On Mon, 07/15 05:42, Xu Wang wrote:
> Add backing file loop check before execute change backing file for
> qcow2 format.
>
> Signed-off-by: Xu Wang <cngesa...@gmail.com>
> ---
> block/qcow2.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 0eceefe..01bd7d5 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -1195,6 +1195,12 @@ fail:
> static int qcow2_change_backing_file(BlockDriverState *bs,
> const char *backing_file, const char *backing_fmt)
> {
> + /* Check if loop exists in backing files chain after changed */
> + if (bdrv_backing_file_loop_check(bs->filename,
> + bs->drv ? bs->drv->format_name : NULL,
> + backing_file, backing_fmt)) {
> + return -EIO;
> + }
> pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
> pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?:
> "");
>
> --
> 1.8.1.4
>
I'm not sure this is needed, there's already loop check in block layer's
bdrv_change_backing_file(), which calls drv->bdrv_change_backing_file().
wouldn't this be redundant?
Thanks.
--
Fam
