Re: [PATCH v1 0/5] io_uring: add xattr support

Clay Harris
2021-11-30T06:37:11Z

On Mon, Nov 29 2021 at 20:16:02 -0700, Andreas Dilger quoth thus:

>
> > On Nov 29, 2021, at 6:08 PM, Clay Harris <bugs@claycon.org> wrote:
> >
> > On Mon, Nov 29 2021 at 14:12:52 -0800, Stefan Roesch quoth thus:
> >
> >> This adds the xattr support to io_uring. The intent is to have a more
> >> complete support for file operations in io_uring.
> >>
> >> This change adds support for the following functions to io_uring:
> >> - fgetxattr
> >> - fsetxattr
> >> - getxattr
> >> - setxattr
> >
> > You may wish to consider the following.
> >
> > Patching for these functions makes for an excellent opportunity
> > to provide a better interface. Rather than implement fXetattr
> > at all, you could enable io_uring to use functions like:
> >
> > int Xetxattr(int dfd, const char *path, const char *name,
> > [const] void *value, size_t size, int flags);
>
> This would naturally be named "...xattrat()"?

Indeed!

> > Not only does this simplify the io_uring interface down to two
> > functions, but modernizes and fixes a deficit in usability.
> > In terms of io_uring, this is just changing internal interfaces.
>
> Even better would be the ability to get/set an array of xattrs in
> one call, to avoid repeated path lookups in the common case of
> handling multiple xattrs on a single file.

True.

> > Although unnecessary for io_uring, it would be nice to at least
> > consider what parts of this code could be leveraged for future
> > Xetxattr2 syscalls.
s/Xetxattr2/Xetxattrat/

> >
> >> Patch 1: fs: make user_path_at_empty() take a struct filename
> >> The user_path_at_empty filename parameter has been changed
> >> from a const char user pointer to a filename struct. io_uring
> >> operates on filenames.
> >> In addition also the functions that call user_path_at_empty
> >> in namei.c and stat.c have been modified for this change.
> >>
> >> Patch 2: fs: split off setxattr_setup function from setxattr
> >> Split off the setup part of the setxattr function
> >>
> >> Patch 3: fs: split off the vfs_getxattr from getxattr
> >> Split of the vfs_getxattr part from getxattr. This will
> >> allow to invoke it from io_uring.
> >>
> >> Patch 4: io_uring: add fsetxattr and setxattr support
> >> This adds new functions to support the fsetxattr and setxattr
> >> functions.
> >>
> >> Patch 5: io_uring: add fgetxattr and getxattr support
> >> This adds new functions to support the fgetxattr and getxattr
> >> functions.
> >>
> >>
> >> There are two additional patches:
> >> liburing: Add support for xattr api's.
> >> This also includes the tests for the new code.
> >> xfstests: Add support for io_uring xattr support.
> >>
> >>
> >> Stefan Roesch (5):
> >> fs: make user_path_at_empty() take a struct filename
> >> fs: split off setxattr_setup function from setxattr
> >> fs: split off the vfs_getxattr from getxattr
> >> io_uring: add fsetxattr and setxattr support
> >> io_uring: add fgetxattr and getxattr support
> >>
> >> fs/internal.h | 23 +++
> >> fs/io_uring.c | 325 ++++++++++++++++++++++++++++++++++
> >> fs/namei.c | 5 +-
> >> fs/stat.c | 7 +-
> >> fs/xattr.c | 114 +++++++-----
> >> include/linux/namei.h | 4 +-
> >> include/uapi/linux/io_uring.h | 8 +-
> >> 7 files changed, 439 insertions(+), 47 deletions(-)
> >>
> >>
> >> Signed-off-by: Stefan Roesch <shr@fb.com>
> >> base-commit: c2626d30f312afc341158e07bf088f5a23b4eeeb
> >> --
> >> 2.30.2
>
>
> Cheers, Andreas
>
>
>
>
>