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target: Add TMR_ABORT_TASK task management support

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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>
This commit is contained in:
Nicholas Bellinger 2012-02-13 02:38:14 -08:00
parent ffc32d5259
commit 3d28934aaa
3 changed files with 79 additions and 7 deletions
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2
drivers/target/target_core_internal.h
View File

@ -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 *);

64
drivers/target/target_core_tmr.c
View File

@ -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,

20
drivers/target/target_core_transport.c
View File

@ -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: