blob: 1125f40233ffd9c849acc0f13d432f520de95e0a [file] [log] [blame]
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -07001/*
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090029#include <linux/slab.h>
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -070030#include "nilfs.h"
Ryusuke Konishi05d0e942010-07-10 20:52:09 +090031#include "btnode.h"
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -070032#include "segment.h"
33#include "page.h"
34#include "mdt.h"
35
Hitoshi Mitakea9cd2072015-11-06 16:32:08 -080036#include <trace/events/nilfs2.h>
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -070037
38#define NILFS_MDT_MAX_RA_BLOCKS (16 - 1)
39
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -070040
41static int
42nilfs_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
Cong Wang7b9c0972011-11-25 23:14:33 +080062 kaddr = kmap_atomic(bh->b_page);
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -070063 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);
Cong Wang7b9c0972011-11-25 23:14:33 +080067 kunmap_atomic(kaddr);
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -070068
69 set_buffer_uptodate(bh);
Ryusuke Konishi5fc7b142011-05-05 12:56:51 +090070 mark_buffer_dirty(bh);
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -070071 nilfs_mdt_mark_dirty(inode);
Hitoshi Mitakea9cd2072015-11-06 16:32:08 -080072
73 trace_nilfs2_mdt_insert_new_block(inode, inode->i_ino, block);
74
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -070075 return 0;
76}
77
78static 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{
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -070084 struct super_block *sb = inode->i_sb;
85 struct nilfs_transaction_info ti;
86 struct buffer_head *bh;
87 int err;
88
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -070089 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;
Ryusuke Konishi14351102009-09-06 17:49:49 +090097 if (buffer_uptodate(bh))
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -070098 goto failed_bh;
Ryusuke Konishi14351102009-09-06 17:49:49 +090099
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700100 wait_on_buffer(bh);
101 if (buffer_uptodate(bh))
102 goto failed_bh;
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700103
Ryusuke Konishi090fd5b2010-09-05 16:17:35 +0900104 bh->b_bdev = sb->s_bdev;
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700105 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);
113 page_cache_release(bh->b_page);
114 brelse(bh);
115
116 failed_unlock:
Ryusuke Konishi47420c72009-04-06 19:01:45 -0700117 if (likely(!err))
118 err = nilfs_transaction_commit(sb);
119 else
120 nilfs_transaction_abort(sb);
Ryusuke Konishi090fd5b2010-09-05 16:17:35 +0900121
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700122 return err;
123}
124
125static int
126nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff,
127 int mode, struct buffer_head **out_bh)
128{
129 struct buffer_head *bh;
Ryusuke Konishi0f3fe332009-08-15 02:29:28 +0900130 __u64 blknum = 0;
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700131 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 }
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700146 } else /* mode == READ */
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700147 lock_buffer(bh);
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700148
149 if (buffer_uptodate(bh)) {
150 unlock_buffer(bh);
151 goto out;
152 }
Ryusuke Konishi14351102009-09-06 17:49:49 +0900153
154 ret = nilfs_bmap_lookup(NILFS_I(inode)->i_bmap, blkoff, &blknum);
155 if (unlikely(ret)) {
156 unlock_buffer(bh);
157 goto failed_bh;
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700158 }
Ryusuke Konishic6e07182010-09-05 00:23:50 +0900159 map_bh(bh, inode->i_sb, (sector_t)blknum);
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700160
161 bh->b_end_io = end_buffer_read_sync;
162 get_bh(bh);
163 submit_bh(mode, bh);
164 ret = 0;
Hitoshi Mitakea9cd2072015-11-06 16:32:08 -0800165
166 trace_nilfs2_mdt_submit_block(inode, inode->i_ino, blkoff, mode);
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700167 out:
168 get_bh(bh);
169 *out_bh = bh;
170
171 failed_bh:
172 unlock_page(bh->b_page);
173 page_cache_release(bh->b_page);
174 brelse(bh);
175 failed:
176 return ret;
177}
178
179static int nilfs_mdt_read_block(struct inode *inode, unsigned long block,
Ryusuke Konishib34a6502009-11-14 00:09:47 +0900180 int readahead, struct buffer_head **out_bh)
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700181{
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
Ryusuke Konishib34a6502009-11-14 00:09:47 +0900194 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 }
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700206 }
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 *
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700246 * %-EROFS - Read only filesystem (for create mode)
247 */
248int 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:
Ryusuke Konishib34a6502009-11-14 00:09:47 +0900257 ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh);
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700258 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
269/**
Ryusuke Konishifa339152015-04-16 12:46:39 -0700270 * 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 */
291int 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 }
319out:
320 return ret;
321}
322
323/**
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700324 * 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
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700334 */
335int 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);
Ryusuke Konishi84338232009-05-05 21:52:06 +0900341 if (!err || err == -ENOENT) {
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700342 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 */
363int nilfs_mdt_forget_block(struct inode *inode, unsigned long block)
364{
365 pgoff_t index = (pgoff_t)block >>
366 (PAGE_CACHE_SHIFT - inode->i_blkbits);
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 <<
379 (PAGE_CACHE_SHIFT - inode->i_blkbits);
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);
388 page_cache_release(page);
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)
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700409 */
410int nilfs_mdt_mark_block_dirty(struct inode *inode, unsigned long block)
411{
412 struct buffer_head *bh;
413 int err;
414
Ryusuke Konishib34a6502009-11-14 00:09:47 +0900415 err = nilfs_mdt_read_block(inode, block, 0, &bh);
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700416 if (unlikely(err))
417 return err;
Ryusuke Konishi5fc7b142011-05-05 12:56:51 +0900418 mark_buffer_dirty(bh);
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700419 nilfs_mdt_mark_dirty(inode);
420 brelse(bh);
421 return 0;
422}
423
424int 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
435static int
436nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
437{
Vyacheslav Dubeyko8c26c4e2013-04-30 15:27:48 -0700438 struct inode *inode = page->mapping->host;
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900439 struct super_block *sb;
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700440 int err = 0;
441
Vyacheslav Dubeyko8c26c4e2013-04-30 15:27:48 -0700442 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
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700454 redirty_page_for_writepage(wbc, page);
455 unlock_page(page);
456
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900457 if (!inode)
458 return 0;
459
460 sb = inode->i_sb;
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700461
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
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700467 return err;
468}
469
470
Alexey Dobriyan7f094102009-09-21 17:01:10 -0700471static const struct address_space_operations def_mdt_aops = {
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700472 .writepage = nilfs_mdt_write_page,
473};
474
Alexey Dobriyan6e1d5dc2009-09-21 17:01:11 -0700475static const struct inode_operations def_mdt_iops;
Alexey Dobriyan828c0952009-10-01 15:43:56 -0700476static const struct file_operations def_mdt_fops;
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700477
Ryusuke Konishi5e19a992010-08-21 22:01:51 +0900478
Ryusuke Konishif1e89c82010-09-05 12:20:59 +0900479int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz)
Ryusuke Konishi5e19a992010-08-21 22:01:51 +0900480{
481 struct nilfs_mdt_info *mi;
482
483 mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS);
484 if (!mi)
485 return -ENOMEM;
486
Ryusuke Konishi5e19a992010-08-21 22:01:51 +0900487 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);
Ryusuke Konishif1e89c82010-09-05 12:20:59 +0900492
493 inode->i_op = &def_mdt_iops;
494 inode->i_fop = &def_mdt_fops;
495 inode->i_mapping->a_ops = &def_mdt_aops;
Ryusuke Konishi5e19a992010-08-21 22:01:51 +0900496
497 return 0;
498}
499
Ryusuke Konishi5eb563f2009-04-06 19:01:28 -0700500void 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
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900510/**
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 */
515int nilfs_mdt_setup_shadow_map(struct inode *inode,
516 struct nilfs_shadow_map *shadow)
517{
518 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900519
520 INIT_LIST_HEAD(&shadow->frozen_buffers);
Miklos Szeredi2aa15892011-02-23 13:49:47 +0100521 address_space_init_once(&shadow->frozen_data);
Christoph Hellwigb83ae6d2015-01-14 10:42:37 +0100522 nilfs_mapping_init(&shadow->frozen_data, inode);
Miklos Szeredi2aa15892011-02-23 13:49:47 +0100523 address_space_init_once(&shadow->frozen_btnodes);
Christoph Hellwigb83ae6d2015-01-14 10:42:37 +0100524 nilfs_mapping_init(&shadow->frozen_btnodes, inode);
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900525 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 */
533int 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
Ryusuke Konishib1f6a4f2010-08-31 11:40:34 +0900554int 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;
Ryusuke Konishib1f6a4f2010-08-31 11:40:34 +0900560
561 page = grab_cache_page(&shadow->frozen_data, bh->b_page->index);
562 if (!page)
Ryusuke Konishia7a84472010-12-27 00:03:02 +0900563 return -ENOMEM;
Ryusuke Konishib1f6a4f2010-08-31 11:40:34 +0900564
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);
Ryusuke Konishia7a84472010-12-27 00:03:02 +0900569
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 */
Ryusuke Konishib1f6a4f2010-08-31 11:40:34 +0900578 }
Ryusuke Konishia7a84472010-12-27 00:03:02 +0900579
Ryusuke Konishib1f6a4f2010-08-31 11:40:34 +0900580 unlock_page(page);
581 page_cache_release(page);
Ryusuke Konishia7a84472010-12-27 00:03:02 +0900582 return 0;
Ryusuke Konishib1f6a4f2010-08-31 11:40:34 +0900583}
584
585struct buffer_head *
586nilfs_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);
600 page_cache_release(page);
601 }
602 return bh_frozen;
603}
604
605static 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
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900618/**
619 * nilfs_mdt_restore_from_shadow_map - restore dirty pages and bmap state
620 * @inode: inode of the metadata file
621 */
622void 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
Vyacheslav Dubeyko8c26c4e2013-04-30 15:27:48 -0700633 nilfs_clear_dirty_pages(inode->i_mapping, true);
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900634 nilfs_copy_back_pages(inode->i_mapping, &shadow->frozen_data);
635
Vyacheslav Dubeyko8c26c4e2013-04-30 15:27:48 -0700636 nilfs_clear_dirty_pages(&ii->i_btnode_cache, true);
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900637 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 */
648void 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);
Ryusuke Konishib1f6a4f2010-08-31 11:40:34 +0900654 nilfs_release_frozen_buffers(shadow);
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900655 truncate_inode_pages(&shadow->frozen_data, 0);
656 truncate_inode_pages(&shadow->frozen_btnodes, 0);
657 up_write(&mi->mi_sem);
658}