[XFS] Fix UP build breakage due to undefined m_icsb_mutex.

SGI-PV: 952227
SGI-Modid: xfs-linux-melb:xfs-kern:27692a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index a2295df..416c89f 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -18,6 +18,7 @@
 #ifndef __XFS_MOUNT_H__
 #define	__XFS_MOUNT_H__
 
+
 typedef struct xfs_trans_reservations {
 	uint	tr_write;	/* extent alloc trans */
 	uint	tr_itruncate;	/* truncate trans */
@@ -564,6 +565,26 @@
 }
 
 /*
+ * Per-cpu superblock locking functions
+ */
+#ifdef HAVE_PERCPU_SB
+STATIC_INLINE void
+xfs_icsb_lock(xfs_mount_t *mp)
+{
+	mutex_lock(&mp->m_icsb_mutex);
+}
+
+STATIC_INLINE void
+xfs_icsb_unlock(xfs_mount_t *mp)
+{
+	mutex_unlock(&mp->m_icsb_mutex);
+}
+#else
+#define xfs_icsb_lock(mp)
+#define xfs_icsb_unlock(mp)
+#endif
+
+/*
  * This structure is for use by the xfs_mod_incore_sb_batch() routine.
  */
 typedef struct xfs_mod_sb {