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

Christoph Hellwig
2025-06-11T06:09:12Z

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.

> +/* 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?

Otherwise looks good:

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