[Qemu-block] [PATCH v8 12/26] blkverify: Make bdrv_dirname() return NULL

[Max Reitz]

blkverify's BDSs have a file BDS, but we do not want this to be
preferred over the raw node. There is no way to decide between the two
(and not really a reason to, either), so just return NULL in blkverify's
implementation of bdrv_dirname().

Signed-off-by: Max Reitz <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Reviewed-by: Alberto Garcia <address@hidden>
---
 block/blkverify.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/block/blkverify.c b/block/blkverify.c
index b2ed8cd70d..d5233eeaf9 100644
--- a/block/blkverify.c
+++ b/block/blkverify.c
@@ -309,6 +309,15 @@ static void blkverify_refresh_filename(BlockDriverState 
*bs, QDict *options)
     }
 }
 
+static char *blkverify_dirname(BlockDriverState *bs, Error **errp)
+{
+    /* In general, there are two BDSs with different dirnames below this one;
+     * so there is no unique dirname we could return (unless both are equal by
+     * chance). Therefore, to be consistent, just always return NULL. */
+    error_setg(errp, "Cannot generate a base directory for blkverify nodes");
+    return NULL;
+}
+
 static BlockDriver bdrv_blkverify = {
     .format_name                      = "blkverify",
     .protocol_name                    = "blkverify",
@@ -320,6 +329,7 @@ static BlockDriver bdrv_blkverify = {
     .bdrv_child_perm                  = bdrv_filter_default_perms,
     .bdrv_getlength                   = blkverify_getlength,
     .bdrv_refresh_filename            = blkverify_refresh_filename,
+    .bdrv_dirname                     = blkverify_dirname,
 
     .bdrv_co_preadv                   = blkverify_co_preadv,
     .bdrv_co_pwritev                  = blkverify_co_pwritev,
-- 
2.14.3