From 7481deb413be132a22193e8a0bce88b311ecb3c2 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Sat, 12 Nov 2011 00:32:17 -0800 Subject: [PATCH] target: Make target_put_sess_cmd use target_release_cmd_kref This patch moves target_put_sess_cmd() to use a se_cmd->cmd_kref callback target_release_cmd_kref when performing driver release of fabric->se_cmd descriptor memory. It sets the default cmd_kref count value to '2' within target_get_sess_cmd() setup, and currently assumes TFO->check_stop_free() usage. It drops se_tfo->check_release_cmd() usage in the main transport_release_cmd codepath. Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 39 ++++++++++++++++---------- include/target/target_core_base.h | 1 + 2 files changed, 25 insertions(+), 15 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 122925686de2..176f956665e8 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -3349,13 +3349,13 @@ static void transport_release_cmd(struct se_cmd *cmd) if (cmd->t_task_cdb != cmd->__t_task_cdb) kfree(cmd->t_task_cdb); /* - * Check if target_wait_for_sess_cmds() is expecting to - * release se_cmd directly here.. + * If this cmd has been setup with target_get_sess_cmd(), drop + * the kref and call ->release_cmd() in kref callback. */ - if (cmd->check_release != 0 && cmd->se_tfo->check_release_cmd) - if (cmd->se_tfo->check_release_cmd(cmd) != 0) - return; - + if (cmd->check_release != 0) { + target_put_sess_cmd(cmd->se_sess, cmd); + return; + } cmd->se_tfo->release_cmd(cmd); } @@ -3915,6 +3915,9 @@ void target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd) { unsigned long flags; + kref_init(&se_cmd->cmd_kref); + kref_get(&se_cmd->cmd_kref); + spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list); se_cmd->check_release = 1; @@ -3922,30 +3925,36 @@ void target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd) } EXPORT_SYMBOL(target_get_sess_cmd); -/* target_put_sess_cmd - Check for active I/O shutdown or list delete - * @se_sess: session to reference - * @se_cmd: command descriptor to drop - */ -int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_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; unsigned long flags; spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); if (list_empty(&se_cmd->se_cmd_list)) { spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); WARN_ON(1); - return 0; + return; } - if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) { spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); complete(&se_cmd->cmd_wait_comp); - return 1; + return; } list_del(&se_cmd->se_cmd_list); spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); - return 0; + se_cmd->se_tfo->release_cmd(se_cmd); +} + +/* target_put_sess_cmd - Check for active I/O shutdown via kref_put + * @se_sess: session to reference + * @se_cmd: command descriptor to drop + */ +int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd) +{ + return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref); } EXPORT_SYMBOL(target_put_sess_cmd); diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index cadd4f6e57e1..af088a9e4905 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -541,6 +541,7 @@ struct se_cmd { struct list_head se_queue_node; struct list_head se_cmd_list; struct completion cmd_wait_comp; + struct kref cmd_kref; struct target_core_fabric_ops *se_tfo; int (*execute_task)(struct se_task *); void (*transport_complete_callback)(struct se_cmd *); -- 2.20.1