1 /*- 2 * Copyright (c) 2002 Poul-Henning Kamp 3 * Copyright (c) 2002 Networks Associates Technology, Inc. 4 * All rights reserved. 5 * 6 * This software was developed for the FreeBSD Project by Poul-Henning Kamp 7 * and NAI Labs, the Security Research Division of Network Associates, Inc. 8 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 9 * DARPA CHATS research program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. The names of the authors may not be used to endorse or promote 20 * products derived from this software without specific prior written 21 * permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * $FreeBSD$ 36 */ 37 38 39 #include <sys/param.h> 40 #ifndef _KERNEL 41 #include <stdio.h> 42 #include <string.h> 43 #include <stdlib.h> 44 #include <signal.h> 45 #include <err.h> 46 #include <sched.h> 47 #else 48 #include <sys/systm.h> 49 #include <sys/kernel.h> 50 #include <sys/malloc.h> 51 #include <sys/bio.h> 52 #endif 53 54 #include <sys/errno.h> 55 #include <geom/geom.h> 56 #include <geom/geom_int.h> 57 58 static struct g_bioq g_bio_run_down; 59 static struct g_bioq g_bio_run_up; 60 static struct g_bioq g_bio_idle; 61 62 #include <machine/atomic.h> 63 64 static void 65 g_bioq_lock(struct g_bioq *bq) 66 { 67 68 mtx_lock(&bq->bio_queue_lock); 69 } 70 71 static void 72 g_bioq_unlock(struct g_bioq *bq) 73 { 74 75 mtx_unlock(&bq->bio_queue_lock); 76 } 77 78 #if 0 79 static void 80 g_bioq_destroy(struct g_bioq *bq) 81 { 82 83 mtx_destroy(&bq->bio_queue_lock); 84 } 85 #endif 86 87 static void 88 g_bioq_init(struct g_bioq *bq) 89 { 90 91 TAILQ_INIT(&bq->bio_queue); 92 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF); 93 } 94 95 static struct bio * 96 g_bioq_first(struct g_bioq *bq) 97 { 98 struct bio *bp; 99 100 g_bioq_lock(bq); 101 bp = TAILQ_FIRST(&bq->bio_queue); 102 if (bp != NULL) { 103 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue); 104 bq->bio_queue_length--; 105 } 106 g_bioq_unlock(bq); 107 return (bp); 108 } 109 110 static void 111 g_bioq_enqueue_tail(struct bio *bp, struct g_bioq *rq) 112 { 113 114 g_bioq_lock(rq); 115 TAILQ_INSERT_TAIL(&rq->bio_queue, bp, bio_queue); 116 rq->bio_queue_length++; 117 g_bioq_unlock(rq); 118 } 119 120 struct bio * 121 g_new_bio(void) 122 { 123 struct bio *bp; 124 125 bp = g_bioq_first(&g_bio_idle); 126 if (bp == NULL) 127 bp = g_malloc(sizeof *bp, M_WAITOK | M_ZERO); 128 g_trace(G_T_BIO, "g_new_bio() = %p", bp); 129 return (bp); 130 } 131 132 void 133 g_destroy_bio(struct bio *bp) 134 { 135 136 g_trace(G_T_BIO, "g_destroy_bio(%p)", bp); 137 bzero(bp, sizeof *bp); 138 g_bioq_enqueue_tail(bp, &g_bio_idle); 139 } 140 141 struct bio * 142 g_clone_bio(struct bio *bp) 143 { 144 struct bio *bp2; 145 146 bp2 = g_new_bio(); 147 bp2->bio_linkage = bp; 148 bp2->bio_cmd = bp->bio_cmd; 149 bp2->bio_length = bp->bio_length; 150 bp2->bio_offset = bp->bio_offset; 151 bp2->bio_data = bp->bio_data; 152 bp2->bio_attribute = bp->bio_attribute; 153 g_trace(G_T_BIO, "g_clone_bio(%p) = %p", bp, bp2); 154 return(bp2); 155 } 156 157 void 158 g_io_init() 159 { 160 161 g_bioq_init(&g_bio_run_down); 162 g_bioq_init(&g_bio_run_up); 163 g_bioq_init(&g_bio_idle); 164 } 165 166 int 167 g_io_setattr(const char *attr, struct g_consumer *cp, int len, void *ptr) 168 { 169 struct bio *bp; 170 int error; 171 172 g_trace(G_T_BIO, "bio_setattr(%s)", attr); 173 do { 174 bp = g_new_bio(); 175 bp->bio_cmd = BIO_SETATTR; 176 bp->bio_done = NULL; 177 bp->bio_attribute = attr; 178 bp->bio_length = len; 179 bp->bio_data = ptr; 180 g_io_request(bp, cp); 181 while ((bp->bio_flags & BIO_DONE) == 0) { 182 mtx_lock(&Giant); 183 tsleep(bp, 0, "setattr", hz / 10); 184 mtx_unlock(&Giant); 185 } 186 error = bp->bio_error; 187 g_destroy_bio(bp); 188 if (error == EBUSY) 189 tsleep(&error, 0, "setattr_busy", hz); 190 } while(error == EBUSY); 191 return (error); 192 } 193 194 195 int 196 g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr) 197 { 198 struct bio *bp; 199 int error; 200 201 g_trace(G_T_BIO, "bio_getattr(%s)", attr); 202 do { 203 bp = g_new_bio(); 204 bp->bio_cmd = BIO_GETATTR; 205 bp->bio_done = NULL; 206 bp->bio_attribute = attr; 207 bp->bio_length = *len; 208 bp->bio_data = ptr; 209 g_io_request(bp, cp); 210 while ((bp->bio_flags & BIO_DONE) == 0) { 211 mtx_lock(&Giant); 212 tsleep(bp, 0, "getattr", hz / 10); 213 mtx_unlock(&Giant); 214 } 215 *len = bp->bio_completed; 216 error = bp->bio_error; 217 g_destroy_bio(bp); 218 if (error == EBUSY) 219 tsleep(&error, 0, "getattr_busy", hz); 220 221 } while(error == EBUSY); 222 return (error); 223 } 224 225 void 226 g_io_fail(struct bio *bp, int error) 227 { 228 229 bp->bio_error = error; 230 231 g_trace(G_T_BIO, 232 "bio_fail(%p) from %p(%s) to %p(%s) cmd %d error %d\n", 233 bp, bp->bio_from, bp->bio_from->geom->name, 234 bp->bio_to, bp->bio_to->name, bp->bio_cmd, bp->bio_error); 235 g_io_deliver(bp); 236 return; 237 } 238 239 void 240 g_io_request(struct bio *bp, struct g_consumer *cp) 241 { 242 int error; 243 off_t excess; 244 245 KASSERT(cp != NULL, ("bio_request on thin air")); 246 error = 0; 247 bp->bio_from = cp; 248 bp->bio_to = cp->provider; 249 bp->bio_error = 0; 250 bp->bio_completed = 0; 251 252 /* begin_stats(&bp->stats); */ 253 254 atomic_add_int(&cp->biocount, 1); 255 /* Fail on unattached consumers */ 256 if (bp->bio_to == NULL) 257 return (g_io_fail(bp, ENXIO)); 258 /* Fail if access doesn't allow operation */ 259 switch(bp->bio_cmd) { 260 case BIO_READ: 261 case BIO_GETATTR: 262 if (cp->acr == 0) 263 return (g_io_fail(bp, EPERM)); 264 break; 265 case BIO_WRITE: 266 case BIO_DELETE: 267 if (cp->acw == 0) 268 return (g_io_fail(bp, EPERM)); 269 break; 270 case BIO_SETATTR: 271 if ((cp->acw == 0) || (cp->ace == 0)) 272 return (g_io_fail(bp, EPERM)); 273 break; 274 default: 275 return (g_io_fail(bp, EPERM)); 276 } 277 /* if provider is marked for error, don't disturb. */ 278 if (bp->bio_to->error) 279 return (g_io_fail(bp, bp->bio_to->error)); 280 switch(bp->bio_cmd) { 281 case BIO_READ: 282 case BIO_WRITE: 283 case BIO_DELETE: 284 /* Reject requests past the end of media. */ 285 if (bp->bio_offset > bp->bio_to->mediasize) 286 return (g_io_fail(bp, EIO)); 287 /* Truncate requests to the end of providers media. */ 288 excess = bp->bio_offset + bp->bio_length; 289 if (excess > bp->bio_to->mediasize) { 290 excess -= bp->bio_to->mediasize; 291 bp->bio_length -= excess; 292 } 293 /* Deliver zero length transfers right here. */ 294 if (bp->bio_length == 0) 295 return (g_io_deliver(bp)); 296 break; 297 default: 298 break; 299 } 300 /* Pass it on down. */ 301 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d", 302 bp, bp->bio_from, bp->bio_from->geom->name, 303 bp->bio_to, bp->bio_to->name, bp->bio_cmd); 304 g_bioq_enqueue_tail(bp, &g_bio_run_down); 305 mtx_lock(&Giant); 306 wakeup(&g_wait_down); 307 mtx_unlock(&Giant); 308 } 309 310 void 311 g_io_deliver(struct bio *bp) 312 { 313 314 g_trace(G_T_BIO, 315 "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d", 316 bp, bp->bio_from, bp->bio_from->geom->name, 317 bp->bio_to, bp->bio_to->name, bp->bio_cmd, bp->bio_error); 318 /* finish_stats(&bp->stats); */ 319 320 g_bioq_enqueue_tail(bp, &g_bio_run_up); 321 322 mtx_lock(&Giant); 323 wakeup(&g_wait_up); 324 mtx_unlock(&Giant); 325 } 326 327 void 328 g_io_schedule_down(struct thread *tp __unused) 329 { 330 struct bio *bp; 331 332 for(;;) { 333 bp = g_bioq_first(&g_bio_run_down); 334 if (bp == NULL) 335 break; 336 bp->bio_to->geom->start(bp); 337 } 338 } 339 340 void 341 g_io_schedule_up(struct thread *tp __unused) 342 { 343 struct bio *bp; 344 struct g_consumer *cp; 345 346 for(;;) { 347 bp = g_bioq_first(&g_bio_run_up); 348 if (bp == NULL) 349 break; 350 351 cp = bp->bio_from; 352 353 bp->bio_flags |= BIO_DONE; 354 atomic_add_int(&cp->biocount, -1); 355 if (bp->bio_done != NULL) { 356 bp->bio_done(bp); 357 } else { 358 mtx_lock(&Giant); 359 wakeup(bp); 360 mtx_unlock(&Giant); 361 } 362 } 363 } 364 365 void * 366 g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error) 367 { 368 struct bio *bp; 369 void *ptr; 370 int errorc; 371 372 do { 373 bp = g_new_bio(); 374 bp->bio_cmd = BIO_READ; 375 bp->bio_done = NULL; 376 bp->bio_offset = offset; 377 bp->bio_length = length; 378 ptr = g_malloc(length, M_WAITOK); 379 bp->bio_data = ptr; 380 g_io_request(bp, cp); 381 while ((bp->bio_flags & BIO_DONE) == 0) { 382 mtx_lock(&Giant); 383 tsleep(bp, 0, "g_read_data", hz / 10); 384 mtx_unlock(&Giant); 385 } 386 errorc = bp->bio_error; 387 if (error != NULL) 388 *error = errorc; 389 g_destroy_bio(bp); 390 if (errorc) { 391 g_free(ptr); 392 ptr = NULL; 393 } 394 if (errorc == EBUSY) 395 tsleep(&errorc, 0, "g_read_data_busy", hz); 396 } while (errorc == EBUSY); 397 return (ptr); 398 } 399