geom_dev.c revision 219950
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_dev.c 219950 2011-03-24 08:37:48Z mav $"); 38 39#include <sys/param.h> 40#include <sys/systm.h> 41#include <sys/malloc.h> 42#include <sys/kernel.h> 43#include <sys/conf.h> 44#include <sys/bio.h> 45#include <sys/lock.h> 46#include <sys/mutex.h> 47#include <sys/proc.h> 48#include <sys/errno.h> 49#include <sys/time.h> 50#include <sys/disk.h> 51#include <sys/fcntl.h> 52#include <sys/limits.h> 53#include <geom/geom.h> 54#include <geom/geom_int.h> 55 56static d_open_t g_dev_open; 57static d_close_t g_dev_close; 58static d_strategy_t g_dev_strategy; 59static d_ioctl_t g_dev_ioctl; 60 61static struct cdevsw g_dev_cdevsw = { 62 .d_version = D_VERSION, 63 .d_open = g_dev_open, 64 .d_close = g_dev_close, 65 .d_read = physread, 66 .d_write = physwrite, 67 .d_ioctl = g_dev_ioctl, 68 .d_strategy = g_dev_strategy, 69 .d_name = "g_dev", 70 .d_flags = D_DISK | D_TRACKCLOSE, 71}; 72 73static g_taste_t g_dev_taste; 74static g_orphan_t g_dev_orphan; 75 76static struct g_class g_dev_class = { 77 .name = "DEV", 78 .version = G_VERSION, 79 .taste = g_dev_taste, 80 .orphan = g_dev_orphan, 81}; 82 83void 84g_dev_print(void) 85{ 86 struct g_geom *gp; 87 char const *p = ""; 88 89 LIST_FOREACH(gp, &g_dev_class.geom, geom) { 90 printf("%s%s", p, gp->name); 91 p = " "; 92 } 93 printf("\n"); 94} 95 96struct g_provider * 97g_dev_getprovider(struct cdev *dev) 98{ 99 struct g_consumer *cp; 100 101 g_topology_assert(); 102 if (dev == NULL) 103 return (NULL); 104 if (dev->si_devsw != &g_dev_cdevsw) 105 return (NULL); 106 cp = dev->si_drv2; 107 return (cp->provider); 108} 109 110 111static struct g_geom * 112g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused) 113{ 114 struct g_geom *gp; 115 struct g_consumer *cp; 116 int error; 117 struct cdev *dev; 118 119 g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name); 120 g_topology_assert(); 121 LIST_FOREACH(cp, &pp->consumers, consumers) 122 if (cp->geom->class == mp) 123 return (NULL); 124 gp = g_new_geomf(mp, pp->name); 125 cp = g_new_consumer(gp); 126 error = g_attach(cp, pp); 127 KASSERT(error == 0, 128 ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error)); 129 error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &dev, 130 &g_dev_cdevsw, NULL, UID_ROOT, GID_OPERATOR, 0640, "%s", gp->name); 131 if (error != 0) { 132 printf("%s: make_dev_p() failed (gp->name=%s, error=%d)\n", 133 __func__, gp->name, error); 134 g_detach(cp); 135 g_destroy_consumer(cp); 136 g_destroy_geom(gp); 137 return (NULL); 138 } 139 if (pp->flags & G_PF_CANDELETE) 140 dev->si_flags |= SI_CANDELETE; 141 dev->si_iosize_max = MAXPHYS; 142 gp->softc = dev; 143 dev->si_drv1 = gp; 144 dev->si_drv2 = cp; 145 return (gp); 146} 147 148static int 149g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td) 150{ 151 struct g_geom *gp; 152 struct g_consumer *cp; 153 int error, r, w, e; 154 155 gp = dev->si_drv1; 156 cp = dev->si_drv2; 157 if (gp == NULL || cp == NULL || gp->softc != dev) 158 return(ENXIO); /* g_dev_taste() not done yet */ 159 160 g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)", 161 gp->name, flags, fmt, td); 162 163 r = flags & FREAD ? 1 : 0; 164 w = flags & FWRITE ? 1 : 0; 165#ifdef notyet 166 e = flags & O_EXCL ? 1 : 0; 167#else 168 e = 0; 169#endif 170 if (w) { 171 /* 172 * When running in very secure mode, do not allow 173 * opens for writing of any disks. 174 */ 175 error = securelevel_ge(td->td_ucred, 2); 176 if (error) 177 return (error); 178 } 179 g_topology_lock(); 180 if (dev->si_devsw == NULL) 181 error = ENXIO; /* We were orphaned */ 182 else 183 error = g_access(cp, r, w, e); 184 g_topology_unlock(); 185 return(error); 186} 187 188static int 189g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td) 190{ 191 struct g_geom *gp; 192 struct g_consumer *cp; 193 int error, r, w, e, i; 194 195 gp = dev->si_drv1; 196 cp = dev->si_drv2; 197 if (gp == NULL || cp == NULL) 198 return(ENXIO); 199 g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)", 200 gp->name, flags, fmt, td); 201 r = flags & FREAD ? -1 : 0; 202 w = flags & FWRITE ? -1 : 0; 203#ifdef notyet 204 e = flags & O_EXCL ? -1 : 0; 205#else 206 e = 0; 207#endif 208 g_topology_lock(); 209 if (dev->si_devsw == NULL) 210 error = ENXIO; /* We were orphaned */ 211 else 212 error = g_access(cp, r, w, e); 213 for (i = 0; i < 10 * hz;) { 214 if (cp->acr != 0 || cp->acw != 0) 215 break; 216 if (cp->nstart == cp->nend) 217 break; 218 pause("gdevwclose", hz / 10); 219 i += hz / 10; 220 } 221 if (cp->acr == 0 && cp->acw == 0 && cp->nstart != cp->nend) { 222 printf("WARNING: Final close of geom_dev(%s) %s %s\n", 223 gp->name, 224 "still has outstanding I/O after 10 seconds.", 225 "Completing close anyway, panic may happen later."); 226 } 227 g_topology_unlock(); 228 return (error); 229} 230 231/* 232 * XXX: Until we have unmessed the ioctl situation, there is a race against 233 * XXX: a concurrent orphanization. We cannot close it by holding topology 234 * XXX: since that would prevent us from doing our job, and stalling events 235 * XXX: will break (actually: stall) the BSD disklabel hacks. 236 */ 237static int 238g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td) 239{ 240 struct g_geom *gp; 241 struct g_consumer *cp; 242 struct g_provider *pp; 243 struct g_kerneldump kd; 244 off_t offset, length, chunk; 245 int i, error; 246 u_int u; 247 248 gp = dev->si_drv1; 249 cp = dev->si_drv2; 250 pp = cp->provider; 251 252 error = 0; 253 KASSERT(cp->acr || cp->acw, 254 ("Consumer with zero access count in g_dev_ioctl")); 255 256 i = IOCPARM_LEN(cmd); 257 switch (cmd) { 258 case DIOCGSECTORSIZE: 259 *(u_int *)data = cp->provider->sectorsize; 260 if (*(u_int *)data == 0) 261 error = ENOENT; 262 break; 263 case DIOCGMEDIASIZE: 264 *(off_t *)data = cp->provider->mediasize; 265 if (*(off_t *)data == 0) 266 error = ENOENT; 267 break; 268 case DIOCGFWSECTORS: 269 error = g_io_getattr("GEOM::fwsectors", cp, &i, data); 270 if (error == 0 && *(u_int *)data == 0) 271 error = ENOENT; 272 break; 273 case DIOCGFWHEADS: 274 error = g_io_getattr("GEOM::fwheads", cp, &i, data); 275 if (error == 0 && *(u_int *)data == 0) 276 error = ENOENT; 277 break; 278 case DIOCGFRONTSTUFF: 279 error = g_io_getattr("GEOM::frontstuff", cp, &i, data); 280 break; 281 case DIOCSKERNELDUMP: 282 u = *((u_int *)data); 283 if (!u) { 284 set_dumper(NULL); 285 error = 0; 286 break; 287 } 288 kd.offset = 0; 289 kd.length = OFF_MAX; 290 i = sizeof kd; 291 error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd); 292 if (!error) { 293 error = set_dumper(&kd.di); 294 if (!error) 295 dev->si_flags |= SI_DUMPDEV; 296 } 297 break; 298 case DIOCGFLUSH: 299 error = g_io_flush(cp); 300 break; 301 case DIOCGDELETE: 302 offset = ((off_t *)data)[0]; 303 length = ((off_t *)data)[1]; 304 if ((offset % cp->provider->sectorsize) != 0 || 305 (length % cp->provider->sectorsize) != 0 || length <= 0) { 306 printf("%s: offset=%jd length=%jd\n", __func__, offset, 307 length); 308 error = EINVAL; 309 break; 310 } 311 while (length > 0) { 312 chunk = length; 313 if (chunk > 65536 * cp->provider->sectorsize) 314 chunk = 65536 * cp->provider->sectorsize; 315 error = g_delete_data(cp, offset, chunk); 316 length -= chunk; 317 offset += chunk; 318 if (error) 319 break; 320 /* 321 * Since the request size is unbounded, the service 322 * time is likewise. We make this ioctl interruptible 323 * by checking for signals for each bio. 324 */ 325 if (SIGPENDING(td)) 326 break; 327 } 328 break; 329 case DIOCGIDENT: 330 error = g_io_getattr("GEOM::ident", cp, &i, data); 331 break; 332 case DIOCGPROVIDERNAME: 333 if (pp == NULL) 334 return (ENOENT); 335 strlcpy(data, pp->name, i); 336 break; 337 case DIOCGSTRIPESIZE: 338 *(off_t *)data = cp->provider->stripesize; 339 break; 340 case DIOCGSTRIPEOFFSET: 341 *(off_t *)data = cp->provider->stripeoffset; 342 break; 343 default: 344 if (cp->provider->geom->ioctl != NULL) { 345 error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td); 346 } else { 347 error = ENOIOCTL; 348 } 349 } 350 351 return (error); 352} 353 354static void 355g_dev_done(struct bio *bp2) 356{ 357 struct bio *bp; 358 359 bp = bp2->bio_parent; 360 bp->bio_error = bp2->bio_error; 361 if (bp->bio_error != 0) { 362 g_trace(G_T_BIO, "g_dev_done(%p) had error %d", 363 bp2, bp->bio_error); 364 bp->bio_flags |= BIO_ERROR; 365 } else { 366 g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd", 367 bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed); 368 } 369 bp->bio_resid = bp->bio_length - bp2->bio_completed; 370 bp->bio_completed = bp2->bio_completed; 371 g_destroy_bio(bp2); 372 biodone(bp); 373} 374 375static void 376g_dev_strategy(struct bio *bp) 377{ 378 struct g_consumer *cp; 379 struct bio *bp2; 380 struct cdev *dev; 381 382 KASSERT(bp->bio_cmd == BIO_READ || 383 bp->bio_cmd == BIO_WRITE || 384 bp->bio_cmd == BIO_DELETE, 385 ("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd)); 386 dev = bp->bio_dev; 387 cp = dev->si_drv2; 388 KASSERT(cp->acr || cp->acw, 389 ("Consumer with zero access count in g_dev_strategy")); 390#ifdef INVARIANTS 391 if ((bp->bio_offset % cp->provider->sectorsize) != 0 || 392 (bp->bio_bcount % cp->provider->sectorsize) != 0) { 393 bp->bio_resid = bp->bio_bcount; 394 biofinish(bp, NULL, EINVAL); 395 return; 396 } 397#endif 398 for (;;) { 399 /* 400 * XXX: This is not an ideal solution, but I belive it to 401 * XXX: deadlock safe, all things considered. 402 */ 403 bp2 = g_clone_bio(bp); 404 if (bp2 != NULL) 405 break; 406 pause("gdstrat", hz / 10); 407 } 408 KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place")); 409 bp2->bio_done = g_dev_done; 410 g_trace(G_T_BIO, 411 "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d", 412 bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length, 413 bp2->bio_data, bp2->bio_cmd); 414 g_io_request(bp2, cp); 415 KASSERT(cp->acr || cp->acw, 416 ("g_dev_strategy raced with g_dev_close and lost")); 417 418} 419 420/* 421 * g_dev_orphan() 422 * 423 * Called from below when the provider orphaned us. 424 * - Clear any dump settings. 425 * - Destroy the struct cdev *to prevent any more request from coming in. The 426 * provider is already marked with an error, so anything which comes in 427 * in the interrim will be returned immediately. 428 * - Wait for any outstanding I/O to finish. 429 * - Set our access counts to zero, whatever they were. 430 * - Detach and self-destruct. 431 */ 432 433static void 434g_dev_orphan(struct g_consumer *cp) 435{ 436 struct g_geom *gp; 437 struct cdev *dev; 438 439 g_topology_assert(); 440 gp = cp->geom; 441 dev = gp->softc; 442 g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name); 443 444 /* Reset any dump-area set on this device */ 445 if (dev->si_flags & SI_DUMPDEV) 446 set_dumper(NULL); 447 448 /* Destroy the struct cdev *so we get no more requests */ 449 destroy_dev(dev); 450 451 /* Wait for the cows to come home */ 452 while (cp->nstart != cp->nend) 453 pause("gdevorphan", hz / 10); 454 455 if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0) 456 g_access(cp, -cp->acr, -cp->acw, -cp->ace); 457 458 g_detach(cp); 459 g_destroy_consumer(cp); 460 g_destroy_geom(gp); 461} 462 463DECLARE_GEOM_CLASS(g_dev_class, g_dev); 464