diff --git a/fs/xfs/xfs_attr.c b/fs/xfs/xfs_attr.c
index aaf472532b3c..888683844d98 100644
--- a/fs/xfs/xfs_attr.c
+++ b/fs/xfs/xfs_attr.c
@@ -300,9 +300,12 @@ xfs_attr_set_int(
 	if (rsvd)
 		args.trans->t_flags |= XFS_TRANS_RESERVE;
 
-	if ((error = xfs_trans_reserve(args.trans, args.total,
-			XFS_ATTRSET_LOG_RES(mp, args.total), 0,
-			XFS_TRANS_PERM_LOG_RES, XFS_ATTRSET_LOG_COUNT))) {
+	error = xfs_trans_reserve(args.trans, args.total,
+				  XFS_ATTRSETM_LOG_RES(mp) +
+				  XFS_ATTRSETRT_LOG_RES(mp) * args.total,
+				  0, XFS_TRANS_PERM_LOG_RES,
+				  XFS_ATTRSET_LOG_COUNT);
+	if (error) {
 		xfs_trans_cancel(args.trans, 0);
 		return(error);
 	}
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 2e30a9a84f9f..bc907061d392 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -34,7 +34,8 @@ typedef struct xfs_trans_reservations {
 	uint	tr_addafork;	/* cvt inode to attributed trans */
 	uint	tr_writeid;	/* write setuid/setgid file */
 	uint	tr_attrinval;	/* attr fork buffer invalidation */
-	uint	tr_attrset;	/* set/create an attribute */
+	uint	tr_attrsetm;	/* set/create an attribute at mount time */
+	uint	tr_attrsetrt;	/* set/create an attribute at runtime */
 	uint	tr_attrrm;	/* remove an attribute */
 	uint	tr_clearagi;	/* clear bad agi unlinked ino bucket */
 	uint	tr_growrtalloc;	/* grow realtime allocations */
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 72da2aa08421..2fd7c1ff1d21 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -489,17 +489,18 @@ xfs_calc_attrinval_reservation(
 }
 
 /*
- * Setting an attribute.
+ * Setting an attribute at mount time.
  *	the inode getting the attribute
  *	the superblock for allocations
  *	the agfs extents are allocated from
  *	the attribute btree * max depth
  *	the inode allocation btree
  * Since attribute transaction space is dependent on the size of the attribute,
- * the calculation is done partially at mount time and partially at runtime.
+ * the calculation is done partially at mount time and partially at runtime(see
+ * below).
  */
 STATIC uint
-xfs_calc_attrset_reservation(
+xfs_calc_attrsetm_reservation(
 	struct xfs_mount	*mp)
 {
 	return XFS_DQUOT_LOGRES(mp) +
@@ -508,6 +509,24 @@ xfs_calc_attrset_reservation(
 		xfs_calc_buf_res(XFS_DA_NODE_MAXDEPTH, XFS_FSB_TO_B(mp, 1));
 }
 
+/*
+ * Setting an attribute at runtime, transaction space unit per block.
+ * 	the superblock for allocations: sector size
+ *	the inode bmap btree could join or split: max depth * block size
+ * Since the runtime attribute transaction space is dependent on the total
+ * blocks needed for the 1st bmap, here we calculate out the space unit for
+ * one block so that the caller could figure out the total space according
+ * to the attibute extent length in blocks by: ext * XFS_ATTRSETRT_LOG_RES(mp).
+ */
+STATIC uint
+xfs_calc_attrsetrt_reservation(
+	struct xfs_mount	*mp)
+{
+	return xfs_calc_buf_res(1, mp->m_sb.sb_sectsize) +
+		xfs_calc_buf_res(XFS_BM_MAXLEVELS(mp, XFS_ATTR_FORK),
+				 XFS_FSB_TO_B(mp, 1));
+}
+
 /*
  * Removing an attribute.
  *    the inode: inode size
@@ -641,7 +660,8 @@ xfs_trans_init(
 	resp->tr_writeid = xfs_calc_writeid_reservation(mp);
 	resp->tr_addafork = xfs_calc_addafork_reservation(mp);
 	resp->tr_attrinval = xfs_calc_attrinval_reservation(mp);
-	resp->tr_attrset = xfs_calc_attrset_reservation(mp);
+	resp->tr_attrsetm = xfs_calc_attrsetm_reservation(mp);
+	resp->tr_attrsetrt = xfs_calc_attrsetrt_reservation(mp);
 	resp->tr_attrrm = xfs_calc_attrrm_reservation(mp);
 	resp->tr_clearagi = xfs_calc_clear_agi_bucket_reservation(mp);
 	resp->tr_growrtalloc = xfs_calc_growrtalloc_reservation(mp);
diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index d06919e28904..cd29f6171021 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -252,15 +252,12 @@ struct xfs_log_item_desc {
  * as long as SWRITE logs the entire inode core
  */
 #define XFS_FSYNC_TS_LOG_RES(mp)        ((mp)->m_reservations.tr_swrite)
-#define	XFS_WRITEID_LOG_RES(mp)	((mp)->m_reservations.tr_swrite)
+#define	XFS_WRITEID_LOG_RES(mp)		((mp)->m_reservations.tr_swrite)
 #define	XFS_ADDAFORK_LOG_RES(mp)	((mp)->m_reservations.tr_addafork)
 #define	XFS_ATTRINVAL_LOG_RES(mp)	((mp)->m_reservations.tr_attrinval)
-#define	XFS_ATTRSET_LOG_RES(mp, ext)	\
-	((mp)->m_reservations.tr_attrset + \
-	 (ext * (mp)->m_sb.sb_sectsize) + \
-	 (ext * XFS_FSB_TO_B((mp), XFS_BM_MAXLEVELS(mp, XFS_ATTR_FORK))) + \
-	 (128 * (ext + (ext * XFS_BM_MAXLEVELS(mp, XFS_ATTR_FORK)))))
-#define	XFS_ATTRRM_LOG_RES(mp)	((mp)->m_reservations.tr_attrrm)
+#define	XFS_ATTRSETM_LOG_RES(mp)	((mp)->m_reservations.tr_attrsetm)
+#define XFS_ATTRSETRT_LOG_RES(mp)	((mp)->m_reservations.tr_attrsetrt)
+#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)