diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 81a9d25ecaba..568d36389259 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1040,6 +1040,12 @@ static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd) u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512); u64 bad_lba; int info_valid; + /* + * resid is optional but mostly filled in. When it's unused, + * its value is zero, so we assume the whole buffer transferred + */ + unsigned int transferred = scsi_bufflen(scmd) - scsi_get_resid(scmd); + unsigned int good_bytes; if (!blk_fs_request(scmd->request)) return 0; @@ -1073,7 +1079,8 @@ static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd) /* 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; + good_bytes = (bad_lba - start_lba) * scmd->device->sector_size; + return min(good_bytes, transferred); } /**