[PATCH net 3/5] net/smc: allow cdc msg send rather than drop it with NULL sndbuf_desc

D. Wythe
2023-10-11T07:33:40Z

From: "D. Wythe" <alibuda@linux.alibaba.com>

This patch re-fix the issues memtianed by commit 22a825c541d7
("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
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>
---
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