1 files changed, 14 insertions, 3 deletions

diff --git a/util-linux/mkfs_vfat.c b/util-linux/mkfs_vfat.c
index 705c75c20..72c2058b5 100644
--- a/util-linux/mkfs_vfat.c
+++ b/util-linux/mkfs_vfat.c
@@ -323,9 +323,20 @@ int mkfs_vfat_main(int argc UNUSED_PARAM, char **argv)
                          * fs size <=  16G: 8k clusters
                          * fs size >   16G: 16k clusters
                          */
-                        sect_per_clust = volume_size_bytes >= ((off_t)16)*1024*1024*1024 ? 32 :
-                                        volume_size_bytes >= ((off_t)8)*1024*1024*1024 ? 16 :
-                                        volume_size_bytes >=        260*1024*1024 ? 8 : 1;
+                        sect_per_clust = 1;
+                        if (volume_size_bytes >= 260*1024*1024) {
+                                sect_per_clust = 8;
+                                /* fight gcc: */
+                                /* "error: integer overflow in expression" */
+                                /* "error: right shift count >= width of type" */
+                                if (sizeof(off_t) > 4) {
+                                        unsigned t = (volume_size_bytes >> 31 >> 1);
+                                        if (t >= 8/4)
+                                                sect_per_clust = 16;
+                                        if (t >= 16/4)
+                                                sect_per_clust = 32;
+                                }
+                        }
                 } else {
                         // floppy, loop, or regular file
                         int not_floppy = ioctl(dev, FDGETPRM, &param);