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>

fs/xfs/xfs_mount.c

@@ -1109,8 +1109,8 @@ xfs_mount_reset_sbqflags(
 		return 0;
 
 	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SBCHANGE);
-	error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
-				      XFS_DEFAULT_LOG_COUNT);
+	error = xfs_trans_reserve(tp, 0, XFS_QM_SBCHANGE_LOG_RES(mp),
+				  0, 0, XFS_DEFAULT_LOG_COUNT);
 	if (error) {
 		xfs_trans_cancel(tp, 0);
 		xfs_alert(mp, "%s: Superblock update failed!", __func__);

fs/xfs/xfs_mount.h

@@ -40,6 +40,7 @@ typedef struct xfs_trans_reservations {
 	uint	tr_growrtalloc;	/* grow realtime allocations */
 	uint	tr_growrtzero;	/* grow realtime zeroing */
 	uint	tr_growrtfree;	/* grow realtime freeing */
+	uint	tr_qm_sbchange;	/* change quota flags */
 } xfs_trans_reservations_t;
 
 #ifndef __KERNEL__

fs/xfs/xfs_trans.c

@@ -545,6 +545,17 @@ xfs_calc_clear_agi_bucket_reservation(
 	return xfs_calc_buf_res(1, mp->m_sb.sb_sectsize);
 }
 
+/*
+ * 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 @@ xfs_trans_init(
 	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);
 }
 
 /*

fs/xfs/xfs_trans.h

@@ -262,7 +262,7 @@ struct xfs_log_item_desc {
 	 (128 * (ext + (ext * XFS_BM_MAXLEVELS(mp, XFS_ATTR_FORK)))))
 #define	XFS_ATTRRM_LOG_RES(mp)	((mp)->m_reservations.tr_attrrm)
 #define	XFS_CLEAR_AGI_BUCKET_LOG_RES(mp)  ((mp)->m_reservations.tr_clearagi)
-
+#define XFS_QM_SBCHANGE_LOG_RES(mp)	((mp)->m_reservations.tr_qm_sbchange)
 
 /*
  * Various log count values.