Re: [PATCH 00/19] VFS: Filesystem information and notifications [ver #16]

[Darrick J. Wong]

On Wed, Feb 19, 2020 at 03:46:13PM +0100, Christian Brauner wrote:
> On Tue, Feb 18, 2020 at 05:04:55PM +0000, David Howells wrote:
> > 
> > Here are a set of patches that adds system calls, that (a) allow
> > information about the VFS, mount topology, superblock and files to be
> > retrieved and (b) allow for notifications of mount topology rearrangement
> > events, mount and superblock attribute changes and other superblock events,
> > such as errors.
> > 
> > ============================
> > FILESYSTEM INFORMATION QUERY
> > ============================
> > 
> > The first system call, fsinfo(), allows information about the filesystem at
> > a particular path point to be queried as a set of attributes, some of which
> > may have more than one value.
> > 
> > Attribute values are of four basic types:
> > 
> >  (1) Version dependent-length structure (size defined by type).
> > 
> >  (2) Variable-length string (up to 4096, including NUL).
> > 
> >  (3) List of structures (up to INT_MAX size).
> > 
> >  (4) Opaque blob (up to INT_MAX size).
> 
> I mainly have an organizational question. :) This is a huge patchset
> with lots and lots of (good) features. Wouldn't it make sense to make
> the fsinfo() syscall a completely separate patchset from the
> watch_mount() and watch_sb() syscalls? It seems that they don't need to
> depend on each other at all. This would make reviewing this so much
> nicer and likely would mean that fsinfo() could proceed a little faster.

Agreed; I was also wondering why it was necessary to have three new
features in the same large(ish) patchset.

--D

> Christian