From 2be18149d9d7ebfde7c3081d60f7c9d8d3b6f8c7 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Fri, 27 May 2011 13:58:48 -0700 Subject: [PATCH] tcm_fc: Convert to wake_up_process and schedule_timeout_interruptible This patch converts ft_queue_cmd() to use wake_up_process() and ft_thread() to use schedule_timeout_interruptible(MAX_SCHEDULE_TIMEOUT) instead of wait_event_interruptible(). This fixes a potential race with the wait_event_interruptible() conditional with qobj->queue_cnt in ft_thread(). This patch also drops the unnecessary set_user_nice(current, -20) in ft_thread(), and drops extra () around two if (!(acl)) conditionals in tfc_conf.c. Reported-by: Christoph Hellwig Signed-off-by: Nicholas A. Bellinger --- drivers/target/tcm_fc/tfc_cmd.c | 17 ++++++++--------- drivers/target/tcm_fc/tfc_conf.c | 4 ++-- 2 files changed, 10 insertions(+), 11 deletions(-) diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c index 74d5bb7..a00951c 100644 --- a/drivers/target/tcm_fc/tfc_cmd.c +++ b/drivers/target/tcm_fc/tfc_cmd.c @@ -94,15 +94,17 @@ void ft_dump_cmd(struct ft_cmd *cmd, const char *caller) static void ft_queue_cmd(struct ft_sess *sess, struct ft_cmd *cmd) { - struct se_queue_obj *qobj; + struct ft_tpg *tpg = sess->tport->tpg; + struct se_queue_obj *qobj = &tpg->qobj; unsigned long flags; qobj = &sess->tport->tpg->qobj; spin_lock_irqsave(&qobj->cmd_queue_lock, flags); list_add_tail(&cmd->se_req.qr_list, &qobj->qobj_list); - spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags); atomic_inc(&qobj->queue_cnt); - wake_up_interruptible(&qobj->thread_wq); + spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags); + + wake_up_process(tpg->thread); } static struct ft_cmd *ft_dequeue_cmd(struct se_queue_obj *qobj) @@ -688,15 +690,12 @@ int ft_thread(void *arg) struct ft_tpg *tpg = arg; struct se_queue_obj *qobj = &tpg->qobj; struct ft_cmd *cmd; - int ret; - - set_user_nice(current, -20); while (!kthread_should_stop()) { - ret = wait_event_interruptible(qobj->thread_wq, - atomic_read(&qobj->queue_cnt) || kthread_should_stop()); - if (ret < 0 || kthread_should_stop()) + schedule_timeout_interruptible(MAX_SCHEDULE_TIMEOUT); + if (kthread_should_stop()) goto out; + cmd = ft_dequeue_cmd(qobj); if (cmd) ft_exec_req(cmd); diff --git a/drivers/target/tcm_fc/tfc_conf.c b/drivers/target/tcm_fc/tfc_conf.c index 1cb3d34..ec9e40d 100644 --- a/drivers/target/tcm_fc/tfc_conf.c +++ b/drivers/target/tcm_fc/tfc_conf.c @@ -223,7 +223,7 @@ static struct se_node_acl *ft_add_acl( return ERR_PTR(-EINVAL); acl = kzalloc(sizeof(struct ft_node_acl), GFP_KERNEL); - if (!(acl)) + if (!acl) return ERR_PTR(-ENOMEM); acl->node_auth.port_name = wwpn; @@ -280,7 +280,7 @@ struct se_node_acl *ft_tpg_alloc_fabric_acl(struct se_portal_group *se_tpg) struct ft_node_acl *acl; acl = kzalloc(sizeof(*acl), GFP_KERNEL); - if (!(acl)) { + if (!acl) { printk(KERN_ERR "Unable to allocate struct ft_node_acl\n"); return NULL; } -- 2.7.4