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 */ 21 struct ulist_iterator { 22 struct list_head *cur_list; /* hint to start search */ 23 }; 24 25 /* 26 * element of the list 27 */ 28 struct 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 36 struct 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 struct ulist_node *prealloc; 45 }; 46 47 void ulist_init(struct ulist *ulist); 48 void ulist_release(struct ulist *ulist); 49 void ulist_reinit(struct ulist *ulist); 50 struct ulist *ulist_alloc(gfp_t gfp_mask); 51 void ulist_prealloc(struct ulist *ulist, gfp_t mask); 52 void ulist_free(struct ulist *ulist); 53 int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask); 54 int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux, 55 u64 *old_aux, gfp_t gfp_mask); 56 int ulist_del(struct ulist *ulist, u64 val, u64 aux); 57 58 /* just like ulist_add_merge() but take a pointer for the aux data */ 59 static 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 == 32 63 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 #else 68 return ulist_add_merge(ulist, val, (u64)aux, (u64 *)old_aux, gfp_mask); 69 #endif 70 } 71 72 struct 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 #endif 78