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grub/disk/raid.c
Colin Watson 31cfe714f2 * disk/mdraid_linux.c: Update copyright years. 
* disk/raid.c: Likewise.
* include/grub/raid.h: Likewise.
* kern/emu/getroot.c: Likewise.
2010-07-20 11:10:49 +01:00

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/* raid.c - module to read RAID arrays. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2006,2007,2008,2009,2010 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>
/* Linked list of RAID arrays. */
static struct grub_raid_array *array_list;
grub_raid5_recover_func_t grub_raid5_recover_func;
grub_raid6_recover_func_t grub_raid6_recover_func;
static char
grub_is_array_readable (struct grub_raid_array *array)
{
switch (array->level)
{
case 0:
if (array->nr_devs == array->total_devs)
return 1;
break;
case 1:
if (array->nr_devs >= 1)
return 1;
break;
case 4:
case 5:
case 6:
case 10:
{
unsigned int n;
if (array->level == 10)
{
n = array->layout & 0xFF;
if (n == 1)
n = (array->layout >> 8) & 0xFF;
n--;
}
else
n = array->level / 3;
if (array->nr_devs >= array->total_devs - n)
return 1;
break;
}
}
return 0;
}
static int
grub_raid_iterate (int (*hook) (const char *name))
{
struct grub_raid_array *array;
for (array = array_list; array != NULL; array = array->next)
{
if (grub_is_array_readable (array))
if (hook (array->name))
return 1;
}
return 0;
}
#ifdef GRUB_UTIL
static grub_disk_memberlist_t
grub_raid_memberlist (grub_disk_t disk)
{
struct grub_raid_array *array = disk->data;
grub_disk_memberlist_t list = NULL, tmp;
unsigned int i;
for (i = 0; i < array->total_devs; i++)
if (array->device[i])
{
tmp = grub_malloc (sizeof (*tmp));
tmp->disk = array->device[i];
tmp->next = list;
list = tmp;
}
return list;
}
#endif
static grub_err_t
grub_raid_open (const char *name, grub_disk_t disk)
{
struct grub_raid_array *array;
unsigned n;
for (array = array_list; array != NULL; array = array->next)
{
if (!grub_strcmp (array->name, name))
if (grub_is_array_readable (array))
break;
}
if (!array)
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "unknown RAID device %s",
name);
disk->has_partitions = 1;
disk->id = array->number;
disk->data = array;
grub_dprintf ("raid", "%s: total_devs=%d, disk_size=%lld\n", name,
array->total_devs, (unsigned long long) array->disk_size);
switch (array->level)
{
case 1:
disk->total_sectors = array->disk_size;
break;
case 10:
n = array->layout & 0xFF;
if (n == 1)
n = (array->layout >> 8) & 0xFF;
disk->total_sectors = grub_divmod64 (array->total_devs *
array->disk_size,
n, 0);
break;
case 0:
case 4:
case 5:
case 6:
n = array->level / 3;
disk->total_sectors = (array->total_devs - n) * array->disk_size;
break;
}
grub_dprintf ("raid", "%s: level=%d, total_sectors=%lld\n", name,
array->level, (unsigned long long) disk->total_sectors);
return 0;
}
static void
grub_raid_close (grub_disk_t disk __attribute ((unused)))
{
return;
}
void
grub_raid_block_xor (char *buf1, const char *buf2, int size)
{
grub_size_t *p1;
const grub_size_t *p2;
p1 = (grub_size_t *) buf1;
p2 = (const grub_size_t *) buf2;
size /= GRUB_CPU_SIZEOF_VOID_P;
while (size)
{
*(p1++) ^= *(p2++);
size--;
}
}
static grub_err_t
grub_raid_read (grub_disk_t disk, grub_disk_addr_t sector,
grub_size_t size, char *buf)
{
struct grub_raid_array *array = disk->data;
grub_err_t err = 0;
switch (array->level)
{
case 0:
case 1:
case 10:
{
grub_disk_addr_t read_sector, far_ofs;
grub_uint32_t disknr, b, near, far, ofs;
read_sector = grub_divmod64 (sector, array->chunk_size, &b);
far = ofs = near = 1;
far_ofs = 0;
if (array->level == 1)
near = array->total_devs;
else if (array->level == 10)
{
near = array->layout & 0xFF;
far = (array->layout >> 8) & 0xFF;
if (array->layout >> 16)
{
ofs = far;
far_ofs = 1;
}
else
far_ofs = grub_divmod64 (array->disk_size,
far * array->chunk_size, 0);
far_ofs *= array->chunk_size;
}
read_sector = grub_divmod64 (read_sector * near, array->total_devs,
&disknr);
ofs *= array->chunk_size;
read_sector *= ofs;
while (1)
{
grub_size_t read_size;
unsigned int i, j;
read_size = array->chunk_size - b;
if (read_size > size)
read_size = size;
for (i = 0; i < near; i++)
{
unsigned int k;
k = disknr;
for (j = 0; j < far; j++)
{
if (array->device[k])
{
if (grub_errno == GRUB_ERR_READ_ERROR)
grub_errno = GRUB_ERR_NONE;
err = grub_disk_read (array->device[k],
array->start_sector[k] +
read_sector + j * far_ofs + b,
0,
read_size << GRUB_DISK_SECTOR_BITS,
buf);
if (! err)
break;
else if (err != GRUB_ERR_READ_ERROR)
return err;
}
else
err = grub_error (GRUB_ERR_READ_ERROR,
"disk missing");
k++;
if (k == array->total_devs)
k = 0;
}
if (! err)
break;
disknr++;
if (disknr == array->total_devs)
{
disknr = 0;
read_sector += ofs;
}
}
if (err)
return err;
buf += read_size << GRUB_DISK_SECTOR_BITS;
size -= read_size;
if (! size)
break;
b = 0;
disknr += (near - i);
while (disknr >= array->total_devs)
{
disknr -= array->total_devs;
read_sector += ofs;
}
}
break;
}
case 4:
case 5:
case 6:
{
grub_disk_addr_t read_sector;
grub_uint32_t b, p, n, disknr, e;
/* n = 1 for level 4 and 5, 2 for level 6. */
n = array->level / 3;
/* Find the first sector to read. */
read_sector = grub_divmod64 (sector, array->chunk_size, &b);
read_sector = grub_divmod64 (read_sector, array->total_devs - n,
&disknr);
if (array->level >= 5)
{
grub_divmod64 (read_sector, array->total_devs, &p);
if (! (array->layout & GRUB_RAID_LAYOUT_RIGHT_MASK))
p = array->total_devs - 1 - p;
if (array->layout & GRUB_RAID_LAYOUT_SYMMETRIC_MASK)
{
disknr += p + n;
}
else
{
grub_uint32_t q;
q = p + (n - 1);
if (q >= array->total_devs)
q -= array->total_devs;
if (disknr >= p)
disknr += n;
else if (disknr >= q)
disknr += q + 1;
}
if (disknr >= array->total_devs)
disknr -= array->total_devs;
}
else
p = array->total_devs - n;
read_sector *= array->chunk_size;
while (1)
{
grub_size_t read_size;
int next_level;
read_size = array->chunk_size - b;
if (read_size > size)
read_size = size;
e = 0;
if (array->device[disknr])
{
/* Reset read error. */
if (grub_errno == GRUB_ERR_READ_ERROR)
grub_errno = GRUB_ERR_NONE;
err = grub_disk_read (array->device[disknr],
array->start_sector[disknr] +
read_sector + b, 0,
read_size << GRUB_DISK_SECTOR_BITS,
buf);
if ((err) && (err != GRUB_ERR_READ_ERROR))
break;
e++;
}
else
err = GRUB_ERR_READ_ERROR;
if (err)
{
if (array->nr_devs < array->total_devs - n + e)
break;
grub_errno = GRUB_ERR_NONE;
if (array->level == 6)
{
err = ((grub_raid6_recover_func) ?
(*grub_raid6_recover_func) (array, disknr, p,
buf, read_sector + b,
read_size) :
grub_error (GRUB_ERR_BAD_DEVICE,
"raid6rec is not loaded"));
}
else
{
err = ((grub_raid5_recover_func) ?
(*grub_raid5_recover_func) (array, disknr,
buf, read_sector + b,
read_size) :
grub_error (GRUB_ERR_BAD_DEVICE,
"raid5rec is not loaded"));
}
if (err)
break;
}
buf += read_size << GRUB_DISK_SECTOR_BITS;
size -= read_size;
if (! size)
break;
b = 0;
disknr++;
if (array->layout & GRUB_RAID_LAYOUT_SYMMETRIC_MASK)
{
if (disknr == array->total_devs)
disknr = 0;
next_level = (disknr == p);
}
else
{
if (disknr == p)
disknr += n;
next_level = (disknr >= array->total_devs);
}
if (next_level)
{
read_sector += array->chunk_size;
if (array->level >= 5)
{
if (array->layout & GRUB_RAID_LAYOUT_RIGHT_MASK)
p = (p == array->total_devs - 1) ? 0 : p + 1;
else
p = (p == 0) ? array->total_devs - 1 : p - 1;
if (array->layout & GRUB_RAID_LAYOUT_SYMMETRIC_MASK)
{
disknr = p + n;
if (disknr >= array->total_devs)
disknr -= array->total_devs;
}
else
{
disknr -= array->total_devs;
if (disknr == p)
disknr += n;
}
}
else
disknr = 0;
}
}
}
break;
}
return err;
}
static grub_err_t
grub_raid_write (grub_disk_t disk __attribute ((unused)),
grub_disk_addr_t sector __attribute ((unused)),
grub_size_t size __attribute ((unused)),
const char *buf __attribute ((unused)))
{
return GRUB_ERR_NOT_IMPLEMENTED_YET;
}
static grub_err_t
insert_array (grub_disk_t disk, struct grub_raid_array *new_array,
grub_disk_addr_t start_sector, const char *scanner_name)
{
struct grub_raid_array *array = 0, *p;
/* See whether the device is part of an array we have already seen a
device from. */
for (p = array_list; p != NULL; p = p->next)
if ((p->uuid_len == new_array->uuid_len) &&
(! grub_memcmp (p->uuid, new_array->uuid, p->uuid_len)))
{
grub_free (new_array->uuid);
array = p;
/* Do some checks before adding the device to the array. */
/* FIXME: Check whether the update time of the superblocks are
the same. */
if (array->total_devs == array->nr_devs)
/* We found more members of the array than the array
actually has according to its superblock. This shouldn't
happen normally. */
grub_dprintf ("raid", "array->nr_devs > array->total_devs (%d)?!?",
array->total_devs);
if (array->device[new_array->index] != NULL)
/* We found multiple devices with the same number. Again,
this shouldn't happen. */
grub_dprintf ("raid", "Found two disks with the number %d?!?",
new_array->number);
if (new_array->disk_size < array->disk_size)
array->disk_size = new_array->disk_size;
break;
}
/* Add an array to the list if we didn't find any. */
if (!array)
{
array = grub_malloc (sizeof (*array));
if (!array)
{
grub_free (new_array->uuid);
return grub_errno;
}
*array = *new_array;
array->nr_devs = 0;
grub_memset (&array->device, 0, sizeof (array->device));
grub_memset (&array->start_sector, 0, sizeof (array->start_sector));
if (array->name)
goto skip_duplicate_check;
/* Check whether we don't have multiple arrays with the same number. */
for (p = array_list; p != NULL; p = p->next)
{
if (p->number == array->number)
break;
}
if (p)
{
/* The number is already in use, so we need to find a new one. */
int i = 0;
while (1)
{
for (p = array_list; p != NULL; p = p->next)
{
if (p->number == i)
break;
}
if (! p)
{
/* We found an unused number. */
array->number = i;
break;
}
i++;
}
}
skip_duplicate_check:
/* mdraid 1.x superblocks have only a name stored not a number.
Use it directly as GRUB device. */
if (! array->name)
{
array->name = grub_xasprintf ("md%d", array->number);
if (! array->name)
{
grub_free (array->uuid);
grub_free (array);
return grub_errno;
}
}
else
{
/* Strip off the homehost if present. */
char *colon = grub_strchr (array->name, ':');
char *new_name = grub_xasprintf ("md/%s",
colon ? colon + 1 : array->name);
if (! new_name)
{
grub_free (array->uuid);
grub_free (array);
return grub_errno;
}
grub_free (array->name);
array->name = new_name;
}
grub_dprintf ("raid", "Found array %s (%s)\n", array->name,
scanner_name);
/* Add our new array to the list. */
array->next = array_list;
array_list = array;
/* RAID 1 doesn't use a chunksize but code assumes one so set
one. */
if (array->level == 1)
array->chunk_size = 64;
}
/* Add the device to the array. */
array->device[new_array->index] = disk;
array->start_sector[new_array->index] = start_sector;
array->nr_devs++;
return 0;
}
static grub_raid_t grub_raid_list;
static void
free_array (void)
{
struct grub_raid_array *array;
array = array_list;
while (array)
{
struct grub_raid_array *p;
int i;
p = array;
array = array->next;
for (i = 0; i < GRUB_RAID_MAX_DEVICES; i++)
if (p->device[i])
grub_disk_close (p->device[i]);
grub_free (p->uuid);
grub_free (p->name);
grub_free (p);
}
array_list = 0;
}
void
grub_raid_register (grub_raid_t raid)
{
auto int hook (const char *name);
int hook (const char *name)
{
grub_disk_t disk;
struct grub_raid_array array;
grub_disk_addr_t start_sector;
grub_dprintf ("raid", "Scanning for RAID devices on disk %s\n", name);
disk = grub_disk_open (name);
if (!disk)
return 0;
if ((disk->total_sectors != GRUB_ULONG_MAX) &&
(! grub_raid_list->detect (disk, &array, &start_sector)) &&
(! insert_array (disk, &array, start_sector, grub_raid_list->name)))
return 0;
/* This error usually means it's not raid, no need to display
it. */
if (grub_errno != GRUB_ERR_OUT_OF_RANGE)
grub_print_error ();
grub_errno = GRUB_ERR_NONE;
grub_disk_close (disk);
return 0;
}
raid->next = grub_raid_list;
grub_raid_list = raid;
grub_device_iterate (&hook);
}
void
grub_raid_unregister (grub_raid_t raid)
{
grub_raid_t *p, q;
for (p = &grub_raid_list, q = *p; q; p = &(q->next), q = q->next)
if (q == raid)
{
*p = q->next;
break;
}
}
static struct grub_disk_dev grub_raid_dev =
{
.name = "raid",
.id = GRUB_DISK_DEVICE_RAID_ID,
.iterate = grub_raid_iterate,
.open = grub_raid_open,
.close = grub_raid_close,
.read = grub_raid_read,
.write = grub_raid_write,
#ifdef GRUB_UTIL
.memberlist = grub_raid_memberlist,
#endif
.next = 0
};
GRUB_MOD_INIT(raid)
{
grub_disk_dev_register (&grub_raid_dev);
}
GRUB_MOD_FINI(raid)
{
grub_disk_dev_unregister (&grub_raid_dev);
free_array ();
}
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