Re: [Qemu-devel] [PATCH v3 3/5] block: Relative backing file for image creation

[Fam Zheng]

On Mon, 11/24 10:43, Max Reitz wrote:
> Relative backing filenames are always relative to the backed image's
> directory; the same applies to image creation. Therefore, if the backing
> file has to be opened for determining its size (in case the size has not
> been explicitly specified) its filename should be interpreted relative
> to the new image's base directory and not relative to qemu's working
> directory.
> 
> Signed-off-by: Max Reitz <address@hidden>
> ---
>  block.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/block.c b/block.c
> index a0cddcd..ed8e187 100644
> --- a/block.c
> +++ b/block.c
> @@ -5633,16 +5633,26 @@ void bdrv_img_create(const char *filename, const char 
> *fmt,
>      if (size == -1) {
>          if (backing_file) {
>              BlockDriverState *bs;
> +            char *full_backing = g_new0(char, PATH_MAX);
>              int64_t size;
>              int back_flags;
>  
> +            bdrv_get_full_backing_filename_from_filename(filename, 
> backing_file,
> +                                                         full_backing, 
> PATH_MAX,
> +                                                         &local_err);
> +            if (local_err) {
> +                g_free(full_backing);
> +                goto out;
> +            }
> +
>              /* backing files always opened read-only */
>              back_flags =
>                  flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
>  
>              bs = NULL;
> -            ret = bdrv_open(&bs, backing_file, NULL, NULL, back_flags,
> +            ret = bdrv_open(&bs, full_backing, NULL, NULL, back_flags,
>                              backing_drv, &local_err);
> +            g_free(full_backing);
>              if (ret < 0) {
>                  goto out;
>              }
> -- 
> 1.9.3
> 
> 

Reviewed-by: Fam Zheng <address@hidden>