[XFS] Add support for hotplug CPUs to the per-CPU superblock counters by

registering a notifier callback that listens to CPU up/down events to
modify the counters appropriately.

SGI-PV: 949726
SGI-Modid: xfs-linux-melb:xfs-kern:25214a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 7cca5110ca44..9d2ffbdc37a9 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -401,6 +401,7 @@ typedef struct xfs_mount {
 #ifdef HAVE_PERCPU_SB
         xfs_icsb_cnts_t         *m_sb_cnts;     /* per-cpu superblock counters */
         unsigned long           m_icsb_counters; /* disabled per-cpu counters */
+        struct notifier_block   m_icsb_notifier; /* hotplug cpu notifier */
 #endif
 } xfs_mount_t;