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Commit cb0a168c authored by Hannes Reinecke's avatar Hannes Reinecke Committed by Martin K. Petersen
Browse files

scsi_dh_alua: update 'access_state' field 



Track attached SCSI devices and update the 'access_state' field whenever
an ALUA state change has been detected.

Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: default avatarEwan Milne <emilne@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 5115fc7e

drivers/scsi/device_handler/scsi_dh_alua.c

+46 −2
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/module.h>

#include <asm/unaligned.h>

#include <scsi/scsi.h>

#include <scsi/scsi_proto.h>

#include <scsi/scsi_dbg.h>

#include <scsi/scsi_eh.h>

#include <scsi/scsi_dh.h>
@@ -75,6 +76,7 @@ struct alua_port_group { 
	struct kref		kref;

	struct rcu_head		rcu;

	struct list_head	node;

	struct list_head	dh_list;

	unsigned char		device_id_str[256];

	int			device_id_len;

	int			group_id;
@@ -92,6 +94,7 @@ struct alua_port_group { 
};



struct alua_dh_data {

	struct list_head	node;

	struct alua_port_group	*pg;

	int			group_id;

	spinlock_t		pg_lock;
@@ -247,6 +250,7 @@ struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev, 
	INIT_DELAYED_WORK(&pg->rtpg_work, alua_rtpg_work);

	INIT_LIST_HEAD(&pg->rtpg_list);

	INIT_LIST_HEAD(&pg->node);

	INIT_LIST_HEAD(&pg->dh_list);

	spin_lock_init(&pg->lock);



	spin_lock(&port_group_lock);
@@ -328,6 +332,8 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h, 
{

	int rel_port = -1, group_id;

	struct alua_port_group *pg, *old_pg = NULL;

	bool pg_updated;

	unsigned long flags;



	group_id = scsi_vpd_tpg_id(sdev, &rel_port);

	if (group_id < 0) {
@@ -357,10 +363,22 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h, 
	old_pg = h->pg;

	if (old_pg != pg) {

		/* port group has changed. Update to new port group */

		if (h->pg) {

			spin_lock_irqsave(&old_pg->lock, flags);

			list_del_rcu(&h->node);

			spin_unlock_irqrestore(&old_pg->lock, flags);

		}

		rcu_assign_pointer(h->pg, pg);

		pg_updated = true;

	}



	spin_lock_irqsave(&pg->lock, flags);

	if (sdev->synchronous_alua)

		pg->flags |= ALUA_SYNC_STPG;

	if (pg_updated)

		list_add_rcu(&h->node, &pg->dh_list);

	spin_unlock_irqrestore(&pg->lock, flags);



	alua_rtpg_queue(h->pg, sdev, NULL, true);

	spin_unlock(&h->pg_lock);
@@ -613,8 +631,18 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) 
			if (spin_trylock_irqsave(&tmp_pg->lock, flags)) {

				if ((tmp_pg == pg) ||

				    !(tmp_pg->flags & ALUA_PG_RUNNING)) {

					struct alua_dh_data *h;



					tmp_pg->state = desc[0] & 0x0f;

					tmp_pg->pref = desc[0] >> 7;

					rcu_read_lock();

					list_for_each_entry_rcu(h,

						&tmp_pg->dh_list, node) {

						/* h->sdev should always be valid */

						BUG_ON(!h->sdev);

						h->sdev->access_state = desc[0];

					}

					rcu_read_unlock();

				}

				if (tmp_pg == pg)

					valid_states = desc[1];
@@ -645,10 +673,22 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) 
			pg->interval = 2;

			err = SCSI_DH_RETRY;

		} else {

			struct alua_dh_data *h;



			/* Transitioning time exceeded, set port to standby */

			err = SCSI_DH_IO;

			pg->state = SCSI_ACCESS_STATE_STANDBY;

			pg->expiry = 0;

			rcu_read_lock();

			list_for_each_entry_rcu(h, &pg->dh_list, node) {

				BUG_ON(!h->sdev);

				h->sdev->access_state =

					(pg->state & SCSI_ACCESS_STATE_MASK);

				if (pg->pref)

					h->sdev->access_state |=

						SCSI_ACCESS_STATE_PREFERRED;

			}

			rcu_read_unlock();

		}

		break;

	case SCSI_ACCESS_STATE_OFFLINE:
@@ -1041,6 +1081,7 @@ static int alua_bus_attach(struct scsi_device *sdev) 
	rcu_assign_pointer(h->pg, NULL);

	h->init_error = SCSI_DH_OK;

	h->sdev = sdev;

	INIT_LIST_HEAD(&h->node);



	mutex_init(&h->init_mutex);

	err = alua_initialize(sdev, h);
@@ -1070,9 +1111,12 @@ static void alua_bus_detach(struct scsi_device *sdev) 
	rcu_assign_pointer(h->pg, NULL);

	h->sdev = NULL;

	spin_unlock(&h->pg_lock);

	if (pg)

	if (pg) {

		spin_lock(&pg->lock);

		list_del_rcu(&h->node);

		spin_unlock(&pg->lock);

		kref_put(&pg->kref, release_port_group);



	}

	sdev->handler_data = NULL;

	kfree(h);

}