diff options
Diffstat (limited to 'grub-core/kern/disk.c')
| -rw-r--r-- | grub-core/kern/disk.c | 544 |
1 files changed, 544 insertions, 0 deletions
diff --git a/grub-core/kern/disk.c b/grub-core/kern/disk.c new file mode 100644 index 0000000..e1b0e07 --- /dev/null +++ b/grub-core/kern/disk.c @@ -0,0 +1,544 @@ +/* + * 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> +#include <grub/i18n.h> + +#define GRUB_CACHE_TIMEOUT 2 + +/* The last time the disk was used. */ +static grub_uint64_t grub_last_time = 0; + +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 + +grub_err_t (*grub_disk_write_weak) (grub_disk_t disk, + grub_disk_addr_t sector, + grub_off_t offset, + grub_size_t size, + const void *buf); +#include "disk_common.c" + +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 cache_index; + + cache_index = grub_disk_cache_get_index (dev_id, disk_id, sector); + cache = grub_disk_cache_table + cache_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 cache_index; + + cache_index = grub_disk_cache_get_index (dev_id, disk_id, sector); + cache = grub_disk_cache_table + cache_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 cache_index; + struct grub_disk_cache *cache; + + cache_index = grub_disk_cache_get_index (dev_id, disk_id, sector); + cache = grub_disk_cache_table + cache_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; + /* Default 1MiB of maximum agglomerate. */ + disk->max_agglomerate = 1048576 >> (GRUB_DISK_SECTOR_BITS + + GRUB_DISK_CACHE_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->disk_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, N_("disk `%s' not found"), + name); + 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) + { + /* TRANSLATORS: It means that the specified partition e.g. + hd0,msdos1=/dev/sda1 doesn't exist. */ + grub_error (GRUB_ERR_UNKNOWN_DEVICE, N_("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->disk_close) + (disk->dev->disk_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); +} + +/* 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_real (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->disk_read) (disk, transform_sector (disk, sector), + 1U << (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 & ~((1ULL << (disk->log_sector_size + - GRUB_DISK_SECTOR_BITS)) + - 1)); + offset += ((sector - aligned_sector) << GRUB_DISK_SECTOR_BITS); + num = ((size + offset + (1ULL << (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->disk_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; + } +} + +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) +{ + grub_err_t err; + + err = grub_disk_read_small_real (disk, sector, offset, size, buf); + if (err) + return err; + if (disk->read_hook) + (disk->read_hook) (sector + (offset >> GRUB_DISK_SECTOR_BITS), + offset & (GRUB_DISK_SECTOR_SIZE - 1), + size, disk->read_hook_data); + 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) +{ + /* 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; + } + + /* 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_addr_t) 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 < disk->max_agglomerate; + 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->disk_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))); + + + if (disk->read_hook) + (disk->read_hook) (sector, 0, agglomerate << (GRUB_DISK_CACHE_BITS + GRUB_DISK_SECTOR_BITS), + disk->read_hook_data); + + 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) + { + if (disk->read_hook) + (disk->read_hook) (sector, 0, (GRUB_DISK_CACHE_SIZE << GRUB_DISK_SECTOR_BITS), + disk->read_hook_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; + } + + return grub_errno; +} + +grub_uint64_t +grub_disk_native_sectors (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; +} |