diff mbox series

[net,v2,1/2] net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error generated by client

Message ID 1646226968-2315-2-git-send-email-alibuda@linux.alibaba.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series fix unexpected SMC_CLC_DECL_ERR_REGRMB error | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers fail 1 blamed authors not CCed: ubraun@linux.vnet.ibm.com; 1 maintainers not CCed: ubraun@linux.vnet.ibm.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 9 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

D. Wythe March 2, 2022, 1:16 p.m. UTC 
From: "D. Wythe" <alibuda@linux.alibaba.com>

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>
---
 net/smc/smc_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 29525d0..f8c9675 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -1161,8 +1161,8 @@  void smc_conn_free(struct smc_connection *conn)
 			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)