xfs: Add helper xfs_attr_node_addname_find_attr

This patch separates the first half of xfs_attr_node_addname into a
helper function xfs_attr_node_addname_find_attr.  It also replaces the
restart goto with an EAGAIN return code driven by a loop in the calling
function.  This looks odd now, but will clean up nicly once we introduce
the state machine.  It will also enable hoisting the last state out of
xfs_attr_node_addname with out having to plumb in a "done" parameter to
know if we need to move to the next state or not.
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>

fs/xfs/libxfs/xfs_attr.c

@@ -52,7 +52,10 @@ STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp);
  * Internal routines when attribute list is more than one block.
  */
 STATIC int xfs_attr_node_get(xfs_da_args_t *args);
-STATIC int xfs_attr_node_addname(xfs_da_args_t *args);
+STATIC int xfs_attr_node_addname(struct xfs_da_args *args,
+				 struct xfs_da_state *state);
+STATIC int xfs_attr_node_addname_find_attr(struct xfs_da_args *args,
+				 struct xfs_da_state **state);
 STATIC int xfs_attr_node_removename(xfs_da_args_t *args);
 STATIC int xfs_attr_node_addname_clear_incomplete(struct xfs_da_args *args);
 STATIC int xfs_attr_node_hasname(xfs_da_args_t *args,
@@ -287,6 +290,7 @@ xfs_attr_set_args(
 	struct xfs_da_args	*args)
 {
 	struct xfs_inode	*dp = args->dp;
+	struct xfs_da_state     *state;
 	int			error;
 
 	/*
@@ -332,7 +336,14 @@ xfs_attr_set_args(
 			return error;
 	}
 
-	return xfs_attr_node_addname(args);
+	do {
+		error = xfs_attr_node_addname_find_attr(args, &state);
+		if (error)
+			return error;
+		error = xfs_attr_node_addname(args, state);
+	} while (error == -EAGAIN);
+
+	return error;
 }
 
 /*
@@ -896,48 +907,26 @@ xfs_attr_node_hasname(
  * External routines when attribute list size > geo->blksize
  *========================================================================*/
 
-/*
- * Add a name to a Btree-format attribute list.
- *
- * This will involve walking down the Btree, and may involve splitting
- * leaf nodes and even splitting intermediate nodes up to and including
- * the root node (a special case of an intermediate node).
- *
- * "Remote" attribute values confuse the issue and atomic rename operations
- * add a whole extra layer of confusion on top of that.
- */
 STATIC int
-xfs_attr_node_addname(
-	struct xfs_da_args	*args)
+xfs_attr_node_addname_find_attr(
+	struct xfs_da_args	*args,
+	struct xfs_da_state     **state)
 {
-	struct xfs_da_state	*state;
-	struct xfs_da_state_blk	*blk;
-	struct xfs_inode	*dp;
-	int			retval, error;
-
-	trace_xfs_attr_node_addname(args);
+	int			retval;
 
-	/*
-	 * Fill in bucket of arguments/results/context to carry around.
-	 */
-	dp = args->dp;
-restart:
 	/*
 	 * Search to see if name already exists, and get back a pointer
 	 * to where it should go.
 	 */
-	error = 0;
-	retval = xfs_attr_node_hasname(args, &state);
+	retval = xfs_attr_node_hasname(args, state);
 	if (retval != -ENOATTR && retval != -EEXIST)
-		goto out;
+		goto error;
 
-	blk = &state->path.blk[ state->path.active-1 ];
-	ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
 	if (retval == -ENOATTR && (args->attr_flags & XATTR_REPLACE))
-		goto out;
+		goto error;
 	if (retval == -EEXIST) {
 		if (args->attr_flags & XATTR_CREATE)
-			goto out;
+			goto error;
 
 		trace_xfs_attr_node_replace(args);
 
@@ -955,6 +944,38 @@ xfs_attr_node_addname(
 		args->rmtvaluelen = 0;
 	}
 
+	return 0;
+error:
+	if (*state)
+		xfs_da_state_free(*state);
+	return retval;
+}
+
+/*
+ * Add a name to a Btree-format attribute list.
+ *
+ * This will involve walking down the Btree, and may involve splitting
+ * leaf nodes and even splitting intermediate nodes up to and including
+ * the root node (a special case of an intermediate node).
+ *
+ * "Remote" attribute values confuse the issue and atomic rename operations
+ * add a whole extra layer of confusion on top of that.
+ */
+STATIC int
+xfs_attr_node_addname(
+	struct xfs_da_args	*args,
+	struct xfs_da_state	*state)
+{
+	struct xfs_da_state_blk	*blk;
+	struct xfs_inode	*dp;
+	int			retval, error;
+
+	trace_xfs_attr_node_addname(args);
+
+	dp = args->dp;
+	blk = &state->path.blk[state->path.active-1];
+	ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
+
 	retval = xfs_attr3_leaf_add(blk->bp, state->args);
 	if (retval == -ENOSPC) {
 		if (state->path.active == 1) {
@@ -980,7 +1001,7 @@ xfs_attr_node_addname(
 			if (error)
 				goto out;
 
-			goto restart;
+			return -EAGAIN;
 		}
 
 		/*