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target: Re-org of core_tmr_lun_reset
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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().

(nab: Include target: Remove non-active tasks from execute list during
      LUN_RESET patch to address original breakage)

Reported-by: Roland Dreier <roland@purestorage.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger <nab@risingtidesystems.com>
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Nicholas Bellinger committed Oct 24, 2011
1 parent 79a7fef commit d050ffb
Showing 1 changed file with 125 additions and 72 deletions.
197 changes: 125 additions & 72 deletions drivers/target/target_core_tmr.c
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Original file line number Diff line number Diff line change
Expand Up @@ -66,15 +66,16 @@ 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);
}
Expand All @@ -99,54 +100,20 @@ 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.
Expand All @@ -168,29 +135,48 @@ 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;
}
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;

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);
(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
Expand Down Expand Up @@ -235,9 +221,23 @@ 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);
/*
* Remove from task execute list before processing drain_task_list
*/
if (atomic_read(&task->task_execute_queue) != 0) {
list_del(&task->t_execute_list);
atomic_set(&task->task_execute_queue, 0);
atomic_dec(&dev->execute_tasks);
}
}
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"
Expand Down Expand Up @@ -274,20 +274,14 @@ int core_tmr_lun_reset(

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);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
pr_debug("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);
Expand All @@ -297,22 +291,31 @@ int core_tmr_lun_reset(
" 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,"
" 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.
*
Expand All @@ -337,10 +340,15 @@ int core_tmr_lun_reset(
if (prout_cmd == cmd)
continue;

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:"
" %d t_fe_count: %d\n", (preempt_and_abort_list) ?
Expand All @@ -353,9 +361,53 @@ 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) {
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);

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
Expand All @@ -378,3 +430,4 @@ int core_tmr_lun_reset(
dev->transport->name);
return 0;
}

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