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| author | Sage Weil <sage@newdream.net> | 2010-10-29 15:37:34 -0400 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2010-10-29 15:37:34 -0400 |
| commit | 99d16cbcaf694c803a1b6bf7e851694ffe1d255d (patch) | |
| tree | dacf7f8eca75dc0d92566b5d3876f3efe8196e35 /mm/kmemcheck.c | |
| parent | fccdae435c1b295cca546f23f6f43126a28ffac3 (diff) | |
| download | blackbird-op-linux-99d16cbcaf694c803a1b6bf7e851694ffe1d255d.tar.gz blackbird-op-linux-99d16cbcaf694c803a1b6bf7e851694ffe1d255d.zip | |
Btrfs: fix deadlock in btrfs_commit_transaction
We calculate timeout (either 1 or MAX_SCHEDULE_TIMEOUT) based on whether
num_writers > 1 or should_grow at the top of the loop. Then, much much
later, we wait for that timeout if either num_writers or should_grow is
true. However, it's possible for a racing process (calling
btrfs_end_transaction()) to decrement num_writers such that we wait
forever instead of for 1.
Fix this by deciding how long to wait when we wait. Include a smp_mb()
before checking if the waitqueue is active to ensure the num_writers
is visible.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'mm/kmemcheck.c')
0 files changed, 0 insertions, 0 deletions
