From a0a62ee15a829ebf8aeec55a4f1688230439b3e0 Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Wed, 9 Oct 2019 10:07:44 +0200 Subject: [PATCH] net/smc: separate locks for SMCD and SMCR link group lists This patch introduces separate locks for the split SMCD and SMCR link group lists. Signed-off-by: Ursula Braun Signed-off-by: Karsten Graul Signed-off-by: Jakub Kicinski --- include/net/smc.h | 1 + net/smc/smc_core.c | 57 ++++++++++++++++++++++++++++++++++------------ net/smc/smc_ism.c | 1 + 3 files changed, 44 insertions(+), 15 deletions(-) diff --git a/include/net/smc.h b/include/net/smc.h index c08e8c4156734..438bb0261f45d 100644 --- a/include/net/smc.h +++ b/include/net/smc.h @@ -76,6 +76,7 @@ struct smcd_dev { u8 pnetid[SMC_MAX_PNETID_LEN]; bool pnetid_by_user; struct list_head lgr_list; + spinlock_t lgr_lock; }; struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name, diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 46d679542b87f..949b1914e11a5 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -42,6 +42,19 @@ static struct smc_lgr_list smc_lgr_list = { /* established link groups */ static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb, struct smc_buf_desc *buf_desc); +/* return head of link group list and its lock for a given link group */ +static inline struct list_head *smc_lgr_list_head(struct smc_link_group *lgr, + spinlock_t **lgr_lock) +{ + if (lgr->is_smcd) { + *lgr_lock = &lgr->smcd->lgr_lock; + return &lgr->smcd->lgr_list; + } + + *lgr_lock = &smc_lgr_list.lock; + return &smc_lgr_list.list; +} + static void smc_lgr_schedule_free_work(struct smc_link_group *lgr) { /* client link group creation always follows the server link group @@ -157,19 +170,21 @@ static void smc_lgr_free_work(struct work_struct *work) struct smc_link_group *lgr = container_of(to_delayed_work(work), struct smc_link_group, free_work); + spinlock_t *lgr_lock; bool conns; - spin_lock_bh(&smc_lgr_list.lock); + smc_lgr_list_head(lgr, &lgr_lock); + spin_lock_bh(lgr_lock); read_lock_bh(&lgr->conns_lock); conns = RB_EMPTY_ROOT(&lgr->conns_all); read_unlock_bh(&lgr->conns_lock); if (!conns) { /* number of lgr connections is no longer zero */ - spin_unlock_bh(&smc_lgr_list.lock); + spin_unlock_bh(lgr_lock); return; } if (!list_empty(&lgr->list)) list_del_init(&lgr->list); /* remove from smc_lgr_list */ - spin_unlock_bh(&smc_lgr_list.lock); + spin_unlock_bh(lgr_lock); if (!lgr->is_smcd && !lgr->terminating) { struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK]; @@ -200,6 +215,7 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini) struct smc_link_group *lgr; struct list_head *lgr_list; struct smc_link *lnk; + spinlock_t *lgr_lock; u8 rndvec[3]; int rc = 0; int i; @@ -235,6 +251,7 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini) lgr->peer_gid = ini->ism_gid; lgr->smcd = ini->ism_dev; lgr_list = &ini->ism_dev->lgr_list; + lgr_lock = &lgr->smcd->lgr_lock; } else { /* SMC-R specific settings */ lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT; @@ -248,6 +265,7 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini) lnk->smcibdev = ini->ib_dev; lnk->ibport = ini->ib_port; lgr_list = &smc_lgr_list.list; + lgr_lock = &smc_lgr_list.lock; lnk->path_mtu = ini->ib_dev->pattr[ini->ib_port - 1].active_mtu; if (!ini->ib_dev->initialized) @@ -277,9 +295,9 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini) goto destroy_qp; } smc->conn.lgr = lgr; - spin_lock_bh(&smc_lgr_list.lock); + spin_lock_bh(lgr_lock); list_add(&lgr->list, lgr_list); - spin_unlock_bh(&smc_lgr_list.lock); + spin_unlock_bh(lgr_lock); return 0; destroy_qp: @@ -442,11 +460,15 @@ static void smc_lgr_free(struct smc_link_group *lgr) void smc_lgr_forget(struct smc_link_group *lgr) { - spin_lock_bh(&smc_lgr_list.lock); + struct list_head *lgr_list; + spinlock_t *lgr_lock; + + lgr_list = smc_lgr_list_head(lgr, &lgr_lock); + spin_lock_bh(lgr_lock); /* do not use this link group for new connections */ - if (!list_empty(&lgr->list)) - list_del_init(&lgr->list); - spin_unlock_bh(&smc_lgr_list.lock); + if (!list_empty(lgr_list)) + list_del_init(lgr_list); + spin_unlock_bh(lgr_lock); } /* terminate linkgroup abnormally */ @@ -487,9 +509,12 @@ static void __smc_lgr_terminate(struct smc_link_group *lgr) void smc_lgr_terminate(struct smc_link_group *lgr) { - spin_lock_bh(&smc_lgr_list.lock); + spinlock_t *lgr_lock; + + smc_lgr_list_head(lgr, &lgr_lock); + spin_lock_bh(lgr_lock); __smc_lgr_terminate(lgr); - spin_unlock_bh(&smc_lgr_list.lock); + spin_unlock_bh(lgr_lock); } /* Called when IB port is terminated */ @@ -514,7 +539,7 @@ void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan) LIST_HEAD(lgr_free_list); /* run common cleanup function and build free list */ - spin_lock_bh(&smc_lgr_list.lock); + spin_lock_bh(&dev->lgr_lock); list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) { if ((!peer_gid || lgr->peer_gid == peer_gid) && (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) { @@ -522,7 +547,7 @@ void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan) list_move(&lgr->list, &lgr_free_list); } } - spin_unlock_bh(&smc_lgr_list.lock); + spin_unlock_bh(&dev->lgr_lock); /* cancel the regular free workers and actually free lgrs */ list_for_each_entry_safe(lgr, l, &lgr_free_list, list) { @@ -609,9 +634,11 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) struct list_head *lgr_list; struct smc_link_group *lgr; enum smc_lgr_role role; + spinlock_t *lgr_lock; int rc = 0; lgr_list = ini->is_smcd ? &ini->ism_dev->lgr_list : &smc_lgr_list.list; + lgr_lock = ini->is_smcd ? &ini->ism_dev->lgr_lock : &smc_lgr_list.lock; ini->cln_first_contact = SMC_FIRST_CONTACT; role = smc->listen_smc ? SMC_SERV : SMC_CLNT; if (role == SMC_CLNT && ini->srv_first_contact) @@ -619,7 +646,7 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) goto create; /* determine if an existing link group can be reused */ - spin_lock_bh(&smc_lgr_list.lock); + spin_lock_bh(lgr_lock); list_for_each_entry(lgr, lgr_list, list) { write_lock_bh(&lgr->conns_lock); if ((ini->is_smcd ? @@ -640,7 +667,7 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) } write_unlock_bh(&lgr->conns_lock); } - spin_unlock_bh(&smc_lgr_list.lock); + spin_unlock_bh(lgr_lock); if (role == SMC_CLNT && !ini->srv_first_contact && ini->cln_first_contact == SMC_FIRST_CONTACT) { diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c index 674eb5ae23201..34dc619655e8e 100644 --- a/net/smc/smc_ism.c +++ b/net/smc/smc_ism.c @@ -286,6 +286,7 @@ struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name, smc_pnetid_by_dev_port(parent, 0, smcd->pnetid); spin_lock_init(&smcd->lock); + spin_lock_init(&smcd->lgr_lock); INIT_LIST_HEAD(&smcd->vlan); INIT_LIST_HEAD(&smcd->lgr_list); smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",