[linux-2.6-block.git] / fs / btrfs / disk-io.c

/*
 * 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.
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/crc32c.h>
#include <linux/scatterlist.h>
#include <linux/swap.h>
#include <linux/radix-tree.h>
#include <linux/writeback.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"

u64 bh_blocknr(struct buffer_head *bh)
{
	return bh->b_blocknr;
}

static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
{
	struct btrfs_node *node = btrfs_buffer_node(buf);
	if (bh_blocknr(buf) != btrfs_header_blocknr(&node->header)) {
		printk(KERN_CRIT "bh_blocknr(buf) is %llu, header is %llu\n",
		       (unsigned long long)bh_blocknr(buf),
		       (unsigned long long)btrfs_header_blocknr(&node->header));
		return 1;
	}
	return 0;
}

struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr)
{
	struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
	int blockbits = root->fs_info->sb->s_blocksize_bits;
	unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
	struct page *page;
	struct buffer_head *bh;
	struct buffer_head *head;
	struct buffer_head *ret = NULL;


	page = find_lock_page(mapping, index);
	if (!page)
		return NULL;

	if (!page_has_buffers(page))
		goto out_unlock;

	head = page_buffers(page);
	bh = head;
	do {
		if (buffer_mapped(bh) && bh_blocknr(bh) == blocknr) {
			ret = bh;
			get_bh(bh);
			goto out_unlock;
		}
		bh = bh->b_this_page;
	} while (bh != head);
out_unlock:
	unlock_page(page);
	page_cache_release(page);
	return ret;
}

int btrfs_map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh,
			     u64 logical)
{
	if (logical == 0) {
		bh->b_bdev = NULL;
		bh->b_blocknr = 0;
		set_buffer_mapped(bh);
	} else {
		map_bh(bh, root->fs_info->sb, logical);
	}
	return 0;
}

struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
						 u64 blocknr)
{
	struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
	int blockbits = root->fs_info->sb->s_blocksize_bits;
	unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
	struct page *page;
	struct buffer_head *bh;
	struct buffer_head *head;
	struct buffer_head *ret = NULL;
	int err;
	u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);

	page = find_or_create_page(mapping, index, GFP_NOFS);
	if (!page)
		return NULL;

	if (!page_has_buffers(page))
		create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0);
	head = page_buffers(page);
	bh = head;
	do {
		if (!buffer_mapped(bh)) {
			err = btrfs_map_bh_to_logical(root, bh, first_block);
			BUG_ON(err);
		}
		if (bh_blocknr(bh) == blocknr) {
			ret = bh;
			get_bh(bh);
			goto out_unlock;
		}
		bh = bh->b_this_page;
		first_block++;
	} while (bh != head);
out_unlock:
	unlock_page(page);
	if (ret)
		touch_buffer(ret);
	page_cache_release(page);
	return ret;
}

static int btree_get_block(struct inode *inode, sector_t iblock,
			   struct buffer_head *bh, int create)
{
	int err;
	struct btrfs_root *root = BTRFS_I(bh->b_page->mapping->host)->root;
	err = btrfs_map_bh_to_logical(root, bh, iblock);
	return err;
}

int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
		    char *result)
{
	u32 crc;
	crc = crc32c(0, data, len);
	memcpy(result, &crc, BTRFS_CRC32_SIZE);
	return 0;
}

static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
			   int verify)
{
	char result[BTRFS_CRC32_SIZE];
	int ret;
	struct btrfs_node *node;

	ret = btrfs_csum_data(root, bh->b_data + BTRFS_CSUM_SIZE,
			      bh->b_size - BTRFS_CSUM_SIZE, result);
	if (ret)
		return ret;
	if (verify) {
		if (memcmp(bh->b_data, result, BTRFS_CRC32_SIZE)) {
			printk("btrfs: %s checksum verify failed on %llu\n",
			       root->fs_info->sb->s_id,
			       (unsigned long long)bh_blocknr(bh));
			return 1;
		}
	} else {
		node = btrfs_buffer_node(bh);
		memcpy(node->header.csum, result, BTRFS_CRC32_SIZE);
	}
	return 0;
}

static int btree_writepage(struct page *page, struct writeback_control *wbc)
{
	struct buffer_head *bh;
	struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
	struct buffer_head *head;
	if (!page_has_buffers(page)) {
		create_empty_buffers(page, root->fs_info->sb->s_blocksize,
					(1 << BH_Dirty)|(1 << BH_Uptodate));
	}
	head = page_buffers(page);
	bh = head;
	do {
		if (buffer_dirty(bh))
			csum_tree_block(root, bh, 0);
		bh = bh->b_this_page;
	} while (bh != head);
	return block_write_full_page(page, btree_get_block, wbc);
}

static int btree_readpage(struct file * file, struct page * page)
{
	return block_read_full_page(page, btree_get_block);
}

static struct address_space_operations btree_aops = {
	.readpage	= btree_readpage,
	.writepage	= btree_writepage,
	.sync_page	= block_sync_page,
};

int readahead_tree_block(struct btrfs_root *root, u64 blocknr)
{
	struct buffer_head *bh = NULL;
	int ret = 0;

	bh = btrfs_find_create_tree_block(root, blocknr);
	if (!bh)
		return 0;
	if (buffer_uptodate(bh)) {
		ret = 1;
		goto done;
	}
	if (test_set_buffer_locked(bh)) {
		ret = 1;
		goto done;
	}
	if (!buffer_uptodate(bh)) {
		get_bh(bh);
		bh->b_end_io = end_buffer_read_sync;
		submit_bh(READ, bh);
	} else {
		unlock_buffer(bh);
		ret = 1;
	}
done:
	brelse(bh);
	return ret;
}

struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
{
	struct buffer_head *bh = NULL;

	bh = btrfs_find_create_tree_block(root, blocknr);
	if (!bh)
		return bh;
	if (buffer_uptodate(bh))
		goto uptodate;
	lock_buffer(bh);
	if (!buffer_uptodate(bh)) {
		get_bh(bh);
		bh->b_end_io = end_buffer_read_sync;
		submit_bh(READ, bh);
		wait_on_buffer(bh);
		if (!buffer_uptodate(bh))
			goto fail;
	} else {
		unlock_buffer(bh);
	}
uptodate:
	if (!buffer_checked(bh)) {
		csum_tree_block(root, bh, 1);
		set_buffer_checked(bh);
	}
	if (check_tree_block(root, bh))
		goto fail;
	return bh;
fail:
	brelse(bh);
	return NULL;
}

int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
		     struct buffer_head *buf)
{
	WARN_ON(atomic_read(&buf->b_count) == 0);
	clear_buffer_dirty(buf);
	return 0;
}

static int __setup_root(int blocksize,
			struct btrfs_root *root,
			struct btrfs_fs_info *fs_info,
			u64 objectid)
{
	root->node = NULL;
	root->inode = NULL;
	root->commit_root = NULL;
	root->blocksize = blocksize;
	root->ref_cows = 0;
	root->fs_info = fs_info;
	root->objectid = objectid;
	root->last_trans = 0;
	root->highest_inode = 0;
	root->last_inode_alloc = 0;
	memset(&root->root_key, 0, sizeof(root->root_key));
	memset(&root->root_item, 0, sizeof(root->root_item));
	root->root_key.objectid = objectid;
	return 0;
}

static int find_and_setup_root(int blocksize,
			       struct btrfs_root *tree_root,
			       struct btrfs_fs_info *fs_info,
			       u64 objectid,
			       struct btrfs_root *root)
{
	int ret;

	__setup_root(blocksize, root, fs_info, objectid);
	ret = btrfs_find_last_root(tree_root, objectid,
				   &root->root_item, &root->root_key);
	BUG_ON(ret);

	root->node = read_tree_block(root,
				     btrfs_root_blocknr(&root->root_item));
	BUG_ON(!root->node);
	return 0;
}

struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
					       struct btrfs_key *location)
{
	struct btrfs_root *root;
	struct btrfs_root *tree_root = fs_info->tree_root;
	struct btrfs_path *path;
	struct btrfs_leaf *l;
	u64 highest_inode;
	int ret = 0;

	root = kzalloc(sizeof(*root), GFP_NOFS);
	if (!root)
		return ERR_PTR(-ENOMEM);
	if (location->offset == (u64)-1) {
		ret = find_and_setup_root(fs_info->sb->s_blocksize,
					  fs_info->tree_root, fs_info,
					  location->objectid, root);
		if (ret) {
			kfree(root);
			return ERR_PTR(ret);
		}
		goto insert;
	}

	__setup_root(fs_info->sb->s_blocksize, root, fs_info,
		     location->objectid);

	path = btrfs_alloc_path();
	BUG_ON(!path);
	ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
	if (ret != 0) {
		if (ret > 0)
			ret = -ENOENT;
		goto out;
	}
	l = btrfs_buffer_leaf(path->nodes[0]);
	memcpy(&root->root_item,
	       btrfs_item_ptr(l, path->slots[0], struct btrfs_root_item),
	       sizeof(root->root_item));
	memcpy(&root->root_key, location, sizeof(*location));
	ret = 0;
out:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	if (ret) {
		kfree(root);
		return ERR_PTR(ret);
	}
	root->node = read_tree_block(root,
				     btrfs_root_blocknr(&root->root_item));
	BUG_ON(!root->node);
insert:
	root->ref_cows = 1;
	ret = btrfs_find_highest_inode(root, &highest_inode);
	if (ret == 0) {
		root->highest_inode = highest_inode;
		root->last_inode_alloc = highest_inode;
	}
	return root;
}

struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
				      struct btrfs_key *location)
{
	struct btrfs_root *root;
	int ret;

	root = radix_tree_lookup(&fs_info->fs_roots_radix,
				 (unsigned long)location->objectid);
	if (root)
		return root;

	root = btrfs_read_fs_root_no_radix(fs_info, location);
	if (IS_ERR(root))
		return root;
	ret = radix_tree_insert(&fs_info->fs_roots_radix,
				(unsigned long)root->root_key.objectid,
				root);
	if (ret) {
		brelse(root->node);
		kfree(root);
		return ERR_PTR(ret);
	}
	return root;
}

struct btrfs_root *open_ctree(struct super_block *sb)
{
	struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
						 GFP_NOFS);
	struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
					       GFP_NOFS);
	struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
						GFP_NOFS);
	int ret;
	int err = -EIO;
	struct btrfs_super_block *disk_super;

	if (!extent_root || !tree_root || !fs_info) {
		err = -ENOMEM;
		goto fail;
	}
	init_bit_radix(&fs_info->pinned_radix);
	init_bit_radix(&fs_info->pending_del_radix);
	init_bit_radix(&fs_info->extent_map_radix);
	INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
	INIT_RADIX_TREE(&fs_info->block_group_radix, GFP_KERNEL);
	INIT_RADIX_TREE(&fs_info->block_group_data_radix, GFP_KERNEL);
	INIT_LIST_HEAD(&fs_info->trans_list);
	INIT_LIST_HEAD(&fs_info->dead_roots);
	sb_set_blocksize(sb, 4096);
	fs_info->running_transaction = NULL;
	fs_info->tree_root = tree_root;
	fs_info->extent_root = extent_root;
	fs_info->sb = sb;
	fs_info->btree_inode = new_inode(sb);
	fs_info->btree_inode->i_ino = 1;
	fs_info->btree_inode->i_nlink = 1;
	fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
	fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
	fs_info->do_barriers = 1;
	fs_info->extent_tree_insert_nr = 0;
	fs_info->extent_tree_prealloc_nr = 0;
	fs_info->closing = 0;

	INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
	BTRFS_I(fs_info->btree_inode)->root = tree_root;
	memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
	       sizeof(struct btrfs_key));
	insert_inode_hash(fs_info->btree_inode);
	mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);

	mutex_init(&fs_info->trans_mutex);
	mutex_init(&fs_info->fs_mutex);

	__setup_root(sb->s_blocksize, tree_root,
		     fs_info, BTRFS_ROOT_TREE_OBJECTID);

	fs_info->sb_buffer = read_tree_block(tree_root,
					     BTRFS_SUPER_INFO_OFFSET /
					     sb->s_blocksize);

	if (!fs_info->sb_buffer)
		goto fail_iput;
	disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
	fs_info->disk_super = disk_super;
	memcpy(&fs_info->super_copy, disk_super, sizeof(fs_info->super_copy));

	if (!btrfs_super_root(disk_super))
		goto fail_sb_buffer;

	i_size_write(fs_info->btree_inode,
		     btrfs_super_total_blocks(disk_super) <<
		     fs_info->btree_inode->i_blkbits);


	if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
		    sizeof(disk_super->magic))) {
		printk("btrfs: valid FS not found on %s\n", sb->s_id);
		goto fail_sb_buffer;
	}
	tree_root->node = read_tree_block(tree_root,
					  btrfs_super_root(disk_super));
	if (!tree_root->node)
		goto fail_sb_buffer;

	mutex_lock(&fs_info->fs_mutex);
	ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
				  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
	if (ret) {
		mutex_unlock(&fs_info->fs_mutex);
		goto fail_tree_root;
	}

	btrfs_read_block_groups(extent_root);

	fs_info->generation = btrfs_super_generation(disk_super) + 1;
	ret = btrfs_find_dead_roots(tree_root);
	if (ret)
		goto fail_tree_root;
	mutex_unlock(&fs_info->fs_mutex);
	return tree_root;

fail_tree_root:
	btrfs_block_release(tree_root, tree_root->node);
fail_sb_buffer:
	btrfs_block_release(tree_root, fs_info->sb_buffer);
fail_iput:
	iput(fs_info->btree_inode);
fail:
	kfree(extent_root);
	kfree(tree_root);
	kfree(fs_info);
	return ERR_PTR(err);
}

int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
		      *root)
{
	int ret;
	struct buffer_head *bh = root->fs_info->sb_buffer;

	lock_buffer(bh);
	WARN_ON(atomic_read(&bh->b_count) < 1);
	clear_buffer_dirty(bh);
	csum_tree_block(root, bh, 0);
	bh->b_end_io = end_buffer_write_sync;
	get_bh(bh);
	if (root->fs_info->do_barriers)
		ret = submit_bh(WRITE_BARRIER, bh);
	else
		ret = submit_bh(WRITE, bh);
	if (ret == -EOPNOTSUPP) {
		get_bh(bh);
		lock_buffer(bh);
		set_buffer_uptodate(bh);
		root->fs_info->do_barriers = 0;
		ret = submit_bh(WRITE, bh);
	}
	wait_on_buffer(bh);
	if (!buffer_uptodate(bh)) {
		WARN_ON(1);
		return -EIO;
	}
	return 0;
}

int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
{
	radix_tree_delete(&fs_info->fs_roots_radix,
			  (unsigned long)root->root_key.objectid);
	if (root->inode)
		iput(root->inode);
	if (root->node)
		brelse(root->node);
	if (root->commit_root)
		brelse(root->commit_root);
	kfree(root);
	return 0;
}

static int del_fs_roots(struct btrfs_fs_info *fs_info)
{
	int ret;
	struct btrfs_root *gang[8];
	int i;

	while(1) {
		ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
					     (void **)gang, 0,
					     ARRAY_SIZE(gang));
		if (!ret)
			break;
		for (i = 0; i < ret; i++)
			btrfs_free_fs_root(fs_info, gang[i]);
	}
	return 0;
}

int close_ctree(struct btrfs_root *root)
{
	int ret;
	struct btrfs_trans_handle *trans;
	struct btrfs_fs_info *fs_info = root->fs_info;

	fs_info->closing = 1;
	btrfs_transaction_flush_work(root);
	mutex_lock(&fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	ret = btrfs_commit_transaction(trans, root);
	/* run commit again to  drop the original snapshot */
	trans = btrfs_start_transaction(root, 1);
	btrfs_commit_transaction(trans, root);
	ret = btrfs_write_and_wait_transaction(NULL, root);
	BUG_ON(ret);
	write_ctree_super(NULL, root);
	mutex_unlock(&fs_info->fs_mutex);

	if (fs_info->extent_root->node)
		btrfs_block_release(fs_info->extent_root,
				    fs_info->extent_root->node);
	if (fs_info->tree_root->node)
		btrfs_block_release(fs_info->tree_root,
				    fs_info->tree_root->node);
	btrfs_block_release(root, fs_info->sb_buffer);
	truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
	iput(fs_info->btree_inode);

	btrfs_free_block_groups(root->fs_info);
	del_fs_roots(fs_info);
	kfree(fs_info->extent_root);
	kfree(fs_info->tree_root);
	return 0;
}

void btrfs_mark_buffer_dirty(struct buffer_head *bh)
{
	struct btrfs_root *root = BTRFS_I(bh->b_page->mapping->host)->root;
	u64 transid = btrfs_header_generation(btrfs_buffer_header(bh));
	WARN_ON(!atomic_read(&bh->b_count));
	if (transid != root->fs_info->generation) {
		printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
			(unsigned long long)bh->b_blocknr,
			transid, root->fs_info->generation);
		WARN_ON(1);
	}
	mark_buffer_dirty(bh);
}

void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf)
{
	brelse(buf);
}

void btrfs_btree_balance_dirty(struct btrfs_root *root)
{
	balance_dirty_pages_ratelimited(root->fs_info->btree_inode->i_mapping);
}
Commit	Line	Data
6cbd5570 CM	1	/*
	2	* Copyright (C) 2007 Oracle. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public
	6	* License v2 as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public
	14	* License along with this program; if not, write to the
	15	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	16	* Boston, MA 021110-1307, USA.
	17	*/
	18
e20d96d6 CM	19	#include <linux/module.h>
e20d96d6 CM	20	#include <linux/fs.h>
d98237b3	21	#include <linux/blkdev.h>
11bd143f	22	#include <linux/crc32c.h>
87cbda5c	23	#include <linux/scatterlist.h>
22b0ebda	24	#include <linux/swap.h>
0f7d52f4	25	#include <linux/radix-tree.h>
35b7e476	26	#include <linux/writeback.h>
eb60ceac CM	27	#include "ctree.h"
eb60ceac CM	28	#include "disk-io.h"
e089f05c	29	#include "transaction.h"
0f7d52f4	30	#include "btrfs_inode.h"
eb60ceac	31
7eccb903 CM	32	u64 bh_blocknr(struct buffer_head *bh)
7eccb903 CM	33	{
0cf6c620	34	return bh->b_blocknr;
7eccb903 CM	35	}
7eccb903 CM	36
e20d96d6	37	static int check_tree_block(struct btrfs_root root, struct buffer_head buf)
eb60ceac	38	{
e20d96d6	39	struct btrfs_node *node = btrfs_buffer_node(buf);
7eccb903	40	if (bh_blocknr(buf) != btrfs_header_blocknr(&node->header)) {
5af3981c CM	41	printk(KERN_CRIT "bh_blocknr(buf) is %llu, header is %llu\n",
	42	(unsigned long long)bh_blocknr(buf),
	43	(unsigned long long)btrfs_header_blocknr(&node->header));
39279cc3	44	return 1;
d98237b3	45	}
9a8dd150	46	return 0;
eb60ceac CM	47	}
eb60ceac CM	48
d98237b3 CM	49	struct buffer_head btrfs_find_tree_block(struct btrfs_root root, u64 blocknr)
	50	{
	51	struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
	52	int blockbits = root->fs_info->sb->s_blocksize_bits;
	53	unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
	54	struct page *page;
	55	struct buffer_head *bh;
	56	struct buffer_head *head;
	57	struct buffer_head *ret = NULL;
	58
2c90e5d6	59
d98237b3 CM	60	page = find_lock_page(mapping, index);
	61	if (!page)
	62	return NULL;
	63
	64	if (!page_has_buffers(page))
	65	goto out_unlock;
	66
	67	head = page_buffers(page);
	68	bh = head;
	69	do {
7eccb903	70	if (buffer_mapped(bh) && bh_blocknr(bh) == blocknr) {
d98237b3 CM	71	ret = bh;
	72	get_bh(bh);
	73	goto out_unlock;
	74	}
	75	bh = bh->b_this_page;
	76	} while (bh != head);
	77	out_unlock:
	78	unlock_page(page);
	79	page_cache_release(page);
	80	return ret;
	81	}
	82
8352d8a4	83	int btrfs_map_bh_to_logical(struct btrfs_root root, struct buffer_head bh,
7eccb903 CM	84	u64 logical)
7eccb903 CM	85	{
236454df CM	86	if (logical == 0) {
	87	bh->b_bdev = NULL;
	88	bh->b_blocknr = 0;
	89	set_buffer_mapped(bh);
0cf6c620 CM	90	} else {
0cf6c620 CM	91	map_bh(bh, root->fs_info->sb, logical);
7eccb903	92	}
0cf6c620	93	return 0;
7eccb903 CM	94	}
7eccb903 CM	95
d98237b3 CM	96	struct buffer_head btrfs_find_create_tree_block(struct btrfs_root root,
	97	u64 blocknr)
	98	{
	99	struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
	100	int blockbits = root->fs_info->sb->s_blocksize_bits;
	101	unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
	102	struct page *page;
	103	struct buffer_head *bh;
	104	struct buffer_head *head;
	105	struct buffer_head *ret = NULL;
7eccb903	106	int err;
d98237b3	107	u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
22b0ebda	108
34088780	109	page = find_or_create_page(mapping, index, GFP_NOFS);
d98237b3 CM	110	if (!page)
	111	return NULL;
	112
d98237b3 CM	113	if (!page_has_buffers(page))
	114	create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0);
	115	head = page_buffers(page);
	116	bh = head;
	117	do {
	118	if (!buffer_mapped(bh)) {
8352d8a4	119	err = btrfs_map_bh_to_logical(root, bh, first_block);
7eccb903	120	BUG_ON(err);
d98237b3	121	}
7eccb903	122	if (bh_blocknr(bh) == blocknr) {
d98237b3 CM	123	ret = bh;
	124	get_bh(bh);
	125	goto out_unlock;
	126	}
	127	bh = bh->b_this_page;
	128	first_block++;
	129	} while (bh != head);
	130	out_unlock:
	131	unlock_page(page);
22b0ebda CM	132	if (ret)
22b0ebda CM	133	touch_buffer(ret);
d98237b3 CM	134	page_cache_release(page);
	135	return ret;
	136	}
	137
d98237b3 CM	138	static int btree_get_block(struct inode *inode, sector_t iblock,
	139	struct buffer_head *bh, int create)
	140	{
7eccb903 CM	141	int err;
7eccb903 CM	142	struct btrfs_root *root = BTRFS_I(bh->b_page->mapping->host)->root;
8352d8a4	143	err = btrfs_map_bh_to_logical(root, bh, iblock);
7eccb903	144	return err;
d98237b3 CM	145	}
d98237b3 CM	146
f254e52c CM	147	int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
f254e52c CM	148	char *result)
87cbda5c	149	{
11bd143f CM	150	u32 crc;
	151	crc = crc32c(0, data, len);
	152	memcpy(result, &crc, BTRFS_CRC32_SIZE);
	153	return 0;
f254e52c	154	}
11bd143f	155
f254e52c CM	156	static int csum_tree_block(struct btrfs_root root, struct buffer_head bh,
	157	int verify)
	158	{
509659cd	159	char result[BTRFS_CRC32_SIZE];
f254e52c CM	160	int ret;
	161	struct btrfs_node *node;
	162
	163	ret = btrfs_csum_data(root, bh->b_data + BTRFS_CSUM_SIZE,
	164	bh->b_size - BTRFS_CSUM_SIZE, result);
	165	if (ret)
	166	return ret;
87cbda5c	167	if (verify) {
509659cd	168	if (memcmp(bh->b_data, result, BTRFS_CRC32_SIZE)) {
5af3981c CM	169	printk("btrfs: %s checksum verify failed on %llu\n",
	170	root->fs_info->sb->s_id,
	171	(unsigned long long)bh_blocknr(bh));
f254e52c CM	172	return 1;
	173	}
	174	} else {
	175	node = btrfs_buffer_node(bh);
509659cd	176	memcpy(node->header.csum, result, BTRFS_CRC32_SIZE);
f254e52c	177	}
87cbda5c CM	178	return 0;
	179	}
	180
d98237b3	181	static int btree_writepage(struct page page, struct writeback_control wbc)
ed2ff2cb	182	{
87cbda5c	183	struct buffer_head *bh;
0f7d52f4	184	struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
87cbda5c	185	struct buffer_head *head;
87cbda5c CM	186	if (!page_has_buffers(page)) {
	187	create_empty_buffers(page, root->fs_info->sb->s_blocksize,
	188	(1 << BH_Dirty)\|(1 << BH_Uptodate));
	189	}
	190	head = page_buffers(page);
	191	bh = head;
	192	do {
	193	if (buffer_dirty(bh))
	194	csum_tree_block(root, bh, 0);
	195	bh = bh->b_this_page;
	196	} while (bh != head);
d98237b3	197	return block_write_full_page(page, btree_get_block, wbc);
ed2ff2cb CM	198	}
ed2ff2cb CM	199
d98237b3	200	static int btree_readpage(struct file * file, struct page * page)
eb60ceac	201	{
d98237b3	202	return block_read_full_page(page, btree_get_block);
eb60ceac CM	203	}
eb60ceac CM	204
d98237b3 CM	205	static struct address_space_operations btree_aops = {
	206	.readpage = btree_readpage,
	207	.writepage = btree_writepage,
	208	.sync_page = block_sync_page,
	209	};
	210
090d1875 CM	211	int readahead_tree_block(struct btrfs_root *root, u64 blocknr)
	212	{
	213	struct buffer_head *bh = NULL;
de428b63	214	int ret = 0;
090d1875 CM	215
	216	bh = btrfs_find_create_tree_block(root, blocknr);
	217	if (!bh)
	218	return 0;
de428b63 CM	219	if (buffer_uptodate(bh)) {
de428b63 CM	220	ret = 1;
090d1875	221	goto done;
de428b63 CM	222	}
	223	if (test_set_buffer_locked(bh)) {
	224	ret = 1;
090d1875	225	goto done;
de428b63	226	}
090d1875 CM	227	if (!buffer_uptodate(bh)) {
	228	get_bh(bh);
	229	bh->b_end_io = end_buffer_read_sync;
	230	submit_bh(READ, bh);
	231	} else {
	232	unlock_buffer(bh);
de428b63	233	ret = 1;
090d1875 CM	234	}
	235	done:
	236	brelse(bh);
de428b63	237	return ret;
090d1875 CM	238	}
090d1875 CM	239
e20d96d6	240	struct buffer_head read_tree_block(struct btrfs_root root, u64 blocknr)
eb60ceac	241	{
d98237b3	242	struct buffer_head *bh = NULL;
eb60ceac	243
d98237b3 CM	244	bh = btrfs_find_create_tree_block(root, blocknr);
	245	if (!bh)
	246	return bh;
9d64272c CM	247	if (buffer_uptodate(bh))
9d64272c CM	248	goto uptodate;
d98237b3 CM	249	lock_buffer(bh);
	250	if (!buffer_uptodate(bh)) {
	251	get_bh(bh);
	252	bh->b_end_io = end_buffer_read_sync;
	253	submit_bh(READ, bh);
	254	wait_on_buffer(bh);
	255	if (!buffer_uptodate(bh))
	256	goto fail;
	257	} else {
	258	unlock_buffer(bh);
	259	}
9d64272c	260	uptodate:
090d1875 CM	261	if (!buffer_checked(bh)) {
	262	csum_tree_block(root, bh, 1);
	263	set_buffer_checked(bh);
	264	}
d98237b3	265	if (check_tree_block(root, bh))
39279cc3	266	goto fail;
d98237b3 CM	267	return bh;
	268	fail:
	269	brelse(bh);
	270	return NULL;
eb60ceac CM	271	}
eb60ceac CM	272
e089f05c	273	int clean_tree_block(struct btrfs_trans_handle trans, struct btrfs_root root,
e20d96d6	274	struct buffer_head *buf)
ed2ff2cb	275	{
d6025579	276	WARN_ON(atomic_read(&buf->b_count) == 0);
e20d96d6	277	clear_buffer_dirty(buf);
ed2ff2cb CM	278	return 0;
	279	}
	280
2c90e5d6	281	static int __setup_root(int blocksize,
9f5fae2f CM	282	struct btrfs_root *root,
9f5fae2f CM	283	struct btrfs_fs_info *fs_info,
e20d96d6	284	u64 objectid)
d97e63b6	285	{
cfaa7295	286	root->node = NULL;
0f7d52f4	287	root->inode = NULL;
a28ec197	288	root->commit_root = NULL;
2c90e5d6	289	root->blocksize = blocksize;
123abc88	290	root->ref_cows = 0;
9f5fae2f	291	root->fs_info = fs_info;
0f7d52f4 CM	292	root->objectid = objectid;
0f7d52f4 CM	293	root->last_trans = 0;
1b05da2e CM	294	root->highest_inode = 0;
1b05da2e CM	295	root->last_inode_alloc = 0;
3768f368 CM	296	memset(&root->root_key, 0, sizeof(root->root_key));
3768f368 CM	297	memset(&root->root_item, 0, sizeof(root->root_item));
4d775673	298	root->root_key.objectid = objectid;
3768f368 CM	299	return 0;
	300	}
	301
2c90e5d6	302	static int find_and_setup_root(int blocksize,
9f5fae2f CM	303	struct btrfs_root *tree_root,
	304	struct btrfs_fs_info *fs_info,
	305	u64 objectid,
e20d96d6	306	struct btrfs_root *root)
3768f368 CM	307	{
	308	int ret;
	309
2c90e5d6	310	__setup_root(blocksize, root, fs_info, objectid);
3768f368 CM	311	ret = btrfs_find_last_root(tree_root, objectid,
	312	&root->root_item, &root->root_key);
	313	BUG_ON(ret);
	314
	315	root->node = read_tree_block(root,
	316	btrfs_root_blocknr(&root->root_item));
3768f368	317	BUG_ON(!root->node);
d97e63b6 CM	318	return 0;
	319	}
	320
5eda7b5e CM	321	struct btrfs_root btrfs_read_fs_root_no_radix(struct btrfs_fs_info fs_info,
5eda7b5e CM	322	struct btrfs_key *location)
0f7d52f4 CM	323	{
	324	struct btrfs_root *root;
	325	struct btrfs_root *tree_root = fs_info->tree_root;
	326	struct btrfs_path *path;
	327	struct btrfs_leaf *l;
1b05da2e	328	u64 highest_inode;
0f7d52f4 CM	329	int ret = 0;
0f7d52f4 CM	330
5eda7b5e	331	root = kzalloc(sizeof(*root), GFP_NOFS);
0cf6c620	332	if (!root)
0f7d52f4	333	return ERR_PTR(-ENOMEM);
0f7d52f4 CM	334	if (location->offset == (u64)-1) {
	335	ret = find_and_setup_root(fs_info->sb->s_blocksize,
	336	fs_info->tree_root, fs_info,
	337	location->objectid, root);
	338	if (ret) {
0f7d52f4 CM	339	kfree(root);
	340	return ERR_PTR(ret);
	341	}
	342	goto insert;
	343	}
	344
	345	__setup_root(fs_info->sb->s_blocksize, root, fs_info,
	346	location->objectid);
	347
	348	path = btrfs_alloc_path();
	349	BUG_ON(!path);
	350	ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
	351	if (ret != 0) {
0f7d52f4 CM	352	if (ret > 0)
	353	ret = -ENOENT;
	354	goto out;
	355	}
	356	l = btrfs_buffer_leaf(path->nodes[0]);
	357	memcpy(&root->root_item,
	358	btrfs_item_ptr(l, path->slots[0], struct btrfs_root_item),
	359	sizeof(root->root_item));
	360	memcpy(&root->root_key, location, sizeof(*location));
	361	ret = 0;
	362	out:
	363	btrfs_release_path(root, path);
	364	btrfs_free_path(path);
	365	if (ret) {
	366	kfree(root);
	367	return ERR_PTR(ret);
	368	}
	369	root->node = read_tree_block(root,
	370	btrfs_root_blocknr(&root->root_item));
	371	BUG_ON(!root->node);
	372	insert:
0f7d52f4	373	root->ref_cows = 1;
5eda7b5e CM	374	ret = btrfs_find_highest_inode(root, &highest_inode);
	375	if (ret == 0) {
	376	root->highest_inode = highest_inode;
	377	root->last_inode_alloc = highest_inode;
	378	}
	379	return root;
	380	}
	381
	382	struct btrfs_root btrfs_read_fs_root(struct btrfs_fs_info fs_info,
	383	struct btrfs_key *location)
	384	{
	385	struct btrfs_root *root;
	386	int ret;
	387
	388	root = radix_tree_lookup(&fs_info->fs_roots_radix,
	389	(unsigned long)location->objectid);
	390	if (root)
	391	return root;
	392
	393	root = btrfs_read_fs_root_no_radix(fs_info, location);
	394	if (IS_ERR(root))
	395	return root;
2619ba1f CM	396	ret = radix_tree_insert(&fs_info->fs_roots_radix,
2619ba1f CM	397	(unsigned long)root->root_key.objectid,
0f7d52f4 CM	398	root);
0f7d52f4 CM	399	if (ret) {
0f7d52f4 CM	400	brelse(root->node);
	401	kfree(root);
	402	return ERR_PTR(ret);
	403	}
0f7d52f4 CM	404	return root;
	405	}
	406
2c90e5d6	407	struct btrfs_root open_ctree(struct super_block sb)
2e635a27	408	{
e20d96d6 CM	409	struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
	410	GFP_NOFS);
	411	struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
	412	GFP_NOFS);
e20d96d6 CM	413	struct btrfs_fs_info fs_info = kmalloc(sizeof(fs_info),
e20d96d6 CM	414	GFP_NOFS);
eb60ceac	415	int ret;
39279cc3	416	int err = -EIO;
2c90e5d6	417	struct btrfs_super_block *disk_super;
eb60ceac	418
39279cc3 CM	419	if (!extent_root \|\| !tree_root \|\| !fs_info) {
	420	err = -ENOMEM;
	421	goto fail;
	422	}
8ef97622 CM	423	init_bit_radix(&fs_info->pinned_radix);
8ef97622 CM	424	init_bit_radix(&fs_info->pending_del_radix);
e37c9e69	425	init_bit_radix(&fs_info->extent_map_radix);
0f7d52f4	426	INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
9078a3e1	427	INIT_RADIX_TREE(&fs_info->block_group_radix, GFP_KERNEL);
be744175	428	INIT_RADIX_TREE(&fs_info->block_group_data_radix, GFP_KERNEL);
8fd17795	429	INIT_LIST_HEAD(&fs_info->trans_list);
facda1e7	430	INIT_LIST_HEAD(&fs_info->dead_roots);
2c90e5d6	431	sb_set_blocksize(sb, 4096);
9f5fae2f	432	fs_info->running_transaction = NULL;
9f5fae2f CM	433	fs_info->tree_root = tree_root;
9f5fae2f CM	434	fs_info->extent_root = extent_root;
e20d96d6	435	fs_info->sb = sb;
d98237b3 CM	436	fs_info->btree_inode = new_inode(sb);
d98237b3 CM	437	fs_info->btree_inode->i_ino = 1;
2c90e5d6	438	fs_info->btree_inode->i_nlink = 1;
d98237b3 CM	439	fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
d98237b3 CM	440	fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
e66f709b	441	fs_info->do_barriers = 1;
f2458e1d CM	442	fs_info->extent_tree_insert_nr = 0;
f2458e1d CM	443	fs_info->extent_tree_prealloc_nr = 0;
facda1e7 CM	444	fs_info->closing = 0;
facda1e7 CM	445
08607c1b	446	INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
0f7d52f4 CM	447	BTRFS_I(fs_info->btree_inode)->root = tree_root;
	448	memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
	449	sizeof(struct btrfs_key));
22b0ebda	450	insert_inode_hash(fs_info->btree_inode);
d98237b3	451	mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
39279cc3	452
79154b1b	453	mutex_init(&fs_info->trans_mutex);
d561c025	454	mutex_init(&fs_info->fs_mutex);
3768f368	455
2c90e5d6 CM	456	__setup_root(sb->s_blocksize, tree_root,
2c90e5d6 CM	457	fs_info, BTRFS_ROOT_TREE_OBJECTID);
7eccb903	458
2c90e5d6 CM	459	fs_info->sb_buffer = read_tree_block(tree_root,
	460	BTRFS_SUPER_INFO_OFFSET /
	461	sb->s_blocksize);
d98237b3	462
0f7d52f4	463	if (!fs_info->sb_buffer)
39279cc3	464	goto fail_iput;
d98237b3	465	disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
4b52dff6 CM	466	fs_info->disk_super = disk_super;
4b52dff6 CM	467	memcpy(&fs_info->super_copy, disk_super, sizeof(fs_info->super_copy));
39279cc3	468
0f7d52f4	469	if (!btrfs_super_root(disk_super))
39279cc3	470	goto fail_sb_buffer;
0f7d52f4	471
8352d8a4 CM	472	i_size_write(fs_info->btree_inode,
	473	btrfs_super_total_blocks(disk_super) <<
	474	fs_info->btree_inode->i_blkbits);
	475
39279cc3 CM	476
	477	if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
	478	sizeof(disk_super->magic))) {
	479	printk("btrfs: valid FS not found on %s\n", sb->s_id);
	480	goto fail_sb_buffer;
	481	}
e20d96d6 CM	482	tree_root->node = read_tree_block(tree_root,
e20d96d6 CM	483	btrfs_super_root(disk_super));
39279cc3 CM	484	if (!tree_root->node)
39279cc3 CM	485	goto fail_sb_buffer;
3768f368	486
2c90e5d6 CM	487	mutex_lock(&fs_info->fs_mutex);
2c90e5d6 CM	488	ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
e20d96d6	489	BTRFS_EXTENT_TREE_OBJECTID, extent_root);
39279cc3 CM	490	if (ret) {
	491	mutex_unlock(&fs_info->fs_mutex);
	492	goto fail_tree_root;
	493	}
3768f368	494
9078a3e1 CM	495	btrfs_read_block_groups(extent_root);
9078a3e1 CM	496
0f7d52f4	497	fs_info->generation = btrfs_super_generation(disk_super) + 1;
5eda7b5e CM	498	ret = btrfs_find_dead_roots(tree_root);
	499	if (ret)
	500	goto fail_tree_root;
5be6f7f1	501	mutex_unlock(&fs_info->fs_mutex);
0f7d52f4	502	return tree_root;
39279cc3 CM	503
	504	fail_tree_root:
	505	btrfs_block_release(tree_root, tree_root->node);
	506	fail_sb_buffer:
	507	btrfs_block_release(tree_root, fs_info->sb_buffer);
	508	fail_iput:
	509	iput(fs_info->btree_inode);
	510	fail:
	511	kfree(extent_root);
	512	kfree(tree_root);
	513	kfree(fs_info);
	514	return ERR_PTR(err);
eb60ceac CM	515	}
eb60ceac CM	516
e089f05c	517	int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
79154b1b	518	*root)
eb60ceac	519	{
e66f709b	520	int ret;
d5719762	521	struct buffer_head *bh = root->fs_info->sb_buffer;
2c90e5d6	522
d5719762	523	lock_buffer(bh);
2c90e5d6	524	WARN_ON(atomic_read(&bh->b_count) < 1);
d5719762	525	clear_buffer_dirty(bh);
87cbda5c	526	csum_tree_block(root, bh, 0);
d5719762 CM	527	bh->b_end_io = end_buffer_write_sync;
d5719762 CM	528	get_bh(bh);
e66f709b CM	529	if (root->fs_info->do_barriers)
	530	ret = submit_bh(WRITE_BARRIER, bh);
	531	else
	532	ret = submit_bh(WRITE, bh);
	533	if (ret == -EOPNOTSUPP) {
8c2383c3 CM	534	get_bh(bh);
8c2383c3 CM	535	lock_buffer(bh);
e66f709b CM	536	set_buffer_uptodate(bh);
	537	root->fs_info->do_barriers = 0;
	538	ret = submit_bh(WRITE, bh);
	539	}
d5719762 CM	540	wait_on_buffer(bh);
	541	if (!buffer_uptodate(bh)) {
	542	WARN_ON(1);
	543	return -EIO;
cfaa7295 CM	544	}
	545	return 0;
	546	}
	547
5eda7b5e	548	int btrfs_free_fs_root(struct btrfs_fs_info fs_info, struct btrfs_root root)
2619ba1f CM	549	{
	550	radix_tree_delete(&fs_info->fs_roots_radix,
	551	(unsigned long)root->root_key.objectid);
	552	if (root->inode)
	553	iput(root->inode);
	554	if (root->node)
	555	brelse(root->node);
	556	if (root->commit_root)
	557	brelse(root->commit_root);
	558	kfree(root);
	559	return 0;
	560	}
	561
35b7e476	562	static int del_fs_roots(struct btrfs_fs_info *fs_info)
0f7d52f4 CM	563	{
	564	int ret;
	565	struct btrfs_root *gang[8];
	566	int i;
	567
	568	while(1) {
	569	ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
	570	(void **)gang, 0,
	571	ARRAY_SIZE(gang));
	572	if (!ret)
	573	break;
2619ba1f	574	for (i = 0; i < ret; i++)
5eda7b5e	575	btrfs_free_fs_root(fs_info, gang[i]);
0f7d52f4 CM	576	}
	577	return 0;
	578	}
b4100d64	579
e20d96d6	580	int close_ctree(struct btrfs_root *root)
cfaa7295	581	{
3768f368	582	int ret;
e089f05c	583	struct btrfs_trans_handle *trans;
0f7d52f4	584	struct btrfs_fs_info *fs_info = root->fs_info;
e089f05c	585
facda1e7	586	fs_info->closing = 1;
08607c1b	587	btrfs_transaction_flush_work(root);
0f7d52f4	588	mutex_lock(&fs_info->fs_mutex);
79154b1b	589	trans = btrfs_start_transaction(root, 1);
54aa1f4d	590	ret = btrfs_commit_transaction(trans, root);
79154b1b CM	591	/* run commit again to drop the original snapshot */
	592	trans = btrfs_start_transaction(root, 1);
	593	btrfs_commit_transaction(trans, root);
	594	ret = btrfs_write_and_wait_transaction(NULL, root);
3768f368	595	BUG_ON(ret);
79154b1b	596	write_ctree_super(NULL, root);
0f7d52f4 CM	597	mutex_unlock(&fs_info->fs_mutex);
	598
	599	if (fs_info->extent_root->node)
	600	btrfs_block_release(fs_info->extent_root,
	601	fs_info->extent_root->node);
0f7d52f4 CM	602	if (fs_info->tree_root->node)
	603	btrfs_block_release(fs_info->tree_root,
	604	fs_info->tree_root->node);
	605	btrfs_block_release(root, fs_info->sb_buffer);
0f7d52f4 CM	606	truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
0f7d52f4 CM	607	iput(fs_info->btree_inode);
7eccb903	608
9078a3e1	609	btrfs_free_block_groups(root->fs_info);
0f7d52f4 CM	610	del_fs_roots(fs_info);
0f7d52f4 CM	611	kfree(fs_info->extent_root);
0f7d52f4	612	kfree(fs_info->tree_root);
eb60ceac CM	613	return 0;
	614	}
	615
ccd467d6 CM	616	void btrfs_mark_buffer_dirty(struct buffer_head *bh)
	617	{
	618	struct btrfs_root *root = BTRFS_I(bh->b_page->mapping->host)->root;
	619	u64 transid = btrfs_header_generation(btrfs_buffer_header(bh));
	620	WARN_ON(!atomic_read(&bh->b_count));
	621	if (transid != root->fs_info->generation) {
	622	printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
	623	(unsigned long long)bh->b_blocknr,
	624	transid, root->fs_info->generation);
	625	WARN_ON(1);
	626	}
	627	mark_buffer_dirty(bh);
	628	}
	629
e20d96d6	630	void btrfs_block_release(struct btrfs_root root, struct buffer_head buf)
eb60ceac	631	{
7cfcc17e	632	brelse(buf);
eb60ceac CM	633	}
eb60ceac CM	634
35b7e476 CM	635	void btrfs_btree_balance_dirty(struct btrfs_root *root)
	636	{
	637	balance_dirty_pages_ratelimited(root->fs_info->btree_inode->i_mapping);
	638	}