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19#include <linux/pagemap.h>
20#include <linux/writeback.h>
21#include <linux/swap.h>
22#include <linux/bitops.h>
23#include <linux/page-flags.h>
24#include <linux/list.h>
25#include <linux/highmem.h>
26#include <linux/pagevec.h>
27#include <linux/gfp.h>
28#include "nilfs.h"
29#include "page.h"
30#include "mdt.h"
31
32
33#define NILFS_BUFFER_INHERENT_BITS \
34 (BIT(BH_Uptodate) | BIT(BH_Mapped) | BIT(BH_NILFS_Node) | \
35 BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Checked))
36
37static struct buffer_head *
38__nilfs_get_page_block(struct page *page, unsigned long block, pgoff_t index,
39 int blkbits, unsigned long b_state)
40
41{
42 unsigned long first_block;
43 struct buffer_head *bh;
44
45 if (!page_has_buffers(page))
46 create_empty_buffers(page, 1 << blkbits, b_state);
47
48 first_block = (unsigned long)index << (PAGE_SHIFT - blkbits);
49 bh = nilfs_page_get_nth_block(page, block - first_block);
50
51 touch_buffer(bh);
52 wait_on_buffer(bh);
53 return bh;
54}
55
56struct buffer_head *nilfs_grab_buffer(struct inode *inode,
57 struct address_space *mapping,
58 unsigned long blkoff,
59 unsigned long b_state)
60{
61 int blkbits = inode->i_blkbits;
62 pgoff_t index = blkoff >> (PAGE_SHIFT - blkbits);
63 struct page *page;
64 struct buffer_head *bh;
65
66 page = grab_cache_page(mapping, index);
67 if (unlikely(!page))
68 return NULL;
69
70 bh = __nilfs_get_page_block(page, blkoff, index, blkbits, b_state);
71 if (unlikely(!bh)) {
72 unlock_page(page);
73 put_page(page);
74 return NULL;
75 }
76 return bh;
77}
78
79
80
81
82
83
84void nilfs_forget_buffer(struct buffer_head *bh)
85{
86 struct page *page = bh->b_page;
87 const unsigned long clear_bits =
88 (BIT(BH_Uptodate) | BIT(BH_Dirty) | BIT(BH_Mapped) |
89 BIT(BH_Async_Write) | BIT(BH_NILFS_Volatile) |
90 BIT(BH_NILFS_Checked) | BIT(BH_NILFS_Redirected));
91
92 lock_buffer(bh);
93 set_mask_bits(&bh->b_state, clear_bits, 0);
94 if (nilfs_page_buffers_clean(page))
95 __nilfs_clear_page_dirty(page);
96
97 bh->b_blocknr = -1;
98 ClearPageUptodate(page);
99 ClearPageMappedToDisk(page);
100 unlock_buffer(bh);
101 brelse(bh);
102}
103
104
105
106
107
108
109void nilfs_copy_buffer(struct buffer_head *dbh, struct buffer_head *sbh)
110{
111 void *kaddr0, *kaddr1;
112 unsigned long bits;
113 struct page *spage = sbh->b_page, *dpage = dbh->b_page;
114 struct buffer_head *bh;
115
116 kaddr0 = kmap_atomic(spage);
117 kaddr1 = kmap_atomic(dpage);
118 memcpy(kaddr1 + bh_offset(dbh), kaddr0 + bh_offset(sbh), sbh->b_size);
119 kunmap_atomic(kaddr1);
120 kunmap_atomic(kaddr0);
121
122 dbh->b_state = sbh->b_state & NILFS_BUFFER_INHERENT_BITS;
123 dbh->b_blocknr = sbh->b_blocknr;
124 dbh->b_bdev = sbh->b_bdev;
125
126 bh = dbh;
127 bits = sbh->b_state & (BIT(BH_Uptodate) | BIT(BH_Mapped));
128 while ((bh = bh->b_this_page) != dbh) {
129 lock_buffer(bh);
130 bits &= bh->b_state;
131 unlock_buffer(bh);
132 }
133 if (bits & BIT(BH_Uptodate))
134 SetPageUptodate(dpage);
135 else
136 ClearPageUptodate(dpage);
137 if (bits & BIT(BH_Mapped))
138 SetPageMappedToDisk(dpage);
139 else
140 ClearPageMappedToDisk(dpage);
141}
142
143
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145
146
147
148
149
150int nilfs_page_buffers_clean(struct page *page)
151{
152 struct buffer_head *bh, *head;
153
154 bh = head = page_buffers(page);
155 do {
156 if (buffer_dirty(bh))
157 return 0;
158 bh = bh->b_this_page;
159 } while (bh != head);
160 return 1;
161}
162
163void nilfs_page_bug(struct page *page)
164{
165 struct address_space *m;
166 unsigned long ino;
167
168 if (unlikely(!page)) {
169 printk(KERN_CRIT "NILFS_PAGE_BUG(NULL)\n");
170 return;
171 }
172
173 m = page->mapping;
174 ino = m ? m->host->i_ino : 0;
175
176 printk(KERN_CRIT "NILFS_PAGE_BUG(%p): cnt=%d index#=%llu flags=0x%lx "
177 "mapping=%p ino=%lu\n",
178 page, page_ref_count(page),
179 (unsigned long long)page->index, page->flags, m, ino);
180
181 if (page_has_buffers(page)) {
182 struct buffer_head *bh, *head;
183 int i = 0;
184
185 bh = head = page_buffers(page);
186 do {
187 printk(KERN_CRIT
188 " BH[%d] %p: cnt=%d block#=%llu state=0x%lx\n",
189 i++, bh, atomic_read(&bh->b_count),
190 (unsigned long long)bh->b_blocknr, bh->b_state);
191 bh = bh->b_this_page;
192 } while (bh != head);
193 }
194}
195
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204
205
206static void nilfs_copy_page(struct page *dst, struct page *src, int copy_dirty)
207{
208 struct buffer_head *dbh, *dbufs, *sbh, *sbufs;
209 unsigned long mask = NILFS_BUFFER_INHERENT_BITS;
210
211 BUG_ON(PageWriteback(dst));
212
213 sbh = sbufs = page_buffers(src);
214 if (!page_has_buffers(dst))
215 create_empty_buffers(dst, sbh->b_size, 0);
216
217 if (copy_dirty)
218 mask |= BIT(BH_Dirty);
219
220 dbh = dbufs = page_buffers(dst);
221 do {
222 lock_buffer(sbh);
223 lock_buffer(dbh);
224 dbh->b_state = sbh->b_state & mask;
225 dbh->b_blocknr = sbh->b_blocknr;
226 dbh->b_bdev = sbh->b_bdev;
227 sbh = sbh->b_this_page;
228 dbh = dbh->b_this_page;
229 } while (dbh != dbufs);
230
231 copy_highpage(dst, src);
232
233 if (PageUptodate(src) && !PageUptodate(dst))
234 SetPageUptodate(dst);
235 else if (!PageUptodate(src) && PageUptodate(dst))
236 ClearPageUptodate(dst);
237 if (PageMappedToDisk(src) && !PageMappedToDisk(dst))
238 SetPageMappedToDisk(dst);
239 else if (!PageMappedToDisk(src) && PageMappedToDisk(dst))
240 ClearPageMappedToDisk(dst);
241
242 do {
243 unlock_buffer(sbh);
244 unlock_buffer(dbh);
245 sbh = sbh->b_this_page;
246 dbh = dbh->b_this_page;
247 } while (dbh != dbufs);
248}
249
250int nilfs_copy_dirty_pages(struct address_space *dmap,
251 struct address_space *smap)
252{
253 struct pagevec pvec;
254 unsigned int i;
255 pgoff_t index = 0;
256 int err = 0;
257
258 pagevec_init(&pvec, 0);
259repeat:
260 if (!pagevec_lookup_tag(&pvec, smap, &index, PAGECACHE_TAG_DIRTY,
261 PAGEVEC_SIZE))
262 return 0;
263
264 for (i = 0; i < pagevec_count(&pvec); i++) {
265 struct page *page = pvec.pages[i], *dpage;
266
267 lock_page(page);
268 if (unlikely(!PageDirty(page)))
269 NILFS_PAGE_BUG(page, "inconsistent dirty state");
270
271 dpage = grab_cache_page(dmap, page->index);
272 if (unlikely(!dpage)) {
273
274 err = -ENOMEM;
275 unlock_page(page);
276 break;
277 }
278 if (unlikely(!page_has_buffers(page)))
279 NILFS_PAGE_BUG(page,
280 "found empty page in dat page cache");
281
282 nilfs_copy_page(dpage, page, 1);
283 __set_page_dirty_nobuffers(dpage);
284
285 unlock_page(dpage);
286 put_page(dpage);
287 unlock_page(page);
288 }
289 pagevec_release(&pvec);
290 cond_resched();
291
292 if (likely(!err))
293 goto repeat;
294 return err;
295}
296
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302
303
304
305void nilfs_copy_back_pages(struct address_space *dmap,
306 struct address_space *smap)
307{
308 struct pagevec pvec;
309 unsigned int i, n;
310 pgoff_t index = 0;
311 int err;
312
313 pagevec_init(&pvec, 0);
314repeat:
315 n = pagevec_lookup(&pvec, smap, &index);
316 if (!n)
317 return;
318
319 for (i = 0; i < pagevec_count(&pvec); i++) {
320 struct page *page = pvec.pages[i], *dpage;
321 pgoff_t offset = page->index;
322
323 lock_page(page);
324 dpage = find_lock_page(dmap, offset);
325 if (dpage) {
326
327 WARN_ON(PageDirty(dpage));
328 nilfs_copy_page(dpage, page, 0);
329 unlock_page(dpage);
330 put_page(dpage);
331 } else {
332 struct page *page2;
333
334
335 spin_lock_irq(&smap->tree_lock);
336 page2 = radix_tree_delete(&smap->page_tree, offset);
337 WARN_ON(page2 != page);
338
339 smap->nrpages--;
340 spin_unlock_irq(&smap->tree_lock);
341
342 spin_lock_irq(&dmap->tree_lock);
343 err = radix_tree_insert(&dmap->page_tree, offset, page);
344 if (unlikely(err < 0)) {
345 WARN_ON(err == -EEXIST);
346 page->mapping = NULL;
347 put_page(page);
348 } else {
349 page->mapping = dmap;
350 dmap->nrpages++;
351 if (PageDirty(page))
352 radix_tree_tag_set(&dmap->page_tree,
353 offset,
354 PAGECACHE_TAG_DIRTY);
355 }
356 spin_unlock_irq(&dmap->tree_lock);
357 }
358 unlock_page(page);
359 }
360 pagevec_release(&pvec);
361 cond_resched();
362
363 goto repeat;
364}
365
366
367
368
369
370
371void nilfs_clear_dirty_pages(struct address_space *mapping, bool silent)
372{
373 struct pagevec pvec;
374 unsigned int i;
375 pgoff_t index = 0;
376
377 pagevec_init(&pvec, 0);
378
379 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
380 PAGEVEC_SIZE)) {
381 for (i = 0; i < pagevec_count(&pvec); i++) {
382 struct page *page = pvec.pages[i];
383
384 lock_page(page);
385 nilfs_clear_dirty_page(page, silent);
386 unlock_page(page);
387 }
388 pagevec_release(&pvec);
389 cond_resched();
390 }
391}
392
393
394
395
396
397
398void nilfs_clear_dirty_page(struct page *page, bool silent)
399{
400 struct inode *inode = page->mapping->host;
401 struct super_block *sb = inode->i_sb;
402
403 BUG_ON(!PageLocked(page));
404
405 if (!silent)
406 nilfs_msg(sb, KERN_WARNING,
407 "discard dirty page: offset=%lld, ino=%lu",
408 page_offset(page), inode->i_ino);
409
410 ClearPageUptodate(page);
411 ClearPageMappedToDisk(page);
412
413 if (page_has_buffers(page)) {
414 struct buffer_head *bh, *head;
415 const unsigned long clear_bits =
416 (BIT(BH_Uptodate) | BIT(BH_Dirty) | BIT(BH_Mapped) |
417 BIT(BH_Async_Write) | BIT(BH_NILFS_Volatile) |
418 BIT(BH_NILFS_Checked) | BIT(BH_NILFS_Redirected));
419
420 bh = head = page_buffers(page);
421 do {
422 lock_buffer(bh);
423 if (!silent)
424 nilfs_msg(sb, KERN_WARNING,
425 "discard dirty block: blocknr=%llu, size=%zu",
426 (u64)bh->b_blocknr, bh->b_size);
427
428 set_mask_bits(&bh->b_state, clear_bits, 0);
429 unlock_buffer(bh);
430 } while (bh = bh->b_this_page, bh != head);
431 }
432
433 __nilfs_clear_page_dirty(page);
434}
435
436unsigned int nilfs_page_count_clean_buffers(struct page *page,
437 unsigned int from, unsigned int to)
438{
439 unsigned int block_start, block_end;
440 struct buffer_head *bh, *head;
441 unsigned int nc = 0;
442
443 for (bh = head = page_buffers(page), block_start = 0;
444 bh != head || !block_start;
445 block_start = block_end, bh = bh->b_this_page) {
446 block_end = block_start + bh->b_size;
447 if (block_end > from && block_start < to && !buffer_dirty(bh))
448 nc++;
449 }
450 return nc;
451}
452
453void nilfs_mapping_init(struct address_space *mapping, struct inode *inode)
454{
455 mapping->host = inode;
456 mapping->flags = 0;
457 mapping_set_gfp_mask(mapping, GFP_NOFS);
458 mapping->private_data = NULL;
459 mapping->a_ops = &empty_aops;
460}
461
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471
472
473int __nilfs_clear_page_dirty(struct page *page)
474{
475 struct address_space *mapping = page->mapping;
476
477 if (mapping) {
478 spin_lock_irq(&mapping->tree_lock);
479 if (test_bit(PG_dirty, &page->flags)) {
480 radix_tree_tag_clear(&mapping->page_tree,
481 page_index(page),
482 PAGECACHE_TAG_DIRTY);
483 spin_unlock_irq(&mapping->tree_lock);
484 return clear_page_dirty_for_io(page);
485 }
486 spin_unlock_irq(&mapping->tree_lock);
487 return 0;
488 }
489 return TestClearPageDirty(page);
490}
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503
504unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
505 sector_t start_blk,
506 sector_t *blkoff)
507{
508 unsigned int i;
509 pgoff_t index;
510 unsigned int nblocks_in_page;
511 unsigned long length = 0;
512 sector_t b;
513 struct pagevec pvec;
514 struct page *page;
515
516 if (inode->i_mapping->nrpages == 0)
517 return 0;
518
519 index = start_blk >> (PAGE_SHIFT - inode->i_blkbits);
520 nblocks_in_page = 1U << (PAGE_SHIFT - inode->i_blkbits);
521
522 pagevec_init(&pvec, 0);
523
524repeat:
525 pvec.nr = find_get_pages_contig(inode->i_mapping, index, PAGEVEC_SIZE,
526 pvec.pages);
527 if (pvec.nr == 0)
528 return length;
529
530 if (length > 0 && pvec.pages[0]->index > index)
531 goto out;
532
533 b = pvec.pages[0]->index << (PAGE_SHIFT - inode->i_blkbits);
534 i = 0;
535 do {
536 page = pvec.pages[i];
537
538 lock_page(page);
539 if (page_has_buffers(page)) {
540 struct buffer_head *bh, *head;
541
542 bh = head = page_buffers(page);
543 do {
544 if (b < start_blk)
545 continue;
546 if (buffer_delay(bh)) {
547 if (length == 0)
548 *blkoff = b;
549 length++;
550 } else if (length > 0) {
551 goto out_locked;
552 }
553 } while (++b, bh = bh->b_this_page, bh != head);
554 } else {
555 if (length > 0)
556 goto out_locked;
557
558 b += nblocks_in_page;
559 }
560 unlock_page(page);
561
562 } while (++i < pagevec_count(&pvec));
563
564 index = page->index + 1;
565 pagevec_release(&pvec);
566 cond_resched();
567 goto repeat;
568
569out_locked:
570 unlock_page(page);
571out:
572 pagevec_release(&pvec);
573 return length;
574}
575