drbd: fix decoding of bitmap vli rle for device sizes > 64 TB

[karo-tx-linux.git] / drivers / block / drbd / drbd_receiver.c

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 12c59eb3b1274ef7f7c9fe0ac5f854eea10f722a..6fa6673b36b396765b58142e8e8abcdc4beaae05 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -4125,7 +4125,11 @@ recv_bm_rle_bits(struct drbd_conf *mdev,
                                (unsigned int)bs.buf_len);
                        return -EIO;
                }
-               look_ahead >>= bits;
+               /* if we consumed all 64 bits, assign 0; >> 64 is "undefined"; */
+               if (likely(bits < 64))
+                       look_ahead >>= bits;
+               else
+                       look_ahead = 0;
                have -= bits;
 
                bits = bitstream_get_bits(&bs, &tmp, 64 - have);