xfs: factor projid hint checking out of xfs_ioctl_setattr

The project ID change checking is one of the few remaining open
coded checks in xfs_ioctl_setattr(). Factor it into a helper
function so that the setattr code mostly becomes a flow of check
and action helpers, making it easier to read and follow.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_ioctl.c

@@ -1142,24 +1142,12 @@ xfs_ioctl_setattr_check_extsize(
 	return 0;
 }
 
-
-STATIC int
-xfs_ioctl_setattr(
-	xfs_inode_t		*ip,
+int
+xfs_ioctl_setattr_check_projid(
+	struct xfs_inode	*ip,
 	struct fsxattr		*fa)
 {
-	struct xfs_mount	*mp = ip->i_mount;
-	struct xfs_trans	*tp;
-	struct xfs_dquot	*udqp = NULL;
-	struct xfs_dquot	*pdqp = NULL;
-	struct xfs_dquot	*olddquot = NULL;
-	int			code;
-
-	trace_xfs_ioctl_setattr(ip);
-
-	/*
-	 * Disallow 32bit project ids when projid32bit feature is not enabled.
-	 */
+	/* Disallow 32bit project ids if projid32bit feature is not enabled. */
 	if (fa->fsx_projid > (__uint16_t)-1 &&
 	    !xfs_sb_version_hasprojid32bit(&ip->i_mount->m_sb))
 		return -EINVAL;
@@ -1169,13 +1157,37 @@ xfs_ioctl_setattr(
 	 * namespace. Enforce that restriction only if we are trying to change
 	 * the quota ID state. Everything else is allowed in user namespaces.
 	 */
-	if (current_user_ns() != &init_user_ns) {
+	if (current_user_ns() == &init_user_ns)
+		return 0;
+
 	if (xfs_get_projid(ip) != fa->fsx_projid)
 		return -EINVAL;
 	if ((fa->fsx_xflags & XFS_XFLAG_PROJINHERIT) !=
 	    (ip->i_d.di_flags & XFS_DIFLAG_PROJINHERIT))
 		return -EINVAL;
-	}
+
+	return 0;
+}
+
+
+
+STATIC int
+xfs_ioctl_setattr(
+	xfs_inode_t		*ip,
+	struct fsxattr		*fa)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_trans	*tp;
+	struct xfs_dquot	*udqp = NULL;
+	struct xfs_dquot	*pdqp = NULL;
+	struct xfs_dquot	*olddquot = NULL;
+	int			code;
+
+	trace_xfs_ioctl_setattr(ip);
+
+	code = xfs_ioctl_setattr_check_projid(ip, fa);
+	if (code)
+		return code;
 
 	/*
 	 * If disk quotas is on, we make sure that the dquots do exist on disk,