[PATCH v4 0/7] 9pfs: fix 'Twalk' protocol violation

[Christian Schoenebeck <qemu_oss@crudebyte.com>]

Currently the implementation of 'Twalk' does not behave exactly as specified
by the 9p2000 protocol specification. Actual fix is patch 5; see the
description of that patch for details of what this overall fix and series is
about.

PREREQUISITES
=============

This series requires the following additional patch to work correctly:
https://lore.kernel.org/qemu-devel/E1nTpyU-0000yR-9o@lizzy.crudebyte.com/

OVERVIEW OF PATCHES
===================

Patch 4 is a preparatory (pure) refactoring change to make actual 'Twalk' fix
patch 5 better readable.

All the other patches are just additional test cases for guarding 'Twalk'
behaviour.

v3 -> v4:

  * QID returned by Twalk request in fs_walk_2nd_nonexistent() test should NOT
    be identical to root node's QID. [patch 7]

  * Fix actual 'fid unaffected' check in fs_walk_2nd_nonexistent() test by
    sending a subsequent 'Tgetattr' request. [patch 7]

Christian Schoenebeck (7):
  tests/9pfs: walk to non-existent dir
  tests/9pfs: Twalk with nwname=0
  tests/9pfs: compare QIDs in fs_walk_none() test
  9pfs: refactor 'name_idx' -> 'nwalked' in v9fs_walk()
  9pfs: fix 'Twalk' to only send error if no component walked
  tests/9pfs: guard recent 'Twalk' behaviour fix
  tests/9pfs: check fid being unaffected in fs_walk_2nd_nonexistent

 hw/9pfs/9p.c                 |  57 ++++++----
 tests/qtest/virtio-9p-test.c | 201 ++++++++++++++++++++++++++++++++++-
 2 files changed, 231 insertions(+), 27 deletions(-)

-- 
2.30.2