blob: 0ba679866e504ec126720f3eb7b78e210703f538 [file] [log] [blame]
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -07001/*
2 * page.c - buffer/page management specific to 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 * Seiji Kihara <kihara@osrg.net>.
22 */
23
24#include <linux/pagemap.h>
25#include <linux/writeback.h>
26#include <linux/swap.h>
27#include <linux/bitops.h>
28#include <linux/page-flags.h>
29#include <linux/list.h>
30#include <linux/highmem.h>
31#include <linux/pagevec.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090032#include <linux/gfp.h>
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -070033#include "nilfs.h"
34#include "page.h"
35#include "mdt.h"
36
37
38#define NILFS_BUFFER_INHERENT_BITS \
39 ((1UL << BH_Uptodate) | (1UL << BH_Mapped) | (1UL << BH_NILFS_Node) | \
Ryusuke Konishi1cb2d382011-04-04 12:53:28 +090040 (1UL << BH_NILFS_Volatile) | (1UL << BH_NILFS_Checked))
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -070041
42static struct buffer_head *
43__nilfs_get_page_block(struct page *page, unsigned long block, pgoff_t index,
44 int blkbits, unsigned long b_state)
45
46{
47 unsigned long first_block;
48 struct buffer_head *bh;
49
50 if (!page_has_buffers(page))
51 create_empty_buffers(page, 1 << blkbits, b_state);
52
53 first_block = (unsigned long)index << (PAGE_CACHE_SHIFT - blkbits);
54 bh = nilfs_page_get_nth_block(page, block - first_block);
55
56 touch_buffer(bh);
57 wait_on_buffer(bh);
58 return bh;
59}
60
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -070061struct buffer_head *nilfs_grab_buffer(struct inode *inode,
62 struct address_space *mapping,
63 unsigned long blkoff,
64 unsigned long b_state)
65{
66 int blkbits = inode->i_blkbits;
67 pgoff_t index = blkoff >> (PAGE_CACHE_SHIFT - blkbits);
Ryusuke Konishic1c1d70922010-08-29 12:44:56 +090068 struct page *page;
69 struct buffer_head *bh;
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -070070
71 page = grab_cache_page(mapping, index);
72 if (unlikely(!page))
73 return NULL;
74
75 bh = __nilfs_get_page_block(page, blkoff, index, blkbits, b_state);
76 if (unlikely(!bh)) {
77 unlock_page(page);
78 page_cache_release(page);
79 return NULL;
80 }
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -070081 return bh;
82}
83
84/**
85 * nilfs_forget_buffer - discard dirty state
86 * @inode: owner inode of the buffer
87 * @bh: buffer head of the buffer to be discarded
88 */
89void nilfs_forget_buffer(struct buffer_head *bh)
90{
91 struct page *page = bh->b_page;
92
93 lock_buffer(bh);
94 clear_buffer_nilfs_volatile(bh);
Ryusuke Konishi4e13e662010-07-18 10:42:25 +090095 clear_buffer_nilfs_checked(bh);
Ryusuke Konishib1f6a4f2010-08-31 11:40:34 +090096 clear_buffer_nilfs_redirected(bh);
Ryusuke Konishi84338232009-05-05 21:52:06 +090097 clear_buffer_dirty(bh);
98 if (nilfs_page_buffers_clean(page))
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -070099 __nilfs_clear_page_dirty(page);
100
101 clear_buffer_uptodate(bh);
102 clear_buffer_mapped(bh);
103 bh->b_blocknr = -1;
104 ClearPageUptodate(page);
105 ClearPageMappedToDisk(page);
106 unlock_buffer(bh);
107 brelse(bh);
108}
109
110/**
111 * nilfs_copy_buffer -- copy buffer data and flags
112 * @dbh: destination buffer
113 * @sbh: source buffer
114 */
115void nilfs_copy_buffer(struct buffer_head *dbh, struct buffer_head *sbh)
116{
117 void *kaddr0, *kaddr1;
118 unsigned long bits;
119 struct page *spage = sbh->b_page, *dpage = dbh->b_page;
120 struct buffer_head *bh;
121
Cong Wang7b9c0972011-11-25 23:14:33 +0800122 kaddr0 = kmap_atomic(spage);
123 kaddr1 = kmap_atomic(dpage);
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700124 memcpy(kaddr1 + bh_offset(dbh), kaddr0 + bh_offset(sbh), sbh->b_size);
Cong Wang7b9c0972011-11-25 23:14:33 +0800125 kunmap_atomic(kaddr1);
126 kunmap_atomic(kaddr0);
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700127
128 dbh->b_state = sbh->b_state & NILFS_BUFFER_INHERENT_BITS;
129 dbh->b_blocknr = sbh->b_blocknr;
130 dbh->b_bdev = sbh->b_bdev;
131
132 bh = dbh;
133 bits = sbh->b_state & ((1UL << BH_Uptodate) | (1UL << BH_Mapped));
134 while ((bh = bh->b_this_page) != dbh) {
135 lock_buffer(bh);
136 bits &= bh->b_state;
137 unlock_buffer(bh);
138 }
139 if (bits & (1UL << BH_Uptodate))
140 SetPageUptodate(dpage);
141 else
142 ClearPageUptodate(dpage);
143 if (bits & (1UL << BH_Mapped))
144 SetPageMappedToDisk(dpage);
145 else
146 ClearPageMappedToDisk(dpage);
147}
148
149/**
150 * nilfs_page_buffers_clean - check if a page has dirty buffers or not.
151 * @page: page to be checked
152 *
153 * nilfs_page_buffers_clean() returns zero if the page has dirty buffers.
154 * Otherwise, it returns non-zero value.
155 */
156int nilfs_page_buffers_clean(struct page *page)
157{
158 struct buffer_head *bh, *head;
159
160 bh = head = page_buffers(page);
161 do {
162 if (buffer_dirty(bh))
163 return 0;
164 bh = bh->b_this_page;
165 } while (bh != head);
166 return 1;
167}
168
169void nilfs_page_bug(struct page *page)
170{
171 struct address_space *m;
Ryusuke Konishiaa405b12011-05-05 12:56:51 +0900172 unsigned long ino;
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700173
174 if (unlikely(!page)) {
175 printk(KERN_CRIT "NILFS_PAGE_BUG(NULL)\n");
176 return;
177 }
178
179 m = page->mapping;
Ryusuke Konishiaa405b12011-05-05 12:56:51 +0900180 ino = m ? m->host->i_ino : 0;
181
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700182 printk(KERN_CRIT "NILFS_PAGE_BUG(%p): cnt=%d index#=%llu flags=0x%lx "
183 "mapping=%p ino=%lu\n",
184 page, atomic_read(&page->_count),
185 (unsigned long long)page->index, page->flags, m, ino);
186
187 if (page_has_buffers(page)) {
188 struct buffer_head *bh, *head;
189 int i = 0;
190
191 bh = head = page_buffers(page);
192 do {
193 printk(KERN_CRIT
194 " BH[%d] %p: cnt=%d block#=%llu state=0x%lx\n",
195 i++, bh, atomic_read(&bh->b_count),
196 (unsigned long long)bh->b_blocknr, bh->b_state);
197 bh = bh->b_this_page;
198 } while (bh != head);
199 }
200}
201
202/**
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700203 * nilfs_copy_page -- copy the page with buffers
204 * @dst: destination page
205 * @src: source page
206 * @copy_dirty: flag whether to copy dirty states on the page's buffer heads.
207 *
Ryusuke Konishi7a650042010-03-14 03:32:40 +0900208 * This function is for both data pages and btnode pages. The dirty flag
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700209 * should be treated by caller. The page must not be under i/o.
210 * Both src and dst page must be locked
211 */
212static void nilfs_copy_page(struct page *dst, struct page *src, int copy_dirty)
213{
214 struct buffer_head *dbh, *dbufs, *sbh, *sbufs;
215 unsigned long mask = NILFS_BUFFER_INHERENT_BITS;
216
217 BUG_ON(PageWriteback(dst));
218
219 sbh = sbufs = page_buffers(src);
220 if (!page_has_buffers(dst))
221 create_empty_buffers(dst, sbh->b_size, 0);
222
223 if (copy_dirty)
224 mask |= (1UL << BH_Dirty);
225
226 dbh = dbufs = page_buffers(dst);
227 do {
228 lock_buffer(sbh);
229 lock_buffer(dbh);
230 dbh->b_state = sbh->b_state & mask;
231 dbh->b_blocknr = sbh->b_blocknr;
232 dbh->b_bdev = sbh->b_bdev;
233 sbh = sbh->b_this_page;
234 dbh = dbh->b_this_page;
235 } while (dbh != dbufs);
236
237 copy_highpage(dst, src);
238
239 if (PageUptodate(src) && !PageUptodate(dst))
240 SetPageUptodate(dst);
241 else if (!PageUptodate(src) && PageUptodate(dst))
242 ClearPageUptodate(dst);
243 if (PageMappedToDisk(src) && !PageMappedToDisk(dst))
244 SetPageMappedToDisk(dst);
245 else if (!PageMappedToDisk(src) && PageMappedToDisk(dst))
246 ClearPageMappedToDisk(dst);
247
248 do {
249 unlock_buffer(sbh);
250 unlock_buffer(dbh);
251 sbh = sbh->b_this_page;
252 dbh = dbh->b_this_page;
253 } while (dbh != dbufs);
254}
255
256int nilfs_copy_dirty_pages(struct address_space *dmap,
257 struct address_space *smap)
258{
259 struct pagevec pvec;
260 unsigned int i;
261 pgoff_t index = 0;
262 int err = 0;
263
264 pagevec_init(&pvec, 0);
265repeat:
266 if (!pagevec_lookup_tag(&pvec, smap, &index, PAGECACHE_TAG_DIRTY,
267 PAGEVEC_SIZE))
268 return 0;
269
270 for (i = 0; i < pagevec_count(&pvec); i++) {
271 struct page *page = pvec.pages[i], *dpage;
272
273 lock_page(page);
274 if (unlikely(!PageDirty(page)))
275 NILFS_PAGE_BUG(page, "inconsistent dirty state");
276
277 dpage = grab_cache_page(dmap, page->index);
278 if (unlikely(!dpage)) {
279 /* No empty page is added to the page cache */
280 err = -ENOMEM;
281 unlock_page(page);
282 break;
283 }
284 if (unlikely(!page_has_buffers(page)))
285 NILFS_PAGE_BUG(page,
286 "found empty page in dat page cache");
287
288 nilfs_copy_page(dpage, page, 1);
289 __set_page_dirty_nobuffers(dpage);
290
291 unlock_page(dpage);
292 page_cache_release(dpage);
293 unlock_page(page);
294 }
295 pagevec_release(&pvec);
296 cond_resched();
297
298 if (likely(!err))
299 goto repeat;
300 return err;
301}
302
303/**
Ryusuke Konishi7a650042010-03-14 03:32:40 +0900304 * nilfs_copy_back_pages -- copy back pages to original cache from shadow cache
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700305 * @dmap: destination page cache
306 * @smap: source page cache
307 *
308 * No pages must no be added to the cache during this process.
309 * This must be ensured by the caller.
310 */
311void nilfs_copy_back_pages(struct address_space *dmap,
312 struct address_space *smap)
313{
314 struct pagevec pvec;
315 unsigned int i, n;
316 pgoff_t index = 0;
317 int err;
318
319 pagevec_init(&pvec, 0);
320repeat:
321 n = pagevec_lookup(&pvec, smap, index, PAGEVEC_SIZE);
322 if (!n)
323 return;
324 index = pvec.pages[n - 1]->index + 1;
325
326 for (i = 0; i < pagevec_count(&pvec); i++) {
327 struct page *page = pvec.pages[i], *dpage;
328 pgoff_t offset = page->index;
329
330 lock_page(page);
331 dpage = find_lock_page(dmap, offset);
332 if (dpage) {
333 /* override existing page on the destination cache */
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700334 WARN_ON(PageDirty(dpage));
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700335 nilfs_copy_page(dpage, page, 0);
336 unlock_page(dpage);
337 page_cache_release(dpage);
338 } else {
339 struct page *page2;
340
341 /* move the page to the destination cache */
342 spin_lock_irq(&smap->tree_lock);
343 page2 = radix_tree_delete(&smap->page_tree, offset);
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700344 WARN_ON(page2 != page);
345
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700346 smap->nrpages--;
347 spin_unlock_irq(&smap->tree_lock);
348
349 spin_lock_irq(&dmap->tree_lock);
350 err = radix_tree_insert(&dmap->page_tree, offset, page);
351 if (unlikely(err < 0)) {
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700352 WARN_ON(err == -EEXIST);
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700353 page->mapping = NULL;
354 page_cache_release(page); /* for cache */
355 } else {
356 page->mapping = dmap;
357 dmap->nrpages++;
358 if (PageDirty(page))
359 radix_tree_tag_set(&dmap->page_tree,
360 offset,
361 PAGECACHE_TAG_DIRTY);
362 }
363 spin_unlock_irq(&dmap->tree_lock);
364 }
365 unlock_page(page);
366 }
367 pagevec_release(&pvec);
368 cond_resched();
369
370 goto repeat;
371}
372
Vyacheslav Dubeyko8c26c4e2013-04-30 15:27:48 -0700373/**
374 * nilfs_clear_dirty_pages - discard dirty pages in address space
375 * @mapping: address space with dirty pages for discarding
376 * @silent: suppress [true] or print [false] warning messages
377 */
378void nilfs_clear_dirty_pages(struct address_space *mapping, bool silent)
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700379{
380 struct pagevec pvec;
381 unsigned int i;
382 pgoff_t index = 0;
383
384 pagevec_init(&pvec, 0);
385
386 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
387 PAGEVEC_SIZE)) {
388 for (i = 0; i < pagevec_count(&pvec); i++) {
389 struct page *page = pvec.pages[i];
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700390
391 lock_page(page);
Vyacheslav Dubeyko8c26c4e2013-04-30 15:27:48 -0700392 nilfs_clear_dirty_page(page, silent);
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700393 unlock_page(page);
394 }
395 pagevec_release(&pvec);
396 cond_resched();
397 }
398}
399
Vyacheslav Dubeyko8c26c4e2013-04-30 15:27:48 -0700400/**
401 * nilfs_clear_dirty_page - discard dirty page
402 * @page: dirty page that will be discarded
403 * @silent: suppress [true] or print [false] warning messages
404 */
405void nilfs_clear_dirty_page(struct page *page, bool silent)
406{
407 struct inode *inode = page->mapping->host;
408 struct super_block *sb = inode->i_sb;
409
Vyacheslav Dubeykodc33f5f2013-04-30 15:27:50 -0700410 BUG_ON(!PageLocked(page));
Vyacheslav Dubeyko8c26c4e2013-04-30 15:27:48 -0700411
412 if (!silent) {
413 nilfs_warning(sb, __func__,
414 "discard page: offset %lld, ino %lu",
415 page_offset(page), inode->i_ino);
416 }
417
418 ClearPageUptodate(page);
419 ClearPageMappedToDisk(page);
420
421 if (page_has_buffers(page)) {
422 struct buffer_head *bh, *head;
423
424 bh = head = page_buffers(page);
425 do {
426 lock_buffer(bh);
427 if (!silent) {
428 nilfs_warning(sb, __func__,
429 "discard block %llu, size %zu",
430 (u64)bh->b_blocknr, bh->b_size);
431 }
432 clear_buffer_dirty(bh);
433 clear_buffer_nilfs_volatile(bh);
434 clear_buffer_nilfs_checked(bh);
435 clear_buffer_nilfs_redirected(bh);
436 clear_buffer_uptodate(bh);
437 clear_buffer_mapped(bh);
438 unlock_buffer(bh);
439 } while (bh = bh->b_this_page, bh != head);
440 }
441
442 __nilfs_clear_page_dirty(page);
443}
444
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700445unsigned nilfs_page_count_clean_buffers(struct page *page,
446 unsigned from, unsigned to)
447{
448 unsigned block_start, block_end;
449 struct buffer_head *bh, *head;
450 unsigned nc = 0;
451
452 for (bh = head = page_buffers(page), block_start = 0;
453 bh != head || !block_start;
454 block_start = block_end, bh = bh->b_this_page) {
455 block_end = block_start + bh->b_size;
456 if (block_end > from && block_start < to && !buffer_dirty(bh))
457 nc++;
458 }
459 return nc;
460}
Ryusuke Konishiae53a0a2010-12-26 23:30:02 +0900461
Ryusuke Konishiaa405b12011-05-05 12:56:51 +0900462void nilfs_mapping_init(struct address_space *mapping, struct inode *inode,
Jens Axboe7eaceac2011-03-10 08:52:07 +0100463 struct backing_dev_info *bdi)
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900464{
Ryusuke Konishiaa405b12011-05-05 12:56:51 +0900465 mapping->host = inode;
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900466 mapping->flags = 0;
467 mapping_set_gfp_mask(mapping, GFP_NOFS);
Rafael Aquini252aa6f2012-12-11 16:02:35 -0800468 mapping->private_data = NULL;
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900469 mapping->backing_dev_info = bdi;
Ryusuke Konishid611b222011-03-30 11:49:20 +0900470 mapping->a_ops = &empty_aops;
Ryusuke Konishiebdfed42010-09-06 12:05:43 +0900471}
Ryusuke Konishi0bd49f92009-04-06 19:01:27 -0700472
473/*
474 * NILFS2 needs clear_page_dirty() in the following two cases:
475 *
476 * 1) For B-tree node pages and data pages of the dat/gcdat, NILFS2 clears
477 * page dirty flags when it copies back pages from the shadow cache
478 * (gcdat->{i_mapping,i_btnode_cache}) to its original cache
479 * (dat->{i_mapping,i_btnode_cache}).
480 *
481 * 2) Some B-tree operations like insertion or deletion may dispose buffers
482 * in dirty state, and this needs to cancel the dirty state of their pages.
483 */
484int __nilfs_clear_page_dirty(struct page *page)
485{
486 struct address_space *mapping = page->mapping;
487
488 if (mapping) {
489 spin_lock_irq(&mapping->tree_lock);
490 if (test_bit(PG_dirty, &page->flags)) {
491 radix_tree_tag_clear(&mapping->page_tree,
492 page_index(page),
493 PAGECACHE_TAG_DIRTY);
494 spin_unlock_irq(&mapping->tree_lock);
495 return clear_page_dirty_for_io(page);
496 }
497 spin_unlock_irq(&mapping->tree_lock);
498 return 0;
499 }
500 return TestClearPageDirty(page);
501}
Ryusuke Konishi622daaff2010-12-26 16:38:43 +0900502
503/**
504 * nilfs_find_uncommitted_extent - find extent of uncommitted data
505 * @inode: inode
506 * @start_blk: start block offset (in)
507 * @blkoff: start offset of the found extent (out)
508 *
509 * This function searches an extent of buffers marked "delayed" which
510 * starts from a block offset equal to or larger than @start_blk. If
511 * such an extent was found, this will store the start offset in
512 * @blkoff and return its length in blocks. Otherwise, zero is
513 * returned.
514 */
515unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
516 sector_t start_blk,
517 sector_t *blkoff)
518{
519 unsigned int i;
520 pgoff_t index;
521 unsigned int nblocks_in_page;
522 unsigned long length = 0;
523 sector_t b;
524 struct pagevec pvec;
525 struct page *page;
526
527 if (inode->i_mapping->nrpages == 0)
528 return 0;
529
530 index = start_blk >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
531 nblocks_in_page = 1U << (PAGE_CACHE_SHIFT - inode->i_blkbits);
532
533 pagevec_init(&pvec, 0);
534
535repeat:
536 pvec.nr = find_get_pages_contig(inode->i_mapping, index, PAGEVEC_SIZE,
537 pvec.pages);
538 if (pvec.nr == 0)
539 return length;
540
541 if (length > 0 && pvec.pages[0]->index > index)
542 goto out;
543
544 b = pvec.pages[0]->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
545 i = 0;
546 do {
547 page = pvec.pages[i];
548
549 lock_page(page);
550 if (page_has_buffers(page)) {
551 struct buffer_head *bh, *head;
552
553 bh = head = page_buffers(page);
554 do {
555 if (b < start_blk)
556 continue;
557 if (buffer_delay(bh)) {
558 if (length == 0)
559 *blkoff = b;
560 length++;
561 } else if (length > 0) {
562 goto out_locked;
563 }
564 } while (++b, bh = bh->b_this_page, bh != head);
565 } else {
566 if (length > 0)
567 goto out_locked;
568
569 b += nblocks_in_page;
570 }
571 unlock_page(page);
572
573 } while (++i < pagevec_count(&pvec));
574
575 index = page->index + 1;
576 pagevec_release(&pvec);
577 cond_resched();
578 goto repeat;
579
580out_locked:
581 unlock_page(page);
582out:
583 pagevec_release(&pvec);
584 return length;
585}