for create mode) |
240 | */ | |
241 | int nilfs_mdt_get_block(struct inode *inode, unsigned long blkoff, int create, | |
242 | void (*init_block)(struct inode *, | |
243 | struct buffer_head *, void *), | |
244 | struct buffer_head **out_bh) | |
245 | { | |
246 | int ret; | |
247 | ||
248 | /* Should be rewritten with merging nilfs_mdt_read_block() */ | |
249 | retry: | |
b34a6506 | 250 | ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh); |
5eb563f5 RK |
251 | if (!create || ret != -ENOENT) |
252 | return ret; | |
253 | ||
254 | ret = nilfs_mdt_create_block(inode, blkoff, out_bh, init_block); | |
255 | if (unlikely(ret == -EEXIST)) { | |
256 | /* create = 0; */ /* limit read-create loop retries */ | |
257 | goto retry; | |
258 | } | |
259 | return ret; | |
260 | } | |
261 | ||
fa33915c RK |
262 | /** |
263 | * nilfs_mdt_find_block - find and get a buffer on meta data file. | |
264 | * @inode: inode of the meta data file | |
265 | * @start: start block offset (inclusive) | |
266 | * @end: end block offset (inclusive) | |
267 | * @blkoff: block offset | |
268 | * @out_bh: place to store a pointer to buffer_head struct | |
269 | * | |
270 | * nilfs_mdt_find_block() looks up an existing block in range of | |
271 | * [@start, @end] and stores pointer to a buffer head of the block to | |
272 | * @out_bh, and block offset to @blkoff, respectively. @out_bh and | |
273 | * @blkoff are substituted only when zero is returned. | |
274 | * | |
275 | * Return Value: On success, it returns 0. On error, the following negative | |
276 | * error code is returned. | |
277 | * | |
278 | * %-ENOMEM - Insufficient memory available. | |
279 | * | |
280 | * %-EIO - I/O error | |
281 | * | |
282 | * %-ENOENT - no block was found in the range | |
283 | */ | |
284 | int nilfs_mdt_find_block(struct inode *inode, unsigned long start, | |
285 | unsigned long end, unsigned long *blkoff, | |
286 | struct buffer_head **out_bh) | |
287 | { | |
288 | __u64 next; | |
289 | int ret; | |
290 | ||
291 | if (unlikely(start > end)) | |
292 | return -ENOENT; | |
293 | ||
294 | ret = nilfs_mdt_read_block(inode, start, true, out_bh); | |
295 | if (!ret) { | |
296 | *blkoff = start; | |
297 | goto out; | |
298 | } | |
299 | if (unlikely(ret != -ENOENT || start == ULONG_MAX)) | |
300 | goto out; | |
301 | ||
302 | ret = nilfs_bmap_seek_key(NILFS_I(inode)->i_bmap, start + 1, &next); | |
303 | if (!ret) { | |
304 | if (next <= end) { | |
305 | ret = nilfs_mdt_read_block(inode, next, true, out_bh); | |
306 | if (!ret) | |
307 | *blkoff = next; | |
308 | } else { | |
309 | ret = -ENOENT; | |
310 | } | |
311 | } | |
312 | out: | |
313 | return ret; | |
314 | } | |
315 | ||
5eb563f5 RK |
316 | /** |
317 | * nilfs_mdt_delete_block - make a hole on the meta data file. | |
318 | * @inode: inode of the meta data file | |
319 | * @block: block offset | |
320 | * | |
321 | * Return Value: On success, zero is returned. | |
322 | * On error, one of the following negative error code is returned. | |
323 | * | |
324 | * %-ENOMEM - Insufficient memory available. | |
325 | * | |
326 | * %-EIO - I/O error | |
5eb563f5 RK |
327 | */ |
328 | int nilfs_mdt_delete_block(struct inode *inode, unsigned long block) | |
329 | { | |
330 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
331 | int err; | |
332 | ||
333 | err = nilfs_bmap_delete(ii->i_bmap, block); | |
84338237 | 334 | if (!err || err == -ENOENT) { |
5eb563f5 RK |
335 | nilfs_mdt_mark_dirty(inode); |
336 | nilfs_mdt_forget_block(inode, block); | |
337 | } | |
338 | return err; | |
339 | } | |
340 | ||
341 | /** | |
342 | * nilfs_mdt_forget_block - discard dirty state and try to remove the page | |
343 | * @inode: inode of the meta data file | |
344 | * @block: block offset | |
345 | * | |
346 | * nilfs_mdt_forget_block() clears a dirty flag of the specified buffer, and | |
347 | * tries to release the page including the buffer from a page cache. | |
348 | * | |
349 | * Return Value: On success, 0 is returned. On error, one of the following | |
350 | * negative error code is returned. | |
351 | * | |
352 | * %-EBUSY - page has an active buffer. | |
353 | * | |
354 | * %-ENOENT - page cache has no page addressed by the offset. | |
355 | */ | |
356 | int nilfs_mdt_forget_block(struct inode *inode, unsigned long block) | |
357 | { | |
358 | pgoff_t index = (pgoff_t)block >> | |
09cbfeaf | 359 | (PAGE_SHIFT - inode->i_blkbits); |
5eb563f5 RK |
360 | struct page *page; |
361 | unsigned long first_block; | |
362 | int ret = 0; | |
363 | int still_dirty; | |
364 | ||
365 | page = find_lock_page(inode->i_mapping, index); | |
366 | if (!page) | |
367 | return -ENOENT; | |
368 | ||
369 | wait_on_page_writeback(page); | |
370 | ||
371 | first_block = (unsigned long)index << | |
09cbfeaf | 372 | (PAGE_SHIFT - inode->i_blkbits); |
5eb563f5 RK |
373 | if (page_has_buffers(page)) { |
374 | struct buffer_head *bh; | |
375 | ||
376 | bh = nilfs_page_get_nth_block(page, block - first_block); | |
377 | nilfs_forget_buffer(bh); | |
378 | } | |
379 | still_dirty = PageDirty(page); | |
380 | unlock_page(page); | |
09cbfeaf | 381 | put_page(page); |
5eb563f5 RK |
382 | |
383 | if (still_dirty || | |
384 | invalidate_inode_pages2_range(inode->i_mapping, index, index) != 0) | |
385 | ret = -EBUSY; | |
386 | return ret; | |
387 | } | |
388 | ||
5eb563f5 RK |
389 | int nilfs_mdt_fetch_dirty(struct inode *inode) |
390 | { | |
391 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
392 | ||
393 | if (nilfs_bmap_test_and_clear_dirty(ii->i_bmap)) { | |
394 | set_bit(NILFS_I_DIRTY, &ii->i_state); | |
395 | return 1; | |
396 | } | |
397 | return test_bit(NILFS_I_DIRTY, &ii->i_state); | |
398 | } | |
399 | ||
400 | static int | |
401 | nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc) | |
402 | { | |
8c26c4e2 | 403 | struct inode *inode = page->mapping->host; |
ebdfed4d | 404 | struct super_block *sb; |
5eb563f5 RK |
405 | int err = 0; |
406 | ||
bc98a42c | 407 | if (inode && sb_rdonly(inode->i_sb)) { |
8c26c4e2 VD |
408 | /* |
409 | * It means that filesystem was remounted in read-only | |
410 | * mode because of error or metadata corruption. But we | |
411 | * have dirty pages that try to be flushed in background. | |
412 | * So, here we simply discard this dirty page. | |
413 | */ | |
414 | nilfs_clear_dirty_page(page, false); | |
415 | unlock_page(page); | |
416 | return -EROFS; | |
417 | } | |
418 | ||
5eb563f5 RK |
419 | redirty_page_for_writepage(wbc, page); |
420 | unlock_page(page); | |
421 | ||
ebdfed4d RK |
422 | if (!inode) |
423 | return 0; | |
424 | ||
425 | sb = inode->i_sb; | |
5eb563f5 RK |
426 | |
427 | if (wbc->sync_mode == WB_SYNC_ALL) | |
428 | err = nilfs_construct_segment(sb); | |
429 | else if (wbc->for_reclaim) | |
430 | nilfs_flush_segment(sb, inode->i_ino); | |
431 | ||
5eb563f5 RK |
432 | return err; |
433 | } | |
434 | ||
435 | ||
7f09410b | 436 | static const struct address_space_operations def_mdt_aops = { |
5eb563f5 RK |
437 | .writepage = nilfs_mdt_write_page, |
438 | }; | |
439 | ||
6e1d5dcc | 440 | static const struct inode_operations def_mdt_iops; |
828c0950 | 441 | static const struct file_operations def_mdt_fops; |
5eb563f5 | 442 | |
5e19a995 | 443 | |
f1e89c86 | 444 | int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz) |
5e19a995 RK |
445 | { |
446 | struct nilfs_mdt_info *mi; | |
447 | ||
448 | mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS); | |
449 | if (!mi) | |
450 | return -ENOMEM; | |
451 | ||
5e19a995 RK |
452 | init_rwsem(&mi->mi_sem); |
453 | inode->i_private = mi; | |
454 | ||
455 | inode->i_mode = S_IFREG; | |
456 | mapping_set_gfp_mask(inode->i_mapping, gfp_mask); | |
f1e89c86 RK |
457 | |
458 | inode->i_op = &def_mdt_iops; | |
459 | inode->i_fop = &def_mdt_fops; | |
460 | inode->i_mapping->a_ops = &def_mdt_aops; | |
5e19a995 RK |
461 | |
462 | return 0; | |
463 | } | |
464 | ||
2d19961d RK |
465 | /** |
466 | * nilfs_mdt_clear - do cleanup for the metadata file | |
467 | * @inode: inode of the metadata file | |
468 | */ | |
469 | void nilfs_mdt_clear(struct inode *inode) | |
470 | { | |
471 | struct nilfs_mdt_info *mdi = NILFS_MDT(inode); | |
472 | ||
473 | if (mdi->mi_palloc_cache) | |
474 | nilfs_palloc_destroy_cache(inode); | |
475 | } | |
476 | ||
477 | /** | |
478 | * nilfs_mdt_destroy - release resources used by the metadata file | |
479 | * @inode: inode of the metadata file | |
480 | */ | |
481 | void nilfs_mdt_destroy(struct inode *inode) | |
482 | { | |
483 | struct nilfs_mdt_info *mdi = NILFS_MDT(inode); | |
484 | ||
485 | kfree(mdi->mi_bgl); /* kfree(NULL) is safe */ | |
486 | kfree(mdi); | |
487 | } | |
488 | ||
0c6c44cb RK |
489 | void nilfs_mdt_set_entry_size(struct inode *inode, unsigned int entry_size, |
490 | unsigned int header_size) | |
5eb563f5 RK |
491 | { |
492 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
493 | ||
494 | mi->mi_entry_size = entry_size; | |
93407472 | 495 | mi->mi_entries_per_block = i_blocksize(inode) / entry_size; |
5eb563f5 RK |
496 | mi->mi_first_entry_offset = DIV_ROUND_UP(header_size, entry_size); |
497 | } | |
498 | ||
ebdfed4d RK |
499 | /** |
500 | * nilfs_mdt_setup_shadow_map - setup shadow map and bind it to metadata file | |
501 | * @inode: inode of the metadata file | |
502 | * @shadow: shadow mapping | |
503 | */ | |
504 | int nilfs_mdt_setup_shadow_map(struct inode *inode, | |
505 | struct nilfs_shadow_map *shadow) | |
506 | { | |
507 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
ebdfed4d RK |
508 | |
509 | INIT_LIST_HEAD(&shadow->frozen_buffers); | |
2aa15890 | 510 | address_space_init_once(&shadow->frozen_data); |
b83ae6d4 | 511 | nilfs_mapping_init(&shadow->frozen_data, inode); |
2aa15890 | 512 | address_space_init_once(&shadow->frozen_btnodes); |
b83ae6d4 | 513 | nilfs_mapping_init(&shadow->frozen_btnodes, inode); |
ebdfed4d RK |
514 | mi->mi_shadow = shadow; |
515 | return 0; | |
516 | } | |
517 | ||
518 | /** | |
519 | * nilfs_mdt_save_to_shadow_map - copy bmap and dirty pages to shadow map | |
520 | * @inode: inode of the metadata file | |
521 | */ | |
522 | int nilfs_mdt_save_to_shadow_map(struct inode *inode) | |
523 | { | |
524 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
525 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
526 | struct nilfs_shadow_map *shadow = mi->mi_shadow; | |
527 | int ret; | |
528 | ||
529 | ret = nilfs_copy_dirty_pages(&shadow->frozen_data, inode->i_mapping); | |
530 | if (ret) | |
531 | goto out; | |
532 | ||
533 | ret = nilfs_copy_dirty_pages(&shadow->frozen_btnodes, | |
534 | &ii->i_btnode_cache); | |
535 | if (ret) | |
536 | goto out; | |
537 | ||
538 | nilfs_bmap_save(ii->i_bmap, &shadow->bmap_store); | |
539 | out: | |
540 | return ret; | |
541 | } | |
542 | ||
b1f6a4f2 RK |
543 | int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh) |
544 | { | |
545 | struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow; | |
546 | struct buffer_head *bh_frozen; | |
547 | struct page *page; | |
548 | int blkbits = inode->i_blkbits; | |
b1f6a4f2 RK |
549 | |
550 | page = grab_cache_page(&shadow->frozen_data, bh->b_page->index); | |
551 | if (!page) | |
a7a8447e | 552 | return -ENOMEM; |
b1f6a4f2 RK |
553 | |
554 | if (!page_has_buffers(page)) | |
555 | create_empty_buffers(page, 1 << blkbits, 0); | |
556 | ||
557 | bh_frozen = nilfs_page_get_nth_block(page, bh_offset(bh) >> blkbits); | |
a7a8447e RK |
558 | |
559 | if (!buffer_uptodate(bh_frozen)) | |
560 | nilfs_copy_buffer(bh_frozen, bh); | |
561 | if (list_empty(&bh_frozen->b_assoc_buffers)) { | |
562 | list_add_tail(&bh_frozen->b_assoc_buffers, | |
563 | &shadow->frozen_buffers); | |
564 | set_buffer_nilfs_redirected(bh); | |
565 | } else { | |
566 | brelse(bh_frozen); /* already frozen */ | |
b1f6a4f2 | 567 | } |
a7a8447e | 568 | |
b1f6a4f2 | 569 | unlock_page(page); |
09cbfeaf | 570 | put_page(page); |
a7a8447e | 571 | return 0; |
b1f6a4f2 RK |
572 | } |
573 | ||
574 | struct buffer_head * | |
575 | nilfs_mdt_get_frozen_buffer(struct inode *inode, struct buffer_head *bh) | |
576 | { | |
577 | struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow; | |
578 | struct buffer_head *bh_frozen = NULL; | |
579 | struct page *page; | |
580 | int n; | |
581 | ||
582 | page = find_lock_page(&shadow->frozen_data, bh->b_page->index); | |
583 | if (page) { | |
584 | if (page_has_buffers(page)) { | |
585 | n = bh_offset(bh) >> inode->i_blkbits; | |
586 | bh_frozen = nilfs_page_get_nth_block(page, n); | |
587 | } | |
588 | unlock_page(page); | |
09cbfeaf | 589 | put_page(page); |
b1f6a4f2 RK |
590 | } |
591 | return bh_frozen; | |
592 | } | |
593 | ||
594 | static void nilfs_release_frozen_buffers(struct nilfs_shadow_map *shadow) | |
595 | { | |
596 | struct list_head *head = &shadow->frozen_buffers; | |
597 | struct buffer_head *bh; | |
598 | ||
599 | while (!list_empty(head)) { | |
600 | bh = list_first_entry(head, struct buffer_head, | |
601 | b_assoc_buffers); | |
602 | list_del_init(&bh->b_assoc_buffers); | |
603 | brelse(bh); /* drop ref-count to make it releasable */ | |
604 | } | |
605 | } | |
606 | ||
ebdfed4d RK |
607 | /** |
608 | * nilfs_mdt_restore_from_shadow_map - restore dirty pages and bmap state | |
609 | * @inode: inode of the metadata file | |
610 | */ | |
611 | void nilfs_mdt_restore_from_shadow_map(struct inode *inode) | |
612 | { | |
613 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
614 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
615 | struct nilfs_shadow_map *shadow = mi->mi_shadow; | |
616 | ||
617 | down_write(&mi->mi_sem); | |
618 | ||
619 | if (mi->mi_palloc_cache) | |
620 | nilfs_palloc_clear_cache(inode); | |
621 | ||
8c26c4e2 | 622 | nilfs_clear_dirty_pages(inode->i_mapping, true); |
ebdfed4d RK |
623 | nilfs_copy_back_pages(inode->i_mapping, &shadow->frozen_data); |
624 | ||
8c26c4e2 | 625 | nilfs_clear_dirty_pages(&ii->i_btnode_cache, true); |
ebdfed4d RK |
626 | nilfs_copy_back_pages(&ii->i_btnode_cache, &shadow->frozen_btnodes); |
627 | ||
628 | nilfs_bmap_restore(ii->i_bmap, &shadow->bmap_store); | |
629 | ||
630 | up_write(&mi->mi_sem); | |
631 | } | |
632 | ||
633 | /** | |
634 | * nilfs_mdt_clear_shadow_map - truncate pages in shadow map caches | |
635 | * @inode: inode of the metadata file | |
636 | */ | |
637 | void nilfs_mdt_clear_shadow_map(struct inode *inode) | |
638 | { | |
639 | struct nilfs_mdt_info *mi = NILFS_MDT(inode); | |
640 | struct nilfs_shadow_map *shadow = mi->mi_shadow; | |
641 | ||
642 | down_write(&mi->mi_sem); | |
b1f6a4f2 | 643 | nilfs_release_frozen_buffers(shadow); |
ebdfed4d RK |
644 | truncate_inode_pages(&shadow->frozen_data, 0); |
645 | truncate_inode_pages(&shadow->frozen_btnodes, 0); | |
646 | up_write(&mi->mi_sem); | |
647 | } |