s390/dasd: retry partition detection

In case somebody attempted to open the device during online processing the partition detection ioctl may have failed. Added a retry loop to avoid not detected partitions. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/dasd: retry partition detection
In case somebody attempted to open the device during online processing the partition detection ioctl may have failed. Added a retry loop to avoid not detected partitions. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Stefan Haberland · Martin Schwidefsky
1 parent 932f0549f8
Showing 1 changed file with 24 additions and 2 deletions Side-by-side Diff
drivers/s390/block/dasd_genhd.c
@@ -99,15 +99,37 @@
 int dasd_scan_partitions(struct dasd_block *block)
 {
 	struct block_device *bdev;
+	int retry, rc;
  
+	retry = 5;
 	bdev = bdget_disk(block->gdp, 0);
-	if (!bdev || blkdev_get(bdev, FMODE_READ, NULL) < 0)
+	if (!bdev) {
+		DBF_DEV_EVENT(DBF_ERR, block->base, "%s",
+			      "scan partitions error, bdget returned NULL");
 		return -ENODEV;
+	}
+
+	rc = blkdev_get(bdev, FMODE_READ, NULL);
+	if (rc < 0) {
+		DBF_DEV_EVENT(DBF_ERR, block->base,
+			      "scan partitions error, blkdev_get returned %d",
+			      rc);
+		return -ENODEV;
+	}
 	/*
 	 * See fs/partition/check.c:register_disk,rescan_partitions
 	 * Can't call rescan_partitions directly. Use ioctl.
 	 */
-	ioctl_by_bdev(bdev, BLKRRPART, 0);
+	rc = ioctl_by_bdev(bdev, BLKRRPART, 0);
+	while (rc == -EBUSY && retry > 0) {
+		schedule();
+		rc = ioctl_by_bdev(bdev, BLKRRPART, 0);
+		retry--;
+		DBF_DEV_EVENT(DBF_ERR, block->base,
+			      "scan partitions error, retry %d rc %d",
+			      retry, rc);
+	}
+
 	/*
 	 * Since the matching blkdev_put call to the blkdev_get in
 	 * this function is not called before dasd_destroy_partitions
...	...	@@ -99,15 +99,37 @@
99	99	int dasd_scan_partitions(struct dasd_block *block)
100	100	{
101	101	struct block_device *bdev;
	102	+ int retry, rc;
102	103
	104	+ retry = 5;
103	105	bdev = bdget_disk(block->gdp, 0);
104		- if (!bdev \|\| blkdev_get(bdev, FMODE_READ, NULL) < 0)
	106	+ if (!bdev) {
	107	+ DBF_DEV_EVENT(DBF_ERR, block->base, "%s",
	108	+ "scan partitions error, bdget returned NULL");
105	109	return -ENODEV;
	110	+ }
	111	+
	112	+ rc = blkdev_get(bdev, FMODE_READ, NULL);
	113	+ if (rc < 0) {
	114	+ DBF_DEV_EVENT(DBF_ERR, block->base,
	115	+ "scan partitions error, blkdev_get returned %d",
	116	+ rc);
	117	+ return -ENODEV;
	118	+ }
106	119	/*
107	120	* See fs/partition/check.c:register_disk,rescan_partitions
108	121	* Can't call rescan_partitions directly. Use ioctl.
109	122	*/
110		- ioctl_by_bdev(bdev, BLKRRPART, 0);
	123	+ rc = ioctl_by_bdev(bdev, BLKRRPART, 0);
	124	+ while (rc == -EBUSY && retry > 0) {
	125	+ schedule();
	126	+ rc = ioctl_by_bdev(bdev, BLKRRPART, 0);
	127	+ retry--;
	128	+ DBF_DEV_EVENT(DBF_ERR, block->base,
	129	+ "scan partitions error, retry %d rc %d",
	130	+ retry, rc);
	131	+ }
	132	+
111	133	/*
112	134	* Since the matching blkdev_put call to the blkdev_get in
113	135	* this function is not called before dasd_destroy_partitions