From 9c6e164c8c28c1f9e24441674f8b8d81551c906b Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Tue, 17 Dec 2013 09:18:46 +0100 Subject: 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 Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_alua.c | 174 +++++++++++++++++++++++++++----------- 1 file changed, 124 insertions(+), 50 deletions(-) (limited to 'drivers/target/target_core_alua.c') diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c index 4805e970295a..01f0c71891d6 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 -- cgit v1.2.3-59-g8ed1b