Re: [Xen-devel] [PATCH 3/4] xen-blkback: check the number of iovecs before allocating a bios

["Roger Pau Monné" <roger.pau@citrix.com>]

On 21/06/13 13:46, Jan Beulich wrote:
>>>> On 21.06.13 at 12:56, Roger Pau Monne <roger.pau@citrix.com> wrote:
>> @@ -1236,7 +1236,8 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
>>  				     seg[i].nsec << 9,
>>  				     seg[i].offset) == 0)) {
>>  
>> -			bio = bio_alloc(GFP_KERNEL, nseg-i);
>> +			int nr_iovecs = (nseg-i) > BIO_MAX_PAGES ? BIO_MAX_PAGES : (nseg-i);
> 
> I'm sure this results in a compiler warning (declaration after
> statement).

No, because it's the first statement inside the while loop.

> And it surely would read much better if you used some form of
> min() - the shorter line would at once allow you to properly
> blank separate operands from operators.

Sure, I will switch it to min, thanks for the comments.

> 
> Jan
> 
>> +			bio = bio_alloc(GFP_KERNEL, nr_iovecs);
>>  			if (unlikely(bio == NULL))
>>  				goto fail_put_bio;
>>  
> 
>