Re: [Qemu-devel] [PATCH for-2.10 1/3] block: Add errp to b{lk, drv}_truncate()

[Kevin Wolf <kwolf@redhat.com>]

Am 06.03.2017 um 20:54 hat Max Reitz geschrieben:
> For one thing, this allows us to drop the error message generation from
> qemu-img.c and blockdev.c and instead have it unified in
> bdrv_truncate().
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>

>  block/commit.c                 |  5 +++--
>  block/mirror.c                 |  2 +-

These still pass NULL after the series. Fixing it would require to add a
way to complete jobs with an Error object, but maybe we should do this
sooner or later anyway. Not necessarily part of this series, though.

>  block/vhdx.c                   |  6 +++---
>  block/vpc.c                    |  2 +-

vpc can easily be fixed to pass the actual errp from vpc_create() to the
blk_truncate() call. In vhdx.c, the blk_truncate() call is a bit more
deeply nested, but it doesn't seem completely unreasonable there either.

> --- a/qemu-io-cmds.c
> +++ b/qemu-io-cmds.c
> @@ -1569,7 +1569,7 @@ static int truncate_f(BlockBackend *blk, int argc, char **argv)
>          return 0;
>      }
>  
> -    ret = blk_truncate(blk, offset);
> +    ret = blk_truncate(blk, offset, NULL);
>      if (ret < 0) {
>          printf("truncate: %s\n", strerror(-ret));
>          return 0;

Come on, using NULL immediately before a printf()? Doing the right thing
here is trivial.

Kevin