Commit 710c69db authored by Daniel Wagner's avatar Daniel Wagner Committed by Keith Busch
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nvmet-fc: avoid deadlock on delete association path 



When deleting an association the shutdown path is deadlocking because we
try to flush the nvmet_wq nested. Avoid this by deadlock by deferring
the put work into its own work item.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDaniel Wagner <dwagner@suse.de>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent 3146345c

drivers/nvme/target/fc.c

+13 −3
Original line number Diff line number Diff line
@@ -111,6 +111,8 @@ struct nvmet_fc_tgtport { 
	struct nvmet_fc_port_entry	*pe;

	struct kref			ref;

	u32				max_sg_cnt;



	struct work_struct		put_work;

};



struct nvmet_fc_port_entry {
@@ -247,6 +249,13 @@ static int nvmet_fc_tgt_a_get(struct nvmet_fc_tgt_assoc *assoc); 
static void nvmet_fc_tgt_q_put(struct nvmet_fc_tgt_queue *queue);

static int nvmet_fc_tgt_q_get(struct nvmet_fc_tgt_queue *queue);

static void nvmet_fc_tgtport_put(struct nvmet_fc_tgtport *tgtport);

static void nvmet_fc_put_tgtport_work(struct work_struct *work)

{

	struct nvmet_fc_tgtport *tgtport =

		container_of(work, struct nvmet_fc_tgtport, put_work);



	nvmet_fc_tgtport_put(tgtport);

}

static int nvmet_fc_tgtport_get(struct nvmet_fc_tgtport *tgtport);

static void nvmet_fc_handle_fcp_rqst(struct nvmet_fc_tgtport *tgtport,

					struct nvmet_fc_fcp_iod *fod);
@@ -358,7 +367,7 @@ __nvmet_fc_finish_ls_req(struct nvmet_fc_ls_req_op *lsop) 


	if (!lsop->req_queued) {

		spin_unlock_irqrestore(&tgtport->lock, flags);

		goto out_puttgtport;

		goto out_putwork;

	}



	list_del(&lsop->lsreq_list);
@@ -371,8 +380,8 @@ __nvmet_fc_finish_ls_req(struct nvmet_fc_ls_req_op *lsop) 
				  (lsreq->rqstlen + lsreq->rsplen),

				  DMA_BIDIRECTIONAL);



out_puttgtport:

	nvmet_fc_tgtport_put(tgtport);

out_putwork:

	queue_work(nvmet_wq, &tgtport->put_work);

}



static int
@@ -1396,6 +1405,7 @@ nvmet_fc_register_targetport(struct nvmet_fc_port_info *pinfo, 
	kref_init(&newrec->ref);

	ida_init(&newrec->assoc_cnt);

	newrec->max_sg_cnt = template->max_sgl_segments;

	INIT_WORK(&newrec->put_work, nvmet_fc_put_tgtport_work);



	ret = nvmet_fc_alloc_ls_iodlist(newrec);

	if (ret) {