block: Fix reopen flag inheritance

When reopening an image, the block layer already takes care to reopen
bs->file as well with recalculated inherited flags. The same must happen
for any other child (most notably missing before this patch: backing
files).

If bs->file (or any other child) didn't originally inherit from bs, e.g.
because it was created separately and then only referenced, it must not
inherit flags on reopen either, so check the inherited_from field before
propagation the reopen down.

VMDK already reopened its extents manually; this code can now be
dropped.

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

2 files changed, 13 insertions, 28 deletions

diff --git a/block.c b/block.c
index 58d12c029d..777753c1e2 100644
--- a/block.c
+++ b/block.c
@@ -1615,6 +1615,8 @@ BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
     assert(bs != NULL);
 
     BlockReopenQueueEntry *bs_entry;
+    BdrvChild *child;
+
     if (bs_queue == NULL) {
         bs_queue = g_new0(BlockReopenQueue, 1);
         QSIMPLEQ_INIT(bs_queue);
@@ -1623,8 +1625,15 @@ BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
     /* bdrv_open() masks this flag out */
     flags &= ~BDRV_O_PROTOCOL;
 
-    if (bs->file) {
-        bdrv_reopen_queue(bs_queue, bs->file, bdrv_inherited_flags(flags));
+    QLIST_FOREACH(child, &bs->children, next) {
+        int child_flags;
+
+        if (child->bs->inherits_from != bs) {
+            continue;
+        }
+
+        child_flags = child->role->inherit_flags(flags);
+        bdrv_reopen_queue(bs_queue, child->bs, child_flags);
     }
 
     bs_entry = g_new0(BlockReopenQueueEntry, 1);
diff --git a/block/vmdk.c b/block/vmdk.c
index 3284bec691..be9263a34e 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -321,37 +321,13 @@ static int vmdk_is_cid_valid(BlockDriverState *bs)
     return 1;
 }
 
-/* Queue extents, if any, for reopen() */
+/* We have nothing to do for VMDK reopen, stubs just return success */
 static int vmdk_reopen_prepare(BDRVReopenState *state,
                                BlockReopenQueue *queue, Error **errp)
 {
-    BDRVVmdkState *s;
-    int ret = -1;
-    int i;
-    VmdkExtent *e;
-
     assert(state != NULL);
     assert(state->bs != NULL);
-
-    if (queue == NULL) {
-        error_setg(errp, "No reopen queue for VMDK extents");
-        goto exit;
-    }
-
-    s = state->bs->opaque;
-
-    assert(s != NULL);
-
-    for (i = 0; i < s->num_extents; i++) {
-        e = &s->extents[i];
-        if (e->file != state->bs->file) {
-            bdrv_reopen_queue(queue, e->file, state->flags);
-        }
-    }
-    ret = 0;
-
-exit:
-    return ret;
+    return 0;
 }
 
 static int vmdk_parent_open(BlockDriverState *bs)