xfs: calculate XFS_TRANS_QM_QUOTAOFF_END space log reservation at mount time

Convert the calculation for end of quotaoff log space reservation
from runtime to 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_mount.h b/fs/xfs/xfs_mount.h
index 4f5e148..b46009d 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -44,6 +44,7 @@
 	uint	tr_qm_setqlim;	/* adjust quota limits */
 	uint	tr_qm_dqalloc;	/* allocate quota on disk */
 	uint	tr_qm_quotaoff;	/* turn quota off */
+	uint	tr_qm_equotaoff;/* end of turn quota off */
 } xfs_trans_reservations_t;
 
 #ifndef __KERNEL__
diff --git a/fs/xfs/xfs_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c
index 4605f89..cf9a340 100644
--- a/fs/xfs/xfs_qm_syscalls.c
+++ b/fs/xfs/xfs_qm_syscalls.c
@@ -639,8 +639,9 @@
 
 	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_QUOTAOFF_END);
 
-	if ((error = xfs_trans_reserve(tp, 0, sizeof(xfs_qoff_logitem_t) * 2,
-				      0, 0, XFS_DEFAULT_LOG_COUNT))) {
+	error = xfs_trans_reserve(tp, 0, XFS_QM_QUOTAOFF_END_LOG_RES(mp),
+				  0, 0, XFS_DEFAULT_LOG_COUNT);
+	if (error) {
 		xfs_trans_cancel(tp, 0);
 		return (error);
 	}
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index a557c82..84643fa 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -595,6 +595,17 @@
 }
 
 /*
+ * End of turning off quotas.
+ *    the xfs_qoff_logitem_t: sizeof(struct xfs_qoff_logitem) * 2
+ */
+STATIC uint
+xfs_calc_qm_quotaoff_end_reservation(
+	struct xfs_mount	*mp)
+{
+	return sizeof(struct xfs_qoff_logitem) * 2;
+}
+
+/*
  * Initialize the precomputed transaction reservation values
  * in the mount structure.
  */
@@ -629,6 +640,7 @@
 	resp->tr_qm_setqlim = xfs_calc_qm_setqlim_reservation(mp);
 	resp->tr_qm_dqalloc = xfs_calc_qm_dqalloc_reservation(mp);
 	resp->tr_qm_quotaoff = xfs_calc_qm_quotaoff_reservation(mp);
+	resp->tr_qm_equotaoff = xfs_calc_qm_quotaoff_end_reservation(mp);
 }
 
 /*
diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index 1e103da..57339e4 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -266,6 +266,7 @@
 #define XFS_QM_SETQLIM_LOG_RES(mp)	((mp)->m_reservations.tr_qm_setqlim)
 #define XFS_QM_DQALLOC_LOG_RES(mp)	((mp)->m_reservations.tr_qm_dqalloc)
 #define XFS_QM_QUOTAOFF_LOG_RES(mp)	((mp)->m_reservations.tr_qm_quotaoff)
+#define XFS_QM_QUOTAOFF_END_LOG_RES(mp)	((mp)->m_reservations.tr_qm_equotaoff)
 
 /*
  * Various log count values.