btrfsck.c - pub/scm/linux/kernel/git/mason/btrfs-progs - Git at Google

 /*
  * Copyright (C) 2007 Oracle.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public
  * License v2 as published by the Free Software Foundation.
  *
  * 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 021110-1307, USA.
  */

 #define _XOPEN_SOURCE 500
 #define _GNU_SOURCE 1
 #include <stdio.h>
 #include <stdlib.h>
 #include <fcntl.h>
 #include "kerncompat.h"
 #include "radix-tree.h"
 #include "ctree.h"
 #include "disk-io.h"
 #include "print-tree.h"
 #include "transaction.h"
 #include "bit-radix.h"

 static u64 blocks_used = 0;
 static u64 total_csum_bytes = 0;
 static u64 total_btree_blocks = 0;
 static u64 btree_space_waste = 0;

 struct extent_record {
 	struct btrfs_disk_key parent_key;
 	u64 start;
 	u64 nr;
 	u64 owner;
 	u32 refs;
 	u32 extent_item_refs;
 	int checked;
 };

 static int check_node(struct btrfs_root *root,
 		      struct btrfs_disk_key *parent_key,
 		      struct btrfs_node *node)
 {
 	int i;
 	u32 nritems = btrfs_header_nritems(&node->header);

 	if (nritems == 0 || nritems > BTRFS_NODEPTRS_PER_BLOCK(root))
 		return 1;
 	if (parent_key->flags) {
 		if (memcmp(parent_key, &node->ptrs[0].key,
 			      sizeof(struct btrfs_disk_key)))
 			return 1;
 	}
 	for (i = 0; nritems > 1 && i < nritems - 2; i++) {
 		struct btrfs_key cpukey;
 		btrfs_disk_key_to_cpu(&cpukey, &node->ptrs[i + 1].key);
 		if (btrfs_comp_keys(&node->ptrs[i].key, &cpukey) >= 0)
 			return 1;
 	}
 	return 0;
 }

 static int check_leaf(struct btrfs_root *root,
 		      struct btrfs_disk_key *parent_key,
 		      struct btrfs_leaf *leaf)
 {
 	int i;
 	u32 nritems = btrfs_header_nritems(&leaf->header);

 	if (btrfs_header_level(&leaf->header) != 0) {
 		fprintf(stderr, "leaf is not a leaf %llu\n",
 		       (unsigned long long)btrfs_header_blocknr(&leaf->header));
 		return 1;
 	}
 	if (btrfs_leaf_free_space(root, leaf) < 0) {
 		fprintf(stderr, "leaf free space incorrect %llu %d\n",
 			(unsigned long long)btrfs_header_blocknr(&leaf->header),
 			btrfs_leaf_free_space(root, leaf));
 		return 1;
 	}

 	if (nritems == 0)
 		return 0;

 	if (parent_key->flags && memcmp(parent_key, &leaf->items[0].key,
 					sizeof(struct btrfs_disk_key))) {
 		fprintf(stderr, "leaf parent key incorrect %llu\n",
 		       (unsigned long long)btrfs_header_blocknr(&leaf->header));
 		return 1;
 	}
 	for (i = 0; nritems > 1 && i < nritems - 2; i++) {
 		struct btrfs_key cpukey;
 		btrfs_disk_key_to_cpu(&cpukey, &leaf->items[i + 1].key);
 		if (btrfs_comp_keys(&leaf->items[i].key,
 		                 &cpukey) >= 0)
 			return 1;
 		if (btrfs_item_offset(leaf->items + i) !=
 			btrfs_item_end(leaf->items + i + 1))
 			return 1;
 		if (i == 0) {
 			if (btrfs_item_offset(leaf->items + i) +
 			       btrfs_item_size(leaf->items + i) !=
 			       BTRFS_LEAF_DATA_SIZE(root))
 				return 1;
 		}
 	}
 	return 0;
 }

 static int maybe_free_extent_rec(struct radix_tree_root *extent_radix,
 				 struct extent_record *rec)
 {
 	if (rec->checked && rec->extent_item_refs == rec->refs &&
 	    rec->refs > 0) {
 		radix_tree_delete(extent_radix, rec->start);
 		free(rec);
 	}
 	return 0;
 }

 static int check_block(struct btrfs_root *root,
 		       struct radix_tree_root *extent_radix,
 		       struct btrfs_buffer *buf)
 {
 	struct extent_record *rec;
 	int ret = 1;

 	rec = radix_tree_lookup(extent_radix, buf->blocknr);
 	if (!rec)
 		return 1;
 	if (btrfs_is_leaf(&buf->node)) {
 		ret = check_leaf(root, &rec->parent_key, &buf->leaf);
 	} else {
 		ret = check_node(root, &rec->parent_key, &buf->node);
 	}
 	rec->checked = 1;
 	if (!ret)
 		maybe_free_extent_rec(extent_radix, rec);
 	return ret;
 }

 static int add_extent_rec(struct radix_tree_root *extent_radix,
 			  struct btrfs_disk_key *parent_key,
 			  u64 ref, u64 start, u64 nr, u64 owner,
 			  u32 extent_item_refs, int inc_ref, int set_checked)
 {
 	struct extent_record *rec;
 	int ret = 0;
 	rec = radix_tree_lookup(extent_radix, start);
 	if (rec) {
 		if (inc_ref)
 			rec->refs++;
 		if (start != rec->start) {
 			fprintf(stderr, "warning, start mismatch %llu %llu\n",
 				(unsigned long long)rec->start,
 				(unsigned long long)start);
 			ret = 1;
 		}
 		if (extent_item_refs) {
 			if (rec->extent_item_refs) {
 				fprintf(stderr, "block %llu rec extent_item_refs %u, passed %u\n", (unsigned long long)start, rec->extent_item_refs, extent_item_refs);
 			}
 			rec->extent_item_refs = extent_item_refs;
 		}
 		if (set_checked)
 			rec->checked = 1;
 		maybe_free_extent_rec(extent_radix, rec);
 		return ret;
 	}
 	rec = malloc(sizeof(*rec));
 	if (start == 0)
 		extent_item_refs = 0;
 	rec->start = start;
 	rec->nr = nr;
 	rec->owner = owner;
 	rec->checked = 0;

 	if (inc_ref)
 		rec->refs = 1;
 	else
 		rec->refs = 0;

 	if (extent_item_refs)
 		rec->extent_item_refs = extent_item_refs;
 	else
 		rec->extent_item_refs = 0;

 	if (parent_key)
 		memcpy(&rec->parent_key, parent_key, sizeof(*parent_key));
 	else
 		memset(&rec->parent_key, 0, sizeof(*parent_key));

 	ret = radix_tree_insert(extent_radix, start, rec);
 	BUG_ON(ret);
 	blocks_used += nr;
 	if (set_checked)
 		rec->checked = 1;
 	return ret;
 }

 static int add_pending(struct radix_tree_root *pending,
 		       struct radix_tree_root *seen, u64 blocknr)
 {
 	if (test_radix_bit(seen, blocknr))
 		return -EEXIST;
 	set_radix_bit(pending, blocknr);
 	set_radix_bit(seen, blocknr);
 	return 0;
 }
 static int pick_next_pending(struct radix_tree_root *pending,
 			struct radix_tree_root *reada,
 			struct radix_tree_root *nodes,
 			u64 last, unsigned long *bits, int bits_nr,
 			int *reada_bits)
 {
 	unsigned long node_start = last;
 	int ret;
 	ret = find_first_radix_bit(reada, bits, 0, 1);
 	if (ret) {
 		*reada_bits = 1;
 		return ret;
 	}
 	*reada_bits = 0;
 	if (node_start > 8)
 		node_start -= 8;
 	ret = find_first_radix_bit(nodes, bits, node_start, bits_nr);
 	if (!ret)
 		ret = find_first_radix_bit(nodes, bits, 0, bits_nr);
 	if (ret) {
 		if (bits_nr - ret > 8) {
 			int ret2;
 			u64 sequential;
 			ret2 = find_first_radix_bit(pending, bits + ret,
 						    bits[0], bits_nr - ret);
 			sequential = bits[0];
 			while(ret2 > 0) {
 				if (bits[ret] - sequential > 8)
 					break;
 				sequential = bits[ret];
 				ret++;
 				ret2--;
 			}
 		}
 		return ret;
 	}
 	return find_first_radix_bit(pending, bits, 0, bits_nr);
 }
 static struct btrfs_buffer reada_buf;

 static int run_next_block(struct btrfs_root *root,
 			  unsigned long *bits,
 			  int bits_nr,
 			  u64 *last,
 			  struct radix_tree_root *pending,
 			  struct radix_tree_root *seen,
 			  struct radix_tree_root *reada,
 			  struct radix_tree_root *nodes,
 			  struct radix_tree_root *extent_radix)
 {
 	struct btrfs_buffer *buf;
 	u64 blocknr;
 	int ret;
 	int i;
 	int nritems;
 	struct btrfs_leaf *leaf;
 	struct btrfs_node *node;
 	struct btrfs_disk_key *disk_key;
 	int reada_bits;

 	u64 last_block = 0;
 	ret = pick_next_pending(pending, reada, nodes, *last, bits,
 				bits_nr, &reada_bits);
 	if (ret == 0) {
 		return 1;
 	}
 	if (!reada_bits) {
 		for(i = 0; i < ret; i++) {
 			u64 offset;
 			set_radix_bit(reada, bits[i]);
 			btrfs_map_bh_to_logical(root, &reada_buf, bits[i]);
 			offset = reada_buf.dev_blocknr * root->blocksize;
 			last_block = bits[i];
 			readahead(reada_buf.fd, offset, root->blocksize);
 		}
 	}
 	*last = bits[0];
 	blocknr = bits[0];
 	clear_radix_bit(pending, blocknr);
 	clear_radix_bit(reada, blocknr);
 	clear_radix_bit(nodes, blocknr);
 	buf = read_tree_block(root, blocknr);
 	nritems = btrfs_header_nritems(&buf->node.header);
 	ret = check_block(root, extent_radix, buf);
 	if (ret) {
 		fprintf(stderr, "bad block %llu\n",
 			(unsigned long long)blocknr);
 	}
 	if (btrfs_is_leaf(&buf->node)) {
 		leaf = &buf->leaf;
 		btree_space_waste += btrfs_leaf_free_space(root, leaf);
 		for (i = 0; i < nritems; i++) {
 			struct btrfs_file_extent_item *fi;
 			disk_key = &leaf->items[i].key;
 			if (btrfs_disk_key_type(disk_key) ==
 			    BTRFS_EXTENT_ITEM_KEY) {
 				struct btrfs_key found;
 				struct btrfs_extent_item *ei;
 				btrfs_disk_key_to_cpu(&found,
 						      &leaf->items[i].key);
 				ei = btrfs_item_ptr(leaf, i,
 						    struct btrfs_extent_item);
 				add_extent_rec(extent_radix, NULL, 0,
 					       found.objectid,
 					       found.offset,
 					       btrfs_extent_owner(ei),
 					       btrfs_extent_refs(ei), 0, 0);
 				continue;
 			}
 			if (btrfs_disk_key_type(disk_key) ==
 			    BTRFS_CSUM_ITEM_KEY) {
 				total_csum_bytes +=
 					btrfs_item_size(leaf->items + i);
 				continue;
 			}
 			if (btrfs_disk_key_type(disk_key) ==
 			    BTRFS_BLOCK_GROUP_ITEM_KEY) {
 				struct btrfs_block_group_item *bi;
 				bi = btrfs_item_ptr(leaf, i,
 					    struct btrfs_block_group_item);
 #if 0
 				fprintf(stderr,"block group %Lu %Lu used %Lu ",
 					btrfs_disk_key_objectid(disk_key),
 					btrfs_disk_key_offset(disk_key),
 					btrfs_block_group_used(bi));
 				fprintf(stderr, "flags %x\n", bi->flags);
 #endif
 				continue;
 			}
 			if (btrfs_disk_key_type(&leaf->items[i].key) !=
 			    BTRFS_EXTENT_DATA_KEY)
 				continue;
 			fi = btrfs_item_ptr(leaf, i,
 					    struct btrfs_file_extent_item);
 			if (btrfs_file_extent_type(fi) !=
 			    BTRFS_FILE_EXTENT_REG)
 				continue;
 			if (btrfs_file_extent_disk_blocknr(fi) == 0)
 				continue;
 			ret = add_extent_rec(extent_radix, NULL, blocknr,
 				   btrfs_file_extent_disk_blocknr(fi),
 				   btrfs_file_extent_disk_num_blocks(fi),
 			           btrfs_disk_key_objectid(&leaf->items[i].key),
 				   0, 1, 1);
 			BUG_ON(ret);
 		}
 	} else {
 		int level;
 		node = &buf->node;
 		level = btrfs_header_level(&node->header);
 		for (i = 0; i < nritems; i++) {
 			u64 ptr = btrfs_node_blockptr(node, i);
 			ret = add_extent_rec(extent_radix,
 					     &node->ptrs[i].key,
 					     blocknr, ptr, 1,
 					     btrfs_header_owner(&node->header),
 					     0, 1, 0);
 			BUG_ON(ret);
 			if (level > 1) {
 				add_pending(nodes, seen, ptr);
 			} else {
 				add_pending(pending, seen, ptr);
 			}
 		}
 		btree_space_waste += (BTRFS_NODEPTRS_PER_BLOCK(root) -
 				      nritems) * sizeof(struct btrfs_key_ptr);
 	}
 	btrfs_block_release(root, buf);
 	total_btree_blocks++;
 	return 0;
 }

 static int add_root_to_pending(struct btrfs_buffer *buf,
 			       unsigned long *bits,
 			       int bits_nr,
 			       struct radix_tree_root *extent_radix,
 			       struct radix_tree_root *pending,
 			       struct radix_tree_root *seen,
 			       struct radix_tree_root *reada,
 			       struct radix_tree_root *nodes)
 {
 	if (btrfs_header_level(&buf->node.header) > 0)
 		add_pending(nodes, seen, buf->blocknr);
 	else
 		add_pending(pending, seen, buf->blocknr);
 	add_extent_rec(extent_radix, NULL, 0, buf->blocknr, 1,
 		       btrfs_header_owner(&buf->node.header), 0, 1, 0);
 	return 0;
 }

 int check_extent_refs(struct btrfs_root *root,
 		      struct radix_tree_root *extent_radix)
 {
 	struct extent_record *rec[64];
 	int i;
 	int ret;
 	int err = 0;

 	while(1) {
 		ret = radix_tree_gang_lookup(extent_radix, (void **)rec, 0,
 					     ARRAY_SIZE(rec));
 		if (!ret)
 			break;
 		for (i = 0; i < ret; i++) {
 			if (rec[i]->refs != rec[i]->extent_item_refs) {
 				fprintf(stderr, "ref mismatch on [%llu %llu] ",
 					(unsigned long long)rec[i]->start,
 					(unsigned long long)rec[i]->nr);
 				fprintf(stderr, "extent item %u, found %u\n",
 					rec[i]->extent_item_refs,
 					rec[i]->refs);
 				err = 1;
 			}
 			radix_tree_delete(extent_radix, rec[i]->start);
 			free(rec[i]);
 		}
 	}
 	return err;
 }

 int main(int ac, char **av) {
 	struct btrfs_super_block super;
 	struct btrfs_root *root;
 	struct radix_tree_root extent_radix;
 	struct radix_tree_root seen;
 	struct radix_tree_root pending;
 	struct radix_tree_root reada;
 	struct radix_tree_root nodes;
 	struct btrfs_path path;
 	struct btrfs_key key;
 	struct btrfs_key found_key;
 	int ret;
 	u64 last = 0;
 	unsigned long *bits;
 	int bits_nr;
 	struct btrfs_leaf *leaf;
 	int slot;
 	struct btrfs_root_item *ri;

 	radix_tree_init();


 	INIT_RADIX_TREE(&extent_radix, GFP_NOFS);
 	init_bit_radix(&seen);
 	init_bit_radix(&pending);
 	init_bit_radix(&reada);
 	init_bit_radix(&nodes);

 	root = open_ctree(av[1], &super);

 	bits_nr = 1024 * 1024 / root->blocksize;
 	bits = malloc(bits_nr * sizeof(unsigned long));
 	if (!bits) {
 		perror("malloc");
 		exit(1);
 	}

 	add_root_to_pending(root->fs_info->tree_root->node, bits, bits_nr,
 			    &extent_radix, &pending, &seen, &reada, &nodes);

 	btrfs_init_path(&path);
 	key.offset = 0;
 	key.objectid = 0;
 	key.flags = 0;
 	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 	ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
 					&key, &path, 0, 0);
 	BUG_ON(ret < 0);
 	while(1) {
 		leaf = &path.nodes[0]->leaf;
 		slot = path.slots[0];
 		if (slot >= btrfs_header_nritems(&leaf->header)) {
 			ret = btrfs_next_leaf(root, &path);
 			if (ret != 0)
 				break;
 			leaf = &path.nodes[0]->leaf;
 			slot = path.slots[0];
 		}
 		btrfs_disk_key_to_cpu(&found_key,
 				      &leaf->items[path.slots[0]].key);
 		if (btrfs_key_type(&found_key) == BTRFS_ROOT_ITEM_KEY) {
 			struct btrfs_buffer *buf;
 			ri = btrfs_item_ptr(leaf, path.slots[0],
 					    struct btrfs_root_item);
 			buf = read_tree_block(root->fs_info->tree_root,
 					      btrfs_root_blocknr(ri));
 			add_root_to_pending(buf, bits, bits_nr, &extent_radix,
 					    &pending, &seen, &reada, &nodes);
 			btrfs_block_release(root->fs_info->tree_root, buf);
 		}
 		path.slots[0]++;
 	}
 	btrfs_release_path(root, &path);
 	while(1) {
 		ret = run_next_block(root, bits, bits_nr, &last, &pending,
 				     &seen, &reada, &nodes, &extent_radix);
 		if (ret != 0)
 			break;
 	}
 	ret = check_extent_refs(root, &extent_radix);
 	close_ctree(root, &super);
 	printf("found %llu blocks used err is %d\n",
 	       (unsigned long long)blocks_used, ret);
 	printf("total csum bytes: %llu\n",(unsigned long long)total_csum_bytes);
 	printf("total tree blocks: %llu\n",
 	       (unsigned long long)total_btree_blocks);
 	printf("btree space waste bytes: %llu\n",
 	       (unsigned long long)btree_space_waste);
 	return ret;
 }
	/*
	* Copyright (C) 2007 Oracle. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public
	* License v2 as published by the Free Software Foundation.
	*
	* 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 021110-1307, USA.
	*/

	#define _XOPEN_SOURCE 500
	#define _GNU_SOURCE 1
	#include <stdio.h>
	#include <stdlib.h>
	#include <fcntl.h>
	#include "kerncompat.h"
	#include "radix-tree.h"
	#include "ctree.h"
	#include "disk-io.h"
	#include "print-tree.h"
	#include "transaction.h"
	#include "bit-radix.h"

	static u64 blocks_used = 0;
	static u64 total_csum_bytes = 0;
	static u64 total_btree_blocks = 0;
	static u64 btree_space_waste = 0;

	struct extent_record {
	struct btrfs_disk_key parent_key;
	u64 start;
	u64 nr;
	u64 owner;
	u32 refs;
	u32 extent_item_refs;
	int checked;
	};

	static int check_node(struct btrfs_root *root,
	struct btrfs_disk_key *parent_key,
	struct btrfs_node *node)
	{
	int i;
	u32 nritems = btrfs_header_nritems(&node->header);

	if (nritems == 0 \|\| nritems > BTRFS_NODEPTRS_PER_BLOCK(root))
	return 1;
	if (parent_key->flags) {
	if (memcmp(parent_key, &node->ptrs[0].key,
	sizeof(struct btrfs_disk_key)))
	return 1;
	}
	for (i = 0; nritems > 1 && i < nritems - 2; i++) {
	struct btrfs_key cpukey;
	btrfs_disk_key_to_cpu(&cpukey, &node->ptrs[i + 1].key);
	if (btrfs_comp_keys(&node->ptrs[i].key, &cpukey) >= 0)
	return 1;
	}
	return 0;
	}

	static int check_leaf(struct btrfs_root *root,
	struct btrfs_disk_key *parent_key,
	struct btrfs_leaf *leaf)
	{
	int i;
	u32 nritems = btrfs_header_nritems(&leaf->header);

	if (btrfs_header_level(&leaf->header) != 0) {
	fprintf(stderr, "leaf is not a leaf %llu\n",
	(unsigned long long)btrfs_header_blocknr(&leaf->header));
	return 1;
	}
	if (btrfs_leaf_free_space(root, leaf) < 0) {
	fprintf(stderr, "leaf free space incorrect %llu %d\n",
	(unsigned long long)btrfs_header_blocknr(&leaf->header),
	btrfs_leaf_free_space(root, leaf));
	return 1;
	}

	if (nritems == 0)
	return 0;

	if (parent_key->flags && memcmp(parent_key, &leaf->items[0].key,
	sizeof(struct btrfs_disk_key))) {
	fprintf(stderr, "leaf parent key incorrect %llu\n",
	(unsigned long long)btrfs_header_blocknr(&leaf->header));
	return 1;
	}
	for (i = 0; nritems > 1 && i < nritems - 2; i++) {
	struct btrfs_key cpukey;
	btrfs_disk_key_to_cpu(&cpukey, &leaf->items[i + 1].key);
	if (btrfs_comp_keys(&leaf->items[i].key,
	&cpukey) >= 0)
	return 1;
	if (btrfs_item_offset(leaf->items + i) !=
	btrfs_item_end(leaf->items + i + 1))
	return 1;
	if (i == 0) {
	if (btrfs_item_offset(leaf->items + i) +
	btrfs_item_size(leaf->items + i) !=
	BTRFS_LEAF_DATA_SIZE(root))
	return 1;
	}
	}
	return 0;
	}

	static int maybe_free_extent_rec(struct radix_tree_root *extent_radix,
	struct extent_record *rec)
	{
	if (rec->checked && rec->extent_item_refs == rec->refs &&
	rec->refs > 0) {
	radix_tree_delete(extent_radix, rec->start);
	free(rec);
	}
	return 0;
	}

	static int check_block(struct btrfs_root *root,
	struct radix_tree_root *extent_radix,
	struct btrfs_buffer *buf)
	{
	struct extent_record *rec;
	int ret = 1;

	rec = radix_tree_lookup(extent_radix, buf->blocknr);
	if (!rec)
	return 1;
	if (btrfs_is_leaf(&buf->node)) {
	ret = check_leaf(root, &rec->parent_key, &buf->leaf);
	} else {
	ret = check_node(root, &rec->parent_key, &buf->node);
	}
	rec->checked = 1;
	if (!ret)
	maybe_free_extent_rec(extent_radix, rec);
	return ret;
	}

	static int add_extent_rec(struct radix_tree_root *extent_radix,
	struct btrfs_disk_key *parent_key,
	u64 ref, u64 start, u64 nr, u64 owner,
	u32 extent_item_refs, int inc_ref, int set_checked)
	{
	struct extent_record *rec;
	int ret = 0;
	rec = radix_tree_lookup(extent_radix, start);
	if (rec) {
	if (inc_ref)
	rec->refs++;
	if (start != rec->start) {
	fprintf(stderr, "warning, start mismatch %llu %llu\n",
	(unsigned long long)rec->start,
	(unsigned long long)start);
	ret = 1;
	}
	if (extent_item_refs) {
	if (rec->extent_item_refs) {
	fprintf(stderr, "block %llu rec extent_item_refs %u, passed %u\n", (unsigned long long)start, rec->extent_item_refs, extent_item_refs);
	}
	rec->extent_item_refs = extent_item_refs;
	}
	if (set_checked)
	rec->checked = 1;
	maybe_free_extent_rec(extent_radix, rec);
	return ret;
	}
	rec = malloc(sizeof(*rec));
	if (start == 0)
	extent_item_refs = 0;
	rec->start = start;
	rec->nr = nr;
	rec->owner = owner;
	rec->checked = 0;

	if (inc_ref)
	rec->refs = 1;
	else
	rec->refs = 0;

	if (extent_item_refs)
	rec->extent_item_refs = extent_item_refs;
	else
	rec->extent_item_refs = 0;

	if (parent_key)
	memcpy(&rec->parent_key, parent_key, sizeof(*parent_key));
	else
	memset(&rec->parent_key, 0, sizeof(*parent_key));

	ret = radix_tree_insert(extent_radix, start, rec);
	BUG_ON(ret);
	blocks_used += nr;
	if (set_checked)
	rec->checked = 1;
	return ret;
	}

	static int add_pending(struct radix_tree_root *pending,
	struct radix_tree_root *seen, u64 blocknr)
	{
	if (test_radix_bit(seen, blocknr))
	return -EEXIST;
	set_radix_bit(pending, blocknr);
	set_radix_bit(seen, blocknr);
	return 0;
	}
	static int pick_next_pending(struct radix_tree_root *pending,
	struct radix_tree_root *reada,
	struct radix_tree_root *nodes,
	u64 last, unsigned long *bits, int bits_nr,
	int *reada_bits)
	{
	unsigned long node_start = last;
	int ret;
	ret = find_first_radix_bit(reada, bits, 0, 1);
	if (ret) {
	*reada_bits = 1;
	return ret;
	}
	*reada_bits = 0;
	if (node_start > 8)
	node_start -= 8;
	ret = find_first_radix_bit(nodes, bits, node_start, bits_nr);
	if (!ret)
	ret = find_first_radix_bit(nodes, bits, 0, bits_nr);
	if (ret) {
	if (bits_nr - ret > 8) {
	int ret2;
	u64 sequential;
	ret2 = find_first_radix_bit(pending, bits + ret,
	bits[0], bits_nr - ret);
	sequential = bits[0];
	while(ret2 > 0) {
	if (bits[ret] - sequential > 8)
	break;
	sequential = bits[ret];
	ret++;
	ret2--;
	}
	}
	return ret;
	}
	return find_first_radix_bit(pending, bits, 0, bits_nr);
	}
	static struct btrfs_buffer reada_buf;

	static int run_next_block(struct btrfs_root *root,
	unsigned long *bits,
	int bits_nr,
	u64 *last,
	struct radix_tree_root *pending,
	struct radix_tree_root *seen,
	struct radix_tree_root *reada,
	struct radix_tree_root *nodes,
	struct radix_tree_root *extent_radix)
	{
	struct btrfs_buffer *buf;
	u64 blocknr;
	int ret;
	int i;
	int nritems;
	struct btrfs_leaf *leaf;
	struct btrfs_node *node;
	struct btrfs_disk_key *disk_key;
	int reada_bits;

	u64 last_block = 0;
	ret = pick_next_pending(pending, reada, nodes, *last, bits,
	bits_nr, &reada_bits);
	if (ret == 0) {
	return 1;
	}
	if (!reada_bits) {
	for(i = 0; i < ret; i++) {
	u64 offset;
	set_radix_bit(reada, bits[i]);
	btrfs_map_bh_to_logical(root, &reada_buf, bits[i]);
	offset = reada_buf.dev_blocknr * root->blocksize;
	last_block = bits[i];
	readahead(reada_buf.fd, offset, root->blocksize);
	}
	}
	*last = bits[0];
	blocknr = bits[0];
	clear_radix_bit(pending, blocknr);
	clear_radix_bit(reada, blocknr);
	clear_radix_bit(nodes, blocknr);
	buf = read_tree_block(root, blocknr);
	nritems = btrfs_header_nritems(&buf->node.header);
	ret = check_block(root, extent_radix, buf);
	if (ret) {
	fprintf(stderr, "bad block %llu\n",
	(unsigned long long)blocknr);
	}
	if (btrfs_is_leaf(&buf->node)) {
	leaf = &buf->leaf;
	btree_space_waste += btrfs_leaf_free_space(root, leaf);
	for (i = 0; i < nritems; i++) {
	struct btrfs_file_extent_item *fi;
	disk_key = &leaf->items[i].key;
	if (btrfs_disk_key_type(disk_key) ==
	BTRFS_EXTENT_ITEM_KEY) {
	struct btrfs_key found;
	struct btrfs_extent_item *ei;
	btrfs_disk_key_to_cpu(&found,
	&leaf->items[i].key);
	ei = btrfs_item_ptr(leaf, i,
	struct btrfs_extent_item);
	add_extent_rec(extent_radix, NULL, 0,
	found.objectid,
	found.offset,
	btrfs_extent_owner(ei),
	btrfs_extent_refs(ei), 0, 0);
	continue;
	}
	if (btrfs_disk_key_type(disk_key) ==
	BTRFS_CSUM_ITEM_KEY) {
	total_csum_bytes +=
	btrfs_item_size(leaf->items + i);
	continue;
	}
	if (btrfs_disk_key_type(disk_key) ==
	BTRFS_BLOCK_GROUP_ITEM_KEY) {
	struct btrfs_block_group_item *bi;
	bi = btrfs_item_ptr(leaf, i,
	struct btrfs_block_group_item);
	#if 0
	fprintf(stderr,"block group %Lu %Lu used %Lu ",
	btrfs_disk_key_objectid(disk_key),
	btrfs_disk_key_offset(disk_key),
	btrfs_block_group_used(bi));
	fprintf(stderr, "flags %x\n", bi->flags);
	#endif
	continue;
	}
	if (btrfs_disk_key_type(&leaf->items[i].key) !=
	BTRFS_EXTENT_DATA_KEY)
	continue;
	fi = btrfs_item_ptr(leaf, i,
	struct btrfs_file_extent_item);
	if (btrfs_file_extent_type(fi) !=
	BTRFS_FILE_EXTENT_REG)
	continue;
	if (btrfs_file_extent_disk_blocknr(fi) == 0)
	continue;
	ret = add_extent_rec(extent_radix, NULL, blocknr,
	btrfs_file_extent_disk_blocknr(fi),
	btrfs_file_extent_disk_num_blocks(fi),
	btrfs_disk_key_objectid(&leaf->items[i].key),
	0, 1, 1);
	BUG_ON(ret);
	}
	} else {
	int level;
	node = &buf->node;
	level = btrfs_header_level(&node->header);
	for (i = 0; i < nritems; i++) {
	u64 ptr = btrfs_node_blockptr(node, i);
	ret = add_extent_rec(extent_radix,
	&node->ptrs[i].key,
	blocknr, ptr, 1,
	btrfs_header_owner(&node->header),
	0, 1, 0);
	BUG_ON(ret);
	if (level > 1) {
	add_pending(nodes, seen, ptr);
	} else {
	add_pending(pending, seen, ptr);
	}
	}
	btree_space_waste += (BTRFS_NODEPTRS_PER_BLOCK(root) -
	nritems) * sizeof(struct btrfs_key_ptr);
	}
	btrfs_block_release(root, buf);
	total_btree_blocks++;
	return 0;
	}

	static int add_root_to_pending(struct btrfs_buffer *buf,
	unsigned long *bits,
	int bits_nr,
	struct radix_tree_root *extent_radix,
	struct radix_tree_root *pending,
	struct radix_tree_root *seen,
	struct radix_tree_root *reada,
	struct radix_tree_root *nodes)
	{
	if (btrfs_header_level(&buf->node.header) > 0)
	add_pending(nodes, seen, buf->blocknr);
	else
	add_pending(pending, seen, buf->blocknr);
	add_extent_rec(extent_radix, NULL, 0, buf->blocknr, 1,
	btrfs_header_owner(&buf->node.header), 0, 1, 0);
	return 0;
	}

	int check_extent_refs(struct btrfs_root *root,
	struct radix_tree_root *extent_radix)
	{
	struct extent_record *rec[64];
	int i;
	int ret;
	int err = 0;

	while(1) {
	ret = radix_tree_gang_lookup(extent_radix, (void **)rec, 0,
	ARRAY_SIZE(rec));
	if (!ret)
	break;
	for (i = 0; i < ret; i++) {
	if (rec[i]->refs != rec[i]->extent_item_refs) {
	fprintf(stderr, "ref mismatch on [%llu %llu] ",
	(unsigned long long)rec[i]->start,
	(unsigned long long)rec[i]->nr);
	fprintf(stderr, "extent item %u, found %u\n",
	rec[i]->extent_item_refs,
	rec[i]->refs);
	err = 1;
	}
	radix_tree_delete(extent_radix, rec[i]->start);
	free(rec[i]);
	}
	}
	return err;
	}

	int main(int ac, char **av) {
	struct btrfs_super_block super;
	struct btrfs_root *root;
	struct radix_tree_root extent_radix;
	struct radix_tree_root seen;
	struct radix_tree_root pending;
	struct radix_tree_root reada;
	struct radix_tree_root nodes;
	struct btrfs_path path;
	struct btrfs_key key;
	struct btrfs_key found_key;
	int ret;
	u64 last = 0;
	unsigned long *bits;
	int bits_nr;
	struct btrfs_leaf *leaf;
	int slot;
	struct btrfs_root_item *ri;

	radix_tree_init();


	INIT_RADIX_TREE(&extent_radix, GFP_NOFS);
	init_bit_radix(&seen);
	init_bit_radix(&pending);
	init_bit_radix(&reada);
	init_bit_radix(&nodes);

	root = open_ctree(av[1], &super);

	bits_nr = 1024 * 1024 / root->blocksize;
	bits = malloc(bits_nr * sizeof(unsigned long));
	if (!bits) {
	perror("malloc");
	exit(1);
	}

	add_root_to_pending(root->fs_info->tree_root->node, bits, bits_nr,
	&extent_radix, &pending, &seen, &reada, &nodes);

	btrfs_init_path(&path);
	key.offset = 0;
	key.objectid = 0;
	key.flags = 0;
	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
	ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
	&key, &path, 0, 0);
	BUG_ON(ret < 0);
	while(1) {
	leaf = &path.nodes[0]->leaf;
	slot = path.slots[0];
	if (slot >= btrfs_header_nritems(&leaf->header)) {
	ret = btrfs_next_leaf(root, &path);
	if (ret != 0)
	break;
	leaf = &path.nodes[0]->leaf;
	slot = path.slots[0];
	}
	btrfs_disk_key_to_cpu(&found_key,
	&leaf->items[path.slots[0]].key);
	if (btrfs_key_type(&found_key) == BTRFS_ROOT_ITEM_KEY) {
	struct btrfs_buffer *buf;
	ri = btrfs_item_ptr(leaf, path.slots[0],
	struct btrfs_root_item);
	buf = read_tree_block(root->fs_info->tree_root,
	btrfs_root_blocknr(ri));
	add_root_to_pending(buf, bits, bits_nr, &extent_radix,
	&pending, &seen, &reada, &nodes);
	btrfs_block_release(root->fs_info->tree_root, buf);
	}
	path.slots[0]++;
	}
	btrfs_release_path(root, &path);
	while(1) {
	ret = run_next_block(root, bits, bits_nr, &last, &pending,
	&seen, &reada, &nodes, &extent_radix);
	if (ret != 0)
	break;
	}
	ret = check_extent_refs(root, &extent_radix);
	close_ctree(root, &super);
	printf("found %llu blocks used err is %d\n",
	(unsigned long long)blocks_used, ret);
	printf("total csum bytes: %llu\n",(unsigned long long)total_csum_bytes);
	printf("total tree blocks: %llu\n",
	(unsigned long long)total_btree_blocks);
	printf("btree space waste bytes: %llu\n",
	(unsigned long long)btree_space_waste);
	return ret;
	}