1/* $NetBSD: md.c,v 1.87 2023/01/13 15:46:40 hannken Exp $ */ 2 3/* 4 * Copyright (c) 1995 Gordon W. Ross, Leo Weppelman. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28/* 29 * This implements a general-purpose memory-disk. 30 * See md.h for notes on the config types. 31 * 32 * Note that this driver provides the same functionality 33 * as the MFS filesystem hack, but this is better because 34 * you can use this for any filesystem type you'd like! 35 * 36 * Credit for most of the kmem ramdisk code goes to: 37 * Leo Weppelman (atari) and Phil Nelson (pc532) 38 * Credit for the ideas behind the "user space memory" code goes 39 * to the authors of the MFS implementation. 40 */ 41 42#include <sys/cdefs.h> 43__KERNEL_RCSID(0, "$NetBSD: md.c,v 1.87 2023/01/13 15:46:40 hannken Exp $"); 44 45#ifdef _KERNEL_OPT 46#include "opt_md.h" 47#else 48#define MEMORY_DISK_SERVER 1 49#endif 50 51#include <sys/param.h> 52#include <sys/kernel.h> 53#include <sys/kmem.h> 54#include <sys/systm.h> 55#include <sys/buf.h> 56#include <sys/bufq.h> 57#include <sys/device.h> 58#include <sys/disk.h> 59#include <sys/stat.h> 60#include <sys/proc.h> 61#include <sys/conf.h> 62#include <sys/disklabel.h> 63 64#include <uvm/uvm_extern.h> 65 66#include <dev/md.h> 67 68#include "ioconf.h" 69/* 70 * The user-space functionality is included by default. 71 * Use `options MEMORY_DISK_SERVER=0' to turn it off. 72 */ 73#ifndef MEMORY_DISK_SERVER 74#error MEMORY_DISK_SERVER should be defined by opt_md.h 75#endif /* MEMORY_DISK_SERVER */ 76 77/* 78 * We should use the raw partition for ioctl. 79 */ 80#define MD_UNIT(unit) DISKUNIT(unit) 81 82/* autoconfig stuff... */ 83 84struct md_softc { 85 device_t sc_dev; /* Self. */ 86 struct disk sc_dkdev; /* hook for generic disk handling */ 87 struct md_conf sc_md; 88 kmutex_t sc_lock; /* Protect self. */ 89 kcondvar_t sc_cv; /* Wait here for work. */ 90 struct bufq_state *sc_buflist; 91}; 92/* shorthand for fields in sc_md: */ 93#define sc_addr sc_md.md_addr 94#define sc_size sc_md.md_size 95#define sc_type sc_md.md_type 96 97static void md_attach(device_t, device_t, void *); 98static int md_detach(device_t, int); 99 100static dev_type_open(mdopen); 101static dev_type_close(mdclose); 102static dev_type_read(mdread); 103static dev_type_write(mdwrite); 104static dev_type_ioctl(mdioctl); 105static dev_type_strategy(mdstrategy); 106static dev_type_size(mdsize); 107 108const struct bdevsw md_bdevsw = { 109 .d_open = mdopen, 110 .d_close = mdclose, 111 .d_strategy = mdstrategy, 112 .d_ioctl = mdioctl, 113 .d_dump = nodump, 114 .d_psize = mdsize, 115 .d_discard = nodiscard, 116 .d_flag = D_DISK | D_MPSAFE 117}; 118 119const struct cdevsw md_cdevsw = { 120 .d_open = mdopen, 121 .d_close = mdclose, 122 .d_read = mdread, 123 .d_write = mdwrite, 124 .d_ioctl = mdioctl, 125 .d_stop = nostop, 126 .d_tty = notty, 127 .d_poll = nopoll, 128 .d_mmap = nommap, 129 .d_kqfilter = nokqfilter, 130 .d_discard = nodiscard, 131 .d_flag = D_DISK | D_MPSAFE 132}; 133 134static const struct dkdriver mddkdriver = { 135 .d_strategy = mdstrategy, 136 .d_minphys = minphys 137}; 138 139CFATTACH_DECL3_NEW(md, sizeof(struct md_softc), 140 0, md_attach, md_detach, NULL, NULL, NULL, DVF_DETACH_SHUTDOWN); 141 142static kmutex_t md_device_lock; /* Protect unit creation / deletion. */ 143extern size_t md_root_size; 144 145static void md_set_disklabel(struct md_softc *); 146 147/* 148 * This is called if we are configured as a pseudo-device 149 */ 150void 151mdattach(int n) 152{ 153 154 mutex_init(&md_device_lock, MUTEX_DEFAULT, IPL_NONE); 155 if (config_cfattach_attach(md_cd.cd_name, &md_ca)) { 156 aprint_error("%s: cfattach_attach failed\n", md_cd.cd_name); 157 return; 158 } 159} 160 161static void 162md_attach(device_t parent, device_t self, void *aux) 163{ 164 struct md_softc *sc = device_private(self); 165 166 sc->sc_dev = self; 167 sc->sc_type = MD_UNCONFIGURED; 168 mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE); 169 cv_init(&sc->sc_cv, "mdidle"); 170 bufq_alloc(&sc->sc_buflist, "fcfs", 0); 171 172 /* XXX - Could accept aux info here to set the config. */ 173#ifdef MEMORY_DISK_HOOKS 174 /* 175 * This external function might setup a pre-loaded disk. 176 * All it would need to do is setup the md_conf struct. 177 * See sys/dev/md_root.c for an example. 178 */ 179 md_attach_hook(device_unit(self), &sc->sc_md); 180#endif 181 182 /* 183 * Initialize and attach the disk structure. 184 */ 185 disk_init(&sc->sc_dkdev, device_xname(self), &mddkdriver); 186 disk_attach(&sc->sc_dkdev); 187 188 if (sc->sc_type != MD_UNCONFIGURED) 189 md_set_disklabel(sc); 190 191 if (!pmf_device_register(self, NULL, NULL)) 192 aprint_error_dev(self, "couldn't establish power handler\n"); 193} 194 195static int 196md_detach(device_t self, int flags) 197{ 198 struct md_softc *sc = device_private(self); 199 int rc; 200 201 rc = 0; 202 mutex_enter(&sc->sc_dkdev.dk_openlock); 203 if (sc->sc_dkdev.dk_openmask == 0 && sc->sc_type == MD_UNCONFIGURED) 204 ; /* nothing to do */ 205 else if ((flags & DETACH_FORCE) == 0) 206 rc = EBUSY; 207 mutex_exit(&sc->sc_dkdev.dk_openlock); 208 209 if (rc != 0) 210 return rc; 211 212 pmf_device_deregister(self); 213 disk_detach(&sc->sc_dkdev); 214 disk_destroy(&sc->sc_dkdev); 215 bufq_free(sc->sc_buflist); 216 mutex_destroy(&sc->sc_lock); 217 cv_destroy(&sc->sc_cv); 218 return 0; 219} 220 221/* 222 * operational routines: 223 * open, close, read, write, strategy, 224 * ioctl, dump, size 225 */ 226 227#if MEMORY_DISK_SERVER 228static int md_server_loop(struct md_softc *sc); 229static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 230 struct lwp *l); 231#endif /* MEMORY_DISK_SERVER */ 232static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 233 struct lwp *l); 234 235static int 236mdsize(dev_t dev) 237{ 238 struct md_softc *sc; 239 int res; 240 241 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 242 if (sc == NULL) 243 return 0; 244 245 mutex_enter(&sc->sc_lock); 246 if (sc->sc_type == MD_UNCONFIGURED) 247 res = 0; 248 else 249 res = sc->sc_size >> DEV_BSHIFT; 250 mutex_exit(&sc->sc_lock); 251 252 return res; 253} 254 255static int 256mdopen(dev_t dev, int flag, int fmt, struct lwp *l) 257{ 258 int unit; 259 int part = DISKPART(dev); 260 int pmask = 1 << part; 261 cfdata_t cf; 262 struct md_softc *sc; 263 struct disk *dk; 264#ifdef MEMORY_DISK_HOOKS 265 bool configured; 266#endif 267 268 mutex_enter(&md_device_lock); 269 unit = MD_UNIT(dev); 270 sc = device_lookup_private(&md_cd, unit); 271 if (sc == NULL) { 272 if (part != RAW_PART) { 273 mutex_exit(&md_device_lock); 274 return ENXIO; 275 } 276 cf = kmem_zalloc(sizeof(*cf), KM_SLEEP); 277 cf->cf_name = md_cd.cd_name; 278 cf->cf_atname = md_cd.cd_name; 279 cf->cf_unit = unit; 280 cf->cf_fstate = FSTATE_STAR; 281 sc = device_private(config_attach_pseudo(cf)); 282 if (sc == NULL) { 283 mutex_exit(&md_device_lock); 284 return ENOMEM; 285 } 286 } 287 288 dk = &sc->sc_dkdev; 289 290 /* 291 * The raw partition is used for ioctl to configure. 292 */ 293 if (part == RAW_PART) 294 goto ok; 295 296#ifdef MEMORY_DISK_HOOKS 297 /* Call the open hook to allow loading the device. */ 298 configured = (sc->sc_type != MD_UNCONFIGURED); 299 md_open_hook(unit, &sc->sc_md); 300 /* initialize disklabel if the device is configured in open hook */ 301 if (!configured && sc->sc_type != MD_UNCONFIGURED) 302 md_set_disklabel(sc); 303#endif 304 305 /* 306 * This is a normal, "slave" device, so 307 * enforce initialized. 308 */ 309 if (sc->sc_type == MD_UNCONFIGURED) { 310 mutex_exit(&md_device_lock); 311 return ENXIO; 312 } 313 314ok: 315 /* XXX duplicates code in dk_open(). Call dk_open(), instead? */ 316 mutex_enter(&dk->dk_openlock); 317 /* Mark our unit as open. */ 318 switch (fmt) { 319 case S_IFCHR: 320 dk->dk_copenmask |= pmask; 321 break; 322 case S_IFBLK: 323 dk->dk_bopenmask |= pmask; 324 break; 325 } 326 327 dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask; 328 329 mutex_exit(&dk->dk_openlock); 330 mutex_exit(&md_device_lock); 331 return 0; 332} 333 334static int 335mdclose(dev_t dev, int flag, int fmt, struct lwp *l) 336{ 337 int part = DISKPART(dev); 338 int pmask = 1 << part; 339 int error; 340 cfdata_t cf; 341 struct md_softc *sc; 342 struct disk *dk; 343 344 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 345 if (sc == NULL) 346 return ENXIO; 347 348 dk = &sc->sc_dkdev; 349 350 mutex_enter(&dk->dk_openlock); 351 352 switch (fmt) { 353 case S_IFCHR: 354 dk->dk_copenmask &= ~pmask; 355 break; 356 case S_IFBLK: 357 dk->dk_bopenmask &= ~pmask; 358 break; 359 } 360 dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask; 361 if (dk->dk_openmask != 0) { 362 mutex_exit(&dk->dk_openlock); 363 return 0; 364 } 365 366 mutex_exit(&dk->dk_openlock); 367 368 mutex_enter(&md_device_lock); 369 cf = device_cfdata(sc->sc_dev); 370 error = config_detach(sc->sc_dev, DETACH_QUIET); 371 if (! error) 372 kmem_free(cf, sizeof(*cf)); 373 mutex_exit(&md_device_lock); 374 return error; 375} 376 377static int 378mdread(dev_t dev, struct uio *uio, int flags) 379{ 380 struct md_softc *sc; 381 382 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 383 384 if (sc == NULL || sc->sc_type == MD_UNCONFIGURED) 385 return ENXIO; 386 387 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 388} 389 390static int 391mdwrite(dev_t dev, struct uio *uio, int flags) 392{ 393 struct md_softc *sc; 394 395 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 396 397 if (sc == NULL || sc->sc_type == MD_UNCONFIGURED) 398 return ENXIO; 399 400 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 401} 402 403/* 404 * Handle I/O requests, either directly, or 405 * by passing them to the server process. 406 */ 407static void 408mdstrategy(struct buf *bp) 409{ 410 struct md_softc *sc; 411 void * addr; 412 size_t off, xfer; 413 bool is_read; 414 415 sc = device_lookup_private(&md_cd, MD_UNIT(bp->b_dev)); 416 417 if (sc == NULL || sc->sc_type == MD_UNCONFIGURED) { 418 bp->b_error = ENXIO; 419 goto done; 420 } 421 422 mutex_enter(&sc->sc_lock); 423 424 switch (sc->sc_type) { 425#if MEMORY_DISK_SERVER 426 case MD_UMEM_SERVER: 427 /* Just add this job to the server's queue. */ 428 bufq_put(sc->sc_buflist, bp); 429 cv_signal(&sc->sc_cv); 430 mutex_exit(&sc->sc_lock); 431 /* see md_server_loop() */ 432 /* no biodone in this case */ 433 return; 434#endif /* MEMORY_DISK_SERVER */ 435 436 case MD_KMEM_FIXED: 437 case MD_KMEM_ALLOCATED: 438 /* These are in kernel space. Access directly. */ 439 is_read = ((bp->b_flags & B_READ) == B_READ); 440 bp->b_resid = bp->b_bcount; 441 off = (bp->b_blkno << DEV_BSHIFT); 442 if (off >= sc->sc_size) { 443 if (is_read) 444 break; /* EOF */ 445 goto set_eio; 446 } 447 xfer = bp->b_resid; 448 if (xfer > (sc->sc_size - off)) 449 xfer = (sc->sc_size - off); 450 addr = (char *)sc->sc_addr + off; 451 disk_busy(&sc->sc_dkdev); 452 if (is_read) 453 memcpy(bp->b_data, addr, xfer); 454 else 455 memcpy(addr, bp->b_data, xfer); 456 disk_unbusy(&sc->sc_dkdev, xfer, is_read); 457 bp->b_resid -= xfer; 458 break; 459 460 default: 461 bp->b_resid = bp->b_bcount; 462 set_eio: 463 bp->b_error = EIO; 464 break; 465 } 466 mutex_exit(&sc->sc_lock); 467 468 done: 469 470 biodone(bp); 471} 472 473static int 474mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 475{ 476 struct md_softc *sc; 477 struct md_conf *umd; 478 int error; 479 480 if ((sc = device_lookup_private(&md_cd, MD_UNIT(dev))) == NULL) 481 return ENXIO; 482 483 if (sc->sc_type != MD_UNCONFIGURED) { 484 error = disk_ioctl(&sc->sc_dkdev, dev, cmd, data, flag, l); 485 if (error != EPASSTHROUGH) { 486 return error; 487 } 488 } 489 490 /* If this is not the raw partition, punt! */ 491 if (DISKPART(dev) != RAW_PART) { 492 return ENOTTY; 493 } 494 495 mutex_enter(&sc->sc_lock); 496 umd = (struct md_conf *)data; 497 error = EINVAL; 498 switch (cmd) { 499 case MD_GETCONF: 500 *umd = sc->sc_md; 501 error = 0; 502 break; 503 504 case MD_SETCONF: 505 /* Can only set it once. */ 506 if (sc->sc_type != MD_UNCONFIGURED) 507 break; 508 switch (umd->md_type) { 509 case MD_KMEM_ALLOCATED: 510 error = md_ioctl_kalloc(sc, umd, l); 511 break; 512#if MEMORY_DISK_SERVER 513 case MD_UMEM_SERVER: 514 error = md_ioctl_server(sc, umd, l); 515 break; 516#endif /* MEMORY_DISK_SERVER */ 517 default: 518 break; 519 } 520 break; 521 } 522 mutex_exit(&sc->sc_lock); 523 return error; 524} 525 526static void 527md_set_disklabel(struct md_softc *sc) 528{ 529 struct disk_geom *dg = &sc->sc_dkdev.dk_geom; 530 struct disklabel *lp = sc->sc_dkdev.dk_label; 531 struct partition *pp; 532 533 memset(lp, 0, sizeof(*lp)); 534 535 lp->d_secsize = DEV_BSIZE; 536 lp->d_secperunit = sc->sc_size / DEV_BSIZE; 537 if (lp->d_secperunit >= (32*64)) { 538 lp->d_nsectors = 32; 539 lp->d_ntracks = 64; 540 lp->d_ncylinders = lp->d_secperunit / (32*64); 541 } else { 542 lp->d_nsectors = 1; 543 lp->d_ntracks = 1; 544 lp->d_ncylinders = lp->d_secperunit; 545 } 546 lp->d_secpercyl = lp->d_ntracks*lp->d_nsectors; 547 548 strncpy(lp->d_typename, md_cd.cd_name, sizeof(lp->d_typename)); 549 lp->d_type = DKTYPE_MD; 550 strncpy(lp->d_packname, "fictitious", sizeof(lp->d_packname)); 551 lp->d_rpm = 3600; 552 lp->d_interleave = 1; 553 lp->d_flags = 0; 554 555 pp = &lp->d_partitions[0]; 556 pp->p_offset = 0; 557 pp->p_size = lp->d_secperunit; 558 pp->p_fstype = FS_BSDFFS; 559 560 pp = &lp->d_partitions[RAW_PART]; 561 pp->p_offset = 0; 562 pp->p_size = lp->d_secperunit; 563 pp->p_fstype = FS_UNUSED; 564 565 lp->d_npartitions = RAW_PART+1; 566 lp->d_magic = DISKMAGIC; 567 lp->d_magic2 = DISKMAGIC; 568 lp->d_checksum = dkcksum(lp); 569 570 memset(dg, 0, sizeof(*dg)); 571 572 dg->dg_secsize = lp->d_secsize; 573 dg->dg_secperunit = lp->d_secperunit; 574 dg->dg_nsectors = lp->d_nsectors; 575 dg->dg_ntracks = lp->d_ntracks = 64; 576 dg->dg_ncylinders = lp->d_ncylinders; 577 578 disk_set_info(sc->sc_dev, &sc->sc_dkdev, NULL); 579} 580 581/* 582 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 583 * Just allocate some kernel memory and return. 584 */ 585static int 586md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 587 struct lwp *l) 588{ 589 vaddr_t addr; 590 vsize_t size; 591 592 /* Sanity check the size. */ 593 size = umd->md_size; 594 if (size < DEV_BSIZE || (size % DEV_BSIZE) != 0) 595 return EINVAL; 596 597 mutex_exit(&sc->sc_lock); 598 599 addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); 600 601 mutex_enter(&sc->sc_lock); 602 603 if (!addr) 604 return ENOMEM; 605 606 /* If another thread beat us to configure this unit: fail. */ 607 if (sc->sc_type != MD_UNCONFIGURED) { 608 uvm_km_free(kernel_map, addr, size, UVM_KMF_WIRED); 609 return EINVAL; 610 } 611 612 /* This unit is now configured. */ 613 sc->sc_addr = (void *)addr; /* kernel space */ 614 sc->sc_size = (size_t)size; 615 sc->sc_type = MD_KMEM_ALLOCATED; 616 md_set_disklabel(sc); 617 return 0; 618} 619 620#if MEMORY_DISK_SERVER 621 622/* 623 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 624 * Set config, then become the I/O server for this unit. 625 */ 626static int 627md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 628 struct lwp *l) 629{ 630 vaddr_t end; 631 int error; 632 633 KASSERT(mutex_owned(&sc->sc_lock)); 634 635 /* Sanity check addr, size. */ 636 end = (vaddr_t) ((char *)umd->md_addr + umd->md_size); 637 638 if ( 639#ifndef _RUMPKERNEL 640 /* 641 * On some architectures (e.g. powerpc) rump kernel provides 642 * "safe" low defaults which make this test fail since malloc 643 * does return higher addresses than the "safe" default. 644 */ 645 (end >= VM_MAXUSER_ADDRESS) || 646#endif 647 (end < ((vaddr_t) umd->md_addr))) 648 return EINVAL; 649 650 /* This unit is now configured. */ 651 sc->sc_addr = umd->md_addr; /* user space */ 652 sc->sc_size = umd->md_size; 653 sc->sc_type = MD_UMEM_SERVER; 654 md_set_disklabel(sc); 655 656 /* Become the server daemon */ 657 error = md_server_loop(sc); 658 659 /* This server is now going away! */ 660 sc->sc_type = MD_UNCONFIGURED; 661 sc->sc_addr = 0; 662 sc->sc_size = 0; 663 664 return (error); 665} 666 667static int 668md_server_loop(struct md_softc *sc) 669{ 670 struct buf *bp; 671 void *addr; /* user space address */ 672 size_t off; /* offset into "device" */ 673 size_t xfer; /* amount to transfer */ 674 int error; 675 bool is_read; 676 677 KASSERT(mutex_owned(&sc->sc_lock)); 678 679 for (;;) { 680 /* Wait for some work to arrive. */ 681 while ((bp = bufq_get(sc->sc_buflist)) == NULL) { 682 error = cv_wait_sig(&sc->sc_cv, &sc->sc_lock); 683 if (error) 684 return error; 685 } 686 687 /* Do the transfer to/from user space. */ 688 mutex_exit(&sc->sc_lock); 689 error = 0; 690 is_read = ((bp->b_flags & B_READ) == B_READ); 691 bp->b_resid = bp->b_bcount; 692 off = (bp->b_blkno << DEV_BSHIFT); 693 if (off >= sc->sc_size) { 694 if (is_read) 695 goto done; /* EOF (not an error) */ 696 error = EIO; 697 goto done; 698 } 699 xfer = bp->b_resid; 700 if (xfer > (sc->sc_size - off)) 701 xfer = (sc->sc_size - off); 702 addr = (char *)sc->sc_addr + off; 703 disk_busy(&sc->sc_dkdev); 704 if (is_read) 705 error = copyin(addr, bp->b_data, xfer); 706 else 707 error = copyout(bp->b_data, addr, xfer); 708 disk_unbusy(&sc->sc_dkdev, (error ? 0 : xfer), is_read); 709 if (!error) 710 bp->b_resid -= xfer; 711 712 done: 713 if (error) { 714 bp->b_error = error; 715 } 716 biodone(bp); 717 mutex_enter(&sc->sc_lock); 718 } 719} 720#endif /* MEMORY_DISK_SERVER */ 721