diff --git a/net/smc/smc.h b/net/smc/smc.h index 1a4fc1c6c4ab..3d0b8e300deb 100644 --- a/net/smc/smc.h +++ b/net/smc/smc.h @@ -221,6 +221,7 @@ struct smc_connection { */ u64 peer_token; /* SMC-D token of peer */ u8 killed : 1; /* abnormal termination */ + u8 freed : 1; /* normal termiation */ u8 out_of_sync : 1; /* out of sync with peer */ }; diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 8935ef4811b0..fcb5e15bfa95 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -218,7 +218,6 @@ static void smc_lgr_unregister_conn(struct smc_connection *conn) __smc_lgr_unregister_conn(conn); } write_unlock_bh(&lgr->conns_lock); - conn->lgr = NULL; } int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb) @@ -752,6 +751,7 @@ int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk, lnk->path_mtu = lnk->smcibdev->pattr[lnk->ibport - 1].active_mtu; lnk->link_id = smcr_next_link_id(lgr); lnk->lgr = lgr; + smc_lgr_hold(lgr); /* lgr_put in smcr_link_clear() */ lnk->link_idx = link_idx; smc_ibdev_cnt_inc(lnk); smcr_copy_dev_info_to_link(lnk); @@ -806,6 +806,7 @@ out: lnk->state = SMC_LNK_UNUSED; if (!atomic_dec_return(&smcibdev->lnk_cnt)) wake_up(&smcibdev->lnks_deleted); + smc_lgr_put(lgr); /* lgr_hold above */ return rc; } @@ -844,6 +845,7 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini) lgr->terminating = 0; lgr->freeing = 0; lgr->vlan_id = ini->vlan_id; + refcount_set(&lgr->refcnt, 1); /* set lgr refcnt to 1 */ mutex_init(&lgr->sndbufs_lock); mutex_init(&lgr->rmbs_lock); rwlock_init(&lgr->conns_lock); @@ -1130,8 +1132,19 @@ void smc_conn_free(struct smc_connection *conn) { struct smc_link_group *lgr = conn->lgr; - if (!lgr) + if (!lgr || conn->freed) + /* Connection has never been registered in a + * link group, or has already been freed. + */ return; + + conn->freed = 1; + if (!conn->alert_token_local) + /* Connection has already unregistered from + * link group. + */ + goto lgr_put; + if (lgr->is_smcd) { if (!list_empty(&lgr->list)) smc_ism_unset_conn(conn); @@ -1148,6 +1161,8 @@ void smc_conn_free(struct smc_connection *conn) if (!lgr->conns_num) smc_lgr_schedule_free_work(lgr); +lgr_put: + smc_lgr_put(lgr); /* lgr_hold in smc_conn_create() */ } /* unregister a link from a buf_desc */ @@ -1206,9 +1221,10 @@ static void smcr_rtoken_clear_link(struct smc_link *lnk) /* must be called under lgr->llc_conf_mutex lock */ void smcr_link_clear(struct smc_link *lnk, bool log) { + struct smc_link_group *lgr = lnk->lgr; struct smc_ib_device *smcibdev; - if (!lnk->lgr || lnk->state == SMC_LNK_UNUSED) + if (!lgr || lnk->state == SMC_LNK_UNUSED) return; lnk->peer_qpn = 0; smc_llc_link_clear(lnk, log); @@ -1226,6 +1242,7 @@ void smcr_link_clear(struct smc_link *lnk, bool log) lnk->state = SMC_LNK_UNUSED; if (!atomic_dec_return(&smcibdev->lnk_cnt)) wake_up(&smcibdev->lnks_deleted); + smc_lgr_put(lgr); /* lgr_hold in smcr_link_init() */ } static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb, @@ -1290,6 +1307,21 @@ static void smc_lgr_free_bufs(struct smc_link_group *lgr) __smc_lgr_free_bufs(lgr, true); } +/* won't be freed until no one accesses to lgr anymore */ +static void __smc_lgr_free(struct smc_link_group *lgr) +{ + smc_lgr_free_bufs(lgr); + if (lgr->is_smcd) { + if (!atomic_dec_return(&lgr->smcd->lgr_cnt)) + wake_up(&lgr->smcd->lgrs_deleted); + } else { + smc_wr_free_lgr_mem(lgr); + if (!atomic_dec_return(&lgr_cnt)) + wake_up(&lgrs_deleted); + } + kfree(lgr); +} + /* remove a link group */ static void smc_lgr_free(struct smc_link_group *lgr) { @@ -1305,19 +1337,23 @@ static void smc_lgr_free(struct smc_link_group *lgr) smc_llc_lgr_clear(lgr); } - smc_lgr_free_bufs(lgr); destroy_workqueue(lgr->tx_wq); if (lgr->is_smcd) { smc_ism_put_vlan(lgr->smcd, lgr->vlan_id); put_device(&lgr->smcd->dev); - if (!atomic_dec_return(&lgr->smcd->lgr_cnt)) - wake_up(&lgr->smcd->lgrs_deleted); - } else { - smc_wr_free_lgr_mem(lgr); - if (!atomic_dec_return(&lgr_cnt)) - wake_up(&lgrs_deleted); } - kfree(lgr); + smc_lgr_put(lgr); /* theoretically last lgr_put */ +} + +void smc_lgr_hold(struct smc_link_group *lgr) +{ + refcount_inc(&lgr->refcnt); +} + +void smc_lgr_put(struct smc_link_group *lgr) +{ + if (refcount_dec_and_test(&lgr->refcnt)) + __smc_lgr_free(lgr); } static void smc_sk_wake_ups(struct smc_sock *smc) @@ -1856,6 +1892,8 @@ create: goto out; } } + smc_lgr_hold(conn->lgr); /* lgr_put in smc_conn_free() */ + conn->freed = 0; conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE; conn->local_tx_ctrl.len = SMC_WR_TX_SIZE; conn->urg_state = SMC_URG_READ; diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index 521c64a3d8d3..f8b5397a9dbe 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -249,6 +249,7 @@ struct smc_link_group { u8 terminating : 1;/* lgr is terminating */ u8 freeing : 1; /* lgr is being freed */ + refcount_t refcnt; /* lgr reference count */ bool is_smcd; /* SMC-R or SMC-D */ u8 smc_version; u8 negotiated_eid[SMC_MAX_EID_LEN]; @@ -487,6 +488,8 @@ struct smc_clc_msg_accept_confirm; void smc_lgr_cleanup_early(struct smc_link_group *lgr); void smc_lgr_terminate_sched(struct smc_link_group *lgr); +void smc_lgr_hold(struct smc_link_group *lgr); +void smc_lgr_put(struct smc_link_group *lgr); void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport); void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport); void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid,