inode.c 66.2 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 <linux/xattr.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, num_bytes,
				 root->root_key.objectid, trans->transid,
				 inode->i_ino, start, 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;
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	ret = btrfs_del_inode_ref(trans, root, name, name_len,
				  dentry->d_inode->i_ino,
				  dentry->d_parent->d_inode->i_ino);
	if (ret) {
		printk("failed to delete reference to %.*s, "
		       "inode %lu parent %lu\n", name_len, name,
		       dentry->d_inode->i_ino,
		       dentry->d_parent->d_inode->i_ino);
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	}
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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_trans_handle *trans;
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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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	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_trans_block_group(trans, dir);

	/* now the directory is empty */
	err = btrfs_unlink_trans(trans, root, dir, dentry);
	if (!err) {
		inode->i_size = 0;
	}
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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;
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	struct btrfs_key found_key;
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	u32 found_type;
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	struct extent_buffer *leaf;
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	struct btrfs_file_extent_item *fi;
	u64 extent_start = 0;
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	u64 extent_num_bytes = 0;
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	u64 item_end = 0;
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	u64 root_gen = 0;
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	u64 root_owner = 0;
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	int found_extent;
	int del_item;
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	int extent_type = -1;
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	btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
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	path = btrfs_alloc_path();
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	path->reada = -1;
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	BUG_ON(!path);
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	/* FIXME, add redo link to tree so we don't leak on crash */
	key.objectid = inode->i_ino;
	key.offset = (u64)-1;
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	key.type = (u8)-1;

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	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]--;
		}
553 554 555
		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
556

557
		if (found_key.objectid != inode->i_ino)
C
Chris Mason 已提交
558
			break;
559

C
Chris Mason 已提交
560 561 562 563 564 565
		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;

566
		item_end = found_key.offset;
C
Chris Mason 已提交
567
		if (found_type == BTRFS_EXTENT_DATA_KEY) {
568
			fi = btrfs_item_ptr(leaf, path->slots[0],
C
Chris Mason 已提交
569
					    struct btrfs_file_extent_item);
570 571
			extent_type = btrfs_file_extent_type(leaf, fi);
			if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
572
				item_end +=
573
				    btrfs_file_extent_num_bytes(leaf, fi);
574 575 576 577 578
			} 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
Chris Mason 已提交
579
			}
580
			item_end--;
C
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581 582 583 584 585 586
		}
		if (found_type == BTRFS_CSUM_ITEM_KEY) {
			ret = btrfs_csum_truncate(trans, root, path,
						  inode->i_size);
			BUG_ON(ret);
		}
587
		if (item_end < inode->i_size) {
588 589 590 591 592 593 594 595
			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
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596
			}
597
			btrfs_set_key_type(&key, found_type);
Y
Yan 已提交
598
			btrfs_release_path(root, path);
599
			continue;
C
Chris Mason 已提交
600
		}
601
		if (found_key.offset >= inode->i_size)
C
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602 603 604 605 606 607
			del_item = 1;
		else
			del_item = 0;
		found_extent = 0;

		/* FIXME, shrink the extent if the ref count is only 1 */
608 609 610 611
		if (found_type != BTRFS_EXTENT_DATA_KEY)
			goto delete;

		if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
C
Chris Mason 已提交
612
			u64 num_dec;
613
			extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
C
Chris Mason 已提交
614
			if (!del_item) {
615 616 617
				u64 orig_num_bytes =
					btrfs_file_extent_num_bytes(leaf, fi);
				extent_num_bytes = inode->i_size -
618
					found_key.offset + root->sectorsize - 1;
619 620 621 622
				btrfs_set_file_extent_num_bytes(leaf, fi,
							 extent_num_bytes);
				num_dec = (orig_num_bytes -
					   extent_num_bytes) >> 9;
623 624 625
				if (extent_start != 0) {
					inode->i_blocks -= num_dec;
				}
626
				btrfs_mark_buffer_dirty(leaf);
C
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627
			} else {
628 629 630
				extent_num_bytes =
					btrfs_file_extent_disk_num_bytes(leaf,
									 fi);
C
Chris Mason 已提交
631
				/* FIXME blocksize != 4096 */
632 633
				num_dec = btrfs_file_extent_num_bytes(leaf,
								       fi) >> 9;
C
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634 635 636 637
				if (extent_start != 0) {
					found_extent = 1;
					inode->i_blocks -= num_dec;
				}
638 639
				root_gen = btrfs_header_generation(leaf);
				root_owner = btrfs_header_owner(leaf);
C
Chris Mason 已提交
640
			}
641 642 643 644 645 646 647
		} 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
Chris Mason 已提交
648
		}
649
delete:
C
Chris Mason 已提交
650 651
		if (del_item) {
			ret = btrfs_del_item(trans, root, path);
652 653
			if (ret)
				goto error;
C
Chris Mason 已提交
654 655 656 657 658 659
		} else {
			break;
		}
		btrfs_release_path(root, path);
		if (found_extent) {
			ret = btrfs_free_extent(trans, root, extent_start,
660
						extent_num_bytes,
661
						root_owner,
662 663
						root_gen, inode->i_ino,
						found_key.offset, 0);
C
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664 665 666 667 668 669 670 671 672 673 674
			BUG_ON(ret);
		}
	}
	ret = 0;
error:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	inode->i_sb->s_dirt = 1;
	return ret;
}

675
static int btrfs_cow_one_page(struct inode *inode, struct page *page,
676 677 678 679
			      size_t zero_start)
{
	char *kaddr;
	int ret = 0;
680
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
681
	u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
682
	u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
683

684
	set_page_extent_mapped(page);
685

686 687 688
	lock_extent(em_tree, page_start, page_end, GFP_NOFS);
	set_extent_delalloc(&BTRFS_I(inode)->extent_tree, page_start,
			    page_end, GFP_NOFS);
689
	if (zero_start != PAGE_CACHE_SIZE) {
690
		kaddr = kmap(page);
691 692
		memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
		flush_dcache_page(page);
693
		kunmap(page);
694
	}
695 696
	set_page_dirty(page);
	unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
697 698 699 700

	return ret;
}

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701 702 703 704 705 706 707
/*
 * 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;
708 709
	struct btrfs_root *root = BTRFS_I(inode)->root;
	u32 blocksize = root->sectorsize;
C
Chris Mason 已提交
710 711 712 713
	pgoff_t index = from >> PAGE_CACHE_SHIFT;
	unsigned offset = from & (PAGE_CACHE_SIZE-1);
	struct page *page;
	int ret = 0;
714
	u64 page_start;
C
Chris Mason 已提交
715 716 717 718

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

719
	down_read(&root->snap_sem);
C
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720 721 722 723 724
	ret = -ENOMEM;
	page = grab_cache_page(mapping, index);
	if (!page)
		goto out;
	if (!PageUptodate(page)) {
C
Chris Mason 已提交
725
		ret = btrfs_readpage(NULL, page);
C
Chris Mason 已提交
726 727 728 729 730 731
		lock_page(page);
		if (!PageUptodate(page)) {
			ret = -EIO;
			goto out;
		}
	}
732
	page_start = (u64)page->index << PAGE_CACHE_SHIFT;
733

734
	ret = btrfs_cow_one_page(inode, page, offset);
C
Chris Mason 已提交
735 736 737

	unlock_page(page);
	page_cache_release(page);
738
	up_read(&BTRFS_I(inode)->root->snap_sem);
C
Chris Mason 已提交
739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755
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
Chris Mason 已提交
756 757
		struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;

758
		u64 mask = root->sectorsize - 1;
C
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759
		u64 pos = (inode->i_size + mask) & ~mask;
C
Chris Mason 已提交
760
		u64 block_end = attr->ia_size | mask;
C
Chris Mason 已提交
761
		u64 hole_size;
762
		u64 alloc_hint = 0;
C
Chris Mason 已提交
763 764 765 766 767 768

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

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

C
Chris Mason 已提交
769
		lock_extent(em_tree, pos, block_end, GFP_NOFS);
C
Chris Mason 已提交
770 771 772 773 774
		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
775
		err = btrfs_drop_extents(trans, root, inode,
776 777
					 pos, pos + hole_size, pos,
					 &alloc_hint);
C
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778

779 780 781 782 783
		if (alloc_hint != EXTENT_MAP_INLINE) {
			err = btrfs_insert_file_extent(trans, root,
						       inode->i_ino,
						       pos, 0, 0, hole_size);
		}
C
Chris Mason 已提交
784 785
		btrfs_end_transaction(trans, root);
		mutex_unlock(&root->fs_info->fs_mutex);
C
Chris Mason 已提交
786
		unlock_extent(em_tree, pos, block_end, GFP_NOFS);
787 788
		if (err)
			return err;
C
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789 790 791 792 793 794 795 796 797 798
	}
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;
799
	unsigned long nr;
C
Chris Mason 已提交
800 801 802 803 804 805
	int ret;

	truncate_inode_pages(&inode->i_data, 0);
	if (is_bad_inode(inode)) {
		goto no_delete;
	}
806

C
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807 808 809
	inode->i_size = 0;
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
810

C
Chris Mason 已提交
811 812
	btrfs_set_trans_block_group(trans, inode);
	ret = btrfs_truncate_in_trans(trans, root, inode);
J
Josef Bacik 已提交
813 814 815
	if (ret)
		goto no_delete_lock;
	ret = btrfs_delete_xattrs(trans, root, inode);
816 817 818 819 820
	if (ret)
		goto no_delete_lock;
	ret = btrfs_free_inode(trans, root, inode);
	if (ret)
		goto no_delete_lock;
821
	nr = trans->blocks_used;
822

C
Chris Mason 已提交
823 824
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
825
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
826
	return;
827 828

no_delete_lock:
829
	nr = trans->blocks_used;
830 831
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
832
	btrfs_btree_balance_dirty(root, nr);
C
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833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848
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
849
	int ret = 0;
C
Chris Mason 已提交
850

851 852 853 854 855 856
	if (namelen == 1 && strcmp(name, ".") == 0) {
		location->objectid = dir->i_ino;
		location->type = BTRFS_INODE_ITEM_KEY;
		location->offset = 0;
		return 0;
	}
C
Chris Mason 已提交
857 858
	path = btrfs_alloc_path();
	BUG_ON(!path);
859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889

	if (namelen == 1 && strcmp(name, "..") == 0) {
		struct btrfs_key key;
		struct extent_buffer *leaf;
		u32 nritems;
		int slot;

		key.objectid = dir->i_ino;
		btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
		key.offset = 0;
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		BUG_ON(ret == 0);
		ret = 0;

		leaf = path->nodes[0];
		slot = path->slots[0];
		nritems = btrfs_header_nritems(leaf);
		if (slot >= nritems)
			goto out_err;

		btrfs_item_key_to_cpu(leaf, &key, slot);
		if (key.objectid != dir->i_ino ||
		    key.type != BTRFS_INODE_REF_KEY) {
			goto out_err;
		}
		location->objectid = key.offset;
		location->type = BTRFS_INODE_ITEM_KEY;
		location->offset = 0;
		goto out;
	}

C
Chris Mason 已提交
890 891
	di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
				    namelen, 0);
Y
Yan 已提交
892 893
	if (IS_ERR(di))
		ret = PTR_ERR(di);
C
Chris Mason 已提交
894
	if (!di || IS_ERR(di)) {
895
		goto out_err;
C
Chris Mason 已提交
896
	}
897
	btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
C
Chris Mason 已提交
898 899 900
out:
	btrfs_free_path(path);
	return ret;
901 902 903
out_err:
	location->objectid = 0;
	goto out;
C
Chris Mason 已提交
904 905 906 907 908 909 910 911 912
}

/*
 * 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,
913 914
			     struct btrfs_root **sub_root,
			     struct dentry *dentry)
C
Chris Mason 已提交
915 916 917 918 919 920 921 922 923 924 925 926 927
{
	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);

928 929 930
	*sub_root = btrfs_read_fs_root(root->fs_info, location,
					dentry->d_name.name,
					dentry->d_name.len);
C
Chris Mason 已提交
931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948
	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;
949 950
	extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
			     inode->i_mapping, GFP_NOFS);
C
Chris Mason 已提交
951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986
	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);
987

C
Chris Mason 已提交
988 989 990
	mutex_lock(&root->fs_info->fs_mutex);
	ret = btrfs_inode_by_name(dir, dentry, &location);
	mutex_unlock(&root->fs_info->fs_mutex);
991

C
Chris Mason 已提交
992 993
	if (ret < 0)
		return ERR_PTR(ret);
994

C
Chris Mason 已提交
995 996
	inode = NULL;
	if (location.objectid) {
997 998
		ret = fixup_tree_root_location(root, &location, &sub_root,
						dentry);
C
Chris Mason 已提交
999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033
		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;
1034
	struct btrfs_key found_key;
C
Chris Mason 已提交
1035 1036 1037
	struct btrfs_path *path;
	int ret;
	u32 nritems;
1038
	struct extent_buffer *leaf;
C
Chris Mason 已提交
1039 1040 1041 1042 1043 1044 1045 1046
	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;
1047 1048 1049
	char tmp_name[32];
	char *name_ptr;
	int name_len;
C
Chris Mason 已提交
1050 1051 1052 1053

	/* FIXME, use a real flag for deciding about the key type */
	if (root->fs_info->tree_root == root)
		key_type = BTRFS_DIR_ITEM_KEY;
1054

1055 1056 1057 1058 1059 1060 1061 1062 1063 1064
	/* special case for "." */
	if (filp->f_pos == 0) {
		over = filldir(dirent, ".", 1,
			       1, inode->i_ino,
			       DT_DIR);
		if (over)
			return 0;
		filp->f_pos = 1;
	}

C
Chris Mason 已提交
1065 1066
	mutex_lock(&root->fs_info->fs_mutex);
	key.objectid = inode->i_ino;
1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095
	path = btrfs_alloc_path();
	path->reada = 2;

	/* special case for .., just use the back ref */
	if (filp->f_pos == 1) {
		btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
		key.offset = 0;
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		BUG_ON(ret == 0);
		leaf = path->nodes[0];
		slot = path->slots[0];
		nritems = btrfs_header_nritems(leaf);
		if (slot >= nritems) {
			btrfs_release_path(root, path);
			goto read_dir_items;
		}
		btrfs_item_key_to_cpu(leaf, &found_key, slot);
		btrfs_release_path(root, path);
		if (found_key.objectid != key.objectid ||
		    found_key.type != BTRFS_INODE_REF_KEY)
			goto read_dir_items;
		over = filldir(dirent, "..", 2,
			       2, found_key.offset, DT_DIR);
		if (over)
			goto nopos;
		filp->f_pos = 2;
	}

read_dir_items:
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Chris Mason 已提交
1096 1097
	btrfs_set_key_type(&key, key_type);
	key.offset = filp->f_pos;
1098

C
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1099 1100 1101 1102 1103
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto err;
	advance = 0;
	while(1) {
1104 1105
		leaf = path->nodes[0];
		nritems = btrfs_header_nritems(leaf);
C
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1106 1107 1108 1109 1110 1111
		slot = path->slots[0];
		if (advance || slot >= nritems) {
			if (slot >= nritems -1) {
				ret = btrfs_next_leaf(root, path);
				if (ret)
					break;
1112 1113
				leaf = path->nodes[0];
				nritems = btrfs_header_nritems(leaf);
C
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1114 1115 1116 1117 1118 1119 1120
				slot = path->slots[0];
			} else {
				slot++;
				path->slots[0]++;
			}
		}
		advance = 1;
1121 1122 1123 1124
		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
1125
			break;
1126
		if (btrfs_key_type(&found_key) != key_type)
C
Chris Mason 已提交
1127
			break;
1128
		if (found_key.offset < filp->f_pos)
C
Chris Mason 已提交
1129
			continue;
1130 1131

		filp->f_pos = found_key.offset;
C
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1132 1133 1134
		advance = 1;
		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
		di_cur = 0;
1135
		di_total = btrfs_item_size(leaf, item);
C
Chris Mason 已提交
1136
		while(di_cur < di_total) {
1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154
			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
1155
				       d_type);
1156 1157 1158 1159

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

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1160 1161
			if (over)
				goto nopos;
J
Josef Bacik 已提交
1162 1163
			di_len = btrfs_dir_name_len(leaf, di) +
				btrfs_dir_data_len(leaf, di) +sizeof(*di);
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1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194
			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;
}

/*
1195
 * This is somewhat expensive, updating the tree every time the
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Chris Mason 已提交
1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219
 * 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;
1220
	struct btrfs_inode_item *inode_item;
C
Chris Mason 已提交
1221
	struct btrfs_key *location;
1222
	struct btrfs_path *path;
C
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1223 1224 1225
	int ret;
	int owner;

1226 1227 1228
	path = btrfs_alloc_path();
	BUG_ON(!path);

C
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1229 1230 1231 1232
	inode = new_inode(root->fs_info->sb);
	if (!inode)
		return ERR_PTR(-ENOMEM);

1233 1234
	extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
			     inode->i_mapping, GFP_NOFS);
C
Chris Mason 已提交
1235
	BTRFS_I(inode)->root = root;
1236

C
Chris Mason 已提交
1237 1238 1239 1240 1241 1242 1243
	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;

1244 1245 1246 1247
	ret = btrfs_insert_empty_inode(trans, root, path, objectid);
	if (ret)
		goto fail;

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Chris Mason 已提交
1248 1249 1250 1251 1252 1253
	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;
1254 1255 1256 1257 1258 1259
	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);

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1260 1261 1262 1263 1264 1265 1266
	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;
1267 1268 1269
fail:
	btrfs_free_path(path);
	return ERR_PTR(ret);
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Chris Mason 已提交
1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282
}

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;
1283
	struct inode *parent_inode;
1284

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Chris Mason 已提交
1285 1286 1287 1288 1289 1290 1291 1292 1293
	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) {
1294 1295 1296 1297 1298
		ret = btrfs_insert_inode_ref(trans, root,
				     dentry->d_name.name,
				     dentry->d_name.len,
				     inode->i_ino,
				     dentry->d_parent->d_inode->i_ino);
1299 1300 1301
		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
1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320
		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;
}

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Josef Bacik 已提交
1321 1322 1323 1324 1325 1326 1327 1328 1329
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;
1330
	unsigned long nr;
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Josef Bacik 已提交
1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357

	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);
1358
		btrfs_update_inode(trans, root, inode);
J
Josef Bacik 已提交
1359 1360 1361 1362 1363
	}
	dir->i_sb->s_dirt = 1;
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);
out_unlock:
1364
	nr = trans->blocks_used;
J
Josef Bacik 已提交
1365 1366 1367 1368 1369 1370 1371
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);

	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
1372
	btrfs_btree_balance_dirty(root, nr);
J
Josef Bacik 已提交
1373 1374 1375
	return err;
}

C
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1376 1377 1378 1379 1380 1381 1382 1383
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;
1384
	unsigned long nr;
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Chris Mason 已提交
1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410
	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;
1411 1412
		extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
				     inode->i_mapping, GFP_NOFS);
1413
		BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
C
Chris Mason 已提交
1414 1415 1416 1417 1418
	}
	dir->i_sb->s_dirt = 1;
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);
out_unlock:
1419
	nr = trans->blocks_used;
C
Chris Mason 已提交
1420 1421 1422 1423 1424 1425 1426
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);

	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
1427
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
1428 1429 1430 1431 1432 1433 1434 1435 1436
	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;
1437
	unsigned long nr;
C
Chris Mason 已提交
1438 1439 1440 1441 1442 1443 1444 1445 1446
	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);
1447

C
Chris Mason 已提交
1448 1449 1450
	btrfs_set_trans_block_group(trans, dir);
	atomic_inc(&inode->i_count);
	err = btrfs_add_nondir(trans, dentry, inode);
1451

C
Chris Mason 已提交
1452 1453
	if (err)
		drop_inode = 1;
1454

C
Chris Mason 已提交
1455 1456
	dir->i_sb->s_dirt = 1;
	btrfs_update_inode_block_group(trans, dir);
1457
	err = btrfs_update_inode(trans, root, inode);
1458

1459 1460
	if (err)
		drop_inode = 1;
C
Chris Mason 已提交
1461

1462
	nr = trans->blocks_used;
C
Chris Mason 已提交
1463 1464 1465 1466 1467 1468 1469
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);

	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
1470
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481
	return err;
}

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;
1482
	unsigned long nr = 1;
C
Chris Mason 已提交
1483 1484 1485 1486

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_trans_block_group(trans, dir);
1487

C
Chris Mason 已提交
1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504
	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;
	}
1505

C
Chris Mason 已提交
1506 1507 1508 1509 1510
	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);

1511
	inode->i_size = 0;
C
Chris Mason 已提交
1512 1513 1514
	err = btrfs_update_inode(trans, root, inode);
	if (err)
		goto out_fail;
1515

C
Chris Mason 已提交
1516 1517 1518
	err = btrfs_add_link(trans, dentry, inode);
	if (err)
		goto out_fail;
1519

C
Chris Mason 已提交
1520 1521 1522 1523 1524 1525 1526
	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:
1527
	nr = trans->blocks_used;
C
Chris Mason 已提交
1528
	btrfs_end_transaction(trans, root);
1529

C
Chris Mason 已提交
1530 1531 1532 1533
out_unlock:
	mutex_unlock(&root->fs_info->fs_mutex);
	if (drop_on_err)
		iput(inode);
1534
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
1535 1536 1537
	return err;
}

1538 1539 1540 1541 1542 1543
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;
1544
	u64 bytenr;
1545 1546 1547 1548 1549 1550 1551 1552
	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;
1553 1554
	struct extent_buffer *leaf;
	struct btrfs_key found_key;
1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573
	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;
		}
1574 1575
		em->start = EXTENT_MAP_HOLE;
		em->end = EXTENT_MAP_HOLE;
1576 1577
	}
	em->bdev = inode->i_sb->s_bdev;
1578 1579
	ret = btrfs_lookup_file_extent(trans, root, path,
				       objectid, start, trans != NULL);
1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590
	if (ret < 0) {
		err = ret;
		goto out;
	}

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

1591 1592
	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0],
1593 1594
			      struct btrfs_file_extent_item);
	/* are we inside the extent that was found? */
1595 1596 1597
	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
	found_type = btrfs_key_type(&found_key);
	if (found_key.objectid != objectid ||
1598 1599 1600 1601
	    found_type != BTRFS_EXTENT_DATA_KEY) {
		goto not_found;
	}

1602 1603
	found_type = btrfs_file_extent_type(leaf, item);
	extent_start = found_key.offset;
1604 1605
	if (found_type == BTRFS_FILE_EXTENT_REG) {
		extent_end = extent_start +
1606
		       btrfs_file_extent_num_bytes(leaf, item);
1607
		err = 0;
1608
		if (start < extent_start || start >= extent_end) {
1609 1610
			em->start = start;
			if (start < extent_start) {
1611 1612
				if (end < extent_start)
					goto not_found;
1613 1614 1615 1616 1617 1618
				em->end = extent_end - 1;
			} else {
				em->end = end;
			}
			goto not_found_em;
		}
1619 1620
		bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
		if (bytenr == 0) {
1621 1622
			em->start = extent_start;
			em->end = extent_end - 1;
1623 1624
			em->block_start = EXTENT_MAP_HOLE;
			em->block_end = EXTENT_MAP_HOLE;
1625 1626
			goto insert;
		}
1627 1628
		bytenr += btrfs_file_extent_offset(leaf, item);
		em->block_start = bytenr;
1629
		em->block_end = em->block_start +
1630
			btrfs_file_extent_num_bytes(leaf, item) - 1;
1631 1632 1633 1634
		em->start = extent_start;
		em->end = extent_end - 1;
		goto insert;
	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1635
		unsigned long ptr;
1636
		char *map;
1637 1638 1639
		size_t size;
		size_t extent_offset;
		size_t copy_size;
1640

1641 1642
		size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
						    path->slots[0]));
1643
		extent_end = (extent_start + size - 1) |
1644
			((u64)root->sectorsize - 1);
1645
		if (start < extent_start || start >= extent_end) {
1646 1647
			em->start = start;
			if (start < extent_start) {
1648 1649
				if (end < extent_start)
					goto not_found;
1650
				em->end = extent_end;
1651 1652 1653 1654 1655
			} else {
				em->end = end;
			}
			goto not_found_em;
		}
1656 1657 1658 1659 1660 1661 1662 1663
		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;
		}
1664

1665
		extent_offset = ((u64)page->index << PAGE_CACHE_SHIFT) -
1666
			extent_start + page_offset;
J
Jens Axboe 已提交
1667
		copy_size = min_t(u64, PAGE_CACHE_SIZE - page_offset,
1668 1669 1670 1671
				size - extent_offset);
		em->start = extent_start + extent_offset;
		em->end = (em->start + copy_size -1) |
			((u64)root->sectorsize -1);
1672 1673
		map = kmap(page);
		ptr = btrfs_file_extent_inline_start(item) + extent_offset;
1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689
		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);
1690 1691
		}
		kunmap(page);
1692
		set_extent_uptodate(em_tree, em->start, em->end, GFP_NOFS);
1693 1694 1695 1696 1697 1698 1699 1700 1701
		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:
1702 1703
	em->block_start = EXTENT_MAP_HOLE;
	em->block_end = EXTENT_MAP_HOLE;
1704 1705 1706
insert:
	btrfs_release_path(root, path);
	if (em->start > start || em->end < start) {
1707
		printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->end, start, end);
1708 1709 1710 1711 1712 1713
		err = -EIO;
		goto out;
	}
	ret = add_extent_mapping(em_tree, em);
	if (ret == -EEXIST) {
		free_extent_map(em);
C
Chris Mason 已提交
1714
		em = NULL;
1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739
		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;
}

1740
static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
C
Chris Mason 已提交
1741
{
1742
	return extent_bmap(mapping, iblock, btrfs_get_extent);
C
Chris Mason 已提交
1743 1744 1745 1746 1747
}

static int btrfs_prepare_write(struct file *file, struct page *page,
			       unsigned from, unsigned to)
{
1748 1749 1750
	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
1751 1752
}

1753
int btrfs_readpage(struct file *file, struct page *page)
C
Chris Mason 已提交
1754
{
1755 1756 1757
	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
1758
}
1759
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
C
Chris Mason 已提交
1760
{
1761
	struct extent_map_tree *tree;
1762 1763 1764 1765 1766 1767 1768


	if (current->flags & PF_MEMALLOC) {
		redirty_page_for_writepage(wbc, page);
		unlock_page(page);
		return 0;
	}
1769 1770
	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
1771 1772
}

C
Chris Mason 已提交
1773 1774 1775 1776 1777 1778 1779 1780
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);
}

C
Chris Mason 已提交
1781 1782 1783 1784 1785 1786 1787 1788 1789 1790
static int
btrfs_readpages(struct file *file, struct address_space *mapping,
		struct list_head *pages, unsigned nr_pages)
{
	struct extent_map_tree *tree;
	tree = &BTRFS_I(mapping->host)->extent_tree;
	return extent_readpages(tree, mapping, pages, nr_pages,
				btrfs_get_extent);
}

1791
static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
C
Chris Mason 已提交
1792
{
1793 1794
	struct extent_map_tree *tree;
	int ret;
1795

1796 1797 1798 1799 1800 1801
	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
1802
	}
1803
	return ret;
C
Chris Mason 已提交
1804 1805
}

1806
static void btrfs_invalidatepage(struct page *page, unsigned long offset)
C
Chris Mason 已提交
1807
{
1808
	struct extent_map_tree *tree;
C
Chris Mason 已提交
1809

1810 1811 1812
	tree = &BTRFS_I(page->mapping->host)->extent_tree;
	extent_invalidatepage(tree, page, offset);
	btrfs_releasepage(page, GFP_NOFS);
C
Chris Mason 已提交
1813 1814
}

C
Chris Mason 已提交
1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835
/*
 * 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;
1836
	u64 page_start;
C
Chris Mason 已提交
1837

1838
	down_read(&BTRFS_I(inode)->root->snap_sem);
C
Chris Mason 已提交
1839 1840 1841
	lock_page(page);
	wait_on_page_writeback(page);
	size = i_size_read(inode);
1842
	page_start = (u64)page->index << PAGE_CACHE_SHIFT;
1843

C
Chris Mason 已提交
1844
	if ((page->mapping != inode->i_mapping) ||
1845
	    (page_start > size)) {
C
Chris Mason 已提交
1846 1847 1848 1849 1850
		/* page got truncated out from underneath us */
		goto out_unlock;
	}

	/* page is wholly or partially inside EOF */
1851
	if (page_start + PAGE_CACHE_SIZE > size)
C
Chris Mason 已提交
1852 1853 1854 1855
		end = size & ~PAGE_CACHE_MASK;
	else
		end = PAGE_CACHE_SIZE;

1856
	ret = btrfs_cow_one_page(inode, page, end);
C
Chris Mason 已提交
1857 1858

out_unlock:
1859
	up_read(&BTRFS_I(inode)->root->snap_sem);
C
Chris Mason 已提交
1860 1861 1862 1863
	unlock_page(page);
	return ret;
}

C
Chris Mason 已提交
1864 1865 1866 1867 1868
static void btrfs_truncate(struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret;
	struct btrfs_trans_handle *trans;
1869
	unsigned long nr;
C
Chris Mason 已提交
1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884

	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);
1885
	nr = trans->blocks_used;
1886

C
Chris Mason 已提交
1887 1888 1889
	ret = btrfs_end_transaction(trans, root);
	BUG_ON(ret);
	mutex_unlock(&root->fs_info->fs_mutex);
1890
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
1891 1892 1893 1894 1895
}

int btrfs_commit_write(struct file *file, struct page *page,
		       unsigned from, unsigned to)
{
1896 1897
	return extent_commit_write(&BTRFS_I(page->mapping->host)->extent_tree,
				   page->mapping->host, page, from, to);
C
Chris Mason 已提交
1898 1899 1900 1901 1902 1903 1904 1905
}

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;
1906
	struct extent_buffer *leaf;
C
Chris Mason 已提交
1907 1908 1909 1910
	struct btrfs_root *new_root;
	struct inode *inode;
	struct inode *dir;
	int ret;
1911
	int err;
C
Chris Mason 已提交
1912 1913
	u64 objectid;
	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
1914
	unsigned long nr = 1;
C
Chris Mason 已提交
1915 1916 1917 1918 1919

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

1920 1921 1922 1923 1924 1925 1926 1927
	ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
				       0, &objectid);
	if (ret)
		goto fail;

	leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
					objectid, trans->transid, 0, 0,
					0, 0);
1928 1929 1930 1931 1932
	if (IS_ERR(leaf))
		return PTR_ERR(leaf);

	btrfs_set_header_nritems(leaf, 0);
	btrfs_set_header_level(leaf, 0);
1933
	btrfs_set_header_bytenr(leaf, leaf->start);
1934
	btrfs_set_header_generation(leaf, trans->transid);
1935 1936
	btrfs_set_header_owner(leaf, objectid);

1937 1938 1939 1940
	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
1941 1942 1943

	inode_item = &root_item.inode;
	memset(inode_item, 0, sizeof(*inode_item));
1944 1945 1946 1947 1948
	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
1949

1950 1951
	btrfs_set_root_bytenr(&root_item, leaf->start);
	btrfs_set_root_level(&root_item, 0);
C
Chris Mason 已提交
1952
	btrfs_set_root_refs(&root_item, 1);
1953 1954
	btrfs_set_root_used(&root_item, 0);

1955 1956
	memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
	root_item.drop_level = 0;
1957 1958 1959

	free_extent_buffer(leaf);
	leaf = NULL;
C
Chris Mason 已提交
1960 1961 1962 1963 1964 1965 1966 1967

	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);
1968 1969
	if (ret)
		goto fail;
C
Chris Mason 已提交
1970 1971 1972 1973 1974 1975 1976 1977 1978

	/*
	 * 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);
1979 1980
	if (ret)
		goto fail;
C
Chris Mason 已提交
1981

1982 1983 1984 1985 1986 1987
	ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
			     name, namelen, objectid,
			     root->fs_info->sb->s_root->d_inode->i_ino);
	if (ret)
		goto fail;

C
Chris Mason 已提交
1988
	ret = btrfs_commit_transaction(trans, root);
1989 1990
	if (ret)
		goto fail_commit;
C
Chris Mason 已提交
1991

1992
	new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
C
Chris Mason 已提交
1993 1994 1995 1996 1997 1998 1999
	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);
2000 2001
	if (IS_ERR(inode))
		goto fail;
C
Chris Mason 已提交
2002 2003
	inode->i_op = &btrfs_dir_inode_operations;
	inode->i_fop = &btrfs_dir_file_operations;
C
Chris Mason 已提交
2004
	new_root->inode = inode;
C
Chris Mason 已提交
2005

2006 2007
	ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
				     new_dirid);
C
Chris Mason 已提交
2008
	inode->i_nlink = 1;
2009
	inode->i_size = 0;
C
Chris Mason 已提交
2010
	ret = btrfs_update_inode(trans, new_root, inode);
2011 2012 2013
	if (ret)
		goto fail;
fail:
2014
	nr = trans->blocks_used;
2015 2016 2017 2018
	err = btrfs_commit_transaction(trans, root);
	if (err && !ret)
		ret = err;
fail_commit:
C
Chris Mason 已提交
2019
	mutex_unlock(&root->fs_info->fs_mutex);
2020
	btrfs_btree_balance_dirty(root, nr);
2021
	return ret;
C
Chris Mason 已提交
2022 2023 2024 2025 2026 2027 2028
}

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;
2029
	struct extent_buffer *tmp;
C
Chris Mason 已提交
2030
	int ret;
2031
	int err;
C
Chris Mason 已提交
2032
	u64 objectid;
2033
	unsigned long nr;
C
Chris Mason 已提交
2034 2035 2036 2037

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

2038 2039 2040 2041
	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
2042 2043 2044 2045 2046
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	BUG_ON(!trans);

	ret = btrfs_update_inode(trans, root, root->inode);
2047 2048
	if (ret)
		goto fail;
C
Chris Mason 已提交
2049 2050 2051

	ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
				       0, &objectid);
2052 2053
	if (ret)
		goto fail;
C
Chris Mason 已提交
2054 2055 2056 2057 2058 2059 2060

	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);
2061
	extent_buffer_get(root->node);
2062
	btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
2063
	free_extent_buffer(tmp);
2064 2065
	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
2066 2067
	ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
				&new_root_item);
2068 2069
	if (ret)
		goto fail;
C
Chris Mason 已提交
2070 2071 2072 2073 2074 2075 2076 2077 2078 2079

	/*
	 * 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);

2080 2081
	if (ret)
		goto fail;
C
Chris Mason 已提交
2082

2083 2084 2085 2086 2087 2088 2089
	ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
			     name, namelen, objectid,
			     root->fs_info->sb->s_root->d_inode->i_ino);

	if (ret)
		goto fail;

2090
	ret = btrfs_inc_root_ref(trans, root, objectid);
2091 2092 2093
	if (ret)
		goto fail;
fail:
2094
	nr = trans->blocks_used;
2095
	err = btrfs_commit_transaction(trans, root);
2096

2097 2098
	if (err && !ret)
		ret = err;
2099

C
Chris Mason 已提交
2100
	mutex_unlock(&root->fs_info->fs_mutex);
2101
	up_write(&root->snap_sem);
2102
	btrfs_btree_balance_dirty(root, nr);
2103
	return ret;
C
Chris Mason 已提交
2104 2105
}

2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151
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;
			}
		}
2152
		page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169
		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
2170
static int btrfs_ioctl_snap_create(struct btrfs_root *root, void __user *arg)
C
Chris Mason 已提交
2171 2172 2173 2174
{
	struct btrfs_ioctl_vol_args vol_args;
	struct btrfs_dir_item *di;
	struct btrfs_path *path;
C
Christoph Hellwig 已提交
2175
	int namelen;
C
Chris Mason 已提交
2176 2177
	u64 root_dirid;

C
Christoph Hellwig 已提交
2178 2179
	if (copy_from_user(&vol_args, arg, sizeof(vol_args)))
		return -EFAULT;
2180

C
Christoph Hellwig 已提交
2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214
	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
2215
		mutex_lock(&root->fs_info->fs_mutex);
C
Christoph Hellwig 已提交
2216 2217
		btrfs_defrag_root(root, 0);
		btrfs_defrag_root(root->fs_info->extent_root, 0);
C
Chris Mason 已提交
2218 2219
		mutex_unlock(&root->fs_info->fs_mutex);
		break;
C
Christoph Hellwig 已提交
2220 2221 2222 2223 2224 2225 2226
	case S_IFREG:
		btrfs_defrag_file(file);
		break;
	}

	return 0;
}
2227

C
Christoph Hellwig 已提交
2228 2229 2230 2231 2232 2233 2234 2235
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);
2236
	case BTRFS_IOC_DEFRAG:
C
Christoph Hellwig 已提交
2237
		return btrfs_ioctl_defrag(file);
C
Chris Mason 已提交
2238
	}
C
Christoph Hellwig 已提交
2239 2240

	return -ENOTTY;
C
Chris Mason 已提交
2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252
}

/*
 * 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;
2253
	ei->last_trans = 0;
C
Chris Mason 已提交
2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264
	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));
}

2265 2266 2267
#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
2268 2269
static void init_once(void * foo, struct kmem_cache * cachep,
		      unsigned long flags)
2270
#endif
C
Chris Mason 已提交
2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290
{
	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);
}

2291
struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2292
				       unsigned long extra_flags,
2293 2294 2295
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
				       void (*ctor)(struct kmem_cache *, void *)
#else
2296
				       void (*ctor)(void *, struct kmem_cache *,
2297 2298 2299
						    unsigned long)
#endif
				     )
2300 2301 2302 2303 2304 2305 2306 2307 2308
{
	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
2309 2310
int btrfs_init_cachep(void)
{
2311
	btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2312 2313
					  sizeof(struct btrfs_inode),
					  0, init_once);
C
Chris Mason 已提交
2314 2315
	if (!btrfs_inode_cachep)
		goto fail;
2316 2317 2318 2319
	btrfs_trans_handle_cachep =
			btrfs_cache_create("btrfs_trans_handle_cache",
					   sizeof(struct btrfs_trans_handle),
					   0, NULL);
C
Chris Mason 已提交
2320 2321
	if (!btrfs_trans_handle_cachep)
		goto fail;
2322
	btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
C
Chris Mason 已提交
2323
					     sizeof(struct btrfs_transaction),
2324
					     0, NULL);
C
Chris Mason 已提交
2325 2326
	if (!btrfs_transaction_cachep)
		goto fail;
2327
	btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2328
					 sizeof(struct btrfs_path),
2329
					 0, NULL);
C
Chris Mason 已提交
2330 2331
	if (!btrfs_path_cachep)
		goto fail;
2332
	btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2333
					      SLAB_DESTROY_BY_RCU, NULL);
C
Chris Mason 已提交
2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365
	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;
	int ret;

	if (S_ISDIR(old_inode->i_mode) && new_inode &&
	    new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
		return -ENOTEMPTY;
	}
2366

C
Chris Mason 已提交
2367 2368
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
2369

C
Chris Mason 已提交
2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380
	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;
2381

C
Chris Mason 已提交
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
	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;
2416
	unsigned long ptr;
C
Chris Mason 已提交
2417
	struct btrfs_file_extent_item *ei;
2418
	struct extent_buffer *leaf;
2419
	unsigned long nr;
C
Chris Mason 已提交
2420 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

	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;
2448 2449
		extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
				     inode->i_mapping, GFP_NOFS);
2450
		BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
C
Chris Mason 已提交
2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465
	}
	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);
2466 2467 2468 2469
	if (err) {
		drop_inode = 1;
		goto out_unlock;
	}
2470 2471 2472 2473 2474
	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
2475 2476
				   BTRFS_FILE_EXTENT_INLINE);
	ptr = btrfs_file_extent_inline_start(ei);
2477 2478
	write_extent_buffer(leaf, symname, ptr, name_len);
	btrfs_mark_buffer_dirty(leaf);
C
Chris Mason 已提交
2479
	btrfs_free_path(path);
2480

C
Chris Mason 已提交
2481 2482 2483
	inode->i_op = &btrfs_symlink_inode_operations;
	inode->i_mapping->a_ops = &btrfs_symlink_aops;
	inode->i_size = name_len - 1;
2484 2485 2486
	err = btrfs_update_inode(trans, root, inode);
	if (err)
		drop_inode = 1;
C
Chris Mason 已提交
2487 2488

out_unlock:
2489
	nr = trans->blocks_used;
C
Chris Mason 已提交
2490 2491 2492 2493 2494 2495
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
2496
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509
	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
2510
	.mknod		= btrfs_mknod,
J
Josef Bacik 已提交
2511 2512 2513 2514
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr	= btrfs_listxattr,
	.removexattr	= generic_removexattr,
C
Chris Mason 已提交
2515 2516 2517 2518 2519 2520 2521 2522 2523 2524
};

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
2525
	.unlocked_ioctl	= btrfs_ioctl,
C
Chris Mason 已提交
2526
#ifdef CONFIG_COMPAT
C
Christoph Hellwig 已提交
2527
	.compat_ioctl	= btrfs_ioctl,
C
Chris Mason 已提交
2528 2529 2530
#endif
};

2531 2532 2533 2534 2535 2536 2537
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
2538 2539 2540
static struct address_space_operations btrfs_aops = {
	.readpage	= btrfs_readpage,
	.writepage	= btrfs_writepage,
C
Chris Mason 已提交
2541
	.writepages	= btrfs_writepages,
C
Chris Mason 已提交
2542
	.readpages	= btrfs_readpages,
C
Chris Mason 已提交
2543 2544 2545 2546
	.sync_page	= block_sync_page,
	.prepare_write	= btrfs_prepare_write,
	.commit_write	= btrfs_commit_write,
	.bmap		= btrfs_bmap,
2547 2548 2549
	.invalidatepage = btrfs_invalidatepage,
	.releasepage	= btrfs_releasepage,
	.set_page_dirty	= __set_page_dirty_nobuffers,
C
Chris Mason 已提交
2550 2551 2552 2553 2554
};

static struct address_space_operations btrfs_symlink_aops = {
	.readpage	= btrfs_readpage,
	.writepage	= btrfs_writepage,
C
Chris Mason 已提交
2555 2556
	.invalidatepage = btrfs_invalidatepage,
	.releasepage	= btrfs_releasepage,
C
Chris Mason 已提交
2557 2558 2559 2560 2561 2562
};

static struct inode_operations btrfs_file_inode_operations = {
	.truncate	= btrfs_truncate,
	.getattr	= btrfs_getattr,
	.setattr	= btrfs_setattr,
J
Josef Bacik 已提交
2563 2564 2565 2566
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr      = btrfs_listxattr,
	.removexattr	= generic_removexattr,
C
Chris Mason 已提交
2567 2568
};

J
Josef Bacik 已提交
2569 2570 2571 2572 2573
static struct inode_operations btrfs_special_inode_operations = {
	.getattr	= btrfs_getattr,
	.setattr	= btrfs_setattr,
};

C
Chris Mason 已提交
2574 2575 2576 2577 2578
static struct inode_operations btrfs_symlink_inode_operations = {
	.readlink	= generic_readlink,
	.follow_link	= page_follow_link_light,
	.put_link	= page_put_link,
};