[Qemu-devel] [PATCH COLO-Block v6 00/16] Block replication for continuous checkpoints

[Wen Congyang]

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-v6

The other newest COLO patchse will be sent soon.

Note: you should apply the following patch first:
http://lists.nongnu.org/archive/html/qemu-devel/2015-05/msg01317.html

TODO:
1. Continuous block replication. It will be started after basic functions
   are accepted.

Changs Log:
V6:
1. Rebase to the newest qemu.
V5:
1. Address the comments from Gong Lei
2. Speed the failover up. The secondary vm can take over very quickly even
   if there are too many I/O requests.
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 (16):
  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
  introduce a new API qemu_opts_absorb_qdict_by_index()
  quorum: allow ignoring child errors
  Implement new driver for block replication

 block.c                    | 279 +++++++++++++++++++++++++++-
 block/Makefile.objs        |   3 +-
 block/backup.c             |  13 ++
 block/nbd.c                |  69 +++++--
 block/quorum.c             | 162 ++++++++++++++++-
 block/replication.c        | 441 +++++++++++++++++++++++++++++++++++++++++++++
 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 ++
 include/qemu/option.h      |   2 +
 qapi/block.json            |  16 ++
 qemu-options.hx            |   4 +
 tests/qemu-iotests/051     |  13 ++
 tests/qemu-iotests/051.out |  13 ++
 util/qemu-option.c         |  44 +++++
 18 files changed, 1266 insertions(+), 30 deletions(-)
 create mode 100644 block/replication.c
 create mode 100644 docs/block-replication.txt

-- 
2.4.3