nvmet-tcp: fix incomplete data digest send

[ 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@chelsio.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 84c387e..2b8bab2 100644 (file)
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -700,10 +700,11 @@ 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, bool last_in_batch)
 {
        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;
 
@@ -717,6 +718,10 @@ static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
                return ret;
 
        cmd->offset += ret;
+       left -= ret;
+
+       if (left)
+               return -EAGAIN;
 
        if (queue->nvme_sq.sqhd_disabled) {
                cmd->queue->snd_cmd = NULL;