drbd: allow petabyte storage on 64bit arch

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

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 77dc022eaf6b..a46bc0287e21 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -527,17 +527,19 @@ static void drbd_md_set_sector_offsets(struct drbd_conf *mdev,
         }
 }
 
+/* input size is expected to be in KB */
 char *ppsize(char *buf, unsigned long long size)
 {
-        /* Needs 9 bytes at max. */
+        /* Needs 9 bytes at max including trailing NUL:
+         * -1ULL ==> "16384 EB" */
         static char units[] = { 'K', 'M', 'G', 'T', 'P', 'E' };
         int base = 0;
-        while (size >= 10000) {
+        while (size >= 10000 && base < sizeof(units)-1) {
                 /* shift + round */
                 size = (size >> 10) + !!(size & (1<<9));
                 base++;
         }
-        sprintf(buf, "%lu %cB", (long)size, units[base]);
+        sprintf(buf, "%u %cB", (unsigned)size, units[base]);
 
         return buf;
 }