[U-Boot] [PATCH v3] Introduced btrfs file-system with btrload command

Adnan Ali
2013-02-15T12:10:49Z

Introduces btrfs file-system to read file
from volume/sub-volumes with btrload command. This
implementation has read-only support.
This btrfs implementation is based on syslinux btrfs
code, commit 269ebc845ebc8b46ef4b0be7fa0005c7fdb95b8d.

Signed-off-by: Adnan Ali <adnan.ali@codethink.co.uk>
---
Makefile | 1 +
common/Makefile | 1 +
common/cmd_btr.c | 53 +++
fs/btrfs/Makefile | 51 ++
fs/btrfs/btrfs.c | 1131 ++++++++++++++++++++++++++++++++++++++++++++
fs/fs.c | 86 +++-
include/btrfs.h | 398 ++++++++++++++++
include/config_fallbacks.h | 4 +
include/crc32c.h | 48 ++
include/fs.h | 1 +
10 files changed, 1769 insertions(+), 5 deletions(-)
create mode 100644 common/cmd_btr.c
create mode 100644 fs/btrfs/Makefile
create mode 100644 fs/btrfs/btrfs.c
create mode 100644 include/btrfs.h
create mode 100644 include/crc32c.h

diff --git a/Makefile b/Makefile
index 3305e8c..cc35e7b 100644
--- a/Makefile
+++ b/Makefile
@@ -261,6 +261,7 @@ endif
LIBS-$(CONFIG_OF_EMBED) += dts/libdts.o
LIBS-y += arch/$(ARCH)/lib/lib$(ARCH).o
LIBS-y += fs/libfs.o \
+ fs/btrfs/libbtrfs.o \
fs/cbfs/libcbfs.o \
fs/cramfs/libcramfs.o \
fs/ext4/libext4fs.o \
diff --git a/common/Makefile b/common/Makefile
index 54fcc81..093dd35 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -73,6 +73,7 @@ COBJS-$(CONFIG_CMD_BEDBUG) += bedbug.o cmd_bedbug.o
COBJS-$(CONFIG_CMD_BMP) += cmd_bmp.o
COBJS-$(CONFIG_CMD_BOOTLDR) += cmd_bootldr.o
COBJS-$(CONFIG_CMD_BOOTSTAGE) += cmd_bootstage.o
+COBJS-$(CONFIG_CMD_BTR) += cmd_btr.o
COBJS-$(CONFIG_CMD_CACHE) += cmd_cache.o
COBJS-$(CONFIG_CMD_CBFS) += cmd_cbfs.o
COBJS-$(CONFIG_CMD_CONSOLE) += cmd_console.o
diff --git a/common/cmd_btr.c b/common/cmd_btr.c
new file mode 100644
index 0000000..faea625
--- /dev/null
+++ b/common/cmd_btr.c
@@ -0,0 +1,53 @@
+/*
+ * (C) Copyright 2013 Codethink Limited
+ * Btrfs port to Uboot by
+ * Adnan Ali <adnan.ali@codethink.co.uk>
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program 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 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * Boot support
+ */
+#include <fs.h>
+#include <btrfs.h>
+
+char subvolname[MAX_SUBVOL_NAME];
+
+int do_btr_fsload(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+ if (argc > 5)
+ strcpy(subvolname, argv[5]);
+ else
+ strcpy(subvolname, "");
+
+ return do_load(cmdtp, flag, argc, argv, FS_TYPE_BTR, 16);
+}
+
+
+U_BOOT_CMD(
+ btrload, 7, 0, do_btr_fsload,
+ "load binary file from a btr filesystem",
+ "<interface> [<dev[:part]>] <addr> <filename> [subvol_name]\n"
+ " - Load binary file 'filename' from 'dev' on 'interface'\n"
+ " to address 'addr' from better filesystem.\n"
+ " the load stops on end of file.\n"
+ " subvol_name is used read that file from this subvolume.\n"
+ " All numeric parameters are assumed to be hex."
+);
+
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
new file mode 100644
index 0000000..a9e2021
--- /dev/null
+++ b/fs/btrfs/Makefile
@@ -0,0 +1,51 @@
+#
+# (C) Copyright 2006
+# Wolfgang Denk, DENX Software Engineering, wd at denx.de.
+#
+# (C) Copyright 2003
+# Pavel Bartusek, Sysgo Real-Time Solutions AG, pba at sysgo.de
+#
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program 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 2 of
+# the License, or (at your option) any later version.
+#
+# This program 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 this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+include $(TOPDIR)/config.mk
+
+LIB = $(obj)libbtrfs.o
+
+AOBJS =
+COBJS-$(CONFIG_FS_BTR) := btrfs.o
+
+SRCS := $(AOBJS:.o=.S) $(COBJS-y:.o=.c)
+OBJS := $(addprefix $(obj),$(AOBJS) $(COBJS-y))
+
+
+all: $(LIB) $(AOBJS)
+
+$(LIB): $(obj).depend $(OBJS)
+ $(call cmd_link_o_target, $(OBJS))
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
diff --git a/fs/btrfs/btrfs.c b/fs/btrfs/btrfs.c
new file mode 100644
index 0000000..9568042
--- /dev/null
+++ b/fs/btrfs/btrfs.c
@@ -0,0 +1,1131 @@
+/*
+ * (C) Copyright 2013 Codethink Limited
+ * Btrfs port to Uboot by
+ * Adnan Ali <adnan.ali@codethink.co.uk>
+
+ * btrfs.c -- readonly btrfs support for syslinux
+ * Some data structures are derivated from btrfs-tools-0.19 ctree.h
+ * Copyright 2009 Intel Corporation; author: alek.du at intel.com
+ *
+ * This program 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, Inc., 53 Temple Place Ste 330,
+ * Boston MA 02111-1307, USA; either version 2 of the License, or
+ * (at your option) any later version; incorporated herein by reference.
+ *
+ */
+
+#include <linux/stat.h>
+#include <command.h>
+#include <asm/byteorder.h>
+#include <linux/compiler.h>
+#include <common.h>
+#include <config.h>
+#include <fs.h>
+#include <btrfs.h>
+
+unsigned long btr_part_offset;
+/* Actual file structures (we don't have malloc yet...) */
+struct file files[MAX_OPEN];
+static u32 btrfs_crc32_table[256];
+static block_dev_desc_t *btrfs_block_dev_desc;
+static disk_partition_t *part_info;
+struct inode parent_inode;
+extern char subvolname[MAX_SUBVOL_NAME];
+
+static void btrfs_init_crc32c(void)
+{
+ /* Bit-reflected CRC32C polynomial */
+ crc32c_init(btrfs_crc32_table, 0x82F63B78);
+}
+
+static inline u32 crc32c_le(u32 crc, const char *data, size_t length)
+{
+ return crc32c_cal(crc, data, length, btrfs_crc32_table);
+}
+
+void btrfs_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info)
+{
+ btrfs_block_dev_desc = rbdd;
+ part_info = info;
+ btr_part_offset = info->start;
+}
+
+
+/* compare function used for bin_search */
+typedef int (*cmp_func)(void *ptr1, void *ptr2);
+
+static int bin_search(void *ptr, int item_size, void *cmp_item, cmp_func func,
+ int min, int max, int *slot)
+{
+ int low = min;
+ int high = max;
+ int mid;
+ int ret;
+ unsigned long offset;
+ void *item;
+
+ while (low < high) {
+ mid = (low + high) / 2;
+ offset = mid * item_size;
+
+ item = ptr + offset;
+ ret = func(item, cmp_item);
+
+ if (ret < 0)
+ low = mid + 1;
+ else if (ret > 0)
+ high = mid;
+ else {
+ *slot = mid;
+ return 0;
+ }
+ }
+ *slot = low;
+ return 1;
+}
+
+/* XXX: these should go into the filesystem instance structure */
+static struct btrfs_chunk_map chunk_map;
+static struct btrfs_super_block sb;
+static u64 fs_tree;
+
+static int btrfs_comp_chunk_map(struct btrfs_chunk_map_item *m1,
+ struct btrfs_chunk_map_item *m2)
+{
+ if (__le64_to_cpu(m1->logical) > __le64_to_cpu(m2->logical))
+ return 1;
+ if (__le64_to_cpu(m1->logical) < __le64_to_cpu(m2->logical))
+ return -1;
+ return 0;
+}
+
+/* insert a new chunk mapping item */
+static void insert_map(struct btrfs_chunk_map_item *item)
+{
+ int ret;
+ int slot;
+ int i;
+
+ if (chunk_map.map == NULL) { /* first item */
+ chunk_map.map_length = BTRFS_MAX_CHUNK_ENTRIES;
+ chunk_map.map = (struct btrfs_chunk_map_item *)
+ malloc(chunk_map.map_length * sizeof(*chunk_map.map));
+ chunk_map.map[0] = *item;
+ chunk_map.cur_length = 1;
+ return;
+ }
+ ret = bin_search(chunk_map.map, sizeof(*item), item,
+ (cmp_func)btrfs_comp_chunk_map, 0,
+ chunk_map.cur_length, &slot);
+ if (ret == 0)/* already in map */
+ return;
+ if (chunk_map.cur_length == BTRFS_MAX_CHUNK_ENTRIES) {
+ /* should be impossible */
+ printf("too many chunk items\n");
+ return;
+ }
+ for (i = chunk_map.cur_length; i > slot; i--)
+ chunk_map.map[i] = chunk_map.map[i-1];
+ chunk_map.map[slot] = *item;
+ chunk_map.cur_length++;
+}
+
+/*
+ * from sys_chunk_array or chunk_tree, we can convert a logical address to
+ * a physical address we can not support multi device case yet
+ */
+static u64 logical_physical(u64 logical)
+{
+ struct btrfs_chunk_map_item item;
+ int slot, ret;
+
+ item.logical = logical;
+ ret = bin_search(chunk_map.map, sizeof(*chunk_map.map), &item,
+ (cmp_func)btrfs_comp_chunk_map, 0,
+ chunk_map.cur_length, &slot);
+ if (ret == 0)
+ slot++;
+ else if (slot == 0)
+ return -1;
+ if (logical >=
+ chunk_map.map[slot-1].logical + chunk_map.map[slot-1].length)
+ return -1;
+ return chunk_map.map[slot-1].physical + logical -
+ chunk_map.map[slot-1].logical;
+}
+
+int btrfs_devread(int sector, int byte_offset, int byte_len, char* buf)
+{
+ ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, SECTOR_SIZE);
+ unsigned block_len;
+
+ /* Get the read to the beginning of a partition */
+ sector += byte_offset >> SECTOR_BITS;
+ byte_offset &= SECTOR_SIZE - 1;
+
+ if (btrfs_block_dev_desc == NULL) {
+ printf("** Invalid Block Device Descriptor (NULL)\n");
+ return 0;
+ }
+ if (byte_offset != 0) {
+ /* read first part which isn't aligned with start of sector */
+ if (btrfs_block_dev_desc->
+ block_read(btrfs_block_dev_desc->dev,
+ part_info->start + sector, 1,
+ (unsigned long *) sec_buf) != 1) {
+ printf(" ** btrfs_devread() read error **\n");
+ return 0;
+ }
+ memcpy(buf, sec_buf + byte_offset,
+ min(SECTOR_SIZE - byte_offset, byte_len));
+ buf += min(SECTOR_SIZE - byte_offset, byte_len);
+ byte_len -= min(SECTOR_SIZE - byte_offset, byte_len);
+ sector++;
+ }
+ /* read sector aligned part */
+
+ block_len = byte_len & ~(SECTOR_SIZE - 1);
+
+ if (block_len == 0) {
+ ALLOC_CACHE_ALIGN_BUFFER(u8, p, SECTOR_SIZE);
+
+ block_len = SECTOR_SIZE;
+ btrfs_block_dev_desc->block_read(btrfs_block_dev_desc->dev,
+ part_info->start + sector,
+ 1, (unsigned long *)p);
+ memcpy(buf, p, byte_len);
+ return 1;
+ }
+ ALLOC_CACHE_ALIGN_BUFFER(u8, t, block_len);
+ if (btrfs_block_dev_desc->block_read(btrfs_block_dev_desc->dev,
+ part_info->start + sector,
+ block_len / SECTOR_SIZE,
+ (unsigned long *) t) !=
+ block_len / SECTOR_SIZE) {
+ printf(" ** %s read error - block\n", __func__);
+ return 0;
+ }
+
+ memcpy(buf, t, block_len);
+ block_len = byte_len & ~(SECTOR_SIZE - 1);
+ buf += block_len;
+ byte_len -= block_len;
+ sector += block_len / SECTOR_SIZE;
+ if (byte_len != 0) {
+ /* read rest of data which are not in whole sector */
+ if (btrfs_block_dev_desc->
+ block_read(btrfs_block_dev_desc->dev,
+ part_info->start + sector, 1,
+ (unsigned long *) sec_buf) != 1) {
+ printf("* %s read error - last part\n", __func__);
+ return 0;
+ }
+ memcpy(buf, sec_buf, byte_len);
+ }
+
+
+ return 1;
+}
+/* btrfs has several super block mirrors, need to calculate their location */
+static inline u64 btrfs_sb_offset(int mirror)
+{
+ u64 start = 16 * 1024;
+ if (mirror)
+ return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
+ return BTRFS_SUPER_INFO_OFFSET;
+}
+
+/* find the most recent super block */
+static int btrfs_read_super_block(struct fs_info *fs)
+{
+ int i;
+ int ret;
+ u8 fsid[BTRFS_FSID_SIZE];
+ u8 boots[512];
+ u64 offset;
+ u64 transid = 0;
+ struct btrfs_super_block buf;
+
+ sb.total_bytes = ~0; /* Unknown as of yet */
+
+ /*Only first header is checked for filesystem verification
+ mirror of this header can be used if required*/
+ offset = btrfs_sb_offset(0);
+
+ if ( btrfs_devread(128, 0, sizeof(struct btrfs_super_block), (char*)&buf)!=1)
+ return -1;
+
+
+ if (buf.bytenr != offset ||
+ strncmp((char *)(&buf.magic), BTRFS_MAGIC, sizeof(buf.magic)))
+ {
+ return -1;
+ }
+
+ if (i == 0)
+ memcpy(fsid, buf.fsid, sizeof(fsid));
+ else if (memcmp(fsid, buf.fsid, sizeof(fsid)))
+ return -1;
+
+ if (buf.generation > transid) {
+ memcpy(&sb, &buf, sizeof(sb));
+ transid = buf.generation;
+ }
+ return 0;
+}
+
+static inline unsigned long btrfs_chunk_item_size(int num_stripes)
+{
+ return sizeof(struct btrfs_chunk) +
+ sizeof(struct btrfs_stripe) * (num_stripes - 1);
+}
+
+static void clear_path(struct btrfs_path *path)
+{
+ memset(path, 0, sizeof(*path));
+}
+
+static int btrfs_comp_keys(struct btrfs_disk_key *k1, struct btrfs_disk_key *k2)
+{
+ if (k1->objectid > k2->objectid)
+ return 1;
+ if (k1->objectid < k2->objectid)
+ return -1;
+ if (k1->type > k2->type)
+ return 1;
+ if (k1->type < k2->type)
+ return -1;
+ if (k1->offset > k2->offset)
+ return 1;
+ if (k1->offset < k2->offset)
+ return -1;
+ return 0;
+}
+
+/* compare keys but ignore offset, is useful to enumerate all same kind keys */
+static int btrfs_comp_keys_type(struct btrfs_disk_key *k1,
+ struct btrfs_disk_key *k2)
+{
+ if (k1->objectid > k2->objectid)
+ return 1;
+ if (k1->objectid < k2->objectid)
+ return -1;
+ if (k1->type > k2->type)
+ return 1;
+ if (k1->type < k2->type)
+ return -1;
+ return 0;
+}
+
+/* seach tree directly on disk ... */
+static int search_tree(struct fs_info *fs, u64 loffset,
+ struct btrfs_disk_key *key, struct btrfs_path *path)
+{
+ u8 buf[BTRFS_MAX_LEAF_SIZE];
+ struct btrfs_header *header = (struct btrfs_header *)buf;
+ struct btrfs_node *node = (struct btrfs_node *)buf;
+ struct btrfs_leaf *leaf = (struct btrfs_leaf *)buf;
+ int slot, ret;
+ u64 offset;
+
+ offset = logical_physical(loffset);
+ btrfs_devread(offset/SECTOR_SIZE, (offset%SECTOR_SIZE), sizeof(*header), (char*)header);
+ if (header->level) {/*node*/
+ btrfs_devread(((offset+sizeof(*header))/SECTOR_SIZE),((offset+sizeof(*header))%SECTOR_SIZE) ,
+ __le32_to_cpu(sb.nodesize) - sizeof(*header), (char *)&node->ptrs[0]);
+ path->itemsnr[header->level] = header->nritems;
+ path->offsets[header->level] = loffset;
+ ret = bin_search(&node->ptrs[0], sizeof(struct btrfs_key_ptr),
+ key, (cmp_func)btrfs_comp_keys,
+ path->slots[header->level], header->nritems, &slot);
+ if (ret && slot > path->slots[header->level])
+ slot--;
+ path->slots[header->level] = slot;
+ ret = search_tree(fs, node->ptrs[slot].blockptr, key, path);
+ } else {/*leaf*/
+
+ btrfs_devread(((offset+sizeof(*header))/SECTOR_SIZE), ((offset+sizeof(*header))%SECTOR_SIZE),
+ (sb.leafsize) - sizeof(*header), (char *)&leaf->items);
+ path->itemsnr[header->level] = header->nritems;
+ path->offsets[0] = loffset;
+ ret = bin_search(&leaf->items[0], sizeof(struct btrfs_item),
+ key, (cmp_func)btrfs_comp_keys, path->slots[0],
+ header->nritems, &slot);
+ if (ret && slot > path->slots[header->level])
+ slot--;
+ path->slots[0] = slot;
+ path->item = leaf->items[slot];
+ btrfs_devread(((offset + sizeof(*header) + leaf->items[slot].offset)/SECTOR_SIZE),
+ ((offset + sizeof(*header) + leaf->items[slot].offset)%SECTOR_SIZE),
+ leaf->items[slot].size, (char*)&path->data);
+ }
+ return ret;
+}
+
+/* return 0 if leaf found */
+static int next_leaf(struct fs_info *fs, struct btrfs_disk_key *key, struct btrfs_path *path)
+{
+ int slot;
+ int level = 1;
+
+ while (level < BTRFS_MAX_LEVEL) {
+ if (!path->itemsnr[level]) /* no more nodes */
+ return 1;
+ slot = path->slots[level] + 1;
+ if (slot >= path->itemsnr[level]) {
+ level++;
+ continue;;
+ }
+ path->slots[level] = slot;
+ path->slots[level-1] = 0; /* reset low level slots info */
+ search_tree(fs, path->offsets[level], key, path);
+ break;
+ }
+ if (level == BTRFS_MAX_LEVEL)
+ return 1;
+ return 0;
+}
+
+/* return 0 if slot found */
+static int next_slot(struct fs_info *fs, struct btrfs_disk_key *key, struct btrfs_path *path)
+{
+ int slot;
+
+ if (!path->itemsnr[0])
+ return 1;
+ slot = path->slots[0] + 1;
+ if (slot >= path->itemsnr[0])
+ return 1;
+ path->slots[0] = slot;
+ search_tree(fs, path->offsets[0], key, path);
+ return 0;
+}
+
+/*
+ * read chunk_array in super block
+ */
+static void btrfs_read_sys_chunk_array(void)
+{
+ struct btrfs_chunk_map_item item;
+ struct btrfs_disk_key *key;
+ struct btrfs_chunk *chunk;
+ int cur;
+
+ /* read chunk array in superblock */
+ cur = 0;
+
+ while (cur < __le32_to_cpu(sb.sys_chunk_array_size)) {
+ key = (struct btrfs_disk_key *)(sb.sys_chunk_array + cur);
+ cur += sizeof(*key);
+ chunk = (struct btrfs_chunk *)(sb.sys_chunk_array + cur);
+ cur += btrfs_chunk_item_size(chunk->num_stripes);
+ /* insert to mapping table, ignore multi stripes */
+ item.logical = key->offset;
+ item.length = chunk->length;
+ item.devid = chunk->stripe.devid;
+ item.physical = chunk->stripe.offset;/*ignore other stripes */
+
+
+ insert_map(&item);
+ }
+}
+
+/* read chunk items from chunk_tree and insert them to chunk map */
+static void btrfs_read_chunk_tree(struct fs_info *fs)
+{
+ struct btrfs_disk_key search_key;
+ struct btrfs_chunk *chunk;
+ struct btrfs_chunk_map_item item;
+ struct btrfs_path path;
+ int status;
+
+ if (!(__le64_to_cpu(sb.flags) & BTRFS_SUPER_FLAG_METADUMP)) {
+ if (__le64_to_cpu(sb.num_devices) > 1)
+ {
+ printf("warning: only support one btrfs device %d\n",
+ __le64_to_cpu(sb.num_devices));
+ return;
+ }
+ /* read chunk from chunk_tree */
+ search_key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ search_key.type = BTRFS_CHUNK_ITEM_KEY;
+ search_key.offset = 0;
+ clear_path(&path);
+ search_tree(fs, (sb.chunk_root), &search_key, &path);
+ do {
+ do {
+
+ if (status=btrfs_comp_keys_type(&search_key,
+ &path.item.key))
+ break;
+ chunk = (struct btrfs_chunk *)(path.data);
+ /* insert to mapping table, ignore stripes */
+ item.logical = path.item.key.offset;
+ item.length = chunk->length;
+ item.devid = chunk->stripe.devid;
+ item.physical = chunk->stripe.offset;
+ insert_map(&item);
+ } while (!next_slot(fs, &search_key, &path));
+ if (btrfs_comp_keys_type(&search_key, &path.item.key))
+ break;
+ } while (!next_leaf(fs, &search_key, &path));
+ }
+}
+
+static inline u64 btrfs_name_hash(const char *name, int len)
+{
+ return btrfs_crc32c((u32)~1, name, len);
+}
+
+static struct inode *btrfs_iget_by_inr(struct fs_info *fs, u64 inr)
+{
+ struct inode *inode;
+ struct btrfs_inode_item inode_item;
+ struct btrfs_disk_key search_key;
+ struct btrfs_path path;
+ int ret;
+
+ /* FIXME: some BTRFS inode member are u64, while our logical inode
+ is u32, we may need change them to u64 later */
+ search_key.objectid = inr;
+ search_key.type = BTRFS_INODE_ITEM_KEY;
+ search_key.offset = 0;
+ clear_path(&path);
+ ret = search_tree(fs, fs_tree, &search_key, &path);
+ if (ret)
+ {
+ printf("%s search_tree failed\n", __func__);
+ return NULL;
+ }
+
+ inode_item = *(struct btrfs_inode_item *)path.data;
+ if (!(inode = alloc_inode(fs, inr, sizeof(struct btrfs_pvt_inode))))
+ {
+ printf("%s alloc_inode failed\n", __func__);
+ return NULL;
+ }
+ inode->ino = inr;
+ inode->size = inode_item.size;
+ inode->mode = IFTODT(inode_item.mode);
+ if (inode->mode == DT_REG || inode->mode == DT_LNK) {
+ struct btrfs_file_extent_item extent_item;
+ u64 offset;
+
+ /* get file_extent_item */
+ search_key.type = BTRFS_EXTENT_DATA_KEY;
+ search_key.offset = 0;
+ clear_path(&path);
+ ret = search_tree(fs, fs_tree, &search_key, &path);
+ if (ret)
+ return NULL; /* impossible */
+ extent_item = *(struct btrfs_file_extent_item *)path.data;
+ if (extent_item.type == BTRFS_FILE_EXTENT_INLINE)/* inline file */
+ offset = path.offsets[0] + sizeof(struct btrfs_header)
+ + path.item.offset
+ + offsetof(struct btrfs_file_extent_item, disk_bytenr);
+ else
+ offset = extent_item.disk_bytenr;
+ PVT(inode)->offset = offset;
+ }
+ return inode;
+}
+
+static struct inode *btrfs_iget_root(struct fs_info *fs)
+{
+ /* BTRFS_FIRST_CHUNK_TREE_OBJECTID(256) actually is first OBJECTID for FS_TREE */
+ return btrfs_iget_by_inr(fs, BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+}
+
+static struct inode *btrfs_iget(const char *name, struct inode *parent)
+{
+ struct fs_info *fs = parent->fs;
+ struct btrfs_disk_key search_key;
+ struct btrfs_path path;
+ struct btrfs_dir_item dir_item;
+ int ret;
+
+ search_key.objectid = parent->ino;
+ search_key.type = BTRFS_DIR_ITEM_KEY;
+ search_key.offset = btrfs_name_hash(name, strlen(name));
+ clear_path(&path);
+ ret = search_tree(fs, fs_tree, &search_key, &path);
+ if (ret)
+ return NULL;
+ dir_item = *(struct btrfs_dir_item *)path.data;
+
+ return btrfs_iget_by_inr(fs, dir_item.location.objectid);
+}
+
+static int btrfs_readlink(struct inode *inode, char *buf)
+{
+ btrfs_devread((logical_physical(PVT(inode)->offset)/SECTOR_SIZE),
+ (logical_physical(PVT(inode)->offset)%SECTOR_SIZE), inode->size, (char*)buf);
+ buf[inode->size] = '\0';
+ return inode->size;
+}
+
+static int btrfs_readdir(struct file *file, struct dirent *dirent)
+{
+ struct fs_info *fs = file->fs;
+ struct inode *inode = file->inode;
+ struct btrfs_disk_key search_key;
+ struct btrfs_path path;
+ struct btrfs_dir_item *dir_item;
+ int ret;
+
+ /*
+ * we use file->offset to store last search key.offset, will will search
+ * key that lower that offset, 0 means first search and we will search
+ * -1UL, which is the biggest possible key
+ */
+ search_key.objectid = inode->ino;
+ search_key.type = BTRFS_DIR_ITEM_KEY;
+ search_key.offset = file->offset - 1;
+ clear_path(&path);
+ ret = search_tree(fs, fs_tree, &search_key, &path);
+
+ if (ret) {
+ if (btrfs_comp_keys_type(&search_key, &path.item.key))
+ return -1;
+ }
+
+ dir_item = (struct btrfs_dir_item *)path.data;
+ file->offset = path.item.key.offset;
+ dirent->d_ino = dir_item->location.objectid;
+ dirent->d_off = file->offset;
+ dirent->d_reclen = offsetof(struct dirent, d_name)
+ + dir_item->name_len + 1;
+ dirent->d_type = IFTODT(dir_item->type);
+ memcpy(dirent->d_name, dir_item + 1, dir_item->name_len);
+ dirent->d_name[dir_item->name_len] = '\0';
+
+ return 0;
+}
+
+static int btrfs_next_extent(struct inode *inode, uint32_t lstart)
+{
+ struct btrfs_disk_key search_key;
+ struct btrfs_file_extent_item extent_item;
+ struct btrfs_path path;
+ int ret;
+ u64 offset;
+ struct fs_info *fs = inode->fs;
+ u32 sec_shift = SECTOR_BITS;
+ u32 sec_size = SECTOR_SIZE;
+
+ search_key.objectid = inode->ino;
+ search_key.type = BTRFS_EXTENT_DATA_KEY;
+ search_key.offset = lstart << sec_shift;
+ clear_path(&path);
+ ret = search_tree(fs, fs_tree, &search_key, &path);
+ if (ret) { /* impossible */
+ printf("btrfs: search extent data error\n");
+ return -1;
+ }
+ extent_item = *(struct btrfs_file_extent_item *)path.data;
+
+ if (extent_item.encryption) {
+ printf("btrfs: found encrypted data, cannot continue\n");
+ return -1;
+ }
+ if (extent_item.compression) {
+ printf("btrfs: found compressed data, cannot continue\n");
+ return -1;
+ }
+
+ if (extent_item.type == BTRFS_FILE_EXTENT_INLINE) {/* inline file */
+ /* we fake a extent here, and PVT of inode will tell us */
+ offset = path.offsets[0] + sizeof(struct btrfs_header)
+ + path.item.offset
+ + offsetof(struct btrfs_file_extent_item, disk_bytenr);
+ inode->next_extent.len =
+ (inode->size + sec_size -1) >> sec_shift;
+ } else {
+ offset = extent_item.disk_bytenr + extent_item.offset;
+ inode->next_extent.len =
+ (extent_item.num_bytes + sec_size - 1) >> sec_shift;
+ }
+ inode->next_extent.pstart =
+ logical_physical(offset) >> sec_shift;
+ PVT(inode)->offset = offset;
+ return 0;
+}
+
+static uint32_t btrfs_getfssec(struct file *file, char *buf, int sectors,
+ char *have_more)
+{
+ u32 ret;
+ struct fs_info *fs = file->fs;
+ u32 off = PVT(file->inode)->offset % SECTOR_SIZE;
+ char handle_inline = 0;
+
+ if (off && !file->offset) {/* inline file first read patch */
+ file->inode->size += off;
+ handle_inline = 1;
+ }
+ ret = generic_getfssec(file, buf, sectors, have_more);
+ if (!ret)
+ return ret;
+ off = PVT(file->inode)->offset % SECTOR_SIZE;
+ if (handle_inline) {/* inline file patch */
+ ret -= off;
+ memcpy(buf, buf + off, ret);
+ }
+ return ret;
+}
+
+static void btrfs_get_fs_tree(struct fs_info *fs)
+{
+ struct btrfs_disk_key search_key;
+ struct btrfs_path path;
+ struct btrfs_root_item *tree;
+ char subvol_ok = 0;
+
+ /* check if subvol is filled by installer */
+ if (*subvolname) {
+ search_key.objectid = BTRFS_FS_TREE_OBJECTID;
+ search_key.type = BTRFS_ROOT_REF_KEY;
+ search_key.offset = 0;
+ clear_path(&path);
+ if (search_tree(fs, __le64_to_cpu(sb.root), &search_key, &path))
+ next_slot(fs, &search_key, &path);
+ do {
+ do {
+ struct btrfs_root_ref *ref;
+ int pathlen, status;
+
+ if (status=btrfs_comp_keys_type(&search_key,
+ &path.item.key))
+ break;
+ ref = (struct btrfs_root_ref *)path.data;
+ pathlen = path.item.size - sizeof(struct btrfs_root_ref);
+ printf("sub_vol found %s\n", (char*)(ref+1));
+ if (!strncmp((char*)(ref + 1), subvolname, pathlen)) {
+ subvol_ok = 1;
+ break;
+ }
+ } while (!next_slot(fs, &search_key, &path));
+ if (subvol_ok)
+ break;
+ if (btrfs_comp_keys_type(&search_key, &path.item.key))
+ break;
+ } while (!next_leaf(fs, &search_key, &path));
+ if (!subvol_ok) /* should be impossible */
+ printf("no subvol found\n");
+ }
+ /* find fs_tree from tree_root */
+ if (subvol_ok)
+ search_key.objectid = path.item.key.offset;
+ else /* "default" volume */
+ search_key.objectid = BTRFS_FS_TREE_OBJECTID;
+ search_key.type = BTRFS_ROOT_ITEM_KEY;
+ search_key.offset =-1;
+ clear_path(&path);
+ search_tree(fs, (sb.root), &search_key, &path);
+ tree = (struct btrfs_root_item *)path.data;
+ fs_tree = tree->bytenr;
+}
+
+/* init. the fs meta data, return the block size shift bits. */
+int btrfs_fs_init(struct fs_info *fs)
+{
+
+ btrfs_init_crc32c();
+ btrfs_read_super_block(fs);
+ if (strncmp((char *)(&sb.magic), BTRFS_MAGIC, sizeof(sb.magic)))
+ return -1;
+
+ btrfs_read_sys_chunk_array();
+ btrfs_read_chunk_tree(fs);
+ btrfs_get_fs_tree(fs);
+ fs->root = btrfs_iget_root(fs);
+ parent_inode=*(fs->root);
+
+ return 1;
+}
+static inline uint16_t file_to_handle(struct file *file)
+{
+ return file ? (file - files)+1 : 0;
+}
+
+static inline struct file *handle_to_file(uint16_t handle)
+{
+ return handle ? &files[handle-1] : NULL;
+}
+
+/*
+ * Free a refcounted inode
+ */
+void put_inode(struct inode *inode)
+{
+ while (inode && --inode->refcnt == 0) {
+ struct inode *dead = inode;
+ inode = inode->parent;
+ if (dead->name)
+ free((char *)dead->name);
+ free(dead);
+ }
+}
+
+/*
+ * Get a new inode structure
+ */
+struct inode *alloc_inode(struct fs_info *fs, uint32_t ino, size_t data)
+{
+ struct inode *inode = malloc(sizeof(struct inode) + data);
+ if (inode) {
+ inode->fs = fs;
+ inode->ino = ino;
+ inode->refcnt = 1;
+ }
+ return inode;
+}
+
+/*
+ * Get an empty file structure
+ */
+static struct file *alloc_file(void)
+{
+ int i;
+ struct file *file = files;
+
+ for (i = 0; i < MAX_OPEN; i++) {
+ if (!file->fs)
+ return file;
+ file++;
+ }
+
+ return NULL;
+}
+
+/*
+ * Close and free a file structure
+ */
+static inline void free_file(struct file *file)
+{
+ memset(file, 0, sizeof *file);
+}
+
+void generic_close_file(struct file *file)
+{
+ if (file->inode) {
+ file->offset = 0;
+ put_inode(file->inode);
+ }
+}
+
+void _close_file(struct file *file)
+{
+ if (file->fs)
+ generic_close_file(file);
+ free_file(file);
+}
+
+void btrfs_mangle_name(char *dst, const char *src)
+{
+ char *p = dst;
+ int i = FILENAME_MAX-1;
+
+ while (not_whitespace(*src)) {
+ if (*src == '/') {
+ if (src[1] == '/') {
+ src++;
+ i--;
+ continue;
+ }
+ }
+ i--;
+ *dst++ = *src++;
+ }
+ while (1) {
+ if (dst == p)
+ break;
+ if (dst[-1] != '/')
+ break;
+ if ((dst[-1] == '/') && ((dst - 1) == p))
+ break;
+
+ dst--;
+ i++;
+ }
+
+ i++;
+ for (; i > 0; i --)
+ *dst++ = '\0';
+
+}
+int btrfs_open_file(const char *name, struct com32_filedata *filedata)
+{
+ int rv;
+ struct file *file;
+ char mangled_name[FILENAME_MAX];
+
+ btrfs_mangle_name(mangled_name, name);
+ rv = searchdir(mangled_name);
+ if (rv < 0)
+ return rv;
+
+ file = handle_to_file(rv);
+ filedata->size = file->inode->size;
+ filedata->handle = rv;
+ return rv;
+}
+
+int searchdir(const char *name)
+{
+ struct inode *inode = NULL;
+ struct inode *parent = &parent_inode;
+ struct file *file;
+ char *pathbuf = NULL;
+ char *part, *p, echar;
+ int symlink_count = MAX_SYMLINK_CNT;
+
+ if (!(file = alloc_file()))
+ goto err_no_close;
+
+ p = pathbuf = strdup(name);
+ if (!pathbuf)
+ goto err;
+
+ do {
+ got_link:
+ if (*p == '/') {
+ put_inode(parent);
+ parent = &parent_inode;// get_inode(this_fs->root);
+ }
+
+ do {
+ inode = get_inode(parent);
+
+ while (*p == '/')
+ p++;
+
+ if (!*p)
+ break;
+
+ part = p;
+ while ((echar = *p) && echar != '/')
+ p++;
+ *p++ = '\0';
+ if (part[0] == '.' && part[1] == '.' && part[2] == '\0') {
+ if (inode->parent) {
+ put_inode(parent);
+ parent = get_inode(inode->parent);
+ put_inode(inode);
+ inode = NULL;
+ if (!echar) {
+ /* Terminal double dots */
+ inode = parent;
+ parent = inode->parent ?
+ get_inode(inode->parent) : NULL;
+ }
+ }
+ } else if (part[0] != '.' || part[1] != '\0') {
+ inode = btrfs_iget(part, parent);
+ if (!inode)
+ goto err;
+ if (inode->mode == DT_LNK) {
+ char *linkbuf, *q;
+ int name_len = echar ? strlen(p) : 0;
+ int total_len = inode->size + name_len + 2;
+ int link_len;
+
+ if (/*!this_fs->fs_ops->readlink ||*/
+ --symlink_count == 0 || /* limit check */
+ total_len > MAX_SYMLINK_BUF)
+ goto err;
+
+ linkbuf = malloc(total_len);
+ if (!linkbuf)
+ goto err;
+
+ link_len = btrfs_readlink(inode, linkbuf);
+ if (link_len <= 0) {
+ free(linkbuf);
+ goto err;
+ }
+
+ q = linkbuf + link_len;
+
+ if (echar) {
+ if (link_len > 0 && q[-1] != '/')
+ *q++ = '/';
+
+ memcpy(q, p, name_len+1);
+ } else {
+ *q = '\0';
+ }
+
+ free(pathbuf);
+ p = pathbuf = linkbuf;
+ put_inode(inode);
+ inode = NULL;
+ goto got_link;
+ }
+
+ inode->name = strdup(part);
+
+ inode->parent = parent;
+ parent = NULL;
+
+ if (!echar)
+ break;
+
+ if (inode->mode != DT_DIR)
+ goto err;
+
+ parent = inode;
+ inode = NULL;
+ }
+ } while (echar);
+ } while (0);
+
+ free(pathbuf);
+ pathbuf = NULL;
+ put_inode(parent);
+ parent = NULL;
+
+ if (!inode)
+ goto err;
+
+ file->inode = inode;
+ file->offset = 0;
+ return file_to_handle(file);
+
+err:
+ put_inode(inode);
+ put_inode(parent);
+ if (pathbuf)
+ free(pathbuf);
+ _close_file(file);
+err_no_close:
+ return -1;
+}
+
+static void get_next_extent(struct inode *inode)
+{
+ /* The logical start address that we care about... */
+ uint32_t lstart = inode->this_extent.lstart + inode->this_extent.len;
+
+ if (btrfs_next_extent(inode, lstart))
+ inode->next_extent.len = 0; /* ERROR */
+ inode->next_extent.lstart = lstart;
+}
+
+int getfssec(struct com32_filedata *filedata, char * buf)
+{
+ int sectors;
+ char have_more;
+ uint32_t bytes_read;
+ struct file *file;
+ uint16_t handle;
+ if(filedata->size>=512)
+ {
+ sectors = filedata->size/SECTOR_SIZE;
+ sectors += (filedata->size%SECTOR_SIZE)?1:0;
+ }
+ else sectors=2;
+
+ file = handle_to_file(filedata->handle);
+
+ bytes_read = btrfs_getfssec(file, buf, sectors, &have_more);
+ if (!have_more) {
+ }
+ return bytes_read;
+}
+
+uint32_t generic_getfssec(struct file *file, char *buf,
+ int sectors, char *have_more)
+{
+ struct inode *inode = file->inode;
+ struct fs_info *fs = file->fs;
+ uint32_t bytes_read = 0;
+ uint32_t bytes_left = inode->size - file->offset;
+ uint32_t sectors_left =
+ (bytes_left + SECTOR_SIZE - 1) >> 9;
+ uint32_t lsector;
+
+ if (sectors > sectors_left)
+ sectors = sectors_left;
+
+ if (!sectors)
+ return 0;
+
+ lsector = file->offset >> 9;
+
+ if (lsector < inode->this_extent.lstart ||
+ lsector >= inode->this_extent.lstart + inode->this_extent.len) {
+ /* inode->this_extent unusable, maybe next_extent is... */
+ inode->this_extent = inode->next_extent;
+ }
+
+ if (lsector < inode->this_extent.lstart ||
+ lsector >= inode->this_extent.lstart + inode->this_extent.len) {
+ /* Still nothing useful... */
+ inode->this_extent.lstart = lsector;
+ inode->this_extent.len = 0;
+ } else {
+ /* We have some usable information */
+ uint32_t delta = lsector - inode->this_extent.lstart;
+ inode->this_extent.lstart = lsector;
+ inode->this_extent.len -= delta;
+ inode->this_extent.pstart
+ = next_psector(inode->this_extent.pstart, delta);
+ }
+
+
+ while (sectors) {
+ uint32_t chunk;
+ size_t len;
+
+ while (sectors > inode->this_extent.len) {
+ if (!inode->next_extent.len ||
+ inode->next_extent.lstart !=
+ inode->this_extent.lstart + inode->this_extent.len)
+ get_next_extent(inode);
+ if (!inode->this_extent.len) {
+ /* Doesn't matter if it's contiguous... */
+ inode->this_extent = inode->next_extent;
+ if (!inode->next_extent.len) {
+ sectors = 0; /* Failed to get anything... we're dead */
+ break;
+ }
+ } else if (inode->next_extent.len &&
+ inode->next_extent.pstart == next_pstart(&inode->this_extent)) {
+ /* Coalesce extents and loop */
+ inode->this_extent.len += inode->next_extent.len;
+ } else {
+ /* Discontiguous extents */
+ break;
+ }
+ }
+
+
+ chunk = min(sectors, inode->this_extent.len);
+ len = chunk << 9;//SECTOR_SHIFT(fs);
+
+
+ if (inode->this_extent.pstart == EXTENT_ZERO) {
+ memset(buf, 0, len);
+ } else {
+ btrfs_block_dev_desc->block_read( btrfs_block_dev_desc->dev,
+ part_info->start+(inode->this_extent.pstart), chunk, buf);
+ inode->this_extent.pstart += chunk;
+ }
+
+ buf += len;
+ sectors -= chunk;
+ bytes_read += len;
+ inode->this_extent.lstart += chunk;
+ inode->this_extent.len -= chunk;
+ }
+
+ bytes_read = min(bytes_read, bytes_left);
+ file->offset += bytes_read;
+
+ if (have_more)
+ *have_more = bytes_read < bytes_left;
+
+ return bytes_read;
+}
diff --git a/fs/fs.c b/fs/fs.c
index 023e7ef..b662a25 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -20,9 +20,8 @@
#include <ext4fs.h>
#include <fat.h>
#include <fs.h>
-
+#include <btrfs.h>
DECLARE_GLOBAL_DATA_PTR;
-
static block_dev_desc_t *fs_dev_desc;
static disk_partition_t fs_partition;
static int fs_type = FS_TYPE_ANY;
@@ -79,6 +78,73 @@ static inline void fs_close_fat(void)
#define fs_read_fat fs_read_unsupported
#endif

+
+#ifdef CONFIG_FS_BTR
+struct fs_info fs;
+static int fs_probe_btr(void)
+{
+
+ btrfs_set_blk_dev(fs_dev_desc, &fs_partition);
+
+ if (btrfs_fs_init(&fs)==-1) {
+ printf("btrfs probe failed\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+static void fs_close_btr(void)
+{
+}
+
+#define fs_ls_btr btrfs_ls
+static int fs_read_btr(const char *filename, ulong addr, int offset, int len)
+{
+ int file_len=0;
+ int len_read;
+ struct com32_filedata filedata;
+ int handle;
+ if (offset != 0) {
+ printf("** Cannot support non-zero offset **\n");
+ return -1;
+ }
+
+ handle=btrfs_open_file(filename, &filedata);
+ if (handle < 0) {
+ printf("** File not found %s Invalid handle**\n", filename);
+ return -1;
+ }
+ //file handle is valid get the size of the file
+ len=filedata.size;
+ if (len == 0)
+ len = file_len;
+
+ len_read = getfssec(&filedata, (char *)addr);
+ if (len_read != len) {
+ printf("** Unable to read file %s **\n", filename);
+ return -1;
+ }
+
+ return len_read;
+}
+
+#else
+static inline int fs_probe_btr(void)
+{
+ return -1;
+}
+
+static inline void fs_close_btr(void)
+{
+}
+
+#define fs_ls_btr fs_ls_unsupported
+#define fs_read_btr fs_read_unsupported
+#endif
+
+
+
#ifdef CONFIG_FS_EXT4
static int fs_probe_ext(void)
{
@@ -155,6 +221,10 @@ static struct {
.fstype = FS_TYPE_EXT,
.probe = fs_probe_ext,
},
+ {
+ .fstype = FS_TYPE_BTR,
+ .probe = fs_probe_btr,
+ },
};

int fs_set_blk_dev(const char *ifname, const char *dev_part_str, int fstype)
@@ -178,7 +248,6 @@ int fs_set_blk_dev(const char *ifname, const char *dev_part_str, int fstype)
for (i = 0; i < ARRAY_SIZE(fstypes); i++) {
if ((fstype != FS_TYPE_ANY) && (fstype != fstypes[i].fstype))
continue;
-
if (!fstypes[i].probe()) {
fs_type = fstypes[i].fstype;
return 0;
@@ -198,6 +267,9 @@ static void fs_close(void)
case FS_TYPE_EXT:
fs_close_ext();
break;
+ case FS_TYPE_BTR:
+ fs_close_btr();
+ break;
default:
break;
}
@@ -208,7 +280,6 @@ static void fs_close(void)
int fs_ls(const char *dirname)
{
int ret;
-
switch (fs_type) {
case FS_TYPE_FAT:
ret = fs_ls_fat(dirname);
@@ -216,6 +287,9 @@ int fs_ls(const char *dirname)
case FS_TYPE_EXT:
ret = fs_ls_ext(dirname);
break;
+ case FS_TYPE_BTR:
+ ret = fs_ls_unsupported(dirname);
+ break;
default:
ret = fs_ls_unsupported(dirname);
break;
@@ -237,11 +311,13 @@ int fs_read(const char *filename, ulong addr, int offset, int len)
case FS_TYPE_EXT:
ret = fs_read_ext(filename, addr, offset, len);
break;
+ case FS_TYPE_BTR:
+ ret = fs_read_btr(filename, addr, offset, len);
+ break;
default:
ret = fs_read_unsupported(filename, addr, offset, len);
break;
}
-
fs_close();

return ret;
diff --git a/include/btrfs.h b/include/btrfs.h
new file mode 100644
index 0000000..4124ca6
--- /dev/null
+++ b/include/btrfs.h
@@ -0,0 +1,398 @@
+#ifndef _BTRFS_H_
+#define _BTRFS_H_
+
+#include <asm/byteorder.h>
+/* type that store on disk, but it is same as cpu type for i386 arch */
+
+#define CURRENTDIR_MAX 15
+#define MAX_OPEN 5
+#define FILENAME_MAX 20
+#define MAX_SYMLINK_CNT 20
+#define MAX_SYMLINK_BUF 4096
+#define SECTOR_SHIFT(fs) ((fs)->sector_shift)
+#define IFTODT(mode) (((mode) & 0170000) >> 12)
+#define SECTOR_SIZE 0x200
+#define SECTOR_BITS 9
+#define EXTENT_ZERO ((__le32)-1) /* All-zero extent */
+#define EXTENT_VOID ((__le32)-2) /* Invalid information */
+#define DT_LNK 10
+#define DT_REG 8
+#define DT_DIR 4
+
+
+#define EXTENT_SPECIAL(x) ((x) >= EXTENT_VOID)
+#define MAX_SUBVOL_NAME 50
+struct com32_filedata {
+ size_t size; /* File size */
+ int blocklg2; /* log2(block size) */
+ uint16_t handle; /* File handle */
+};
+
+struct fs_info {
+ const struct fs_ops *fs_ops;
+ struct device *fs_dev;
+ void *fs_info; /* The fs-specific information */
+ int sector_shift, sector_size;
+ int block_shift, block_size;
+ struct inode *root, *cwd; /* Root and current directories */
+ char cwd_name[CURRENTDIR_MAX]; /* Current directory by name */
+};
+/*
+ * Extent structure: contains the mapping of some chunk of a file
+ * that is contiguous on disk.
+ */
+struct extent {
+ //sector_t pstart; /* Physical start sector */
+ __le64 pstart;
+ __le32 lstart; /* Logical start sector */
+ __le32 len; /* Number of contiguous sectors */
+}__attribute__ ((__packed__));
+
+
+struct inode {
+ struct fs_info *fs; /* The filesystem this inode is associated with */
+ struct inode *parent; /* Parent directory, if any */
+ const u8 *name; /* Name, valid for generic path search only */
+ __le32 refcnt;
+ __le32 mode; /* FILE , DIR or SYMLINK */
+ __le32 size;
+ __le32 blocks; /* How many blocks the file take */
+ __le32 ino; /* Inode number */
+ __le32 atime; /* Access time */
+ __le32 mtime; /* Modify time */
+ __le32 ctime; /* Create time */
+ __le32 dtime; /* Delete time */
+ __le32 flags;
+ __le32 file_acl;
+ struct extent this_extent, next_extent;
+ u8 pvt[0]; /* Private filesystem data */
+}__attribute__ ((__packed__));
+struct file {
+ struct fs_info *fs;
+ __le64 offset; /* for next read */
+ struct inode *inode; /* The file-specific information */
+}__attribute__ ((__packed__));
+
+#define NAME_MAX 20
+struct dirent {
+ uint32_t d_ino;
+ uint32_t d_off;
+ uint16_t d_reclen;
+ uint16_t d_type;
+ char d_name[NAME_MAX + 1];
+};
+
+
+#include "crc32c.h"
+#define btrfs_crc32c crc32c_le
+
+#define BTRFS_SUPER_INFO_OFFSET (64 * 1024)
+#define BTRFS_SUPER_INFO_SIZE 4096
+#define BTRFS_MAX_LEAF_SIZE 4096
+#define BTRFS_BLOCK_SHIFT 12
+
+#define BTRFS_SUPER_MIRROR_MAX 3
+#define BTRFS_SUPER_MIRROR_SHIFT 12
+#define BTRFS_CSUM_SIZE 32
+#define BTRFS_FSID_SIZE 16
+#define BTRFS_LABEL_SIZE 256
+#define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
+#define BTRFS_UUID_SIZE 16
+
+#define BTRFS_MAGIC "_BHRfS_M"
+
+#define BTRFS_SUPER_FLAG_METADUMP (1ULL << 33)
+
+#define BTRFS_DEV_ITEM_KEY 216
+#define BTRFS_CHUNK_ITEM_KEY 228
+#define BTRFS_ROOT_REF_KEY 156
+#define BTRFS_ROOT_ITEM_KEY 132
+#define BTRFS_EXTENT_DATA_KEY 108
+#define BTRFS_DIR_ITEM_KEY 84
+#define BTRFS_INODE_ITEM_KEY 1
+
+#define BTRFS_EXTENT_TREE_OBJECTID 2ULL
+#define BTRFS_FS_TREE_OBJECTID 5ULL
+
+#define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
+
+#define BTRFS_FILE_EXTENT_INLINE 0
+#define BTRFS_FILE_EXTENT_REG 1
+#define BTRFS_FILE_EXTENT_PREALLOC 2
+
+#define BTRFS_MAX_LEVEL 8
+#define BTRFS_MAX_CHUNK_ENTRIES 256
+
+#define BTRFS_FT_REG_FILE 1
+#define BTRFS_FT_DIR 2
+#define BTRFS_FT_SYMLINK 7
+
+#define ROOT_DIR_WORD 0x002f
+
+struct btrfs_dev_item {
+ __le64 devid;
+ __le64 total_bytes;
+ __le64 bytes_used;
+ __le32 io_align;
+ __le32 io_width;
+ __le32 sector_size;
+ __le64 type;
+ __le64 generation;
+ __le64 start_offset;
+ __le32 dev_group;
+ u8 seek_speed;
+ u8 bandwidth;
+ u8 uuid[BTRFS_UUID_SIZE];
+ u8 fsid[BTRFS_UUID_SIZE];
+} __attribute__ ((__packed__));
+
+struct btrfs_super_block {
+ u8 csum[BTRFS_CSUM_SIZE];
+ /* the first 4 fields must match struct btrfs_header */
+ u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
+ __le64 bytenr; /* this block number */
+ __le64 flags;
+
+ /* allowed to be different from the btrfs_header from here own down */
+ __le64 magic;
+ __le64 generation;
+ __le64 root;
+ __le64 chunk_root;
+ __le64 log_root;
+
+ /* this will help find the new super based on the log root */
+ __le64 log_root_transid;
+ __le64 total_bytes;
+ __le64 bytes_used;
+ __le64 root_dir_objectid;
+ __le64 num_devices;
+ __le32 sectorsize;
+ __le32 nodesize;
+ __le32 leafsize;
+ __le32 stripesize;
+ __le32 sys_chunk_array_size;
+ __le64 chunk_root_generation;
+ __le64 compat_flags;
+ __le64 compat_ro_flags;
+ __le64 incompat_flags;
+ __le16 csum_type;
+ u8 root_level;
+ u8 chunk_root_level;
+ u8 log_root_level;
+ struct btrfs_dev_item dev_item;
+
+ char label[BTRFS_LABEL_SIZE];
+
+ __le64 cache_generation;
+
+ /* future expansion */
+ __le64 reserved[31];
+ u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
+} __attribute__ ((__packed__));
+struct btrfs_disk_key {
+ __le64 objectid;
+ u8 type;
+ __le64 offset;
+} __attribute__ ((__packed__));
+
+struct btrfs_stripe {
+ __le64 devid;
+ __le64 offset;
+ u8 dev_uuid[BTRFS_UUID_SIZE];
+} __attribute__ ((__packed__));
+
+struct btrfs_chunk {
+ __le64 length;
+ __le64 owner;
+ __le64 stripe_len;
+ __le64 type;
+ __le32 io_align;
+ __le32 io_width;
+ __le32 sector_size;
+ __le16 num_stripes;
+ __le16 sub_stripes;
+ struct btrfs_stripe stripe;
+} __attribute__ ((__packed__));
+
+struct btrfs_header {
+ /* these first four must match the super block */
+ u8 csum[BTRFS_CSUM_SIZE];
+ u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
+ __le64 bytenr; /* which block this node is supposed to live in */
+ __le64 flags;
+
+ /* allowed to be different from the super from here on down */
+ u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
+ __le64 generation;
+ __le64 owner;
+ __le32 nritems;
+ u8 level;
+} __attribute__ ((__packed__));
+
+struct btrfs_item {
+ struct btrfs_disk_key key;
+ __le32 offset;
+ __le32 size;
+} __attribute__ ((__packed__));
+
+struct btrfs_leaf {
+ struct btrfs_header header;
+ struct btrfs_item items[];
+} __attribute__ ((__packed__));
+
+struct btrfs_key_ptr {
+ struct btrfs_disk_key key;
+ __le64 blockptr;
+ __le64 generation;
+} __attribute__ ((__packed__));
+
+struct btrfs_node {
+ struct btrfs_header header;
+ struct btrfs_key_ptr ptrs[];
+} __attribute__ ((__packed__));
+
+/* remember how we get to a node/leaf */
+struct btrfs_path {
+ __le64 offsets[BTRFS_MAX_LEVEL];
+ __le32 itemsnr[BTRFS_MAX_LEVEL];
+ __le32 slots[BTRFS_MAX_LEVEL];
+ /* remember last slot's item and data */
+ struct btrfs_item item;
+ u8 data[BTRFS_MAX_LEAF_SIZE];
+}__attribute__ ((__packed__));
+
+/* store logical offset to physical offset mapping */
+struct btrfs_chunk_map_item {
+ __le64 logical;
+ __le64 length;
+ __le64 devid;
+ __le64 physical;
+} __attribute__ ((__packed__));
+
+struct btrfs_chunk_map {
+ struct btrfs_chunk_map_item *map;
+ __le32 map_length;
+ __le32 cur_length;
+} __attribute__ ((__packed__));;
+
+struct btrfs_timespec {
+ __le64 sec;
+ __le32 nsec;
+} __attribute__ ((__packed__));
+
+struct btrfs_inode_item {
+ /* nfs style generation number */
+ __le64 generation;
+ /* transid that last touched this inode */
+ __le64 transid;
+ __le64 size;
+ __le64 nbytes;
+ __le64 block_group;
+ __le32 nlink;
+ __le32 uid;
+ __le32 gid;
+ __le32 mode;
+ __le64 rdev;
+ __le64 flags;
+
+ /* modification sequence number for NFS */
+ __le64 sequence;
+
+ /*
+ * a little future expansion, for more than this we can
+ * just grow the inode item and version it
+ */
+ __le64 reserved[4];
+ struct btrfs_timespec atime;
+ struct btrfs_timespec ctime;
+ struct btrfs_timespec mtime;
+ struct btrfs_timespec otime;
+} __attribute__ ((__packed__));
+
+struct btrfs_root_item {
+ struct btrfs_inode_item inode;
+ __le64 generation;
+ __le64 root_dirid;
+ __le64 bytenr;
+ __le64 byte_limit;
+ __le64 bytes_used;
+ __le64 last_snapshot;
+ __le64 flags;
+ __le32 refs;
+ struct btrfs_disk_key drop_progress;
+ u8 drop_level;
+ u8 level;
+} __attribute__ ((__packed__));
+
+struct btrfs_dir_item {
+ struct btrfs_disk_key location;
+ __le64 transid;
+ __le16 data_len;
+ __le16 name_len;
+ u8 type;
+} __attribute__ ((__packed__));
+
+struct btrfs_file_extent_item {
+ __le64 generation;
+ __le64 ram_bytes;
+ u8 compression;
+ u8 encryption;
+ __le16 other_encoding; /* spare for later use */
+ u8 type;
+ __le64 disk_bytenr;
+ __le64 disk_num_bytes;
+ __le64 offset;
+ __le64 num_bytes;
+} __attribute__ ((__packed__));
+
+struct btrfs_root_ref {
+ __le64 dirid;
+ __le64 sequence;
+ __le16 name_len;
+} __attribute__ ((__packed__));
+
+/*
+ * btrfs private inode information
+ */
+struct btrfs_pvt_inode {
+ __le64 offset;
+}__attribute__ ((__packed__));
+
+void btrfs_set_blk_dev(block_dev_desc_t* rbdd , disk_partition_t *info);
+int btrfs_fs_init(struct fs_info *fs);
+void put_inode(struct inode *inode);
+struct inode *alloc_inode(struct fs_info *fs, uint32_t ino, size_t data);
+int btrfs_open_file(const char *name, struct com32_filedata *filedata);
+int getfssec(struct com32_filedata *filedata, char * buf);
+uint32_t generic_getfssec(struct file *file, char *buf,
+ int sectors, char *have_more);
+#define PVT(i) ((struct btrfs_pvt_inode *)((i)->pvt))
+static inline __le32 next_psector(__le32 psector, uint32_t skip)
+{
+ if (EXTENT_SPECIAL(psector))
+ return psector;
+ else
+ return psector + skip;
+}
+
+static inline __le32 next_pstart(const struct extent *e)
+{
+ return next_psector(e->pstart, e->len);
+}
+
+/*
+ * Our definition of "not whitespace"
+ */
+static inline char not_whitespace(char c)
+{
+ return (unsigned char)c > ' ';
+}
+
+static inline struct inode *get_inode(struct inode *inode)
+{
+ inode->refcnt++;
+ return inode;
+}
+
+
+#endif
diff --git a/include/config_fallbacks.h b/include/config_fallbacks.h
index bfb9680..28a0a66 100644
--- a/include/config_fallbacks.h
+++ b/include/config_fallbacks.h
@@ -26,4 +26,8 @@
#define CONFIG_EXT4_WRITE
#endif

+#if defined(CONFIG_CMD_BTR) && !defined(CONFIG_FS_BTR)
+#define CONFIG_FS_BTR
+#endif
+
#endif /* __CONFIG_FALLBACKS_H */
diff --git a/include/crc32c.h b/include/crc32c.h
new file mode 100644
index 0000000..d04916e
--- /dev/null
+++ b/include/crc32c.h
@@ -0,0 +1,48 @@
+/*
+ * Copied from Linux kernel crypto/crc32c.c
+ * Copyright (c) 2004 Cisco Systems, Inc.
+ * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * This program 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 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+/*
+ * This is the CRC-32C table
+ * Generated with:
+ * width = 32 bits
+ * poly = 0x1EDC6F41
+ * reflect input bytes = true
+ * reflect output bytes = true
+ */
+
+/*
+ * Steps through buffer one byte at at time, calculates reflected
+ * crc using table.
+ */
+
+static inline u32 crc32c_cal(u32 crc, const char *data, size_t length, u32 *crc32c_table)
+{
+ while (length--)
+ crc = crc32c_table[(u8)(crc ^ *data++)] ^ (crc >> 8);
+
+ return crc;
+}
+
+static inline void crc32c_init(u32 *crc32c_table, u32 pol)
+{
+ int i, j;
+ u32 v;
+ const u32 poly = pol; /* Bit-reflected CRC32C polynomial */
+
+ for (i = 0; i < 256; i++) {
+ v = i;
+ for (j = 0; j < 8; j++) {
+ v = (v >> 1) ^ ((v & 1) ? poly : 0);
+ }
+ crc32c_table[i] = v;
+ }
+}
diff --git a/include/fs.h b/include/fs.h
index 4f30a38..3a0e7d4 100644
--- a/include/fs.h
+++ b/include/fs.h
@@ -21,6 +21,7 @@
#define FS_TYPE_ANY 0
#define FS_TYPE_FAT 1
#define FS_TYPE_EXT 2
+#define FS_TYPE_BTR 3

/*
* Tell the fs layer which block device an partition to use for future
--
1.7.9.5