Am 26.04.2016 um 23:32 hat Max Reitz geschrieben:
> Basically, bdrv_refresh_filename() should respect all children of a
> BlockDriverState. However, generally those children are driver-specific,
> so this function cannot handle the general case. On the other hand,
> there are only few drivers which use other children than @file and
> @backing (that being vmdk, quorum, and blkverify).
>
> Most block drivers only use @file and/or @backing (if they use any
> children at all). Both can be implemented directly in
> bdrv_refresh_filename.
>
> The user overriding the file's filename is already handled, however, the
> user overriding the backing file is not. If this is done, opening the
> BDS with the plain filename of its file will not be correct, so we may
> not set bs->exact_filename in that case.
>
> iotest 051 contains test cases for overwriting the backing file, and so
> its output changes with this patch applied (which I consider a good
> thing).
>
> Signed-off-by: Max Reitz <mre...@redhat.com>
> ---
> block.c | 14 +++++++++++++-
> tests/qemu-iotests/051.out | 8 ++++----
> tests/qemu-iotests/051.pc.out | 8 ++++----
> 3 files changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/block.c b/block.c
> index e178488..aff9ea3 100644
> --- a/block.c
> +++ b/block.c
> @@ -3925,6 +3925,7 @@ void bdrv_refresh_filename(BlockDriverState *bs)
>
> opts = qdict_new();
> has_open_options = append_open_options(opts, bs);
> + has_open_options |= bs->backing_overridden;
>
> /* If no specific options have been given for this BDS, the filename
> of
> * the underlying file should suffice for this one as well */
> @@ -3936,13 +3937,24 @@ void bdrv_refresh_filename(BlockDriverState *bs)
> * file BDS. The full options QDict of that file BDS should somehow
> * contain a representation of the filename, therefore the following
> * suffices without querying the (exact_)filename of this BDS. */
> - if (bs->file->bs->full_open_options) {
> + if (bs->file->bs->full_open_options &&
> + (!bs->backing || bs->backing->bs->full_open_options))
> + {
> qdict_put_obj(opts, "driver",
> QOBJECT(qstring_from_str(drv->format_name)));
> +
> QINCREF(bs->file->bs->full_open_options);
> qdict_put_obj(opts, "file",
> QOBJECT(bs->file->bs->full_open_options));
>
> + if (bs->backing) {
> + QINCREF(bs->backing->bs->full_open_options);
> + qdict_put_obj(opts, "backing",
> + QOBJECT(bs->backing->bs->full_open_options));
> + } else if (bs->backing_overridden && !bs->backing) {
> + qdict_put_obj(opts, "backing", QOBJECT(qstring_new()));
> + }
I see that the surrounding code does the same, but what's wrong with
qdict_put()?
Kevin
