/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2002,2003,2004,2006,2007,2008,2009,2010 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/disk.h>
#include <grub/err.h>
#include <grub/mm.h>
#include <grub/types.h>
#include <grub/partition.h>
#include <grub/misc.h>
#include <grub/time.h>
#include <grub/file.h>
#define GRUB_CACHE_TIMEOUT 2
/* The last time the disk was used. */
static grub_uint64_t grub_last_time = 0;
/* Disk cache. */
struct grub_disk_cache
{
enum grub_disk_dev_id dev_id;
unsigned long disk_id;
grub_disk_addr_t sector;
char *data;
int lock;
};
static struct grub_disk_cache grub_disk_cache_table[GRUB_DISK_CACHE_NUM];
void (*grub_disk_firmware_fini) (void);
int grub_disk_firmware_is_tainted;
#if DISK_CACHE_STATS
static unsigned long grub_disk_cache_hits;
static unsigned long grub_disk_cache_misses;
void
grub_disk_cache_get_performance (unsigned long *hits, unsigned long *misses)
{
*hits = grub_disk_cache_hits;
*misses = grub_disk_cache_misses;
}
#endif
static unsigned
grub_disk_cache_get_index (unsigned long dev_id, unsigned long disk_id,
grub_disk_addr_t sector)
{
return ((dev_id * 524287UL + disk_id * 2606459UL
+ ((unsigned) (sector >> GRUB_DISK_CACHE_BITS)))
% GRUB_DISK_CACHE_NUM);
}
static void
grub_disk_cache_invalidate (unsigned long dev_id, unsigned long disk_id,
grub_disk_addr_t sector)
{
unsigned index;
struct grub_disk_cache *cache;
sector &= ~(GRUB_DISK_CACHE_SIZE - 1);
index = grub_disk_cache_get_index (dev_id, disk_id, sector);
cache = grub_disk_cache_table + index;
if (cache->dev_id == dev_id && cache->disk_id == disk_id
&& cache->sector == sector && cache->data)
{
cache->lock = 1;
grub_free (cache->data);
cache->data = 0;
cache->lock = 0;
}
}
void
grub_disk_cache_invalidate_all (void)
{
unsigned i;
for (i = 0; i < GRUB_DISK_CACHE_NUM; i++)
{
struct grub_disk_cache *cache = grub_disk_cache_table + i;
if (cache->data && ! cache->lock)
{
grub_free (cache->data);
cache->data = 0;
}
}
}
static char *
grub_disk_cache_fetch (unsigned long dev_id, unsigned long disk_id,
grub_disk_addr_t sector)
{
struct grub_disk_cache *cache;
unsigned index;
index = grub_disk_cache_get_index (dev_id, disk_id, sector);
cache = grub_disk_cache_table + index;
if (cache->dev_id == dev_id && cache->disk_id == disk_id
&& cache->sector == sector)
{
cache->lock = 1;
#if DISK_CACHE_STATS
grub_disk_cache_hits++;
#endif
return cache->data;
}
#if DISK_CACHE_STATS
grub_disk_cache_misses++;
#endif
return 0;
}
static void
grub_disk_cache_unlock (unsigned long dev_id, unsigned long disk_id,
grub_disk_addr_t sector)
{
struct grub_disk_cache *cache;
unsigned index;
index = grub_disk_cache_get_index (dev_id, disk_id, sector);
cache = grub_disk_cache_table + index;
if (cache->dev_id == dev_id && cache->disk_id == disk_id
&& cache->sector == sector)
cache->lock = 0;
}
static grub_err_t
grub_disk_cache_store (unsigned long dev_id, unsigned long disk_id,
grub_disk_addr_t sector, const char *data)
{
unsigned index;
struct grub_disk_cache *cache;
index = grub_disk_cache_get_index (dev_id, disk_id, sector);
cache = grub_disk_cache_table + index;
cache->lock = 1;
grub_free (cache->data);
cache->data = 0;
cache->lock = 0;
cache->data = grub_malloc (GRUB_DISK_SECTOR_SIZE << GRUB_DISK_CACHE_BITS);
if (! cache->data)
return grub_errno;
grub_memcpy (cache->data, data,
GRUB_DISK_SECTOR_SIZE << GRUB_DISK_CACHE_BITS);
cache->dev_id = dev_id;
cache->disk_id = disk_id;
cache->sector = sector;
return GRUB_ERR_NONE;
}
grub_disk_dev_t grub_disk_dev_list;
void
grub_disk_dev_register (grub_disk_dev_t dev)
{
dev->next = grub_disk_dev_list;
grub_disk_dev_list = dev;
}
void
grub_disk_dev_unregister (grub_disk_dev_t dev)
{
grub_disk_dev_t *p, q;
for (p = &grub_disk_dev_list, q = *p; q; p = &(q->next), q = q->next)
if (q == dev)
{
*p = q->next;
break;
}
}
/* Return the location of the first ',', if any, which is not
escaped by a '\'. */
static const char *
find_part_sep (const char *name)
{
const char *p = name;
char c;
while ((c = *p++) != '\0')
{
if (c == '\\' && *p == ',')
p++;
else if (c == ',')
return p - 1;
}
return NULL;
}
grub_disk_t
grub_disk_open (const char *name)
{
const char *p;
grub_disk_t disk;
grub_disk_dev_t dev;
char *raw = (char *) name;
grub_uint64_t current_time;
grub_dprintf ("disk", "Opening `%s'...\n", name);
disk = (grub_disk_t) grub_zalloc (sizeof (*disk));
if (! disk)
return 0;
disk->log_sector_size = GRUB_DISK_SECTOR_BITS;
p = find_part_sep (name);
if (p)
{
grub_size_t len = p - name;
raw = grub_malloc (len + 1);
if (! raw)
goto fail;
grub_memcpy (raw, name, len);
raw[len] = '\0';
disk->name = grub_strdup (raw);
}
else
disk->name = grub_strdup (name);
if (! disk->name)
goto fail;
for (dev = grub_disk_dev_list; dev; dev = dev->next)
{
if ((dev->open) (raw, disk) == GRUB_ERR_NONE)
break;
else if (grub_errno == GRUB_ERR_UNKNOWN_DEVICE)
grub_errno = GRUB_ERR_NONE;
else
goto fail;
}
if (! dev)
{
grub_error (GRUB_ERR_UNKNOWN_DEVICE, "no such disk");
goto fail;
}
if (disk->log_sector_size > GRUB_DISK_CACHE_BITS + GRUB_DISK_SECTOR_BITS
|| disk->log_sector_size < GRUB_DISK_SECTOR_BITS)
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"sector sizes of %d bytes aren't supported yet",
(1 << disk->log_sector_size));
goto fail;
}
disk->dev = dev;
if (p)
{
disk->partition = grub_partition_probe (disk, p + 1);
if (! disk->partition)
{
grub_error (GRUB_ERR_UNKNOWN_DEVICE, "no such partition");
goto fail;
}
}
/* The cache will be invalidated about 2 seconds after a device was
closed. */
current_time = grub_get_time_ms ();
if (current_time > (grub_last_time
+ GRUB_CACHE_TIMEOUT * 1000))
grub_disk_cache_invalidate_all ();
grub_last_time = current_time;
fail:
if (raw && raw != name)
grub_free (raw);
if (grub_errno != GRUB_ERR_NONE)
{
grub_error_push ();
grub_dprintf ("disk", "Opening `%s' failed.\n", name);
grub_error_pop ();
grub_disk_close (disk);
return 0;
}
return disk;
}
void
grub_disk_close (grub_disk_t disk)
{
grub_partition_t part;
grub_dprintf ("disk", "Closing `%s'.\n", disk->name);
if (disk->dev && disk->dev->close)
(disk->dev->close) (disk);
/* Reset the timer. */
grub_last_time = grub_get_time_ms ();
while (disk->partition)
{
part = disk->partition->parent;
grub_free (disk->partition);
disk->partition = part;
}
grub_free ((void *) disk->name);
grub_free (disk);
}
/* This function performs three tasks:
- Make sectors disk relative from partition relative.
- Normalize offset to be less than the sector size.
- Verify that the range is inside the partition. */
static grub_err_t
grub_disk_adjust_range (grub_disk_t disk, grub_disk_addr_t *sector,
grub_off_t *offset, grub_size_t size)
{
grub_partition_t part;
*sector += *offset >> GRUB_DISK_SECTOR_BITS;
*offset &= GRUB_DISK_SECTOR_SIZE - 1;
for (part = disk->partition; part; part = part->parent)
{
grub_disk_addr_t start;
grub_uint64_t len;
start = part->start;
len = part->len;
if (*sector >= len
|| len - *sector < ((*offset + size + GRUB_DISK_SECTOR_SIZE - 1)
>> GRUB_DISK_SECTOR_BITS))
return grub_error (GRUB_ERR_OUT_OF_RANGE, "out of partition");
*sector += start;
}
if (disk->total_sectors != GRUB_DISK_SIZE_UNKNOWN
&& ((disk->total_sectors << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)) <= *sector
|| ((*offset + size + GRUB_DISK_SECTOR_SIZE - 1)
>> GRUB_DISK_SECTOR_BITS) > (disk->total_sectors
<< (disk->log_sector_size
- GRUB_DISK_SECTOR_BITS)) - *sector))
return grub_error (GRUB_ERR_OUT_OF_RANGE, "out of disk");
return GRUB_ERR_NONE;
}
static inline grub_disk_addr_t
transform_sector (grub_disk_t disk, grub_disk_addr_t sector)
{
return sector >> (disk->log_sector_size - GRUB_DISK_SECTOR_BITS);
}
/* Small read (less than cache size and not pass across cache unit boundaries).
sector is already adjusted and is divisible by cache unit size.
*/
static grub_err_t
grub_disk_read_small (grub_disk_t disk, grub_disk_addr_t sector,
grub_off_t offset, grub_size_t size, void *buf)
{
char *data;
char *tmp_buf;
/* Fetch the cache. */
data = grub_disk_cache_fetch (disk->dev->id, disk->id, sector);
if (data)
{
/* Just copy it! */
grub_memcpy (buf, data + offset, size);
grub_disk_cache_unlock (disk->dev->id, disk->id, sector);
return GRUB_ERR_NONE;
}
/* Allocate a temporary buffer. */
tmp_buf = grub_malloc (GRUB_DISK_SECTOR_SIZE << GRUB_DISK_CACHE_BITS);
if (! tmp_buf)
return grub_errno;
/* Otherwise read data from the disk actually. */
if (disk->total_sectors == GRUB_DISK_SIZE_UNKNOWN
|| sector + GRUB_DISK_CACHE_SIZE
< (disk->total_sectors << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)))
{
grub_err_t err;
err = (disk->dev->read) (disk, transform_sector (disk, sector),
1 << (GRUB_DISK_CACHE_BITS
+ GRUB_DISK_SECTOR_BITS
- disk->log_sector_size), tmp_buf);
if (!err)
{
/* Copy it and store it in the disk cache. */
grub_memcpy (buf, tmp_buf + offset, size);
grub_disk_cache_store (disk->dev->id, disk->id,
sector, tmp_buf);
grub_free (tmp_buf);
return GRUB_ERR_NONE;
}
}
grub_free (tmp_buf);
grub_errno = GRUB_ERR_NONE;
{
/* Uggh... Failed. Instead, just read necessary data. */
unsigned num;
grub_disk_addr_t aligned_sector;
sector += (offset >> GRUB_DISK_SECTOR_BITS);
offset &= ((1 << GRUB_DISK_SECTOR_BITS) - 1);
aligned_sector = (sector & ~((1 << (disk->log_sector_size
- GRUB_DISK_SECTOR_BITS))
- 1));
offset += ((sector - aligned_sector) << GRUB_DISK_SECTOR_BITS);
num = ((size + offset + (1 << (disk->log_sector_size))
- 1) >> (disk->log_sector_size));
tmp_buf = grub_malloc (num << disk->log_sector_size);
if (!tmp_buf)
return grub_errno;
if ((disk->dev->read) (disk, transform_sector (disk, aligned_sector),
num, tmp_buf))
{
grub_error_push ();
grub_dprintf ("disk", "%s read failed\n", disk->name);
grub_error_pop ();
grub_free (tmp_buf);
return grub_errno;
}
grub_memcpy (buf, tmp_buf + offset, size);
grub_free (tmp_buf);
return GRUB_ERR_NONE;
}
}
/* Read data from the disk. */
grub_err_t
grub_disk_read (grub_disk_t disk, grub_disk_addr_t sector,
grub_off_t offset, grub_size_t size, void *buf)
{
grub_off_t real_offset;
grub_disk_addr_t real_sector;
grub_size_t real_size;
/* First of all, check if the region is within the disk. */
if (grub_disk_adjust_range (disk, §or, &offset, size) != GRUB_ERR_NONE)
{
grub_error_push ();
grub_dprintf ("disk", "Read out of range: sector 0x%llx (%s).\n",
(unsigned long long) sector, grub_errmsg);
grub_error_pop ();
return grub_errno;
}
real_sector = sector;
real_offset = offset;
real_size = size;
/* First read until first cache boundary. */
if (offset || (sector & (GRUB_DISK_CACHE_SIZE - 1)))
{
grub_disk_addr_t start_sector;
grub_size_t pos;
grub_err_t err;
grub_size_t len;
start_sector = sector & ~(GRUB_DISK_CACHE_SIZE - 1);
pos = (sector - start_sector) << GRUB_DISK_SECTOR_BITS;
len = ((GRUB_DISK_SECTOR_SIZE << GRUB_DISK_CACHE_BITS)
- pos - offset);
if (len > size)
len = size;
err = grub_disk_read_small (disk, start_sector,
offset + pos, len, buf);
if (err)
return err;
buf = (char *) buf + len;
size -= len;
offset += len;
sector += (offset >> GRUB_DISK_SECTOR_BITS);
offset &= ((1 << GRUB_DISK_SECTOR_BITS) - 1);
}
/* Until SIZE is zero... */
while (size >= (GRUB_DISK_CACHE_SIZE << GRUB_DISK_SECTOR_BITS))
{
char *data = NULL;
grub_disk_addr_t agglomerate;
grub_err_t err;
/* agglomerate read until we find a first cached entry. */
for (agglomerate = 0; agglomerate
< (size >> (GRUB_DISK_SECTOR_BITS + GRUB_DISK_CACHE_BITS));
agglomerate++)
{
data = grub_disk_cache_fetch (disk->dev->id, disk->id,
sector + (agglomerate
<< GRUB_DISK_CACHE_BITS));
if (data)
break;
}
if (data)
{
grub_memcpy ((char *) buf
+ (agglomerate << (GRUB_DISK_CACHE_BITS
+ GRUB_DISK_SECTOR_BITS)),
data, GRUB_DISK_CACHE_SIZE << GRUB_DISK_SECTOR_BITS);
grub_disk_cache_unlock (disk->dev->id, disk->id,
sector + (agglomerate
<< GRUB_DISK_CACHE_BITS));
}
if (agglomerate)
{
grub_disk_addr_t i;
err = (disk->dev->read) (disk, transform_sector (disk, sector),
agglomerate << (GRUB_DISK_CACHE_BITS
+ GRUB_DISK_SECTOR_BITS
- disk->log_sector_size),
buf);
if (err)
return err;
for (i = 0; i < agglomerate; i ++)
grub_disk_cache_store (disk->dev->id, disk->id,
sector + (i << GRUB_DISK_CACHE_BITS),
(char *) buf
+ (i << (GRUB_DISK_CACHE_BITS
+ GRUB_DISK_SECTOR_BITS)));
sector += agglomerate << GRUB_DISK_CACHE_BITS;
size -= agglomerate << (GRUB_DISK_CACHE_BITS + GRUB_DISK_SECTOR_BITS);
buf = (char *) buf
+ (agglomerate << (GRUB_DISK_CACHE_BITS + GRUB_DISK_SECTOR_BITS));
}
if (data)
{
sector += GRUB_DISK_CACHE_SIZE;
buf = (char *) buf + (GRUB_DISK_CACHE_SIZE << GRUB_DISK_SECTOR_BITS);
size -= (GRUB_DISK_CACHE_SIZE << GRUB_DISK_SECTOR_BITS);
}
}
/* And now read the last part. */
if (size)
{
grub_err_t err;
err = grub_disk_read_small (disk, sector, 0, size, buf);
if (err)
return err;
}
/* Call the read hook, if any. */
if (disk->read_hook)
{
grub_disk_addr_t s = real_sector;
grub_size_t l = real_size;
grub_off_t o = real_offset;
while (l)
{
grub_size_t cl;
cl = GRUB_DISK_SECTOR_SIZE - o;
if (cl > l)
cl = l;
(disk->read_hook) (s, o, cl);
s++;
l -= cl;
o = 0;
}
}
return grub_errno;
}
grub_err_t
grub_disk_write (grub_disk_t disk, grub_disk_addr_t sector,
grub_off_t offset, grub_size_t size, const void *buf)
{
unsigned real_offset;
grub_disk_addr_t aligned_sector;
grub_dprintf ("disk", "Writing `%s'...\n", disk->name);
if (grub_disk_adjust_range (disk, §or, &offset, size) != GRUB_ERR_NONE)
return -1;
aligned_sector = (sector & ~((1 << (disk->log_sector_size
- GRUB_DISK_SECTOR_BITS)) - 1));
real_offset = offset + ((sector - aligned_sector) << GRUB_DISK_SECTOR_BITS);
sector = aligned_sector;
while (size)
{
if (real_offset != 0 || (size < (1U << disk->log_sector_size)
&& size != 0))
{
char tmp_buf[1 << disk->log_sector_size];
grub_size_t len;
grub_partition_t part;
part = disk->partition;
disk->partition = 0;
if (grub_disk_read (disk, sector,
0, (1 << disk->log_sector_size), tmp_buf)
!= GRUB_ERR_NONE)
{
disk->partition = part;
goto finish;
}
disk->partition = part;
len = (1 << disk->log_sector_size) - real_offset;
if (len > size)
len = size;
grub_memcpy (tmp_buf + real_offset, buf, len);
grub_disk_cache_invalidate (disk->dev->id, disk->id, sector);
if ((disk->dev->write) (disk, sector, 1, tmp_buf) != GRUB_ERR_NONE)
goto finish;
sector += (1 << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS));
buf = (char *) buf + len;
size -= len;
real_offset = 0;
}
else
{
grub_size_t len;
grub_size_t n;
len = size & ~((1 << disk->log_sector_size) - 1);
n = size >> disk->log_sector_size;
if ((disk->dev->write) (disk, sector, n, buf) != GRUB_ERR_NONE)
goto finish;
while (n--)
grub_disk_cache_invalidate (disk->dev->id, disk->id, sector++);
buf = (char *) buf + len;
size -= len;
}
}
finish:
return grub_errno;
}
grub_uint64_t
grub_disk_get_size (grub_disk_t disk)
{
if (disk->partition)
return grub_partition_get_len (disk->partition);
else if (disk->total_sectors != GRUB_DISK_SIZE_UNKNOWN)
return disk->total_sectors << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS);
else
return GRUB_DISK_SIZE_UNKNOWN;
}