| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.10 052/105] net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error generated by client | Date | Mon, 7 Mar 2022 10:18:55 +0100 |
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From: D. Wythe <alibuda@linux.alibaba.com>
commit 0537f0a2151375dcf90c1bbfda6a0aaf57164e89 upstream.
The main reason for this unexpected SMC_CLC_DECL_ERR_REGRMB in client dues to following execution sequence:
Server Conn A: Server Conn B: Client Conn B:
smc_lgr_unregister_conn smc_lgr_register_conn smc_clc_send_accept -> smc_rtoken_add smcr_buf_unuse -> Client Conn A: smc_rtoken_delete
smc_lgr_unregister_conn() makes current link available to assigned to new incoming connection, while smcr_buf_unuse() has not executed yet, which means that smc_rtoken_add may fail because of insufficient rtoken_entry, reversing their execution order will avoid this problem.
Fixes: 3e034725c0d8 ("net/smc: common functions for RMBs and send buffers") Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/smc/smc_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -662,8 +662,8 @@ void smc_conn_free(struct smc_connection cancel_work_sync(&conn->abort_work); } if (!list_empty(&lgr->list)) { - smc_lgr_unregister_conn(conn); smc_buf_unuse(conn, lgr); /* allow buffer reuse */ + smc_lgr_unregister_conn(conn); } if (!lgr->conns_num)
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