1 files changed, 258 insertions, 0 deletions

diff --git a/libblkid/linux_raid.c b/libblkid/linux_raid.c
new file mode 100644
index 000000000..a3f9d67d5
--- /dev/null
+++ b/libblkid/linux_raid.c
@@ -0,0 +1,258 @@
+/*
+ * Copyright (C) 2008 Karel Zak <kzak@redhat.com>
+ *
+ * Inspired by libvolume_id by
+ *     Kay Sievers <kay.sievers@vrfy.org>
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdint.h>
+
+#include "superblocks.h"
+
+struct mdp0_super_block {
+	uint32_t	md_magic;
+	uint32_t	major_version;
+	uint32_t	minor_version;
+	uint32_t	patch_version;
+	uint32_t	gvalid_words;
+	uint32_t	set_uuid0;
+	uint32_t	ctime;
+	uint32_t	level;
+	uint32_t	size;
+	uint32_t	nr_disks;
+	uint32_t	raid_disks;
+	uint32_t	md_minor;
+	uint32_t	not_persistent;
+	uint32_t	set_uuid1;
+	uint32_t	set_uuid2;
+	uint32_t	set_uuid3;
+};
+
+/*
+ * Version-1, little-endian.
+ */
+struct mdp1_super_block {
+	/* constant array information - 128 bytes */
+	uint32_t	magic;		/* MD_SB_MAGIC: 0xa92b4efc - little endian */
+	uint32_t	major_version;	/* 1 */
+	uint32_t	feature_map;	/* 0 for now */
+	uint32_t	pad0;		/* always set to 0 when writing */
+
+	uint8_t		set_uuid[16];	/* user-space generated. */
+	unsigned char	set_name[32];	/* set and interpreted by user-space */
+
+	uint64_t	ctime;		/* lo 40 bits are seconds, top 24 are microseconds or 0*/
+	uint32_t	level;		/* -4 (multipath), -1 (linear), 0,1,4,5 */
+	uint32_t	layout;		/* only for raid5 currently */
+	uint64_t	size;		/* used size of component devices, in 512byte sectors */
+
+	uint32_t	chunksize;	/* in 512byte sectors */
+	uint32_t	raid_disks;
+	uint32_t	bitmap_offset;	/* sectors after start of superblock that bitmap starts
+					 * NOTE: signed, so bitmap can be before superblock
+					 * only meaningful of feature_map[0] is set.
+					 */
+
+	/* These are only valid with feature bit '4' */
+	uint32_t	new_level;	/* new level we are reshaping to		*/
+	uint64_t	reshape_position;	/* next address in array-space for reshape */
+	uint32_t	delta_disks;	/* change in number of raid_disks		*/
+	uint32_t	new_layout;	/* new layout					*/
+	uint32_t	new_chunk;	/* new chunk size (bytes)			*/
+	uint8_t		pad1[128-124];	/* set to 0 when written */
+
+	/* constant this-device information - 64 bytes */
+	uint64_t	data_offset;	/* sector start of data, often 0 */
+	uint64_t	data_size;	/* sectors in this device that can be used for data */
+	uint64_t	super_offset;	/* sector start of this superblock */
+	uint64_t	recovery_offset;/* sectors before this offset (from data_offset) have been recovered */
+	uint32_t	dev_number;	/* permanent identifier of this  device - not role in raid */
+	uint32_t	cnt_corrected_read; /* number of read errors that were corrected by re-writing */
+	uint8_t		device_uuid[16]; /* user-space setable, ignored by kernel */
+        uint8_t		devflags;        /* per-device flags.  Only one defined...*/
+	uint8_t		pad2[64-57];	/* set to 0 when writing */
+
+	/* array state information - 64 bytes */
+	uint64_t	utime;		/* 40 bits second, 24 btes microseconds */
+	uint64_t	events;		/* incremented when superblock updated */
+	uint64_t	resync_offset;	/* data before this offset (from data_offset) known to be in sync */
+	uint32_t	sb_csum;	/* checksum up to dev_roles[max_dev] */
+	uint32_t	max_dev;	/* size of dev_roles[] array to consider */
+	uint8_t		pad3[64-32];	/* set to 0 when writing */
+
+	/* device state information. Indexed by dev_number.
+	 * 2 bytes per device
+	 * Note there are no per-device state flags. State information is rolled
+	 * into the 'roles' value.  If a device is spare or faulty, then it doesn't
+	 * have a meaningful role.
+	 */
+	uint16_t	dev_roles[0];	/* role in array, or 0xffff for a spare, or 0xfffe for faulty */
+};
+
+
+#define MD_RESERVED_BYTES		0x10000
+#define MD_SB_MAGIC			0xa92b4efc
+
+static int probe_raid0(blkid_probe pr, blkid_loff_t off)
+{
+	struct mdp0_super_block *mdp0;
+	union {
+		uint32_t ints[4];
+		uint8_t bytes[16];
+	} uuid;
+	uint32_t ma, mi, pa;
+	uint64_t size;
+
+	if (pr->size < MD_RESERVED_BYTES)
+		return -1;
+	mdp0 = (struct mdp0_super_block *)
+			blkid_probe_get_buffer(pr,
+				off,
+				sizeof(struct mdp0_super_block));
+	if (!mdp0)
+		return -1;
+
+	memset(uuid.ints, 0, sizeof(uuid.ints));
+
+	if (le32_to_cpu(mdp0->md_magic) == MD_SB_MAGIC) {
+		uuid.ints[0] = swab32(mdp0->set_uuid0);
+		if (le32_to_cpu(mdp0->minor_version) >= 90) {
+			uuid.ints[1] = swab32(mdp0->set_uuid1);
+			uuid.ints[2] = swab32(mdp0->set_uuid2);
+			uuid.ints[3] = swab32(mdp0->set_uuid3);
+		}
+		ma = le32_to_cpu(mdp0->major_version);
+		mi = le32_to_cpu(mdp0->minor_version);
+		pa = le32_to_cpu(mdp0->patch_version);
+		size = le32_to_cpu(mdp0->size);
+
+	} else if (be32_to_cpu(mdp0->md_magic) == MD_SB_MAGIC) {
+		uuid.ints[0] = mdp0->set_uuid0;
+		if (be32_to_cpu(mdp0->minor_version) >= 90) {
+			uuid.ints[1] = mdp0->set_uuid1;
+			uuid.ints[2] = mdp0->set_uuid2;
+			uuid.ints[3] = mdp0->set_uuid3;
+		}
+		ma = be32_to_cpu(mdp0->major_version);
+		mi = be32_to_cpu(mdp0->minor_version);
+		pa = be32_to_cpu(mdp0->patch_version);
+		size = be32_to_cpu(mdp0->size);
+	} else
+		return 1;
+
+	size <<= 10;	/* convert KiB to bytes */
+
+	if (pr->size < 0 || (uint64_t) pr->size < size + MD_RESERVED_BYTES)
+		/* device is too small */
+		return 1;
+
+	if (off < 0 || (uint64_t) off < size)
+		/* no space before superblock */
+		return 1;
+
+	/*
+	 * Check for collisions between RAID and partition table
+	 *
+	 * For example the superblock is at the end of the last partition, it's
+	 * the same position as at the end of the disk...
+	 */
+	if ((S_ISREG(pr->mode) || blkid_probe_is_wholedisk(pr)) &&
+	    blkid_probe_is_covered_by_pt(pr,
+			off - size,				/* min. start  */
+			size + MD_RESERVED_BYTES)) {		/* min. length */
+
+		/* ignore this superblock, it's within any partition and
+		 * we are working with whole-disk now */
+		return 1;
+	}
+
+	if (blkid_probe_sprintf_version(pr, "%u.%u.%u", ma, mi, pa) != 0)
+		return -1;
+	if (blkid_probe_set_uuid(pr, (unsigned char *) uuid.bytes) != 0)
+		return -1;
+	if (blkid_probe_set_magic(pr, off, sizeof(mdp0->md_magic),
+				(unsigned char *) &mdp0->md_magic))
+		return -1;
+	return 0;
+}
+
+static int probe_raid1(blkid_probe pr, off_t off)
+{
+	struct mdp1_super_block *mdp1;
+
+	mdp1 = (struct mdp1_super_block *)
+			blkid_probe_get_buffer(pr,
+				off,
+				sizeof(struct mdp1_super_block));
+	if (!mdp1)
+		return -1;
+	if (le32_to_cpu(mdp1->magic) != MD_SB_MAGIC)
+		return -1;
+	if (le32_to_cpu(mdp1->major_version) != 1U)
+		return -1;
+	if (le64_to_cpu(mdp1->super_offset) != (uint64_t) off >> 9)
+		return -1;
+	if (blkid_probe_set_uuid(pr, (unsigned char *) mdp1->set_uuid) != 0)
+		return -1;
+	if (blkid_probe_set_uuid_as(pr,
+			(unsigned char *) mdp1->device_uuid, "UUID_SUB") != 0)
+		return -1;
+	if (blkid_probe_set_label(pr, mdp1->set_name,
+				sizeof(mdp1->set_name)) != 0)
+		return -1;
+	if (blkid_probe_set_magic(pr, off, sizeof(mdp1->magic),
+				(unsigned char *) &mdp1->magic))
+		return -1;
+	return 0;
+}
+
+int probe_raid(blkid_probe pr,
+		const struct blkid_idmag *mag __attribute__((__unused__)))
+{
+	const char *ver = NULL;
+
+	if (pr->size > MD_RESERVED_BYTES) {
+		/* version 0 at the end of the device */
+		uint64_t sboff = (pr->size & ~(MD_RESERVED_BYTES - 1))
+			         - MD_RESERVED_BYTES;
+		if (probe_raid0(pr, sboff) == 0)
+			return 0;
+
+		/* version 1.0 at the end of the device */
+		sboff = (pr->size & ~(0x1000 - 1)) - 0x2000;
+		if (probe_raid1(pr, sboff) == 0)
+			ver = "1.0";
+	}
+
+	if (!ver) {
+		/* version 1.1 at the start of the device */
+		if (probe_raid1(pr, 0) == 0)
+			ver = "1.1";
+
+		/* version 1.2 at 4k offset from the start */
+		else if (probe_raid1(pr, 0x1000) == 0)
+			ver = "1.2";
+	}
+
+	if (ver) {
+		blkid_probe_set_version(pr, ver);
+		return 0;
+	}
+	return -1;
+}
+
+
+const struct blkid_idinfo linuxraid_idinfo = {
+	.name		= "linux_raid_member",
+	.usage		= BLKID_USAGE_RAID,
+	.probefunc	= probe_raid,
+	.magics		= BLKID_NONE_MAGIC
+};
+
+