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From:   Daniel Wagner <dwagner@suse.de>
To:     linux-nvme@lists.infradead.org
Cc:     linux-kernel@vger.kernel.org, Keith Busch <kbusch@kernel.org>,
        Jens Axboe <axboe@fb.com>, Christoph Hellwig <hch@lst.de>,
        Sagi Grimberg <sagi@grimberg.me>,
        Daniel Wagner <dwagner@suse.de>
Subject: [PATCH] nvme: verify MNAN value if ANA is enabled
Date:   Mon, 31 May 2021 12:36:51 +0200
Message-Id: <20210531103651.109426-1-dwagner@suse.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The controller is required to have a non-zero MNAN value if it supports
ANA:

   If the controller supports Asymmetric Namespace Access Reporting, then
   this field shall be set to a non-zero value that is less than or equal
   to the NN value.

Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
This is a follow up to the discussion in

  https://lore.kernel.org/linux-nvme/20210521144734.90044-1-dwagner@suse.de/

 drivers/nvme/host/core.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index cb1a76a3d42a..4c412adc9e14 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2972,6 +2972,16 @@ static int nvme_init_identify(struct nvme_ctrl *ctrl)
 	if (ret < 0)
 		goto out_free;
 
+#ifdef CONFIG_NVME_MULTIPATH
+	if (ctrl->ana_log_buf && (!ctrl->max_namespaces ||
+				  ctrl->max_namespaces > le32_to_cpu(id->nn))) {
+		dev_err(ctrl->device,
+			"Invalid MNAN value %u\n", ctrl->max_namespaces);
+		ret = -EINVAL;
+		goto out_free;
+	}
+#endif
+
 	if (ctrl->apst_enabled && !prev_apst_enabled)
 		dev_pm_qos_expose_latency_tolerance(ctrl->device);
 	else if (!ctrl->apst_enabled && prev_apst_enabled)
-- 
2.29.2