xfs: fold xfs_attr_get_int into xfs_attr_get

This allows doing an unlocked check if an attr for is present at all and
slightly reduce the lock hold time if we actually do an attr get.

Plus various minor style fixes to the new xfs_attr_get.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_attr.c

@@ -106,26 +106,34 @@ xfs_inode_hasattr(
  * Overall external interface routines.
  *========================================================================*/
 
-STATIC int
-xfs_attr_get_int(
+int
+xfs_attr_get(
 	struct xfs_inode	*ip,
-	struct xfs_name		*name,
+	const unsigned char	*name,
 	unsigned char		*value,
 	int			*valuelenp,
 	int			flags)
 {
-	xfs_da_args_t   args;
-	int             error;
+	struct xfs_da_args	args;
+	struct xfs_name		xname;
+	uint			lock_mode;
+	int			error;
+
+	XFS_STATS_INC(xs_attr_get);
+
+	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+		return EIO;
 
 	if (!xfs_inode_hasattr(ip))
 		return ENOATTR;
 
-	/*
-	 * Fill in the arg structure for this request.
-	 */
-	memset((char *)&args, 0, sizeof(args));
-	args.name = name->name;
-	args.namelen = name->len;
+	error = xfs_attr_name_to_xname(&xname, name);
+	if (error)
+		return error;
+
+	memset(&args, 0, sizeof(args));
+	args.name = xname.name;
+	args.namelen = xname.len;
 	args.value = value;
 	args.valuelen = *valuelenp;
 	args.flags = flags;
@@ -133,52 +141,19 @@ xfs_attr_get_int(
 	args.dp = ip;
 	args.whichfork = XFS_ATTR_FORK;
 
-	/*
-	 * Decide on what work routines to call based on the inode size.
-	 */
-	if (ip->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
+	lock_mode = xfs_ilock_attr_map_shared(ip);
+	if (!xfs_inode_hasattr(ip))
+		error = ENOATTR;
+	else if (ip->i_d.di_aformat == XFS_DINODE_FMT_LOCAL)
 		error = xfs_attr_shortform_getvalue(&args);
-	} else if (xfs_bmap_one_block(ip, XFS_ATTR_FORK)) {
+	else if (xfs_bmap_one_block(ip, XFS_ATTR_FORK))
 		error = xfs_attr_leaf_get(&args);
-	} else {
+	else
 		error = xfs_attr_node_get(&args);
-	}
+	xfs_iunlock(ip, lock_mode);
 
-	/*
-	 * Return the number of bytes in the value to the caller.
-	 */
 	*valuelenp = args.valuelen;
-
-	if (error == EEXIST)
-		error = 0;
-	return(error);
-}
-
-int
-xfs_attr_get(
-	xfs_inode_t	*ip,
-	const unsigned char *name,
-	unsigned char	*value,
-	int		*valuelenp,
-	int		flags)
-{
-	int		error;
-	struct xfs_name	xname;
-	uint		lock_mode;
-
-	XFS_STATS_INC(xs_attr_get);
-
-	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
-		return(EIO);
-
-	error = xfs_attr_name_to_xname(&xname, name);
-	if (error)
-		return error;
-
-	lock_mode = xfs_ilock_attr_map_shared(ip);
-	error = xfs_attr_get_int(ip, &xname, value, valuelenp, flags);
-	xfs_iunlock(ip, lock_mode);
-	return(error);
+	return error == EEXIST ? 0 : error;
 }
 
 /*