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| author |   Josef Bacik <jbacik@fusionio.com> | 2012-07-20 16:11:08 -0400 |
|---|---|---|
| committer |   Chris Mason <chris.mason@fusionio.com> | 2012-07-23 16:28:09 -0400 |
| commit | 594831c4b232b094d645503ecedec2e35dcebdf3 (patch) | |
| tree | 27867ddba8f36d9dc4946c5beee2f18d7be8c861 /tools/perf/scripts/python/syscall-counts.py | |
| parent | Btrfs: don't return true in releasepage unless we actually freed the eb (diff) | |
| download | linux-dev-594831c4b232b094d645503ecedec2e35dcebdf3.tar.xz linux-dev-594831c4b232b094d645503ecedec2e35dcebdf3.zip | |
Btrfs: fix potential race in extent buffer freeing
This sounds sort of impossible but it is the only thing I can think of and
at the very least it is theoretically possible so here it goes.
If we are in try_release_extent_buffer we will check that the ref count on
the extent buffer is 1 and not under IO, and then go down and clear the tree
ref. If between this check and clearing the tree ref somebody else comes in
and grabs a ref on the eb and the marks it dirty before
try_release_extent_buffer() does it's tree ref clear we can end up with a
dirty eb that will be freed while it is still dirty which will result in a
panic. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to 'tools/perf/scripts/python/syscall-counts.py')
0 files changed, 0 insertions, 0 deletions