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grub/grub-core/fs/btrfs.c
Vladimir 'phcoder' Serbinenko 1f60e35331 initialise the type of search for root
2010-12-02 00:03:19 +01:00

1066 lines
27 KiB
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/* btrfs.c - B-tree file system. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 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/err.h>
#include <grub/file.h>
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/disk.h>
#include <grub/dl.h>
#include <grub/types.h>
#include <grub/lib/crc.h>
#define BTRFS_SIGNATURE "_BHRfS_M"
typedef grub_uint8_t btrfs_checksum_t[0x20];
typedef grub_uint16_t btrfs_uuid_t[8];
struct grub_btrfs_device
{
grub_uint64_t device_id;
grub_uint8_t dummy[0x62 - 8];
} __attribute__ ((packed));
struct btrfs_superblock
{
btrfs_checksum_t checksum;
btrfs_uuid_t uuid;
grub_uint8_t dummy[0x10];
grub_uint8_t signature[sizeof (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];
} __attribute__ ((packed));
struct btrfs_header
{
btrfs_checksum_t checksum;
btrfs_uuid_t uuid;
grub_uint8_t dummy[0x30];
grub_uint32_t nitems;
grub_uint8_t level;
} __attribute__ ((packed));
struct grub_btrfs_data
{
struct btrfs_superblock sblock;
unsigned int sblock_number;
grub_uint64_t tree;
grub_uint64_t inode;
};
struct grub_btrfs_key
{
grub_uint64_t object_id;
#define GRUB_BTRFS_ITEM_TYPE_INODE_ITEM 0x01
#define GRUB_BTRFS_ITEM_TYPE_DIR_ITEM 0x54
#define GRUB_BTRFS_ITEM_TYPE_EXTENT_ITEM 0x6c
#define GRUB_BTRFS_ITEM_TYPE_ROOT_ITEM 0x84
#define GRUB_BTRFS_ITEM_TYPE_DEVICE 0xd8
#define GRUB_BTRFS_ITEM_TYPE_CHUNK 0xe4
grub_uint8_t type;
grub_uint64_t offset;
} __attribute__ ((packed));
struct grub_btrfs_chunk_item
{
grub_uint64_t size;
grub_uint64_t dummy;
grub_uint64_t stripe_length;
grub_uint8_t dummy2[0x14];
grub_uint16_t nstripes;
grub_uint16_t dummy3;
} __attribute__ ((packed));
struct grub_btrfs_chunk_stripe
{
grub_uint64_t device_id;
grub_uint64_t offset;
btrfs_uuid_t device_uuid;
} __attribute__ ((packed));
struct grub_btrfs_leaf_node
{
struct grub_btrfs_key key;
grub_uint32_t offset;
grub_uint32_t size;
} __attribute__ ((packed));
struct grub_btrfs_internal_node
{
struct grub_btrfs_key key;
grub_uint64_t blockn;
grub_uint64_t dummy;
} __attribute__ ((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];
} __attribute__ ((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_root_item
{
grub_uint8_t dummy[0xb0];
grub_uint64_t tree;
grub_uint64_t inode;
};
struct grub_btrfs_inode
{
grub_uint8_t dummy[0x10];
grub_uint64_t size;
} __attribute__ ((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];
grub_uint64_t laddr;
};
} __attribute__ ((packed));
#define GRUB_BTRFS_EXTENT_INLINE 0
#define GRUB_BTRFS_EXTENT_REGULAR 1
#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_t disk, grub_disk_addr_t addr,
void *buf, grub_size_t size);
static int
key_cmp (const struct grub_btrfs_key *a, const struct grub_btrfs_key *b)
{
if (grub_cpu_to_le64 (a->object_id) < grub_cpu_to_le64 (b->object_id))
return -1;
if (grub_cpu_to_le64 (a->object_id) > grub_cpu_to_le64 (b->object_id))
return +1;
if (a->type < b->type)
return -1;
if (a->type > b->type)
return +1;
if (grub_cpu_to_le64 (a->offset) < grub_cpu_to_le64 (b->offset))
return -1;
if (grub_cpu_to_le64 (a->offset) > grub_cpu_to_le64 (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, grub_disk_t disk,
struct grub_btrfs_leaf_descriptor *desc,
grub_disk_addr_t *outaddr, grub_size_t *outsize,
struct grub_btrfs_key *key_out)
{
int i;
grub_err_t err;
struct grub_btrfs_leaf_node leaf;
if (desc->depth == 0)
return 0;
for (i = desc->depth - 1; i >= 0; i--)
{
desc->data[i].iter++;
if (desc->data[i].iter
< desc->data[desc->depth - 1].maxiter)
break;
desc->depth--;
}
if (i == -1)
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, disk,
desc->data[desc->depth - 1].iter
* sizeof (node)
+ sizeof (struct btrfs_header)
+ desc->data[desc->depth - 1].addr, &node,
sizeof (node));
if (err)
return -err;
err = grub_btrfs_read_logical (data, disk,
grub_le_to_cpu64 (node.blockn), &head,
sizeof (head));
if (err)
return -err;
save_ref (desc, grub_le_to_cpu64 (node.blockn), 0,
grub_le_to_cpu32 (head.nitems), !head.level);
}
err = grub_btrfs_read_logical (data, disk,
desc->data[desc->depth - 1].iter
* sizeof (leaf)
+ sizeof (struct btrfs_header)
+ desc->data[desc->depth - 1].addr, &leaf,
sizeof (leaf));
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, grub_disk_t disk,
const struct grub_btrfs_key *key_in,
struct grub_btrfs_key *key_out,
grub_disk_addr_t root,
grub_disk_addr_t *outaddr, grub_size_t *outsize,
struct grub_btrfs_leaf_descriptor *desc)
{
grub_disk_addr_t addr = 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;
}
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, disk, addr, &head, sizeof (head));
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, disk, addr
+ i * sizeof (node),
&node, sizeof (node));
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.blockn);
goto reiter;
}
if (key_cmp (&node.key, key_in) > 0)
break;
node_last = node;
have_last = 1;
}
if (have_last)
{
addr = grub_le_to_cpu64 (node_last.blockn);
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;
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, disk, addr + i * sizeof (leaf),
&leaf, sizeof (leaf));
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;
}
}
}
static grub_err_t
grub_btrfs_read_logical (struct grub_btrfs_data *data,
grub_disk_t disk, grub_disk_addr_t addr,
void *buf, grub_size_t size)
{
while (size > 0)
{
grub_uint8_t *ptr;
struct grub_btrfs_key *key;
struct grub_btrfs_chunk_item *chunk;
struct grub_btrfs_chunk_stripe *stripe;
grub_size_t csize;
grub_err_t err;
grub_disk_addr_t paddr;
grub_uint64_t stripen;
grub_uint32_t stripe_length;
grub_uint32_t stripe_offset;
struct grub_btrfs_key key_out;
int challoc = 0;
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 (*stripe) * grub_le_to_cpu16 (chunk->nstripes);
}
struct grub_btrfs_key key_in;
grub_size_t chsize;
grub_disk_addr_t chaddr;
key_in.object_id = GRUB_BTRFS_OBJECT_ID_CHUNK;
key_in.type = GRUB_BTRFS_ITEM_TYPE_CHUNK;
key_in.offset = addr;
err = lower_bound (data, disk,
&key_in, &key_out,
grub_le_to_cpu64 (data->sblock.chunk_tree),
&chaddr, &chsize, NULL);
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, disk, chaddr,
chunk, chsize);
if (err)
{
grub_free (chunk);
return err;
}
if (!(addr < grub_le_to_cpu64 (key->offset)
+ grub_le_to_cpu64 (chunk->size)))
return grub_error (GRUB_ERR_BAD_FS,
"couldn't find the chunk descriptor");
chunk_found:
stripe_length = grub_divmod64 (grub_le_to_cpu64 (chunk->size),
grub_le_to_cpu16 (chunk->nstripes),
NULL);
stripen = grub_divmod64 (addr - grub_le_to_cpu64 (key->offset),
stripe_length, &stripe_offset);
stripe = (struct grub_btrfs_chunk_stripe *) (chunk + 1);
stripe += stripen;
csize = grub_le_to_cpu64 (key->offset) + grub_le_to_cpu64 (chunk->size)
- addr;
if (csize > size)
csize = size;
if (grub_le_to_cpu64 (stripe->device_id) != grub_le_to_cpu64 (data->sblock.this_device.device_id))
{
if (challoc)
grub_free (chunk);
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"multidevice isn't implemented yet");
}
grub_dprintf ("btrfs", "chunk 0x%" PRIxGRUB_UINT64_T
"+0x%" PRIxGRUB_UINT64_T " (%d stripes 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_cpu64 (chunk->stripe_length),
stripen,
stripe->offset);
paddr = stripe->offset + stripe_offset;
grub_dprintf ("btrfs", "reading paddr 0x%" PRIxGRUB_UINT64_T
" for laddr 0x%" PRIxGRUB_UINT64_T"\n", paddr,
addr);
err = grub_disk_read (disk, paddr >> GRUB_DISK_SECTOR_BITS,
paddr & (GRUB_DISK_SECTOR_SIZE - 1), csize, buf);
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_disk_t disk)
{
struct grub_btrfs_data *data = grub_malloc (sizeof (*data));
unsigned i;
grub_err_t err = GRUB_ERR_NONE;
if (! data)
return NULL;
for (i = 0; i < ARRAY_SIZE (superblock_sectors); i++)
{
struct btrfs_superblock sblock;
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, BTRFS_SIGNATURE,
sizeof (BTRFS_SIGNATURE) - 1))
break;
if (i == 0 || grub_le_to_cpu64 (sblock.generation)
> grub_le_to_cpu64 (data->sblock.generation))
{
grub_memcpy (&data->sblock, &sblock, sizeof (sblock));
data->sblock_number = i;
}
}
if ((err == GRUB_ERR_OUT_OF_RANGE || !err) && i == 0)
{
grub_error (GRUB_ERR_BAD_FS, "not a Btrfs filesystem");
goto fail;
}
if (err == GRUB_ERR_OUT_OF_RANGE)
grub_errno = err = GRUB_ERR_NONE;
grub_dprintf ("btrfs", "using superblock %d\n", data->sblock_number);
return data;
fail:
grub_free (data);
return NULL;
}
static grub_err_t
find_path (struct grub_btrfs_data *data,
grub_disk_t disk,
const char *path, struct grub_btrfs_key *key,
grub_uint64_t *tree, grub_uint8_t *type)
{
const char *slash;
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;
*type = GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY;
*tree = data->sblock.root_tree;
key->object_id = data->sblock.root_dir_objectid;
key->type = GRUB_BTRFS_ITEM_TYPE_DIR_ITEM;
key->offset = 0;
while (1)
{
while (path[0] == '/')
path++;
if (!path[0])
break;
if (*type != GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY)
return grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
key->type = GRUB_BTRFS_ITEM_TYPE_DIR_ITEM;
key->offset = 0;
slash = grub_strchr (path, '/');
if (!slash)
slash = path + grub_strlen (path);
key->offset = grub_cpu_to_le64 (~grub_getcrc32c (1, path, slash - path));
err = lower_bound (data, disk, key, &key_out, *tree,
&elemaddr, &elemsize, NULL);
if (err)
{
grub_free (direl);
return err;
}
if (key_cmp (key, &key_out) != 0)
{
grub_free (direl);
return grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
}
struct grub_btrfs_dir_item *cdirel;
if (elemsize > allocated)
{
allocated = 2 * elemsize;
grub_free (direl);
direl = grub_malloc (allocated + 1);
if (!direl)
return grub_errno;
}
err = grub_btrfs_read_logical (data, disk, elemaddr,
direl, elemsize);
if (err)
{
grub_free (direl);
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)))
{
char c;
c = cdirel->name[grub_le_to_cpu16 (cdirel->n)];
cdirel->name[grub_le_to_cpu16 (cdirel->n)] = 0;
if (grub_strncmp (cdirel->name, path, slash - path) == 0)
break;
cdirel->name[grub_le_to_cpu16 (cdirel->n)] = c;
}
if ((grub_uint8_t *) cdirel - (grub_uint8_t *) direl
>= (grub_ssize_t) elemsize)
{
grub_free (direl);
return grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
}
path = slash;
*type = cdirel->type;
if (*type == GRUB_BTRFS_DIR_ITEM_TYPE_SYMLINK)
{
grub_free (direl);
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"symlinks not supported");
}
switch (cdirel->key.type)
{
case GRUB_BTRFS_ITEM_TYPE_ROOT_ITEM:
{
struct grub_btrfs_root_item ri;
err = lower_bound (data, disk, &cdirel->key, &key_out, *tree,
&elemaddr, &elemsize, NULL);
if (err)
return err;
if (cdirel->key.object_id != key_out.object_id
|| cdirel->key.type != key_out.type)
return grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
err = grub_btrfs_read_logical (data, disk, elemaddr,
&ri, sizeof (ri));
if (err)
return err;
key->type = GRUB_BTRFS_ITEM_TYPE_DIR_ITEM;
key->offset = 0;
key->object_id = GRUB_BTRFS_OBJECT_ID_CHUNK;
*tree = grub_le_to_cpu64 (ri.tree);
break;
}
case GRUB_BTRFS_ITEM_TYPE_INODE_ITEM:
if (*slash)
return grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
*key = cdirel->key;
break;
default:
return grub_error (GRUB_ERR_BAD_FS, "unrecognised object type 0x%x",
cdirel->key.type);
}
}
grub_free (direl);
return GRUB_ERR_NONE;
}
static grub_err_t
grub_btrfs_dir (grub_device_t device,
const char *path __attribute__ ((unused)),
int (*hook) (const char *filename,
const struct grub_dirhook_info *info))
{
struct grub_btrfs_data *data = grub_btrfs_mount (device->disk);
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, device->disk, path, &key_in, &tree, &type);
if (err)
return err;
if (type != GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY)
return grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
err = lower_bound (data, device->disk, &key_in, &key_out,
tree,
&elemaddr, &elemsize, &desc);
if (err)
return err;
if (key_out.type != GRUB_BTRFS_ITEM_TYPE_DIR_ITEM
|| key_out.object_id != key_in.object_id)
{
r = next (data, device->disk, &desc, &elemaddr, &elemsize, &key_out);
if (r <= 0)
{
free_iterator (&desc);
return -r;
}
}
do
{
struct grub_dirhook_info info;
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)
{
free_iterator (&desc);
return grub_errno;
}
}
err = grub_btrfs_read_logical (data, device->disk, elemaddr,
direl, elemsize);
if (err)
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)))
{
char c;
c = cdirel->name[grub_le_to_cpu16 (cdirel->n)];
cdirel->name[grub_le_to_cpu16 (cdirel->n)] = 0;
grub_memset (&info, 0, sizeof (info));
info.dir = (cdirel->type == GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY);
if (hook (cdirel->name, &info))
goto out;
cdirel->name[grub_le_to_cpu16 (cdirel->n)] = c;
}
r = next (data, device->disk, &desc, &elemaddr, &elemsize, &key_out);
}
while (r > 0);
out:
grub_free (direl);
free_iterator (&desc);
grub_free (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->disk);
struct grub_btrfs_key key_in, key_out;
grub_err_t err;
grub_disk_addr_t elemaddr;
grub_size_t elemsize;
struct grub_btrfs_inode inode;
grub_uint8_t type;
if (!data)
return grub_errno;
err = find_path (data, file->device->disk, name, &key_in, &data->tree, &type);
if (err)
{
grub_free (data);
return err;
}
if (type != GRUB_BTRFS_DIR_ITEM_TYPE_REGULAR)
return grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a regular file");
data->inode = key_in.object_id;
key_in.type = GRUB_BTRFS_ITEM_TYPE_INODE_ITEM;
err = lower_bound (data, file->device->disk, &key_in, &key_out,
data->tree,
&elemaddr, &elemsize, NULL);
if (err)
return err;
if (data->inode != key_out.object_id
|| key_out.type != GRUB_BTRFS_ITEM_TYPE_INODE_ITEM)
return grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a regular file");
err = grub_btrfs_read_logical (data, file->device->disk, elemaddr,
&inode, sizeof (inode));
if (err)
return err;
file->data = data;
file->size = grub_le_to_cpu64 (inode.size);
return GRUB_ERR_NONE;
}
static grub_err_t
grub_btrfs_close (grub_file_t file)
{
grub_free (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;
grub_off_t pos = file->offset;
grub_disk_addr_t elemaddr;
grub_size_t elemsize;
struct grub_btrfs_key key_in, key_out;
while (len)
{
grub_size_t csize;
struct grub_btrfs_extent_data *extent;
grub_err_t err;
key_in.object_id = data->inode;
key_in.type = GRUB_BTRFS_ITEM_TYPE_EXTENT_ITEM;
key_in.offset = grub_cpu_to_le64 (pos);
err = lower_bound (data, file->device->disk, &key_in, &key_out,
data->tree,
&elemaddr, &elemsize, NULL);
if (err)
return -1;
if (key_out.object_id != data->inode
|| key_out.type != GRUB_BTRFS_ITEM_TYPE_EXTENT_ITEM)
{
grub_error (GRUB_ERR_BAD_FS, "extent not found");
return -1;
}
extent = grub_malloc (elemsize);
if (!extent)
return grub_errno;
err = grub_btrfs_read_logical (data, file->device->disk, elemaddr,
extent, elemsize);
if (err)
{
grub_free (extent);
return err;
}
if (grub_le_to_cpu64 (extent->size) + grub_le_to_cpu64 (key_out.offset)
<= pos)
{
grub_free (extent);
return grub_error (GRUB_ERR_BAD_FS, "extent not found");
}
grub_dprintf ("btrfs", "extent 0x%" PRIxGRUB_UINT64_T "+0x%"
PRIxGRUB_UINT64_T "\n",
grub_le_to_cpu64 (key_out.offset),
grub_le_to_cpu64 (extent->size));
csize = grub_le_to_cpu64 (extent->size)
+ grub_le_to_cpu64 (key_out.offset) - pos;
if (csize > len)
csize = len;
if (extent->encryption)
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"encryption not supported");
return -1;
}
if (extent->compression)
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"compression not supported");
return -1;
}
if (extent->encoding)
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"encoding not supported");
return -1;
}
switch (extent->type)
{
case GRUB_BTRFS_EXTENT_INLINE:
grub_memcpy (buf, extent->inl, csize);
grub_free (extent);
break;
case GRUB_BTRFS_EXTENT_REGULAR:
if (!extent->laddr)
{
grub_memset (buf, 0, csize);
break;
}
err = grub_btrfs_read_logical (data, file->device->disk,
grub_le_to_cpu64 (extent->laddr),
buf, csize);
grub_free (extent);
if (err)
return -1;
break;
default:
grub_free (extent);
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"unsupported extent type 0x%x", extent->type);
return -1;
}
buf += csize;
pos += csize;
len -= csize;
}
return pos - file->offset;
}
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->disk);
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_free (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->disk);
if (! data)
return grub_errno;
*label = grub_strndup (data->sblock.label, sizeof (data->sblock.label));
grub_free (data);
return grub_errno;
}
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,
};
GRUB_MOD_INIT(btrfs)
{
grub_fs_register (&grub_btrfs_fs);
}
GRUB_MOD_FINI(btrfs)
{
grub_fs_unregister (&grub_btrfs_fs);
}
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