[XFS] optimize XFS_IS_REALTIME_INODE w/o realtime config

Use XFS_IS_REALTIME_INODE in more places, and #define it to 0 if
CONFIG_XFS_RT is off. This should be safe because mount checks in
xfs_rtmount_init:

so if we get mounted w/o CONFIG_XFS_RT, no realtime inodes should be
encountered after that.

Defining XFS_IS_REALTIME_INODE to 0 saves a bit of stack space,
presumeably gcc can optimize around the various "if (0)" type checks:

xfs_alloc_file_space -8 xfs_bmap_adjacent -16 xfs_bmapi -8
xfs_bmap_rtalloc -16 xfs_bunmapi -28 xfs_free_file_space -64 xfs_imap +8
<-- ? hmm. xfs_iomap_write_direct -12 xfs_qm_dqusage_adjust -4
xfs_qm_vop_chown_reserve -4

SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30014a

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/xfs/xfs_dfrag.c b/fs/xfs/xfs_dfrag.c
index 4ad29cbb4233..03a42d21610a 100644
--- a/fs/xfs/xfs_dfrag.c
+++ b/fs/xfs/xfs_dfrag.c
@@ -185,8 +185,7 @@ xfs_swap_extents(
         }
 
         /* Verify both files are either real-time or non-realtime */
-        if ((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) !=
-            (tip->i_d.di_flags & XFS_DIFLAG_REALTIME)) {
+        if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
                 error = XFS_ERROR(EINVAL);
                 goto error0;
         }