block: Always pass driver name through options QDict

The "driver" entry in the options QDict is now only missing if we're
opening an image with format probing.

We also catch cases now where both the drv argument and a "driver"
option is specified, e.g. by specifying -drive format=qcow2,driver=raw

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

1 files changed, 40 insertions, 36 deletions

diff --git a/block.c b/block.c
index 0d97fde366..0aa444e6ba 100644
--- a/block.c
+++ b/block.c
@@ -1037,14 +1037,13 @@ static QDict *parse_json_filename(const char *filename, Error **errp)
  * filename/flags pair to option QDict entries.
  */
 static int bdrv_fill_options(QDict **options, const char **pfilename, int flags,
-                             Error **errp)
+                             BlockDriver *drv, Error **errp)
 {
     const char *filename = *pfilename;
     const char *drvname;
     bool protocol = flags & BDRV_O_PROTOCOL;
     bool parse_filename = false;
     Error *local_err = NULL;
-    BlockDriver *drv;
 
     /* Parse json: pseudo-protocol */
     if (filename && g_str_has_prefix(filename, "json:")) {
@@ -1061,12 +1060,8 @@ static int bdrv_fill_options(QDict **options, const char **pfilename, int flags,
         *pfilename = filename = NULL;
     }
 
-    if (!protocol) {
-        return 0;
-    }
-
     /* Fetch the file name from the options QDict if necessary */
-    if (filename) {
+    if (protocol && filename) {
         if (!qdict_haskey(*options, "filename")) {
             qdict_put(*options, "filename", qstring_from_str(filename));
             parse_filename = true;
@@ -1081,30 +1076,41 @@ static int bdrv_fill_options(QDict **options, const char **pfilename, int flags,
     filename = qdict_get_try_str(*options, "filename");
     drvname = qdict_get_try_str(*options, "driver");
 
-    if (!drvname) {
-        if (filename) {
-            drv = bdrv_find_protocol(filename, parse_filename);
-            if (!drv) {
-                error_setg(errp, "Unknown protocol");
+    if (drv) {
+        if (drvname) {
+            error_setg(errp, "Driver specified twice");
+            return -EINVAL;
+        }
+        drvname = drv->format_name;
+        qdict_put(*options, "driver", qstring_from_str(drvname));
+    } else {
+        if (!drvname && protocol) {
+            if (filename) {
+                drv = bdrv_find_protocol(filename, parse_filename);
+                if (!drv) {
+                    error_setg(errp, "Unknown protocol");
+                    return -EINVAL;
+                }
+
+                drvname = drv->format_name;
+                qdict_put(*options, "driver", qstring_from_str(drvname));
+            } else {
+                error_setg(errp, "Must specify either driver or file");
                 return -EINVAL;
             }
-
-            drvname = drv->format_name;
-            qdict_put(*options, "driver", qstring_from_str(drvname));
-        } else {
-            error_setg(errp, "Must specify either driver or file");
-            return -EINVAL;
+        } else if (drvname) {
+            drv = bdrv_find_format(drvname);
+            if (!drv) {
+                error_setg(errp, "Unknown driver '%s'", drvname);
+                return -ENOENT;
+            }
         }
     }
 
-    drv = bdrv_find_format(drvname);
-    if (!drv) {
-        error_setg(errp, "Unknown driver '%s'", drvname);
-        return -ENOENT;
-    }
+    assert(drv || !protocol);
 
     /* Driver-specific filename parsing */
-    if (drv->bdrv_parse_filename && parse_filename) {
+    if (drv && drv->bdrv_parse_filename && parse_filename) {
         drv->bdrv_parse_filename(filename, *options, &local_err);
         if (local_err) {
             error_propagate(errp, local_err);
@@ -1438,7 +1444,7 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
         options = qdict_new();
     }
 
-    ret = bdrv_fill_options(&options, &filename, flags, &local_err);
+    ret = bdrv_fill_options(&options, &filename, flags, drv, &local_err);
     if (local_err) {
         goto fail;
     }
@@ -1478,7 +1484,10 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
     }
 
     /* Find the right image format driver */
+    drv = NULL;
     drvname = qdict_get_try_str(options, "driver");
+    assert(drvname || !(flags & BDRV_O_PROTOCOL));
+
     if (drvname) {
         drv = bdrv_find_format(drvname);
         qdict_del(options, "driver");
@@ -1487,19 +1496,14 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
             ret = -EINVAL;
             goto fail;
         }
-    }
-
-    if (!drv) {
-        if (file) {
-            ret = find_image_format(file, filename, &drv, &local_err);
-        } else {
-            error_setg(errp, "Must specify either driver or file");
-            ret = -EINVAL;
+    } else if (file) {
+        ret = find_image_format(file, filename, &drv, &local_err);
+        if (ret < 0) {
             goto fail;
         }
-    }
-
-    if (!drv) {
+    } else {
+        error_setg(errp, "Must specify either driver or file");
+        ret = -EINVAL;
         goto fail;
     }