btrfs-progs/dir-item.c

#include <stdio.h>
#include <stdlib.h>
#include "kerncompat.h"
#include "radix-tree.h"
#include "ctree.h"
#include "disk-io.h"
#include "hash.h"
#include "transaction.h"

int insert_with_overflow(struct btrfs_trans_handle *trans, struct btrfs_root
			    *root, struct btrfs_path *path, struct btrfs_key
			    *cpu_key, u32 data_size)
{
	int overflow;
	int ret;

	ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
	overflow = btrfs_key_overflow(cpu_key);

	while(ret == -EEXIST && overflow < BTRFS_KEY_OVERFLOW_MAX) {
		overflow++;
		btrfs_set_key_overflow(cpu_key, overflow);
		btrfs_release_path(root, path);
		ret = btrfs_insert_empty_item(trans, root, path, cpu_key,
					      data_size);
	}
	return ret;
}

int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
			  *root, char *name, int name_len, u64 dir, u64
			  objectid, u8 type)
{
	int ret = 0;
	struct btrfs_path path;
	struct btrfs_dir_item *dir_item;
	char *name_ptr;
	struct btrfs_key key;
	u32 data_size;

	key.objectid = dir;
	key.flags = 0;
	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
	if (name_len == 1 && *name == '.')
		key.offset = 1;
	else if (name_len == 2 && name[0] == '.' && name[1] == '.')
		key.offset = 2;
	else
		ret = btrfs_name_hash(name, name_len, &key.offset);
	BUG_ON(ret);
	btrfs_init_path(&path);
	data_size = sizeof(*dir_item) + name_len;
	ret = insert_with_overflow(trans, root, &path, &key, data_size);
	if (ret)
		goto out;

	dir_item = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0],
				  struct btrfs_dir_item);
	btrfs_set_dir_objectid(dir_item, objectid);
	btrfs_set_dir_type(dir_item, type);
	btrfs_set_dir_flags(dir_item, 0);
	btrfs_set_dir_name_len(dir_item, name_len);
	name_ptr = (char *)(dir_item + 1);
	memcpy(name_ptr, name, name_len);

	btrfs_release_path(root, &path);
	btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
	key.offset = objectid;
	ret = insert_with_overflow(trans, root, &path, &key, data_size);
	if (ret)
		goto out;

	dir_item = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0],
				  struct btrfs_dir_item);
	btrfs_set_dir_objectid(dir_item, objectid);
	btrfs_set_dir_type(dir_item, type);
	btrfs_set_dir_flags(dir_item, 0);
	btrfs_set_dir_name_len(dir_item, name_len);
	name_ptr = (char *)(dir_item + 1);
	memcpy(name_ptr, name, name_len);
out:
	btrfs_release_path(root, &path);
	return ret;
}

int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
			  *root, struct btrfs_path *path, u64 dir, char *name,
			  int name_len, int mod)
{
	int ret;
	struct btrfs_key key;
	int ins_len = mod < 0 ? -1 : 0;
	int cow = mod != 0;

	key.objectid = dir;
	key.flags = 0;
	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
	btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX);
	ret = btrfs_name_hash(name, name_len, &key.offset);
	BUG_ON(ret);
	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
	return ret;
}

int btrfs_match_dir_item_name(struct btrfs_root *root,
			      struct btrfs_path *path, char
			      *name, int name_len)
{
	struct btrfs_dir_item *dir_item;
	char *name_ptr;

	dir_item = btrfs_item_ptr(&path->nodes[0]->leaf, path->slots[0],
				  struct btrfs_dir_item);
	if (btrfs_dir_name_len(dir_item) != name_len)
		return 0;
	name_ptr = (char *)(dir_item + 1);
	if (memcmp(name_ptr, name, name_len))
		return 0;
	return 1;
}