[PATCH 0/6 resend] statfs: handle mount propagation

From: Christian Brauner
Date: Wed May 02 2018 - 11:45:45 EST


Hey,

This is the second resend of this patchset. I'm not sure whether it has
simply been overlooked but the number of people get_maintainer.pl was
rather small and seemed a little random so I added Linus and Christoph,
two people I know that do look at VFS stuff at least from time to time,
although they weren't listed by get_maintainer.pl. I hope that's ok.

This little series
- unifies the definition of constants in statfs.h and fs.h
*Note, that Andreas has expressed doubts whether this unification is
useful. Please see https://lkml.org/lkml/2018/4/13/571 . I still think
it is but I'm happy to drop these two patches if others agree.*
- extends statfs to handle mount propagation. This will let userspace
easily query a given mountpoint for MS_UNBINDABLE, MS_SHARED,
MS_PRIVATE and MS_SLAVE without always having to do costly parsing of
/proc/<pid>/mountinfo.
To this end the flags:
- ST_UNBINDABLE
- ST_SHARED
- ST_PRIVATE
- ST_SLAVE
are added. They have the same value as their MS_* counterparts.

Thanks!
Christian

Christian Brauner (6):
fs: use << for MS_* flags
statfs: use << to align with fs header
statfs: add ST_UNBINDABLE
statfs: add ST_SHARED
statfs: add ST_SLAVE
statfs: add ST_PRIVATE

fs/statfs.c | 16 +++++++++++++++-
include/linux/statfs.h | 30 +++++++++++++++++-------------
include/uapi/linux/fs.h | 33 +++++++++++++++++----------------
3 files changed, 49 insertions(+), 30 deletions(-)

--
2.17.0