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.")); 159 160 sx_xlock(&osdm[type].osd_module_lock); 161 rm_wlock(&osdm[type].osd_object_lock); 162 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 163 164 /* 165 * Free all OSD for the given slot. 166 */ 167 mtx_lock(&osdm[type].osd_list_lock); 168 LIST_FOREACH_SAFE(osd, &osdm[type].osd_list, osd_next, tosd) 169 do_osd_del(type, osd, slot, 1); 170 mtx_unlock(&osdm[type].osd_list_lock); 171 /* 172 * Set destructor to NULL to free the slot. 173 */ 174 osdm[type].osd_destructors[slot - 1] = NULL; 175 if (slot == osdm[type].osd_ntslots) { 176 osdm[type].osd_ntslots--; 177 osdm[type].osd_destructors = realloc(osdm[type].osd_destructors, 178 sizeof(osd_destructor_t) * osdm[type].osd_ntslots, M_OSD, 179 M_NOWAIT | M_ZERO); 180 if (osdm[type].osd_nmethods != 0) 181 osdm[type].osd_methods = realloc(osdm[type].osd_methods, 182 sizeof(osd_method_t) * osdm[type].osd_ntslots * 183 osdm[type].osd_nmethods, M_OSD, M_NOWAIT | M_ZERO); 184 /* 185 * We always reallocate to smaller size, so we assume it will 186 * always succeed. 187 */ 188 KASSERT(osdm[type].osd_destructors != NULL && 189 (osdm[type].osd_nmethods == 0 || 190 osdm[type].osd_methods != NULL), ("realloc() failed")); 191 OSD_DEBUG("Deregistration of the last slot (type=%u, slot=%u).", 192 type, slot); 193 } else { 194 OSD_DEBUG("Slot deregistration (type=%u, slot=%u).", 195 type, slot); 196 } 197 rm_wunlock(&osdm[type].osd_object_lock); 198 sx_xunlock(&osdm[type].osd_module_lock); 199 } 200 201 int 202 osd_set(u_int type, struct osd *osd, u_int slot, void *value) 203 { 204 205 return (osd_set_reserved(type, osd, slot, NULL, value)); 206 } 207 208 void ** 209 osd_reserve(u_int slot) 210 { 211 212 KASSERT(slot > 0, ("Invalid slot.")); 213 214 OSD_DEBUG("Reserving slot array (slot=%u).", slot); 215 return (malloc(sizeof(void *) * slot, M_OSD, M_WAITOK | M_ZERO)); 216 } 217 218 int 219 osd_set_reserved(u_int type, struct osd *osd, u_int slot, void **rsv, 220 void *value) 221 { 222 struct rm_priotracker tracker; 223 224 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 225 KASSERT(slot > 0, ("Invalid slot.")); 226 227 rm_rlock(&osdm[type].osd_object_lock, &tracker); 228 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 229 230 if (slot > osd->osd_nslots) { 231 void **newptr; 232 233 if (value == NULL) { 234 OSD_DEBUG( 235 "Not allocating null slot (type=%u, slot=%u).", 236 type, slot); 237 rm_runlock(&osdm[type].osd_object_lock, &tracker); 238 if (rsv) 239 osd_free_reserved(rsv); 240 return (0); 241 } 242 243 /* 244 * Too few slots allocated here, so we need to extend or create 245 * the array. 246 */ 247 if (rsv) { 248 /* 249 * Use the reserve passed in (assumed to be 250 * the right size). 251 */ 252 newptr = rsv; 253 if (osd->osd_nslots != 0) { 254 memcpy(newptr, osd->osd_slots, 255 sizeof(void *) * osd->osd_nslots); 256 free(osd->osd_slots, M_OSD); 257 } 258 } else { 259 newptr = realloc(osd->osd_slots, sizeof(void *) * slot, 260 M_OSD, M_NOWAIT | M_ZERO); 261 if (newptr == NULL) { 262 rm_runlock(&osdm[type].osd_object_lock, 263 &tracker); 264 return (ENOMEM); 265 } 266 } 267 if (osd->osd_nslots == 0) { 268 /* 269 * First OSD for this object, so we need to put it 270 * onto the list. 271 */ 272 mtx_lock(&osdm[type].osd_list_lock); 273 LIST_INSERT_HEAD(&osdm[type].osd_list, osd, osd_next); 274 mtx_unlock(&osdm[type].osd_list_lock); 275 OSD_DEBUG("Setting first slot (type=%u).", type); 276 } else 277 OSD_DEBUG("Growing slots array (type=%u).", type); 278 osd->osd_slots = newptr; 279 osd->osd_nslots = slot; 280 } else if (rsv) 281 osd_free_reserved(rsv); 282 OSD_DEBUG("Setting slot value (type=%u, slot=%u, value=%p).", type, 283 slot, value); 284 osd->osd_slots[slot - 1] = value; 285 rm_runlock(&osdm[type].osd_object_lock, &tracker); 286 return (0); 287 } 288 289 void 290 osd_free_reserved(void **rsv) 291 { 292 293 OSD_DEBUG("Discarding reserved slot array."); 294 free(rsv, M_OSD); 295 } 296 297 void * 298 osd_get(u_int type, struct osd *osd, u_int slot) 299 { 300 struct rm_priotracker tracker; 301 void *value; 302 303 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 304 KASSERT(slot > 0, ("Invalid slot.")); 305 306 rm_rlock(&osdm[type].osd_object_lock, &tracker); 307 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 308 309 if (slot > osd->osd_nslots) { 310 value = NULL; 311 OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot); 312 } else { 313 value = osd->osd_slots[slot - 1]; 314 OSD_DEBUG("Returning slot value (type=%u, slot=%u, value=%p).", 315 type, slot, value); 316 } 317 rm_runlock(&osdm[type].osd_object_lock, &tracker); 318 return (value); 319 } 320 321 void 322 osd_del(u_int type, struct osd *osd, u_int slot) 323 { 324 struct rm_priotracker tracker; 325 326 rm_rlock(&osdm[type].osd_object_lock, &tracker); 327 do_osd_del(type, osd, slot, 0); 328 rm_runlock(&osdm[type].osd_object_lock, &tracker); 329 } 330 331 static void 332 do_osd_del(u_int type, struct osd *osd, u_int slot, int list_locked) 333 { 334 int i; 335 336 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 337 KASSERT(slot > 0, ("Invalid slot.")); 338 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 339 340 OSD_DEBUG("Deleting slot (type=%u, slot=%u).", type, slot); 341 342 if (slot > osd->osd_nslots) { 343 OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot); 344 return; 345 } 346 if (osd->osd_slots[slot - 1] != NULL) { 347 osdm[type].osd_destructors[slot - 1](osd->osd_slots[slot - 1]); 348 osd->osd_slots[slot - 1] = NULL; 349 } 350 for (i = osd->osd_nslots - 1; i >= 0; i--) { 351 if (osd->osd_slots[i] != NULL) { 352 OSD_DEBUG("Slot still has a value (type=%u, slot=%u).", 353 type, i + 1); 354 break; 355 } 356 } 357 if (i == -1) { 358 /* No values left for this object. */ 359 OSD_DEBUG("No more slots left (type=%u).", type); 360 if (!list_locked) 361 mtx_lock(&osdm[type].osd_list_lock); 362 LIST_REMOVE(osd, osd_next); 363 if (!list_locked) 364 mtx_unlock(&osdm[type].osd_list_lock); 365 free(osd->osd_slots, M_OSD); 366 osd->osd_slots = NULL; 367 osd->osd_nslots = 0; 368 } else if (slot == osd->osd_nslots) { 369 /* This was the last slot. */ 370 osd->osd_slots = realloc(osd->osd_slots, 371 sizeof(void *) * (i + 1), M_OSD, M_NOWAIT | M_ZERO); 372 /* 373 * We always reallocate to smaller size, so we assume it will 374 * always succeed. 375 */ 376 KASSERT(osd->osd_slots != NULL, ("realloc() failed")); 377 osd->osd_nslots = i + 1; 378 OSD_DEBUG("Reducing slots array to %u (type=%u).", 379 osd->osd_nslots, type); 380 } 381 } 382 383 int 384 osd_call(u_int type, u_int method, void *obj, void *data) 385 { 386 osd_method_t methodfun; 387 int error, i; 388 389 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 390 KASSERT(method < osdm[type].osd_nmethods, ("Invalid method.")); 391 392 /* 393 * Call this method for every slot that defines it, stopping if an 394 * error is encountered. 395 */ 396 error = 0; 397 sx_slock(&osdm[type].osd_module_lock); 398 for (i = 0; i < osdm[type].osd_ntslots; i++) { 399 methodfun = osdm[type].osd_methods[i * osdm[type].osd_nmethods + 400 method]; 401 if (methodfun != NULL && (error = methodfun(obj, data)) != 0) 402 break; 403 } 404 sx_sunlock(&osdm[type].osd_module_lock); 405 return (error); 406 } 407 408 void 409 osd_exit(u_int type, struct osd *osd) 410 { 411 struct rm_priotracker tracker; 412 u_int i; 413 414 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 415 416 if (osd->osd_nslots == 0) { 417 KASSERT(osd->osd_slots == NULL, ("Non-null osd_slots.")); 418 /* No OSD attached, just leave. */ 419 return; 420 } 421 422 rm_rlock(&osdm[type].osd_object_lock, &tracker); 423 for (i = 1; i <= osd->osd_nslots; i++) { 424 if (osdm[type].osd_destructors[i - 1] != NULL) 425 do_osd_del(type, osd, i, 0); 426 else 427 OSD_DEBUG("Unused slot (type=%u, slot=%u).", type, i); 428 } 429 rm_runlock(&osdm[type].osd_object_lock, &tracker); 430 OSD_DEBUG("Object exit (type=%u).", type); 431 } 432 433 static void 434 osd_init(void *arg __unused) 435 { 436 u_int i; 437 438 for (i = OSD_FIRST; i <= OSD_LAST; i++) { 439 sx_init(&osdm[i].osd_module_lock, "osd_module"); 440 rm_init(&osdm[i].osd_object_lock, "osd_object"); 441 mtx_init(&osdm[i].osd_list_lock, "osd_list", NULL, MTX_DEF); 442 LIST_INIT(&osdm[i].osd_list); 443 osdm[i].osd_destructors = NULL; 444 osdm[i].osd_ntslots = 0; 445 osdm[i].osd_methods = NULL; 446 } 447 } 448 SYSINIT(osd, SI_SUB_LOCK, SI_ORDER_ANY, osd_init, NULL); 449