xfs: store xfs_mount in the buftarg instead of in the xfs_buf

Each buffer contains both a buftarg pointer and a mount pointer. If
we add a mount pointer into the buftarg, we can avoid needing the
b_mount field in every buffer and grab it from the buftarg when
needed instead. This shrinks the xfs_buf by 8 bytes.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 83154c0a3175..4759be4daa26 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -758,18 +758,20 @@ xfs_open_devices(
          * Setup xfs_mount buffer target pointers
          */
         error = ENOMEM;
-        mp->m_ddev_targp = xfs_alloc_buftarg(ddev, 0, mp->m_fsname);
+        mp->m_ddev_targp = xfs_alloc_buftarg(mp, ddev, 0, mp->m_fsname);
         if (!mp->m_ddev_targp)
                 goto out_close_rtdev;
 
         if (rtdev) {
-                mp->m_rtdev_targp = xfs_alloc_buftarg(rtdev, 1, mp->m_fsname);
+                mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev, 1,
+                                                        mp->m_fsname);
                 if (!mp->m_rtdev_targp)
                         goto out_free_ddev_targ;
         }
 
         if (logdev && logdev != ddev) {
-                mp->m_logdev_targp = xfs_alloc_buftarg(logdev, 1, mp->m_fsname);
+                mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev, 1,
+                                                        mp->m_fsname);
                 if (!mp->m_logdev_targp)
                         goto out_free_rtdev_targ;
         } else {