tree 9e5ca7c9c3d14c45f469feb58cab15212cee9d6b
parent af9d2ff9afaae8040dbf09238b2579f92c93579e
author Stefan Haberland <stefan.haberland@de.ibm.com> 1254818055 +0200
committer Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> 1254818111 +0200

[S390] dasd: fix race condition in resume code

There is a race while re-reading the device characteristics. After
cleaning the memory area a cqr is build which reads the device
characteristics. This may take a rather long time and the device
characteristics structure is zero during this. Now it could be
possible that the block tasklet starts working and a new cqr will be
build. The build_cp command refers to the device characteristics
structure and this may lead into a divide by zero exception.
Fix this by re-reading the device characteristics into a temporary
structur and copy the data to the original structure. Also take the
ccwdev_lock.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>