On 25/03/2015 10:36, Wen Congyang wrote: > The secondary qemu starts later than the primary qemu, so we > cannot connect to nbd server in bdrv_open(). > > Signed-off-by: Wen Congyang <we...@cn.fujitsu.com> > Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com> > Signed-off-by: Gonglei <arei.gong...@huawei.com> > --- > block/nbd.c | 122 > +++++++++++++++++++++++++++++++++++++++++++++++++++++------- > 1 file changed, 108 insertions(+), 14 deletions(-) > > diff --git a/block/nbd.c b/block/nbd.c > index 2176186..3faf865 100644 > --- a/block/nbd.c > +++ b/block/nbd.c > @@ -44,6 +44,8 @@ > typedef struct BDRVNBDState { > NbdClientSession client; > QemuOpts *socket_opts; > + char *export; > + bool connected; > } BDRVNBDState; > > static int nbd_parse_uri(const char *filename, QDict *options) > @@ -254,50 +256,95 @@ static int nbd_establish_connection(BlockDriverState > *bs, Error **errp) > return sock; > } > > -static int nbd_open(BlockDriverState *bs, QDict *options, int flags, > - Error **errp) > +static int nbd_connect_server(BlockDriverState *bs, Error **errp) > { > BDRVNBDState *s = bs->opaque; > - char *export = NULL; > int result, sock; > - Error *local_err = NULL; > - > - /* Pop the config into our state object. Exit if invalid. */ > - nbd_config(s, options, &export, &local_err); > - if (local_err) { > - error_propagate(errp, local_err); > - return -EINVAL; > - } > > /* establish TCP connection, return error if it fails > * TODO: Configurable retry-until-timeout behaviour. > */ > sock = nbd_establish_connection(bs, errp); > if (sock < 0) { > - g_free(export); > + g_free(s->export); > return sock; > } > > /* NBD handshake */ > - result = nbd_client_init(bs, sock, export, errp); > - g_free(export); > + result = nbd_client_init(bs, sock, s->export, errp); > + g_free(s->export); > + s->export = NULL; > + if (!result) { > + s->connected = true; > + } > + > return result; > } > > +static int nbd_open(BlockDriverState *bs, QDict *options, int flags, > + Error **errp) > +{ > + BDRVNBDState *s = bs->opaque; > + Error *local_err = NULL; > + > + /* Pop the config into our state object. Exit if invalid. */ > + nbd_config(s, options, &s->export, &local_err); > + if (local_err) { > + error_propagate(errp, local_err); > + return -EINVAL; > + } > + > + return nbd_connect_server(bs, errp); > +} > + > +static int nbd_open_colo(BlockDriverState *bs, QDict *options, int flags, > + Error **errp) > +{ > + BDRVNBDState *s = bs->opaque; > + Error *local_err = NULL; > + > + /* Pop the config into our state object. Exit if invalid. */ > + nbd_config(s, options, &s->export, &local_err); > + if (local_err) { > + error_propagate(errp, local_err); > + return -EINVAL; > + } > + > + return 0; > +} > + > static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num, > int nb_sectors, QEMUIOVector *qiov) > { > + BDRVNBDState *s = bs->opaque; > + > + if (!s->connected) { > + return -EIO; > + } > + > return nbd_client_co_readv(bs, sector_num, nb_sectors, qiov); > } > > static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num, > int nb_sectors, QEMUIOVector *qiov) > { > + BDRVNBDState *s = bs->opaque; > + > + if (!s->connected) { > + return -EIO; > + } > + > return nbd_client_co_writev(bs, sector_num, nb_sectors, qiov); > } > > static int nbd_co_flush(BlockDriverState *bs) > { > + BDRVNBDState *s = bs->opaque; > + > + if (!s->connected) { > + return -EIO; > + } > + > return nbd_client_co_flush(bs); > } > > @@ -310,6 +357,12 @@ static void nbd_refresh_limits(BlockDriverState *bs, > Error **errp) > static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num, > int nb_sectors) > { > + BDRVNBDState *s = bs->opaque; > + > + if (!s->connected) { > + return -EIO; > + } > + > return nbd_client_co_discard(bs, sector_num, nb_sectors); > } > > @@ -319,23 +372,44 @@ static void nbd_close(BlockDriverState *bs) > > qemu_opts_del(s->socket_opts); > nbd_client_close(bs); > + s->connected = false; > } > > static int64_t nbd_getlength(BlockDriverState *bs) > { > BDRVNBDState *s = bs->opaque; > > + if (!s->connected) { > + /* > + * We cannot return -ENOTCONN, otherwise refresh_total_sectors() > + * will fail, and we cannot open nbd client. > + */ > + return 0; > + } > + > return s->client.size; > } > > static void nbd_detach_aio_context(BlockDriverState *bs) > { > + BDRVNBDState *s = bs->opaque; > + > + if (!s->connected) { > + return; > + } > + > nbd_client_detach_aio_context(bs); > } > > static void nbd_attach_aio_context(BlockDriverState *bs, > AioContext *new_context) > { > + BDRVNBDState *s = bs->opaque; > + > + if (!s->connected) { > + return; > + } > + > nbd_client_attach_aio_context(bs, new_context); > } > > @@ -438,11 +512,31 @@ static BlockDriver bdrv_nbd_unix = { > .bdrv_refresh_filename = nbd_refresh_filename, > }; > > +static BlockDriver bdrv_nbd_colo = { > + .format_name = "nbd+colo", > + .protocol_name = "nbd+colo", > + .instance_size = sizeof(BDRVNBDState), > + .bdrv_parse_filename = nbd_parse_filename, > + .bdrv_file_open = nbd_open_colo, > + .bdrv_co_readv = nbd_co_readv, > + .bdrv_co_writev = nbd_co_writev, > + .bdrv_close = nbd_close, > + .bdrv_co_flush_to_os = nbd_co_flush, > + .bdrv_co_discard = nbd_co_discard, > + .bdrv_getlength = nbd_getlength, > + .bdrv_detach_aio_context = nbd_detach_aio_context, > + .bdrv_attach_aio_context = nbd_attach_aio_context, > + .bdrv_refresh_filename = nbd_refresh_filename, > + > + .has_variable_length = true, > +}; > + > static void bdrv_nbd_init(void) > { > bdrv_register(&bdrv_nbd); > bdrv_register(&bdrv_nbd_tcp); > bdrv_register(&bdrv_nbd_unix); > + bdrv_register(&bdrv_nbd_colo); > } > > block_init(bdrv_nbd_init); >
Acked-by: Paolo Bonzini <pbonz...@redhat.com>