@@ -3,4 +3,4 @@
# 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
obj-y := btrfs.o chunk-map.o compression.o ctree.o dev.o dir-item.o \
- extent-io.o inode.o root.o subvolume.o super.o crypto/hash.o disk-io.o
+ extent-io.o inode.o root.o subvolume.o crypto/hash.o disk-io.o
@@ -11,6 +11,7 @@
#include <linux/time.h>
#include "btrfs.h"
#include "crypto/hash.h"
+#include "disk-io.h"
struct btrfs_info btrfs_info;
new file mode 100644
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#ifndef __BTRFS_COMPAT_H__
+#define __BTRFS_COMPAT_H__
+
+#include <linux/errno.h>
+#include <fs_internal.h>
+#include <uuid.h>
+
+/* Provide a compatibility layer to make code syncing easier */
+
+/* A simple wraper to for error() used in btrfs-progs */
+__attribute__((format (__printf__, 1, 2)))
+static inline void error(const char *fmt, ...)
+{
+ printf("BTRFS: ");
+ printf(fmt, __builtin_va_arg_pack());
+ printf("\n");
+}
+
+#define BTRFS_UUID_UNPARSED_SIZE 37
+
+/*
+ * Macros to generate set/get funcs for the struct fields
+ * assume there is a lefoo_to_cpu for every type, so lets make a simple
+ * one for u8:
+ */
+#define le8_to_cpu(v) (v)
+#define cpu_to_le8(v) (v)
+#define __le8 u8
+
+/*
+ * Read data from device specified by @desc and @part
+ *
+ * U-boot equivalent of pread().
+ *
+ * Return the bytes of data read.
+ * Return <0 for error.
+ */
+static inline int __btrfs_devread(struct blk_desc *desc,
+ struct disk_partition *part,
+ void *buf, size_t size, u64 offset)
+{
+ lbaint_t sector;
+ int byte_offset;
+ int ret;
+
+ sector = offset >> desc->log2blksz;
+ byte_offset = offset % desc->blksz;
+
+ /* fs_devread() return 0 for error, >0 for success */
+ ret = fs_devread(desc, part, sector, byte_offset, size, buf);
+ if (!ret)
+ return -EIO;
+ return size;
+}
+
+static inline void uuid_unparse(const u8 *uuid, char *out)
+{
+ return uuid_bin_to_str((unsigned char *)uuid, out, 0);
+}
+
+#endif
@@ -10,6 +10,38 @@
#include <malloc.h>
#include <memalign.h>
+static const struct btrfs_csum {
+ u16 size;
+ const char name[14];
+} btrfs_csums[] = {
+ [BTRFS_CSUM_TYPE_CRC32] = { 4, "crc32c" },
+ [BTRFS_CSUM_TYPE_XXHASH] = { 8, "xxhash64" },
+ [BTRFS_CSUM_TYPE_SHA256] = { 32, "sha256" },
+ [BTRFS_CSUM_TYPE_BLAKE2] = { 32, "blake2" },
+};
+
+u16 btrfs_super_csum_size(const struct btrfs_super_block *sb)
+{
+ const u16 csum_type = btrfs_super_csum_type(sb);
+
+ return btrfs_csums[csum_type].size;
+}
+
+const char *btrfs_super_csum_name(u16 csum_type)
+{
+ return btrfs_csums[csum_type].name;
+}
+
+size_t btrfs_super_num_csums(void)
+{
+ return ARRAY_SIZE(btrfs_csums);
+}
+
+u16 btrfs_csum_type_size(u16 csum_type)
+{
+ return btrfs_csums[csum_type].size;
+}
+
int btrfs_comp_keys(struct btrfs_key *a, struct btrfs_key *b)
{
if (a->objectid > b->objectid)
@@ -12,6 +12,7 @@
#include <common.h>
#include <compiler.h>
#include "kernel-shared/btrfs_tree.h"
+#include "compat.h"
#define BTRFS_MAX_MIRRORS 3
@@ -47,6 +48,16 @@
#define BTRFS_FS_STATE_DEV_REPLACING 3
#define BTRFS_FS_STATE_DUMMY_FS_INFO 4
+#define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits) \
+static inline u##bits btrfs_##name(const type *s) \
+{ \
+ return le##bits##_to_cpu(s->member); \
+} \
+static inline void btrfs_set_##name(type *s, u##bits val) \
+{ \
+ s->member = cpu_to_le##bits(val); \
+}
+
union btrfs_tree_node {
struct btrfs_header header;
struct btrfs_leaf leaf;
@@ -122,4 +133,60 @@ static inline void *btrfs_path_leaf_data(struct btrfs_path *p)
#define btrfs_path_item_ptr(p,t) \
((t *) btrfs_path_leaf_data((p)))
+u16 btrfs_super_csum_size(const struct btrfs_super_block *s);
+const char *btrfs_super_csum_name(u16 csum_type);
+u16 btrfs_csum_type_size(u16 csum_type);
+size_t btrfs_super_num_csums(void);
+
+/* struct btrfs_super_block */
+
+BTRFS_SETGET_STACK_FUNCS(super_bytenr, struct btrfs_super_block, bytenr, 64);
+BTRFS_SETGET_STACK_FUNCS(super_flags, struct btrfs_super_block, flags, 64);
+BTRFS_SETGET_STACK_FUNCS(super_generation, struct btrfs_super_block,
+ generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_root, struct btrfs_super_block, root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_sys_array_size,
+ struct btrfs_super_block, sys_chunk_array_size, 32);
+BTRFS_SETGET_STACK_FUNCS(super_chunk_root_generation,
+ struct btrfs_super_block, chunk_root_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_root_level, struct btrfs_super_block,
+ root_level, 8);
+BTRFS_SETGET_STACK_FUNCS(super_chunk_root, struct btrfs_super_block,
+ chunk_root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_chunk_root_level, struct btrfs_super_block,
+ chunk_root_level, 8);
+BTRFS_SETGET_STACK_FUNCS(super_log_root, struct btrfs_super_block,
+ log_root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_log_root_transid, struct btrfs_super_block,
+ log_root_transid, 64);
+BTRFS_SETGET_STACK_FUNCS(super_log_root_level, struct btrfs_super_block,
+ log_root_level, 8);
+BTRFS_SETGET_STACK_FUNCS(super_total_bytes, struct btrfs_super_block,
+ total_bytes, 64);
+BTRFS_SETGET_STACK_FUNCS(super_bytes_used, struct btrfs_super_block,
+ bytes_used, 64);
+BTRFS_SETGET_STACK_FUNCS(super_sectorsize, struct btrfs_super_block,
+ sectorsize, 32);
+BTRFS_SETGET_STACK_FUNCS(super_nodesize, struct btrfs_super_block,
+ nodesize, 32);
+BTRFS_SETGET_STACK_FUNCS(super_stripesize, struct btrfs_super_block,
+ stripesize, 32);
+BTRFS_SETGET_STACK_FUNCS(super_root_dir, struct btrfs_super_block,
+ root_dir_objectid, 64);
+BTRFS_SETGET_STACK_FUNCS(super_num_devices, struct btrfs_super_block,
+ num_devices, 64);
+BTRFS_SETGET_STACK_FUNCS(super_compat_flags, struct btrfs_super_block,
+ compat_flags, 64);
+BTRFS_SETGET_STACK_FUNCS(super_compat_ro_flags, struct btrfs_super_block,
+ compat_ro_flags, 64);
+BTRFS_SETGET_STACK_FUNCS(super_incompat_flags, struct btrfs_super_block,
+ incompat_flags, 64);
+BTRFS_SETGET_STACK_FUNCS(super_csum_type, struct btrfs_super_block,
+ csum_type, 16);
+BTRFS_SETGET_STACK_FUNCS(super_cache_generation, struct btrfs_super_block,
+ cache_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,
+ uuid_tree_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_magic, struct btrfs_super_block, magic, 64);
+
#endif /* __BTRFS_CTREE_H__ */
@@ -1,7 +1,12 @@
// SPDX-License-Identifier: GPL-2.0+
#include <common.h>
#include <fs_internal.h>
+#include <uuid.h>
+#include <memalign.h>
+#include "kernel-shared/btrfs_tree.h"
#include "disk-io.h"
+#include "ctree.h"
+#include "btrfs.h"
#include "crypto/hash.h"
int btrfs_csum_data(u16 csum_type, const u8 *data, u8 *out, size_t len)
@@ -20,3 +25,211 @@ int btrfs_csum_data(u16 csum_type, const u8 *data, u8 *out, size_t len)
return -EINVAL;
}
}
+
+/*
+ * Check if the super is valid:
+ * - nodesize/sectorsize - minimum, maximum, alignment
+ * - tree block starts - alignment
+ * - number of devices - something sane
+ * - sys array size - maximum
+ */
+static int btrfs_check_super(struct btrfs_super_block *sb)
+{
+ u8 result[BTRFS_CSUM_SIZE];
+ u16 csum_type;
+ int csum_size;
+ u8 *metadata_uuid;
+
+ if (btrfs_super_magic(sb) != BTRFS_MAGIC)
+ return -EIO;
+
+ csum_type = btrfs_super_csum_type(sb);
+ if (csum_type >= btrfs_super_num_csums()) {
+ error("unsupported checksum algorithm %u", csum_type);
+ return -EIO;
+ }
+ csum_size = btrfs_super_csum_size(sb);
+
+ btrfs_csum_data(csum_type, (u8 *)sb + BTRFS_CSUM_SIZE,
+ result, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+
+ if (memcmp(result, sb->csum, csum_size)) {
+ error("superblock checksum mismatch");
+ return -EIO;
+ }
+ if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
+ error("tree_root level too big: %d >= %d",
+ btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
+ goto error_out;
+ }
+ if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
+ error("chunk_root level too big: %d >= %d",
+ btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
+ goto error_out;
+ }
+ if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
+ error("log_root level too big: %d >= %d",
+ btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
+ goto error_out;
+ }
+
+ if (!IS_ALIGNED(btrfs_super_root(sb), 4096)) {
+ error("tree_root block unaligned: %llu", btrfs_super_root(sb));
+ goto error_out;
+ }
+ if (!IS_ALIGNED(btrfs_super_chunk_root(sb), 4096)) {
+ error("chunk_root block unaligned: %llu",
+ btrfs_super_chunk_root(sb));
+ goto error_out;
+ }
+ if (!IS_ALIGNED(btrfs_super_log_root(sb), 4096)) {
+ error("log_root block unaligned: %llu",
+ btrfs_super_log_root(sb));
+ goto error_out;
+ }
+ if (btrfs_super_nodesize(sb) < 4096) {
+ error("nodesize too small: %u < 4096",
+ btrfs_super_nodesize(sb));
+ goto error_out;
+ }
+ if (!IS_ALIGNED(btrfs_super_nodesize(sb), 4096)) {
+ error("nodesize unaligned: %u", btrfs_super_nodesize(sb));
+ goto error_out;
+ }
+ if (btrfs_super_sectorsize(sb) < 4096) {
+ error("sectorsize too small: %u < 4096",
+ btrfs_super_sectorsize(sb));
+ goto error_out;
+ }
+ if (!IS_ALIGNED(btrfs_super_sectorsize(sb), 4096)) {
+ error("sectorsize unaligned: %u", btrfs_super_sectorsize(sb));
+ goto error_out;
+ }
+ if (btrfs_super_total_bytes(sb) == 0) {
+ error("invalid total_bytes 0");
+ goto error_out;
+ }
+ if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
+ error("invalid bytes_used %llu", btrfs_super_bytes_used(sb));
+ goto error_out;
+ }
+ if ((btrfs_super_stripesize(sb) != 4096)
+ && (btrfs_super_stripesize(sb) != btrfs_super_sectorsize(sb))) {
+ error("invalid stripesize %u", btrfs_super_stripesize(sb));
+ goto error_out;
+ }
+
+ if (btrfs_super_incompat_flags(sb) & BTRFS_FEATURE_INCOMPAT_METADATA_UUID)
+ metadata_uuid = sb->metadata_uuid;
+ else
+ metadata_uuid = sb->fsid;
+
+ if (memcmp(metadata_uuid, sb->dev_item.fsid, BTRFS_FSID_SIZE) != 0) {
+ char fsid[BTRFS_UUID_UNPARSED_SIZE];
+ char dev_fsid[BTRFS_UUID_UNPARSED_SIZE];
+
+ uuid_unparse(sb->metadata_uuid, fsid);
+ uuid_unparse(sb->dev_item.fsid, dev_fsid);
+ error("dev_item UUID does not match fsid: %s != %s",
+ dev_fsid, fsid);
+ goto error_out;
+ }
+
+ /*
+ * Hint to catch really bogus numbers, bitflips or so
+ */
+ if (btrfs_super_num_devices(sb) > (1UL << 31)) {
+ error("suspicious number of devices: %llu",
+ btrfs_super_num_devices(sb));
+ }
+
+ if (btrfs_super_num_devices(sb) == 0) {
+ error("number of devices is 0");
+ goto error_out;
+ }
+
+ /*
+ * Obvious sys_chunk_array corruptions, it must hold at least one key
+ * and one chunk
+ */
+ if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
+ error("system chunk array too big %u > %u",
+ btrfs_super_sys_array_size(sb),
+ BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
+ goto error_out;
+ }
+ if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
+ + sizeof(struct btrfs_chunk)) {
+ error("system chunk array too small %u < %zu",
+ btrfs_super_sys_array_size(sb),
+ sizeof(struct btrfs_disk_key) +
+ sizeof(struct btrfs_chunk));
+ goto error_out;
+ }
+
+ return 0;
+
+error_out:
+ error("superblock checksum matches but it has invalid members");
+ return -EIO;
+}
+
+/*
+ * btrfs_read_dev_super - read a valid primary superblock from a block device
+ * @desc,@part: file descriptor of the device
+ * @sb: buffer where the superblock is going to be read in
+ *
+ * Unlike the btrfs-progs/kernel version, here we ony care about the first
+ * super block, thus it's much simpler.
+ */
+int btrfs_read_dev_super(struct blk_desc *desc, struct disk_partition *part,
+ struct btrfs_super_block *sb)
+{
+ char tmp[BTRFS_SUPER_INFO_SIZE];
+ struct btrfs_super_block *buf = (struct btrfs_super_block *)tmp;
+ int ret;
+
+ ret = __btrfs_devread(desc, part, tmp, BTRFS_SUPER_INFO_SIZE,
+ BTRFS_SUPER_INFO_OFFSET);
+ if (ret < BTRFS_SUPER_INFO_SIZE)
+ return -EIO;
+
+ if (btrfs_super_bytenr(buf) != BTRFS_SUPER_INFO_OFFSET)
+ return -EIO;
+
+ if (btrfs_check_super(buf))
+ return -EIO;
+
+ memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
+ return 0;
+}
+
+int btrfs_read_superblock(void)
+{
+ ALLOC_CACHE_ALIGN_BUFFER(char, raw_sb, BTRFS_SUPER_INFO_SIZE);
+ struct btrfs_super_block *sb = (struct btrfs_super_block *) raw_sb;
+ int ret;
+
+
+ btrfs_info.sb.generation = 0;
+
+ ret = btrfs_read_dev_super(btrfs_blk_desc, btrfs_part_info, sb);
+ if (ret < 0) {
+ pr_debug("%s: No valid BTRFS superblock found!\n", __func__);
+ return ret;
+ }
+ btrfs_super_block_to_cpu(sb);
+ memcpy(&btrfs_info.sb, sb, sizeof(*sb));
+
+ 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;
+ }
+
+ pr_debug("Chosen superblock with generation = %llu\n",
+ btrfs_info.sb.generation);
+
+ return 0;
+}
@@ -2,10 +2,14 @@
#ifndef __BTRFS_DISK_IO_H__
#define __BTRFS_DISK_IO_H__
+#include <linux/sizes.h>
+#include <fs_internal.h>
#include "crypto/hash.h"
#include "ctree.h"
#include "disk-io.h"
+#define BTRFS_SUPER_INFO_OFFSET SZ_64K
+#define BTRFS_SUPER_INFO_SIZE SZ_4K
static inline u64 btrfs_name_hash(const char *name, int len)
{
u32 crc;
@@ -17,4 +21,7 @@ static inline u64 btrfs_name_hash(const char *name, int len)
int btrfs_csum_data(u16 csum_type, const u8 *data, u8 *out, size_t len);
+int btrfs_read_dev_super(struct blk_desc *desc, struct disk_partition *part,
+ struct btrfs_super_block *sb);
+int btrfs_read_superblock(void);
#endif
deleted file mode 100644
@@ -1,258 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * BTRFS filesystem implementation for U-Boot
- *
- * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
- */
-
-#include <common.h>
-#include <log.h>
-#include <memalign.h>
-#include <part.h>
-#include <linux/compat.h>
-#include "btrfs.h"
-#include "disk-io.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 ||
- csum_type == BTRFS_CSUM_TYPE_SHA256 ||
- csum_type == BTRFS_CSUM_TYPE_XXHASH) {
- u8 result[BTRFS_CSUM_SIZE];
-
- btrfs_csum_data(csum_type, (u8 *)raw_disk_sb + BTRFS_CSUM_SIZE,
- result, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
-
- if (memcmp(raw_disk_sb, result, BTRFS_CSUM_SIZE))
- return -EIO;
- } else if (csum_type == BTRFS_CSUM_TYPE_BLAKE2) {
- printf("Blake2 csum type is not supported yet\n");
- return -ENOTSUPP;
- }
-
- 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;
-}