[PATCH net-next v2 02/10] net/smc: fix SMC_CLC_DECL_ERR_REGRMB without smc_server_lgr_pending
From: "D. Wythe" <alibuda@linux.alibaba.com>
Date: 2022-08-26 09:52:13
Also in:
linux-rdma, linux-s390
Subsystem:
networking [general], shared memory communications (smc) sockets, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, D. Wythe, Dust Li, Sidraya Jayagond, Wenjia Zhang, Linus Torvalds
From: "D. Wythe" <alibuda@linux.alibaba.com>
As commit 4940a1fdf31c ("net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB
error cause by server") mentioned, it works only when all connection
creations are completely protected by smc_server_lgr_pending, since we
already remove this lock, we need to re-fix the issues.
Fixes: 4940a1fdf31c ("net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error cause by server")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
---
net/smc/af_smc.c | 2 ++
net/smc/smc_core.c | 11 ++++++++---
net/smc/smc_core.h | 18 ++++++++++++++++++
3 files changed, 28 insertions(+), 3 deletions(-)
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index d0e6bec..ddca170 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c@@ -2411,6 +2411,7 @@ static void smc_listen_work(struct work_struct *work) if (rc) goto out_unlock; } + smc_conn_leave_rtoken_pending(new_smc, ini); smc_conn_save_peer_info(new_smc, cclc); smc_listen_out_connected(new_smc); SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
@@ -2420,6 +2421,7 @@ static void smc_listen_work(struct work_struct *work) if (ini->is_smcd) mutex_unlock(&smc_server_lgr_pending); out_decl: + smc_conn_leave_rtoken_pending(new_smc, ini); smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0, proposal_version); out_free:
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index cfaddf2..f93c69f 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c@@ -2167,14 +2167,19 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) lgr->vlan_id == ini->vlan_id) && (role == SMC_CLNT || ini->is_smcd || (lgr->conns_num < SMC_RMBS_PER_LGR_MAX && - !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) { + (SMC_RMBS_PER_LGR_MAX - + bitmap_weight(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) + > atomic_read(&lgr->rtoken_pendings))))) { /* link group found */ ini->first_contact_local = 0; conn->lgr = lgr; rc = smc_lgr_register_conn(conn, false); write_unlock_bh(&lgr->conns_lock); - if (!rc && delayed_work_pending(&lgr->free_work)) - cancel_delayed_work(&lgr->free_work); + if (!rc) { + smc_conn_enter_rtoken_pending(smc, ini); + if (delayed_work_pending(&lgr->free_work)) + cancel_delayed_work(&lgr->free_work); + } break; } write_unlock_bh(&lgr->conns_lock);
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 3c3bc11..a304ef3 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h@@ -298,6 +298,9 @@ struct smc_link_group { struct rb_root conns_all; /* connection tree */ rwlock_t conns_lock; /* protects conns_all */ unsigned int conns_num; /* current # of connections */ + atomic_t rtoken_pendings;/* number of connection that + * lgr assigned but no rtoken got yet + */ unsigned short vlan_id; /* vlan id of link group */ struct list_head sndbufs[SMC_RMBE_SIZES];/* tx buffers */
@@ -609,6 +612,21 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr, int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb); void smcr_link_cluster_on_link_state(struct smc_link *lnk); +static inline void smc_conn_enter_rtoken_pending(struct smc_sock *smc, struct smc_init_info *ini) +{ + struct smc_link_group *lgr = smc->conn.lgr; + + if (lgr && !ini->first_contact_local) + atomic_inc(&lgr->rtoken_pendings); +} + +static inline void smc_conn_leave_rtoken_pending(struct smc_sock *smc, struct smc_init_info *ini) +{ + struct smc_link_group *lgr = smc->conn.lgr; + + if (lgr && !ini->first_contact_local) + atomic_dec(&lgr->rtoken_pendings); +} static inline struct smc_link_group *smc_get_lgr(struct smc_link *link) {
--
1.8.3.1