1 files changed, 16 insertions, 3 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3aafbde8b637..1c54e2eb74ab 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -697,6 +697,7 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
         unsigned long cur = trans->delayed_ref_updates;
         int lock = (trans->type != TRANS_JOIN_NOLOCK);
         int err = 0;
+        int must_run_delayed_refs = 0;
 
         if (trans->use_count > 1) {
                 trans->use_count--;
@@ -711,10 +712,18 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
                 btrfs_create_pending_block_groups(trans, root);
 
         trans->delayed_ref_updates = 0;
-        if (!trans->sync && btrfs_should_throttle_delayed_refs(trans, root)) {
+        if (!trans->sync) {
+                must_run_delayed_refs =
+                        btrfs_should_throttle_delayed_refs(trans, root);
                 cur = max_t(unsigned long, cur, 32);
-                trans->delayed_ref_updates = 0;
-                btrfs_run_delayed_refs(trans, root, cur);
+
+                /*
+                 * don't make the caller wait if they are from a NOLOCK
+                 * or ATTACH transaction, it will deadlock with commit
+                 */
+                if (must_run_delayed_refs == 1 &&
+                    (trans->type & (__TRANS_JOIN_NOLOCK | __TRANS_ATTACH)))
+                        must_run_delayed_refs = 2;
         }
 
         if (trans->qgroup_reserved) {
@@ -775,6 +784,10 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
         assert_qgroups_uptodate(trans);
 
         kmem_cache_free(btrfs_trans_handle_cachep, trans);
+        if (must_run_delayed_refs) {
+                btrfs_async_run_delayed_refs(root, cur,
+                                             must_run_delayed_refs == 1);
+        }
         return err;
 }