[Qemu-block] [PATCH v6 4/9] block: Do not blindly copy filename from file

[Max Reitz]

bdrv_refresh_filename() can do the same and it has some checks whether
the filename can actually be inherited or not, so we can let it do its
job in bdrv_open_inherit() after bdrv_open_common() has been called.

The only thing we need to set in bdrv_open_common() is the
exact_filename of a BDS without an underlying file, for two reasons:
(1) It cannot be inherited from an underlying file BDS, so it has to be
    set somewhere.
(2) The driver may need the filename in its bdrv_file_open()
    implementation (format drivers do not need their own filename,
    though they may need their file BDS's name).

Signed-off-by: Max Reitz <address@hidden>
---
 block.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/block.c b/block.c
index 9943d8eff6..19f8a84d03 100644
--- a/block.c
+++ b/block.c
@@ -1116,12 +1116,11 @@ static int bdrv_open_common(BlockDriverState *bs, 
BdrvChild *file,
         bs->detect_zeroes = value;
     }
 
-    if (filename != NULL) {
-        pstrcpy(bs->filename, sizeof(bs->filename), filename);
+    if (!file && filename) {
+        pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), filename);
     } else {
-        bs->filename[0] = '\0';
+        assert(!drv->bdrv_needs_filename);
     }
-    pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename);
 
     bs->drv = drv;
     bs->opaque = g_malloc0(drv->instance_size);
-- 
2.11.0