| commit | 08db141b5313ac2f64b844fb5725b8d81744b417 | |
| author | Jeff Mahoney <jeffm@suse.com> | |
| Thu, 22 Jun 2017 20:47:34 +0000 (22 16:47 -0400) | ||
| committer | Jan Kara <jack@suse.cz> | |
| Fri, 23 Jun 2017 07:40:30 +0000 (23 09:40 +0200) | ||
| tree | 377bea15d7bbcc73f800c0be9938d69000ad09e8 | treesnapshot (tar.gz zip) |
| parent | 54930dfeb46e978b447af0fb8ab4e181c1bf9d7a | commitdiff |
reiserfs: fix race in prealloc discard
The main loop in __discard_prealloc is protected by the reiserfs write lock
which is dropped across schedules like the BKL it replaced. The problem is
that it checks the value, calls a routine that schedules, and then adjusts
the state. As a result, two threads that are calling
reiserfs_prealloc_discard at the same time can race when one calls
reiserfs_free_prealloc_block, the lock is dropped, and the other calls
reiserfs_free_prealloc_block with the same block number. In the right
circumstances, it can cause the prealloc count to go negative.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
The main loop in __discard_prealloc is protected by the reiserfs write lock
which is dropped across schedules like the BKL it replaced. The problem is
that it checks the value, calls a routine that schedules, and then adjusts
the state. As a result, two threads that are calling
reiserfs_prealloc_discard at the same time can race when one calls
reiserfs_free_prealloc_block, the lock is dropped, and the other calls
reiserfs_free_prealloc_block with the same block number. In the right
circumstances, it can cause the prealloc count to go negative.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
| fs/reiserfs/bitmap.c | diffblobblamehistory |