Re: [PATCH net 2/3] net/smc: allow cdc msg send rather than drop it with NULL sndbuf_desc

Dust Li
2023-11-01T08:19:25Z

On Wed, Nov 01, 2023 at 11:42:56AM +0800, D. Wythe wrote:
>From: "D. Wythe" <alibuda@linux.alibaba.com>
>
>This patch re-fix the issues memtianed by commit 22a825c541d7

memtianed -> mentioned ?

>("net/smc: fix NULL sndbuf_desc in smc_cdc_tx_handler()").
>
>Blocking sending message do solve the issues though, but it also
>prevents the peer to receive the final message. Besides, in logic,
>whether the sndbuf_desc is NULL or not have no impact on the processing
>of cdc message sending.
>
>Hence that, this patch allow the cdc message sending but to check the
allows

>sndbuf_desc with care in smc_cdc_tx_handler().
>
>Fixes: 22a825c541d7 ("net/smc: fix NULL sndbuf_desc in smc_cdc_tx_handler()")
>Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
>Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>

Reviewed-by: Dust Li <dust.li@linux.alibaba.com>

>---
> net/smc/smc_cdc.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
>diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
>index 01bdb79..3c06625 100644
>--- a/net/smc/smc_cdc.c
>+++ b/net/smc/smc_cdc.c
>@@ -28,13 +28,15 @@ static void smc_cdc_tx_handler(struct smc_wr_tx_pend_priv *pnd_snd,
> {
> struct smc_cdc_tx_pend *cdcpend = (struct smc_cdc_tx_pend *)pnd_snd;
> struct smc_connection *conn = cdcpend->conn;
>+ struct smc_buf_desc *sndbuf_desc;
> struct smc_sock *smc;
> int diff;
>
>+ sndbuf_desc = conn->sndbuf_desc;
> smc = container_of(conn, struct smc_sock, conn);
> bh_lock_sock(&smc->sk);
>- if (!wc_status) {
>- diff = smc_curs_diff(cdcpend->conn->sndbuf_desc->len,
>+ if (!wc_status && sndbuf_desc) {
>+ diff = smc_curs_diff(sndbuf_desc->len,
> &cdcpend->conn->tx_curs_fin,
> &cdcpend->cursor);
> /* sndbuf_space is decreased in smc_sendmsg */
>@@ -114,9 +116,6 @@ int smc_cdc_msg_send(struct smc_connection *conn,
> union smc_host_cursor cfed;
> int rc;
>
>- if (unlikely(!READ_ONCE(conn->sndbuf_desc)))
>- return -ENOBUFS;
>-
> smc_cdc_add_pending_send(conn, pend);
>
> conn->tx_cdc_seq++;
>--
>1.8.3.1