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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * mm/truncate.c - code for taking down pages from address_spaces | |
3 | * | |
4 | * Copyright (C) 2002, Linus Torvalds | |
5 | * | |
e1f8e874 | 6 | * 10Sep2002 Andrew Morton |
1da177e4 LT |
7 | * Initial version. |
8 | */ | |
9 | ||
10 | #include <linux/kernel.h> | |
4af3c9cc | 11 | #include <linux/backing-dev.h> |
5a0e3ad6 | 12 | #include <linux/gfp.h> |
1da177e4 | 13 | #include <linux/mm.h> |
0fd0e6b0 | 14 | #include <linux/swap.h> |
b95f1b31 | 15 | #include <linux/export.h> |
1da177e4 | 16 | #include <linux/pagemap.h> |
01f2705d | 17 | #include <linux/highmem.h> |
1da177e4 | 18 | #include <linux/pagevec.h> |
e08748ce | 19 | #include <linux/task_io_accounting_ops.h> |
1da177e4 | 20 | #include <linux/buffer_head.h> /* grr. try_to_release_page, |
aaa4059b | 21 | do_invalidatepage */ |
c515e1fd | 22 | #include <linux/cleancache.h> |
ba470de4 | 23 | #include "internal.h" |
1da177e4 | 24 | |
0cd6144a JW |
25 | static void clear_exceptional_entry(struct address_space *mapping, |
26 | pgoff_t index, void *entry) | |
27 | { | |
449dd698 JW |
28 | struct radix_tree_node *node; |
29 | void **slot; | |
30 | ||
0cd6144a JW |
31 | /* Handled by shmem itself */ |
32 | if (shmem_mapping(mapping)) | |
33 | return; | |
34 | ||
35 | spin_lock_irq(&mapping->tree_lock); | |
36 | /* | |
37 | * Regular page slots are stabilized by the page lock even | |
38 | * without the tree itself locked. These unlocked entries | |
39 | * need verification under the tree lock. | |
40 | */ | |
449dd698 JW |
41 | if (!__radix_tree_lookup(&mapping->page_tree, index, &node, &slot)) |
42 | goto unlock; | |
43 | if (*slot != entry) | |
44 | goto unlock; | |
45 | radix_tree_replace_slot(slot, NULL); | |
46 | mapping->nrshadows--; | |
47 | if (!node) | |
48 | goto unlock; | |
49 | workingset_node_shadows_dec(node); | |
50 | /* | |
51 | * Don't track node without shadow entries. | |
52 | * | |
53 | * Avoid acquiring the list_lru lock if already untracked. | |
54 | * The list_empty() test is safe as node->private_list is | |
55 | * protected by mapping->tree_lock. | |
56 | */ | |
57 | if (!workingset_node_shadows(node) && | |
58 | !list_empty(&node->private_list)) | |
59 | list_lru_del(&workingset_shadow_nodes, &node->private_list); | |
60 | __radix_tree_delete_node(&mapping->page_tree, node); | |
61 | unlock: | |
0cd6144a JW |
62 | spin_unlock_irq(&mapping->tree_lock); |
63 | } | |
1da177e4 | 64 | |
cf9a2ae8 | 65 | /** |
28bc44d7 | 66 | * do_invalidatepage - invalidate part or all of a page |
cf9a2ae8 | 67 | * @page: the page which is affected |
d47992f8 LC |
68 | * @offset: start of the range to invalidate |
69 | * @length: length of the range to invalidate | |
cf9a2ae8 DH |
70 | * |
71 | * do_invalidatepage() is called when all or part of the page has become | |
72 | * invalidated by a truncate operation. | |
73 | * | |
74 | * do_invalidatepage() does not have to release all buffers, but it must | |
75 | * ensure that no dirty buffer is left outside @offset and that no I/O | |
76 | * is underway against any of the blocks which are outside the truncation | |
77 | * point. Because the caller is about to free (and possibly reuse) those | |
78 | * blocks on-disk. | |
79 | */ | |
d47992f8 LC |
80 | void do_invalidatepage(struct page *page, unsigned int offset, |
81 | unsigned int length) | |
cf9a2ae8 | 82 | { |
d47992f8 LC |
83 | void (*invalidatepage)(struct page *, unsigned int, unsigned int); |
84 | ||
cf9a2ae8 | 85 | invalidatepage = page->mapping->a_ops->invalidatepage; |
9361401e | 86 | #ifdef CONFIG_BLOCK |
cf9a2ae8 DH |
87 | if (!invalidatepage) |
88 | invalidatepage = block_invalidatepage; | |
9361401e | 89 | #endif |
cf9a2ae8 | 90 | if (invalidatepage) |
d47992f8 | 91 | (*invalidatepage)(page, offset, length); |
cf9a2ae8 DH |
92 | } |
93 | ||
ecdfc978 LT |
94 | /* |
95 | * This cancels just the dirty bit on the kernel page itself, it | |
96 | * does NOT actually remove dirty bits on any mmap's that may be | |
97 | * around. It also leaves the page tagged dirty, so any sync | |
98 | * activity will still find it on the dirty lists, and in particular, | |
99 | * clear_page_dirty_for_io() will still look at the dirty bits in | |
100 | * the VM. | |
101 | * | |
102 | * Doing this should *normally* only ever be done when a page | |
103 | * is truncated, and is not actually mapped anywhere at all. However, | |
104 | * fs/buffer.c does this when it notices that somebody has cleaned | |
105 | * out all the buffers on a page without actually doing it through | |
106 | * the VM. Can you say "ext3 is horribly ugly"? Tought you could. | |
107 | */ | |
fba2591b LT |
108 | void cancel_dirty_page(struct page *page, unsigned int account_size) |
109 | { | |
8368e328 LT |
110 | if (TestClearPageDirty(page)) { |
111 | struct address_space *mapping = page->mapping; | |
112 | if (mapping && mapping_cap_account_dirty(mapping)) { | |
113 | dec_zone_page_state(page, NR_FILE_DIRTY); | |
c9e51e41 PZ |
114 | dec_bdi_stat(mapping->backing_dev_info, |
115 | BDI_RECLAIMABLE); | |
8368e328 LT |
116 | if (account_size) |
117 | task_io_account_cancelled_write(account_size); | |
118 | } | |
3e67c098 | 119 | } |
fba2591b | 120 | } |
8368e328 | 121 | EXPORT_SYMBOL(cancel_dirty_page); |
fba2591b | 122 | |
1da177e4 LT |
123 | /* |
124 | * If truncate cannot remove the fs-private metadata from the page, the page | |
62e1c553 | 125 | * becomes orphaned. It will be left on the LRU and may even be mapped into |
54cb8821 | 126 | * user pagetables if we're racing with filemap_fault(). |
1da177e4 LT |
127 | * |
128 | * We need to bale out if page->mapping is no longer equal to the original | |
129 | * mapping. This happens a) when the VM reclaimed the page while we waited on | |
fc0ecff6 | 130 | * its lock, b) when a concurrent invalidate_mapping_pages got there first and |
1da177e4 LT |
131 | * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space. |
132 | */ | |
750b4987 | 133 | static int |
1da177e4 LT |
134 | truncate_complete_page(struct address_space *mapping, struct page *page) |
135 | { | |
136 | if (page->mapping != mapping) | |
750b4987 | 137 | return -EIO; |
1da177e4 | 138 | |
266cf658 | 139 | if (page_has_private(page)) |
d47992f8 | 140 | do_invalidatepage(page, 0, PAGE_CACHE_SIZE); |
1da177e4 | 141 | |
a2b34564 BS |
142 | cancel_dirty_page(page, PAGE_CACHE_SIZE); |
143 | ||
1da177e4 | 144 | ClearPageMappedToDisk(page); |
5adc7b51 | 145 | delete_from_page_cache(page); |
750b4987 | 146 | return 0; |
1da177e4 LT |
147 | } |
148 | ||
149 | /* | |
fc0ecff6 | 150 | * This is for invalidate_mapping_pages(). That function can be called at |
1da177e4 | 151 | * any time, and is not supposed to throw away dirty pages. But pages can |
0fd0e6b0 NP |
152 | * be marked dirty at any time too, so use remove_mapping which safely |
153 | * discards clean, unused pages. | |
1da177e4 LT |
154 | * |
155 | * Returns non-zero if the page was successfully invalidated. | |
156 | */ | |
157 | static int | |
158 | invalidate_complete_page(struct address_space *mapping, struct page *page) | |
159 | { | |
0fd0e6b0 NP |
160 | int ret; |
161 | ||
1da177e4 LT |
162 | if (page->mapping != mapping) |
163 | return 0; | |
164 | ||
266cf658 | 165 | if (page_has_private(page) && !try_to_release_page(page, 0)) |
1da177e4 LT |
166 | return 0; |
167 | ||
0fd0e6b0 | 168 | ret = remove_mapping(mapping, page); |
0fd0e6b0 NP |
169 | |
170 | return ret; | |
1da177e4 LT |
171 | } |
172 | ||
750b4987 NP |
173 | int truncate_inode_page(struct address_space *mapping, struct page *page) |
174 | { | |
175 | if (page_mapped(page)) { | |
176 | unmap_mapping_range(mapping, | |
177 | (loff_t)page->index << PAGE_CACHE_SHIFT, | |
178 | PAGE_CACHE_SIZE, 0); | |
179 | } | |
180 | return truncate_complete_page(mapping, page); | |
181 | } | |
182 | ||
25718736 AK |
183 | /* |
184 | * Used to get rid of pages on hardware memory corruption. | |
185 | */ | |
186 | int generic_error_remove_page(struct address_space *mapping, struct page *page) | |
187 | { | |
188 | if (!mapping) | |
189 | return -EINVAL; | |
190 | /* | |
191 | * Only punch for normal data pages for now. | |
192 | * Handling other types like directories would need more auditing. | |
193 | */ | |
194 | if (!S_ISREG(mapping->host->i_mode)) | |
195 | return -EIO; | |
196 | return truncate_inode_page(mapping, page); | |
197 | } | |
198 | EXPORT_SYMBOL(generic_error_remove_page); | |
199 | ||
83f78668 WF |
200 | /* |
201 | * Safely invalidate one page from its pagecache mapping. | |
202 | * It only drops clean, unused pages. The page must be locked. | |
203 | * | |
204 | * Returns 1 if the page is successfully invalidated, otherwise 0. | |
205 | */ | |
206 | int invalidate_inode_page(struct page *page) | |
207 | { | |
208 | struct address_space *mapping = page_mapping(page); | |
209 | if (!mapping) | |
210 | return 0; | |
211 | if (PageDirty(page) || PageWriteback(page)) | |
212 | return 0; | |
213 | if (page_mapped(page)) | |
214 | return 0; | |
215 | return invalidate_complete_page(mapping, page); | |
216 | } | |
217 | ||
1da177e4 | 218 | /** |
73c1e204 | 219 | * truncate_inode_pages_range - truncate range of pages specified by start & end byte offsets |
1da177e4 LT |
220 | * @mapping: mapping to truncate |
221 | * @lstart: offset from which to truncate | |
5a720394 | 222 | * @lend: offset to which to truncate (inclusive) |
1da177e4 | 223 | * |
d7339071 | 224 | * Truncate the page cache, removing the pages that are between |
5a720394 LC |
225 | * specified offsets (and zeroing out partial pages |
226 | * if lstart or lend + 1 is not page aligned). | |
1da177e4 LT |
227 | * |
228 | * Truncate takes two passes - the first pass is nonblocking. It will not | |
229 | * block on page locks and it will not block on writeback. The second pass | |
230 | * will wait. This is to prevent as much IO as possible in the affected region. | |
231 | * The first pass will remove most pages, so the search cost of the second pass | |
232 | * is low. | |
233 | * | |
1da177e4 LT |
234 | * We pass down the cache-hot hint to the page freeing code. Even if the |
235 | * mapping is large, it is probably the case that the final pages are the most | |
236 | * recently touched, and freeing happens in ascending file offset order. | |
5a720394 LC |
237 | * |
238 | * Note that since ->invalidatepage() accepts range to invalidate | |
239 | * truncate_inode_pages_range is able to handle cases where lend + 1 is not | |
240 | * page aligned properly. | |
1da177e4 | 241 | */ |
d7339071 HR |
242 | void truncate_inode_pages_range(struct address_space *mapping, |
243 | loff_t lstart, loff_t lend) | |
1da177e4 | 244 | { |
5a720394 LC |
245 | pgoff_t start; /* inclusive */ |
246 | pgoff_t end; /* exclusive */ | |
247 | unsigned int partial_start; /* inclusive */ | |
248 | unsigned int partial_end; /* exclusive */ | |
249 | struct pagevec pvec; | |
0cd6144a | 250 | pgoff_t indices[PAGEVEC_SIZE]; |
5a720394 LC |
251 | pgoff_t index; |
252 | int i; | |
1da177e4 | 253 | |
3167760f | 254 | cleancache_invalidate_inode(mapping); |
91b0abe3 | 255 | if (mapping->nrpages == 0 && mapping->nrshadows == 0) |
1da177e4 LT |
256 | return; |
257 | ||
5a720394 LC |
258 | /* Offsets within partial pages */ |
259 | partial_start = lstart & (PAGE_CACHE_SIZE - 1); | |
260 | partial_end = (lend + 1) & (PAGE_CACHE_SIZE - 1); | |
261 | ||
262 | /* | |
263 | * 'start' and 'end' always covers the range of pages to be fully | |
264 | * truncated. Partial pages are covered with 'partial_start' at the | |
265 | * start of the range and 'partial_end' at the end of the range. | |
266 | * Note that 'end' is exclusive while 'lend' is inclusive. | |
267 | */ | |
268 | start = (lstart + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
269 | if (lend == -1) | |
270 | /* | |
271 | * lend == -1 indicates end-of-file so we have to set 'end' | |
272 | * to the highest possible pgoff_t and since the type is | |
273 | * unsigned we're using -1. | |
274 | */ | |
275 | end = -1; | |
276 | else | |
277 | end = (lend + 1) >> PAGE_CACHE_SHIFT; | |
d7339071 | 278 | |
1da177e4 | 279 | pagevec_init(&pvec, 0); |
b85e0eff | 280 | index = start; |
0cd6144a JW |
281 | while (index < end && pagevec_lookup_entries(&pvec, mapping, index, |
282 | min(end - index, (pgoff_t)PAGEVEC_SIZE), | |
283 | indices)) { | |
e5598f8b | 284 | mem_cgroup_uncharge_start(); |
1da177e4 LT |
285 | for (i = 0; i < pagevec_count(&pvec); i++) { |
286 | struct page *page = pvec.pages[i]; | |
1da177e4 | 287 | |
b85e0eff | 288 | /* We rely upon deletion not changing page->index */ |
0cd6144a | 289 | index = indices[i]; |
5a720394 | 290 | if (index >= end) |
d7339071 | 291 | break; |
d7339071 | 292 | |
0cd6144a JW |
293 | if (radix_tree_exceptional_entry(page)) { |
294 | clear_exceptional_entry(mapping, index, page); | |
295 | continue; | |
296 | } | |
297 | ||
529ae9aa | 298 | if (!trylock_page(page)) |
1da177e4 | 299 | continue; |
b85e0eff | 300 | WARN_ON(page->index != index); |
1da177e4 LT |
301 | if (PageWriteback(page)) { |
302 | unlock_page(page); | |
303 | continue; | |
304 | } | |
750b4987 | 305 | truncate_inode_page(mapping, page); |
1da177e4 LT |
306 | unlock_page(page); |
307 | } | |
0cd6144a | 308 | pagevec_remove_exceptionals(&pvec); |
1da177e4 | 309 | pagevec_release(&pvec); |
e5598f8b | 310 | mem_cgroup_uncharge_end(); |
1da177e4 | 311 | cond_resched(); |
b85e0eff | 312 | index++; |
1da177e4 LT |
313 | } |
314 | ||
5a720394 | 315 | if (partial_start) { |
1da177e4 LT |
316 | struct page *page = find_lock_page(mapping, start - 1); |
317 | if (page) { | |
5a720394 LC |
318 | unsigned int top = PAGE_CACHE_SIZE; |
319 | if (start > end) { | |
320 | /* Truncation within a single page */ | |
321 | top = partial_end; | |
322 | partial_end = 0; | |
323 | } | |
1da177e4 | 324 | wait_on_page_writeback(page); |
5a720394 LC |
325 | zero_user_segment(page, partial_start, top); |
326 | cleancache_invalidate_page(mapping, page); | |
327 | if (page_has_private(page)) | |
328 | do_invalidatepage(page, partial_start, | |
329 | top - partial_start); | |
1da177e4 LT |
330 | unlock_page(page); |
331 | page_cache_release(page); | |
332 | } | |
333 | } | |
5a720394 LC |
334 | if (partial_end) { |
335 | struct page *page = find_lock_page(mapping, end); | |
336 | if (page) { | |
337 | wait_on_page_writeback(page); | |
338 | zero_user_segment(page, 0, partial_end); | |
339 | cleancache_invalidate_page(mapping, page); | |
340 | if (page_has_private(page)) | |
341 | do_invalidatepage(page, 0, | |
342 | partial_end); | |
343 | unlock_page(page); | |
344 | page_cache_release(page); | |
345 | } | |
346 | } | |
347 | /* | |
348 | * If the truncation happened within a single page no pages | |
349 | * will be released, just zeroed, so we can bail out now. | |
350 | */ | |
351 | if (start >= end) | |
352 | return; | |
1da177e4 | 353 | |
b85e0eff | 354 | index = start; |
1da177e4 LT |
355 | for ( ; ; ) { |
356 | cond_resched(); | |
0cd6144a JW |
357 | if (!pagevec_lookup_entries(&pvec, mapping, index, |
358 | min(end - index, (pgoff_t)PAGEVEC_SIZE), | |
359 | indices)) { | |
b85e0eff | 360 | if (index == start) |
1da177e4 | 361 | break; |
b85e0eff | 362 | index = start; |
1da177e4 LT |
363 | continue; |
364 | } | |
0cd6144a JW |
365 | if (index == start && indices[0] >= end) { |
366 | pagevec_remove_exceptionals(&pvec); | |
d7339071 HR |
367 | pagevec_release(&pvec); |
368 | break; | |
369 | } | |
569b846d | 370 | mem_cgroup_uncharge_start(); |
1da177e4 LT |
371 | for (i = 0; i < pagevec_count(&pvec); i++) { |
372 | struct page *page = pvec.pages[i]; | |
373 | ||
b85e0eff | 374 | /* We rely upon deletion not changing page->index */ |
0cd6144a | 375 | index = indices[i]; |
5a720394 | 376 | if (index >= end) |
d7339071 | 377 | break; |
b85e0eff | 378 | |
0cd6144a JW |
379 | if (radix_tree_exceptional_entry(page)) { |
380 | clear_exceptional_entry(mapping, index, page); | |
381 | continue; | |
382 | } | |
383 | ||
1da177e4 | 384 | lock_page(page); |
b85e0eff | 385 | WARN_ON(page->index != index); |
1da177e4 | 386 | wait_on_page_writeback(page); |
750b4987 | 387 | truncate_inode_page(mapping, page); |
1da177e4 LT |
388 | unlock_page(page); |
389 | } | |
0cd6144a | 390 | pagevec_remove_exceptionals(&pvec); |
1da177e4 | 391 | pagevec_release(&pvec); |
569b846d | 392 | mem_cgroup_uncharge_end(); |
b85e0eff | 393 | index++; |
1da177e4 | 394 | } |
3167760f | 395 | cleancache_invalidate_inode(mapping); |
1da177e4 | 396 | } |
d7339071 | 397 | EXPORT_SYMBOL(truncate_inode_pages_range); |
1da177e4 | 398 | |
d7339071 HR |
399 | /** |
400 | * truncate_inode_pages - truncate *all* the pages from an offset | |
401 | * @mapping: mapping to truncate | |
402 | * @lstart: offset from which to truncate | |
403 | * | |
1b1dcc1b | 404 | * Called under (and serialised by) inode->i_mutex. |
08142579 JK |
405 | * |
406 | * Note: When this function returns, there can be a page in the process of | |
407 | * deletion (inside __delete_from_page_cache()) in the specified range. Thus | |
408 | * mapping->nrpages can be non-zero when this function returns even after | |
409 | * truncation of the whole mapping. | |
d7339071 HR |
410 | */ |
411 | void truncate_inode_pages(struct address_space *mapping, loff_t lstart) | |
412 | { | |
413 | truncate_inode_pages_range(mapping, lstart, (loff_t)-1); | |
414 | } | |
1da177e4 LT |
415 | EXPORT_SYMBOL(truncate_inode_pages); |
416 | ||
91b0abe3 JW |
417 | /** |
418 | * truncate_inode_pages_final - truncate *all* pages before inode dies | |
419 | * @mapping: mapping to truncate | |
420 | * | |
421 | * Called under (and serialized by) inode->i_mutex. | |
422 | * | |
423 | * Filesystems have to use this in the .evict_inode path to inform the | |
424 | * VM that this is the final truncate and the inode is going away. | |
425 | */ | |
426 | void truncate_inode_pages_final(struct address_space *mapping) | |
427 | { | |
428 | unsigned long nrshadows; | |
429 | unsigned long nrpages; | |
430 | ||
431 | /* | |
432 | * Page reclaim can not participate in regular inode lifetime | |
433 | * management (can't call iput()) and thus can race with the | |
434 | * inode teardown. Tell it when the address space is exiting, | |
435 | * so that it does not install eviction information after the | |
436 | * final truncate has begun. | |
437 | */ | |
438 | mapping_set_exiting(mapping); | |
439 | ||
440 | /* | |
441 | * When reclaim installs eviction entries, it increases | |
442 | * nrshadows first, then decreases nrpages. Make sure we see | |
443 | * this in the right order or we might miss an entry. | |
444 | */ | |
445 | nrpages = mapping->nrpages; | |
446 | smp_rmb(); | |
447 | nrshadows = mapping->nrshadows; | |
448 | ||
449 | if (nrpages || nrshadows) { | |
450 | /* | |
451 | * As truncation uses a lockless tree lookup, cycle | |
452 | * the tree lock to make sure any ongoing tree | |
453 | * modification that does not see AS_EXITING is | |
454 | * completed before starting the final truncate. | |
455 | */ | |
456 | spin_lock_irq(&mapping->tree_lock); | |
457 | spin_unlock_irq(&mapping->tree_lock); | |
458 | ||
459 | truncate_inode_pages(mapping, 0); | |
460 | } | |
461 | } | |
462 | EXPORT_SYMBOL(truncate_inode_pages_final); | |
463 | ||
28697355 MW |
464 | /** |
465 | * invalidate_mapping_pages - Invalidate all the unlocked pages of one inode | |
466 | * @mapping: the address_space which holds the pages to invalidate | |
467 | * @start: the offset 'from' which to invalidate | |
468 | * @end: the offset 'to' which to invalidate (inclusive) | |
469 | * | |
470 | * This function only removes the unlocked pages, if you want to | |
471 | * remove all the pages of one inode, you must call truncate_inode_pages. | |
472 | * | |
473 | * invalidate_mapping_pages() will not block on IO activity. It will not | |
474 | * invalidate pages which are dirty, locked, under writeback or mapped into | |
475 | * pagetables. | |
476 | */ | |
477 | unsigned long invalidate_mapping_pages(struct address_space *mapping, | |
31560180 | 478 | pgoff_t start, pgoff_t end) |
1da177e4 | 479 | { |
0cd6144a | 480 | pgoff_t indices[PAGEVEC_SIZE]; |
1da177e4 | 481 | struct pagevec pvec; |
b85e0eff | 482 | pgoff_t index = start; |
31560180 MK |
483 | unsigned long ret; |
484 | unsigned long count = 0; | |
1da177e4 LT |
485 | int i; |
486 | ||
487 | pagevec_init(&pvec, 0); | |
0cd6144a JW |
488 | while (index <= end && pagevec_lookup_entries(&pvec, mapping, index, |
489 | min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1, | |
490 | indices)) { | |
569b846d | 491 | mem_cgroup_uncharge_start(); |
1da177e4 LT |
492 | for (i = 0; i < pagevec_count(&pvec); i++) { |
493 | struct page *page = pvec.pages[i]; | |
e0f23603 | 494 | |
b85e0eff | 495 | /* We rely upon deletion not changing page->index */ |
0cd6144a | 496 | index = indices[i]; |
b85e0eff HD |
497 | if (index > end) |
498 | break; | |
e0f23603 | 499 | |
0cd6144a JW |
500 | if (radix_tree_exceptional_entry(page)) { |
501 | clear_exceptional_entry(mapping, index, page); | |
502 | continue; | |
503 | } | |
504 | ||
b85e0eff HD |
505 | if (!trylock_page(page)) |
506 | continue; | |
507 | WARN_ON(page->index != index); | |
31560180 | 508 | ret = invalidate_inode_page(page); |
1da177e4 | 509 | unlock_page(page); |
31560180 MK |
510 | /* |
511 | * Invalidation is a hint that the page is no longer | |
512 | * of interest and try to speed up its reclaim. | |
513 | */ | |
514 | if (!ret) | |
515 | deactivate_page(page); | |
516 | count += ret; | |
1da177e4 | 517 | } |
0cd6144a | 518 | pagevec_remove_exceptionals(&pvec); |
1da177e4 | 519 | pagevec_release(&pvec); |
569b846d | 520 | mem_cgroup_uncharge_end(); |
28697355 | 521 | cond_resched(); |
b85e0eff | 522 | index++; |
1da177e4 | 523 | } |
31560180 | 524 | return count; |
1da177e4 | 525 | } |
54bc4855 | 526 | EXPORT_SYMBOL(invalidate_mapping_pages); |
1da177e4 | 527 | |
bd4c8ce4 AM |
528 | /* |
529 | * This is like invalidate_complete_page(), except it ignores the page's | |
530 | * refcount. We do this because invalidate_inode_pages2() needs stronger | |
531 | * invalidation guarantees, and cannot afford to leave pages behind because | |
2706a1b8 AB |
532 | * shrink_page_list() has a temp ref on them, or because they're transiently |
533 | * sitting in the lru_cache_add() pagevecs. | |
bd4c8ce4 AM |
534 | */ |
535 | static int | |
536 | invalidate_complete_page2(struct address_space *mapping, struct page *page) | |
537 | { | |
538 | if (page->mapping != mapping) | |
539 | return 0; | |
540 | ||
266cf658 | 541 | if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) |
bd4c8ce4 AM |
542 | return 0; |
543 | ||
19fd6231 | 544 | spin_lock_irq(&mapping->tree_lock); |
bd4c8ce4 AM |
545 | if (PageDirty(page)) |
546 | goto failed; | |
547 | ||
266cf658 | 548 | BUG_ON(page_has_private(page)); |
91b0abe3 | 549 | __delete_from_page_cache(page, NULL); |
19fd6231 | 550 | spin_unlock_irq(&mapping->tree_lock); |
e767e056 | 551 | mem_cgroup_uncharge_cache_page(page); |
6072d13c LT |
552 | |
553 | if (mapping->a_ops->freepage) | |
554 | mapping->a_ops->freepage(page); | |
555 | ||
bd4c8ce4 AM |
556 | page_cache_release(page); /* pagecache ref */ |
557 | return 1; | |
558 | failed: | |
19fd6231 | 559 | spin_unlock_irq(&mapping->tree_lock); |
bd4c8ce4 AM |
560 | return 0; |
561 | } | |
562 | ||
e3db7691 TM |
563 | static int do_launder_page(struct address_space *mapping, struct page *page) |
564 | { | |
565 | if (!PageDirty(page)) | |
566 | return 0; | |
567 | if (page->mapping != mapping || mapping->a_ops->launder_page == NULL) | |
568 | return 0; | |
569 | return mapping->a_ops->launder_page(page); | |
570 | } | |
571 | ||
1da177e4 LT |
572 | /** |
573 | * invalidate_inode_pages2_range - remove range of pages from an address_space | |
67be2dd1 | 574 | * @mapping: the address_space |
1da177e4 LT |
575 | * @start: the page offset 'from' which to invalidate |
576 | * @end: the page offset 'to' which to invalidate (inclusive) | |
577 | * | |
578 | * Any pages which are found to be mapped into pagetables are unmapped prior to | |
579 | * invalidation. | |
580 | * | |
6ccfa806 | 581 | * Returns -EBUSY if any pages could not be invalidated. |
1da177e4 LT |
582 | */ |
583 | int invalidate_inode_pages2_range(struct address_space *mapping, | |
584 | pgoff_t start, pgoff_t end) | |
585 | { | |
0cd6144a | 586 | pgoff_t indices[PAGEVEC_SIZE]; |
1da177e4 | 587 | struct pagevec pvec; |
b85e0eff | 588 | pgoff_t index; |
1da177e4 LT |
589 | int i; |
590 | int ret = 0; | |
0dd1334f | 591 | int ret2 = 0; |
1da177e4 | 592 | int did_range_unmap = 0; |
1da177e4 | 593 | |
3167760f | 594 | cleancache_invalidate_inode(mapping); |
1da177e4 | 595 | pagevec_init(&pvec, 0); |
b85e0eff | 596 | index = start; |
0cd6144a JW |
597 | while (index <= end && pagevec_lookup_entries(&pvec, mapping, index, |
598 | min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1, | |
599 | indices)) { | |
569b846d | 600 | mem_cgroup_uncharge_start(); |
7b965e08 | 601 | for (i = 0; i < pagevec_count(&pvec); i++) { |
1da177e4 | 602 | struct page *page = pvec.pages[i]; |
b85e0eff HD |
603 | |
604 | /* We rely upon deletion not changing page->index */ | |
0cd6144a | 605 | index = indices[i]; |
b85e0eff HD |
606 | if (index > end) |
607 | break; | |
1da177e4 | 608 | |
0cd6144a JW |
609 | if (radix_tree_exceptional_entry(page)) { |
610 | clear_exceptional_entry(mapping, index, page); | |
611 | continue; | |
612 | } | |
613 | ||
1da177e4 | 614 | lock_page(page); |
b85e0eff | 615 | WARN_ON(page->index != index); |
1da177e4 LT |
616 | if (page->mapping != mapping) { |
617 | unlock_page(page); | |
618 | continue; | |
619 | } | |
1da177e4 | 620 | wait_on_page_writeback(page); |
d00806b1 | 621 | if (page_mapped(page)) { |
1da177e4 LT |
622 | if (!did_range_unmap) { |
623 | /* | |
624 | * Zap the rest of the file in one hit. | |
625 | */ | |
626 | unmap_mapping_range(mapping, | |
b85e0eff HD |
627 | (loff_t)index << PAGE_CACHE_SHIFT, |
628 | (loff_t)(1 + end - index) | |
629 | << PAGE_CACHE_SHIFT, | |
1da177e4 LT |
630 | 0); |
631 | did_range_unmap = 1; | |
632 | } else { | |
633 | /* | |
634 | * Just zap this page | |
635 | */ | |
636 | unmap_mapping_range(mapping, | |
b85e0eff HD |
637 | (loff_t)index << PAGE_CACHE_SHIFT, |
638 | PAGE_CACHE_SIZE, 0); | |
1da177e4 LT |
639 | } |
640 | } | |
d00806b1 | 641 | BUG_ON(page_mapped(page)); |
0dd1334f HH |
642 | ret2 = do_launder_page(mapping, page); |
643 | if (ret2 == 0) { | |
644 | if (!invalidate_complete_page2(mapping, page)) | |
6ccfa806 | 645 | ret2 = -EBUSY; |
0dd1334f HH |
646 | } |
647 | if (ret2 < 0) | |
648 | ret = ret2; | |
1da177e4 LT |
649 | unlock_page(page); |
650 | } | |
0cd6144a | 651 | pagevec_remove_exceptionals(&pvec); |
1da177e4 | 652 | pagevec_release(&pvec); |
569b846d | 653 | mem_cgroup_uncharge_end(); |
1da177e4 | 654 | cond_resched(); |
b85e0eff | 655 | index++; |
1da177e4 | 656 | } |
3167760f | 657 | cleancache_invalidate_inode(mapping); |
1da177e4 LT |
658 | return ret; |
659 | } | |
660 | EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range); | |
661 | ||
662 | /** | |
663 | * invalidate_inode_pages2 - remove all pages from an address_space | |
67be2dd1 | 664 | * @mapping: the address_space |
1da177e4 LT |
665 | * |
666 | * Any pages which are found to be mapped into pagetables are unmapped prior to | |
667 | * invalidation. | |
668 | * | |
e9de25dd | 669 | * Returns -EBUSY if any pages could not be invalidated. |
1da177e4 LT |
670 | */ |
671 | int invalidate_inode_pages2(struct address_space *mapping) | |
672 | { | |
673 | return invalidate_inode_pages2_range(mapping, 0, -1); | |
674 | } | |
675 | EXPORT_SYMBOL_GPL(invalidate_inode_pages2); | |
25d9e2d1 | 676 | |
677 | /** | |
678 | * truncate_pagecache - unmap and remove pagecache that has been truncated | |
679 | * @inode: inode | |
8a549bea | 680 | * @newsize: new file size |
25d9e2d1 | 681 | * |
682 | * inode's new i_size must already be written before truncate_pagecache | |
683 | * is called. | |
684 | * | |
685 | * This function should typically be called before the filesystem | |
686 | * releases resources associated with the freed range (eg. deallocates | |
687 | * blocks). This way, pagecache will always stay logically coherent | |
688 | * with on-disk format, and the filesystem would not have to deal with | |
689 | * situations such as writepage being called for a page that has already | |
690 | * had its underlying blocks deallocated. | |
691 | */ | |
7caef267 | 692 | void truncate_pagecache(struct inode *inode, loff_t newsize) |
25d9e2d1 | 693 | { |
cedabed4 | 694 | struct address_space *mapping = inode->i_mapping; |
8a549bea | 695 | loff_t holebegin = round_up(newsize, PAGE_SIZE); |
cedabed4 OH |
696 | |
697 | /* | |
698 | * unmap_mapping_range is called twice, first simply for | |
699 | * efficiency so that truncate_inode_pages does fewer | |
700 | * single-page unmaps. However after this first call, and | |
701 | * before truncate_inode_pages finishes, it is possible for | |
702 | * private pages to be COWed, which remain after | |
703 | * truncate_inode_pages finishes, hence the second | |
704 | * unmap_mapping_range call must be made for correctness. | |
705 | */ | |
8a549bea HD |
706 | unmap_mapping_range(mapping, holebegin, 0, 1); |
707 | truncate_inode_pages(mapping, newsize); | |
708 | unmap_mapping_range(mapping, holebegin, 0, 1); | |
25d9e2d1 | 709 | } |
710 | EXPORT_SYMBOL(truncate_pagecache); | |
711 | ||
2c27c65e CH |
712 | /** |
713 | * truncate_setsize - update inode and pagecache for a new file size | |
714 | * @inode: inode | |
715 | * @newsize: new file size | |
716 | * | |
382e27da JK |
717 | * truncate_setsize updates i_size and performs pagecache truncation (if |
718 | * necessary) to @newsize. It will be typically be called from the filesystem's | |
719 | * setattr function when ATTR_SIZE is passed in. | |
2c27c65e | 720 | * |
382e27da JK |
721 | * Must be called with inode_mutex held and before all filesystem specific |
722 | * block truncation has been performed. | |
2c27c65e CH |
723 | */ |
724 | void truncate_setsize(struct inode *inode, loff_t newsize) | |
725 | { | |
2c27c65e | 726 | i_size_write(inode, newsize); |
7caef267 | 727 | truncate_pagecache(inode, newsize); |
2c27c65e CH |
728 | } |
729 | EXPORT_SYMBOL(truncate_setsize); | |
730 | ||
623e3db9 HD |
731 | /** |
732 | * truncate_pagecache_range - unmap and remove pagecache that is hole-punched | |
733 | * @inode: inode | |
734 | * @lstart: offset of beginning of hole | |
735 | * @lend: offset of last byte of hole | |
736 | * | |
737 | * This function should typically be called before the filesystem | |
738 | * releases resources associated with the freed range (eg. deallocates | |
739 | * blocks). This way, pagecache will always stay logically coherent | |
740 | * with on-disk format, and the filesystem would not have to deal with | |
741 | * situations such as writepage being called for a page that has already | |
742 | * had its underlying blocks deallocated. | |
743 | */ | |
744 | void truncate_pagecache_range(struct inode *inode, loff_t lstart, loff_t lend) | |
745 | { | |
746 | struct address_space *mapping = inode->i_mapping; | |
747 | loff_t unmap_start = round_up(lstart, PAGE_SIZE); | |
748 | loff_t unmap_end = round_down(1 + lend, PAGE_SIZE) - 1; | |
749 | /* | |
750 | * This rounding is currently just for example: unmap_mapping_range | |
751 | * expands its hole outwards, whereas we want it to contract the hole | |
752 | * inwards. However, existing callers of truncate_pagecache_range are | |
5a720394 LC |
753 | * doing their own page rounding first. Note that unmap_mapping_range |
754 | * allows holelen 0 for all, and we allow lend -1 for end of file. | |
623e3db9 HD |
755 | */ |
756 | ||
757 | /* | |
758 | * Unlike in truncate_pagecache, unmap_mapping_range is called only | |
759 | * once (before truncating pagecache), and without "even_cows" flag: | |
760 | * hole-punching should not remove private COWed pages from the hole. | |
761 | */ | |
762 | if ((u64)unmap_end > (u64)unmap_start) | |
763 | unmap_mapping_range(mapping, unmap_start, | |
764 | 1 + unmap_end - unmap_start, 0); | |
765 | truncate_inode_pages_range(mapping, lstart, lend); | |
766 | } | |
767 | EXPORT_SYMBOL(truncate_pagecache_range); |