xfs: calcuate XFS_TRANS_QM_SETQLIM space log reservation at mount time

For adjusting quota limits transactions, we calculate out the log space
reservation at runtime, this patch does it 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.h

@@ -41,6 +41,7 @@ typedef struct xfs_trans_reservations {
 	uint	tr_growrtzero;	/* grow realtime zeroing */
 	uint	tr_growrtfree;	/* grow realtime freeing */
 	uint	tr_qm_sbchange;	/* change quota flags */
+	uint	tr_qm_setqlim;	/* adjust quota limits */
 } xfs_trans_reservations_t;
 
 #ifndef __KERNEL__

fs/xfs/xfs_qm_syscalls.c

@@ -490,8 +490,9 @@ xfs_qm_scall_setqlim(
 		return 0;
 
 	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SETQLIM);
-	if ((error = xfs_trans_reserve(tp, 0, sizeof(xfs_disk_dquot_t) + 128,
-				      0, 0, XFS_DEFAULT_LOG_COUNT))) {
+	error = xfs_trans_reserve(tp, 0, XFS_QM_SETQLIM_LOG_RES(mp),
+				  0, 0, XFS_DEFAULT_LOG_COUNT);
+	if (error) {
 		xfs_trans_cancel(tp, 0);
 		return (error);
 	}

fs/xfs/xfs_trans.c

@@ -556,6 +556,17 @@ xfs_calc_qm_sbchange_reservation(
 	return xfs_calc_buf_res(1, mp->m_sb.sb_sectsize);
 }
 
+/*
+ * Adjusting quota limits.
+ *    the xfs_disk_dquot_t: sizeof(struct xfs_disk_dquot)
+ */
+STATIC uint
+xfs_calc_qm_setqlim_reservation(
+	struct xfs_mount	*mp)
+{
+	return xfs_calc_buf_res(1, sizeof(struct xfs_disk_dquot));
+}
+
 /*
  * Initialize the precomputed transaction reservation values
  * in the mount structure.
@@ -588,6 +599,7 @@ xfs_trans_init(
 	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);
+	resp->tr_qm_setqlim = xfs_calc_qm_setqlim_reservation(mp);
 }
 
 /*

fs/xfs/xfs_trans.h

@@ -263,6 +263,7 @@ struct xfs_log_item_desc {
 #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)
+#define XFS_QM_SETQLIM_LOG_RES(mp)	((mp)->m_reservations.tr_qm_setqlim)
 
 /*
  * Various log count values.