tmpfs: don't undo fallocate past its last page
authorAnthony Romano <anthony.romano@coreos.com>
Fri, 24 Jun 2016 21:48:43 +0000 (14:48 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 25 Jun 2016 00:23:52 +0000 (17:23 -0700)
commitb9b4bb26af017dbe930cd4df7f9b2fc3a0497bfe
tree876ddeec4c6f173304dc30a16ecaadca6eca23b8
parenta7b50abc90afb2e3c27e1bd212643cc53eaf0b60
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@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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/shmem.c