[PATCH-RFC] btrfs: for unclustered allocation don't consider ffe_ctl->empty_cluster

[Alex Lyakas <alex.lyakas@zadara.com>]

I encountered an issue when performing unclustered allocation for metadata:

free_space_ctl->free_space = 2MB
ffe_ctl->num_bytes = 4096
ffe_ctl->empty_cluster = 2MB
ffe_ctl->empty_size = 0

So early check for free_space_ctl->free_space skips the block group, even though
it has enough space to do the allocation.
I think when doing unclustered allocation we should not look at ffe_ctl->empty_cluster.

I tested this on stable kernel 6.6.

Signed-off-by: Alex Lyakas <alex.lyakas@zadara.com>
---
 fs/btrfs/extent-tree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 03cf9f242c70..84b340a67882 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3885,7 +3885,7 @@ static int find_free_extent_unclustered(struct btrfs_block_group *bg,
 		free_space_ctl = bg->free_space_ctl;
 		spin_lock(&free_space_ctl->tree_lock);
 		if (free_space_ctl->free_space <
-		    ffe_ctl->num_bytes + ffe_ctl->empty_cluster +
+		    ffe_ctl->num_bytes +
 		    ffe_ctl->empty_size) {
 			ffe_ctl->total_free_space = max_t(u64,
 					ffe_ctl->total_free_space,
-- 
2.43.0