[PATCH 5/6] xfs: refactor setflags to use setattr code directly

["Darrick J. Wong" <darrick.wong@oracle.com>]

From: Darrick J. Wong <darrick.wong@oracle.com>

Refactor the SETFLAGS implementation to use the SETXATTR code directly
instead of partially constructing a struct fsxattr and calling bits and
pieces of the setxattr code.  This reduces code size and becomes
necessary in the next patch to maintain the behavior of allowing
userspace to set immutable on an immutable file so long as nothing
/else/ about the attributes change.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/xfs_ioctl.c |   40 +++-------------------------------------
 1 file changed, 3 insertions(+), 37 deletions(-)


diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 88583b3e1e76..7b19ba2956ad 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1491,11 +1491,8 @@ xfs_ioc_setxflags(
 	struct file		*filp,
 	void			__user *arg)
 {
-	struct xfs_trans	*tp;
 	struct fsxattr		fa;
-	struct fsxattr		old_fa;
 	unsigned int		flags;
-	int			join_flags = 0;
 	int			error;
 
 	if (copy_from_user(&flags, arg, sizeof(flags)))
@@ -1506,44 +1503,13 @@ xfs_ioc_setxflags(
 		      FS_SYNC_FL))
 		return -EOPNOTSUPP;
 
-	fa.fsx_xflags = xfs_merge_ioc_xflags(flags, xfs_ip2xflags(ip));
+	__xfs_ioc_fsgetxattr(ip, false, &fa);
+	fa.fsx_xflags = xfs_merge_ioc_xflags(flags, fa.fsx_xflags);
 
 	error = mnt_want_write_file(filp);
 	if (error)
 		return error;
-
-	/*
-	 * Changing DAX config may require inode locking for mapping
-	 * invalidation. These need to be held all the way to transaction commit
-	 * or cancel time, so need to be passed through to
-	 * xfs_ioctl_setattr_get_trans() so it can apply them to the join call
-	 * appropriately.
-	 */
-	error = xfs_ioctl_setattr_dax_invalidate(ip, &fa, &join_flags);
-	if (error)
-		goto out_drop_write;
-
-	tp = xfs_ioctl_setattr_get_trans(ip, join_flags);
-	if (IS_ERR(tp)) {
-		error = PTR_ERR(tp);
-		goto out_drop_write;
-	}
-
-	__xfs_ioc_fsgetxattr(ip, false, &old_fa);
-	error = vfs_ioc_fssetxattr_check(VFS_I(ip), &old_fa, &fa);
-	if (error) {
-		xfs_trans_cancel(tp);
-		goto out_drop_write;
-	}
-
-	error = xfs_ioctl_setattr_xflags(tp, ip, &fa);
-	if (error) {
-		xfs_trans_cancel(tp);
-		goto out_drop_write;
-	}
-
-	error = xfs_trans_commit(tp);
-out_drop_write:
+	error = xfs_ioctl_setattr(ip, &fa);
 	mnt_drop_write_file(filp);
 	return error;
 }