geom_io.c revision 120852
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 36#include <sys/cdefs.h> 37__FBSDID("$FreeBSD: head/sys/geom/geom_io.c 120852 2003-10-06 09:07:35Z phk $"); 38 39#include <sys/param.h> 40#include <sys/systm.h> 41#include <sys/kernel.h> 42#include <sys/malloc.h> 43#include <sys/bio.h> 44 45#include <sys/errno.h> 46#include <geom/geom.h> 47#include <geom/geom_int.h> 48#include <sys/devicestat.h> 49 50#include <vm/uma.h> 51 52static struct g_bioq g_bio_run_down; 53static struct g_bioq g_bio_run_up; 54 55static u_int pace; 56static uma_zone_t biozone; 57 58#include <machine/atomic.h> 59 60static void 61g_bioq_lock(struct g_bioq *bq) 62{ 63 64 mtx_lock(&bq->bio_queue_lock); 65} 66 67static void 68g_bioq_unlock(struct g_bioq *bq) 69{ 70 71 mtx_unlock(&bq->bio_queue_lock); 72} 73 74#if 0 75static void 76g_bioq_destroy(struct g_bioq *bq) 77{ 78 79 mtx_destroy(&bq->bio_queue_lock); 80} 81#endif 82 83static void 84g_bioq_init(struct g_bioq *bq) 85{ 86 87 TAILQ_INIT(&bq->bio_queue); 88 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF); 89} 90 91static struct bio * 92g_bioq_first(struct g_bioq *bq) 93{ 94 struct bio *bp; 95 96 bp = TAILQ_FIRST(&bq->bio_queue); 97 if (bp != NULL) { 98 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue); 99 bq->bio_queue_length--; 100 } 101 return (bp); 102} 103 104static void 105g_bioq_enqueue_tail(struct bio *bp, struct g_bioq *rq) 106{ 107 108 g_bioq_lock(rq); 109 TAILQ_INSERT_TAIL(&rq->bio_queue, bp, bio_queue); 110 rq->bio_queue_length++; 111 g_bioq_unlock(rq); 112} 113 114struct bio * 115g_new_bio(void) 116{ 117 struct bio *bp; 118 119 bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO); 120 return (bp); 121} 122 123void 124g_destroy_bio(struct bio *bp) 125{ 126 127 uma_zfree(biozone, bp); 128} 129 130struct bio * 131g_clone_bio(struct bio *bp) 132{ 133 struct bio *bp2; 134 135 bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO); 136 if (bp2 != NULL) { 137 bp2->bio_parent = bp; 138 bp2->bio_cmd = bp->bio_cmd; 139 bp2->bio_length = bp->bio_length; 140 bp2->bio_offset = bp->bio_offset; 141 bp2->bio_data = bp->bio_data; 142 bp2->bio_attribute = bp->bio_attribute; 143 bp->bio_children++; 144 } 145 return(bp2); 146} 147 148void 149g_io_init() 150{ 151 152 g_bioq_init(&g_bio_run_down); 153 g_bioq_init(&g_bio_run_up); 154 biozone = uma_zcreate("g_bio", sizeof (struct bio), 155 NULL, NULL, 156 NULL, NULL, 157 0, 0); 158} 159 160int 161g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr) 162{ 163 struct bio *bp; 164 int error; 165 166 g_trace(G_T_BIO, "bio_getattr(%s)", attr); 167 bp = g_new_bio(); 168 bp->bio_cmd = BIO_GETATTR; 169 bp->bio_done = NULL; 170 bp->bio_attribute = attr; 171 bp->bio_length = *len; 172 bp->bio_data = ptr; 173 g_io_request(bp, cp); 174 error = biowait(bp, "ggetattr"); 175 *len = bp->bio_completed; 176 g_destroy_bio(bp); 177 return (error); 178} 179 180static int 181g_io_check(struct bio *bp) 182{ 183 struct g_consumer *cp; 184 struct g_provider *pp; 185 186 cp = bp->bio_from; 187 pp = bp->bio_to; 188 189 /* Fail if access counters dont allow the operation */ 190 switch(bp->bio_cmd) { 191 case BIO_READ: 192 case BIO_GETATTR: 193 if (cp->acr == 0) 194 return (EPERM); 195 break; 196 case BIO_WRITE: 197 case BIO_DELETE: 198 if (cp->acw == 0) 199 return (EPERM); 200 break; 201 default: 202 return (EPERM); 203 } 204 /* if provider is marked for error, don't disturb. */ 205 if (pp->error) 206 return (pp->error); 207 208 switch(bp->bio_cmd) { 209 case BIO_READ: 210 case BIO_WRITE: 211 case BIO_DELETE: 212 /* Noisily reject zero size sectors */ 213 if (pp->sectorsize == 0) { 214 printf("GEOM provider %s has zero sectorsize\n", 215 pp->name); 216 return (EDOOFUS); 217 } 218 /* Reject I/O not on sector boundary */ 219 if (bp->bio_offset % pp->sectorsize) 220 return (EINVAL); 221 /* Reject I/O not integral sector long */ 222 if (bp->bio_length % pp->sectorsize) 223 return (EINVAL); 224 /* Reject requests past the end of media. */ 225 if (bp->bio_offset > pp->mediasize) 226 return (EIO); 227 break; 228 default: 229 break; 230 } 231 return (0); 232} 233 234void 235g_io_request(struct bio *bp, struct g_consumer *cp) 236{ 237 struct g_provider *pp; 238 239 KASSERT(cp != NULL, ("NULL cp in g_io_request")); 240 KASSERT(bp != NULL, ("NULL bp in g_io_request")); 241 KASSERT(bp->bio_data != NULL, ("NULL bp->data in g_io_request")); 242 pp = cp->provider; 243 KASSERT(pp != NULL, ("consumer not attached in g_io_request")); 244 245 bp->bio_from = cp; 246 bp->bio_to = pp; 247 bp->bio_error = 0; 248 bp->bio_completed = 0; 249 250 if (g_collectstats) { 251 devstat_start_transaction_bio(cp->stat, bp); 252 devstat_start_transaction_bio(pp->stat, bp); 253 } 254 cp->nstart++; 255 pp->nstart++; 256 257 /* Pass it on down. */ 258 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d", 259 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd); 260 g_bioq_enqueue_tail(bp, &g_bio_run_down); 261 wakeup(&g_wait_down); 262} 263 264void 265g_io_deliver(struct bio *bp, int error) 266{ 267 struct g_consumer *cp; 268 struct g_provider *pp; 269 270 KASSERT(bp != NULL, ("NULL bp in g_io_deliver")); 271 pp = bp->bio_to; 272 KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver")); 273 cp = bp->bio_from; 274 if (cp == NULL) { 275 bp->bio_error = error; 276 bp->bio_done(bp); 277 return; 278 } 279 KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver")); 280 KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver")); 281 282 g_trace(G_T_BIO, 283"g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd", 284 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error, 285 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length); 286 287 bp->bio_bcount = bp->bio_length; 288 if (g_collectstats) { 289 bp->bio_resid = bp->bio_bcount - bp->bio_completed; 290 devstat_end_transaction_bio(cp->stat, bp); 291 devstat_end_transaction_bio(pp->stat, bp); 292 } 293 cp->nend++; 294 pp->nend++; 295 296 if (error == ENOMEM) { 297 if (bootverbose) 298 printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name); 299 g_io_request(bp, cp); 300 pace++; 301 return; 302 } 303 bp->bio_error = error; 304 g_bioq_enqueue_tail(bp, &g_bio_run_up); 305 wakeup(&g_wait_up); 306} 307 308void 309g_io_schedule_down(struct thread *tp __unused) 310{ 311 struct bio *bp; 312 off_t excess; 313 int error; 314 struct mtx mymutex; 315 316 bzero(&mymutex, sizeof mymutex); 317 mtx_init(&mymutex, "g_xdown", MTX_DEF, 0); 318 319 for(;;) { 320 g_bioq_lock(&g_bio_run_down); 321 bp = g_bioq_first(&g_bio_run_down); 322 if (bp == NULL) { 323 msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock, 324 PRIBIO | PDROP, "-", hz/10); 325 continue; 326 } 327 g_bioq_unlock(&g_bio_run_down); 328 if (pace > 0) { 329 msleep(&error, NULL, PRIBIO, "g_down", hz/10); 330 pace--; 331 } 332 error = g_io_check(bp); 333 if (error) { 334 g_io_deliver(bp, error); 335 continue; 336 } 337 switch (bp->bio_cmd) { 338 case BIO_READ: 339 case BIO_WRITE: 340 case BIO_DELETE: 341 /* Truncate requests to the end of providers media. */ 342 excess = bp->bio_offset + bp->bio_length; 343 if (excess > bp->bio_to->mediasize) { 344 excess -= bp->bio_to->mediasize; 345 bp->bio_length -= excess; 346 } 347 /* Deliver zero length transfers right here. */ 348 if (bp->bio_length == 0) { 349 g_io_deliver(bp, 0); 350 continue; 351 } 352 break; 353 default: 354 break; 355 } 356 mtx_lock(&mymutex); 357 bp->bio_to->geom->start(bp); 358 mtx_unlock(&mymutex); 359 } 360} 361 362void 363g_io_schedule_up(struct thread *tp __unused) 364{ 365 struct bio *bp; 366 struct mtx mymutex; 367 368 bzero(&mymutex, sizeof mymutex); 369 mtx_init(&mymutex, "g_xup", MTX_DEF, 0); 370 for(;;) { 371 g_bioq_lock(&g_bio_run_up); 372 bp = g_bioq_first(&g_bio_run_up); 373 if (bp != NULL) { 374 g_bioq_unlock(&g_bio_run_up); 375 mtx_lock(&mymutex); 376 biodone(bp); 377 mtx_unlock(&mymutex); 378 continue; 379 } 380 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock, 381 PRIBIO | PDROP, "-", hz/10); 382 } 383} 384 385void * 386g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error) 387{ 388 struct bio *bp; 389 void *ptr; 390 int errorc; 391 392 KASSERT(length >= 512 && length <= DFLTPHYS, 393 ("g_read_data(): invalid length %jd", (intmax_t)length)); 394 395 bp = g_new_bio(); 396 bp->bio_cmd = BIO_READ; 397 bp->bio_done = NULL; 398 bp->bio_offset = offset; 399 bp->bio_length = length; 400 ptr = g_malloc(length, M_WAITOK); 401 bp->bio_data = ptr; 402 g_io_request(bp, cp); 403 errorc = biowait(bp, "gread"); 404 if (error != NULL) 405 *error = errorc; 406 g_destroy_bio(bp); 407 if (errorc) { 408 g_free(ptr); 409 ptr = NULL; 410 } 411 return (ptr); 412} 413 414int 415g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length) 416{ 417 struct bio *bp; 418 int error; 419 420 KASSERT(length >= 512 && length <= DFLTPHYS, 421 ("g_write_data(): invalid length %jd", (intmax_t)length)); 422 423 bp = g_new_bio(); 424 bp->bio_cmd = BIO_WRITE; 425 bp->bio_done = NULL; 426 bp->bio_offset = offset; 427 bp->bio_length = length; 428 bp->bio_data = ptr; 429 g_io_request(bp, cp); 430 error = biowait(bp, "gwrite"); 431 g_destroy_bio(bp); 432 return (error); 433} 434