Re: [PATCH 01/10] block: introduce BLK_FEAT_WRITE_ZEROES_UNMAP to queue limits features

Zhang Yi
2025-06-11T07:31:26Z

On 2025/6/11 14:09, Christoph Hellwig wrote:
> On Wed, Jun 04, 2025 at 10:08:41AM +0800, Zhang Yi wrote:
>> +static ssize_t queue_write_zeroes_unmap_show(struct gendisk *disk, char *page)
>
> ..
>
>> +static int queue_write_zeroes_unmap_store(struct gendisk *disk,
>> + const char *page, size_t count, struct queue_limits *lim)
>
> We're probably getting close to wanting macros for the sysfs
> flags, similar to the one for the features (QUEUE_SYSFS_FEATURE).
>
> No need to do this now, just thinking along.

Yes.

>
>> +/* supports unmap write zeroes command */
>> +#define BLK_FEAT_WRITE_ZEROES_UNMAP ((__force blk_features_t)(1u << 17))
>
>
> Should this be exposed through sysfs as a read-only value?

Uh, are you suggesting adding another sysfs interface to expose
this feature?

>
> Otherwise looks good:
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Thanks,
Yi.