Re: [Qemu-block] [PATCH v4 2/6] replication: add shared-disk and shared-disk-id options

[Hailiang Zhang]

On 2017/4/18 13:59, Xie Changlong wrote:
> On 04/12/2017 10:05 PM, zhanghailiang wrote:
> > We use these two options to identify which disk is
> > shared
> >
> > Signed-off-by: zhanghailiang <address@hidden>
> > Signed-off-by: Wen Congyang <address@hidden>
> > Signed-off-by: Zhang Chen <address@hidden>
> > ---
> > v4:
> > - Add proper comment for primary_disk (Stefan)
> > v2:
> > - Move g_free(s->shared_disk_id) to the common fail process place (Stefan)
> > - Fix comments for these two options
> > ---
> >    block/replication.c  | 43 +++++++++++++++++++++++++++++++++++++++++--
> >    qapi/block-core.json | 10 +++++++++-
> >    2 files changed, 50 insertions(+), 3 deletions(-)
> >
> > diff --git a/block/replication.c b/block/replication.c
> > index bf3c395..418b81b 100644
> > --- a/block/replication.c
> > +++ b/block/replication.c
> > @@ -25,9 +25,12 @@
> >    typedef struct BDRVReplicationState {
> >        ReplicationMode mode;
> >        int replication_state;
> > +    bool is_shared_disk;
> > +    char *shared_disk_id;
> >        BdrvChild *active_disk;
> >        BdrvChild *hidden_disk;
> >        BdrvChild *secondary_disk;
> > +    BdrvChild *primary_disk;
> >        char *top_id;
> >        ReplicationState *rs;
> >        Error *blocker;
> > @@ -53,6 +56,9 @@ static void replication_stop(ReplicationState *rs, bool 
> > failover,
> >    
> >    #define REPLICATION_MODE        "mode"
> >    #define REPLICATION_TOP_ID      "top-id"
> > +#define REPLICATION_SHARED_DISK "shared-disk"
> > +#define REPLICATION_SHARED_DISK_ID "shared-disk-id"
> > +
> >    static QemuOptsList replication_runtime_opts = {
> >        .name = "replication",
> >        .head = QTAILQ_HEAD_INITIALIZER(replication_runtime_opts.head),
> > @@ -65,6 +71,14 @@ static QemuOptsList replication_runtime_opts = {
> >                .name = REPLICATION_TOP_ID,
> >                .type = QEMU_OPT_STRING,
> >            },
> > +        {
> > +            .name = REPLICATION_SHARED_DISK_ID,
> > +            .type = QEMU_OPT_STRING,
> > +        },
> > +        {
> > +            .name = REPLICATION_SHARED_DISK,
> > +            .type = QEMU_OPT_BOOL,
> > +        },
> >            { /* end of list */ }
> >        },
> >    };
> > @@ -85,6 +99,9 @@ static int replication_open(BlockDriverState *bs, QDict 
> > *options,
> >        QemuOpts *opts = NULL;
> >        const char *mode;
> >        const char *top_id;
> > +    const char *shared_disk_id;
> > +    BlockBackend *blk;
> > +    BlockDriverState *tmp_bs;
> >    
> >        bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
> >                                   false, errp);
> > @@ -125,12 +142,33 @@ static int replication_open(BlockDriverState *bs, QDict 
> > *options,
> >                       "The option mode's value should be primary or secondary");
> >            goto fail;
> >        }
> > +    s->is_shared_disk = qemu_opt_get_bool(opts, REPLICATION_SHARED_DISK,
> > +
> What If secondary side is supplied with 'REPLICATION_SHARED_DISK_ID'?
> Pls refer f4f2539bc to pefect the logical.

Hmm, we should not configure it for secondary side, i'll fix it in next version.


> >                                           false);
> > +    if (s->is_shared_disk && (s->mode == REPLICATION_MODE_PRIMARY)) {
> > +        shared_disk_id = qemu_opt_get(opts, REPLICATION_SHARED_DISK_ID);
> > +        if (!shared_disk_id) {
> > +            error_setg(&local_err, "Missing shared disk blk option");
> > +            goto fail;
> > +        }
> > +        s->shared_disk_id = g_strdup(shared_disk_id);
> > +        blk = blk_by_name(s->shared_disk_id);
> > +        if (!blk) {
> > +            error_setg(&local_err, "There is no %s block", s->shared_disk_id);
> > +            goto fail;
> > +        }
> > +        /* We have a BlockBackend for the primary disk but use BdrvChild for
> > +         * consistency - active_disk, secondary_disk, etc are also BdrvChild.
> > +         */
> > +        tmp_bs = blk_bs(blk);
> > +        s->primary_disk = QLIST_FIRST(&tmp_bs->parents);
> > +    }
> >    
> >        s->rs = replication_new(bs, &replication_ops);
> >    
> > -    ret = 0;
> > -
> > +    qemu_opts_del(opts);
> > +    return 0;
> >    fail:
> > +    g_free(s->shared_disk_id);
> >        qemu_opts_del(opts);
> >        error_propagate(errp, local_err);
> >    
> > @@ -141,6 +179,7 @@ static void replication_close(BlockDriverState *bs)
> >    {
> >        BDRVReplicationState *s = bs->opaque;
> >    
> > +    g_free(s->shared_disk_id);
> >        if (s->replication_state == BLOCK_REPLICATION_RUNNING) {
> >            replication_stop(s->rs, false, NULL);
> >        }
> > diff --git a/qapi/block-core.json b/qapi/block-core.json
> > index 033457c..361c932 100644
> > --- a/qapi/block-core.json
> > +++ b/qapi/block-core.json
> > @@ -2661,12 +2661,20 @@
> >    #          node who owns the replication node chain. Must not be given in
> >    #          primary mode.
> >    #
> > +# @shared-disk-id: Id of shared disk while is replication mode, if @shared-disk
> > +#                  is true, this option is required (Since: 2.10)
> > +#
> Further explanations:
>
> For @shared-disk-id, it must/only be given when @shared-disk enable on
> Primary side.

OK.
> > +# @shared-disk: To indicate whether or not a disk is shared by primary VM
> > +#               and secondary VM. (The default is false) (Since: 2.10)
> > +#
> Further explanations:
>
> For @shared-disk, it must be given or not-given on both side at the same
> time.

OK, will fix it, thanks.

> >    # Since: 2.9
> >    ##
> >    { 'struct': 'BlockdevOptionsReplication',
> >      'base': 'BlockdevOptionsGenericFormat',
> >      'data': { 'mode': 'ReplicationMode',
> > -            '*top-id': 'str' } }
> > +            '*top-id': 'str',
> > +            '*shared-disk-id': 'str',
> > +            '*shared-disk': 'bool' } }
> >    
> >    ##
> >    # @NFSTransport:
>
>
>
> .