We have another test case that demonstrates this issue involving duplicate invocations of scsi_device_dev_release() on the same device. This other test case involves repeated log in / log out of an iSCSI target. (The first test case I mentioned in an earlier mail was an oscillating FC port with a low dev_loss_tmo value.)
The iSCSI test was not fixed by Jason Yan's patch, however adding Bart's change to use kobject_get_unless_zero() in get_device() as well seems to have resolved it. We are going to try with just Bart's change next. -Ewan
