Re: [Qemu-devel] [PATCH v2 4/4] raw-posix: Clean up around raw_co_get_block_status()

[Max Reitz <mreitz@redhat.com>]

On 2014-11-13 at 11:17, Markus Armbruster wrote:
> try_seek_hole() doesn't really seek to a hole, it tries to find out
> whether its argument is in a hole or not, and where the hole or
> non-hole ends.  Rename to find_allocation() and add a proper function
> comment.
>
> Using arguments passed by reference like local variables is a bad
> habit.  Only assign to them right before return.
>
> Avoid nesting of conditionals.
>
> When find_allocation() fails, don't make up a range that'll get mapped
> to nb_sectors, simply set *pnum = nb_sectors directly.
>
> Don't repeat BDRV_BLOCK_OFFSET_VALID | start.
>
> Drop a pointless assertion, add some meaningful ones.
>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>   block/raw-posix.c | 62 +++++++++++++++++++++++++++++++++----------------------
>   1 file changed, 37 insertions(+), 25 deletions(-)
>
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index 2a12a50..ea5b3b8 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c
> @@ -1478,28 +1478,43 @@ out:
>       return result;
>   }
>   
> -static int try_seek_hole(BlockDriverState *bs, off_t start, off_t *data,
> -                         off_t *hole)
> +/*
> + * Find allocation range in @bs around offset @start.
> + * If @start is in a hole, store @start in @hole and the end of the
> + * hole in @data, and return 0.
> + * If @start is in a data, store @start to @data, and the end of the

"is in a data" sounds funny enough I'd even like to keep it. Probably 
should be "data extent" or something similar.

> + * data to @hole, and return 0.

Here, too.

With or without that changed:

Reviewed-by: Max Reitz <mreitz@redhat.com>