Commit 0c9b36e0 authored by Liu Bo's avatar Liu Bo Committed by David Sterba
Browse files

Btrfs: try to avoid acquiring free space ctl's lock 



We don't need to take the lock if the block group has not been cached.

Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 6f6b643e

fs/btrfs/extent-tree.c

+13 −11
Original line number Diff line number Diff line
@@ -7714,18 +7714,20 @@ static noinline int find_free_extent(struct btrfs_root *orig_root, 
			last_ptr->fragmented = 1;

			spin_unlock(&last_ptr->lock);

		}

		spin_lock(&block_group->free_space_ctl->tree_lock);

		if (cached &&

		    block_group->free_space_ctl->free_space <

		if (cached) {

			struct btrfs_free_space_ctl *ctl =

				block_group->free_space_ctl;



			spin_lock(&ctl->tree_lock);

			if (ctl->free_space <

			    num_bytes + empty_cluster + empty_size) {

			if (block_group->free_space_ctl->free_space >

			    max_extent_size)

				max_extent_size =

					block_group->free_space_ctl->free_space;

			spin_unlock(&block_group->free_space_ctl->tree_lock);

				if (ctl->free_space > max_extent_size)

					max_extent_size = ctl->free_space;

				spin_unlock(&ctl->tree_lock);

				goto loop;

			}

		spin_unlock(&block_group->free_space_ctl->tree_lock);

			spin_unlock(&ctl->tree_lock);

		}



		offset = btrfs_find_space_for_alloc(block_group, search_start,

						    num_bytes, empty_size,