From: Daniel Wagner <wagi@kernel.org>
Date: Tue, 8 Apr 2025 15:29:09 +0000 (+0200)
Subject: nvmet-fc: take tgtport reference only once
X-Git-Tag: nvme-6.15-2025-04-10~1
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=b0b26ad0e1943de25ce82a7e5af3574f31b1cf99;p=nvme.git

nvmet-fc: take tgtport reference only once

The reference counting code can be simplified. Instead taking a tgtport
refrerence at the beginning of nvmet_fc_alloc_hostport and put it back
if not a new hostport object is allocated, only take it when a new
hostport object is allocated.

Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
index 42613280c06e..61e9eea3bee4 100644
--- a/drivers/nvme/target/fc.c
+++ b/drivers/nvme/target/fc.c
@@ -1018,33 +1018,24 @@ nvmet_fc_alloc_hostport(struct nvmet_fc_tgtport *tgtport, void *hosthandle)
 	struct nvmet_fc_hostport *newhost, *match = NULL;
 	unsigned long flags;
 
+	/*
+	 * Caller holds a reference on tgtport.
+	 */
+
 	/* if LLDD not implemented, leave as NULL */
 	if (!hosthandle)
 		return NULL;
 
-	/*
-	 * take reference for what will be the newly allocated hostport if
-	 * we end up using a new allocation
-	 */
-	if (!nvmet_fc_tgtport_get(tgtport))
-		return ERR_PTR(-EINVAL);
-
 	spin_lock_irqsave(&tgtport->lock, flags);
 	match = nvmet_fc_match_hostport(tgtport, hosthandle);
 	spin_unlock_irqrestore(&tgtport->lock, flags);
 
-	if (match) {
-		/* no new allocation - release reference */
-		nvmet_fc_tgtport_put(tgtport);
+	if (match)
 		return match;
-	}
 
 	newhost = kzalloc(sizeof(*newhost), GFP_KERNEL);
-	if (!newhost) {
-		/* no new allocation - release reference */
-		nvmet_fc_tgtport_put(tgtport);
+	if (!newhost)
 		return ERR_PTR(-ENOMEM);
-	}
 
 	spin_lock_irqsave(&tgtport->lock, flags);
 	match = nvmet_fc_match_hostport(tgtport, hosthandle);
@@ -1053,6 +1044,7 @@ nvmet_fc_alloc_hostport(struct nvmet_fc_tgtport *tgtport, void *hosthandle)
 		kfree(newhost);
 		newhost = match;
 	} else {
+		nvmet_fc_tgtport_get(tgtport);
 		newhost->tgtport = tgtport;
 		newhost->hosthandle = hosthandle;
 		INIT_LIST_HEAD(&newhost->host_list);