[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, 2 deletions

diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c
index 459d36480b16..19a1f077dbd6 100644
--- a/fs/xfs/linux-2.6/xfs_lrw.c
+++ b/fs/xfs/linux-2.6/xfs_lrw.c
@@ -202,7 +202,7 @@ xfs_read(
 
         if (unlikely(ioflags & IO_ISDIRECT)) {
                 xfs_buftarg_t   *target =
-                        (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) ?
+                        XFS_IS_REALTIME_INODE(ip) ?
                                 mp->m_rtdev_targp : mp->m_ddev_targp;
                 if ((*offset & target->bt_smask) ||
                     (size & target->bt_smask)) {
@@ -657,7 +657,7 @@ start:
 
         if (ioflags & IO_ISDIRECT) {
                 xfs_buftarg_t   *target =
-                        (xip->i_d.di_flags & XFS_DIFLAG_REALTIME) ?
+                        XFS_IS_REALTIME_INODE(xip) ?
                                 mp->m_rtdev_targp : mp->m_ddev_targp;
 
                 if ((pos & target->bt_smask) || (count & target->bt_smask)) {