linux/fs/btrfs/dir-item.c

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#include <linux/module.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, const char *name, int name_len, u64 dir,
struct btrfs_key *location, 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);
ret = btrfs_name_hash(name, name_len, &key.offset);
BUG_ON(ret);
path = btrfs_alloc_path();
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(btrfs_buffer_leaf(path->nodes[0]),
path->slots[0],
struct btrfs_dir_item);
btrfs_cpu_key_to_disk(&dir_item->location, location);
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);
btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
btrfs_mark_buffer_dirty(path->nodes[0]);
out:
btrfs_release_path(root, path);
btrfs_free_path(path);
return ret;
}
int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, u64 dir,
const char *name, int name_len, int mod)
{
int ret;
struct btrfs_key key;
int ins_len = mod < 0 ? -1 : 0;
int cow = mod != 0;
struct btrfs_disk_key *found_key;
struct btrfs_leaf *leaf;
u32 overflow;
key.objectid = dir;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
// btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
ret = btrfs_name_hash(name, name_len, &key.offset);
BUG_ON(ret);
while(1) {
ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
if (ret < 0)
return ret;
if (ret > 0) {
if (path->slots[0] == 0)
return 1;
path->slots[0]--;
}
leaf = btrfs_buffer_leaf(path->nodes[0]);
found_key = &leaf->items[path->slots[0]].key;
if (btrfs_disk_key_objectid(found_key) != dir ||
btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
btrfs_disk_key_offset(found_key) != key.offset)
return 1;
if (btrfs_match_dir_item_name(root, path, name, name_len))
return 0;
overflow = btrfs_disk_key_overflow(found_key);
if (overflow == 0)
return 1;
btrfs_set_key_overflow(&key, overflow - 1);
btrfs_release_path(root, path);
}
return 1;
}
int btrfs_match_dir_item_name(struct btrfs_root *root,
struct btrfs_path *path,
const char *name, int name_len)
{
struct btrfs_dir_item *dir_item;
char *name_ptr;
dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
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;
}