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

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"


static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
{
	struct btrfs_node *node = btrfs_buffer_node(buf);
	if (buf->b_blocknr != btrfs_header_blocknr(&node->header)) {
		BUG();
	}
	if (root->node && btrfs_header_parentid(&node->header) !=
	    btrfs_header_parentid(btrfs_buffer_header(root->node))) {
		BUG();
	}
	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->b_blocknr == 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;
}

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;
	u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
	page = grab_cache_page(mapping, index);
	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)) {
			bh->b_bdev = root->fs_info->sb->s_bdev;
			bh->b_blocknr = first_block;
			set_buffer_mapped(bh);
		}
		if (bh->b_blocknr == blocknr) {
			ret = bh;
			get_bh(bh);
			goto out_unlock;
		}
		bh = bh->b_this_page;
		first_block++;
	} while (bh != head);
out_unlock:
	unlock_page(page);
	page_cache_release(page);
	return ret;
}

static sector_t max_block(struct block_device *bdev)
{
	sector_t retval = ~((sector_t)0);
	loff_t sz = i_size_read(bdev->bd_inode);

	if (sz) {
		unsigned int size = block_size(bdev);
		unsigned int sizebits = blksize_bits(size);
		retval = (sz >> sizebits);
	}
	return retval;
}

static int btree_get_block(struct inode *inode, sector_t iblock,
			   struct buffer_head *bh, int create)
{
	if (iblock >= max_block(inode->i_sb->s_bdev)) {
		if (create)
			return -EIO;

		/*
		 * for reads, we're just trying to fill a partial page.
		 * return a hole, they will have to call get_block again
		 * before they can fill it, and they will get -EIO at that
		 * time
		 */
		return 0;
	}
	bh->b_bdev = inode->i_sb->s_bdev;
	bh->b_blocknr = iblock;
	set_buffer_mapped(bh);
	return 0;
}

int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
		    char *result)
{
	struct scatterlist sg;
	struct crypto_hash *tfm = root->fs_info->hash_tfm;
	struct hash_desc desc;
	int ret;

	desc.tfm = tfm;
	desc.flags = 0;
	sg_init_one(&sg, data, len);
	spin_lock(&root->fs_info->hash_lock);
	ret = crypto_hash_digest(&desc, &sg, len, result);
	spin_unlock(&root->fs_info->hash_lock);
	if (ret) {
		printk("sha256 digest failed\n");
	}
	return ret;
}
static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
			   int verify)
{
	char result[BTRFS_CSUM_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_CSUM_SIZE)) {
			printk("checksum verify failed on %lu\n",
			       bh->b_blocknr);
			return 1;
		}
	} else {
		node = btrfs_buffer_node(bh);
		memcpy(&node->header.csum, result, BTRFS_CSUM_SIZE);
	}
	return 0;
}

static int btree_writepage(struct page *page, struct writeback_control *wbc)
{
	struct buffer_head *bh;
	struct btrfs_root *root = btrfs_sb(page->mapping->host->i_sb);
	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,
};

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;
	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;
		csum_tree_block(root, bh, 1);
	} else {
		unlock_buffer(bh);
	}
	if (check_tree_block(root, bh))
		BUG();
	return bh;
fail:
	brelse(bh);
	return NULL;

}

int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
		     struct buffer_head *buf)
{
	mark_buffer_dirty(buf);
	return 0;
}

int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
		     struct buffer_head *buf)
{
	clear_buffer_dirty(buf);
	return 0;
}

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

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

	__setup_root(super, 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 *open_ctree(struct super_block *sb,
			      struct buffer_head *sb_buffer,
			      struct btrfs_super_block *disk_super)
{
	struct btrfs_root *root = kmalloc(sizeof(struct btrfs_root),
					  GFP_NOFS);
	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_root *inode_root = kmalloc(sizeof(struct btrfs_root),
						GFP_NOFS);
	struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
						GFP_NOFS);
	int ret;

	if (!btrfs_super_root(disk_super)) {
		return NULL;
	}
	init_bit_radix(&fs_info->pinned_radix);
	init_bit_radix(&fs_info->pending_del_radix);
	sb_set_blocksize(sb, sb_buffer->b_size);
	fs_info->running_transaction = NULL;
	fs_info->fs_root = root;
	fs_info->tree_root = tree_root;
	fs_info->extent_root = extent_root;
	fs_info->inode_root = inode_root;
	fs_info->last_inode_alloc = 0;
	fs_info->last_inode_alloc_dirid = 0;
	fs_info->disk_super = disk_super;
	fs_info->sb = sb;
	fs_info->btree_inode = new_inode(sb);
	fs_info->btree_inode->i_ino = 1;
	fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
	fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
	mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
	fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
	spin_lock_init(&fs_info->hash_lock);

	if (!fs_info->hash_tfm || IS_ERR(fs_info->hash_tfm)) {
		printk("failed to allocate sha256 hash\n");
		return NULL;
	}

	mutex_init(&fs_info->trans_mutex);
	mutex_init(&fs_info->fs_mutex);
	memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert));
	memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert));

	__setup_root(disk_super, tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID);

	fs_info->sb_buffer = read_tree_block(tree_root, sb_buffer->b_blocknr);

	if (!fs_info->sb_buffer) {
printk("failed2\n");
		return NULL;
	}
	brelse(sb_buffer);
	sb_buffer = NULL;
	disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
	fs_info->disk_super = disk_super;

	tree_root->node = read_tree_block(tree_root,
					  btrfs_super_root(disk_super));
	BUG_ON(!tree_root->node);

	ret = find_and_setup_root(disk_super, tree_root, fs_info,
				  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
	BUG_ON(ret);

	ret = find_and_setup_root(disk_super, tree_root, fs_info,
				  BTRFS_INODE_MAP_OBJECTID, inode_root);
	BUG_ON(ret);

	ret = find_and_setup_root(disk_super, tree_root, fs_info,
				  BTRFS_FS_TREE_OBJECTID, root);
	BUG_ON(ret);
	root->commit_root = root->node;
	get_bh(root->node);
	root->ref_cows = 1;
	root->fs_info->generation = root->root_key.offset + 1;
	return root;
}

int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
		      *root)
{
	struct buffer_head *bh = root->fs_info->sb_buffer;
	btrfs_set_super_root(root->fs_info->disk_super,
			     root->fs_info->tree_root->node->b_blocknr);
	lock_buffer(bh);
	clear_buffer_dirty(bh);
	csum_tree_block(root, bh, 0);
	bh->b_end_io = end_buffer_write_sync;
	get_bh(bh);
	submit_bh(WRITE, bh);
	wait_on_buffer(bh);
	if (!buffer_uptodate(bh)) {
		WARN_ON(1);
		return -EIO;
	}
	return 0;
}

int close_ctree(struct btrfs_root *root)
{
	int ret;
	struct btrfs_trans_handle *trans;

	trans = btrfs_start_transaction(root, 1);
	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);

	if (root->node)
		btrfs_block_release(root, root->node);
	if (root->fs_info->extent_root->node)
		btrfs_block_release(root->fs_info->extent_root,
				    root->fs_info->extent_root->node);
	if (root->fs_info->inode_root->node)
		btrfs_block_release(root->fs_info->inode_root,
				    root->fs_info->inode_root->node);
	if (root->fs_info->tree_root->node)
		btrfs_block_release(root->fs_info->tree_root,
				    root->fs_info->tree_root->node);
	btrfs_block_release(root, root->commit_root);
	btrfs_block_release(root, root->fs_info->sb_buffer);
	crypto_free_hash(root->fs_info->hash_tfm);
	truncate_inode_pages(root->fs_info->btree_inode->i_mapping, 0);
	iput(root->fs_info->btree_inode);
	kfree(root->fs_info->extent_root);
	kfree(root->fs_info->inode_root);
	kfree(root->fs_info->tree_root);
	kfree(root->fs_info);
	kfree(root);
	return 0;
}

void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf)
{
	brelse(buf);
}
Commit	Line	Data
	1	#include <linux/module.h>
	2	#include <linux/fs.h>
	3	#include <linux/blkdev.h>
	4	#include <linux/crypto.h>
	5	#include <linux/scatterlist.h>
	6	#include "ctree.h"
	7	#include "disk-io.h"
	8	#include "transaction.h"
	9
	10
	11	static int check_tree_block(struct btrfs_root root, struct buffer_head buf)
	12	{
	13	struct btrfs_node *node = btrfs_buffer_node(buf);
	14	if (buf->b_blocknr != btrfs_header_blocknr(&node->header)) {
	15	BUG();
	16	}
	17	if (root->node && btrfs_header_parentid(&node->header) !=
	18	btrfs_header_parentid(btrfs_buffer_header(root->node))) {
	19	BUG();
	20	}
	21	return 0;
	22	}
	23
	24	struct buffer_head btrfs_find_tree_block(struct btrfs_root root, u64 blocknr)
	25	{
	26	struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
	27	int blockbits = root->fs_info->sb->s_blocksize_bits;
	28	unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
	29	struct page *page;
	30	struct buffer_head *bh;
	31	struct buffer_head *head;
	32	struct buffer_head *ret = NULL;
	33
	34	page = find_lock_page(mapping, index);
	35	if (!page)
	36	return NULL;
	37
	38	if (!page_has_buffers(page))
	39	goto out_unlock;
	40
	41	head = page_buffers(page);
	42	bh = head;
	43	do {
	44	if (buffer_mapped(bh) && bh->b_blocknr == blocknr) {
	45	ret = bh;
	46	get_bh(bh);
	47	goto out_unlock;
	48	}
	49	bh = bh->b_this_page;
	50	} while (bh != head);
	51	out_unlock:
	52	unlock_page(page);
	53	page_cache_release(page);
	54	return ret;
	55	}
	56
	57	struct buffer_head btrfs_find_create_tree_block(struct btrfs_root root,
	58	u64 blocknr)
	59	{
	60	struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
	61	int blockbits = root->fs_info->sb->s_blocksize_bits;
	62	unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
	63	struct page *page;
	64	struct buffer_head *bh;
	65	struct buffer_head *head;
	66	struct buffer_head *ret = NULL;
	67	u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
	68	page = grab_cache_page(mapping, index);
	69	if (!page)
	70	return NULL;
	71
	72	if (!page_has_buffers(page))
	73	create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0);
	74	head = page_buffers(page);
	75	bh = head;
	76	do {
	77	if (!buffer_mapped(bh)) {
	78	bh->b_bdev = root->fs_info->sb->s_bdev;
	79	bh->b_blocknr = first_block;
	80	set_buffer_mapped(bh);
	81	}
	82	if (bh->b_blocknr == blocknr) {
	83	ret = bh;
	84	get_bh(bh);
	85	goto out_unlock;
	86	}
	87	bh = bh->b_this_page;
	88	first_block++;
	89	} while (bh != head);
	90	out_unlock:
	91	unlock_page(page);
	92	page_cache_release(page);
	93	return ret;
	94	}
	95
	96	static sector_t max_block(struct block_device *bdev)
	97	{
	98	sector_t retval = ~((sector_t)0);
	99	loff_t sz = i_size_read(bdev->bd_inode);
	100
	101	if (sz) {
	102	unsigned int size = block_size(bdev);
	103	unsigned int sizebits = blksize_bits(size);
	104	retval = (sz >> sizebits);
	105	}
	106	return retval;
	107	}
	108
	109	static int btree_get_block(struct inode *inode, sector_t iblock,
	110	struct buffer_head *bh, int create)
	111	{
	112	if (iblock >= max_block(inode->i_sb->s_bdev)) {
	113	if (create)
	114	return -EIO;
	115
	116	/*
	117	* for reads, we're just trying to fill a partial page.
	118	* return a hole, they will have to call get_block again
	119	* before they can fill it, and they will get -EIO at that
	120	* time
	121	*/
	122	return 0;
	123	}
	124	bh->b_bdev = inode->i_sb->s_bdev;
	125	bh->b_blocknr = iblock;
	126	set_buffer_mapped(bh);
	127	return 0;
	128	}
	129
	130	int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
	131	char *result)
	132	{
	133	struct scatterlist sg;
	134	struct crypto_hash *tfm = root->fs_info->hash_tfm;
	135	struct hash_desc desc;
	136	int ret;
	137
	138	desc.tfm = tfm;
	139	desc.flags = 0;
	140	sg_init_one(&sg, data, len);
	141	spin_lock(&root->fs_info->hash_lock);
	142	ret = crypto_hash_digest(&desc, &sg, len, result);
	143	spin_unlock(&root->fs_info->hash_lock);
	144	if (ret) {
	145	printk("sha256 digest failed\n");
	146	}
	147	return ret;
	148	}
	149	static int csum_tree_block(struct btrfs_root root, struct buffer_head bh,
	150	int verify)
	151	{
	152	char result[BTRFS_CSUM_SIZE];
	153	int ret;
	154	struct btrfs_node *node;
	155
	156	ret = btrfs_csum_data(root, bh->b_data + BTRFS_CSUM_SIZE,
	157	bh->b_size - BTRFS_CSUM_SIZE, result);
	158	if (ret)
	159	return ret;
	160	if (verify) {
	161	if (memcmp(bh->b_data, result, BTRFS_CSUM_SIZE)) {
	162	printk("checksum verify failed on %lu\n",
	163	bh->b_blocknr);
	164	return 1;
	165	}
	166	} else {
	167	node = btrfs_buffer_node(bh);
	168	memcpy(&node->header.csum, result, BTRFS_CSUM_SIZE);
	169	}
	170	return 0;
	171	}
	172
	173	static int btree_writepage(struct page page, struct writeback_control wbc)
	174	{
	175	struct buffer_head *bh;
	176	struct btrfs_root *root = btrfs_sb(page->mapping->host->i_sb);
	177	struct buffer_head *head;
	178
	179	if (!page_has_buffers(page)) {
	180	create_empty_buffers(page, root->fs_info->sb->s_blocksize,
	181	(1 << BH_Dirty)\|(1 << BH_Uptodate));
	182	}
	183	head = page_buffers(page);
	184	bh = head;
	185	do {
	186	if (buffer_dirty(bh))
	187	csum_tree_block(root, bh, 0);
	188	bh = bh->b_this_page;
	189	} while (bh != head);
	190	return block_write_full_page(page, btree_get_block, wbc);
	191	}
	192
	193	static int btree_readpage(struct file * file, struct page * page)
	194	{
	195	return block_read_full_page(page, btree_get_block);
	196	}
	197
	198	static struct address_space_operations btree_aops = {
	199	.readpage = btree_readpage,
	200	.writepage = btree_writepage,
	201	.sync_page = block_sync_page,
	202	};
	203
	204	struct buffer_head read_tree_block(struct btrfs_root root, u64 blocknr)
	205	{
	206	struct buffer_head *bh = NULL;
	207
	208	bh = btrfs_find_create_tree_block(root, blocknr);
	209	if (!bh)
	210	return bh;
	211	lock_buffer(bh);
	212	if (!buffer_uptodate(bh)) {
	213	get_bh(bh);
	214	bh->b_end_io = end_buffer_read_sync;
	215	submit_bh(READ, bh);
	216	wait_on_buffer(bh);
	217	if (!buffer_uptodate(bh))
	218	goto fail;
	219	csum_tree_block(root, bh, 1);
	220	} else {
	221	unlock_buffer(bh);
	222	}
	223	if (check_tree_block(root, bh))
	224	BUG();
	225	return bh;
	226	fail:
	227	brelse(bh);
	228	return NULL;
	229
	230	}
	231
	232	int dirty_tree_block(struct btrfs_trans_handle trans, struct btrfs_root root,
	233	struct buffer_head *buf)
	234	{
	235	mark_buffer_dirty(buf);
	236	return 0;
	237	}
	238
	239	int clean_tree_block(struct btrfs_trans_handle trans, struct btrfs_root root,
	240	struct buffer_head *buf)
	241	{
	242	clear_buffer_dirty(buf);
	243	return 0;
	244	}
	245
	246	static int __setup_root(struct btrfs_super_block *super,
	247	struct btrfs_root *root,
	248	struct btrfs_fs_info *fs_info,
	249	u64 objectid)
	250	{
	251	root->node = NULL;
	252	root->commit_root = NULL;
	253	root->blocksize = btrfs_super_blocksize(super);
	254	root->ref_cows = 0;
	255	root->fs_info = fs_info;
	256	memset(&root->root_key, 0, sizeof(root->root_key));
	257	memset(&root->root_item, 0, sizeof(root->root_item));
	258	return 0;
	259	}
	260
	261	static int find_and_setup_root(struct btrfs_super_block *super,
	262	struct btrfs_root *tree_root,
	263	struct btrfs_fs_info *fs_info,
	264	u64 objectid,
	265	struct btrfs_root *root)
	266	{
	267	int ret;
	268
	269	__setup_root(super, root, fs_info, objectid);
	270	ret = btrfs_find_last_root(tree_root, objectid,
	271	&root->root_item, &root->root_key);
	272	BUG_ON(ret);
	273
	274	root->node = read_tree_block(root,
	275	btrfs_root_blocknr(&root->root_item));
	276	BUG_ON(!root->node);
	277	return 0;
	278	}
	279
	280	struct btrfs_root open_ctree(struct super_block sb,
	281	struct buffer_head *sb_buffer,
	282	struct btrfs_super_block *disk_super)
	283	{
	284	struct btrfs_root *root = kmalloc(sizeof(struct btrfs_root),
	285	GFP_NOFS);
	286	struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
	287	GFP_NOFS);
	288	struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
	289	GFP_NOFS);
	290	struct btrfs_root *inode_root = kmalloc(sizeof(struct btrfs_root),
	291	GFP_NOFS);
	292	struct btrfs_fs_info fs_info = kmalloc(sizeof(fs_info),
	293	GFP_NOFS);
	294	int ret;
	295
	296	if (!btrfs_super_root(disk_super)) {
	297	return NULL;
	298	}
	299	init_bit_radix(&fs_info->pinned_radix);
	300	init_bit_radix(&fs_info->pending_del_radix);
	301	sb_set_blocksize(sb, sb_buffer->b_size);
	302	fs_info->running_transaction = NULL;
	303	fs_info->fs_root = root;
	304	fs_info->tree_root = tree_root;
	305	fs_info->extent_root = extent_root;
	306	fs_info->inode_root = inode_root;
	307	fs_info->last_inode_alloc = 0;
	308	fs_info->last_inode_alloc_dirid = 0;
	309	fs_info->disk_super = disk_super;
	310	fs_info->sb = sb;
	311	fs_info->btree_inode = new_inode(sb);
	312	fs_info->btree_inode->i_ino = 1;
	313	fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
	314	fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
	315	mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
	316	fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
	317	spin_lock_init(&fs_info->hash_lock);
	318
	319	if (!fs_info->hash_tfm \|\| IS_ERR(fs_info->hash_tfm)) {
	320	printk("failed to allocate sha256 hash\n");
	321	return NULL;
	322	}
	323
	324	mutex_init(&fs_info->trans_mutex);
	325	mutex_init(&fs_info->fs_mutex);
	326	memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert));
	327	memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert));
	328
	329	__setup_root(disk_super, tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
	330
	331	fs_info->sb_buffer = read_tree_block(tree_root, sb_buffer->b_blocknr);
	332
	333	if (!fs_info->sb_buffer) {
	334	printk("failed2\n");
	335	return NULL;
	336	}
	337	brelse(sb_buffer);
	338	sb_buffer = NULL;
	339	disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
	340	fs_info->disk_super = disk_super;
	341
	342	tree_root->node = read_tree_block(tree_root,
	343	btrfs_super_root(disk_super));
	344	BUG_ON(!tree_root->node);
	345
	346	ret = find_and_setup_root(disk_super, tree_root, fs_info,
	347	BTRFS_EXTENT_TREE_OBJECTID, extent_root);
	348	BUG_ON(ret);
	349
	350	ret = find_and_setup_root(disk_super, tree_root, fs_info,
	351	BTRFS_INODE_MAP_OBJECTID, inode_root);
	352	BUG_ON(ret);
	353
	354	ret = find_and_setup_root(disk_super, tree_root, fs_info,
	355	BTRFS_FS_TREE_OBJECTID, root);
	356	BUG_ON(ret);
	357	root->commit_root = root->node;
	358	get_bh(root->node);
	359	root->ref_cows = 1;
	360	root->fs_info->generation = root->root_key.offset + 1;
	361	return root;
	362	}
	363
	364	int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
	365	*root)
	366	{
	367	struct buffer_head *bh = root->fs_info->sb_buffer;
	368	btrfs_set_super_root(root->fs_info->disk_super,
	369	root->fs_info->tree_root->node->b_blocknr);
	370	lock_buffer(bh);
	371	clear_buffer_dirty(bh);
	372	csum_tree_block(root, bh, 0);
	373	bh->b_end_io = end_buffer_write_sync;
	374	get_bh(bh);
	375	submit_bh(WRITE, bh);
	376	wait_on_buffer(bh);
	377	if (!buffer_uptodate(bh)) {
	378	WARN_ON(1);
	379	return -EIO;
	380	}
	381	return 0;
	382	}
	383
	384	int close_ctree(struct btrfs_root *root)
	385	{
	386	int ret;
	387	struct btrfs_trans_handle *trans;
	388
	389	trans = btrfs_start_transaction(root, 1);
	390	btrfs_commit_transaction(trans, root);
	391	/* run commit again to drop the original snapshot */
	392	trans = btrfs_start_transaction(root, 1);
	393	btrfs_commit_transaction(trans, root);
	394	ret = btrfs_write_and_wait_transaction(NULL, root);
	395	BUG_ON(ret);
	396	write_ctree_super(NULL, root);
	397
	398	if (root->node)
	399	btrfs_block_release(root, root->node);
	400	if (root->fs_info->extent_root->node)
	401	btrfs_block_release(root->fs_info->extent_root,
	402	root->fs_info->extent_root->node);
	403	if (root->fs_info->inode_root->node)
	404	btrfs_block_release(root->fs_info->inode_root,
	405	root->fs_info->inode_root->node);
	406	if (root->fs_info->tree_root->node)
	407	btrfs_block_release(root->fs_info->tree_root,
	408	root->fs_info->tree_root->node);
	409	btrfs_block_release(root, root->commit_root);
	410	btrfs_block_release(root, root->fs_info->sb_buffer);
	411	crypto_free_hash(root->fs_info->hash_tfm);
	412	truncate_inode_pages(root->fs_info->btree_inode->i_mapping, 0);
	413	iput(root->fs_info->btree_inode);
	414	kfree(root->fs_info->extent_root);
	415	kfree(root->fs_info->inode_root);
	416	kfree(root->fs_info->tree_root);
	417	kfree(root->fs_info);
	418	kfree(root);
	419	return 0;
	420	}
	421
	422	void btrfs_block_release(struct btrfs_root root, struct buffer_head buf)
	423	{
	424	brelse(buf);
	425	}
	426