1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2011 STRATO AG
4*4882a593Smuzhiyun * written by Arne Jansen <sensille@gmx.net>
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #ifndef BTRFS_ULIST_H
8*4882a593Smuzhiyun #define BTRFS_ULIST_H
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/list.h>
11*4882a593Smuzhiyun #include <linux/rbtree.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun /*
14*4882a593Smuzhiyun * ulist is a generic data structure to hold a collection of unique u64
15*4882a593Smuzhiyun * values. The only operations it supports is adding to the list and
16*4882a593Smuzhiyun * enumerating it.
17*4882a593Smuzhiyun * It is possible to store an auxiliary value along with the key.
18*4882a593Smuzhiyun *
19*4882a593Smuzhiyun */
20*4882a593Smuzhiyun struct ulist_iterator {
21*4882a593Smuzhiyun struct list_head *cur_list; /* hint to start search */
22*4882a593Smuzhiyun };
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun /*
25*4882a593Smuzhiyun * element of the list
26*4882a593Smuzhiyun */
27*4882a593Smuzhiyun struct ulist_node {
28*4882a593Smuzhiyun u64 val; /* value to store */
29*4882a593Smuzhiyun u64 aux; /* auxiliary value saved along with the val */
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun struct list_head list; /* used to link node */
32*4882a593Smuzhiyun struct rb_node rb_node; /* used to speed up search */
33*4882a593Smuzhiyun };
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun struct ulist {
36*4882a593Smuzhiyun /*
37*4882a593Smuzhiyun * number of elements stored in list
38*4882a593Smuzhiyun */
39*4882a593Smuzhiyun unsigned long nnodes;
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun struct list_head nodes;
42*4882a593Smuzhiyun struct rb_root root;
43*4882a593Smuzhiyun };
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun void ulist_init(struct ulist *ulist);
46*4882a593Smuzhiyun void ulist_release(struct ulist *ulist);
47*4882a593Smuzhiyun void ulist_reinit(struct ulist *ulist);
48*4882a593Smuzhiyun struct ulist *ulist_alloc(gfp_t gfp_mask);
49*4882a593Smuzhiyun void ulist_free(struct ulist *ulist);
50*4882a593Smuzhiyun int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask);
51*4882a593Smuzhiyun int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,
52*4882a593Smuzhiyun u64 *old_aux, gfp_t gfp_mask);
53*4882a593Smuzhiyun int ulist_del(struct ulist *ulist, u64 val, u64 aux);
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun /* 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*4882a593Smuzhiyun static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux,
57*4882a593Smuzhiyun void **old_aux, gfp_t gfp_mask)
58*4882a593Smuzhiyun {
59*4882a593Smuzhiyun #if BITS_PER_LONG == 32
60*4882a593Smuzhiyun u64 old64 = (uintptr_t)*old_aux;
61*4882a593Smuzhiyun int ret = ulist_add_merge(ulist, val, (uintptr_t)aux, &old64, gfp_mask);
62*4882a593Smuzhiyun *old_aux = (void *)((uintptr_t)old64);
63*4882a593Smuzhiyun return ret;
64*4882a593Smuzhiyun #else
65*4882a593Smuzhiyun return ulist_add_merge(ulist, val, (u64)aux, (u64 *)old_aux, gfp_mask);
66*4882a593Smuzhiyun #endif
67*4882a593Smuzhiyun }
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun struct ulist_node *ulist_next(struct ulist *ulist,
70*4882a593Smuzhiyun struct ulist_iterator *uiter);
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun #define ULIST_ITER_INIT(uiter) ((uiter)->cur_list = NULL)
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun #endif
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