[Qemu-devel] [PATCH v3 for-2.7 00/14] qapi: Allow blockdev-add for NBD

[Max Reitz]

Turns out NBD is not so simple to do if you do it right. Anyway, this
series adds blockdev-add support for NBD clients.

Patch 1 adds a QDict function which I needed in later NBD patches for
handling legacy options (move "host" to "address.data.host" etc.).

Patches 2, 3, 4, and 5 are minor patches with no functional relation to
this series, other than later patches will touch the code they touch,
too.

Patches 6 and 7 prepare the code for the addition of a new option
prefix, which is "address.".

Patch 8 makes the NBD client accept a SocketAddress under the "address"
option (or rather, a flattened SocketAddress QDict with its keys
prefixed by "address."). The old options "host", "port", and "path" are
supported as legacy options and translated to the respective
SocketAddress representation.

Patch 9 drops usage of "host", "port", and "path" outside of
nbd_has_filename_options_conflict(),
nbd_process_legacy_socket_options(), and nbd_refresh_filename(), making
those options nothing but legacy.

Patch 10, the goal of this series, is again not very complicated.

Patches 11, 12, and 13 are required for the iotest added in patch 16. It
will invoke qemu-nbd, so patch 13 is required. Besides qemu-nbd, it will
launch an NBD server VM concurrently to the client VM, which is why
patch 14 is required. And finally, it will test whether we can add an
NBD BDS by passing it a file descriptor, which patch 15 is needed for
(so we use the socket_scm_helper to pass sockets to qemu).

Patch 14 then adds the iotest for NBD's blockdev-add interface.


*** This series requires Daniel's qdict_crumple() function (from his
    "Provide a QOM-based authorization API" series). ***


v2:
- Dropped patches 2 and 3; use Daniel's qdict_crumple() instead.
- Patch 7: Not sure why the diff differs, seems functionally like the
  same patch to me. Maybe git changed something about its default diff
  algorithm.
- Patch 8: Use qdict_crumple() instead of qdict_unflatten()
- Patch 10: Rebase conflicts


git-backport-diff against v2:

Key:
[----] : patches are identical
[####] : number of functional differences between upstream/downstream patch
[down] : patch is downstream-only
The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively

001/14:[----] [--] 'qdict: Add qdict_change_key()'
002/14:[----] [--] 'block/nbd: Drop trailing "." in error messages'
003/14:[----] [--] 'block/nbd: Reject port parameter without host'
004/14:[----] [--] 'block/nbd: Default port in nbd_refresh_filename()'
005/14:[----] [--] 'block/nbd: Use qdict_put()'
006/14:[----] [--] 'block/nbd: Add nbd_has_filename_options_conflict()'
007/14:[0008] [FC] 'block/nbd: "address" in nbd_refresh_filename()'
008/14:[0024] [FC] 'block/nbd: Accept SocketAddress'
009/14:[----] [--] 'block/nbd: Use SocketAddress options'
010/14:[0004] [FC] 'qapi: Allow blockdev-add for NBD'
011/14:[----] [-C] 'iotests.py: Add qemu_nbd function'
012/14:[----] [--] 'iotests.py: Allow concurrent qemu instances'
013/14:[----] [--] 'socket_scm_helper: Accept fd directly'
014/14:[----] [-C] 'iotests: Add test for NBD's blockdev-add interface'


Max Reitz (14):
  qdict: Add qdict_change_key()
  block/nbd: Drop trailing "." in error messages
  block/nbd: Reject port parameter without host
  block/nbd: Default port in nbd_refresh_filename()
  block/nbd: Use qdict_put()
  block/nbd: Add nbd_has_filename_options_conflict()
  block/nbd: "address" in nbd_refresh_filename()
  block/nbd: Accept SocketAddress
  block/nbd: Use SocketAddress options
  qapi: Allow blockdev-add for NBD
  iotests.py: Add qemu_nbd function
  iotests.py: Allow concurrent qemu instances
  socket_scm_helper: Accept fd directly
  iotests: Add test for NBD's blockdev-add interface

 block/nbd.c                            | 235 ++++++++++++++++++++++-----------
 include/qapi/qmp/qdict.h               |   1 +
 qapi/block-core.json                   |  23 +++-
 qobject/qdict.c                        |  23 ++++
 tests/qemu-iotests/051.out             |   4 +-
 tests/qemu-iotests/051.pc.out          |   4 +-
 tests/qemu-iotests/147                 | 194 +++++++++++++++++++++++++++
 tests/qemu-iotests/147.out             |   5 +
 tests/qemu-iotests/group               |   1 +
 tests/qemu-iotests/iotests.py          |  22 ++-
 tests/qemu-iotests/socket_scm_helper.c |  29 ++--
 11 files changed, 443 insertions(+), 98 deletions(-)
 create mode 100755 tests/qemu-iotests/147
 create mode 100644 tests/qemu-iotests/147.out

-- 
2.8.0