nvmet-fcloop: access fcpreq only when holding reqlock

[ Upstream commit 47a827c ]

The abort handling logic expects that the state and the fcpreq are only
accessed when holding the reqlock lock.

While at it, only handle the aborts in the abort handler.

Signed-off-by: Daniel Wagner <wagi@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: igaw

drivers/nvme/target/fcloop.c

@@ -618,12 +618,13 @@ 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;
+	struct nvmefc_fcp_req *fcpreq;
 	unsigned long flags;
 	int ret = 0;
 	bool aborted = false;
 
 	spin_lock_irqsave(&tfcp_req->reqlock, flags);
+	fcpreq = tfcp_req->fcpreq;
 	switch (tfcp_req->inistate) {
 	case INI_IO_START:
 		tfcp_req->inistate = INI_IO_ACTIVE;
@@ -638,16 +639,19 @@ fcloop_fcp_recv_work(struct work_struct *work)
 	}
 	spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
 
-	if (unlikely(aborted))
-		ret = -ECANCELED;
-	else {
-		if (likely(!check_for_drop(tfcp_req)))
-			ret = nvmet_fc_rcv_fcp_req(tfcp_req->tport->targetport,
-				&tfcp_req->tgt_fcp_req,
-				fcpreq->cmdaddr, fcpreq->cmdlen);
-		else
-			pr_info("%s: dropped command ********\n", __func__);
+	if (unlikely(aborted)) {
+		/* the abort handler will call fcloop_call_host_done */
+		return;
+	}
+
+	if (unlikely(check_for_drop(tfcp_req))) {
+		pr_info("%s: dropped command ********\n", __func__);
+		return;
 	}
+
+	ret = nvmet_fc_rcv_fcp_req(tfcp_req->tport->targetport,
+				   &tfcp_req->tgt_fcp_req,
+				   fcpreq->cmdaddr, fcpreq->cmdlen);
 	if (ret)
 		fcloop_call_host_done(fcpreq, tfcp_req, ret);
 }
@@ -662,9 +666,10 @@ fcloop_fcp_abort_recv_work(struct work_struct *work)
 	unsigned long flags;
 
 	spin_lock_irqsave(&tfcp_req->reqlock, flags);
-	fcpreq = tfcp_req->fcpreq;
 	switch (tfcp_req->inistate) {
 	case INI_IO_ABORTED:
+		fcpreq = tfcp_req->fcpreq;
+		tfcp_req->fcpreq = NULL;
 		break;
 	case INI_IO_COMPLETED:
 		completed = true;
@@ -686,10 +691,6 @@ 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_irqsave(&tfcp_req->reqlock, flags);
-	tfcp_req->fcpreq = NULL;
-	spin_unlock_irqrestore(&tfcp_req->reqlock, flags);
-
 	fcloop_call_host_done(fcpreq, tfcp_req, -ECANCELED);
 	/* call_host_done releases reference for abort downcall */
 }