Commit 55231e5c authored May 22, 2014 by Johannes Weiner Committed by Linus Torvalds May 23, 2014

mm: madvise: fix MADV_WILLNEED on shmem swapouts

MADV_WILLNEED currently does not read swapped out shmem pages back in.

Commit 0cd6144a ("mm + fs: prepare for non-page entries in page
cache radix trees") made find_get_page() filter exceptional radix tree
entries but failed to convert all find_get_page() callers that WANT
exceptional entries over to find_get_entry(). One of them is shmem swap
readahead in madvise, which now skips over any swap-out records.

Convert it to find_get_entry().

Fixes: 0cd6144a ("mm + fs: prepare for non-page entries in page cache radix trees")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 7fcbbaf1

mm/madvise.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -195,7 +195,7 @@ static void force_shm_swapin_readahead(struct vm_area_struct *vma,
		for (; start < end; start += PAGE_SIZE) {
		index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;

		page = find_get_page(mapping, index);
		page = find_get_entry(mapping, index);
		if (!radix_tree_exceptional_entry(page)) {
		if (page)
		page_cache_release(page);

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