From: Baolin Wang <baolin.wang@linaro.org>
Subject: Re: [RFC v2 1/3] block: Introduce blk_bio_map_sg() to map one bio
Date: Mon, 6 Jun 2016 13:04:17 +0800
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To: Jens Axboe <axboe@kernel.dk>
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On 3 June 2016 at 22:38, Jens Axboe <axboe@kernel.dk> wrote:
> On 05/27/2016 05:11 AM, Baolin Wang wrote:
>>
>> +/*
>> + * Map a bio to scatterlist, return number of sg entries setup. Caller
>> must
>> + * make sure sg can hold bio segments entries.
>> + */
>> +int blk_bio_map_sg(struct request_queue *q, struct bio *bio,
>> +                  struct scatterlist *sglist)
>> +{
>> +       struct scatterlist *sg = NULL;
>> +       int nsegs = 0;
>> +
>> +       if (bio)
>> +               nsegs = __blk_bios_map_sg(q, bio, sglist, &sg, true);
>> +
>> +       if (sg)
>> +               sg_mark_end(sg);
>
>
> Put that if (sg) inside the if (bio) section, 'sg' isn't going to be
> non-NULL outside of that.
>
> Additionally, who would call this with a NULL bio? That seems odd, I'd
> get rid of that check completely.

OK. I'll fix these in next version. Thanks for your comments.

-- 
Baolin.wang
Best Regards