2 * mm/truncate.c - code for taking down pages from address_spaces
4 * Copyright (C) 2002, Linus Torvalds
6 * 10Sep2002 Andrew Morton
10 #include <linux/kernel.h>
11 #include <linux/backing-dev.h>
12 #include <linux/dax.h>
13 #include <linux/gfp.h>
15 #include <linux/swap.h>
16 #include <linux/export.h>
17 #include <linux/pagemap.h>
18 #include <linux/highmem.h>
19 #include <linux/pagevec.h>
20 #include <linux/task_io_accounting_ops.h>
21 #include <linux/buffer_head.h> /* grr. try_to_release_page,
23 #include <linux/shmem_fs.h>
24 #include <linux/cleancache.h>
25 #include <linux/rmap.h>
28 static void clear_shadow_entry(struct address_space
*mapping
, pgoff_t index
,
31 struct radix_tree_node
*node
;
34 spin_lock_irq(&mapping
->tree_lock
);
36 * Regular page slots are stabilized by the page lock even
37 * without the tree itself locked. These unlocked entries
38 * need verification under the tree lock.
40 if (!__radix_tree_lookup(&mapping
->page_tree
, index
, &node
, &slot
))
44 __radix_tree_replace(&mapping
->page_tree
, node
, slot
, NULL
,
45 workingset_update_node
, mapping
);
46 mapping
->nrexceptional
--;
48 spin_unlock_irq(&mapping
->tree_lock
);
52 * Unconditionally remove exceptional entry. Usually called from truncate path.
54 static void truncate_exceptional_entry(struct address_space
*mapping
,
55 pgoff_t index
, void *entry
)
57 /* Handled by shmem itself */
58 if (shmem_mapping(mapping
))
61 if (dax_mapping(mapping
)) {
62 dax_delete_mapping_entry(mapping
, index
);
65 clear_shadow_entry(mapping
, index
, entry
);
69 * Invalidate exceptional entry if easily possible. This handles exceptional
70 * entries for invalidate_inode_pages().
72 static int invalidate_exceptional_entry(struct address_space
*mapping
,
73 pgoff_t index
, void *entry
)
75 /* Handled by shmem itself, or for DAX we do nothing. */
76 if (shmem_mapping(mapping
) || dax_mapping(mapping
))
78 clear_shadow_entry(mapping
, index
, entry
);
83 * Invalidate exceptional entry if clean. This handles exceptional entries for
84 * invalidate_inode_pages2() so for DAX it evicts only clean entries.
86 static int invalidate_exceptional_entry2(struct address_space
*mapping
,
87 pgoff_t index
, void *entry
)
89 /* Handled by shmem itself */
90 if (shmem_mapping(mapping
))
92 if (dax_mapping(mapping
))
93 return dax_invalidate_mapping_entry_sync(mapping
, index
);
94 clear_shadow_entry(mapping
, index
, entry
);
99 * do_invalidatepage - invalidate part or all of a page
100 * @page: the page which is affected
101 * @offset: start of the range to invalidate
102 * @length: length of the range to invalidate
104 * do_invalidatepage() is called when all or part of the page has become
105 * invalidated by a truncate operation.
107 * do_invalidatepage() does not have to release all buffers, but it must
108 * ensure that no dirty buffer is left outside @offset and that no I/O
109 * is underway against any of the blocks which are outside the truncation
110 * point. Because the caller is about to free (and possibly reuse) those
113 void do_invalidatepage(struct page
*page
, unsigned int offset
,
116 void (*invalidatepage
)(struct page
*, unsigned int, unsigned int);
118 invalidatepage
= page
->mapping
->a_ops
->invalidatepage
;
121 invalidatepage
= block_invalidatepage
;
124 (*invalidatepage
)(page
, offset
, length
);
128 * If truncate cannot remove the fs-private metadata from the page, the page
129 * becomes orphaned. It will be left on the LRU and may even be mapped into
130 * user pagetables if we're racing with filemap_fault().
132 * We need to bale out if page->mapping is no longer equal to the original
133 * mapping. This happens a) when the VM reclaimed the page while we waited on
134 * its lock, b) when a concurrent invalidate_mapping_pages got there first and
135 * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space.
138 truncate_complete_page(struct address_space
*mapping
, struct page
*page
)
140 if (page
->mapping
!= mapping
)
143 if (page_has_private(page
))
144 do_invalidatepage(page
, 0, PAGE_SIZE
);
147 * Some filesystems seem to re-dirty the page even after
148 * the VM has canceled the dirty bit (eg ext3 journaling).
149 * Hence dirty accounting check is placed after invalidation.
151 cancel_dirty_page(page
);
152 ClearPageMappedToDisk(page
);
153 delete_from_page_cache(page
);
158 * This is for invalidate_mapping_pages(). That function can be called at
159 * any time, and is not supposed to throw away dirty pages. But pages can
160 * be marked dirty at any time too, so use remove_mapping which safely
161 * discards clean, unused pages.
163 * Returns non-zero if the page was successfully invalidated.
166 invalidate_complete_page(struct address_space
*mapping
, struct page
*page
)
170 if (page
->mapping
!= mapping
)
173 if (page_has_private(page
) && !try_to_release_page(page
, 0))
176 ret
= remove_mapping(mapping
, page
);
181 int truncate_inode_page(struct address_space
*mapping
, struct page
*page
)
184 VM_BUG_ON_PAGE(PageTail(page
), page
);
186 holelen
= PageTransHuge(page
) ? HPAGE_PMD_SIZE
: PAGE_SIZE
;
187 if (page_mapped(page
)) {
188 unmap_mapping_range(mapping
,
189 (loff_t
)page
->index
<< PAGE_SHIFT
,
192 return truncate_complete_page(mapping
, page
);
196 * Used to get rid of pages on hardware memory corruption.
198 int generic_error_remove_page(struct address_space
*mapping
, struct page
*page
)
203 * Only punch for normal data pages for now.
204 * Handling other types like directories would need more auditing.
206 if (!S_ISREG(mapping
->host
->i_mode
))
208 return truncate_inode_page(mapping
, page
);
210 EXPORT_SYMBOL(generic_error_remove_page
);
213 * Safely invalidate one page from its pagecache mapping.
214 * It only drops clean, unused pages. The page must be locked.
216 * Returns 1 if the page is successfully invalidated, otherwise 0.
218 int invalidate_inode_page(struct page
*page
)
220 struct address_space
*mapping
= page_mapping(page
);
223 if (PageDirty(page
) || PageWriteback(page
))
225 if (page_mapped(page
))
227 return invalidate_complete_page(mapping
, page
);
231 * truncate_inode_pages_range - truncate range of pages specified by start & end byte offsets
232 * @mapping: mapping to truncate
233 * @lstart: offset from which to truncate
234 * @lend: offset to which to truncate (inclusive)
236 * Truncate the page cache, removing the pages that are between
237 * specified offsets (and zeroing out partial pages
238 * if lstart or lend + 1 is not page aligned).
240 * Truncate takes two passes - the first pass is nonblocking. It will not
241 * block on page locks and it will not block on writeback. The second pass
242 * will wait. This is to prevent as much IO as possible in the affected region.
243 * The first pass will remove most pages, so the search cost of the second pass
246 * We pass down the cache-hot hint to the page freeing code. Even if the
247 * mapping is large, it is probably the case that the final pages are the most
248 * recently touched, and freeing happens in ascending file offset order.
250 * Note that since ->invalidatepage() accepts range to invalidate
251 * truncate_inode_pages_range is able to handle cases where lend + 1 is not
252 * page aligned properly.
254 void truncate_inode_pages_range(struct address_space
*mapping
,
255 loff_t lstart
, loff_t lend
)
257 pgoff_t start
; /* inclusive */
258 pgoff_t end
; /* exclusive */
259 unsigned int partial_start
; /* inclusive */
260 unsigned int partial_end
; /* exclusive */
262 pgoff_t indices
[PAGEVEC_SIZE
];
266 if (mapping
->nrpages
== 0 && mapping
->nrexceptional
== 0)
269 /* Offsets within partial pages */
270 partial_start
= lstart
& (PAGE_SIZE
- 1);
271 partial_end
= (lend
+ 1) & (PAGE_SIZE
- 1);
274 * 'start' and 'end' always covers the range of pages to be fully
275 * truncated. Partial pages are covered with 'partial_start' at the
276 * start of the range and 'partial_end' at the end of the range.
277 * Note that 'end' is exclusive while 'lend' is inclusive.
279 start
= (lstart
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
282 * lend == -1 indicates end-of-file so we have to set 'end'
283 * to the highest possible pgoff_t and since the type is
284 * unsigned we're using -1.
288 end
= (lend
+ 1) >> PAGE_SHIFT
;
290 pagevec_init(&pvec
, 0);
292 while (index
< end
&& pagevec_lookup_entries(&pvec
, mapping
, index
,
293 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
),
295 for (i
= 0; i
< pagevec_count(&pvec
); i
++) {
296 struct page
*page
= pvec
.pages
[i
];
298 /* We rely upon deletion not changing page->index */
303 if (radix_tree_exceptional_entry(page
)) {
304 truncate_exceptional_entry(mapping
, index
,
309 if (!trylock_page(page
))
311 WARN_ON(page_to_index(page
) != index
);
312 if (PageWriteback(page
)) {
316 truncate_inode_page(mapping
, page
);
319 pagevec_remove_exceptionals(&pvec
);
320 pagevec_release(&pvec
);
326 struct page
*page
= find_lock_page(mapping
, start
- 1);
328 unsigned int top
= PAGE_SIZE
;
330 /* Truncation within a single page */
334 wait_on_page_writeback(page
);
335 zero_user_segment(page
, partial_start
, top
);
336 cleancache_invalidate_page(mapping
, page
);
337 if (page_has_private(page
))
338 do_invalidatepage(page
, partial_start
,
339 top
- partial_start
);
345 struct page
*page
= find_lock_page(mapping
, end
);
347 wait_on_page_writeback(page
);
348 zero_user_segment(page
, 0, partial_end
);
349 cleancache_invalidate_page(mapping
, page
);
350 if (page_has_private(page
))
351 do_invalidatepage(page
, 0,
358 * If the truncation happened within a single page no pages
359 * will be released, just zeroed, so we can bail out now.
367 if (!pagevec_lookup_entries(&pvec
, mapping
, index
,
368 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
), indices
)) {
369 /* If all gone from start onwards, we're done */
372 /* Otherwise restart to make sure all gone */
376 if (index
== start
&& indices
[0] >= end
) {
377 /* All gone out of hole to be punched, we're done */
378 pagevec_remove_exceptionals(&pvec
);
379 pagevec_release(&pvec
);
382 for (i
= 0; i
< pagevec_count(&pvec
); i
++) {
383 struct page
*page
= pvec
.pages
[i
];
385 /* We rely upon deletion not changing page->index */
388 /* Restart punch to make sure all gone */
393 if (radix_tree_exceptional_entry(page
)) {
394 truncate_exceptional_entry(mapping
, index
,
400 WARN_ON(page_to_index(page
) != index
);
401 wait_on_page_writeback(page
);
402 truncate_inode_page(mapping
, page
);
405 pagevec_remove_exceptionals(&pvec
);
406 pagevec_release(&pvec
);
411 cleancache_invalidate_inode(mapping
);
413 EXPORT_SYMBOL(truncate_inode_pages_range
);
416 * truncate_inode_pages - truncate *all* the pages from an offset
417 * @mapping: mapping to truncate
418 * @lstart: offset from which to truncate
420 * Called under (and serialised by) inode->i_mutex.
422 * Note: When this function returns, there can be a page in the process of
423 * deletion (inside __delete_from_page_cache()) in the specified range. Thus
424 * mapping->nrpages can be non-zero when this function returns even after
425 * truncation of the whole mapping.
427 void truncate_inode_pages(struct address_space
*mapping
, loff_t lstart
)
429 truncate_inode_pages_range(mapping
, lstart
, (loff_t
)-1);
431 EXPORT_SYMBOL(truncate_inode_pages
);
434 * truncate_inode_pages_final - truncate *all* pages before inode dies
435 * @mapping: mapping to truncate
437 * Called under (and serialized by) inode->i_mutex.
439 * Filesystems have to use this in the .evict_inode path to inform the
440 * VM that this is the final truncate and the inode is going away.
442 void truncate_inode_pages_final(struct address_space
*mapping
)
444 unsigned long nrexceptional
;
445 unsigned long nrpages
;
448 * Page reclaim can not participate in regular inode lifetime
449 * management (can't call iput()) and thus can race with the
450 * inode teardown. Tell it when the address space is exiting,
451 * so that it does not install eviction information after the
452 * final truncate has begun.
454 mapping_set_exiting(mapping
);
457 * When reclaim installs eviction entries, it increases
458 * nrexceptional first, then decreases nrpages. Make sure we see
459 * this in the right order or we might miss an entry.
461 nrpages
= mapping
->nrpages
;
463 nrexceptional
= mapping
->nrexceptional
;
465 if (nrpages
|| nrexceptional
) {
467 * As truncation uses a lockless tree lookup, cycle
468 * the tree lock to make sure any ongoing tree
469 * modification that does not see AS_EXITING is
470 * completed before starting the final truncate.
472 spin_lock_irq(&mapping
->tree_lock
);
473 spin_unlock_irq(&mapping
->tree_lock
);
477 * Cleancache needs notification even if there are no pages or shadow
480 truncate_inode_pages(mapping
, 0);
482 EXPORT_SYMBOL(truncate_inode_pages_final
);
485 * invalidate_mapping_pages - Invalidate all the unlocked pages of one inode
486 * @mapping: the address_space which holds the pages to invalidate
487 * @start: the offset 'from' which to invalidate
488 * @end: the offset 'to' which to invalidate (inclusive)
490 * This function only removes the unlocked pages, if you want to
491 * remove all the pages of one inode, you must call truncate_inode_pages.
493 * invalidate_mapping_pages() will not block on IO activity. It will not
494 * invalidate pages which are dirty, locked, under writeback or mapped into
497 unsigned long invalidate_mapping_pages(struct address_space
*mapping
,
498 pgoff_t start
, pgoff_t end
)
500 pgoff_t indices
[PAGEVEC_SIZE
];
502 pgoff_t index
= start
;
504 unsigned long count
= 0;
507 pagevec_init(&pvec
, 0);
508 while (index
<= end
&& pagevec_lookup_entries(&pvec
, mapping
, index
,
509 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
- 1) + 1,
511 for (i
= 0; i
< pagevec_count(&pvec
); i
++) {
512 struct page
*page
= pvec
.pages
[i
];
514 /* We rely upon deletion not changing page->index */
519 if (radix_tree_exceptional_entry(page
)) {
520 invalidate_exceptional_entry(mapping
, index
,
525 if (!trylock_page(page
))
528 WARN_ON(page_to_index(page
) != index
);
530 /* Middle of THP: skip */
531 if (PageTransTail(page
)) {
534 } else if (PageTransHuge(page
)) {
535 index
+= HPAGE_PMD_NR
- 1;
536 i
+= HPAGE_PMD_NR
- 1;
538 * 'end' is in the middle of THP. Don't
539 * invalidate the page as the part outside of
540 * 'end' could be still useful.
548 ret
= invalidate_inode_page(page
);
551 * Invalidation is a hint that the page is no longer
552 * of interest and try to speed up its reclaim.
555 deactivate_file_page(page
);
558 pagevec_remove_exceptionals(&pvec
);
559 pagevec_release(&pvec
);
565 EXPORT_SYMBOL(invalidate_mapping_pages
);
568 * This is like invalidate_complete_page(), except it ignores the page's
569 * refcount. We do this because invalidate_inode_pages2() needs stronger
570 * invalidation guarantees, and cannot afford to leave pages behind because
571 * shrink_page_list() has a temp ref on them, or because they're transiently
572 * sitting in the lru_cache_add() pagevecs.
575 invalidate_complete_page2(struct address_space
*mapping
, struct page
*page
)
579 if (page
->mapping
!= mapping
)
582 if (page_has_private(page
) && !try_to_release_page(page
, GFP_KERNEL
))
585 spin_lock_irqsave(&mapping
->tree_lock
, flags
);
589 BUG_ON(page_has_private(page
));
590 __delete_from_page_cache(page
, NULL
);
591 spin_unlock_irqrestore(&mapping
->tree_lock
, flags
);
593 if (mapping
->a_ops
->freepage
)
594 mapping
->a_ops
->freepage(page
);
596 put_page(page
); /* pagecache ref */
599 spin_unlock_irqrestore(&mapping
->tree_lock
, flags
);
603 static int do_launder_page(struct address_space
*mapping
, struct page
*page
)
605 if (!PageDirty(page
))
607 if (page
->mapping
!= mapping
|| mapping
->a_ops
->launder_page
== NULL
)
609 return mapping
->a_ops
->launder_page(page
);
613 * invalidate_inode_pages2_range - remove range of pages from an address_space
614 * @mapping: the address_space
615 * @start: the page offset 'from' which to invalidate
616 * @end: the page offset 'to' which to invalidate (inclusive)
618 * Any pages which are found to be mapped into pagetables are unmapped prior to
621 * Returns -EBUSY if any pages could not be invalidated.
623 int invalidate_inode_pages2_range(struct address_space
*mapping
,
624 pgoff_t start
, pgoff_t end
)
626 pgoff_t indices
[PAGEVEC_SIZE
];
632 int did_range_unmap
= 0;
634 if (mapping
->nrpages
== 0 && mapping
->nrexceptional
== 0)
637 pagevec_init(&pvec
, 0);
639 while (index
<= end
&& pagevec_lookup_entries(&pvec
, mapping
, index
,
640 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
- 1) + 1,
642 for (i
= 0; i
< pagevec_count(&pvec
); i
++) {
643 struct page
*page
= pvec
.pages
[i
];
645 /* We rely upon deletion not changing page->index */
650 if (radix_tree_exceptional_entry(page
)) {
651 if (!invalidate_exceptional_entry2(mapping
,
658 WARN_ON(page_to_index(page
) != index
);
659 if (page
->mapping
!= mapping
) {
663 wait_on_page_writeback(page
);
664 if (page_mapped(page
)) {
665 if (!did_range_unmap
) {
667 * Zap the rest of the file in one hit.
669 unmap_mapping_range(mapping
,
670 (loff_t
)index
<< PAGE_SHIFT
,
671 (loff_t
)(1 + end
- index
)
679 unmap_mapping_range(mapping
,
680 (loff_t
)index
<< PAGE_SHIFT
,
684 BUG_ON(page_mapped(page
));
685 ret2
= do_launder_page(mapping
, page
);
687 if (!invalidate_complete_page2(mapping
, page
))
694 pagevec_remove_exceptionals(&pvec
);
695 pagevec_release(&pvec
);
700 * For DAX we invalidate page tables after invalidating radix tree. We
701 * could invalidate page tables while invalidating each entry however
702 * that would be expensive. And doing range unmapping before doesn't
703 * work as we have no cheap way to find whether radix tree entry didn't
704 * get remapped later.
706 if (dax_mapping(mapping
)) {
707 unmap_mapping_range(mapping
, (loff_t
)start
<< PAGE_SHIFT
,
708 (loff_t
)(end
- start
+ 1) << PAGE_SHIFT
, 0);
711 cleancache_invalidate_inode(mapping
);
714 EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range
);
717 * invalidate_inode_pages2 - remove all pages from an address_space
718 * @mapping: the address_space
720 * Any pages which are found to be mapped into pagetables are unmapped prior to
723 * Returns -EBUSY if any pages could not be invalidated.
725 int invalidate_inode_pages2(struct address_space
*mapping
)
727 return invalidate_inode_pages2_range(mapping
, 0, -1);
729 EXPORT_SYMBOL_GPL(invalidate_inode_pages2
);
732 * truncate_pagecache - unmap and remove pagecache that has been truncated
734 * @newsize: new file size
736 * inode's new i_size must already be written before truncate_pagecache
739 * This function should typically be called before the filesystem
740 * releases resources associated with the freed range (eg. deallocates
741 * blocks). This way, pagecache will always stay logically coherent
742 * with on-disk format, and the filesystem would not have to deal with
743 * situations such as writepage being called for a page that has already
744 * had its underlying blocks deallocated.
746 void truncate_pagecache(struct inode
*inode
, loff_t newsize
)
748 struct address_space
*mapping
= inode
->i_mapping
;
749 loff_t holebegin
= round_up(newsize
, PAGE_SIZE
);
752 * unmap_mapping_range is called twice, first simply for
753 * efficiency so that truncate_inode_pages does fewer
754 * single-page unmaps. However after this first call, and
755 * before truncate_inode_pages finishes, it is possible for
756 * private pages to be COWed, which remain after
757 * truncate_inode_pages finishes, hence the second
758 * unmap_mapping_range call must be made for correctness.
760 unmap_mapping_range(mapping
, holebegin
, 0, 1);
761 truncate_inode_pages(mapping
, newsize
);
762 unmap_mapping_range(mapping
, holebegin
, 0, 1);
764 EXPORT_SYMBOL(truncate_pagecache
);
767 * truncate_setsize - update inode and pagecache for a new file size
769 * @newsize: new file size
771 * truncate_setsize updates i_size and performs pagecache truncation (if
772 * necessary) to @newsize. It will be typically be called from the filesystem's
773 * setattr function when ATTR_SIZE is passed in.
775 * Must be called with a lock serializing truncates and writes (generally
776 * i_mutex but e.g. xfs uses a different lock) and before all filesystem
777 * specific block truncation has been performed.
779 void truncate_setsize(struct inode
*inode
, loff_t newsize
)
781 loff_t oldsize
= inode
->i_size
;
783 i_size_write(inode
, newsize
);
784 if (newsize
> oldsize
)
785 pagecache_isize_extended(inode
, oldsize
, newsize
);
786 truncate_pagecache(inode
, newsize
);
788 EXPORT_SYMBOL(truncate_setsize
);
791 * pagecache_isize_extended - update pagecache after extension of i_size
792 * @inode: inode for which i_size was extended
793 * @from: original inode size
794 * @to: new inode size
796 * Handle extension of inode size either caused by extending truncate or by
797 * write starting after current i_size. We mark the page straddling current
798 * i_size RO so that page_mkwrite() is called on the nearest write access to
799 * the page. This way filesystem can be sure that page_mkwrite() is called on
800 * the page before user writes to the page via mmap after the i_size has been
803 * The function must be called after i_size is updated so that page fault
804 * coming after we unlock the page will already see the new i_size.
805 * The function must be called while we still hold i_mutex - this not only
806 * makes sure i_size is stable but also that userspace cannot observe new
807 * i_size value before we are prepared to store mmap writes at new inode size.
809 void pagecache_isize_extended(struct inode
*inode
, loff_t from
, loff_t to
)
811 int bsize
= i_blocksize(inode
);
816 WARN_ON(to
> inode
->i_size
);
818 if (from
>= to
|| bsize
== PAGE_SIZE
)
820 /* Page straddling @from will not have any hole block created? */
821 rounded_from
= round_up(from
, bsize
);
822 if (to
<= rounded_from
|| !(rounded_from
& (PAGE_SIZE
- 1)))
825 index
= from
>> PAGE_SHIFT
;
826 page
= find_lock_page(inode
->i_mapping
, index
);
827 /* Page not cached? Nothing to do */
831 * See clear_page_dirty_for_io() for details why set_page_dirty()
834 if (page_mkclean(page
))
835 set_page_dirty(page
);
839 EXPORT_SYMBOL(pagecache_isize_extended
);
842 * truncate_pagecache_range - unmap and remove pagecache that is hole-punched
844 * @lstart: offset of beginning of hole
845 * @lend: offset of last byte of hole
847 * This function should typically be called before the filesystem
848 * releases resources associated with the freed range (eg. deallocates
849 * blocks). This way, pagecache will always stay logically coherent
850 * with on-disk format, and the filesystem would not have to deal with
851 * situations such as writepage being called for a page that has already
852 * had its underlying blocks deallocated.
854 void truncate_pagecache_range(struct inode
*inode
, loff_t lstart
, loff_t lend
)
856 struct address_space
*mapping
= inode
->i_mapping
;
857 loff_t unmap_start
= round_up(lstart
, PAGE_SIZE
);
858 loff_t unmap_end
= round_down(1 + lend
, PAGE_SIZE
) - 1;
860 * This rounding is currently just for example: unmap_mapping_range
861 * expands its hole outwards, whereas we want it to contract the hole
862 * inwards. However, existing callers of truncate_pagecache_range are
863 * doing their own page rounding first. Note that unmap_mapping_range
864 * allows holelen 0 for all, and we allow lend -1 for end of file.
868 * Unlike in truncate_pagecache, unmap_mapping_range is called only
869 * once (before truncating pagecache), and without "even_cows" flag:
870 * hole-punching should not remove private COWed pages from the hole.
872 if ((u64
)unmap_end
> (u64
)unmap_start
)
873 unmap_mapping_range(mapping
, unmap_start
,
874 1 + unmap_end
- unmap_start
, 0);
875 truncate_inode_pages_range(mapping
, lstart
, lend
);
877 EXPORT_SYMBOL(truncate_pagecache_range
);