[Qemu-devel] [PATCH 00/18] nbd: BLOCK_STATUS

[Vladimir Sementsov-Ogievskiy]

Hi all!

We really need exporting dirty bitmaps feature as well as remote
get_block_status for nbd devices. So, here is minimalistic and restricted
realization of 'structured reply' and 'block status' nbd protocol extension
(as second is developed over the first the combined spec may be found here:
https://github.com/NetworkBlockDevice/nbd/blob/extension-blockstatus/doc/proto.md)

What is done:

server:
 - can send not fragmented structured replies for CMD_READ (this was done only
   because the spec doesn't allow structure reply feature without maintaining
   structured read)
 - can export dirty bitmap through BLOCK_STATUS. Only one bitmap can be 
exported,
   negotiation query should be 'qemu-dirty-bitmap:<bitmap name>'
 - cab export block status through BLOCK_STATUS. Client can negotiate only one
   entity for exporting through BLOCK_STATUS - bitmap _or_ block status.
   negotiation query should be 'base:allocation', as defined in the spec.
   server sends only one extent on each BLOCK_STATUS query.

client:
 - can receive not fragmented structured replies for CMD_READ
 - can get load dirty bitmap through nbd. Be careful: bitmap for export is
   is selected during nbd negotiation - actually in open(). So, name argument 
for
   qmp block-dirty-bitmap-load is just a _new_ name for loaded bitmap.
   (any way, for us block-dirty-bitmap-load is just a way to test the feature,
    really we need only server part)
 - get_block_status works now through nbd CMD_BLOCK_STATUS, if base:allocation 
is
   negotiated for export.

It should be minimal but fully compatible realization of the spec.

web: 
https://src.openvz.org/users/vsementsov/repos/qemu/browse?at=nbd-block-status-v1
git: https://src.openvz.org/scm/~vsementsov/qemu.git (tag nbd-block-status-v1)

Vladimir Sementsov-Ogievskiy (18):
  nbd: rename NBD_REPLY_MAGIC to NBD_SIMPLE_REPLY_MAGIC
  nbd-server: refactor simple reply sending
  nbd: Minimal structured read for server
  nbd/client: refactor nbd_receive_starttls
  nbd/client: fix drop_sync
  nbd/client: refactor drop_sync
  nbd: Minimal structured read for client
  hbitmap: add next_zero function
  block/dirty-bitmap: add bdrv_dirty_bitmap_next()
  block/dirty-bitmap: add bdrv_load_dirty_bitmap
  nbd: BLOCK_STATUS for bitmap export: server part
  nbd: BLOCK_STATUS for bitmap export: client part
  nbd: add nbd_dirty_bitmap_load
  qmp: add x-debug-block-dirty-bitmap-sha256
  qmp: add block-dirty-bitmap-load
  iotests: add test for nbd dirty bitmap export
  nbd: BLOCK_STATUS for standard get_block_status function: server part
  nbd: BLOCK_STATUS for standard get_block_status function: client part

 block/dirty-bitmap.c                     |  70 ++++
 block/nbd-client.c                       | 230 ++++++++++-
 block/nbd-client.h                       |  13 +
 block/nbd.c                              |  44 +-
 blockdev.c                               |  57 +++
 include/block/block_int.h                |   4 +
 include/block/dirty-bitmap.h             |  10 +
 include/block/nbd.h                      |  73 +++-
 include/qemu/hbitmap.h                   |  16 +
 nbd/client.c                             | 373 ++++++++++++++---
 nbd/nbd-internal.h                       |  25 +-
 nbd/server.c                             | 661 ++++++++++++++++++++++++++++++-
 qapi/block-core.json                     |  46 ++-
 qemu-nbd.c                               |   2 +-
 tests/Makefile.include                   |   2 +-
 tests/qemu-iotests/180                   | 133 +++++++
 tests/qemu-iotests/180.out               |   5 +
 tests/qemu-iotests/group                 |   1 +
 tests/qemu-iotests/nbd-fault-injector.py |   4 +-
 util/hbitmap.c                           |  37 ++
 20 files changed, 1713 insertions(+), 93 deletions(-)
 create mode 100755 tests/qemu-iotests/180
 create mode 100644 tests/qemu-iotests/180.out

-- 
2.11.0