2 * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
3 * Copyright (C) 2007 The Regents of the University of California.
4 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
5 * Written by Brian Behlendorf <behlendorf1@llnl.gov>.
8 * This file is part of the SPL, Solaris Porting Layer.
9 * For details, see <http://zfsonlinux.org/>.
11 * The SPL is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2 of the License, or (at your
14 * option) any later version.
16 * The SPL is distributed in the hope that it will be useful, but WITHOUT
17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
21 * You should have received a copy of the GNU General Public License along
22 * with the SPL. If not, see <http://www.gnu.org/licenses/>.
28 #include <sys/types.h>
29 #include <sys/debug.h>
30 #include <linux/list.h>
33 * NOTE: I have implemented the Solaris list API in terms of the native
34 * linux API. This has certain advantages in terms of leveraging the linux
35 * list debugging infrastructure, but it also means that the internals of a
36 * list differ slightly than on Solaris. This is not a problem as long as
37 * all callers stick to the published API. The two major differences are:
39 * 1) A list_node_t is mapped to a linux list_head struct which changes
40 * the name of the list_next/list_prev pointers to next/prev respectively.
42 * 2) A list_node_t which is not attached to a list on Solaris is denoted
43 * by having its list_next/list_prev pointers set to NULL. Under linux
44 * the next/prev pointers are set to LIST_POISON1 and LIST_POISON2
45 * respectively. At this moment this only impacts the implementation
46 * of the list_link_init() and list_link_active() functions.
49 typedef struct list_head list_node_t;
54 list_node_t list_head;
57 #define list_d2l(a, obj) ((list_node_t *)(((char *)obj) + (a)->list_offset))
58 #define list_object(a, node) ((void *)(((char *)node) - (a)->list_offset))
61 list_is_empty(list_t *list)
63 return (list_empty(&list->list_head));
67 list_link_init(list_node_t *node)
69 node->next = LIST_POISON1;
70 node->prev = LIST_POISON2;
74 list_create(list_t *list, size_t size, size_t offset)
76 list->list_size = size;
77 list->list_offset = offset;
78 INIT_LIST_HEAD(&list->list_head);
82 list_destroy(list_t *list)
84 list_del(&list->list_head);
88 list_insert_head(list_t *list, void *object)
90 list_add(list_d2l(list, object), &list->list_head);
94 list_insert_tail(list_t *list, void *object)
96 list_add_tail(list_d2l(list, object), &list->list_head);
100 list_insert_after(list_t *list, void *object, void *nobject)
103 list_insert_head(list, nobject);
105 list_add(list_d2l(list, nobject), list_d2l(list, object));
109 list_insert_before(list_t *list, void *object, void *nobject)
112 list_insert_tail(list, nobject);
114 list_add_tail(list_d2l(list, nobject), list_d2l(list, object));
118 list_remove(list_t *list, void *object)
120 list_del(list_d2l(list, object));
124 list_remove_head(list_t *list)
126 list_node_t *head = list->list_head.next;
127 if (head == &list->list_head)
131 return (list_object(list, head));
135 list_remove_tail(list_t *list)
137 list_node_t *tail = list->list_head.prev;
138 if (tail == &list->list_head)
142 return (list_object(list, tail));
146 list_head(list_t *list)
148 if (list_is_empty(list))
151 return (list_object(list, list->list_head.next));
155 list_tail(list_t *list)
157 if (list_is_empty(list))
160 return (list_object(list, list->list_head.prev));
164 list_next(list_t *list, void *object)
166 list_node_t *node = list_d2l(list, object);
168 if (node->next != &list->list_head)
169 return (list_object(list, node->next));
175 list_prev(list_t *list, void *object)
177 list_node_t *node = list_d2l(list, object);
179 if (node->prev != &list->list_head)
180 return (list_object(list, node->prev));
186 list_link_active(list_node_t *node)
188 EQUIV(node->next == LIST_POISON1, node->prev == LIST_POISON2);
189 return (node->next != LIST_POISON1);
193 spl_list_move_tail(list_t *dst, list_t *src)
195 list_splice_init(&src->list_head, dst->list_head.prev);
198 #define list_move_tail(dst, src) spl_list_move_tail(dst, src)
201 list_link_replace(list_node_t *old_node, list_node_t *new_node)
203 new_node->next = old_node->next;
204 new_node->prev = old_node->prev;
205 old_node->prev->next = new_node;
206 old_node->next->prev = new_node;
207 list_link_init(old_node);
210 #endif /* SPL_LIST_H */