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>
diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index 4805e97..01f0c71 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -769,8 +769,7 @@
* 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 @@
"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 @@
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 @@
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 @@
*/
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 @@
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 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 @@
* 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 @@
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 @@
* 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 @@
}
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 @@
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 @@
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