[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, 2 insertions, 3 deletions

diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index b02452b11456..aca51e7e5c5a 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -2969,7 +2969,7 @@ STATIC int
 xfs_bmap_alloc(
         xfs_bmalloca_t  *ap)            /* bmap alloc argument struct */
 {
-        if ((ap->ip->i_d.di_flags & XFS_DIFLAG_REALTIME) && ap->userdata)
+        if (XFS_IS_REALTIME_INODE(ap->ip) && ap->userdata)
                 return xfs_bmap_rtalloc(ap);
         return xfs_bmap_btalloc(ap);
 }
@@ -3096,8 +3096,7 @@ xfs_bmap_del_extent(
                 /*
                  * Realtime allocation.  Free it and record di_nblocks update.
                  */
-                if (whichfork == XFS_DATA_FORK &&
-                    (ip->i_d.di_flags & XFS_DIFLAG_REALTIME)) {
+                if (whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip)) {
                         xfs_fsblock_t   bno;
                         xfs_filblks_t   len;