/* mdraid_linux.c - module to handle Linux Software RAID. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2008,2009,2010 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see .
*/
#include
#include
#include
#include
#include
#include
GRUB_MOD_LICENSE ("GPLv3+");
/* Linux RAID on disk structures and constants,
copied from include/linux/raid/md_p.h. */
#define SB_MAGIC 0xa92b4efc
/*
* The version-1 superblock :
* All numeric fields are little-endian.
*
* Total size: 256 bytes plus 2 per device.
* 1K allows 384 devices.
*/
struct grub_raid_super_1x
{
/* Constant array information - 128 bytes. */
grub_uint32_t magic; /* MD_SB_MAGIC: 0xa92b4efc - little endian. */
grub_uint32_t major_version; /* 1. */
grub_uint32_t feature_map; /* Bit 0 set if 'bitmap_offset' is meaningful. */
grub_uint32_t pad0; /* Always set to 0 when writing. */
grub_uint8_t set_uuid[16]; /* User-space generated. */
char set_name[32]; /* Set and interpreted by user-space. */
grub_uint64_t ctime; /* Lo 40 bits are seconds, top 24 are microseconds or 0. */
grub_uint32_t level; /* -4 (multipath), -1 (linear), 0,1,4,5. */
grub_uint32_t layout; /* only for raid5 and raid10 currently. */
grub_uint64_t size; /* Used size of component devices, in 512byte sectors. */
grub_uint32_t chunksize; /* In 512byte sectors. */
grub_uint32_t raid_disks;
grub_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'. */
grub_uint32_t new_level; /* New level we are reshaping to. */
grub_uint64_t reshape_position; /* Next address in array-space for reshape. */
grub_uint32_t delta_disks; /* Change in number of raid_disks. */
grub_uint32_t new_layout; /* New layout. */
grub_uint32_t new_chunk; /* New chunk size (512byte sectors). */
grub_uint8_t pad1[128 - 124]; /* Set to 0 when written. */
/* Constant this-device information - 64 bytes. */
grub_uint64_t data_offset; /* Sector start of data, often 0. */
grub_uint64_t data_size; /* Sectors in this device that can be used for data. */
grub_uint64_t super_offset; /* Sector start of this superblock. */
grub_uint64_t recovery_offset; /* Sectors before this offset (from data_offset) have been recovered. */
grub_uint32_t dev_number; /* Permanent identifier of this device - not role in raid. */
grub_uint32_t cnt_corrected_read; /* Number of read errors that were corrected by re-writing. */
grub_uint8_t device_uuid[16]; /* User-space setable, ignored by kernel. */
grub_uint8_t devflags; /* Per-device flags. Only one defined... */
grub_uint8_t pad2[64 - 57]; /* Set to 0 when writing. */
/* Array state information - 64 bytes. */
grub_uint64_t utime; /* 40 bits second, 24 btes microseconds. */
grub_uint64_t events; /* Incremented when superblock updated. */
grub_uint64_t resync_offset; /* Data before this offset (from data_offset) known to be in sync. */
grub_uint32_t sb_csum; /* Checksum upto devs[max_dev]. */
grub_uint32_t max_dev; /* Size of devs[] array to consider. */
grub_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.
*/
grub_uint16_t dev_roles[0]; /* Role in array, or 0xffff for a spare, or 0xfffe for faulty. */
};
/* Could be __attribute__ ((packed)), but since all members in this struct
are already appropriately aligned, we can omit this and avoid suboptimal
assembly in some cases. */
#define WriteMostly1 1 /* Mask for writemostly flag in above devflags. */
static struct grub_diskfilter_vg *
grub_mdraid_detect (grub_disk_t disk,
struct grub_diskfilter_pv_id *id,
grub_disk_addr_t *start_sector)
{
grub_disk_addr_t sector = 0;
grub_uint64_t size;
struct grub_raid_super_1x sb;
grub_uint8_t minor_version;
size = grub_disk_get_size (disk);
/* Check for an 1.x superblock.
* It's always aligned to a 4K boundary
* and depending on the minor version it can be:
* 0: At least 8K, but less than 12K, from end of device
* 1: At start of device
* 2: 4K from start of device.
*/
for (minor_version = 0; minor_version < 3; ++minor_version)
{
if (size == GRUB_DISK_SIZE_UNKNOWN && minor_version == 0)
continue;
switch (minor_version)
{
case 0:
sector = (size - 8 * 2) & ~(4 * 2 - 1);
break;
case 1:
sector = 0;
break;
case 2:
sector = 4 * 2;
break;
}
if (grub_disk_read (disk, sector, 0, sizeof (struct grub_raid_super_1x),
&sb))
return NULL;
if (grub_le_to_cpu32 (sb.magic) != SB_MAGIC
|| grub_le_to_cpu64 (sb.super_offset) != sector)
continue;
{
grub_uint64_t sb_size;
struct grub_raid_super_1x *real_sb;
grub_uint32_t level;
if (grub_le_to_cpu32 (sb.major_version) != 1)
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"Unsupported RAID version: %d",
grub_le_to_cpu32 (sb.major_version));
return NULL;
}
level = grub_le_to_cpu32 (sb.level);
/* Multipath. */
if ((int) level == -4)
level = 1;
if (level != 0 && level != 1 && level != 4 &&
level != 5 && level != 6 && level != 10)
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"Unsupported RAID level: %d", sb.level);
return NULL;
}
/* 1.x superblocks don't have a fixed size on disk. So we have to
read it again now that we now the max device count. */
sb_size = sizeof (struct grub_raid_super_1x)
+ 2 * grub_le_to_cpu32 (sb.max_dev);
real_sb = grub_malloc (sb_size);
if (! real_sb)
return NULL;
if (grub_disk_read (disk, sector, 0, sb_size, real_sb))
{
grub_free (real_sb);
return NULL;
}
struct grub_diskfilter_vg *array;
char *uuid;
if (grub_le_to_cpu32 (real_sb->dev_number) >=
grub_le_to_cpu32 (real_sb->max_dev))
{
grub_error (GRUB_ERR_OUT_OF_RANGE,
"spares aren't implemented");
return NULL;
}
id->uuidlen = 0;
id->id = grub_le_to_cpu16
(real_sb->dev_roles[grub_le_to_cpu32 (real_sb->dev_number)]);
uuid = grub_malloc (16);
if (!uuid)
{
grub_free (real_sb);
return NULL;
}
grub_memcpy (uuid, real_sb->set_uuid, 16);
*start_sector = grub_le_to_cpu64 (real_sb->data_offset);
if (grub_le_to_cpu32 (real_sb->dev_number)
>= grub_le_to_cpu32 (real_sb->raid_disks))
{
grub_error (GRUB_ERR_OUT_OF_RANGE,
"spares aren't implemented");
return NULL;
}
array = grub_diskfilter_make_raid (16, uuid,
grub_le_to_cpu32 (real_sb->raid_disks),
real_sb->set_name,
(real_sb->size)
? grub_le_to_cpu64 (real_sb->size)
: grub_le_to_cpu64 (real_sb->data_size),
grub_le_to_cpu32 (real_sb->chunksize),
grub_le_to_cpu32 (real_sb->layout),
grub_le_to_cpu32 (real_sb->level));
grub_free (real_sb);
return array;
}
}
grub_error (GRUB_ERR_OUT_OF_RANGE, "not 1.x raid");
return NULL;
}
static struct grub_diskfilter grub_mdraid_dev = {
.name = "mdraid1x",
.detect = grub_mdraid_detect,
.next = 0
};
GRUB_MOD_INIT (mdraid1x)
{
grub_diskfilter_register (&grub_mdraid_dev);
}
GRUB_MOD_FINI (mdraid1x)
{
grub_diskfilter_unregister (&grub_mdraid_dev);
}