Re: [Qemu-devel] [PATCH v2 5/5] block/vpc: remove disabled code from get_sector_offset

[Max Reitz <mreitz@redhat.com>]

On 2015-03-03 at 05:41, Peter Lieven wrote:
> The code to check the bitmap for the allocation status of each sector
> has been "disabled by reason" ever since the vpc driver existed.
>
> The reason might be that we might end up reading sector by sector
> in vpc_read if we really used it. This would be a performance desaster.
>
> The current code would furthermore not work if the disabled parts get
> reactivated since vpc_read and vpc_write only use get_sector_offset to
> check the allocation status of the first sector of a read/write operation.
> This might lead to sectors incorrectly treated as zero in vpc_read and
> to sectors getting allocated twice in vpc_write.
>
> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>   block/vpc.c | 32 --------------------------------
>   1 file changed, 32 deletions(-)

Awww, that code nearly had its ten-year anniversary. Too bad it won't 
live to see it (I hope...).

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