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Commit 735f7d2f authored by Dan Williams's avatar Dan Williams Committed by James Bottomley
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[SCSI] libsas: fix domain_device leak 



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: default avatarJack Wang <jack_wang@usish.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarJames Bottomley <JBottomley@Parallels.com>
parent 6f4e75a4

Documentation/scsi/libsas.txt

+0 −15
Original line number Diff line number Diff line
@@ -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

---------

drivers/scsi/libsas/sas_discover.c

+24 −12
Original line number Diff line number Diff line
@@ -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;

	}

drivers/scsi/libsas/sas_expander.c

+6 −4
Original line number Diff line number Diff line
@@ -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);

drivers/scsi/libsas/sas_internal.h

+19 −0
Original line number Diff line number Diff line
@@ -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_ */

drivers/scsi/libsas/sas_scsi_host.c

+6 −10
Original line number Diff line number Diff line
@@ -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)