[PATCH v2 0/7] filesystem visibililty ioctls

[Kent Overstreet <kent.overstreet@linux.dev>]

previous:
https://lore.kernel.org/linux-fsdevel/20240206-aufwuchs-atomkraftgegner-dc53ce1e435f@brauner/T/

Changes since v1:
 - super_set_uuid() helper, per Dave

 - nix FS_IOC_SETUUID - Al raised this and I'm in 100% agreement,
   changing a UUID on an existing filesystem is a rare operation that
   should only be done when the filesystem is offline; we'd need to
   audit/fix a bunch of stuff if we wanted to support this

 - fix iocl numberisng, no longer using btrfs's space

 - flags argument in struct fsuuid2 is gone; since we're no longer
   setting this is no longer needed. As discussed previously, this
   interface is only for exporting the public, user-changable UUID (and
   there's now a comment saying that this exports the same UUID that
   libblkid reports, per Darrick).

Darrick also noticed that fscrypt (!) is using sb->s_uuid, which looks
busted - they want to be using the "this can never change" UUID, but
that is not an item for this patchset.

 - FS_IOC_GETSYSFSNAME -> FS_IOC_GETSYSFSPATH, per Darrick (the commit
   messages didn't get updated, whoops); and there's now a comment to
   reflect that this patch is also for finding filesystem info under
   debugfs, if present.

Christain, if nothing else comes up, are you ready to take this?

Cheers,
Kent

Kent Overstreet (7):
  fs: super_set_uuid()
  overlayfs: Convert to super_set_uuid()
  fs: FS_IOC_GETUUID
  fat: Hook up sb->s_uuid
  fs: FS_IOC_GETSYSFSNAME
  xfs: add support for FS_IOC_GETSYSFSNAME
  bcachefs: add support for FS_IOC_GETSYSFSNAME

 fs/bcachefs/fs.c        |  3 ++-
 fs/ext4/super.c         |  2 +-
 fs/f2fs/super.c         |  2 +-
 fs/fat/inode.c          |  3 +++
 fs/gfs2/ops_fstype.c    |  2 +-
 fs/ioctl.c              | 33 +++++++++++++++++++++++++++++++++
 fs/kernfs/mount.c       |  4 +++-
 fs/ocfs2/super.c        |  4 ++--
 fs/overlayfs/util.c     | 14 +++++++++-----
 fs/ubifs/super.c        |  2 +-
 fs/xfs/xfs_mount.c      |  4 +++-
 include/linux/fs.h      | 10 ++++++++++
 include/uapi/linux/fs.h | 27 +++++++++++++++++++++++++++
 mm/shmem.c              |  4 +++-
 14 files changed, 99 insertions(+), 15 deletions(-)

-- 
2.43.0