From 727f7bfa4995b79c16f836f14eea98404bb9e213 Mon Sep 17 00:00:00 2001
From: Milan Broz <mbroz@redhat.com>
Date: Thu, 19 Aug 2010 23:08:18 +0000
Subject: [PATCH] Detect LUKS signature in pvcreate

One shiny day we should use libblkid here. But now using LUKS is
very common together with LVM and pvcreate destroys LUKS completely.

So for user's convenience, try to detect LUKS signature and allow abort.
---
 WHATS_NEW               |  1 +
 lib/Makefile.in         |  1 +
 lib/device/dev-luks.c   | 43 +++++++++++++++++++++++++++++++++++++++++
 lib/device/device.h     |  1 +
 lib/metadata/metadata.c |  3 +++
 5 files changed, 49 insertions(+)
 create mode 100644 lib/device/dev-luks.c

diff --git a/WHATS_NEW b/WHATS_NEW
index 70821da05..848b696af 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -3,6 +3,7 @@ Version 2.02.74 -
   Simplify MD/swap signature detection in pvcreate and allow aborting.
   Remove assumption that --yes must be used only in --force mode.
   Fix file descriptor leak in swap signature detection error path.
+  Detect and allow abort in pvcreate if LUKS signature is detected.
 
 Version 2.02.73 - 18th August 2010
 ==================================
diff --git a/lib/Makefile.in b/lib/Makefile.in
index ae8104053..1c58bdd8c 100644
--- a/lib/Makefile.in
+++ b/lib/Makefile.in
@@ -47,6 +47,7 @@ SOURCES =\
 	device/dev-io.c \
 	device/dev-md.c \
 	device/dev-swap.c \
+	device/dev-luks.c \
 	device/device.c \
 	display/display.c \
 	error/errseg.c \
diff --git a/lib/device/dev-luks.c b/lib/device/dev-luks.c
new file mode 100644
index 000000000..6337992e5
--- /dev/null
+++ b/lib/device/dev-luks.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2010 Red Hat, Inc. All rights reserved.
+ *
+ * This file is part of LVM2.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU Lesser General Public License v.2.1.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "lib.h"
+#include "metadata.h"
+
+#define LUKS_SIGNATURE "LUKS\xba\xbe"
+#define LUKS_SIGNATURE_SIZE 6
+
+int dev_is_luks(struct device *dev, uint64_t *signature)
+{
+	char buf[LUKS_SIGNATURE_SIZE];
+	int ret = -1;
+
+	if (!dev_open(dev)) {
+		stack;
+		return -1;
+	}
+
+	*signature = 0;
+
+	if (!dev_read(dev, 0, LUKS_SIGNATURE_SIZE, buf))
+		goto_out;
+
+	ret = memcmp(buf, LUKS_SIGNATURE, LUKS_SIGNATURE_SIZE) ? 0 : 1;
+
+out:
+	if (!dev_close(dev))
+		stack;
+
+	return ret;
+}
diff --git a/lib/device/device.h b/lib/device/device.h
index 8bf33e658..5a5995086 100644
--- a/lib/device/device.h
+++ b/lib/device/device.h
@@ -96,6 +96,7 @@ const char *dev_name_confirmed(struct device *dev, int quiet);
 /* Does device contain md superblock?  If so, where? */
 int dev_is_md(struct device *dev, uint64_t *sb);
 int dev_is_swap(struct device *dev, uint64_t *signature);
+int dev_is_luks(struct device *dev, uint64_t *signature);
 unsigned long dev_md_stripe_width(const char *sysfs_dir, struct device *dev);
 
 int is_partitioned_dev(struct device *dev);
diff --git a/lib/metadata/metadata.c b/lib/metadata/metadata.c
index db196d647..ed00ffa18 100644
--- a/lib/metadata/metadata.c
+++ b/lib/metadata/metadata.c
@@ -1640,6 +1640,9 @@ static int pvcreate_check(struct cmd_context *cmd, const char *name,
 	if (!_wipe_sb(dev, "swap signature", name, 10, pp, dev_is_swap))
 		return 0;
 
+	if (!_wipe_sb(dev, "LUKS signature", name, 8, pp, dev_is_luks))
+		return 0;
+
 	if (sigint_caught())
 		return 0;