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("$FreeBSD$"); 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; /* (m) */ 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 SYSCTL_INT(_debug, OID_AUTO, osd, CTLFLAG_RWTUN, &osd_debug, 0, "OSD debug level"); 68 69 #define OSD_DEBUG(...) do { \ 70 if (osd_debug) { \ 71 printf("OSD (%s:%u): ", __func__, __LINE__); \ 72 printf(__VA_ARGS__); \ 73 printf("\n"); \ 74 } \ 75 } while (0) 76 77 static void do_osd_del(u_int type, struct osd *osd, u_int slot, 78 int list_locked); 79 80 /* 81 * List of objects with OSD. 82 */ 83 struct osd_master osdm[OSD_LAST + 1] = { 84 [OSD_JAIL] = { .osd_nmethods = PR_MAXMETHOD }, 85 }; 86 87 static void 88 osd_default_destructor(void *value __unused) 89 { 90 /* Do nothing. */ 91 } 92 93 int 94 osd_register(u_int type, osd_destructor_t destructor, osd_method_t *methods) 95 { 96 void *newptr; 97 u_int i, m; 98 99 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 100 101 /* 102 * If no destructor is given, use default one. We need to use some 103 * destructor, because NULL destructor means unused slot. 104 */ 105 if (destructor == NULL) 106 destructor = osd_default_destructor; 107 108 sx_xlock(&osdm[type].osd_module_lock); 109 /* 110 * First, we try to find unused slot. 111 */ 112 for (i = 0; i < osdm[type].osd_ntslots; i++) { 113 if (osdm[type].osd_destructors[i] == NULL) { 114 OSD_DEBUG("Unused slot found (type=%u, slot=%u).", 115 type, i); 116 break; 117 } 118 } 119 /* 120 * If no unused slot was found, allocate one. 121 */ 122 if (i == osdm[type].osd_ntslots) { 123 osdm[type].osd_ntslots++; 124 if (osdm[type].osd_nmethods != 0) 125 osdm[type].osd_methods = realloc(osdm[type].osd_methods, 126 sizeof(osd_method_t) * osdm[type].osd_ntslots * 127 osdm[type].osd_nmethods, M_OSD, M_WAITOK); 128 newptr = malloc(sizeof(osd_destructor_t) * 129 osdm[type].osd_ntslots, M_OSD, M_WAITOK); 130 rm_wlock(&osdm[type].osd_object_lock); 131 bcopy(osdm[type].osd_destructors, newptr, 132 sizeof(osd_destructor_t) * i); 133 free(osdm[type].osd_destructors, M_OSD); 134 osdm[type].osd_destructors = newptr; 135 rm_wunlock(&osdm[type].osd_object_lock); 136 OSD_DEBUG("New slot allocated (type=%u, slot=%u).", 137 type, i + 1); 138 } 139 140 osdm[type].osd_destructors[i] = destructor; 141 if (osdm[type].osd_nmethods != 0) { 142 for (m = 0; m < osdm[type].osd_nmethods; m++) 143 osdm[type].osd_methods[i * osdm[type].osd_nmethods + m] 144 = methods != NULL ? methods[m] : NULL; 145 } 146 sx_xunlock(&osdm[type].osd_module_lock); 147 return (i + 1); 148 } 149 150 void 151 osd_deregister(u_int type, u_int slot) 152 { 153 struct osd *osd, *tosd; 154 155 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 156 KASSERT(slot > 0, ("Invalid slot.")); 157 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 158 159 sx_xlock(&osdm[type].osd_module_lock); 160 rm_wlock(&osdm[type].osd_object_lock); 161 /* 162 * Free all OSD for the given slot. 163 */ 164 mtx_lock(&osdm[type].osd_list_lock); 165 LIST_FOREACH_SAFE(osd, &osdm[type].osd_list, osd_next, tosd) 166 do_osd_del(type, osd, slot, 1); 167 mtx_unlock(&osdm[type].osd_list_lock); 168 /* 169 * Set destructor to NULL to free the slot. 170 */ 171 osdm[type].osd_destructors[slot - 1] = NULL; 172 if (slot == osdm[type].osd_ntslots) { 173 osdm[type].osd_ntslots--; 174 osdm[type].osd_destructors = realloc(osdm[type].osd_destructors, 175 sizeof(osd_destructor_t) * osdm[type].osd_ntslots, M_OSD, 176 M_NOWAIT | M_ZERO); 177 if (osdm[type].osd_nmethods != 0) 178 osdm[type].osd_methods = realloc(osdm[type].osd_methods, 179 sizeof(osd_method_t) * osdm[type].osd_ntslots * 180 osdm[type].osd_nmethods, M_OSD, M_NOWAIT | M_ZERO); 181 /* 182 * We always reallocate to smaller size, so we assume it will 183 * always succeed. 184 */ 185 KASSERT(osdm[type].osd_destructors != NULL && 186 (osdm[type].osd_nmethods == 0 || 187 osdm[type].osd_methods != NULL), ("realloc() failed")); 188 OSD_DEBUG("Deregistration of the last slot (type=%u, slot=%u).", 189 type, slot); 190 } else { 191 OSD_DEBUG("Slot deregistration (type=%u, slot=%u).", 192 type, slot); 193 } 194 rm_wunlock(&osdm[type].osd_object_lock); 195 sx_xunlock(&osdm[type].osd_module_lock); 196 } 197 198 int 199 osd_set(u_int type, struct osd *osd, u_int slot, void *value) 200 { 201 struct rm_priotracker tracker; 202 203 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 204 KASSERT(slot > 0, ("Invalid slot.")); 205 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 206 207 rm_rlock(&osdm[type].osd_object_lock, &tracker); 208 if (slot > osd->osd_nslots) { 209 if (value == NULL) { 210 OSD_DEBUG( 211 "Not allocating null slot (type=%u, slot=%u).", 212 type, slot); 213 rm_runlock(&osdm[type].osd_object_lock, &tracker); 214 return (0); 215 } else if (osd->osd_nslots == 0) { 216 /* 217 * First OSD for this object, so we need to allocate 218 * space and put it onto the list. 219 */ 220 osd->osd_slots = malloc(sizeof(void *) * slot, M_OSD, 221 M_NOWAIT | M_ZERO); 222 if (osd->osd_slots == NULL) { 223 rm_runlock(&osdm[type].osd_object_lock, 224 &tracker); 225 return (ENOMEM); 226 } 227 osd->osd_nslots = slot; 228 mtx_lock(&osdm[type].osd_list_lock); 229 LIST_INSERT_HEAD(&osdm[type].osd_list, osd, osd_next); 230 mtx_unlock(&osdm[type].osd_list_lock); 231 OSD_DEBUG("Setting first slot (type=%u).", type); 232 } else { 233 void *newptr; 234 235 /* 236 * Too few slots allocated here, needs to extend 237 * the array. 238 */ 239 newptr = realloc(osd->osd_slots, sizeof(void *) * slot, 240 M_OSD, M_NOWAIT | M_ZERO); 241 if (newptr == NULL) { 242 rm_runlock(&osdm[type].osd_object_lock, 243 &tracker); 244 return (ENOMEM); 245 } 246 osd->osd_slots = newptr; 247 osd->osd_nslots = slot; 248 OSD_DEBUG("Growing slots array (type=%u).", type); 249 } 250 } 251 OSD_DEBUG("Setting slot value (type=%u, slot=%u, value=%p).", type, 252 slot, value); 253 osd->osd_slots[slot - 1] = value; 254 rm_runlock(&osdm[type].osd_object_lock, &tracker); 255 return (0); 256 } 257 258 void * 259 osd_get(u_int type, struct osd *osd, u_int slot) 260 { 261 struct rm_priotracker tracker; 262 void *value; 263 264 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 265 KASSERT(slot > 0, ("Invalid slot.")); 266 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 267 268 rm_rlock(&osdm[type].osd_object_lock, &tracker); 269 if (slot > osd->osd_nslots) { 270 value = NULL; 271 OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot); 272 } else { 273 value = osd->osd_slots[slot - 1]; 274 OSD_DEBUG("Returning slot value (type=%u, slot=%u, value=%p).", 275 type, slot, value); 276 } 277 rm_runlock(&osdm[type].osd_object_lock, &tracker); 278 return (value); 279 } 280 281 void 282 osd_del(u_int type, struct osd *osd, u_int slot) 283 { 284 struct rm_priotracker tracker; 285 286 rm_rlock(&osdm[type].osd_object_lock, &tracker); 287 do_osd_del(type, osd, slot, 0); 288 rm_runlock(&osdm[type].osd_object_lock, &tracker); 289 } 290 291 static void 292 do_osd_del(u_int type, struct osd *osd, u_int slot, int list_locked) 293 { 294 int i; 295 296 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 297 KASSERT(slot > 0, ("Invalid slot.")); 298 KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot.")); 299 300 OSD_DEBUG("Deleting slot (type=%u, slot=%u).", type, slot); 301 302 if (slot > osd->osd_nslots) { 303 OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot); 304 return; 305 } 306 if (osd->osd_slots[slot - 1] != NULL) { 307 osdm[type].osd_destructors[slot - 1](osd->osd_slots[slot - 1]); 308 osd->osd_slots[slot - 1] = NULL; 309 } 310 for (i = osd->osd_nslots - 1; i >= 0; i--) { 311 if (osd->osd_slots[i] != NULL) { 312 OSD_DEBUG("Slot still has a value (type=%u, slot=%u).", 313 type, i + 1); 314 break; 315 } 316 } 317 if (i == -1) { 318 /* No values left for this object. */ 319 OSD_DEBUG("No more slots left (type=%u).", type); 320 if (!list_locked) 321 mtx_lock(&osdm[type].osd_list_lock); 322 LIST_REMOVE(osd, osd_next); 323 if (!list_locked) 324 mtx_unlock(&osdm[type].osd_list_lock); 325 free(osd->osd_slots, M_OSD); 326 osd->osd_slots = NULL; 327 osd->osd_nslots = 0; 328 } else if (slot == osd->osd_nslots) { 329 /* This was the last slot. */ 330 osd->osd_slots = realloc(osd->osd_slots, 331 sizeof(void *) * (i + 1), M_OSD, M_NOWAIT | M_ZERO); 332 /* 333 * We always reallocate to smaller size, so we assume it will 334 * always succeed. 335 */ 336 KASSERT(osd->osd_slots != NULL, ("realloc() failed")); 337 osd->osd_nslots = i + 1; 338 OSD_DEBUG("Reducing slots array to %u (type=%u).", 339 osd->osd_nslots, type); 340 } 341 } 342 343 int 344 osd_call(u_int type, u_int method, void *obj, void *data) 345 { 346 osd_method_t methodfun; 347 int error, i; 348 349 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 350 KASSERT(method < osdm[type].osd_nmethods, ("Invalid method.")); 351 352 /* 353 * Call this method for every slot that defines it, stopping if an 354 * error is encountered. 355 */ 356 error = 0; 357 sx_slock(&osdm[type].osd_module_lock); 358 for (i = 0; i < osdm[type].osd_ntslots; i++) { 359 methodfun = osdm[type].osd_methods[i * osdm[type].osd_nmethods + 360 method]; 361 if (methodfun != NULL && (error = methodfun(obj, data)) != 0) 362 break; 363 } 364 sx_sunlock(&osdm[type].osd_module_lock); 365 return (error); 366 } 367 368 void 369 osd_exit(u_int type, struct osd *osd) 370 { 371 struct rm_priotracker tracker; 372 u_int i; 373 374 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 375 376 if (osd->osd_nslots == 0) { 377 KASSERT(osd->osd_slots == NULL, ("Non-null osd_slots.")); 378 /* No OSD attached, just leave. */ 379 return; 380 } 381 382 rm_rlock(&osdm[type].osd_object_lock, &tracker); 383 for (i = 1; i <= osd->osd_nslots; i++) { 384 if (osdm[type].osd_destructors[i - 1] != NULL) 385 do_osd_del(type, osd, i, 0); 386 else 387 OSD_DEBUG("Unused slot (type=%u, slot=%u).", type, i); 388 } 389 rm_runlock(&osdm[type].osd_object_lock, &tracker); 390 OSD_DEBUG("Object exit (type=%u).", type); 391 } 392 393 static void 394 osd_init(void *arg __unused) 395 { 396 u_int i; 397 398 for (i = OSD_FIRST; i <= OSD_LAST; i++) { 399 sx_init(&osdm[i].osd_module_lock, "osd_module"); 400 rm_init(&osdm[i].osd_object_lock, "osd_object"); 401 mtx_init(&osdm[i].osd_list_lock, "osd_list", NULL, MTX_DEF); 402 LIST_INIT(&osdm[i].osd_list); 403 osdm[i].osd_destructors = NULL; 404 osdm[i].osd_ntslots = 0; 405 osdm[i].osd_methods = NULL; 406 } 407 } 408 SYSINIT(osd, SI_SUB_LOCK, SI_ORDER_ANY, osd_init, NULL); 409