[Qemu-devel] [PATCH COLO v4 00/15] Block replication for continuous checkpoints

[Wen Congyang <wency@cn.fujitsu.com>]

Block replication is a very important feature which is used for
continuous checkpoints(for example: COLO).

Usage:
Please refer to docs/block-replication.txt

You can get the patch here:
https://github.com/wencongyang/qemu-colo/commits/block-replication-v4

You can get the patch with the other COLO patches here:
https://github.com/wencongyang/qemu-colo/tree/colo_huawei_v4.7

TODO:
1. Test failover when the guest does too many I/O operations. If it
   takes too much time, we need to optimize it.
2. Continuous block replication. It will be started after basic functions
   are accepted.

Changs Log:
V4:
1. Introduce a new driver replication to avoid touch nbd and qcow2.
V3:
1: use error_setg() instead of error_set()
2. Add a new block job API
3. Active disk, hidden disk and nbd target uses the same AioContext
4. Add a testcase to test new hbitmap API
V2:
1. Redesign the secondary qemu(use image-fleecing)
2. Use Error objects to return error message
3. Address the comments from Max Reitz and Eric Blake

Wen Congyang (15):
  docs: block replication's description
  allow writing to the backing file
  Allow creating backup jobs when opening BDS
  block: Parse "backing_reference" option to reference existing BDS
  Backup: clear all bitmap when doing block checkpoint
  Don't allow a disk use backing reference target
  Add new block driver interface to connect/disconnect the remote target
  NBD client: implement block driver interfaces to connect/disconnect
    NBD server
  Introduce a new -drive option to control whether to connect to remote
    target
  NBD client: connect to nbd server later
  Add new block driver interfaces to control block replication
  skip nbd_target when starting block replication
  quorum: implement block driver interfaces for block replication
  quorum: allow ignoring child errors
  Implement new driver for block replication

 block.c                    | 270 +++++++++++++++++++++++-
 block/Makefile.objs        |   3 +-
 block/backup.c             |  13 ++
 block/nbd.c                |  67 ++++--
 block/quorum.c             | 142 ++++++++++++-
 block/replication.c        | 512 +++++++++++++++++++++++++++++++++++++++++++++
 blockdev.c                 |   8 +
 blockjob.c                 |  10 +
 docs/block-replication.txt | 179 ++++++++++++++++
 include/block/block.h      |  10 +
 include/block/block_int.h  |  18 ++
 include/block/blockjob.h   |  12 ++
 qapi/block.json            |  16 ++
 qemu-options.hx            |   4 +
 tests/qemu-iotests/051     |  13 ++
 tests/qemu-iotests/051.out |  13 ++
 16 files changed, 1260 insertions(+), 30 deletions(-)
 create mode 100644 block/replication.c
 create mode 100644 docs/block-replication.txt

-- 
2.1.0