net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error generated by client
authorD. Wythe <alibuda@linux.alibaba.com>
Wed, 2 Mar 2022 13:25:11 +0000 (21:25 +0800)
committerDavid S. Miller <davem@davemloft.net>
Thu, 3 Mar 2022 10:34:18 +0000 (10:34 +0000)
commit0537f0a2151375dcf90c1bbfda6a0aaf57164e89
treec0d3e478c5976f8bec5a201d1cbb30e5dfeb9bfb
parentbd6f1fd5d33dfe5d1b4f2502d3694a7cc13f166d
net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error generated by client

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>
net/smc/smc_core.c