diff options
Diffstat (limited to 'grub-core/kern/fs.c')
| -rw-r--r-- | grub-core/kern/fs.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/grub-core/kern/fs.c b/grub-core/kern/fs.c new file mode 100644 index 0000000..c698295 --- /dev/null +++ b/grub-core/kern/fs.c @@ -0,0 +1,253 @@ +/* fs.c - filesystem manager */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2002,2005,2007 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/net.h> +#include <grub/fs.h> +#include <grub/file.h> +#include <grub/err.h> +#include <grub/misc.h> +#include <grub/types.h> +#include <grub/mm.h> +#include <grub/term.h> +#include <grub/i18n.h> + +grub_fs_t grub_fs_list = 0; + +grub_fs_autoload_hook_t grub_fs_autoload_hook = 0; + +/* Helper for grub_fs_probe. */ +static int +probe_dummy_iter (const char *filename __attribute__ ((unused)), + const struct grub_dirhook_info *info __attribute__ ((unused)), + void *data __attribute__ ((unused))) +{ + return 1; +} + +grub_fs_t +grub_fs_probe (grub_device_t device) +{ + grub_fs_t p; + + if (device->disk) + { + /* Make it sure not to have an infinite recursive calls. */ + static int count = 0; + + for (p = grub_fs_list; p; p = p->next) + { + grub_dprintf ("fs", "Detecting %s...\n", p->name); + + /* This is evil: newly-created just mounted BtrFS after copying all + GRUB files has a very peculiar unrecoverable corruption which + will be fixed at sync but we'd rather not do a global sync and + syncing just files doesn't seem to help. Relax the check for + this time. */ +#ifdef GRUB_UTIL + if (grub_strcmp (p->name, "btrfs") == 0) + { + char *label = 0; + p->fs_uuid (device, &label); + if (label) + grub_free (label); + } + else +#endif + (p->fs_dir) (device, "/", probe_dummy_iter, NULL); + if (grub_errno == GRUB_ERR_NONE) + return p; + + grub_error_push (); + grub_dprintf ("fs", "%s detection failed.\n", p->name); + grub_error_pop (); + + if (grub_errno != GRUB_ERR_BAD_FS + && grub_errno != GRUB_ERR_OUT_OF_RANGE) + return 0; + + grub_errno = GRUB_ERR_NONE; + } + + /* Let's load modules automatically. */ + if (grub_fs_autoload_hook && count == 0) + { + count++; + + while (grub_fs_autoload_hook ()) + { + p = grub_fs_list; + + (p->fs_dir) (device, "/", probe_dummy_iter, NULL); + if (grub_errno == GRUB_ERR_NONE) + { + count--; + return p; + } + + if (grub_errno != GRUB_ERR_BAD_FS + && grub_errno != GRUB_ERR_OUT_OF_RANGE) + { + count--; + return 0; + } + + grub_errno = GRUB_ERR_NONE; + } + + count--; + } + } + else if (device->net && device->net->fs) + return device->net->fs; + + grub_error (GRUB_ERR_UNKNOWN_FS, N_("unknown filesystem")); + return 0; +} + + + +/* Block list support routines. */ + +struct grub_fs_block +{ + grub_disk_addr_t offset; + unsigned long length; +}; + +static grub_err_t +grub_fs_blocklist_open (grub_file_t file, const char *name) +{ + const char *p = name; + unsigned num = 0; + unsigned i; + grub_disk_t disk = file->device->disk; + struct grub_fs_block *blocks; + grub_size_t max_sectors; + + /* First, count the number of blocks. */ + do + { + num++; + p = grub_strchr (p, ','); + if (p) + p++; + } + while (p); + + /* Allocate a block list. */ + blocks = grub_calloc (num + 1, sizeof (struct grub_fs_block)); + if (! blocks) + return 0; + + file->size = 0; + max_sectors = grub_disk_from_native_sector (disk, disk->total_sectors); + p = (char *) name; + for (i = 0; i < num; i++) + { + if (*p != '+') + { + blocks[i].offset = grub_strtoull (p, &p, 0); + if (grub_errno != GRUB_ERR_NONE || *p != '+') + { + grub_error (GRUB_ERR_BAD_FILENAME, + N_("invalid file name `%s'"), name); + goto fail; + } + } + + p++; + blocks[i].length = grub_strtoul (p, &p, 0); + if (grub_errno != GRUB_ERR_NONE + || blocks[i].length == 0 + || (*p && *p != ',' && ! grub_isspace (*p))) + { + grub_error (GRUB_ERR_BAD_FILENAME, + N_("invalid file name `%s'"), name); + goto fail; + } + + if (max_sectors < blocks[i].offset + blocks[i].length) + { + grub_error (GRUB_ERR_BAD_FILENAME, "beyond the total sectors"); + goto fail; + } + + file->size += (blocks[i].length << GRUB_DISK_SECTOR_BITS); + p++; + } + + file->data = blocks; + + return GRUB_ERR_NONE; + + fail: + grub_free (blocks); + return grub_errno; +} + +static grub_ssize_t +grub_fs_blocklist_read (grub_file_t file, char *buf, grub_size_t len) +{ + struct grub_fs_block *p; + grub_disk_addr_t sector; + grub_off_t offset; + grub_ssize_t ret = 0; + + if (len > file->size - file->offset) + len = file->size - file->offset; + + sector = (file->offset >> GRUB_DISK_SECTOR_BITS); + offset = (file->offset & (GRUB_DISK_SECTOR_SIZE - 1)); + for (p = file->data; p->length && len > 0; p++) + { + if (sector < p->length) + { + grub_size_t size; + + size = len; + if (((size + offset + GRUB_DISK_SECTOR_SIZE - 1) + >> GRUB_DISK_SECTOR_BITS) > p->length - sector) + size = ((p->length - sector) << GRUB_DISK_SECTOR_BITS) - offset; + + if (grub_disk_read (file->device->disk, p->offset + sector, offset, + size, buf) != GRUB_ERR_NONE) + return -1; + + ret += size; + len -= size; + sector -= ((size + offset) >> GRUB_DISK_SECTOR_BITS); + offset = ((size + offset) & (GRUB_DISK_SECTOR_SIZE - 1)); + } + else + sector -= p->length; + } + + return ret; +} + +struct grub_fs grub_fs_blocklist = + { + .name = "blocklist", + .fs_dir = 0, + .fs_open = grub_fs_blocklist_open, + .fs_read = grub_fs_blocklist_read, + .fs_close = 0, + .next = 0 + }; |