Re: [Qemu-devel] [PATCH v2 14/17] raw-posix: return get_block_status data and flags

[Eric Blake]

On 07/16/2013 10:29 AM, Paolo Bonzini wrote:
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>  block/raw-posix.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 

> +++ b/block/raw-posix.c
> @@ -1089,7 +1089,7 @@ static int64_t coroutine_fn 
> raw_co_get_block_status(BlockDriverState *bs,
>                                              int nb_sectors, int *pnum)
>  {
>      off_t start, data, hole;
> -    int ret;
> +    int64_t ret;
>  
>      ret = fd_open(bs);
>      if (ret < 0) {
> @@ -1097,6 +1097,7 @@ static int64_t coroutine_fn 
> raw_co_get_block_status(BlockDriverState *bs,
>      }
>  
>      start = sector_num * BDRV_SECTOR_SIZE;
> +    ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start;

off_t is a signed type; if you are compiling on a platform with 32-bit
off_t, is it possible that you will get unintended sign extension for
values of 'start' between 2 and 4 GB?  Or are such files already
impossible to open?  [Or do we intentionally require off_t be 64-bits on
all platforms we care about?]

Reviewed-by: Eric Blake <address@hidden>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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