xref: /netbsd-src/external/gpl2/lvm2/dist/lib/zero/zero.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: zero.c,v 1.1.1.1 2008/12/22 00:17:52 haad Exp $	*/
2 
3 /*
4  * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
5  *
6  * This file is part of LVM2.
7  *
8  * This copyrighted material is made available to anyone wishing to use,
9  * modify, copy, or redistribute it subject to the terms and conditions
10  * of the GNU Lesser General Public License v.2.1.
11  *
12  * You should have received a copy of the GNU Lesser General Public License
13  * along with this program; if not, write to the Free Software Foundation,
14  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
15  */
16 
17 #include "lib.h"
18 #include "toolcontext.h"
19 #include "segtype.h"
20 #include "display.h"
21 #include "text_export.h"
22 #include "text_import.h"
23 #include "config.h"
24 #include "str_list.h"
25 #include "targets.h"
26 #include "lvm-string.h"
27 #include "activate.h"
28 #include "metadata.h"
29 
30 static const char *_zero_name(const struct lv_segment *seg)
31 {
32 	return seg->segtype->name;
33 }
34 
35 static int _zero_merge_segments(struct lv_segment *seg1, struct lv_segment *seg2)
36 {
37 	seg1->len += seg2->len;
38 	seg1->area_len += seg2->area_len;
39 
40 	return 1;
41 }
42 
43 #ifdef DEVMAPPER_SUPPORT
44 static int _zero_add_target_line(struct dev_manager *dm __attribute((unused)),
45 				 struct dm_pool *mem __attribute((unused)),
46 				 struct cmd_context *cmd __attribute((unused)),
47 				 void **target_state __attribute((unused)),
48 				 struct lv_segment *seg __attribute((unused)),
49 				 struct dm_tree_node *node,uint64_t len,
50 				 uint32_t *pvmove_mirror_count __attribute((unused)))
51 {
52 	return dm_tree_node_add_zero_target(node, len);
53 }
54 
55 static int _zero_target_present(const struct lv_segment *seg __attribute((unused)),
56 				unsigned *attributes __attribute((unused)))
57 {
58 	static int _zero_checked = 0;
59 	static int _zero_present = 0;
60 
61 	if (!_zero_checked)
62 		_zero_present = target_present("zero", 0);
63 
64 	_zero_checked = 1;
65 
66 	return _zero_present;
67 }
68 #endif
69 
70 static int _zero_modules_needed(struct dm_pool *mem,
71 				const struct lv_segment *seg __attribute((unused)),
72 				struct dm_list *modules)
73 {
74 	if (!str_list_add(mem, modules, "zero")) {
75 		log_error("zero module string list allocation failed");
76 		return 0;
77 	}
78 
79 	return 1;
80 }
81 
82 static void _zero_destroy(const struct segment_type *segtype)
83 {
84 	dm_free((void *) segtype);
85 }
86 
87 static struct segtype_handler _zero_ops = {
88 	.name = _zero_name,
89 	.merge_segments = _zero_merge_segments,
90 #ifdef DEVMAPPER_SUPPORT
91 	.add_target_line = _zero_add_target_line,
92 	.target_present = _zero_target_present,
93 #endif
94 	.modules_needed = _zero_modules_needed,
95 	.destroy = _zero_destroy,
96 };
97 
98 struct segment_type *init_zero_segtype(struct cmd_context *cmd)
99 {
100 	struct segment_type *segtype = dm_malloc(sizeof(*segtype));
101 
102 	if (!segtype)
103 		return_NULL;
104 
105 	segtype->cmd = cmd;
106 	segtype->ops = &_zero_ops;
107 	segtype->name = "zero";
108 	segtype->private = NULL;
109 	segtype->flags = SEG_CAN_SPLIT | SEG_VIRTUAL | SEG_CANNOT_BE_ZEROED;
110 
111 	log_very_verbose("Initialised segtype: %s", segtype->name);
112 
113 	return segtype;
114 }
115