diff options
Diffstat (limited to 'drivers/target/target_core_transport.c')
| -rw-r--r-- | drivers/target/target_core_transport.c | 116 |
1 files changed, 84 insertions, 32 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index aa517c4fadb9..df2059984e14 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -341,7 +341,6 @@ void __transport_register_session( &buf[0], PR_REG_ISID_LEN); se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]); } - kref_get(&se_nacl->acl_kref); spin_lock_irq(&se_nacl->nacl_sess_lock); /* @@ -424,14 +423,27 @@ static void target_complete_nacl(struct kref *kref) { struct se_node_acl *nacl = container_of(kref, struct se_node_acl, acl_kref); + struct se_portal_group *se_tpg = nacl->se_tpg; - complete(&nacl->acl_free_comp); + if (!nacl->dynamic_stop) { + complete(&nacl->acl_free_comp); + return; + } + + mutex_lock(&se_tpg->acl_node_mutex); + list_del(&nacl->acl_list); + mutex_unlock(&se_tpg->acl_node_mutex); + + core_tpg_wait_for_nacl_pr_ref(nacl); + core_free_device_list_for_node(nacl, se_tpg); + kfree(nacl); } void target_put_nacl(struct se_node_acl *nacl) { kref_put(&nacl->acl_kref, target_complete_nacl); } +EXPORT_SYMBOL(target_put_nacl); void transport_deregister_session_configfs(struct se_session *se_sess) { @@ -464,6 +476,42 @@ EXPORT_SYMBOL(transport_deregister_session_configfs); void transport_free_session(struct se_session *se_sess) { + struct se_node_acl *se_nacl = se_sess->se_node_acl; + + /* + * Drop the se_node_acl->nacl_kref obtained from within + * core_tpg_get_initiator_node_acl(). + */ + if (se_nacl) { + struct se_portal_group *se_tpg = se_nacl->se_tpg; + const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo; + unsigned long flags; + + se_sess->se_node_acl = NULL; + + /* + * Also determine if we need to drop the extra ->cmd_kref if + * it had been previously dynamically generated, and + * the endpoint is not caching dynamic ACLs. + */ + mutex_lock(&se_tpg->acl_node_mutex); + if (se_nacl->dynamic_node_acl && + !se_tfo->tpg_check_demo_mode_cache(se_tpg)) { + spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags); + if (list_empty(&se_nacl->acl_sess_list)) + se_nacl->dynamic_stop = true; + spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags); + + if (se_nacl->dynamic_stop) + list_del(&se_nacl->acl_list); + } + mutex_unlock(&se_tpg->acl_node_mutex); + + if (se_nacl->dynamic_stop) + target_put_nacl(se_nacl); + + target_put_nacl(se_nacl); + } if (se_sess->sess_cmd_map) { percpu_ida_destroy(&se_sess->sess_tag_pool); kvfree(se_sess->sess_cmd_map); @@ -475,16 +523,12 @@ EXPORT_SYMBOL(transport_free_session); void transport_deregister_session(struct se_session *se_sess) { struct se_portal_group *se_tpg = se_sess->se_tpg; - const struct target_core_fabric_ops *se_tfo; - struct se_node_acl *se_nacl; unsigned long flags; - bool comp_nacl = true, drop_nacl = false; if (!se_tpg) { transport_free_session(se_sess); return; } - se_tfo = se_tpg->se_tpg_tfo; spin_lock_irqsave(&se_tpg->session_lock, flags); list_del(&se_sess->sess_list); @@ -492,37 +536,16 @@ void transport_deregister_session(struct se_session *se_sess) se_sess->fabric_sess_ptr = NULL; spin_unlock_irqrestore(&se_tpg->session_lock, flags); - /* - * Determine if we need to do extra work for this initiator node's - * struct se_node_acl if it had been previously dynamically generated. - */ - se_nacl = se_sess->se_node_acl; - - mutex_lock(&se_tpg->acl_node_mutex); - if (se_nacl && se_nacl->dynamic_node_acl) { - if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) { - list_del(&se_nacl->acl_list); - se_tpg->num_node_acls--; - drop_nacl = true; - } - } - mutex_unlock(&se_tpg->acl_node_mutex); - - if (drop_nacl) { - core_tpg_wait_for_nacl_pr_ref(se_nacl); - core_free_device_list_for_node(se_nacl, se_tpg); - kfree(se_nacl); - comp_nacl = false; - } pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n", se_tpg->se_tpg_tfo->get_fabric_name()); /* * If last kref is dropping now for an explicit NodeACL, awake sleeping * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group - * removal context. + * removal context from within transport_free_session() code. + * + * For dynamic ACL, target_put_nacl() uses target_complete_nacl() + * to release all remaining generate_node_acl=1 created ACL resources. */ - if (se_nacl && comp_nacl) - target_put_nacl(se_nacl); transport_free_session(se_sess); } @@ -2657,10 +2680,39 @@ void target_wait_for_sess_cmds(struct se_session *se_sess) } EXPORT_SYMBOL(target_wait_for_sess_cmds); +static void target_lun_confirm(struct percpu_ref *ref) +{ + struct se_lun *lun = container_of(ref, struct se_lun, lun_ref); + + complete(&lun->lun_ref_comp); +} + void transport_clear_lun_ref(struct se_lun *lun) { - percpu_ref_kill(&lun->lun_ref); + /* + * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop + * the initial reference and schedule confirm kill to be + * executed after one full RCU grace period has completed. + */ + percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm); + /* + * The first completion waits for percpu_ref_switch_to_atomic_rcu() + * to call target_lun_confirm after lun->lun_ref has been marked + * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t + * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref + * fails for all new incoming I/O. + */ wait_for_completion(&lun->lun_ref_comp); + /* + * The second completion waits for percpu_ref_put_many() to + * invoke ->release() after lun->lun_ref has switched to + * atomic_t mode, and lun->lun_ref.count has reached zero. + * + * At this point all target-core lun->lun_ref references have + * been dropped via transport_lun_remove_cmd(), and it's safe + * to proceed with the remaining LUN shutdown. + */ + wait_for_completion(&lun->lun_shutdown_comp); } static bool |