From: Maurizio Lombardi <mlombard@redhat.com>
Date: Tue, 16 Nov 2021 16:49:19 +0100
Subject: nvmet-tcp: add an helper to free the cmd buffers
Patch-mainline: v5.16-rc3
Git-commit: 69b85e1f1d1d1e49601ec3e85d2031188657cca2
References: jsc#PED-1183

Makes the code easier to read and to debug.

Sets the freed pointers to NULL, it will be useful
when destroying the queues to understand if the commands'
buffers have been released already or not.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/target/tcp.c |   28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -166,6 +166,8 @@ static struct workqueue_struct *nvmet_tc
 static const struct nvmet_fabrics_ops nvmet_tcp_ops;
 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c);
 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd);
+static void nvmet_tcp_free_cmd_buffers(struct nvmet_tcp_cmd *cmd);
+static void nvmet_tcp_unmap_pdu_iovec(struct nvmet_tcp_cmd *cmd);
 
 static inline u16 nvmet_tcp_cmd_tag(struct nvmet_tcp_queue *queue,
 		struct nvmet_tcp_cmd *cmd)
@@ -297,6 +299,16 @@ static int nvmet_tcp_check_ddgst(struct
 	return 0;
 }
 
+static void nvmet_tcp_free_cmd_buffers(struct nvmet_tcp_cmd *cmd)
+{
+	WARN_ON(unlikely(cmd->nr_mapped > 0));
+
+	kfree(cmd->iov);
+	sgl_free(cmd->req.sg);
+	cmd->iov = NULL;
+	cmd->req.sg = NULL;
+}
+
 static void nvmet_tcp_unmap_pdu_iovec(struct nvmet_tcp_cmd *cmd)
 {
 	struct scatterlist *sg;
@@ -306,6 +318,8 @@ static void nvmet_tcp_unmap_pdu_iovec(st
 
 	for (i = 0; i < cmd->nr_mapped; i++)
 		kunmap(sg_page(&sg[i]));
+
+	cmd->nr_mapped = 0;
 }
 
 static void nvmet_tcp_map_pdu_iovec(struct nvmet_tcp_cmd *cmd)
@@ -387,7 +401,7 @@ static int nvmet_tcp_map_data(struct nvm
 
 	return 0;
 err:
-	sgl_free(cmd->req.sg);
+	nvmet_tcp_free_cmd_buffers(cmd);
 	return NVME_SC_INTERNAL;
 }
 
@@ -632,10 +646,8 @@ static int nvmet_try_send_data(struct nv
 		}
 	}
 
-	if (queue->nvme_sq.sqhd_disabled) {
-		kfree(cmd->iov);
-		sgl_free(cmd->req.sg);
-	}
+	if (queue->nvme_sq.sqhd_disabled)
+		nvmet_tcp_free_cmd_buffers(cmd);
 
 	return 1;
 
@@ -664,8 +676,7 @@ static int nvmet_try_send_response(struc
 	if (left)
 		return -EAGAIN;
 
-	kfree(cmd->iov);
-	sgl_free(cmd->req.sg);
+	nvmet_tcp_free_cmd_buffers(cmd);
 	cmd->queue->snd_cmd = NULL;
 	nvmet_tcp_put_cmd(cmd);
 	return 1;
@@ -1406,8 +1417,7 @@ static void nvmet_tcp_finish_cmd(struct
 {
 	nvmet_req_uninit(&cmd->req);
 	nvmet_tcp_unmap_pdu_iovec(cmd);
-	kfree(cmd->iov);
-	sgl_free(cmd->req.sg);
+	nvmet_tcp_free_cmd_buffers(cmd);
 }
 
 static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)