Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Linjun Bao <meljbao@gmail.com>
Cc:     Linjun Bao <meljbao@gmail.com>, Keith Busch <kbusch@kernel.org>,
        Jens Axboe <axboe@fb.com>, Christoph Hellwig <hch@lst.de>,
        Sagi Grimberg <sagi@grimberg.me>,
        linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] nvme: add comment for unaligned "fake" nqn
Date:   Thu, 11 Aug 2022 15:40:24 +0800
Message-Id: <20220811074024.4382-1-meljbao@gmail.com>
In-Reply-To: <20220810140812.GA24773@lst.de>
References: <20220810140812.GA24773@lst.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
To:     unlisted-recipients:; (no To-header on input)
Precedence: bulk

Current "fake" nqn field is "nqn.2014.08.org.nvmexpress:", it is
not aligned with the canonical version for history reasons.

Signed-off-by: Linjun Bao <meljbao@gmail.com>
---
 drivers/nvme/host/core.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index af367b22871b..e72021212971 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2704,7 +2704,11 @@ static void nvme_init_subnqn(struct nvme_subsystem *subsys, struct nvme_ctrl *ct
 			dev_warn(ctrl->device, "missing or invalid SUBNQN field.\n");
 	}
 
-	/* Generate a "fake" NQN per Figure 254 in NVMe 1.3 + ECN 001 */
+	/*
+	 * Generate a "fake" NQN per Figure 254 in NVMe 1.3 + ECN 001,
+	 * the NSS field is different from the canonical version 
+	 * "nqn.2014-08.org.nvmexpress:" for historic reasons. 
+	 */
 	off = snprintf(subsys->subnqn, NVMF_NQN_SIZE,
 			"nqn.2014.08.org.nvmexpress:%04x%04x",
 			le16_to_cpu(id->vid), le16_to_cpu(id->ssvid));
-- 
2.25.1