[Qemu-devel] [PATCH v2 1/2] block: Do not prematurely remove "filename"

[Max Reitz]

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 <mre...@redhat.com>
---
 block.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/block.c b/block.c
index ff44e76..850c5d7 100644
--- a/block.c
+++ b/block.c
@@ -881,7 +881,8 @@ static void bdrv_assign_node_name(BlockDriverState *bs,
  * Removes all processed options from *options.
  */
 static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
-    QDict *options, int flags, BlockDriver *drv, Error **errp)
+    QDict *options, int flags, BlockDriver *drv, bool parsed_filename,
+    Error **errp)
 {
     int ret, open_flags;
     const char *filename;
@@ -954,6 +955,14 @@ static int bdrv_open_common(BlockDriverState *bs, 
BlockDriverState *file,
         bs->filename[0] = '\0';
     }
 
+    if (parsed_filename && !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);
 
@@ -1020,7 +1029,7 @@ static int bdrv_file_open(BlockDriverState *bs, const 
char *filename,
 {
     BlockDriver *drv;
     const char *drvname;
-    bool parse_filename = false;
+    bool parse_filename = false, parsed_filename = false;
     Error *local_err = NULL;
     int ret;
 
@@ -1070,18 +1079,19 @@ 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");
         }
+
+        parsed_filename = true;
     }
 
     if (!drv->bdrv_file_open) {
         ret = bdrv_open(&bs, filename, NULL, *options, flags, drv, &local_err);
         *options = NULL;
     } else {
-        ret = bdrv_open_common(bs, NULL, *options, flags, drv, &local_err);
+        ret = bdrv_open_common(bs, NULL, *options, flags, drv, parsed_filename,
+                               &local_err);
     }
     if (ret < 0) {
         error_propagate(errp, local_err);
@@ -1471,7 +1481,7 @@ int bdrv_open(BlockDriverState **pbs, const char 
*filename,
     }
 
     /* Open the image */
-    ret = bdrv_open_common(bs, file, options, flags, drv, &local_err);
+    ret = bdrv_open_common(bs, file, options, flags, drv, false, &local_err);
     if (ret < 0) {
         goto fail;
     }
-- 
2.0.0