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authorNicholas Bellinger <nab@linux-iscsi.org>2012-02-13 11:38:14 +0100
committerNicholas Bellinger <nab@linux-iscsi.org>2012-02-25 23:37:49 +0100
commit3d28934aaae5e924afedf0f5cb42e1316514da6b (patch)
tree6a11e13b7da8187339f262c14726107ccb32eb1b /drivers/target
parenttarget: Make target_release_cmd_kref release on empty list (diff)
downloadlinux-3d28934aaae5e924afedf0f5cb42e1316514da6b.tar.xz
linux-3d28934aaae5e924afedf0f5cb42e1316514da6b.zip
target: Add TMR_ABORT_TASK task management support
This patch adds initial support for TMR_ABORT_TASK ops for se_cmd descriptors using se_sess->sess_cmd_list and se_cmd->cmd_kref counting. It will perform an explict abort for all outstanding se_cmd ops based upon tmr->ref_task_tag that have not been set CMD_T_COMPLETE. It will cancel se_cmd->work and wait for backing I/O to complete before attempting to send SAM_STAT_TASK_ABORTED and perform target_put_sess_cmd() to release the referenced descriptor. It also adds a CMD_T_ABORTED check into transport_complete_task() to catch the completion from backend I/O that has been aborted, and updates transport_wait_for_tasks() to allow CMD_T_ABORTED usage with core_tmr_abort_task() context. Reported-by: Roland Dreier <roland@purestorage.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target')
-rw-r--r--drivers/target/target_core_internal.h2
-rw-r--r--drivers/target/target_core_tmr.c64
-rw-r--r--drivers/target/target_core_transport.c20
3 files changed, 79 insertions, 7 deletions
diff --git a/drivers/target/target_core_internal.h b/drivers/target/target_core_internal.h
index 45001364788a..b026dedb8184 100644
--- a/drivers/target/target_core_internal.h
+++ b/drivers/target/target_core_internal.h
@@ -75,6 +75,8 @@ struct se_hba *core_alloc_hba(const char *, u32, u32);
int core_delete_hba(struct se_hba *);
/* target_core_tmr.c */
+void core_tmr_abort_task(struct se_device *, struct se_tmr_req *,
+ struct se_session *);
int core_tmr_lun_reset(struct se_device *, struct se_tmr_req *,
struct list_head *, struct se_cmd *);
diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index 5d3eb9e6c2ed..f015839aef89 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -118,6 +118,70 @@ static int target_check_cdb_and_preempt(struct list_head *list,
return 1;
}
+void core_tmr_abort_task(
+ struct se_device *dev,
+ struct se_tmr_req *tmr,
+ struct se_session *se_sess)
+{
+ struct se_cmd *se_cmd, *tmp_cmd;
+ unsigned long flags;
+ int ref_tag;
+
+ spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
+ list_for_each_entry_safe(se_cmd, tmp_cmd,
+ &se_sess->sess_cmd_list, se_cmd_list) {
+
+ if (dev != se_cmd->se_dev)
+ continue;
+ ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd);
+ if (tmr->ref_task_tag != ref_tag)
+ continue;
+
+ printk("ABORT_TASK: Found referenced %s task_tag: %u\n",
+ se_cmd->se_tfo->get_fabric_name(), ref_tag);
+
+ spin_lock_irq(&se_cmd->t_state_lock);
+ if (se_cmd->transport_state & CMD_T_COMPLETE) {
+ printk("ABORT_TASK: ref_tag: %u already complete, skipping\n", ref_tag);
+ spin_unlock_irq(&se_cmd->t_state_lock);
+ spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+ goto out;
+ }
+ se_cmd->transport_state |= CMD_T_ABORTED;
+ spin_unlock_irq(&se_cmd->t_state_lock);
+
+ list_del_init(&se_cmd->se_cmd_list);
+ kref_get(&se_cmd->cmd_kref);
+ spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+
+ cancel_work_sync(&se_cmd->work);
+ transport_wait_for_tasks(se_cmd);
+ /*
+ * Now send SAM_STAT_TASK_ABORTED status for the referenced
+ * se_cmd descriptor..
+ */
+ transport_send_task_abort(se_cmd);
+ /*
+ * Also deal with possible extra acknowledge reference..
+ */
+ if (se_cmd->se_cmd_flags & SCF_ACK_KREF)
+ target_put_sess_cmd(se_sess, se_cmd);
+
+ target_put_sess_cmd(se_sess, se_cmd);
+
+ printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
+ " ref_tag: %d\n", ref_tag);
+ tmr->response = TMR_FUNCTION_COMPLETE;
+ return;
+ }
+ spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+
+out:
+ printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n",
+ tmr->ref_task_tag);
+ tmr->response = TMR_TASK_DOES_NOT_EXIST;
+}
+
static void core_tmr_drain_tmr_list(
struct se_device *dev,
struct se_tmr_req *tmr,
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 52a66710a293..19804b6fdbaa 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -699,17 +699,24 @@ void transport_complete_task(struct se_task *task, int success)
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
return;
}
-
- if (cmd->transport_state & CMD_T_FAILED) {
+ /*
+ * Check for case where an explict ABORT_TASK has been received
+ * and transport_wait_for_tasks() will be waiting for completion..
+ */
+ if (cmd->transport_state & CMD_T_ABORTED &&
+ cmd->transport_state & CMD_T_STOP) {
+ spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+ complete(&cmd->t_transport_stop_comp);
+ return;
+ } else if (cmd->transport_state & CMD_T_FAILED) {
cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
INIT_WORK(&cmd->work, target_complete_failure_work);
} else {
- cmd->transport_state |= CMD_T_COMPLETE;
INIT_WORK(&cmd->work, target_complete_ok_work);
}
cmd->t_state = TRANSPORT_COMPLETE;
- cmd->transport_state |= CMD_T_ACTIVE;
+ cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
queue_work(target_completion_wq, &cmd->work);
@@ -4374,8 +4381,7 @@ bool transport_wait_for_tasks(struct se_cmd *cmd)
cmd->transport_state &= ~CMD_T_LUN_STOP;
}
- if (!(cmd->transport_state & CMD_T_ACTIVE) ||
- (cmd->transport_state & CMD_T_ABORTED)) {
+ if (!(cmd->transport_state & CMD_T_ACTIVE)) {
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
return false;
}
@@ -4681,7 +4687,7 @@ static int transport_generic_do_tmr(struct se_cmd *cmd)
switch (tmr->function) {
case TMR_ABORT_TASK:
- tmr->response = TMR_FUNCTION_REJECTED;
+ core_tmr_abort_task(dev, tmr, cmd->se_sess);
break;
case TMR_ABORT_TASK_SET:
case TMR_CLEAR_ACA: