dm_table.c revision 1.8 1 1.8 christos /* $NetBSD: dm_table.c,v 1.8 2018/01/05 14:22:26 christos 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 1.8 christos __KERNEL_RCSID(0, "$NetBSD: dm_table.c,v 1.8 2018/01/05 14:22:26 christos 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 1.5 haad 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 id = 0;
71 1.2 haad
72 1.2 haad mutex_enter(&head->table_mtx);
73 1.2 haad
74 1.2 haad if (table_id == DM_TABLE_ACTIVE)
75 1.2 haad id = head->cur_active_table;
76 1.2 haad else
77 1.2 haad id = 1 - head->cur_active_table;
78 1.2 haad
79 1.2 haad head->io_cnt++;
80 1.2 haad
81 1.2 haad mutex_exit(&head->table_mtx);
82 1.2 haad return id;
83 1.2 haad }
84 1.8 christos
85 1.2 haad /*
86 1.2 haad * Function release table lock and eventually wakeup all waiters.
87 1.2 haad */
88 1.2 haad static void
89 1.5 haad dm_table_unbusy(dm_table_head_t * head)
90 1.2 haad {
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 1.5 haad 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 1.5 haad dm_table_release(dm_table_head_t * head, uint8_t table_id)
118 1.2 haad {
119 1.2 haad dm_table_unbusy(head);
120 1.2 haad }
121 1.8 christos
122 1.2 haad /*
123 1.2 haad * Switch table from inactive to active mode. Have to wait until io_cnt is 0.
124 1.2 haad */
125 1.2 haad void
126 1.5 haad dm_table_switch_tables(dm_table_head_t * head)
127 1.2 haad {
128 1.2 haad mutex_enter(&head->table_mtx);
129 1.2 haad
130 1.2 haad while (head->io_cnt != 0)
131 1.2 haad cv_wait(&head->table_cv, &head->table_mtx);
132 1.2 haad
133 1.2 haad head->cur_active_table = 1 - head->cur_active_table;
134 1.2 haad
135 1.2 haad mutex_exit(&head->table_mtx);
136 1.2 haad }
137 1.8 christos
138 1.2 haad /*
139 1.2 haad * Destroy all table data. This function can run when there are no
140 1.2 haad * readers on table lists.
141 1.2 haad *
142 1.2 haad * XXX Is it ok to call kmem_free and potentialy VOP_CLOSE with held mutex ?xs
143 1.2 haad */
144 1.2 haad int
145 1.5 haad dm_table_destroy(dm_table_head_t * head, uint8_t table_id)
146 1.2 haad {
147 1.5 haad dm_table_t *tbl;
148 1.2 haad dm_table_entry_t *table_en;
149 1.2 haad uint8_t id;
150 1.2 haad
151 1.2 haad mutex_enter(&head->table_mtx);
152 1.2 haad
153 1.4 joerg aprint_debug("dm_Table_destroy called with %d--%d\n", table_id, head->io_cnt);
154 1.4 joerg
155 1.2 haad while (head->io_cnt != 0)
156 1.2 haad cv_wait(&head->table_cv, &head->table_mtx);
157 1.2 haad
158 1.2 haad if (table_id == DM_TABLE_ACTIVE)
159 1.2 haad id = head->cur_active_table;
160 1.2 haad else
161 1.2 haad id = 1 - head->cur_active_table;
162 1.5 haad
163 1.2 haad tbl = &head->tables[id];
164 1.5 haad
165 1.5 haad while (!SLIST_EMPTY(tbl)) { /* List Deletion. */
166 1.2 haad table_en = SLIST_FIRST(tbl);
167 1.2 haad /*
168 1.2 haad * Remove target specific config data. After successfull
169 1.2 haad * call table_en->target_config must be set to NULL.
170 1.2 haad */
171 1.5 haad table_en->target->destroy(table_en);
172 1.5 haad
173 1.2 haad SLIST_REMOVE_HEAD(tbl, next);
174 1.2 haad
175 1.2 haad kmem_free(table_en, sizeof(*table_en));
176 1.2 haad }
177 1.2 haad
178 1.2 haad mutex_exit(&head->table_mtx);
179 1.5 haad
180 1.2 haad return 0;
181 1.2 haad }
182 1.8 christos
183 1.2 haad /*
184 1.2 haad * Return length of active table in device.
185 1.2 haad */
186 1.7 ahoka static inline uint64_t
187 1.7 ahoka dm_table_size_impl(dm_table_head_t * head, int table)
188 1.2 haad {
189 1.5 haad dm_table_t *tbl;
190 1.2 haad dm_table_entry_t *table_en;
191 1.2 haad uint64_t length;
192 1.2 haad uint8_t id;
193 1.5 haad
194 1.2 haad length = 0;
195 1.2 haad
196 1.7 ahoka id = dm_table_busy(head, table);
197 1.5 haad
198 1.2 haad /* Select active table */
199 1.2 haad tbl = &head->tables[id];
200 1.5 haad
201 1.2 haad /*
202 1.2 haad * Find out what tables I want to select.
203 1.2 haad * if length => rawblkno then we should used that table.
204 1.2 haad */
205 1.2 haad SLIST_FOREACH(table_en, tbl, next)
206 1.2 haad length += table_en->length;
207 1.2 haad
208 1.2 haad dm_table_unbusy(head);
209 1.5 haad
210 1.3 jakllsch return length;
211 1.2 haad }
212 1.7 ahoka
213 1.7 ahoka /*
214 1.7 ahoka * Return length of active table in device.
215 1.7 ahoka */
216 1.7 ahoka uint64_t
217 1.7 ahoka dm_table_size(dm_table_head_t * head)
218 1.7 ahoka {
219 1.7 ahoka return dm_table_size_impl(head, DM_TABLE_ACTIVE);
220 1.7 ahoka }
221 1.7 ahoka
222 1.7 ahoka /*
223 1.7 ahoka * Return length of active table in device.
224 1.7 ahoka */
225 1.7 ahoka uint64_t
226 1.7 ahoka dm_inactive_table_size(dm_table_head_t * head)
227 1.7 ahoka {
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 1.6 mlelstv dm_table_disksize(dm_table_head_t * head, uint64_t *numsecp, unsigned *secsizep)
236 1.6 mlelstv {
237 1.6 mlelstv dm_table_t *tbl;
238 1.6 mlelstv dm_table_entry_t *table_en;
239 1.6 mlelstv uint64_t length;
240 1.6 mlelstv unsigned secsize, tsecsize;
241 1.6 mlelstv uint8_t id;
242 1.6 mlelstv
243 1.6 mlelstv length = 0;
244 1.6 mlelstv
245 1.6 mlelstv id = dm_table_busy(head, DM_TABLE_ACTIVE);
246 1.6 mlelstv
247 1.6 mlelstv /* Select active table */
248 1.6 mlelstv tbl = &head->tables[id];
249 1.6 mlelstv
250 1.6 mlelstv /*
251 1.6 mlelstv * Find out what tables I want to select.
252 1.6 mlelstv * if length => rawblkno then we should used that table.
253 1.6 mlelstv */
254 1.6 mlelstv secsize = 0;
255 1.6 mlelstv SLIST_FOREACH(table_en, tbl, next) {
256 1.6 mlelstv length += table_en->length;
257 1.6 mlelstv (void)table_en->target->secsize(table_en, &tsecsize);
258 1.6 mlelstv if (secsize < tsecsize)
259 1.6 mlelstv secsize = tsecsize;
260 1.6 mlelstv }
261 1.6 mlelstv *numsecp = secsize > 0 ? dbtob(length) / secsize : 0;
262 1.6 mlelstv *secsizep = secsize;
263 1.6 mlelstv
264 1.6 mlelstv dm_table_unbusy(head);
265 1.6 mlelstv }
266 1.8 christos
267 1.6 mlelstv /*
268 1.2 haad * Return > 0 if table is at least one table entry (returns number of entries)
269 1.2 haad * and return 0 if there is not. Target count returned from this function
270 1.2 haad * doesn't need to be true when userspace user receive it (after return
271 1.2 haad * there can be dm_dev_resume_ioctl), therfore this isonly informative.
272 1.2 haad */
273 1.2 haad int
274 1.5 haad dm_table_get_target_count(dm_table_head_t * head, uint8_t table_id)
275 1.5 haad {
276 1.2 haad dm_table_entry_t *table_en;
277 1.2 haad dm_table_t *tbl;
278 1.2 haad uint32_t target_count;
279 1.2 haad uint8_t id;
280 1.2 haad
281 1.2 haad target_count = 0;
282 1.2 haad
283 1.2 haad id = dm_table_busy(head, table_id);
284 1.2 haad
285 1.2 haad tbl = &head->tables[id];
286 1.2 haad
287 1.2 haad SLIST_FOREACH(table_en, tbl, next)
288 1.2 haad target_count++;
289 1.2 haad
290 1.2 haad dm_table_unbusy(head);
291 1.5 haad
292 1.2 haad return target_count;
293 1.2 haad }
294 1.2 haad
295 1.2 haad
296 1.2 haad /*
297 1.2 haad * Initialize table_head structures, I'm trying to keep this structure as
298 1.2 haad * opaque as possible.
299 1.2 haad */
300 1.2 haad void
301 1.5 haad dm_table_head_init(dm_table_head_t * head)
302 1.2 haad {
303 1.2 haad head->cur_active_table = 0;
304 1.2 haad head->io_cnt = 0;
305 1.5 haad
306 1.2 haad /* Initialize tables. */
307 1.2 haad SLIST_INIT(&head->tables[0]);
308 1.2 haad SLIST_INIT(&head->tables[1]);
309 1.2 haad
310 1.2 haad mutex_init(&head->table_mtx, MUTEX_DEFAULT, IPL_NONE);
311 1.2 haad cv_init(&head->table_cv, "dm_io");
312 1.2 haad }
313 1.8 christos
314 1.2 haad /*
315 1.2 haad * Destroy all variables in table_head
316 1.2 haad */
317 1.2 haad void
318 1.5 haad dm_table_head_destroy(dm_table_head_t * head)
319 1.2 haad {
320 1.2 haad KASSERT(!mutex_owned(&head->table_mtx));
321 1.2 haad KASSERT(!cv_has_waiters(&head->table_cv));
322 1.5 haad /* tables doens't exists when I call this routine, therefore it
323 1.5 haad * doesn't make sense to have io_cnt != 0 */
324 1.5 haad KASSERT(head->io_cnt == 0);
325 1.5 haad
326 1.2 haad cv_destroy(&head->table_cv);
327 1.2 haad mutex_destroy(&head->table_mtx);
328 1.2 haad }
329