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Diffstat (limited to 'util-linux/volume_id/btrfs.c')
| -rw-r--r-- | util-linux/volume_id/btrfs.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/util-linux/volume_id/btrfs.c b/util-linux/volume_id/btrfs.c new file mode 100644 index 0000000..98f1507 --- /dev/null +++ b/util-linux/volume_id/btrfs.c @@ -0,0 +1,100 @@ +/* + * volume_id - reads filesystem label and uuid + * + * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> + * Copyright (C) 2009 Vladimir Dronnikov <dronnikov@gmail.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include "volume_id_internal.h" + +#define BTRFS_UUID_SIZE 16 +#define BTRFS_LABEL_SIZE 256 +#define BTRFS_CSUM_SIZE 32 +#define BTRFS_FSID_SIZE 16 + +#define BTRFS_MAGIC "_BHRfS_M" + +struct btrfs_dev_item { + uint64_t devid; + uint64_t total_bytes; + uint64_t bytes_used; + uint32_t io_align; + uint32_t io_width; + uint32_t sector_size; + uint64_t type; + uint64_t generation; + uint64_t start_offset; + uint32_t dev_group; + uint8_t seek_speed; + uint8_t bandwidth; + uint8_t uuid[BTRFS_UUID_SIZE]; + uint8_t fsid[BTRFS_UUID_SIZE]; +} PACKED; + +struct btrfs_super_block { + uint8_t csum[BTRFS_CSUM_SIZE]; + uint8_t fsid[BTRFS_FSID_SIZE]; // UUID + uint64_t bytenr; + uint64_t flags; + uint8_t magic[8]; + uint64_t generation; + uint64_t root; + uint64_t chunk_root; + uint64_t log_root; + uint64_t log_root_transid; + uint64_t total_bytes; + uint64_t bytes_used; + uint64_t root_dir_objectid; + uint64_t num_devices; + uint32_t sectorsize; + uint32_t nodesize; + uint32_t leafsize; + uint32_t stripesize; + uint32_t sys_chunk_array_size; + uint64_t chunk_root_generation; + uint64_t compat_flags; + uint64_t compat_ro_flags; + uint64_t incompat_flags; + uint16_t csum_type; + uint8_t root_level; + uint8_t chunk_root_level; + uint8_t log_root_level; + struct btrfs_dev_item dev_item; + uint8_t label[BTRFS_LABEL_SIZE]; // LABEL + // ... +} PACKED; + +int volume_id_probe_btrfs(struct volume_id *id /*,uint64_t off*/) +{ +#define off ((uint64_t) (64 * 1024)) + struct btrfs_super_block *sb; + + dbg("btrfs: probing at offset 0x%llx", (unsigned long long) off); + + sb = volume_id_get_buffer(id, off, sizeof(*sb)); + if (sb == NULL) + return -1; + + if (memcmp(sb->magic, BTRFS_MAGIC, 8) != 0) + return -1; + + // N.B.: btrfs supports 256-byte labels + volume_id_set_label_string(id, sb->label, VOLUME_ID_LABEL_SIZE); + volume_id_set_uuid(id, sb->fsid, UUID_DCE); + + return 0; +} |