Make transport_wait_for_tasks() use a completion that has been
allocated on the stack instead of the t_transport_stop_comp member
of struct se_cmd. Introduce a callback mechanism in struct se_cmd.
This is a first step towards removing the t_transport_stop_comp
member. That member variable cannot yet be removed via this patch
because the tcm_qla2xxx driver uses it directly.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 34 ++++++++++++++++++++++++++++++----
include/target/target_core_base.h | 12 ++++++++++++
include/target/target_core_fabric.h | 3 +++
3 files changed, 45 insertions(+), 4 deletions(-)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 19c9241..3538a36 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -598,7 +598,6 @@ static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
- complete_all(&cmd->t_transport_stop_comp);
return 1;
}
@@ -723,7 +722,6 @@ void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
if (cmd->transport_state & CMD_T_ABORTED &&
cmd->transport_state & CMD_T_STOP) {
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
- complete_all(&cmd->t_transport_stop_comp);
return;
} else if (!success) {
INIT_WORK(&cmd->work, target_complete_failure_work);
@@ -1177,10 +1175,25 @@ void transport_init_se_cmd(
cmd->sam_task_attr = task_attr;
cmd->sense_buffer = sense_buffer;
+ cmd->cb_count = 0;
cmd->state_active = false;
}
EXPORT_SYMBOL(transport_init_se_cmd);
+void __target_add_cmd_cb(struct se_cmd *cmd, void (*done)(void *),
+ void *done_arg)
+{
+ int i;
+
+ lockdep_assert_held(&cmd->t_state_lock);
+
+ i = cmd->cb_count++;
+ BUG_ON(i >= ARRAY_SIZE(cmd->done_cb));
+ cmd->done_cb[i].cb = done;
+ cmd->done_cb[i].arg = done_arg;
+}
+EXPORT_SYMBOL(__target_add_cmd_cb);
+
static sense_reason_t
transport_check_alloc_task_attr(struct se_cmd *cmd)
{
@@ -1853,7 +1866,6 @@ void target_execute_cmd(struct se_cmd *cmd)
__func__, __LINE__, cmd->tag);
spin_unlock_irq(&cmd->t_state_lock);
- complete_all(&cmd->t_transport_stop_comp);
return;
}
@@ -2510,6 +2522,8 @@ 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 se_cmd_done_cb *cbe;
+ int i;
if (list_empty(&se_cmd->se_cmd_list)) {
se_cmd->se_tfo->release_cmd(se_cmd);
@@ -2524,6 +2538,11 @@ static void target_release_cmd_kref(struct kref *kref)
list_del(&se_cmd->se_cmd_list);
spin_unlock(&se_sess->sess_cmd_lock);
+ for (i = 0; i < se_cmd->cb_count; i++) {
+ cbe = &se_cmd->done_cb[i];
+ cbe->cb(cbe->arg);
+ }
+
se_cmd->se_tfo->release_cmd(se_cmd);
}
@@ -2609,6 +2628,11 @@ void transport_clear_lun_ref(struct se_lun *lun)
wait_for_completion(&lun->lun_ref_comp);
}
+static void target_cmd_done(void *arg)
+{
+ complete(arg);
+}
+
/**
* transport_wait_for_tasks - wait for completion to occur
* @cmd: command to wait
@@ -2618,6 +2642,7 @@ void transport_clear_lun_ref(struct se_lun *lun)
*/
bool transport_wait_for_tasks(struct se_cmd *cmd)
{
+ DECLARE_COMPLETION_ONSTACK(cmd_done);
unsigned long flags;
spin_lock_irqsave(&cmd->t_state_lock, flags);
@@ -2643,9 +2668,10 @@ bool transport_wait_for_tasks(struct se_cmd *cmd)
pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d, t_state: %d, CMD_T_STOP\n",
cmd, cmd->tag, cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
+ __target_add_cmd_cb(cmd, target_cmd_done, &cmd_done);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
- wait_for_completion(&cmd->t_transport_stop_comp);
+ wait_for_completion(&cmd_done);
spin_lock_irqsave(&cmd->t_state_lock, flags);
cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 2b57314..65f7258 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -466,6 +466,16 @@ struct se_dif_v1_tuple {
#define TCM_ORDERED_TAG 0x22
#define TCM_ACA_TAG 0x24
+/**
+ * struct se_cmd_done_cb - callback function invoked after a se_cmd finished
+ * @cb: Callback function.
+ * @cb_arg: Argument that will be passed to the callback function.
+ */
+struct se_cmd_done_cb {
+ void (*cb)(void *);
+ void *arg;
+};
+
struct se_cmd {
/* SAM response code being sent to initiator */
u8 scsi_status;
@@ -527,6 +537,8 @@ struct se_cmd {
#define CMD_T_BUSY (1 << 9)
spinlock_t t_state_lock;
struct completion t_transport_stop_comp;
+ unsigned int cb_count; /* protected by t_state_lock */
+ struct se_cmd_done_cb done_cb[1]; /* protected by t_state_lock */
struct work_struct work;
diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h
index ecaa792..33e98b9 100644
--- a/include/target/target_core_fabric.h
+++ b/include/target/target_core_fabric.h
@@ -131,6 +131,9 @@ int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
int transport_handle_cdb_direct(struct se_cmd *);
sense_reason_t transport_generic_new_cmd(struct se_cmd *);
+void __target_add_cmd_cb(struct se_cmd *cmd, void (*done)(void *),
+ void *done_arg);
+
void target_execute_cmd(struct se_cmd *cmd);
int transport_generic_free_cmd(struct se_cmd *, int);
--
2.1.4
--
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