1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2011 STRATO AG
4 * written by Arne Jansen <sensille@gmx.net>
5 */
6
7#ifndef BTRFS_ULIST_H
8#define BTRFS_ULIST_H
9
10#include <linux/types.h>
11#include <linux/list.h>
12#include <linux/rbtree.h>
13
14/*
15 * ulist is a generic data structure to hold a collection of unique u64
16 * values. The only operations it supports is adding to the list and
17 * enumerating it.
18 * It is possible to store an auxiliary value along with the key.
19 *
20 */
21struct ulist_iterator {
22 struct list_head *cur_list; /* hint to start search */
23};
24
25/*
26 * element of the list
27 */
28struct ulist_node {
29 u64 val; /* value to store */
30 u64 aux; /* auxiliary value saved along with the val */
31
32 struct list_head list; /* used to link node */
33 struct rb_node rb_node; /* used to speed up search */
34};
35
36struct ulist {
37 /*
38 * number of elements stored in list
39 */
40 unsigned long nnodes;
41
42 struct list_head nodes;
43 struct rb_root root;
44};
45
46void ulist_init(struct ulist *ulist);
47void ulist_release(struct ulist *ulist);
48void ulist_reinit(struct ulist *ulist);
49struct ulist *ulist_alloc(gfp_t gfp_mask);
50void ulist_free(struct ulist *ulist);
51int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask);
52int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,
53 u64 *old_aux, gfp_t gfp_mask);
54int ulist_del(struct ulist *ulist, u64 val, u64 aux);
55
56/* just like ulist_add_merge() but take a pointer for the aux data */
57static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux,
58 void **old_aux, gfp_t gfp_mask)
59{
60#if BITS_PER_LONG == 32
61 u64 old64 = (uintptr_t)*old_aux;
62 int ret = ulist_add_merge(ulist, val, (uintptr_t)aux, &old64, gfp_mask);
63 *old_aux = (void *)((uintptr_t)old64);
64 return ret;
65#else
66 return ulist_add_merge(ulist, val, aux: (u64)aux, old_aux: (u64 *)old_aux, gfp_mask);
67#endif
68}
69
70struct ulist_node *ulist_next(const struct ulist *ulist,
71 struct ulist_iterator *uiter);
72
73#define ULIST_ITER_INIT(uiter) ((uiter)->cur_list = NULL)
74
75#endif
76

source code of linux/fs/btrfs/ulist.h