Re: [RFC][PATCH v5 00/09] common implementation of dirent file types

[Phillip Potter <phil@philpotter.co.uk>]

On Mon, Jan 21, 2019 at 01:35:10AM -0800, Matthew Wilcox wrote:
> On Mon, Jan 21, 2019 at 12:54:25AM +0000, Phillip Potter wrote:
> > These patches mostly no longer include compile-time checks to ensure
> > the filesystem specific on-disk bits are equivalent to the common
> > implementation FT_* bits, and instead op to remove the filesystem
> > specific definitions entirely where possible, as a result of the
> > referenced discussion above.
> > 
> > With the ext4 patch, the EXT4_FT_* definitions are instead defined
> > to be FT_*, to give less code churn with the same result (no need
> > to modify fs/ext4/namei.c). Also, the nilfs2 and btrfs filesystems
> > keep their filesystem specific definitions in the include/uapi/linux
> > directory, so these cannot be changed trivially without breaking
> > userspace. For this reason, the compile time checks remain in these
> > two filesystems.
> 
> Just because something is exposed through the uapi directory today
> doesn't mean userspace actually uses it.  For example,
> https://codesearch.debian.net/search?q=BTRFS_FT_DIR
> 
> The only code which uses the filetype defines is going to be code which
> actually looks at a raw filesystem image.  All three examples of userspace
> code in Debian have their own definitions instead of using the one which
> the kernel provides.

Thank you for this suggestion. I will wait and then possibly refactor the
last two patches of the series.

Regards,
Phil