Block replication is a very important feature which is used for
continuous checkpoints(for example: COLO).
You can get the detailed information about block replication from here:
http://wiki.qemu.org/Features/BlockReplication
Usage:
Please refer to docs/block-replication.txt
This patch series is based on the following patch series:
http://lists.nongnu.org/archive/html/qemu-devel/2016-04/msg02093.html
You can get the patch here:
https://github.com/Pating/qemu/tree/changlox/block-replication-v18
You can get the patch with framework here:
https://github.com/Pating/qemu/tree/changlox/colo_framework_v17
TODO:
1. Continuous block replication. It will be started after basic functions
are accepted.
Changs Log:
V18:
p6: add local_err in all replication callbacks to prevent "errp == NULL"
p7: add missing qemu_iovec_destroy(xxx)
V17:
1. Rebase to the lastest codes
p2: refactor backup_do_checkpoint addressed comments from Jeff Cody
p4: fix bugs in "drive_add buddy xxx" hmp commands
p6: add "since: 2.7"
p7: fix bug in replication_close(), add missing "qapi/error.h", add
test-replication
p8: add "since: 2.7"
V16:
1. Rebase to the newest codes
2. Address comments from Stefan & hailiang
p3: we don't need this patch now
p4: add "top-id" parameters for secondary
p6: fix NULL pointer in replication callbacks, remove unnecessary typedefs,
add doc comments that explain the semantics of Replication
p7: Refactor AioContext for thread-safe, remove unnecessary get_top_bs()
*Note*: I'm working on replication testcase now, will send out in V17
V15:
1. Rebase to the newest codes
2. Fix typos and coding style addresed Eric's comments
3. Address Stefan's comments
1) Make backup_do_checkpoint public, drop the changes on BlockJobDriver
2) Update the message and description for [PATCH 4/9]
3) Make replication_(start/stop/do_checkpoint)_all as global interfaces
4) Introduce AioContext lock to protect start/stop/do_checkpoint callbacks
5) Use BdrvChild instead of holding on to BlockDriverState * pointers
4. Clear BDRV_O_INACTIVE for hidden disk's open_flags since commit 09e0c771
5. Introduce replication_get_error_all to check replication status
6. Remove useless discard interface
V14:
1. Implement auto complete active commit
2. Implement active commit block job for replication.c
3. Address the comments from Stefan, add replication-specific API and data
structure, also remove old block layer APIs
V13:
1. Rebase to the newest codes
2. Remove redundant marcos and semicolon in replication.c
3. Fix typos in block-replication.txt
V12:
1. Rebase to the newest codes
2. Use backing reference to replcace 'allow-write-backing-file'
V11:
1. Reopen the backing file when starting blcok replication if it is not
opened in R/W mode
2. Unblock BLOCK_OP_TYPE_BACKUP_SOURCE and BLOCK_OP_TYPE_BACKUP_TARGET
when opening backing file
3. Block the top BDS so there is only one block job for the top BDS and
its backing chain.
V10:
1. Use blockdev-remove-medium and blockdev-insert-medium to replace backing
reference.
2. Address the comments from Eric Blake
V9:
1. Update the error messages
2. Rebase to the newest qemu
3. Split child add/delete support. These patches are sent in another patchset.
V8:
1. Address Alberto Garcia's comments
V7:
1. Implement adding/removing quorum child. Remove the option non-connect.
2. Simplify the backing refrence option according to Stefan Hajnoczi's
suggestion
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
Changlong Xie (1):
Introduce new APIs to do replication operation
Wen Congyang (7):
unblock backup operations in backing file
Backup: clear all bitmap when doing block checkpoint
Link backup into block core
docs: block replication's description
auto complete active commit
Implement new driver for block replication
support replication driver in blockdev-add
Makefile.objs | 1 +
block.c | 17 ++
block/Makefile.objs | 3 +-
block/backup.c | 17 ++
block/mirror.c | 13 +-
block/replication.c | 625 +++++++++++++++++++++++++++++++++++++++++++++
blockdev.c | 2 +-
docs/block-replication.txt | 239 +++++++++++++++++
include/block/block_int.h | 5 +-
qapi/block-core.json | 33 ++-
qemu-img.c | 2 +-
replication.c | 105 ++++++++
replication.h | 176 +++++++++++++
tests/.gitignore | 1 +
tests/Makefile | 4 +
tests/test-replication.c | 505 ++++++++++++++++++++++++++++++++++++
16 files changed, 1738 insertions(+), 10 deletions(-)
create mode 100644 block/replication.c
create mode 100644 docs/block-replication.txt
create mode 100644 replication.c
create mode 100644 replication.h
create mode 100644 tests/test-replication.c