[PATCH 5.4 64/92] nvmet-tcp: fix incomplete data digest send

From: Greg Kroah-Hartman
Date: Mon Nov 29 2021 - 15:54:33 EST


From: Varun Prakash <varun@xxxxxxxxxxx>

[ Upstream commit 102110efdff6beedece6ab9b51664c32ac01e2db ]

Current nvmet_try_send_ddgst() code does not check whether
all data digest bytes are transmitted, fix this by returning
-EAGAIN if all data digest bytes are not transmitted.

Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver")
Signed-off-by: Varun Prakash <varun@xxxxxxxxxxx>
Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nvme/target/tcp.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index fac1985870765..4341c72446628 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -631,10 +631,11 @@ static int nvmet_try_send_r2t(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd)
{
struct nvmet_tcp_queue *queue = cmd->queue;
+ int left = NVME_TCP_DIGEST_LENGTH - cmd->offset;
struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
struct kvec iov = {
.iov_base = (u8 *)&cmd->exp_ddgst + cmd->offset,
- .iov_len = NVME_TCP_DIGEST_LENGTH - cmd->offset
+ .iov_len = left
};
int ret;

@@ -643,6 +644,10 @@ static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd)
return ret;

cmd->offset += ret;
+ left -= ret;
+
+ if (left)
+ return -EAGAIN;

if (queue->nvme_sq.sqhd_disabled) {
cmd->queue->snd_cmd = NULL;
--
2.33.0