michaelc@xxxxxxxxxxx wrote:
From: Mike Christie <michaelc@xxxxxxxxxxx>
In 2.6.25 we started using class_find_child instead of implementing
our own loop and lookup. The problem is that class_find_child would get a
reference to the host's device, then scsi_host_lookup would get an extra
reference to it when it called scsi_host_get().
In 2.6.26 we started using class_find_device, and this function also
gets a reference to the device, so we end up with an extra ref
and the host will not get released.
This patch is made against scsi-rc-fixes and adds a put_device to
balance the class_find_device() get. I kept the scsi_host_get in
scsi_host_lookup, because the target layer is using scsi_host_lookup
and it looks like it needs the SHOST_DEL check.
For 2.6.25 we need a similar patch, but instead of calling
put_device we have to call class_device_put() due to the differences
in the the driver model device/class_device between 2.6.25 and
2.6.26. I can send a patch for 2.6.25 in a seperate mail.
Attached is a patch for 2.6.25. Sorry it is late and attached instead of
inlined. I can send it in a new thread if you want too. I just want to
make sure people know it is slightly different from the scsi-rc-fixes
patch because of the driver model changes.
In 2.6.25 we started using class_find_child instead of implementing
our own loop and lookup. The problem is that class_find_child would get a
reference to the host's device, then scsi_host_lookup would get an extra
reference to it when it called scsi_host_get(). This patch drops the
ref from class_find_child because scsi_host_get gets a ref if the host
is not being removed.
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
--- linux-2.6.25.2/drivers/scsi/hosts.c 2008-05-06 18:21:32.000000000 -0500
+++ linux-2.6.25.2.work/drivers/scsi/hosts.c 2008-06-13 19:43:15.000000000 -0500
@@ -455,9 +455,10 @@ struct Scsi_Host *scsi_host_lookup(unsig
struct Scsi_Host *shost = ERR_PTR(-ENXIO);
cdev = class_find_child(&shost_class, &hostnum, __scsi_host_match);
- if (cdev)
+ if (cdev) {
shost = scsi_host_get(class_to_shost(cdev));
-
+ class_device_put(cdev);
+ }
return shost;
}
EXPORT_SYMBOL(scsi_host_lookup);
