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