drbd: fix potential wrap of 32bit oos:%lu display in /proc/drbd

When converting bits (4k resolution, still) to kB, we shift left.  If it
was a large number of bits on a 32bit box (>= 4 TiB storage), we may
wrap the 32bit unsigned long base type, resulting in incorrect display.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/block/drbd/drbd_proc.c b/drivers/block/drbd/drbd_proc.c
index fab3fde3477b..07368b75392a 100644
--- a/drivers/block/drbd/drbd_proc.c
+++ b/drivers/block/drbd/drbd_proc.c
@@ -259,8 +259,9 @@ static int drbd_seq_show(struct seq_file *seq, void *v)
                            mdev->epochs,
                            write_ordering_chars[mdev->write_ordering]
                         );
-                        seq_printf(seq, " oos:%lu\n",
-                                   Bit2KB(drbd_bm_total_weight(mdev)));
+                        seq_printf(seq, " oos:%llu\n",
+                                   Bit2KB((unsigned long long)
+                                           drbd_bm_total_weight(mdev)));
                 }
                 if (mdev->state.conn == C_SYNC_SOURCE ||
                     mdev->state.conn == C_SYNC_TARGET ||