[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: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index b6ba0e0..a65598b 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -577,8 +577,6 @@
out_err:
sas_notify_lldd_dev_gone(dev);
out_err2:
- sas_rphy_free(dev->rphy);
- dev->rphy = NULL;
return res;
}
@@ -600,24 +598,11 @@
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 @@
*/
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 @@
&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;
}