[RFC PATCH v4 07/11] fs: statx add write zeroes unmap attribute

[Christoph Hellwig]

On Tue, May 06, 2025 at 07:16:56PM +0800, Zhang Yi wrote:
> Sorry, but I don't understand your suggestion. The
> STATX_ATTR_WRITE_ZEROES_UNMAP attribute only indicate whether the bdev
> and the block device that under the specified file support unmap write
> zeroes commoand. It does not reflect whether the bdev and the
> filesystems support FALLOC_FL_WRITE_ZEROES. The implementation of
> FALLOC_FL_WRITE_ZEROES doesn't fully rely on the unmap write zeroes
> commoand now, users simply refer to this attribute flag to determine
> whether to use FALLOC_FL_WRITE_ZEROES when preallocating a file.
> So, STATX_ATTR_WRITE_ZEROES_UNMAP and FALLOC_FL_WRITE_ZEROES doesn't
> have strong relations, why do you suggested to put this into the ext4
> and bdev patches that adding FALLOC_FL_WRITE_ZEROES?

So what is the point of STATX_ATTR_WRITE_ZEROES_UNMAP?