sfdisk: setting default geometry values

The cfdisk and fdisk set defaults for heads and sectors in order to handle a
situation when the get_geometry() ends up with zeroes for the disk geometry for
device-mapper devices. This patch add same functionally to sfdisk.

You know that a dmsetup setgeometry of the the dm device can be used to
circumvent the issue but users may not immediately realize they need to do
that.

diff --git a/fdisk/sfdisk.c b/fdisk/sfdisk.c
index 79e9c20eeae47891a01bf3e938268c3b273c0fc0..baacc077644f64ecbcd3105c42d8994b19b27d59 100644 (file)
--- a/fdisk/sfdisk.c
+++ b/fdisk/sfdisk.c
@@ -469,8 +469,8 @@ get_cylindersize(char *dev, int fd, int silent) {
 
     R = get_geometry(dev, fd, silent);
 
-    B.heads = (U.heads ? U.heads : R.heads);
-    B.sectors = (U.sectors ? U.sectors : R.sectors);
+    B.heads = (U.heads ? U.heads : R.heads ? R.heads : 255);
+    B.sectors = (U.sectors ? U.sectors : R.sectors ? R.sectors : 63);
     B.cylinders = (U.cylinders ? U.cylinders : R.cylinders);
 
     B.cylindersize = B.heads * B.sectors;