super.c 25.0 KB
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#include <linux/module.h>
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#include <linux/buffer_head.h>
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#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/backing-dev.h>
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#include <linux/mpage.h>
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#include "ctree.h"
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#include "disk-io.h"
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#include "transaction.h"
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#define BTRFS_SUPER_MAGIC 0x9123682E
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static struct inode_operations btrfs_dir_inode_operations;
static struct super_operations btrfs_super_ops;
static struct file_operations btrfs_dir_file_operations;
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static struct inode_operations btrfs_file_inode_operations;
static struct address_space_operations btrfs_aops;
static struct file_operations btrfs_file_operations;
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static void btrfs_read_locked_inode(struct inode *inode)
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{
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	struct btrfs_path path;
	struct btrfs_inode_item *inode_item;
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	int ret;
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	btrfs_init_path(&path);
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	mutex_lock(&root->fs_info->fs_mutex);

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	ret = btrfs_lookup_inode(NULL, root, &path, inode->i_ino, 0);
	if (ret) {
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		btrfs_release_path(root, &path);
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		mutex_unlock(&root->fs_info->fs_mutex);
		make_bad_inode(inode);
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		return;
	}
	inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
				  path.slots[0],
				  struct btrfs_inode_item);
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	inode->i_mode = btrfs_inode_mode(inode_item);
	inode->i_nlink = btrfs_inode_nlink(inode_item);
	inode->i_uid = btrfs_inode_uid(inode_item);
	inode->i_gid = btrfs_inode_gid(inode_item);
	inode->i_size = btrfs_inode_size(inode_item);
	inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
	inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
	inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
	inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
	inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
	inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
	inode->i_blocks = btrfs_inode_nblocks(inode_item);
	inode->i_generation = btrfs_inode_generation(inode_item);
	btrfs_release_path(root, &path);
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	mutex_unlock(&root->fs_info->fs_mutex);
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	switch (inode->i_mode & S_IFMT) {
#if 0
	default:
		init_special_inode(inode, inode->i_mode,
				   btrfs_inode_rdev(inode_item));
		break;
#endif
	case S_IFREG:
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		inode->i_mapping->a_ops = &btrfs_aops;
		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
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		break;
	case S_IFDIR:
		inode->i_op = &btrfs_dir_inode_operations;
		inode->i_fop = &btrfs_dir_file_operations;
		break;
	case S_IFLNK:
		// inode->i_op = &page_symlink_inode_operations;
		break;
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	}
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	return;
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}

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static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
			      struct btrfs_root *root,
			      struct inode *dir,
			      struct dentry *dentry)
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{
	struct btrfs_path path;
	const char *name = dentry->d_name.name;
	int name_len = dentry->d_name.len;
	int ret;
	u64 objectid;
	struct btrfs_dir_item *di;

	btrfs_init_path(&path);
	ret = btrfs_lookup_dir_item(trans, root, &path, dir->i_ino,
				    name, name_len, -1);
	if (ret < 0)
		goto err;
	if (ret > 0) {
		ret = -ENOENT;
		goto err;
	}
	di = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
			    struct btrfs_dir_item);
	objectid = btrfs_dir_objectid(di);

	ret = btrfs_del_item(trans, root, &path);
	BUG_ON(ret);
	dentry->d_inode->i_ctime = dir->i_ctime;
err:
	btrfs_release_path(root, &path);
	if (ret == 0)
		inode_dec_link_count(dentry->d_inode);
	return ret;
}

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static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct btrfs_root *root;
	struct btrfs_trans_handle *trans;
	int ret;

	root = btrfs_sb(dir->i_sb);
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	ret = btrfs_unlink_trans(trans, root, dir, dentry);
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	return ret;
}

static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
	int err;
	int ret;
	struct btrfs_root *root = btrfs_sb(dir->i_sb);
	struct btrfs_path path;
	struct btrfs_key key;
	struct btrfs_trans_handle *trans;
	struct btrfs_disk_key *found_key;
	struct btrfs_leaf *leaf;

	btrfs_init_path(&path);
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	key.objectid = inode->i_ino;
	key.offset = (u64)-1;
	key.flags = 0;
	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
	ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
	if (ret < 0) {
		err = ret;
		goto out;
	}

	BUG_ON(ret == 0);
	BUG_ON(path.slots[0] == 0);
	path.slots[0]--;
	leaf = btrfs_buffer_leaf(path.nodes[0]);
	found_key = &leaf->items[path.slots[0]].key;
	if (btrfs_disk_key_objectid(found_key) != inode->i_ino) {
		err = -ENOENT;
		goto out;
	}
	if (btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
	    btrfs_disk_key_offset(found_key) != 2) {
		err = -ENOTEMPTY;
		goto out;
	}
	ret = btrfs_del_item(trans, root, &path);
	BUG_ON(ret);
	btrfs_release_path(root, &path);
	key.offset = 1;
	ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
	if (ret < 0) {
		err = ret;
		goto out;
	}
	if (ret > 0) {
		err = -ENOTEMPTY;
		goto out;
	}
	ret = btrfs_del_item(trans, root, &path);
	if (ret) {
		err = ret;
		goto out;
	}
	btrfs_release_path(root, &path);

	/* now the directory is empty */
	err = btrfs_unlink_trans(trans, root, dir, dentry);
	if (!err) {
		inode->i_size = 0;
	}
out:
	mutex_unlock(&root->fs_info->fs_mutex);
	ret = btrfs_end_transaction(trans, root);
	if (ret && !err)
		err = ret;
	return err;
}

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static int btrfs_free_inode(struct btrfs_trans_handle *trans,
			    struct btrfs_root *root,
			    struct inode *inode)
{
	u64 objectid = inode->i_ino;
	struct btrfs_path path;
	struct btrfs_inode_map_item *map;
	struct btrfs_key stat_data_key;
	int ret;
	clear_inode(inode);
	btrfs_init_path(&path);
	ret = btrfs_lookup_inode_map(trans, root, &path, objectid, -1);
	if (ret) {
		if (ret > 0)
			ret = -ENOENT;
		btrfs_release_path(root, &path);
		goto error;
	}
	map = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
			    struct btrfs_inode_map_item);
	btrfs_disk_key_to_cpu(&stat_data_key, &map->key);
	ret = btrfs_del_item(trans, root->fs_info->inode_root, &path);
	BUG_ON(ret);
	btrfs_release_path(root, &path);
	btrfs_init_path(&path);

	ret = btrfs_lookup_inode(trans, root, &path, objectid, -1);
	BUG_ON(ret);
	ret = btrfs_del_item(trans, root, &path);
	BUG_ON(ret);
	btrfs_release_path(root, &path);
error:
	return ret;
}

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static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
				   struct btrfs_root *root,
				   struct inode *inode)
{
	int ret;
	struct btrfs_path path;
	struct btrfs_key key;
	struct btrfs_disk_key *found_key;
	struct btrfs_leaf *leaf;
	struct btrfs_file_extent_item *fi;
	u64 extent_start;
	u64 extent_num_blocks;

	/* FIXME, add redo link to tree so we don't leak on crash */
	key.objectid = inode->i_ino;
	key.offset = (u64)-1;
	key.flags = 0;
	btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
	while(1) {
		btrfs_init_path(&path);
		ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
		if (ret < 0) {
			btrfs_release_path(root, &path);
			goto error;
		}
		if (ret > 0) {
			BUG_ON(path.slots[0] == 0);
			path.slots[0]--;
		}
		leaf = btrfs_buffer_leaf(path.nodes[0]);
		found_key = &leaf->items[path.slots[0]].key;
		if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
			break;
		if (btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY)
			break;
		if (btrfs_disk_key_offset(found_key) < inode->i_size)
			break;
		fi = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
				    path.slots[0],
				    struct btrfs_file_extent_item);
		extent_start = btrfs_file_extent_disk_blocknr(fi);
		extent_num_blocks = btrfs_file_extent_disk_num_blocks(fi);
		key.offset = btrfs_disk_key_offset(found_key) - 1;
		ret = btrfs_del_item(trans, root, &path);
		BUG_ON(ret);
		inode->i_blocks -= btrfs_file_extent_num_blocks(fi) >> 9;
		btrfs_release_path(root, &path);
		ret = btrfs_free_extent(trans, root, extent_start,
					extent_num_blocks, 0);
		BUG_ON(ret);
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		if (key.offset + 1 == 0)
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			break;
	}
	btrfs_release_path(root, &path);
	ret = 0;
error:
	return ret;
}

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static void btrfs_delete_inode(struct inode *inode)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
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	int ret;

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	truncate_inode_pages(&inode->i_data, 0);
	if (is_bad_inode(inode)) {
		goto no_delete;
	}
	inode->i_size = 0;
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
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	if (S_ISREG(inode->i_mode)) {
		ret = btrfs_truncate_in_trans(trans, root, inode);
		BUG_ON(ret);
	}
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	btrfs_free_inode(trans, root, inode);
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	return;
no_delete:
	clear_inode(inode);
}

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static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
			      ino_t *ino)
{
	const char *name = dentry->d_name.name;
	int namelen = dentry->d_name.len;
	struct btrfs_dir_item *di;
	struct btrfs_path path;
	struct btrfs_root *root = btrfs_sb(dir->i_sb);
	int ret;

	btrfs_init_path(&path);
	ret = btrfs_lookup_dir_item(NULL, root, &path, dir->i_ino, name,
				    namelen, 0);
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	if (ret || !btrfs_match_dir_item_name(root, &path, name, namelen)) {
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		*ino = 0;
		goto out;
	}
	di = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
			    struct btrfs_dir_item);
	*ino = btrfs_dir_objectid(di);
out:
	btrfs_release_path(root, &path);
	return ret;
}

static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
				   struct nameidata *nd)
{
	struct inode * inode;
	ino_t ino;
	int ret;

	if (dentry->d_name.len > BTRFS_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);

	ret = btrfs_inode_by_name(dir, dentry, &ino);
	if (ret < 0)
		return ERR_PTR(ret);
	inode = NULL;
	if (ino) {
		inode = iget(dir->i_sb, ino);
		if (!inode)
			return ERR_PTR(-EACCES);
	}
	return d_splice_alias(inode, dentry);
}

static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct inode *inode = filp->f_path.dentry->d_inode;
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	struct btrfs_item *item;
	struct btrfs_dir_item *di;
	struct btrfs_key key;
	struct btrfs_path path;
	int ret;
	u32 nritems;
	struct btrfs_leaf *leaf;
	int slot;
	int advance;
	unsigned char d_type = DT_UNKNOWN;
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	int over = 0;
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	key.objectid = inode->i_ino;
	key.flags = 0;
	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
	key.offset = filp->f_pos;
	btrfs_init_path(&path);
	ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
	if (ret < 0) {
		goto err;
	}
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	advance = 0;
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	while(1) {
		leaf = btrfs_buffer_leaf(path.nodes[0]);
		nritems = btrfs_header_nritems(&leaf->header);
		slot = path.slots[0];
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		if (advance || slot >= nritems) {
			if (slot >= nritems -1) {
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				ret = btrfs_next_leaf(root, &path);
				if (ret)
					break;
				leaf = btrfs_buffer_leaf(path.nodes[0]);
				nritems = btrfs_header_nritems(&leaf->header);
				slot = path.slots[0];
			} else {
				slot++;
				path.slots[0]++;
			}
		}
		advance = 1;
		item = leaf->items + slot;
		if (btrfs_disk_key_objectid(&item->key) != key.objectid)
			break;
		if (btrfs_disk_key_type(&item->key) != BTRFS_DIR_ITEM_KEY)
			continue;
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		if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
			continue;
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		advance = 1;
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		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
		over = filldir(dirent, (const char *)(di + 1),
			       btrfs_dir_name_len(di),
			       btrfs_disk_key_offset(&item->key),
			       btrfs_dir_objectid(di), d_type);
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		if (over) {
			filp->f_pos = btrfs_disk_key_offset(&item->key);
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			break;
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		}
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		filp->f_pos = btrfs_disk_key_offset(&item->key) + 1;
	}
	ret = 0;
err:
	btrfs_release_path(root, &path);
	return ret;
}

static void btrfs_put_super (struct super_block * sb)
{
	struct btrfs_root *root = btrfs_sb(sb);
	int ret;

	ret = close_ctree(root);
	if (ret) {
		printk("close ctree returns %d\n", ret);
	}
	sb->s_fs_info = NULL;
}
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static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
{
	struct inode * inode;
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	struct dentry * root_dentry;
	struct btrfs_super_block *disk_super;
	struct buffer_head *bh;
	struct btrfs_root *root;
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	sb->s_maxbytes = MAX_LFS_FILESIZE;
	sb->s_blocksize = PAGE_CACHE_SIZE;
	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	sb->s_magic = BTRFS_SUPER_MAGIC;
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	sb->s_op = &btrfs_super_ops;
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	sb->s_time_gran = 1;
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	bh = sb_bread(sb, BTRFS_SUPER_INFO_OFFSET / sb->s_blocksize);
	if (!bh) {
		printk("btrfs: unable to read on disk super\n");
		return -EIO;
	}
	disk_super = (struct btrfs_super_block *)bh->b_data;
	root = open_ctree(sb, bh, disk_super);
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	if (!root) {
		printk("btrfs: open_ctree failed\n");
		return -EIO;
	}
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	sb->s_fs_info = root;
	disk_super = root->fs_info->disk_super;
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	printk("read in super total blocks %Lu root %Lu\n",
	       btrfs_super_total_blocks(disk_super),
	       btrfs_super_root_dir(disk_super));

	inode = iget_locked(sb, btrfs_super_root_dir(disk_super));
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	if (!inode)
		return -ENOMEM;
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	if (inode->i_state & I_NEW) {
		btrfs_read_locked_inode(inode);
		unlock_new_inode(inode);
	}
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	root_dentry = d_alloc_root(inode);
	if (!root_dentry) {
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		iput(inode);
		return -ENOMEM;
	}
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	sb->s_root = root_dentry;

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	return 0;
}

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static void fill_inode_item(struct btrfs_inode_item *item,
			    struct inode *inode)
{
	btrfs_set_inode_uid(item, inode->i_uid);
	btrfs_set_inode_gid(item, inode->i_gid);
	btrfs_set_inode_size(item, inode->i_size);
	btrfs_set_inode_mode(item, inode->i_mode);
	btrfs_set_inode_nlink(item, inode->i_nlink);
	btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
	btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
	btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
	btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
	btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
	btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
	btrfs_set_inode_nblocks(item, inode->i_blocks);
	btrfs_set_inode_generation(item, inode->i_generation);
}

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static int btrfs_update_inode(struct btrfs_trans_handle *trans,
			      struct btrfs_root *root,
			      struct inode *inode)
{
	struct btrfs_inode_item *inode_item;
	struct btrfs_path path;
	int ret;

	btrfs_init_path(&path);

	ret = btrfs_lookup_inode(trans, root, &path, inode->i_ino, 1);
	if (ret) {
		if (ret > 0)
			ret = -ENOENT;
		goto failed;
	}

	inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
				  path.slots[0],
				  struct btrfs_inode_item);

	fill_inode_item(inode_item, inode);
	mark_buffer_dirty(path.nodes[0]);
failed:
	btrfs_release_path(root, &path);
	return 0;
}

static int btrfs_write_inode(struct inode *inode, int wait)
{
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	struct btrfs_trans_handle *trans;
	int ret;

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	ret = btrfs_update_inode(trans, root, inode);
	if (wait)
		btrfs_commit_transaction(trans, root);
	else
		btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	return ret;
}

568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
				     struct inode *dir, int mode)
{
	struct inode *inode;
	struct btrfs_inode_item inode_item;
	struct btrfs_root *root = btrfs_sb(dir->i_sb);
	struct btrfs_key key;
	int ret;
	u64 objectid;

	inode = new_inode(dir->i_sb);
	if (!inode)
		return ERR_PTR(-ENOMEM);

	ret = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
	BUG_ON(ret);

	inode->i_uid = current->fsuid;
	inode->i_gid = current->fsgid;
	inode->i_mode = mode;
	inode->i_ino = objectid;
	inode->i_blocks = 0;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
	fill_inode_item(&inode_item, inode);

	key.objectid = objectid;
	key.flags = 0;
	key.offset = 0;
	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
	ret = btrfs_insert_inode_map(trans, root, objectid, &key);
	BUG_ON(ret);

	ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
	BUG_ON(ret);

	insert_inode_hash(inode);
	return inode;
}

static int btrfs_add_link(struct btrfs_trans_handle *trans,
			    struct dentry *dentry, struct inode *inode)
{
	int ret;
	ret = btrfs_insert_dir_item(trans, btrfs_sb(inode->i_sb),
				    dentry->d_name.name, dentry->d_name.len,
				    dentry->d_parent->d_inode->i_ino,
				    inode->i_ino, 0);
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	if (ret == 0) {
		dentry->d_parent->d_inode->i_size += dentry->d_name.len;
		ret = btrfs_update_inode(trans, btrfs_sb(inode->i_sb),
					 dentry->d_parent->d_inode);
	}

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	return ret;
}

static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
			    struct dentry *dentry, struct inode *inode)
{
	int err = btrfs_add_link(trans, dentry, inode);
	if (!err) {
		d_instantiate(dentry, inode);
		return 0;
	}
	return err;
}

static int btrfs_create(struct inode *dir, struct dentry *dentry,
			int mode, struct nameidata *nd)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = btrfs_sb(dir->i_sb);
	struct inode *inode;
	int err;
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	int drop_inode = 0;
643

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	mutex_lock(&root->fs_info->fs_mutex);
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	trans = btrfs_start_transaction(root, 1);
	inode = btrfs_new_inode(trans, dir, mode);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
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		goto out_unlock;
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	// FIXME mark the inode dirty
	err = btrfs_add_nondir(trans, dentry, inode);
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	if (err)
		drop_inode = 1;
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	else {
		inode->i_mapping->a_ops = &btrfs_aops;
		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
	}
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	dir->i_sb->s_dirt = 1;
	btrfs_end_transaction(trans, root);
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out_unlock:
	mutex_unlock(&root->fs_info->fs_mutex);
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	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
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	return err;
}

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static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
				struct inode *inode, struct inode *dir)
{
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	int ret;
	char buf[2];
	buf[0] = '.';
	buf[1] = '.';

	ret = btrfs_insert_dir_item(trans, root, buf, 1, inode->i_ino,
				    inode->i_ino, 1);
	if (ret)
		goto error;
	ret = btrfs_insert_dir_item(trans, root, buf, 2, inode->i_ino,
				    dir->i_ino, 1);
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	if (ret)
		goto error;
	inode->i_size = 3;
	ret = btrfs_update_inode(trans, root, inode);
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error:
	return ret;
}

static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
	struct inode *inode;
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = btrfs_sb(dir->i_sb);
	int err = 0;
	int drop_on_err = 0;

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	if (IS_ERR(trans)) {
		err = PTR_ERR(trans);
		goto out_unlock;
	}
	inode = btrfs_new_inode(trans, dir, S_IFDIR | mode);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_fail;
	}
	drop_on_err = 1;
	inode->i_op = &btrfs_dir_inode_operations;
	inode->i_fop = &btrfs_dir_file_operations;

	err = btrfs_make_empty_dir(trans, inode, dir);
	if (err)
		goto out_fail;
	err = btrfs_add_link(trans, dentry, inode);
	if (err)
		goto out_fail;
	d_instantiate(dentry, inode);
	drop_on_err = 0;

out_fail:
	btrfs_end_transaction(trans, root);
out_unlock:
	mutex_unlock(&root->fs_info->fs_mutex);
	if (drop_on_err)
		iput(inode);
	return err;
}

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static int btrfs_sync_fs(struct super_block *sb, int wait)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root;
	int ret;
739
	root = btrfs_sb(sb);
740

741
	sb->s_dirt = 0;
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	if (!wait) {
743
		filemap_flush(root->fs_info->btree_inode->i_mapping);
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		return 0;
	}
746
	filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
747

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	mutex_lock(&root->fs_info->fs_mutex);
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	trans = btrfs_start_transaction(root, 1);
	ret = btrfs_commit_transaction(trans, root);
	sb->s_dirt = 0;
	BUG_ON(ret);
printk("btrfs sync_fs\n");
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	mutex_unlock(&root->fs_info->fs_mutex);
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	return 0;
}

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static int btrfs_get_block(struct inode *inode, sector_t iblock,
			   struct buffer_head *result, int create)
{
	int ret;
	int err = 0;
	u64 blocknr;
	u64 extent_start = 0;
	u64 extent_end = 0;
	u64 objectid = inode->i_ino;
	struct btrfs_path path;
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	struct btrfs_trans_handle *trans = NULL;
	struct btrfs_file_extent_item *item;
	struct btrfs_leaf *leaf;
	struct btrfs_disk_key *found_key;

	btrfs_init_path(&path);
	mutex_lock(&root->fs_info->fs_mutex);
	if (create)
		trans = btrfs_start_transaction(root, 1);


	ret = btrfs_lookup_file_extent(trans, root, &path,
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				       inode->i_ino,
				       iblock << inode->i_blkbits, 0);
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	if (ret < 0) {
		btrfs_release_path(root, &path);
		err = ret;
		goto out;
	}

	if (ret != 0) {
		if (path.slots[0] == 0) {
			btrfs_release_path(root, &path);
			goto allocate;
		}
		path.slots[0]--;
	}

	item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
			      struct btrfs_file_extent_item);
	leaf = btrfs_buffer_leaf(path.nodes[0]);
	blocknr = btrfs_file_extent_disk_blocknr(item);
	blocknr += btrfs_file_extent_offset(item);

	/* exact match found, use it */
	if (ret == 0) {
		err = 0;
		map_bh(result, inode->i_sb, blocknr);
		btrfs_release_path(root, &path);
		goto out;
	}

	/* are we inside the extent that was found? */
	found_key = &leaf->items[path.slots[0]].key;
	if (btrfs_disk_key_objectid(found_key) != objectid ||
	    btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY) {
		extent_end = 0;
		extent_start = 0;
		btrfs_release_path(root, &path);
		goto allocate;
	}

	extent_start = btrfs_disk_key_offset(&leaf->items[path.slots[0]].key);
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	extent_start = extent_start >> inode->i_blkbits;
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	extent_start += btrfs_file_extent_offset(item);
	extent_end = extent_start + btrfs_file_extent_num_blocks(item);
	btrfs_release_path(root, &path);
	if (iblock >= extent_start && iblock < extent_end) {
		err = 0;
		map_bh(result, inode->i_sb, blocknr + iblock - extent_start);
		goto out;
	}
allocate:
	/* ok, create a new extent */
	if (!create) {
		err = 0;
		goto out;
	}
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	ret = btrfs_alloc_file_extent(trans, root, objectid,
				      iblock << inode->i_blkbits,
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				      1, extent_end, &blocknr);
	if (ret) {
		err = ret;
		goto out;
	}
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	inode->i_blocks += inode->i_sb->s_blocksize >> 9;
	set_buffer_new(result);
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	map_bh(result, inode->i_sb, blocknr);

out:
	if (trans)
		btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	return err;
}

static int btrfs_prepare_write(struct file *file, struct page *page,
			       unsigned from, unsigned to)
{
858
	return nobh_prepare_write(page, from, to, btrfs_get_block);
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}

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static void btrfs_write_super(struct super_block *sb)
{
	btrfs_sync_fs(sb, 1);
}

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static int btrfs_readpage(struct file *file, struct page *page)
{
	return mpage_readpage(page, btrfs_get_block);
}

static int btrfs_readpages(struct file *file, struct address_space *mapping,
			   struct list_head *pages, unsigned nr_pages)
{
	return mpage_readpages(mapping, pages, nr_pages, btrfs_get_block);
}

static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
{
879
	return nobh_writepage(page, btrfs_get_block, wbc);
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}
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static void btrfs_truncate(struct inode *inode)
{
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	int ret;
	struct btrfs_trans_handle *trans;

	if (!S_ISREG(inode->i_mode))
		return;
	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
		return;

	nobh_truncate_page(inode->i_mapping, inode->i_size);

	/* FIXME, add redo link to tree so we don't leak on crash */
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	ret = btrfs_truncate_in_trans(trans, root, inode);
	BUG_ON(ret);
	ret = btrfs_end_transaction(trans, root);
	BUG_ON(ret);
	mutex_unlock(&root->fs_info->fs_mutex);
	mark_inode_dirty(inode);
}

906 907 908 909 910 911 912 913 914 915 916 917 918 919 920
static int btrfs_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
	return get_sb_bdev(fs_type, flags, dev_name, data,
			   btrfs_fill_super, mnt);
}

static struct file_system_type btrfs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "btrfs",
	.get_sb		= btrfs_get_sb,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};

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static struct super_operations btrfs_super_ops = {
	.statfs		= simple_statfs,
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	.delete_inode	= btrfs_delete_inode,
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	.put_super	= btrfs_put_super,
	.read_inode	= btrfs_read_locked_inode,
926 927
	.write_super	= btrfs_write_super,
	.sync_fs	= btrfs_sync_fs,
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	.write_inode	= btrfs_write_inode,
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};

static struct inode_operations btrfs_dir_inode_operations = {
	.lookup		= btrfs_lookup,
933
	.create		= btrfs_create,
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	.unlink		= btrfs_unlink,
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	.mkdir		= btrfs_mkdir,
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	.rmdir		= btrfs_rmdir,
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};

static struct file_operations btrfs_dir_file_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.readdir	= btrfs_readdir,
};

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static struct address_space_operations btrfs_aops = {
	.readpage	= btrfs_readpage,
	.readpages	= btrfs_readpages,
	.writepage	= btrfs_writepage,
	.sync_page	= block_sync_page,
	.prepare_write	= btrfs_prepare_write,
951
	.commit_write	= nobh_commit_write,
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};

static struct inode_operations btrfs_file_inode_operations = {
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	.truncate	= btrfs_truncate,
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};

static struct file_operations btrfs_file_operations = {
	.llseek		= generic_file_llseek,
	.read		= do_sync_read,
	.write		= do_sync_write,
	.aio_read	= generic_file_aio_read,
	.aio_write	= generic_file_aio_write,
	.mmap		= generic_file_mmap,
	.open		= generic_file_open,
	.sendfile	= generic_file_sendfile,
	.splice_read	= generic_file_splice_read,
	.splice_write	= generic_file_splice_write,
};
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static int __init init_btrfs_fs(void)
{
	printk("btrfs loaded!\n");
	return register_filesystem(&btrfs_fs_type);
}

static void __exit exit_btrfs_fs(void)
{
	unregister_filesystem(&btrfs_fs_type);
	printk("btrfs unloaded\n");
}

module_init(init_btrfs_fs)
module_exit(exit_btrfs_fs)

MODULE_LICENSE("GPL");