1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #include <sys/systm.h> 35 #include <sys/sysctl.h> 36 #include <sys/errno.h> 37 #include <sys/jail.h> 38 #include <sys/malloc.h> 39 #include <sys/lock.h> 40 #include <sys/mutex.h> 41 #include <sys/rmlock.h> 42 #include <sys/sx.h> 43 #include <sys/queue.h> 44 #include <sys/proc.h> 45 #include <sys/osd.h> 46 47 /* OSD (Object Specific Data) */ 48 49 /* 50 * Lock key: 51 * (m) osd_module_lock 52 * (o) osd_object_lock 53 * (l) osd_list_lock 54 */ 55 struct osd_master { 56 struct sx osd_module_lock; 57 struct rmlock osd_object_lock; 58 struct mtx osd_list_lock; 59 LIST_HEAD(, osd) osd_list; /* (l) */ 60 osd_destructor_t *osd_destructors; /* (o) */ 61 osd_method_t *osd_methods; /* (m) */ 62 u_int osd_ntslots; /* (m) */ 63 const u_int osd_nmethods; 64 }; 65 66 static MALLOC_DEFINE(M_OSD, "osd", "Object Specific Data"); 67 68 static int osd_debug = 0; 69 SYSCTL_INT(_debug, OID_AUTO, osd, CTLFLAG_RWTUN, &osd_debug, 0, "OSD debug level"); 70 71 #define OSD_DEBUG(...) do { \ 72 if (osd_debug) { \ 73 printf("OSD (%s:%u): ", __func__, __LINE__); \ 74 printf(__VA_ARGS__); \ 75 printf("\n"); \ 76 } \ 77 } while (0) 78 79 static void do_osd_del(u_int type, struct osd *osd, u_int slot, 80 int list_locked); 81 82 /* 83 * List of objects with OSD. 84 */ 85 struct osd_master osdm[OSD_LAST + 1] = { 86 [OSD_JAIL] = { .osd_nmethods = PR_MAXMETHOD }, 87 }; 88 89 static void 90 osd_default_destructor(void *value __unused) 91 { 92 /* Do nothing. */ 93 } 94 95 int 96 osd_register(u_int type, osd_destructor_t destructor, osd_method_t *methods) 97 { 98 void *newptr; 99 u_int i, m; 100 101 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 102 103 /* 104 * If no destructor is given, use default one. We need to use some 105 * destructor, because NULL destructor means unused slot. 106 */ 107 if (destructor == NULL) 108 destructor = osd_default_destructor; 109 110 sx_xlock(&osdm[type].osd_module_lock); 111 /* 112 * First, we try to find unused slot. 113 */ 114 for (i = 0; i < osdm[type].osd_ntslots; i++) { 115 if (osdm[type].osd_destructors[i] == NULL) { 116 OSD_DEBUG("Unused slot found (type=%u, slot=%u).", 117 type, i); 118 break; 119 } 120 } 121 /* 122 * If no unused slot was found, allocate one. 123 */ 124 if (i == osdm[type].osd_ntslots) { 125 osdm[type].osd_ntslots++; 126 if (osdm[type].osd_nmethods != 0) 127 osdm[type].osd_methods = realloc(osdm[type].osd_methods, 128 sizeof(osd_method_t) * osdm[type].osd_ntslots * 129 osdm[type].osd_nmethods, M_OSD, M_WAITOK); 130 newptr = malloc(sizeof(osd_destructor_t) * 131 osdm[type].osd_ntslots, M_OSD, M_WAITOK); 132 rm_wlock(&osdm[type].osd_object_lock); 133 bcopy(osdm[type].osd_destructors, newptr, 134 sizeof(osd_destructor_t) * i); 135 free(osdm[type].osd_destructors, M_OSD); 136 osdm[type].osd_destructors = newptr; 137 rm_wunlock(&osdm[type].osd_object_lock); 138 OSD_DEBUG("New slot allocated (type=%u, slot=%u).", 139 type, i + 1); 140 } 141 142 osdm[type].osd_destructors[i] = destructor; 143 if (osdm[type].osd_nmethods != 0) { 144 for (m = 0; m < osdm[type].osd_nmethods; m++) 145 osdm[type].osd_methods[i * osdm[type].osd_nmethods + m] 146 = methods != NULL ? methods[m] : NULL; 147 } 148 sx_xunlock(&osdm[type].osd_module_lock); 149 return (i + 1); 150 } 151 152 void 153 osd_deregister(u_int type, u_int slot) 154 { 155 struct osd *osd, *tosd; 156 157 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 158 KASSERT(slot > 0, ("Invalid slot.")); 159 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 160 161 sx_xlock(&osdm[type].osd_module_lock); 162 rm_wlock(&osdm[type].osd_object_lock); 163 /* 164 * Free all OSD for the given slot. 165 */ 166 mtx_lock(&osdm[type].osd_list_lock); 167 LIST_FOREACH_SAFE(osd, &osdm[type].osd_list, osd_next, tosd) 168 do_osd_del(type, osd, slot, 1); 169 mtx_unlock(&osdm[type].osd_list_lock); 170 /* 171 * Set destructor to NULL to free the slot. 172 */ 173 osdm[type].osd_destructors[slot - 1] = NULL; 174 if (slot == osdm[type].osd_ntslots) { 175 osdm[type].osd_ntslots--; 176 osdm[type].osd_destructors = realloc(osdm[type].osd_destructors, 177 sizeof(osd_destructor_t) * osdm[type].osd_ntslots, M_OSD, 178 M_NOWAIT | M_ZERO); 179 if (osdm[type].osd_nmethods != 0) 180 osdm[type].osd_methods = realloc(osdm[type].osd_methods, 181 sizeof(osd_method_t) * osdm[type].osd_ntslots * 182 osdm[type].osd_nmethods, M_OSD, M_NOWAIT | M_ZERO); 183 /* 184 * We always reallocate to smaller size, so we assume it will 185 * always succeed. 186 */ 187 KASSERT(osdm[type].osd_destructors != NULL && 188 (osdm[type].osd_nmethods == 0 || 189 osdm[type].osd_methods != NULL), ("realloc() failed")); 190 OSD_DEBUG("Deregistration of the last slot (type=%u, slot=%u).", 191 type, slot); 192 } else { 193 OSD_DEBUG("Slot deregistration (type=%u, slot=%u).", 194 type, slot); 195 } 196 rm_wunlock(&osdm[type].osd_object_lock); 197 sx_xunlock(&osdm[type].osd_module_lock); 198 } 199 200 int 201 osd_set(u_int type, struct osd *osd, u_int slot, void *value) 202 { 203 204 return (osd_set_reserved(type, osd, slot, NULL, value)); 205 } 206 207 void ** 208 osd_reserve(u_int slot) 209 { 210 211 KASSERT(slot > 0, ("Invalid slot.")); 212 213 OSD_DEBUG("Reserving slot array (slot=%u).", slot); 214 return (malloc(sizeof(void *) * slot, M_OSD, M_WAITOK | M_ZERO)); 215 } 216 217 int 218 osd_set_reserved(u_int type, struct osd *osd, u_int slot, void **rsv, 219 void *value) 220 { 221 struct rm_priotracker tracker; 222 223 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 224 KASSERT(slot > 0, ("Invalid slot.")); 225 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 226 227 rm_rlock(&osdm[type].osd_object_lock, &tracker); 228 if (slot > osd->osd_nslots) { 229 void **newptr; 230 231 if (value == NULL) { 232 OSD_DEBUG( 233 "Not allocating null slot (type=%u, slot=%u).", 234 type, slot); 235 rm_runlock(&osdm[type].osd_object_lock, &tracker); 236 if (rsv) 237 osd_free_reserved(rsv); 238 return (0); 239 } 240 241 /* 242 * Too few slots allocated here, so we need to extend or create 243 * the array. 244 */ 245 if (rsv) { 246 /* 247 * Use the reserve passed in (assumed to be 248 * the right size). 249 */ 250 newptr = rsv; 251 if (osd->osd_nslots != 0) { 252 memcpy(newptr, osd->osd_slots, 253 sizeof(void *) * osd->osd_nslots); 254 free(osd->osd_slots, M_OSD); 255 } 256 } else { 257 newptr = realloc(osd->osd_slots, sizeof(void *) * slot, 258 M_OSD, M_NOWAIT | M_ZERO); 259 if (newptr == NULL) { 260 rm_runlock(&osdm[type].osd_object_lock, 261 &tracker); 262 return (ENOMEM); 263 } 264 } 265 if (osd->osd_nslots == 0) { 266 /* 267 * First OSD for this object, so we need to put it 268 * onto the list. 269 */ 270 mtx_lock(&osdm[type].osd_list_lock); 271 LIST_INSERT_HEAD(&osdm[type].osd_list, osd, osd_next); 272 mtx_unlock(&osdm[type].osd_list_lock); 273 OSD_DEBUG("Setting first slot (type=%u).", type); 274 } else 275 OSD_DEBUG("Growing slots array (type=%u).", type); 276 osd->osd_slots = newptr; 277 osd->osd_nslots = slot; 278 } else if (rsv) 279 osd_free_reserved(rsv); 280 OSD_DEBUG("Setting slot value (type=%u, slot=%u, value=%p).", type, 281 slot, value); 282 osd->osd_slots[slot - 1] = value; 283 rm_runlock(&osdm[type].osd_object_lock, &tracker); 284 return (0); 285 } 286 287 void 288 osd_free_reserved(void **rsv) 289 { 290 291 OSD_DEBUG("Discarding reserved slot array."); 292 free(rsv, M_OSD); 293 } 294 295 void * 296 osd_get(u_int type, struct osd *osd, u_int slot) 297 { 298 struct rm_priotracker tracker; 299 void *value; 300 301 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 302 KASSERT(slot > 0, ("Invalid slot.")); 303 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 304 305 rm_rlock(&osdm[type].osd_object_lock, &tracker); 306 if (slot > osd->osd_nslots) { 307 value = NULL; 308 OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot); 309 } else { 310 value = osd->osd_slots[slot - 1]; 311 OSD_DEBUG("Returning slot value (type=%u, slot=%u, value=%p).", 312 type, slot, value); 313 } 314 rm_runlock(&osdm[type].osd_object_lock, &tracker); 315 return (value); 316 } 317 318 void 319 osd_del(u_int type, struct osd *osd, u_int slot) 320 { 321 struct rm_priotracker tracker; 322 323 rm_rlock(&osdm[type].osd_object_lock, &tracker); 324 do_osd_del(type, osd, slot, 0); 325 rm_runlock(&osdm[type].osd_object_lock, &tracker); 326 } 327 328 static void 329 do_osd_del(u_int type, struct osd *osd, u_int slot, int list_locked) 330 { 331 int i; 332 333 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 334 KASSERT(slot > 0, ("Invalid slot.")); 335 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 336 337 OSD_DEBUG("Deleting slot (type=%u, slot=%u).", type, slot); 338 339 if (slot > osd->osd_nslots) { 340 OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot); 341 return; 342 } 343 if (osd->osd_slots[slot - 1] != NULL) { 344 osdm[type].osd_destructors[slot - 1](osd->osd_slots[slot - 1]); 345 osd->osd_slots[slot - 1] = NULL; 346 } 347 for (i = osd->osd_nslots - 1; i >= 0; i--) { 348 if (osd->osd_slots[i] != NULL) { 349 OSD_DEBUG("Slot still has a value (type=%u, slot=%u).", 350 type, i + 1); 351 break; 352 } 353 } 354 if (i == -1) { 355 /* No values left for this object. */ 356 OSD_DEBUG("No more slots left (type=%u).", type); 357 if (!list_locked) 358 mtx_lock(&osdm[type].osd_list_lock); 359 LIST_REMOVE(osd, osd_next); 360 if (!list_locked) 361 mtx_unlock(&osdm[type].osd_list_lock); 362 free(osd->osd_slots, M_OSD); 363 osd->osd_slots = NULL; 364 osd->osd_nslots = 0; 365 } else if (slot == osd->osd_nslots) { 366 /* This was the last slot. */ 367 osd->osd_slots = realloc(osd->osd_slots, 368 sizeof(void *) * (i + 1), M_OSD, M_NOWAIT | M_ZERO); 369 /* 370 * We always reallocate to smaller size, so we assume it will 371 * always succeed. 372 */ 373 KASSERT(osd->osd_slots != NULL, ("realloc() failed")); 374 osd->osd_nslots = i + 1; 375 OSD_DEBUG("Reducing slots array to %u (type=%u).", 376 osd->osd_nslots, type); 377 } 378 } 379 380 int 381 osd_call(u_int type, u_int method, void *obj, void *data) 382 { 383 osd_method_t methodfun; 384 int error, i; 385 386 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 387 KASSERT(method < osdm[type].osd_nmethods, ("Invalid method.")); 388 389 /* 390 * Call this method for every slot that defines it, stopping if an 391 * error is encountered. 392 */ 393 error = 0; 394 sx_slock(&osdm[type].osd_module_lock); 395 for (i = 0; i < osdm[type].osd_ntslots; i++) { 396 methodfun = osdm[type].osd_methods[i * osdm[type].osd_nmethods + 397 method]; 398 if (methodfun != NULL && (error = methodfun(obj, data)) != 0) 399 break; 400 } 401 sx_sunlock(&osdm[type].osd_module_lock); 402 return (error); 403 } 404 405 void 406 osd_exit(u_int type, struct osd *osd) 407 { 408 struct rm_priotracker tracker; 409 u_int i; 410 411 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 412 413 if (osd->osd_nslots == 0) { 414 KASSERT(osd->osd_slots == NULL, ("Non-null osd_slots.")); 415 /* No OSD attached, just leave. */ 416 return; 417 } 418 419 rm_rlock(&osdm[type].osd_object_lock, &tracker); 420 for (i = 1; i <= osd->osd_nslots; i++) { 421 if (osdm[type].osd_destructors[i - 1] != NULL) 422 do_osd_del(type, osd, i, 0); 423 else 424 OSD_DEBUG("Unused slot (type=%u, slot=%u).", type, i); 425 } 426 rm_runlock(&osdm[type].osd_object_lock, &tracker); 427 OSD_DEBUG("Object exit (type=%u).", type); 428 } 429 430 static void 431 osd_init(void *arg __unused) 432 { 433 u_int i; 434 435 for (i = OSD_FIRST; i <= OSD_LAST; i++) { 436 sx_init(&osdm[i].osd_module_lock, "osd_module"); 437 rm_init(&osdm[i].osd_object_lock, "osd_object"); 438 mtx_init(&osdm[i].osd_list_lock, "osd_list", NULL, MTX_DEF); 439 LIST_INIT(&osdm[i].osd_list); 440 osdm[i].osd_destructors = NULL; 441 osdm[i].osd_ntslots = 0; 442 osdm[i].osd_methods = NULL; 443 } 444 } 445 SYSINIT(osd, SI_SUB_LOCK, SI_ORDER_ANY, osd_init, NULL); 446