+static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
+{
+ u64 start_lba = scmd->request->sector;
+ u64 end_lba = scmd->request->sector + (scsi_bufflen(scmd) / 512);
+ u64 bad_lba;
+ int info_valid;
+
+ if (!blk_fs_request(scmd->request))
+ return 0;
+
+ info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
+ SCSI_SENSE_BUFFERSIZE,
+ &bad_lba);
+ if (!info_valid)
+ return 0;
+
+ if (scsi_bufflen(scmd) <= scmd->device->sector_size)
+ return 0;
+
+ if (scmd->device->sector_size < 512) {
+ /* only legitimate sector_size here is 256 */
+ start_lba <<= 1;
+ end_lba <<= 1;
+ } else {
+ /* be careful ... don't want any overflows */
+ u64 factor = scmd->device->sector_size / 512;
+ do_div(start_lba, factor);
+ do_div(end_lba, factor);
+ }
+
+ /* The bad lba was reported incorrectly, we have no idea where
+ * the error is.
+ */
+ if (bad_lba < start_lba || bad_lba >= end_lba)
+ return 0;
+
+ /* This computation should always be done in terms of
+ * the resolution of the device's medium.
+ */
+ return (bad_lba - start_lba) * scmd->device->sector_size;
+}
+