dm_table.c revision 1.20 1 1.20 andvar /* $NetBSD: dm_table.c,v 1.20 2021/08/20 20:25:27 andvar 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 1.20 andvar __KERNEL_RCSID(0, "$NetBSD: dm_table.c,v 1.20 2021/08/20 20:25:27 andvar 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 #include <sys/kmem.h>
37 1.2 haad
38 1.2 haad #include "dm.h"
39 1.2 haad
40 1.2 haad /*
41 1.2 haad * There are two types of users of this interface:
42 1.5 haad *
43 1.2 haad * a) Readers such as
44 1.2 haad * dmstrategy, dmgetdisklabel, dmsize, dm_dev_status_ioctl,
45 1.2 haad * dm_table_deps_ioctl, dm_table_status_ioctl, dm_table_reload_ioctl
46 1.2 haad *
47 1.2 haad * b) Writers such as
48 1.2 haad * dm_dev_remove_ioctl, dm_dev_resume_ioctl, dm_table_clear_ioctl
49 1.2 haad *
50 1.2 haad * Writers can work with table_head only when there are no readers. I
51 1.2 haad * use reference counting on io_cnt.
52 1.2 haad *
53 1.2 haad */
54 1.2 haad
55 1.5 haad static int dm_table_busy(dm_table_head_t *, uint8_t);
56 1.2 haad static void dm_table_unbusy(dm_table_head_t *);
57 1.17 tkusumi static void dm_table_free_deps(dm_table_entry_t *);
58 1.17 tkusumi
59 1.2 haad
60 1.2 haad /*
61 1.2 haad * Function to increment table user reference counter. Return id
62 1.2 haad * of table_id table.
63 1.2 haad * DM_TABLE_ACTIVE will return active table id.
64 1.2 haad * DM_TABLE_INACTIVE will return inactive table id.
65 1.2 haad */
66 1.2 haad static int
67 1.12 tkusumi dm_table_busy(dm_table_head_t *head, uint8_t table_id)
68 1.2 haad {
69 1.2 haad uint8_t id;
70 1.2 haad
71 1.2 haad mutex_enter(&head->table_mtx);
72 1.2 haad
73 1.2 haad if (table_id == DM_TABLE_ACTIVE)
74 1.2 haad id = head->cur_active_table;
75 1.2 haad else
76 1.2 haad id = 1 - head->cur_active_table;
77 1.2 haad
78 1.2 haad head->io_cnt++;
79 1.2 haad
80 1.2 haad mutex_exit(&head->table_mtx);
81 1.2 haad return id;
82 1.2 haad }
83 1.8 christos
84 1.2 haad /*
85 1.2 haad * Function release table lock and eventually wakeup all waiters.
86 1.2 haad */
87 1.2 haad static void
88 1.12 tkusumi dm_table_unbusy(dm_table_head_t *head)
89 1.2 haad {
90 1.16 tkusumi
91 1.2 haad KASSERT(head->io_cnt != 0);
92 1.2 haad
93 1.2 haad mutex_enter(&head->table_mtx);
94 1.5 haad
95 1.2 haad if (--head->io_cnt == 0)
96 1.2 haad cv_broadcast(&head->table_cv);
97 1.5 haad
98 1.2 haad mutex_exit(&head->table_mtx);
99 1.2 haad }
100 1.8 christos
101 1.2 haad /*
102 1.2 haad * Return current active table to caller, increment io_cnt reference counter.
103 1.2 haad */
104 1.2 haad dm_table_t *
105 1.12 tkusumi dm_table_get_entry(dm_table_head_t *head, uint8_t table_id)
106 1.2 haad {
107 1.2 haad uint8_t id;
108 1.2 haad
109 1.2 haad id = dm_table_busy(head, table_id);
110 1.5 haad
111 1.2 haad return &head->tables[id];
112 1.2 haad }
113 1.2 haad /*
114 1.2 haad * Decrement io reference counter and wake up all callers, with table_head cv.
115 1.2 haad */
116 1.2 haad void
117 1.12 tkusumi dm_table_release(dm_table_head_t *head, uint8_t table_id)
118 1.2 haad {
119 1.16 tkusumi
120 1.2 haad dm_table_unbusy(head);
121 1.2 haad }
122 1.8 christos
123 1.2 haad /*
124 1.2 haad * Switch table from inactive to active mode. Have to wait until io_cnt is 0.
125 1.2 haad */
126 1.2 haad void
127 1.12 tkusumi dm_table_switch_tables(dm_table_head_t *head)
128 1.2 haad {
129 1.16 tkusumi
130 1.2 haad mutex_enter(&head->table_mtx);
131 1.2 haad
132 1.2 haad while (head->io_cnt != 0)
133 1.2 haad cv_wait(&head->table_cv, &head->table_mtx);
134 1.2 haad
135 1.2 haad head->cur_active_table = 1 - head->cur_active_table;
136 1.2 haad
137 1.2 haad mutex_exit(&head->table_mtx);
138 1.2 haad }
139 1.8 christos
140 1.2 haad /*
141 1.2 haad * Destroy all table data. This function can run when there are no
142 1.2 haad * readers on table lists.
143 1.2 haad *
144 1.2 haad * XXX Is it ok to call kmem_free and potentialy VOP_CLOSE with held mutex ?xs
145 1.2 haad */
146 1.2 haad int
147 1.12 tkusumi dm_table_destroy(dm_table_head_t *head, uint8_t table_id)
148 1.2 haad {
149 1.5 haad dm_table_t *tbl;
150 1.2 haad dm_table_entry_t *table_en;
151 1.2 haad uint8_t id;
152 1.2 haad
153 1.2 haad mutex_enter(&head->table_mtx);
154 1.2 haad
155 1.4 joerg aprint_debug("dm_Table_destroy called with %d--%d\n", table_id, head->io_cnt);
156 1.4 joerg
157 1.2 haad while (head->io_cnt != 0)
158 1.2 haad cv_wait(&head->table_cv, &head->table_mtx);
159 1.2 haad
160 1.2 haad if (table_id == DM_TABLE_ACTIVE)
161 1.2 haad id = head->cur_active_table;
162 1.2 haad else
163 1.2 haad id = 1 - head->cur_active_table;
164 1.5 haad
165 1.2 haad tbl = &head->tables[id];
166 1.5 haad
167 1.11 tkusumi while ((table_en = SLIST_FIRST(tbl)) != NULL) {
168 1.11 tkusumi SLIST_REMOVE(tbl, table_en, dm_table_entry, next);
169 1.10 tkusumi if (table_en->target->destroy(table_en) == 0)
170 1.10 tkusumi table_en->target_config = NULL;
171 1.17 tkusumi dm_table_free_deps(table_en);
172 1.2 haad kmem_free(table_en, sizeof(*table_en));
173 1.2 haad }
174 1.11 tkusumi KASSERT(SLIST_EMPTY(tbl));
175 1.2 haad
176 1.2 haad mutex_exit(&head->table_mtx);
177 1.5 haad
178 1.2 haad return 0;
179 1.2 haad }
180 1.8 christos
181 1.2 haad /*
182 1.2 haad * Return length of active table in device.
183 1.2 haad */
184 1.19 tkusumi static uint64_t
185 1.12 tkusumi dm_table_size_impl(dm_table_head_t *head, int table)
186 1.2 haad {
187 1.5 haad dm_table_t *tbl;
188 1.2 haad dm_table_entry_t *table_en;
189 1.2 haad uint64_t length;
190 1.2 haad uint8_t id;
191 1.5 haad
192 1.2 haad length = 0;
193 1.2 haad
194 1.7 ahoka id = dm_table_busy(head, table);
195 1.5 haad
196 1.2 haad /* Select active table */
197 1.2 haad tbl = &head->tables[id];
198 1.5 haad
199 1.2 haad /*
200 1.2 haad * Find out what tables I want to select.
201 1.2 haad * if length => rawblkno then we should used that table.
202 1.2 haad */
203 1.2 haad SLIST_FOREACH(table_en, tbl, next)
204 1.9 tkusumi length += table_en->length;
205 1.2 haad
206 1.2 haad dm_table_unbusy(head);
207 1.5 haad
208 1.3 jakllsch return length;
209 1.2 haad }
210 1.7 ahoka
211 1.7 ahoka /*
212 1.7 ahoka * Return length of active table in device.
213 1.7 ahoka */
214 1.7 ahoka uint64_t
215 1.12 tkusumi dm_table_size(dm_table_head_t *head)
216 1.7 ahoka {
217 1.16 tkusumi
218 1.7 ahoka return dm_table_size_impl(head, DM_TABLE_ACTIVE);
219 1.7 ahoka }
220 1.7 ahoka
221 1.7 ahoka /*
222 1.7 ahoka * Return length of active table in device.
223 1.7 ahoka */
224 1.7 ahoka uint64_t
225 1.12 tkusumi dm_inactive_table_size(dm_table_head_t *head)
226 1.7 ahoka {
227 1.16 tkusumi
228 1.7 ahoka return dm_table_size_impl(head, DM_TABLE_INACTIVE);
229 1.7 ahoka }
230 1.7 ahoka
231 1.2 haad /*
232 1.6 mlelstv * Return combined disk geometry
233 1.6 mlelstv */
234 1.6 mlelstv void
235 1.16 tkusumi dm_table_disksize(dm_table_head_t *head, uint64_t *numsecp,
236 1.16 tkusumi unsigned int *secsizep)
237 1.6 mlelstv {
238 1.6 mlelstv dm_table_t *tbl;
239 1.6 mlelstv dm_table_entry_t *table_en;
240 1.6 mlelstv uint64_t length;
241 1.14 tkusumi unsigned int secsize, tsecsize;
242 1.6 mlelstv uint8_t id;
243 1.6 mlelstv
244 1.6 mlelstv length = 0;
245 1.6 mlelstv
246 1.6 mlelstv id = dm_table_busy(head, DM_TABLE_ACTIVE);
247 1.6 mlelstv
248 1.6 mlelstv /* Select active table */
249 1.6 mlelstv tbl = &head->tables[id];
250 1.6 mlelstv
251 1.6 mlelstv /*
252 1.6 mlelstv * Find out what tables I want to select.
253 1.6 mlelstv * if length => rawblkno then we should used that table.
254 1.6 mlelstv */
255 1.6 mlelstv secsize = 0;
256 1.6 mlelstv SLIST_FOREACH(table_en, tbl, next) {
257 1.9 tkusumi length += table_en->length;
258 1.15 tkusumi if (table_en->target->secsize)
259 1.15 tkusumi table_en->target->secsize(table_en, &tsecsize);
260 1.15 tkusumi else
261 1.15 tkusumi tsecsize = 0;
262 1.9 tkusumi if (secsize < tsecsize)
263 1.9 tkusumi secsize = tsecsize;
264 1.6 mlelstv }
265 1.18 tkusumi
266 1.18 tkusumi if (numsecp)
267 1.18 tkusumi *numsecp = secsize > 0 ? dbtob(length) / secsize : 0;
268 1.18 tkusumi if (secsizep)
269 1.18 tkusumi *secsizep = secsize;
270 1.6 mlelstv
271 1.6 mlelstv dm_table_unbusy(head);
272 1.6 mlelstv }
273 1.8 christos
274 1.6 mlelstv /*
275 1.2 haad * Return > 0 if table is at least one table entry (returns number of entries)
276 1.2 haad * and return 0 if there is not. Target count returned from this function
277 1.2 haad * doesn't need to be true when userspace user receive it (after return
278 1.2 haad * there can be dm_dev_resume_ioctl), therfore this isonly informative.
279 1.2 haad */
280 1.2 haad int
281 1.12 tkusumi dm_table_get_target_count(dm_table_head_t *head, uint8_t table_id)
282 1.5 haad {
283 1.2 haad dm_table_entry_t *table_en;
284 1.2 haad dm_table_t *tbl;
285 1.2 haad uint32_t target_count;
286 1.2 haad uint8_t id;
287 1.2 haad
288 1.2 haad target_count = 0;
289 1.2 haad
290 1.2 haad id = dm_table_busy(head, table_id);
291 1.2 haad tbl = &head->tables[id];
292 1.2 haad
293 1.2 haad SLIST_FOREACH(table_en, tbl, next)
294 1.9 tkusumi target_count++;
295 1.2 haad
296 1.2 haad dm_table_unbusy(head);
297 1.5 haad
298 1.2 haad return target_count;
299 1.2 haad }
300 1.2 haad
301 1.2 haad /*
302 1.2 haad * Initialize table_head structures, I'm trying to keep this structure as
303 1.2 haad * opaque as possible.
304 1.2 haad */
305 1.2 haad void
306 1.12 tkusumi dm_table_head_init(dm_table_head_t *head)
307 1.2 haad {
308 1.16 tkusumi
309 1.2 haad head->cur_active_table = 0;
310 1.2 haad head->io_cnt = 0;
311 1.5 haad
312 1.2 haad /* Initialize tables. */
313 1.2 haad SLIST_INIT(&head->tables[0]);
314 1.2 haad SLIST_INIT(&head->tables[1]);
315 1.2 haad
316 1.2 haad mutex_init(&head->table_mtx, MUTEX_DEFAULT, IPL_NONE);
317 1.2 haad cv_init(&head->table_cv, "dm_io");
318 1.2 haad }
319 1.8 christos
320 1.2 haad /*
321 1.2 haad * Destroy all variables in table_head
322 1.2 haad */
323 1.2 haad void
324 1.12 tkusumi dm_table_head_destroy(dm_table_head_t *head)
325 1.2 haad {
326 1.16 tkusumi
327 1.2 haad KASSERT(!mutex_owned(&head->table_mtx));
328 1.2 haad KASSERT(!cv_has_waiters(&head->table_cv));
329 1.20 andvar /* tables don't exist when I call this routine, therefore it
330 1.5 haad * doesn't make sense to have io_cnt != 0 */
331 1.5 haad KASSERT(head->io_cnt == 0);
332 1.5 haad
333 1.2 haad cv_destroy(&head->table_cv);
334 1.2 haad mutex_destroy(&head->table_mtx);
335 1.2 haad }
336 1.17 tkusumi
337 1.17 tkusumi int
338 1.17 tkusumi dm_table_add_deps(dm_table_entry_t *table_en, dm_pdev_t *pdev)
339 1.17 tkusumi {
340 1.17 tkusumi dm_table_head_t *head;
341 1.17 tkusumi dm_mapping_t *map;
342 1.17 tkusumi
343 1.17 tkusumi if (!pdev)
344 1.17 tkusumi return -1;
345 1.17 tkusumi
346 1.17 tkusumi head = &table_en->dm_dev->table_head;
347 1.17 tkusumi mutex_enter(&head->table_mtx);
348 1.17 tkusumi
349 1.17 tkusumi TAILQ_FOREACH(map, &table_en->pdev_maps, next) {
350 1.17 tkusumi if (map->data.pdev->pdev_vnode->v_rdev ==
351 1.17 tkusumi pdev->pdev_vnode->v_rdev) {
352 1.17 tkusumi mutex_exit(&head->table_mtx);
353 1.17 tkusumi return -1;
354 1.17 tkusumi }
355 1.17 tkusumi }
356 1.17 tkusumi
357 1.17 tkusumi map = kmem_alloc(sizeof(*map), KM_SLEEP);
358 1.17 tkusumi map->data.pdev = pdev;
359 1.17 tkusumi aprint_debug("%s: %s\n", __func__, pdev->name);
360 1.17 tkusumi TAILQ_INSERT_TAIL(&table_en->pdev_maps, map, next);
361 1.17 tkusumi
362 1.17 tkusumi mutex_exit(&head->table_mtx);
363 1.17 tkusumi
364 1.17 tkusumi return 0;
365 1.17 tkusumi }
366 1.17 tkusumi
367 1.17 tkusumi /* caller must hold ->table_mtx */
368 1.17 tkusumi static void
369 1.17 tkusumi dm_table_free_deps(dm_table_entry_t *table_en)
370 1.17 tkusumi {
371 1.17 tkusumi dm_mapping_t *map;
372 1.17 tkusumi
373 1.17 tkusumi while ((map = TAILQ_FIRST(&table_en->pdev_maps)) != NULL) {
374 1.17 tkusumi TAILQ_REMOVE(&table_en->pdev_maps, map, next);
375 1.17 tkusumi aprint_debug("%s: %s\n", __func__, map->data.pdev->name);
376 1.17 tkusumi kmem_free(map, sizeof(*map));
377 1.17 tkusumi }
378 1.17 tkusumi KASSERT(TAILQ_EMPTY(&table_en->pdev_maps));
379 1.17 tkusumi }
380