+/*
+ * unmap a request that was previously mapped to this sg_io_hdr. handles
+ * both sg and non-sg sg_io_hdr.
+ */
+static int blk_unmap_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr)
+{
+ blk_rq_unmap_user(rq->bio);
+ blk_put_request(rq);
+ return 0;
+}
+
+static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
+ struct bio *bio)
+{
+ int r, ret = 0;
+
+ /*
+ * fill in all the output members
+ */
+ hdr->status = rq->errors & 0xff;
+ hdr->masked_status = status_byte(rq->errors);
+ hdr->msg_status = msg_byte(rq->errors);
+ hdr->host_status = host_byte(rq->errors);
+ hdr->driver_status = driver_byte(rq->errors);
+ hdr->info = 0;
+ if (hdr->masked_status || hdr->host_status || hdr->driver_status)
+ hdr->info |= SG_INFO_CHECK;
+ hdr->resid = rq->data_len;
+ hdr->sb_len_wr = 0;
+
+ if (rq->sense_len && hdr->sbp) {
+ int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);
+
+ if (!copy_to_user(hdr->sbp, rq->sense, len))
+ hdr->sb_len_wr = len;
+ else
+ ret = -EFAULT;
+ }
+
+ rq->bio = bio;
+ r = blk_unmap_sghdr_rq(rq, hdr);
+ if (ret)
+ r = ret;
+
+ return r;
+}
+
+static int sg_io(struct file *file, struct request_queue *q,