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author | Hugh Dickins <hughd@google.com> | 2016-07-10 16:46:32 -0700 |
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committer | Sasha Levin <sasha.levin@oracle.com> | 2016-07-12 08:41:10 -0400 |
commit | 116c75f642ad4a6d267f399c9f1fe8b91fb822c5 (patch) | |
tree | 180133ef4e45a3ebb7dc2e689f4312a3ada43005 /arch/powerpc | |
parent | b7aa372fec2c1d4a1fcf4398ae88ba94134b9522 (diff) |
tmpfs: fix regression hang in fallocate undo
[ Upstream commit 7f556567036cb7f89aabe2f0954b08566b4efb53 ]
The well-spotted fallocate undo fix is good in most cases, but not when
fallocate failed on the very first page. index 0 then passes lend -1
to shmem_undo_range(), and that has two bad effects: (a) that it will
undo every fallocation throughout the file, unrestricted by the current
range; but more importantly (b) it can cause the undo to hang, because
lend -1 is treated as truncation, which makes it keep on retrying until
every page has gone, but those already fully instantiated will never go
away. Big thank you to xfstests generic/269 which demonstrates this.
Fixes: b9b4bb26af01 ("tmpfs: don't undo fallocate past its last page")
Cc: stable@vger.kernel.org
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'arch/powerpc')
0 files changed, 0 insertions, 0 deletions