1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index d8e2caf9f468..365024b0c407 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1188,6 +1188,12 @@ 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 (scmd->request->cmd_type != REQ_TYPE_FS)
                 return 0;
@@ -1221,7 +1227,8 @@ 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);
 }
 
 /**