libfdisk: allow to change partition type for extended partitions

Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1248115
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libfdisk/src/dos.c b/libfdisk/src/dos.c
index b9fb77cb78e4e213a9fcaceafd8632885c18f703..4fc68f548c0e3d2aba618ec178ca577377cdc8ec 100644 (file)
--- a/libfdisk/src/dos.c
+++ b/libfdisk/src/dos.c
@@ -1528,7 +1528,7 @@ static int dos_add_partition(struct fdisk_context *cxt,
                goto done;
 
        /* pa specifies that extended partition is wanted */
-       } else if (pa && pa->type && pa->type->code == MBR_DOS_EXTENDED_PARTITION) {
+       } else if (pa && pa->type && IS_EXTENDED(pa->type->code)) {
                DBG(LABEL, ul_debug("DOS: pa template %p: add extened", pa));
                if (l->ext_offset) {
                        fdisk_warnx(cxt, _("Extended partition already exists."));
@@ -1914,11 +1914,25 @@ static int dos_get_partition(struct fdisk_context *cxt, size_t n,
        return 0;
 }
 
+static int has_logical(struct fdisk_context *cxt)
+{
+       size_t i;
+       struct fdisk_dos_label *l = self_label(cxt);
+
+       for (i = 4; i < cxt->label->nparts_max; i++) {
+               if (l->ptes[i].pt_entry)
+                       return 1;
+       }
+       return 0;
+}
+
 static int dos_set_partition(struct fdisk_context *cxt, size_t n,
                             struct fdisk_partition *pa)
 {
+       struct fdisk_dos_label *l;
        struct dos_partition *p;
        struct pte *pe;
+       int orgtype;
        fdisk_sector_t start, size;
 
        assert(cxt);
@@ -1929,17 +1943,29 @@ static int dos_set_partition(struct fdisk_context *cxt, size_t n,
        if (n >= cxt->label->nparts_max)
                return -EINVAL;
 
-       if (pa->type && IS_EXTENDED(pa->type->code)) {
-               fdisk_warnx(cxt, _("You cannot change a partition into an "
-                       "extended one or vice versa. Delete it first."));
-               return -EINVAL;
-       }
-
-       if (pa->type && !pa->type->code)
-               fdisk_warnx(cxt, _("Type 0 means free space to many systems. "
-                                  "Having partitions of type 0 is probably unwise."));
+       l = self_label(cxt);
        p = self_partition(cxt, n);
        pe = self_pte(cxt, n);
+       orgtype = p->sys_ind;
+
+       if (pa->type) {
+               if (IS_EXTENDED(pa->type->code) && l->ext_offset) {
+                       fdisk_warnx(cxt, _("Extended partition already exists."));
+                       return -EINVAL;
+               }
+
+               if (!pa->type->code)
+                       fdisk_warnx(cxt, _("Type 0 means free space to many systems. "
+                                  "Having partitions of type 0 is probably unwise."));
+
+               if (IS_EXTENDED(p->sys_ind) && !IS_EXTENDED(pa->type->code) && has_logical(cxt)) {
+                       fdisk_warnx(cxt, _(
+                               "Cannot change type of the extended partition which is "
+                               "already used by logical partitons. Delete logical "
+                               "partitions first."));
+                       return -EINVAL;
+               }
+       }
 
        FDISK_INIT_UNDEF(start);
        FDISK_INIT_UNDEF(size);
@@ -1970,6 +1996,21 @@ static int dos_set_partition(struct fdisk_context *cxt, size_t n,
                        p->boot_ind = fdisk_partition_is_bootable(pa) ? ACTIVE_FLAG : 0;
        }
 
+       if (pa->type) {
+               if (IS_EXTENDED(pa->type->code) && !IS_EXTENDED(orgtype)) {
+                       /* new extended partition - create a reference  */
+                       l->ext_index = n;
+                       l->ext_offset = dos_partition_get_start(p);
+                       pe->ex_entry = p;
+                } else if (IS_EXTENDED(orgtype)) {
+                       /* remove extended partition */
+                       cxt->label->nparts_max = 4;
+                       l->ptes[l->ext_index].ex_entry = NULL;
+                       l->ext_offset = 0;
+                       l->ext_index = 0;
+                }
+       }
+
        partition_set_changed(cxt, n, 1);
        return 0;
 }