Commit 6f63caae authored by Darrick J. Wong's avatar Darrick J. Wong Committed by James Bottomley
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[SCSI] libsas: Clean up discovery failure handler code



sas_rphy_delete does two things: it removes the sas_rphy from the transport
layer and frees the sas_rphy.  This can be broken down into two functions,
sas_rphy_remove and sas_rphy_free; sas_rphy_remove is of interest to
sas_discover_root_expander because it calls functions that require
sas_rphy_add as a prerequisite and can fail (namely sas_discover_expander).
In that case, sas_discover_root_expander needs to be able to undo the effects
of sas_rphy_add yet leave the job of freeing the sas_rphy to the caller of
sas_discover_root_expander.

This patch also removes some unnecessary code from sas_discover_end_dev
to eliminate an unnecessary cycle of sas_notify_lldd_gone/found for SAS
devices, thus eliminating a sas_rphy_remove call (and fixing a race condition
where a SCSI target scan can come in between the gone and found call).
It also moves the sas_rphy_free calls into sas_discover_domain and
sas_ex_discover_end_dev to complement the sas_rphy_allocation via
sas_get_port_device.

This patch does not change the semantics of sas_rphy_delete.
Signed-off-by: default avatarDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent 3b6e9faf
......@@ -577,8 +577,6 @@ int sas_discover_sata(struct domain_device *dev)
out_err:
sas_notify_lldd_dev_gone(dev);
out_err2:
sas_rphy_free(dev->rphy);
dev->rphy = NULL;
return res;
}
......@@ -600,24 +598,11 @@ int sas_discover_end_dev(struct domain_device *dev)
if (res)
goto out_err;
/* do this to get the end device port attributes which will have
* been scanned in sas_rphy_add */
sas_notify_lldd_dev_gone(dev);
res = sas_notify_lldd_dev_found(dev);
if (res)
goto out_err3;
return 0;
out_err:
sas_notify_lldd_dev_gone(dev);
out_err2:
sas_rphy_free(dev->rphy);
dev->rphy = NULL;
return res;
out_err3:
sas_rphy_delete(dev->rphy);
dev->rphy = NULL;
return res;
}
......@@ -672,6 +657,7 @@ void sas_unregister_domain_devices(struct asd_sas_port *port)
*/
static void sas_discover_domain(struct work_struct *work)
{
struct domain_device *dev;
int error = 0;
struct sas_discovery_event *ev =
container_of(work, struct sas_discovery_event, work);
......@@ -681,39 +667,42 @@ static void sas_discover_domain(struct work_struct *work)
&port->disc.pending);
if (port->port_dev)
return ;
else {
error = sas_get_port_device(port);
if (error)
return;
}
return;
error = sas_get_port_device(port);
if (error)
return;
dev = port->port_dev;
SAS_DPRINTK("DOING DISCOVERY on port %d, pid:%d\n", port->id,
current->pid);
switch (port->port_dev->dev_type) {
switch (dev->dev_type) {
case SAS_END_DEV:
error = sas_discover_end_dev(port->port_dev);
error = sas_discover_end_dev(dev);
break;
case EDGE_DEV:
case FANOUT_DEV:
error = sas_discover_root_expander(port->port_dev);
error = sas_discover_root_expander(dev);
break;
case SATA_DEV:
case SATA_PM:
error = sas_discover_sata(port->port_dev);
error = sas_discover_sata(dev);
break;
default:
SAS_DPRINTK("unhandled device %d\n", port->port_dev->dev_type);
SAS_DPRINTK("unhandled device %d\n", dev->dev_type);
break;
}
if (error) {
sas_rphy_free(dev->rphy);
dev->rphy = NULL;
spin_lock(&port->dev_list_lock);
list_del_init(&port->port_dev->dev_list_node);
list_del_init(&dev->dev_list_node);
spin_unlock(&port->dev_list_lock);
kfree(port->port_dev); /* not kobject_register-ed yet */
kfree(dev); /* not kobject_register-ed yet */
port->port_dev = NULL;
}
......
......@@ -667,6 +667,8 @@ static struct domain_device *sas_ex_discover_end_dev(
return child;
out_list_del:
sas_rphy_free(child->rphy);
child->rphy = NULL;
list_del(&child->dev_list_node);
out_free:
sas_port_delete(phy->port);
......@@ -1444,12 +1446,8 @@ int sas_discover_root_expander(struct domain_device *dev)
return res;
out_err2:
sas_rphy_delete(dev->rphy);
dev->rphy = NULL;
return res;
sas_rphy_remove(dev->rphy);
out_err:
sas_rphy_free(dev->rphy);
dev->rphy = NULL;
return res;
}
......
......@@ -1299,7 +1299,7 @@ EXPORT_SYMBOL(sas_rphy_add);
* Note:
* This function must only be called on a remote
* PHY that has not sucessfully been added using
* sas_rphy_add().
* sas_rphy_add() (or has been sas_rphy_remove()'d)
*/
void sas_rphy_free(struct sas_rphy *rphy)
{
......@@ -1318,18 +1318,30 @@ void sas_rphy_free(struct sas_rphy *rphy)
EXPORT_SYMBOL(sas_rphy_free);
/**
* sas_rphy_delete -- remove SAS remote PHY
* @rphy: SAS remote PHY to remove
* sas_rphy_delete -- remove and free SAS remote PHY
* @rphy: SAS remote PHY to remove and free
*
* Removes the specified SAS remote PHY.
* Removes the specified SAS remote PHY and frees it.
*/
void
sas_rphy_delete(struct sas_rphy *rphy)
{
sas_rphy_remove(rphy);
sas_rphy_free(rphy);
}
EXPORT_SYMBOL(sas_rphy_delete);
/**
* sas_rphy_remove -- remove SAS remote PHY
* @rphy: SAS remote phy to remove
*
* Removes the specified SAS remote PHY.
*/
void
sas_rphy_remove(struct sas_rphy *rphy)
{
struct device *dev = &rphy->dev;
struct sas_port *parent = dev_to_sas_port(dev->parent);
struct Scsi_Host *shost = dev_to_shost(parent->dev.parent);
struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
switch (rphy->identify.device_type) {
case SAS_END_DEVICE:
......@@ -1345,17 +1357,10 @@ sas_rphy_delete(struct sas_rphy *rphy)
transport_remove_device(dev);
device_del(dev);
transport_destroy_device(dev);
mutex_lock(&sas_host->lock);
list_del(&rphy->list);
mutex_unlock(&sas_host->lock);
parent->rphy = NULL;
put_device(dev);
}
EXPORT_SYMBOL(sas_rphy_delete);
EXPORT_SYMBOL(sas_rphy_remove);
/**
* scsi_is_sas_rphy -- check if a struct device represents a SAS remote PHY
......
......@@ -182,6 +182,7 @@ extern struct sas_rphy *sas_end_device_alloc(struct sas_port *);
extern struct sas_rphy *sas_expander_alloc(struct sas_port *, enum sas_device_type);
void sas_rphy_free(struct sas_rphy *);
extern int sas_rphy_add(struct sas_rphy *);
extern void sas_rphy_remove(struct sas_rphy *);
extern void sas_rphy_delete(struct sas_rphy *);
extern int scsi_is_sas_rphy(const struct device *);
......
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