nvme-fcloop: fix "inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage"

fcloop_fcp_op() could be called from flush request's ->end_io(flush_end_io) in
which the spinlock of fq->mq_flush_lock is grabbed with irq saved/disabled.

So fcloop_fcp_op() can't call spin_unlock_irq(&tfcp_req->reqlock) simply
which enables irq unconditionally.

Fixes the warning by switching to spin_lock_irqsave()/spin_unlock_irqrestore()

Fixes: c38dbbfa ("nvme-fcloop: fix inconsistent lock state warnings")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/target/fcloop.c

@@ -614,10 +614,11 @@ fcloop_fcp_recv_work(struct work_struct *work)
 	struct fcloop_fcpreq *tfcp_req =
 		container_of(work, struct fcloop_fcpreq, fcp_rcv_work);
 	struct nvmefc_fcp_req *fcpreq = tfcp_req->fcpreq;
+	unsigned long flags;
 	int ret = 0;
 	bool aborted = false;
 
-	spin_lock_irq(&tfcp_req->reqlock);
+	spin_lock_irqsave(&tfcp_req->reqlock, flags);
 	switch (tfcp_req->inistate) {
 	case INI_IO_START:
 		tfcp_req->inistate = INI_IO_ACTIVE;
@@ -626,11 +627,11 @@ fcloop_fcp_recv_work(struct work_struct *work)
 		aborted = true;
 		break;
 	default:
-		spin_unlock_irq(&tfcp_req->reqlock);
+		spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 		WARN_ON(1);
 		return;
 	}
-	spin_unlock_irq(&tfcp_req->reqlock);
+	spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 
 	if (unlikely(aborted))
 		ret = -ECANCELED;
@@ -655,8 +656,9 @@ fcloop_fcp_abort_recv_work(struct work_struct *work)
 		container_of(work, struct fcloop_fcpreq, abort_rcv_work);
 	struct nvmefc_fcp_req *fcpreq;
 	bool completed = false;
+	unsigned long flags;
 
-	spin_lock_irq(&tfcp_req->reqlock);
+	spin_lock_irqsave(&tfcp_req->reqlock, flags);
 	fcpreq = tfcp_req->fcpreq;
 	switch (tfcp_req->inistate) {
 	case INI_IO_ABORTED:
@@ -665,11 +667,11 @@ fcloop_fcp_abort_recv_work(struct work_struct *work)
 		completed = true;
 		break;
 	default:
-		spin_unlock_irq(&tfcp_req->reqlock);
+		spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 		WARN_ON(1);
 		return;
 	}
-	spin_unlock_irq(&tfcp_req->reqlock);
+	spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 
 	if (unlikely(completed)) {
 		/* remove reference taken in original abort downcall */
@@ -681,9 +683,9 @@ fcloop_fcp_abort_recv_work(struct work_struct *work)
 		nvmet_fc_rcv_fcp_abort(tfcp_req->tport->targetport,
 					&tfcp_req->tgt_fcp_req);
 
-	spin_lock_irq(&tfcp_req->reqlock);
+	spin_lock_irqsave(&tfcp_req->reqlock, flags);
 	tfcp_req->fcpreq = NULL;
-	spin_unlock_irq(&tfcp_req->reqlock);
+	spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 
 	fcloop_call_host_done(fcpreq, tfcp_req, -ECANCELED);
 	/* call_host_done releases reference for abort downcall */
@@ -699,11 +701,12 @@ fcloop_tgt_fcprqst_done_work(struct work_struct *work)
 	struct fcloop_fcpreq *tfcp_req =
 		container_of(work, struct fcloop_fcpreq, tio_done_work);
 	struct nvmefc_fcp_req *fcpreq;
+	unsigned long flags;
 
-	spin_lock_irq(&tfcp_req->reqlock);
+	spin_lock_irqsave(&tfcp_req->reqlock, flags);
 	fcpreq = tfcp_req->fcpreq;
 	tfcp_req->inistate = INI_IO_COMPLETED;
-	spin_unlock_irq(&tfcp_req->reqlock);
+	spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 
 	fcloop_call_host_done(fcpreq, tfcp_req, tfcp_req->status);
 }
@@ -807,13 +810,14 @@ fcloop_fcp_op(struct nvmet_fc_target_port *tgtport,
 	u32 rsplen = 0, xfrlen = 0;
 	int fcp_err = 0, active, aborted;
 	u8 op = tgt_fcpreq->op;
+	unsigned long flags;
 
-	spin_lock_irq(&tfcp_req->reqlock);
+	spin_lock_irqsave(&tfcp_req->reqlock, flags);
 	fcpreq = tfcp_req->fcpreq;
 	active = tfcp_req->active;
 	aborted = tfcp_req->aborted;
 	tfcp_req->active = true;
-	spin_unlock_irq(&tfcp_req->reqlock);
+	spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 
 	if (unlikely(active))
 		/* illegal - call while i/o active */
@@ -821,9 +825,9 @@ fcloop_fcp_op(struct nvmet_fc_target_port *tgtport,
 
 	if (unlikely(aborted)) {
 		/* target transport has aborted i/o prior */
-		spin_lock_irq(&tfcp_req->reqlock);
+		spin_lock_irqsave(&tfcp_req->reqlock, flags);
 		tfcp_req->active = false;
-		spin_unlock_irq(&tfcp_req->reqlock);
+		spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 		tgt_fcpreq->transferred_length = 0;
 		tgt_fcpreq->fcp_error = -ECANCELED;
 		tgt_fcpreq->done(tgt_fcpreq);
@@ -880,9 +884,9 @@ fcloop_fcp_op(struct nvmet_fc_target_port *tgtport,
 		break;
 	}
 
-	spin_lock_irq(&tfcp_req->reqlock);
+	spin_lock_irqsave(&tfcp_req->reqlock, flags);
 	tfcp_req->active = false;
-	spin_unlock_irq(&tfcp_req->reqlock);
+	spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 
 	tgt_fcpreq->transferred_length = xfrlen;
 	tgt_fcpreq->fcp_error = fcp_err;
@@ -896,15 +900,16 @@ fcloop_tgt_fcp_abort(struct nvmet_fc_target_port *tgtport,
 			struct nvmefc_tgt_fcp_req *tgt_fcpreq)
 {
 	struct fcloop_fcpreq *tfcp_req = tgt_fcp_req_to_fcpreq(tgt_fcpreq);
+	unsigned long flags;
 
 	/*
 	 * mark aborted only in case there were 2 threads in transport
 	 * (one doing io, other doing abort) and only kills ops posted
 	 * after the abort request
 	 */
-	spin_lock_irq(&tfcp_req->reqlock);
+	spin_lock_irqsave(&tfcp_req->reqlock, flags);
 	tfcp_req->aborted = true;
-	spin_unlock_irq(&tfcp_req->reqlock);
+	spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 
 	tfcp_req->status = NVME_SC_INTERNAL;
 
@@ -946,6 +951,7 @@ fcloop_fcp_abort(struct nvme_fc_local_port *localport,
 	struct fcloop_ini_fcpreq *inireq = fcpreq->private;
 	struct fcloop_fcpreq *tfcp_req;
 	bool abortio = true;
+	unsigned long flags;
 
 	spin_lock(&inireq->inilock);
 	tfcp_req = inireq->tfcp_req;
@@ -958,7 +964,7 @@ fcloop_fcp_abort(struct nvme_fc_local_port *localport,
 		return;
 
 	/* break initiator/target relationship for io */
-	spin_lock_irq(&tfcp_req->reqlock);
+	spin_lock_irqsave(&tfcp_req->reqlock, flags);
 	switch (tfcp_req->inistate) {
 	case INI_IO_START:
 	case INI_IO_ACTIVE:
@@ -968,11 +974,11 @@ fcloop_fcp_abort(struct nvme_fc_local_port *localport,
 		abortio = false;
 		break;
 	default:
-		spin_unlock_irq(&tfcp_req->reqlock);
+		spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 		WARN_ON(1);
 		return;
 	}
-	spin_unlock_irq(&tfcp_req->reqlock);
+	spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 
 	if (abortio)
 		/* leave the reference while the work item is scheduled */