Btrfs: avoid taking the chunk_mutex in do_chunk_alloc
Everytime we try to allocate disk space we try and see if we can pre-emptively
allocate a chunk, but in the common case we don't allocate anything, so there is
no sense in taking the chunk_mutex at all. So instead if we are allocating a
chunk, mark it in the space_info so we don't get two people trying to allocate
at the same time. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Reviewed-by: Liu Bo <liubo2009@cn.fujitsu.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0d00a07..2e61fe1 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -740,8 +740,10 @@
*/
unsigned long reservation_progress;
- int full; /* indicates that we cannot allocate any more
+ int full:1; /* indicates that we cannot allocate any more
chunks for this space */
+ int chunk_alloc:1; /* set if we are allocating a chunk */
+
int force_alloc; /* set if we need to force a chunk alloc for
this space */