1 /* $NetBSD: fss.c,v 1.95 2016/07/31 12:17:36 hannken Exp $ */ 2 3 /*- 4 * Copyright (c) 2003 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Juergen Hannken-Illjes. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * File system snapshot disk driver. 34 * 35 * Block/character interface to the snapshot of a mounted file system. 36 */ 37 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: fss.c,v 1.95 2016/07/31 12:17:36 hannken Exp $"); 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/namei.h> 44 #include <sys/proc.h> 45 #include <sys/errno.h> 46 #include <sys/malloc.h> 47 #include <sys/buf.h> 48 #include <sys/ioctl.h> 49 #include <sys/disklabel.h> 50 #include <sys/device.h> 51 #include <sys/disk.h> 52 #include <sys/stat.h> 53 #include <sys/mount.h> 54 #include <sys/vnode.h> 55 #include <sys/file.h> 56 #include <sys/uio.h> 57 #include <sys/conf.h> 58 #include <sys/kthread.h> 59 #include <sys/fstrans.h> 60 #include <sys/vfs_syscalls.h> /* For do_sys_unlink(). */ 61 62 #include <miscfs/specfs/specdev.h> 63 64 #include <dev/fssvar.h> 65 66 #include <uvm/uvm.h> 67 68 #include "ioconf.h" 69 70 dev_type_open(fss_open); 71 dev_type_close(fss_close); 72 dev_type_read(fss_read); 73 dev_type_write(fss_write); 74 dev_type_ioctl(fss_ioctl); 75 dev_type_strategy(fss_strategy); 76 dev_type_dump(fss_dump); 77 dev_type_size(fss_size); 78 79 static void fss_unmount_hook(struct mount *); 80 static int fss_copy_on_write(void *, struct buf *, bool); 81 static inline void fss_error(struct fss_softc *, const char *); 82 static int fss_create_files(struct fss_softc *, struct fss_set *, 83 off_t *, struct lwp *); 84 static int fss_create_snapshot(struct fss_softc *, struct fss_set *, 85 struct lwp *); 86 static int fss_delete_snapshot(struct fss_softc *, struct lwp *); 87 static int fss_softc_alloc(struct fss_softc *); 88 static void fss_softc_free(struct fss_softc *); 89 static int fss_read_cluster(struct fss_softc *, u_int32_t); 90 static void fss_bs_thread(void *); 91 static int fss_bs_io(struct fss_softc *, fss_io_type, 92 u_int32_t, off_t, int, void *); 93 static u_int32_t *fss_bs_indir(struct fss_softc *, u_int32_t); 94 95 static kmutex_t fss_device_lock; /* Protect all units. */ 96 static int fss_num_attached = 0; /* Number of attached devices. */ 97 static struct vfs_hooks fss_vfs_hooks = { 98 .vh_unmount = fss_unmount_hook 99 }; 100 101 const struct bdevsw fss_bdevsw = { 102 .d_open = fss_open, 103 .d_close = fss_close, 104 .d_strategy = fss_strategy, 105 .d_ioctl = fss_ioctl, 106 .d_dump = fss_dump, 107 .d_psize = fss_size, 108 .d_discard = nodiscard, 109 .d_flag = D_DISK | D_MPSAFE 110 }; 111 112 const struct cdevsw fss_cdevsw = { 113 .d_open = fss_open, 114 .d_close = fss_close, 115 .d_read = fss_read, 116 .d_write = fss_write, 117 .d_ioctl = fss_ioctl, 118 .d_stop = nostop, 119 .d_tty = notty, 120 .d_poll = nopoll, 121 .d_mmap = nommap, 122 .d_kqfilter = nokqfilter, 123 .d_discard = nodiscard, 124 .d_flag = D_DISK | D_MPSAFE 125 }; 126 127 static int fss_match(device_t, cfdata_t, void *); 128 static void fss_attach(device_t, device_t, void *); 129 static int fss_detach(device_t, int); 130 131 CFATTACH_DECL_NEW(fss, sizeof(struct fss_softc), 132 fss_match, fss_attach, fss_detach, NULL); 133 extern struct cfdriver fss_cd; 134 135 void 136 fssattach(int num) 137 { 138 139 mutex_init(&fss_device_lock, MUTEX_DEFAULT, IPL_NONE); 140 if (config_cfattach_attach(fss_cd.cd_name, &fss_ca)) 141 aprint_error("%s: unable to register\n", fss_cd.cd_name); 142 } 143 144 static int 145 fss_match(device_t self, cfdata_t cfdata, void *aux) 146 { 147 return 1; 148 } 149 150 static void 151 fss_attach(device_t parent, device_t self, void *aux) 152 { 153 struct fss_softc *sc = device_private(self); 154 155 sc->sc_dev = self; 156 sc->sc_bdev = NODEV; 157 mutex_init(&sc->sc_slock, MUTEX_DEFAULT, IPL_NONE); 158 mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE); 159 cv_init(&sc->sc_work_cv, "fssbs"); 160 cv_init(&sc->sc_cache_cv, "cowwait"); 161 bufq_alloc(&sc->sc_bufq, "fcfs", 0); 162 sc->sc_dkdev = malloc(sizeof(*sc->sc_dkdev), M_DEVBUF, M_WAITOK); 163 sc->sc_dkdev->dk_info = NULL; 164 disk_init(sc->sc_dkdev, device_xname(self), NULL); 165 if (!pmf_device_register(self, NULL, NULL)) 166 aprint_error_dev(self, "couldn't establish power handler\n"); 167 168 if (fss_num_attached++ == 0) 169 vfs_hooks_attach(&fss_vfs_hooks); 170 } 171 172 static int 173 fss_detach(device_t self, int flags) 174 { 175 struct fss_softc *sc = device_private(self); 176 177 if (sc->sc_flags & FSS_ACTIVE) 178 return EBUSY; 179 180 if (--fss_num_attached == 0) 181 vfs_hooks_detach(&fss_vfs_hooks); 182 183 pmf_device_deregister(self); 184 mutex_destroy(&sc->sc_slock); 185 mutex_destroy(&sc->sc_lock); 186 cv_destroy(&sc->sc_work_cv); 187 cv_destroy(&sc->sc_cache_cv); 188 bufq_drain(sc->sc_bufq); 189 bufq_free(sc->sc_bufq); 190 disk_destroy(sc->sc_dkdev); 191 free(sc->sc_dkdev, M_DEVBUF); 192 193 return 0; 194 } 195 196 int 197 fss_open(dev_t dev, int flags, int mode, struct lwp *l) 198 { 199 int mflag; 200 cfdata_t cf; 201 struct fss_softc *sc; 202 203 mflag = (mode == S_IFCHR ? FSS_CDEV_OPEN : FSS_BDEV_OPEN); 204 205 mutex_enter(&fss_device_lock); 206 207 sc = device_lookup_private(&fss_cd, minor(dev)); 208 if (sc == NULL) { 209 cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); 210 cf->cf_name = fss_cd.cd_name; 211 cf->cf_atname = fss_cd.cd_name; 212 cf->cf_unit = minor(dev); 213 cf->cf_fstate = FSTATE_STAR; 214 sc = device_private(config_attach_pseudo(cf)); 215 if (sc == NULL) { 216 mutex_exit(&fss_device_lock); 217 return ENOMEM; 218 } 219 } 220 221 mutex_enter(&sc->sc_slock); 222 223 sc->sc_flags |= mflag; 224 225 mutex_exit(&sc->sc_slock); 226 mutex_exit(&fss_device_lock); 227 228 return 0; 229 } 230 231 int 232 fss_close(dev_t dev, int flags, int mode, struct lwp *l) 233 { 234 int mflag, error; 235 cfdata_t cf; 236 struct fss_softc *sc = device_lookup_private(&fss_cd, minor(dev)); 237 238 mflag = (mode == S_IFCHR ? FSS_CDEV_OPEN : FSS_BDEV_OPEN); 239 error = 0; 240 241 mutex_enter(&fss_device_lock); 242 restart: 243 mutex_enter(&sc->sc_slock); 244 if ((sc->sc_flags & (FSS_CDEV_OPEN|FSS_BDEV_OPEN)) != mflag) { 245 sc->sc_flags &= ~mflag; 246 mutex_exit(&sc->sc_slock); 247 mutex_exit(&fss_device_lock); 248 return 0; 249 } 250 if ((sc->sc_flags & FSS_ACTIVE) != 0 && 251 (sc->sc_uflags & FSS_UNCONFIG_ON_CLOSE) != 0) { 252 sc->sc_uflags &= ~FSS_UNCONFIG_ON_CLOSE; 253 mutex_exit(&sc->sc_slock); 254 error = fss_ioctl(dev, FSSIOCCLR, NULL, FWRITE, l); 255 goto restart; 256 } 257 if ((sc->sc_flags & FSS_ACTIVE) != 0) { 258 mutex_exit(&sc->sc_slock); 259 mutex_exit(&fss_device_lock); 260 return error; 261 } 262 263 KASSERT((sc->sc_flags & FSS_ACTIVE) == 0); 264 KASSERT((sc->sc_flags & (FSS_CDEV_OPEN|FSS_BDEV_OPEN)) == mflag); 265 mutex_exit(&sc->sc_slock); 266 cf = device_cfdata(sc->sc_dev); 267 error = config_detach(sc->sc_dev, DETACH_QUIET); 268 if (! error) 269 free(cf, M_DEVBUF); 270 mutex_exit(&fss_device_lock); 271 272 return error; 273 } 274 275 void 276 fss_strategy(struct buf *bp) 277 { 278 const bool write = ((bp->b_flags & B_READ) != B_READ); 279 struct fss_softc *sc = device_lookup_private(&fss_cd, minor(bp->b_dev)); 280 281 mutex_enter(&sc->sc_slock); 282 283 if (write || !FSS_ISVALID(sc)) { 284 285 mutex_exit(&sc->sc_slock); 286 287 bp->b_error = (write ? EROFS : ENXIO); 288 bp->b_resid = bp->b_bcount; 289 biodone(bp); 290 return; 291 } 292 293 bp->b_rawblkno = bp->b_blkno; 294 bufq_put(sc->sc_bufq, bp); 295 cv_signal(&sc->sc_work_cv); 296 297 mutex_exit(&sc->sc_slock); 298 } 299 300 int 301 fss_read(dev_t dev, struct uio *uio, int flags) 302 { 303 return physio(fss_strategy, NULL, dev, B_READ, minphys, uio); 304 } 305 306 int 307 fss_write(dev_t dev, struct uio *uio, int flags) 308 { 309 return physio(fss_strategy, NULL, dev, B_WRITE, minphys, uio); 310 } 311 312 int 313 fss_ioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 314 { 315 int error; 316 struct fss_softc *sc = device_lookup_private(&fss_cd, minor(dev)); 317 struct fss_set _fss; 318 struct fss_set *fss = (struct fss_set *)data; 319 struct fss_set50 *fss50 = (struct fss_set50 *)data; 320 struct fss_get *fsg = (struct fss_get *)data; 321 #ifndef _LP64 322 struct fss_get50 *fsg50 = (struct fss_get50 *)data; 323 #endif 324 325 switch (cmd) { 326 case FSSIOCSET50: 327 fss = &_fss; 328 fss->fss_mount = fss50->fss_mount; 329 fss->fss_bstore = fss50->fss_bstore; 330 fss->fss_csize = fss50->fss_csize; 331 fss->fss_flags = 0; 332 /* Fall through */ 333 case FSSIOCSET: 334 mutex_enter(&sc->sc_lock); 335 if ((flag & FWRITE) == 0) 336 error = EPERM; 337 else if ((sc->sc_flags & FSS_ACTIVE) != 0) 338 error = EBUSY; 339 else 340 error = fss_create_snapshot(sc, fss, l); 341 if (error == 0) 342 sc->sc_uflags = fss->fss_flags; 343 mutex_exit(&sc->sc_lock); 344 break; 345 346 case FSSIOCCLR: 347 mutex_enter(&sc->sc_lock); 348 if ((flag & FWRITE) == 0) 349 error = EPERM; 350 else if ((sc->sc_flags & FSS_ACTIVE) == 0) 351 error = ENXIO; 352 else 353 error = fss_delete_snapshot(sc, l); 354 mutex_exit(&sc->sc_lock); 355 break; 356 357 #ifndef _LP64 358 case FSSIOCGET50: 359 mutex_enter(&sc->sc_lock); 360 switch (sc->sc_flags & (FSS_PERSISTENT | FSS_ACTIVE)) { 361 case FSS_ACTIVE: 362 memcpy(fsg50->fsg_mount, sc->sc_mntname, MNAMELEN); 363 fsg50->fsg_csize = FSS_CLSIZE(sc); 364 timeval_to_timeval50(&sc->sc_time, &fsg50->fsg_time); 365 fsg50->fsg_mount_size = sc->sc_clcount; 366 fsg50->fsg_bs_size = sc->sc_clnext; 367 error = 0; 368 break; 369 case FSS_PERSISTENT | FSS_ACTIVE: 370 memcpy(fsg50->fsg_mount, sc->sc_mntname, MNAMELEN); 371 fsg50->fsg_csize = 0; 372 timeval_to_timeval50(&sc->sc_time, &fsg50->fsg_time); 373 fsg50->fsg_mount_size = 0; 374 fsg50->fsg_bs_size = 0; 375 error = 0; 376 break; 377 default: 378 error = ENXIO; 379 break; 380 } 381 mutex_exit(&sc->sc_lock); 382 break; 383 #endif /* _LP64 */ 384 385 case FSSIOCGET: 386 mutex_enter(&sc->sc_lock); 387 switch (sc->sc_flags & (FSS_PERSISTENT | FSS_ACTIVE)) { 388 case FSS_ACTIVE: 389 memcpy(fsg->fsg_mount, sc->sc_mntname, MNAMELEN); 390 fsg->fsg_csize = FSS_CLSIZE(sc); 391 fsg->fsg_time = sc->sc_time; 392 fsg->fsg_mount_size = sc->sc_clcount; 393 fsg->fsg_bs_size = sc->sc_clnext; 394 error = 0; 395 break; 396 case FSS_PERSISTENT | FSS_ACTIVE: 397 memcpy(fsg->fsg_mount, sc->sc_mntname, MNAMELEN); 398 fsg->fsg_csize = 0; 399 fsg->fsg_time = sc->sc_time; 400 fsg->fsg_mount_size = 0; 401 fsg->fsg_bs_size = 0; 402 error = 0; 403 break; 404 default: 405 error = ENXIO; 406 break; 407 } 408 mutex_exit(&sc->sc_lock); 409 break; 410 411 case FSSIOFSET: 412 mutex_enter(&sc->sc_slock); 413 sc->sc_uflags = *(int *)data; 414 mutex_exit(&sc->sc_slock); 415 error = 0; 416 break; 417 418 case FSSIOFGET: 419 mutex_enter(&sc->sc_slock); 420 *(int *)data = sc->sc_uflags; 421 mutex_exit(&sc->sc_slock); 422 error = 0; 423 break; 424 425 default: 426 error = EINVAL; 427 break; 428 } 429 430 return error; 431 } 432 433 int 434 fss_size(dev_t dev) 435 { 436 return -1; 437 } 438 439 int 440 fss_dump(dev_t dev, daddr_t blkno, void *va, 441 size_t size) 442 { 443 return EROFS; 444 } 445 446 /* 447 * An error occurred reading or writing the snapshot or backing store. 448 * If it is the first error log to console and disestablish cow handler. 449 * The caller holds the mutex. 450 */ 451 static inline void 452 fss_error(struct fss_softc *sc, const char *msg) 453 { 454 455 if ((sc->sc_flags & (FSS_ACTIVE | FSS_ERROR)) != FSS_ACTIVE) 456 return; 457 458 aprint_error_dev(sc->sc_dev, "snapshot invalid: %s\n", msg); 459 if ((sc->sc_flags & FSS_PERSISTENT) == 0) 460 fscow_disestablish(sc->sc_mount, fss_copy_on_write, sc); 461 sc->sc_flags |= FSS_ERROR; 462 } 463 464 /* 465 * Allocate the variable sized parts of the softc and 466 * fork the kernel thread. 467 * 468 * The fields sc_clcount, sc_clshift, sc_cache_size and sc_indir_size 469 * must be initialized. 470 */ 471 static int 472 fss_softc_alloc(struct fss_softc *sc) 473 { 474 int i, error; 475 476 if ((sc->sc_flags & FSS_PERSISTENT) == 0) { 477 sc->sc_copied = 478 kmem_zalloc(howmany(sc->sc_clcount, NBBY), KM_SLEEP); 479 if (sc->sc_copied == NULL) 480 return(ENOMEM); 481 482 sc->sc_cache = kmem_alloc(sc->sc_cache_size * 483 sizeof(struct fss_cache), KM_SLEEP); 484 if (sc->sc_cache == NULL) 485 return(ENOMEM); 486 487 for (i = 0; i < sc->sc_cache_size; i++) { 488 sc->sc_cache[i].fc_type = FSS_CACHE_FREE; 489 sc->sc_cache[i].fc_data = 490 kmem_alloc(FSS_CLSIZE(sc), KM_SLEEP); 491 if (sc->sc_cache[i].fc_data == NULL) 492 return(ENOMEM); 493 cv_init(&sc->sc_cache[i].fc_state_cv, "cowwait1"); 494 } 495 496 sc->sc_indir_valid = 497 kmem_zalloc(howmany(sc->sc_indir_size, NBBY), KM_SLEEP); 498 if (sc->sc_indir_valid == NULL) 499 return(ENOMEM); 500 501 sc->sc_indir_data = kmem_zalloc(FSS_CLSIZE(sc), KM_SLEEP); 502 if (sc->sc_indir_data == NULL) 503 return(ENOMEM); 504 } else { 505 sc->sc_copied = NULL; 506 sc->sc_cache = NULL; 507 sc->sc_indir_valid = NULL; 508 sc->sc_indir_data = NULL; 509 } 510 511 sc->sc_flags |= FSS_BS_THREAD; 512 if ((error = kthread_create(PRI_BIO, KTHREAD_MUSTJOIN, NULL, 513 fss_bs_thread, sc, &sc->sc_bs_lwp, 514 "%s", device_xname(sc->sc_dev))) != 0) { 515 sc->sc_flags &= ~FSS_BS_THREAD; 516 return error; 517 } 518 519 disk_attach(sc->sc_dkdev); 520 521 return 0; 522 } 523 524 /* 525 * Free the variable sized parts of the softc. 526 */ 527 static void 528 fss_softc_free(struct fss_softc *sc) 529 { 530 int i; 531 532 if ((sc->sc_flags & FSS_BS_THREAD) != 0) { 533 mutex_enter(&sc->sc_slock); 534 sc->sc_flags &= ~FSS_BS_THREAD; 535 cv_signal(&sc->sc_work_cv); 536 mutex_exit(&sc->sc_slock); 537 kthread_join(sc->sc_bs_lwp); 538 539 disk_detach(sc->sc_dkdev); 540 } 541 542 if (sc->sc_copied != NULL) 543 kmem_free(sc->sc_copied, howmany(sc->sc_clcount, NBBY)); 544 sc->sc_copied = NULL; 545 546 if (sc->sc_cache != NULL) { 547 for (i = 0; i < sc->sc_cache_size; i++) 548 if (sc->sc_cache[i].fc_data != NULL) { 549 cv_destroy(&sc->sc_cache[i].fc_state_cv); 550 kmem_free(sc->sc_cache[i].fc_data, 551 FSS_CLSIZE(sc)); 552 } 553 kmem_free(sc->sc_cache, 554 sc->sc_cache_size*sizeof(struct fss_cache)); 555 } 556 sc->sc_cache = NULL; 557 558 if (sc->sc_indir_valid != NULL) 559 kmem_free(sc->sc_indir_valid, howmany(sc->sc_indir_size, NBBY)); 560 sc->sc_indir_valid = NULL; 561 562 if (sc->sc_indir_data != NULL) 563 kmem_free(sc->sc_indir_data, FSS_CLSIZE(sc)); 564 sc->sc_indir_data = NULL; 565 } 566 567 /* 568 * Set all active snapshots on this file system into ERROR state. 569 */ 570 static void 571 fss_unmount_hook(struct mount *mp) 572 { 573 int i; 574 struct fss_softc *sc; 575 576 mutex_enter(&fss_device_lock); 577 for (i = 0; i < fss_cd.cd_ndevs; i++) { 578 if ((sc = device_lookup_private(&fss_cd, i)) == NULL) 579 continue; 580 mutex_enter(&sc->sc_slock); 581 if ((sc->sc_flags & FSS_ACTIVE) != 0 && sc->sc_mount == mp) 582 fss_error(sc, "forced by unmount"); 583 mutex_exit(&sc->sc_slock); 584 } 585 mutex_exit(&fss_device_lock); 586 } 587 588 /* 589 * A buffer is written to the snapshotted block device. Copy to 590 * backing store if needed. 591 */ 592 static int 593 fss_copy_on_write(void *v, struct buf *bp, bool data_valid) 594 { 595 int error; 596 u_int32_t cl, ch, c; 597 struct fss_softc *sc = v; 598 599 mutex_enter(&sc->sc_slock); 600 if (!FSS_ISVALID(sc)) { 601 mutex_exit(&sc->sc_slock); 602 return 0; 603 } 604 605 cl = FSS_BTOCL(sc, dbtob(bp->b_blkno)); 606 ch = FSS_BTOCL(sc, dbtob(bp->b_blkno)+bp->b_bcount-1); 607 error = 0; 608 if (curlwp == uvm.pagedaemon_lwp) { 609 for (c = cl; c <= ch; c++) 610 if (isclr(sc->sc_copied, c)) { 611 error = ENOMEM; 612 break; 613 } 614 } 615 mutex_exit(&sc->sc_slock); 616 617 if (error == 0) 618 for (c = cl; c <= ch; c++) { 619 error = fss_read_cluster(sc, c); 620 if (error) 621 break; 622 } 623 624 return error; 625 } 626 627 /* 628 * Lookup and open needed files. 629 * 630 * For file system internal snapshot initializes sc_mntname, sc_mount, 631 * sc_bs_vp and sc_time. 632 * 633 * Otherwise returns dev and size of the underlying block device. 634 * Initializes sc_mntname, sc_mount, sc_bdev, sc_bs_vp and sc_mount 635 */ 636 static int 637 fss_create_files(struct fss_softc *sc, struct fss_set *fss, 638 off_t *bsize, struct lwp *l) 639 { 640 int error, bits, fsbsize; 641 uint64_t numsec; 642 unsigned int secsize; 643 struct timespec ts; 644 /* nd -> nd2 to reduce mistakes while updating only some namei calls */ 645 struct pathbuf *pb2; 646 struct nameidata nd2; 647 struct vnode *vp; 648 649 /* 650 * Get the mounted file system. 651 */ 652 653 error = namei_simple_user(fss->fss_mount, 654 NSM_FOLLOW_NOEMULROOT, &vp); 655 if (error != 0) 656 return error; 657 658 if ((vp->v_vflag & VV_ROOT) != VV_ROOT) { 659 vrele(vp); 660 return EINVAL; 661 } 662 663 sc->sc_mount = vp->v_mount; 664 memcpy(sc->sc_mntname, sc->sc_mount->mnt_stat.f_mntonname, MNAMELEN); 665 666 vrele(vp); 667 668 /* 669 * Check for file system internal snapshot. 670 */ 671 672 error = namei_simple_user(fss->fss_bstore, 673 NSM_FOLLOW_NOEMULROOT, &vp); 674 if (error != 0) 675 return error; 676 677 if (vp->v_type == VREG && vp->v_mount == sc->sc_mount) { 678 sc->sc_flags |= FSS_PERSISTENT; 679 sc->sc_bs_vp = vp; 680 681 fsbsize = sc->sc_bs_vp->v_mount->mnt_stat.f_iosize; 682 bits = sizeof(sc->sc_bs_bshift)*NBBY; 683 for (sc->sc_bs_bshift = 1; sc->sc_bs_bshift < bits; 684 sc->sc_bs_bshift++) 685 if (FSS_FSBSIZE(sc) == fsbsize) 686 break; 687 if (sc->sc_bs_bshift >= bits) 688 return EINVAL; 689 690 sc->sc_bs_bmask = FSS_FSBSIZE(sc)-1; 691 sc->sc_clshift = 0; 692 693 if ((fss->fss_flags & FSS_UNLINK_ON_CREATE) != 0) { 694 error = do_sys_unlink(fss->fss_bstore, UIO_USERSPACE); 695 if (error) 696 return error; 697 } 698 error = vn_lock(vp, LK_EXCLUSIVE); 699 if (error != 0) 700 return error; 701 error = VFS_SNAPSHOT(sc->sc_mount, sc->sc_bs_vp, &ts); 702 TIMESPEC_TO_TIMEVAL(&sc->sc_time, &ts); 703 704 VOP_UNLOCK(sc->sc_bs_vp); 705 706 return error; 707 } 708 vrele(vp); 709 710 /* 711 * Get the block device it is mounted on and its size. 712 */ 713 714 error = spec_node_lookup_by_mount(sc->sc_mount, &vp); 715 if (error) 716 return error; 717 sc->sc_bdev = vp->v_rdev; 718 719 error = getdisksize(vp, &numsec, &secsize); 720 vrele(vp); 721 if (error) 722 return error; 723 724 *bsize = (off_t)numsec*secsize; 725 726 /* 727 * Get the backing store 728 */ 729 730 error = pathbuf_copyin(fss->fss_bstore, &pb2); 731 if (error) { 732 return error; 733 } 734 NDINIT(&nd2, LOOKUP, FOLLOW, pb2); 735 if ((error = vn_open(&nd2, FREAD|FWRITE, 0)) != 0) { 736 pathbuf_destroy(pb2); 737 return error; 738 } 739 VOP_UNLOCK(nd2.ni_vp); 740 741 sc->sc_bs_vp = nd2.ni_vp; 742 743 if (nd2.ni_vp->v_type != VREG && nd2.ni_vp->v_type != VCHR) { 744 pathbuf_destroy(pb2); 745 return EINVAL; 746 } 747 pathbuf_destroy(pb2); 748 749 if ((fss->fss_flags & FSS_UNLINK_ON_CREATE) != 0) { 750 error = do_sys_unlink(fss->fss_bstore, UIO_USERSPACE); 751 if (error) 752 return error; 753 } 754 if (sc->sc_bs_vp->v_type == VREG) { 755 fsbsize = sc->sc_bs_vp->v_mount->mnt_stat.f_iosize; 756 if (fsbsize & (fsbsize-1)) /* No power of two */ 757 return EINVAL; 758 for (sc->sc_bs_bshift = 1; sc->sc_bs_bshift < 32; 759 sc->sc_bs_bshift++) 760 if (FSS_FSBSIZE(sc) == fsbsize) 761 break; 762 if (sc->sc_bs_bshift >= 32) 763 return EINVAL; 764 sc->sc_bs_bmask = FSS_FSBSIZE(sc)-1; 765 } else { 766 sc->sc_bs_bshift = DEV_BSHIFT; 767 sc->sc_bs_bmask = FSS_FSBSIZE(sc)-1; 768 } 769 770 return 0; 771 } 772 773 /* 774 * Create a snapshot. 775 */ 776 static int 777 fss_create_snapshot(struct fss_softc *sc, struct fss_set *fss, struct lwp *l) 778 { 779 int len, error; 780 u_int32_t csize; 781 off_t bsize; 782 783 bsize = 0; /* XXX gcc */ 784 785 /* 786 * Open needed files. 787 */ 788 if ((error = fss_create_files(sc, fss, &bsize, l)) != 0) 789 goto bad; 790 791 if (sc->sc_flags & FSS_PERSISTENT) { 792 fss_softc_alloc(sc); 793 sc->sc_flags |= FSS_ACTIVE; 794 return 0; 795 } 796 797 /* 798 * Set cluster size. Must be a power of two and 799 * a multiple of backing store block size. 800 */ 801 if (fss->fss_csize <= 0) 802 csize = MAXPHYS; 803 else 804 csize = fss->fss_csize; 805 if (bsize/csize > FSS_CLUSTER_MAX) 806 csize = bsize/FSS_CLUSTER_MAX+1; 807 808 for (sc->sc_clshift = sc->sc_bs_bshift; sc->sc_clshift < 32; 809 sc->sc_clshift++) 810 if (FSS_CLSIZE(sc) >= csize) 811 break; 812 if (sc->sc_clshift >= 32) { 813 error = EINVAL; 814 goto bad; 815 } 816 sc->sc_clmask = FSS_CLSIZE(sc)-1; 817 818 /* 819 * Set number of cache slots. 820 */ 821 if (FSS_CLSIZE(sc) <= 8192) 822 sc->sc_cache_size = 32; 823 else if (FSS_CLSIZE(sc) <= 65536) 824 sc->sc_cache_size = 8; 825 else 826 sc->sc_cache_size = 4; 827 828 /* 829 * Set number of clusters and size of last cluster. 830 */ 831 sc->sc_clcount = FSS_BTOCL(sc, bsize-1)+1; 832 sc->sc_clresid = FSS_CLOFF(sc, bsize-1)+1; 833 834 /* 835 * Set size of indirect table. 836 */ 837 len = sc->sc_clcount*sizeof(u_int32_t); 838 sc->sc_indir_size = FSS_BTOCL(sc, len)+1; 839 sc->sc_clnext = sc->sc_indir_size; 840 sc->sc_indir_cur = 0; 841 842 if ((error = fss_softc_alloc(sc)) != 0) 843 goto bad; 844 845 /* 846 * Activate the snapshot. 847 */ 848 849 if ((error = vfs_suspend(sc->sc_mount, 0)) != 0) 850 goto bad; 851 852 microtime(&sc->sc_time); 853 854 error = fscow_establish(sc->sc_mount, fss_copy_on_write, sc); 855 if (error == 0) 856 sc->sc_flags |= FSS_ACTIVE; 857 858 vfs_resume(sc->sc_mount); 859 860 if (error != 0) 861 goto bad; 862 863 aprint_debug_dev(sc->sc_dev, "%s snapshot active\n", sc->sc_mntname); 864 aprint_debug_dev(sc->sc_dev, 865 "%u clusters of %u, %u cache slots, %u indir clusters\n", 866 sc->sc_clcount, FSS_CLSIZE(sc), 867 sc->sc_cache_size, sc->sc_indir_size); 868 869 return 0; 870 871 bad: 872 fss_softc_free(sc); 873 if (sc->sc_bs_vp != NULL) { 874 if (sc->sc_flags & FSS_PERSISTENT) 875 vrele(sc->sc_bs_vp); 876 else 877 vn_close(sc->sc_bs_vp, FREAD|FWRITE, l->l_cred); 878 } 879 sc->sc_bs_vp = NULL; 880 881 return error; 882 } 883 884 /* 885 * Delete a snapshot. 886 */ 887 static int 888 fss_delete_snapshot(struct fss_softc *sc, struct lwp *l) 889 { 890 891 if ((sc->sc_flags & (FSS_PERSISTENT | FSS_ERROR)) == 0) 892 fscow_disestablish(sc->sc_mount, fss_copy_on_write, sc); 893 894 mutex_enter(&sc->sc_slock); 895 sc->sc_flags &= ~(FSS_ACTIVE|FSS_ERROR); 896 sc->sc_mount = NULL; 897 sc->sc_bdev = NODEV; 898 mutex_exit(&sc->sc_slock); 899 900 fss_softc_free(sc); 901 if (sc->sc_flags & FSS_PERSISTENT) 902 vrele(sc->sc_bs_vp); 903 else 904 vn_close(sc->sc_bs_vp, FREAD|FWRITE, l->l_cred); 905 sc->sc_bs_vp = NULL; 906 sc->sc_flags &= ~FSS_PERSISTENT; 907 908 return 0; 909 } 910 911 /* 912 * Read a cluster from the snapshotted block device to the cache. 913 */ 914 static int 915 fss_read_cluster(struct fss_softc *sc, u_int32_t cl) 916 { 917 int error, todo, offset, len; 918 daddr_t dblk; 919 struct buf *bp, *mbp; 920 struct fss_cache *scp, *scl; 921 922 /* 923 * Get a free cache slot. 924 */ 925 scl = sc->sc_cache+sc->sc_cache_size; 926 927 mutex_enter(&sc->sc_slock); 928 929 restart: 930 if (isset(sc->sc_copied, cl) || !FSS_ISVALID(sc)) { 931 mutex_exit(&sc->sc_slock); 932 return 0; 933 } 934 935 for (scp = sc->sc_cache; scp < scl; scp++) 936 if (scp->fc_cluster == cl) { 937 if (scp->fc_type == FSS_CACHE_VALID) { 938 mutex_exit(&sc->sc_slock); 939 return 0; 940 } else if (scp->fc_type == FSS_CACHE_BUSY) { 941 cv_wait(&scp->fc_state_cv, &sc->sc_slock); 942 goto restart; 943 } 944 } 945 946 for (scp = sc->sc_cache; scp < scl; scp++) 947 if (scp->fc_type == FSS_CACHE_FREE) { 948 scp->fc_type = FSS_CACHE_BUSY; 949 scp->fc_cluster = cl; 950 break; 951 } 952 if (scp >= scl) { 953 cv_wait(&sc->sc_cache_cv, &sc->sc_slock); 954 goto restart; 955 } 956 957 mutex_exit(&sc->sc_slock); 958 959 /* 960 * Start the read. 961 */ 962 dblk = btodb(FSS_CLTOB(sc, cl)); 963 if (cl == sc->sc_clcount-1) { 964 todo = sc->sc_clresid; 965 memset((char *)scp->fc_data + todo, 0, FSS_CLSIZE(sc) - todo); 966 } else 967 todo = FSS_CLSIZE(sc); 968 offset = 0; 969 mbp = getiobuf(NULL, true); 970 mbp->b_bufsize = todo; 971 mbp->b_data = scp->fc_data; 972 mbp->b_resid = mbp->b_bcount = todo; 973 mbp->b_flags = B_READ; 974 mbp->b_cflags = BC_BUSY; 975 mbp->b_dev = sc->sc_bdev; 976 while (todo > 0) { 977 len = todo; 978 if (len > MAXPHYS) 979 len = MAXPHYS; 980 if (btodb(FSS_CLTOB(sc, cl)) == dblk && len == todo) 981 bp = mbp; 982 else { 983 bp = getiobuf(NULL, true); 984 nestiobuf_setup(mbp, bp, offset, len); 985 } 986 bp->b_lblkno = 0; 987 bp->b_blkno = dblk; 988 bdev_strategy(bp); 989 dblk += btodb(len); 990 offset += len; 991 todo -= len; 992 } 993 error = biowait(mbp); 994 putiobuf(mbp); 995 996 mutex_enter(&sc->sc_slock); 997 scp->fc_type = (error ? FSS_CACHE_FREE : FSS_CACHE_VALID); 998 cv_broadcast(&scp->fc_state_cv); 999 if (error == 0) { 1000 setbit(sc->sc_copied, scp->fc_cluster); 1001 cv_signal(&sc->sc_work_cv); 1002 } 1003 mutex_exit(&sc->sc_slock); 1004 1005 return error; 1006 } 1007 1008 /* 1009 * Read/write clusters from/to backing store. 1010 * For persistent snapshots must be called with cl == 0. off is the 1011 * offset into the snapshot. 1012 */ 1013 static int 1014 fss_bs_io(struct fss_softc *sc, fss_io_type rw, 1015 u_int32_t cl, off_t off, int len, void *data) 1016 { 1017 int error; 1018 1019 off += FSS_CLTOB(sc, cl); 1020 1021 vn_lock(sc->sc_bs_vp, LK_EXCLUSIVE|LK_RETRY); 1022 1023 error = vn_rdwr((rw == FSS_READ ? UIO_READ : UIO_WRITE), sc->sc_bs_vp, 1024 data, len, off, UIO_SYSSPACE, 1025 IO_ADV_ENCODE(POSIX_FADV_NOREUSE) | IO_NODELOCKED, 1026 sc->sc_bs_lwp->l_cred, NULL, NULL); 1027 if (error == 0) { 1028 mutex_enter(sc->sc_bs_vp->v_interlock); 1029 error = VOP_PUTPAGES(sc->sc_bs_vp, trunc_page(off), 1030 round_page(off+len), PGO_CLEANIT | PGO_FREE | PGO_SYNCIO); 1031 } 1032 1033 VOP_UNLOCK(sc->sc_bs_vp); 1034 1035 return error; 1036 } 1037 1038 /* 1039 * Get a pointer to the indirect slot for this cluster. 1040 */ 1041 static u_int32_t * 1042 fss_bs_indir(struct fss_softc *sc, u_int32_t cl) 1043 { 1044 u_int32_t icl; 1045 int ioff; 1046 1047 icl = cl/(FSS_CLSIZE(sc)/sizeof(u_int32_t)); 1048 ioff = cl%(FSS_CLSIZE(sc)/sizeof(u_int32_t)); 1049 1050 if (sc->sc_indir_cur == icl) 1051 return &sc->sc_indir_data[ioff]; 1052 1053 if (sc->sc_indir_dirty) { 1054 if (fss_bs_io(sc, FSS_WRITE, sc->sc_indir_cur, 0, 1055 FSS_CLSIZE(sc), (void *)sc->sc_indir_data) != 0) 1056 return NULL; 1057 setbit(sc->sc_indir_valid, sc->sc_indir_cur); 1058 } 1059 1060 sc->sc_indir_dirty = 0; 1061 sc->sc_indir_cur = icl; 1062 1063 if (isset(sc->sc_indir_valid, sc->sc_indir_cur)) { 1064 if (fss_bs_io(sc, FSS_READ, sc->sc_indir_cur, 0, 1065 FSS_CLSIZE(sc), (void *)sc->sc_indir_data) != 0) 1066 return NULL; 1067 } else 1068 memset(sc->sc_indir_data, 0, FSS_CLSIZE(sc)); 1069 1070 return &sc->sc_indir_data[ioff]; 1071 } 1072 1073 /* 1074 * The kernel thread (one for every active snapshot). 1075 * 1076 * After wakeup it cleans the cache and runs the I/O requests. 1077 */ 1078 static void 1079 fss_bs_thread(void *arg) 1080 { 1081 bool thread_idle, is_valid; 1082 int error, i, todo, len, crotor, is_read; 1083 long off; 1084 char *addr; 1085 u_int32_t c, cl, ch, *indirp; 1086 struct buf *bp, *nbp; 1087 struct fss_softc *sc; 1088 struct fss_cache *scp, *scl; 1089 1090 sc = arg; 1091 scl = sc->sc_cache+sc->sc_cache_size; 1092 crotor = 0; 1093 thread_idle = false; 1094 1095 mutex_enter(&sc->sc_slock); 1096 1097 for (;;) { 1098 if (thread_idle) 1099 cv_wait(&sc->sc_work_cv, &sc->sc_slock); 1100 thread_idle = true; 1101 if ((sc->sc_flags & FSS_BS_THREAD) == 0) { 1102 mutex_exit(&sc->sc_slock); 1103 kthread_exit(0); 1104 } 1105 1106 /* 1107 * Process I/O requests (persistent) 1108 */ 1109 1110 if (sc->sc_flags & FSS_PERSISTENT) { 1111 if ((bp = bufq_get(sc->sc_bufq)) == NULL) 1112 continue; 1113 is_valid = FSS_ISVALID(sc); 1114 is_read = (bp->b_flags & B_READ); 1115 thread_idle = false; 1116 mutex_exit(&sc->sc_slock); 1117 1118 if (is_valid) { 1119 disk_busy(sc->sc_dkdev); 1120 error = fss_bs_io(sc, FSS_READ, 0, 1121 dbtob(bp->b_blkno), bp->b_bcount, 1122 bp->b_data); 1123 disk_unbusy(sc->sc_dkdev, 1124 (error ? 0 : bp->b_bcount), is_read); 1125 } else 1126 error = ENXIO; 1127 1128 bp->b_error = error; 1129 bp->b_resid = (error ? bp->b_bcount : 0); 1130 biodone(bp); 1131 1132 mutex_enter(&sc->sc_slock); 1133 continue; 1134 } 1135 1136 /* 1137 * Clean the cache 1138 */ 1139 for (i = 0; i < sc->sc_cache_size; i++) { 1140 crotor = (crotor + 1) % sc->sc_cache_size; 1141 scp = sc->sc_cache + crotor; 1142 if (scp->fc_type != FSS_CACHE_VALID) 1143 continue; 1144 mutex_exit(&sc->sc_slock); 1145 1146 thread_idle = false; 1147 indirp = fss_bs_indir(sc, scp->fc_cluster); 1148 if (indirp != NULL) { 1149 error = fss_bs_io(sc, FSS_WRITE, sc->sc_clnext, 1150 0, FSS_CLSIZE(sc), scp->fc_data); 1151 } else 1152 error = EIO; 1153 1154 mutex_enter(&sc->sc_slock); 1155 if (error == 0) { 1156 *indirp = sc->sc_clnext++; 1157 sc->sc_indir_dirty = 1; 1158 } else 1159 fss_error(sc, "write error on backing store"); 1160 1161 scp->fc_type = FSS_CACHE_FREE; 1162 cv_broadcast(&sc->sc_cache_cv); 1163 break; 1164 } 1165 1166 /* 1167 * Process I/O requests 1168 */ 1169 if ((bp = bufq_get(sc->sc_bufq)) == NULL) 1170 continue; 1171 is_valid = FSS_ISVALID(sc); 1172 is_read = (bp->b_flags & B_READ); 1173 thread_idle = false; 1174 1175 if (!is_valid) { 1176 mutex_exit(&sc->sc_slock); 1177 1178 bp->b_error = ENXIO; 1179 bp->b_resid = bp->b_bcount; 1180 biodone(bp); 1181 1182 mutex_enter(&sc->sc_slock); 1183 continue; 1184 } 1185 1186 disk_busy(sc->sc_dkdev); 1187 1188 /* 1189 * First read from the snapshotted block device unless 1190 * this request is completely covered by backing store. 1191 */ 1192 1193 cl = FSS_BTOCL(sc, dbtob(bp->b_blkno)); 1194 off = FSS_CLOFF(sc, dbtob(bp->b_blkno)); 1195 ch = FSS_BTOCL(sc, dbtob(bp->b_blkno)+bp->b_bcount-1); 1196 error = 0; 1197 bp->b_resid = 0; 1198 bp->b_error = 0; 1199 for (c = cl; c <= ch; c++) { 1200 if (isset(sc->sc_copied, c)) 1201 continue; 1202 mutex_exit(&sc->sc_slock); 1203 1204 /* Not on backing store, read from device. */ 1205 nbp = getiobuf(NULL, true); 1206 nbp->b_flags = B_READ; 1207 nbp->b_resid = nbp->b_bcount = bp->b_bcount; 1208 nbp->b_bufsize = bp->b_bcount; 1209 nbp->b_data = bp->b_data; 1210 nbp->b_blkno = bp->b_blkno; 1211 nbp->b_lblkno = 0; 1212 nbp->b_dev = sc->sc_bdev; 1213 SET(nbp->b_cflags, BC_BUSY); /* mark buffer busy */ 1214 1215 bdev_strategy(nbp); 1216 1217 error = biowait(nbp); 1218 if (error != 0) { 1219 bp->b_resid = bp->b_bcount; 1220 bp->b_error = nbp->b_error; 1221 disk_unbusy(sc->sc_dkdev, 0, is_read); 1222 biodone(bp); 1223 } 1224 putiobuf(nbp); 1225 1226 mutex_enter(&sc->sc_slock); 1227 break; 1228 } 1229 if (error) 1230 continue; 1231 1232 /* 1233 * Replace those parts that have been saved to backing store. 1234 */ 1235 1236 addr = bp->b_data; 1237 todo = bp->b_bcount; 1238 for (c = cl; c <= ch; c++, off = 0, todo -= len, addr += len) { 1239 len = FSS_CLSIZE(sc)-off; 1240 if (len > todo) 1241 len = todo; 1242 if (isclr(sc->sc_copied, c)) 1243 continue; 1244 mutex_exit(&sc->sc_slock); 1245 1246 indirp = fss_bs_indir(sc, c); 1247 if (indirp == NULL || *indirp == 0) { 1248 /* 1249 * Not on backing store. Either in cache 1250 * or hole in the snapshotted block device. 1251 */ 1252 1253 mutex_enter(&sc->sc_slock); 1254 for (scp = sc->sc_cache; scp < scl; scp++) 1255 if (scp->fc_type == FSS_CACHE_VALID && 1256 scp->fc_cluster == c) 1257 break; 1258 if (scp < scl) 1259 memcpy(addr, (char *)scp->fc_data+off, 1260 len); 1261 else 1262 memset(addr, 0, len); 1263 continue; 1264 } 1265 1266 /* 1267 * Read from backing store. 1268 */ 1269 error = 1270 fss_bs_io(sc, FSS_READ, *indirp, off, len, addr); 1271 1272 mutex_enter(&sc->sc_slock); 1273 if (error) { 1274 bp->b_resid = bp->b_bcount; 1275 bp->b_error = error; 1276 break; 1277 } 1278 } 1279 mutex_exit(&sc->sc_slock); 1280 1281 disk_unbusy(sc->sc_dkdev, (error ? 0 : bp->b_bcount), is_read); 1282 biodone(bp); 1283 1284 mutex_enter(&sc->sc_slock); 1285 } 1286 } 1287 1288 #ifdef _MODULE 1289 1290 #include <sys/module.h> 1291 1292 MODULE(MODULE_CLASS_DRIVER, fss, NULL); 1293 CFDRIVER_DECL(fss, DV_DISK, NULL); 1294 1295 devmajor_t fss_bmajor = -1, fss_cmajor = -1; 1296 1297 static int 1298 fss_modcmd(modcmd_t cmd, void *arg) 1299 { 1300 int error = 0; 1301 1302 switch (cmd) { 1303 case MODULE_CMD_INIT: 1304 mutex_init(&fss_device_lock, MUTEX_DEFAULT, IPL_NONE); 1305 error = config_cfdriver_attach(&fss_cd); 1306 if (error) { 1307 mutex_destroy(&fss_device_lock); 1308 break; 1309 } 1310 error = config_cfattach_attach(fss_cd.cd_name, &fss_ca); 1311 if (error) { 1312 config_cfdriver_detach(&fss_cd); 1313 mutex_destroy(&fss_device_lock); 1314 break; 1315 } 1316 error = devsw_attach(fss_cd.cd_name, 1317 &fss_bdevsw, &fss_bmajor, &fss_cdevsw, &fss_cmajor); 1318 1319 if (error) { 1320 config_cfattach_detach(fss_cd.cd_name, &fss_ca); 1321 config_cfdriver_detach(&fss_cd); 1322 mutex_destroy(&fss_device_lock); 1323 break; 1324 } 1325 break; 1326 1327 case MODULE_CMD_FINI: 1328 devsw_detach(&fss_bdevsw, &fss_cdevsw); 1329 error = config_cfattach_detach(fss_cd.cd_name, &fss_ca); 1330 if (error) { 1331 devsw_attach(fss_cd.cd_name, &fss_bdevsw, &fss_bmajor, 1332 &fss_cdevsw, &fss_cmajor); 1333 break; 1334 } 1335 config_cfdriver_detach(&fss_cd); 1336 mutex_destroy(&fss_device_lock); 1337 break; 1338 1339 default: 1340 error = ENOTTY; 1341 break; 1342 } 1343 1344 return error; 1345 } 1346 1347 #endif /* _MODULE */ 1348