Abstract init_gh() and init_gp() from GPT_init().

Restore original gh/gp if initialization fails.

No other functional change.

diff --git a/sbin/fdisk/gpt.c b/sbin/fdisk/gpt.c
index e7a5658..352c88e 100644 (file)
--- a/sbin/fdisk/gpt.c
+++ b/sbin/fdisk/gpt.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: gpt.c,v 1.24 2021/06/12 17:19:13 krw Exp $    */
+/*     $OpenBSD: gpt.c,v 1.25 2021/06/12 17:49:00 krw Exp $    */
 /*
  * Copyright (c) 2015 Markus Muller <mmu@grummel.net>
  * Copyright (c) 2015 Kenneth R Westerback <krw@openbsd.org>
@@ -48,6 +48,8 @@ int                     lba_free(uint64_t *, uint64_t *);
 int                      add_partition(const uint8_t *, const char *, uint64_t);
 int                      get_header(off_t);
 int                      get_partition_table(void);
+int                      init_gh(void);
+int                      init_gp(void);
 
 int
 get_header(off_t where)
@@ -367,21 +369,19 @@ add_partition(const uint8_t *beuuid, const char *name, uint64_t sectors)
 }
 
 int
-GPT_init(void)
+init_gh(void)
 {
-       extern uint32_t b_arg;
-       const int secsize = unit_types[SECTORS].conversion;
-       struct uuid guid;
-       int needed, rslt;
-       uint32_t status;
-       const uint8_t gpt_uuid_efi_system[] = GPT_UUID_EFI_SYSTEM;
-       const uint8_t gpt_uuid_openbsd[] = GPT_UUID_OPENBSD;
+       const int               secsize = unit_types[SECTORS].conversion;
+       struct gpt_header       oldgh;
+       struct uuid             guid;
+       int                     needed;
+       uint32_t                status;
 
-       memset(&gh, 0, sizeof(gh));
-       memset(&gp, 0, sizeof(gp));
+       memcpy(&oldgh, &gh, sizeof(oldgh));
 
-       needed = sizeof(gp) / secsize + 2;
-       /* Start on 64 sector boundary */
+       needed = sizeof(gh) / secsize + 2;
+
+       /* Start usable LBA area on 64 sector boundary. */
        if (needed % 64)
                needed += (64 - (needed % 64));
 
@@ -399,9 +399,25 @@ GPT_init(void)
        gh.gh_part_size = htole32(GPTMINPARTSIZE);
 
        uuid_create(&guid, &status);
-       if (status != uuid_s_ok)
-               return (1);
+       if (status != uuid_s_ok) {
+               memcpy(&gh, &oldgh, sizeof(gh));
+               return 1;
+       }
+
        uuid_enc_le(&gh.gh_guid, &guid);
+       return 0;
+}
+
+int
+init_gp(void)
+{
+       extern uint32_t b_arg;
+       const uint8_t gpt_uuid_efi_system[] = GPT_UUID_EFI_SYSTEM;
+       const uint8_t gpt_uuid_openbsd[] = GPT_UUID_OPENBSD;
+       struct gpt_partition oldgp[NGPTPARTITIONS];
+       int rslt;
+
+       memcpy(&oldgp, &gp, sizeof(oldgp));
 
        rslt = 0;
        if (b_arg > 0) {
@@ -411,6 +427,21 @@ GPT_init(void)
        if (rslt == 0)
                rslt = add_partition(gpt_uuid_openbsd, "OpenBSD Area", 0);
 
+       if (rslt != 0)
+               memcpy(&gp, &oldgp, sizeof(gp));
+
+       return rslt;
+}
+
+int
+GPT_init(void)
+{
+       int rslt;
+
+       rslt = init_gh();
+       if (rslt == 0)
+               rslt = init_gp();
+
        return rslt;
 }