From becd9be6069e7b183c084f460f0eb363e43cc487 Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Sat, 18 Mar 2023 20:56:12 -0500 Subject: scsi: target: Move sess cmd counter to new struct iSCSI needs to wait on outstanding commands like how SRP and the FC/FCoE drivers do. It can't use target_stop_session() because for MCS support we can't stop the entire session during recovery because if other connections are OK then we want to be able to continue to execute I/O on them. Move the per session cmd counters to a new struct so iSCSI can allocate them per connection. The xcopy code can also just not allocate in the future since it doesn't need to track commands. Signed-off-by: Mike Christie Link: https://lore.kernel.org/r/20230319015620.96006-2-michael.christie@oracle.com Reviewed-by: Maurizio Lombardi Signed-off-by: Martin K. Petersen --- drivers/target/target_core_tpg.c | 2 +- drivers/target/target_core_transport.c | 135 +++++++++++++++++++++++---------- 2 files changed, 97 insertions(+), 40 deletions(-) (limited to 'drivers') diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c index 736847c933e5..8ebccdbd94f0 100644 --- a/drivers/target/target_core_tpg.c +++ b/drivers/target/target_core_tpg.c @@ -328,7 +328,7 @@ static void target_shutdown_sessions(struct se_node_acl *acl) restart: spin_lock_irqsave(&acl->nacl_sess_lock, flags); list_for_each_entry(sess, &acl->acl_sess_list, sess_acl_list) { - if (atomic_read(&sess->stopped)) + if (sess->cmd_cnt && atomic_read(&sess->cmd_cnt->stopped)) continue; list_del_init(&sess->sess_acl_list); diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 5926316252eb..3d6034f00dcd 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -220,11 +220,49 @@ void transport_subsystem_check_init(void) sub_api_initialized = 1; } -static void target_release_sess_cmd_refcnt(struct percpu_ref *ref) +static void target_release_cmd_refcnt(struct percpu_ref *ref) { - struct se_session *sess = container_of(ref, typeof(*sess), cmd_count); + struct target_cmd_counter *cmd_cnt = container_of(ref, + typeof(*cmd_cnt), + refcnt); + wake_up(&cmd_cnt->refcnt_wq); +} + +static struct target_cmd_counter *target_alloc_cmd_counter(void) +{ + struct target_cmd_counter *cmd_cnt; + int rc; + + cmd_cnt = kzalloc(sizeof(*cmd_cnt), GFP_KERNEL); + if (!cmd_cnt) + return NULL; - wake_up(&sess->cmd_count_wq); + init_completion(&cmd_cnt->stop_done); + init_waitqueue_head(&cmd_cnt->refcnt_wq); + atomic_set(&cmd_cnt->stopped, 0); + + rc = percpu_ref_init(&cmd_cnt->refcnt, target_release_cmd_refcnt, 0, + GFP_KERNEL); + if (rc) + goto free_cmd_cnt; + + return cmd_cnt; + +free_cmd_cnt: + kfree(cmd_cnt); + return NULL; +} + +static void target_free_cmd_counter(struct target_cmd_counter *cmd_cnt) +{ + /* + * Drivers like loop do not call target_stop_session during session + * shutdown so we have to drop the ref taken at init time here. + */ + if (!atomic_read(&cmd_cnt->stopped)) + percpu_ref_put(&cmd_cnt->refcnt); + + percpu_ref_exit(&cmd_cnt->refcnt); } /** @@ -238,25 +276,17 @@ int transport_init_session(struct se_session *se_sess) INIT_LIST_HEAD(&se_sess->sess_list); INIT_LIST_HEAD(&se_sess->sess_acl_list); spin_lock_init(&se_sess->sess_cmd_lock); - init_waitqueue_head(&se_sess->cmd_count_wq); - init_completion(&se_sess->stop_done); - atomic_set(&se_sess->stopped, 0); - return percpu_ref_init(&se_sess->cmd_count, - target_release_sess_cmd_refcnt, 0, GFP_KERNEL); + se_sess->cmd_cnt = target_alloc_cmd_counter(); + if (!se_sess->cmd_cnt) + return -ENOMEM; + + return 0; } EXPORT_SYMBOL(transport_init_session); void transport_uninit_session(struct se_session *se_sess) { - /* - * Drivers like iscsi and loop do not call target_stop_session - * during session shutdown so we have to drop the ref taken at init - * time here. - */ - if (!atomic_read(&se_sess->stopped)) - percpu_ref_put(&se_sess->cmd_count); - - percpu_ref_exit(&se_sess->cmd_count); + target_free_cmd_counter(se_sess->cmd_cnt); } /** @@ -2970,9 +3000,16 @@ int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref) se_cmd->se_cmd_flags |= SCF_ACK_KREF; } - if (!percpu_ref_tryget_live(&se_sess->cmd_count)) - ret = -ESHUTDOWN; - + /* + * Users like xcopy do not use counters since they never do a stop + * and wait. + */ + if (se_sess->cmd_cnt) { + if (!percpu_ref_tryget_live(&se_sess->cmd_cnt->refcnt)) + ret = -ESHUTDOWN; + else + se_cmd->cmd_cnt = se_sess->cmd_cnt; + } if (ret && ack_kref) target_put_sess_cmd(se_cmd); @@ -2993,7 +3030,7 @@ static void target_free_cmd_mem(struct se_cmd *cmd) static void target_release_cmd_kref(struct kref *kref) { struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref); - struct se_session *se_sess = se_cmd->se_sess; + struct target_cmd_counter *cmd_cnt = se_cmd->cmd_cnt; struct completion *free_compl = se_cmd->free_compl; struct completion *abrt_compl = se_cmd->abrt_compl; @@ -3004,7 +3041,8 @@ static void target_release_cmd_kref(struct kref *kref) if (abrt_compl) complete(abrt_compl); - percpu_ref_put(&se_sess->cmd_count); + if (cmd_cnt) + percpu_ref_put(&cmd_cnt->refcnt); } /** @@ -3123,46 +3161,65 @@ void target_show_cmd(const char *pfx, struct se_cmd *cmd) } EXPORT_SYMBOL(target_show_cmd); -static void target_stop_session_confirm(struct percpu_ref *ref) +static void target_stop_cmd_counter_confirm(struct percpu_ref *ref) +{ + struct target_cmd_counter *cmd_cnt = container_of(ref, + struct target_cmd_counter, + refcnt); + complete_all(&cmd_cnt->stop_done); +} + +/** + * target_stop_cmd_counter - Stop new IO from being added to the counter. + * @cmd_cnt: counter to stop + */ +static void target_stop_cmd_counter(struct target_cmd_counter *cmd_cnt) { - struct se_session *se_sess = container_of(ref, struct se_session, - cmd_count); - complete_all(&se_sess->stop_done); + pr_debug("Stopping command counter.\n"); + if (!atomic_cmpxchg(&cmd_cnt->stopped, 0, 1)) + percpu_ref_kill_and_confirm(&cmd_cnt->refcnt, + target_stop_cmd_counter_confirm); } /** * target_stop_session - Stop new IO from being queued on the session. - * @se_sess: session to stop + * @se_sess: session to stop */ void target_stop_session(struct se_session *se_sess) { - pr_debug("Stopping session queue.\n"); - if (atomic_cmpxchg(&se_sess->stopped, 0, 1) == 0) - percpu_ref_kill_and_confirm(&se_sess->cmd_count, - target_stop_session_confirm); + target_stop_cmd_counter(se_sess->cmd_cnt); } EXPORT_SYMBOL(target_stop_session); /** - * target_wait_for_sess_cmds - Wait for outstanding commands - * @se_sess: session to wait for active I/O + * target_wait_for_cmds - Wait for outstanding cmds. + * @cmd_cnt: counter to wait for active I/O for. */ -void target_wait_for_sess_cmds(struct se_session *se_sess) +static void target_wait_for_cmds(struct target_cmd_counter *cmd_cnt) { int ret; - WARN_ON_ONCE(!atomic_read(&se_sess->stopped)); + WARN_ON_ONCE(!atomic_read(&cmd_cnt->stopped)); do { pr_debug("Waiting for running cmds to complete.\n"); - ret = wait_event_timeout(se_sess->cmd_count_wq, - percpu_ref_is_zero(&se_sess->cmd_count), - 180 * HZ); + ret = wait_event_timeout(cmd_cnt->refcnt_wq, + percpu_ref_is_zero(&cmd_cnt->refcnt), + 180 * HZ); } while (ret <= 0); - wait_for_completion(&se_sess->stop_done); + wait_for_completion(&cmd_cnt->stop_done); pr_debug("Waiting for cmds done.\n"); } + +/** + * target_wait_for_sess_cmds - Wait for outstanding commands + * @se_sess: session to wait for active I/O + */ +void target_wait_for_sess_cmds(struct se_session *se_sess) +{ + target_wait_for_cmds(se_sess->cmd_cnt); +} EXPORT_SYMBOL(target_wait_for_sess_cmds); /* -- cgit v1.2.3