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grub/grub-core/fs/btrfs.c
Goffredo Baroncelli 72e80c0255 btrfs: Add RAID 6 recovery for a btrfs filesystem 
Add the RAID 6 recovery, in order to use a RAID 6 filesystem even if some
disks (up to two) are missing. This code use the md RAID 6 code already
present in grub.

Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2018-10-31 12:45:39 +01:00

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/* 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 <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>
#include <grub/deflate.h>
#include <minilzo.h>
#include <grub/i18n.h>
#include <grub/btrfs.h>
#include <grub/crypto.h>
#include <grub/diskfilter.h>
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_uint64_t bytenr;
grub_uint8_t dummy[0x28];
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
#define GRUB_BTRFS_CHUNK_TYPE_RAID5 0x80
#define GRUB_BTRFS_CHUNK_TYPE_RAID6 0x100
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;
} GRUB_PACKED;
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)
{
struct grub_btrfs_superblock sblock;
unsigned i;
grub_err_t err = GRUB_ERR_NONE;
for (i = 0; i < ARRAY_SIZE (superblock_sectors); i++)
{
/* 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
check_btrfs_header (struct grub_btrfs_data *data, struct btrfs_header *header,
grub_disk_addr_t addr)
{
if (grub_le_to_cpu64 (header->bytenr) != addr)
{
grub_dprintf ("btrfs", "btrfs_header.bytenr is not equal node addr\n");
return grub_error (GRUB_ERR_BAD_FS,
"header bytenr is not equal node addr");
}
if (grub_memcmp (data->sblock.uuid, header->uuid, sizeof(grub_btrfs_uuid_t)))
{
grub_dprintf ("btrfs", "btrfs_header.uuid doesn't match sblock uuid\n");
return grub_error (GRUB_ERR_BAD_FS,
"header uuid doesn't match sblock uuid");
}
return GRUB_ERR_NONE;
}
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);
check_btrfs_header (data, &head, grub_le_to_cpu64 (node.addr));
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);
check_btrfs_header (data, &head, addr);
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)
{
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;
grub_device_iterate (find_device_iter, &ctx);
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)
{
if (ctx.dev_found)
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
btrfs_read_from_chunk (struct grub_btrfs_data *data,
struct grub_btrfs_chunk_item *chunk,
grub_uint64_t stripen, grub_uint64_t stripe_offset,
int redundancy, grub_uint64_t csize,
void *buf)
{
struct grub_btrfs_chunk_stripe *stripe;
grub_disk_addr_t paddr;
grub_device_t dev;
grub_err_t err;
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 + redundancy;
paddr = grub_le_to_cpu64 (stripe->offset) + stripe_offset;
grub_dprintf ("btrfs", "stripe %" PRIxGRUB_UINT64_T
" maps to 0x%" PRIxGRUB_UINT64_T "\n"
"reading paddr 0x%" PRIxGRUB_UINT64_T "\n",
stripen, stripe->offset, paddr);
dev = find_device (data, stripe->device_id);
if (!dev)
{
grub_dprintf ("btrfs",
"couldn't find a necessary member device "
"of multi-device filesystem\n");
grub_errno = GRUB_ERR_NONE;
return GRUB_ERR_READ_ERROR;
}
err = grub_disk_read (dev->disk, paddr >> GRUB_DISK_SECTOR_BITS,
paddr & (GRUB_DISK_SECTOR_SIZE - 1),
csize, buf);
return err;
}
struct raid56_buffer {
void *buf;
int data_is_valid;
};
static void
rebuild_raid5 (char *dest, struct raid56_buffer *buffers,
grub_uint64_t nstripes, grub_uint64_t csize)
{
grub_uint64_t i;
int first;
for(i = 0; buffers[i].data_is_valid && i < nstripes; i++);
if (i == nstripes)
{
grub_dprintf ("btrfs", "called rebuild_raid5(), but all disks are OK\n");
return;
}
grub_dprintf ("btrfs", "rebuilding RAID 5 stripe #%" PRIuGRUB_UINT64_T "\n", i);
for (i = 0, first = 1; i < nstripes; i++)
{
if (!buffers[i].data_is_valid)
continue;
if (first) {
grub_memcpy(dest, buffers[i].buf, csize);
first = 0;
} else
grub_crypto_xor (dest, dest, buffers[i].buf, csize);
}
}
static grub_err_t
raid6_recover_read_buffer (void *data, int disk_nr,
grub_uint64_t addr __attribute__ ((unused)),
void *dest, grub_size_t size)
{
struct raid56_buffer *buffers = data;
if (!buffers[disk_nr].data_is_valid)
return grub_errno = GRUB_ERR_READ_ERROR;
grub_memcpy(dest, buffers[disk_nr].buf, size);
return grub_errno = GRUB_ERR_NONE;
}
static void
rebuild_raid6 (struct raid56_buffer *buffers, grub_uint64_t nstripes,
grub_uint64_t csize, grub_uint64_t parities_pos, void *dest,
grub_uint64_t stripen)
{
grub_raid6_recover_gen (buffers, nstripes, stripen, parities_pos,
dest, 0, csize, 0, raid6_recover_read_buffer);
}
static grub_err_t
raid56_read_retry (struct grub_btrfs_data *data,
struct grub_btrfs_chunk_item *chunk,
grub_uint64_t stripe_offset, grub_uint64_t stripen,
grub_uint64_t csize, void *buf, grub_uint64_t parities_pos)
{
struct raid56_buffer *buffers;
grub_uint64_t nstripes = grub_le_to_cpu16 (chunk->nstripes);
grub_uint64_t chunk_type = grub_le_to_cpu64 (chunk->type);
grub_err_t ret = GRUB_ERR_OUT_OF_MEMORY;
grub_uint64_t i, failed_devices;
buffers = grub_zalloc (sizeof(*buffers) * nstripes);
if (!buffers)
goto cleanup;
for (i = 0; i < nstripes; i++)
{
buffers[i].buf = grub_zalloc (csize);
if (!buffers[i].buf)
goto cleanup;
}
for (failed_devices = 0, i = 0; i < nstripes; i++)
{
struct grub_btrfs_chunk_stripe *stripe;
grub_disk_addr_t paddr;
grub_device_t dev;
grub_err_t err;
/*
* The struct grub_btrfs_chunk_stripe array lives
* behind struct grub_btrfs_chunk_item.
*/
stripe = (struct grub_btrfs_chunk_stripe *) (chunk + 1) + i;
paddr = grub_le_to_cpu64 (stripe->offset) + stripe_offset;
grub_dprintf ("btrfs", "reading paddr %" PRIxGRUB_UINT64_T
" from stripe ID %" PRIxGRUB_UINT64_T "\n",
paddr, stripe->device_id);
dev = find_device (data, stripe->device_id);
if (!dev)
{
grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T " FAILED (dev ID %"
PRIxGRUB_UINT64_T ")\n", i, stripe->device_id);
failed_devices++;
continue;
}
err = grub_disk_read (dev->disk, paddr >> GRUB_DISK_SECTOR_BITS,
paddr & (GRUB_DISK_SECTOR_SIZE - 1),
csize, buffers[i].buf);
if (err == GRUB_ERR_NONE)
{
buffers[i].data_is_valid = 1;
grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T " OK (dev ID %"
PRIxGRUB_UINT64_T ")\n", i, stripe->device_id);
}
else
{
grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T
" READ FAILED (dev ID %" PRIxGRUB_UINT64_T ")\n",
i, stripe->device_id);
failed_devices++;
}
}
if (failed_devices > 1 && (chunk_type & GRUB_BTRFS_CHUNK_TYPE_RAID5))
{
grub_dprintf ("btrfs", "not enough disks for RAID 5: total %" PRIuGRUB_UINT64_T
", missing %" PRIuGRUB_UINT64_T "\n",
nstripes, failed_devices);
ret = GRUB_ERR_READ_ERROR;
goto cleanup;
}
else if (failed_devices > 2 && (chunk_type & GRUB_BTRFS_CHUNK_TYPE_RAID6))
{
grub_dprintf ("btrfs", "not enough disks for RAID 6: total %" PRIuGRUB_UINT64_T
", missing %" PRIuGRUB_UINT64_T "\n",
nstripes, failed_devices);
ret = GRUB_ERR_READ_ERROR;
goto cleanup;
}
else
grub_dprintf ("btrfs", "enough disks for RAID 5: total %"
PRIuGRUB_UINT64_T ", missing %" PRIuGRUB_UINT64_T "\n",
nstripes, failed_devices);
/* We have enough disks. So, rebuild the data. */
if (chunk_type & GRUB_BTRFS_CHUNK_TYPE_RAID5)
rebuild_raid5 (buf, buffers, nstripes, csize);
else
rebuild_raid6 (buffers, nstripes, csize, parities_pos, buf, stripen);
ret = GRUB_ERR_NONE;
cleanup:
if (buffers)
for (i = 0; i < nstripes; i++)
grub_free (buffers[i].buf);
grub_free (buffers);
return ret;
}
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;
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);
grub_uint64_t chunk_stripe_length;
grub_uint16_t nstripes;
unsigned redundancy = 1;
unsigned i, j;
int is_raid56;
grub_uint64_t parities_pos = 0;
is_raid56 = !!(grub_le_to_cpu64 (chunk->type) &
(GRUB_BTRFS_CHUNK_TYPE_RAID5 |
GRUB_BTRFS_CHUNK_TYPE_RAID6));
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");
}
nstripes = grub_le_to_cpu16 (chunk->nstripes) ? : 1;
chunk_stripe_length = grub_le_to_cpu64 (chunk->stripe_length) ? : 512;
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),
nstripes,
grub_le_to_cpu16 (chunk->nsubstripes),
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),
nstripes,
NULL);
if (stripe_length == 0)
stripe_length = 512;
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,
chunk_stripe_length,
&low);
high = grub_divmod64 (middle, nstripes,
&stripen);
stripe_offset =
low + chunk_stripe_length * high;
csize = chunk_stripe_length - low;
break;
}
case GRUB_BTRFS_CHUNK_TYPE_RAID10:
{
grub_uint64_t middle, high;
grub_uint64_t low;
grub_uint16_t nsubstripes;
nsubstripes = grub_le_to_cpu16 (chunk->nsubstripes) ? : 1;
middle = grub_divmod64 (off,
chunk_stripe_length,
&low);
high = grub_divmod64 (middle,
nstripes / nsubstripes ? : 1,
&stripen);
stripen *= nsubstripes;
redundancy = nsubstripes;
stripe_offset = low + chunk_stripe_length
* high;
csize = chunk_stripe_length - low;
break;
}
case GRUB_BTRFS_CHUNK_TYPE_RAID5:
case GRUB_BTRFS_CHUNK_TYPE_RAID6:
{
grub_uint64_t nparities, stripe_nr, high, low;
redundancy = 1; /* no redundancy for now */
if (grub_le_to_cpu64 (chunk->type) & GRUB_BTRFS_CHUNK_TYPE_RAID5)
{
grub_dprintf ("btrfs", "RAID5\n");
nparities = 1;
}
else
{
grub_dprintf ("btrfs", "RAID6\n");
nparities = 2;
}
/*
* RAID 6 layout consists of several stripes spread over
* the disks, e.g.:
*
* Disk_0 Disk_1 Disk_2 Disk_3
* A0 B0 P0 Q0
* Q1 A1 B1 P1
* P2 Q2 A2 B2
*
* Note: placement of the parities depend on row number.
*
* Pay attention that the btrfs terminology may differ from
* terminology used in other RAID implementations, e.g. LVM,
* dm or md. The main difference is that btrfs calls contiguous
* block of data on a given disk, e.g. A0, stripe instead of chunk.
*
* The variables listed below have following meaning:
* - stripe_nr is the stripe number excluding the parities
* (A0 = 0, B0 = 1, A1 = 2, B1 = 3, etc.),
* - high is the row number (0 for A0...Q0, 1 for Q1...P1, etc.),
* - stripen is the disk number in a row (0 for A0, Q1, P2,
* 1 for B0, A1, Q2, etc.),
* - off is the logical address to read,
* - chunk_stripe_length is the size of a stripe (typically 64 KiB),
* - nstripes is the number of disks in a row,
* - low is the offset of the data inside a stripe,
* - stripe_offset is the data offset in an array,
* - csize is the "potential" data to read; it will be reduced
* to size if the latter is smaller,
* - nparities is the number of parities (1 for RAID 5, 2 for
* RAID 6); used only in RAID 5/6 code.
*/
stripe_nr = grub_divmod64 (off, chunk_stripe_length, &low);
/*
* stripen is computed without the parities
* (0 for A0, A1, A2, 1 for B0, B1, B2, etc.).
*/
high = grub_divmod64 (stripe_nr, nstripes - nparities, &stripen);
/*
* The stripes are spread over the disks. Every each row their
* positions are shifted by 1 place. So, the real disks number
* change. Hence, we have to take into account current row number
* modulo nstripes (0 for A0, 1 for A1, 2 for A2, etc.).
*/
grub_divmod64 (high + stripen, nstripes, &stripen);
/*
* parities_pos is equal to ((high - nparities) % nstripes)
* (see the diagram above). However, (high - nparities) can
* be negative, e.g. when high == 0, leading to an incorrect
* results. (high + nstripes - nparities) is always positive and
* modulo nstripes is equal to ((high - nparities) % nstripes).
*/
grub_divmod64 (high + nstripes - nparities, nstripes, &parities_pos);
stripe_offset = chunk_stripe_length * high + low;
csize = 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++)
{
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));
grub_dprintf ("btrfs", "reading laddr 0x%" PRIxGRUB_UINT64_T "\n",
addr);
if (is_raid56)
{
err = btrfs_read_from_chunk (data, chunk, stripen,
stripe_offset,
0, /* no mirror */
csize, buf);
grub_errno = GRUB_ERR_NONE;
if (err)
err = raid56_read_retry (data, chunk, stripe_offset,
stripen, csize, buf, parities_pos);
}
else
for (i = 0; i < redundancy; i++)
{
err = btrfs_read_from_chunk (data, chunk, stripen,
stripe_offset,
i, /* redundancy */
csize, buf);
if (!err)
break;
grub_errno = GRUB_ERR_NONE;
}
if (!err)
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++)
if (data->devices_attached[i].dev)
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);
}
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