From 7b2cc7dc0dbf5da9cf16ffcf1ca8e904ab574ff5 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 22 Jun 2018 14:52:59 -0700 Subject: [PATCH] scsi: target: Simplify the code for waiting for command completion Instead of embedding the completion that is used for waiting for command completion in struct se_cmd, let the context that waits for command completion allocate it. This makes it possible to have a single code path for non-aborted and aborted commands in target_release_cmd_kref() and avoids that transport_generic_free_cmd() has to call cmd->se_tfo->release_cmd() directly. This patch does not change any functionality. Note: transport_generic_free_cmd() only waits until the se_cmd reference count has reached zero after it has set both CMD_T_FABRIC_STOP and CMD_T_ABORTED. Signed-off-by: Bart Van Assche Reviewed-by: Mike Christie Cc: Hannes Reinecke Cc: Christoph Hellwig Signed-off-by: Martin K. Petersen --- drivers/target/target_core_transport.c | 24 ++++++++---------------- include/target/target_core_base.h | 2 +- 2 files changed, 9 insertions(+), 17 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index ebd54fc1f13a..cb48dbc2c9ba 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -1309,7 +1309,7 @@ void transport_init_se_cmd( INIT_LIST_HEAD(&cmd->se_cmd_list); INIT_LIST_HEAD(&cmd->state_list); init_completion(&cmd->t_transport_stop_comp); - init_completion(&cmd->cmd_wait_comp); + cmd->compl = NULL; spin_lock_init(&cmd->t_state_lock); INIT_WORK(&cmd->work, NULL); kref_init(&cmd->cmd_kref); @@ -2658,6 +2658,7 @@ static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas) */ int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks) { + DECLARE_COMPLETION_ONSTACK(compl); int ret = 0; bool aborted = false, tas = false; @@ -2676,12 +2677,13 @@ int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks) if (cmd->se_lun) transport_lun_remove_cmd(cmd); } + if (aborted) + cmd->compl = &compl; if (!aborted || tas) ret = target_put_sess_cmd(cmd); if (aborted) { pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag); - wait_for_completion(&cmd->cmd_wait_comp); - cmd->se_tfo->release_cmd(cmd); + wait_for_completion(&compl); ret = 1; } return ret; @@ -2742,31 +2744,21 @@ 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 completion *compl = se_cmd->compl; unsigned long flags; - bool fabric_stop; if (se_sess) { spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); list_del_init(&se_cmd->se_cmd_list); if (list_empty(&se_sess->sess_cmd_list)) wake_up(&se_sess->cmd_list_wq); - - spin_lock(&se_cmd->t_state_lock); - fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) && - (se_cmd->transport_state & CMD_T_ABORTED); - spin_unlock(&se_cmd->t_state_lock); - - if (fabric_stop) { - spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); - target_free_cmd_mem(se_cmd); - complete(&se_cmd->cmd_wait_comp); - return; - } spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); } target_free_cmd_mem(se_cmd); se_cmd->se_tfo->release_cmd(se_cmd); + if (compl) + complete(compl); } /** diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 906c1fc485e4..ca59e065c1fd 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -475,7 +475,7 @@ struct se_cmd { struct se_session *se_sess; struct se_tmr_req *se_tmr_req; struct list_head se_cmd_list; - struct completion cmd_wait_comp; + struct completion *compl; const struct target_core_fabric_ops *se_tfo; sense_reason_t (*execute_cmd)(struct se_cmd *); sense_reason_t (*transport_complete_callback)(struct se_cmd *, bool, int *);