Re: [Qemu-stable] [Qemu-devel] [PATCH 1/1] block: fix possible return code clobbering in bdrv_co_pdiscard

[Eric Blake]

On 07/10/2017 03:35 AM, Denis V. Lunev wrote:
> Signed-off-by: Denis V. Lunev <address@hidden>
> CC: Stefan Hajnoczi <address@hidden> (supporter:Block I/O path)
> CC: Fam Zheng <address@hidden> (supporter:Block I/O path)

The commit message is a bit sparse; I might have written:

block: fix shadowed variable in bdrv_co_pdiscard

We've had a shadowed 'ret' variable, which risks returning the wrong
value, introduced in commit b9c64947.

> ---
>  block/io.c | 1 -
>  1 file changed, 1 deletion(-)

Adding qemu-stable in cc, and you can add:
Reviewed-by: Eric Blake <address@hidden>

[and I wonder why gcc doesn't flag the shadowed variable for me - I
definitely touched that code in commit 9f1963b3, but didn't notice that
I kept the shadowing in place.  I guess we don't have that compiler
warning flag turned on for default configuration]

> 
> diff --git a/block/io.c b/block/io.c
> index ed31810c0a..e5c6dc77d3 100644
> --- a/block/io.c
> +++ b/block/io.c
> @@ -2464,7 +2464,6 @@ int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, 
> int64_t offset,
>      assert(max_pdiscard >= bs->bl.request_alignment);
>  
>      while (count > 0) {
> -        int ret;
>          int num = count;
>  
>          if (head) {
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

signature.asc
Description: OpenPGP digital signature