From 3d69435ee3292b4b1db2d61c4784789d75883821 Mon Sep 17 00:00:00 2001 From: Dimitri John Ledkov Date: Tue, 26 Jul 2016 13:24:39 +0100 Subject: Imported Upstream version 4.6.1 --- ulist.h | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 ulist.h (limited to 'ulist.h') diff --git a/ulist.h b/ulist.h new file mode 100644 index 00000000..88f5b826 --- /dev/null +++ b/ulist.h @@ -0,0 +1,81 @@ +/* + * Copyright (C) 2011 STRATO AG + * written by Arne Jansen + * Distributed under the GNU GPL license version 2. + * + */ + +#ifndef __ULIST_H__ +#define __ULIST_H__ + +#include "kerncompat.h" +#include "list.h" +#include "rbtree.h" + +/* + * ulist is a generic data structure to hold a collection of unique u64 + * values. The only operations it supports is adding to the list and + * enumerating it. + * It is possible to store an auxiliary value along with the key. + * + */ +struct ulist_iterator { +#ifdef CONFIG_BTRFS_DEBUG + int i; +#endif + struct list_head *cur_list; /* hint to start search */ +}; + +/* + * element of the list + */ +struct ulist_node { + u64 val; /* value to store */ + u64 aux; /* auxiliary value saved along with the val */ + +#ifdef CONFIG_BTRFS_DEBUG + int seqnum; /* sequence number this node is added */ +#endif + + struct list_head list; /* used to link node */ + struct rb_node rb_node; /* used to speed up search */ +}; + +struct ulist { + /* + * number of elements stored in list + */ + unsigned long nnodes; + + struct list_head nodes; + struct rb_root root; +}; + +void ulist_init(struct ulist *ulist); +void ulist_reinit(struct ulist *ulist); +struct ulist *ulist_alloc(gfp_t gfp_mask); +void ulist_free(struct ulist *ulist); +int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask); +int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux, + u64 *old_aux, gfp_t gfp_mask); + +/* just like ulist_add_merge() but take a pointer for the aux data */ +static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux, + void **old_aux, gfp_t gfp_mask) +{ +#if BITS_PER_LONG == 32 + u64 old64 = (uintptr_t)*old_aux; + int ret = ulist_add_merge(ulist, val, (uintptr_t)aux, &old64, gfp_mask); + *old_aux = (void *)((uintptr_t)old64); + return ret; +#else + return ulist_add_merge(ulist, val, (u64)aux, (u64 *)old_aux, gfp_mask); +#endif +} + +struct ulist_node *ulist_next(struct ulist *ulist, + struct ulist_iterator *uiter); + +#define ULIST_ITER_INIT(uiter) ((uiter)->cur_list = NULL) + +#endif -- cgit v1.2.3