| From b9b4bb26af017dbe930cd4df7f9b2fc3a0497bfe Mon Sep 17 00:00:00 2001 |
| From: Anthony Romano <anthony.romano@coreos.com> |
| Date: Fri, 24 Jun 2016 14:48:43 -0700 |
| Subject: tmpfs: don't undo fallocate past its last page |
| |
| From: Anthony Romano <anthony.romano@coreos.com> |
| |
| commit b9b4bb26af017dbe930cd4df7f9b2fc3a0497bfe upstream. |
| |
| 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@coreos.com |
| Signed-off-by: Anthony Romano <anthony.romano@coreos.com> |
| Cc: Vlastimil Babka <vbabka@suse.cz> |
| Cc: Hugh Dickins <hughd@google.com> |
| Cc: Brandon Philips <brandon@ifup.co> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| mm/shmem.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/mm/shmem.c |
| +++ b/mm/shmem.c |
| @@ -2155,7 +2155,7 @@ static long shmem_fallocate(struct file |
| /* Remove the !PageUptodate pages we added */ |
| shmem_undo_range(inode, |
| (loff_t)start << PAGE_CACHE_SHIFT, |
| - (loff_t)index << PAGE_CACHE_SHIFT, true); |
| + ((loff_t)index << PAGE_CACHE_SHIFT) - 1, true); |
| goto undone; |
| } |
| |