From cb0a168cb6b8f77097d69872349278a17383c38e Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Thu, 3 Mar 2016 07:54:09 +0100 Subject: [PATCH] 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: Hannes Reinecke Reviewed-by: Bart Van Assche Reviewed-by: Ewan Milne Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Martin K. Petersen --- drivers/scsi/device_handler/scsi_dh_alua.c | 48 +++++++++++++++++++++- 1 file changed, 46 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index 19f653930f7c..5bcdf8dd6fb0 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -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); } -- 2.20.1