Mike Christie wrote:
Pete Wyckoff wrote:
I think this used not to happen; not sure. But I changed two things
This most likely did not happen before 2.6.25-rc* or it broke in
slightly different ways, because iscsi used to try and do
echo 1 > /sys/block/sdX/device/delete
from userspace instead of calling scsi_remove_target from the kernel.
As you know around 2.6.21, the behavior of doing the echo to the delete
file changed due to a driver model and scsi change and that broke the
iscsi tools. The iscsi tools userspace removal was sort of hack in the
first place and was racey, so we switched to removing devices/target
like the FC class.
lately. 2.6.25-rc1 to -rc4 and fedora 8 iscsi-initiator-utils (865) to
fedora devel (868). Bidi and varlen patches always too.
I'll follow with some more variations on this theme. Looks like bsg
needs to protect more carefully against the device going away. Any
ideas how best to do this? What was the approach in sg?
I think sg is broken in similar ways. The iser guys have some tests
cases that have broken sg while IO is outstanding. I am ccing Erez.
Actually one of the problems looks a little different than some of the
problems hit with sg and are caused because we remove the bsg device too
soon. I think we want to wait until all the references from the
commands/requests are released. The attached patch (untested) moves the
bsg unreg call to the scsi device release fn.
Delay bsg unregistration, because we want to wait until all the request/cmds
have released their reference.
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index ed83cdb..b9b09a7 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -294,6 +294,7 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work)
}
if (sdev->request_queue) {
+ bsg_unregister_queue(sdev->request_queue);
sdev->request_queue->queuedata = NULL;
/* user context needed to free queue */
scsi_free_queue(sdev->request_queue);
@@ -857,7 +858,6 @@ void __scsi_remove_device(struct scsi_device *sdev)
if (scsi_device_set_state(sdev, SDEV_CANCEL) != 0)
return;
- bsg_unregister_queue(sdev->request_queue);
class_device_unregister(&sdev->sdev_classdev);
transport_remove_device(dev);
device_del(dev);
