Re: [Qemu-devel] [PATCH v3 18/22] block: Drop raw_refresh_limits()

[Fam Zheng <famz@redhat.com>]

On Thu, 06/23 16:37, Eric Blake wrote:
> The raw block driver was blindly copying all limits from bs->file,
> even though: 1. the main bdrv_refresh_limits() already does this
> for many of the limits, and 2. blindly copying from the children
> can weaken any stricter limits that were already inherited from
> the backing chain during the main bdrv_refresh_limits().  Also,
> a future patch is about to move .request_alignment into
> BlockLimits, and that is a limit that should NOT be copied from
> other layers in the BDS chain.
> 
> Thus, we can completely drop raw_refresh_limits(), and rely on
> the block layer setting up the proper limits.
> 
> Signed-off-by: Eric Blake <eblake@redhat.com>
> 
> ---
> v3: new patch, split out from 'block: Split bdrv_merge_limits()...'
> ---
>  block/raw_bsd.c | 8 +-------
>  1 file changed, 1 insertion(+), 7 deletions(-)
> 
> diff --git a/block/raw_bsd.c b/block/raw_bsd.c
> index 7f63791..5855e84 100644
> --- a/block/raw_bsd.c
> +++ b/block/raw_bsd.c
> @@ -1,6 +1,6 @@
>  /* BlockDriver implementation for "raw"
>   *
> - * Copyright (C) 2010, 2013, Red Hat, Inc.
> + * Copyright (C) 2010-2016 Red Hat, Inc.
>   * Copyright (C) 2010, Blue Swirl <blauwirbel@gmail.com>
>   * Copyright (C) 2009, Anthony Liguori <aliguori@us.ibm.com>
>   *
> @@ -150,11 +150,6 @@ static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
>      return bdrv_get_info(bs->file->bs, bdi);
>  }
> 
> -static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
> -{
> -    bs->bl = bs->file->bs->bl;
> -}
> -
>  static int raw_truncate(BlockDriverState *bs, int64_t offset)
>  {
>      return bdrv_truncate(bs->file->bs, offset);
> @@ -252,7 +247,6 @@ BlockDriver bdrv_raw = {
>      .bdrv_getlength       = &raw_getlength,
>      .has_variable_length  = true,
>      .bdrv_get_info        = &raw_get_info,
> -    .bdrv_refresh_limits  = &raw_refresh_limits,
>      .bdrv_probe_blocksizes = &raw_probe_blocksizes,
>      .bdrv_probe_geometry  = &raw_probe_geometry,
>      .bdrv_media_changed   = &raw_media_changed,
> -- 
> 2.5.5
> 

Reviewed-by: Fam Zheng <famz@redhat.com>