On Jul 08 Roland Dreier wrote: > This fixes crashes such as the below that I see when the storage > underlying a dm-multipath device is hot-removed. The problem is that > dm requeues a request to a device whose block queue has already been > cleaned up, and blk_insert_cloned_request() doesn't check if the queue > is alive, but rather goes ahead and tries to queue the request. This > ends up dereferencing the elevator that was already freed in > blk_cleanup_queue(). [...] > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1706,6 +1706,9 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq) > return -EIO; > #endif > > + if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) > + return -EIO; > + > spin_lock_irqsave(q->queue_lock, flags); > > /* Not knowing the calling contexts or having tried to learn about them, I am wondering: What prevents the elevator to be freed right after the flag was checked? -- Stefan Richter -=====-==-== -=== -=--= http://arcgraph.de/sr/ -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
