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btrfsclone.c

/**
 * btrfsclone.c - part of Partclone project
 *
 * Copyright (c) 2007~ Thomas Tsai <thomas at nchc org tw>
 *
 * read btrfs super block and extent
 *
 * 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.
 */

#include <stdio.h>
#include <stdio.h>
#include "btrfs/version.h"
#include "btrfs/ctree.h"
#include "btrfs/disk-io.h"
#include "btrfs/volumes.h"

#include "partclone.h"
#include "btrfsclone.h"
#include "progress.h"
#include "fs_common.h"

char *EXECNAME = "partclone.btrfs";
extern fs_cmd_opt fs_opt;

struct btrfs_root *root;
struct btrfs_path *path;
int block_size = 0;

///set useb block
static void set_bitmap(char* bitmap, uint64_t pos, uint64_t length){
    uint64_t block;
    uint64_t pos_block;
    uint64_t count;

    pos_block = pos/block_size;
    count = length/block_size;

    for(block = pos_block; block < (pos_block+count); block++){
      bitmap[block] = 1;
      log_mesg(3, 0, 0, fs_opt.debug, "block %i is used\n", block);
    }
}

/// open device
static void fs_open(char* device){
    radix_tree_init();
    root = open_ctree(device, 0, 0);
    if(!root){
      log_mesg(0, 1, 1, fs_opt.debug, "%s: Unable to open %s\n", __FILE__, device); 
    }
    path = btrfs_alloc_path();

}

/// close device
static void fs_close(){
    int ret = 0;
    btrfs_free_path(path);
    ret = close_ctree(root);

}

/// readbitmap - read bitmap
extern void readbitmap(char* device, image_head image_hdr, char*bitmap, int pui)
{
    uint64_t super_block = 0;
    struct btrfs_root *extent_root;
    struct btrfs_extent_item *ei;
    struct extent_buffer *leaf;
    struct extent_buffer *eb;
    struct btrfs_key key;
    uint64_t bytenr;
    uint64_t num_bytes;
    uint64_t length;
    uint64_t block_offset;
    int leafsize = 0;
    struct btrfs_multi_bio *multi = NULL;
    int ret;
    int i;

    fs_open(device);
    block_size = image_hdr.block_size;
    //initial all block as free
    memset(bitmap, 0, image_hdr.totalblock);

    // set super block and tree as used
    super_block = BTRFS_SUPER_INFO_OFFSET / block_size;
    leafsize = btrfs_super_leafsize(&root->fs_info->super_copy);
    log_mesg(1, 0, 0, fs_opt.debug, "%s: leafsize %i\n", __FILE__, leafsize);
    log_mesg(1, 0, 0, fs_opt.debug, "%s: super block %i\n", __FILE__, super_block);
    bitmap[super_block] = 1;
    for (i = 1; i < 7; i++) {
      bytenr = (BTRFS_SUPER_INFO_OFFSET + 1024 * 1024 + leafsize * i ) / block_size;
      log_mesg(1, 0, 0, fs_opt.debug, "%s: tree block %llu\n", __FILE__, bytenr);
      bitmap[bytenr] = 1;
    }


    extent_root = root->fs_info->extent_root;
    bytenr = BTRFS_SUPER_INFO_OFFSET + 4096;
    key.objectid = bytenr;
    key.type = BTRFS_EXTENT_ITEM_KEY;
    key.offset = 0;

    ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
    while(1){
      leaf = path->nodes[0];
      if (path->slots[0] >= btrfs_header_nritems(leaf)){
          ret = btrfs_next_leaf(extent_root, path);
          if(ret > 0)
            break;
          leaf = path->nodes[0];
      }

      btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
      if(key.objectid < bytenr || key.type != BTRFS_EXTENT_ITEM_KEY){
          path->slots[0]++;
          continue;
      }

      bytenr = key.objectid;
        block_offset = bytenr;
      num_bytes = key.offset;
        log_mesg(2, 0, 0, fs_opt.debug, "bytenr = %llu, size = %llu\n", bytenr, num_bytes);

        if (btrfs_item_size_nr(leaf, path->slots[0]) > sizeof(*ei)) {
          ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
          if (btrfs_extent_flags(leaf, ei) & BTRFS_EXTENT_FLAG_TREE_BLOCK) {

                /*disk_io.c*/
            eb = btrfs_find_tree_block(root, bytenr, num_bytes);
            if (eb && btrfs_buffer_uptodate(eb, 0)) {
                  free_extent_buffer(eb);
            }

            /*READ=0, mirror=0*/
            ret = btrfs_map_block(&root->fs_info->mapping_tree, 0, bytenr, &length, &multi, 0);
                block_offset = multi->stripes[0].physical;
            log_mesg(2, 0, 0, fs_opt.debug, "1 bytenr = %llu, size = %llu physical=%llu \n", bytenr, num_bytes, block_offset);
            set_bitmap(bitmap, block_offset, num_bytes);
          } else {
            /*READ=0, mirror=0*/
            ret = btrfs_map_block(&root->fs_info->mapping_tree, 0, bytenr, &length, &multi, 0);
                block_offset = multi->stripes[0].physical;
            log_mesg(2, 0, 0, fs_opt.debug, "2 bytenr = %llu, size = %llu physical=%llu \n", bytenr, num_bytes, block_offset);
            set_bitmap(bitmap, block_offset, num_bytes);
            }
      } else {
          /*READ=0, mirror=0*/
          ret = btrfs_map_block(&root->fs_info->mapping_tree, 0, bytenr, &length, &multi, 0);
          block_offset = multi->stripes[0].physical;
          log_mesg(2, 0, 0, fs_opt.debug, "3 bytenr = %llu, size = %llu physical=%llu \n", bytenr, num_bytes, block_offset);
          set_bitmap(bitmap, block_offset, num_bytes);
      }
      bytenr+=num_bytes;
    }
    fs_close();
}

/// read super block and write to image head
extern void initial_image_hdr(char* device, image_head* image_hdr)
{    
    fs_open(device);

    strncpy(image_hdr->magic, IMAGE_MAGIC, IMAGE_MAGIC_SIZE);
    strncpy(image_hdr->fs, btrfs_MAGIC, FS_MAGIC_SIZE);

    image_hdr->block_size  = btrfs_super_nodesize(&root->fs_info->super_copy);
    image_hdr->usedblocks  = (btrfs_super_bytes_used(&root->fs_info->super_copy)/image_hdr->block_size);
    image_hdr->device_size = btrfs_super_total_bytes(&root->fs_info->super_copy);
    image_hdr->totalblock  = (uint64_t)(image_hdr->device_size/image_hdr->block_size);
    log_mesg(0, 0, 0, fs_opt.debug, "block_size = %i\n", image_hdr->block_size);
    log_mesg(0, 0, 0, fs_opt.debug, "usedblock = %lli\n", image_hdr->usedblocks);
    log_mesg(0, 0, 0, fs_opt.debug, "device_size = %llu\n", image_hdr->device_size);
    log_mesg(0, 0, 0, fs_opt.debug, "totalblock = %lli\n", image_hdr->totalblock);

    fs_close();
}


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