commit 39c4ae941ed992a3bb5647fe7fafdd66d9278f43
author Kevin Wolf <kwolf@redhat.com> Fri Nov 13 14:45:42 2015 +0100
committer Kevin Wolf <kwolf@redhat.com> Fri Dec 18 14:34:43 2015 +0100
tree af43e40152f7132491e4ac521dd5479a1ff9d2c4
parent 145f598e4a96f6bb78664852bd589e4ea326be94

blockdev: Set 'format' indicates non-empty drive

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>
Reviewed-by: Max Reitz <mreitz@redhat.com>

blockdev.c

diff --git a/blockdev.c b/blockdev.c
index 13eaa77..2f88004 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -490,7 +490,6 @@
     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 @@
         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 @@
     }
 
     /* 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);