]> git.kernelconcepts.de Git - karo-tx-linux.git/blobdiff - block/blk-merge.c
GFS2: Don't call file_accessed() with a shared glock
[karo-tx-linux.git] / block / blk-merge.c
index 576b68e792487493fed68a440743f15551f1b782..e76279e411622519eebb54d4802eb11b796788db 100644 (file)
@@ -209,6 +209,43 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
 }
 EXPORT_SYMBOL(blk_rq_map_sg);
 
+/**
+ * blk_bio_map_sg - map a bio to a scatterlist
+ * @q: request_queue in question
+ * @bio: bio being mapped
+ * @sglist: scatterlist being mapped
+ *
+ * Note:
+ *    Caller must make sure sg can hold bio->bi_phys_segments entries
+ *
+ * Will return the number of sg entries setup
+ */
+int blk_bio_map_sg(struct request_queue *q, struct bio *bio,
+                  struct scatterlist *sglist)
+{
+       struct bio_vec *bvec, *bvprv;
+       struct scatterlist *sg;
+       int nsegs, cluster;
+       unsigned long i;
+
+       nsegs = 0;
+       cluster = blk_queue_cluster(q);
+
+       bvprv = NULL;
+       sg = NULL;
+       bio_for_each_segment(bvec, bio, i) {
+               __blk_segment_map_sg(q, bvec, sglist, &bvprv, &sg,
+                                    &nsegs, &cluster);
+       } /* segments in bio */
+
+       if (sg)
+               sg_mark_end(sg);
+
+       BUG_ON(bio->bi_phys_segments && nsegs > bio->bi_phys_segments);
+       return nsegs;
+}
+EXPORT_SYMBOL(blk_bio_map_sg);
+
 static inline int ll_new_hw_segment(struct request_queue *q,
                                    struct request *req,
                                    struct bio *bio)