s390/dasd: check blockdevice pointer before trying to sync blockdevice
authorStefan Haberland <sth@linux.vnet.ibm.com>
Wed, 25 Jan 2017 15:56:41 +0000 (16:56 +0100)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Tue, 31 Jan 2017 09:47:25 +0000 (10:47 +0100)
commitca732e111ff7017e79a0cbb8aa0636c6ce48eb7d
tree7097bbd9bf7f90edefde0fed88ffdb8bcd582618
parent2202134e48a3b50320aeb9e3dd1186833e9d7e66
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>
drivers/s390/block/dasd.c