xfs: calculate XFS_TRANS_QM_SBCHANGE space log reservation at mount time

The transaction log space for clearing/reseting the quota flags
is calculated out at runtime, this patch can figure it out at
mount time.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index a81625c..6ba62c0 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -546,6 +546,17 @@
 }
 
 /*
+ * Clearing the quotaflags in the superblock.
+ *	the super block for changing quota flags: sector size
+ */
+STATIC uint
+xfs_calc_qm_sbchange_reservation(
+	struct xfs_mount	*mp)
+{
+	return xfs_calc_buf_res(1, mp->m_sb.sb_sectsize);
+}
+
+/*
  * Initialize the precomputed transaction reservation values
  * in the mount structure.
  */
@@ -576,6 +587,7 @@
 	resp->tr_growrtalloc = xfs_calc_growrtalloc_reservation(mp);
 	resp->tr_growrtzero = xfs_calc_growrtzero_reservation(mp);
 	resp->tr_growrtfree = xfs_calc_growrtfree_reservation(mp);
+	resp->tr_qm_sbchange = xfs_calc_qm_sbchange_reservation(mp);
 }
 
 /*