Re: [PATCH v2 2/2] block: cope with WRITE ZEROES failing in blkdev_issue_zeroout()

[Ilya Dryomov]

On Mon, Oct 16, 2017 at 1:44 PM, Christoph Hellwig <h...@infradead.org> wrote:
> On Fri, Oct 06, 2017 at 02:31:20PM +0200, Ilya Dryomov wrote:
>> This would unconditionally overwrite any WRITE ZEROS error.  If we get
>> e.g. -EIO, and manual zeroing is not allowed, I don't think we want to
>> return -EOPNOTSUPP?
>>
>> Returning -EOPNOTSUPP to mean "can't zero using either method" doesn't
>> make sense to me, because manual zeroing is always supported, just not
>> always allowed.
>
> Then thow the throw bdev_write_zeroes_sectors check back in:
>
>         if (ret && try_write_zeroes) {
>                 if (!(flags & BLKDEV_ZERO_NOFALLBACK))
>                         try_write_zeroes = false;
>                         goto retry;
>                 }
>                 if (!bdev_write_zeroes_sectors(bdev))
>                         ret = -EOPNOTSUPP;
>         }
>
> The important bit is that the structure in the current patch where the
> bdev_write_zeroes_sectors check is on the same level as the method
> selection is extremely confusing.

I see.  An updated version should be in your inbox.

Thanks,

                Ilya