| Message ID | 20190417034410.31957-3-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | blk-mq: fix races related with freeing queue | expand |
On 4/17/19 5:44 AM, Ming Lei wrote: > With holding queue's kobject refcount, it is safe for driver > to schedule requeue. However, blk_mq_kick_requeue_list() may > be called after blk_sync_queue() is done because of concurrent > requeue activities, then requeue work may not be completed when > freeing queue, and kernel oops is triggered. > > So moving the cancel of requeue_work into blk_mq_release() for > avoiding race between requeue and freeing queue. > > Cc: Dongli Zhang <dongli.zhang@oracle.com> > Cc: James Smart <james.smart@broadcom.com> > Cc: Bart Van Assche <bart.vanassche@wdc.com> > Cc: linux-scsi@vger.kernel.org, > Cc: Martin K . Petersen <martin.petersen@oracle.com>, > Cc: Christoph Hellwig <hch@lst.de>, > Cc: James E . J . Bottomley <jejb@linux.vnet.ibm.com>, > Cc: jianchao wang <jianchao.w.wang@oracle.com> > Reviewed-by: Bart Van Assche <bvanassche@acm.org> > Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > block/blk-core.c | 1 - > block/blk-mq.c | 2 ++ > 2 files changed, 2 insertions(+), 1 deletion(-) > Reviewed-by: Hannes Reinecke <hare@suse.com> Cheers, Hannes
diff --git a/block/blk-core.c b/block/blk-core.c index a55389ba8779..93dc588fabe2 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -237,7 +237,6 @@ void blk_sync_queue(struct request_queue *q) struct blk_mq_hw_ctx *hctx; int i; - cancel_delayed_work_sync(&q->requeue_work); queue_for_each_hw_ctx(q, hctx, i) cancel_delayed_work_sync(&hctx->run_work); } diff --git a/block/blk-mq.c b/block/blk-mq.c index ef5a16a2d6fb..55776a6e2586 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2640,6 +2640,8 @@ void blk_mq_release(struct request_queue *q) struct blk_mq_hw_ctx *hctx; unsigned int i; + cancel_delayed_work_sync(&q->requeue_work); + /* hctx kobj stays in hctx */ queue_for_each_hw_ctx(q, hctx, i) { if (!hctx)