md.c revision 1.78.6.6
1 /* $NetBSD: md.c,v 1.78.6.6 2017/05/17 01:44:17 pgoyette 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 1.78.6.6 2017/05/17 01:44:17 pgoyette 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/malloc.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 84 struct 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 97 static void md_attach(device_t, device_t, void *); 98 static int md_detach(device_t, int); 99 100 static dev_type_open(mdopen); 101 static dev_type_close(mdclose); 102 static dev_type_read(mdread); 103 static dev_type_write(mdwrite); 104 static dev_type_ioctl(mdioctl); 105 static dev_type_strategy(mdstrategy); 106 static dev_type_size(mdsize); 107 108 const struct bdevsw md_bdevsw = { 109 DEVSW_MODULE_INIT 110 .d_open = mdopen, 111 .d_close = mdclose, 112 .d_strategy = mdstrategy, 113 .d_ioctl = mdioctl, 114 .d_dump = nodump, 115 .d_psize = mdsize, 116 .d_discard = nodiscard, 117 .d_flag = D_DISK | D_MPSAFE 118 }; 119 120 const struct cdevsw md_cdevsw = { 121 DEVSW_MODULE_INIT 122 .d_open = mdopen, 123 .d_close = mdclose, 124 .d_read = mdread, 125 .d_write = mdwrite, 126 .d_ioctl = mdioctl, 127 .d_stop = nostop, 128 .d_tty = notty, 129 .d_poll = nopoll, 130 .d_mmap = nommap, 131 .d_kqfilter = nokqfilter, 132 .d_discard = nodiscard, 133 .d_flag = D_DISK 134 }; 135 136 static struct dkdriver mddkdriver = { 137 .d_strategy = mdstrategy 138 }; 139 140 extern struct cfdriver md_cd; 141 CFATTACH_DECL3_NEW(md, sizeof(struct md_softc), 142 0, md_attach, md_detach, NULL, NULL, NULL, DVF_DETACH_SHUTDOWN); 143 144 static kmutex_t md_device_lock; /* Protect unit creation / deletion. */ 145 extern size_t md_root_size; 146 147 static void md_set_disklabel(struct md_softc *); 148 149 /* 150 * This is called if we are configured as a pseudo-device 151 */ 152 void 153 mdattach(int n) 154 { 155 156 mutex_init(&md_device_lock, MUTEX_DEFAULT, IPL_NONE); 157 if (config_cfattach_attach(md_cd.cd_name, &md_ca)) { 158 aprint_error("%s: cfattach_attach failed\n", md_cd.cd_name); 159 return; 160 } 161 } 162 163 static void 164 md_attach(device_t parent, device_t self, void *aux) 165 { 166 struct md_softc *sc = device_private(self); 167 168 sc->sc_dev = self; 169 sc->sc_type = MD_UNCONFIGURED; 170 mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE); 171 cv_init(&sc->sc_cv, "mdidle"); 172 bufq_alloc(&sc->sc_buflist, "fcfs", 0); 173 174 /* XXX - Could accept aux info here to set the config. */ 175 #ifdef MEMORY_DISK_HOOKS 176 /* 177 * This external function might setup a pre-loaded disk. 178 * All it would need to do is setup the md_conf struct. 179 * See sys/dev/md_root.c for an example. 180 */ 181 md_attach_hook(device_unit(self), &sc->sc_md); 182 #endif 183 184 /* 185 * Initialize and attach the disk structure. 186 */ 187 disk_init(&sc->sc_dkdev, device_xname(self), &mddkdriver); 188 disk_attach(&sc->sc_dkdev); 189 190 if (sc->sc_type != MD_UNCONFIGURED) 191 md_set_disklabel(sc); 192 193 if (!pmf_device_register(self, NULL, NULL)) 194 aprint_error_dev(self, "couldn't establish power handler\n"); 195 } 196 197 /* 198 * Caller must hold a reference to the device's localcount. 199 */ 200 static int 201 md_detach(device_t self, int flags) 202 { 203 struct md_softc *sc = device_private(self); 204 int rc; 205 206 rc = 0; 207 mutex_enter(&sc->sc_dkdev.dk_openlock); 208 if (sc->sc_dkdev.dk_openmask == 0 && sc->sc_type == MD_UNCONFIGURED) 209 ; /* nothing to do */ 210 else if ((flags & DETACH_FORCE) == 0) 211 rc = EBUSY; 212 mutex_exit(&sc->sc_dkdev.dk_openlock); 213 214 if (rc != 0) 215 return rc; 216 217 pmf_device_deregister(self); 218 disk_detach(&sc->sc_dkdev); 219 disk_destroy(&sc->sc_dkdev); 220 bufq_free(sc->sc_buflist); 221 mutex_destroy(&sc->sc_lock); 222 cv_destroy(&sc->sc_cv); 223 return 0; 224 } 225 226 /* 227 * operational routines: 228 * open, close, read, write, strategy, 229 * ioctl, dump, size 230 */ 231 232 #if MEMORY_DISK_SERVER 233 static int md_server_loop(struct md_softc *sc); 234 static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 235 struct lwp *l); 236 #endif /* MEMORY_DISK_SERVER */ 237 static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 238 struct lwp *l); 239 240 static int 241 mdsize(dev_t dev) 242 { 243 struct md_softc *sc; 244 int res; 245 246 sc = device_lookup_private_acquire(&md_cd, MD_UNIT(dev)); 247 if (sc == NULL) 248 return 0; 249 250 mutex_enter(&sc->sc_lock); 251 if (sc->sc_type == MD_UNCONFIGURED) 252 res = 0; 253 else 254 res = sc->sc_size >> DEV_BSHIFT; 255 mutex_exit(&sc->sc_lock); 256 257 device_release(sc->sc_dev); 258 return res; 259 } 260 261 static int 262 mdopen(dev_t dev, int flag, int fmt, struct lwp *l) 263 { 264 device_t self; 265 int unit; 266 int part = DISKPART(dev); 267 int pmask = 1 << part; 268 cfdata_t cf; 269 struct md_softc *sc; 270 struct disk *dk; 271 #ifdef MEMORY_DISK_HOOKS 272 bool configured; 273 #endif 274 275 mutex_enter(&md_device_lock); 276 unit = MD_UNIT(dev); 277 sc = device_lookup_private_acquire(&md_cd, unit); 278 if (sc == NULL) { 279 if (part != RAW_PART) { 280 mutex_exit(&md_device_lock); 281 return ENXIO; 282 } 283 cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); 284 cf->cf_name = md_cd.cd_name; 285 cf->cf_atname = md_cd.cd_name; 286 cf->cf_unit = unit; 287 cf->cf_fstate = FSTATE_STAR; 288 self = config_attach_pseudo(cf); 289 sc = device_private(self); 290 if (sc == NULL) { 291 mutex_exit(&md_device_lock); 292 device_release(self); 293 return ENOMEM; 294 } 295 } 296 297 dk = &sc->sc_dkdev; 298 299 /* 300 * The raw partition is used for ioctl to configure. 301 */ 302 if (part == RAW_PART) 303 goto ok; 304 305 #ifdef MEMORY_DISK_HOOKS 306 /* Call the open hook to allow loading the device. */ 307 configured = (sc->sc_type != MD_UNCONFIGURED); 308 md_open_hook(unit, &sc->sc_md); 309 /* initialize disklabel if the device is configured in open hook */ 310 if (!configured && sc->sc_type != MD_UNCONFIGURED) 311 md_set_disklabel(sc); 312 #endif 313 314 /* 315 * This is a normal, "slave" device, so 316 * enforce initialized. 317 */ 318 if (sc->sc_type == MD_UNCONFIGURED) { 319 mutex_exit(&md_device_lock); 320 device_release(sc->sc_dev); 321 return ENXIO; 322 } 323 324 ok: 325 /* XXX duplicates code in dk_open(). Call dk_open(), instead? */ 326 mutex_enter(&dk->dk_openlock); 327 /* Mark our unit as open. */ 328 switch (fmt) { 329 case S_IFCHR: 330 dk->dk_copenmask |= pmask; 331 break; 332 case S_IFBLK: 333 dk->dk_bopenmask |= pmask; 334 break; 335 } 336 337 dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask; 338 339 mutex_exit(&dk->dk_openlock); 340 mutex_exit(&md_device_lock); 341 device_release(sc->sc_dev); 342 return 0; 343 } 344 345 static int 346 mdclose(dev_t dev, int flag, int fmt, struct lwp *l) 347 { 348 int part = DISKPART(dev); 349 int pmask = 1 << part; 350 int error; 351 cfdata_t cf; 352 struct md_softc *sc; 353 struct disk *dk; 354 355 sc = device_lookup_private_acquire(&md_cd, MD_UNIT(dev)); 356 if (sc == NULL) 357 return ENXIO; 358 359 dk = &sc->sc_dkdev; 360 361 mutex_enter(&dk->dk_openlock); 362 363 switch (fmt) { 364 case S_IFCHR: 365 dk->dk_copenmask &= ~pmask; 366 break; 367 case S_IFBLK: 368 dk->dk_bopenmask &= ~pmask; 369 break; 370 } 371 dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask; 372 if (dk->dk_openmask != 0) { 373 mutex_exit(&dk->dk_openlock); 374 device_release(sc->sc_dev); 375 return 0; 376 } 377 378 mutex_exit(&dk->dk_openlock); 379 380 mutex_enter(&md_device_lock); 381 cf = device_cfdata(sc->sc_dev); 382 error = config_detach_release(sc->sc_dev, DETACH_QUIET); 383 if (! error) 384 free(cf, M_DEVBUF); 385 mutex_exit(&md_device_lock); 386 387 return error; 388 } 389 390 static int 391 mdread(dev_t dev, struct uio *uio, int flags) 392 { 393 struct md_softc *sc; 394 int error; 395 396 sc = device_lookup_private_acquire(&md_cd, MD_UNIT(dev)); 397 398 if (sc == NULL || sc->sc_type == MD_UNCONFIGURED) { 399 if (sc != NULL) 400 device_release(sc->sc_dev); 401 return ENXIO; 402 } 403 404 error = (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 405 device_release(sc->sc_dev); 406 return error; 407 } 408 409 static int 410 mdwrite(dev_t dev, struct uio *uio, int flags) 411 { 412 struct md_softc *sc; 413 int error; 414 415 sc = device_lookup_private_acquire(&md_cd, MD_UNIT(dev)); 416 417 if (sc == NULL || sc->sc_type == MD_UNCONFIGURED) { 418 if (sc != NULL) { 419 device_release(sc->sc_dev); 420 } 421 return ENXIO; 422 } 423 424 error = physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio); 425 426 device_release(sc->sc_dev); 427 return error; 428 } 429 430 /* 431 * Handle I/O requests, either directly, or 432 * by passing them to the server process. 433 */ 434 static void 435 mdstrategy(struct buf *bp) 436 { 437 struct md_softc *sc; 438 void * addr; 439 size_t off, xfer; 440 bool is_read; 441 442 sc = device_lookup_private_acquire(&md_cd, MD_UNIT(bp->b_dev)); 443 if (sc == NULL || sc->sc_type == MD_UNCONFIGURED) { 444 bp->b_error = ENXIO; 445 goto done; 446 } 447 448 mutex_enter(&sc->sc_lock); 449 450 switch (sc->sc_type) { 451 #if MEMORY_DISK_SERVER 452 case MD_UMEM_SERVER: 453 /* Just add this job to the server's queue. */ 454 bufq_put(sc->sc_buflist, bp); 455 cv_signal(&sc->sc_cv); 456 mutex_exit(&sc->sc_lock); 457 /* see md_server_loop() */ 458 /* no biodone in this case */ 459 device_release(sc->sc_dev); 460 return; 461 #endif /* MEMORY_DISK_SERVER */ 462 463 case MD_KMEM_FIXED: 464 case MD_KMEM_ALLOCATED: 465 /* These are in kernel space. Access directly. */ 466 is_read = ((bp->b_flags & B_READ) == B_READ); 467 bp->b_resid = bp->b_bcount; 468 off = (bp->b_blkno << DEV_BSHIFT); 469 if (off >= sc->sc_size) { 470 if (is_read) 471 break; /* EOF */ 472 goto set_eio; 473 } 474 xfer = bp->b_resid; 475 if (xfer > (sc->sc_size - off)) 476 xfer = (sc->sc_size - off); 477 addr = (char *)sc->sc_addr + off; 478 disk_busy(&sc->sc_dkdev); 479 if (is_read) 480 memcpy(bp->b_data, addr, xfer); 481 else 482 memcpy(addr, bp->b_data, xfer); 483 disk_unbusy(&sc->sc_dkdev, xfer, is_read); 484 bp->b_resid -= xfer; 485 break; 486 487 default: 488 bp->b_resid = bp->b_bcount; 489 set_eio: 490 bp->b_error = EIO; 491 break; 492 } 493 mutex_exit(&sc->sc_lock); 494 495 done: 496 biodone(bp); 497 if (sc != NULL) 498 device_release(sc->sc_dev); 499 } 500 501 static int 502 mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 503 { 504 struct md_softc *sc; 505 struct md_conf *umd; 506 int error; 507 508 sc = device_lookup_private_acquire(&md_cd, MD_UNIT(dev)); 509 if (sc == NULL) 510 return ENXIO; 511 512 mutex_enter(&sc->sc_lock); 513 if (sc->sc_type != MD_UNCONFIGURED) { 514 error = disk_ioctl(&sc->sc_dkdev, dev, cmd, data, flag, l); 515 if (error != EPASSTHROUGH) { 516 mutex_exit(&sc->sc_lock); 517 device_release(sc->sc_dev); 518 return 0; 519 } 520 } 521 522 /* If this is not the raw partition, punt! */ 523 if (DISKPART(dev) != RAW_PART) { 524 mutex_exit(&sc->sc_lock); 525 device_release(sc->sc_dev); 526 return ENOTTY; 527 } 528 529 umd = (struct md_conf *)data; 530 error = EINVAL; 531 switch (cmd) { 532 case MD_GETCONF: 533 *umd = sc->sc_md; 534 error = 0; 535 break; 536 537 case MD_SETCONF: 538 /* Can only set it once. */ 539 if (sc->sc_type != MD_UNCONFIGURED) 540 break; 541 switch (umd->md_type) { 542 case MD_KMEM_ALLOCATED: 543 error = md_ioctl_kalloc(sc, umd, l); 544 break; 545 #if MEMORY_DISK_SERVER 546 case MD_UMEM_SERVER: 547 error = md_ioctl_server(sc, umd, l); 548 break; 549 #endif /* MEMORY_DISK_SERVER */ 550 default: 551 break; 552 } 553 break; 554 } 555 mutex_exit(&sc->sc_lock); 556 device_release(sc->sc_dev); 557 return error; 558 } 559 560 static void 561 md_set_disklabel(struct md_softc *sc) 562 { 563 struct disk_geom *dg = &sc->sc_dkdev.dk_geom; 564 struct disklabel *lp = sc->sc_dkdev.dk_label; 565 struct partition *pp; 566 567 memset(lp, 0, sizeof(*lp)); 568 569 lp->d_secsize = DEV_BSIZE; 570 lp->d_secperunit = sc->sc_size / DEV_BSIZE; 571 if (lp->d_secperunit >= (32*64)) { 572 lp->d_nsectors = 32; 573 lp->d_ntracks = 64; 574 lp->d_ncylinders = lp->d_secperunit / (32*64); 575 } else { 576 lp->d_nsectors = 1; 577 lp->d_ntracks = 1; 578 lp->d_ncylinders = lp->d_secperunit; 579 } 580 lp->d_secpercyl = lp->d_ntracks*lp->d_nsectors; 581 582 strncpy(lp->d_typename, md_cd.cd_name, sizeof(lp->d_typename)); 583 lp->d_type = DKTYPE_MD; 584 strncpy(lp->d_packname, "fictitious", sizeof(lp->d_packname)); 585 lp->d_rpm = 3600; 586 lp->d_interleave = 1; 587 lp->d_flags = 0; 588 589 pp = &lp->d_partitions[0]; 590 pp->p_offset = 0; 591 pp->p_size = lp->d_secperunit; 592 pp->p_fstype = FS_BSDFFS; 593 594 pp = &lp->d_partitions[RAW_PART]; 595 pp->p_offset = 0; 596 pp->p_size = lp->d_secperunit; 597 pp->p_fstype = FS_UNUSED; 598 599 lp->d_npartitions = RAW_PART+1; 600 lp->d_magic = DISKMAGIC; 601 lp->d_magic2 = DISKMAGIC; 602 lp->d_checksum = dkcksum(lp); 603 604 memset(dg, 0, sizeof(*dg)); 605 606 dg->dg_secsize = lp->d_secsize; 607 dg->dg_secperunit = lp->d_secperunit; 608 dg->dg_nsectors = lp->d_nsectors; 609 dg->dg_ntracks = lp->d_ntracks = 64;; 610 dg->dg_ncylinders = lp->d_ncylinders; 611 612 disk_set_info(sc->sc_dev, &sc->sc_dkdev, NULL); 613 } 614 615 /* 616 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 617 * Just allocate some kernel memory and return. 618 */ 619 static int 620 md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 621 struct lwp *l) 622 { 623 vaddr_t addr; 624 vsize_t size; 625 626 mutex_exit(&sc->sc_lock); 627 628 /* Sanity check the size. */ 629 size = umd->md_size; 630 addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); 631 632 mutex_enter(&sc->sc_lock); 633 634 if (!addr) 635 return ENOMEM; 636 637 /* If another thread beat us to configure this unit: fail. */ 638 if (sc->sc_type != MD_UNCONFIGURED) { 639 uvm_km_free(kernel_map, addr, size, UVM_KMF_WIRED); 640 return EINVAL; 641 } 642 643 /* This unit is now configured. */ 644 sc->sc_addr = (void *)addr; /* kernel space */ 645 sc->sc_size = (size_t)size; 646 sc->sc_type = MD_KMEM_ALLOCATED; 647 md_set_disklabel(sc); 648 return 0; 649 } 650 651 #if MEMORY_DISK_SERVER 652 653 /* 654 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 655 * Set config, then become the I/O server for this unit. 656 */ 657 static int 658 md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 659 struct lwp *l) 660 { 661 vaddr_t end; 662 int error; 663 664 KASSERT(mutex_owned(&sc->sc_lock)); 665 666 /* Sanity check addr, size. */ 667 end = (vaddr_t) ((char *)umd->md_addr + umd->md_size); 668 669 if ((end >= VM_MAXUSER_ADDRESS) || 670 (end < ((vaddr_t) umd->md_addr)) ) 671 return EINVAL; 672 673 /* This unit is now configured. */ 674 sc->sc_addr = umd->md_addr; /* user space */ 675 sc->sc_size = umd->md_size; 676 sc->sc_type = MD_UMEM_SERVER; 677 md_set_disklabel(sc); 678 679 /* Become the server daemon */ 680 error = md_server_loop(sc); 681 682 /* This server is now going away! */ 683 sc->sc_type = MD_UNCONFIGURED; 684 sc->sc_addr = 0; 685 sc->sc_size = 0; 686 687 return (error); 688 } 689 690 static int 691 md_server_loop(struct md_softc *sc) 692 { 693 struct buf *bp; 694 void *addr; /* user space address */ 695 size_t off; /* offset into "device" */ 696 size_t xfer; /* amount to transfer */ 697 int error; 698 bool is_read; 699 700 KASSERT(mutex_owned(&sc->sc_lock)); 701 702 for (;;) { 703 /* Wait for some work to arrive. */ 704 while ((bp = bufq_get(sc->sc_buflist)) == NULL) { 705 error = cv_wait_sig(&sc->sc_cv, &sc->sc_lock); 706 if (error) 707 return error; 708 } 709 710 /* Do the transfer to/from user space. */ 711 mutex_exit(&sc->sc_lock); 712 error = 0; 713 is_read = ((bp->b_flags & B_READ) == B_READ); 714 bp->b_resid = bp->b_bcount; 715 off = (bp->b_blkno << DEV_BSHIFT); 716 if (off >= sc->sc_size) { 717 if (is_read) 718 goto done; /* EOF (not an error) */ 719 error = EIO; 720 goto done; 721 } 722 xfer = bp->b_resid; 723 if (xfer > (sc->sc_size - off)) 724 xfer = (sc->sc_size - off); 725 addr = (char *)sc->sc_addr + off; 726 disk_busy(&sc->sc_dkdev); 727 if (is_read) 728 error = copyin(addr, bp->b_data, xfer); 729 else 730 error = copyout(bp->b_data, addr, xfer); 731 disk_unbusy(&sc->sc_dkdev, (error ? 0 : xfer), is_read); 732 if (!error) 733 bp->b_resid -= xfer; 734 735 done: 736 if (error) { 737 bp->b_error = error; 738 } 739 biodone(bp); 740 mutex_enter(&sc->sc_lock); 741 } 742 } 743 #endif /* MEMORY_DISK_SERVER */ 744
Indexes created Tue Sep 30 20:09:53 GMT 2025