u-boot/fs/btrfs/super.c
Qu Wenruo a62db24526 fs: btrfs: Reject fs with sector size other than PAGE_SIZE
Although in theory u-boot fs driver could easily support more sector
sizes, current code base doesn't have good enough way to grab sector
size yet.

This would cause problem for later LZO fixes which rely on sector size.

And considering that most u-boot boards are using 4K page size, which is
also the most common sector size for btrfs, rejecting fs with
non-page-sized sector size shouldn't cause much problem.

This should only be a quick fix before we implement better sector size
support.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Cc: Marek Behun <marek.behun@nic.cz>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
2020-04-16 22:13:50 -04:00

254 lines
6.4 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* BTRFS filesystem implementation for U-Boot
*
* 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
*/
#include "btrfs.h"
#include <memalign.h>
#include <linux/compat.h>
#define BTRFS_SUPER_FLAG_SUPP (BTRFS_HEADER_FLAG_WRITTEN \
| BTRFS_HEADER_FLAG_RELOC \
| BTRFS_SUPER_FLAG_ERROR \
| BTRFS_SUPER_FLAG_SEEDING \
| BTRFS_SUPER_FLAG_METADUMP)
#define BTRFS_SUPER_INFO_SIZE 4096
/*
* checks if a valid root backup is present.
* considers the case when all root backups empty valid.
* returns -1 in case of invalid root backup and 0 for valid.
*/
static int btrfs_check_super_roots(struct btrfs_super_block *sb)
{
struct btrfs_root_backup *root_backup;
int i, newest = -1;
int num_empty = 0;
for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; ++i) {
root_backup = sb->super_roots + i;
if (root_backup->tree_root == 0 && root_backup->tree_root_gen == 0)
num_empty++;
if (root_backup->tree_root_gen == sb->generation)
newest = i;
}
if (num_empty == BTRFS_NUM_BACKUP_ROOTS) {
return 0;
} else if (newest >= 0) {
return 0;
}
return -1;
}
static inline int is_power_of_2(u64 x)
{
return !(x & (x - 1));
}
static int btrfs_check_super_csum(char *raw_disk_sb)
{
struct btrfs_super_block *disk_sb =
(struct btrfs_super_block *) raw_disk_sb;
u16 csum_type = le16_to_cpu(disk_sb->csum_type);
if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
u32 crc = ~(u32) 0;
const int csum_size = sizeof(crc);
char result[csum_size];
crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE, crc,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
btrfs_csum_final(crc, result);
if (memcmp(raw_disk_sb, result, csum_size))
return -1;
} else {
return -1;
}
return 0;
}
static int btrfs_check_super(struct btrfs_super_block *sb)
{
int ret = 0;
if (sb->flags & ~BTRFS_SUPER_FLAG_SUPP) {
printf("%s: Unsupported flags: %llu\n", __func__,
sb->flags & ~BTRFS_SUPER_FLAG_SUPP);
}
if (sb->root_level > BTRFS_MAX_LEVEL) {
printf("%s: tree_root level too big: %d >= %d\n", __func__,
sb->root_level, BTRFS_MAX_LEVEL);
ret = -1;
}
if (sb->chunk_root_level > BTRFS_MAX_LEVEL) {
printf("%s: chunk_root level too big: %d >= %d\n", __func__,
sb->chunk_root_level, BTRFS_MAX_LEVEL);
ret = -1;
}
if (sb->log_root_level > BTRFS_MAX_LEVEL) {
printf("%s: log_root level too big: %d >= %d\n", __func__,
sb->log_root_level, BTRFS_MAX_LEVEL);
ret = -1;
}
if (!is_power_of_2(sb->sectorsize) || sb->sectorsize < 4096 ||
sb->sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
printf("%s: invalid sectorsize %u\n", __func__,
sb->sectorsize);
ret = -1;
}
if (!is_power_of_2(sb->nodesize) || sb->nodesize < sb->sectorsize ||
sb->nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
printf("%s: invalid nodesize %u\n", __func__, sb->nodesize);
ret = -1;
}
if (sb->nodesize != sb->__unused_leafsize) {
printf("%s: invalid leafsize %u, should be %u\n", __func__,
sb->__unused_leafsize, sb->nodesize);
ret = -1;
}
if (!IS_ALIGNED(sb->root, sb->sectorsize)) {
printf("%s: tree_root block unaligned: %llu\n", __func__,
sb->root);
ret = -1;
}
if (!IS_ALIGNED(sb->chunk_root, sb->sectorsize)) {
printf("%s: chunk_root block unaligned: %llu\n", __func__,
sb->chunk_root);
ret = -1;
}
if (!IS_ALIGNED(sb->log_root, sb->sectorsize)) {
printf("%s: log_root block unaligned: %llu\n", __func__,
sb->log_root);
ret = -1;
}
if (memcmp(sb->fsid, sb->dev_item.fsid, BTRFS_UUID_SIZE) != 0) {
printf("%s: dev_item UUID does not match fsid\n", __func__);
ret = -1;
}
if (sb->bytes_used < 6*sb->nodesize) {
printf("%s: bytes_used is too small %llu\n", __func__,
sb->bytes_used);
ret = -1;
}
if (!is_power_of_2(sb->stripesize)) {
printf("%s: invalid stripesize %u\n", __func__, sb->stripesize);
ret = -1;
}
if (sb->sys_chunk_array_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
printf("%s: system chunk array too big %u > %u\n", __func__,
sb->sys_chunk_array_size, BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
ret = -1;
}
if (sb->sys_chunk_array_size < sizeof(struct btrfs_key) +
sizeof(struct btrfs_chunk)) {
printf("%s: system chunk array too small %u < %zu\n", __func__,
sb->sys_chunk_array_size, sizeof(struct btrfs_key)
+ sizeof(struct btrfs_chunk));
ret = -1;
}
return ret;
}
int btrfs_read_superblock(void)
{
const u64 superblock_offsets[4] = {
0x10000ull,
0x4000000ull,
0x4000000000ull,
0x4000000000000ull
};
ALLOC_CACHE_ALIGN_BUFFER(char, raw_sb, BTRFS_SUPER_INFO_SIZE);
struct btrfs_super_block *sb = (struct btrfs_super_block *) raw_sb;
u64 dev_total_bytes;
int i;
dev_total_bytes = (u64) btrfs_part_info->size * btrfs_part_info->blksz;
btrfs_info.sb.generation = 0;
for (i = 0; i < 4; ++i) {
if (superblock_offsets[i] + sizeof(sb) > dev_total_bytes)
break;
if (!btrfs_devread(superblock_offsets[i], BTRFS_SUPER_INFO_SIZE,
raw_sb))
break;
if (btrfs_check_super_csum(raw_sb)) {
debug("%s: invalid checksum at superblock mirror %i\n",
__func__, i);
continue;
}
btrfs_super_block_to_cpu(sb);
if (sb->magic != BTRFS_MAGIC) {
debug("%s: invalid BTRFS magic 0x%016llX at "
"superblock mirror %i\n", __func__, sb->magic, i);
} else if (sb->bytenr != superblock_offsets[i]) {
printf("%s: invalid bytenr 0x%016llX (expected "
"0x%016llX) at superblock mirror %i\n",
__func__, sb->bytenr, superblock_offsets[i], i);
} else if (btrfs_check_super(sb)) {
printf("%s: Checking superblock mirror %i failed\n",
__func__, i);
} else if (sb->generation > btrfs_info.sb.generation) {
memcpy(&btrfs_info.sb, sb, sizeof(*sb));
} else {
/* Nothing */
}
}
if (!btrfs_info.sb.generation) {
debug("%s: No valid BTRFS superblock found!\n", __func__);
return -1;
}
if (btrfs_check_super_roots(&btrfs_info.sb)) {
printf("%s: No valid root_backup found!\n", __func__);
return -1;
}
if (sb->sectorsize != PAGE_SIZE) {
printf(
"%s: Unsupported sector size (%u), only supports %u as sector size\n",
__func__, sb->sectorsize, PAGE_SIZE);
return -1;
}
if (btrfs_info.sb.num_devices != 1) {
printf("%s: Unsupported number of devices (%lli). This driver "
"only supports filesystem on one device.\n", __func__,
btrfs_info.sb.num_devices);
return -1;
}
debug("Chosen superblock with generation = %llu\n",
btrfs_info.sb.generation);
return 0;
}