[SRU][Focal][PATCH 1/2] nvmet-tcp: move send/recv error handling in the send/recv methods instead of call-sites

[Yuxuan Luo]

From: Sagi Grimberg <sagi at grimberg.me>

Have routines handle errors and just bail out of the poll loop.
This simplifies the code and will help as we may enhance the poll
loop logic and these are somewhat in the way.

Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
Signed-off-by: Christoph Hellwig <hch at lst.de>
(cherry picked from commit 0236d3437909ff888e5c79228e2d5a851651c4c6)
CVE-2023-5178
Signed-off-by: Yuxuan Luo <yuxuan.luo at canonical.com>
---
 drivers/nvme/target/tcp.c | 43 ++++++++++++++++++++++-----------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index df7a911d303f9..e63a50e22e5a0 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -321,6 +321,14 @@ static void nvmet_tcp_fatal_error(struct nvmet_tcp_queue *queue)
 		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
 }
 
+static void nvmet_tcp_socket_error(struct nvmet_tcp_queue *queue, int status)
+{
+	if (status == -EPIPE || status == -ECONNRESET)
+		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
+	else
+		nvmet_tcp_fatal_error(queue);
+}
+
 static int nvmet_tcp_map_data(struct nvmet_tcp_cmd *cmd)
 {
 	struct nvme_sgl_desc *sgl = &cmd->req.cmd->common.dptr.sgl;
@@ -714,11 +722,15 @@ static int nvmet_tcp_try_send(struct nvmet_tcp_queue *queue,
 
 	for (i = 0; i < budget; i++) {
 		ret = nvmet_tcp_try_send_one(queue, i == budget - 1);
-		if (ret <= 0)
+		if (unlikely(ret < 0)) {
+			nvmet_tcp_socket_error(queue, ret);
+			goto done;
+		} else if (ret == 0) {
 			break;
+		}
 		(*sends)++;
 	}
-
+done:
 	return ret;
 }
 
@@ -1167,11 +1179,15 @@ static int nvmet_tcp_try_recv(struct nvmet_tcp_queue *queue,
 
 	for (i = 0; i < budget; i++) {
 		ret = nvmet_tcp_try_recv_one(queue);
-		if (ret <= 0)
+		if (unlikely(ret < 0)) {
+			nvmet_tcp_socket_error(queue, ret);
+			goto done;
+		} else if (ret == 0) {
 			break;
+		}
 		(*recvs)++;
 	}
-
+done:
 	return ret;
 }
 
@@ -1196,27 +1212,16 @@ static void nvmet_tcp_io_work(struct work_struct *w)
 		pending = false;
 
 		ret = nvmet_tcp_try_recv(queue, NVMET_TCP_RECV_BUDGET, &ops);
-		if (ret > 0) {
+		if (ret > 0)
 			pending = true;
-		} else if (ret < 0) {
-			if (ret == -EPIPE || ret == -ECONNRESET)
-				kernel_sock_shutdown(queue->sock, SHUT_RDWR);
-			else
-				nvmet_tcp_fatal_error(queue);
+		else if (ret < 0)
 			return;
-		}
 
 		ret = nvmet_tcp_try_send(queue, NVMET_TCP_SEND_BUDGET, &ops);
-		if (ret > 0) {
-			/* transmitted message/data */
+		if (ret > 0)
 			pending = true;
-		} else if (ret < 0) {
-			if (ret == -EPIPE || ret == -ECONNRESET)
-				kernel_sock_shutdown(queue->sock, SHUT_RDWR);
-			else
-				nvmet_tcp_fatal_error(queue);
+		else if (ret < 0)
 			return;
-		}
 
 	} while (pending && ops < NVMET_TCP_IO_WORK_BUDGET);
 
-- 
2.34.1