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ae98043f | 1 | // SPDX-License-Identifier: GPL-2.0+ |
0bd49f94 | 2 | /* |
94ee1d91 | 3 | * Buffer/page management specific to NILFS |
0bd49f94 RK |
4 | * |
5 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. | |
6 | * | |
4b420ab4 | 7 | * Written by Ryusuke Konishi and Seiji Kihara. |
0bd49f94 RK |
8 | */ |
9 | ||
10 | #include <linux/pagemap.h> | |
11 | #include <linux/writeback.h> | |
12 | #include <linux/swap.h> | |
13 | #include <linux/bitops.h> | |
14 | #include <linux/page-flags.h> | |
15 | #include <linux/list.h> | |
16 | #include <linux/highmem.h> | |
17 | #include <linux/pagevec.h> | |
5a0e3ad6 | 18 | #include <linux/gfp.h> |
0bd49f94 RK |
19 | #include "nilfs.h" |
20 | #include "page.h" | |
21 | #include "mdt.h" | |
22 | ||
23 | ||
4ce5c342 RK |
24 | #define NILFS_BUFFER_INHERENT_BITS \ |
25 | (BIT(BH_Uptodate) | BIT(BH_Mapped) | BIT(BH_NILFS_Node) | \ | |
26 | BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Checked)) | |
0bd49f94 RK |
27 | |
28 | static struct buffer_head * | |
29 | __nilfs_get_page_block(struct page *page, unsigned long block, pgoff_t index, | |
30 | int blkbits, unsigned long b_state) | |
31 | ||
32 | { | |
33 | unsigned long first_block; | |
34 | struct buffer_head *bh; | |
35 | ||
36 | if (!page_has_buffers(page)) | |
37 | create_empty_buffers(page, 1 << blkbits, b_state); | |
38 | ||
09cbfeaf | 39 | first_block = (unsigned long)index << (PAGE_SHIFT - blkbits); |
0bd49f94 RK |
40 | bh = nilfs_page_get_nth_block(page, block - first_block); |
41 | ||
42 | touch_buffer(bh); | |
43 | wait_on_buffer(bh); | |
44 | return bh; | |
45 | } | |
46 | ||
0bd49f94 RK |
47 | struct buffer_head *nilfs_grab_buffer(struct inode *inode, |
48 | struct address_space *mapping, | |
49 | unsigned long blkoff, | |
50 | unsigned long b_state) | |
51 | { | |
52 | int blkbits = inode->i_blkbits; | |
09cbfeaf | 53 | pgoff_t index = blkoff >> (PAGE_SHIFT - blkbits); |
c1c1d709 RK |
54 | struct page *page; |
55 | struct buffer_head *bh; | |
0bd49f94 RK |
56 | |
57 | page = grab_cache_page(mapping, index); | |
58 | if (unlikely(!page)) | |
59 | return NULL; | |
60 | ||
61 | bh = __nilfs_get_page_block(page, blkoff, index, blkbits, b_state); | |
62 | if (unlikely(!bh)) { | |
63 | unlock_page(page); | |
09cbfeaf | 64 | put_page(page); |
0bd49f94 RK |
65 | return NULL; |
66 | } | |
0bd49f94 RK |
67 | return bh; |
68 | } | |
69 | ||
70 | /** | |
71 | * nilfs_forget_buffer - discard dirty state | |
0bd49f94 RK |
72 | * @bh: buffer head of the buffer to be discarded |
73 | */ | |
74 | void nilfs_forget_buffer(struct buffer_head *bh) | |
75 | { | |
76 | struct page *page = bh->b_page; | |
ead8ecff | 77 | const unsigned long clear_bits = |
4ce5c342 RK |
78 | (BIT(BH_Uptodate) | BIT(BH_Dirty) | BIT(BH_Mapped) | |
79 | BIT(BH_Async_Write) | BIT(BH_NILFS_Volatile) | | |
80 | BIT(BH_NILFS_Checked) | BIT(BH_NILFS_Redirected)); | |
0bd49f94 RK |
81 | |
82 | lock_buffer(bh); | |
ead8ecff | 83 | set_mask_bits(&bh->b_state, clear_bits, 0); |
84338237 | 84 | if (nilfs_page_buffers_clean(page)) |
0bd49f94 RK |
85 | __nilfs_clear_page_dirty(page); |
86 | ||
0bd49f94 RK |
87 | bh->b_blocknr = -1; |
88 | ClearPageUptodate(page); | |
89 | ClearPageMappedToDisk(page); | |
90 | unlock_buffer(bh); | |
91 | brelse(bh); | |
92 | } | |
93 | ||
94 | /** | |
95 | * nilfs_copy_buffer -- copy buffer data and flags | |
96 | * @dbh: destination buffer | |
97 | * @sbh: source buffer | |
98 | */ | |
99 | void nilfs_copy_buffer(struct buffer_head *dbh, struct buffer_head *sbh) | |
100 | { | |
101 | void *kaddr0, *kaddr1; | |
102 | unsigned long bits; | |
103 | struct page *spage = sbh->b_page, *dpage = dbh->b_page; | |
104 | struct buffer_head *bh; | |
105 | ||
7b9c0976 CW |
106 | kaddr0 = kmap_atomic(spage); |
107 | kaddr1 = kmap_atomic(dpage); | |
0bd49f94 | 108 | memcpy(kaddr1 + bh_offset(dbh), kaddr0 + bh_offset(sbh), sbh->b_size); |
7b9c0976 CW |
109 | kunmap_atomic(kaddr1); |
110 | kunmap_atomic(kaddr0); | |
0bd49f94 RK |
111 | |
112 | dbh->b_state = sbh->b_state & NILFS_BUFFER_INHERENT_BITS; | |
113 | dbh->b_blocknr = sbh->b_blocknr; | |
114 | dbh->b_bdev = sbh->b_bdev; | |
115 | ||
116 | bh = dbh; | |
4ce5c342 | 117 | bits = sbh->b_state & (BIT(BH_Uptodate) | BIT(BH_Mapped)); |
0bd49f94 RK |
118 | while ((bh = bh->b_this_page) != dbh) { |
119 | lock_buffer(bh); | |
120 | bits &= bh->b_state; | |
121 | unlock_buffer(bh); | |
122 | } | |
4ce5c342 | 123 | if (bits & BIT(BH_Uptodate)) |
0bd49f94 RK |
124 | SetPageUptodate(dpage); |
125 | else | |
126 | ClearPageUptodate(dpage); | |
4ce5c342 | 127 | if (bits & BIT(BH_Mapped)) |
0bd49f94 RK |
128 | SetPageMappedToDisk(dpage); |
129 | else | |
130 | ClearPageMappedToDisk(dpage); | |
131 | } | |
132 | ||
133 | /** | |
134 | * nilfs_page_buffers_clean - check if a page has dirty buffers or not. | |
135 | * @page: page to be checked | |
136 | * | |
137 | * nilfs_page_buffers_clean() returns zero if the page has dirty buffers. | |
138 | * Otherwise, it returns non-zero value. | |
139 | */ | |
140 | int nilfs_page_buffers_clean(struct page *page) | |
141 | { | |
142 | struct buffer_head *bh, *head; | |
143 | ||
144 | bh = head = page_buffers(page); | |
145 | do { | |
146 | if (buffer_dirty(bh)) | |
147 | return 0; | |
148 | bh = bh->b_this_page; | |
149 | } while (bh != head); | |
150 | return 1; | |
151 | } | |
152 | ||
153 | void nilfs_page_bug(struct page *page) | |
154 | { | |
155 | struct address_space *m; | |
aa405b1f | 156 | unsigned long ino; |
0bd49f94 RK |
157 | |
158 | if (unlikely(!page)) { | |
159 | printk(KERN_CRIT "NILFS_PAGE_BUG(NULL)\n"); | |
160 | return; | |
161 | } | |
162 | ||
163 | m = page->mapping; | |
aa405b1f RK |
164 | ino = m ? m->host->i_ino : 0; |
165 | ||
0bd49f94 RK |
166 | printk(KERN_CRIT "NILFS_PAGE_BUG(%p): cnt=%d index#=%llu flags=0x%lx " |
167 | "mapping=%p ino=%lu\n", | |
fe896d18 | 168 | page, page_ref_count(page), |
0bd49f94 RK |
169 | (unsigned long long)page->index, page->flags, m, ino); |
170 | ||
171 | if (page_has_buffers(page)) { | |
172 | struct buffer_head *bh, *head; | |
173 | int i = 0; | |
174 | ||
175 | bh = head = page_buffers(page); | |
176 | do { | |
177 | printk(KERN_CRIT | |
178 | " BH[%d] %p: cnt=%d block#=%llu state=0x%lx\n", | |
179 | i++, bh, atomic_read(&bh->b_count), | |
180 | (unsigned long long)bh->b_blocknr, bh->b_state); | |
181 | bh = bh->b_this_page; | |
182 | } while (bh != head); | |
183 | } | |
184 | } | |
185 | ||
0bd49f94 RK |
186 | /** |
187 | * nilfs_copy_page -- copy the page with buffers | |
188 | * @dst: destination page | |
189 | * @src: source page | |
190 | * @copy_dirty: flag whether to copy dirty states on the page's buffer heads. | |
191 | * | |
7a65004b | 192 | * This function is for both data pages and btnode pages. The dirty flag |
0bd49f94 RK |
193 | * should be treated by caller. The page must not be under i/o. |
194 | * Both src and dst page must be locked | |
195 | */ | |
196 | static void nilfs_copy_page(struct page *dst, struct page *src, int copy_dirty) | |
197 | { | |
e1ce8a97 | 198 | struct buffer_head *dbh, *dbufs, *sbh; |
0bd49f94 RK |
199 | unsigned long mask = NILFS_BUFFER_INHERENT_BITS; |
200 | ||
201 | BUG_ON(PageWriteback(dst)); | |
202 | ||
e1ce8a97 | 203 | sbh = page_buffers(src); |
0bd49f94 RK |
204 | if (!page_has_buffers(dst)) |
205 | create_empty_buffers(dst, sbh->b_size, 0); | |
206 | ||
207 | if (copy_dirty) | |
4ce5c342 | 208 | mask |= BIT(BH_Dirty); |
0bd49f94 RK |
209 | |
210 | dbh = dbufs = page_buffers(dst); | |
211 | do { | |
212 | lock_buffer(sbh); | |
213 | lock_buffer(dbh); | |
214 | dbh->b_state = sbh->b_state & mask; | |
215 | dbh->b_blocknr = sbh->b_blocknr; | |
216 | dbh->b_bdev = sbh->b_bdev; | |
217 | sbh = sbh->b_this_page; | |
218 | dbh = dbh->b_this_page; | |
219 | } while (dbh != dbufs); | |
220 | ||
221 | copy_highpage(dst, src); | |
222 | ||
223 | if (PageUptodate(src) && !PageUptodate(dst)) | |
224 | SetPageUptodate(dst); | |
225 | else if (!PageUptodate(src) && PageUptodate(dst)) | |
226 | ClearPageUptodate(dst); | |
227 | if (PageMappedToDisk(src) && !PageMappedToDisk(dst)) | |
228 | SetPageMappedToDisk(dst); | |
229 | else if (!PageMappedToDisk(src) && PageMappedToDisk(dst)) | |
230 | ClearPageMappedToDisk(dst); | |
231 | ||
232 | do { | |
233 | unlock_buffer(sbh); | |
234 | unlock_buffer(dbh); | |
235 | sbh = sbh->b_this_page; | |
236 | dbh = dbh->b_this_page; | |
237 | } while (dbh != dbufs); | |
238 | } | |
239 | ||
240 | int nilfs_copy_dirty_pages(struct address_space *dmap, | |
241 | struct address_space *smap) | |
242 | { | |
d4a16d31 | 243 | struct folio_batch fbatch; |
0bd49f94 RK |
244 | unsigned int i; |
245 | pgoff_t index = 0; | |
246 | int err = 0; | |
247 | ||
d4a16d31 | 248 | folio_batch_init(&fbatch); |
0bd49f94 | 249 | repeat: |
d4a16d31 VMO |
250 | if (!filemap_get_folios_tag(smap, &index, (pgoff_t)-1, |
251 | PAGECACHE_TAG_DIRTY, &fbatch)) | |
0bd49f94 RK |
252 | return 0; |
253 | ||
d4a16d31 VMO |
254 | for (i = 0; i < folio_batch_count(&fbatch); i++) { |
255 | struct folio *folio = fbatch.folios[i], *dfolio; | |
0bd49f94 | 256 | |
d4a16d31 VMO |
257 | folio_lock(folio); |
258 | if (unlikely(!folio_test_dirty(folio))) | |
259 | NILFS_PAGE_BUG(&folio->page, "inconsistent dirty state"); | |
0bd49f94 | 260 | |
d4a16d31 VMO |
261 | dfolio = filemap_grab_folio(dmap, folio->index); |
262 | if (unlikely(!dfolio)) { | |
0bd49f94 RK |
263 | /* No empty page is added to the page cache */ |
264 | err = -ENOMEM; | |
d4a16d31 | 265 | folio_unlock(folio); |
0bd49f94 RK |
266 | break; |
267 | } | |
d4a16d31 VMO |
268 | if (unlikely(!folio_buffers(folio))) |
269 | NILFS_PAGE_BUG(&folio->page, | |
0bd49f94 RK |
270 | "found empty page in dat page cache"); |
271 | ||
d4a16d31 VMO |
272 | nilfs_copy_page(&dfolio->page, &folio->page, 1); |
273 | filemap_dirty_folio(folio_mapping(dfolio), dfolio); | |
0bd49f94 | 274 | |
d4a16d31 VMO |
275 | folio_unlock(dfolio); |
276 | folio_put(dfolio); | |
277 | folio_unlock(folio); | |
0bd49f94 | 278 | } |
d4a16d31 | 279 | folio_batch_release(&fbatch); |
0bd49f94 RK |
280 | cond_resched(); |
281 | ||
282 | if (likely(!err)) | |
283 | goto repeat; | |
284 | return err; | |
285 | } | |
286 | ||
287 | /** | |
7a65004b | 288 | * nilfs_copy_back_pages -- copy back pages to original cache from shadow cache |
0bd49f94 RK |
289 | * @dmap: destination page cache |
290 | * @smap: source page cache | |
291 | * | |
f611ff63 | 292 | * No pages must be added to the cache during this process. |
0bd49f94 RK |
293 | * This must be ensured by the caller. |
294 | */ | |
295 | void nilfs_copy_back_pages(struct address_space *dmap, | |
296 | struct address_space *smap) | |
297 | { | |
f6e0e173 | 298 | struct folio_batch fbatch; |
0bd49f94 | 299 | unsigned int i, n; |
f6e0e173 | 300 | pgoff_t start = 0; |
0bd49f94 | 301 | |
f6e0e173 | 302 | folio_batch_init(&fbatch); |
0bd49f94 | 303 | repeat: |
f6e0e173 | 304 | n = filemap_get_folios(smap, &start, ~0UL, &fbatch); |
0bd49f94 RK |
305 | if (!n) |
306 | return; | |
0bd49f94 | 307 | |
f6e0e173 MWO |
308 | for (i = 0; i < folio_batch_count(&fbatch); i++) { |
309 | struct folio *folio = fbatch.folios[i], *dfolio; | |
310 | pgoff_t index = folio->index; | |
311 | ||
312 | folio_lock(folio); | |
313 | dfolio = filemap_lock_folio(dmap, index); | |
314 | if (dfolio) { | |
315 | /* overwrite existing folio in the destination cache */ | |
316 | WARN_ON(folio_test_dirty(dfolio)); | |
317 | nilfs_copy_page(&dfolio->page, &folio->page, 0); | |
318 | folio_unlock(dfolio); | |
319 | folio_put(dfolio); | |
320 | /* Do we not need to remove folio from smap here? */ | |
0bd49f94 | 321 | } else { |
f6e0e173 | 322 | struct folio *f; |
0bd49f94 | 323 | |
f6e0e173 | 324 | /* move the folio to the destination cache */ |
b93b0163 | 325 | xa_lock_irq(&smap->i_pages); |
f6e0e173 MWO |
326 | f = __xa_erase(&smap->i_pages, index); |
327 | WARN_ON(folio != f); | |
0bd49f94 | 328 | smap->nrpages--; |
b93b0163 | 329 | xa_unlock_irq(&smap->i_pages); |
0bd49f94 | 330 | |
b93b0163 | 331 | xa_lock_irq(&dmap->i_pages); |
f6e0e173 MWO |
332 | f = __xa_store(&dmap->i_pages, index, folio, GFP_NOFS); |
333 | if (unlikely(f)) { | |
f611ff63 | 334 | /* Probably -ENOMEM */ |
f6e0e173 MWO |
335 | folio->mapping = NULL; |
336 | folio_put(folio); | |
0bd49f94 | 337 | } else { |
f6e0e173 | 338 | folio->mapping = dmap; |
0bd49f94 | 339 | dmap->nrpages++; |
f6e0e173 MWO |
340 | if (folio_test_dirty(folio)) |
341 | __xa_set_mark(&dmap->i_pages, index, | |
f611ff63 | 342 | PAGECACHE_TAG_DIRTY); |
0bd49f94 | 343 | } |
b93b0163 | 344 | xa_unlock_irq(&dmap->i_pages); |
0bd49f94 | 345 | } |
f6e0e173 | 346 | folio_unlock(folio); |
0bd49f94 | 347 | } |
f6e0e173 | 348 | folio_batch_release(&fbatch); |
0bd49f94 RK |
349 | cond_resched(); |
350 | ||
351 | goto repeat; | |
352 | } | |
353 | ||
8c26c4e2 VD |
354 | /** |
355 | * nilfs_clear_dirty_pages - discard dirty pages in address space | |
356 | * @mapping: address space with dirty pages for discarding | |
357 | * @silent: suppress [true] or print [false] warning messages | |
358 | */ | |
359 | void nilfs_clear_dirty_pages(struct address_space *mapping, bool silent) | |
0bd49f94 | 360 | { |
243c5ea4 | 361 | struct folio_batch fbatch; |
0bd49f94 RK |
362 | unsigned int i; |
363 | pgoff_t index = 0; | |
364 | ||
243c5ea4 | 365 | folio_batch_init(&fbatch); |
0bd49f94 | 366 | |
243c5ea4 VMO |
367 | while (filemap_get_folios_tag(mapping, &index, (pgoff_t)-1, |
368 | PAGECACHE_TAG_DIRTY, &fbatch)) { | |
369 | for (i = 0; i < folio_batch_count(&fbatch); i++) { | |
370 | struct folio *folio = fbatch.folios[i]; | |
0bd49f94 | 371 | |
243c5ea4 VMO |
372 | folio_lock(folio); |
373 | nilfs_clear_dirty_page(&folio->page, silent); | |
374 | folio_unlock(folio); | |
0bd49f94 | 375 | } |
243c5ea4 | 376 | folio_batch_release(&fbatch); |
0bd49f94 RK |
377 | cond_resched(); |
378 | } | |
379 | } | |
380 | ||
8c26c4e2 VD |
381 | /** |
382 | * nilfs_clear_dirty_page - discard dirty page | |
383 | * @page: dirty page that will be discarded | |
384 | * @silent: suppress [true] or print [false] warning messages | |
385 | */ | |
386 | void nilfs_clear_dirty_page(struct page *page, bool silent) | |
387 | { | |
388 | struct inode *inode = page->mapping->host; | |
389 | struct super_block *sb = inode->i_sb; | |
390 | ||
dc33f5f3 | 391 | BUG_ON(!PageLocked(page)); |
8c26c4e2 | 392 | |
d6517deb | 393 | if (!silent) |
a1d0747a JP |
394 | nilfs_warn(sb, "discard dirty page: offset=%lld, ino=%lu", |
395 | page_offset(page), inode->i_ino); | |
8c26c4e2 VD |
396 | |
397 | ClearPageUptodate(page); | |
398 | ClearPageMappedToDisk(page); | |
399 | ||
400 | if (page_has_buffers(page)) { | |
401 | struct buffer_head *bh, *head; | |
ead8ecff | 402 | const unsigned long clear_bits = |
4ce5c342 RK |
403 | (BIT(BH_Uptodate) | BIT(BH_Dirty) | BIT(BH_Mapped) | |
404 | BIT(BH_Async_Write) | BIT(BH_NILFS_Volatile) | | |
405 | BIT(BH_NILFS_Checked) | BIT(BH_NILFS_Redirected)); | |
8c26c4e2 VD |
406 | |
407 | bh = head = page_buffers(page); | |
408 | do { | |
409 | lock_buffer(bh); | |
d6517deb | 410 | if (!silent) |
a1d0747a JP |
411 | nilfs_warn(sb, |
412 | "discard dirty block: blocknr=%llu, size=%zu", | |
413 | (u64)bh->b_blocknr, bh->b_size); | |
d6517deb | 414 | |
ead8ecff | 415 | set_mask_bits(&bh->b_state, clear_bits, 0); |
8c26c4e2 VD |
416 | unlock_buffer(bh); |
417 | } while (bh = bh->b_this_page, bh != head); | |
418 | } | |
419 | ||
420 | __nilfs_clear_page_dirty(page); | |
421 | } | |
422 | ||
0c6c44cb RK |
423 | unsigned int nilfs_page_count_clean_buffers(struct page *page, |
424 | unsigned int from, unsigned int to) | |
0bd49f94 | 425 | { |
0c6c44cb | 426 | unsigned int block_start, block_end; |
0bd49f94 | 427 | struct buffer_head *bh, *head; |
0c6c44cb | 428 | unsigned int nc = 0; |
0bd49f94 RK |
429 | |
430 | for (bh = head = page_buffers(page), block_start = 0; | |
431 | bh != head || !block_start; | |
432 | block_start = block_end, bh = bh->b_this_page) { | |
433 | block_end = block_start + bh->b_size; | |
434 | if (block_end > from && block_start < to && !buffer_dirty(bh)) | |
435 | nc++; | |
436 | } | |
437 | return nc; | |
438 | } | |
ae53a0a2 | 439 | |
0bd49f94 RK |
440 | /* |
441 | * NILFS2 needs clear_page_dirty() in the following two cases: | |
442 | * | |
e897be17 RK |
443 | * 1) For B-tree node pages and data pages of DAT file, NILFS2 clears dirty |
444 | * flag of pages when it copies back pages from shadow cache to the | |
445 | * original cache. | |
0bd49f94 RK |
446 | * |
447 | * 2) Some B-tree operations like insertion or deletion may dispose buffers | |
448 | * in dirty state, and this needs to cancel the dirty state of their pages. | |
449 | */ | |
450 | int __nilfs_clear_page_dirty(struct page *page) | |
451 | { | |
452 | struct address_space *mapping = page->mapping; | |
453 | ||
454 | if (mapping) { | |
b93b0163 | 455 | xa_lock_irq(&mapping->i_pages); |
0bd49f94 | 456 | if (test_bit(PG_dirty, &page->flags)) { |
f611ff63 | 457 | __xa_clear_mark(&mapping->i_pages, page_index(page), |
0bd49f94 | 458 | PAGECACHE_TAG_DIRTY); |
b93b0163 | 459 | xa_unlock_irq(&mapping->i_pages); |
0bd49f94 RK |
460 | return clear_page_dirty_for_io(page); |
461 | } | |
b93b0163 | 462 | xa_unlock_irq(&mapping->i_pages); |
0bd49f94 RK |
463 | return 0; |
464 | } | |
465 | return TestClearPageDirty(page); | |
466 | } | |
622daaff RK |
467 | |
468 | /** | |
469 | * nilfs_find_uncommitted_extent - find extent of uncommitted data | |
470 | * @inode: inode | |
471 | * @start_blk: start block offset (in) | |
472 | * @blkoff: start offset of the found extent (out) | |
473 | * | |
474 | * This function searches an extent of buffers marked "delayed" which | |
475 | * starts from a block offset equal to or larger than @start_blk. If | |
476 | * such an extent was found, this will store the start offset in | |
477 | * @blkoff and return its length in blocks. Otherwise, zero is | |
478 | * returned. | |
479 | */ | |
480 | unsigned long nilfs_find_uncommitted_extent(struct inode *inode, | |
481 | sector_t start_blk, | |
482 | sector_t *blkoff) | |
483 | { | |
24a1efb4 | 484 | unsigned int i, nr_folios; |
622daaff | 485 | pgoff_t index; |
622daaff | 486 | unsigned long length = 0; |
24a1efb4 VMO |
487 | struct folio_batch fbatch; |
488 | struct folio *folio; | |
622daaff RK |
489 | |
490 | if (inode->i_mapping->nrpages == 0) | |
491 | return 0; | |
492 | ||
09cbfeaf | 493 | index = start_blk >> (PAGE_SHIFT - inode->i_blkbits); |
622daaff | 494 | |
24a1efb4 | 495 | folio_batch_init(&fbatch); |
622daaff RK |
496 | |
497 | repeat: | |
24a1efb4 VMO |
498 | nr_folios = filemap_get_folios_contig(inode->i_mapping, &index, ULONG_MAX, |
499 | &fbatch); | |
500 | if (nr_folios == 0) | |
622daaff RK |
501 | return length; |
502 | ||
622daaff RK |
503 | i = 0; |
504 | do { | |
24a1efb4 | 505 | folio = fbatch.folios[i]; |
622daaff | 506 | |
24a1efb4 VMO |
507 | folio_lock(folio); |
508 | if (folio_buffers(folio)) { | |
622daaff | 509 | struct buffer_head *bh, *head; |
24a1efb4 | 510 | sector_t b; |
622daaff | 511 | |
24a1efb4 VMO |
512 | b = folio->index << (PAGE_SHIFT - inode->i_blkbits); |
513 | bh = head = folio_buffers(folio); | |
622daaff RK |
514 | do { |
515 | if (b < start_blk) | |
516 | continue; | |
517 | if (buffer_delay(bh)) { | |
518 | if (length == 0) | |
519 | *blkoff = b; | |
520 | length++; | |
521 | } else if (length > 0) { | |
522 | goto out_locked; | |
523 | } | |
524 | } while (++b, bh = bh->b_this_page, bh != head); | |
525 | } else { | |
526 | if (length > 0) | |
527 | goto out_locked; | |
622daaff | 528 | } |
24a1efb4 | 529 | folio_unlock(folio); |
622daaff | 530 | |
24a1efb4 | 531 | } while (++i < nr_folios); |
622daaff | 532 | |
24a1efb4 | 533 | folio_batch_release(&fbatch); |
622daaff RK |
534 | cond_resched(); |
535 | goto repeat; | |
536 | ||
537 | out_locked: | |
24a1efb4 VMO |
538 | folio_unlock(folio); |
539 | folio_batch_release(&fbatch); | |
622daaff RK |
540 | return length; |
541 | } |