From 6fca97a958bc3c67566aa91eafc6a5be2e66d6b3 Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Tue, 6 Oct 2009 10:34:15 +0200 Subject: [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 Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/s390/block/dasd.c') diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index dad0449475b..53b8c255360 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -2508,8 +2508,6 @@ int dasd_generic_restore_device(struct ccw_device *cdev) device->stopped &= ~DASD_UNRESUMED_PM; dasd_schedule_device_bh(device); - if (device->block) - dasd_schedule_block_bh(device->block); if (device->discipline->restore) rc = device->discipline->restore(device); @@ -2520,6 +2518,9 @@ int dasd_generic_restore_device(struct ccw_device *cdev) */ device->stopped |= DASD_UNRESUMED_PM; + if (device->block) + dasd_schedule_block_bh(device->block); + dasd_put_device(device); return 0; } -- cgit v1.2.3-18-g5258