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Changlong XiestefanhaRH
Changlong Xie
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stefanhaRH
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replication: Introduce new APIs to do replication operation
This commit introduces six replication interfaces(for block, network etc). Firstly we can use replication_(new/remove) to create/destroy replication instances, then in migration we can use replication_(start/stop/do_checkpoint /get_error)_all to handle all replication operations. More detail please refer to replication.h Signed-off-by: Wen Congyang <[email protected]> Signed-off-by: Changlong Xie <[email protected]> Signed-off-by: Wang WeiWei <[email protected]> Signed-off-by: zhanghailiang <[email protected]> Signed-off-by: Gonglei <[email protected]> Message-id: [email protected] Signed-off-by: Stefan Hajnoczi <[email protected]>
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‎Makefile.objs

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@@ -15,6 +15,7 @@ block-obj-$(CONFIG_POSIX) += aio-posix.o
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block-obj-$(CONFIG_WIN32) += aio-win32.o
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block-obj-y += block/
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block-obj-y += qemu-io-cmds.o
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block-obj-$(CONFIG_REPLICATION) += replication.o
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block-obj-m = block/
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‎qapi/block-core.json

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@@ -2162,6 +2162,19 @@
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'server': ['GlusterServer'],
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'*debug-level': 'int' } }
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##
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# @ReplicationMode
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#
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# An enumeration of replication modes.
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#
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# @primary: Primary mode, the vm's state will be sent to secondary QEMU.
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#
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# @secondary: Secondary mode, receive the vm's state from primary QEMU.
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#
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# Since: 2.8
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##
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{ 'enum' : 'ReplicationMode', 'data' : [ 'primary', 'secondary' ] }
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##
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# @BlockdevOptions
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#

‎replication.c

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/*
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* Replication filter
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*
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* Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
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* Copyright (c) 2016 Intel Corporation
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* Copyright (c) 2016 FUJITSU LIMITED
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*
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* Author:
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* Changlong Xie <[email protected]>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*/
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#include "qemu/osdep.h"
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#include "qapi/error.h"
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#include "replication.h"
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static QLIST_HEAD(, ReplicationState) replication_states;
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ReplicationState *replication_new(void *opaque, ReplicationOps *ops)
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{
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ReplicationState *rs;
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assert(ops != NULL);
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rs = g_new0(ReplicationState, 1);
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rs->opaque = opaque;
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rs->ops = ops;
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QLIST_INSERT_HEAD(&replication_states, rs, node);
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return rs;
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}
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void replication_remove(ReplicationState *rs)
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{
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if (rs) {
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QLIST_REMOVE(rs, node);
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g_free(rs);
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}
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}
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/*
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* The caller of the function MUST make sure vm stopped
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*/
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void replication_start_all(ReplicationMode mode, Error **errp)
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{
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ReplicationState *rs, *next;
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Error *local_err = NULL;
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QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
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if (rs->ops && rs->ops->start) {
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rs->ops->start(rs, mode, &local_err);
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}
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if (local_err) {
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error_propagate(errp, local_err);
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return;
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}
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}
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}
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void replication_do_checkpoint_all(Error **errp)
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{
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ReplicationState *rs, *next;
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Error *local_err = NULL;
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QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
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if (rs->ops && rs->ops->checkpoint) {
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rs->ops->checkpoint(rs, &local_err);
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}
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if (local_err) {
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error_propagate(errp, local_err);
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return;
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}
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}
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}
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void replication_get_error_all(Error **errp)
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{
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ReplicationState *rs, *next;
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Error *local_err = NULL;
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QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
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if (rs->ops && rs->ops->get_error) {
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rs->ops->get_error(rs, &local_err);
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}
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if (local_err) {
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error_propagate(errp, local_err);
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return;
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}
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}
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}
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void replication_stop_all(bool failover, Error **errp)
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{
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ReplicationState *rs, *next;
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Error *local_err = NULL;
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QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
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if (rs->ops && rs->ops->stop) {
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rs->ops->stop(rs, failover, &local_err);
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}
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if (local_err) {
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error_propagate(errp, local_err);
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return;
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}
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}
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}

‎replication.h

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/*
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* Replication filter
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*
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* Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
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* Copyright (c) 2016 Intel Corporation
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* Copyright (c) 2016 FUJITSU LIMITED
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*
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* Author:
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* Changlong Xie <[email protected]>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*/
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#ifndef REPLICATION_H
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#define REPLICATION_H
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#include "qemu/queue.h"
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typedef struct ReplicationOps ReplicationOps;
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typedef struct ReplicationState ReplicationState;
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/**
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* SECTION:replication.h
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* @title:Base Replication System
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* @short_description: interfaces for handling replication
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*
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* The Replication Model provides a framework for handling Replication
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*
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* <example>
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* <title>How to use replication interfaces</title>
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* <programlisting>
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* #include "replication.h"
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*
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* typedef struct BDRVReplicationState {
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* ReplicationState *rs;
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* } BDRVReplicationState;
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*
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* static void replication_start(ReplicationState *rs, ReplicationMode mode,
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* Error **errp);
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* static void replication_do_checkpoint(ReplicationState *rs, Error **errp);
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* static void replication_get_error(ReplicationState *rs, Error **errp);
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* static void replication_stop(ReplicationState *rs, bool failover,
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* Error **errp);
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*
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* static ReplicationOps replication_ops = {
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* .start = replication_start,
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* .checkpoint = replication_do_checkpoint,
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* .get_error = replication_get_error,
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* .stop = replication_stop,
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* }
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*
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* static int replication_open(BlockDriverState *bs, QDict *options,
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* int flags, Error **errp)
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* {
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* BDRVReplicationState *s = bs->opaque;
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* s->rs = replication_new(bs, &replication_ops);
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* return 0;
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* }
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*
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* static void replication_close(BlockDriverState *bs)
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* {
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* BDRVReplicationState *s = bs->opaque;
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* replication_remove(s->rs);
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* }
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*
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* BlockDriver bdrv_replication = {
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* .format_name = "replication",
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* .protocol_name = "replication",
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* .instance_size = sizeof(BDRVReplicationState),
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*
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* .bdrv_open = replication_open,
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* .bdrv_close = replication_close,
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* };
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*
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* static void bdrv_replication_init(void)
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* {
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* bdrv_register(&bdrv_replication);
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* }
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*
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* block_init(bdrv_replication_init);
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* </programlisting>
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* </example>
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*
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* We create an example about how to use replication interfaces in above.
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* Then in migration, we can use replication_(start/stop/do_checkpoint/
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* get_error)_all to handle all replication operations.
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*/
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/**
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* ReplicationState:
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* @opaque: opaque pointer value passed to this ReplicationState
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* @ops: replication operation of this ReplicationState
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* @node: node that we will insert into @replication_states QLIST
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*/
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struct ReplicationState {
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void *opaque;
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ReplicationOps *ops;
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QLIST_ENTRY(ReplicationState) node;
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};
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/**
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* ReplicationOps:
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* @start: callback to start replication
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* @stop: callback to stop replication
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* @checkpoint: callback to do checkpoint
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* @get_error: callback to check if error occurred during replication
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*/
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struct ReplicationOps {
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void (*start)(ReplicationState *rs, ReplicationMode mode, Error **errp);
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void (*stop)(ReplicationState *rs, bool failover, Error **errp);
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void (*checkpoint)(ReplicationState *rs, Error **errp);
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void (*get_error)(ReplicationState *rs, Error **errp);
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};
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/**
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* replication_new:
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* @opaque: opaque pointer value passed to ReplicationState
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* @ops: replication operation of the new relevant ReplicationState
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*
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* Called to create a new ReplicationState instance, and then insert it
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* into @replication_states QLIST
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*
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* Returns: the new ReplicationState instance
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*/
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ReplicationState *replication_new(void *opaque, ReplicationOps *ops);
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/**
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* replication_remove:
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* @rs: the ReplicationState instance to remove
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*
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* Called to remove a ReplicationState instance, and then delete it from
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* @replication_states QLIST
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*/
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void replication_remove(ReplicationState *rs);
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/**
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* replication_start_all:
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* @mode: replication mode that could be "primary" or "secondary"
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* @errp: returns an error if this function fails
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*
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* Start replication, called in migration/checkpoint thread
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*
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* Note: the caller of the function MUST make sure vm stopped
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*/
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void replication_start_all(ReplicationMode mode, Error **errp);
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/**
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* replication_do_checkpoint_all:
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* @errp: returns an error if this function fails
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*
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* This interface is called after all VM state is transferred to Secondary QEMU
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*/
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void replication_do_checkpoint_all(Error **errp);
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/**
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* replication_get_error_all:
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* @errp: returns an error if this function fails
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*
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* This interface is called to check if error occurred during replication
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*/
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void replication_get_error_all(Error **errp);
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/**
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* replication_stop_all:
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* @failover: boolean value that indicates if we need do failover or not
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* @errp: returns an error if this function fails
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*
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* It is called on failover. The vm should be stopped before calling it, if you
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* use this API to shutdown the guest, or other things except failover
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*/
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void replication_stop_all(bool failover, Error **errp);
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#endif /* REPLICATION_H */

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