On 17.03.2011 00:10, Arne Jansen wrote:
On 16.03.2011 23:07, Andi Kleen wrote:
Arne Jansen<sensille@xxxxxxx> writes:
+ */
+ mutex_lock(&fs_info->scrub_lock);
+ atomic_inc(&fs_info->scrubs_running);
+ mutex_unlock(&fs_info->scrub_lock);
It seems odd to protect an atomic_inc with a mutex.
Is that done for some side effect? Otherwise you either
don't need atomic or don't need the lock.
The reason it is atomic is because it is checked inside a wait_event,
where I can't hold a lock. The mutex is there to protect the check
in btrfs_scrub_pause and btrfs_scrub_cancel. But, now that I think
of it, there is still a race condition left. I'll rethink the locking
there
and see if I can eliminate some of the mutex_locks.
On third look I can't find the race condition I thought was there...
Just removing the locks around most inc/dec looks ok.
Thanks,
Arne
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