78 lines · c
1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * Copyright (C) 2011 STRATO AG4 * written by Arne Jansen <sensille@gmx.net>5 */6 7#ifndef BTRFS_ULIST_H8#define BTRFS_ULIST_H9 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 u6416 * values. The only operations it supports is adding to the list and17 * 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 list27 */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 list39 */40 unsigned long nnodes;41 42 struct list_head nodes;43 struct rb_root root;44 struct ulist_node *prealloc;45};46 47void ulist_init(struct ulist *ulist);48void ulist_release(struct ulist *ulist);49void ulist_reinit(struct ulist *ulist);50struct ulist *ulist_alloc(gfp_t gfp_mask);51void ulist_prealloc(struct ulist *ulist, gfp_t mask);52void ulist_free(struct ulist *ulist);53int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask);54int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,55 u64 *old_aux, gfp_t gfp_mask);56int ulist_del(struct ulist *ulist, u64 val, u64 aux);57 58/* just like ulist_add_merge() but take a pointer for the aux data */59static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux,60 void **old_aux, gfp_t gfp_mask)61{62#if BITS_PER_LONG == 3263 u64 old64 = (uintptr_t)*old_aux;64 int ret = ulist_add_merge(ulist, val, (uintptr_t)aux, &old64, gfp_mask);65 *old_aux = (void *)((uintptr_t)old64);66 return ret;67#else68 return ulist_add_merge(ulist, val, (u64)aux, (u64 *)old_aux, gfp_mask);69#endif70}71 72struct ulist_node *ulist_next(const struct ulist *ulist,73 struct ulist_iterator *uiter);74 75#define ULIST_ITER_INIT(uiter) ((uiter)->cur_list = NULL)76 77#endif78