[Qemu-devel] [PATCH 1/2] block: Do not prematurely remove "filename"

[Max Reitz <mreitz@redhat.com>]

If "filename" is removed from the options QDict before entering
bdrv_open_common(), it cannot be stored in the BDS. Therefore, wait
until it has been copied there and remove it from the options only
afterwards.

This fixes "filename" in the BDS being empty for block drivers which do
not need the filename because they have parsed it already (e.g. NBD).

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/block.c b/block.c
index 43abe96..1fdfa66 100644
--- a/block.c
+++ b/block.c
@@ -954,6 +954,14 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
         bs->filename[0] = '\0';
     }
 
+    if (!drv->bdrv_needs_filename) {
+        qdict_del(options, "filename");
+        /* The pointer "filename" may reference the just deleted QDict entry; in
+         * any case, it is no longer needed, so indicate that by setting it to
+         * NULL. */
+        filename = NULL;
+    }
+
     bs->drv = drv;
     bs->opaque = g_malloc0(drv->instance_size);
 
@@ -1070,9 +1078,7 @@ static int bdrv_file_open(BlockDriverState *bs, const char *filename,
             goto fail;
         }
 
-        if (!drv->bdrv_needs_filename) {
-            qdict_del(*options, "filename");
-        } else {
+        if (drv->bdrv_needs_filename) {
             filename = qdict_get_str(*options, "filename");
         }
     }
-- 
2.0.0