[linux-lvm] [PATCH] automatically filter disks with imsm or ddf superblocks, v2

[Miquel van Smoorenburg <mikevs@xs4all.net>]

According to Miquel van Smoorenburg:
> On 14-09-12 3:35 PM, Alasdair G Kergon wrote:
> [review]
> 
> thanks for the comments. I'll send a v2 soon (after the weekend, probably).

Here's version two of the patch. I've taken your comments into account,
and I've also fixed some wrong assumptions (like size being in sectors,
not bytes). It's been tested on both imsm and ddf formatted disks.

Thanks,

Mike.

#====#

lvm.conf has a setting called md_component_detection, which makes lvm
ignore disks with a linux "md" raid superblock. This patch adds detection
of more raid superblock formats, ddf and imsm.

diff -ruN orig/LVM2.2.02.97/lib/Makefile.in LVM2.2.02.97/lib/Makefile.in
--- orig/LVM2.2.02.97/lib/Makefile.in	2012-08-07 21:05:15.000000000 +0000
+++ LVM2.2.02.97/lib/Makefile.in	2012-09-17 08:38:14.357742657 +0000
@@ -54,6 +54,8 @@
 	device/dev-cache.c \
 	device/dev-io.c \
 	device/dev-md.c \
+	device/dev-ddf.c \
+	device/dev-imsm.c \
 	device/dev-swap.c \
 	device/dev-luks.c \
 	device/device.c \
diff -ruN orig/LVM2.2.02.97/lib/device/dev-ddf.c LVM2.2.02.97/lib/device/dev-ddf.c
--- orig/LVM2.2.02.97/lib/device/dev-ddf.c	1970-01-01 00:00:00.000000000 +0000
+++ LVM2.2.02.97/lib/device/dev-ddf.c	2012-09-17 08:47:21.298861940 +0000
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2004 Luca Berra
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2012 Miquel van Smoorenburg
+ *
+ * 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"
+#include "xlate.h"
+#include "crc.h"
+
+#define DDF_MAGIC 0xDE11DE11
+struct ddf_header {
+	uint32_t magic;
+	uint32_t crc;
+	char guid[24];
+	char revision[8];
+	char padding[472];
+} __attribute__ ((packed));
+
+/*
+ * Returns -1 on error
+ */
+int dev_is_ddf(struct device *dev, uint64_t *sb)
+{
+	struct ddf_header hdr;
+	uint64_t size, sb_offset;
+	uint32_t crc;
+	int ret = 0;
+
+	if (!dev_get_size(dev, &size)) {
+		stack;
+		return -1;
+	}
+
+	if (!dev_open_readonly(dev)) {
+		stack;
+		return -1;
+	}
+
+	/* Also calculate CRC so we have at least 8 bytes to check */
+	sb_offset = (size - 1) << SECTOR_SHIFT;
+	if (dev_read(dev, sb_offset, 512, &hdr) &&
+	    xlate32_be(hdr.magic) == DDF_MAGIC) {
+		crc = xlate32_be(hdr.crc);
+		hdr.crc = 0xffffffff;
+		if (calc_crc(0, (const uint8_t *)&hdr, 512) == crc)
+			ret = 1;
+	}
+
+	if (!dev_close(dev))
+		stack;
+
+	if (ret && sb)
+		*sb = sb_offset;
+
+	return ret;
+}
+
diff -ruN orig/LVM2.2.02.97/lib/device/dev-imsm.c LVM2.2.02.97/lib/device/dev-imsm.c
--- orig/LVM2.2.02.97/lib/device/dev-imsm.c	1970-01-01 00:00:00.000000000 +0000
+++ LVM2.2.02.97/lib/device/dev-imsm.c	2012-09-17 08:47:38.319145785 +0000
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2004 Luca Berra
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2012 Miquel van Smoorenburg
+ *
+ * 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 IMSM_SIGNATURE "Intel Raid ISM Cfg Sig. "
+#define IMSM_SIG_LEN (strlen(IMSM_SIGNATURE))
+
+/*
+ * Returns -1 on error
+ */
+int dev_is_imsm(struct device *dev, uint64_t *sb)
+{
+	char imsm_signature[IMSM_SIG_LEN];
+	uint64_t size, sb_offset;
+	int ret = 0;
+
+	if (!dev_get_size(dev, &size)) {
+		stack;
+		return -1;
+	}
+
+	if (!dev_open_readonly(dev)) {
+		stack;
+		return -1;
+	}
+
+	sb_offset = (size - 2) << SECTOR_SHIFT;
+	if (dev_read(dev, sb_offset, IMSM_SIG_LEN, imsm_signature) &&
+	    memcmp(imsm_signature, IMSM_SIGNATURE, IMSM_SIG_LEN) == 0)
+		ret = 1;
+
+	if (!dev_close(dev))
+		stack;
+
+	if (ret && sb)
+		*sb = sb_offset;
+
+	return ret;
+}
+
diff -ruN orig/LVM2.2.02.97/lib/device/device.h LVM2.2.02.97/lib/device/device.h
--- orig/LVM2.2.02.97/lib/device/device.h	2012-08-07 21:05:15.000000000 +0000
+++ LVM2.2.02.97/lib/device/device.h	2012-09-17 08:38:14.357742656 +0000
@@ -101,6 +101,8 @@
 
 /* Does device contain md superblock?  If so, where? */
 int dev_is_md(struct device *dev, uint64_t *sb);
+int dev_is_ddf(struct device *dev, uint64_t *sb);
+int dev_is_imsm(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);
diff -ruN orig/LVM2.2.02.97/lib/filters/filter-md.c LVM2.2.02.97/lib/filters/filter-md.c
--- orig/LVM2.2.02.97/lib/filters/filter-md.c	2012-08-07 21:05:15.000000000 +0000
+++ LVM2.2.02.97/lib/filters/filter-md.c	2012-09-17 08:49:17.096793026 +0000
@@ -23,20 +23,26 @@
 		      struct device *dev)
 {
 	int ret;
+	const char *sb_type;
 	
 	if (!md_filtering())
 		return 1;
 	
-	ret = dev_is_md(dev, NULL);
+	if ((ret = dev_is_md(dev, NULL)) != 0)
+		sb_type = "ddf";
+	else if ((ret = dev_is_ddf(dev, NULL)) != 0)
+		sb_type = "ddf";
+	else if ((ret = dev_is_imsm(dev, NULL)) != 0)
+		sb_type = "imsm";
 
 	if (ret == 1) {
-		log_debug("%s: Skipping md component device", dev_name(dev));
+		log_debug("%s: Skipping %s component device", dev_name(dev), sb_type);
 		return 0;
 	}
 
 	if (ret < 0) {
-		log_debug("%s: Skipping: error in md component detection",
-			  dev_name(dev));
+		log_debug("%s: Skipping: error in %s component detection",
+			  dev_name(dev), sb_type);
 		return 0;
 	}
 
diff -ruN orig/LVM2.2.02.97/lib/metadata/metadata.c LVM2.2.02.97/lib/metadata/metadata.c
--- orig/LVM2.2.02.97/lib/metadata/metadata.c	2012-08-07 21:05:15.000000000 +0000
+++ LVM2.2.02.97/lib/metadata/metadata.c	2012-09-17 08:38:14.357742656 +0000
@@ -1392,6 +1392,12 @@
 	if (!_wipe_sb(dev, "software RAID md superblock", name, 4, pp, dev_is_md))
 		goto_bad;
 
+	if (!_wipe_sb(dev, "software RAID imsm superblock", name, 1024, pp, dev_is_imsm))
+		goto_bad;
+
+	if (!_wipe_sb(dev, "RAID ddf superblock", name, 512, pp, dev_is_ddf))
+		goto_bad;
+
 	if (!_wipe_sb(dev, "swap signature", name, 10, pp, dev_is_swap))
 		goto_bad;
 
diff -ruN orig/LVM2.2.02.97/man/lvm.conf.5.in LVM2.2.02.97/man/lvm.conf.5.in
--- orig/LVM2.2.02.97/man/lvm.conf.5.in	2012-08-07 21:05:15.000000000 +0000
+++ LVM2.2.02.97/man/lvm.conf.5.in	2012-09-17 08:44:52.296377375 +0000
@@ -130,8 +130,10 @@
 .IP
 \fBmd_component_detection\fP \(em If set to 1, LVM2 will ignore devices
 used as components of software RAID (md) devices by looking for md
-superblocks. This doesn't always work satisfactorily e.g. if a device
-has been reused without wiping the md superblocks first.
+superblocks, ddf (common raid Disk Data Format) superblocks, and imsm
+(Intel Matrix Raid or Intel RST) superblocks.  This doesn't always work
+satisfactorily e.g. if a device has been reused without wiping the raid
+superblocks first.
 .IP
 \fBmd_chunk_alignment\fP \(em If set to 1, and a Physical Volume is placed
 directly upon an md device, LVM2 will align its data blocks with the