libfdisk: make it possible to reset device properties

 - remember user C/H/S and sector size
 - reset all device properties before create a new label (maybe the
   old setting has been affected by previous on-disk label)
 - always apply user setting after the reset
 - improve topology/geometry debug messages

Note that for fdisk "user C/H/S and sector size" means on command line
specified values. If you override the setting by c/h/s commands in
expert menu then the setting is applied to the current disk label
only. If you create a new disk label (e.g change MBR to GPT) then
fdisk will use the original setting.

Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/libfdisk/src/label.c b/libfdisk/src/label.c
index d518d876d..cabf3d751 100644
--- a/libfdisk/src/label.c
+++ b/libfdisk/src/label.c
@@ -182,6 +182,8 @@ int fdisk_delete_partition(struct fdisk_context *cxt, size_t partnum)
  */
 int fdisk_create_disklabel(struct fdisk_context *cxt, const char *name)
 {
+	int haslabel = 0;
+
 	if (!cxt)
 		return -EINVAL;
 
@@ -193,8 +195,10 @@ int fdisk_create_disklabel(struct fdisk_context *cxt, const char *name)
 #endif
 	}
 
-	if (cxt->label)
+	if (cxt->label) {
 		fdisk_deinit_label(cxt->label);
+		haslabel = 1;
+	}
 
 	cxt->label = fdisk_context_get_label(cxt, name);
 	if (!cxt->label)
@@ -204,7 +208,8 @@ int fdisk_create_disklabel(struct fdisk_context *cxt, const char *name)
 	if (!cxt->label->op->create)
 		return -ENOSYS;
 
-	fdisk_reset_alignment(cxt);
+	if (haslabel)
+		fdisk_reset_device_properties(cxt);
 	return cxt->label->op->create(cxt);
 }