On Tue, 2013-12-17 at 09:18 +0100, Hannes Reinecke wrote:
> Use a workqueue for processing ALUA state transitions; this allows
> us to process implicit delay properly.
>
> Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
> ---
> drivers/target/target_core_alua.c | 174 +++++++++++++++++++++++++++-----------
> include/target/target_core_base.h | 4 +
> 2 files changed, 128 insertions(+), 50 deletions(-)
>
Applied to for-next.
--nab
> 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 @@ 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
> diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
> index 6758e81..65390f6 100644
> --- a/include/target/target_core_base.h
> +++ b/include/target/target_core_base.h
> @@ -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 {
--
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