[Qemu-devel] [PATCH v2 14/21] blockdev: Set 'format' indicates non-empty drive

[Kevin Wolf <kwolf@redhat.com>]

Creating an empty drive while specifying 'format' doesn't make sense.
The specified format driver would simply be ignored.

Make a set 'format' option an indication that a non-empty drive should
be created. This makes 'format' consistent with 'driver' and allows
using it with a block driver that doesn't need any other options (like
null-co/null-aio).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 blockdev.c                    | 5 +----
 tests/qemu-iotests/iotests.py | 2 +-
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 313841b..afaeef9 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -490,7 +490,6 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
     QDict *interval_dict = NULL;
     QList *interval_list = NULL;
     const char *id;
-    bool has_driver_specific_opts;
     BlockdevDetectZeroesOptions detect_zeroes =
         BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
     const char *throttling_group = NULL;
@@ -514,8 +513,6 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
         qdict_del(bs_opts, "id");
     }
 
-    has_driver_specific_opts = !!qdict_size(bs_opts);
-
     /* extract parameters */
     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
 
@@ -578,7 +575,7 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
     }
 
     /* init */
-    if ((!file || !*file) && !has_driver_specific_opts) {
+    if ((!file || !*file) && !qdict_size(bs_opts)) {
         BlockBackendRootState *blk_rs;
 
         blk = blk_new(qemu_opts_id(opts), errp);
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index ff5905f..f36add8 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -143,12 +143,12 @@ class VM(object):
     def add_drive(self, path, opts='', interface='virtio'):
         '''Add a virtio-blk drive to the VM'''
         options = ['if=%s' % interface,
-                   'format=%s' % imgfmt,
                    'cache=%s' % cachemode,
                    'id=drive%d' % self._num_drives]
 
         if path is not None:
             options.append('file=%s' % path)
+            options.append('format=%s' % imgfmt)
 
         if opts:
             options.append(opts)
-- 
1.8.3.1