From 7e5cea7a6c9776f494cc9c98e08f2974cd23e23e Mon Sep 17 00:00:00 2001 From: "D. Wythe" Date: Sat, 28 May 2022 16:06:22 +0800 Subject: [PATCH] net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error cause by server stable inclusion from stable-v5.10.104 commit 9bb7237cc740b9f4f8904d1823ed71c71a5e83e8 bugzilla: https://gitee.com/openeuler/kernel/issues/I56XAC Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9bb7237cc740b9f4f8904d1823ed71c71a5e83e8 -------------------------------- commit 4940a1fdf31c39f0806ac831cde333134862030b upstream. The problem of SMC_CLC_DECL_ERR_REGRMB on the server is very clear. Based on the fact that whether a new SMC connection can be accepted or not depends on not only the limit of conn nums, but also the available entries of rtoken. Since the rtoken release is trigger by peer, while the conn nums is decrease by local, tons of thing can happen in this time difference. This only thing that needs to be mentioned is that now all connection creations are completely protected by smc_server_lgr_pending lock, it's enough to check only the available entries in rtokens_used_mask. Fixes: cd6851f30386 ("smc: remote memory buffers (RMBs)") Signed-off-by: D. Wythe Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yu Liao Reviewed-by: Wei Li Signed-off-by: Zheng Zengkai --- net/smc/smc_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 18c4eefc88e6..d69aac6c1fce 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1316,7 +1316,8 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) (ini->smcd_version == SMC_V2 || lgr->vlan_id == ini->vlan_id) && (role == SMC_CLNT || ini->is_smcd || - lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) { + (lgr->conns_num < SMC_RMBS_PER_LGR_MAX && + !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) { /* link group found */ ini->first_contact_local = 0; conn->lgr = lgr; -- GitLab