[Qemu-devel] [PATCH v5 12/22] block: Allow recursive "file"s

[Max Reitz <mreitz@redhat.com>]

It should be possible to use a format as a driver for a file which in
turn requires another file, i.e., nesting file formats.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/block.c b/block.c
index 9659eb5..9222669 100644
--- a/block.c
+++ b/block.c
@@ -948,14 +948,19 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
         goto fail;
     }
 
-    ret = bdrv_open_common(bs, NULL, options, flags, drv, &local_err);
+    if (!drv->bdrv_file_open) {
+        ret = bdrv_open(bs, filename, options, flags, drv, &local_err);
+        options = NULL;
+    } else {
+        ret = bdrv_open_common(bs, NULL, options, flags, drv, &local_err);
+    }
     if (ret < 0) {
         error_propagate(errp, local_err);
         goto fail;
     }
 
     /* Check if any unknown options were used */
-    if (qdict_size(options) != 0) {
+    if (options && (qdict_size(options) != 0)) {
         const QDictEntry *entry = qdict_first(options);
         error_setg(errp, "Block protocol '%s' doesn't support the option '%s'",
                    drv->format_name, entry->key);
@@ -970,10 +975,12 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
 
 fail:
     QDECREF(options);
-    if (!bs->drv) {
-        QDECREF(bs->options);
+    if (bs) {
+        if (!bs->drv) {
+            QDECREF(bs->options);
+        }
+        bdrv_unref(bs);
     }
-    bdrv_unref(bs);
     return ret;
 }
 
-- 
1.8.5.1