3 files changed, 38 insertions, 18 deletions

diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 455894f1ca3b..b7a0641ead77 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -426,6 +426,14 @@ again:
         return 1;
 }
 
+void btrfs_release_ref_cluster(struct list_head *cluster)
+{
+        struct list_head *pos, *q;
+
+        list_for_each_safe(pos, q, cluster)
+                list_del_init(pos);
+}
+
 /*
  * helper function to update an extent delayed ref in the
  * rbtree.  existing and update must both have the same
diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index fe50392cdf76..7939149f8f27 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -211,8 +211,14 @@ struct btrfs_delayed_ref_head *
 btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr);
 int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
                            struct btrfs_delayed_ref_head *head);
+static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
+{
+        mutex_unlock(&head->mutex);
+}
+
 int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
                            struct list_head *cluster, u64 search_start);
+void btrfs_release_ref_cluster(struct list_head *cluster);
 
 int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
                             struct btrfs_delayed_ref_root *delayed_refs,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 9bd87f0d73d0..b4cb8186035f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2143,7 +2143,6 @@ static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
                                                       node->num_bytes);
                         }
                 }
-                mutex_unlock(&head->mutex);
                 return ret;
         }
 
@@ -2258,7 +2257,7 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
                          * process of being added. Don't run this ref yet.
                          */
                         list_del_init(&locked_ref->cluster);
-                        mutex_unlock(&locked_ref->mutex);
+                        btrfs_delayed_ref_unlock(locked_ref);
                         locked_ref = NULL;
                         delayed_refs->num_heads_ready++;
                         spin_unlock(&delayed_refs->lock);
@@ -2297,25 +2296,22 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
                                 btrfs_free_delayed_extent_op(extent_op);
 
                                 if (ret) {
-                                        list_del_init(&locked_ref->cluster);
-                                        mutex_unlock(&locked_ref->mutex);
-
-                                        printk(KERN_DEBUG "btrfs: run_delayed_extent_op returned %d\n", ret);
+                                        printk(KERN_DEBUG
+                                               "btrfs: run_delayed_extent_op "
+                                               "returned %d\n", ret);
                                         spin_lock(&delayed_refs->lock);
+                                        btrfs_delayed_ref_unlock(locked_ref);
                                         return ret;
                                 }
 
                                 goto next;
                         }
-
-                        list_del_init(&locked_ref->cluster);
-                        locked_ref = NULL;
                 }
 
                 ref->in_tree = 0;
                 rb_erase(&ref->rb_node, &delayed_refs->root);
                 delayed_refs->num_entries--;
-                if (locked_ref) {
+                if (!btrfs_delayed_ref_is_head(ref)) {
                         /*
                          * when we play the delayed ref, also correct the
                          * ref_mod on head
@@ -2337,20 +2333,29 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
                 ret = run_one_delayed_ref(trans, root, ref, extent_op,
                                           must_insert_reserved);
 
-                btrfs_put_delayed_ref(ref);
                 btrfs_free_delayed_extent_op(extent_op);
-                count++;
-
                 if (ret) {
-                        if (locked_ref) {
-                                list_del_init(&locked_ref->cluster);
-                                mutex_unlock(&locked_ref->mutex);
-                        }
-                        printk(KERN_DEBUG "btrfs: run_one_delayed_ref returned %d\n", ret);
+                        btrfs_delayed_ref_unlock(locked_ref);
+                        btrfs_put_delayed_ref(ref);
+                        printk(KERN_DEBUG
+                               "btrfs: run_one_delayed_ref returned %d\n", ret);
                         spin_lock(&delayed_refs->lock);
                         return ret;
                 }
 
+                /*
+                 * If this node is a head, that means all the refs in this head
+                 * have been dealt with, and we will pick the next head to deal
+                 * with, so we must unlock the head and drop it from the cluster
+                 * list before we release it.
+                 */
+                if (btrfs_delayed_ref_is_head(ref)) {
+                        list_del_init(&locked_ref->cluster);
+                        btrfs_delayed_ref_unlock(locked_ref);
+                        locked_ref = NULL;
+                }
+                btrfs_put_delayed_ref(ref);
+                count++;
 next:
                 cond_resched();
                 spin_lock(&delayed_refs->lock);
@@ -2500,6 +2505,7 @@ again:
 
                 ret = run_clustered_refs(trans, root, &cluster);
                 if (ret < 0) {
+                        btrfs_release_ref_cluster(&cluster);
                         spin_unlock(&delayed_refs->lock);
                         btrfs_abort_transaction(trans, root, ret);
                         return ret;