diff --git a/tapset/vfs.stp b/tapset/vfs.stp
index 7f2312d..2ac8256 100644
--- a/tapset/vfs.stp
+++ b/tapset/vfs.stp
@@ -800,6 +800,8 @@ probe vfs.read = kernel.function ("vfs_read")
 	pos = $pos
 	buf = $buf
 	bytes_to_read = $count
+	dev = __file_dev($file)
+	devname = __find_bdevname(dev, __file_bdev($file))
 }
 
 probe vfs.read.return = kernel.function ("vfs_read").return
@@ -808,6 +810,8 @@ probe vfs.read.return = kernel.function ("vfs_read").return
 	pos = $pos
 	buf = $buf
 	bytes_to_read = $count
+	dev = __file_dev($file)
+	devname = __find_bdevname(dev, __file_bdev($file))
 
 	ret = $return
 	bytes_read = ret > 0 ? ret : 0
@@ -844,6 +848,8 @@ probe vfs.write = kernel.function ("vfs_write")
 	pos = $pos
 	buf = $buf
 	bytes_to_write = $count
+	dev = __file_dev($file)
+	devname = __find_bdevname(dev, __file_bdev($file))
 }
 
 probe vfs.write.return = kernel.function ("vfs_write").return
@@ -852,6 +858,8 @@ probe vfs.write.return = kernel.function ("vfs_write").return
 	pos = $pos
 	buf = $buf
 	bytes_to_write = $count
+	dev = __file_dev($file)
+	devname = __find_bdevname(dev, __file_bdev($file))
 
 	ret = $return
 	bytes_written = ret > 0 ? ret : 0
diff --git a/testsuite/systemtap.examples/io/disktop.stp b/testsuite/systemtap.examples/io/disktop.stp
index e2c4fc3..20462f0 100755
--- a/testsuite/systemtap.examples/io/disktop.stp
+++ b/testsuite/systemtap.examples/io/disktop.stp
@@ -16,9 +16,6 @@ global read_bytes,write_bytes
 
 probe vfs.read.return {
 	if ($return>0) {
-		dev = __file_dev($file)
-		devname = __find_bdevname(dev,__file_bdev($file))
-
 		if (devname!="N/A") {/*skip read from cache*/
 			io_stat[pid(),execname(),uid(),ppid(),"R"] += $return
 			device[pid(),execname(),uid(),ppid(),"R"] = devname
@@ -29,9 +26,6 @@ probe vfs.read.return {
 
 probe vfs.write.return {
 	if ($return>0) {
-		dev = __file_dev($file)
-		devname = __find_bdevname(dev,__file_bdev($file))
-
 		if (devname!="N/A") { /*skip update cache*/
 			io_stat[pid(),execname(),uid(),ppid(),"W"] += $return
 			device[pid(),execname(),uid(),ppid(),"W"] = devname
@@ -43,16 +37,21 @@ probe vfs.write.return {
 probe timer.ms(5000) {
 	/* skip non-read/write disk */
 	if (read_bytes+write_bytes) {
-
-		printf("\n%-25s, %-8s%4dKb/sec, %-7s%6dKb, %-7s%6dKb\n\n",ctime(gettimeofday_s()),"Average:",
-      		((read_bytes+write_bytes)/1024)/5,"Read:",read_bytes/1024,"Write:",write_bytes/1024)
+		printf("\n%-25s, %-8s%4dKb/sec, %-7s%6dKb, %-7s%6dKb\n\n",
+				 ctime(gettimeofday_s()),"Average:",
+      		((read_bytes+write_bytes)/1024)/5,"Read:",
+				read_bytes/1024,"Write:",write_bytes/1024)
 
 		/* print header */
-		printf("%8s %8s %8s %25s %8s %4s %12s\n","UID","PID","PPID","CMD","DEVICE","T","BYTES")
+		printf("%8s %8s %8s %25s %8s %4s %12s\n",
+			    "UID","PID","PPID","CMD","DEVICE","T","BYTES")
 	}
 	/* print top ten I/O */
 	foreach ([process,cmd,userid,parent,action] in io_stat- limit 10)
-	  printf("%8d %8d %8d %25s %8s %4s %12d\n",userid,process,parent,cmd,device[process,cmd,userid,parent,action],action,io_stat[process,cmd,userid,parent,action])
+	  printf("%8d %8d %8d %25s %8s %4s %12d\n",
+	  	      userid,process,parent,cmd,
+		      device[process,cmd,userid,parent,action],
+		      action,io_stat[process,cmd,userid,parent,action])
 
 	/* clear data */
 	delete io_stat