133 lines
3.3 KiB
C
133 lines
3.3 KiB
C
/* btrfs.c - B-tree file system. */
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2010 Free Software Foundation, Inc.
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*
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <grub/err.h>
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#include <grub/file.h>
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#include <grub/mm.h>
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#include <grub/misc.h>
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#include <grub/disk.h>
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#include <grub/dl.h>
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#include <grub/types.h>
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#define BTRFS_SIGNATURE "_BHRfS_M"
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struct btrfs_superblock
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{
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grub_uint8_t dummy1[32];
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grub_uint16_t uuid[8];
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grub_uint8_t dummy2[16];
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grub_uint8_t signature[sizeof (BTRFS_SIGNATURE) - 1];
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} __attribute__ ((packed));
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struct grub_btrfs_data
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{
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struct btrfs_superblock sblock;
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};
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static struct grub_btrfs_data *
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grub_btrfs_mount (grub_disk_t disk)
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{
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struct grub_btrfs_data *data = grub_malloc (sizeof (*data));
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if (! data)
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return NULL;
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if (grub_disk_read (disk, 128, 0, sizeof (data->sblock),
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&data->sblock) != GRUB_ERR_NONE)
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goto fail;
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if (grub_strncmp ((char *) data->sblock.signature, BTRFS_SIGNATURE, sizeof (BTRFS_SIGNATURE) - 1))
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{
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grub_error (GRUB_ERR_BAD_FS, "not a Btrfs filesystem");
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goto fail;
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}
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return data;
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fail:
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grub_free (data);
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return NULL;
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}
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static grub_err_t
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grub_btrfs_open (struct grub_file *file __attribute__ ((unused)),
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const char *name __attribute__ ((unused)))
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{
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return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, "only detection is supported for Btrfs");
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}
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static grub_err_t
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grub_btrfs_dir (grub_device_t device,
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const char *path __attribute__ ((unused)),
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int (*hook) (const char *filename,
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const struct grub_dirhook_info *info)
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__attribute__ ((unused)))
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{
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struct grub_btrfs_data *data = grub_btrfs_mount (device->disk);
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if (grub_errno)
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return grub_errno;
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grub_free (data);
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return GRUB_ERR_NONE;
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}
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static grub_err_t
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grub_btrfs_uuid (grub_device_t device, char **uuid)
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{
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struct grub_btrfs_data *data;
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*uuid = NULL;
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data = grub_btrfs_mount (device->disk);
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if (! data)
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return grub_errno;
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*uuid = grub_xasprintf ("%04x%04x-%04x-%04x-%04x-%04x%04x%04x",
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grub_be_to_cpu16 (data->sblock.uuid[0]),
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grub_be_to_cpu16 (data->sblock.uuid[1]),
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grub_be_to_cpu16 (data->sblock.uuid[2]),
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grub_be_to_cpu16 (data->sblock.uuid[3]),
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grub_be_to_cpu16 (data->sblock.uuid[4]),
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grub_be_to_cpu16 (data->sblock.uuid[5]),
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grub_be_to_cpu16 (data->sblock.uuid[6]),
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grub_be_to_cpu16 (data->sblock.uuid[7]));
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grub_free (data);
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return grub_errno;
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}
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static struct grub_fs grub_btrfs_fs =
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{
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.name = "btrfs",
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.dir = grub_btrfs_dir,
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.open = grub_btrfs_open,
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.uuid = grub_btrfs_uuid,
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};
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GRUB_MOD_INIT(btrfs)
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{
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grub_fs_register (&grub_btrfs_fs);
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}
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GRUB_MOD_FINI(btrfs)
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{
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grub_fs_unregister (&grub_btrfs_fs);
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}
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