Re: [PATCH v3 0/4] scsi: ufs & ums-* & esp_scsi: fix module reference counting

[Christoph Hellwig <hch@lst.de>]

On Sun, Jan 11, 2015 at 10:50:02PM +0900, Akinobu Mita wrote:
> While accessing a scsi_device, the use count of the underlying LLDD module
> is incremented.  The module reference is retrieved through .module field of
> struct scsi_host_template.
> 
> This mapping between scsi_device and underlying LLDD module works well
> except ufs, unusual usb storage drivers, and sub drivers for esp_scsi.
> These drivers consist with core driver and actual LLDDs, and
> scsi_host_template is defined in the core driver.  So the actual LLDDs can
> be unloaded even if the scsi_device is being accessed.
> 
> This patch series first adds ability to adjust module reference for
> scsi host by LLDDs and then fixes actual LLDDs by adjusting module
> reference after scsi host allocation.

Why don't we move the module into the Scsi_Host only, and use
the same macro that passes THIS_MODULE trick you are using in
the sub drivers?  That seems to be a fairly common scheme in other
subsystems as well.