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 */ 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