Re: [PATCH V2] scsi: add a new flag to set whether SCSI disks support WRITE_SAME_16 by default

[Christoph Hellwig <hch@infradead.org>]

On Sat, Feb 01, 2020 at 02:54:31PM +0800, AlexChen wrote:
> When the SCSI device is initialized, check whether it supports
> WRITE_SAME_16 or WRITE_SAME_10 in the sd_read_write_same(). If
> the back-end storage device does not support queries, it will not
> set sdkp->ws16 as 1.
> 
> When the WRITE_SAME io is issued through the blkdev_issue_write_same(),
> the WRITE_SAME type is set to WRITE_SAME_10 by default in
> the sd_setup_write_same_cmnd() since of "sdkp->ws16=0". If the storage
> device does not support WRITE_SAME_10, then the SCSI device is set to
> not support WRITE_SAME.
> 
> Currently, some storage devices do not provide queries for WRITE_SAME_16
> support, and only WRITE_SAME_16 is supported, not WRITE_SAME_10.
> Therefore, we need to provide a new flag for these storage devices. When
> initializing these devices, we will no longer query for support for
> WRITE_SAME_16 in the sd_read_write_same(), but set these SCSI disks to
> support WRITE_SAME_16 by default. In that way, we can add
> 'vendor:product:flag' to the module parameter 'dev_flags' for these
> storage devices.

Please send this along with the patch that actually sets the flag
somewhere..