From: Michael Holzheu <holzheu@xxxxxxxxxx> Due to incorrect function call sequence it can happen that a tape block request is finished before the request is taken from the block request queue. The following sequence leads to that condition: * tapeblock_start_request() -> start CCW program * Request finishes -> IO interrupt * tapeblock_end_request() * end_that_request_last() If blkdev_dequeue_request() has not been called before end_that_request_last(), a kernel bug is triggered in end_that_request_last() because the request is still queued. To solve that problem blkdev_dequeue_request() has to be called before starting the CCW program. Signed-off-by: Michael Holzheu <holzheu@xxxxxxxxxx> --- drivers/s390/char/tape_block.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Index: quilt-2.6/drivers/s390/char/tape_block.c =================================================================== --- quilt-2.6.orig/drivers/s390/char/tape_block.c +++ quilt-2.6/drivers/s390/char/tape_block.c @@ -179,11 +179,11 @@ tapeblock_requeue(struct work_struct *wo tapeblock_end_request(req, -EIO); continue; } + blkdev_dequeue_request(req); + nr_queued++; spin_unlock_irq(&device->blk_data.request_queue_lock); rc = tapeblock_start_request(device, req); spin_lock_irq(&device->blk_data.request_queue_lock); - blkdev_dequeue_request(req); - nr_queued++; } spin_unlock_irq(&device->blk_data.request_queue_lock); atomic_set(&device->blk_data.requeue_scheduled, 0); -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
