Commit ca732e11 authored Jan 25, 2017 by Stefan Haberland Committed by Martin Schwidefsky Jan 31, 2017

s390/dasd: check blockdevice pointer before trying to sync blockdevice



If safe offline is called for a DASD alias device a null pointer is passed
to fsync_bdev. So check for existence of the blockdevice before calling
fsync_bdev.
Should not be a real world problem since safe offline for an alias device
does not make sense and fsync_bdev can deal with a NULL pointer which it
gets after successful NULL pointer dereferencing on s390.

Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 2202134e

drivers/s390/block/dasd.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -3601,10 +3601,11 @@ int dasd_generic_set_offline(struct ccw_device *cdev)
		* empty
		*/
		/* sync blockdev and partitions */
		if (device->block) {
		rc = fsync_bdev(device->block->bdev);
		if (rc != 0)
		goto interrupted;

		}
		/* schedule device tasklet and wait for completion */
		dasd_schedule_device_bh(device);
		rc = wait_event_interruptible(shutdown_waitq,