fdisk: (dos) move fix order code to fdiskdoslabe.c

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

1 files changed, 133 insertions, 0 deletions

diff --git a/fdisks/fdiskdoslabel.c b/fdisks/fdiskdoslabel.c
index da6526e3f..d174c735a 100644
--- a/fdisks/fdiskdoslabel.c
+++ b/fdisks/fdiskdoslabel.c
@@ -964,6 +964,39 @@ static int dos_set_parttype(
 	return 0;
 }
 
+/*
+ * Check whether partition entries are ordered by their starting positions.
+ * Return 0 if OK. Return i if partition i should have been earlier.
+ * Two separate checks: primary and logical partitions.
+ */
+static int wrong_p_order(int *prev)
+{
+	struct pte *pe;
+	struct partition *p;
+	unsigned int last_p_start_pos = 0, p_start_pos;
+	int i, last_i = 0;
+
+	for (i = 0 ; i < partitions; i++) {
+		if (i == 4) {
+			last_i = 4;
+			last_p_start_pos = 0;
+		}
+		pe = &ptes[i];
+		if ((p = pe->part_table)->sys_ind) {
+			p_start_pos = get_partition_start(pe);
+
+			if (last_p_start_pos > p_start_pos) {
+				if (prev)
+					*prev = last_i;
+				return i;
+			}
+
+			last_p_start_pos = p_start_pos;
+			last_i = i;
+		}
+	}
+	return 0;
+}
 
 static int is_garbage_table(void)
 {
@@ -1047,6 +1080,106 @@ int dos_list_table(struct fdisk_context *cxt,
 	return 0;
 }
 
+/*
+ * Fix the chain of logicals.
+ * extended_offset is unchanged, the set of sectors used is unchanged
+ * The chain is sorted so that sectors increase, and so that
+ * starting sectors increase.
+ *
+ * After this it may still be that cfdisk doesn't like the table.
+ * (This is because cfdisk considers expanded parts, from link to
+ * end of partition, and these may still overlap.)
+ * Now
+ *   sfdisk /dev/hda > ohda; sfdisk /dev/hda < ohda
+ * may help.
+ */
+static void fix_chain_of_logicals(void)
+{
+	int j, oj, ojj, sj, sjj;
+	struct partition *pj,*pjj,tmp;
+
+	/* Stage 1: sort sectors but leave sector of part 4 */
+	/* (Its sector is the global extended_offset.) */
+ stage1:
+	for (j = 5; j < partitions-1; j++) {
+		oj = ptes[j].offset;
+		ojj = ptes[j+1].offset;
+		if (oj > ojj) {
+			ptes[j].offset = ojj;
+			ptes[j+1].offset = oj;
+			pj = ptes[j].part_table;
+			set_start_sect(pj, get_start_sect(pj)+oj-ojj);
+			pjj = ptes[j+1].part_table;
+			set_start_sect(pjj, get_start_sect(pjj)+ojj-oj);
+			set_start_sect(ptes[j-1].ext_pointer,
+				       ojj-extended_offset);
+			set_start_sect(ptes[j].ext_pointer,
+				       oj-extended_offset);
+			goto stage1;
+		}
+	}
+
+	/* Stage 2: sort starting sectors */
+ stage2:
+	for (j = 4; j < partitions-1; j++) {
+		pj = ptes[j].part_table;
+		pjj = ptes[j+1].part_table;
+		sj = get_start_sect(pj);
+		sjj = get_start_sect(pjj);
+		oj = ptes[j].offset;
+		ojj = ptes[j+1].offset;
+		if (oj+sj > ojj+sjj) {
+			tmp = *pj;
+			*pj = *pjj;
+			*pjj = tmp;
+			set_start_sect(pj, ojj+sjj-oj);
+			set_start_sect(pjj, oj+sj-ojj);
+			goto stage2;
+		}
+	}
+
+	/* Probably something was changed */
+	for (j = 4; j < partitions; j++)
+		ptes[j].changed = 1;
+}
+
+void dos_fix_partition_table_order(void)
+{
+	struct pte *pei, *pek;
+	int i,k;
+
+	if (!wrong_p_order(NULL)) {
+		printf(_("Nothing to do. Ordering is correct already.\n\n"));
+		return;
+	}
+
+	while ((i = wrong_p_order(&k)) != 0 && i < 4) {
+		/* partition i should have come earlier, move it */
+		/* We have to move data in the MBR */
+		struct partition *pi, *pk, *pe, pbuf;
+		pei = &ptes[i];
+		pek = &ptes[k];
+
+		pe = pei->ext_pointer;
+		pei->ext_pointer = pek->ext_pointer;
+		pek->ext_pointer = pe;
+
+		pi = pei->part_table;
+		pk = pek->part_table;
+
+		memmove(&pbuf, pi, sizeof(struct partition));
+		memmove(pi, pk, sizeof(struct partition));
+		memmove(pk, &pbuf, sizeof(struct partition));
+
+		pei->changed = pek->changed = 1;
+	}
+
+	if (i)
+		fix_chain_of_logicals();
+
+	printf(_("Done.\n"));
+
+}
 
 
 static const struct fdisk_label_operations dos_operations =