1 files changed, 9 insertions, 12 deletions

diff --git a/fs/btrfs/block-rsv.c b/fs/btrfs/block-rsv.c
index 5367a14d44d2..3ab707e26fa2 100644
--- a/fs/btrfs/block-rsv.c
+++ b/fs/btrfs/block-rsv.c
@@ -232,9 +232,6 @@ int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_percent)
 	u64 num_bytes = 0;
 	int ret = -ENOSPC;
 
-	if (!block_rsv)
-		return 0;
-
 	spin_lock(&block_rsv->lock);
 	num_bytes = mult_perc(block_rsv->size, min_percent);
 	if (block_rsv->reserved >= num_bytes)
@@ -245,17 +242,15 @@ int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_percent)
 }
 
 int btrfs_block_rsv_refill(struct btrfs_fs_info *fs_info,
-			   struct btrfs_block_rsv *block_rsv, u64 min_reserved,
+			   struct btrfs_block_rsv *block_rsv, u64 num_bytes,
 			   enum btrfs_reserve_flush_enum flush)
 {
-	u64 num_bytes = 0;
 	int ret = -ENOSPC;
 
 	if (!block_rsv)
 		return 0;
 
 	spin_lock(&block_rsv->lock);
-	num_bytes = min_reserved;
 	if (block_rsv->reserved >= num_bytes)
 		ret = 0;
 	else
@@ -355,17 +350,19 @@ void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info)
 
 	/*
 	 * But we also want to reserve enough space so we can do the fallback
-	 * global reserve for an unlink, which is an additional 5 items (see the
-	 * comment in __unlink_start_trans for what we're modifying.)
+	 * global reserve for an unlink, which is an additional
+	 * BTRFS_UNLINK_METADATA_UNITS items.
 	 *
 	 * But we also need space for the delayed ref updates from the unlink,
-	 * so its 10, 5 for the actual operation, and 5 for the delayed ref
-	 * updates.
+	 * so add BTRFS_UNLINK_METADATA_UNITS units for delayed refs, one for
+	 * each unlink metadata item.
 	 */
-	min_items += 10;
+	min_items += BTRFS_UNLINK_METADATA_UNITS;
 
 	num_bytes = max_t(u64, num_bytes,
-			  btrfs_calc_insert_metadata_size(fs_info, min_items));
+			  btrfs_calc_insert_metadata_size(fs_info, min_items) +
+			  btrfs_calc_delayed_ref_bytes(fs_info,
+					       BTRFS_UNLINK_METADATA_UNITS));
 
 	spin_lock(&sinfo->lock);
 	spin_lock(&block_rsv->lock);