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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 <wency@cn.fujitsu.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Signed-off-by: Wang WeiWei <wangww.fnst@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Message-id: 1469602913-20979-9-git-send-email-xiecl.fnst@cn.fujitsu.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
tags/v2.8.0-rc0
Changlong Xie 3 years ago
parent
commit
190b9a8b55
4 changed files with 295 additions and 0 deletions
  1. +1
    -0
      Makefile.objs
  2. +13
    -0
      qapi/block-core.json
  3. +107
    -0
      replication.c
  4. +174
    -0
      replication.h

+ 1
- 0
Makefile.objs View File

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

block-obj-m = block/


+ 13
- 0
qapi/block-core.json View File

@@ -2162,6 +2162,19 @@
'server': ['GlusterServer'],
'*debug-level': 'int' } }

##
# @ReplicationMode
#
# An enumeration of replication modes.
#
# @primary: Primary mode, the vm's state will be sent to secondary QEMU.
#
# @secondary: Secondary mode, receive the vm's state from primary QEMU.
#
# Since: 2.8
##
{ 'enum' : 'ReplicationMode', 'data' : [ 'primary', 'secondary' ] }

##
# @BlockdevOptions
#

+ 107
- 0
replication.c View File

@@ -0,0 +1,107 @@
/*
* Replication filter
*
* Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
* Copyright (c) 2016 Intel Corporation
* Copyright (c) 2016 FUJITSU LIMITED
*
* Author:
* Changlong Xie <xiecl.fnst@cn.fujitsu.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/

#include "qemu/osdep.h"
#include "qapi/error.h"
#include "replication.h"

static QLIST_HEAD(, ReplicationState) replication_states;

ReplicationState *replication_new(void *opaque, ReplicationOps *ops)
{
ReplicationState *rs;

assert(ops != NULL);
rs = g_new0(ReplicationState, 1);
rs->opaque = opaque;
rs->ops = ops;
QLIST_INSERT_HEAD(&replication_states, rs, node);

return rs;
}

void replication_remove(ReplicationState *rs)
{
if (rs) {
QLIST_REMOVE(rs, node);
g_free(rs);
}
}

/*
* The caller of the function MUST make sure vm stopped
*/
void replication_start_all(ReplicationMode mode, Error **errp)
{
ReplicationState *rs, *next;
Error *local_err = NULL;

QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
if (rs->ops && rs->ops->start) {
rs->ops->start(rs, mode, &local_err);
}
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
}

void replication_do_checkpoint_all(Error **errp)
{
ReplicationState *rs, *next;
Error *local_err = NULL;

QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
if (rs->ops && rs->ops->checkpoint) {
rs->ops->checkpoint(rs, &local_err);
}
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
}

void replication_get_error_all(Error **errp)
{
ReplicationState *rs, *next;
Error *local_err = NULL;

QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
if (rs->ops && rs->ops->get_error) {
rs->ops->get_error(rs, &local_err);
}
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
}

void replication_stop_all(bool failover, Error **errp)
{
ReplicationState *rs, *next;
Error *local_err = NULL;

QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
if (rs->ops && rs->ops->stop) {
rs->ops->stop(rs, failover, &local_err);
}
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
}

+ 174
- 0
replication.h View File

@@ -0,0 +1,174 @@
/*
* Replication filter
*
* Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
* Copyright (c) 2016 Intel Corporation
* Copyright (c) 2016 FUJITSU LIMITED
*
* Author:
* Changlong Xie <xiecl.fnst@cn.fujitsu.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/

#ifndef REPLICATION_H
#define REPLICATION_H

#include "qemu/queue.h"

typedef struct ReplicationOps ReplicationOps;
typedef struct ReplicationState ReplicationState;

/**
* SECTION:replication.h
* @title:Base Replication System
* @short_description: interfaces for handling replication
*
* The Replication Model provides a framework for handling Replication
*
* <example>
* <title>How to use replication interfaces</title>
* <programlisting>
* #include "replication.h"
*
* typedef struct BDRVReplicationState {
* ReplicationState *rs;
* } BDRVReplicationState;
*
* static void replication_start(ReplicationState *rs, ReplicationMode mode,
* Error **errp);
* static void replication_do_checkpoint(ReplicationState *rs, Error **errp);
* static void replication_get_error(ReplicationState *rs, Error **errp);
* static void replication_stop(ReplicationState *rs, bool failover,
* Error **errp);
*
* static ReplicationOps replication_ops = {
* .start = replication_start,
* .checkpoint = replication_do_checkpoint,
* .get_error = replication_get_error,
* .stop = replication_stop,
* }
*
* static int replication_open(BlockDriverState *bs, QDict *options,
* int flags, Error **errp)
* {
* BDRVReplicationState *s = bs->opaque;
* s->rs = replication_new(bs, &replication_ops);
* return 0;
* }
*
* static void replication_close(BlockDriverState *bs)
* {
* BDRVReplicationState *s = bs->opaque;
* replication_remove(s->rs);
* }
*
* BlockDriver bdrv_replication = {
* .format_name = "replication",
* .protocol_name = "replication",
* .instance_size = sizeof(BDRVReplicationState),
*
* .bdrv_open = replication_open,
* .bdrv_close = replication_close,
* };
*
* static void bdrv_replication_init(void)
* {
* bdrv_register(&bdrv_replication);
* }
*
* block_init(bdrv_replication_init);
* </programlisting>
* </example>
*
* We create an example about how to use replication interfaces in above.
* Then in migration, we can use replication_(start/stop/do_checkpoint/
* get_error)_all to handle all replication operations.
*/

/**
* ReplicationState:
* @opaque: opaque pointer value passed to this ReplicationState
* @ops: replication operation of this ReplicationState
* @node: node that we will insert into @replication_states QLIST
*/
struct ReplicationState {
void *opaque;
ReplicationOps *ops;
QLIST_ENTRY(ReplicationState) node;
};

/**
* ReplicationOps:
* @start: callback to start replication
* @stop: callback to stop replication
* @checkpoint: callback to do checkpoint
* @get_error: callback to check if error occurred during replication
*/
struct ReplicationOps {
void (*start)(ReplicationState *rs, ReplicationMode mode, Error **errp);
void (*stop)(ReplicationState *rs, bool failover, Error **errp);
void (*checkpoint)(ReplicationState *rs, Error **errp);
void (*get_error)(ReplicationState *rs, Error **errp);
};

/**
* replication_new:
* @opaque: opaque pointer value passed to ReplicationState
* @ops: replication operation of the new relevant ReplicationState
*
* Called to create a new ReplicationState instance, and then insert it
* into @replication_states QLIST
*
* Returns: the new ReplicationState instance
*/
ReplicationState *replication_new(void *opaque, ReplicationOps *ops);

/**
* replication_remove:
* @rs: the ReplicationState instance to remove
*
* Called to remove a ReplicationState instance, and then delete it from
* @replication_states QLIST
*/
void replication_remove(ReplicationState *rs);

/**
* replication_start_all:
* @mode: replication mode that could be "primary" or "secondary"
* @errp: returns an error if this function fails
*
* Start replication, called in migration/checkpoint thread
*
* Note: the caller of the function MUST make sure vm stopped
*/
void replication_start_all(ReplicationMode mode, Error **errp);

/**
* replication_do_checkpoint_all:
* @errp: returns an error if this function fails
*
* This interface is called after all VM state is transferred to Secondary QEMU
*/
void replication_do_checkpoint_all(Error **errp);

/**
* replication_get_error_all:
* @errp: returns an error if this function fails
*
* This interface is called to check if error occurred during replication
*/
void replication_get_error_all(Error **errp);

/**
* replication_stop_all:
* @failover: boolean value that indicates if we need do failover or not
* @errp: returns an error if this function fails
*
* It is called on failover. The vm should be stopped before calling it, if you
* use this API to shutdown the guest, or other things except failover
*/
void replication_stop_all(bool failover, Error **errp);

#endif /* REPLICATION_H */

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