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 static MALLOC_DEFINE(M_OSD, "osd", "Object Specific Data"); 48 49 static int osd_debug = 0; 50 TUNABLE_INT("debug.osd", &osd_debug); 51 SYSCTL_INT(_debug, OID_AUTO, osd, CTLFLAG_RW, &osd_debug, 0, "OSD debug level"); 52 53 #define OSD_DEBUG(...) do { \ 54 if (osd_debug) { \ 55 printf("OSD (%s:%u): ", __func__, __LINE__); \ 56 printf(__VA_ARGS__); \ 57 printf("\n"); \ 58 } \ 59 } while (0) 60 61 static void do_osd_del(u_int type, struct osd *osd, u_int slot, 62 int list_locked); 63 64 /* 65 * Lists of objects with OSD. 66 * 67 * Lock key: 68 * (m) osd_module_lock 69 * (o) osd_object_lock 70 * (l) osd_list_lock 71 */ 72 static LIST_HEAD(, osd) osd_list[OSD_LAST + 1]; /* (m) */ 73 static osd_method_t *osd_methods[OSD_LAST + 1]; /* (m) */ 74 static u_int osd_nslots[OSD_LAST + 1]; /* (m) */ 75 static osd_destructor_t *osd_destructors[OSD_LAST + 1]; /* (o) */ 76 static const u_int osd_nmethods[OSD_LAST + 1] = { 77 [OSD_JAIL] = PR_MAXMETHOD, 78 }; 79 80 static struct sx osd_module_lock[OSD_LAST + 1]; 81 static struct rmlock osd_object_lock[OSD_LAST + 1]; 82 static struct mtx osd_list_lock[OSD_LAST + 1]; 83 84 static void 85 osd_default_destructor(void *value __unused) 86 { 87 /* Do nothing. */ 88 } 89 90 int 91 osd_register(u_int type, osd_destructor_t destructor, osd_method_t *methods) 92 { 93 void *newptr; 94 u_int i, m; 95 96 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 97 98 /* 99 * If no destructor is given, use default one. We need to use some 100 * destructor, because NULL destructor means unused slot. 101 */ 102 if (destructor == NULL) 103 destructor = osd_default_destructor; 104 105 sx_xlock(&osd_module_lock[type]); 106 /* 107 * First, we try to find unused slot. 108 */ 109 for (i = 0; i < osd_nslots[type]; i++) { 110 if (osd_destructors[type][i] == NULL) { 111 OSD_DEBUG("Unused slot found (type=%u, slot=%u).", 112 type, i); 113 break; 114 } 115 } 116 /* 117 * If no unused slot was found, allocate one. 118 */ 119 if (i == osd_nslots[type]) { 120 osd_nslots[type]++; 121 if (osd_nmethods[type] != 0) 122 osd_methods[type] = realloc(osd_methods[type], 123 sizeof(osd_method_t) * osd_nslots[type] * 124 osd_nmethods[type], M_OSD, M_WAITOK); 125 newptr = malloc(sizeof(osd_destructor_t) * osd_nslots[type], 126 M_OSD, M_WAITOK); 127 rm_wlock(&osd_object_lock[type]); 128 bcopy(osd_destructors[type], newptr, 129 sizeof(osd_destructor_t) * i); 130 free(osd_destructors[type], M_OSD); 131 osd_destructors[type] = newptr; 132 rm_wunlock(&osd_object_lock[type]); 133 OSD_DEBUG("New slot allocated (type=%u, slot=%u).", 134 type, i + 1); 135 } 136 137 osd_destructors[type][i] = destructor; 138 if (osd_nmethods[type] != 0) { 139 for (m = 0; m < osd_nmethods[type]; m++) 140 osd_methods[type][i * osd_nmethods[type] + m] = 141 methods != NULL ? methods[m] : NULL; 142 } 143 sx_xunlock(&osd_module_lock[type]); 144 return (i + 1); 145 } 146 147 void 148 osd_deregister(u_int type, u_int slot) 149 { 150 struct osd *osd, *tosd; 151 152 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 153 KASSERT(slot > 0, ("Invalid slot.")); 154 KASSERT(osd_destructors[type][slot - 1] != NULL, ("Unused slot.")); 155 156 sx_xlock(&osd_module_lock[type]); 157 rm_wlock(&osd_object_lock[type]); 158 /* 159 * Free all OSD for the given slot. 160 */ 161 mtx_lock(&osd_list_lock[type]); 162 LIST_FOREACH_SAFE(osd, &osd_list[type], osd_next, tosd) 163 do_osd_del(type, osd, slot, 1); 164 mtx_unlock(&osd_list_lock[type]); 165 /* 166 * Set destructor to NULL to free the slot. 167 */ 168 osd_destructors[type][slot - 1] = NULL; 169 if (slot == osd_nslots[type]) { 170 osd_nslots[type]--; 171 osd_destructors[type] = realloc(osd_destructors[type], 172 sizeof(osd_destructor_t) * osd_nslots[type], M_OSD, 173 M_NOWAIT | M_ZERO); 174 if (osd_nmethods[type] != 0) 175 osd_methods[type] = realloc(osd_methods[type], 176 sizeof(osd_method_t) * osd_nslots[type] * 177 osd_nmethods[type], M_OSD, M_NOWAIT | M_ZERO); 178 /* 179 * We always reallocate to smaller size, so we assume it will 180 * always succeed. 181 */ 182 KASSERT(osd_destructors[type] != NULL && 183 (osd_nmethods[type] == 0 || osd_methods[type] != NULL), 184 ("realloc() failed")); 185 OSD_DEBUG("Deregistration of the last slot (type=%u, slot=%u).", 186 type, slot); 187 } else { 188 OSD_DEBUG("Slot deregistration (type=%u, slot=%u).", 189 type, slot); 190 } 191 rm_wunlock(&osd_object_lock[type]); 192 sx_xunlock(&osd_module_lock[type]); 193 } 194 195 int 196 osd_set(u_int type, struct osd *osd, u_int slot, void *value) 197 { 198 struct rm_priotracker tracker; 199 200 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 201 KASSERT(slot > 0, ("Invalid slot.")); 202 KASSERT(osd_destructors[type][slot - 1] != NULL, ("Unused slot.")); 203 204 rm_rlock(&osd_object_lock[type], &tracker); 205 if (slot > osd->osd_nslots) { 206 if (value == NULL) { 207 OSD_DEBUG( 208 "Not allocating null slot (type=%u, slot=%u).", 209 type, slot); 210 rm_runlock(&osd_object_lock[type], &tracker); 211 return (0); 212 } else if (osd->osd_nslots == 0) { 213 /* 214 * First OSD for this object, so we need to allocate 215 * space and put it onto the list. 216 */ 217 osd->osd_slots = malloc(sizeof(void *) * slot, M_OSD, 218 M_NOWAIT | M_ZERO); 219 if (osd->osd_slots == NULL) { 220 rm_runlock(&osd_object_lock[type], &tracker); 221 return (ENOMEM); 222 } 223 osd->osd_nslots = slot; 224 mtx_lock(&osd_list_lock[type]); 225 LIST_INSERT_HEAD(&osd_list[type], osd, osd_next); 226 mtx_unlock(&osd_list_lock[type]); 227 OSD_DEBUG("Setting first slot (type=%u).", type); 228 } else { 229 void *newptr; 230 231 /* 232 * Too few slots allocated here, needs to extend 233 * the array. 234 */ 235 newptr = realloc(osd->osd_slots, sizeof(void *) * slot, 236 M_OSD, M_NOWAIT | M_ZERO); 237 if (newptr == NULL) { 238 rm_runlock(&osd_object_lock[type], &tracker); 239 return (ENOMEM); 240 } 241 osd->osd_slots = newptr; 242 osd->osd_nslots = slot; 243 OSD_DEBUG("Growing slots array (type=%u).", type); 244 } 245 } 246 OSD_DEBUG("Setting slot value (type=%u, slot=%u, value=%p).", type, 247 slot, value); 248 osd->osd_slots[slot - 1] = value; 249 rm_runlock(&osd_object_lock[type], &tracker); 250 return (0); 251 } 252 253 void * 254 osd_get(u_int type, struct osd *osd, u_int slot) 255 { 256 struct rm_priotracker tracker; 257 void *value; 258 259 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 260 KASSERT(slot > 0, ("Invalid slot.")); 261 KASSERT(osd_destructors[type][slot - 1] != NULL, ("Unused slot.")); 262 263 rm_rlock(&osd_object_lock[type], &tracker); 264 if (slot > osd->osd_nslots) { 265 value = NULL; 266 OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot); 267 } else { 268 value = osd->osd_slots[slot - 1]; 269 OSD_DEBUG("Returning slot value (type=%u, slot=%u, value=%p).", 270 type, slot, value); 271 } 272 rm_runlock(&osd_object_lock[type], &tracker); 273 return (value); 274 } 275 276 void 277 osd_del(u_int type, struct osd *osd, u_int slot) 278 { 279 struct rm_priotracker tracker; 280 281 rm_rlock(&osd_object_lock[type], &tracker); 282 do_osd_del(type, osd, slot, 0); 283 rm_runlock(&osd_object_lock[type], &tracker); 284 } 285 286 static void 287 do_osd_del(u_int type, struct osd *osd, u_int slot, int list_locked) 288 { 289 int i; 290 291 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 292 KASSERT(slot > 0, ("Invalid slot.")); 293 KASSERT(osd_destructors[type][slot - 1] != NULL, ("Unused slot.")); 294 295 OSD_DEBUG("Deleting slot (type=%u, slot=%u).", type, slot); 296 297 if (slot > osd->osd_nslots) { 298 OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot); 299 return; 300 } 301 if (osd->osd_slots[slot - 1] != NULL) { 302 osd_destructors[type][slot - 1](osd->osd_slots[slot - 1]); 303 osd->osd_slots[slot - 1] = NULL; 304 } 305 for (i = osd->osd_nslots - 1; i >= 0; i--) { 306 if (osd->osd_slots[i] != NULL) { 307 OSD_DEBUG("Slot still has a value (type=%u, slot=%u).", 308 type, i + 1); 309 break; 310 } 311 } 312 if (i == -1) { 313 /* No values left for this object. */ 314 OSD_DEBUG("No more slots left (type=%u).", type); 315 if (!list_locked) 316 mtx_lock(&osd_list_lock[type]); 317 LIST_REMOVE(osd, osd_next); 318 if (!list_locked) 319 mtx_unlock(&osd_list_lock[type]); 320 free(osd->osd_slots, M_OSD); 321 osd->osd_slots = NULL; 322 osd->osd_nslots = 0; 323 } else if (slot == osd->osd_nslots) { 324 /* This was the last slot. */ 325 osd->osd_slots = realloc(osd->osd_slots, 326 sizeof(void *) * (i + 1), M_OSD, M_NOWAIT | M_ZERO); 327 /* 328 * We always reallocate to smaller size, so we assume it will 329 * always succeed. 330 */ 331 KASSERT(osd->osd_slots != NULL, ("realloc() failed")); 332 osd->osd_nslots = i + 1; 333 OSD_DEBUG("Reducing slots array to %u (type=%u).", 334 osd->osd_nslots, type); 335 } 336 } 337 338 int 339 osd_call(u_int type, u_int method, void *obj, void *data) 340 { 341 osd_method_t methodfun; 342 int error, i; 343 344 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 345 KASSERT(method < osd_nmethods[type], ("Invalid method.")); 346 347 /* 348 * Call this method for every slot that defines it, stopping if an 349 * error is encountered. 350 */ 351 error = 0; 352 sx_slock(&osd_module_lock[type]); 353 for (i = 0; i < osd_nslots[type]; i++) { 354 methodfun = 355 osd_methods[type][i * osd_nmethods[type] + method]; 356 if (methodfun != NULL && (error = methodfun(obj, data)) != 0) 357 break; 358 } 359 sx_sunlock(&osd_module_lock[type]); 360 return (error); 361 } 362 363 void 364 osd_exit(u_int type, struct osd *osd) 365 { 366 struct rm_priotracker tracker; 367 u_int i; 368 369 KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type.")); 370 371 if (osd->osd_nslots == 0) { 372 KASSERT(osd->osd_slots == NULL, ("Non-null osd_slots.")); 373 /* No OSD attached, just leave. */ 374 return; 375 } 376 377 rm_rlock(&osd_object_lock[type], &tracker); 378 for (i = 1; i <= osd->osd_nslots; i++) { 379 if (osd_destructors[type][i - 1] != NULL) 380 do_osd_del(type, osd, i, 0); 381 else 382 OSD_DEBUG("Unused slot (type=%u, slot=%u).", type, i); 383 } 384 rm_runlock(&osd_object_lock[type], &tracker); 385 OSD_DEBUG("Object exit (type=%u).", type); 386 } 387 388 static void 389 osd_init(void *arg __unused) 390 { 391 u_int i; 392 393 for (i = OSD_FIRST; i <= OSD_LAST; i++) { 394 osd_nslots[i] = 0; 395 LIST_INIT(&osd_list[i]); 396 sx_init(&osd_module_lock[i], "osd_module"); 397 rm_init(&osd_object_lock[i], "osd_object"); 398 mtx_init(&osd_list_lock[i], "osd_list", NULL, MTX_DEF); 399 osd_destructors[i] = NULL; 400 osd_methods[i] = NULL; 401 } 402 } 403 SYSINIT(osd, SI_SUB_LOCK, SI_ORDER_ANY, osd_init, NULL); 404