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Member "btrfs-progs-v5.4/kernel-shared/ulist.h" (3 Dec 2019, 1978 Bytes) of package /linux/misc/btrfs-progs-v5.4.tar.xz:


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    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_H__
    9 #define __ULIST_H__
   10 
   11 #include "kerncompat.h"
   12 #include "kernel-lib/list.h"
   13 #include "kernel-lib/rbtree.h"
   14 
   15 /*
   16  * ulist is a generic data structure to hold a collection of unique u64
   17  * values. The only operations it supports is adding to the list and
   18  * enumerating it.
   19  * It is possible to store an auxiliary value along with the key.
   20  *
   21  */
   22 struct ulist_iterator {
   23     struct list_head *cur_list;  /* hint to start search */
   24 };
   25 
   26 /*
   27  * element of the list
   28  */
   29 struct ulist_node {
   30     u64 val;        /* value to store */
   31     u64 aux;        /* auxiliary value saved along with the val */
   32 
   33     struct list_head list;  /* used to link node */
   34     struct rb_node rb_node; /* used to speed up search */
   35 };
   36 
   37 struct ulist {
   38     /*
   39      * number of elements stored in list
   40      */
   41     unsigned long nnodes;
   42 
   43     struct list_head nodes;
   44     struct rb_root root;
   45 };
   46 
   47 void ulist_init(struct ulist *ulist);
   48 void ulist_reinit(struct ulist *ulist);
   49 struct ulist *ulist_alloc(gfp_t gfp_mask);
   50 void ulist_free(struct ulist *ulist);
   51 int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask);
   52 int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,
   53             u64 *old_aux, gfp_t gfp_mask);
   54 int ulist_del(struct ulist *ulist, u64 val, u64 aux);
   55 
   56 /* just like ulist_add_merge() but take a pointer for the aux data */
   57 static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux,
   58                       void **old_aux, gfp_t gfp_mask)
   59 {
   60 #if BITS_PER_LONG == 32
   61     u64 old64 = (uintptr_t)*old_aux;
   62     int ret = ulist_add_merge(ulist, val, (uintptr_t)aux, &old64, gfp_mask);
   63     *old_aux = (void *)((uintptr_t)old64);
   64     return ret;
   65 #else
   66     return ulist_add_merge(ulist, val, (u64)aux, (u64 *)old_aux, gfp_mask);
   67 #endif
   68 }
   69 
   70 struct ulist_node *ulist_next(struct ulist *ulist,
   71                   struct ulist_iterator *uiter);
   72 
   73 #define ULIST_ITER_INIT(uiter) ((uiter)->cur_list = NULL)
   74 
   75 #endif