Re: [PATCH] scsi: avoid a permanent stop of the scsi device's request queue

["Ewan D. Milne" <emilne@redhat.com>]

On Wed, 2016-12-07 at 12:09 -0800, James Bottomley wrote:
> Hm, it looks like the state set in scsi_sysfs_add_sdev() is bogus.  We
> expect the state to have been properly set before that (in
> scsi_add_lun), so can we not simply remove it?
> 
> James
> 

I was considering that, but...

enum scsi_device_state {
        SDEV_CREATED = 1,       /* device created but not added to sysfs                                                                                                                                           
                                 * Only internal commands allowed (for inq) */

So it seems the intent was for the state to not change until then.

The call to set the SDEV_RUNNING state earlier in scsi_add_lun()
was added with:

commit 6f4267e3bd1211b3d09130e626b0b3d885077610
Author: James Bottomley <James.Bottomley@HansenPartnership.com>
Date:   Fri Aug 22 16:53:31 2008 -0500

    [SCSI] Update the SCSI state model to allow blocking in the created state

Which allows the device to go into ->BLOCK (which is needed, since it
actually happens).

Should we remove the call from scsi_sysfs_add_sdev() and change the
comment in scsi_device.h to reflect the intent?

I have not verified the async vs. non-async scan path yet but it looks
like it would be OK.

-Ewan