/* 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 <http://www.gnu.org/licenses/>.
*/
#include <grub/dl.h>
#include <grub/disk.h>
#include <grub/mm.h>
#include <grub/err.h>
#include <grub/misc.h>
#include <grub/raid.h>
/* Linux RAID on disk structures and constants,
copied from include/linux/raid/md_p.h. */
#define RESERVED_BYTES (64 * 1024)
#define RESERVED_SECTORS (RESERVED_BYTES / 512)
#define NEW_SIZE_SECTORS(x) ((x & ~(RESERVED_SECTORS - 1)) \
- RESERVED_SECTORS)
#define SB_BYTES 4096
#define SB_WORDS (SB_BYTES / 4)
#define SB_SECTORS (SB_BYTES / 512)
/*
* The following are counted in 32-bit words
*/
#define SB_GENERIC_OFFSET 0
#define SB_PERSONALITY_OFFSET 64
#define SB_DISKS_OFFSET 128
#define SB_DESCRIPTOR_OFFSET 992
#define SB_GENERIC_CONSTANT_WORDS 32
#define SB_GENERIC_STATE_WORDS 32
#define SB_GENERIC_WORDS (SB_GENERIC_CONSTANT_WORDS + \
SB_GENERIC_STATE_WORDS)
#define SB_PERSONALITY_WORDS 64
#define SB_DESCRIPTOR_WORDS 32
#define SB_DISKS 27
#define SB_DISKS_WORDS (SB_DISKS * SB_DESCRIPTOR_WORDS)
#define SB_RESERVED_WORDS (1024 \
- SB_GENERIC_WORDS \
- SB_PERSONALITY_WORDS \
- SB_DISKS_WORDS \
- SB_DESCRIPTOR_WORDS)
#define SB_EQUAL_WORDS (SB_GENERIC_WORDS \
+ SB_PERSONALITY_WORDS \
+ SB_DISKS_WORDS)
/*
* Device "operational" state bits
*/
#define DISK_FAULTY 0
#define DISK_ACTIVE 1
#define DISK_SYNC 2
#define DISK_REMOVED 3
#define DISK_WRITEMOSTLY 9
#define SB_MAGIC 0xa92b4efc
/*
* Superblock state bits
*/
#define SB_CLEAN 0
#define SB_ERRORS 1
#define SB_BITMAP_PRESENT 8
struct grub_raid_disk_09
{
grub_uint32_t number; /* Device number in the entire set. */
grub_uint32_t major; /* Device major number. */
grub_uint32_t minor; /* Device minor number. */
grub_uint32_t raid_disk; /* The role of the device in the raid set. */
grub_uint32_t state; /* Operational state. */
grub_uint32_t reserved[SB_DESCRIPTOR_WORDS - 5];
};
struct grub_raid_super_09
{
/*
* Constant generic information
*/
grub_uint32_t md_magic; /* MD identifier. */
grub_uint32_t major_version; /* Major version. */
grub_uint32_t minor_version; /* Minor version. */
grub_uint32_t patch_version; /* Patchlevel version. */
grub_uint32_t gvalid_words; /* Number of used words in this section. */
grub_uint32_t set_uuid0; /* Raid set identifier. */
grub_uint32_t ctime; /* Creation time. */
grub_uint32_t level; /* Raid personality. */
grub_uint32_t size; /* Apparent size of each individual disk. */
grub_uint32_t nr_disks; /* Total disks in the raid set. */
grub_uint32_t raid_disks; /* Disks in a fully functional raid set. */
grub_uint32_t md_minor; /* Preferred MD minor device number. */
grub_uint32_t not_persistent; /* Does it have a persistent superblock. */
grub_uint32_t set_uuid1; /* Raid set identifier #2. */
grub_uint32_t set_uuid2; /* Raid set identifier #3. */
grub_uint32_t set_uuid3; /* Raid set identifier #4. */
grub_uint32_t gstate_creserved[SB_GENERIC_CONSTANT_WORDS - 16];
/*
* Generic state information
*/
grub_uint32_t utime; /* Superblock update time. */
grub_uint32_t state; /* State bits (clean, ...). */
grub_uint32_t active_disks; /* Number of currently active disks. */
grub_uint32_t working_disks; /* Number of working disks. */
grub_uint32_t failed_disks; /* Number of failed disks. */
grub_uint32_t spare_disks; /* Number of spare disks. */
grub_uint32_t sb_csum; /* Checksum of the whole superblock. */
grub_uint64_t events; /* Superblock update count. */
grub_uint64_t cp_events; /* Checkpoint update count. */
grub_uint32_t recovery_cp; /* Recovery checkpoint sector count. */
grub_uint32_t gstate_sreserved[SB_GENERIC_STATE_WORDS - 12];
/*
* Personality information
*/
grub_uint32_t layout; /* The array's physical layout. */
grub_uint32_t chunk_size; /* Chunk size in bytes. */
grub_uint32_t root_pv; /* LV root PV. */
grub_uint32_t root_block; /* LV root block. */
grub_uint32_t pstate_reserved[SB_PERSONALITY_WORDS - 4];
/*
* Disks information
*/
struct grub_raid_disk_09 disks[SB_DISKS];
/*
* Reserved
*/
grub_uint32_t reserved[SB_RESERVED_WORDS];
/*
* Active descriptor
*/
struct grub_raid_disk_09 this_disk;
} __attribute__ ((packed));
/*
* 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 grub_err_t
grub_mdraid_detect_09 (grub_disk_addr_t sector,
struct grub_raid_super_09 *sb,
struct grub_raid_array *array,
grub_disk_addr_t *start_sector)
{
grub_uint32_t *uuid;
if (sb->major_version != 0 || sb->minor_version != 90)
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"unsupported RAID version: %d.%d",
sb->major_version, sb->minor_version);
/* FIXME: Check the checksum. */
/* Multipath. */
if ((int) sb->level == -4)
sb->level = 1;
if (sb->level != 0 && sb->level != 1 && sb->level != 4 &&
sb->level != 5 && sb->level != 6 && sb->level != 10)
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"unsupported RAID level: %d", sb->level);
array->name = NULL;
array->number = sb->md_minor;
array->level = sb->level;
array->layout = sb->layout;
array->total_devs = sb->raid_disks;
array->disk_size = (sb->size) ? sb->size * 2 : sector;
array->chunk_size = sb->chunk_size >> 9;
array->index = sb->this_disk.number;
array->uuid_len = 16;
array->uuid = grub_malloc (16);
if (!array->uuid)
return grub_errno;
uuid = (grub_uint32_t *) array->uuid;
uuid[0] = sb->set_uuid0;
uuid[1] = sb->set_uuid1;
uuid[2] = sb->set_uuid2;
uuid[3] = sb->set_uuid3;
*start_sector = 0;
return 0;
}
static grub_err_t
grub_mdraid_detect_1x (grub_disk_t disk, grub_disk_addr_t sector,
struct grub_raid_super_1x *sb,
struct grub_raid_array *array,
grub_disk_addr_t *start_sector)
{
grub_uint64_t sb_size;
struct grub_raid_super_1x *real_sb;
if (sb->major_version != 1)
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"Unsupported RAID version: %d",
sb->major_version);
/* Multipath. */
if ((int) sb->level == -4)
sb->level = 1;
if (sb->level != 0 && sb->level != 1 && sb->level != 4 &&
sb->level != 5 && sb->level != 6 && sb->level != 10)
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"Unsupported RAID level: %d", sb->level);
/* 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 grub_errno;
if (grub_disk_read (disk, sector, 0, sb_size, real_sb))
{
grub_free (real_sb);
return grub_errno;
}
array->name = grub_strdup (real_sb->set_name);
if (! array->name)
{
grub_free (real_sb);
return grub_errno;
}
array->number = 0;
array->level = grub_le_to_cpu32 (real_sb->level);
array->layout = grub_le_to_cpu32 (real_sb->layout);
array->total_devs = grub_le_to_cpu32 (real_sb->raid_disks);
array->disk_size = grub_le_to_cpu64 (real_sb->size);
array->chunk_size = grub_le_to_cpu32 (real_sb->chunksize);
if (grub_le_to_cpu32 (real_sb->dev_number) <
grub_le_to_cpu32 (real_sb->max_dev))
array->index = grub_le_to_cpu16
(real_sb->dev_roles[grub_le_to_cpu32 (real_sb->dev_number)]);
else
array->index = 0xffff; /* disk will be later not used! */
array->uuid_len = 16;
array->uuid = grub_malloc (16);
if (!array->uuid)
{
grub_free (real_sb);
return grub_errno;
}
grub_memcpy (array->uuid, real_sb->set_uuid, 16);
*start_sector = real_sb->data_offset;
grub_free (real_sb);
return 0;
}
static grub_err_t
grub_mdraid_detect (grub_disk_t disk, struct grub_raid_array *array,
grub_disk_addr_t *start_sector)
{
grub_disk_addr_t sector;
grub_uint64_t size;
struct grub_raid_super_09 sb_09;
struct grub_raid_super_1x sb_1x;
grub_uint8_t minor_version;
/* The sector where the mdraid 0.90 superblock is stored, if available. */
size = grub_disk_get_size (disk);
sector = NEW_SIZE_SECTORS (size);
if (grub_disk_read (disk, sector, 0, SB_BYTES, &sb_09))
return grub_errno;
/* Look whether there is a mdraid 0.90 superblock. */
if (sb_09.md_magic == SB_MAGIC)
return grub_mdraid_detect_09 (sector, &sb_09, array, start_sector);
/* 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)
{
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_1x))
return grub_errno;
if (sb_1x.magic == SB_MAGIC)
return grub_mdraid_detect_1x (disk, sector, &sb_1x, array,
start_sector);
}
/* Neither 0.90 nor 1.x. */
return grub_error (GRUB_ERR_OUT_OF_RANGE, "not raid");
}
static struct grub_raid grub_mdraid_dev = {
.name = "mdraid",
.detect = grub_mdraid_detect,
.next = 0
};
GRUB_MOD_INIT (mdraid)
{
grub_raid_register (&grub_mdraid_dev);
}
GRUB_MOD_FINI (mdraid)
{
grub_raid_unregister (&grub_mdraid_dev);
}