On 3 June 2016 at 22:38, Jens Axboe [off-list ref] wrote:

On 05/27/2016 05:11 AM, Baolin Wang wrote:

quoted

+/*
+ * 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