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/*
* Copyright (C) 2009 by Bastian Friedrich <bastian.friedrich@collax.com>
*
* This file may be redistributed under the terms of the
* GNU Lesser General Public License.
*
* defines, structs taken from drbd source; file names represent drbd source
* files.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <inttypes.h>
#include <stddef.h>
#include "superblocks.h"
enum {
DRBD_VERSION_08,
DRBD_VERSION_09,
};
/*
* drbd/drbd_int.h
*/
#define BM_BLOCK_SHIFT 12 /* 4k per bit */
#define BM_BLOCK_SIZE (1<<BM_BLOCK_SHIFT)
/*
* user/drbdmeta.c
* We support v08 and v09
*/
#define DRBD_MD_MAGIC_08 "\x83\x74\x02\x6b"
#define DRBD_MD_MAGIC_84_UNCLEAN "\x83\x74\x02\x6c"
#define DRBD_MD_MAGIC_09 "\x83\x74\x02\x6d"
/* there is no DRBD_MD_MAGIC_09_UNCLEAN */
/*
* drbd/linux/drbd.h
*/
enum drbd_uuid_index {
UI_CURRENT,
UI_BITMAP,
UI_HISTORY_START,
UI_HISTORY_END,
UI_SIZE, /* nl-packet: number of dirty bits */
UI_FLAGS, /* nl-packet: flags */
UI_EXTENDED_SIZE /* Everything. */
};
/*
* Used by libblkid to avoid unnecessary padding at the end of the structs and
* too large unused structs in memory.
*/
#define DRBD_MD_OFFSET 4096
/*
* user/shared/drbdmeta.c
* Minor modifications wrt. types
*/
struct md_on_disk_08 {
uint64_t la_sect; /* last agreed size. */
uint64_t uuid[UI_SIZE]; /* UUIDs */
uint64_t device_uuid;
uint64_t reserved_u64_1;
uint32_t flags;
uint32_t magic;
uint32_t md_size_sect;
int32_t al_offset; /* signed sector offset to this block */
uint32_t al_nr_extents; /* important for restoring the AL */
int32_t bm_offset; /* signed sector offset to the bitmap, from here */
uint32_t bm_bytes_per_bit;
uint32_t reserved_u32[4];
unsigned char padding_start[0];
unsigned char padding_end[0] __attribute__((aligned(4096)));
};
/*
* linux/drbd.h, v9 only
*/
#define DRBD_PEERS_MAX 32
#define HISTORY_UUIDS DRBD_PEERS_MAX
/*
* drbd-headers/drbd_meta_data.h
* Minor modifications wrt. types
*/
struct peer_dev_md_on_disk_9 {
uint64_t bitmap_uuid;
uint64_t bitmap_dagtag;
uint32_t flags;
int32_t bitmap_index;
uint32_t reserved_u32[2];
} __attribute__((packed));
struct meta_data_on_disk_9 {
uint64_t effective_size; /* last agreed size */
uint64_t current_uuid;
uint64_t reserved_u64[4]; /* to have the magic at the same position as in v07, and v08 */
uint64_t device_uuid;
uint32_t flags; /* MDF */
uint32_t magic;
uint32_t md_size_sect;
uint32_t al_offset; /* offset to this block */
uint32_t al_nr_extents; /* important for restoring the AL */
uint32_t bm_offset; /* offset to the bitmap, from here */
uint32_t bm_bytes_per_bit; /* BM_BLOCK_SIZE */
uint32_t la_peer_max_bio_size; /* last peer max_bio_size */
uint32_t bm_max_peers;
int32_t node_id;
/* see al_tr_number_to_on_disk_sector() */
uint32_t al_stripes;
uint32_t al_stripe_size_4k;
uint32_t reserved_u32[2];
struct peer_dev_md_on_disk_9 peers[DRBD_PEERS_MAX];
uint64_t history_uuids[HISTORY_UUIDS];
unsigned char padding_start[0];
unsigned char padding_end[0] __attribute__((aligned(4096)));
} __attribute__((packed));
static int is_zero_padded(const unsigned char *padding_start,
const unsigned char *padding_end)
{
for (; padding_start < padding_end; padding_start++) {
if (*padding_start != 0)
return 0;
}
return 1;
}
static int probe_drbd_84(blkid_probe pr, const struct blkid_idmag *mag)
{
const struct md_on_disk_08 *md;
md = blkid_probe_get_sb(pr, mag, struct md_on_disk_08);
if (!md)
return errno ? -errno : 1;
if (be32_to_cpu(read_unaligned_member(md, bm_bytes_per_bit)) != BM_BLOCK_SIZE)
return 1;
if (!is_zero_padded(member_ptr(md, padding_start),
member_ptr(md, padding_end)))
return 1;
/*
* DRBD does not have "real" uuids; the following resembles DRBD's
* notion of uuids (64 bit, see struct above)
*/
blkid_probe_sprintf_uuid(pr,
member_ptr(md, device_uuid), sizeof(md->device_uuid),
"%" PRIx64, be64_to_cpu(read_unaligned_member(md, device_uuid)));
blkid_probe_set_version(pr, "v08");
return 0;
}
static int probe_drbd_90(blkid_probe pr, const struct blkid_idmag *mag)
{
const struct meta_data_on_disk_9 *md;
md = blkid_probe_get_sb(pr, mag, struct meta_data_on_disk_9);
if (!md)
return errno ? -errno : 1;
if (be32_to_cpu(read_unaligned_member(md, bm_bytes_per_bit)) != BM_BLOCK_SIZE)
return 1;
if (!is_zero_padded(member_ptr(md, padding_start),
member_ptr(md, padding_end)))
return 1;
/*
* DRBD does not have "real" uuids; the following resembles DRBD's
* notion of uuids (64 bit, see struct above)
*/
blkid_probe_sprintf_uuid(pr,
member_ptr(md, device_uuid), sizeof(md->device_uuid),
"%" PRIx64, be64_to_cpu(read_unaligned_member(md, device_uuid)));
blkid_probe_set_version(pr, "v09");
return 0;
}
static int probe_drbd(blkid_probe pr, const struct blkid_idmag *mag)
{
if (mag->hint == DRBD_VERSION_08)
return probe_drbd_84(pr, mag);
if (mag->hint == DRBD_VERSION_09)
return probe_drbd_90(pr, mag);
return 1;
}
const struct blkid_idinfo drbd_idinfo =
{
.name = "drbd",
.usage = BLKID_USAGE_RAID,
.probefunc = probe_drbd,
/*
* Smaller ones are certainly not DRBD9 devices.
* Recent utils even refuse to generate larger ones,
* keep this as a sufficient lower bound.
*/
.minsz = 0x10000,
.magics = {
{
.magic = DRBD_MD_MAGIC_08,
.len = sizeof(DRBD_MD_MAGIC_08) - 1,
.hint = DRBD_VERSION_08,
.kboff = -(DRBD_MD_OFFSET >> 10),
.sboff = offsetof(struct md_on_disk_08, magic),
},
{
.magic = DRBD_MD_MAGIC_84_UNCLEAN,
.len = sizeof(DRBD_MD_MAGIC_84_UNCLEAN) - 1,
.hint = DRBD_VERSION_08,
.kboff = -(DRBD_MD_OFFSET >> 10),
.sboff = offsetof(struct md_on_disk_08, magic),
},
{
.magic = DRBD_MD_MAGIC_09,
.len = sizeof(DRBD_MD_MAGIC_09) - 1,
.hint = DRBD_VERSION_09,
.kboff = -(DRBD_MD_OFFSET >> 10),
.sboff = offsetof(struct meta_data_on_disk_9, magic),
},
{ NULL }
}
};
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