From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch is a re-orginzation of core_tmr_lun_reset() logic to properly
scan the active tmr_list, dev->state_task_list and qobj->qobj_list w/ the
relivent locks held, and performing a list_move_tail onto seperate local
scope lists before performing the full drain.
This involves breaking out the code into three seperate list specific
functions: core_tmr_drain_tmr_list(), core_tmr_drain_task_list() and
core_tmr_drain_cmd_list().
This patch also includes a bugfix related to TRANSPORT_FREE_CMD_INTR
operation, where core_tmr_drain_cmd_list will skip this cause in order
to prevent an ABORT_TASK status from being returned for descriptors that
are already queued up to be related by processing thread context.
Reported-by: Roland Dreier <roland@xxxxxxxxxxxxxxx>
Cc: Roland Dreier <roland@xxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/target/target_core_tmr.c | 226 ++++++++++++++++++++++++--------------
1 files changed, 141 insertions(+), 85 deletions(-)
diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index 7bce92f..a536f8a 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -67,15 +67,16 @@ void core_tmr_release_req(
struct se_tmr_req *tmr)
{
struct se_device *dev = tmr->tmr_dev;
+ unsigned long flags;
if (!dev) {
kmem_cache_free(se_tmr_req_cache, tmr);
return;
}
- spin_lock_irq(&dev->se_tmr_lock);
+ spin_lock_irqsave(&dev->se_tmr_lock, flags);
list_del(&tmr->tmr_list);
- spin_unlock_irq(&dev->se_tmr_lock);
+ spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
kmem_cache_free(se_tmr_req_cache, tmr);
}
@@ -100,54 +101,20 @@ static void core_tmr_handle_tas_abort(
transport_cmd_finish_abort(cmd, 0);
}
-int core_tmr_lun_reset(
+static void core_tmr_drain_tmr_list(
struct se_device *dev,
struct se_tmr_req *tmr,
- struct list_head *preempt_and_abort_list,
- struct se_cmd *prout_cmd)
+ struct list_head *preempt_and_abort_list)
{
- struct se_cmd *cmd, *tcmd;
- struct se_node_acl *tmr_nacl = NULL;
- struct se_portal_group *tmr_tpg = NULL;
- struct se_queue_obj *qobj = &dev->dev_queue_obj;
+ LIST_HEAD(drain_tmr_list);
struct se_tmr_req *tmr_p, *tmr_pp;
- struct se_task *task, *task_tmp;
+ struct se_cmd *cmd;
unsigned long flags;
- int fe_count, tas;
- /*
- * TASK_ABORTED status bit, this is configurable via ConfigFS
- * struct se_device attributes. spc4r17 section 7.4.6 Control mode page
- *
- * A task aborted status (TAS) bit set to zero specifies that aborted
- * tasks shall be terminated by the device server without any response
- * to the application client. A TAS bit set to one specifies that tasks
- * aborted by the actions of an I_T nexus other than the I_T nexus on
- * which the command was received shall be completed with TASK ABORTED
- * status (see SAM-4).
- */
- tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
- /*
- * Determine if this se_tmr is coming from a $FABRIC_MOD
- * or struct se_device passthrough..
- */
- if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
- tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
- tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
- if (tmr_nacl && tmr_tpg) {
- pr_debug("LUN_RESET: TMR caller fabric: %s"
- " initiator port %s\n",
- tmr_tpg->se_tpg_tfo->get_fabric_name(),
- tmr_nacl->initiatorname);
- }
- }
- pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
- (preempt_and_abort_list) ? "Preempt" : "TMR",
- dev->transport->name, tas);
/*
* Release all pending and outgoing TMRs aside from the received
* LUN_RESET tmr..
*/
- spin_lock_irq(&dev->se_tmr_lock);
+ spin_lock_irqsave(&dev->se_tmr_lock, flags);
list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
/*
* Allow the received TMR to return with FUNCTION_COMPLETE.
@@ -169,29 +136,48 @@ int core_tmr_lun_reset(
(core_scsi3_check_cdb_abort_and_preempt(
preempt_and_abort_list, cmd) != 0))
continue;
- spin_unlock_irq(&dev->se_tmr_lock);
-
- spin_lock_irqsave(&cmd->t_state_lock, flags);
+
+ spin_lock(&cmd->t_state_lock);
if (!atomic_read(&cmd->t_transport_active)) {
- spin_unlock_irqrestore(&cmd->t_state_lock, flags);
- spin_lock_irq(&dev->se_tmr_lock);
+ spin_unlock(&cmd->t_state_lock);
continue;
}
if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
- spin_unlock_irqrestore(&cmd->t_state_lock, flags);
- spin_lock_irq(&dev->se_tmr_lock);
+ spin_unlock(&cmd->t_state_lock);
continue;
}
- pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
- " Response: 0x%02x, t_state: %d\n",
- (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
- tmr_p->function, tmr_p->response, cmd->t_state);
- spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+ spin_unlock(&cmd->t_state_lock);
+
+ list_move_tail(&tmr->tmr_list, &drain_tmr_list);
+ }
+ spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
+ while (!list_empty(&drain_tmr_list)) {
+ tmr = list_entry(drain_tmr_list.next, struct se_tmr_req, tmr_list);
+ list_del(&tmr->tmr_list);
+ cmd = tmr_p->task_cmd;
+
+ printk("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
+ " Response: 0x%02x, t_state: %d\n",
+ (preempt_and_abort_list) ? "Preempt" : "", tmr,
+ tmr->function, tmr->response, cmd->t_state);
+
transport_cmd_finish_abort_tmr(cmd);
- spin_lock_irq(&dev->se_tmr_lock);
}
- spin_unlock_irq(&dev->se_tmr_lock);
+}
+
+static void core_tmr_drain_task_list(
+ struct se_device *dev,
+ struct se_cmd *prout_cmd,
+ struct se_node_acl *tmr_nacl,
+ int tas,
+ struct list_head *preempt_and_abort_list)
+{
+ LIST_HEAD(drain_task_list);
+ struct se_cmd *cmd;
+ struct se_task *task, *task_tmp;
+ unsigned long flags;
+ int fe_count;
/*
* Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
* This is following sam4r17, section 5.6 Aborting commands, Table 38
@@ -236,19 +222,26 @@ int core_tmr_lun_reset(
if (prout_cmd == cmd)
continue;
- list_del(&task->t_state_list);
+ list_move_tail(&task->t_state_list, &drain_task_list);
atomic_set(&task->task_state_active, 0);
- spin_unlock_irqrestore(&dev->execute_task_lock, flags);
+ atomic_set(&task->task_execute_queue, 0);
+ }
+ spin_unlock_irqrestore(&dev->execute_task_lock, flags);
+
+ while (!list_empty(&drain_task_list)) {
+ task = list_entry(drain_task_list.next, struct se_task, t_state_list);
+ list_del(&task->t_state_list);
+ cmd = task->task_se_cmd;
spin_lock_irqsave(&cmd->t_state_lock, flags);
- pr_debug("LUN_RESET: %s cmd: %p task: %p"
+ printk("LUN_RESET: %s cmd: %p task: %p"
" ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
"def_t_state: %d/%d cdb: 0x%02x\n",
(preempt_and_abort_list) ? "Preempt" : "", cmd, task,
cmd->se_tfo->get_task_tag(cmd), 0,
cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
cmd->deferred_t_state, cmd->t_task_cdb[0]);
- pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
+ printk("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
" t_task_cdbs: %d t_task_cdbs_left: %d"
" t_task_cdbs_sent: %d -- t_transport_active: %d"
" t_transport_stop: %d t_transport_sent: %d\n",
@@ -265,55 +258,58 @@ int core_tmr_lun_reset(
spin_unlock_irqrestore(
&cmd->t_state_lock, flags);
- pr_debug("LUN_RESET: Waiting for task: %p to shutdown"
+ printk("LUN_RESET: Waiting for task: %p to shutdown"
" for dev: %p\n", task, dev);
wait_for_completion(&task->task_stop_comp);
- pr_debug("LUN_RESET Completed task: %p shutdown for"
+ printk("LUN_RESET Completed task: %p shutdown for"
" dev: %p\n", task, dev);
spin_lock_irqsave(&cmd->t_state_lock, flags);
atomic_dec(&cmd->t_task_cdbs_left);
atomic_set(&task->task_active, 0);
atomic_set(&task->task_stop, 0);
- } else {
- if (atomic_read(&task->task_execute_queue) != 0)
- transport_remove_task_from_execute_queue(task, dev);
}
__transport_stop_task_timer(task, &flags);
if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
- spin_unlock_irqrestore(
- &cmd->t_state_lock, flags);
- pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
+ spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+ printk("LUN_RESET: Skipping task: %p, dev: %p for"
" t_task_cdbs_ex_left: %d\n", task, dev,
atomic_read(&cmd->t_task_cdbs_ex_left));
-
- spin_lock_irqsave(&dev->execute_task_lock, flags);
continue;
}
fe_count = atomic_read(&cmd->t_fe_count);
if (atomic_read(&cmd->t_transport_active)) {
- pr_debug("LUN_RESET: got t_transport_active = 1 for"
+ printk("LUN_RESET: got t_transport_active = 1 for"
" task: %p, t_fe_count: %d dev: %p\n", task,
fe_count, dev);
atomic_set(&cmd->t_transport_aborted, 1);
- spin_unlock_irqrestore(&cmd->t_state_lock,
- flags);
- core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
+ spin_unlock_irqrestore(&cmd->t_state_lock, flags);
- spin_lock_irqsave(&dev->execute_task_lock, flags);
+ core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
continue;
}
- pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"
+ printk("LUN_RESET: Got t_transport_active = 0 for task: %p,"
" t_fe_count: %d dev: %p\n", task, fe_count, dev);
atomic_set(&cmd->t_transport_aborted, 1);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
- core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
- spin_lock_irqsave(&dev->execute_task_lock, flags);
+ core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
}
- spin_unlock_irqrestore(&dev->execute_task_lock, flags);
+}
+
+static void core_tmr_drain_cmd_list(
+ struct se_device *dev,
+ struct se_cmd *prout_cmd,
+ struct se_node_acl *tmr_nacl,
+ int tas,
+ struct list_head *preempt_and_abort_list)
+{
+ LIST_HEAD(drain_cmd_list);
+ struct se_queue_obj *qobj = &dev->dev_queue_obj;
+ struct se_cmd *cmd, *tcmd;
+ unsigned long flags;
/*
* Release all commands remaining in the struct se_device cmd queue.
*
@@ -337,13 +333,28 @@ int core_tmr_lun_reset(
*/
if (prout_cmd == cmd)
continue;
+ /*
+ * Skip direct processing of TRANSPORT_FREE_CMD_INTR for
+ * HW target mode fabrics.
+ */
+ spin_lock(&cmd->t_state_lock);
+ if (cmd->t_state == TRANSPORT_FREE_CMD_INTR) {
+ spin_unlock(&cmd->t_state_lock);
+ continue;
+ }
+ spin_unlock(&cmd->t_state_lock);
- atomic_dec(&cmd->t_transport_queue_active);
+ atomic_set(&cmd->t_transport_queue_active, 0);
atomic_dec(&qobj->queue_cnt);
+ list_move_tail(&cmd->se_queue_node, &drain_cmd_list);
+ }
+ spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
+
+ while (!list_empty(&drain_cmd_list)) {
+ cmd = list_entry(drain_cmd_list.next, struct se_cmd, se_queue_node);
list_del_init(&cmd->se_queue_node);
- spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
- pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
+ printk("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
" %d t_fe_count: %d\n", (preempt_and_abort_list) ?
"Preempt" : "", cmd, cmd->t_state,
atomic_read(&cmd->t_fe_count));
@@ -354,9 +365,53 @@ int core_tmr_lun_reset(
core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
atomic_read(&cmd->t_fe_count));
- spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
}
- spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
+}
+
+int core_tmr_lun_reset(
+ struct se_device *dev,
+ struct se_tmr_req *tmr,
+ struct list_head *preempt_and_abort_list,
+ struct se_cmd *prout_cmd)
+{
+ struct se_node_acl *tmr_nacl = NULL;
+ struct se_portal_group *tmr_tpg = NULL;
+ int tas;
+ /*
+ * TASK_ABORTED status bit, this is configurable via ConfigFS
+ * struct se_device attributes. spc4r17 section 7.4.6 Control mode page
+ *
+ * A task aborted status (TAS) bit set to zero specifies that aborted
+ * tasks shall be terminated by the device server without any response
+ * to the application client. A TAS bit set to one specifies that tasks
+ * aborted by the actions of an I_T nexus other than the I_T nexus on
+ * which the command was received shall be completed with TASK ABORTED
+ * status (see SAM-4).
+ */
+ tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
+ /*
+ * Determine if this se_tmr is coming from a $FABRIC_MOD
+ * or struct se_device passthrough..
+ */
+ if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
+ tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
+ tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
+ if (tmr_nacl && tmr_tpg) {
+ printk("LUN_RESET: TMR caller fabric: %s"
+ " initiator port %s\n",
+ tmr_tpg->se_tpg_tfo->get_fabric_name(),
+ tmr_nacl->initiatorname);
+ }
+ }
+ printk("LUN_RESET: %s starting for [%s], tas: %d\n",
+ (preempt_and_abort_list) ? "Preempt" : "TMR",
+ dev->transport->name, tas);
+
+ core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
+ core_tmr_drain_task_list(dev, prout_cmd, tmr_nacl, tas,
+ preempt_and_abort_list);
+ core_tmr_drain_cmd_list(dev, prout_cmd, tmr_nacl, tas,
+ preempt_and_abort_list);
/*
* Clear any legacy SPC-2 reservation when called during
* LOGICAL UNIT RESET
@@ -367,15 +422,16 @@ int core_tmr_lun_reset(
dev->dev_reserved_node_acl = NULL;
dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
spin_unlock(&dev->dev_reservation_lock);
- pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
+ printk("LUN_RESET: SCSI-2 Released reservation\n");
}
spin_lock_irq(&dev->stats_lock);
dev->num_resets++;
spin_unlock_irq(&dev->stats_lock);
- pr_debug("LUN_RESET: %s for [%s] Complete\n",
+ printk("LUN_RESET: %s for [%s] Complete\n",
(preempt_and_abort_list) ? "Preempt" : "TMR",
dev->transport->name);
return 0;
}
+
--
1.7.2.5
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
