Line data    Source code

       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      643325 :         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