geom_io.c revision 103283
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: head/sys/geom/geom_io.c 103283 2002-09-13 11:39:11Z phk $ 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 58static struct g_bioq g_bio_run_down; 59static struct g_bioq g_bio_run_up; 60static struct g_bioq g_bio_idle; 61 62#include <machine/atomic.h> 63 64static void 65g_bioq_lock(struct g_bioq *bq) 66{ 67 68 mtx_lock(&bq->bio_queue_lock); 69} 70 71static void 72g_bioq_unlock(struct g_bioq *bq) 73{ 74 75 mtx_unlock(&bq->bio_queue_lock); 76} 77 78#if 0 79static void 80g_bioq_destroy(struct g_bioq *bq) 81{ 82 83 mtx_destroy(&bq->bio_queue_lock); 84} 85#endif 86 87static void 88g_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 95static struct bio * 96g_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 110static void 111g_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 120struct bio * 121g_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 132void 133g_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 141struct bio * 142g_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 157void 158g_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 166int 167g_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 error = biowait(bp, "gsetattr"); 182 g_destroy_bio(bp); 183 if (error == EBUSY) 184 tsleep(&error, 0, "setattr_busy", hz); 185 } while(error == EBUSY); 186 return (error); 187} 188 189 190int 191g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr) 192{ 193 struct bio *bp; 194 int error; 195 196 g_trace(G_T_BIO, "bio_getattr(%s)", attr); 197 do { 198 bp = g_new_bio(); 199 bp->bio_cmd = BIO_GETATTR; 200 bp->bio_done = NULL; 201 bp->bio_attribute = attr; 202 bp->bio_length = *len; 203 bp->bio_data = ptr; 204 g_io_request(bp, cp); 205 error = biowait(bp, "ggetattr"); 206 *len = bp->bio_completed; 207 g_destroy_bio(bp); 208 if (error == EBUSY) 209 tsleep(&error, 0, "getattr_busy", hz); 210 211 } while(error == EBUSY); 212 return (error); 213} 214 215void 216g_io_fail(struct bio *bp, int error) 217{ 218 219 bp->bio_error = error; 220 221 g_trace(G_T_BIO, 222 "bio_fail(%p) from %p(%s) to %p(%s) cmd %d error %d\n", 223 bp, bp->bio_from, bp->bio_from->geom->name, 224 bp->bio_to, bp->bio_to->name, bp->bio_cmd, bp->bio_error); 225 g_io_deliver(bp); 226 return; 227} 228 229void 230g_io_request(struct bio *bp, struct g_consumer *cp) 231{ 232 int error; 233 off_t excess; 234 235 KASSERT(cp != NULL, ("bio_request on thin air")); 236 error = 0; 237 bp->bio_from = cp; 238 bp->bio_to = cp->provider; 239 bp->bio_error = 0; 240 bp->bio_completed = 0; 241 242 /* begin_stats(&bp->stats); */ 243 244 atomic_add_int(&cp->biocount, 1); 245 /* Fail on unattached consumers */ 246 if (bp->bio_to == NULL) 247 return (g_io_fail(bp, ENXIO)); 248 /* Fail if access doesn't allow operation */ 249 switch(bp->bio_cmd) { 250 case BIO_READ: 251 case BIO_GETATTR: 252 if (cp->acr == 0) 253 return (g_io_fail(bp, EPERM)); 254 break; 255 case BIO_WRITE: 256 case BIO_DELETE: 257 if (cp->acw == 0) 258 return (g_io_fail(bp, EPERM)); 259 break; 260 case BIO_SETATTR: 261 if ((cp->acw == 0) || (cp->ace == 0)) 262 return (g_io_fail(bp, EPERM)); 263 break; 264 default: 265 return (g_io_fail(bp, EPERM)); 266 } 267 /* if provider is marked for error, don't disturb. */ 268 if (bp->bio_to->error) 269 return (g_io_fail(bp, bp->bio_to->error)); 270 switch(bp->bio_cmd) { 271 case BIO_READ: 272 case BIO_WRITE: 273 case BIO_DELETE: 274 /* Reject requests past the end of media. */ 275 if (bp->bio_offset > bp->bio_to->mediasize) 276 return (g_io_fail(bp, EIO)); 277 /* Truncate requests to the end of providers media. */ 278 excess = bp->bio_offset + bp->bio_length; 279 if (excess > bp->bio_to->mediasize) { 280 excess -= bp->bio_to->mediasize; 281 bp->bio_length -= excess; 282 } 283 /* Deliver zero length transfers right here. */ 284 if (bp->bio_length == 0) 285 return (g_io_deliver(bp)); 286 break; 287 default: 288 break; 289 } 290 /* Pass it on down. */ 291 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d", 292 bp, bp->bio_from, bp->bio_from->geom->name, 293 bp->bio_to, bp->bio_to->name, bp->bio_cmd); 294 g_bioq_enqueue_tail(bp, &g_bio_run_down); 295 wakeup(&g_wait_down); 296} 297 298void 299g_io_deliver(struct bio *bp) 300{ 301 302 g_trace(G_T_BIO, 303 "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d", 304 bp, bp->bio_from, bp->bio_from->geom->name, 305 bp->bio_to, bp->bio_to->name, bp->bio_cmd, bp->bio_error); 306 /* finish_stats(&bp->stats); */ 307 308 g_bioq_enqueue_tail(bp, &g_bio_run_up); 309 310 wakeup(&g_wait_up); 311} 312 313void 314g_io_schedule_down(struct thread *tp __unused) 315{ 316 struct bio *bp; 317 318 for(;;) { 319 bp = g_bioq_first(&g_bio_run_down); 320 if (bp == NULL) 321 break; 322 bp->bio_to->geom->start(bp); 323 } 324} 325 326void 327g_io_schedule_up(struct thread *tp __unused) 328{ 329 struct bio *bp; 330 struct g_consumer *cp; 331 332 for(;;) { 333 bp = g_bioq_first(&g_bio_run_up); 334 if (bp == NULL) 335 break; 336 337 cp = bp->bio_from; 338 339 atomic_add_int(&cp->biocount, -1); 340 biodone(bp); 341 } 342} 343 344void * 345g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error) 346{ 347 struct bio *bp; 348 void *ptr; 349 int errorc; 350 351 do { 352 bp = g_new_bio(); 353 bp->bio_cmd = BIO_READ; 354 bp->bio_done = NULL; 355 bp->bio_offset = offset; 356 bp->bio_length = length; 357 ptr = g_malloc(length, M_WAITOK); 358 bp->bio_data = ptr; 359 g_io_request(bp, cp); 360 errorc = biowait(bp, "gread"); 361 if (error != NULL) 362 *error = errorc; 363 g_destroy_bio(bp); 364 if (errorc) { 365 g_free(ptr); 366 ptr = NULL; 367 } 368 if (errorc == EBUSY) 369 tsleep(&errorc, 0, "g_read_data_busy", hz); 370 } while (errorc == EBUSY); 371 return (ptr); 372} 373