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| author | Jeff Mahoney <jeffm@suse.com> | 2017-06-22 16:47:34 -0400 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2017-06-23 09:40:30 +0200 |
| commit | 08db141b5313ac2f64b844fb5725b8d81744b417 (patch) | |
| tree | 377bea15d7bbcc73f800c0be9938d69000ad09e8 /fs/nfs/callback_xdr.c | |
| parent | 54930dfeb46e978b447af0fb8ab4e181c1bf9d7a (diff) | |
| download | linux-stable-08db141b5313ac2f64b844fb5725b8d81744b417.tar.gz linux-stable-08db141b5313ac2f64b844fb5725b8d81744b417.tar.bz2 linux-stable-08db141b5313ac2f64b844fb5725b8d81744b417.zip | |
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>
Diffstat (limited to 'fs/nfs/callback_xdr.c')
0 files changed, 0 insertions, 0 deletions