stefanr@xxxxxxxxxxxxxxxxx wrote:
> scameron@xxxxxxxxxxxxxxxxxx wrote:
> > On Thu, Jan 14, 2010 at 01:24:59PM -0500, Douglas Gilbert wrote:
> >> scameron@xxxxxxxxxxxxxxxxxx wrote:
> >>> I'm seeing a problem which I think is a problem in the SCSI mid layer.
> [...]
> >>> Remove the device while something has it open:
> [...]
> >>> [root@slicer ~]# rmmod hpsa
> >>> ERROR: Module hpsa is in use
>
> The sg driver's open method takes a reference to the underlying SCSI
> device representation of the mid layer. Among else, this step increases
> the module use count of the respective low-level driver (transport layer
> driver) so that the SCSI mid layer can be sure that function pointers to
> driver methods stay valid during the lifetime of the SCSI device
> representation.
>
> This reference taking is of course being reversed when the sg driver
> finishes its last uses of the underlying SCSI device. This may be at
> the respective close() or even later.
>
> In short, it is normal, expected, and necessary what you are seeing.
> --
> Stefan Richter
>
I don't think you are correct. Look more closely at my test cases.
When I attempt the rmmod, *nothing* has the device open. The last
close has already occurred -- albeit *after* the device was
removed.
In my test, the module *never* becomes rmmod-able. Doesn't matter
how long you wait, and nothing will ever decrement the reference
count.
Are you saying that this is correct behavior, that once a device
is removed while a process has it open that it shoule *never*
be rmmod'able?
Because that is the behavior I am seeing.
-- steve
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