30.11.2018 5:32, Eric Blake wrote: > If nbd_client_init() fails after we are already connected, > then the server will spam logs with: > > Disconnect client, due to: Unexpected end-of-file before all bytes were read > > unless we gracefully disconnect before closing the connection. > > Ways to trigger this: > > $ > opts=driver=nbd,export=foo,server.type=inet,server.host=localhost,server.port=10809 > $ qemu-img map --output=json --image-opts $opts,read-only=off > $ qemu-img map --output=json --image-opts $opts,x-dirty-bitmap=nosuch: > > Signed-off-by: Eric Blake <[email protected]>
Reviewed-by: Vladimir Sementsov-Ogievskiy <[email protected]> > --- > block/nbd-client.c | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/block/nbd-client.c b/block/nbd-client.c > index e6e27dafa6a..fc5b7eda8ee 100644 > --- a/block/nbd-client.c > +++ b/block/nbd-client.c > @@ -995,12 +995,13 @@ int nbd_client_init(BlockDriverState *bs, > if (x_dirty_bitmap && !client->info.base_allocation) { > error_setg(errp, "requested x-dirty-bitmap %s not found", > x_dirty_bitmap); > - return -EINVAL; > + ret = -EINVAL; > + goto fail; > } > if (client->info.flags & NBD_FLAG_READ_ONLY) { > ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", > errp); > if (ret < 0) { > - return ret; > + goto fail; > } > } > if (client->info.flags & NBD_FLAG_SEND_FUA) { > @@ -1029,4 +1030,17 @@ int nbd_client_init(BlockDriverState *bs, > > logout("Established connection with NBD server\n"); > return 0; > + > + fail: > + /* > + * We have connected, but must fail for other reasons. The > + * connection is still blocking; send NBD_CMD_DISC as a courtesy > + * to the server. > + */ > + { > + NBDRequest request = { .type = NBD_CMD_DISC }; > + > + nbd_send_request(client->ioc ?: QIO_CHANNEL(sioc), &request); > + return ret; > + } > } > -- Best regards, Vladimir
