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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Minwoo Im <minwoo.im.dev@gmail.com>,
        Christoph Hellwig <hch@lst.de>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 21/50] nvme: free sq/cq dbbuf pointers when dbbuf set fails
Date:   Tue,  1 Dec 2020 09:53:20 +0100
Message-Id: <20201201084647.730069293@linuxfoundation.org>
In-Reply-To: <20201201084644.803812112@linuxfoundation.org>
References: <20201201084644.803812112@linuxfoundation.org>
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From: Minwoo Im <minwoo.im.dev@gmail.com>

[ Upstream commit 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf ]

If Doorbell Buffer Config command fails even 'dev->dbbuf_dbs != NULL'
which means OACS indicates that NVME_CTRL_OACS_DBBUF_SUPP is set,
nvme_dbbuf_update_and_check_event() will check event even it's not been
successfully set.

This patch fixes mismatch among dbbuf for sq/cqs in case that dbbuf
command fails.

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/host/pci.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 3788c053a0b19..540fab9f850dd 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -266,9 +266,21 @@ static void nvme_dbbuf_init(struct nvme_dev *dev,
 	nvmeq->dbbuf_cq_ei = &dev->dbbuf_eis[cq_idx(qid, dev->db_stride)];
 }
 
+static void nvme_dbbuf_free(struct nvme_queue *nvmeq)
+{
+	if (!nvmeq->qid)
+		return;
+
+	nvmeq->dbbuf_sq_db = NULL;
+	nvmeq->dbbuf_cq_db = NULL;
+	nvmeq->dbbuf_sq_ei = NULL;
+	nvmeq->dbbuf_cq_ei = NULL;
+}
+
 static void nvme_dbbuf_set(struct nvme_dev *dev)
 {
 	struct nvme_command c;
+	unsigned int i;
 
 	if (!dev->dbbuf_dbs)
 		return;
@@ -282,6 +294,9 @@ static void nvme_dbbuf_set(struct nvme_dev *dev)
 		dev_warn(dev->ctrl.device, "unable to set dbbuf\n");
 		/* Free memory and continue on */
 		nvme_dbbuf_dma_free(dev);
+
+		for (i = 1; i <= dev->online_queues; i++)
+			nvme_dbbuf_free(&dev->queues[i]);
 	}
 }
 
-- 
2.27.0