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target_core_alua: Use workqueue for ALUA transitioning 

Use a workqueue for processing ALUA state transitions; this allows
us to process implicit delay properly.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Hannes Reinecke 2013-12-17 09:18:46 +01:00 committed by Nicholas Bellinger
parent dfbce75ac8
commit 9c6e164c8c
2 changed files with 128 additions and 50 deletions
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174
drivers/target/target_core_alua.c
View File

@ -769,8 +769,7 @@ static int core_alua_write_tpg_metadata(
* Called with tg_pt_gp->tg_pt_gp_md_mutex held
*/
static int core_alua_update_tpg_primary_metadata(
struct t10_alua_tg_pt_gp *tg_pt_gp,
int primary_state)
struct t10_alua_tg_pt_gp *tg_pt_gp)
{
unsigned char *md_buf;
struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
@ -789,7 +788,8 @@ static int core_alua_update_tpg_primary_metadata(
"tg_pt_gp_id=%hu\n"
"alua_access_state=0x%02x\n"
"alua_access_status=0x%02x\n",
tg_pt_gp->tg_pt_gp_id, primary_state,
tg_pt_gp->tg_pt_gp_id,
tg_pt_gp->tg_pt_gp_alua_pending_state,
tg_pt_gp->tg_pt_gp_alua_access_status);
snprintf(path, ALUA_METADATA_PATH_LEN,
@ -801,36 +801,17 @@ static int core_alua_update_tpg_primary_metadata(
return rc;
}
static int core_alua_do_transition_tg_pt(
struct t10_alua_tg_pt_gp *tg_pt_gp,
struct se_port *l_port,
struct se_node_acl *nacl,
int new_state,
int explicit)
static void core_alua_do_transition_tg_pt_work(struct work_struct *work)
{
struct t10_alua_tg_pt_gp *tg_pt_gp = container_of(work,
struct t10_alua_tg_pt_gp, tg_pt_gp_transition_work.work);
struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
struct se_dev_entry *se_deve;
struct se_lun_acl *lacl;
struct se_port *port;
struct t10_alua_tg_pt_gp_member *mem;
/*
* Save the old primary ALUA access state, and set the current state
* to ALUA_ACCESS_STATE_TRANSITION.
*/
tg_pt_gp->tg_pt_gp_alua_previous_state =
atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
tg_pt_gp->tg_pt_gp_alua_pending_state = new_state;
atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
ALUA_ACCESS_STATE_TRANSITION);
tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
/*
* Check for the optional ALUA primary state transition delay
*/
if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
bool explicit = (tg_pt_gp->tg_pt_gp_alua_access_status ==
ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG);
spin_lock(&tg_pt_gp->tg_pt_gp_lock);
list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
@ -865,9 +846,12 @@ static int core_alua_do_transition_tg_pt(
if (!lacl)
continue;
if (explicit &&
(nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
(l_port != NULL) && (l_port == port))
if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
(tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
(tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl) &&
(tg_pt_gp->tg_pt_gp_alua_port != NULL) &&
(tg_pt_gp->tg_pt_gp_alua_port == port))
continue;
core_scsi3_ua_allocate(lacl->se_lun_nacl,
@ -895,7 +879,7 @@ static int core_alua_do_transition_tg_pt(
*/
if (tg_pt_gp->tg_pt_gp_write_metadata) {
mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
core_alua_update_tpg_primary_metadata(tg_pt_gp, new_state);
core_alua_update_tpg_primary_metadata(tg_pt_gp);
mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
}
/*
@ -910,6 +894,87 @@ static int core_alua_do_transition_tg_pt(
tg_pt_gp->tg_pt_gp_id,
core_alua_dump_state(tg_pt_gp->tg_pt_gp_alua_previous_state),
core_alua_dump_state(tg_pt_gp->tg_pt_gp_alua_pending_state));
spin_lock(&dev->t10_alua.tg_pt_gps_lock);
atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
smp_mb__after_atomic_dec();
spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
if (tg_pt_gp->tg_pt_gp_transition_complete)
complete(tg_pt_gp->tg_pt_gp_transition_complete);
}
static int core_alua_do_transition_tg_pt(
struct t10_alua_tg_pt_gp *tg_pt_gp,
int new_state,
int explicit)
{
struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
DECLARE_COMPLETION_ONSTACK(wait);
/* Nothing to be done here */
if (atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) == new_state)
return 0;
if (new_state == ALUA_ACCESS_STATE_TRANSITION)
return -EAGAIN;
/*
* Flush any pending transitions
*/
if (!explicit && tg_pt_gp->tg_pt_gp_implicit_trans_secs &&
atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) ==
ALUA_ACCESS_STATE_TRANSITION) {
/* Just in case */
tg_pt_gp->tg_pt_gp_alua_pending_state = new_state;
tg_pt_gp->tg_pt_gp_transition_complete = &wait;
flush_delayed_work(&tg_pt_gp->tg_pt_gp_transition_work);
wait_for_completion(&wait);
tg_pt_gp->tg_pt_gp_transition_complete = NULL;
return 0;
}
/*
* Save the old primary ALUA access state, and set the current state
* to ALUA_ACCESS_STATE_TRANSITION.
*/
tg_pt_gp->tg_pt_gp_alua_previous_state =
atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
tg_pt_gp->tg_pt_gp_alua_pending_state = new_state;
atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
ALUA_ACCESS_STATE_TRANSITION);
tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
/*
* Check for the optional ALUA primary state transition delay
*/
if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
/*
* Take a reference for workqueue item
*/
spin_lock(&dev->t10_alua.tg_pt_gps_lock);
atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
smp_mb__after_atomic_inc();
spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
if (!explicit && tg_pt_gp->tg_pt_gp_implicit_trans_secs) {
unsigned long transition_tmo;
transition_tmo = tg_pt_gp->tg_pt_gp_implicit_trans_secs * HZ;
queue_delayed_work(tg_pt_gp->tg_pt_gp_dev->tmr_wq,
&tg_pt_gp->tg_pt_gp_transition_work,
transition_tmo);
} else {
tg_pt_gp->tg_pt_gp_transition_complete = &wait;
queue_delayed_work(tg_pt_gp->tg_pt_gp_dev->tmr_wq,
&tg_pt_gp->tg_pt_gp_transition_work, 0);
wait_for_completion(&wait);
tg_pt_gp->tg_pt_gp_transition_complete = NULL;
}
return 0;
}
@ -923,12 +988,10 @@ int core_alua_do_port_transition(
int explicit)
{
struct se_device *dev;
struct se_port *port;
struct se_node_acl *nacl;
struct t10_alua_lu_gp *lu_gp;
struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
struct t10_alua_tg_pt_gp *tg_pt_gp;
int primary, valid_states;
int primary, valid_states, rc = 0;
valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
if (core_alua_check_transition(new_state, valid_states, &primary) != 0)
@ -950,11 +1013,13 @@ int core_alua_do_port_transition(
* core_alua_do_transition_tg_pt() will always return
* success.
*/
core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
new_state, explicit);
l_tg_pt_gp->tg_pt_gp_alua_port = l_port;
l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
new_state, explicit);
atomic_dec(&lu_gp->lu_gp_ref_cnt);
smp_mb__after_atomic_dec();
return 0;
return rc;
}
/*
* For all other LU groups aside from 'default_lu_gp', walk all of
@ -989,11 +1054,11 @@ int core_alua_do_port_transition(
continue;
if (l_tg_pt_gp == tg_pt_gp) {
port = l_port;
nacl = l_nacl;
tg_pt_gp->tg_pt_gp_alua_port = l_port;
tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
} else {
port = NULL;
nacl = NULL;
tg_pt_gp->tg_pt_gp_alua_port = NULL;
tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
}
atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
smp_mb__after_atomic_inc();
@ -1002,12 +1067,14 @@ int core_alua_do_port_transition(
* core_alua_do_transition_tg_pt() will always return
* success.
*/
core_alua_do_transition_tg_pt(tg_pt_gp, port,
nacl, new_state, explicit);
rc = core_alua_do_transition_tg_pt(tg_pt_gp,
new_state, explicit);
spin_lock(&dev->t10_alua.tg_pt_gps_lock);
atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
smp_mb__after_atomic_dec();
if (rc)
break;
}
spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
@ -1017,15 +1084,18 @@ int core_alua_do_port_transition(
}
spin_unlock(&lu_gp->lu_gp_lock);
pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
" Group IDs: %hu %s transition to primary state: %s\n",
config_item_name(&lu_gp->lu_gp_group.cg_item),
l_tg_pt_gp->tg_pt_gp_id, (explicit) ? "explicit" : "implicit",
core_alua_dump_state(new_state));
if (!rc) {
pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
" Group IDs: %hu %s transition to primary state: %s\n",
config_item_name(&lu_gp->lu_gp_group.cg_item),
l_tg_pt_gp->tg_pt_gp_id,
(explicit) ? "explicit" : "implicit",
core_alua_dump_state(new_state));
}
atomic_dec(&lu_gp->lu_gp_ref_cnt);
smp_mb__after_atomic_dec();
return 0;
return rc;
}
/*
@ -1379,6 +1449,8 @@ struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
INIT_DELAYED_WORK(&tg_pt_gp->tg_pt_gp_transition_work,
core_alua_do_transition_tg_pt_work);
tg_pt_gp->tg_pt_gp_dev = dev;
atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED);
@ -1507,6 +1579,8 @@ void core_alua_free_tg_pt_gp(
dev->t10_alua.alua_tg_pt_gps_counter--;
spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
flush_delayed_work(&tg_pt_gp->tg_pt_gp_transition_work);
/*
* Allow a struct t10_alua_tg_pt_gp_member * referenced by
* core_alua_get_tg_pt_gp_by_name() in

4
include/target/target_core_base.h
View File

@ -302,6 +302,10 @@ struct t10_alua_tg_pt_gp {
struct config_group tg_pt_gp_group;
struct list_head tg_pt_gp_list;
struct list_head tg_pt_gp_mem_list;
struct se_port *tg_pt_gp_alua_port;
struct se_node_acl *tg_pt_gp_alua_nacl;
struct delayed_work tg_pt_gp_transition_work;
struct completion *tg_pt_gp_transition_complete;
};
struct t10_alua_tg_pt_gp_member {