[PATCH v5 0/3] btrfs: Add three new unprivileged ioctls to allow normal users to call "sub list/show" etc.

[Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>]

[based on current misc-next]

changelog:
v4 -> v5
  - Update error handling of 1st/2nd patch. See each log for details
  - Fix misspelling
v3 -> v4
  - call btrfs_next_leaf() after btrfs_search_slot() when the slot
    position exceeds the number of items
  - rebased to current misc-next
v2 -> v3
  - fix kbuild test bot warning
v1 -> v2
  - completely reimplement 1st/2nd ioctl to have user friendly api
  - various cleanup, remove unnecessary goto
===

This adds three new unprivileged ioctls:

1st patch:
  ioctl which returns subvolume information of ROOT_ITEM and ROOT_BACKREF
2nd patch:
  ioctl which returns subvolume information of ROOT_REF (without subvolume name)
3rd patch: 
  user version of ino_lookup ioctl which also performs permission check.

They will be used to implement user version of "subvolume list/show" etc.
in user tools.
See each commit log for more detals.

The implementation of btrfs-progs can be found in the ML titled as follows: 
  [PATCH 0/11] btrfs-progs: Rework of "subvolume list/show" and relax the root privileges of them

Tomohiro Misono (3):
  btrfs: Add unprivileged ioctl which returns subvolume information
  btrfs: Add unprivileged ioctl which returns subvolume's ROOT_REF
  btrfs: Add unprivileged version of ino_lookup ioctl

 fs/btrfs/ioctl.c           | 452 +++++++++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/btrfs.h |  84 +++++++++
 2 files changed, 536 insertions(+)

-- 
2.14.3