/*
* 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 bits 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, uint64_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 errno ? -errno : 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 < size + MD_RESERVED_BYTES)
/* device is too small */
return 1;
if (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 errno ? -errno : 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;
}
static int probe_raid(blkid_probe pr,
const struct blkid_idmag *mag __attribute__((__unused__)))
{
const char *ver = NULL;
int ret = BLKID_PROBE_NONE;
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;
ret = probe_raid0(pr, sboff);
if (ret < 1)
return ret; /* error */
/* version 1.0 at the end of the device */
sboff = (pr->size & ~(0x1000 - 1)) - 0x2000;
ret = probe_raid1(pr, sboff);
if (ret < 0)
return ret; /* error */
if (ret == 0)
ver = "1.0";
}
if (!ver) {
/* version 1.1 at the start of the device */
ret = probe_raid1(pr, 0);
if (ret == 0)
ver = "1.1";
/* version 1.2 at 4k offset from the start */
else if (ret == BLKID_PROBE_NONE) {
ret = probe_raid1(pr, 0x1000);
if (ret == 0)
ver = "1.2";
}
}
if (ver) {
blkid_probe_set_version(pr, ver);
return BLKID_PROBE_OK;
}
return ret;
}
const struct blkid_idinfo linuxraid_idinfo = {
.name = "linux_raid_member",
.usage = BLKID_USAGE_RAID,
.probefunc = probe_raid,
.magics = BLKID_NONE_MAGIC
};
