Re: [Qemu-block] [PATCH v2 2/6] qapi: add name parameter to nbd-server-add

[Vladimir Sementsov-Ogievskiy]

08.12.2017 20:33, Dr. David Alan Gilbert wrote:
> * Vladimir Sementsov-Ogievskiy (address@hidden) wrote:
> > Allow user to specify name for new export, to not reuse internal
> > node name and to not show it to clients.
> >
> > This also allows creating several exports per device.
> >
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
> > ---
> >   qapi/block.json |  9 +++++++--
> >   blockdev-nbd.c  | 14 +++++++++-----
> >   hmp.c           |  5 +++--
> >   3 files changed, 19 insertions(+), 9 deletions(-)
> >
> > diff --git a/qapi/block.json b/qapi/block.json
> > index f093fa3f27..503d4b287b 100644
> > --- a/qapi/block.json
> > +++ b/qapi/block.json
> > @@ -213,14 +213,19 @@
> >   #
> >   # @device: The device name or node name of the node to be exported
> >   #
> > +# @name: Export name. If unspecified @device parameter used as export name.
> > +#        (Since 2.12)
> > +#
> >   # @writable: Whether clients should be able to write to the device via the
> >   #     NBD connection (default false).
> >   #
> > -# Returns: error if the device is already marked for export.
> > +# Returns: error if the server is not running, or export with the same name
> > +#          already exists.
> >   #
> >   # Since: 1.3.0
> >   ##
> > -{ 'command': 'nbd-server-add', 'data': {'device': 'str', '*writable': 'bool'} }
> > +{ 'command': 'nbd-server-add',
> > +  'data': {'device': 'str', '*name': 'str', '*writable': 'bool'} }
> >   
> >   ##
> >   # @nbd-server-stop:
> > diff --git a/blockdev-nbd.c b/blockdev-nbd.c
> > index 28f551a7b0..46c885aa35 100644
> > --- a/blockdev-nbd.c
> > +++ b/blockdev-nbd.c
> > @@ -158,8 +158,8 @@ void qmp_nbd_server_start(SocketAddressLegacy *addr,
> >       qapi_free_SocketAddress(addr_flat);
> >   }
> >   
> > -void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,
> > -                        Error **errp)
> > +void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
> > +                        bool has_writable, bool writable, Error **errp)
> >   {
> >       BlockDriverState *bs = NULL;
> >       BlockBackend *on_eject_blk;
> > @@ -170,8 +170,12 @@ void qmp_nbd_server_add(const char *device, bool 
> > has_writable, bool writable,
> >           return;
> >       }
> >   
> > -    if (nbd_export_find(device)) {
> > -        error_setg(errp, "NBD server already exporting device '%s'", device);
> > +    if (!has_name) {
> > +        name = device;
> > +    }
> > +
> > +    if (nbd_export_find(name)) {
> > +        error_setg(errp, "NBD server already has export named '%s'", name);
> >           return;
> >       }
> >   
> > @@ -195,7 +199,7 @@ void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,
> >           return;
> >       }
> >   
> > -    nbd_export_set_name(exp, device);
> > +    nbd_export_set_name(exp, name);
> >   
> >       /* The list of named exports has a strong reference to this export now and
> >        * our only way of accessing it is through nbd_export_find(), so we can 
> > drop
> > diff --git a/hmp.c b/hmp.c
> > index 35a7041824..0ea9c09b58 100644
> > --- a/hmp.c
> > +++ b/hmp.c
> > @@ -2203,7 +2203,8 @@ void hmp_nbd_server_start(Monitor *mon, const QDict 
> > *qdict)
> >               continue;
> >           }
> >   
> > -        qmp_nbd_server_add(info->value->device, true, writable, &local_err);
> > +        qmp_nbd_server_add(info->value->device, false, NULL,
> > +                           true, writable, &local_err);
> >   
> >           if (local_err != NULL) {
> >               qmp_nbd_server_stop(NULL);
> > @@ -2223,7 +2224,7 @@ void hmp_nbd_server_add(Monitor *mon, const QDict *qdict)
> >       bool writable = qdict_get_try_bool(qdict, "writable", false);
> >       Error *local_err = NULL;
> >   
> > -    qmp_nbd_server_add(device, true, writable, &local_err);
> > +    qmp_nbd_server_add(device, false, NULL, true, writable, &local_err);
> I wont insist, but it would be nice if you wired up an optional
> parameter on HMP as well.
>
> Dave

Hmm.. Honestly, I don't see real usage of it.

> >       if (local_err != NULL) {
> >           hmp_handle_error(mon, &local_err);
> > --
> > 2.11.1
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK


--
Best regards,
Vladimir