Re: [PATCH] btrfs/294: reject zoned devices for now

[Qu Wenruo <wqu@suse.com>]

On 2023/7/25 08:22, Naohiro Aota wrote:
> On Mon, Jul 24, 2023 at 07:10:51AM -0700, Christoph Hellwig wrote:
>> On Mon, Jul 24, 2023 at 11:04:23AM +0800, Qu Wenruo wrote:
>>> The test case itself is utilizing RAID5/6, which is not yet supported on
>>> zoned device.
>>>
>>> In the future we would use raid-stripe-tree (RST) feature, but for now
>>> just reject zoned devices completely.
>>>
>>> And since we're here, also update the _fixed_by_kernel_commit lines, as
>>> the proper fix is already merged upstream.
>>
>> Hmm, instead of spreading these checks, shouldn't we check that the
>> RAID level is supported, and have one single nob for that based off
>> it, similar to _btrfs_get_profile_configs()?
>>
> 
> That's beneficial. We need to declare which profile the test going to use,
> something like this?
> 
>    _btrfs_require_profile raid5 raid6
> 
> or
> 
>    _btrfs_require_profile data:dup
> 
> as the zoned mode cannot work with the DUP profile for data.

The latter one sounds good, considering zoned support differs for data 
and metadata profiles.

Another thing is, do we have any sysfs files to indicate what profiles 
we support?
For now we only have a "zoned" features, but no dedicated zoned specific 
sysfs files.

Would that be a good thing to consider?

Thanks,
Qu