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 61 /* just like ulist_add_merge() but take a pointer for the aux data */ 62 static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux, 63 void **old_aux, gfp_t gfp_mask) 64 { 65 #if BITS_PER_LONG == 32 66 u64 old64 = (uintptr_t)*old_aux; 67 int ret = ulist_add_merge(ulist, val, (uintptr_t)aux, &old64, gfp_mask); 68 *old_aux = (void *)((uintptr_t)old64); 69 return ret; 70 #else 71 return ulist_add_merge(ulist, val, (u64)aux, (u64 *)old_aux, gfp_mask); 72 #endif 73 } 74 75 struct ulist_node *ulist_next(struct ulist *ulist, 76 struct ulist_iterator *uiter); 77 78 #define ULIST_ITER_INIT(uiter) ((uiter)->cur_list = NULL) 79 80 #endif 81