[deliverable/linux.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;
}

static int csum_tree_block(struct btrfs_root * root, struct buffer_head *bh,
			    int verify)
{
	struct btrfs_node *node = btrfs_buffer_node(bh);
	struct scatterlist sg;
	struct crypto_hash *tfm = root->fs_info->hash_tfm;
	struct hash_desc desc;
	int ret;
	char result[32];

	desc.tfm = tfm;
	desc.flags = 0;
	sg_init_one(&sg, bh->b_data + 32, bh->b_size - 32);
	spin_lock(&root->fs_info->hash_lock);
	ret = crypto_hash_digest(&desc, &sg, bh->b_size - 32, result);
	spin_unlock(&root->fs_info->hash_lock);
	if (ret) {
		printk("sha256 digest failed\n");
	}
	if (verify) {
		if (memcmp(node->header.csum, result, sizeof(result)))
			printk("csum verify failed on %Lu\n", bh->b_blocknr);
		return -EINVAL;
	} else
		memcpy(node->header.csum, result, sizeof(node->header.csum));
	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
e20d96d6 CM	1	#include <linux/module.h>
e20d96d6 CM	2	#include <linux/fs.h>
d98237b3	3	#include <linux/blkdev.h>
87cbda5c CM	4	#include <linux/crypto.h>
87cbda5c CM	5	#include <linux/scatterlist.h>
eb60ceac CM	6	#include "ctree.h"
eb60ceac CM	7	#include "disk-io.h"
e089f05c	8	#include "transaction.h"
eb60ceac	9
d98237b3	10
e20d96d6	11	static int check_tree_block(struct btrfs_root root, struct buffer_head buf)
eb60ceac	12	{
e20d96d6	13	struct btrfs_node *node = btrfs_buffer_node(buf);
d98237b3	14	if (buf->b_blocknr != btrfs_header_blocknr(&node->header)) {
9a8dd150	15	BUG();
d98237b3	16	}
e20d96d6	17	if (root->node && btrfs_header_parentid(&node->header) !=
df2ce34c	18	btrfs_header_parentid(btrfs_buffer_header(root->node))) {
7f5c1516	19	BUG();
df2ce34c	20	}
9a8dd150	21	return 0;
eb60ceac CM	22	}
eb60ceac CM	23
d98237b3 CM	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
d98237b3 CM	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
87cbda5c CM	130	static int csum_tree_block(struct btrfs_root * root, struct buffer_head *bh,
	131	int verify)
	132	{
	133	struct btrfs_node *node = btrfs_buffer_node(bh);
	134	struct scatterlist sg;
	135	struct crypto_hash *tfm = root->fs_info->hash_tfm;
	136	struct hash_desc desc;
	137	int ret;
	138	char result[32];
	139
	140	desc.tfm = tfm;
	141	desc.flags = 0;
	142	sg_init_one(&sg, bh->b_data + 32, bh->b_size - 32);
	143	spin_lock(&root->fs_info->hash_lock);
	144	ret = crypto_hash_digest(&desc, &sg, bh->b_size - 32, result);
	145	spin_unlock(&root->fs_info->hash_lock);
	146	if (ret) {
	147	printk("sha256 digest failed\n");
	148	}
	149	if (verify) {
	150	if (memcmp(node->header.csum, result, sizeof(result)))
	151	printk("csum verify failed on %Lu\n", bh->b_blocknr);
	152	return -EINVAL;
	153	} else
	154	memcpy(node->header.csum, result, sizeof(node->header.csum));
	155	return 0;
	156	}
	157
d98237b3	158	static int btree_writepage(struct page page, struct writeback_control wbc)
ed2ff2cb	159	{
87cbda5c CM	160	struct buffer_head *bh;
	161	struct btrfs_root *root = btrfs_sb(page->mapping->host->i_sb);
	162	struct buffer_head *head;
	163
	164	if (!page_has_buffers(page)) {
	165	create_empty_buffers(page, root->fs_info->sb->s_blocksize,
	166	(1 << BH_Dirty)\|(1 << BH_Uptodate));
	167	}
	168	head = page_buffers(page);
	169	bh = head;
	170	do {
	171	if (buffer_dirty(bh))
	172	csum_tree_block(root, bh, 0);
	173	bh = bh->b_this_page;
	174	} while (bh != head);
d98237b3	175	return block_write_full_page(page, btree_get_block, wbc);
ed2ff2cb CM	176	}
ed2ff2cb CM	177
d98237b3	178	static int btree_readpage(struct file * file, struct page * page)
eb60ceac	179	{
d98237b3	180	return block_read_full_page(page, btree_get_block);
eb60ceac CM	181	}
eb60ceac CM	182
d98237b3 CM	183	static struct address_space_operations btree_aops = {
	184	.readpage = btree_readpage,
	185	.writepage = btree_writepage,
	186	.sync_page = block_sync_page,
	187	};
	188
e20d96d6	189	struct buffer_head read_tree_block(struct btrfs_root root, u64 blocknr)
eb60ceac	190	{
d98237b3	191	struct buffer_head *bh = NULL;
eb60ceac	192
d98237b3 CM	193	bh = btrfs_find_create_tree_block(root, blocknr);
	194	if (!bh)
	195	return bh;
	196	lock_buffer(bh);
	197	if (!buffer_uptodate(bh)) {
	198	get_bh(bh);
	199	bh->b_end_io = end_buffer_read_sync;
	200	submit_bh(READ, bh);
	201	wait_on_buffer(bh);
	202	if (!buffer_uptodate(bh))
	203	goto fail;
87cbda5c	204	csum_tree_block(root, bh, 1);
d98237b3 CM	205	} else {
	206	unlock_buffer(bh);
	207	}
	208	if (check_tree_block(root, bh))
cfaa7295	209	BUG();
d98237b3 CM	210	return bh;
	211	fail:
	212	brelse(bh);
	213	return NULL;
	214
eb60ceac CM	215	}
eb60ceac CM	216
e089f05c	217	int dirty_tree_block(struct btrfs_trans_handle trans, struct btrfs_root root,
e20d96d6	218	struct buffer_head *buf)
ed2ff2cb	219	{
e20d96d6	220	mark_buffer_dirty(buf);
ed2ff2cb CM	221	return 0;
	222	}
	223
e089f05c	224	int clean_tree_block(struct btrfs_trans_handle trans, struct btrfs_root root,
e20d96d6	225	struct buffer_head *buf)
ed2ff2cb	226	{
e20d96d6	227	clear_buffer_dirty(buf);
ed2ff2cb CM	228	return 0;
	229	}
	230
123abc88	231	static int __setup_root(struct btrfs_super_block *super,
9f5fae2f CM	232	struct btrfs_root *root,
9f5fae2f CM	233	struct btrfs_fs_info *fs_info,
e20d96d6	234	u64 objectid)
d97e63b6	235	{
cfaa7295	236	root->node = NULL;
a28ec197	237	root->commit_root = NULL;
123abc88 CM	238	root->blocksize = btrfs_super_blocksize(super);
123abc88 CM	239	root->ref_cows = 0;
9f5fae2f	240	root->fs_info = fs_info;
3768f368 CM	241	memset(&root->root_key, 0, sizeof(root->root_key));
	242	memset(&root->root_item, 0, sizeof(root->root_item));
	243	return 0;
	244	}
	245
123abc88	246	static int find_and_setup_root(struct btrfs_super_block *super,
9f5fae2f CM	247	struct btrfs_root *tree_root,
	248	struct btrfs_fs_info *fs_info,
	249	u64 objectid,
e20d96d6	250	struct btrfs_root *root)
3768f368 CM	251	{
	252	int ret;
	253
e20d96d6	254	__setup_root(super, root, fs_info, objectid);
3768f368 CM	255	ret = btrfs_find_last_root(tree_root, objectid,
	256	&root->root_item, &root->root_key);
	257	BUG_ON(ret);
	258
	259	root->node = read_tree_block(root,
	260	btrfs_root_blocknr(&root->root_item));
3768f368	261	BUG_ON(!root->node);
d97e63b6 CM	262	return 0;
	263	}
	264
e20d96d6 CM	265	struct btrfs_root open_ctree(struct super_block sb,
	266	struct buffer_head *sb_buffer,
	267	struct btrfs_super_block *disk_super)
2e635a27	268	{
e20d96d6 CM	269	struct btrfs_root *root = kmalloc(sizeof(struct btrfs_root),
	270	GFP_NOFS);
	271	struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
	272	GFP_NOFS);
	273	struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
	274	GFP_NOFS);
	275	struct btrfs_root *inode_root = kmalloc(sizeof(struct btrfs_root),
	276	GFP_NOFS);
	277	struct btrfs_fs_info fs_info = kmalloc(sizeof(fs_info),
	278	GFP_NOFS);
eb60ceac CM	279	int ret;
eb60ceac CM	280
87cbda5c	281	if (!btrfs_super_root(disk_super)) {
e20d96d6	282	return NULL;
87cbda5c	283	}
8ef97622 CM	284	init_bit_radix(&fs_info->pinned_radix);
8ef97622 CM	285	init_bit_radix(&fs_info->pending_del_radix);
d98237b3	286	sb_set_blocksize(sb, sb_buffer->b_size);
9f5fae2f CM	287	fs_info->running_transaction = NULL;
	288	fs_info->fs_root = root;
	289	fs_info->tree_root = tree_root;
	290	fs_info->extent_root = extent_root;
	291	fs_info->inode_root = inode_root;
	292	fs_info->last_inode_alloc = 0;
	293	fs_info->last_inode_alloc_dirid = 0;
e20d96d6	294	fs_info->disk_super = disk_super;
e20d96d6	295	fs_info->sb = sb;
d98237b3 CM	296	fs_info->btree_inode = new_inode(sb);
	297	fs_info->btree_inode->i_ino = 1;
	298	fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
	299	fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
	300	mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
87cbda5c	301	fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
30ae8467 CM	302	spin_lock_init(&fs_info->hash_lock);
	303
	304	if (!fs_info->hash_tfm \|\| IS_ERR(fs_info->hash_tfm)) {
87cbda5c CM	305	printk("failed to allocate sha256 hash\n");
	306	return NULL;
	307	}
d98237b3	308
79154b1b	309	mutex_init(&fs_info->trans_mutex);
d561c025	310	mutex_init(&fs_info->fs_mutex);
9f5fae2f CM	311	memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert));
9f5fae2f CM	312	memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert));
3768f368	313
e20d96d6	314	__setup_root(disk_super, tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
d98237b3 CM	315
	316	fs_info->sb_buffer = read_tree_block(tree_root, sb_buffer->b_blocknr);
	317
87cbda5c CM	318	if (!fs_info->sb_buffer) {
87cbda5c CM	319	printk("failed2\n");
d98237b3	320	return NULL;
87cbda5c	321	}
d98237b3 CM	322	brelse(sb_buffer);
	323	sb_buffer = NULL;
	324	disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
	325	fs_info->disk_super = disk_super;
	326
e20d96d6 CM	327	tree_root->node = read_tree_block(tree_root,
e20d96d6 CM	328	btrfs_super_root(disk_super));
3768f368 CM	329	BUG_ON(!tree_root->node);
3768f368 CM	330
e20d96d6 CM	331	ret = find_and_setup_root(disk_super, tree_root, fs_info,
e20d96d6 CM	332	BTRFS_EXTENT_TREE_OBJECTID, extent_root);
3768f368 CM	333	BUG_ON(ret);
3768f368 CM	334
e20d96d6 CM	335	ret = find_and_setup_root(disk_super, tree_root, fs_info,
e20d96d6 CM	336	BTRFS_INODE_MAP_OBJECTID, inode_root);
9f5fae2f CM	337	BUG_ON(ret);
9f5fae2f CM	338
e20d96d6 CM	339	ret = find_and_setup_root(disk_super, tree_root, fs_info,
e20d96d6 CM	340	BTRFS_FS_TREE_OBJECTID, root);
3768f368	341	BUG_ON(ret);
a28ec197	342	root->commit_root = root->node;
e20d96d6	343	get_bh(root->node);
3768f368	344	root->ref_cows = 1;
293ffd5f	345	root->fs_info->generation = root->root_key.offset + 1;
eb60ceac CM	346	return root;
	347	}
	348
e089f05c	349	int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
79154b1b	350	*root)
eb60ceac	351	{
d5719762 CM	352	struct buffer_head *bh = root->fs_info->sb_buffer;
	353	btrfs_set_super_root(root->fs_info->disk_super,
	354	root->fs_info->tree_root->node->b_blocknr);
	355	lock_buffer(bh);
	356	clear_buffer_dirty(bh);
87cbda5c	357	csum_tree_block(root, bh, 0);
d5719762 CM	358	bh->b_end_io = end_buffer_write_sync;
	359	get_bh(bh);
	360	submit_bh(WRITE, bh);
	361	wait_on_buffer(bh);
	362	if (!buffer_uptodate(bh)) {
	363	WARN_ON(1);
	364	return -EIO;
cfaa7295 CM	365	}
	366	return 0;
	367	}
	368
e20d96d6	369	int close_ctree(struct btrfs_root *root)
cfaa7295	370	{
3768f368	371	int ret;
e089f05c CM	372	struct btrfs_trans_handle *trans;
e089f05c CM	373
79154b1b CM	374	trans = btrfs_start_transaction(root, 1);
	375	btrfs_commit_transaction(trans, root);
	376	/* run commit again to drop the original snapshot */
	377	trans = btrfs_start_transaction(root, 1);
	378	btrfs_commit_transaction(trans, root);
	379	ret = btrfs_write_and_wait_transaction(NULL, root);
3768f368	380	BUG_ON(ret);
79154b1b	381	write_ctree_super(NULL, root);
ed2ff2cb	382
cfaa7295	383	if (root->node)
234b63a0	384	btrfs_block_release(root, root->node);
9f5fae2f CM	385	if (root->fs_info->extent_root->node)
	386	btrfs_block_release(root->fs_info->extent_root,
	387	root->fs_info->extent_root->node);
	388	if (root->fs_info->inode_root->node)
	389	btrfs_block_release(root->fs_info->inode_root,
	390	root->fs_info->inode_root->node);
	391	if (root->fs_info->tree_root->node)
	392	btrfs_block_release(root->fs_info->tree_root,
	393	root->fs_info->tree_root->node);
234b63a0	394	btrfs_block_release(root, root->commit_root);
e20d96d6	395	btrfs_block_release(root, root->fs_info->sb_buffer);
87cbda5c	396	crypto_free_hash(root->fs_info->hash_tfm);
30ae8467	397	truncate_inode_pages(root->fs_info->btree_inode->i_mapping, 0);
d98237b3	398	iput(root->fs_info->btree_inode);
e20d96d6 CM	399	kfree(root->fs_info->extent_root);
	400	kfree(root->fs_info->inode_root);
	401	kfree(root->fs_info->tree_root);
	402	kfree(root->fs_info);
	403	kfree(root);
eb60ceac CM	404	return 0;
	405	}
	406
e20d96d6	407	void btrfs_block_release(struct btrfs_root root, struct buffer_head buf)
eb60ceac	408	{
e20d96d6	409	brelse(buf);
eb60ceac CM	410	}
eb60ceac CM	411