+/**
+ * blkdev_issue_flush - queue a flush
+ * @bdev: blockdev to issue flush for
+ * @error_sector: error sector
+ *
+ * Description:
+ * Issue a flush for the block device in question. Caller can supply
+ * room for storing the error offset in case of a flush error, if they
+ * wish to. Caller must run wait_for_completion() on its own.
+ */
+int blkdev_issue_flush(struct block_device *bdev, sector_t *error_sector)
+{
+ request_queue_t *q;
+
+ if (bdev->bd_disk == NULL)
+ return -ENXIO;
+
+ q = bdev_get_queue(bdev);
+ if (!q)
+ return -ENXIO;
+ if (!q->issue_flush_fn)
+ return -EOPNOTSUPP;
+
+ return q->issue_flush_fn(q, bdev->bd_disk, error_sector);
+}
+
+EXPORT_SYMBOL(blkdev_issue_flush);
+
+/**
+ * blkdev_scsi_issue_flush_fn - issue flush for SCSI devices
+ * @q: device queue
+ * @disk: gendisk
+ * @error_sector: error offset
+ *
+ * Description:
+ * Devices understanding the SCSI command set, can use this function as
+ * a helper for issuing a cache flush. Note: driver is required to store
+ * the error offset (in case of error flushing) in ->sector of struct
+ * request.
+ */
+int blkdev_scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk,
+ sector_t *error_sector)
+{
+ struct request *rq = blk_get_request(q, WRITE, __GFP_WAIT);
+ int ret;
+
+ rq->flags |= REQ_BLOCK_PC | REQ_SOFTBARRIER;
+ rq->sector = 0;
+ memset(rq->cmd, 0, sizeof(rq->cmd));
+ rq->cmd[0] = 0x35;
+ rq->cmd_len = 12;
+ rq->data = NULL;
+ rq->data_len = 0;
+ rq->timeout = 60 * HZ;
+
+ ret = blk_execute_rq(q, disk, rq);
+
+ if (ret && error_sector)
+ *error_sector = rq->sector;
+
+ blk_put_request(rq);
+ return ret;
+}
+
+EXPORT_SYMBOL(blkdev_scsi_issue_flush_fn);
+