From: Karel Zak <kzak@redhat.com>
Date: Tue, 4 Dec 2012 13:49:17 +0000 (+0100)
Subject: fdisk: (gpt) use topology to define FirstUsableLBA
X-Git-Tag: v2.23-rc1~455
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b41846909f7ea7f2445f71c5cbedcb140410d1fd;p=thirdparty%2Futil-linux.git

fdisk: (gpt) use topology to define FirstUsableLBA

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

diff --git a/fdisks/gpt.c b/fdisks/gpt.c
index cc20ba937a..21a7cad67d 100644
--- a/fdisks/gpt.c
+++ b/fdisks/gpt.c
@@ -390,7 +390,7 @@ static int gpt_mknew_header_from_bkp(struct fdisk_context *cxt,
 static int gpt_mknew_header(struct fdisk_context *cxt,
 			    struct gpt_header *header, uint64_t lba)
 {
-	uint64_t esz = 0;
+	uint64_t esz = 0, first, last;
 
 	if (!cxt || !header)
 		return -ENOSYS;
@@ -407,8 +407,16 @@ static int gpt_mknew_header(struct fdisk_context *cxt,
 	 */
 	header->npartition_entries     = cpu_to_le32(GPT_NPARTITIONS);
 	header->sizeof_partition_entry = cpu_to_le32(sizeof(struct gpt_entry));
-	header->first_usable_lba       = cpu_to_le64(esz + 2);
-	header->last_usable_lba        = cpu_to_le64(cxt->total_sectors - 2 - esz);
+
+	last = cxt->total_sectors - 2 - esz;
+	first = esz + 2;
+
+	if (first < cxt->first_lba && cxt->first_lba < last)
+		/* Align according to topology */
+		first = cxt->first_lba;
+
+	header->first_usable_lba = cpu_to_le64(first);
+	header->last_usable_lba  = cpu_to_le64(last);
 
 	gpt_mknew_header_common(cxt, header, lba);
 	uuid_generate_random((unsigned char *) &header->disk_guid);