fss.c revision 1.104
1 /* $NetBSD: fss.c,v 1.104 2018/01/23 22:42:29 pgoyette 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 1.104 2018/01/23 22:42:29 pgoyette 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 *, size_t *); 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); 133 134 void 135 fssattach(int num) 136 { 137 138 mutex_init(&fss_device_lock, MUTEX_DEFAULT, IPL_NONE); 139 if (config_cfattach_attach(fss_cd.cd_name, &fss_ca)) 140 aprint_error("%s: unable to register\n", fss_cd.cd_name); 141 } 142 143 static int 144 fss_match(device_t self, cfdata_t cfdata, void *aux) 145 { 146 return 1; 147 } 148 149 static void 150 fss_attach(device_t parent, device_t self, void *aux) 151 { 152 struct fss_softc *sc = device_private(self); 153 154 sc->sc_dev = self; 155 sc->sc_bdev = NODEV; 156 mutex_init(&sc->sc_slock, MUTEX_DEFAULT, IPL_NONE); 157 mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE); 158 cv_init(&sc->sc_work_cv, "fssbs"); 159 cv_init(&sc->sc_cache_cv, "cowwait"); 160 bufq_alloc(&sc->sc_bufq, "fcfs", 0); 161 sc->sc_dkdev = malloc(sizeof(*sc->sc_dkdev), M_DEVBUF, M_WAITOK); 162 sc->sc_dkdev->dk_info = NULL; 163 disk_init(sc->sc_dkdev, device_xname(self), NULL); 164 if (!pmf_device_register(self, NULL, NULL)) 165 aprint_error_dev(self, "couldn't establish power handler\n"); 166 167 if (fss_num_attached++ == 0) 168 vfs_hooks_attach(&fss_vfs_hooks); 169 } 170 171 static int 172 fss_detach(device_t self, int flags) 173 { 174 struct fss_softc *sc = device_private(self); 175 176 if (sc->sc_flags & FSS_ACTIVE) 177 return EBUSY; 178 179 if (--fss_num_attached == 0) 180 vfs_hooks_detach(&fss_vfs_hooks); 181 182 pmf_device_deregister(self); 183 mutex_destroy(&sc->sc_slock); 184 mutex_destroy(&sc->sc_lock); 185 cv_destroy(&sc->sc_work_cv); 186 cv_destroy(&sc->sc_cache_cv); 187 bufq_drain(sc->sc_bufq); 188 bufq_free(sc->sc_bufq); 189 disk_destroy(sc->sc_dkdev); 190 free(sc->sc_dkdev, M_DEVBUF); 191 192 return 0; 193 } 194 195 int 196 fss_open(dev_t dev, int flags, int mode, struct lwp *l) 197 { 198 int mflag; 199 cfdata_t cf; 200 struct fss_softc *sc; 201 202 mflag = (mode == S_IFCHR ? FSS_CDEV_OPEN : FSS_BDEV_OPEN); 203 204 mutex_enter(&fss_device_lock); 205 206 sc = device_lookup_private(&fss_cd, minor(dev)); 207 if (sc == NULL) { 208 cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); 209 cf->cf_name = fss_cd.cd_name; 210 cf->cf_atname = fss_cd.cd_name; 211 cf->cf_unit = minor(dev); 212 cf->cf_fstate = FSTATE_STAR; 213 sc = device_private(config_attach_pseudo(cf)); 214 if (sc == NULL) { 215 mutex_exit(&fss_device_lock); 216 return ENOMEM; 217 } 218 } 219 220 mutex_enter(&sc->sc_slock); 221 222 sc->sc_flags |= mflag; 223 224 mutex_exit(&sc->sc_slock); 225 mutex_exit(&fss_device_lock); 226 227 return 0; 228 } 229 230 int 231 fss_close(dev_t dev, int flags, int mode, struct lwp *l) 232 { 233 int mflag, error; 234 cfdata_t cf; 235 struct fss_softc *sc = device_lookup_private(&fss_cd, minor(dev)); 236 237 mflag = (mode == S_IFCHR ? FSS_CDEV_OPEN : FSS_BDEV_OPEN); 238 error = 0; 239 240 mutex_enter(&fss_device_lock); 241 restart: 242 mutex_enter(&sc->sc_slock); 243 if ((sc->sc_flags & (FSS_CDEV_OPEN|FSS_BDEV_OPEN)) != mflag) { 244 sc->sc_flags &= ~mflag; 245 mutex_exit(&sc->sc_slock); 246 mutex_exit(&fss_device_lock); 247 return 0; 248 } 249 if ((sc->sc_flags & FSS_ACTIVE) != 0 && 250 (sc->sc_uflags & FSS_UNCONFIG_ON_CLOSE) != 0) { 251 sc->sc_uflags &= ~FSS_UNCONFIG_ON_CLOSE; 252 mutex_exit(&sc->sc_slock); 253 error = fss_ioctl(dev, FSSIOCCLR, NULL, FWRITE, l); 254 goto restart; 255 } 256 if ((sc->sc_flags & FSS_ACTIVE) != 0) { 257 mutex_exit(&sc->sc_slock); 258 mutex_exit(&fss_device_lock); 259 return error; 260 } 261 262 KASSERT((sc->sc_flags & FSS_ACTIVE) == 0); 263 KASSERT((sc->sc_flags & (FSS_CDEV_OPEN|FSS_BDEV_OPEN)) == mflag); 264 mutex_exit(&sc->sc_slock); 265 cf = device_cfdata(sc->sc_dev); 266 error = config_detach(sc->sc_dev, DETACH_QUIET); 267 if (! error) 268 free(cf, M_DEVBUF); 269 mutex_exit(&fss_device_lock); 270 271 return error; 272 } 273 274 void 275 fss_strategy(struct buf *bp) 276 { 277 const bool write = ((bp->b_flags & B_READ) != B_READ); 278 struct fss_softc *sc = device_lookup_private(&fss_cd, minor(bp->b_dev)); 279 280 mutex_enter(&sc->sc_slock); 281 282 if (write || !FSS_ISVALID(sc)) { 283 bp->b_error = (write ? EROFS : ENXIO); 284 goto done; 285 } 286 /* Check bounds for non-persistent snapshots. */ 287 if ((sc->sc_flags & FSS_PERSISTENT) == 0 && 288 bounds_check_with_mediasize(bp, DEV_BSIZE, 289 btodb(FSS_CLTOB(sc, sc->sc_clcount - 1) + sc->sc_clresid)) <= 0) 290 goto done; 291 292 bp->b_rawblkno = bp->b_blkno; 293 bufq_put(sc->sc_bufq, bp); 294 cv_signal(&sc->sc_work_cv); 295 296 mutex_exit(&sc->sc_slock); 297 return; 298 299 done: 300 mutex_exit(&sc->sc_slock); 301 bp->b_resid = bp->b_bcount; 302 biodone(bp); 303 } 304 305 int 306 fss_read(dev_t dev, struct uio *uio, int flags) 307 { 308 return physio(fss_strategy, NULL, dev, B_READ, minphys, uio); 309 } 310 311 int 312 fss_write(dev_t dev, struct uio *uio, int flags) 313 { 314 return physio(fss_strategy, NULL, dev, B_WRITE, minphys, uio); 315 } 316 317 int 318 fss_ioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 319 { 320 int error; 321 struct fss_softc *sc = device_lookup_private(&fss_cd, minor(dev)); 322 struct fss_set _fss; 323 struct fss_set *fss = (struct fss_set *)data; 324 struct fss_set50 *fss50 = (struct fss_set50 *)data; 325 struct fss_get *fsg = (struct fss_get *)data; 326 #ifndef _LP64 327 struct fss_get50 *fsg50 = (struct fss_get50 *)data; 328 #endif 329 330 switch (cmd) { 331 case FSSIOCSET50: 332 fss = &_fss; 333 fss->fss_mount = fss50->fss_mount; 334 fss->fss_bstore = fss50->fss_bstore; 335 fss->fss_csize = fss50->fss_csize; 336 fss->fss_flags = 0; 337 /* Fall through */ 338 case FSSIOCSET: 339 mutex_enter(&sc->sc_lock); 340 if ((flag & FWRITE) == 0) 341 error = EPERM; 342 else if ((sc->sc_flags & FSS_ACTIVE) != 0) 343 error = EBUSY; 344 else 345 error = fss_create_snapshot(sc, fss, l); 346 if (error == 0) 347 sc->sc_uflags = fss->fss_flags; 348 mutex_exit(&sc->sc_lock); 349 break; 350 351 case FSSIOCCLR: 352 mutex_enter(&sc->sc_lock); 353 if ((flag & FWRITE) == 0) 354 error = EPERM; 355 else if ((sc->sc_flags & FSS_ACTIVE) == 0) 356 error = ENXIO; 357 else 358 error = fss_delete_snapshot(sc, l); 359 mutex_exit(&sc->sc_lock); 360 break; 361 362 #ifndef _LP64 363 case FSSIOCGET50: 364 mutex_enter(&sc->sc_lock); 365 switch (sc->sc_flags & (FSS_PERSISTENT | FSS_ACTIVE)) { 366 case FSS_ACTIVE: 367 memcpy(fsg50->fsg_mount, sc->sc_mntname, MNAMELEN); 368 fsg50->fsg_csize = FSS_CLSIZE(sc); 369 timeval_to_timeval50(&sc->sc_time, &fsg50->fsg_time); 370 fsg50->fsg_mount_size = sc->sc_clcount; 371 fsg50->fsg_bs_size = sc->sc_clnext; 372 error = 0; 373 break; 374 case FSS_PERSISTENT | FSS_ACTIVE: 375 memcpy(fsg50->fsg_mount, sc->sc_mntname, MNAMELEN); 376 fsg50->fsg_csize = 0; 377 timeval_to_timeval50(&sc->sc_time, &fsg50->fsg_time); 378 fsg50->fsg_mount_size = 0; 379 fsg50->fsg_bs_size = 0; 380 error = 0; 381 break; 382 default: 383 error = ENXIO; 384 break; 385 } 386 mutex_exit(&sc->sc_lock); 387 break; 388 #endif /* _LP64 */ 389 390 case FSSIOCGET: 391 mutex_enter(&sc->sc_lock); 392 switch (sc->sc_flags & (FSS_PERSISTENT | FSS_ACTIVE)) { 393 case FSS_ACTIVE: 394 memcpy(fsg->fsg_mount, sc->sc_mntname, MNAMELEN); 395 fsg->fsg_csize = FSS_CLSIZE(sc); 396 fsg->fsg_time = sc->sc_time; 397 fsg->fsg_mount_size = sc->sc_clcount; 398 fsg->fsg_bs_size = sc->sc_clnext; 399 error = 0; 400 break; 401 case FSS_PERSISTENT | FSS_ACTIVE: 402 memcpy(fsg->fsg_mount, sc->sc_mntname, MNAMELEN); 403 fsg->fsg_csize = 0; 404 fsg->fsg_time = sc->sc_time; 405 fsg->fsg_mount_size = 0; 406 fsg->fsg_bs_size = 0; 407 error = 0; 408 break; 409 default: 410 error = ENXIO; 411 break; 412 } 413 mutex_exit(&sc->sc_lock); 414 break; 415 416 case FSSIOFSET: 417 mutex_enter(&sc->sc_slock); 418 sc->sc_uflags = *(int *)data; 419 mutex_exit(&sc->sc_slock); 420 error = 0; 421 break; 422 423 case FSSIOFGET: 424 mutex_enter(&sc->sc_slock); 425 *(int *)data = sc->sc_uflags; 426 mutex_exit(&sc->sc_slock); 427 error = 0; 428 break; 429 430 default: 431 error = EINVAL; 432 break; 433 } 434 435 return error; 436 } 437 438 int 439 fss_size(dev_t dev) 440 { 441 return -1; 442 } 443 444 int 445 fss_dump(dev_t dev, daddr_t blkno, void *va, 446 size_t size) 447 { 448 return EROFS; 449 } 450 451 /* 452 * An error occurred reading or writing the snapshot or backing store. 453 * If it is the first error log to console and disestablish cow handler. 454 * The caller holds the mutex. 455 */ 456 static inline void 457 fss_error(struct fss_softc *sc, const char *msg) 458 { 459 460 if ((sc->sc_flags & (FSS_ACTIVE | FSS_ERROR)) != FSS_ACTIVE) 461 return; 462 463 aprint_error_dev(sc->sc_dev, "snapshot invalid: %s\n", msg); 464 if ((sc->sc_flags & FSS_PERSISTENT) == 0) 465 fscow_disestablish(sc->sc_mount, fss_copy_on_write, sc); 466 sc->sc_flags |= FSS_ERROR; 467 } 468 469 /* 470 * Allocate the variable sized parts of the softc and 471 * fork the kernel thread. 472 * 473 * The fields sc_clcount, sc_clshift, sc_cache_size and sc_indir_size 474 * must be initialized. 475 */ 476 static int 477 fss_softc_alloc(struct fss_softc *sc) 478 { 479 int i, error; 480 481 if ((sc->sc_flags & FSS_PERSISTENT) == 0) { 482 sc->sc_copied = 483 kmem_zalloc(howmany(sc->sc_clcount, NBBY), KM_SLEEP); 484 sc->sc_cache = kmem_alloc(sc->sc_cache_size * 485 sizeof(struct fss_cache), KM_SLEEP); 486 for (i = 0; i < sc->sc_cache_size; i++) { 487 sc->sc_cache[i].fc_type = FSS_CACHE_FREE; 488 sc->sc_cache[i].fc_data = 489 kmem_alloc(FSS_CLSIZE(sc), KM_SLEEP); 490 cv_init(&sc->sc_cache[i].fc_state_cv, "cowwait1"); 491 } 492 493 sc->sc_indir_valid = 494 kmem_zalloc(howmany(sc->sc_indir_size, NBBY), KM_SLEEP); 495 sc->sc_indir_data = kmem_zalloc(FSS_CLSIZE(sc), KM_SLEEP); 496 } else { 497 sc->sc_copied = NULL; 498 sc->sc_cache = NULL; 499 sc->sc_indir_valid = NULL; 500 sc->sc_indir_data = NULL; 501 } 502 503 sc->sc_flags |= FSS_BS_THREAD; 504 if ((error = kthread_create(PRI_BIO, KTHREAD_MUSTJOIN, NULL, 505 fss_bs_thread, sc, &sc->sc_bs_lwp, 506 "%s", device_xname(sc->sc_dev))) != 0) { 507 sc->sc_flags &= ~FSS_BS_THREAD; 508 return error; 509 } 510 511 disk_attach(sc->sc_dkdev); 512 513 return 0; 514 } 515 516 /* 517 * Free the variable sized parts of the softc. 518 */ 519 static void 520 fss_softc_free(struct fss_softc *sc) 521 { 522 int i; 523 524 if ((sc->sc_flags & FSS_BS_THREAD) != 0) { 525 mutex_enter(&sc->sc_slock); 526 sc->sc_flags &= ~FSS_BS_THREAD; 527 cv_signal(&sc->sc_work_cv); 528 mutex_exit(&sc->sc_slock); 529 kthread_join(sc->sc_bs_lwp); 530 531 disk_detach(sc->sc_dkdev); 532 } 533 534 if (sc->sc_copied != NULL) 535 kmem_free(sc->sc_copied, howmany(sc->sc_clcount, NBBY)); 536 sc->sc_copied = NULL; 537 538 if (sc->sc_cache != NULL) { 539 for (i = 0; i < sc->sc_cache_size; i++) 540 if (sc->sc_cache[i].fc_data != NULL) { 541 cv_destroy(&sc->sc_cache[i].fc_state_cv); 542 kmem_free(sc->sc_cache[i].fc_data, 543 FSS_CLSIZE(sc)); 544 } 545 kmem_free(sc->sc_cache, 546 sc->sc_cache_size*sizeof(struct fss_cache)); 547 } 548 sc->sc_cache = NULL; 549 550 if (sc->sc_indir_valid != NULL) 551 kmem_free(sc->sc_indir_valid, howmany(sc->sc_indir_size, NBBY)); 552 sc->sc_indir_valid = NULL; 553 554 if (sc->sc_indir_data != NULL) 555 kmem_free(sc->sc_indir_data, FSS_CLSIZE(sc)); 556 sc->sc_indir_data = NULL; 557 } 558 559 /* 560 * Set all active snapshots on this file system into ERROR state. 561 */ 562 static void 563 fss_unmount_hook(struct mount *mp) 564 { 565 int i; 566 struct fss_softc *sc; 567 568 mutex_enter(&fss_device_lock); 569 for (i = 0; i < fss_cd.cd_ndevs; i++) { 570 if ((sc = device_lookup_private(&fss_cd, i)) == NULL) 571 continue; 572 mutex_enter(&sc->sc_slock); 573 if ((sc->sc_flags & FSS_ACTIVE) != 0 && sc->sc_mount == mp) 574 fss_error(sc, "forced by unmount"); 575 mutex_exit(&sc->sc_slock); 576 } 577 mutex_exit(&fss_device_lock); 578 } 579 580 /* 581 * A buffer is written to the snapshotted block device. Copy to 582 * backing store if needed. 583 */ 584 static int 585 fss_copy_on_write(void *v, struct buf *bp, bool data_valid) 586 { 587 int error; 588 u_int32_t cl, ch, c; 589 struct fss_softc *sc = v; 590 591 mutex_enter(&sc->sc_slock); 592 if (!FSS_ISVALID(sc)) { 593 mutex_exit(&sc->sc_slock); 594 return 0; 595 } 596 597 cl = FSS_BTOCL(sc, dbtob(bp->b_blkno)); 598 ch = FSS_BTOCL(sc, dbtob(bp->b_blkno)+bp->b_bcount-1); 599 error = 0; 600 if (curlwp == uvm.pagedaemon_lwp) { 601 for (c = cl; c <= ch; c++) 602 if (isclr(sc->sc_copied, c)) { 603 error = ENOMEM; 604 break; 605 } 606 } 607 mutex_exit(&sc->sc_slock); 608 609 if (error == 0) 610 for (c = cl; c <= ch; c++) { 611 error = fss_read_cluster(sc, c); 612 if (error) 613 break; 614 } 615 616 return error; 617 } 618 619 /* 620 * Lookup and open needed files. 621 * 622 * For file system internal snapshot initializes sc_mntname, sc_mount, 623 * sc_bs_vp and sc_time. 624 * 625 * Otherwise returns dev and size of the underlying block device. 626 * Initializes sc_mntname, sc_mount, sc_bdev, sc_bs_vp and sc_mount 627 */ 628 static int 629 fss_create_files(struct fss_softc *sc, struct fss_set *fss, 630 off_t *bsize, struct lwp *l) 631 { 632 int error, bits, fsbsize; 633 uint64_t numsec; 634 unsigned int secsize; 635 struct timespec ts; 636 /* nd -> nd2 to reduce mistakes while updating only some namei calls */ 637 struct pathbuf *pb2; 638 struct nameidata nd2; 639 struct vnode *vp; 640 641 /* 642 * Get the mounted file system. 643 */ 644 645 error = namei_simple_user(fss->fss_mount, 646 NSM_FOLLOW_NOEMULROOT, &vp); 647 if (error != 0) 648 return error; 649 650 if ((vp->v_vflag & VV_ROOT) != VV_ROOT) { 651 vrele(vp); 652 return EINVAL; 653 } 654 655 sc->sc_mount = vp->v_mount; 656 memcpy(sc->sc_mntname, sc->sc_mount->mnt_stat.f_mntonname, MNAMELEN); 657 658 vrele(vp); 659 660 /* 661 * Check for file system internal snapshot. 662 */ 663 664 error = namei_simple_user(fss->fss_bstore, 665 NSM_FOLLOW_NOEMULROOT, &vp); 666 if (error != 0) 667 return error; 668 669 if (vp->v_type == VREG && vp->v_mount == sc->sc_mount) { 670 sc->sc_flags |= FSS_PERSISTENT; 671 sc->sc_bs_vp = vp; 672 673 fsbsize = sc->sc_bs_vp->v_mount->mnt_stat.f_iosize; 674 bits = sizeof(sc->sc_bs_bshift)*NBBY; 675 for (sc->sc_bs_bshift = 1; sc->sc_bs_bshift < bits; 676 sc->sc_bs_bshift++) 677 if (FSS_FSBSIZE(sc) == fsbsize) 678 break; 679 if (sc->sc_bs_bshift >= bits) 680 return EINVAL; 681 682 sc->sc_bs_bmask = FSS_FSBSIZE(sc)-1; 683 sc->sc_clshift = 0; 684 685 if ((fss->fss_flags & FSS_UNLINK_ON_CREATE) != 0) { 686 error = do_sys_unlink(fss->fss_bstore, UIO_USERSPACE); 687 if (error) 688 return error; 689 } 690 error = vn_lock(vp, LK_EXCLUSIVE); 691 if (error != 0) 692 return error; 693 error = VFS_SNAPSHOT(sc->sc_mount, sc->sc_bs_vp, &ts); 694 TIMESPEC_TO_TIMEVAL(&sc->sc_time, &ts); 695 696 VOP_UNLOCK(sc->sc_bs_vp); 697 698 return error; 699 } 700 vrele(vp); 701 702 /* 703 * Get the block device it is mounted on and its size. 704 */ 705 706 error = spec_node_lookup_by_mount(sc->sc_mount, &vp); 707 if (error) 708 return error; 709 sc->sc_bdev = vp->v_rdev; 710 711 error = getdisksize(vp, &numsec, &secsize); 712 vrele(vp); 713 if (error) 714 return error; 715 716 *bsize = (off_t)numsec*secsize; 717 718 /* 719 * Get the backing store 720 */ 721 722 error = pathbuf_copyin(fss->fss_bstore, &pb2); 723 if (error) { 724 return error; 725 } 726 NDINIT(&nd2, LOOKUP, FOLLOW, pb2); 727 if ((error = vn_open(&nd2, FREAD|FWRITE, 0)) != 0) { 728 pathbuf_destroy(pb2); 729 return error; 730 } 731 VOP_UNLOCK(nd2.ni_vp); 732 733 sc->sc_bs_vp = nd2.ni_vp; 734 735 if (nd2.ni_vp->v_type != VREG && nd2.ni_vp->v_type != VCHR) { 736 pathbuf_destroy(pb2); 737 return EINVAL; 738 } 739 pathbuf_destroy(pb2); 740 741 if ((fss->fss_flags & FSS_UNLINK_ON_CREATE) != 0) { 742 error = do_sys_unlink(fss->fss_bstore, UIO_USERSPACE); 743 if (error) 744 return error; 745 } 746 if (sc->sc_bs_vp->v_type == VREG) { 747 fsbsize = sc->sc_bs_vp->v_mount->mnt_stat.f_iosize; 748 if (fsbsize & (fsbsize-1)) /* No power of two */ 749 return EINVAL; 750 for (sc->sc_bs_bshift = 1; sc->sc_bs_bshift < 32; 751 sc->sc_bs_bshift++) 752 if (FSS_FSBSIZE(sc) == fsbsize) 753 break; 754 if (sc->sc_bs_bshift >= 32) 755 return EINVAL; 756 sc->sc_bs_bmask = FSS_FSBSIZE(sc)-1; 757 } else { 758 sc->sc_bs_bshift = DEV_BSHIFT; 759 sc->sc_bs_bmask = FSS_FSBSIZE(sc)-1; 760 } 761 762 return 0; 763 } 764 765 /* 766 * Create a snapshot. 767 */ 768 static int 769 fss_create_snapshot(struct fss_softc *sc, struct fss_set *fss, struct lwp *l) 770 { 771 int len, error; 772 u_int32_t csize; 773 off_t bsize; 774 775 bsize = 0; /* XXX gcc */ 776 777 /* 778 * Open needed files. 779 */ 780 if ((error = fss_create_files(sc, fss, &bsize, l)) != 0) 781 goto bad; 782 783 if (sc->sc_flags & FSS_PERSISTENT) { 784 fss_softc_alloc(sc); 785 sc->sc_flags |= FSS_ACTIVE; 786 return 0; 787 } 788 789 /* 790 * Set cluster size. Must be a power of two and 791 * a multiple of backing store block size. 792 */ 793 if (fss->fss_csize <= 0) 794 csize = MAXPHYS; 795 else 796 csize = fss->fss_csize; 797 if (bsize/csize > FSS_CLUSTER_MAX) 798 csize = bsize/FSS_CLUSTER_MAX+1; 799 800 for (sc->sc_clshift = sc->sc_bs_bshift; sc->sc_clshift < 32; 801 sc->sc_clshift++) 802 if (FSS_CLSIZE(sc) >= csize) 803 break; 804 if (sc->sc_clshift >= 32) { 805 error = EINVAL; 806 goto bad; 807 } 808 sc->sc_clmask = FSS_CLSIZE(sc)-1; 809 810 /* 811 * Set number of cache slots. 812 */ 813 if (FSS_CLSIZE(sc) <= 8192) 814 sc->sc_cache_size = 32; 815 else if (FSS_CLSIZE(sc) <= 65536) 816 sc->sc_cache_size = 8; 817 else 818 sc->sc_cache_size = 4; 819 820 /* 821 * Set number of clusters and size of last cluster. 822 */ 823 sc->sc_clcount = FSS_BTOCL(sc, bsize-1)+1; 824 sc->sc_clresid = FSS_CLOFF(sc, bsize-1)+1; 825 826 /* 827 * Set size of indirect table. 828 */ 829 len = sc->sc_clcount*sizeof(u_int32_t); 830 sc->sc_indir_size = FSS_BTOCL(sc, len)+1; 831 sc->sc_clnext = sc->sc_indir_size; 832 sc->sc_indir_cur = 0; 833 834 if ((error = fss_softc_alloc(sc)) != 0) 835 goto bad; 836 837 /* 838 * Activate the snapshot. 839 */ 840 841 if ((error = vfs_suspend(sc->sc_mount, 0)) != 0) 842 goto bad; 843 844 microtime(&sc->sc_time); 845 846 vrele_flush(sc->sc_mount); 847 error = VFS_SYNC(sc->sc_mount, MNT_WAIT, curlwp->l_cred); 848 if (error == 0) 849 error = fscow_establish(sc->sc_mount, fss_copy_on_write, sc); 850 if (error == 0) 851 sc->sc_flags |= FSS_ACTIVE; 852 853 vfs_resume(sc->sc_mount); 854 855 if (error != 0) 856 goto bad; 857 858 aprint_debug_dev(sc->sc_dev, "%s snapshot active\n", sc->sc_mntname); 859 aprint_debug_dev(sc->sc_dev, 860 "%u clusters of %u, %u cache slots, %u indir clusters\n", 861 sc->sc_clcount, FSS_CLSIZE(sc), 862 sc->sc_cache_size, sc->sc_indir_size); 863 864 return 0; 865 866 bad: 867 fss_softc_free(sc); 868 if (sc->sc_bs_vp != NULL) { 869 if (sc->sc_flags & FSS_PERSISTENT) 870 vrele(sc->sc_bs_vp); 871 else 872 vn_close(sc->sc_bs_vp, FREAD|FWRITE, l->l_cred); 873 } 874 sc->sc_bs_vp = NULL; 875 876 return error; 877 } 878 879 /* 880 * Delete a snapshot. 881 */ 882 static int 883 fss_delete_snapshot(struct fss_softc *sc, struct lwp *l) 884 { 885 886 if ((sc->sc_flags & (FSS_PERSISTENT | FSS_ERROR)) == 0) 887 fscow_disestablish(sc->sc_mount, fss_copy_on_write, sc); 888 889 mutex_enter(&sc->sc_slock); 890 sc->sc_flags &= ~(FSS_ACTIVE|FSS_ERROR); 891 sc->sc_mount = NULL; 892 sc->sc_bdev = NODEV; 893 mutex_exit(&sc->sc_slock); 894 895 fss_softc_free(sc); 896 if (sc->sc_flags & FSS_PERSISTENT) 897 vrele(sc->sc_bs_vp); 898 else 899 vn_close(sc->sc_bs_vp, FREAD|FWRITE, l->l_cred); 900 sc->sc_bs_vp = NULL; 901 sc->sc_flags &= ~FSS_PERSISTENT; 902 903 return 0; 904 } 905 906 /* 907 * Read a cluster from the snapshotted block device to the cache. 908 */ 909 static int 910 fss_read_cluster(struct fss_softc *sc, u_int32_t cl) 911 { 912 int error, todo, offset, len; 913 daddr_t dblk; 914 struct buf *bp, *mbp; 915 struct fss_cache *scp, *scl; 916 917 /* 918 * Get a free cache slot. 919 */ 920 scl = sc->sc_cache+sc->sc_cache_size; 921 922 mutex_enter(&sc->sc_slock); 923 924 restart: 925 if (isset(sc->sc_copied, cl) || !FSS_ISVALID(sc)) { 926 mutex_exit(&sc->sc_slock); 927 return 0; 928 } 929 930 for (scp = sc->sc_cache; scp < scl; scp++) 931 if (scp->fc_cluster == cl) { 932 if (scp->fc_type == FSS_CACHE_VALID) { 933 mutex_exit(&sc->sc_slock); 934 return 0; 935 } else if (scp->fc_type == FSS_CACHE_BUSY) { 936 cv_wait(&scp->fc_state_cv, &sc->sc_slock); 937 goto restart; 938 } 939 } 940 941 for (scp = sc->sc_cache; scp < scl; scp++) 942 if (scp->fc_type == FSS_CACHE_FREE) { 943 scp->fc_type = FSS_CACHE_BUSY; 944 scp->fc_cluster = cl; 945 break; 946 } 947 if (scp >= scl) { 948 cv_wait(&sc->sc_cache_cv, &sc->sc_slock); 949 goto restart; 950 } 951 952 mutex_exit(&sc->sc_slock); 953 954 /* 955 * Start the read. 956 */ 957 dblk = btodb(FSS_CLTOB(sc, cl)); 958 if (cl == sc->sc_clcount-1) { 959 todo = sc->sc_clresid; 960 memset((char *)scp->fc_data + todo, 0, FSS_CLSIZE(sc) - todo); 961 } else 962 todo = FSS_CLSIZE(sc); 963 offset = 0; 964 mbp = getiobuf(NULL, true); 965 mbp->b_bufsize = todo; 966 mbp->b_data = scp->fc_data; 967 mbp->b_resid = mbp->b_bcount = todo; 968 mbp->b_flags = B_READ; 969 mbp->b_cflags = BC_BUSY; 970 mbp->b_dev = sc->sc_bdev; 971 while (todo > 0) { 972 len = todo; 973 if (len > MAXPHYS) 974 len = MAXPHYS; 975 if (btodb(FSS_CLTOB(sc, cl)) == dblk && len == todo) 976 bp = mbp; 977 else { 978 bp = getiobuf(NULL, true); 979 nestiobuf_setup(mbp, bp, offset, len); 980 } 981 bp->b_lblkno = 0; 982 bp->b_blkno = dblk; 983 bdev_strategy(bp); 984 dblk += btodb(len); 985 offset += len; 986 todo -= len; 987 } 988 error = biowait(mbp); 989 if (error == 0 && mbp->b_resid != 0) 990 error = EIO; 991 putiobuf(mbp); 992 993 mutex_enter(&sc->sc_slock); 994 scp->fc_type = (error ? FSS_CACHE_FREE : FSS_CACHE_VALID); 995 cv_broadcast(&scp->fc_state_cv); 996 if (error == 0) { 997 setbit(sc->sc_copied, scp->fc_cluster); 998 cv_signal(&sc->sc_work_cv); 999 } 1000 mutex_exit(&sc->sc_slock); 1001 1002 return error; 1003 } 1004 1005 /* 1006 * Read/write clusters from/to backing store. 1007 * For persistent snapshots must be called with cl == 0. off is the 1008 * offset into the snapshot. 1009 */ 1010 static int 1011 fss_bs_io(struct fss_softc *sc, fss_io_type rw, 1012 u_int32_t cl, off_t off, int len, void *data, size_t *resid) 1013 { 1014 int error; 1015 1016 off += FSS_CLTOB(sc, cl); 1017 1018 vn_lock(sc->sc_bs_vp, LK_EXCLUSIVE|LK_RETRY); 1019 1020 error = vn_rdwr((rw == FSS_READ ? UIO_READ : UIO_WRITE), sc->sc_bs_vp, 1021 data, len, off, UIO_SYSSPACE, 1022 IO_ADV_ENCODE(POSIX_FADV_NOREUSE) | IO_NODELOCKED, 1023 sc->sc_bs_lwp->l_cred, resid, NULL); 1024 if (error == 0) { 1025 mutex_enter(sc->sc_bs_vp->v_interlock); 1026 error = VOP_PUTPAGES(sc->sc_bs_vp, trunc_page(off), 1027 round_page(off+len), PGO_CLEANIT | PGO_FREE | PGO_SYNCIO); 1028 } 1029 1030 VOP_UNLOCK(sc->sc_bs_vp); 1031 1032 return error; 1033 } 1034 1035 /* 1036 * Get a pointer to the indirect slot for this cluster. 1037 */ 1038 static u_int32_t * 1039 fss_bs_indir(struct fss_softc *sc, u_int32_t cl) 1040 { 1041 u_int32_t icl; 1042 int ioff; 1043 1044 icl = cl/(FSS_CLSIZE(sc)/sizeof(u_int32_t)); 1045 ioff = cl%(FSS_CLSIZE(sc)/sizeof(u_int32_t)); 1046 1047 if (sc->sc_indir_cur == icl) 1048 return &sc->sc_indir_data[ioff]; 1049 1050 if (sc->sc_indir_dirty) { 1051 if (fss_bs_io(sc, FSS_WRITE, sc->sc_indir_cur, 0, 1052 FSS_CLSIZE(sc), (void *)sc->sc_indir_data, NULL) != 0) 1053 return NULL; 1054 setbit(sc->sc_indir_valid, sc->sc_indir_cur); 1055 } 1056 1057 sc->sc_indir_dirty = 0; 1058 sc->sc_indir_cur = icl; 1059 1060 if (isset(sc->sc_indir_valid, sc->sc_indir_cur)) { 1061 if (fss_bs_io(sc, FSS_READ, sc->sc_indir_cur, 0, 1062 FSS_CLSIZE(sc), (void *)sc->sc_indir_data, NULL) != 0) 1063 return NULL; 1064 } else 1065 memset(sc->sc_indir_data, 0, FSS_CLSIZE(sc)); 1066 1067 return &sc->sc_indir_data[ioff]; 1068 } 1069 1070 /* 1071 * The kernel thread (one for every active snapshot). 1072 * 1073 * After wakeup it cleans the cache and runs the I/O requests. 1074 */ 1075 static void 1076 fss_bs_thread(void *arg) 1077 { 1078 bool thread_idle, is_valid; 1079 int error, i, todo, len, crotor, is_read; 1080 long off; 1081 char *addr; 1082 u_int32_t c, cl, ch, *indirp; 1083 size_t resid; 1084 struct buf *bp, *nbp; 1085 struct fss_softc *sc; 1086 struct fss_cache *scp, *scl; 1087 1088 sc = arg; 1089 scl = sc->sc_cache+sc->sc_cache_size; 1090 crotor = 0; 1091 thread_idle = false; 1092 1093 mutex_enter(&sc->sc_slock); 1094 1095 for (;;) { 1096 if (thread_idle) 1097 cv_wait(&sc->sc_work_cv, &sc->sc_slock); 1098 thread_idle = true; 1099 if ((sc->sc_flags & FSS_BS_THREAD) == 0) { 1100 mutex_exit(&sc->sc_slock); 1101 kthread_exit(0); 1102 } 1103 1104 /* 1105 * Process I/O requests (persistent) 1106 */ 1107 1108 if (sc->sc_flags & FSS_PERSISTENT) { 1109 if ((bp = bufq_get(sc->sc_bufq)) == NULL) 1110 continue; 1111 is_valid = FSS_ISVALID(sc); 1112 is_read = (bp->b_flags & B_READ); 1113 thread_idle = false; 1114 mutex_exit(&sc->sc_slock); 1115 1116 if (is_valid) { 1117 disk_busy(sc->sc_dkdev); 1118 error = fss_bs_io(sc, FSS_READ, 0, 1119 dbtob(bp->b_blkno), bp->b_bcount, 1120 bp->b_data, &resid); 1121 if (error) 1122 resid = bp->b_bcount; 1123 disk_unbusy(sc->sc_dkdev, 1124 (error ? 0 : bp->b_bcount), is_read); 1125 } else { 1126 error = ENXIO; 1127 resid = bp->b_bcount; 1128 } 1129 1130 bp->b_error = error; 1131 bp->b_resid = resid; 1132 biodone(bp); 1133 1134 mutex_enter(&sc->sc_slock); 1135 continue; 1136 } 1137 1138 /* 1139 * Clean the cache 1140 */ 1141 for (i = 0; i < sc->sc_cache_size; i++) { 1142 crotor = (crotor + 1) % sc->sc_cache_size; 1143 scp = sc->sc_cache + crotor; 1144 if (scp->fc_type != FSS_CACHE_VALID) 1145 continue; 1146 mutex_exit(&sc->sc_slock); 1147 1148 thread_idle = false; 1149 indirp = fss_bs_indir(sc, scp->fc_cluster); 1150 if (indirp != NULL) { 1151 error = fss_bs_io(sc, FSS_WRITE, sc->sc_clnext, 1152 0, FSS_CLSIZE(sc), scp->fc_data, NULL); 1153 } else 1154 error = EIO; 1155 1156 mutex_enter(&sc->sc_slock); 1157 if (error == 0) { 1158 *indirp = sc->sc_clnext++; 1159 sc->sc_indir_dirty = 1; 1160 } else 1161 fss_error(sc, "write error on backing store"); 1162 1163 scp->fc_type = FSS_CACHE_FREE; 1164 cv_broadcast(&sc->sc_cache_cv); 1165 break; 1166 } 1167 1168 /* 1169 * Process I/O requests 1170 */ 1171 if ((bp = bufq_get(sc->sc_bufq)) == NULL) 1172 continue; 1173 is_valid = FSS_ISVALID(sc); 1174 is_read = (bp->b_flags & B_READ); 1175 thread_idle = false; 1176 1177 if (!is_valid) { 1178 mutex_exit(&sc->sc_slock); 1179 1180 bp->b_error = ENXIO; 1181 bp->b_resid = bp->b_bcount; 1182 biodone(bp); 1183 1184 mutex_enter(&sc->sc_slock); 1185 continue; 1186 } 1187 1188 disk_busy(sc->sc_dkdev); 1189 1190 /* 1191 * First read from the snapshotted block device unless 1192 * this request is completely covered by backing store. 1193 */ 1194 1195 cl = FSS_BTOCL(sc, dbtob(bp->b_blkno)); 1196 off = FSS_CLOFF(sc, dbtob(bp->b_blkno)); 1197 ch = FSS_BTOCL(sc, dbtob(bp->b_blkno)+bp->b_bcount-1); 1198 error = 0; 1199 bp->b_resid = 0; 1200 bp->b_error = 0; 1201 for (c = cl; c <= ch; c++) { 1202 if (isset(sc->sc_copied, c)) 1203 continue; 1204 mutex_exit(&sc->sc_slock); 1205 1206 /* Not on backing store, read from device. */ 1207 nbp = getiobuf(NULL, true); 1208 nbp->b_flags = B_READ; 1209 nbp->b_resid = nbp->b_bcount = bp->b_bcount; 1210 nbp->b_bufsize = bp->b_bcount; 1211 nbp->b_data = bp->b_data; 1212 nbp->b_blkno = bp->b_blkno; 1213 nbp->b_lblkno = 0; 1214 nbp->b_dev = sc->sc_bdev; 1215 SET(nbp->b_cflags, BC_BUSY); /* mark buffer busy */ 1216 1217 bdev_strategy(nbp); 1218 1219 error = biowait(nbp); 1220 if (error == 0 && nbp->b_resid != 0) 1221 error = EIO; 1222 if (error != 0) { 1223 bp->b_resid = bp->b_bcount; 1224 bp->b_error = nbp->b_error; 1225 disk_unbusy(sc->sc_dkdev, 0, is_read); 1226 biodone(bp); 1227 } 1228 putiobuf(nbp); 1229 1230 mutex_enter(&sc->sc_slock); 1231 break; 1232 } 1233 if (error) 1234 continue; 1235 1236 /* 1237 * Replace those parts that have been saved to backing store. 1238 */ 1239 1240 addr = bp->b_data; 1241 todo = bp->b_bcount; 1242 for (c = cl; c <= ch; c++, off = 0, todo -= len, addr += len) { 1243 len = FSS_CLSIZE(sc)-off; 1244 if (len > todo) 1245 len = todo; 1246 if (isclr(sc->sc_copied, c)) 1247 continue; 1248 mutex_exit(&sc->sc_slock); 1249 1250 indirp = fss_bs_indir(sc, c); 1251 if (indirp == NULL || *indirp == 0) { 1252 /* 1253 * Not on backing store. Either in cache 1254 * or hole in the snapshotted block device. 1255 */ 1256 1257 mutex_enter(&sc->sc_slock); 1258 for (scp = sc->sc_cache; scp < scl; scp++) 1259 if (scp->fc_type == FSS_CACHE_VALID && 1260 scp->fc_cluster == c) 1261 break; 1262 if (scp < scl) 1263 memcpy(addr, (char *)scp->fc_data+off, 1264 len); 1265 else 1266 memset(addr, 0, len); 1267 continue; 1268 } 1269 1270 /* 1271 * Read from backing store. 1272 */ 1273 error = fss_bs_io(sc, FSS_READ, 1274 *indirp, off, len, addr, NULL); 1275 1276 mutex_enter(&sc->sc_slock); 1277 if (error) { 1278 bp->b_resid = bp->b_bcount; 1279 bp->b_error = error; 1280 break; 1281 } 1282 } 1283 mutex_exit(&sc->sc_slock); 1284 1285 disk_unbusy(sc->sc_dkdev, (error ? 0 : bp->b_bcount), is_read); 1286 biodone(bp); 1287 1288 mutex_enter(&sc->sc_slock); 1289 } 1290 } 1291 1292 #ifdef _MODULE 1293 1294 #include <sys/module.h> 1295 1296 MODULE(MODULE_CLASS_DRIVER, fss, "bufq_fcfs"); 1297 CFDRIVER_DECL(fss, DV_DISK, NULL); 1298 1299 devmajor_t fss_bmajor = -1, fss_cmajor = -1; 1300 1301 static int 1302 fss_modcmd(modcmd_t cmd, void *arg) 1303 { 1304 int error = 0; 1305 1306 switch (cmd) { 1307 case MODULE_CMD_INIT: 1308 mutex_init(&fss_device_lock, MUTEX_DEFAULT, IPL_NONE); 1309 error = config_cfdriver_attach(&fss_cd); 1310 if (error) { 1311 mutex_destroy(&fss_device_lock); 1312 break; 1313 } 1314 error = config_cfattach_attach(fss_cd.cd_name, &fss_ca); 1315 if (error) { 1316 config_cfdriver_detach(&fss_cd); 1317 mutex_destroy(&fss_device_lock); 1318 break; 1319 } 1320 error = devsw_attach(fss_cd.cd_name, 1321 &fss_bdevsw, &fss_bmajor, &fss_cdevsw, &fss_cmajor); 1322 1323 if (error) { 1324 config_cfattach_detach(fss_cd.cd_name, &fss_ca); 1325 config_cfdriver_detach(&fss_cd); 1326 mutex_destroy(&fss_device_lock); 1327 break; 1328 } 1329 break; 1330 1331 case MODULE_CMD_FINI: 1332 devsw_detach(&fss_bdevsw, &fss_cdevsw); 1333 error = config_cfattach_detach(fss_cd.cd_name, &fss_ca); 1334 if (error) { 1335 devsw_attach(fss_cd.cd_name, &fss_bdevsw, &fss_bmajor, 1336 &fss_cdevsw, &fss_cmajor); 1337 break; 1338 } 1339 error = config_cfdriver_detach(&fss_cd); 1340 if (error) { 1341 devsw_attach(fss_cd.cd_name, 1342 &fss_bdevsw, &fss_bmajor, &fss_cdevsw, &fss_cmajor); 1343 devsw_attach(fss_cd.cd_name, &fss_bdevsw, &fss_bmajor, 1344 &fss_cdevsw, &fss_cmajor); 1345 break; 1346 } 1347 mutex_destroy(&fss_device_lock); 1348 break; 1349 1350 default: 1351 error = ENOTTY; 1352 break; 1353 } 1354 1355 return error; 1356 } 1357 1358 #endif /* _MODULE */ 1359
Indexes created Wed Nov 11 00:26:22 UTC 2026