From: Anthony Romano <anthony.romano@xxxxxxxxxx>
Subject: tmpfs: don't undo fallocate past its last page
When fallocate is interrupted it will undo a range that extends one byte
past its range of allocated pages. This can corrupt an in-use page by
zeroing out its first byte. Instead, undo using the inclusive byte range.
Fixes: 1635f6a74152f1d ("tmpfs: undo fallocation on failure")
Link: http://lkml.kernel.org/r/1462713387-16724-1-git-send-email-anthony.romano@xxxxxxxxxx
Signed-off-by: Anthony Romano <anthony.romano@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Brandon Philips <brandon@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN mm/shmem.c~tmpfs-dont-undo-fallocate-past-its-last-page mm/shmem.c
--- a/mm/shmem.c~tmpfs-dont-undo-fallocate-past-its-last-page
+++ a/mm/shmem.c
@@ -2227,7 +2227,7 @@ static long shmem_fallocate(struct file
/* Remove the !PageUptodate pages we added */
shmem_undo_range(inode,
(loff_t)start << PAGE_SHIFT,
- (loff_t)index << PAGE_SHIFT, true);
+ ((loff_t)index << PAGE_SHIFT) - 1, true);
goto undone;
}
_
--
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