1 /* 2 * Copyright (C) 2011 STRATO AG 3 * written by Arne Jansen <sensille@gmx.net> 4 * Distributed under the GNU GPL license version 2. 5 * 6 */ 7 8 #ifndef __ULIST__ 9 #define __ULIST__ 10 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 #ifdef CONFIG_BTRFS_DEBUG 23 int i; 24 #endif 25 struct list_head *cur_list; /* hint to start search */ 26 }; 27 28 /* 29 * element of the list 30 */ 31 struct ulist_node { 32 u64 val; /* value to store */ 33 u64 aux; /* auxiliary value saved along with the val */ 34 35 #ifdef CONFIG_BTRFS_DEBUG 36 int seqnum; /* sequence number this node is added */ 37 #endif 38 39 struct list_head list; /* used to link node */ 40 struct rb_node rb_node; /* used to speed up search */ 41 }; 42 43 struct ulist { 44 /* 45 * number of elements stored in list 46 */ 47 unsigned long nnodes; 48 49 struct list_head nodes; 50 struct rb_root root; 51 }; 52 53 void ulist_init(struct ulist *ulist); 54 void ulist_reinit(struct ulist *ulist); 55 struct ulist *ulist_alloc(gfp_t gfp_mask); 56 void ulist_free(struct ulist *ulist); 57 int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask); 58 int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux, 59 u64 *old_aux, gfp_t gfp_mask); 60 int ulist_del(struct ulist *ulist, u64 val, u64 aux); 61 62 /* just like ulist_add_merge() but take a pointer for the aux data */ 63 static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux, 64 void **old_aux, gfp_t gfp_mask) 65 { 66 #if BITS_PER_LONG == 32 67 u64 old64 = (uintptr_t)*old_aux; 68 int ret = ulist_add_merge(ulist, val, (uintptr_t)aux, &old64, gfp_mask); 69 *old_aux = (void *)((uintptr_t)old64); 70 return ret; 71 #else 72 return ulist_add_merge(ulist, val, (u64)aux, (u64 *)old_aux, gfp_mask); 73 #endif 74 } 75 76 struct ulist_node *ulist_next(struct ulist *ulist, 77 struct ulist_iterator *uiter); 78 79 #define ULIST_ITER_INIT(uiter) ((uiter)->cur_list = NULL) 80 81 #endif 82