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author | Hugh Dickins <hughd@google.com> | 2011-05-14 19:06:42 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-14 19:18:55 (GMT) |
commit | 05bf86b4ccfd0f197da61c67bd372111d15a6620 (patch) | |
tree | 23db61517fad9b68b19fdbe044fa3dbe8fc2bd19 /drivers/ata/libata-eh.c | |
parent | afa49791caae70cc3fd665a182eea61250795265 (diff) | |
download | linux-fsl-qoriq-05bf86b4ccfd0f197da61c67bd372111d15a6620.tar.xz |
tmpfs: fix race between swapoff and writepage
Shame on me! Commit b1dea800ac39 "tmpfs: fix race between umount and
writepage" fixed the advertized race, but introduced another: as even
its comment makes clear, we cannot safely rely on a peek at list_empty()
while holding no lock - until info->swapped is set, shmem_unuse_inode()
may delete any formerly-swapped inode from the shmem_swaplist, which
in this case would leave a swap area impossible to swapoff.
Although I don't relish taking the mutex every time, I don't care much
for the alternatives either; and at least the peek at list_empty() in
shmem_evict_inode() (a hotter path since most inodes would never have
been swapped) remains safe, because we already truncated the whole file.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/ata/libata-eh.c')
0 files changed, 0 insertions, 0 deletions