dm_table.c revision 1.12 1 1.12 tkusumi /* $NetBSD: dm_table.c,v 1.12 2019/12/07 15:28:39 tkusumi Exp $ */
2 1.2 haad
3 1.2 haad /*
4 1.2 haad * Copyright (c) 2008 The NetBSD Foundation, Inc.
5 1.2 haad * All rights reserved.
6 1.2 haad *
7 1.2 haad * This code is derived from software contributed to The NetBSD Foundation
8 1.2 haad * by Adam Hamsik.
9 1.2 haad *
10 1.2 haad * Redistribution and use in source and binary forms, with or without
11 1.2 haad * modification, are permitted provided that the following conditions
12 1.2 haad * are met:
13 1.2 haad * 1. Redistributions of source code must retain the above copyright
14 1.2 haad * notice, this list of conditions and the following disclaimer.
15 1.2 haad * 2. Redistributions in binary form must reproduce the above copyright
16 1.2 haad * notice, this list of conditions and the following disclaimer in the
17 1.2 haad * documentation and/or other materials provided with the distribution.
18 1.2 haad *
19 1.2 haad * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 1.2 haad * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 1.2 haad * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 1.2 haad * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 1.2 haad * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 1.2 haad * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 1.2 haad * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 1.2 haad * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 1.2 haad * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 1.2 haad * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 1.2 haad * POSSIBILITY OF SUCH DAMAGE.
30 1.2 haad */
31 1.8 christos #include <sys/cdefs.h>
32 1.12 tkusumi __KERNEL_RCSID(0, "$NetBSD: dm_table.c,v 1.12 2019/12/07 15:28:39 tkusumi Exp $");
33 1.2 haad
34 1.2 haad #include <sys/types.h>
35 1.2 haad #include <sys/param.h>
36 1.2 haad
37 1.2 haad #include <sys/kmem.h>
38 1.2 haad
39 1.2 haad #include "dm.h"
40 1.2 haad
41 1.2 haad /*
42 1.2 haad * There are two types of users of this interface:
43 1.5 haad *
44 1.2 haad * a) Readers such as
45 1.2 haad * dmstrategy, dmgetdisklabel, dmsize, dm_dev_status_ioctl,
46 1.2 haad * dm_table_deps_ioctl, dm_table_status_ioctl, dm_table_reload_ioctl
47 1.2 haad *
48 1.2 haad * b) Writers such as
49 1.2 haad * dm_dev_remove_ioctl, dm_dev_resume_ioctl, dm_table_clear_ioctl
50 1.2 haad *
51 1.2 haad * Writers can work with table_head only when there are no readers. I
52 1.2 haad * use reference counting on io_cnt.
53 1.2 haad *
54 1.2 haad */
55 1.2 haad
56 1.5 haad static int dm_table_busy(dm_table_head_t *, uint8_t);
57 1.2 haad static void dm_table_unbusy(dm_table_head_t *);
58 1.2 haad
59 1.2 haad /*
60 1.2 haad * Function to increment table user reference counter. Return id
61 1.2 haad * of table_id table.
62 1.2 haad * DM_TABLE_ACTIVE will return active table id.
63 1.2 haad * DM_TABLE_INACTIVE will return inactive table id.
64 1.2 haad */
65 1.2 haad static int
66 1.12 tkusumi dm_table_busy(dm_table_head_t *head, uint8_t table_id)
67 1.2 haad {
68 1.2 haad uint8_t id;
69 1.2 haad
70 1.2 haad mutex_enter(&head->table_mtx);
71 1.2 haad
72 1.2 haad if (table_id == DM_TABLE_ACTIVE)
73 1.2 haad id = head->cur_active_table;
74 1.2 haad else
75 1.2 haad id = 1 - head->cur_active_table;
76 1.2 haad
77 1.2 haad head->io_cnt++;
78 1.2 haad
79 1.2 haad mutex_exit(&head->table_mtx);
80 1.2 haad return id;
81 1.2 haad }
82 1.8 christos
83 1.2 haad /*
84 1.2 haad * Function release table lock and eventually wakeup all waiters.
85 1.2 haad */
86 1.2 haad static void
87 1.12 tkusumi dm_table_unbusy(dm_table_head_t *head)
88 1.2 haad {
89 1.2 haad KASSERT(head->io_cnt != 0);
90 1.2 haad
91 1.2 haad mutex_enter(&head->table_mtx);
92 1.5 haad
93 1.2 haad if (--head->io_cnt == 0)
94 1.2 haad cv_broadcast(&head->table_cv);
95 1.5 haad
96 1.2 haad mutex_exit(&head->table_mtx);
97 1.2 haad }
98 1.8 christos
99 1.2 haad /*
100 1.2 haad * Return current active table to caller, increment io_cnt reference counter.
101 1.2 haad */
102 1.2 haad dm_table_t *
103 1.12 tkusumi dm_table_get_entry(dm_table_head_t *head, uint8_t table_id)
104 1.2 haad {
105 1.2 haad uint8_t id;
106 1.2 haad
107 1.2 haad id = dm_table_busy(head, table_id);
108 1.5 haad
109 1.2 haad return &head->tables[id];
110 1.2 haad }
111 1.2 haad /*
112 1.2 haad * Decrement io reference counter and wake up all callers, with table_head cv.
113 1.2 haad */
114 1.2 haad void
115 1.12 tkusumi dm_table_release(dm_table_head_t *head, uint8_t table_id)
116 1.2 haad {
117 1.2 haad dm_table_unbusy(head);
118 1.2 haad }
119 1.8 christos
120 1.2 haad /*
121 1.2 haad * Switch table from inactive to active mode. Have to wait until io_cnt is 0.
122 1.2 haad */
123 1.2 haad void
124 1.12 tkusumi dm_table_switch_tables(dm_table_head_t *head)
125 1.2 haad {
126 1.2 haad mutex_enter(&head->table_mtx);
127 1.2 haad
128 1.2 haad while (head->io_cnt != 0)
129 1.2 haad cv_wait(&head->table_cv, &head->table_mtx);
130 1.2 haad
131 1.2 haad head->cur_active_table = 1 - head->cur_active_table;
132 1.2 haad
133 1.2 haad mutex_exit(&head->table_mtx);
134 1.2 haad }
135 1.8 christos
136 1.2 haad /*
137 1.2 haad * Destroy all table data. This function can run when there are no
138 1.2 haad * readers on table lists.
139 1.2 haad *
140 1.2 haad * XXX Is it ok to call kmem_free and potentialy VOP_CLOSE with held mutex ?xs
141 1.2 haad */
142 1.2 haad int
143 1.12 tkusumi dm_table_destroy(dm_table_head_t *head, uint8_t table_id)
144 1.2 haad {
145 1.5 haad dm_table_t *tbl;
146 1.2 haad dm_table_entry_t *table_en;
147 1.2 haad uint8_t id;
148 1.2 haad
149 1.2 haad mutex_enter(&head->table_mtx);
150 1.2 haad
151 1.4 joerg aprint_debug("dm_Table_destroy called with %d--%d\n", table_id, head->io_cnt);
152 1.4 joerg
153 1.2 haad while (head->io_cnt != 0)
154 1.2 haad cv_wait(&head->table_cv, &head->table_mtx);
155 1.2 haad
156 1.2 haad if (table_id == DM_TABLE_ACTIVE)
157 1.2 haad id = head->cur_active_table;
158 1.2 haad else
159 1.2 haad id = 1 - head->cur_active_table;
160 1.5 haad
161 1.2 haad tbl = &head->tables[id];
162 1.5 haad
163 1.11 tkusumi while ((table_en = SLIST_FIRST(tbl)) != NULL) {
164 1.11 tkusumi SLIST_REMOVE(tbl, table_en, dm_table_entry, next);
165 1.10 tkusumi if (table_en->target->destroy(table_en) == 0)
166 1.10 tkusumi table_en->target_config = NULL;
167 1.5 haad
168 1.2 haad kmem_free(table_en, sizeof(*table_en));
169 1.2 haad }
170 1.11 tkusumi KASSERT(SLIST_EMPTY(tbl));
171 1.2 haad
172 1.2 haad mutex_exit(&head->table_mtx);
173 1.5 haad
174 1.2 haad return 0;
175 1.2 haad }
176 1.8 christos
177 1.2 haad /*
178 1.2 haad * Return length of active table in device.
179 1.2 haad */
180 1.7 ahoka static inline uint64_t
181 1.12 tkusumi dm_table_size_impl(dm_table_head_t *head, int table)
182 1.2 haad {
183 1.5 haad dm_table_t *tbl;
184 1.2 haad dm_table_entry_t *table_en;
185 1.2 haad uint64_t length;
186 1.2 haad uint8_t id;
187 1.5 haad
188 1.2 haad length = 0;
189 1.2 haad
190 1.7 ahoka id = dm_table_busy(head, table);
191 1.5 haad
192 1.2 haad /* Select active table */
193 1.2 haad tbl = &head->tables[id];
194 1.5 haad
195 1.2 haad /*
196 1.2 haad * Find out what tables I want to select.
197 1.2 haad * if length => rawblkno then we should used that table.
198 1.2 haad */
199 1.2 haad SLIST_FOREACH(table_en, tbl, next)
200 1.9 tkusumi length += table_en->length;
201 1.2 haad
202 1.2 haad dm_table_unbusy(head);
203 1.5 haad
204 1.3 jakllsch return length;
205 1.2 haad }
206 1.7 ahoka
207 1.7 ahoka /*
208 1.7 ahoka * Return length of active table in device.
209 1.7 ahoka */
210 1.7 ahoka uint64_t
211 1.12 tkusumi dm_table_size(dm_table_head_t *head)
212 1.7 ahoka {
213 1.7 ahoka return dm_table_size_impl(head, DM_TABLE_ACTIVE);
214 1.7 ahoka }
215 1.7 ahoka
216 1.7 ahoka /*
217 1.7 ahoka * Return length of active table in device.
218 1.7 ahoka */
219 1.7 ahoka uint64_t
220 1.12 tkusumi dm_inactive_table_size(dm_table_head_t *head)
221 1.7 ahoka {
222 1.7 ahoka return dm_table_size_impl(head, DM_TABLE_INACTIVE);
223 1.7 ahoka }
224 1.7 ahoka
225 1.2 haad /*
226 1.6 mlelstv * Return combined disk geometry
227 1.6 mlelstv */
228 1.6 mlelstv void
229 1.12 tkusumi dm_table_disksize(dm_table_head_t *head, uint64_t *numsecp, unsigned *secsizep)
230 1.6 mlelstv {
231 1.6 mlelstv dm_table_t *tbl;
232 1.6 mlelstv dm_table_entry_t *table_en;
233 1.6 mlelstv uint64_t length;
234 1.6 mlelstv unsigned secsize, tsecsize;
235 1.6 mlelstv uint8_t id;
236 1.6 mlelstv
237 1.6 mlelstv length = 0;
238 1.6 mlelstv
239 1.6 mlelstv id = dm_table_busy(head, DM_TABLE_ACTIVE);
240 1.6 mlelstv
241 1.6 mlelstv /* Select active table */
242 1.6 mlelstv tbl = &head->tables[id];
243 1.6 mlelstv
244 1.6 mlelstv /*
245 1.6 mlelstv * Find out what tables I want to select.
246 1.6 mlelstv * if length => rawblkno then we should used that table.
247 1.6 mlelstv */
248 1.6 mlelstv secsize = 0;
249 1.6 mlelstv SLIST_FOREACH(table_en, tbl, next) {
250 1.9 tkusumi length += table_en->length;
251 1.9 tkusumi (void)table_en->target->secsize(table_en, &tsecsize);
252 1.9 tkusumi if (secsize < tsecsize)
253 1.9 tkusumi secsize = tsecsize;
254 1.6 mlelstv }
255 1.6 mlelstv *numsecp = secsize > 0 ? dbtob(length) / secsize : 0;
256 1.6 mlelstv *secsizep = secsize;
257 1.6 mlelstv
258 1.6 mlelstv dm_table_unbusy(head);
259 1.6 mlelstv }
260 1.8 christos
261 1.6 mlelstv /*
262 1.2 haad * Return > 0 if table is at least one table entry (returns number of entries)
263 1.2 haad * and return 0 if there is not. Target count returned from this function
264 1.2 haad * doesn't need to be true when userspace user receive it (after return
265 1.2 haad * there can be dm_dev_resume_ioctl), therfore this isonly informative.
266 1.2 haad */
267 1.2 haad int
268 1.12 tkusumi dm_table_get_target_count(dm_table_head_t *head, uint8_t table_id)
269 1.5 haad {
270 1.2 haad dm_table_entry_t *table_en;
271 1.2 haad dm_table_t *tbl;
272 1.2 haad uint32_t target_count;
273 1.2 haad uint8_t id;
274 1.2 haad
275 1.2 haad target_count = 0;
276 1.2 haad
277 1.2 haad id = dm_table_busy(head, table_id);
278 1.2 haad
279 1.2 haad tbl = &head->tables[id];
280 1.2 haad
281 1.2 haad SLIST_FOREACH(table_en, tbl, next)
282 1.9 tkusumi target_count++;
283 1.2 haad
284 1.2 haad dm_table_unbusy(head);
285 1.5 haad
286 1.2 haad return target_count;
287 1.2 haad }
288 1.2 haad
289 1.2 haad
290 1.2 haad /*
291 1.2 haad * Initialize table_head structures, I'm trying to keep this structure as
292 1.2 haad * opaque as possible.
293 1.2 haad */
294 1.2 haad void
295 1.12 tkusumi dm_table_head_init(dm_table_head_t *head)
296 1.2 haad {
297 1.2 haad head->cur_active_table = 0;
298 1.2 haad head->io_cnt = 0;
299 1.5 haad
300 1.2 haad /* Initialize tables. */
301 1.2 haad SLIST_INIT(&head->tables[0]);
302 1.2 haad SLIST_INIT(&head->tables[1]);
303 1.2 haad
304 1.2 haad mutex_init(&head->table_mtx, MUTEX_DEFAULT, IPL_NONE);
305 1.2 haad cv_init(&head->table_cv, "dm_io");
306 1.2 haad }
307 1.8 christos
308 1.2 haad /*
309 1.2 haad * Destroy all variables in table_head
310 1.2 haad */
311 1.2 haad void
312 1.12 tkusumi dm_table_head_destroy(dm_table_head_t *head)
313 1.2 haad {
314 1.2 haad KASSERT(!mutex_owned(&head->table_mtx));
315 1.2 haad KASSERT(!cv_has_waiters(&head->table_cv));
316 1.5 haad /* tables doens't exists when I call this routine, therefore it
317 1.5 haad * doesn't make sense to have io_cnt != 0 */
318 1.5 haad KASSERT(head->io_cnt == 0);
319 1.5 haad
320 1.2 haad cv_destroy(&head->table_cv);
321 1.2 haad mutex_destroy(&head->table_mtx);
322 1.2 haad }
323