Arrange for the deallocation of a struct domain_device object when it no
longer has:
1/ any children
2/ references by any scsi_targets
3/ references by a lldd
The comment about domain_device lifetime in
Documentation/scsi/libsas.txt is stale as it appears mainline never had
a version of a struct domain_device that was registered as a kobject.
We now manage domain_device reference counts on behalf of external
agents.
Reviewed-by: Jack Wang <jack_wang@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
Documentation/scsi/libsas.txt | 15 ---------------
drivers/scsi/libsas/sas_discover.c | 36 +++++++++++++++++++++++------------
drivers/scsi/libsas/sas_expander.c | 10 ++++++----
drivers/scsi/libsas/sas_internal.h | 19 ++++++++++++++++++
drivers/scsi/libsas/sas_scsi_host.c | 16 ++++++----------
include/scsi/libsas.h | 1 +
6 files changed, 56 insertions(+), 41 deletions(-)
diff --git a/Documentation/scsi/libsas.txt b/Documentation/scsi/libsas.txt
index aa54f54..3cc9c78 100644
--- a/Documentation/scsi/libsas.txt
+++ b/Documentation/scsi/libsas.txt
@@ -398,21 +398,6 @@ struct sas_task {
task_done -- callback when the task has finished execution
};
-When an external entity, entity other than the LLDD or the
-SAS Layer, wants to work with a struct domain_device, it
-_must_ call kobject_get() when getting a handle on the
-device and kobject_put() when it is done with the device.
-
-This does two things:
- A) implements proper kfree() for the device;
- B) increments/decrements the kref for all players:
- domain_device
- all domain_device's ... (if past an expander)
- port
- host adapter
- pci device
- and up the ladder, etc.
-
DISCOVERY
---------
diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index 54a5199..4e64930 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -36,8 +36,6 @@
void sas_init_dev(struct domain_device *dev)
{
- INIT_LIST_HEAD(&dev->siblings);
- INIT_LIST_HEAD(&dev->dev_list_node);
switch (dev->dev_type) {
case SAS_END_DEV:
break;
@@ -73,14 +71,14 @@ static int sas_get_port_device(struct asd_sas_port *port)
struct sas_rphy *rphy;
struct domain_device *dev;
- dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ dev = sas_alloc_device();
if (!dev)
return -ENOMEM;
spin_lock_irqsave(&port->phy_list_lock, flags);
if (list_empty(&port->phy_list)) {
spin_unlock_irqrestore(&port->phy_list_lock, flags);
- kfree(dev);
+ sas_put_device(dev);
return -ENODEV;
}
phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
@@ -130,7 +128,7 @@ static int sas_get_port_device(struct asd_sas_port *port)
}
if (!rphy) {
- kfree(dev);
+ sas_put_device(dev);
return -ENODEV;
}
rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
@@ -173,6 +171,7 @@ int sas_notify_lldd_dev_found(struct domain_device *dev)
dev_name(sas_ha->dev),
SAS_ADDR(dev->sas_addr), res);
}
+ kref_get(&dev->kref);
}
return res;
}
@@ -184,8 +183,10 @@ void sas_notify_lldd_dev_gone(struct domain_device *dev)
struct Scsi_Host *shost = sas_ha->core.shost;
struct sas_internal *i = to_sas_internal(shost->transportt);
- if (i->dft->lldd_dev_gone)
+ if (i->dft->lldd_dev_gone) {
i->dft->lldd_dev_gone(dev);
+ sas_put_device(dev);
+ }
}
/* ---------- Common/dispatchers ---------- */
@@ -219,6 +220,20 @@ out_err2:
/* ---------- Device registration and unregistration ---------- */
+void sas_free_device(struct kref *kref)
+{
+ struct domain_device *dev = container_of(kref, typeof(*dev), kref);
+
+ if (dev->parent)
+ sas_put_device(dev->parent);
+
+ /* remove the phys and ports, everything else should be gone */
+ if (dev->dev_type == EDGE_DEV || dev->dev_type == FANOUT_DEV)
+ kfree(dev->ex_dev.ex_phy);
+
+ kfree(dev);
+}
+
static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
{
sas_notify_lldd_dev_gone(dev);
@@ -230,6 +245,8 @@ static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_d
spin_lock_irq(&port->dev_list_lock);
list_del_init(&dev->dev_list_node);
spin_unlock_irq(&port->dev_list_lock);
+
+ sas_put_device(dev);
}
void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
@@ -239,11 +256,6 @@ void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
sas_rphy_delete(dev->rphy);
dev->rphy = NULL;
}
- if (dev->dev_type == EDGE_DEV || dev->dev_type == FANOUT_DEV) {
- /* remove the phys and ports, everything else should be gone */
- kfree(dev->ex_dev.ex_phy);
- dev->ex_dev.ex_phy = NULL;
- }
sas_unregister_common_dev(port, dev);
}
@@ -322,7 +334,7 @@ static void sas_discover_domain(struct work_struct *work)
list_del_init(&dev->dev_list_node);
spin_unlock_irq(&port->dev_list_lock);
- kfree(dev); /* not kobject_register-ed yet */
+ sas_put_device(dev);
port->port_dev = NULL;
}
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 1b831c5..15d2239 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -657,10 +657,11 @@ static struct domain_device *sas_ex_discover_end_dev(
if (phy->attached_sata_host || phy->attached_sata_ps)
return NULL;
- child = kzalloc(sizeof(*child), GFP_KERNEL);
+ child = sas_alloc_device();
if (!child)
return NULL;
+ kref_get(&parent->kref);
child->parent = parent;
child->port = parent->port;
child->iproto = phy->attached_iproto;
@@ -762,7 +763,7 @@ static struct domain_device *sas_ex_discover_end_dev(
sas_port_delete(phy->port);
out_err:
phy->port = NULL;
- kfree(child);
+ sas_put_device(child);
return NULL;
}
@@ -809,7 +810,7 @@ static struct domain_device *sas_ex_discover_expander(
phy->attached_phy_id);
return NULL;
}
- child = kzalloc(sizeof(*child), GFP_KERNEL);
+ child = sas_alloc_device();
if (!child)
return NULL;
@@ -835,6 +836,7 @@ static struct domain_device *sas_ex_discover_expander(
child->rphy = rphy;
edev = rphy_to_expander_device(rphy);
child->dev_type = phy->attached_dev_type;
+ kref_get(&parent->kref);
child->parent = parent;
child->port = port;
child->iproto = phy->attached_iproto;
@@ -858,7 +860,7 @@ static struct domain_device *sas_ex_discover_expander(
spin_lock_irq(&parent->port->dev_list_lock);
list_del(&child->dev_list_node);
spin_unlock_irq(&parent->port->dev_list_lock);
- kfree(child);
+ sas_put_device(child);
return NULL;
}
list_add_tail(&child->siblings, &parent->ex_dev.children);
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index 14e21b5..0d43408 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -76,6 +76,8 @@ struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy);
void sas_hae_reset(struct work_struct *work);
+void sas_free_device(struct kref *kref);
+
#ifdef CONFIG_SCSI_SAS_HOST_SMP
extern int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
struct request *rsp);
@@ -161,4 +163,21 @@ static inline void sas_add_parent_port(struct domain_device *dev, int phy_id)
sas_port_add_phy(ex->parent_port, ex_phy->phy);
}
+static inline struct domain_device *sas_alloc_device(void)
+{
+ struct domain_device *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+
+ if (dev) {
+ INIT_LIST_HEAD(&dev->siblings);
+ INIT_LIST_HEAD(&dev->dev_list_node);
+ kref_init(&dev->kref);
+ }
+ return dev;
+}
+
+static inline void sas_put_device(struct domain_device *dev)
+{
+ kref_put(&dev->kref, sas_free_device);
+}
+
#endif /* _SAS_INTERNAL_H_ */
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index e95e5e1..2a163c7 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -737,16 +737,10 @@ struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
return found_dev;
}
-static inline struct domain_device *sas_find_target(struct scsi_target *starget)
-{
- struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
-
- return sas_find_dev_by_rphy(rphy);
-}
-
int sas_target_alloc(struct scsi_target *starget)
{
- struct domain_device *found_dev = sas_find_target(starget);
+ struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
+ struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
int res;
if (!found_dev)
@@ -758,6 +752,7 @@ int sas_target_alloc(struct scsi_target *starget)
return res;
}
+ kref_get(&found_dev->kref);
starget->hostdata = found_dev;
return 0;
}
@@ -1047,7 +1042,7 @@ int sas_slave_alloc(struct scsi_device *scsi_dev)
void sas_target_destroy(struct scsi_target *starget)
{
- struct domain_device *found_dev = sas_find_target(starget);
+ struct domain_device *found_dev = starget->hostdata;
if (!found_dev)
return;
@@ -1055,7 +1050,8 @@ void sas_target_destroy(struct scsi_target *starget)
if (dev_is_sata(found_dev))
ata_sas_port_destroy(found_dev->sata_dev.ap);
- return;
+ starget->hostdata = NULL;
+ sas_put_device(found_dev);
}
static void sas_parse_addr(u8 *sas_addr, const char *p)
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index 2b14348..7ecb5c1 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -206,6 +206,7 @@ struct domain_device {
void *lldd_dev;
int gone;
+ struct kref kref;
};
struct sas_discovery_event {
--
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