scsi/device_handler/scsi_dh_alua.c

85 	struct alua_port_group __rcu *pg;
104 static bool alua_rtpg_queue(struct alua_port_group *pg,
111 	struct alua_port_group *pg;
113 	pg = container_of(kref, struct alua_port_group, kref);
114 	if (pg->rtpg_sdev)
115 		flush_delayed_work(&pg->rtpg_work);
117 	list_del(&pg->node);
119 	kfree_rcu(pg, rcu);
188 	struct alua_port_group *pg;
193 	list_for_each_entry(pg, &port_group_list, node) {
194 		if (pg->group_id != group_id)
196 		if (!pg->device_id_len || pg->device_id_len != id_size)
198 		if (strncmp(pg->device_id_str, id_str, id_size))
200 		if (!kref_get_unless_zero(&pg->kref))
202 		return pg;
220 	struct alua_port_group *pg, *tmp_pg;
222 	pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL);
223 	if (!pg)
226 	pg->device_id_len = scsi_vpd_lun_id(sdev, pg->device_id_str,
227 					    sizeof(pg->device_id_str));
228 	if (pg->device_id_len <= 0) {
236 		pg->device_id_str[0] = '\0';
237 		pg->device_id_len = 0;
239 	pg->group_id = group_id;
240 	pg->tpgs = tpgs;
241 	pg->state = SCSI_ACCESS_STATE_OPTIMAL;
242 	pg->valid_states = TPGS_SUPPORT_ALL;
244 		pg->flags |= ALUA_OPTIMIZE_STPG;
245 	kref_init(&pg->kref);
246 	INIT_DELAYED_WORK(&pg->rtpg_work, alua_rtpg_work);
247 	INIT_LIST_HEAD(&pg->rtpg_list);
248 	INIT_LIST_HEAD(&pg->node);
249 	INIT_LIST_HEAD(&pg->dh_list);
250 	spin_lock_init(&pg->lock);
253 	tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len,
257 		kfree(pg);
261 	list_add(&pg->node, &port_group_list);
264 	return pg;
330 	struct alua_port_group *pg, *old_pg = NULL;
347 	pg = alua_alloc_pg(sdev, group_id, tpgs);
348 	if (IS_ERR(pg)) {
349 		if (PTR_ERR(pg) == -ENOMEM)
353 	if (pg->device_id_len)
356 			    ALUA_DH_NAME, pg->device_id_str,
363 	kref_get(&pg->kref);
367 	old_pg = rcu_dereference_protected(h->pg, lockdep_is_held(&h->pg_lock));
368 	if (old_pg != pg) {
370 		if (h->pg) {
375 		rcu_assign_pointer(h->pg, pg);
379 	spin_lock_irqsave(&pg->lock, flags);
381 		list_add_rcu(&h->node, &pg->dh_list);
382 	spin_unlock_irqrestore(&pg->lock, flags);
386 	alua_rtpg_queue(pg, sdev, NULL, true);
387 	kref_put(&pg->kref, release_port_group);
421 	struct alua_port_group *pg;
430 			pg = rcu_dereference(h->pg);
431 			if (pg)
432 				pg->state = SCSI_ACCESS_STATE_TRANSITIONING;
522 static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
536 	group_id_old = pg->group_id;
537 	state_old = pg->state;
538 	pref_old = pg->pref;
539 	valid_states_old = pg->valid_states;
541 	if (!pg->expiry) {
544 		if (pg->transition_tmo)
545 			transition_tmo = pg->transition_tmo * HZ;
547 		pg->expiry = round_jiffies_up(jiffies + transition_tmo);
556 	retval = submit_rtpg(sdev, buff, bufflen, &sense_hdr, pg->flags);
568 		if ((pg->valid_states & ~TPGS_SUPPORT_OPTIMIZED) == 0) {
597 		if (!(pg->flags & ALUA_RTPG_EXT_HDR_UNSUPP) &&
599 			pg->flags |= ALUA_RTPG_EXT_HDR_UNSUPP;
618 		    pg->expiry != 0 && time_before(jiffies, pg->expiry)) {
629 		pg->expiry = 0;
644 			pg->expiry = 0;
650 	orig_transition_tmo = pg->transition_tmo;
652 		pg->transition_tmo = buff[5];
654 		pg->transition_tmo = ALUA_FAILOVER_TIMEOUT;
656 	if (orig_transition_tmo != pg->transition_tmo) {
659 			    ALUA_DH_NAME, pg->transition_tmo);
660 		pg->expiry = jiffies + pg->transition_tmo * HZ;
674 		tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len,
679 				if ((tmp_pg == pg) ||
694 				if (tmp_pg == pg)
704 	spin_lock_irqsave(&pg->lock, flags);
706 		pg->state = SCSI_ACCESS_STATE_TRANSITIONING;
708 	if (group_id_old != pg->group_id || state_old != pg->state ||
709 		pref_old != pg->pref || valid_states_old != pg->valid_states)
712 			ALUA_DH_NAME, pg->group_id, print_alua_state(pg->state),
713 			pg->pref ? "preferred" : "non-preferred",
714 			pg->valid_states&TPGS_SUPPORT_TRANSITION?'T':'t',
715 			pg->valid_states&TPGS_SUPPORT_OFFLINE?'O':'o',
716 			pg->valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l',
717 			pg->valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u',
718 			pg->valid_states&TPGS_SUPPORT_STANDBY?'S':'s',
719 			pg->valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n',
720 			pg->valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a');
722 	switch (pg->state) {
724 		if (time_before(jiffies, pg->expiry)) {
726 			pg->interval = ALUA_RTPG_RETRY_DELAY;
733 			pg->state = SCSI_ACCESS_STATE_STANDBY;
734 			pg->expiry = 0;
736 			list_for_each_entry_rcu(h, &pg->dh_list, node) {
740 					(pg->state & SCSI_ACCESS_STATE_MASK);
741 				if (pg->pref)
751 		pg->expiry = 0;
756 		pg->expiry = 0;
759 	spin_unlock_irqrestore(&pg->lock, flags);
772 static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg)
777 	if (!(pg->tpgs & TPGS_MODE_EXPLICIT)) {
781 	switch (pg->state) {
785 		if ((pg->flags & ALUA_OPTIMIZE_STPG) &&
786 		    !pg->pref &&
787 		    (pg->tpgs & TPGS_MODE_IMPLICIT))
800 			    ALUA_DH_NAME, pg->state);
803 	retval = submit_stpg(sdev, pg->group_id, &sense_hdr);
827 alua_rtpg_select_sdev(struct alua_port_group *pg)
832 	lockdep_assert_held(&pg->lock);
833 	if (WARN_ON(!pg->rtpg_sdev))
838 	 * as we hold pg->lock, but for access to h->pg.
841 	list_for_each_entry_rcu(h, &pg->dh_list, node) {
844 		if (h->sdev == pg->rtpg_sdev) {
848 		if (rcu_dereference(h->pg) == pg &&
859 			(pg->device_id_len ?
860 			 (char *)pg->device_id_str : "(nameless PG)"));
866 	prev_sdev = pg->rtpg_sdev;
867 	pg->rtpg_sdev = sdev;
874 	struct alua_port_group *pg =
883 	spin_lock_irqsave(&pg->lock, flags);
884 	sdev = pg->rtpg_sdev;
886 		WARN_ON(pg->flags & ALUA_PG_RUN_RTPG);
887 		WARN_ON(pg->flags & ALUA_PG_RUN_STPG);
888 		spin_unlock_irqrestore(&pg->lock, flags);
889 		kref_put(&pg->kref, release_port_group);
892 	pg->flags |= ALUA_PG_RUNNING;
893 	if (pg->flags & ALUA_PG_RUN_RTPG) {
894 		int state = pg->state;
896 		pg->flags &= ~ALUA_PG_RUN_RTPG;
897 		spin_unlock_irqrestore(&pg->lock, flags);
900 				spin_lock_irqsave(&pg->lock, flags);
901 				pg->flags &= ~ALUA_PG_RUNNING;
902 				pg->flags |= ALUA_PG_RUN_RTPG;
903 				if (!pg->interval)
904 					pg->interval = ALUA_RTPG_RETRY_DELAY;
905 				spin_unlock_irqrestore(&pg->lock, flags);
906 				queue_delayed_work(kaluad_wq, &pg->rtpg_work,
907 						   pg->interval * HZ);
912 		err = alua_rtpg(sdev, pg);
913 		spin_lock_irqsave(&pg->lock, flags);
917 		    (prev_sdev = alua_rtpg_select_sdev(pg)))
921 		    pg->flags & ALUA_PG_RUN_RTPG) {
922 			pg->flags &= ~ALUA_PG_RUNNING;
924 				pg->interval = 0;
925 			else if (!pg->interval && !(pg->flags & ALUA_PG_RUN_RTPG))
926 				pg->interval = ALUA_RTPG_RETRY_DELAY;
927 			pg->flags |= ALUA_PG_RUN_RTPG;
928 			spin_unlock_irqrestore(&pg->lock, flags);
932 			pg->flags &= ~ALUA_PG_RUN_STPG;
934 	if (pg->flags & ALUA_PG_RUN_STPG) {
935 		pg->flags &= ~ALUA_PG_RUN_STPG;
936 		spin_unlock_irqrestore(&pg->lock, flags);
937 		err = alua_stpg(sdev, pg);
938 		spin_lock_irqsave(&pg->lock, flags);
939 		if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) {
940 			pg->flags |= ALUA_PG_RUN_RTPG;
941 			pg->interval = 0;
942 			pg->flags &= ~ALUA_PG_RUNNING;
943 			spin_unlock_irqrestore(&pg->lock, flags);
948 	list_splice_init(&pg->rtpg_list, &qdata_list);
953 	list_for_each_entry(h, &pg->dh_list, node)
955 	pg->rtpg_sdev = NULL;
956 	spin_unlock_irqrestore(&pg->lock, flags);
967 	spin_lock_irqsave(&pg->lock, flags);
968 	pg->flags &= ~ALUA_PG_RUNNING;
969 	spin_unlock_irqrestore(&pg->lock, flags);
971 	kref_put(&pg->kref, release_port_group);
977 	queue_delayed_work(kaluad_wq, &pg->rtpg_work, pg->interval * HZ);
982  * @pg: ALUA port group associated with @sdev.
994 static bool alua_rtpg_queue(struct alua_port_group *pg,
1001 	if (WARN_ON_ONCE(!pg) || scsi_device_get(sdev))
1004 	spin_lock_irqsave(&pg->lock, flags);
1006 		list_add_tail(&qdata->entry, &pg->rtpg_list);
1007 		pg->flags |= ALUA_PG_RUN_STPG;
1010 	if (pg->rtpg_sdev == NULL) {
1014 		if (h && rcu_dereference(h->pg) == pg) {
1015 			pg->interval = 0;
1016 			pg->flags |= ALUA_PG_RUN_RTPG;
1017 			kref_get(&pg->kref);
1018 			pg->rtpg_sdev = sdev;
1022 	} else if (!(pg->flags & ALUA_PG_RUN_RTPG) && force) {
1023 		pg->flags |= ALUA_PG_RUN_RTPG;
1025 		if (!(pg->flags & ALUA_PG_RUNNING)) {
1026 			kref_get(&pg->kref);
1031 	spin_unlock_irqrestore(&pg->lock, flags);
1034 		if (queue_delayed_work(kaluad_wq, &pg->rtpg_work,
1038 			kref_put(&pg->kref, release_port_group);
1078 	struct alua_port_group *pg = NULL;
1093 	pg = rcu_dereference(h->pg);
1094 	if (!pg) {
1098 	spin_lock_irqsave(&pg->lock, flags);
1100 		pg->flags |= ALUA_OPTIMIZE_STPG;
1102 		pg->flags &= ~ALUA_OPTIMIZE_STPG;
1103 	spin_unlock_irqrestore(&pg->lock, flags);
1125 	struct alua_port_group *pg;
1137 	pg = rcu_dereference(h->pg);
1138 	if (!pg || !kref_get_unless_zero(&pg->kref)) {
1148 	if (alua_rtpg_queue(pg, sdev, qdata, true)) {
1154 	kref_put(&pg->kref, release_port_group);
1170 	struct alua_port_group *pg;
1173 	pg = rcu_dereference(h->pg);
1174 	if (!pg || !kref_get_unless_zero(&pg->kref)) {
1179 	alua_rtpg_queue(pg, sdev, NULL, force);
1180 	kref_put(&pg->kref, release_port_group);
1192 	struct alua_port_group *pg;
1196 	pg = rcu_dereference(h->pg);
1197 	if (pg)
1198 		state = pg->state;
1233 	rcu_assign_pointer(h->pg, NULL);
1257 	struct alua_port_group *pg;
1260 	pg = rcu_dereference_protected(h->pg, lockdep_is_held(&h->pg_lock));
1261 	rcu_assign_pointer(h->pg, NULL);
1263 	if (pg) {
1264 		spin_lock_irq(&pg->lock);
1266 		spin_unlock_irq(&pg->lock);
1267 		kref_put(&pg->kref, release_port_group);