btrfs: Remove redundant memory barriers around dio_private error status
Using any kind of memory barriers around atomic operations which have
a return value is redundant, since those operations themselves are
fully ordered. atomic_t.txt states:
- RMW operations that have a return value are fully ordered;
Fully ordered primitives are ordered against everything prior and
everything subsequent. Therefore a fully ordered primitive is like
having an smp_mb() before and an smp_mb() after the primitive.
Given this let's replace the extra memory barriers with comments.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
1 file changed