xref: /freebsd/sys/contrib/openzfs/module/zfs/objlist.c (revision 22649d4dba730d46244fd2dff4fd174903c8379f)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * This file and its contents are supplied under the terms of the
4  * Common Development and Distribution License ("CDDL"), version 1.0.
5  * You may only use this file in accordance with the terms of version
6  * 1.0 of the CDDL.
7  *
8  * A full copy of the text of the CDDL should have accompanied this
9  * source.  A copy of the CDDL is also available via the Internet at
10  * https://opensource.org/license/CDDL-1.0.
11  */
12 /*
13  * Copyright (c) 2018 by Delphix. All rights reserved.
14  */
15 
16 #include	<sys/objlist.h>
17 #include	<sys/zfs_context.h>
18 
19 objlist_t *
objlist_create(void)20 objlist_create(void)
21 {
22 	objlist_t *list = kmem_alloc(sizeof (*list), KM_SLEEP);
23 	list_create(&list->ol_list, sizeof (objlist_node_t),
24 	    offsetof(objlist_node_t, on_node));
25 	list->ol_last_lookup = 0;
26 	return (list);
27 }
28 
29 void
objlist_destroy(objlist_t * list)30 objlist_destroy(objlist_t *list)
31 {
32 	for (objlist_node_t *n = list_remove_head(&list->ol_list);
33 	    n != NULL; n = list_remove_head(&list->ol_list)) {
34 		kmem_free(n, sizeof (*n));
35 	}
36 	list_destroy(&list->ol_list);
37 	kmem_free(list, sizeof (*list));
38 }
39 
40 /*
41  * This function looks through the objlist to see if the specified object number
42  * is contained in the objlist.  In the process, it will remove all object
43  * numbers in the list that are smaller than the specified object number.  Thus,
44  * any lookup of an object number smaller than a previously looked up object
45  * number will always return false; therefore, all lookups should be done in
46  * ascending order.
47  */
48 boolean_t
objlist_exists(objlist_t * list,uint64_t object)49 objlist_exists(objlist_t *list, uint64_t object)
50 {
51 	objlist_node_t *node = list_head(&list->ol_list);
52 	ASSERT3U(object, >=, list->ol_last_lookup);
53 	list->ol_last_lookup = object;
54 	while (node != NULL && node->on_object < object) {
55 		VERIFY3P(node, ==, list_remove_head(&list->ol_list));
56 		kmem_free(node, sizeof (*node));
57 		node = list_head(&list->ol_list);
58 	}
59 	return (node != NULL && node->on_object == object);
60 }
61 
62 /*
63  * The objlist is a list of object numbers stored in ascending order.  However,
64  * the insertion of new object numbers does not seek out the correct location to
65  * store a new object number; instead, it appends it to the list for simplicity.
66  * Thus, any users must take care to only insert new object numbers in ascending
67  * order.
68  */
69 void
objlist_insert(objlist_t * list,uint64_t object)70 objlist_insert(objlist_t *list, uint64_t object)
71 {
72 	objlist_node_t *node = kmem_zalloc(sizeof (*node), KM_SLEEP);
73 	node->on_object = object;
74 #ifdef ZFS_DEBUG
75 	objlist_node_t *last_object = list_tail(&list->ol_list);
76 	uint64_t last_objnum = (last_object != NULL ? last_object->on_object :
77 	    0);
78 	ASSERT3U(node->on_object, >, last_objnum);
79 #endif
80 	list_insert_tail(&list->ol_list, node);
81 }
82