/* btrfs.c - B-tree file system. */ /* * GRUB -- GRand Unified Bootloader * Copyright (C) 2010,2011,2012,2013 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 . */ #include #include #include #include #include #include #include #include #include #include #include #include GRUB_MOD_LICENSE ("GPLv3+"); #define GRUB_BTRFS_SIGNATURE "_BHRfS_M" /* From http://www.oberhumer.com/opensource/lzo/lzofaq.php * LZO will expand incompressible data by a little amount. I still haven't * computed the exact values, but I suggest using these formulas for * a worst-case expansion calculation: * * output_block_size = input_block_size + (input_block_size / 16) + 64 + 3 * */ #define GRUB_BTRFS_LZO_BLOCK_SIZE 4096 #define GRUB_BTRFS_LZO_BLOCK_MAX_CSIZE (GRUB_BTRFS_LZO_BLOCK_SIZE + \ (GRUB_BTRFS_LZO_BLOCK_SIZE / 16) + 64 + 3) typedef grub_uint8_t grub_btrfs_checksum_t[0x20]; typedef grub_uint16_t grub_btrfs_uuid_t[8]; struct grub_btrfs_device { grub_uint64_t device_id; grub_uint64_t size; grub_uint8_t dummy[0x62 - 0x10]; } GRUB_PACKED; struct grub_btrfs_superblock { grub_btrfs_checksum_t checksum; grub_btrfs_uuid_t uuid; grub_uint8_t dummy[0x10]; grub_uint8_t signature[sizeof (GRUB_BTRFS_SIGNATURE) - 1]; grub_uint64_t generation; grub_uint64_t root_tree; grub_uint64_t chunk_tree; grub_uint8_t dummy2[0x20]; grub_uint64_t root_dir_objectid; grub_uint8_t dummy3[0x41]; struct grub_btrfs_device this_device; char label[0x100]; grub_uint8_t dummy4[0x100]; grub_uint8_t bootstrap_mapping[0x800]; } GRUB_PACKED; struct btrfs_header { grub_btrfs_checksum_t checksum; grub_btrfs_uuid_t uuid; grub_uint8_t dummy[0x30]; grub_uint32_t nitems; grub_uint8_t level; } GRUB_PACKED; struct grub_btrfs_device_desc { grub_device_t dev; grub_uint64_t id; }; struct grub_btrfs_data { struct grub_btrfs_superblock sblock; grub_uint64_t tree; grub_uint64_t inode; struct grub_btrfs_device_desc *devices_attached; unsigned n_devices_attached; unsigned n_devices_allocated; /* Cached extent data. */ grub_uint64_t extstart; grub_uint64_t extend; grub_uint64_t extino; grub_uint64_t exttree; grub_size_t extsize; struct grub_btrfs_extent_data *extent; }; struct grub_btrfs_chunk_item { grub_uint64_t size; grub_uint64_t dummy; grub_uint64_t stripe_length; grub_uint64_t type; #define GRUB_BTRFS_CHUNK_TYPE_BITS_DONTCARE 0x07 #define GRUB_BTRFS_CHUNK_TYPE_SINGLE 0x00 #define GRUB_BTRFS_CHUNK_TYPE_RAID0 0x08 #define GRUB_BTRFS_CHUNK_TYPE_RAID1 0x10 #define GRUB_BTRFS_CHUNK_TYPE_DUPLICATED 0x20 #define GRUB_BTRFS_CHUNK_TYPE_RAID10 0x40 grub_uint8_t dummy2[0xc]; grub_uint16_t nstripes; grub_uint16_t nsubstripes; } GRUB_PACKED; struct grub_btrfs_chunk_stripe { grub_uint64_t device_id; grub_uint64_t offset; grub_btrfs_uuid_t device_uuid; } GRUB_PACKED; struct grub_btrfs_leaf_node { struct grub_btrfs_key key; grub_uint32_t offset; grub_uint32_t size; } GRUB_PACKED; struct grub_btrfs_internal_node { struct grub_btrfs_key key; grub_uint64_t addr; grub_uint64_t dummy; } GRUB_PACKED; struct grub_btrfs_dir_item { struct grub_btrfs_key key; grub_uint8_t dummy[8]; grub_uint16_t m; grub_uint16_t n; #define GRUB_BTRFS_DIR_ITEM_TYPE_REGULAR 1 #define GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY 2 #define GRUB_BTRFS_DIR_ITEM_TYPE_SYMLINK 7 grub_uint8_t type; char name[0]; } GRUB_PACKED; struct grub_btrfs_leaf_descriptor { unsigned depth; unsigned allocated; struct { grub_disk_addr_t addr; unsigned iter; unsigned maxiter; int leaf; } *data; }; struct grub_btrfs_time { grub_int64_t sec; grub_uint32_t nanosec; } __attribute__ ((aligned (4))); struct grub_btrfs_inode { grub_uint8_t dummy1[0x10]; grub_uint64_t size; grub_uint8_t dummy2[0x70]; struct grub_btrfs_time mtime; } GRUB_PACKED; struct grub_btrfs_extent_data { grub_uint64_t dummy; grub_uint64_t size; grub_uint8_t compression; grub_uint8_t encryption; grub_uint16_t encoding; grub_uint8_t type; union { char inl[0]; struct { grub_uint64_t laddr; grub_uint64_t compressed_size; grub_uint64_t offset; grub_uint64_t filled; }; }; } GRUB_PACKED; #define GRUB_BTRFS_EXTENT_INLINE 0 #define GRUB_BTRFS_EXTENT_REGULAR 1 #define GRUB_BTRFS_COMPRESSION_NONE 0 #define GRUB_BTRFS_COMPRESSION_ZLIB 1 #define GRUB_BTRFS_COMPRESSION_LZO 2 #define GRUB_BTRFS_OBJECT_ID_CHUNK 0x100 static grub_disk_addr_t superblock_sectors[] = { 64 * 2, 64 * 1024 * 2, 256 * 1048576 * 2, 1048576ULL * 1048576ULL * 2 }; static grub_err_t grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr, void *buf, grub_size_t size, int recursion_depth); static grub_err_t read_sblock (grub_disk_t disk, struct grub_btrfs_superblock *sb) { unsigned i; grub_err_t err = GRUB_ERR_NONE; for (i = 0; i < ARRAY_SIZE (superblock_sectors); i++) { struct grub_btrfs_superblock sblock; /* Don't try additional superblocks beyond device size. */ if (i && (grub_le_to_cpu64 (sblock.this_device.size) >> GRUB_DISK_SECTOR_BITS) <= superblock_sectors[i]) break; err = grub_disk_read (disk, superblock_sectors[i], 0, sizeof (sblock), &sblock); if (err == GRUB_ERR_OUT_OF_RANGE) break; if (grub_memcmp ((char *) sblock.signature, GRUB_BTRFS_SIGNATURE, sizeof (GRUB_BTRFS_SIGNATURE) - 1) != 0) break; if (i == 0 || grub_le_to_cpu64 (sblock.generation) > grub_le_to_cpu64 (sb->generation)) grub_memcpy (sb, &sblock, sizeof (sblock)); } if ((err == GRUB_ERR_OUT_OF_RANGE || !err) && i == 0) return grub_error (GRUB_ERR_BAD_FS, "not a Btrfs filesystem"); if (err == GRUB_ERR_OUT_OF_RANGE) grub_errno = err = GRUB_ERR_NONE; return err; } static int key_cmp (const struct grub_btrfs_key *a, const struct grub_btrfs_key *b) { if (grub_le_to_cpu64 (a->object_id) < grub_le_to_cpu64 (b->object_id)) return -1; if (grub_le_to_cpu64 (a->object_id) > grub_le_to_cpu64 (b->object_id)) return +1; if (a->type < b->type) return -1; if (a->type > b->type) return +1; if (grub_le_to_cpu64 (a->offset) < grub_le_to_cpu64 (b->offset)) return -1; if (grub_le_to_cpu64 (a->offset) > grub_le_to_cpu64 (b->offset)) return +1; return 0; } static void free_iterator (struct grub_btrfs_leaf_descriptor *desc) { grub_free (desc->data); } static grub_err_t save_ref (struct grub_btrfs_leaf_descriptor *desc, grub_disk_addr_t addr, unsigned i, unsigned m, int l) { desc->depth++; if (desc->allocated < desc->depth) { void *newdata; desc->allocated *= 2; newdata = grub_realloc (desc->data, sizeof (desc->data[0]) * desc->allocated); if (!newdata) return grub_errno; desc->data = newdata; } desc->data[desc->depth - 1].addr = addr; desc->data[desc->depth - 1].iter = i; desc->data[desc->depth - 1].maxiter = m; desc->data[desc->depth - 1].leaf = l; return GRUB_ERR_NONE; } static int next (struct grub_btrfs_data *data, struct grub_btrfs_leaf_descriptor *desc, grub_disk_addr_t * outaddr, grub_size_t * outsize, struct grub_btrfs_key *key_out) { grub_err_t err; struct grub_btrfs_leaf_node leaf; for (; desc->depth > 0; desc->depth--) { desc->data[desc->depth - 1].iter++; if (desc->data[desc->depth - 1].iter < desc->data[desc->depth - 1].maxiter) break; } if (desc->depth == 0) return 0; while (!desc->data[desc->depth - 1].leaf) { struct grub_btrfs_internal_node node; struct btrfs_header head; err = grub_btrfs_read_logical (data, desc->data[desc->depth - 1].iter * sizeof (node) + sizeof (struct btrfs_header) + desc->data[desc->depth - 1].addr, &node, sizeof (node), 0); if (err) return -err; err = grub_btrfs_read_logical (data, grub_le_to_cpu64 (node.addr), &head, sizeof (head), 0); if (err) return -err; save_ref (desc, grub_le_to_cpu64 (node.addr), 0, grub_le_to_cpu32 (head.nitems), !head.level); } err = grub_btrfs_read_logical (data, desc->data[desc->depth - 1].iter * sizeof (leaf) + sizeof (struct btrfs_header) + desc->data[desc->depth - 1].addr, &leaf, sizeof (leaf), 0); if (err) return -err; *outsize = grub_le_to_cpu32 (leaf.size); *outaddr = desc->data[desc->depth - 1].addr + sizeof (struct btrfs_header) + grub_le_to_cpu32 (leaf.offset); *key_out = leaf.key; return 1; } static grub_err_t lower_bound (struct grub_btrfs_data *data, const struct grub_btrfs_key *key_in, struct grub_btrfs_key *key_out, grub_uint64_t root, grub_disk_addr_t *outaddr, grub_size_t *outsize, struct grub_btrfs_leaf_descriptor *desc, int recursion_depth) { grub_disk_addr_t addr = grub_le_to_cpu64 (root); int depth = -1; if (desc) { desc->allocated = 16; desc->depth = 0; desc->data = grub_malloc (sizeof (desc->data[0]) * desc->allocated); if (!desc->data) return grub_errno; } /* > 2 would work as well but be robust and allow a bit more just in case. */ if (recursion_depth > 10) return grub_error (GRUB_ERR_BAD_FS, "too deep btrfs virtual nesting"); grub_dprintf ("btrfs", "retrieving %" PRIxGRUB_UINT64_T " %x %" PRIxGRUB_UINT64_T "\n", key_in->object_id, key_in->type, key_in->offset); while (1) { grub_err_t err; struct btrfs_header head; reiter: depth++; /* FIXME: preread few nodes into buffer. */ err = grub_btrfs_read_logical (data, addr, &head, sizeof (head), recursion_depth + 1); if (err) return err; addr += sizeof (head); if (head.level) { unsigned i; struct grub_btrfs_internal_node node, node_last; int have_last = 0; grub_memset (&node_last, 0, sizeof (node_last)); for (i = 0; i < grub_le_to_cpu32 (head.nitems); i++) { err = grub_btrfs_read_logical (data, addr + i * sizeof (node), &node, sizeof (node), recursion_depth + 1); if (err) return err; grub_dprintf ("btrfs", "internal node (depth %d) %" PRIxGRUB_UINT64_T " %x %" PRIxGRUB_UINT64_T "\n", depth, node.key.object_id, node.key.type, node.key.offset); if (key_cmp (&node.key, key_in) == 0) { err = GRUB_ERR_NONE; if (desc) err = save_ref (desc, addr - sizeof (head), i, grub_le_to_cpu32 (head.nitems), 0); if (err) return err; addr = grub_le_to_cpu64 (node.addr); goto reiter; } if (key_cmp (&node.key, key_in) > 0) break; node_last = node; have_last = 1; } if (have_last) { err = GRUB_ERR_NONE; if (desc) err = save_ref (desc, addr - sizeof (head), i - 1, grub_le_to_cpu32 (head.nitems), 0); if (err) return err; addr = grub_le_to_cpu64 (node_last.addr); goto reiter; } *outsize = 0; *outaddr = 0; grub_memset (key_out, 0, sizeof (*key_out)); if (desc) return save_ref (desc, addr - sizeof (head), -1, grub_le_to_cpu32 (head.nitems), 0); return GRUB_ERR_NONE; } { unsigned i; struct grub_btrfs_leaf_node leaf, leaf_last; int have_last = 0; for (i = 0; i < grub_le_to_cpu32 (head.nitems); i++) { err = grub_btrfs_read_logical (data, addr + i * sizeof (leaf), &leaf, sizeof (leaf), recursion_depth + 1); if (err) return err; grub_dprintf ("btrfs", "leaf (depth %d) %" PRIxGRUB_UINT64_T " %x %" PRIxGRUB_UINT64_T "\n", depth, leaf.key.object_id, leaf.key.type, leaf.key.offset); if (key_cmp (&leaf.key, key_in) == 0) { grub_memcpy (key_out, &leaf.key, sizeof (*key_out)); *outsize = grub_le_to_cpu32 (leaf.size); *outaddr = addr + grub_le_to_cpu32 (leaf.offset); if (desc) return save_ref (desc, addr - sizeof (head), i, grub_le_to_cpu32 (head.nitems), 1); return GRUB_ERR_NONE; } if (key_cmp (&leaf.key, key_in) > 0) break; have_last = 1; leaf_last = leaf; } if (have_last) { grub_memcpy (key_out, &leaf_last.key, sizeof (*key_out)); *outsize = grub_le_to_cpu32 (leaf_last.size); *outaddr = addr + grub_le_to_cpu32 (leaf_last.offset); if (desc) return save_ref (desc, addr - sizeof (head), i - 1, grub_le_to_cpu32 (head.nitems), 1); return GRUB_ERR_NONE; } *outsize = 0; *outaddr = 0; grub_memset (key_out, 0, sizeof (*key_out)); if (desc) return save_ref (desc, addr - sizeof (head), -1, grub_le_to_cpu32 (head.nitems), 1); return GRUB_ERR_NONE; } } } /* Context for find_device. */ struct find_device_ctx { struct grub_btrfs_data *data; grub_uint64_t id; grub_device_t dev_found; }; /* Helper for find_device. */ static int find_device_iter (const char *name, void *data) { struct find_device_ctx *ctx = data; grub_device_t dev; grub_err_t err; struct grub_btrfs_superblock sb; dev = grub_device_open (name); if (!dev) return 0; if (!dev->disk) { grub_device_close (dev); return 0; } err = read_sblock (dev->disk, &sb); if (err == GRUB_ERR_BAD_FS) { grub_device_close (dev); grub_errno = GRUB_ERR_NONE; return 0; } if (err) { grub_device_close (dev); grub_print_error (); return 0; } if (grub_memcmp (ctx->data->sblock.uuid, sb.uuid, sizeof (sb.uuid)) != 0 || sb.this_device.device_id != ctx->id) { grub_device_close (dev); return 0; } ctx->dev_found = dev; return 1; } static grub_device_t find_device (struct grub_btrfs_data *data, grub_uint64_t id, int do_rescan) { struct find_device_ctx ctx = { .data = data, .id = id, .dev_found = NULL }; unsigned i; for (i = 0; i < data->n_devices_attached; i++) if (id == data->devices_attached[i].id) return data->devices_attached[i].dev; if (do_rescan) grub_device_iterate (find_device_iter, &ctx); if (!ctx.dev_found) { grub_error (GRUB_ERR_BAD_FS, N_("couldn't find a necessary member device " "of multi-device filesystem")); return NULL; } data->n_devices_attached++; if (data->n_devices_attached > data->n_devices_allocated) { void *tmp; data->n_devices_allocated = 2 * data->n_devices_attached + 1; data->devices_attached = grub_realloc (tmp = data->devices_attached, data->n_devices_allocated * sizeof (data->devices_attached[0])); if (!data->devices_attached) { grub_device_close (ctx.dev_found); data->devices_attached = tmp; return NULL; } } data->devices_attached[data->n_devices_attached - 1].id = id; data->devices_attached[data->n_devices_attached - 1].dev = ctx.dev_found; return ctx.dev_found; } static grub_err_t grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr, void *buf, grub_size_t size, int recursion_depth) { while (size > 0) { grub_uint8_t *ptr; struct grub_btrfs_key *key; struct grub_btrfs_chunk_item *chunk; grub_uint64_t csize; grub_err_t err = 0; struct grub_btrfs_key key_out; int challoc = 0; grub_device_t dev; struct grub_btrfs_key key_in; grub_size_t chsize; grub_disk_addr_t chaddr; grub_dprintf ("btrfs", "searching for laddr %" PRIxGRUB_UINT64_T "\n", addr); for (ptr = data->sblock.bootstrap_mapping; ptr < data->sblock.bootstrap_mapping + sizeof (data->sblock.bootstrap_mapping) - sizeof (struct grub_btrfs_key);) { key = (struct grub_btrfs_key *) ptr; if (key->type != GRUB_BTRFS_ITEM_TYPE_CHUNK) break; chunk = (struct grub_btrfs_chunk_item *) (key + 1); grub_dprintf ("btrfs", "%" PRIxGRUB_UINT64_T " %" PRIxGRUB_UINT64_T " \n", grub_le_to_cpu64 (key->offset), grub_le_to_cpu64 (chunk->size)); if (grub_le_to_cpu64 (key->offset) <= addr && addr < grub_le_to_cpu64 (key->offset) + grub_le_to_cpu64 (chunk->size)) goto chunk_found; ptr += sizeof (*key) + sizeof (*chunk) + sizeof (struct grub_btrfs_chunk_stripe) * grub_le_to_cpu16 (chunk->nstripes); } key_in.object_id = grub_cpu_to_le64_compile_time (GRUB_BTRFS_OBJECT_ID_CHUNK); key_in.type = GRUB_BTRFS_ITEM_TYPE_CHUNK; key_in.offset = grub_cpu_to_le64 (addr); err = lower_bound (data, &key_in, &key_out, data->sblock.chunk_tree, &chaddr, &chsize, NULL, recursion_depth); if (err) return err; key = &key_out; if (key->type != GRUB_BTRFS_ITEM_TYPE_CHUNK || !(grub_le_to_cpu64 (key->offset) <= addr)) return grub_error (GRUB_ERR_BAD_FS, "couldn't find the chunk descriptor"); chunk = grub_malloc (chsize); if (!chunk) return grub_errno; challoc = 1; err = grub_btrfs_read_logical (data, chaddr, chunk, chsize, recursion_depth); if (err) { grub_free (chunk); return err; } chunk_found: { grub_uint64_t stripen; grub_uint64_t stripe_offset; grub_uint64_t off = addr - grub_le_to_cpu64 (key->offset); unsigned redundancy = 1; unsigned i, j; if (grub_le_to_cpu64 (chunk->size) <= off) { grub_dprintf ("btrfs", "no chunk\n"); return grub_error (GRUB_ERR_BAD_FS, "couldn't find the chunk descriptor"); } grub_dprintf ("btrfs", "chunk 0x%" PRIxGRUB_UINT64_T "+0x%" PRIxGRUB_UINT64_T " (%d stripes (%d substripes) of %" PRIxGRUB_UINT64_T ")\n", grub_le_to_cpu64 (key->offset), grub_le_to_cpu64 (chunk->size), grub_le_to_cpu16 (chunk->nstripes), grub_le_to_cpu16 (chunk->nsubstripes), grub_le_to_cpu64 (chunk->stripe_length)); switch (grub_le_to_cpu64 (chunk->type) & ~GRUB_BTRFS_CHUNK_TYPE_BITS_DONTCARE) { case GRUB_BTRFS_CHUNK_TYPE_SINGLE: { grub_uint64_t stripe_length; grub_dprintf ("btrfs", "single\n"); stripe_length = grub_divmod64 (grub_le_to_cpu64 (chunk->size), grub_le_to_cpu16 (chunk->nstripes), NULL); stripen = grub_divmod64 (off, stripe_length, &stripe_offset); csize = (stripen + 1) * stripe_length - off; break; } case GRUB_BTRFS_CHUNK_TYPE_DUPLICATED: case GRUB_BTRFS_CHUNK_TYPE_RAID1: { grub_dprintf ("btrfs", "RAID1\n"); stripen = 0; stripe_offset = off; csize = grub_le_to_cpu64 (chunk->size) - off; redundancy = 2; break; } case GRUB_BTRFS_CHUNK_TYPE_RAID0: { grub_uint64_t middle, high; grub_uint64_t low; grub_dprintf ("btrfs", "RAID0\n"); middle = grub_divmod64 (off, grub_le_to_cpu64 (chunk->stripe_length), &low); high = grub_divmod64 (middle, grub_le_to_cpu16 (chunk->nstripes), &stripen); stripe_offset = low + grub_le_to_cpu64 (chunk->stripe_length) * high; csize = grub_le_to_cpu64 (chunk->stripe_length) - low; break; } case GRUB_BTRFS_CHUNK_TYPE_RAID10: { grub_uint64_t middle, high; grub_uint64_t low; middle = grub_divmod64 (off, grub_le_to_cpu64 (chunk->stripe_length), &low); high = grub_divmod64 (middle, grub_le_to_cpu16 (chunk->nstripes) / grub_le_to_cpu16 (chunk->nsubstripes), &stripen); stripen *= grub_le_to_cpu16 (chunk->nsubstripes); redundancy = grub_le_to_cpu16 (chunk->nsubstripes); stripe_offset = low + grub_le_to_cpu64 (chunk->stripe_length) * high; csize = grub_le_to_cpu64 (chunk->stripe_length) - low; break; } default: grub_dprintf ("btrfs", "unsupported RAID\n"); return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, "unsupported RAID flags %" PRIxGRUB_UINT64_T, grub_le_to_cpu64 (chunk->type)); } if (csize == 0) return grub_error (GRUB_ERR_BUG, "couldn't find the chunk descriptor"); if (csize > (grub_uint64_t) size) csize = size; for (j = 0; j < 2; j++) { for (i = 0; i < redundancy; i++) { struct grub_btrfs_chunk_stripe *stripe; grub_disk_addr_t paddr; stripe = (struct grub_btrfs_chunk_stripe *) (chunk + 1); /* Right now the redundancy handling is easy. With RAID5-like it will be more difficult. */ stripe += stripen + i; paddr = grub_le_to_cpu64 (stripe->offset) + stripe_offset; grub_dprintf ("btrfs", "chunk 0x%" PRIxGRUB_UINT64_T "+0x%" PRIxGRUB_UINT64_T " (%d stripes (%d substripes) of %" PRIxGRUB_UINT64_T ") stripe %" PRIxGRUB_UINT64_T " maps to 0x%" PRIxGRUB_UINT64_T "\n", grub_le_to_cpu64 (key->offset), grub_le_to_cpu64 (chunk->size), grub_le_to_cpu16 (chunk->nstripes), grub_le_to_cpu16 (chunk->nsubstripes), grub_le_to_cpu64 (chunk->stripe_length), stripen, stripe->offset); grub_dprintf ("btrfs", "reading paddr 0x%" PRIxGRUB_UINT64_T " for laddr 0x%" PRIxGRUB_UINT64_T "\n", paddr, addr); dev = find_device (data, stripe->device_id, j); if (!dev) { err = grub_errno; grub_errno = GRUB_ERR_NONE; continue; } err = grub_disk_read (dev->disk, paddr >> GRUB_DISK_SECTOR_BITS, paddr & (GRUB_DISK_SECTOR_SIZE - 1), csize, buf); if (!err) break; grub_errno = GRUB_ERR_NONE; } if (i != redundancy) break; } if (err) return grub_errno = err; } size -= csize; buf = (grub_uint8_t *) buf + csize; addr += csize; if (challoc) grub_free (chunk); } return GRUB_ERR_NONE; } static struct grub_btrfs_data * grub_btrfs_mount (grub_device_t dev) { struct grub_btrfs_data *data; grub_err_t err; if (!dev->disk) { grub_error (GRUB_ERR_BAD_FS, "not BtrFS"); return NULL; } data = grub_zalloc (sizeof (*data)); if (!data) return NULL; err = read_sblock (dev->disk, &data->sblock); if (err) { grub_free (data); return NULL; } data->n_devices_allocated = 16; data->devices_attached = grub_malloc (sizeof (data->devices_attached[0]) * data->n_devices_allocated); if (!data->devices_attached) { grub_free (data); return NULL; } data->n_devices_attached = 1; data->devices_attached[0].dev = dev; data->devices_attached[0].id = data->sblock.this_device.device_id; return data; } static void grub_btrfs_unmount (struct grub_btrfs_data *data) { unsigned i; /* The device 0 is closed one layer upper. */ for (i = 1; i < data->n_devices_attached; i++) grub_device_close (data->devices_attached[i].dev); grub_free (data->devices_attached); grub_free (data->extent); grub_free (data); } static grub_err_t grub_btrfs_read_inode (struct grub_btrfs_data *data, struct grub_btrfs_inode *inode, grub_uint64_t num, grub_uint64_t tree) { struct grub_btrfs_key key_in, key_out; grub_disk_addr_t elemaddr; grub_size_t elemsize; grub_err_t err; key_in.object_id = num; key_in.type = GRUB_BTRFS_ITEM_TYPE_INODE_ITEM; key_in.offset = 0; err = lower_bound (data, &key_in, &key_out, tree, &elemaddr, &elemsize, NULL, 0); if (err) return err; if (num != key_out.object_id || key_out.type != GRUB_BTRFS_ITEM_TYPE_INODE_ITEM) return grub_error (GRUB_ERR_BAD_FS, "inode not found"); return grub_btrfs_read_logical (data, elemaddr, inode, sizeof (*inode), 0); } static grub_ssize_t grub_btrfs_lzo_decompress(char *ibuf, grub_size_t isize, grub_off_t off, char *obuf, grub_size_t osize) { grub_uint32_t total_size, cblock_size; grub_size_t ret = 0; char *ibuf0 = ibuf; total_size = grub_le_to_cpu32 (grub_get_unaligned32 (ibuf)); ibuf += sizeof (total_size); if (isize < total_size) return -1; /* Jump forward to first block with requested data. */ while (off >= GRUB_BTRFS_LZO_BLOCK_SIZE) { /* Don't let following uint32_t cross the page boundary. */ if (((ibuf - ibuf0) & 0xffc) == 0xffc) ibuf = ((ibuf - ibuf0 + 3) & ~3) + ibuf0; cblock_size = grub_le_to_cpu32 (grub_get_unaligned32 (ibuf)); ibuf += sizeof (cblock_size); if (cblock_size > GRUB_BTRFS_LZO_BLOCK_MAX_CSIZE) return -1; off -= GRUB_BTRFS_LZO_BLOCK_SIZE; ibuf += cblock_size; } while (osize > 0) { lzo_uint usize = GRUB_BTRFS_LZO_BLOCK_SIZE; /* Don't let following uint32_t cross the page boundary. */ if (((ibuf - ibuf0) & 0xffc) == 0xffc) ibuf = ((ibuf - ibuf0 + 3) & ~3) + ibuf0; cblock_size = grub_le_to_cpu32 (grub_get_unaligned32 (ibuf)); ibuf += sizeof (cblock_size); if (cblock_size > GRUB_BTRFS_LZO_BLOCK_MAX_CSIZE) return -1; /* Block partially filled with requested data. */ if (off > 0 || osize < GRUB_BTRFS_LZO_BLOCK_SIZE) { grub_size_t to_copy = GRUB_BTRFS_LZO_BLOCK_SIZE - off; grub_uint8_t *buf; if (to_copy > osize) to_copy = osize; buf = grub_malloc (GRUB_BTRFS_LZO_BLOCK_SIZE); if (!buf) return -1; if (lzo1x_decompress_safe ((lzo_bytep)ibuf, cblock_size, buf, &usize, NULL) != LZO_E_OK) { grub_free (buf); return -1; } if (to_copy > usize) to_copy = usize; grub_memcpy(obuf, buf + off, to_copy); osize -= to_copy; ret += to_copy; obuf += to_copy; ibuf += cblock_size; off = 0; grub_free (buf); continue; } /* Decompress whole block directly to output buffer. */ if (lzo1x_decompress_safe ((lzo_bytep)ibuf, cblock_size, (lzo_bytep)obuf, &usize, NULL) != LZO_E_OK) return -1; osize -= usize; ret += usize; obuf += usize; ibuf += cblock_size; } return ret; } static grub_ssize_t grub_btrfs_extent_read (struct grub_btrfs_data *data, grub_uint64_t ino, grub_uint64_t tree, grub_off_t pos0, char *buf, grub_size_t len) { grub_off_t pos = pos0; while (len) { grub_size_t csize; grub_err_t err; grub_off_t extoff; if (!data->extent || data->extstart > pos || data->extino != ino || data->exttree != tree || data->extend <= pos) { struct grub_btrfs_key key_in, key_out; grub_disk_addr_t elemaddr; grub_size_t elemsize; grub_free (data->extent); key_in.object_id = ino; key_in.type = GRUB_BTRFS_ITEM_TYPE_EXTENT_ITEM; key_in.offset = grub_cpu_to_le64 (pos); err = lower_bound (data, &key_in, &key_out, tree, &elemaddr, &elemsize, NULL, 0); if (err) return -1; if (key_out.object_id != ino || key_out.type != GRUB_BTRFS_ITEM_TYPE_EXTENT_ITEM) { grub_error (GRUB_ERR_BAD_FS, "extent not found"); return -1; } if ((grub_ssize_t) elemsize < ((char *) &data->extent->inl - (char *) data->extent)) { grub_error (GRUB_ERR_BAD_FS, "extent descriptor is too short"); return -1; } data->extstart = grub_le_to_cpu64 (key_out.offset); data->extsize = elemsize; data->extent = grub_malloc (elemsize); data->extino = ino; data->exttree = tree; if (!data->extent) return grub_errno; err = grub_btrfs_read_logical (data, elemaddr, data->extent, elemsize, 0); if (err) return err; data->extend = data->extstart + grub_le_to_cpu64 (data->extent->size); if (data->extent->type == GRUB_BTRFS_EXTENT_REGULAR && (char *) data->extent + elemsize >= (char *) &data->extent->filled + sizeof (data->extent->filled)) data->extend = data->extstart + grub_le_to_cpu64 (data->extent->filled); grub_dprintf ("btrfs", "regular extent 0x%" PRIxGRUB_UINT64_T "+0x%" PRIxGRUB_UINT64_T "\n", grub_le_to_cpu64 (key_out.offset), grub_le_to_cpu64 (data->extent->size)); if (data->extend <= pos) { grub_error (GRUB_ERR_BAD_FS, "extent not found"); return -1; } } csize = data->extend - pos; extoff = pos - data->extstart; if (csize > len) csize = len; if (data->extent->encryption) { grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, "encryption not supported"); return -1; } if (data->extent->compression != GRUB_BTRFS_COMPRESSION_NONE && data->extent->compression != GRUB_BTRFS_COMPRESSION_ZLIB && data->extent->compression != GRUB_BTRFS_COMPRESSION_LZO) { grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, "compression type 0x%x not supported", data->extent->compression); return -1; } if (data->extent->encoding) { grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, "encoding not supported"); return -1; } switch (data->extent->type) { case GRUB_BTRFS_EXTENT_INLINE: if (data->extent->compression == GRUB_BTRFS_COMPRESSION_ZLIB) { if (grub_zlib_decompress (data->extent->inl, data->extsize - ((grub_uint8_t *) data->extent->inl - (grub_uint8_t *) data->extent), extoff, buf, csize) != (grub_ssize_t) csize) { if (!grub_errno) grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "premature end of compressed"); return -1; } } else if (data->extent->compression == GRUB_BTRFS_COMPRESSION_LZO) { if (grub_btrfs_lzo_decompress(data->extent->inl, data->extsize - ((grub_uint8_t *) data->extent->inl - (grub_uint8_t *) data->extent), extoff, buf, csize) != (grub_ssize_t) csize) return -1; } else grub_memcpy (buf, data->extent->inl + extoff, csize); break; case GRUB_BTRFS_EXTENT_REGULAR: if (!data->extent->laddr) { grub_memset (buf, 0, csize); break; } if (data->extent->compression != GRUB_BTRFS_COMPRESSION_NONE) { char *tmp; grub_uint64_t zsize; grub_ssize_t ret; zsize = grub_le_to_cpu64 (data->extent->compressed_size); tmp = grub_malloc (zsize); if (!tmp) return -1; err = grub_btrfs_read_logical (data, grub_le_to_cpu64 (data->extent->laddr), tmp, zsize, 0); if (err) { grub_free (tmp); return -1; } if (data->extent->compression == GRUB_BTRFS_COMPRESSION_ZLIB) ret = grub_zlib_decompress (tmp, zsize, extoff + grub_le_to_cpu64 (data->extent->offset), buf, csize); else if (data->extent->compression == GRUB_BTRFS_COMPRESSION_LZO) ret = grub_btrfs_lzo_decompress (tmp, zsize, extoff + grub_le_to_cpu64 (data->extent->offset), buf, csize); else ret = -1; grub_free (tmp); if (ret != (grub_ssize_t) csize) { if (!grub_errno) grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "premature end of compressed"); return -1; } break; } err = grub_btrfs_read_logical (data, grub_le_to_cpu64 (data->extent->laddr) + grub_le_to_cpu64 (data->extent->offset) + extoff, buf, csize, 0); if (err) return -1; break; default: grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, "unsupported extent type 0x%x", data->extent->type); return -1; } buf += csize; pos += csize; len -= csize; } return pos - pos0; } static grub_err_t get_root (struct grub_btrfs_data *data, struct grub_btrfs_key *key, grub_uint64_t *tree, grub_uint8_t *type) { grub_err_t err; grub_disk_addr_t elemaddr; grub_size_t elemsize; struct grub_btrfs_key key_out, key_in; struct grub_btrfs_root_item ri; key_in.object_id = grub_cpu_to_le64_compile_time (GRUB_BTRFS_ROOT_VOL_OBJECTID); key_in.offset = 0; key_in.type = GRUB_BTRFS_ITEM_TYPE_ROOT_ITEM; err = lower_bound (data, &key_in, &key_out, data->sblock.root_tree, &elemaddr, &elemsize, NULL, 0); if (err) return err; if (key_in.object_id != key_out.object_id || key_in.type != key_out.type || key_in.offset != key_out.offset) return grub_error (GRUB_ERR_BAD_FS, "no root"); err = grub_btrfs_read_logical (data, elemaddr, &ri, sizeof (ri), 0); if (err) return err; key->type = GRUB_BTRFS_ITEM_TYPE_DIR_ITEM; key->offset = 0; key->object_id = grub_cpu_to_le64_compile_time (GRUB_BTRFS_OBJECT_ID_CHUNK); *tree = ri.tree; *type = GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY; return GRUB_ERR_NONE; } static grub_err_t find_path (struct grub_btrfs_data *data, const char *path, struct grub_btrfs_key *key, grub_uint64_t *tree, grub_uint8_t *type) { const char *slash = path; grub_err_t err; grub_disk_addr_t elemaddr; grub_size_t elemsize; grub_size_t allocated = 0; struct grub_btrfs_dir_item *direl = NULL; struct grub_btrfs_key key_out; const char *ctoken; grub_size_t ctokenlen; char *path_alloc = NULL; char *origpath = NULL; unsigned symlinks_max = 32; err = get_root (data, key, tree, type); if (err) return err; origpath = grub_strdup (path); if (!origpath) return grub_errno; while (1) { while (path[0] == '/') path++; if (!path[0]) break; slash = grub_strchr (path, '/'); if (!slash) slash = path + grub_strlen (path); ctoken = path; ctokenlen = slash - path; if (*type != GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY) { grub_free (path_alloc); grub_free (origpath); return grub_error (GRUB_ERR_BAD_FILE_TYPE, N_("not a directory")); } if (ctokenlen == 1 && ctoken[0] == '.') { path = slash; continue; } if (ctokenlen == 2 && ctoken[0] == '.' && ctoken[1] == '.') { key->type = GRUB_BTRFS_ITEM_TYPE_INODE_REF; key->offset = -1; err = lower_bound (data, key, &key_out, *tree, &elemaddr, &elemsize, NULL, 0); if (err) { grub_free (direl); grub_free (path_alloc); grub_free (origpath); return err; } if (key_out.type != key->type || key->object_id != key_out.object_id) { grub_free (direl); grub_free (path_alloc); err = grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("file `%s' not found"), origpath); grub_free (origpath); return err; } *type = GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY; key->object_id = key_out.offset; path = slash; continue; } key->type = GRUB_BTRFS_ITEM_TYPE_DIR_ITEM; key->offset = grub_cpu_to_le64 (~grub_getcrc32c (1, ctoken, ctokenlen)); err = lower_bound (data, key, &key_out, *tree, &elemaddr, &elemsize, NULL, 0); if (err) { grub_free (direl); grub_free (path_alloc); grub_free (origpath); return err; } if (key_cmp (key, &key_out) != 0) { grub_free (direl); grub_free (path_alloc); err = grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("file `%s' not found"), origpath); grub_free (origpath); return err; } struct grub_btrfs_dir_item *cdirel; if (elemsize > allocated) { allocated = 2 * elemsize; grub_free (direl); direl = grub_malloc (allocated + 1); if (!direl) { grub_free (path_alloc); grub_free (origpath); return grub_errno; } } err = grub_btrfs_read_logical (data, elemaddr, direl, elemsize, 0); if (err) { grub_free (direl); grub_free (path_alloc); grub_free (origpath); return err; } for (cdirel = direl; (grub_uint8_t *) cdirel - (grub_uint8_t *) direl < (grub_ssize_t) elemsize; cdirel = (void *) ((grub_uint8_t *) (direl + 1) + grub_le_to_cpu16 (cdirel->n) + grub_le_to_cpu16 (cdirel->m))) { if (ctokenlen == grub_le_to_cpu16 (cdirel->n) && grub_memcmp (cdirel->name, ctoken, ctokenlen) == 0) break; } if ((grub_uint8_t *) cdirel - (grub_uint8_t *) direl >= (grub_ssize_t) elemsize) { grub_free (direl); grub_free (path_alloc); err = grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("file `%s' not found"), origpath); grub_free (origpath); return err; } path = slash; if (cdirel->type == GRUB_BTRFS_DIR_ITEM_TYPE_SYMLINK) { struct grub_btrfs_inode inode; char *tmp; if (--symlinks_max == 0) { grub_free (direl); grub_free (path_alloc); grub_free (origpath); return grub_error (GRUB_ERR_SYMLINK_LOOP, N_("too deep nesting of symlinks")); } err = grub_btrfs_read_inode (data, &inode, cdirel->key.object_id, *tree); if (err) { grub_free (direl); grub_free (path_alloc); grub_free (origpath); return err; } tmp = grub_malloc (grub_le_to_cpu64 (inode.size) + grub_strlen (path) + 1); if (!tmp) { grub_free (direl); grub_free (path_alloc); grub_free (origpath); return grub_errno; } if (grub_btrfs_extent_read (data, cdirel->key.object_id, *tree, 0, tmp, grub_le_to_cpu64 (inode.size)) != (grub_ssize_t) grub_le_to_cpu64 (inode.size)) { grub_free (direl); grub_free (path_alloc); grub_free (origpath); grub_free (tmp); return grub_errno; } grub_memcpy (tmp + grub_le_to_cpu64 (inode.size), path, grub_strlen (path) + 1); grub_free (path_alloc); path = path_alloc = tmp; if (path[0] == '/') { err = get_root (data, key, tree, type); if (err) return err; } continue; } *type = cdirel->type; switch (cdirel->key.type) { case GRUB_BTRFS_ITEM_TYPE_ROOT_ITEM: { struct grub_btrfs_root_item ri; err = lower_bound (data, &cdirel->key, &key_out, data->sblock.root_tree, &elemaddr, &elemsize, NULL, 0); if (err) { grub_free (direl); grub_free (path_alloc); grub_free (origpath); return err; } if (cdirel->key.object_id != key_out.object_id || cdirel->key.type != key_out.type) { grub_free (direl); grub_free (path_alloc); err = grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("file `%s' not found"), origpath); grub_free (origpath); return err; } err = grub_btrfs_read_logical (data, elemaddr, &ri, sizeof (ri), 0); if (err) { grub_free (direl); grub_free (path_alloc); grub_free (origpath); return err; } key->type = GRUB_BTRFS_ITEM_TYPE_DIR_ITEM; key->offset = 0; key->object_id = grub_cpu_to_le64_compile_time (GRUB_BTRFS_OBJECT_ID_CHUNK); *tree = ri.tree; break; } case GRUB_BTRFS_ITEM_TYPE_INODE_ITEM: if (*slash && *type == GRUB_BTRFS_DIR_ITEM_TYPE_REGULAR) { grub_free (direl); grub_free (path_alloc); err = grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("file `%s' not found"), origpath); grub_free (origpath); return err; } *key = cdirel->key; if (*type == GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY) key->type = GRUB_BTRFS_ITEM_TYPE_DIR_ITEM; break; default: grub_free (path_alloc); grub_free (origpath); grub_free (direl); return grub_error (GRUB_ERR_BAD_FS, "unrecognised object type 0x%x", cdirel->key.type); } } grub_free (direl); grub_free (origpath); grub_free (path_alloc); return GRUB_ERR_NONE; } static grub_err_t grub_btrfs_dir (grub_device_t device, const char *path, grub_fs_dir_hook_t hook, void *hook_data) { struct grub_btrfs_data *data = grub_btrfs_mount (device); struct grub_btrfs_key key_in, key_out; grub_err_t err; grub_disk_addr_t elemaddr; grub_size_t elemsize; grub_size_t allocated = 0; struct grub_btrfs_dir_item *direl = NULL; struct grub_btrfs_leaf_descriptor desc; int r = 0; grub_uint64_t tree; grub_uint8_t type; if (!data) return grub_errno; err = find_path (data, path, &key_in, &tree, &type); if (err) { grub_btrfs_unmount (data); return err; } if (type != GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY) { grub_btrfs_unmount (data); return grub_error (GRUB_ERR_BAD_FILE_TYPE, N_("not a directory")); } err = lower_bound (data, &key_in, &key_out, tree, &elemaddr, &elemsize, &desc, 0); if (err) { grub_btrfs_unmount (data); return err; } if (key_out.type != GRUB_BTRFS_ITEM_TYPE_DIR_ITEM || key_out.object_id != key_in.object_id) { r = next (data, &desc, &elemaddr, &elemsize, &key_out); if (r <= 0) goto out; } do { struct grub_btrfs_dir_item *cdirel; if (key_out.type != GRUB_BTRFS_ITEM_TYPE_DIR_ITEM || key_out.object_id != key_in.object_id) { r = 0; break; } if (elemsize > allocated) { allocated = 2 * elemsize; grub_free (direl); direl = grub_malloc (allocated + 1); if (!direl) { r = -grub_errno; break; } } err = grub_btrfs_read_logical (data, elemaddr, direl, elemsize, 0); if (err) { r = -err; break; } for (cdirel = direl; (grub_uint8_t *) cdirel - (grub_uint8_t *) direl < (grub_ssize_t) elemsize; cdirel = (void *) ((grub_uint8_t *) (direl + 1) + grub_le_to_cpu16 (cdirel->n) + grub_le_to_cpu16 (cdirel->m))) { char c; struct grub_btrfs_inode inode; struct grub_dirhook_info info; err = grub_btrfs_read_inode (data, &inode, cdirel->key.object_id, tree); grub_memset (&info, 0, sizeof (info)); if (err) grub_errno = GRUB_ERR_NONE; else { info.mtime = grub_le_to_cpu64 (inode.mtime.sec); info.mtimeset = 1; } c = cdirel->name[grub_le_to_cpu16 (cdirel->n)]; cdirel->name[grub_le_to_cpu16 (cdirel->n)] = 0; info.dir = (cdirel->type == GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY); if (hook (cdirel->name, &info, hook_data)) goto out; cdirel->name[grub_le_to_cpu16 (cdirel->n)] = c; } r = next (data, &desc, &elemaddr, &elemsize, &key_out); } while (r > 0); out: grub_free (direl); free_iterator (&desc); grub_btrfs_unmount (data); return -r; } static grub_err_t grub_btrfs_open (struct grub_file *file, const char *name) { struct grub_btrfs_data *data = grub_btrfs_mount (file->device); grub_err_t err; struct grub_btrfs_inode inode; grub_uint8_t type; struct grub_btrfs_key key_in; if (!data) return grub_errno; err = find_path (data, name, &key_in, &data->tree, &type); if (err) { grub_btrfs_unmount (data); return err; } if (type != GRUB_BTRFS_DIR_ITEM_TYPE_REGULAR) { grub_btrfs_unmount (data); return grub_error (GRUB_ERR_BAD_FILE_TYPE, N_("not a regular file")); } data->inode = key_in.object_id; err = grub_btrfs_read_inode (data, &inode, data->inode, data->tree); if (err) { grub_btrfs_unmount (data); return err; } file->data = data; file->size = grub_le_to_cpu64 (inode.size); return err; } static grub_err_t grub_btrfs_close (grub_file_t file) { grub_btrfs_unmount (file->data); return GRUB_ERR_NONE; } static grub_ssize_t grub_btrfs_read (grub_file_t file, char *buf, grub_size_t len) { struct grub_btrfs_data *data = file->data; return grub_btrfs_extent_read (data, data->inode, data->tree, file->offset, buf, len); } static grub_err_t grub_btrfs_uuid (grub_device_t device, char **uuid) { struct grub_btrfs_data *data; *uuid = NULL; data = grub_btrfs_mount (device); if (!data) return grub_errno; *uuid = grub_xasprintf ("%04x%04x-%04x-%04x-%04x-%04x%04x%04x", grub_be_to_cpu16 (data->sblock.uuid[0]), grub_be_to_cpu16 (data->sblock.uuid[1]), grub_be_to_cpu16 (data->sblock.uuid[2]), grub_be_to_cpu16 (data->sblock.uuid[3]), grub_be_to_cpu16 (data->sblock.uuid[4]), grub_be_to_cpu16 (data->sblock.uuid[5]), grub_be_to_cpu16 (data->sblock.uuid[6]), grub_be_to_cpu16 (data->sblock.uuid[7])); grub_btrfs_unmount (data); return grub_errno; } static grub_err_t grub_btrfs_label (grub_device_t device, char **label) { struct grub_btrfs_data *data; *label = NULL; data = grub_btrfs_mount (device); if (!data) return grub_errno; *label = grub_strndup (data->sblock.label, sizeof (data->sblock.label)); grub_btrfs_unmount (data); return grub_errno; } #ifdef GRUB_UTIL static grub_err_t grub_btrfs_embed (grub_device_t device __attribute__ ((unused)), unsigned int *nsectors, unsigned int max_nsectors, grub_embed_type_t embed_type, grub_disk_addr_t **sectors) { unsigned i; if (embed_type != GRUB_EMBED_PCBIOS) return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, "BtrFS currently supports only PC-BIOS embedding"); if (64 * 2 - 1 < *nsectors) return grub_error (GRUB_ERR_OUT_OF_RANGE, N_("your core.img is unusually large. " "It won't fit in the embedding area")); *nsectors = 64 * 2 - 1; if (*nsectors > max_nsectors) *nsectors = max_nsectors; *sectors = grub_malloc (*nsectors * sizeof (**sectors)); if (!*sectors) return grub_errno; for (i = 0; i < *nsectors; i++) (*sectors)[i] = i + 1; return GRUB_ERR_NONE; } #endif static struct grub_fs grub_btrfs_fs = { .name = "btrfs", .dir = grub_btrfs_dir, .open = grub_btrfs_open, .read = grub_btrfs_read, .close = grub_btrfs_close, .uuid = grub_btrfs_uuid, .label = grub_btrfs_label, #ifdef GRUB_UTIL .embed = grub_btrfs_embed, .reserved_first_sector = 1, .blocklist_install = 0, #endif }; GRUB_MOD_INIT (btrfs) { grub_fs_register (&grub_btrfs_fs); } GRUB_MOD_FINI (btrfs) { grub_fs_unregister (&grub_btrfs_fs); }