diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3002e5d4da0b2ff41b8100d8ea6e4d5a81d3a200..6bb34fc1ff226eeba1f0f791867020ce9c9a36ae 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2353,6 +2353,9 @@ void btrfs_free_block_rsv(struct btrfs_root *root,
 int btrfs_block_rsv_add(struct btrfs_root *root,
 			struct btrfs_block_rsv *block_rsv,
 			u64 num_bytes);
+int btrfs_block_rsv_add_noflush(struct btrfs_root *root,
+				struct btrfs_block_rsv *block_rsv,
+				u64 num_bytes);
 int btrfs_block_rsv_check(struct btrfs_root *root,
 			  struct btrfs_block_rsv *block_rsv, int min_factor);
 int btrfs_block_rsv_refill(struct btrfs_root *root,
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index fc4026af72901f349f79dd5ed9d426f7bd8730a5..bbe8496d5339f24a5939ceb32778338f06869a49 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -624,13 +624,36 @@ static int btrfs_delayed_inode_reserve_metadata(
 	u64 num_bytes;
 	int ret;
 
-	if (!trans->bytes_reserved)
-		return 0;
-
 	src_rsv = trans->block_rsv;
 	dst_rsv = &root->fs_info->delayed_block_rsv;
 
 	num_bytes = btrfs_calc_trans_metadata_size(root, 1);
+
+	/*
+	 * btrfs_dirty_inode will update the inode under btrfs_join_transaction
+	 * which doesn't reserve space for speed.  This is a problem since we
+	 * still need to reserve space for this update, so try to reserve the
+	 * space.
+	 *
+	 * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
+	 * we're accounted for.
+	 */
+	if (!trans->bytes_reserved &&
+	    src_rsv != &root->fs_info->delalloc_block_rsv) {
+		ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
+		/*
+		 * Since we're under a transaction reserve_metadata_bytes could
+		 * try to commit the transaction which will make it return
+		 * EAGAIN to make us stop the transaction we have, so return
+		 * ENOSPC instead so that btrfs_dirty_inode knows what to do.
+		 */
+		if (ret == -EAGAIN)
+			ret = -ENOSPC;
+		if (!ret)
+			node->bytes_reserved = num_bytes;
+		return ret;
+	}
+
 	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
 	if (!ret)
 		node->bytes_reserved = num_bytes;
@@ -1686,11 +1709,8 @@ int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
 	}
 
 	ret = btrfs_delayed_inode_reserve_metadata(trans, root, delayed_node);
-	/*
-	 * we must reserve enough space when we start a new transaction,
-	 * so reserving metadata failure is impossible
-	 */
-	BUG_ON(ret);
+	if (ret)
+		goto release_node;
 
 	fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
 	delayed_node->inode_dirty = 1;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 5b84205e76851e9fcedc2f9a95ab9766154db888..23e936c3de76aaed14cb364c8dae89049ae3ea63 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3814,6 +3814,24 @@ int btrfs_block_rsv_add(struct btrfs_root *root,
 	return ret;
 }
 
+int btrfs_block_rsv_add_noflush(struct btrfs_root *root,
+				struct btrfs_block_rsv *block_rsv,
+				u64 num_bytes)
+{
+	int ret;
+
+	if (num_bytes == 0)
+		return 0;
+
+	ret = reserve_metadata_bytes(root, block_rsv, num_bytes, 0);
+	if (!ret) {
+		block_rsv_add_bytes(block_rsv, num_bytes, 1);
+		return 0;
+	}
+
+	return ret;
+}
+
 int btrfs_block_rsv_check(struct btrfs_root *root,
 			  struct btrfs_block_rsv *block_rsv, int min_factor)
 {