| Message ID | 80b64d8a0408e7c8c30b363aaf6d39e735521c1d.1599597940.git.osandov@osandov.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: only call sched requeue_request() for scheduled requests | expand |
On 9/8/20 2:46 PM, Omar Sandoval wrote: > From: Omar Sandoval <osandov@fb.com> > > Yang Yang reported the following crash caused by requeueing a flush > request in Kyber: > > [ 2.517297] Unable to handle kernel paging request at virtual address ffffffd8071c0b00 > ... > [ 2.517468] pc : clear_bit+0x18/0x2c > [ 2.517502] lr : sbitmap_queue_clear+0x40/0x228 > [ 2.517503] sp : ffffff800832bc60 pstate : 00c00145 > ... > [ 2.517599] Process ksoftirqd/5 (pid: 51, stack limit = 0xffffff8008328000) > [ 2.517602] Call trace: > [ 2.517606] clear_bit+0x18/0x2c > [ 2.517619] kyber_finish_request+0x74/0x80 > [ 2.517627] blk_mq_requeue_request+0x3c/0xc0 > [ 2.517637] __scsi_queue_insert+0x11c/0x148 > [ 2.517640] scsi_softirq_done+0x114/0x130 > [ 2.517643] blk_done_softirq+0x7c/0xb0 > [ 2.517651] __do_softirq+0x208/0x3bc > [ 2.517657] run_ksoftirqd+0x34/0x60 > [ 2.517663] smpboot_thread_fn+0x1c4/0x2c0 > [ 2.517667] kthread+0x110/0x120 > [ 2.517669] ret_from_fork+0x10/0x18 > > This happens because Kyber doesn't track flush requests, so > kyber_finish_request() reads a garbage domain token. Only call the > scheduler's requeue_request() hook if RQF_ELVPRIV is set (like we do for > the finish_request() hook in blk_mq_free_request()). Now that we're > handling it in blk-mq, also remove the check from BFQ. Thanks, applied.
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index a4c0bec920cb..ee767fa000e4 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -5895,18 +5895,6 @@ static void bfq_finish_requeue_request(struct request *rq) struct bfq_queue *bfqq = RQ_BFQQ(rq); struct bfq_data *bfqd; - /* - * Requeue and finish hooks are invoked in blk-mq without - * checking whether the involved request is actually still - * referenced in the scheduler. To handle this fact, the - * following two checks make this function exit in case of - * spurious invocations, for which there is nothing to do. - * - * First, check whether rq has nothing to do with an elevator. - */ - if (unlikely(!(rq->rq_flags & RQF_ELVPRIV))) - return; - /* * rq either is not associated with any icq, or is an already * requeued request that has not (yet) been re-inserted into diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index 126021fc3a11..e81ca1bf6e10 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -66,7 +66,7 @@ static inline void blk_mq_sched_requeue_request(struct request *rq) struct request_queue *q = rq->q; struct elevator_queue *e = q->elevator; - if (e && e->type->ops.requeue_request) + if ((rq->rq_flags & RQF_ELVPRIV) && e && e->type->ops.requeue_request) e->type->ops.requeue_request(rq); }