diff options
| author | Josef Bacik <[email protected]> | 2012-07-20 20:11:08 +0000 |
|---|---|---|
| committer | Chris Mason <[email protected]> | 2012-07-23 20:28:09 +0000 |
| commit | 594831c4b232b094d645503ecedec2e35dcebdf3 (patch) | |
| tree | 27867ddba8f36d9dc4946c5beee2f18d7be8c861 /fs/btrfs/async-thread.c | |
| parent | Btrfs: don't return true in releasepage unless we actually freed the eb (diff) | |
| download | kernel-594831c4b232b094d645503ecedec2e35dcebdf3.tar.gz kernel-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 <[email protected]>
Diffstat (limited to 'fs/btrfs/async-thread.c')
0 files changed, 0 insertions, 0 deletions