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: 1. http://lists.nongnu.org/archive/html/qemu-devel/2015-12/msg04570.html Patch status: 1. Acked patches: none 2. Reviewed patches: patch 4 3. Updated patches: patch 3, 4, 5, 7, 8 Note: patch 7 is a new patch that introduces genernal start/stop/checkpoint/ get_error APIs. You can get the patch here: https://github.com/Pating/qemu/tree/changlox/block-replication-v15 You can get the patch with framework here: https://github.com/Pating/qemu/tree/changlox/colo_framework_v14 TODO: 1. Continuous block replication. It will be started after basic functions are accepted. Changs Log: 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 (8): unblock backup operations in backing file Store parent BDS in BdrvChild 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 | 19 ++ block/Makefile.objs | 3 +- block/backup.c | 15 ++ block/mirror.c | 13 +- block/replication.c | 594 +++++++++++++++++++++++++++++++++++++++++++++ blockdev.c | 2 +- docs/block-replication.txt | 238 ++++++++++++++++++ include/block/block_int.h | 6 +- qapi/block-core.json | 33 ++- qemu-img.c | 2 +- replication.c | 94 +++++++ replication.h | 53 ++++ 13 files changed, 1063 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 -- 1.9.3
