| Message ID | 1449560260-53407-20-git-send-email-hare@suse.de (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
On Tue, Dec 08, 2015 at 08:37:39AM +0100, Hannes Reinecke wrote: > Track attached SCSI devices and update the 'access_state' field > whenever an ALUA state change has been detected. > > Signed-off-by: Hannes Reinecke <hare@suse.de> > --- > drivers/scsi/device_handler/scsi_dh_alua.c | 29 +++++++++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c > index 6c6ff0b..d01c86407 100644 > --- a/drivers/scsi/device_handler/scsi_dh_alua.c > +++ b/drivers/scsi/device_handler/scsi_dh_alua.c > @@ -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> > @@ -76,6 +77,7 @@ static struct workqueue_struct *kaluad_wq; > struct alua_port_group { > struct kref kref; > struct list_head node; > + struct list_head dh_list; > unsigned char device_id_str[256]; > int device_id_len; > int group_id; > @@ -93,6 +95,7 @@ struct alua_port_group { > }; > > struct alua_dh_data { > + struct list_head node; > struct alua_port_group *pg; > int rel_port; > spinlock_t pg_lock; > @@ -243,6 +246,7 @@ struct alua_port_group *alua_get_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); > > /* Re-check list again to catch concurrent updates */ > @@ -370,13 +374,26 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h, > old_pg = pg; > /* port_group has changed. Update to new port group */ > if (h->pg != pg) { > + unsigned long flags; > + > old_pg = h->pg; > rcu_assign_pointer(h->pg, pg); > + spin_lock_irqsave(&old_pg->lock, flags); > + list_del_rcu(&h->node); > + spin_unlock_irqrestore(&old_pg->lock, flags); > + spin_lock_irqsave(&pg->lock, flags); > + list_add_rcu(&h->node, &pg->dh_list); > + spin_unlock_irqrestore(&pg->lock, flags); I think it makes more sense to remove it from the old list before assining the new h->pg pointer to stay consistant. Also the add code is not common with the other half of the outer branch, it would be nice to find a way to share the code between those two branches. > list_for_each_entry(tmp_pg, &port_group_list, node) { > + struct alua_dh_data *h; > + > if (tmp_pg->group_id != group_id) > continue; > if (tmp_pg->device_id_len != pg->device_id_len) > @@ -639,6 +658,12 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) > continue; > 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) { > + if (h->sdev) > + h->sdev->access_state = desc[0]; > + } > + rcu_read_unlock(); ?'d expect h->?dev to always be non-NULL. With a little tweak (see below) that should indeed be the case. > @@ -1086,6 +1112,9 @@ static void alua_bus_detach(struct scsi_device *sdev) > h->sdev = NULL; > spin_unlock(&h->pg_lock); > if (pg) { > + spin_lock(&pg->lock); > + list_del_rcu(&h->node); > + spin_unlock(&pg->lock); > synchronize_rcu(); > if (pg->rtpg_sdev) > flush_delayed_work(&pg->rtpg_work); Here we'd just need to make sure to do the list_del before setting h->sdev to NULL. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 12/30/2015 02:34 PM, Christoph Hellwig wrote: > On Tue, Dec 08, 2015 at 08:37:39AM +0100, Hannes Reinecke wrote: >> Track attached SCSI devices and update the 'access_state' field >> whenever an ALUA state change has been detected. >> >> Signed-off-by: Hannes Reinecke <hare@suse.de> >> --- >> drivers/scsi/device_handler/scsi_dh_alua.c | 29 +++++++++++++++++++++++++++++ >> 1 file changed, 29 insertions(+) >> >> diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c >> index 6c6ff0b..d01c86407 100644 >> --- a/drivers/scsi/device_handler/scsi_dh_alua.c >> +++ b/drivers/scsi/device_handler/scsi_dh_alua.c >> @@ -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> >> @@ -76,6 +77,7 @@ static struct workqueue_struct *kaluad_wq; >> struct alua_port_group { >> struct kref kref; >> struct list_head node; >> + struct list_head dh_list; >> unsigned char device_id_str[256]; >> int device_id_len; >> int group_id; >> @@ -93,6 +95,7 @@ struct alua_port_group { >> }; >> >> struct alua_dh_data { >> + struct list_head node; >> struct alua_port_group *pg; >> int rel_port; >> spinlock_t pg_lock; >> @@ -243,6 +246,7 @@ struct alua_port_group *alua_get_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); >> >> /* Re-check list again to catch concurrent updates */ >> @@ -370,13 +374,26 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h, >> old_pg = pg; >> /* port_group has changed. Update to new port group */ >> if (h->pg != pg) { >> + unsigned long flags; >> + >> old_pg = h->pg; >> rcu_assign_pointer(h->pg, pg); >> + spin_lock_irqsave(&old_pg->lock, flags); >> + list_del_rcu(&h->node); >> + spin_unlock_irqrestore(&old_pg->lock, flags); >> + spin_lock_irqsave(&pg->lock, flags); >> + list_add_rcu(&h->node, &pg->dh_list); >> + spin_unlock_irqrestore(&pg->lock, flags); > > I think it makes more sense to remove it from the old list > before assining the new h->pg pointer to stay consistant. > Hmm. Yes, good point. > Also the add code is not common with the other half of the outer > branch, it would be nice to find a way to share the code between > those two branches. > Indeed, it would. But so far I haven't found a nice way for that... >> list_for_each_entry(tmp_pg, &port_group_list, node) { >> + struct alua_dh_data *h; >> + >> if (tmp_pg->group_id != group_id) >> continue; >> if (tmp_pg->device_id_len != pg->device_id_len) >> @@ -639,6 +658,12 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) >> continue; >> 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) { >> + if (h->sdev) >> + h->sdev->access_state = desc[0]; >> + } >> + rcu_read_unlock(); > > ?'d expect h->?dev to always be non-NULL. With a little tweak (see below) > that should indeed be the case. > >> @@ -1086,6 +1112,9 @@ static void alua_bus_detach(struct scsi_device *sdev) >> h->sdev = NULL; >> spin_unlock(&h->pg_lock); >> if (pg) { >> + spin_lock(&pg->lock); >> + list_del_rcu(&h->node); >> + spin_unlock(&pg->lock); >> synchronize_rcu(); >> if (pg->rtpg_sdev) >> flush_delayed_work(&pg->rtpg_work); > > Here we'd just need to make sure to do the list_del before setting > h->sdev to NULL. > Okay, true. Will do. Cheers, Hannes
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index 6c6ff0b..d01c86407 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -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> @@ -76,6 +77,7 @@ static struct workqueue_struct *kaluad_wq; struct alua_port_group { struct kref kref; struct list_head node; + struct list_head dh_list; unsigned char device_id_str[256]; int device_id_len; int group_id; @@ -93,6 +95,7 @@ struct alua_port_group { }; struct alua_dh_data { + struct list_head node; struct alua_port_group *pg; int rel_port; spinlock_t pg_lock; @@ -243,6 +246,7 @@ struct alua_port_group *alua_get_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); /* Re-check list again to catch concurrent updates */ @@ -370,13 +374,26 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h, old_pg = pg; /* port_group has changed. Update to new port group */ if (h->pg != pg) { + unsigned long flags; + old_pg = h->pg; rcu_assign_pointer(h->pg, pg); + spin_lock_irqsave(&old_pg->lock, flags); + list_del_rcu(&h->node); + spin_unlock_irqrestore(&old_pg->lock, flags); + spin_lock_irqsave(&pg->lock, flags); + list_add_rcu(&h->node, &pg->dh_list); + spin_unlock_irqrestore(&pg->lock, flags); h->pg->expiry = 0; pg_found = true; } } else { + unsigned long flags; + rcu_assign_pointer(h->pg, pg); + spin_lock_irqsave(&pg->lock, flags); + list_add_rcu(&h->node, &pg->dh_list); + spin_unlock_irqrestore(&pg->lock, flags); pg_found = true; } alua_rtpg_queue(h->pg, sdev, NULL, true); @@ -630,6 +647,8 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) spin_lock_irqsave(&port_group_lock, flags); list_for_each_entry(tmp_pg, &port_group_list, node) { + struct alua_dh_data *h; + if (tmp_pg->group_id != group_id) continue; if (tmp_pg->device_id_len != pg->device_id_len) @@ -639,6 +658,12 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) continue; 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) { + if (h->sdev) + h->sdev->access_state = desc[0]; + } + rcu_read_unlock(); if (tmp_pg == pg) valid_states = desc[1]; } @@ -1056,6 +1081,7 @@ static int alua_bus_attach(struct scsi_device *sdev) h->rel_port = -1; h->init_error = SCSI_DH_OK; h->sdev = sdev; + INIT_LIST_HEAD(&h->node); mutex_init(&h->init_mutex); err = alua_initialize(sdev, h); @@ -1086,6 +1112,9 @@ static void alua_bus_detach(struct scsi_device *sdev) h->sdev = NULL; spin_unlock(&h->pg_lock); if (pg) { + spin_lock(&pg->lock); + list_del_rcu(&h->node); + spin_unlock(&pg->lock); synchronize_rcu(); if (pg->rtpg_sdev) flush_delayed_work(&pg->rtpg_work);
Track attached SCSI devices and update the 'access_state' field whenever an ALUA state change has been detected. Signed-off-by: Hannes Reinecke <hare@suse.de> --- drivers/scsi/device_handler/scsi_dh_alua.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)