From 565b7da63e87211ef78a7b4e67dcc66119813640 Mon Sep 17 00:00:00 2001
From: Karel Zak
Date: Wed, 9 Oct 2013 16:02:42 +0200
Subject: fdisk: add -t <type> to enable only specified type

In some cases (for example hybrid GPT) it's useful to force fdisk to
read only specified disk label and ignore everything else.

For example:

	# fdisk -l /dev/sda

	Disk /dev/sda: 149.1 GiB, 160041885696 bytes, 312581808 sectors
	Units: sectors of 1 * 512 = 512 bytes
	Sector size (logical/physical): 512 bytes / 512 bytes
	I/O size (minimum/optimal): 512 bytes / 512 bytes
	Disklabel type: gpt
	Disk identifier: 3549290F-417C-4941-8503-F7835109B821

	Device           Start          End   Size Type
	/dev/sda1         2048      2050047  1000M EFI System
	/dev/sda2      2050048      6146047     2G Microsoft basic data
	/dev/sda3      6146048     26462207   9.7G Linux swap
	/dev/sda4     26462208     98142207  34.2G Microsoft basic data
	/dev/sda5     98142208    230662143  63.2G Microsoft basic data
	/dev/sda6    230662144    312580095  39.1G Microsoft basic data

but when GPT is disabled we can access PMBR:

	# fdisk -l -t dos /dev/sda

	Disk /dev/sda: 149.1 GiB, 160041885696 bytes, 312581808 sectors
	Units: sectors of 1 * 512 = 512 bytes
	Sector size (logical/physical): 512 bytes / 512 bytes
	I/O size (minimum/optimal): 512 bytes / 512 bytes
	Disklabel type: dos
	Disk identifier: 0x00000000

	Device    Boot Start       End    Blocks  Id System
	/dev/sda1          1 312581807 156290903+ ee GPT

Reported-by: Craig <util-linux_contact@magister.com.au>
Signed-off-by: Karel Zak <kzak@redhat.com>
---
 fdisks/fdisk.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

(limited to 'fdisks/fdisk.c')

diff --git a/fdisks/fdisk.c b/fdisks/fdisk.c
index 50f3d412a..5df78f6a5 100644
--- a/fdisks/fdisk.c
+++ b/fdisks/fdisk.c
@@ -60,6 +60,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE *out)
 	fputs(_(" -h                print this help text\n"), out);
 	fputs(_(" -c[=<mode>]       compatible mode: 'dos' or 'nondos' (default)\n"), out);
 	fputs(_(" -L[=<when>]       colorize output (auto, always or never)\n"), out);
+	fputs(_(" -t <type>         force fdisk to recognize specified partition table type only\n"), out);
 	fputs(_(" -u[=<unit>]       display units: 'cylinders' or 'sectors' (default)\n"), out);
 	fputs(_(" -v                print program version\n"), out);
 	fputs(_(" -C <number>       specify the number of cylinders\n"), out);
@@ -410,7 +411,7 @@ int main(int argc, char **argv)
 
 	fdisk_context_set_ask(cxt, ask_callback, NULL);
 
-	while ((c = getopt(argc, argv, "b:c::C:hH:lL::sS:u::vV")) != -1) {
+	while ((c = getopt(argc, argv, "b:c::C:hH:lL::sS:t:u::vV")) != -1) {
 		switch (c) {
 		case 'b':
 		{
@@ -465,6 +466,18 @@ int main(int argc, char **argv)
 		case 's':
 			act = ACT_SHOWSIZE;
 			break;
+		case 't':
+		{
+			struct fdisk_label *lb = NULL;
+
+			while (fdisk_context_next_label(cxt, &lb) == 0)
+				fdisk_label_set_disabled(lb, 1);
+
+			lb = fdisk_context_get_label(cxt, optarg);
+			if (!lb)
+				errx(EXIT_FAILURE, _("unsupported disklabel: %s"), optarg);
+			fdisk_label_set_disabled(lb, 0);
+		}
 		case 'u':
 			if (optarg && *optarg == '=')
 				optarg++;
-- 
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