xfs: Split apart xfs_attr_leaf_addname

Split out new helper function xfs_attr_leaf_try_add from
xfs_attr_leaf_addname. Because new delayed attribute routines cannot
roll transactions, we split off the parts of xfs_attr_leaf_addname that
we can use, and move the commit into the calling function.
Signed-off-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/libxfs/xfs_attr.c

@@ -256,10 +256,31 @@ xfs_attr_set_args(
 		}
 	}
 
-	if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
+	if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
 		error = xfs_attr_leaf_addname(args);
-	else
-		error = xfs_attr_node_addname(args);
+		if (error != -ENOSPC)
+			return error;
+
+		/*
+		 * Finish any deferred work items and roll the transaction once
+		 * more.  The goal here is to call node_addname with the inode
+		 * and transaction in the same state (inode locked and joined,
+		 * transaction clean) no matter how we got to this step.
+		 */
+		error = xfs_defer_finish(&args->trans);
+		if (error)
+			return error;
+
+		/*
+		 * Commit the current trans (including the inode) and
+		 * start a new one.
+		 */
+		error = xfs_trans_roll_inode(&args->trans, dp);
+		if (error)
+			return error;
+	}
+
+	error = xfs_attr_node_addname(args);
 	return error;
 }
 
@@ -507,20 +528,21 @@ xfs_attr_shortform_addname(xfs_da_args_t *args)
  *========================================================================*/
 
 /*
- * Add a name to the leaf attribute list structure
+ * Tries to add an attribute to an inode in leaf form
  *
- * This leaf block cannot have a "remote" value, we only call this routine
- * if bmap_one_block() says there is only one block (ie: no remote blks).
+ * This function is meant to execute as part of a delayed operation and leaves
+ * the transaction handling to the caller.  On success the attribute is added
+ * and the inode and transaction are left dirty.  If there is not enough space,
+ * the attr data is converted to node format and -ENOSPC is returned. Caller is
+ * responsible for handling the dirty inode and transaction or adding the attr
+ * in node format.
  */
 STATIC int
-xfs_attr_leaf_addname(
-	struct xfs_da_args	*args)
+xfs_attr_leaf_try_add(
+	struct xfs_da_args	*args,
+	struct xfs_buf		*bp)
 {
-	struct xfs_buf		*bp;
-	int			retval, error, forkoff;
-	struct xfs_inode	*dp = args->dp;
-
-	trace_xfs_attr_leaf_addname(args);
+	int			retval, error;
 
 	/*
 	 * Look up the given attribute in the leaf block.  Figure out if
@@ -562,31 +584,39 @@ xfs_attr_leaf_addname(
 	retval = xfs_attr3_leaf_add(bp, args);
 	if (retval == -ENOSPC) {
 		/*
-		 * Promote the attribute list to the Btree format, then
-		 * Commit that transaction so that the node_addname() call
-		 * can manage its own transactions.
+		 * Promote the attribute list to the Btree format. Unless an
+		 * error occurs, retain the -ENOSPC retval
 		 */
 		error = xfs_attr3_leaf_to_node(args);
 		if (error)
 			return error;
-		error = xfs_defer_finish(&args->trans);
-		if (error)
-			return error;
+	}
+	return retval;
+out_brelse:
+	xfs_trans_brelse(args->trans, bp);
+	return retval;
+}
 
-		/*
-		 * Commit the current trans (including the inode) and start
-		 * a new one.
-		 */
-		error = xfs_trans_roll_inode(&args->trans, dp);
-		if (error)
-			return error;
 
-		/*
-		 * Fob the whole rest of the problem off on the Btree code.
-		 */
-		error = xfs_attr_node_addname(args);
+/*
+ * Add a name to the leaf attribute list structure
+ *
+ * This leaf block cannot have a "remote" value, we only call this routine
+ * if bmap_one_block() says there is only one block (ie: no remote blks).
+ */
+STATIC int
+xfs_attr_leaf_addname(
+	struct xfs_da_args	*args)
+{
+	int			error, forkoff;
+	struct xfs_buf		*bp = NULL;
+	struct xfs_inode	*dp = args->dp;
+
+	trace_xfs_attr_leaf_addname(args);
+
+	error = xfs_attr_leaf_try_add(args, bp);
+	if (error)
 		return error;
-	}
 
 	/*
 	 * Commit the transaction that added the attr name so that
@@ -681,9 +711,6 @@ xfs_attr_leaf_addname(
 		error = xfs_attr3_leaf_clearflag(args);
 	}
 	return error;
-out_brelse:
-	xfs_trans_brelse(args->trans, bp);
-	return retval;
 }
 
 /*