1 /*-
2 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: stable/10/sys/kern/kern_osd.c 298834 2016-04-30 04:01:22Z jamie $");
29
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.h>
33 #include <sys/sysctl.h>
34 #include <sys/errno.h>
35 #include <sys/jail.h>
36 #include <sys/malloc.h>
37 #include <sys/lock.h>
38 #include <sys/mutex.h>
39 #include <sys/rmlock.h>
40 #include <sys/sx.h>
41 #include <sys/queue.h>
42 #include <sys/proc.h>
43 #include <sys/osd.h>
44
45 /* OSD (Object Specific Data) */
46
47 /*
48 * Lock key:
49 * (m) osd_module_lock
50 * (o) osd_object_lock
51 * (l) osd_list_lock
52 */
53 struct osd_master {
54 struct sx osd_module_lock;
55 struct rmlock osd_object_lock;
56 struct mtx osd_list_lock;
57 LIST_HEAD(, osd) osd_list; /* (l) */
58 osd_destructor_t *osd_destructors; /* (o) */
59 osd_method_t *osd_methods; /* (m) */
60 u_int osd_ntslots; /* (m) */
61 const u_int osd_nmethods;
62 };
63
64 static MALLOC_DEFINE(M_OSD, "osd", "Object Specific Data");
65
66 static int osd_debug = 0;
67 TUNABLE_INT("debug.osd", &osd_debug);
68 SYSCTL_INT(_debug, OID_AUTO, osd, CTLFLAG_RW, &osd_debug, 0, "OSD debug level");
69
70 #define OSD_DEBUG(...) do { \
71 if (osd_debug) { \
72 printf("OSD (%s:%u): ", __func__, __LINE__); \
73 printf(__VA_ARGS__); \
74 printf("\n"); \
75 } \
76 } while (0)
77
78 static void do_osd_del(u_int type, struct osd *osd, u_int slot,
79 int list_locked);
80
81 /*
82 * List of objects with OSD.
83 */
84 struct osd_master osdm[OSD_LAST + 1] = {
85 [OSD_JAIL] = { .osd_nmethods = PR_MAXMETHOD },
86 };
87
88 static void
osd_default_destructor(void * value __unused)89 osd_default_destructor(void *value __unused)
90 {
91 /* Do nothing. */
92 }
93
94 int
osd_register(u_int type,osd_destructor_t destructor,osd_method_t * methods)95 osd_register(u_int type, osd_destructor_t destructor, osd_method_t *methods)
96 {
97 void *newptr;
98 u_int i, m;
99
100 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
101
102 /*
103 * If no destructor is given, use default one. We need to use some
104 * destructor, because NULL destructor means unused slot.
105 */
106 if (destructor == NULL)
107 destructor = osd_default_destructor;
108
109 sx_xlock(&osdm[type].osd_module_lock);
110 /*
111 * First, we try to find unused slot.
112 */
113 for (i = 0; i < osdm[type].osd_ntslots; i++) {
114 if (osdm[type].osd_destructors[i] == NULL) {
115 OSD_DEBUG("Unused slot found (type=%u, slot=%u).",
116 type, i);
117 break;
118 }
119 }
120 /*
121 * If no unused slot was found, allocate one.
122 */
123 if (i == osdm[type].osd_ntslots) {
124 osdm[type].osd_ntslots++;
125 if (osdm[type].osd_nmethods != 0)
126 osdm[type].osd_methods = realloc(osdm[type].osd_methods,
127 sizeof(osd_method_t) * osdm[type].osd_ntslots *
128 osdm[type].osd_nmethods, M_OSD, M_WAITOK);
129 newptr = malloc(sizeof(osd_destructor_t) *
130 osdm[type].osd_ntslots, M_OSD, M_WAITOK);
131 rm_wlock(&osdm[type].osd_object_lock);
132 bcopy(osdm[type].osd_destructors, newptr,
133 sizeof(osd_destructor_t) * i);
134 free(osdm[type].osd_destructors, M_OSD);
135 osdm[type].osd_destructors = newptr;
136 rm_wunlock(&osdm[type].osd_object_lock);
137 OSD_DEBUG("New slot allocated (type=%u, slot=%u).",
138 type, i + 1);
139 }
140
141 osdm[type].osd_destructors[i] = destructor;
142 if (osdm[type].osd_nmethods != 0) {
143 for (m = 0; m < osdm[type].osd_nmethods; m++)
144 osdm[type].osd_methods[i * osdm[type].osd_nmethods + m]
145 = methods != NULL ? methods[m] : NULL;
146 }
147 sx_xunlock(&osdm[type].osd_module_lock);
148 return (i + 1);
149 }
150
151 void
osd_deregister(u_int type,u_int slot)152 osd_deregister(u_int type, u_int slot)
153 {
154 struct osd *osd, *tosd;
155
156 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
157 KASSERT(slot > 0, ("Invalid slot."));
158 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot."));
159
160 sx_xlock(&osdm[type].osd_module_lock);
161 rm_wlock(&osdm[type].osd_object_lock);
162 /*
163 * Free all OSD for the given slot.
164 */
165 mtx_lock(&osdm[type].osd_list_lock);
166 LIST_FOREACH_SAFE(osd, &osdm[type].osd_list, osd_next, tosd)
167 do_osd_del(type, osd, slot, 1);
168 mtx_unlock(&osdm[type].osd_list_lock);
169 /*
170 * Set destructor to NULL to free the slot.
171 */
172 osdm[type].osd_destructors[slot - 1] = NULL;
173 if (slot == osdm[type].osd_ntslots) {
174 osdm[type].osd_ntslots--;
175 osdm[type].osd_destructors = realloc(osdm[type].osd_destructors,
176 sizeof(osd_destructor_t) * osdm[type].osd_ntslots, M_OSD,
177 M_NOWAIT | M_ZERO);
178 if (osdm[type].osd_nmethods != 0)
179 osdm[type].osd_methods = realloc(osdm[type].osd_methods,
180 sizeof(osd_method_t) * osdm[type].osd_ntslots *
181 osdm[type].osd_nmethods, M_OSD, M_NOWAIT | M_ZERO);
182 /*
183 * We always reallocate to smaller size, so we assume it will
184 * always succeed.
185 */
186 KASSERT(osdm[type].osd_destructors != NULL &&
187 (osdm[type].osd_nmethods == 0 ||
188 osdm[type].osd_methods != NULL), ("realloc() failed"));
189 OSD_DEBUG("Deregistration of the last slot (type=%u, slot=%u).",
190 type, slot);
191 } else {
192 OSD_DEBUG("Slot deregistration (type=%u, slot=%u).",
193 type, slot);
194 }
195 rm_wunlock(&osdm[type].osd_object_lock);
196 sx_xunlock(&osdm[type].osd_module_lock);
197 }
198
199 int
osd_set(u_int type,struct osd * osd,u_int slot,void * value)200 osd_set(u_int type, struct osd *osd, u_int slot, void *value)
201 {
202
203 return (osd_set_reserved(type, osd, slot, NULL, value));
204 }
205
206 void *
osd_reserve(u_int slot)207 osd_reserve(u_int slot)
208 {
209
210 KASSERT(slot > 0, ("Invalid slot."));
211
212 OSD_DEBUG("Reserving slot array (slot=%u).", slot);
213 return (malloc(sizeof(void *) * slot, M_OSD, M_WAITOK | M_ZERO));
214 }
215
216 int
osd_set_reserved(u_int type,struct osd * osd,u_int slot,void * rsv,void * value)217 osd_set_reserved(u_int type, struct osd *osd, u_int slot, void *rsv,
218 void *value)
219 {
220 struct rm_priotracker tracker;
221
222 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
223 KASSERT(slot > 0, ("Invalid slot."));
224 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot."));
225
226 rm_rlock(&osdm[type].osd_object_lock, &tracker);
227 if (slot > osd->osd_nslots) {
228 void *newptr;
229
230 if (value == NULL) {
231 OSD_DEBUG(
232 "Not allocating null slot (type=%u, slot=%u).",
233 type, slot);
234 rm_runlock(&osdm[type].osd_object_lock, &tracker);
235 if (rsv)
236 osd_free_reserved(rsv);
237 return (0);
238 }
239
240 /*
241 * Too few slots allocated here, so we need to extend or create
242 * the array.
243 */
244 if (rsv) {
245 /*
246 * Use the reserve passed in (assumed to be
247 * the right size).
248 */
249 newptr = rsv;
250 if (osd->osd_nslots != 0) {
251 memcpy(newptr, osd->osd_slots,
252 sizeof(void *) * osd->osd_nslots);
253 free(osd->osd_slots, M_OSD);
254 }
255 } else {
256 newptr = realloc(osd->osd_slots, sizeof(void *) * slot,
257 M_OSD, M_NOWAIT | M_ZERO);
258 if (newptr == NULL) {
259 rm_runlock(&osdm[type].osd_object_lock,
260 &tracker);
261 return (ENOMEM);
262 }
263 }
264 if (osd->osd_nslots == 0) {
265 /*
266 * First OSD for this object, so we need to put it
267 * onto the list.
268 */
269 mtx_lock(&osdm[type].osd_list_lock);
270 LIST_INSERT_HEAD(&osdm[type].osd_list, osd, osd_next);
271 mtx_unlock(&osdm[type].osd_list_lock);
272 OSD_DEBUG("Setting first slot (type=%u).", type);
273 } else
274 OSD_DEBUG("Growing slots array (type=%u).", type);
275 osd->osd_slots = newptr;
276 osd->osd_nslots = slot;
277 } else if (rsv)
278 osd_free_reserved(rsv);
279 OSD_DEBUG("Setting slot value (type=%u, slot=%u, value=%p).", type,
280 slot, value);
281 osd->osd_slots[slot - 1] = value;
282 rm_runlock(&osdm[type].osd_object_lock, &tracker);
283 return (0);
284 }
285
286 void
osd_free_reserved(void * rsv)287 osd_free_reserved(void *rsv)
288 {
289
290 OSD_DEBUG("Discarding reserved slot array.");
291 free(rsv, M_OSD);
292 }
293
294 void *
osd_get(u_int type,struct osd * osd,u_int slot)295 osd_get(u_int type, struct osd *osd, u_int slot)
296 {
297 struct rm_priotracker tracker;
298 void *value;
299
300 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
301 KASSERT(slot > 0, ("Invalid slot."));
302 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot."));
303
304 rm_rlock(&osdm[type].osd_object_lock, &tracker);
305 if (slot > osd->osd_nslots) {
306 value = NULL;
307 OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot);
308 } else {
309 value = osd->osd_slots[slot - 1];
310 OSD_DEBUG("Returning slot value (type=%u, slot=%u, value=%p).",
311 type, slot, value);
312 }
313 rm_runlock(&osdm[type].osd_object_lock, &tracker);
314 return (value);
315 }
316
317 void
osd_del(u_int type,struct osd * osd,u_int slot)318 osd_del(u_int type, struct osd *osd, u_int slot)
319 {
320 struct rm_priotracker tracker;
321
322 rm_rlock(&osdm[type].osd_object_lock, &tracker);
323 do_osd_del(type, osd, slot, 0);
324 rm_runlock(&osdm[type].osd_object_lock, &tracker);
325 }
326
327 static void
do_osd_del(u_int type,struct osd * osd,u_int slot,int list_locked)328 do_osd_del(u_int type, struct osd *osd, u_int slot, int list_locked)
329 {
330 int i;
331
332 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
333 KASSERT(slot > 0, ("Invalid slot."));
334 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot."));
335
336 OSD_DEBUG("Deleting slot (type=%u, slot=%u).", type, slot);
337
338 if (slot > osd->osd_nslots) {
339 OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot);
340 return;
341 }
342 if (osd->osd_slots[slot - 1] != NULL) {
343 osdm[type].osd_destructors[slot - 1](osd->osd_slots[slot - 1]);
344 osd->osd_slots[slot - 1] = NULL;
345 }
346 for (i = osd->osd_nslots - 1; i >= 0; i--) {
347 if (osd->osd_slots[i] != NULL) {
348 OSD_DEBUG("Slot still has a value (type=%u, slot=%u).",
349 type, i + 1);
350 break;
351 }
352 }
353 if (i == -1) {
354 /* No values left for this object. */
355 OSD_DEBUG("No more slots left (type=%u).", type);
356 if (!list_locked)
357 mtx_lock(&osdm[type].osd_list_lock);
358 LIST_REMOVE(osd, osd_next);
359 if (!list_locked)
360 mtx_unlock(&osdm[type].osd_list_lock);
361 free(osd->osd_slots, M_OSD);
362 osd->osd_slots = NULL;
363 osd->osd_nslots = 0;
364 } else if (slot == osd->osd_nslots) {
365 /* This was the last slot. */
366 osd->osd_slots = realloc(osd->osd_slots,
367 sizeof(void *) * (i + 1), M_OSD, M_NOWAIT | M_ZERO);
368 /*
369 * We always reallocate to smaller size, so we assume it will
370 * always succeed.
371 */
372 KASSERT(osd->osd_slots != NULL, ("realloc() failed"));
373 osd->osd_nslots = i + 1;
374 OSD_DEBUG("Reducing slots array to %u (type=%u).",
375 osd->osd_nslots, type);
376 }
377 }
378
379 int
osd_call(u_int type,u_int method,void * obj,void * data)380 osd_call(u_int type, u_int method, void *obj, void *data)
381 {
382 osd_method_t methodfun;
383 int error, i;
384
385 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
386 KASSERT(method < osdm[type].osd_nmethods, ("Invalid method."));
387
388 /*
389 * Call this method for every slot that defines it, stopping if an
390 * error is encountered.
391 */
392 error = 0;
393 sx_slock(&osdm[type].osd_module_lock);
394 for (i = 0; i < osdm[type].osd_ntslots; i++) {
395 methodfun = osdm[type].osd_methods[i * osdm[type].osd_nmethods +
396 method];
397 if (methodfun != NULL && (error = methodfun(obj, data)) != 0)
398 break;
399 }
400 sx_sunlock(&osdm[type].osd_module_lock);
401 return (error);
402 }
403
404 void
osd_exit(u_int type,struct osd * osd)405 osd_exit(u_int type, struct osd *osd)
406 {
407 struct rm_priotracker tracker;
408 u_int i;
409
410 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
411
412 if (osd->osd_nslots == 0) {
413 KASSERT(osd->osd_slots == NULL, ("Non-null osd_slots."));
414 /* No OSD attached, just leave. */
415 return;
416 }
417
418 rm_rlock(&osdm[type].osd_object_lock, &tracker);
419 for (i = 1; i <= osd->osd_nslots; i++) {
420 if (osdm[type].osd_destructors[i - 1] != NULL)
421 do_osd_del(type, osd, i, 0);
422 else
423 OSD_DEBUG("Unused slot (type=%u, slot=%u).", type, i);
424 }
425 rm_runlock(&osdm[type].osd_object_lock, &tracker);
426 OSD_DEBUG("Object exit (type=%u).", type);
427 }
428
429 static void
osd_init(void * arg __unused)430 osd_init(void *arg __unused)
431 {
432 u_int i;
433
434 for (i = OSD_FIRST; i <= OSD_LAST; i++) {
435 sx_init(&osdm[i].osd_module_lock, "osd_module");
436 rm_init(&osdm[i].osd_object_lock, "osd_object");
437 mtx_init(&osdm[i].osd_list_lock, "osd_list", NULL, MTX_DEF);
438 LIST_INIT(&osdm[i].osd_list);
439 osdm[i].osd_destructors = NULL;
440 osdm[i].osd_ntslots = 0;
441 osdm[i].osd_methods = NULL;
442 }
443 }
444 SYSINIT(osd, SI_SUB_LOCK, SI_ORDER_ANY, osd_init, NULL);
445