geom_disk.c revision 237518
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_disk.c 237518 2012-06-24 04:29:03Z ken $"); 38 39#include "opt_geom.h" 40 41#include <sys/param.h> 42#include <sys/systm.h> 43#include <sys/kernel.h> 44#include <sys/sysctl.h> 45#include <sys/bio.h> 46#include <sys/ctype.h> 47#include <sys/fcntl.h> 48#include <sys/malloc.h> 49#include <sys/sbuf.h> 50#include <sys/sysctl.h> 51#include <sys/devicestat.h> 52#include <machine/md_var.h> 53 54#include <sys/lock.h> 55#include <sys/mutex.h> 56#include <geom/geom.h> 57#include <geom/geom_disk.h> 58#include <geom/geom_int.h> 59 60#include <dev/led/led.h> 61 62struct g_disk_softc { 63 struct disk *dp; 64 struct sysctl_ctx_list sysctl_ctx; 65 struct sysctl_oid *sysctl_tree; 66 char led[64]; 67 uint32_t state; 68}; 69 70static struct mtx g_disk_done_mtx; 71 72static g_access_t g_disk_access; 73static g_init_t g_disk_init; 74static g_fini_t g_disk_fini; 75static g_start_t g_disk_start; 76static g_ioctl_t g_disk_ioctl; 77static g_dumpconf_t g_disk_dumpconf; 78static g_provgone_t g_disk_providergone; 79 80static struct g_class g_disk_class = { 81 .name = "DISK", 82 .version = G_VERSION, 83 .init = g_disk_init, 84 .fini = g_disk_fini, 85 .start = g_disk_start, 86 .access = g_disk_access, 87 .ioctl = g_disk_ioctl, 88 .providergone = g_disk_providergone, 89 .dumpconf = g_disk_dumpconf, 90}; 91 92SYSCTL_DECL(_kern_geom); 93static SYSCTL_NODE(_kern_geom, OID_AUTO, disk, CTLFLAG_RW, 0, 94 "GEOM_DISK stuff"); 95 96static void 97g_disk_init(struct g_class *mp __unused) 98{ 99 100 mtx_init(&g_disk_done_mtx, "g_disk_done", NULL, MTX_DEF); 101} 102 103static void 104g_disk_fini(struct g_class *mp __unused) 105{ 106 107 mtx_destroy(&g_disk_done_mtx); 108} 109 110DECLARE_GEOM_CLASS(g_disk_class, g_disk); 111 112static void __inline 113g_disk_lock_giant(struct disk *dp) 114{ 115 116 if (dp->d_flags & DISKFLAG_NEEDSGIANT) 117 mtx_lock(&Giant); 118} 119 120static void __inline 121g_disk_unlock_giant(struct disk *dp) 122{ 123 124 if (dp->d_flags & DISKFLAG_NEEDSGIANT) 125 mtx_unlock(&Giant); 126} 127 128static int 129g_disk_access(struct g_provider *pp, int r, int w, int e) 130{ 131 struct disk *dp; 132 struct g_disk_softc *sc; 133 int error; 134 135 g_trace(G_T_ACCESS, "g_disk_access(%s, %d, %d, %d)", 136 pp->name, r, w, e); 137 g_topology_assert(); 138 sc = pp->geom->softc; 139 if (sc == NULL || (dp = sc->dp) == NULL || dp->d_destroyed) { 140 /* 141 * Allow decreasing access count even if disk is not 142 * avaliable anymore. 143 */ 144 if (r <= 0 && w <= 0 && e <= 0) 145 return (0); 146 return (ENXIO); 147 } 148 r += pp->acr; 149 w += pp->acw; 150 e += pp->ace; 151 error = 0; 152 if ((pp->acr + pp->acw + pp->ace) == 0 && (r + w + e) > 0) { 153 if (dp->d_open != NULL) { 154 g_disk_lock_giant(dp); 155 error = dp->d_open(dp); 156 if (bootverbose && error != 0) 157 printf("Opened disk %s -> %d\n", 158 pp->name, error); 159 g_disk_unlock_giant(dp); 160 } 161 pp->mediasize = dp->d_mediasize; 162 pp->sectorsize = dp->d_sectorsize; 163 if (dp->d_flags & DISKFLAG_CANDELETE) 164 pp->flags |= G_PF_CANDELETE; 165 else 166 pp->flags &= ~G_PF_CANDELETE; 167 pp->stripeoffset = dp->d_stripeoffset; 168 pp->stripesize = dp->d_stripesize; 169 dp->d_flags |= DISKFLAG_OPEN; 170 if (dp->d_maxsize == 0) { 171 printf("WARNING: Disk drive %s%d has no d_maxsize\n", 172 dp->d_name, dp->d_unit); 173 dp->d_maxsize = DFLTPHYS; 174 } 175 } else if ((pp->acr + pp->acw + pp->ace) > 0 && (r + w + e) == 0) { 176 if (dp->d_close != NULL) { 177 g_disk_lock_giant(dp); 178 error = dp->d_close(dp); 179 if (error != 0) 180 printf("Closed disk %s -> %d\n", 181 pp->name, error); 182 g_disk_unlock_giant(dp); 183 } 184 sc->state = G_STATE_ACTIVE; 185 if (sc->led[0] != 0) 186 led_set(sc->led, "0"); 187 dp->d_flags &= ~DISKFLAG_OPEN; 188 } 189 return (error); 190} 191 192static void 193g_disk_kerneldump(struct bio *bp, struct disk *dp) 194{ 195 struct g_kerneldump *gkd; 196 struct g_geom *gp; 197 198 gkd = (struct g_kerneldump*)bp->bio_data; 199 gp = bp->bio_to->geom; 200 g_trace(G_T_TOPOLOGY, "g_disk_kernedump(%s, %jd, %jd)", 201 gp->name, (intmax_t)gkd->offset, (intmax_t)gkd->length); 202 if (dp->d_dump == NULL) { 203 g_io_deliver(bp, ENODEV); 204 return; 205 } 206 gkd->di.dumper = dp->d_dump; 207 gkd->di.priv = dp; 208 gkd->di.blocksize = dp->d_sectorsize; 209 gkd->di.maxiosize = dp->d_maxsize; 210 gkd->di.mediaoffset = gkd->offset; 211 if ((gkd->offset + gkd->length) > dp->d_mediasize) 212 gkd->length = dp->d_mediasize - gkd->offset; 213 gkd->di.mediasize = gkd->length; 214 g_io_deliver(bp, 0); 215} 216 217static void 218g_disk_setstate(struct bio *bp, struct g_disk_softc *sc) 219{ 220 const char *cmd; 221 222 memcpy(&sc->state, bp->bio_data, sizeof(sc->state)); 223 if (sc->led[0] != 0) { 224 switch (sc->state) { 225 case G_STATE_FAILED: 226 cmd = "1"; 227 break; 228 case G_STATE_REBUILD: 229 cmd = "f5"; 230 break; 231 case G_STATE_RESYNC: 232 cmd = "f1"; 233 break; 234 default: 235 cmd = "0"; 236 break; 237 } 238 led_set(sc->led, cmd); 239 } 240 g_io_deliver(bp, 0); 241} 242 243static void 244g_disk_done(struct bio *bp) 245{ 246 struct bio *bp2; 247 struct disk *dp; 248 struct g_disk_softc *sc; 249 250 /* See "notes" for why we need a mutex here */ 251 /* XXX: will witness accept a mix of Giant/unGiant drivers here ? */ 252 mtx_lock(&g_disk_done_mtx); 253 bp->bio_completed = bp->bio_length - bp->bio_resid; 254 255 bp2 = bp->bio_parent; 256 if (bp2->bio_error == 0) 257 bp2->bio_error = bp->bio_error; 258 bp2->bio_completed += bp->bio_completed; 259 if ((bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) != 0 && 260 (sc = bp2->bio_to->geom->softc) != NULL && 261 (dp = sc->dp) != NULL) { 262 devstat_end_transaction_bio(dp->d_devstat, bp); 263 } 264 g_destroy_bio(bp); 265 bp2->bio_inbed++; 266 if (bp2->bio_children == bp2->bio_inbed) { 267 bp2->bio_resid = bp2->bio_bcount - bp2->bio_completed; 268 g_io_deliver(bp2, bp2->bio_error); 269 } 270 mtx_unlock(&g_disk_done_mtx); 271} 272 273static int 274g_disk_ioctl(struct g_provider *pp, u_long cmd, void * data, int fflag, struct thread *td) 275{ 276 struct g_geom *gp; 277 struct disk *dp; 278 struct g_disk_softc *sc; 279 int error; 280 281 gp = pp->geom; 282 sc = gp->softc; 283 dp = sc->dp; 284 285 if (dp->d_ioctl == NULL) 286 return (ENOIOCTL); 287 g_disk_lock_giant(dp); 288 error = dp->d_ioctl(dp, cmd, data, fflag, td); 289 g_disk_unlock_giant(dp); 290 return (error); 291} 292 293static void 294g_disk_start(struct bio *bp) 295{ 296 struct bio *bp2, *bp3; 297 struct disk *dp; 298 struct g_disk_softc *sc; 299 int error; 300 off_t off; 301 302 sc = bp->bio_to->geom->softc; 303 if (sc == NULL || (dp = sc->dp) == NULL || dp->d_destroyed) { 304 g_io_deliver(bp, ENXIO); 305 return; 306 } 307 error = EJUSTRETURN; 308 switch(bp->bio_cmd) { 309 case BIO_DELETE: 310 if (!(dp->d_flags & DISKFLAG_CANDELETE)) { 311 error = EOPNOTSUPP; 312 break; 313 } 314 /* fall-through */ 315 case BIO_READ: 316 case BIO_WRITE: 317 off = 0; 318 bp3 = NULL; 319 bp2 = g_clone_bio(bp); 320 if (bp2 == NULL) { 321 error = ENOMEM; 322 break; 323 } 324 do { 325 bp2->bio_offset += off; 326 bp2->bio_length -= off; 327 bp2->bio_data += off; 328 if (bp2->bio_length > dp->d_maxsize) { 329 /* 330 * XXX: If we have a stripesize we should really 331 * use it here. 332 */ 333 bp2->bio_length = dp->d_maxsize; 334 off += dp->d_maxsize; 335 /* 336 * To avoid a race, we need to grab the next bio 337 * before we schedule this one. See "notes". 338 */ 339 bp3 = g_clone_bio(bp); 340 if (bp3 == NULL) 341 bp->bio_error = ENOMEM; 342 } 343 bp2->bio_done = g_disk_done; 344 bp2->bio_pblkno = bp2->bio_offset / dp->d_sectorsize; 345 bp2->bio_bcount = bp2->bio_length; 346 bp2->bio_disk = dp; 347 devstat_start_transaction_bio(dp->d_devstat, bp2); 348 g_disk_lock_giant(dp); 349 dp->d_strategy(bp2); 350 g_disk_unlock_giant(dp); 351 bp2 = bp3; 352 bp3 = NULL; 353 } while (bp2 != NULL); 354 break; 355 case BIO_GETATTR: 356 /* Give the driver a chance to override */ 357 if (dp->d_getattr != NULL) { 358 if (bp->bio_disk == NULL) 359 bp->bio_disk = dp; 360 error = dp->d_getattr(bp); 361 if (error != -1) 362 break; 363 error = EJUSTRETURN; 364 } 365 if (g_handleattr_int(bp, "GEOM::candelete", 366 (dp->d_flags & DISKFLAG_CANDELETE) != 0)) 367 break; 368 else if (g_handleattr_int(bp, "GEOM::fwsectors", 369 dp->d_fwsectors)) 370 break; 371 else if (g_handleattr_int(bp, "GEOM::fwheads", dp->d_fwheads)) 372 break; 373 else if (g_handleattr_off_t(bp, "GEOM::frontstuff", 0)) 374 break; 375 else if (g_handleattr_str(bp, "GEOM::ident", dp->d_ident)) 376 break; 377 else if (g_handleattr(bp, "GEOM::hba_vendor", 378 &dp->d_hba_vendor, 2)) 379 break; 380 else if (g_handleattr(bp, "GEOM::hba_device", 381 &dp->d_hba_device, 2)) 382 break; 383 else if (g_handleattr(bp, "GEOM::hba_subvendor", 384 &dp->d_hba_subvendor, 2)) 385 break; 386 else if (g_handleattr(bp, "GEOM::hba_subdevice", 387 &dp->d_hba_subdevice, 2)) 388 break; 389 else if (!strcmp(bp->bio_attribute, "GEOM::kerneldump")) 390 g_disk_kerneldump(bp, dp); 391 else if (!strcmp(bp->bio_attribute, "GEOM::setstate")) 392 g_disk_setstate(bp, sc); 393 else 394 error = ENOIOCTL; 395 break; 396 case BIO_FLUSH: 397 g_trace(G_T_TOPOLOGY, "g_disk_flushcache(%s)", 398 bp->bio_to->name); 399 if (!(dp->d_flags & DISKFLAG_CANFLUSHCACHE)) { 400 error = EOPNOTSUPP; 401 break; 402 } 403 bp2 = g_clone_bio(bp); 404 if (bp2 == NULL) { 405 g_io_deliver(bp, ENOMEM); 406 return; 407 } 408 bp2->bio_done = g_disk_done; 409 bp2->bio_disk = dp; 410 g_disk_lock_giant(dp); 411 dp->d_strategy(bp2); 412 g_disk_unlock_giant(dp); 413 break; 414 default: 415 error = EOPNOTSUPP; 416 break; 417 } 418 if (error != EJUSTRETURN) 419 g_io_deliver(bp, error); 420 return; 421} 422 423static void 424g_disk_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp) 425{ 426 struct disk *dp; 427 struct g_disk_softc *sc; 428 429 sc = gp->softc; 430 if (sc == NULL || (dp = sc->dp) == NULL) 431 return; 432 if (indent == NULL) { 433 sbuf_printf(sb, " hd %u", dp->d_fwheads); 434 sbuf_printf(sb, " sc %u", dp->d_fwsectors); 435 return; 436 } 437 if (pp != NULL) { 438 sbuf_printf(sb, "%s<fwheads>%u</fwheads>\n", 439 indent, dp->d_fwheads); 440 sbuf_printf(sb, "%s<fwsectors>%u</fwsectors>\n", 441 indent, dp->d_fwsectors); 442 sbuf_printf(sb, "%s<ident>%s</ident>\n", indent, dp->d_ident); 443 sbuf_printf(sb, "%s<descr>%s</descr>\n", indent, dp->d_descr); 444 } 445} 446 447static void 448g_disk_create(void *arg, int flag) 449{ 450 struct g_geom *gp; 451 struct g_provider *pp; 452 struct disk *dp; 453 struct g_disk_softc *sc; 454 char tmpstr[80]; 455 456 if (flag == EV_CANCEL) 457 return; 458 g_topology_assert(); 459 dp = arg; 460 sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO); 461 sc->dp = dp; 462 gp = g_new_geomf(&g_disk_class, "%s%d", dp->d_name, dp->d_unit); 463 gp->softc = sc; 464 pp = g_new_providerf(gp, "%s", gp->name); 465 pp->mediasize = dp->d_mediasize; 466 pp->sectorsize = dp->d_sectorsize; 467 if (dp->d_flags & DISKFLAG_CANDELETE) 468 pp->flags |= G_PF_CANDELETE; 469 pp->stripeoffset = dp->d_stripeoffset; 470 pp->stripesize = dp->d_stripesize; 471 if (bootverbose) 472 printf("GEOM: new disk %s\n", gp->name); 473 sysctl_ctx_init(&sc->sysctl_ctx); 474 snprintf(tmpstr, sizeof(tmpstr), "GEOM disk %s", gp->name); 475 sc->sysctl_tree = SYSCTL_ADD_NODE(&sc->sysctl_ctx, 476 SYSCTL_STATIC_CHILDREN(_kern_geom_disk), OID_AUTO, gp->name, 477 CTLFLAG_RD, 0, tmpstr); 478 if (sc->sysctl_tree != NULL) { 479 snprintf(tmpstr, sizeof(tmpstr), 480 "kern.geom.disk.%s.led", gp->name); 481 TUNABLE_STR_FETCH(tmpstr, sc->led, sizeof(sc->led)); 482 SYSCTL_ADD_STRING(&sc->sysctl_ctx, 483 SYSCTL_CHILDREN(sc->sysctl_tree), OID_AUTO, "led", 484 CTLFLAG_RW | CTLFLAG_TUN, sc->led, sizeof(sc->led), 485 "LED name"); 486 } 487 pp->private = sc; 488 dp->d_geom = gp; 489 g_error_provider(pp, 0); 490} 491 492/* 493 * We get this callback after all of the consumers have gone away, and just 494 * before the provider is freed. If the disk driver provided a d_gone 495 * callback, let them know that it is okay to free resources -- they won't 496 * be getting any more accesses from GEOM. 497 */ 498static void 499g_disk_providergone(struct g_provider *pp) 500{ 501 struct disk *dp; 502 struct g_disk_softc *sc; 503 504 sc = (struct g_disk_softc *)pp->geom->softc; 505 dp = sc->dp; 506 507 if (dp->d_gone != NULL) 508 dp->d_gone(dp); 509} 510 511static void 512g_disk_destroy(void *ptr, int flag) 513{ 514 struct disk *dp; 515 struct g_geom *gp; 516 struct g_disk_softc *sc; 517 518 g_topology_assert(); 519 dp = ptr; 520 gp = dp->d_geom; 521 if (gp != NULL) { 522 sc = gp->softc; 523 if (sc->sysctl_tree != NULL) { 524 sysctl_ctx_free(&sc->sysctl_ctx); 525 sc->sysctl_tree = NULL; 526 } 527 if (sc->led[0] != 0) { 528 led_set(sc->led, "0"); 529 sc->led[0] = 0; 530 } 531 g_free(sc); 532 gp->softc = NULL; 533 g_wither_geom(gp, ENXIO); 534 } 535 g_free(dp); 536} 537 538/* 539 * We only allow printable characters in disk ident, 540 * the rest is converted to 'x<HH>'. 541 */ 542static void 543g_disk_ident_adjust(char *ident, size_t size) 544{ 545 char *p, tmp[4], newid[DISK_IDENT_SIZE]; 546 547 newid[0] = '\0'; 548 for (p = ident; *p != '\0'; p++) { 549 if (isprint(*p)) { 550 tmp[0] = *p; 551 tmp[1] = '\0'; 552 } else { 553 snprintf(tmp, sizeof(tmp), "x%02hhx", 554 *(unsigned char *)p); 555 } 556 if (strlcat(newid, tmp, sizeof(newid)) >= sizeof(newid)) 557 break; 558 } 559 bzero(ident, size); 560 strlcpy(ident, newid, size); 561} 562 563struct disk * 564disk_alloc(void) 565{ 566 567 return (g_malloc(sizeof(struct disk), M_WAITOK | M_ZERO)); 568} 569 570void 571disk_create(struct disk *dp, int version) 572{ 573 574 if (version != DISK_VERSION_02) { 575 printf("WARNING: Attempt to add disk %s%d %s", 576 dp->d_name, dp->d_unit, 577 " using incompatible ABI version of disk(9)\n"); 578 printf("WARNING: Ignoring disk %s%d\n", 579 dp->d_name, dp->d_unit); 580 return; 581 } 582 KASSERT(dp->d_strategy != NULL, ("disk_create need d_strategy")); 583 KASSERT(dp->d_name != NULL, ("disk_create need d_name")); 584 KASSERT(*dp->d_name != 0, ("disk_create need d_name")); 585 KASSERT(strlen(dp->d_name) < SPECNAMELEN - 4, ("disk name too long")); 586 if (dp->d_devstat == NULL) 587 dp->d_devstat = devstat_new_entry(dp->d_name, dp->d_unit, 588 dp->d_sectorsize, DEVSTAT_ALL_SUPPORTED, 589 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX); 590 dp->d_geom = NULL; 591 g_disk_ident_adjust(dp->d_ident, sizeof(dp->d_ident)); 592 g_post_event(g_disk_create, dp, M_WAITOK, dp, NULL); 593} 594 595void 596disk_destroy(struct disk *dp) 597{ 598 599 g_cancel_event(dp); 600 dp->d_destroyed = 1; 601 if (dp->d_devstat != NULL) 602 devstat_remove_entry(dp->d_devstat); 603 g_post_event(g_disk_destroy, dp, M_WAITOK, NULL); 604} 605 606void 607disk_gone(struct disk *dp) 608{ 609 struct g_geom *gp; 610 struct g_provider *pp; 611 612 gp = dp->d_geom; 613 if (gp != NULL) 614 LIST_FOREACH(pp, &gp->provider, provider) 615 g_wither_provider(pp, ENXIO); 616} 617 618void 619disk_attr_changed(struct disk *dp, const char *attr, int flag) 620{ 621 struct g_geom *gp; 622 struct g_provider *pp; 623 624 gp = dp->d_geom; 625 if (gp != NULL) 626 LIST_FOREACH(pp, &gp->provider, provider) 627 (void)g_attr_changed(pp, attr, flag); 628} 629 630static void 631g_kern_disks(void *p, int flag __unused) 632{ 633 struct sbuf *sb; 634 struct g_geom *gp; 635 char *sp; 636 637 sb = p; 638 sp = ""; 639 g_topology_assert(); 640 LIST_FOREACH(gp, &g_disk_class.geom, geom) { 641 sbuf_printf(sb, "%s%s", sp, gp->name); 642 sp = " "; 643 } 644 sbuf_finish(sb); 645} 646 647static int 648sysctl_disks(SYSCTL_HANDLER_ARGS) 649{ 650 int error; 651 struct sbuf *sb; 652 653 sb = sbuf_new_auto(); 654 g_waitfor_event(g_kern_disks, sb, M_WAITOK, NULL); 655 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); 656 sbuf_delete(sb); 657 return error; 658} 659 660SYSCTL_PROC(_kern, OID_AUTO, disks, 661 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, 662 sysctl_disks, "A", "names of available disks"); 663