inode.c 65.5 KB
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/*
 * 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.
 */

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#include <linux/buffer_head.h>
#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>
#include <linux/mpage.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
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#include <linux/bit_spinlock.h>
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#include <linux/version.h>
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#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"

struct btrfs_iget_args {
	u64 ino;
	struct btrfs_root *root;
};

static struct inode_operations btrfs_dir_inode_operations;
static struct inode_operations btrfs_symlink_inode_operations;
static struct inode_operations btrfs_dir_ro_inode_operations;
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static struct inode_operations btrfs_special_inode_operations;
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static struct inode_operations btrfs_file_inode_operations;
static struct address_space_operations btrfs_aops;
static struct address_space_operations btrfs_symlink_aops;
static struct file_operations btrfs_dir_file_operations;
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static struct extent_map_ops btrfs_extent_map_ops;
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static struct kmem_cache *btrfs_inode_cachep;
struct kmem_cache *btrfs_trans_handle_cachep;
struct kmem_cache *btrfs_transaction_cachep;
struct kmem_cache *btrfs_bit_radix_cachep;
struct kmem_cache *btrfs_path_cachep;

#define S_SHIFT 12
static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
	[S_IFREG >> S_SHIFT]	= BTRFS_FT_REG_FILE,
	[S_IFDIR >> S_SHIFT]	= BTRFS_FT_DIR,
	[S_IFCHR >> S_SHIFT]	= BTRFS_FT_CHRDEV,
	[S_IFBLK >> S_SHIFT]	= BTRFS_FT_BLKDEV,
	[S_IFIFO >> S_SHIFT]	= BTRFS_FT_FIFO,
	[S_IFSOCK >> S_SHIFT]	= BTRFS_FT_SOCK,
	[S_IFLNK >> S_SHIFT]	= BTRFS_FT_SYMLINK,
};

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static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
	struct btrfs_key ins;
	u64 alloc_hint = 0;
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	u64 num_bytes;
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	int ret;
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	u64 blocksize = root->sectorsize;
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	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_trans_block_group(trans, inode);
	BUG_ON(!trans);
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	num_bytes = (end - start + blocksize) & ~(blocksize - 1);
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	ret = btrfs_drop_extents(trans, root, inode,
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				 start, start + num_bytes, start, &alloc_hint);
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	if (alloc_hint == EXTENT_MAP_INLINE)
		goto out;

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	ret = btrfs_alloc_extent(trans, root, inode->i_ino, num_bytes, 0,
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				 alloc_hint, (u64)-1, &ins, 1);
	if (ret) {
		WARN_ON(1);
		goto out;
	}
	ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
				       start, ins.objectid, ins.offset,
				       ins.offset);
out:
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	return ret;
}

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int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
{
	struct inode *inode = page->mapping->host;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
	char *kaddr;
	int ret;
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	u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
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	size_t offset = start - page_start;

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_trans_block_group(trans, inode);
	kaddr = kmap(page);
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	btrfs_csum_file_block(trans, root, inode, inode->i_ino,
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			      start, kaddr + offset, end - start + 1);
	kunmap(page);
	ret = btrfs_end_transaction(trans, root);
	BUG_ON(ret);
	mutex_unlock(&root->fs_info->fs_mutex);
	return ret;
}

int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
{
	int ret = 0;
	struct inode *inode = page->mapping->host;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	struct btrfs_csum_item *item;
	struct btrfs_path *path = NULL;
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	u32 csum;
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	mutex_lock(&root->fs_info->fs_mutex);
	path = btrfs_alloc_path();
	item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
	if (IS_ERR(item)) {
		ret = PTR_ERR(item);
		/* a csum that isn't present is a preallocated region. */
		if (ret == -ENOENT || ret == -EFBIG)
			ret = 0;
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		csum = 0;
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		goto out;
	}
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	read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
			   BTRFS_CRC32_SIZE);
	set_state_private(em_tree, start, csum);
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out:
	if (path)
		btrfs_free_path(path);
	mutex_unlock(&root->fs_info->fs_mutex);
	return ret;
}

int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end)
{
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	size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
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	struct inode *inode = page->mapping->host;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	char *kaddr;
	u64 private;
	int ret;
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	struct btrfs_root *root = BTRFS_I(inode)->root;
	u32 csum = ~(u32)0;
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	unsigned long flags;
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	ret = get_state_private(em_tree, start, &private);
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	local_irq_save(flags);
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	kaddr = kmap_atomic(page, KM_IRQ0);
	if (ret) {
		goto zeroit;
	}
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	csum = btrfs_csum_data(root, kaddr + offset, csum,  end - start + 1);
	btrfs_csum_final(csum, (char *)&csum);
	if (csum != private) {
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		goto zeroit;
	}
	kunmap_atomic(kaddr, KM_IRQ0);
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	local_irq_restore(flags);
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	return 0;

zeroit:
	printk("btrfs csum failed ino %lu off %llu\n",
	       page->mapping->host->i_ino, (unsigned long long)start);
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	memset(kaddr + offset, 1, end - start + 1);
	flush_dcache_page(page);
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	kunmap_atomic(kaddr, KM_IRQ0);
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	local_irq_restore(flags);
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	return 0;
}
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void btrfs_read_locked_inode(struct inode *inode)
{
	struct btrfs_path *path;
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	struct extent_buffer *leaf;
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	struct btrfs_inode_item *inode_item;
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	struct btrfs_inode_timespec *tspec;
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	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_key location;
	u64 alloc_group_block;
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	u32 rdev;
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	int ret;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	mutex_lock(&root->fs_info->fs_mutex);

	memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
	ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
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	if (ret)
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		goto make_bad;

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	leaf = path->nodes[0];
	inode_item = btrfs_item_ptr(leaf, path->slots[0],
				    struct btrfs_inode_item);

	inode->i_mode = btrfs_inode_mode(leaf, inode_item);
	inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
	inode->i_uid = btrfs_inode_uid(leaf, inode_item);
	inode->i_gid = btrfs_inode_gid(leaf, inode_item);
	inode->i_size = btrfs_inode_size(leaf, inode_item);

	tspec = btrfs_inode_atime(inode_item);
	inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
	inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);

	tspec = btrfs_inode_mtime(inode_item);
	inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
	inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);

	tspec = btrfs_inode_ctime(inode_item);
	inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
	inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);

	inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
	inode->i_generation = btrfs_inode_generation(leaf, inode_item);
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	inode->i_rdev = 0;
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	rdev = btrfs_inode_rdev(leaf, inode_item);

	alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
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	BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
						       alloc_group_block);

	btrfs_free_path(path);
	inode_item = NULL;

	mutex_unlock(&root->fs_info->fs_mutex);

	switch (inode->i_mode & S_IFMT) {
	case S_IFREG:
		inode->i_mapping->a_ops = &btrfs_aops;
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		BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
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		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
		break;
	case S_IFDIR:
		inode->i_fop = &btrfs_dir_file_operations;
		if (root == root->fs_info->tree_root)
			inode->i_op = &btrfs_dir_ro_inode_operations;
		else
			inode->i_op = &btrfs_dir_inode_operations;
		break;
	case S_IFLNK:
		inode->i_op = &btrfs_symlink_inode_operations;
		inode->i_mapping->a_ops = &btrfs_symlink_aops;
		break;
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	default:
		init_special_inode(inode, inode->i_mode, rdev);
		break;
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	}
	return;

make_bad:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	mutex_unlock(&root->fs_info->fs_mutex);
	make_bad_inode(inode);
}

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static void fill_inode_item(struct extent_buffer *leaf,
			    struct btrfs_inode_item *item,
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			    struct inode *inode)
{
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	btrfs_set_inode_uid(leaf, item, inode->i_uid);
	btrfs_set_inode_gid(leaf, item, inode->i_gid);
	btrfs_set_inode_size(leaf, item, inode->i_size);
	btrfs_set_inode_mode(leaf, item, inode->i_mode);
	btrfs_set_inode_nlink(leaf, item, inode->i_nlink);

	btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
			       inode->i_atime.tv_sec);
	btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
				inode->i_atime.tv_nsec);

	btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
			       inode->i_mtime.tv_sec);
	btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
				inode->i_mtime.tv_nsec);

	btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
			       inode->i_ctime.tv_sec);
	btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
				inode->i_ctime.tv_nsec);

	btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
	btrfs_set_inode_generation(leaf, item, inode->i_generation);
	btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
	btrfs_set_inode_block_group(leaf, item,
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				    BTRFS_I(inode)->block_group->key.objectid);
}

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

	path = btrfs_alloc_path();
	BUG_ON(!path);
	ret = btrfs_lookup_inode(trans, root, path,
				 &BTRFS_I(inode)->location, 1);
	if (ret) {
		if (ret > 0)
			ret = -ENOENT;
		goto failed;
	}

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	leaf = path->nodes[0];
	inode_item = btrfs_item_ptr(leaf, path->slots[0],
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				  struct btrfs_inode_item);

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	fill_inode_item(leaf, inode_item, inode);
	btrfs_mark_buffer_dirty(leaf);
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	btrfs_set_inode_last_trans(trans, inode);
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	ret = 0;
failed:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	return ret;
}


static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
			      struct btrfs_root *root,
			      struct inode *dir,
			      struct dentry *dentry)
{
	struct btrfs_path *path;
	const char *name = dentry->d_name.name;
	int name_len = dentry->d_name.len;
	int ret = 0;
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	struct extent_buffer *leaf;
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	struct btrfs_dir_item *di;
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	struct btrfs_key key;
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	path = btrfs_alloc_path();
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	if (!path) {
		ret = -ENOMEM;
		goto err;
	}

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	di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
				    name, name_len, -1);
	if (IS_ERR(di)) {
		ret = PTR_ERR(di);
		goto err;
	}
	if (!di) {
		ret = -ENOENT;
		goto err;
	}
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	leaf = path->nodes[0];
	btrfs_dir_item_key_to_cpu(leaf, di, &key);
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	ret = btrfs_delete_one_dir_name(trans, root, path, di);
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	if (ret)
		goto err;
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	btrfs_release_path(root, path);

	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
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					 key.objectid, name, name_len, -1);
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	if (IS_ERR(di)) {
		ret = PTR_ERR(di);
		goto err;
	}
	if (!di) {
		ret = -ENOENT;
		goto err;
	}
	ret = btrfs_delete_one_dir_name(trans, root, path, di);

	dentry->d_inode->i_ctime = dir->i_ctime;
err:
	btrfs_free_path(path);
	if (!ret) {
		dir->i_size -= name_len * 2;
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		dir->i_mtime = dir->i_ctime = CURRENT_TIME;
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		btrfs_update_inode(trans, root, dir);
		drop_nlink(dentry->d_inode);
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		ret = btrfs_update_inode(trans, root, dentry->d_inode);
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		dir->i_sb->s_dirt = 1;
	}
	return ret;
}

static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct btrfs_root *root;
	struct btrfs_trans_handle *trans;
	int ret;
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	unsigned long nr;
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	root = BTRFS_I(dir)->root;
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
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	btrfs_set_trans_block_group(trans, dir);
	ret = btrfs_unlink_trans(trans, root, dir, dentry);
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	nr = trans->blocks_used;
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	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
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	btrfs_btree_balance_dirty(root, nr);
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	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_I(dir)->root;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_trans_handle *trans;
	struct btrfs_key found_key;
	int found_type;
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	struct extent_buffer *leaf;
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	char *goodnames = "..";
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	unsigned long nr;
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	if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
		return -ENOTEMPTY;

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	path = btrfs_alloc_path();
	BUG_ON(!path);
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
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	btrfs_set_trans_block_group(trans, dir);
	key.objectid = inode->i_ino;
	key.offset = (u64)-1;
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	key.type = (u8)-1;
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	while(1) {
		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
		if (ret < 0) {
			err = ret;
			goto out;
		}
		BUG_ON(ret == 0);
		if (path->slots[0] == 0) {
			err = -ENOENT;
			goto out;
		}
		path->slots[0]--;
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		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
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		found_type = btrfs_key_type(&found_key);
		if (found_key.objectid != inode->i_ino) {
			err = -ENOENT;
			goto out;
		}
		if ((found_type != BTRFS_DIR_ITEM_KEY &&
		     found_type != BTRFS_DIR_INDEX_KEY) ||
	            (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
	            !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
			err = -ENOTEMPTY;
			goto out;
		}
		ret = btrfs_del_item(trans, root, path);
		BUG_ON(ret);

		if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
			break;
		btrfs_release_path(root, path);
	}
	ret = 0;
	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:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
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	nr = trans->blocks_used;
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	ret = btrfs_end_transaction(trans, root);
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	mutex_unlock(&root->fs_info->fs_mutex);
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	btrfs_btree_balance_dirty(root, nr);
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	if (ret && !err)
		err = ret;
	return err;
}

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

	clear_inode(inode);

	path = btrfs_alloc_path();
	BUG_ON(!path);
	ret = btrfs_lookup_inode(trans, root, path,
				 &BTRFS_I(inode)->location, -1);
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	if (ret > 0)
		ret = -ENOENT;
	if (!ret)
		ret = btrfs_del_item(trans, root, path);
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	btrfs_free_path(path);
	return ret;
}

/*
 * this can truncate away extent items, csum items and directory items.
 * It starts at a high offset and removes keys until it can't find
 * any higher than i_size.
 *
 * csum items that cross the new i_size are truncated to the new size
 * as well.
 */
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;
555
	struct btrfs_key found_key;
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Chris Mason 已提交
556
	u32 found_type;
557
	struct extent_buffer *leaf;
C
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558 559
	struct btrfs_file_extent_item *fi;
	u64 extent_start = 0;
560
	u64 extent_num_bytes = 0;
C
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561 562 563
	u64 item_end = 0;
	int found_extent;
	int del_item;
564
	int extent_type = -1;
C
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565

566
	btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
C
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567
	path = btrfs_alloc_path();
568
	path->reada = -1;
C
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569
	BUG_ON(!path);
570

C
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571 572 573
	/* FIXME, add redo link to tree so we don't leak on crash */
	key.objectid = inode->i_ino;
	key.offset = (u64)-1;
574 575
	key.type = (u8)-1;

C
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576 577 578 579 580 581 582 583 584 585 586
	while(1) {
		btrfs_init_path(path);
		fi = NULL;
		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
		if (ret < 0) {
			goto error;
		}
		if (ret > 0) {
			BUG_ON(path->slots[0] == 0);
			path->slots[0]--;
		}
587 588 589
		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
		found_type = btrfs_key_type(&found_key);
C
Chris Mason 已提交
590

591
		if (found_key.objectid != inode->i_ino)
C
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592
			break;
593

C
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594 595 596 597 598 599
		if (found_type != BTRFS_CSUM_ITEM_KEY &&
		    found_type != BTRFS_DIR_ITEM_KEY &&
		    found_type != BTRFS_DIR_INDEX_KEY &&
		    found_type != BTRFS_EXTENT_DATA_KEY)
			break;

600
		item_end = found_key.offset;
C
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601
		if (found_type == BTRFS_EXTENT_DATA_KEY) {
602
			fi = btrfs_item_ptr(leaf, path->slots[0],
C
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603
					    struct btrfs_file_extent_item);
604 605
			extent_type = btrfs_file_extent_type(leaf, fi);
			if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
606
				item_end +=
607
				    btrfs_file_extent_num_bytes(leaf, fi);
608 609 610 611 612
			} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
				struct btrfs_item *item = btrfs_item_nr(leaf,
							        path->slots[0]);
				item_end += btrfs_file_extent_inline_len(leaf,
									 item);
C
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613 614 615 616 617 618 619
			}
		}
		if (found_type == BTRFS_CSUM_ITEM_KEY) {
			ret = btrfs_csum_truncate(trans, root, path,
						  inode->i_size);
			BUG_ON(ret);
		}
620
		if (item_end <= inode->i_size) {
621 622 623 624 625 626 627 628
			if (found_type == BTRFS_DIR_ITEM_KEY) {
				found_type = BTRFS_INODE_ITEM_KEY;
			} else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
				found_type = BTRFS_CSUM_ITEM_KEY;
			} else if (found_type) {
				found_type--;
			} else {
				break;
C
Chris Mason 已提交
629
			}
630
			btrfs_set_key_type(&key, found_type);
Y
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631
			btrfs_release_path(root, path);
632
			continue;
C
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633
		}
634
		if (found_key.offset >= inode->i_size)
C
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635 636 637 638 639 640
			del_item = 1;
		else
			del_item = 0;
		found_extent = 0;

		/* FIXME, shrink the extent if the ref count is only 1 */
641 642 643 644
		if (found_type != BTRFS_EXTENT_DATA_KEY)
			goto delete;

		if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
C
Chris Mason 已提交
645
			u64 num_dec;
646
			extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
C
Chris Mason 已提交
647
			if (!del_item) {
648 649 650
				u64 orig_num_bytes =
					btrfs_file_extent_num_bytes(leaf, fi);
				extent_num_bytes = inode->i_size -
651
					found_key.offset + root->sectorsize - 1;
652 653 654 655
				btrfs_set_file_extent_num_bytes(leaf, fi,
							 extent_num_bytes);
				num_dec = (orig_num_bytes -
					   extent_num_bytes) >> 9;
656 657 658
				if (extent_start != 0) {
					inode->i_blocks -= num_dec;
				}
659
				btrfs_mark_buffer_dirty(leaf);
C
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660
			} else {
661 662 663
				extent_num_bytes =
					btrfs_file_extent_disk_num_bytes(leaf,
									 fi);
C
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664
				/* FIXME blocksize != 4096 */
665 666
				num_dec = btrfs_file_extent_num_bytes(leaf,
								       fi) >> 9;
C
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667 668 669 670 671
				if (extent_start != 0) {
					found_extent = 1;
					inode->i_blocks -= num_dec;
				}
			}
672 673 674 675 676 677 678
		} else if (extent_type == BTRFS_FILE_EXTENT_INLINE &&
			   !del_item) {
			u32 newsize = inode->i_size - found_key.offset;
			newsize = btrfs_file_extent_calc_inline_size(newsize);
			ret = btrfs_truncate_item(trans, root, path,
						  newsize, 1);
			BUG_ON(ret);
C
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679
		}
680
delete:
C
Chris Mason 已提交
681 682
		if (del_item) {
			ret = btrfs_del_item(trans, root, path);
683 684
			if (ret)
				goto error;
C
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685 686 687 688 689 690
		} else {
			break;
		}
		btrfs_release_path(root, path);
		if (found_extent) {
			ret = btrfs_free_extent(trans, root, extent_start,
691
						extent_num_bytes, 0);
C
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692 693 694 695 696 697 698 699 700 701 702
			BUG_ON(ret);
		}
	}
	ret = 0;
error:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	inode->i_sb->s_dirt = 1;
	return ret;
}

703
static int btrfs_cow_one_page(struct inode *inode, struct page *page,
704 705 706 707
			      size_t zero_start)
{
	char *kaddr;
	int ret = 0;
708
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
709
	u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
710
	u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
711

712
	set_page_extent_mapped(page);
713

714 715 716
	lock_extent(em_tree, page_start, page_end, GFP_NOFS);
	set_extent_delalloc(&BTRFS_I(inode)->extent_tree, page_start,
			    page_end, GFP_NOFS);
717
	if (zero_start != PAGE_CACHE_SIZE) {
718
		kaddr = kmap(page);
719 720
		memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
		flush_dcache_page(page);
721
		kunmap(page);
722
	}
723 724
	set_page_dirty(page);
	unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
725 726 727 728

	return ret;
}

C
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729 730 731 732 733 734 735
/*
 * taken from block_truncate_page, but does cow as it zeros out
 * any bytes left in the last page in the file.
 */
static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
{
	struct inode *inode = mapping->host;
736 737
	struct btrfs_root *root = BTRFS_I(inode)->root;
	u32 blocksize = root->sectorsize;
C
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738 739 740 741
	pgoff_t index = from >> PAGE_CACHE_SHIFT;
	unsigned offset = from & (PAGE_CACHE_SIZE-1);
	struct page *page;
	int ret = 0;
742
	u64 page_start;
C
Chris Mason 已提交
743 744 745 746

	if ((offset & (blocksize - 1)) == 0)
		goto out;

747
	down_read(&root->snap_sem);
C
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748 749 750 751 752
	ret = -ENOMEM;
	page = grab_cache_page(mapping, index);
	if (!page)
		goto out;
	if (!PageUptodate(page)) {
C
Chris Mason 已提交
753
		ret = btrfs_readpage(NULL, page);
C
Chris Mason 已提交
754 755 756 757 758 759
		lock_page(page);
		if (!PageUptodate(page)) {
			ret = -EIO;
			goto out;
		}
	}
760
	page_start = (u64)page->index << PAGE_CACHE_SHIFT;
761

762
	ret = btrfs_cow_one_page(inode, page, offset);
C
Chris Mason 已提交
763 764 765

	unlock_page(page);
	page_cache_release(page);
766
	up_read(&BTRFS_I(inode)->root->snap_sem);
C
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767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783
out:
	return ret;
}

static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
{
	struct inode *inode = dentry->d_inode;
	int err;

	err = inode_change_ok(inode, attr);
	if (err)
		return err;

	if (S_ISREG(inode->i_mode) &&
	    attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
		struct btrfs_trans_handle *trans;
		struct btrfs_root *root = BTRFS_I(inode)->root;
C
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784 785
		struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;

786
		u64 mask = root->sectorsize - 1;
C
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787
		u64 pos = (inode->i_size + mask) & ~mask;
C
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788
		u64 block_end = attr->ia_size | mask;
C
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789
		u64 hole_size;
790
		u64 alloc_hint = 0;
C
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791 792 793 794 795 796

		if (attr->ia_size <= pos)
			goto out;

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

C
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797
		lock_extent(em_tree, pos, block_end, GFP_NOFS);
C
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798 799 800 801 802
		hole_size = (attr->ia_size - pos + mask) & ~mask;

		mutex_lock(&root->fs_info->fs_mutex);
		trans = btrfs_start_transaction(root, 1);
		btrfs_set_trans_block_group(trans, inode);
C
Chris Mason 已提交
803
		err = btrfs_drop_extents(trans, root, inode,
804 805
					 pos, pos + hole_size, pos,
					 &alloc_hint);
C
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806

807 808 809 810 811
		if (alloc_hint != EXTENT_MAP_INLINE) {
			err = btrfs_insert_file_extent(trans, root,
						       inode->i_ino,
						       pos, 0, 0, hole_size);
		}
C
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812 813
		btrfs_end_transaction(trans, root);
		mutex_unlock(&root->fs_info->fs_mutex);
C
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814
		unlock_extent(em_tree, pos, block_end, GFP_NOFS);
815 816
		if (err)
			return err;
C
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817 818 819 820 821 822 823 824 825 826
	}
out:
	err = inode_setattr(inode, attr);

	return err;
}
void btrfs_delete_inode(struct inode *inode)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(inode)->root;
827
	unsigned long nr;
C
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828 829 830 831 832 833
	int ret;

	truncate_inode_pages(&inode->i_data, 0);
	if (is_bad_inode(inode)) {
		goto no_delete;
	}
834

C
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835 836 837
	inode->i_size = 0;
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
838

C
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839 840
	btrfs_set_trans_block_group(trans, inode);
	ret = btrfs_truncate_in_trans(trans, root, inode);
841 842 843 844 845
	if (ret)
		goto no_delete_lock;
	ret = btrfs_free_inode(trans, root, inode);
	if (ret)
		goto no_delete_lock;
846
	nr = trans->blocks_used;
847

C
Chris Mason 已提交
848 849
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
850
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
851
	return;
852 853

no_delete_lock:
854
	nr = trans->blocks_used;
855 856
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
857
	btrfs_btree_balance_dirty(root, nr);
C
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858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873
no_delete:
	clear_inode(inode);
}

/*
 * this returns the key found in the dir entry in the location pointer.
 * If no dir entries were found, location->objectid is 0.
 */
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
			       struct btrfs_key *location)
{
	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_I(dir)->root;
Y
Yan 已提交
874
	int ret = 0;
C
Chris Mason 已提交
875 876 877 878 879

	path = btrfs_alloc_path();
	BUG_ON(!path);
	di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
				    namelen, 0);
Y
Yan 已提交
880 881
	if (IS_ERR(di))
		ret = PTR_ERR(di);
C
Chris Mason 已提交
882 883 884 885
	if (!di || IS_ERR(di)) {
		location->objectid = 0;
		goto out;
	}
886
	btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
C
Chris Mason 已提交
887 888 889 890 891 892 893 894 895 896 897 898 899
out:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	return ret;
}

/*
 * when we hit a tree root in a directory, the btrfs part of the inode
 * needs to be changed to reflect the root directory of the tree root.  This
 * is kind of like crossing a mount point.
 */
static int fixup_tree_root_location(struct btrfs_root *root,
			     struct btrfs_key *location,
900 901
			     struct btrfs_root **sub_root,
			     struct dentry *dentry)
C
Chris Mason 已提交
902 903 904 905 906 907 908 909 910 911 912 913 914
{
	struct btrfs_path *path;
	struct btrfs_root_item *ri;

	if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
		return 0;
	if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
		return 0;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	mutex_lock(&root->fs_info->fs_mutex);

915 916 917
	*sub_root = btrfs_read_fs_root(root->fs_info, location,
					dentry->d_name.name,
					dentry->d_name.len);
C
Chris Mason 已提交
918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935
	if (IS_ERR(*sub_root))
		return PTR_ERR(*sub_root);

	ri = &(*sub_root)->root_item;
	location->objectid = btrfs_root_dirid(ri);
	btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
	location->offset = 0;

	btrfs_free_path(path);
	mutex_unlock(&root->fs_info->fs_mutex);
	return 0;
}

static int btrfs_init_locked_inode(struct inode *inode, void *p)
{
	struct btrfs_iget_args *args = p;
	inode->i_ino = args->ino;
	BTRFS_I(inode)->root = args->root;
936 937
	extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
			     inode->i_mapping, GFP_NOFS);
C
Chris Mason 已提交
938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973
	return 0;
}

static int btrfs_find_actor(struct inode *inode, void *opaque)
{
	struct btrfs_iget_args *args = opaque;
	return (args->ino == inode->i_ino &&
		args->root == BTRFS_I(inode)->root);
}

struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
				struct btrfs_root *root)
{
	struct inode *inode;
	struct btrfs_iget_args args;
	args.ino = objectid;
	args.root = root;

	inode = iget5_locked(s, objectid, btrfs_find_actor,
			     btrfs_init_locked_inode,
			     (void *)&args);
	return inode;
}

static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
				   struct nameidata *nd)
{
	struct inode * inode;
	struct btrfs_inode *bi = BTRFS_I(dir);
	struct btrfs_root *root = bi->root;
	struct btrfs_root *sub_root = root;
	struct btrfs_key location;
	int ret;

	if (dentry->d_name.len > BTRFS_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);
974

C
Chris Mason 已提交
975 976 977
	mutex_lock(&root->fs_info->fs_mutex);
	ret = btrfs_inode_by_name(dir, dentry, &location);
	mutex_unlock(&root->fs_info->fs_mutex);
978

C
Chris Mason 已提交
979 980
	if (ret < 0)
		return ERR_PTR(ret);
981

C
Chris Mason 已提交
982 983
	inode = NULL;
	if (location.objectid) {
984 985
		ret = fixup_tree_root_location(root, &location, &sub_root,
						dentry);
C
Chris Mason 已提交
986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020
		if (ret < 0)
			return ERR_PTR(ret);
		if (ret > 0)
			return ERR_PTR(-ENOENT);
		inode = btrfs_iget_locked(dir->i_sb, location.objectid,
					  sub_root);
		if (!inode)
			return ERR_PTR(-EACCES);
		if (inode->i_state & I_NEW) {
			/* the inode and parent dir are two different roots */
			if (sub_root != root) {
				igrab(inode);
				sub_root->inode = inode;
			}
			BTRFS_I(inode)->root = sub_root;
			memcpy(&BTRFS_I(inode)->location, &location,
			       sizeof(location));
			btrfs_read_locked_inode(inode);
			unlock_new_inode(inode);
		}
	}
	return d_splice_alias(inode, dentry);
}

static unsigned char btrfs_filetype_table[] = {
	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
};

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_I(inode)->root;
	struct btrfs_item *item;
	struct btrfs_dir_item *di;
	struct btrfs_key key;
1021
	struct btrfs_key found_key;
C
Chris Mason 已提交
1022 1023 1024
	struct btrfs_path *path;
	int ret;
	u32 nritems;
1025
	struct extent_buffer *leaf;
C
Chris Mason 已提交
1026 1027 1028 1029 1030 1031 1032 1033
	int slot;
	int advance;
	unsigned char d_type;
	int over = 0;
	u32 di_cur;
	u32 di_total;
	u32 di_len;
	int key_type = BTRFS_DIR_INDEX_KEY;
1034 1035 1036
	char tmp_name[32];
	char *name_ptr;
	int name_len;
C
Chris Mason 已提交
1037 1038 1039 1040

	/* FIXME, use a real flag for deciding about the key type */
	if (root->fs_info->tree_root == root)
		key_type = BTRFS_DIR_ITEM_KEY;
1041

C
Chris Mason 已提交
1042 1043 1044 1045
	mutex_lock(&root->fs_info->fs_mutex);
	key.objectid = inode->i_ino;
	btrfs_set_key_type(&key, key_type);
	key.offset = filp->f_pos;
1046

C
Chris Mason 已提交
1047
	path = btrfs_alloc_path();
1048
	path->reada = 2;
C
Chris Mason 已提交
1049 1050 1051 1052 1053
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto err;
	advance = 0;
	while(1) {
1054 1055
		leaf = path->nodes[0];
		nritems = btrfs_header_nritems(leaf);
C
Chris Mason 已提交
1056 1057 1058 1059 1060 1061
		slot = path->slots[0];
		if (advance || slot >= nritems) {
			if (slot >= nritems -1) {
				ret = btrfs_next_leaf(root, path);
				if (ret)
					break;
1062 1063
				leaf = path->nodes[0];
				nritems = btrfs_header_nritems(leaf);
C
Chris Mason 已提交
1064 1065 1066 1067 1068 1069 1070
				slot = path->slots[0];
			} else {
				slot++;
				path->slots[0]++;
			}
		}
		advance = 1;
1071 1072 1073 1074
		item = btrfs_item_nr(leaf, slot);
		btrfs_item_key_to_cpu(leaf, &found_key, slot);

		if (found_key.objectid != key.objectid)
C
Chris Mason 已提交
1075
			break;
1076
		if (btrfs_key_type(&found_key) != key_type)
C
Chris Mason 已提交
1077
			break;
1078
		if (found_key.offset < filp->f_pos)
C
Chris Mason 已提交
1079
			continue;
1080 1081

		filp->f_pos = found_key.offset;
C
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1082 1083 1084
		advance = 1;
		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
		di_cur = 0;
1085
		di_total = btrfs_item_size(leaf, item);
C
Chris Mason 已提交
1086
		while(di_cur < di_total) {
1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104
			struct btrfs_key location;

			name_len = btrfs_dir_name_len(leaf, di);
			if (name_len < 32) {
				name_ptr = tmp_name;
			} else {
				name_ptr = kmalloc(name_len, GFP_NOFS);
				BUG_ON(!name_ptr);
			}
			read_extent_buffer(leaf, name_ptr,
					   (unsigned long)(di + 1), name_len);

			d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
			btrfs_dir_item_key_to_cpu(leaf, di, &location);

			over = filldir(dirent, name_ptr, name_len,
				       found_key.offset,
				       location.objectid,
C
Chris Mason 已提交
1105
				       d_type);
1106 1107 1108 1109

			if (name_ptr != tmp_name)
				kfree(name_ptr);

C
Chris Mason 已提交
1110 1111
			if (over)
				goto nopos;
1112
			di_len = btrfs_dir_name_len(leaf, di) + sizeof(*di);
C
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1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143
			di_cur += di_len;
			di = (struct btrfs_dir_item *)((char *)di + di_len);
		}
	}
	filp->f_pos++;
nopos:
	ret = 0;
err:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	mutex_unlock(&root->fs_info->fs_mutex);
	return ret;
}

int btrfs_write_inode(struct inode *inode, int wait)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
	int ret = 0;

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

/*
1144
 * This is somewhat expensive, updating the tree every time the
C
Chris Mason 已提交
1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168
 * inode changes.  But, it is most likely to find the inode in cache.
 * FIXME, needs more benchmarking...there are no reasons other than performance
 * to keep or drop this code.
 */
void btrfs_dirty_inode(struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_trans_block_group(trans, inode);
	btrfs_update_inode(trans, root, inode);
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
}

static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
				     struct btrfs_root *root,
				     u64 objectid,
				     struct btrfs_block_group_cache *group,
				     int mode)
{
	struct inode *inode;
1169
	struct btrfs_inode_item *inode_item;
C
Chris Mason 已提交
1170
	struct btrfs_key *location;
1171
	struct btrfs_path *path;
C
Chris Mason 已提交
1172 1173 1174
	int ret;
	int owner;

1175 1176 1177
	path = btrfs_alloc_path();
	BUG_ON(!path);

C
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1178 1179 1180 1181
	inode = new_inode(root->fs_info->sb);
	if (!inode)
		return ERR_PTR(-ENOMEM);

1182 1183
	extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
			     inode->i_mapping, GFP_NOFS);
C
Chris Mason 已提交
1184
	BTRFS_I(inode)->root = root;
1185

C
Chris Mason 已提交
1186 1187 1188 1189 1190 1191 1192
	if (mode & S_IFDIR)
		owner = 0;
	else
		owner = 1;
	group = btrfs_find_block_group(root, group, 0, 0, owner);
	BTRFS_I(inode)->block_group = group;

1193 1194 1195 1196
	ret = btrfs_insert_empty_inode(trans, root, path, objectid);
	if (ret)
		goto fail;

C
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1197 1198 1199 1200 1201 1202
	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;
1203 1204 1205 1206 1207 1208
	inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
				  struct btrfs_inode_item);
	fill_inode_item(path->nodes[0], inode_item, inode);
	btrfs_mark_buffer_dirty(path->nodes[0]);
	btrfs_free_path(path);

C
Chris Mason 已提交
1209 1210 1211 1212 1213 1214 1215
	location = &BTRFS_I(inode)->location;
	location->objectid = objectid;
	location->offset = 0;
	btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);

	insert_inode_hash(inode);
	return inode;
1216 1217 1218
fail:
	btrfs_free_path(path);
	return ERR_PTR(ret);
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Chris Mason 已提交
1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231
}

static inline u8 btrfs_inode_type(struct inode *inode)
{
	return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
}

static int btrfs_add_link(struct btrfs_trans_handle *trans,
			    struct dentry *dentry, struct inode *inode)
{
	int ret;
	struct btrfs_key key;
	struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1232
	struct inode *parent_inode;
1233

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1234 1235 1236 1237 1238 1239 1240 1241 1242
	key.objectid = inode->i_ino;
	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
	key.offset = 0;

	ret = btrfs_insert_dir_item(trans, root,
				    dentry->d_name.name, dentry->d_name.len,
				    dentry->d_parent->d_inode->i_ino,
				    &key, btrfs_inode_type(inode));
	if (ret == 0) {
1243 1244 1245
		parent_inode = dentry->d_parent->d_inode;
		parent_inode->i_size += dentry->d_name.len * 2;
		parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
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Chris Mason 已提交
1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264
		ret = btrfs_update_inode(trans, root,
					 dentry->d_parent->d_inode);
	}
	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;
	}
	if (err > 0)
		err = -EEXIST;
	return err;
}

J
Josef Bacik 已提交
1265 1266 1267 1268 1269 1270 1271 1272 1273
static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
			int mode, dev_t rdev)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct inode *inode;
	int err;
	int drop_inode = 0;
	u64 objectid;
1274
	unsigned long nr;
J
Josef Bacik 已提交
1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301

	if (!new_valid_dev(rdev))
		return -EINVAL;

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_trans_block_group(trans, dir);

	err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
	if (err) {
		err = -ENOSPC;
		goto out_unlock;
	}

	inode = btrfs_new_inode(trans, root, objectid,
				BTRFS_I(dir)->block_group, mode);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_unlock;

	btrfs_set_trans_block_group(trans, inode);
	err = btrfs_add_nondir(trans, dentry, inode);
	if (err)
		drop_inode = 1;
	else {
		inode->i_op = &btrfs_special_inode_operations;
		init_special_inode(inode, inode->i_mode, rdev);
1302
		btrfs_update_inode(trans, root, inode);
J
Josef Bacik 已提交
1303 1304 1305 1306 1307
	}
	dir->i_sb->s_dirt = 1;
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);
out_unlock:
1308
	nr = trans->blocks_used;
J
Josef Bacik 已提交
1309 1310 1311 1312 1313 1314 1315
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);

	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
1316
	btrfs_btree_balance_dirty(root, nr);
J
Josef Bacik 已提交
1317 1318 1319
	return err;
}

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1320 1321 1322 1323 1324 1325 1326 1327
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_I(dir)->root;
	struct inode *inode;
	int err;
	int drop_inode = 0;
1328
	unsigned long nr;
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Chris Mason 已提交
1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354
	u64 objectid;

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_trans_block_group(trans, dir);

	err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
	if (err) {
		err = -ENOSPC;
		goto out_unlock;
	}

	inode = btrfs_new_inode(trans, root, objectid,
				BTRFS_I(dir)->block_group, mode);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_unlock;

	btrfs_set_trans_block_group(trans, inode);
	err = btrfs_add_nondir(trans, dentry, inode);
	if (err)
		drop_inode = 1;
	else {
		inode->i_mapping->a_ops = &btrfs_aops;
		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
1355 1356
		extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
				     inode->i_mapping, GFP_NOFS);
1357
		BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
C
Chris Mason 已提交
1358 1359 1360 1361 1362
	}
	dir->i_sb->s_dirt = 1;
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);
out_unlock:
1363
	nr = trans->blocks_used;
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Chris Mason 已提交
1364 1365 1366 1367 1368 1369 1370
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);

	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
1371
	btrfs_btree_balance_dirty(root, nr);
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1372 1373 1374 1375 1376 1377 1378 1379 1380
	return err;
}

static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
		      struct dentry *dentry)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct inode *inode = old_dentry->d_inode;
1381
	unsigned long nr;
C
Chris Mason 已提交
1382 1383 1384 1385 1386 1387 1388 1389 1390
	int err;
	int drop_inode = 0;

	if (inode->i_nlink == 0)
		return -ENOENT;

	inc_nlink(inode);
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
1391

C
Chris Mason 已提交
1392 1393 1394
	btrfs_set_trans_block_group(trans, dir);
	atomic_inc(&inode->i_count);
	err = btrfs_add_nondir(trans, dentry, inode);
1395

C
Chris Mason 已提交
1396 1397
	if (err)
		drop_inode = 1;
1398

C
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1399 1400
	dir->i_sb->s_dirt = 1;
	btrfs_update_inode_block_group(trans, dir);
1401
	err = btrfs_update_inode(trans, root, inode);
1402

1403 1404
	if (err)
		drop_inode = 1;
C
Chris Mason 已提交
1405

1406
	nr = trans->blocks_used;
C
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1407 1408 1409 1410 1411 1412 1413
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);

	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
1414
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436
	return err;
}

static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
				struct btrfs_root *root,
				u64 objectid, u64 dirid)
{
	int ret;
	char buf[2];
	struct btrfs_key key;

	buf[0] = '.';
	buf[1] = '.';

	key.objectid = objectid;
	key.offset = 0;
	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);

	ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
				    &key, BTRFS_FT_DIR);
	if (ret)
		goto error;
1437

C
Chris Mason 已提交
1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454
	key.objectid = dirid;
	ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
				    &key, BTRFS_FT_DIR);
	if (ret)
		goto error;
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_I(dir)->root;
	int err = 0;
	int drop_on_err = 0;
	u64 objectid;
1455
	unsigned long nr = 1;
C
Chris Mason 已提交
1456 1457 1458 1459

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_trans_block_group(trans, dir);
1460

C
Chris Mason 已提交
1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477
	if (IS_ERR(trans)) {
		err = PTR_ERR(trans);
		goto out_unlock;
	}

	err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
	if (err) {
		err = -ENOSPC;
		goto out_unlock;
	}

	inode = btrfs_new_inode(trans, root, objectid,
				BTRFS_I(dir)->block_group, S_IFDIR | mode);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_fail;
	}
1478

C
Chris Mason 已提交
1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491
	drop_on_err = 1;
	inode->i_op = &btrfs_dir_inode_operations;
	inode->i_fop = &btrfs_dir_file_operations;
	btrfs_set_trans_block_group(trans, inode);

	err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
	if (err)
		goto out_fail;

	inode->i_size = 6;
	err = btrfs_update_inode(trans, root, inode);
	if (err)
		goto out_fail;
1492

C
Chris Mason 已提交
1493 1494 1495
	err = btrfs_add_link(trans, dentry, inode);
	if (err)
		goto out_fail;
1496

C
Chris Mason 已提交
1497 1498 1499 1500 1501 1502 1503
	d_instantiate(dentry, inode);
	drop_on_err = 0;
	dir->i_sb->s_dirt = 1;
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);

out_fail:
1504
	nr = trans->blocks_used;
C
Chris Mason 已提交
1505
	btrfs_end_transaction(trans, root);
1506

C
Chris Mason 已提交
1507 1508 1509 1510
out_unlock:
	mutex_unlock(&root->fs_info->fs_mutex);
	if (drop_on_err)
		iput(inode);
1511
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
1512 1513 1514
	return err;
}

1515 1516 1517 1518 1519 1520
struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
				    size_t page_offset, u64 start, u64 end,
				    int create)
{
	int ret;
	int err = 0;
1521
	u64 bytenr;
1522 1523 1524 1525 1526 1527 1528 1529
	u64 extent_start = 0;
	u64 extent_end = 0;
	u64 objectid = inode->i_ino;
	u32 found_type;
	int failed_insert = 0;
	struct btrfs_path *path;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_file_extent_item *item;
1530 1531
	struct extent_buffer *leaf;
	struct btrfs_key found_key;
1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550
	struct extent_map *em = NULL;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	struct btrfs_trans_handle *trans = NULL;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	mutex_lock(&root->fs_info->fs_mutex);

again:
	em = lookup_extent_mapping(em_tree, start, end);
	if (em) {
		goto out;
	}
	if (!em) {
		em = alloc_extent_map(GFP_NOFS);
		if (!em) {
			err = -ENOMEM;
			goto out;
		}
1551 1552
		em->start = EXTENT_MAP_HOLE;
		em->end = EXTENT_MAP_HOLE;
1553 1554
	}
	em->bdev = inode->i_sb->s_bdev;
1555 1556
	ret = btrfs_lookup_file_extent(trans, root, path,
				       objectid, start, trans != NULL);
1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567
	if (ret < 0) {
		err = ret;
		goto out;
	}

	if (ret != 0) {
		if (path->slots[0] == 0)
			goto not_found;
		path->slots[0]--;
	}

1568 1569
	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0],
1570 1571
			      struct btrfs_file_extent_item);
	/* are we inside the extent that was found? */
1572 1573 1574
	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
	found_type = btrfs_key_type(&found_key);
	if (found_key.objectid != objectid ||
1575 1576 1577 1578
	    found_type != BTRFS_EXTENT_DATA_KEY) {
		goto not_found;
	}

1579 1580
	found_type = btrfs_file_extent_type(leaf, item);
	extent_start = found_key.offset;
1581 1582
	if (found_type == BTRFS_FILE_EXTENT_REG) {
		extent_end = extent_start +
1583
		       btrfs_file_extent_num_bytes(leaf, item);
1584
		err = 0;
1585
		if (start < extent_start || start >= extent_end) {
1586 1587
			em->start = start;
			if (start < extent_start) {
1588 1589
				if (end < extent_start)
					goto not_found;
1590 1591 1592 1593 1594 1595
				em->end = extent_end - 1;
			} else {
				em->end = end;
			}
			goto not_found_em;
		}
1596 1597
		bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
		if (bytenr == 0) {
1598 1599
			em->start = extent_start;
			em->end = extent_end - 1;
1600 1601
			em->block_start = EXTENT_MAP_HOLE;
			em->block_end = EXTENT_MAP_HOLE;
1602 1603
			goto insert;
		}
1604 1605
		bytenr += btrfs_file_extent_offset(leaf, item);
		em->block_start = bytenr;
1606
		em->block_end = em->block_start +
1607
			btrfs_file_extent_num_bytes(leaf, item) - 1;
1608 1609 1610 1611
		em->start = extent_start;
		em->end = extent_end - 1;
		goto insert;
	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1612
		unsigned long ptr;
1613
		char *map;
1614 1615 1616
		size_t size;
		size_t extent_offset;
		size_t copy_size;
1617

1618 1619
		size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
						    path->slots[0]));
1620
		extent_end = (extent_start + size - 1) |
1621
			((u64)root->sectorsize - 1);
1622
		if (start < extent_start || start >= extent_end) {
1623 1624
			em->start = start;
			if (start < extent_start) {
1625 1626
				if (end < extent_start)
					goto not_found;
1627
				em->end = extent_end;
1628 1629 1630 1631 1632
			} else {
				em->end = end;
			}
			goto not_found_em;
		}
1633 1634 1635 1636 1637 1638 1639 1640
		em->block_start = EXTENT_MAP_INLINE;
		em->block_end = EXTENT_MAP_INLINE;

		if (!page) {
			em->start = extent_start;
			em->end = extent_start + size - 1;
			goto out;
		}
1641

1642
		extent_offset = ((u64)page->index << PAGE_CACHE_SHIFT) -
1643
			extent_start + page_offset;
J
Jens Axboe 已提交
1644
		copy_size = min_t(u64, PAGE_CACHE_SIZE - page_offset,
1645 1646 1647 1648
				size - extent_offset);
		em->start = extent_start + extent_offset;
		em->end = (em->start + copy_size -1) |
			((u64)root->sectorsize -1);
1649 1650
		map = kmap(page);
		ptr = btrfs_file_extent_inline_start(item) + extent_offset;
1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666
		if (create == 0 && !PageUptodate(page)) {
			read_extent_buffer(leaf, map + page_offset, ptr,
					   copy_size);
			flush_dcache_page(page);
		} else if (create && PageUptodate(page)) {
			if (!trans) {
				kunmap(page);
				free_extent_map(em);
				em = NULL;
				btrfs_release_path(root, path);
				trans = btrfs_start_transaction(root, 1);
				goto again;
			}
			write_extent_buffer(leaf, map + page_offset, ptr,
					    copy_size);
			btrfs_mark_buffer_dirty(leaf);
1667 1668
		}
		kunmap(page);
1669
		set_extent_uptodate(em_tree, em->start, em->end, GFP_NOFS);
1670 1671 1672 1673 1674 1675 1676 1677 1678
		goto insert;
	} else {
		printk("unkknown found_type %d\n", found_type);
		WARN_ON(1);
	}
not_found:
	em->start = start;
	em->end = end;
not_found_em:
1679 1680
	em->block_start = EXTENT_MAP_HOLE;
	em->block_end = EXTENT_MAP_HOLE;
1681 1682 1683
insert:
	btrfs_release_path(root, path);
	if (em->start > start || em->end < start) {
1684
		printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->end, start, end);
1685 1686 1687 1688 1689 1690
		err = -EIO;
		goto out;
	}
	ret = add_extent_mapping(em_tree, em);
	if (ret == -EEXIST) {
		free_extent_map(em);
C
Chris Mason 已提交
1691
		em = NULL;
1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716
		failed_insert++;
		if (failed_insert > 5) {
			printk("failing to insert %Lu %Lu\n", start, end);
			err = -EIO;
			goto out;
		}
		goto again;
	}
	err = 0;
out:
	btrfs_free_path(path);
	if (trans) {
		ret = btrfs_end_transaction(trans, root);
		if (!err)
			err = ret;
	}
	mutex_unlock(&root->fs_info->fs_mutex);
	if (err) {
		free_extent_map(em);
		WARN_ON(1);
		return ERR_PTR(err);
	}
	return em;
}

1717
static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
C
Chris Mason 已提交
1718
{
1719
	return extent_bmap(mapping, iblock, btrfs_get_extent);
C
Chris Mason 已提交
1720 1721 1722 1723 1724
}

static int btrfs_prepare_write(struct file *file, struct page *page,
			       unsigned from, unsigned to)
{
1725 1726 1727
	return extent_prepare_write(&BTRFS_I(page->mapping->host)->extent_tree,
				    page->mapping->host, page, from, to,
				    btrfs_get_extent);
C
Chris Mason 已提交
1728 1729
}

1730
int btrfs_readpage(struct file *file, struct page *page)
C
Chris Mason 已提交
1731
{
1732 1733 1734
	struct extent_map_tree *tree;
	tree = &BTRFS_I(page->mapping->host)->extent_tree;
	return extent_read_full_page(tree, page, btrfs_get_extent);
C
Chris Mason 已提交
1735
}
1736
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
C
Chris Mason 已提交
1737
{
1738
	struct extent_map_tree *tree;
1739 1740 1741 1742 1743 1744 1745


	if (current->flags & PF_MEMALLOC) {
		redirty_page_for_writepage(wbc, page);
		unlock_page(page);
		return 0;
	}
1746 1747
	tree = &BTRFS_I(page->mapping->host)->extent_tree;
	return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
C
Chris Mason 已提交
1748 1749
}

C
Chris Mason 已提交
1750 1751 1752 1753 1754 1755 1756 1757 1758

static int btrfs_writepages(struct address_space *mapping,
			    struct writeback_control *wbc)
{
	struct extent_map_tree *tree;
	tree = &BTRFS_I(mapping->host)->extent_tree;
	return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
}

1759
static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
C
Chris Mason 已提交
1760
{
1761 1762
	struct extent_map_tree *tree;
	int ret;
1763

1764 1765 1766 1767 1768 1769
	tree = &BTRFS_I(page->mapping->host)->extent_tree;
	ret = try_release_extent_mapping(tree, page);
	if (ret == 1) {
		ClearPagePrivate(page);
		set_page_private(page, 0);
		page_cache_release(page);
C
Chris Mason 已提交
1770
	}
1771
	return ret;
C
Chris Mason 已提交
1772 1773
}

1774
static void btrfs_invalidatepage(struct page *page, unsigned long offset)
C
Chris Mason 已提交
1775
{
1776
	struct extent_map_tree *tree;
C
Chris Mason 已提交
1777

1778 1779 1780
	tree = &BTRFS_I(page->mapping->host)->extent_tree;
	extent_invalidatepage(tree, page, offset);
	btrfs_releasepage(page, GFP_NOFS);
C
Chris Mason 已提交
1781 1782
}

C
Chris Mason 已提交
1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803
/*
 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
 * called from a page fault handler when a page is first dirtied. Hence we must
 * be careful to check for EOF conditions here. We set the page up correctly
 * for a written page which means we get ENOSPC checking when writing into
 * holes and correct delalloc and unwritten extent mapping on filesystems that
 * support these features.
 *
 * We are not allowed to take the i_mutex here so we have to play games to
 * protect against truncate races as the page could now be beyond EOF.  Because
 * vmtruncate() writes the inode size before removing pages, once we have the
 * page lock we can determine safely if the page is beyond EOF. If it is not
 * beyond EOF, then the page is guaranteed safe against truncation until we
 * unlock the page.
 */
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
{
	struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
	unsigned long end;
	loff_t size;
	int ret = -EINVAL;
1804
	u64 page_start;
C
Chris Mason 已提交
1805

1806
	down_read(&BTRFS_I(inode)->root->snap_sem);
C
Chris Mason 已提交
1807 1808 1809
	lock_page(page);
	wait_on_page_writeback(page);
	size = i_size_read(inode);
1810
	page_start = (u64)page->index << PAGE_CACHE_SHIFT;
1811

C
Chris Mason 已提交
1812
	if ((page->mapping != inode->i_mapping) ||
1813
	    (page_start > size)) {
C
Chris Mason 已提交
1814 1815 1816 1817 1818
		/* page got truncated out from underneath us */
		goto out_unlock;
	}

	/* page is wholly or partially inside EOF */
1819
	if (page_start + PAGE_CACHE_SIZE > size)
C
Chris Mason 已提交
1820 1821 1822 1823
		end = size & ~PAGE_CACHE_MASK;
	else
		end = PAGE_CACHE_SIZE;

1824
	ret = btrfs_cow_one_page(inode, page, end);
C
Chris Mason 已提交
1825 1826

out_unlock:
1827
	up_read(&BTRFS_I(inode)->root->snap_sem);
C
Chris Mason 已提交
1828 1829 1830 1831
	unlock_page(page);
	return ret;
}

C
Chris Mason 已提交
1832 1833 1834 1835 1836
static void btrfs_truncate(struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret;
	struct btrfs_trans_handle *trans;
1837
	unsigned long nr;
C
Chris Mason 已提交
1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852

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

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

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_trans_block_group(trans, inode);

	/* FIXME, add redo link to tree so we don't leak on crash */
	ret = btrfs_truncate_in_trans(trans, root, inode);
	btrfs_update_inode(trans, root, inode);
1853
	nr = trans->blocks_used;
1854

C
Chris Mason 已提交
1855 1856 1857
	ret = btrfs_end_transaction(trans, root);
	BUG_ON(ret);
	mutex_unlock(&root->fs_info->fs_mutex);
1858
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
1859 1860 1861 1862 1863
}

int btrfs_commit_write(struct file *file, struct page *page,
		       unsigned from, unsigned to)
{
1864 1865
	return extent_commit_write(&BTRFS_I(page->mapping->host)->extent_tree,
				   page->mapping->host, page, from, to);
C
Chris Mason 已提交
1866 1867 1868 1869 1870 1871 1872 1873
}

static int create_subvol(struct btrfs_root *root, char *name, int namelen)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_key key;
	struct btrfs_root_item root_item;
	struct btrfs_inode_item *inode_item;
1874
	struct extent_buffer *leaf;
C
Chris Mason 已提交
1875 1876 1877 1878
	struct btrfs_root *new_root;
	struct inode *inode;
	struct inode *dir;
	int ret;
1879
	int err;
C
Chris Mason 已提交
1880 1881
	u64 objectid;
	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
1882
	unsigned long nr = 1;
C
Chris Mason 已提交
1883 1884 1885 1886 1887

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	BUG_ON(!trans);

1888
	leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0, 0);
1889 1890 1891 1892 1893
	if (IS_ERR(leaf))
		return PTR_ERR(leaf);

	btrfs_set_header_nritems(leaf, 0);
	btrfs_set_header_level(leaf, 0);
1894
	btrfs_set_header_bytenr(leaf, leaf->start);
1895 1896 1897 1898 1899 1900
	btrfs_set_header_generation(leaf, trans->transid);
	btrfs_set_header_owner(leaf, root->root_key.objectid);
	write_extent_buffer(leaf, root->fs_info->fsid,
			    (unsigned long)btrfs_header_fsid(leaf),
			    BTRFS_FSID_SIZE);
	btrfs_mark_buffer_dirty(leaf);
C
Chris Mason 已提交
1901 1902 1903

	inode_item = &root_item.inode;
	memset(inode_item, 0, sizeof(*inode_item));
1904 1905 1906 1907 1908
	inode_item->generation = cpu_to_le64(1);
	inode_item->size = cpu_to_le64(3);
	inode_item->nlink = cpu_to_le32(1);
	inode_item->nblocks = cpu_to_le64(1);
	inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
C
Chris Mason 已提交
1909

1910 1911
	btrfs_set_root_bytenr(&root_item, leaf->start);
	btrfs_set_root_level(&root_item, 0);
C
Chris Mason 已提交
1912
	btrfs_set_root_refs(&root_item, 1);
1913 1914
	btrfs_set_root_used(&root_item, 0);

1915 1916
	memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
	root_item.drop_level = 0;
1917 1918 1919

	free_extent_buffer(leaf);
	leaf = NULL;
C
Chris Mason 已提交
1920 1921 1922

	ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
				       0, &objectid);
1923 1924
	if (ret)
		goto fail;
C
Chris Mason 已提交
1925 1926 1927 1928 1929 1930 1931 1932

	btrfs_set_root_dirid(&root_item, new_dirid);

	key.objectid = objectid;
	key.offset = 1;
	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
	ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
				&root_item);
1933 1934
	if (ret)
		goto fail;
C
Chris Mason 已提交
1935 1936 1937 1938 1939 1940 1941 1942 1943

	/*
	 * insert the directory item
	 */
	key.offset = (u64)-1;
	dir = root->fs_info->sb->s_root->d_inode;
	ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
				    name, namelen, dir->i_ino, &key,
				    BTRFS_FT_DIR);
1944 1945
	if (ret)
		goto fail;
C
Chris Mason 已提交
1946 1947

	ret = btrfs_commit_transaction(trans, root);
1948 1949
	if (ret)
		goto fail_commit;
C
Chris Mason 已提交
1950

1951
	new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
C
Chris Mason 已提交
1952 1953 1954 1955 1956 1957 1958
	BUG_ON(!new_root);

	trans = btrfs_start_transaction(new_root, 1);
	BUG_ON(!trans);

	inode = btrfs_new_inode(trans, new_root, new_dirid,
				BTRFS_I(dir)->block_group, S_IFDIR | 0700);
1959 1960
	if (IS_ERR(inode))
		goto fail;
C
Chris Mason 已提交
1961 1962
	inode->i_op = &btrfs_dir_inode_operations;
	inode->i_fop = &btrfs_dir_file_operations;
C
Chris Mason 已提交
1963
	new_root->inode = inode;
C
Chris Mason 已提交
1964 1965

	ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
1966 1967
	if (ret)
		goto fail;
C
Chris Mason 已提交
1968 1969 1970 1971

	inode->i_nlink = 1;
	inode->i_size = 6;
	ret = btrfs_update_inode(trans, new_root, inode);
1972 1973 1974
	if (ret)
		goto fail;
fail:
1975
	nr = trans->blocks_used;
1976 1977 1978 1979
	err = btrfs_commit_transaction(trans, root);
	if (err && !ret)
		ret = err;
fail_commit:
C
Chris Mason 已提交
1980
	mutex_unlock(&root->fs_info->fs_mutex);
1981
	btrfs_btree_balance_dirty(root, nr);
1982
	return ret;
C
Chris Mason 已提交
1983 1984 1985 1986 1987 1988 1989
}

static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_key key;
	struct btrfs_root_item new_root_item;
1990
	struct extent_buffer *tmp;
C
Chris Mason 已提交
1991
	int ret;
1992
	int err;
C
Chris Mason 已提交
1993
	u64 objectid;
1994
	unsigned long nr;
C
Chris Mason 已提交
1995 1996 1997 1998

	if (!root->ref_cows)
		return -EINVAL;

1999 2000 2001 2002
	down_write(&root->snap_sem);
	freeze_bdev(root->fs_info->sb->s_bdev);
	thaw_bdev(root->fs_info->sb->s_bdev, root->fs_info->sb);

C
Chris Mason 已提交
2003 2004 2005 2006 2007
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	BUG_ON(!trans);

	ret = btrfs_update_inode(trans, root, root->inode);
2008 2009
	if (ret)
		goto fail;
C
Chris Mason 已提交
2010 2011 2012

	ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
				       0, &objectid);
2013 2014
	if (ret)
		goto fail;
C
Chris Mason 已提交
2015 2016 2017 2018 2019 2020 2021

	memcpy(&new_root_item, &root->root_item,
	       sizeof(new_root_item));

	key.objectid = objectid;
	key.offset = 1;
	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2022

2023
	btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
2024 2025
	btrfs_set_root_bytenr(&new_root_item, root->node->start);
	btrfs_set_root_level(&new_root_item, btrfs_header_level(root->node));
C
Chris Mason 已提交
2026 2027 2028

	ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
				&new_root_item);
2029 2030
	if (ret)
		goto fail;
C
Chris Mason 已提交
2031 2032 2033 2034 2035 2036 2037 2038 2039 2040

	/*
	 * insert the directory item
	 */
	key.offset = (u64)-1;
	ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
				    name, namelen,
				    root->fs_info->sb->s_root->d_inode->i_ino,
				    &key, BTRFS_FT_DIR);

2041 2042
	if (ret)
		goto fail;
C
Chris Mason 已提交
2043 2044

	ret = btrfs_inc_root_ref(trans, root);
2045 2046 2047
	if (ret)
		goto fail;
fail:
2048
	nr = trans->blocks_used;
2049
	err = btrfs_commit_transaction(trans, root);
2050

2051 2052
	if (err && !ret)
		ret = err;
2053

C
Chris Mason 已提交
2054
	mutex_unlock(&root->fs_info->fs_mutex);
2055
	up_write(&root->snap_sem);
2056
	btrfs_btree_balance_dirty(root, nr);
2057
	return ret;
C
Chris Mason 已提交
2058 2059
}

2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105
static unsigned long force_ra(struct address_space *mapping,
			      struct file_ra_state *ra, struct file *file,
			      pgoff_t offset, pgoff_t last_index)
{
	pgoff_t req_size;

#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
	req_size = last_index - offset + 1;
	offset = page_cache_readahead(mapping, ra, file, offset, req_size);
	return offset;
#else
	req_size = min(last_index - offset + 1, (pgoff_t)128);
	page_cache_sync_readahead(mapping, ra, file, offset, req_size);
	return offset + req_size;
#endif
}

int btrfs_defrag_file(struct file *file) {
	struct inode *inode = file->f_path.dentry->d_inode;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	struct page *page;
	unsigned long last_index;
	unsigned long ra_index = 0;
	u64 page_start;
	u64 page_end;
	unsigned long i;

	mutex_lock(&inode->i_mutex);
	last_index = inode->i_size >> PAGE_CACHE_SHIFT;
	for (i = 0; i <= last_index; i++) {
		if (i == ra_index) {
			ra_index = force_ra(inode->i_mapping, &file->f_ra,
					    file, ra_index, last_index);
		}
		page = grab_cache_page(inode->i_mapping, i);
		if (!page)
			goto out_unlock;
		if (!PageUptodate(page)) {
			btrfs_readpage(NULL, page);
			lock_page(page);
			if (!PageUptodate(page)) {
				unlock_page(page);
				page_cache_release(page);
				goto out_unlock;
			}
		}
2106
		page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123
		page_end = page_start + PAGE_CACHE_SIZE - 1;

		lock_extent(em_tree, page_start, page_end, GFP_NOFS);
		set_extent_delalloc(em_tree, page_start,
				    page_end, GFP_NOFS);
		unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
		set_page_dirty(page);
		unlock_page(page);
		page_cache_release(page);
		balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
	}

out_unlock:
	mutex_unlock(&inode->i_mutex);
	return 0;
}

C
Christoph Hellwig 已提交
2124
static int btrfs_ioctl_snap_create(struct btrfs_root *root, void __user *arg)
C
Chris Mason 已提交
2125 2126 2127 2128
{
	struct btrfs_ioctl_vol_args vol_args;
	struct btrfs_dir_item *di;
	struct btrfs_path *path;
C
Christoph Hellwig 已提交
2129
	int namelen;
C
Chris Mason 已提交
2130 2131
	u64 root_dirid;

C
Christoph Hellwig 已提交
2132 2133
	if (copy_from_user(&vol_args, arg, sizeof(vol_args)))
		return -EFAULT;
2134

C
Christoph Hellwig 已提交
2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168
	namelen = strlen(vol_args.name);
	if (namelen > BTRFS_VOL_NAME_MAX)
		return -EINVAL;
	if (strchr(vol_args.name, '/'))
		return -EINVAL;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
	mutex_lock(&root->fs_info->fs_mutex);
	di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
			    path, root_dirid,
			    vol_args.name, namelen, 0);
	mutex_unlock(&root->fs_info->fs_mutex);
	btrfs_free_path(path);
	if (di && !IS_ERR(di))
		return -EEXIST;
	if (IS_ERR(di))
		return PTR_ERR(di);

	if (root == root->fs_info->tree_root)
		return create_subvol(root, vol_args.name, namelen);
	return create_snapshot(root, vol_args.name, namelen);
}

static int btrfs_ioctl_defrag(struct file *file)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	struct btrfs_root *root = BTRFS_I(inode)->root;

	switch (inode->i_mode & S_IFMT) {
	case S_IFDIR:
C
Chris Mason 已提交
2169
		mutex_lock(&root->fs_info->fs_mutex);
C
Christoph Hellwig 已提交
2170 2171
		btrfs_defrag_root(root, 0);
		btrfs_defrag_root(root->fs_info->extent_root, 0);
C
Chris Mason 已提交
2172 2173
		mutex_unlock(&root->fs_info->fs_mutex);
		break;
C
Christoph Hellwig 已提交
2174 2175 2176 2177 2178 2179 2180
	case S_IFREG:
		btrfs_defrag_file(file);
		break;
	}

	return 0;
}
2181

C
Christoph Hellwig 已提交
2182 2183 2184 2185 2186 2187 2188 2189
long btrfs_ioctl(struct file *file, unsigned int
		cmd, unsigned long arg)
{
	struct btrfs_root *root = BTRFS_I(file->f_path.dentry->d_inode)->root;

	switch (cmd) {
	case BTRFS_IOC_SNAP_CREATE:
		return btrfs_ioctl_snap_create(root, (void __user *)arg);
2190
	case BTRFS_IOC_DEFRAG:
C
Christoph Hellwig 已提交
2191
		return btrfs_ioctl_defrag(file);
C
Chris Mason 已提交
2192
	}
C
Christoph Hellwig 已提交
2193 2194

	return -ENOTTY;
C
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2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206
}

/*
 * Called inside transaction, so use GFP_NOFS
 */
struct inode *btrfs_alloc_inode(struct super_block *sb)
{
	struct btrfs_inode *ei;

	ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
	if (!ei)
		return NULL;
2207
	ei->last_trans = 0;
C
Chris Mason 已提交
2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218
	return &ei->vfs_inode;
}

void btrfs_destroy_inode(struct inode *inode)
{
	WARN_ON(!list_empty(&inode->i_dentry));
	WARN_ON(inode->i_data.nrpages);

	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}

2219 2220 2221
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
static void init_once(struct kmem_cache * cachep, void *foo)
#else
C
Chris Mason 已提交
2222 2223
static void init_once(void * foo, struct kmem_cache * cachep,
		      unsigned long flags)
2224
#endif
C
Chris Mason 已提交
2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244
{
	struct btrfs_inode *ei = (struct btrfs_inode *) foo;

	inode_init_once(&ei->vfs_inode);
}

void btrfs_destroy_cachep(void)
{
	if (btrfs_inode_cachep)
		kmem_cache_destroy(btrfs_inode_cachep);
	if (btrfs_trans_handle_cachep)
		kmem_cache_destroy(btrfs_trans_handle_cachep);
	if (btrfs_transaction_cachep)
		kmem_cache_destroy(btrfs_transaction_cachep);
	if (btrfs_bit_radix_cachep)
		kmem_cache_destroy(btrfs_bit_radix_cachep);
	if (btrfs_path_cachep)
		kmem_cache_destroy(btrfs_path_cachep);
}

2245
struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2246
				       unsigned long extra_flags,
2247 2248 2249
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
				       void (*ctor)(struct kmem_cache *, void *)
#else
2250
				       void (*ctor)(void *, struct kmem_cache *,
2251 2252 2253
						    unsigned long)
#endif
				     )
2254 2255 2256 2257 2258 2259 2260 2261 2262
{
	return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
				 SLAB_MEM_SPREAD | extra_flags), ctor
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
				 ,NULL
#endif
				);
}

C
Chris Mason 已提交
2263 2264
int btrfs_init_cachep(void)
{
2265
	btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2266 2267
					  sizeof(struct btrfs_inode),
					  0, init_once);
C
Chris Mason 已提交
2268 2269
	if (!btrfs_inode_cachep)
		goto fail;
2270 2271 2272 2273
	btrfs_trans_handle_cachep =
			btrfs_cache_create("btrfs_trans_handle_cache",
					   sizeof(struct btrfs_trans_handle),
					   0, NULL);
C
Chris Mason 已提交
2274 2275
	if (!btrfs_trans_handle_cachep)
		goto fail;
2276
	btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
C
Chris Mason 已提交
2277
					     sizeof(struct btrfs_transaction),
2278
					     0, NULL);
C
Chris Mason 已提交
2279 2280
	if (!btrfs_transaction_cachep)
		goto fail;
2281
	btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2282
					 sizeof(struct btrfs_path),
2283
					 0, NULL);
C
Chris Mason 已提交
2284 2285
	if (!btrfs_path_cachep)
		goto fail;
2286
	btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2287
					      SLAB_DESTROY_BY_RCU, NULL);
C
Chris Mason 已提交
2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320
	if (!btrfs_bit_radix_cachep)
		goto fail;
	return 0;
fail:
	btrfs_destroy_cachep();
	return -ENOMEM;
}

static int btrfs_getattr(struct vfsmount *mnt,
			 struct dentry *dentry, struct kstat *stat)
{
	struct inode *inode = dentry->d_inode;
	generic_fillattr(inode, stat);
	stat->blksize = 256 * 1024;
	return 0;
}

static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
			   struct inode * new_dir,struct dentry *new_dentry)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(old_dir)->root;
	struct inode *new_inode = new_dentry->d_inode;
	struct inode *old_inode = old_dentry->d_inode;
	struct timespec ctime = CURRENT_TIME;
	struct btrfs_path *path;
	struct btrfs_dir_item *di;
	int ret;

	if (S_ISDIR(old_inode->i_mode) && new_inode &&
	    new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
		return -ENOTEMPTY;
	}
2321

C
Chris Mason 已提交
2322 2323
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
2324

C
Chris Mason 已提交
2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335
	btrfs_set_trans_block_group(trans, new_dir);
	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out_fail;
	}

	old_dentry->d_inode->i_nlink++;
	old_dir->i_ctime = old_dir->i_mtime = ctime;
	new_dir->i_ctime = new_dir->i_mtime = ctime;
	old_inode->i_ctime = ctime;
2336

C
Chris Mason 已提交
2337 2338
	if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
		struct btrfs_key *location = &BTRFS_I(new_dir)->location;
2339
		struct btrfs_key old_parent_key;
C
Chris Mason 已提交
2340 2341 2342 2343 2344 2345 2346 2347 2348 2349
		di = btrfs_lookup_dir_item(trans, root, path, old_inode->i_ino,
					   "..", 2, -1);
		if (IS_ERR(di)) {
			ret = PTR_ERR(di);
			goto out_fail;
		}
		if (!di) {
			ret = -ENOENT;
			goto out_fail;
		}
2350
		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &old_parent_key);
C
Chris Mason 已提交
2351 2352 2353 2354 2355 2356 2357 2358
		ret = btrfs_del_item(trans, root, path);
		if (ret) {
			goto out_fail;
		}
		btrfs_release_path(root, path);

		di = btrfs_lookup_dir_index_item(trans, root, path,
						 old_inode->i_ino,
2359
						 old_parent_key.objectid,
C
Chris Mason 已提交
2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416
						 "..", 2, -1);
		if (IS_ERR(di)) {
			ret = PTR_ERR(di);
			goto out_fail;
		}
		if (!di) {
			ret = -ENOENT;
			goto out_fail;
		}
		ret = btrfs_del_item(trans, root, path);
		if (ret) {
			goto out_fail;
		}
		btrfs_release_path(root, path);

		ret = btrfs_insert_dir_item(trans, root, "..", 2,
					    old_inode->i_ino, location,
					    BTRFS_FT_DIR);
		if (ret)
			goto out_fail;
	}


	ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
	if (ret)
		goto out_fail;

	if (new_inode) {
		new_inode->i_ctime = CURRENT_TIME;
		ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
		if (ret)
			goto out_fail;
	}
	ret = btrfs_add_link(trans, new_dentry, old_inode);
	if (ret)
		goto out_fail;

out_fail:
	btrfs_free_path(path);
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	return ret;
}

static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
			 const char *symname)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct inode *inode;
	int err;
	int drop_inode = 0;
	u64 objectid;
	int name_len;
	int datasize;
2417
	unsigned long ptr;
C
Chris Mason 已提交
2418
	struct btrfs_file_extent_item *ei;
2419
	struct extent_buffer *leaf;
2420
	unsigned long nr;
C
Chris Mason 已提交
2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448

	name_len = strlen(symname) + 1;
	if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
		return -ENAMETOOLONG;
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_trans_block_group(trans, dir);

	err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
	if (err) {
		err = -ENOSPC;
		goto out_unlock;
	}

	inode = btrfs_new_inode(trans, root, objectid,
				BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_unlock;

	btrfs_set_trans_block_group(trans, inode);
	err = btrfs_add_nondir(trans, dentry, inode);
	if (err)
		drop_inode = 1;
	else {
		inode->i_mapping->a_ops = &btrfs_aops;
		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
2449 2450
		extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
				     inode->i_mapping, GFP_NOFS);
2451
		BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
C
Chris Mason 已提交
2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466
	}
	dir->i_sb->s_dirt = 1;
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);
	if (drop_inode)
		goto out_unlock;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	key.objectid = inode->i_ino;
	key.offset = 0;
	btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
	datasize = btrfs_file_extent_calc_inline_size(name_len);
	err = btrfs_insert_empty_item(trans, root, path, &key,
				      datasize);
2467 2468 2469 2470
	if (err) {
		drop_inode = 1;
		goto out_unlock;
	}
2471 2472 2473 2474 2475
	leaf = path->nodes[0];
	ei = btrfs_item_ptr(leaf, path->slots[0],
			    struct btrfs_file_extent_item);
	btrfs_set_file_extent_generation(leaf, ei, trans->transid);
	btrfs_set_file_extent_type(leaf, ei,
C
Chris Mason 已提交
2476 2477
				   BTRFS_FILE_EXTENT_INLINE);
	ptr = btrfs_file_extent_inline_start(ei);
2478 2479
	write_extent_buffer(leaf, symname, ptr, name_len);
	btrfs_mark_buffer_dirty(leaf);
C
Chris Mason 已提交
2480
	btrfs_free_path(path);
2481

C
Chris Mason 已提交
2482 2483 2484
	inode->i_op = &btrfs_symlink_inode_operations;
	inode->i_mapping->a_ops = &btrfs_symlink_aops;
	inode->i_size = name_len - 1;
2485 2486 2487
	err = btrfs_update_inode(trans, root, inode);
	if (err)
		drop_inode = 1;
C
Chris Mason 已提交
2488 2489

out_unlock:
2490
	nr = trans->blocks_used;
C
Chris Mason 已提交
2491 2492 2493 2494 2495 2496
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
2497
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510
	return err;
}

static struct inode_operations btrfs_dir_inode_operations = {
	.lookup		= btrfs_lookup,
	.create		= btrfs_create,
	.unlink		= btrfs_unlink,
	.link		= btrfs_link,
	.mkdir		= btrfs_mkdir,
	.rmdir		= btrfs_rmdir,
	.rename		= btrfs_rename,
	.symlink	= btrfs_symlink,
	.setattr	= btrfs_setattr,
J
Josef Bacik 已提交
2511
	.mknod		= btrfs_mknod,
C
Chris Mason 已提交
2512 2513 2514 2515 2516 2517 2518 2519 2520 2521
};

static struct inode_operations btrfs_dir_ro_inode_operations = {
	.lookup		= btrfs_lookup,
};

static struct file_operations btrfs_dir_file_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.readdir	= btrfs_readdir,
C
Christoph Hellwig 已提交
2522
	.unlocked_ioctl	= btrfs_ioctl,
C
Chris Mason 已提交
2523
#ifdef CONFIG_COMPAT
C
Christoph Hellwig 已提交
2524
	.compat_ioctl	= btrfs_ioctl,
C
Chris Mason 已提交
2525 2526 2527
#endif
};

2528 2529 2530 2531 2532 2533 2534
static struct extent_map_ops btrfs_extent_map_ops = {
	.fill_delalloc = run_delalloc_range,
	.writepage_io_hook = btrfs_writepage_io_hook,
	.readpage_io_hook = btrfs_readpage_io_hook,
	.readpage_end_io_hook = btrfs_readpage_end_io_hook,
};

C
Chris Mason 已提交
2535 2536 2537
static struct address_space_operations btrfs_aops = {
	.readpage	= btrfs_readpage,
	.writepage	= btrfs_writepage,
C
Chris Mason 已提交
2538
	.writepages	= btrfs_writepages,
C
Chris Mason 已提交
2539 2540 2541 2542
	.sync_page	= block_sync_page,
	.prepare_write	= btrfs_prepare_write,
	.commit_write	= btrfs_commit_write,
	.bmap		= btrfs_bmap,
2543 2544 2545
	.invalidatepage = btrfs_invalidatepage,
	.releasepage	= btrfs_releasepage,
	.set_page_dirty	= __set_page_dirty_nobuffers,
C
Chris Mason 已提交
2546 2547 2548 2549 2550
};

static struct address_space_operations btrfs_symlink_aops = {
	.readpage	= btrfs_readpage,
	.writepage	= btrfs_writepage,
C
Chris Mason 已提交
2551 2552
	.invalidatepage = btrfs_invalidatepage,
	.releasepage	= btrfs_releasepage,
C
Chris Mason 已提交
2553 2554 2555 2556 2557 2558 2559 2560
};

static struct inode_operations btrfs_file_inode_operations = {
	.truncate	= btrfs_truncate,
	.getattr	= btrfs_getattr,
	.setattr	= btrfs_setattr,
};

J
Josef Bacik 已提交
2561 2562 2563 2564 2565
static struct inode_operations btrfs_special_inode_operations = {
	.getattr	= btrfs_getattr,
	.setattr	= btrfs_setattr,
};

C
Chris Mason 已提交
2566 2567 2568 2569 2570
static struct inode_operations btrfs_symlink_inode_operations = {
	.readlink	= generic_readlink,
	.follow_link	= page_follow_link_light,
	.put_link	= page_put_link,
};