These are needed to print "info block" output correctly. QCOW2 does
this already because it needs it to write the header, but QED does not,
and common code is a better place to do it.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
block.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/block.c b/block.c
index e293882..afff23f 100644
--- a/block.c
+++ b/block.c
@@ -1402,6 +1402,7 @@ int bdrv_change_backing_file(BlockDriverState *bs,
const char *backing_file, const char *backing_fmt)
{
BlockDriver *drv = bs->drv;
+ int ret;
/* Backing file format doesn't make sense without a backing file */
if (backing_fmt && !backing_file) {
@@ -1409,10 +1410,16 @@ int bdrv_change_backing_file(BlockDriverState *bs,
}
if (drv->bdrv_change_backing_file != NULL) {
- return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
+ ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
} else {
- return -ENOTSUP;
+ ret = -ENOTSUP;
+ }
+
+ if (ret == 0) {
+ pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?:
"");
+ pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?:
"");
}
+ return ret;
}
static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
--
1.7.9.3
