1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1999-2004 Poul-Henning Kamp 5 * Copyright (c) 1999 Michael Smith 6 * Copyright (c) 1989, 1993 7 * The Regents of the University of California. All rights reserved. 8 * (c) UNIX System Laboratories, Inc. 9 * All or some portions of this file are derived from material licensed 10 * to the University of California by American Telephone and Telegraph 11 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 12 * the permission of UNIX System Laboratories, Inc. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include <sys/param.h> 43 #include <sys/conf.h> 44 #include <sys/smp.h> 45 #include <sys/devctl.h> 46 #include <sys/eventhandler.h> 47 #include <sys/fcntl.h> 48 #include <sys/jail.h> 49 #include <sys/kernel.h> 50 #include <sys/ktr.h> 51 #include <sys/libkern.h> 52 #include <sys/limits.h> 53 #include <sys/malloc.h> 54 #include <sys/mount.h> 55 #include <sys/mutex.h> 56 #include <sys/namei.h> 57 #include <sys/priv.h> 58 #include <sys/proc.h> 59 #include <sys/filedesc.h> 60 #include <sys/reboot.h> 61 #include <sys/sbuf.h> 62 #include <sys/syscallsubr.h> 63 #include <sys/sysproto.h> 64 #include <sys/sx.h> 65 #include <sys/sysctl.h> 66 #include <sys/systm.h> 67 #include <sys/taskqueue.h> 68 #include <sys/vnode.h> 69 #include <vm/uma.h> 70 71 #include <geom/geom.h> 72 73 #include <machine/stdarg.h> 74 75 #include <security/audit/audit.h> 76 #include <security/mac/mac_framework.h> 77 78 #define VFS_MOUNTARG_SIZE_MAX (1024 * 64) 79 80 static int vfs_domount(struct thread *td, const char *fstype, char *fspath, 81 uint64_t fsflags, bool jail_export, 82 struct vfsoptlist **optlist); 83 static void free_mntarg(struct mntarg *ma); 84 85 static int usermount = 0; 86 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 87 "Unprivileged users may mount and unmount file systems"); 88 89 static bool default_autoro = false; 90 SYSCTL_BOOL(_vfs, OID_AUTO, default_autoro, CTLFLAG_RW, &default_autoro, 0, 91 "Retry failed r/w mount as r/o if no explicit ro/rw option is specified"); 92 93 static bool recursive_forced_unmount = false; 94 SYSCTL_BOOL(_vfs, OID_AUTO, recursive_forced_unmount, CTLFLAG_RW, 95 &recursive_forced_unmount, 0, "Recursively unmount stacked upper mounts" 96 " when a file system is forcibly unmounted"); 97 98 static SYSCTL_NODE(_vfs, OID_AUTO, deferred_unmount, 99 CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "deferred unmount controls"); 100 101 static unsigned int deferred_unmount_retry_limit = 10; 102 SYSCTL_UINT(_vfs_deferred_unmount, OID_AUTO, retry_limit, CTLFLAG_RW, 103 &deferred_unmount_retry_limit, 0, 104 "Maximum number of retries for deferred unmount failure"); 105 106 static int deferred_unmount_retry_delay_hz; 107 SYSCTL_INT(_vfs_deferred_unmount, OID_AUTO, retry_delay_hz, CTLFLAG_RW, 108 &deferred_unmount_retry_delay_hz, 0, 109 "Delay in units of [1/kern.hz]s when retrying a failed deferred unmount"); 110 111 static int deferred_unmount_total_retries = 0; 112 SYSCTL_INT(_vfs_deferred_unmount, OID_AUTO, total_retries, CTLFLAG_RD, 113 &deferred_unmount_total_retries, 0, 114 "Total number of retried deferred unmounts"); 115 116 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 117 MALLOC_DEFINE(M_STATFS, "statfs", "statfs structure"); 118 static uma_zone_t mount_zone; 119 120 /* List of mounted filesystems. */ 121 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 122 123 /* For any iteration/modification of mountlist */ 124 struct mtx_padalign __exclusive_cache_line mountlist_mtx; 125 126 EVENTHANDLER_LIST_DEFINE(vfs_mounted); 127 EVENTHANDLER_LIST_DEFINE(vfs_unmounted); 128 129 static void vfs_deferred_unmount(void *arg, int pending); 130 static struct timeout_task deferred_unmount_task; 131 static struct mtx deferred_unmount_lock; 132 MTX_SYSINIT(deferred_unmount, &deferred_unmount_lock, "deferred_unmount", 133 MTX_DEF); 134 static STAILQ_HEAD(, mount) deferred_unmount_list = 135 STAILQ_HEAD_INITIALIZER(deferred_unmount_list); 136 TASKQUEUE_DEFINE_THREAD(deferred_unmount); 137 138 static void mount_devctl_event(const char *type, struct mount *mp, bool donew); 139 140 /* 141 * Global opts, taken by all filesystems 142 */ 143 static const char *global_opts[] = { 144 "errmsg", 145 "fstype", 146 "fspath", 147 "ro", 148 "rw", 149 "nosuid", 150 "noexec", 151 NULL 152 }; 153 154 static int 155 mount_init(void *mem, int size, int flags) 156 { 157 struct mount *mp; 158 159 mp = (struct mount *)mem; 160 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 161 mtx_init(&mp->mnt_listmtx, "struct mount vlist mtx", NULL, MTX_DEF); 162 lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0); 163 mp->mnt_pcpu = uma_zalloc_pcpu(pcpu_zone_16, M_WAITOK | M_ZERO); 164 mp->mnt_ref = 0; 165 mp->mnt_vfs_ops = 1; 166 mp->mnt_rootvnode = NULL; 167 return (0); 168 } 169 170 static void 171 mount_fini(void *mem, int size) 172 { 173 struct mount *mp; 174 175 mp = (struct mount *)mem; 176 uma_zfree_pcpu(pcpu_zone_16, mp->mnt_pcpu); 177 lockdestroy(&mp->mnt_explock); 178 mtx_destroy(&mp->mnt_listmtx); 179 mtx_destroy(&mp->mnt_mtx); 180 } 181 182 static void 183 vfs_mount_init(void *dummy __unused) 184 { 185 TIMEOUT_TASK_INIT(taskqueue_deferred_unmount, &deferred_unmount_task, 186 0, vfs_deferred_unmount, NULL); 187 deferred_unmount_retry_delay_hz = hz; 188 mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), NULL, 189 NULL, mount_init, mount_fini, UMA_ALIGN_CACHE, UMA_ZONE_NOFREE); 190 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 191 } 192 SYSINIT(vfs_mount, SI_SUB_VFS, SI_ORDER_ANY, vfs_mount_init, NULL); 193 194 /* 195 * --------------------------------------------------------------------- 196 * Functions for building and sanitizing the mount options 197 */ 198 199 /* Remove one mount option. */ 200 static void 201 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 202 { 203 204 TAILQ_REMOVE(opts, opt, link); 205 free(opt->name, M_MOUNT); 206 if (opt->value != NULL) 207 free(opt->value, M_MOUNT); 208 free(opt, M_MOUNT); 209 } 210 211 /* Release all resources related to the mount options. */ 212 void 213 vfs_freeopts(struct vfsoptlist *opts) 214 { 215 struct vfsopt *opt; 216 217 while (!TAILQ_EMPTY(opts)) { 218 opt = TAILQ_FIRST(opts); 219 vfs_freeopt(opts, opt); 220 } 221 free(opts, M_MOUNT); 222 } 223 224 void 225 vfs_deleteopt(struct vfsoptlist *opts, const char *name) 226 { 227 struct vfsopt *opt, *temp; 228 229 if (opts == NULL) 230 return; 231 TAILQ_FOREACH_SAFE(opt, opts, link, temp) { 232 if (strcmp(opt->name, name) == 0) 233 vfs_freeopt(opts, opt); 234 } 235 } 236 237 static int 238 vfs_isopt_ro(const char *opt) 239 { 240 241 if (strcmp(opt, "ro") == 0 || strcmp(opt, "rdonly") == 0 || 242 strcmp(opt, "norw") == 0) 243 return (1); 244 return (0); 245 } 246 247 static int 248 vfs_isopt_rw(const char *opt) 249 { 250 251 if (strcmp(opt, "rw") == 0 || strcmp(opt, "noro") == 0) 252 return (1); 253 return (0); 254 } 255 256 /* 257 * Check if options are equal (with or without the "no" prefix). 258 */ 259 static int 260 vfs_equalopts(const char *opt1, const char *opt2) 261 { 262 char *p; 263 264 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 265 if (strcmp(opt1, opt2) == 0) 266 return (1); 267 /* "noopt" vs. "opt" */ 268 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 269 return (1); 270 /* "opt" vs. "noopt" */ 271 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 272 return (1); 273 while ((p = strchr(opt1, '.')) != NULL && 274 !strncmp(opt1, opt2, ++p - opt1)) { 275 opt2 += p - opt1; 276 opt1 = p; 277 /* "foo.noopt" vs. "foo.opt" */ 278 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 279 return (1); 280 /* "foo.opt" vs. "foo.noopt" */ 281 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 282 return (1); 283 } 284 /* "ro" / "rdonly" / "norw" / "rw" / "noro" */ 285 if ((vfs_isopt_ro(opt1) || vfs_isopt_rw(opt1)) && 286 (vfs_isopt_ro(opt2) || vfs_isopt_rw(opt2))) 287 return (1); 288 return (0); 289 } 290 291 /* 292 * If a mount option is specified several times, 293 * (with or without the "no" prefix) only keep 294 * the last occurrence of it. 295 */ 296 static void 297 vfs_sanitizeopts(struct vfsoptlist *opts) 298 { 299 struct vfsopt *opt, *opt2, *tmp; 300 301 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 302 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 303 while (opt2 != NULL) { 304 if (vfs_equalopts(opt->name, opt2->name)) { 305 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 306 vfs_freeopt(opts, opt2); 307 opt2 = tmp; 308 } else { 309 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 310 } 311 } 312 } 313 } 314 315 /* 316 * Build a linked list of mount options from a struct uio. 317 */ 318 int 319 vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 320 { 321 struct vfsoptlist *opts; 322 struct vfsopt *opt; 323 size_t memused, namelen, optlen; 324 unsigned int i, iovcnt; 325 int error; 326 327 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 328 TAILQ_INIT(opts); 329 memused = 0; 330 iovcnt = auio->uio_iovcnt; 331 for (i = 0; i < iovcnt; i += 2) { 332 namelen = auio->uio_iov[i].iov_len; 333 optlen = auio->uio_iov[i + 1].iov_len; 334 memused += sizeof(struct vfsopt) + optlen + namelen; 335 /* 336 * Avoid consuming too much memory, and attempts to overflow 337 * memused. 338 */ 339 if (memused > VFS_MOUNTARG_SIZE_MAX || 340 optlen > VFS_MOUNTARG_SIZE_MAX || 341 namelen > VFS_MOUNTARG_SIZE_MAX) { 342 error = EINVAL; 343 goto bad; 344 } 345 346 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 347 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 348 opt->value = NULL; 349 opt->len = 0; 350 opt->pos = i / 2; 351 opt->seen = 0; 352 353 /* 354 * Do this early, so jumps to "bad" will free the current 355 * option. 356 */ 357 TAILQ_INSERT_TAIL(opts, opt, link); 358 359 if (auio->uio_segflg == UIO_SYSSPACE) { 360 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 361 } else { 362 error = copyin(auio->uio_iov[i].iov_base, opt->name, 363 namelen); 364 if (error) 365 goto bad; 366 } 367 /* Ensure names are null-terminated strings. */ 368 if (namelen == 0 || opt->name[namelen - 1] != '\0') { 369 error = EINVAL; 370 goto bad; 371 } 372 if (optlen != 0) { 373 opt->len = optlen; 374 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 375 if (auio->uio_segflg == UIO_SYSSPACE) { 376 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 377 optlen); 378 } else { 379 error = copyin(auio->uio_iov[i + 1].iov_base, 380 opt->value, optlen); 381 if (error) 382 goto bad; 383 } 384 } 385 } 386 vfs_sanitizeopts(opts); 387 *options = opts; 388 return (0); 389 bad: 390 vfs_freeopts(opts); 391 return (error); 392 } 393 394 /* 395 * Merge the old mount options with the new ones passed 396 * in the MNT_UPDATE case. 397 * 398 * XXX: This function will keep a "nofoo" option in the new 399 * options. E.g, if the option's canonical name is "foo", 400 * "nofoo" ends up in the mount point's active options. 401 */ 402 static void 403 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *oldopts) 404 { 405 struct vfsopt *opt, *new; 406 407 TAILQ_FOREACH(opt, oldopts, link) { 408 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 409 new->name = strdup(opt->name, M_MOUNT); 410 if (opt->len != 0) { 411 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 412 bcopy(opt->value, new->value, opt->len); 413 } else 414 new->value = NULL; 415 new->len = opt->len; 416 new->seen = opt->seen; 417 TAILQ_INSERT_HEAD(toopts, new, link); 418 } 419 vfs_sanitizeopts(toopts); 420 } 421 422 /* 423 * Mount a filesystem. 424 */ 425 #ifndef _SYS_SYSPROTO_H_ 426 struct nmount_args { 427 struct iovec *iovp; 428 unsigned int iovcnt; 429 int flags; 430 }; 431 #endif 432 int 433 sys_nmount(struct thread *td, struct nmount_args *uap) 434 { 435 struct uio *auio; 436 int error; 437 u_int iovcnt; 438 uint64_t flags; 439 440 /* 441 * Mount flags are now 64-bits. On 32-bit archtectures only 442 * 32-bits are passed in, but from here on everything handles 443 * 64-bit flags correctly. 444 */ 445 flags = uap->flags; 446 447 AUDIT_ARG_FFLAGS(flags); 448 CTR4(KTR_VFS, "%s: iovp %p with iovcnt %d and flags %d", __func__, 449 uap->iovp, uap->iovcnt, flags); 450 451 /* 452 * Filter out MNT_ROOTFS. We do not want clients of nmount() in 453 * userspace to set this flag, but we must filter it out if we want 454 * MNT_UPDATE on the root file system to work. 455 * MNT_ROOTFS should only be set by the kernel when mounting its 456 * root file system. 457 */ 458 flags &= ~MNT_ROOTFS; 459 460 iovcnt = uap->iovcnt; 461 /* 462 * Check that we have an even number of iovec's 463 * and that we have at least two options. 464 */ 465 if ((iovcnt & 1) || (iovcnt < 4)) { 466 CTR2(KTR_VFS, "%s: failed for invalid iovcnt %d", __func__, 467 uap->iovcnt); 468 return (EINVAL); 469 } 470 471 error = copyinuio(uap->iovp, iovcnt, &auio); 472 if (error) { 473 CTR2(KTR_VFS, "%s: failed for invalid uio op with %d errno", 474 __func__, error); 475 return (error); 476 } 477 error = vfs_donmount(td, flags, auio); 478 479 free(auio, M_IOV); 480 return (error); 481 } 482 483 /* 484 * --------------------------------------------------------------------- 485 * Various utility functions 486 */ 487 488 /* 489 * Get a reference on a mount point from a vnode. 490 * 491 * The vnode is allowed to be passed unlocked and race against dooming. Note in 492 * such case there are no guarantees the referenced mount point will still be 493 * associated with it after the function returns. 494 */ 495 struct mount * 496 vfs_ref_from_vp(struct vnode *vp) 497 { 498 struct mount *mp; 499 struct mount_pcpu *mpcpu; 500 501 mp = atomic_load_ptr(&vp->v_mount); 502 if (__predict_false(mp == NULL)) { 503 return (mp); 504 } 505 if (vfs_op_thread_enter(mp, mpcpu)) { 506 if (__predict_true(mp == vp->v_mount)) { 507 vfs_mp_count_add_pcpu(mpcpu, ref, 1); 508 vfs_op_thread_exit(mp, mpcpu); 509 } else { 510 vfs_op_thread_exit(mp, mpcpu); 511 mp = NULL; 512 } 513 } else { 514 MNT_ILOCK(mp); 515 if (mp == vp->v_mount) { 516 MNT_REF(mp); 517 MNT_IUNLOCK(mp); 518 } else { 519 MNT_IUNLOCK(mp); 520 mp = NULL; 521 } 522 } 523 return (mp); 524 } 525 526 void 527 vfs_ref(struct mount *mp) 528 { 529 struct mount_pcpu *mpcpu; 530 531 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 532 if (vfs_op_thread_enter(mp, mpcpu)) { 533 vfs_mp_count_add_pcpu(mpcpu, ref, 1); 534 vfs_op_thread_exit(mp, mpcpu); 535 return; 536 } 537 538 MNT_ILOCK(mp); 539 MNT_REF(mp); 540 MNT_IUNLOCK(mp); 541 } 542 543 /* 544 * Register ump as an upper mount of the mount associated with 545 * vnode vp. This registration will be tracked through 546 * mount_upper_node upper, which should be allocated by the 547 * caller and stored in per-mount data associated with mp. 548 * 549 * If successful, this function will return the mount associated 550 * with vp, and will ensure that it cannot be unmounted until 551 * ump has been unregistered as one of its upper mounts. 552 * 553 * Upon failure this function will return NULL. 554 */ 555 struct mount * 556 vfs_register_upper_from_vp(struct vnode *vp, struct mount *ump, 557 struct mount_upper_node *upper) 558 { 559 struct mount *mp; 560 561 mp = atomic_load_ptr(&vp->v_mount); 562 if (mp == NULL) 563 return (NULL); 564 MNT_ILOCK(mp); 565 if (mp != vp->v_mount || 566 ((mp->mnt_kern_flag & (MNTK_UNMOUNT | MNTK_RECURSE)) != 0)) { 567 MNT_IUNLOCK(mp); 568 return (NULL); 569 } 570 KASSERT(ump != mp, ("upper and lower mounts are identical")); 571 upper->mp = ump; 572 MNT_REF(mp); 573 TAILQ_INSERT_TAIL(&mp->mnt_uppers, upper, mnt_upper_link); 574 MNT_IUNLOCK(mp); 575 return (mp); 576 } 577 578 /* 579 * Register upper mount ump to receive vnode unlink/reclaim 580 * notifications from lower mount mp. This registration will 581 * be tracked through mount_upper_node upper, which should be 582 * allocated by the caller and stored in per-mount data 583 * associated with mp. 584 * 585 * ump must already be registered as an upper mount of mp 586 * through a call to vfs_register_upper_from_vp(). 587 */ 588 void 589 vfs_register_for_notification(struct mount *mp, struct mount *ump, 590 struct mount_upper_node *upper) 591 { 592 upper->mp = ump; 593 MNT_ILOCK(mp); 594 TAILQ_INSERT_TAIL(&mp->mnt_notify, upper, mnt_upper_link); 595 MNT_IUNLOCK(mp); 596 } 597 598 static void 599 vfs_drain_upper_locked(struct mount *mp) 600 { 601 mtx_assert(MNT_MTX(mp), MA_OWNED); 602 while (mp->mnt_upper_pending != 0) { 603 mp->mnt_kern_flag |= MNTK_UPPER_WAITER; 604 msleep(&mp->mnt_uppers, MNT_MTX(mp), 0, "mntupw", 0); 605 } 606 } 607 608 /* 609 * Undo a previous call to vfs_register_for_notification(). 610 * The mount represented by upper must be currently registered 611 * as an upper mount for mp. 612 */ 613 void 614 vfs_unregister_for_notification(struct mount *mp, 615 struct mount_upper_node *upper) 616 { 617 MNT_ILOCK(mp); 618 vfs_drain_upper_locked(mp); 619 TAILQ_REMOVE(&mp->mnt_notify, upper, mnt_upper_link); 620 MNT_IUNLOCK(mp); 621 } 622 623 /* 624 * Undo a previous call to vfs_register_upper_from_vp(). 625 * This must be done before mp can be unmounted. 626 */ 627 void 628 vfs_unregister_upper(struct mount *mp, struct mount_upper_node *upper) 629 { 630 MNT_ILOCK(mp); 631 KASSERT((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0, 632 ("registered upper with pending unmount")); 633 vfs_drain_upper_locked(mp); 634 TAILQ_REMOVE(&mp->mnt_uppers, upper, mnt_upper_link); 635 if ((mp->mnt_kern_flag & MNTK_TASKQUEUE_WAITER) != 0 && 636 TAILQ_EMPTY(&mp->mnt_uppers)) { 637 mp->mnt_kern_flag &= ~MNTK_TASKQUEUE_WAITER; 638 wakeup(&mp->mnt_taskqueue_link); 639 } 640 MNT_REL(mp); 641 MNT_IUNLOCK(mp); 642 } 643 644 void 645 vfs_rel(struct mount *mp) 646 { 647 struct mount_pcpu *mpcpu; 648 649 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 650 if (vfs_op_thread_enter(mp, mpcpu)) { 651 vfs_mp_count_sub_pcpu(mpcpu, ref, 1); 652 vfs_op_thread_exit(mp, mpcpu); 653 return; 654 } 655 656 MNT_ILOCK(mp); 657 MNT_REL(mp); 658 MNT_IUNLOCK(mp); 659 } 660 661 /* 662 * Allocate and initialize the mount point struct. 663 */ 664 struct mount * 665 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath, 666 struct ucred *cred) 667 { 668 struct mount *mp; 669 670 mp = uma_zalloc(mount_zone, M_WAITOK); 671 bzero(&mp->mnt_startzero, 672 __rangeof(struct mount, mnt_startzero, mnt_endzero)); 673 mp->mnt_kern_flag = 0; 674 mp->mnt_flag = 0; 675 mp->mnt_rootvnode = NULL; 676 mp->mnt_vnodecovered = NULL; 677 mp->mnt_op = NULL; 678 mp->mnt_vfc = NULL; 679 TAILQ_INIT(&mp->mnt_nvnodelist); 680 mp->mnt_nvnodelistsize = 0; 681 TAILQ_INIT(&mp->mnt_lazyvnodelist); 682 mp->mnt_lazyvnodelistsize = 0; 683 MPPASS(mp->mnt_ref == 0 && mp->mnt_lockref == 0 && 684 mp->mnt_writeopcount == 0, mp); 685 MPASSERT(mp->mnt_vfs_ops == 1, mp, 686 ("vfs_ops should be 1 but %d found", mp->mnt_vfs_ops)); 687 (void) vfs_busy(mp, MBF_NOWAIT); 688 atomic_add_acq_int(&vfsp->vfc_refcount, 1); 689 mp->mnt_op = vfsp->vfc_vfsops; 690 mp->mnt_vfc = vfsp; 691 mp->mnt_stat.f_type = vfsp->vfc_typenum; 692 mp->mnt_gen++; 693 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 694 mp->mnt_vnodecovered = vp; 695 mp->mnt_cred = crdup(cred); 696 mp->mnt_stat.f_owner = cred->cr_uid; 697 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 698 mp->mnt_iosize_max = DFLTPHYS; 699 #ifdef MAC 700 mac_mount_init(mp); 701 mac_mount_create(cred, mp); 702 #endif 703 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0); 704 mp->mnt_upper_pending = 0; 705 TAILQ_INIT(&mp->mnt_uppers); 706 TAILQ_INIT(&mp->mnt_notify); 707 mp->mnt_taskqueue_flags = 0; 708 mp->mnt_unmount_retries = 0; 709 return (mp); 710 } 711 712 /* 713 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 714 */ 715 void 716 vfs_mount_destroy(struct mount *mp) 717 { 718 719 MPPASS(mp->mnt_vfs_ops != 0, mp); 720 721 vfs_assert_mount_counters(mp); 722 723 MNT_ILOCK(mp); 724 mp->mnt_kern_flag |= MNTK_REFEXPIRE; 725 if (mp->mnt_kern_flag & MNTK_MWAIT) { 726 mp->mnt_kern_flag &= ~MNTK_MWAIT; 727 wakeup(mp); 728 } 729 while (mp->mnt_ref) 730 msleep(mp, MNT_MTX(mp), PVFS, "mntref", 0); 731 KASSERT(mp->mnt_ref == 0, 732 ("%s: invalid refcount in the drain path @ %s:%d", __func__, 733 __FILE__, __LINE__)); 734 MPPASS(mp->mnt_writeopcount == 0, mp); 735 MPPASS(mp->mnt_secondary_writes == 0, mp); 736 atomic_subtract_rel_int(&mp->mnt_vfc->vfc_refcount, 1); 737 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) { 738 struct vnode *vp; 739 740 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) 741 vn_printf(vp, "dangling vnode "); 742 panic("unmount: dangling vnode"); 743 } 744 KASSERT(mp->mnt_upper_pending == 0, ("mnt_upper_pending")); 745 KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers")); 746 KASSERT(TAILQ_EMPTY(&mp->mnt_notify), ("mnt_notify")); 747 MPPASS(mp->mnt_nvnodelistsize == 0, mp); 748 MPPASS(mp->mnt_lazyvnodelistsize == 0, mp); 749 MPPASS(mp->mnt_lockref == 0, mp); 750 MNT_IUNLOCK(mp); 751 752 MPASSERT(mp->mnt_vfs_ops == 1, mp, 753 ("vfs_ops should be 1 but %d found", mp->mnt_vfs_ops)); 754 755 MPASSERT(mp->mnt_rootvnode == NULL, mp, 756 ("mount point still has a root vnode %p", mp->mnt_rootvnode)); 757 758 if (mp->mnt_vnodecovered != NULL) 759 vrele(mp->mnt_vnodecovered); 760 #ifdef MAC 761 mac_mount_destroy(mp); 762 #endif 763 if (mp->mnt_opt != NULL) 764 vfs_freeopts(mp->mnt_opt); 765 if (mp->mnt_exjail != NULL) { 766 atomic_subtract_int(&mp->mnt_exjail->cr_prison->pr_exportcnt, 767 1); 768 crfree(mp->mnt_exjail); 769 } 770 if (mp->mnt_export != NULL) { 771 vfs_free_addrlist(mp->mnt_export); 772 free(mp->mnt_export, M_MOUNT); 773 } 774 crfree(mp->mnt_cred); 775 uma_zfree(mount_zone, mp); 776 } 777 778 static bool 779 vfs_should_downgrade_to_ro_mount(uint64_t fsflags, int error) 780 { 781 /* This is an upgrade of an exisiting mount. */ 782 if ((fsflags & MNT_UPDATE) != 0) 783 return (false); 784 /* This is already an R/O mount. */ 785 if ((fsflags & MNT_RDONLY) != 0) 786 return (false); 787 788 switch (error) { 789 case ENODEV: /* generic, geom, ... */ 790 case EACCES: /* cam/scsi, ... */ 791 case EROFS: /* md, mmcsd, ... */ 792 /* 793 * These errors can be returned by the storage layer to signal 794 * that the media is read-only. No harm in the R/O mount 795 * attempt if the error was returned for some other reason. 796 */ 797 return (true); 798 default: 799 return (false); 800 } 801 } 802 803 int 804 vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions) 805 { 806 struct vfsoptlist *optlist; 807 struct vfsopt *opt, *tmp_opt; 808 char *fstype, *fspath, *errmsg; 809 int error, fstypelen, fspathlen, errmsg_len, errmsg_pos; 810 bool autoro, has_nonexport, jail_export; 811 812 errmsg = fspath = NULL; 813 errmsg_len = fspathlen = 0; 814 errmsg_pos = -1; 815 autoro = default_autoro; 816 817 error = vfs_buildopts(fsoptions, &optlist); 818 if (error) 819 return (error); 820 821 if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0) 822 errmsg_pos = vfs_getopt_pos(optlist, "errmsg"); 823 824 /* 825 * We need these two options before the others, 826 * and they are mandatory for any filesystem. 827 * Ensure they are NUL terminated as well. 828 */ 829 fstypelen = 0; 830 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 831 if (error || fstypelen <= 0 || fstype[fstypelen - 1] != '\0') { 832 error = EINVAL; 833 if (errmsg != NULL) 834 strncpy(errmsg, "Invalid fstype", errmsg_len); 835 goto bail; 836 } 837 fspathlen = 0; 838 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 839 if (error || fspathlen <= 0 || fspath[fspathlen - 1] != '\0') { 840 error = EINVAL; 841 if (errmsg != NULL) 842 strncpy(errmsg, "Invalid fspath", errmsg_len); 843 goto bail; 844 } 845 846 /* 847 * Check to see that "export" is only used with the "update", "fstype", 848 * "fspath", "from" and "errmsg" options when in a vnet jail. 849 * These are the ones used to set/update exports by mountd(8). 850 * If only the above options are set in a jail that can run mountd(8), 851 * then the jail_export argument of vfs_domount() will be true. 852 * When jail_export is true, the vfs_suser() check does not cause 853 * failure, but limits the update to exports only. 854 * This allows mountd(8) running within the vnet jail 855 * to export file systems visible within the jail, but 856 * mounted outside of the jail. 857 */ 858 /* 859 * We need to see if we have the "update" option 860 * before we call vfs_domount(), since vfs_domount() has special 861 * logic based on MNT_UPDATE. This is very important 862 * when we want to update the root filesystem. 863 */ 864 has_nonexport = false; 865 jail_export = false; 866 TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) { 867 int do_freeopt = 0; 868 869 if (jailed(td->td_ucred) && 870 strcmp(opt->name, "export") != 0 && 871 strcmp(opt->name, "update") != 0 && 872 strcmp(opt->name, "fstype") != 0 && 873 strcmp(opt->name, "fspath") != 0 && 874 strcmp(opt->name, "from") != 0 && 875 strcmp(opt->name, "errmsg") != 0) 876 has_nonexport = true; 877 if (strcmp(opt->name, "update") == 0) { 878 fsflags |= MNT_UPDATE; 879 do_freeopt = 1; 880 } 881 else if (strcmp(opt->name, "async") == 0) 882 fsflags |= MNT_ASYNC; 883 else if (strcmp(opt->name, "force") == 0) { 884 fsflags |= MNT_FORCE; 885 do_freeopt = 1; 886 } 887 else if (strcmp(opt->name, "reload") == 0) { 888 fsflags |= MNT_RELOAD; 889 do_freeopt = 1; 890 } 891 else if (strcmp(opt->name, "multilabel") == 0) 892 fsflags |= MNT_MULTILABEL; 893 else if (strcmp(opt->name, "noasync") == 0) 894 fsflags &= ~MNT_ASYNC; 895 else if (strcmp(opt->name, "noatime") == 0) 896 fsflags |= MNT_NOATIME; 897 else if (strcmp(opt->name, "atime") == 0) { 898 free(opt->name, M_MOUNT); 899 opt->name = strdup("nonoatime", M_MOUNT); 900 } 901 else if (strcmp(opt->name, "noclusterr") == 0) 902 fsflags |= MNT_NOCLUSTERR; 903 else if (strcmp(opt->name, "clusterr") == 0) { 904 free(opt->name, M_MOUNT); 905 opt->name = strdup("nonoclusterr", M_MOUNT); 906 } 907 else if (strcmp(opt->name, "noclusterw") == 0) 908 fsflags |= MNT_NOCLUSTERW; 909 else if (strcmp(opt->name, "clusterw") == 0) { 910 free(opt->name, M_MOUNT); 911 opt->name = strdup("nonoclusterw", M_MOUNT); 912 } 913 else if (strcmp(opt->name, "noexec") == 0) 914 fsflags |= MNT_NOEXEC; 915 else if (strcmp(opt->name, "exec") == 0) { 916 free(opt->name, M_MOUNT); 917 opt->name = strdup("nonoexec", M_MOUNT); 918 } 919 else if (strcmp(opt->name, "nosuid") == 0) 920 fsflags |= MNT_NOSUID; 921 else if (strcmp(opt->name, "suid") == 0) { 922 free(opt->name, M_MOUNT); 923 opt->name = strdup("nonosuid", M_MOUNT); 924 } 925 else if (strcmp(opt->name, "nosymfollow") == 0) 926 fsflags |= MNT_NOSYMFOLLOW; 927 else if (strcmp(opt->name, "symfollow") == 0) { 928 free(opt->name, M_MOUNT); 929 opt->name = strdup("nonosymfollow", M_MOUNT); 930 } 931 else if (strcmp(opt->name, "noro") == 0) { 932 fsflags &= ~MNT_RDONLY; 933 autoro = false; 934 } 935 else if (strcmp(opt->name, "rw") == 0) { 936 fsflags &= ~MNT_RDONLY; 937 autoro = false; 938 } 939 else if (strcmp(opt->name, "ro") == 0) { 940 fsflags |= MNT_RDONLY; 941 autoro = false; 942 } 943 else if (strcmp(opt->name, "rdonly") == 0) { 944 free(opt->name, M_MOUNT); 945 opt->name = strdup("ro", M_MOUNT); 946 fsflags |= MNT_RDONLY; 947 autoro = false; 948 } 949 else if (strcmp(opt->name, "autoro") == 0) { 950 do_freeopt = 1; 951 autoro = true; 952 } 953 else if (strcmp(opt->name, "suiddir") == 0) 954 fsflags |= MNT_SUIDDIR; 955 else if (strcmp(opt->name, "sync") == 0) 956 fsflags |= MNT_SYNCHRONOUS; 957 else if (strcmp(opt->name, "union") == 0) 958 fsflags |= MNT_UNION; 959 else if (strcmp(opt->name, "export") == 0) { 960 fsflags |= MNT_EXPORTED; 961 jail_export = true; 962 } else if (strcmp(opt->name, "automounted") == 0) { 963 fsflags |= MNT_AUTOMOUNTED; 964 do_freeopt = 1; 965 } else if (strcmp(opt->name, "nocover") == 0) { 966 fsflags |= MNT_NOCOVER; 967 do_freeopt = 1; 968 } else if (strcmp(opt->name, "cover") == 0) { 969 fsflags &= ~MNT_NOCOVER; 970 do_freeopt = 1; 971 } else if (strcmp(opt->name, "emptydir") == 0) { 972 fsflags |= MNT_EMPTYDIR; 973 do_freeopt = 1; 974 } else if (strcmp(opt->name, "noemptydir") == 0) { 975 fsflags &= ~MNT_EMPTYDIR; 976 do_freeopt = 1; 977 } 978 if (do_freeopt) 979 vfs_freeopt(optlist, opt); 980 } 981 982 /* 983 * Be ultra-paranoid about making sure the type and fspath 984 * variables will fit in our mp buffers, including the 985 * terminating NUL. 986 */ 987 if (fstypelen > MFSNAMELEN || fspathlen > MNAMELEN) { 988 error = ENAMETOOLONG; 989 goto bail; 990 } 991 992 /* 993 * If has_nonexport is true or the caller is not running within a 994 * vnet prison that can run mountd(8), set jail_export false. 995 */ 996 if (has_nonexport || !jailed(td->td_ucred) || 997 !prison_check_nfsd(td->td_ucred)) 998 jail_export = false; 999 1000 error = vfs_domount(td, fstype, fspath, fsflags, jail_export, &optlist); 1001 if (error == ENOENT) { 1002 error = EINVAL; 1003 if (errmsg != NULL) 1004 strncpy(errmsg, "Invalid fstype", errmsg_len); 1005 goto bail; 1006 } 1007 1008 /* 1009 * See if we can mount in the read-only mode if the error code suggests 1010 * that it could be possible and the mount options allow for that. 1011 * Never try it if "[no]{ro|rw}" has been explicitly requested and not 1012 * overridden by "autoro". 1013 */ 1014 if (autoro && vfs_should_downgrade_to_ro_mount(fsflags, error)) { 1015 printf("%s: R/W mount failed, possibly R/O media," 1016 " trying R/O mount\n", __func__); 1017 fsflags |= MNT_RDONLY; 1018 error = vfs_domount(td, fstype, fspath, fsflags, jail_export, 1019 &optlist); 1020 } 1021 bail: 1022 /* copyout the errmsg */ 1023 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt) 1024 && errmsg_len > 0 && errmsg != NULL) { 1025 if (fsoptions->uio_segflg == UIO_SYSSPACE) { 1026 bcopy(errmsg, 1027 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 1028 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 1029 } else { 1030 copyout(errmsg, 1031 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 1032 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 1033 } 1034 } 1035 1036 if (optlist != NULL) 1037 vfs_freeopts(optlist); 1038 return (error); 1039 } 1040 1041 /* 1042 * Old mount API. 1043 */ 1044 #ifndef _SYS_SYSPROTO_H_ 1045 struct mount_args { 1046 char *type; 1047 char *path; 1048 int flags; 1049 caddr_t data; 1050 }; 1051 #endif 1052 /* ARGSUSED */ 1053 int 1054 sys_mount(struct thread *td, struct mount_args *uap) 1055 { 1056 char *fstype; 1057 struct vfsconf *vfsp = NULL; 1058 struct mntarg *ma = NULL; 1059 uint64_t flags; 1060 int error; 1061 1062 /* 1063 * Mount flags are now 64-bits. On 32-bit architectures only 1064 * 32-bits are passed in, but from here on everything handles 1065 * 64-bit flags correctly. 1066 */ 1067 flags = uap->flags; 1068 1069 AUDIT_ARG_FFLAGS(flags); 1070 1071 /* 1072 * Filter out MNT_ROOTFS. We do not want clients of mount() in 1073 * userspace to set this flag, but we must filter it out if we want 1074 * MNT_UPDATE on the root file system to work. 1075 * MNT_ROOTFS should only be set by the kernel when mounting its 1076 * root file system. 1077 */ 1078 flags &= ~MNT_ROOTFS; 1079 1080 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 1081 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 1082 if (error) { 1083 free(fstype, M_TEMP); 1084 return (error); 1085 } 1086 1087 AUDIT_ARG_TEXT(fstype); 1088 vfsp = vfs_byname_kld(fstype, td, &error); 1089 free(fstype, M_TEMP); 1090 if (vfsp == NULL) 1091 return (ENOENT); 1092 if (((vfsp->vfc_flags & VFCF_SBDRY) != 0 && 1093 vfsp->vfc_vfsops_sd->vfs_cmount == NULL) || 1094 ((vfsp->vfc_flags & VFCF_SBDRY) == 0 && 1095 vfsp->vfc_vfsops->vfs_cmount == NULL)) 1096 return (EOPNOTSUPP); 1097 1098 ma = mount_argsu(ma, "fstype", uap->type, MFSNAMELEN); 1099 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 1100 ma = mount_argb(ma, flags & MNT_RDONLY, "noro"); 1101 ma = mount_argb(ma, !(flags & MNT_NOSUID), "nosuid"); 1102 ma = mount_argb(ma, !(flags & MNT_NOEXEC), "noexec"); 1103 1104 if ((vfsp->vfc_flags & VFCF_SBDRY) != 0) 1105 return (vfsp->vfc_vfsops_sd->vfs_cmount(ma, uap->data, flags)); 1106 return (vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, flags)); 1107 } 1108 1109 /* 1110 * vfs_domount_first(): first file system mount (not update) 1111 */ 1112 static int 1113 vfs_domount_first( 1114 struct thread *td, /* Calling thread. */ 1115 struct vfsconf *vfsp, /* File system type. */ 1116 char *fspath, /* Mount path. */ 1117 struct vnode *vp, /* Vnode to be covered. */ 1118 uint64_t fsflags, /* Flags common to all filesystems. */ 1119 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1120 ) 1121 { 1122 struct vattr va; 1123 struct mount *mp; 1124 struct vnode *newdp, *rootvp; 1125 int error, error1; 1126 bool unmounted; 1127 1128 ASSERT_VOP_ELOCKED(vp, __func__); 1129 KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here")); 1130 1131 /* 1132 * If the jail of the calling thread lacks permission for this type of 1133 * file system, or is trying to cover its own root, deny immediately. 1134 */ 1135 if (jailed(td->td_ucred) && (!prison_allow(td->td_ucred, 1136 vfsp->vfc_prison_flag) || vp == td->td_ucred->cr_prison->pr_root)) { 1137 vput(vp); 1138 return (EPERM); 1139 } 1140 1141 /* 1142 * If the user is not root, ensure that they own the directory 1143 * onto which we are attempting to mount. 1144 */ 1145 error = VOP_GETATTR(vp, &va, td->td_ucred); 1146 if (error == 0 && va.va_uid != td->td_ucred->cr_uid) 1147 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN); 1148 if (error == 0) 1149 error = vinvalbuf(vp, V_SAVE, 0, 0); 1150 if (vfsp->vfc_flags & VFCF_FILEMOUNT) { 1151 if (error == 0 && vp->v_type != VDIR && vp->v_type != VREG) 1152 error = EINVAL; 1153 /* 1154 * For file mounts, ensure that there is only one hardlink to the file. 1155 */ 1156 if (error == 0 && vp->v_type == VREG && va.va_nlink != 1) 1157 error = EINVAL; 1158 } else { 1159 if (error == 0 && vp->v_type != VDIR) 1160 error = ENOTDIR; 1161 } 1162 if (error == 0 && (fsflags & MNT_EMPTYDIR) != 0) 1163 error = vn_dir_check_empty(vp); 1164 if (error == 0) { 1165 VI_LOCK(vp); 1166 if ((vp->v_iflag & VI_MOUNT) == 0 && vp->v_mountedhere == NULL) 1167 vp->v_iflag |= VI_MOUNT; 1168 else 1169 error = EBUSY; 1170 VI_UNLOCK(vp); 1171 } 1172 if (error != 0) { 1173 vput(vp); 1174 return (error); 1175 } 1176 vn_seqc_write_begin(vp); 1177 VOP_UNLOCK(vp); 1178 1179 /* Allocate and initialize the filesystem. */ 1180 mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred); 1181 /* XXXMAC: pass to vfs_mount_alloc? */ 1182 mp->mnt_optnew = *optlist; 1183 /* Set the mount level flags. */ 1184 mp->mnt_flag = (fsflags & 1185 (MNT_UPDATEMASK | MNT_ROOTFS | MNT_RDONLY | MNT_FORCE)); 1186 1187 /* 1188 * Mount the filesystem. 1189 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1190 * get. No freeing of cn_pnbuf. 1191 */ 1192 error1 = 0; 1193 unmounted = true; 1194 if ((error = VFS_MOUNT(mp)) != 0 || 1195 (error1 = VFS_STATFS(mp, &mp->mnt_stat)) != 0 || 1196 (error1 = VFS_ROOT(mp, LK_EXCLUSIVE, &newdp)) != 0) { 1197 rootvp = NULL; 1198 if (error1 != 0) { 1199 MPASS(error == 0); 1200 rootvp = vfs_cache_root_clear(mp); 1201 if (rootvp != NULL) { 1202 vhold(rootvp); 1203 vrele(rootvp); 1204 } 1205 (void)vn_start_write(NULL, &mp, V_WAIT); 1206 MNT_ILOCK(mp); 1207 mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_UNMOUNTF; 1208 MNT_IUNLOCK(mp); 1209 VFS_PURGE(mp); 1210 error = VFS_UNMOUNT(mp, 0); 1211 vn_finished_write(mp); 1212 if (error != 0) { 1213 printf( 1214 "failed post-mount (%d): rollback unmount returned %d\n", 1215 error1, error); 1216 unmounted = false; 1217 } 1218 error = error1; 1219 } 1220 vfs_unbusy(mp); 1221 mp->mnt_vnodecovered = NULL; 1222 if (unmounted) { 1223 /* XXXKIB wait for mnt_lockref drain? */ 1224 vfs_mount_destroy(mp); 1225 } 1226 VI_LOCK(vp); 1227 vp->v_iflag &= ~VI_MOUNT; 1228 VI_UNLOCK(vp); 1229 if (rootvp != NULL) { 1230 vn_seqc_write_end(rootvp); 1231 vdrop(rootvp); 1232 } 1233 vn_seqc_write_end(vp); 1234 vrele(vp); 1235 return (error); 1236 } 1237 vn_seqc_write_begin(newdp); 1238 VOP_UNLOCK(newdp); 1239 1240 if (mp->mnt_opt != NULL) 1241 vfs_freeopts(mp->mnt_opt); 1242 mp->mnt_opt = mp->mnt_optnew; 1243 *optlist = NULL; 1244 1245 /* 1246 * Prevent external consumers of mount options from reading mnt_optnew. 1247 */ 1248 mp->mnt_optnew = NULL; 1249 1250 MNT_ILOCK(mp); 1251 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 1252 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 1253 mp->mnt_kern_flag |= MNTK_ASYNC; 1254 else 1255 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1256 MNT_IUNLOCK(mp); 1257 1258 /* 1259 * VIRF_MOUNTPOINT and v_mountedhere need to be set under the 1260 * vp lock to satisfy vfs_lookup() requirements. 1261 */ 1262 VOP_LOCK(vp, LK_EXCLUSIVE | LK_RETRY); 1263 VI_LOCK(vp); 1264 vn_irflag_set_locked(vp, VIRF_MOUNTPOINT); 1265 vp->v_mountedhere = mp; 1266 VI_UNLOCK(vp); 1267 VOP_UNLOCK(vp); 1268 cache_purge(vp); 1269 1270 /* 1271 * We need to lock both vnodes. 1272 * 1273 * Use vn_lock_pair to avoid establishing an ordering between vnodes 1274 * from different filesystems. 1275 */ 1276 vn_lock_pair(vp, false, LK_EXCLUSIVE, newdp, false, LK_EXCLUSIVE); 1277 1278 VI_LOCK(vp); 1279 vp->v_iflag &= ~VI_MOUNT; 1280 VI_UNLOCK(vp); 1281 /* Place the new filesystem at the end of the mount list. */ 1282 mtx_lock(&mountlist_mtx); 1283 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1284 mtx_unlock(&mountlist_mtx); 1285 vfs_event_signal(NULL, VQ_MOUNT, 0); 1286 VOP_UNLOCK(vp); 1287 EVENTHANDLER_DIRECT_INVOKE(vfs_mounted, mp, newdp, td); 1288 VOP_UNLOCK(newdp); 1289 mount_devctl_event("MOUNT", mp, false); 1290 mountcheckdirs(vp, newdp); 1291 vn_seqc_write_end(vp); 1292 vn_seqc_write_end(newdp); 1293 vrele(newdp); 1294 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1295 vfs_allocate_syncvnode(mp); 1296 vfs_op_exit(mp); 1297 vfs_unbusy(mp); 1298 return (0); 1299 } 1300 1301 /* 1302 * vfs_domount_update(): update of mounted file system 1303 */ 1304 static int 1305 vfs_domount_update( 1306 struct thread *td, /* Calling thread. */ 1307 struct vnode *vp, /* Mount point vnode. */ 1308 uint64_t fsflags, /* Flags common to all filesystems. */ 1309 bool jail_export, /* Got export option in vnet prison. */ 1310 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1311 ) 1312 { 1313 struct export_args export; 1314 struct o2export_args o2export; 1315 struct vnode *rootvp; 1316 void *bufp; 1317 struct mount *mp; 1318 int error, export_error, i, len; 1319 uint64_t flag; 1320 gid_t *grps; 1321 bool vfs_suser_failed; 1322 1323 ASSERT_VOP_ELOCKED(vp, __func__); 1324 KASSERT((fsflags & MNT_UPDATE) != 0, ("MNT_UPDATE should be here")); 1325 mp = vp->v_mount; 1326 1327 if ((vp->v_vflag & VV_ROOT) == 0) { 1328 if (vfs_copyopt(*optlist, "export", &export, sizeof(export)) 1329 == 0) 1330 error = EXDEV; 1331 else 1332 error = EINVAL; 1333 vput(vp); 1334 return (error); 1335 } 1336 1337 /* 1338 * We only allow the filesystem to be reloaded if it 1339 * is currently mounted read-only. 1340 */ 1341 flag = mp->mnt_flag; 1342 if ((fsflags & MNT_RELOAD) != 0 && (flag & MNT_RDONLY) == 0) { 1343 vput(vp); 1344 return (EOPNOTSUPP); /* Needs translation */ 1345 } 1346 /* 1347 * Only privileged root, or (if MNT_USER is set) the user that 1348 * did the original mount is permitted to update it. 1349 */ 1350 /* 1351 * For the case of mountd(8) doing exports in a jail, the vfs_suser() 1352 * call does not cause failure. vfs_domount() has already checked 1353 * that "root" is doing this and vfs_suser() will fail when 1354 * the file system has been mounted outside the jail. 1355 * jail_export set true indicates that "export" is not mixed 1356 * with other options that change mount behaviour. 1357 */ 1358 vfs_suser_failed = false; 1359 error = vfs_suser(mp, td); 1360 if (jail_export && error != 0) { 1361 error = 0; 1362 vfs_suser_failed = true; 1363 } 1364 if (error != 0) { 1365 vput(vp); 1366 return (error); 1367 } 1368 if (vfs_busy(mp, MBF_NOWAIT)) { 1369 vput(vp); 1370 return (EBUSY); 1371 } 1372 VI_LOCK(vp); 1373 if ((vp->v_iflag & VI_MOUNT) != 0 || vp->v_mountedhere != NULL) { 1374 VI_UNLOCK(vp); 1375 vfs_unbusy(mp); 1376 vput(vp); 1377 return (EBUSY); 1378 } 1379 vp->v_iflag |= VI_MOUNT; 1380 VI_UNLOCK(vp); 1381 VOP_UNLOCK(vp); 1382 1383 vfs_op_enter(mp); 1384 vn_seqc_write_begin(vp); 1385 1386 rootvp = NULL; 1387 MNT_ILOCK(mp); 1388 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1389 MNT_IUNLOCK(mp); 1390 error = EBUSY; 1391 goto end; 1392 } 1393 if (vfs_suser_failed) { 1394 KASSERT((fsflags & (MNT_EXPORTED | MNT_UPDATE)) == 1395 (MNT_EXPORTED | MNT_UPDATE), 1396 ("%s: jailed export did not set expected fsflags", 1397 __func__)); 1398 /* 1399 * For this case, only MNT_UPDATE and 1400 * MNT_EXPORTED have been set in fsflags 1401 * by the options. Only set MNT_UPDATE, 1402 * since that is the one that would be set 1403 * when set in fsflags, below. 1404 */ 1405 mp->mnt_flag |= MNT_UPDATE; 1406 } else { 1407 mp->mnt_flag &= ~MNT_UPDATEMASK; 1408 mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | 1409 MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY); 1410 if ((mp->mnt_flag & MNT_ASYNC) == 0) 1411 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1412 } 1413 rootvp = vfs_cache_root_clear(mp); 1414 MNT_IUNLOCK(mp); 1415 mp->mnt_optnew = *optlist; 1416 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 1417 1418 /* 1419 * Mount the filesystem. 1420 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1421 * get. No freeing of cn_pnbuf. 1422 */ 1423 /* 1424 * For the case of mountd(8) doing exports from within a vnet jail, 1425 * "from" is typically not set correctly such that VFS_MOUNT() will 1426 * return ENOENT. It is not obvious that VFS_MOUNT() ever needs to be 1427 * called when mountd is doing exports, but this check only applies to 1428 * the specific case where it is running inside a vnet jail, to 1429 * avoid any POLA violation. 1430 */ 1431 error = 0; 1432 if (!jail_export) 1433 error = VFS_MOUNT(mp); 1434 1435 export_error = 0; 1436 /* Process the export option. */ 1437 if (error == 0 && vfs_getopt(mp->mnt_optnew, "export", &bufp, 1438 &len) == 0) { 1439 /* Assume that there is only 1 ABI for each length. */ 1440 switch (len) { 1441 case (sizeof(struct oexport_args)): 1442 bzero(&o2export, sizeof(o2export)); 1443 /* FALLTHROUGH */ 1444 case (sizeof(o2export)): 1445 bcopy(bufp, &o2export, len); 1446 export.ex_flags = (uint64_t)o2export.ex_flags; 1447 export.ex_root = o2export.ex_root; 1448 export.ex_uid = o2export.ex_anon.cr_uid; 1449 export.ex_groups = NULL; 1450 export.ex_ngroups = o2export.ex_anon.cr_ngroups; 1451 if (export.ex_ngroups > 0) { 1452 if (export.ex_ngroups <= XU_NGROUPS) { 1453 export.ex_groups = malloc( 1454 export.ex_ngroups * sizeof(gid_t), 1455 M_TEMP, M_WAITOK); 1456 for (i = 0; i < export.ex_ngroups; i++) 1457 export.ex_groups[i] = 1458 o2export.ex_anon.cr_groups[i]; 1459 } else 1460 export_error = EINVAL; 1461 } else if (export.ex_ngroups < 0) 1462 export_error = EINVAL; 1463 export.ex_addr = o2export.ex_addr; 1464 export.ex_addrlen = o2export.ex_addrlen; 1465 export.ex_mask = o2export.ex_mask; 1466 export.ex_masklen = o2export.ex_masklen; 1467 export.ex_indexfile = o2export.ex_indexfile; 1468 export.ex_numsecflavors = o2export.ex_numsecflavors; 1469 if (export.ex_numsecflavors < MAXSECFLAVORS) { 1470 for (i = 0; i < export.ex_numsecflavors; i++) 1471 export.ex_secflavors[i] = 1472 o2export.ex_secflavors[i]; 1473 } else 1474 export_error = EINVAL; 1475 if (export_error == 0) 1476 export_error = vfs_export(mp, &export, true); 1477 free(export.ex_groups, M_TEMP); 1478 break; 1479 case (sizeof(export)): 1480 bcopy(bufp, &export, len); 1481 grps = NULL; 1482 if (export.ex_ngroups > 0) { 1483 if (export.ex_ngroups <= NGROUPS_MAX) { 1484 grps = malloc(export.ex_ngroups * 1485 sizeof(gid_t), M_TEMP, M_WAITOK); 1486 export_error = copyin(export.ex_groups, 1487 grps, export.ex_ngroups * 1488 sizeof(gid_t)); 1489 if (export_error == 0) 1490 export.ex_groups = grps; 1491 } else 1492 export_error = EINVAL; 1493 } else if (export.ex_ngroups == 0) 1494 export.ex_groups = NULL; 1495 else 1496 export_error = EINVAL; 1497 if (export_error == 0) 1498 export_error = vfs_export(mp, &export, true); 1499 free(grps, M_TEMP); 1500 break; 1501 default: 1502 export_error = EINVAL; 1503 break; 1504 } 1505 } 1506 1507 MNT_ILOCK(mp); 1508 if (error == 0) { 1509 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | 1510 MNT_SNAPSHOT); 1511 } else { 1512 /* 1513 * If we fail, restore old mount flags. MNT_QUOTA is special, 1514 * because it is not part of MNT_UPDATEMASK, but it could have 1515 * changed in the meantime if quotactl(2) was called. 1516 * All in all we want current value of MNT_QUOTA, not the old 1517 * one. 1518 */ 1519 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA); 1520 } 1521 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 1522 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 1523 mp->mnt_kern_flag |= MNTK_ASYNC; 1524 else 1525 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1526 MNT_IUNLOCK(mp); 1527 1528 if (error != 0) 1529 goto end; 1530 1531 mount_devctl_event("REMOUNT", mp, true); 1532 if (mp->mnt_opt != NULL) 1533 vfs_freeopts(mp->mnt_opt); 1534 mp->mnt_opt = mp->mnt_optnew; 1535 *optlist = NULL; 1536 (void)VFS_STATFS(mp, &mp->mnt_stat); 1537 /* 1538 * Prevent external consumers of mount options from reading 1539 * mnt_optnew. 1540 */ 1541 mp->mnt_optnew = NULL; 1542 1543 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1544 vfs_allocate_syncvnode(mp); 1545 else 1546 vfs_deallocate_syncvnode(mp); 1547 end: 1548 vfs_op_exit(mp); 1549 if (rootvp != NULL) { 1550 vn_seqc_write_end(rootvp); 1551 vrele(rootvp); 1552 } 1553 vn_seqc_write_end(vp); 1554 vfs_unbusy(mp); 1555 VI_LOCK(vp); 1556 vp->v_iflag &= ~VI_MOUNT; 1557 VI_UNLOCK(vp); 1558 vrele(vp); 1559 return (error != 0 ? error : export_error); 1560 } 1561 1562 /* 1563 * vfs_domount(): actually attempt a filesystem mount. 1564 */ 1565 static int 1566 vfs_domount( 1567 struct thread *td, /* Calling thread. */ 1568 const char *fstype, /* Filesystem type. */ 1569 char *fspath, /* Mount path. */ 1570 uint64_t fsflags, /* Flags common to all filesystems. */ 1571 bool jail_export, /* Got export option in vnet prison. */ 1572 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1573 ) 1574 { 1575 struct vfsconf *vfsp; 1576 struct nameidata nd; 1577 struct vnode *vp; 1578 char *pathbuf; 1579 int error; 1580 1581 /* 1582 * Be ultra-paranoid about making sure the type and fspath 1583 * variables will fit in our mp buffers, including the 1584 * terminating NUL. 1585 */ 1586 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 1587 return (ENAMETOOLONG); 1588 1589 if (jail_export) { 1590 error = priv_check(td, PRIV_NFS_DAEMON); 1591 if (error) 1592 return (error); 1593 } else if (jailed(td->td_ucred) || usermount == 0) { 1594 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0) 1595 return (error); 1596 } 1597 1598 /* 1599 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 1600 */ 1601 if (fsflags & MNT_EXPORTED) { 1602 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED); 1603 if (error) 1604 return (error); 1605 } 1606 if (fsflags & MNT_SUIDDIR) { 1607 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR); 1608 if (error) 1609 return (error); 1610 } 1611 /* 1612 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users. 1613 */ 1614 if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) { 1615 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0) 1616 fsflags |= MNT_NOSUID | MNT_USER; 1617 } 1618 1619 /* Load KLDs before we lock the covered vnode to avoid reversals. */ 1620 vfsp = NULL; 1621 if ((fsflags & MNT_UPDATE) == 0) { 1622 /* Don't try to load KLDs if we're mounting the root. */ 1623 if (fsflags & MNT_ROOTFS) { 1624 if ((vfsp = vfs_byname(fstype)) == NULL) 1625 return (ENODEV); 1626 } else { 1627 if ((vfsp = vfs_byname_kld(fstype, td, &error)) == NULL) 1628 return (error); 1629 } 1630 } 1631 1632 /* 1633 * Get vnode to be covered or mount point's vnode in case of MNT_UPDATE. 1634 */ 1635 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1 | WANTPARENT, 1636 UIO_SYSSPACE, fspath); 1637 error = namei(&nd); 1638 if (error != 0) 1639 return (error); 1640 vp = nd.ni_vp; 1641 /* 1642 * Don't allow stacking file mounts to work around problems with the way 1643 * that namei sets nd.ni_dvp to vp_crossmp for these. 1644 */ 1645 if (vp->v_type == VREG) 1646 fsflags |= MNT_NOCOVER; 1647 if ((fsflags & MNT_UPDATE) == 0) { 1648 if ((vp->v_vflag & VV_ROOT) != 0 && 1649 (fsflags & MNT_NOCOVER) != 0) { 1650 vput(vp); 1651 error = EBUSY; 1652 goto out; 1653 } 1654 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1655 strcpy(pathbuf, fspath); 1656 /* 1657 * Note: we allow any vnode type here. If the path sanity check 1658 * succeeds, the type will be validated in vfs_domount_first 1659 * above. 1660 */ 1661 if (vp->v_type == VDIR) 1662 error = vn_path_to_global_path(td, vp, pathbuf, 1663 MNAMELEN); 1664 else 1665 error = vn_path_to_global_path_hardlink(td, vp, 1666 nd.ni_dvp, pathbuf, MNAMELEN, 1667 nd.ni_cnd.cn_nameptr, nd.ni_cnd.cn_namelen); 1668 if (error == 0) { 1669 error = vfs_domount_first(td, vfsp, pathbuf, vp, 1670 fsflags, optlist); 1671 } 1672 free(pathbuf, M_TEMP); 1673 } else 1674 error = vfs_domount_update(td, vp, fsflags, jail_export, 1675 optlist); 1676 1677 out: 1678 NDFREE_PNBUF(&nd); 1679 vrele(nd.ni_dvp); 1680 1681 return (error); 1682 } 1683 1684 /* 1685 * Unmount a filesystem. 1686 * 1687 * Note: unmount takes a path to the vnode mounted on as argument, not 1688 * special file (as before). 1689 */ 1690 #ifndef _SYS_SYSPROTO_H_ 1691 struct unmount_args { 1692 char *path; 1693 int flags; 1694 }; 1695 #endif 1696 /* ARGSUSED */ 1697 int 1698 sys_unmount(struct thread *td, struct unmount_args *uap) 1699 { 1700 1701 return (kern_unmount(td, uap->path, uap->flags)); 1702 } 1703 1704 int 1705 kern_unmount(struct thread *td, const char *path, int flags) 1706 { 1707 struct nameidata nd; 1708 struct mount *mp; 1709 char *fsidbuf, *pathbuf; 1710 fsid_t fsid; 1711 int error; 1712 1713 AUDIT_ARG_VALUE(flags); 1714 if (jailed(td->td_ucred) || usermount == 0) { 1715 error = priv_check(td, PRIV_VFS_UNMOUNT); 1716 if (error) 1717 return (error); 1718 } 1719 1720 if (flags & MNT_BYFSID) { 1721 fsidbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1722 error = copyinstr(path, fsidbuf, MNAMELEN, NULL); 1723 if (error) { 1724 free(fsidbuf, M_TEMP); 1725 return (error); 1726 } 1727 1728 AUDIT_ARG_TEXT(fsidbuf); 1729 /* Decode the filesystem ID. */ 1730 if (sscanf(fsidbuf, "FSID:%d:%d", &fsid.val[0], &fsid.val[1]) != 2) { 1731 free(fsidbuf, M_TEMP); 1732 return (EINVAL); 1733 } 1734 1735 mp = vfs_getvfs(&fsid); 1736 free(fsidbuf, M_TEMP); 1737 if (mp == NULL) { 1738 return (ENOENT); 1739 } 1740 } else { 1741 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1742 error = copyinstr(path, pathbuf, MNAMELEN, NULL); 1743 if (error) { 1744 free(pathbuf, M_TEMP); 1745 return (error); 1746 } 1747 1748 /* 1749 * Try to find global path for path argument. 1750 */ 1751 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, 1752 UIO_SYSSPACE, pathbuf); 1753 if (namei(&nd) == 0) { 1754 NDFREE_PNBUF(&nd); 1755 error = vn_path_to_global_path(td, nd.ni_vp, pathbuf, 1756 MNAMELEN); 1757 if (error == 0) 1758 vput(nd.ni_vp); 1759 } 1760 mtx_lock(&mountlist_mtx); 1761 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1762 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) { 1763 vfs_ref(mp); 1764 break; 1765 } 1766 } 1767 mtx_unlock(&mountlist_mtx); 1768 free(pathbuf, M_TEMP); 1769 if (mp == NULL) { 1770 /* 1771 * Previously we returned ENOENT for a nonexistent path and 1772 * EINVAL for a non-mountpoint. We cannot tell these apart 1773 * now, so in the !MNT_BYFSID case return the more likely 1774 * EINVAL for compatibility. 1775 */ 1776 return (EINVAL); 1777 } 1778 } 1779 1780 /* 1781 * Don't allow unmounting the root filesystem. 1782 */ 1783 if (mp->mnt_flag & MNT_ROOTFS) { 1784 vfs_rel(mp); 1785 return (EINVAL); 1786 } 1787 error = dounmount(mp, flags, td); 1788 return (error); 1789 } 1790 1791 /* 1792 * Return error if any of the vnodes, ignoring the root vnode 1793 * and the syncer vnode, have non-zero usecount. 1794 * 1795 * This function is purely advisory - it can return false positives 1796 * and negatives. 1797 */ 1798 static int 1799 vfs_check_usecounts(struct mount *mp) 1800 { 1801 struct vnode *vp, *mvp; 1802 1803 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 1804 if ((vp->v_vflag & VV_ROOT) == 0 && vp->v_type != VNON && 1805 vp->v_usecount != 0) { 1806 VI_UNLOCK(vp); 1807 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 1808 return (EBUSY); 1809 } 1810 VI_UNLOCK(vp); 1811 } 1812 1813 return (0); 1814 } 1815 1816 static void 1817 dounmount_cleanup(struct mount *mp, struct vnode *coveredvp, int mntkflags) 1818 { 1819 1820 mtx_assert(MNT_MTX(mp), MA_OWNED); 1821 mp->mnt_kern_flag &= ~mntkflags; 1822 if ((mp->mnt_kern_flag & MNTK_MWAIT) != 0) { 1823 mp->mnt_kern_flag &= ~MNTK_MWAIT; 1824 wakeup(mp); 1825 } 1826 vfs_op_exit_locked(mp); 1827 MNT_IUNLOCK(mp); 1828 if (coveredvp != NULL) { 1829 VOP_UNLOCK(coveredvp); 1830 vdrop(coveredvp); 1831 } 1832 vn_finished_write(mp); 1833 vfs_rel(mp); 1834 } 1835 1836 /* 1837 * There are various reference counters associated with the mount point. 1838 * Normally it is permitted to modify them without taking the mnt ilock, 1839 * but this behavior can be temporarily disabled if stable value is needed 1840 * or callers are expected to block (e.g. to not allow new users during 1841 * forced unmount). 1842 */ 1843 void 1844 vfs_op_enter(struct mount *mp) 1845 { 1846 struct mount_pcpu *mpcpu; 1847 int cpu; 1848 1849 MNT_ILOCK(mp); 1850 mp->mnt_vfs_ops++; 1851 if (mp->mnt_vfs_ops > 1) { 1852 MNT_IUNLOCK(mp); 1853 return; 1854 } 1855 vfs_op_barrier_wait(mp); 1856 CPU_FOREACH(cpu) { 1857 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1858 1859 mp->mnt_ref += mpcpu->mntp_ref; 1860 mpcpu->mntp_ref = 0; 1861 1862 mp->mnt_lockref += mpcpu->mntp_lockref; 1863 mpcpu->mntp_lockref = 0; 1864 1865 mp->mnt_writeopcount += mpcpu->mntp_writeopcount; 1866 mpcpu->mntp_writeopcount = 0; 1867 } 1868 MPASSERT(mp->mnt_ref > 0 && mp->mnt_lockref >= 0 && 1869 mp->mnt_writeopcount >= 0, mp, 1870 ("invalid count(s): ref %d lockref %d writeopcount %d", 1871 mp->mnt_ref, mp->mnt_lockref, mp->mnt_writeopcount)); 1872 MNT_IUNLOCK(mp); 1873 vfs_assert_mount_counters(mp); 1874 } 1875 1876 void 1877 vfs_op_exit_locked(struct mount *mp) 1878 { 1879 1880 mtx_assert(MNT_MTX(mp), MA_OWNED); 1881 1882 MPASSERT(mp->mnt_vfs_ops > 0, mp, 1883 ("invalid vfs_ops count %d", mp->mnt_vfs_ops)); 1884 MPASSERT(mp->mnt_vfs_ops > 1 || 1885 (mp->mnt_kern_flag & (MNTK_UNMOUNT | MNTK_SUSPEND)) == 0, mp, 1886 ("vfs_ops too low %d in unmount or suspend", mp->mnt_vfs_ops)); 1887 mp->mnt_vfs_ops--; 1888 } 1889 1890 void 1891 vfs_op_exit(struct mount *mp) 1892 { 1893 1894 MNT_ILOCK(mp); 1895 vfs_op_exit_locked(mp); 1896 MNT_IUNLOCK(mp); 1897 } 1898 1899 struct vfs_op_barrier_ipi { 1900 struct mount *mp; 1901 struct smp_rendezvous_cpus_retry_arg srcra; 1902 }; 1903 1904 static void 1905 vfs_op_action_func(void *arg) 1906 { 1907 struct vfs_op_barrier_ipi *vfsopipi; 1908 struct mount *mp; 1909 1910 vfsopipi = __containerof(arg, struct vfs_op_barrier_ipi, srcra); 1911 mp = vfsopipi->mp; 1912 1913 if (!vfs_op_thread_entered(mp)) 1914 smp_rendezvous_cpus_done(arg); 1915 } 1916 1917 static void 1918 vfs_op_wait_func(void *arg, int cpu) 1919 { 1920 struct vfs_op_barrier_ipi *vfsopipi; 1921 struct mount *mp; 1922 struct mount_pcpu *mpcpu; 1923 1924 vfsopipi = __containerof(arg, struct vfs_op_barrier_ipi, srcra); 1925 mp = vfsopipi->mp; 1926 1927 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1928 while (atomic_load_int(&mpcpu->mntp_thread_in_ops)) 1929 cpu_spinwait(); 1930 } 1931 1932 void 1933 vfs_op_barrier_wait(struct mount *mp) 1934 { 1935 struct vfs_op_barrier_ipi vfsopipi; 1936 1937 vfsopipi.mp = mp; 1938 1939 smp_rendezvous_cpus_retry(all_cpus, 1940 smp_no_rendezvous_barrier, 1941 vfs_op_action_func, 1942 smp_no_rendezvous_barrier, 1943 vfs_op_wait_func, 1944 &vfsopipi.srcra); 1945 } 1946 1947 #ifdef DIAGNOSTIC 1948 void 1949 vfs_assert_mount_counters(struct mount *mp) 1950 { 1951 struct mount_pcpu *mpcpu; 1952 int cpu; 1953 1954 if (mp->mnt_vfs_ops == 0) 1955 return; 1956 1957 CPU_FOREACH(cpu) { 1958 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1959 if (mpcpu->mntp_ref != 0 || 1960 mpcpu->mntp_lockref != 0 || 1961 mpcpu->mntp_writeopcount != 0) 1962 vfs_dump_mount_counters(mp); 1963 } 1964 } 1965 1966 void 1967 vfs_dump_mount_counters(struct mount *mp) 1968 { 1969 struct mount_pcpu *mpcpu; 1970 int ref, lockref, writeopcount; 1971 int cpu; 1972 1973 printf("%s: mp %p vfs_ops %d\n", __func__, mp, mp->mnt_vfs_ops); 1974 1975 printf(" ref : "); 1976 ref = mp->mnt_ref; 1977 CPU_FOREACH(cpu) { 1978 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1979 printf("%d ", mpcpu->mntp_ref); 1980 ref += mpcpu->mntp_ref; 1981 } 1982 printf("\n"); 1983 printf(" lockref : "); 1984 lockref = mp->mnt_lockref; 1985 CPU_FOREACH(cpu) { 1986 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1987 printf("%d ", mpcpu->mntp_lockref); 1988 lockref += mpcpu->mntp_lockref; 1989 } 1990 printf("\n"); 1991 printf("writeopcount: "); 1992 writeopcount = mp->mnt_writeopcount; 1993 CPU_FOREACH(cpu) { 1994 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1995 printf("%d ", mpcpu->mntp_writeopcount); 1996 writeopcount += mpcpu->mntp_writeopcount; 1997 } 1998 printf("\n"); 1999 2000 printf("counter struct total\n"); 2001 printf("ref %-5d %-5d\n", mp->mnt_ref, ref); 2002 printf("lockref %-5d %-5d\n", mp->mnt_lockref, lockref); 2003 printf("writeopcount %-5d %-5d\n", mp->mnt_writeopcount, writeopcount); 2004 2005 panic("invalid counts on struct mount"); 2006 } 2007 #endif 2008 2009 int 2010 vfs_mount_fetch_counter(struct mount *mp, enum mount_counter which) 2011 { 2012 struct mount_pcpu *mpcpu; 2013 int cpu, sum; 2014 2015 switch (which) { 2016 case MNT_COUNT_REF: 2017 sum = mp->mnt_ref; 2018 break; 2019 case MNT_COUNT_LOCKREF: 2020 sum = mp->mnt_lockref; 2021 break; 2022 case MNT_COUNT_WRITEOPCOUNT: 2023 sum = mp->mnt_writeopcount; 2024 break; 2025 } 2026 2027 CPU_FOREACH(cpu) { 2028 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 2029 switch (which) { 2030 case MNT_COUNT_REF: 2031 sum += mpcpu->mntp_ref; 2032 break; 2033 case MNT_COUNT_LOCKREF: 2034 sum += mpcpu->mntp_lockref; 2035 break; 2036 case MNT_COUNT_WRITEOPCOUNT: 2037 sum += mpcpu->mntp_writeopcount; 2038 break; 2039 } 2040 } 2041 return (sum); 2042 } 2043 2044 static bool 2045 deferred_unmount_enqueue(struct mount *mp, uint64_t flags, bool requeue, 2046 int timeout_ticks) 2047 { 2048 bool enqueued; 2049 2050 enqueued = false; 2051 mtx_lock(&deferred_unmount_lock); 2052 if ((mp->mnt_taskqueue_flags & MNT_DEFERRED) == 0 || requeue) { 2053 mp->mnt_taskqueue_flags = flags | MNT_DEFERRED; 2054 STAILQ_INSERT_TAIL(&deferred_unmount_list, mp, 2055 mnt_taskqueue_link); 2056 enqueued = true; 2057 } 2058 mtx_unlock(&deferred_unmount_lock); 2059 2060 if (enqueued) { 2061 taskqueue_enqueue_timeout(taskqueue_deferred_unmount, 2062 &deferred_unmount_task, timeout_ticks); 2063 } 2064 2065 return (enqueued); 2066 } 2067 2068 /* 2069 * Taskqueue handler for processing async/recursive unmounts 2070 */ 2071 static void 2072 vfs_deferred_unmount(void *argi __unused, int pending __unused) 2073 { 2074 STAILQ_HEAD(, mount) local_unmounts; 2075 uint64_t flags; 2076 struct mount *mp, *tmp; 2077 int error; 2078 unsigned int retries; 2079 bool unmounted; 2080 2081 STAILQ_INIT(&local_unmounts); 2082 mtx_lock(&deferred_unmount_lock); 2083 STAILQ_CONCAT(&local_unmounts, &deferred_unmount_list); 2084 mtx_unlock(&deferred_unmount_lock); 2085 2086 STAILQ_FOREACH_SAFE(mp, &local_unmounts, mnt_taskqueue_link, tmp) { 2087 flags = mp->mnt_taskqueue_flags; 2088 KASSERT((flags & MNT_DEFERRED) != 0, 2089 ("taskqueue unmount without MNT_DEFERRED")); 2090 error = dounmount(mp, flags, curthread); 2091 if (error != 0) { 2092 MNT_ILOCK(mp); 2093 unmounted = ((mp->mnt_kern_flag & MNTK_REFEXPIRE) != 0); 2094 MNT_IUNLOCK(mp); 2095 2096 /* 2097 * The deferred unmount thread is the only thread that 2098 * modifies the retry counts, so locking/atomics aren't 2099 * needed here. 2100 */ 2101 retries = (mp->mnt_unmount_retries)++; 2102 deferred_unmount_total_retries++; 2103 if (!unmounted && retries < deferred_unmount_retry_limit) { 2104 deferred_unmount_enqueue(mp, flags, true, 2105 -deferred_unmount_retry_delay_hz); 2106 } else { 2107 if (retries >= deferred_unmount_retry_limit) { 2108 printf("giving up on deferred unmount " 2109 "of %s after %d retries, error %d\n", 2110 mp->mnt_stat.f_mntonname, retries, error); 2111 } 2112 vfs_rel(mp); 2113 } 2114 } 2115 } 2116 } 2117 2118 /* 2119 * Do the actual filesystem unmount. 2120 */ 2121 int 2122 dounmount(struct mount *mp, uint64_t flags, struct thread *td) 2123 { 2124 struct mount_upper_node *upper; 2125 struct vnode *coveredvp, *rootvp; 2126 int error; 2127 uint64_t async_flag; 2128 int mnt_gen_r; 2129 unsigned int retries; 2130 2131 KASSERT((flags & MNT_DEFERRED) == 0 || 2132 (flags & (MNT_RECURSE | MNT_FORCE)) == (MNT_RECURSE | MNT_FORCE), 2133 ("MNT_DEFERRED requires MNT_RECURSE | MNT_FORCE")); 2134 2135 /* 2136 * If the caller has explicitly requested the unmount to be handled by 2137 * the taskqueue and we're not already in taskqueue context, queue 2138 * up the unmount request and exit. This is done prior to any 2139 * credential checks; MNT_DEFERRED should be used only for kernel- 2140 * initiated unmounts and will therefore be processed with the 2141 * (kernel) credentials of the taskqueue thread. Still, callers 2142 * should be sure this is the behavior they want. 2143 */ 2144 if ((flags & MNT_DEFERRED) != 0 && 2145 taskqueue_member(taskqueue_deferred_unmount, curthread) == 0) { 2146 if (!deferred_unmount_enqueue(mp, flags, false, 0)) 2147 vfs_rel(mp); 2148 return (EINPROGRESS); 2149 } 2150 2151 /* 2152 * Only privileged root, or (if MNT_USER is set) the user that did the 2153 * original mount is permitted to unmount this filesystem. 2154 * This check should be made prior to queueing up any recursive 2155 * unmounts of upper filesystems. Those unmounts will be executed 2156 * with kernel thread credentials and are expected to succeed, so 2157 * we must at least ensure the originating context has sufficient 2158 * privilege to unmount the base filesystem before proceeding with 2159 * the uppers. 2160 */ 2161 error = vfs_suser(mp, td); 2162 if (error != 0) { 2163 KASSERT((flags & MNT_DEFERRED) == 0, 2164 ("taskqueue unmount with insufficient privilege")); 2165 vfs_rel(mp); 2166 return (error); 2167 } 2168 2169 if (recursive_forced_unmount && ((flags & MNT_FORCE) != 0)) 2170 flags |= MNT_RECURSE; 2171 2172 if ((flags & MNT_RECURSE) != 0) { 2173 KASSERT((flags & MNT_FORCE) != 0, 2174 ("MNT_RECURSE requires MNT_FORCE")); 2175 2176 MNT_ILOCK(mp); 2177 /* 2178 * Set MNTK_RECURSE to prevent new upper mounts from being 2179 * added, and note that an operation on the uppers list is in 2180 * progress. This will ensure that unregistration from the 2181 * uppers list, and therefore any pending unmount of the upper 2182 * FS, can't complete until after we finish walking the list. 2183 */ 2184 mp->mnt_kern_flag |= MNTK_RECURSE; 2185 mp->mnt_upper_pending++; 2186 TAILQ_FOREACH(upper, &mp->mnt_uppers, mnt_upper_link) { 2187 retries = upper->mp->mnt_unmount_retries; 2188 if (retries > deferred_unmount_retry_limit) { 2189 error = EBUSY; 2190 continue; 2191 } 2192 MNT_IUNLOCK(mp); 2193 2194 vfs_ref(upper->mp); 2195 if (!deferred_unmount_enqueue(upper->mp, flags, 2196 false, 0)) 2197 vfs_rel(upper->mp); 2198 MNT_ILOCK(mp); 2199 } 2200 mp->mnt_upper_pending--; 2201 if ((mp->mnt_kern_flag & MNTK_UPPER_WAITER) != 0 && 2202 mp->mnt_upper_pending == 0) { 2203 mp->mnt_kern_flag &= ~MNTK_UPPER_WAITER; 2204 wakeup(&mp->mnt_uppers); 2205 } 2206 2207 /* 2208 * If we're not on the taskqueue, wait until the uppers list 2209 * is drained before proceeding with unmount. Otherwise, if 2210 * we are on the taskqueue and there are still pending uppers, 2211 * just re-enqueue on the end of the taskqueue. 2212 */ 2213 if ((flags & MNT_DEFERRED) == 0) { 2214 while (error == 0 && !TAILQ_EMPTY(&mp->mnt_uppers)) { 2215 mp->mnt_kern_flag |= MNTK_TASKQUEUE_WAITER; 2216 error = msleep(&mp->mnt_taskqueue_link, 2217 MNT_MTX(mp), PCATCH, "umntqw", 0); 2218 } 2219 if (error != 0) { 2220 MNT_REL(mp); 2221 MNT_IUNLOCK(mp); 2222 return (error); 2223 } 2224 } else if (!TAILQ_EMPTY(&mp->mnt_uppers)) { 2225 MNT_IUNLOCK(mp); 2226 if (error == 0) 2227 deferred_unmount_enqueue(mp, flags, true, 0); 2228 return (error); 2229 } 2230 MNT_IUNLOCK(mp); 2231 KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers not empty")); 2232 } 2233 2234 /* Allow the taskqueue to safely re-enqueue on failure */ 2235 if ((flags & MNT_DEFERRED) != 0) 2236 vfs_ref(mp); 2237 2238 if ((coveredvp = mp->mnt_vnodecovered) != NULL) { 2239 mnt_gen_r = mp->mnt_gen; 2240 VI_LOCK(coveredvp); 2241 vholdl(coveredvp); 2242 vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY); 2243 /* 2244 * Check for mp being unmounted while waiting for the 2245 * covered vnode lock. 2246 */ 2247 if (coveredvp->v_mountedhere != mp || 2248 coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) { 2249 VOP_UNLOCK(coveredvp); 2250 vdrop(coveredvp); 2251 vfs_rel(mp); 2252 return (EBUSY); 2253 } 2254 } 2255 2256 vfs_op_enter(mp); 2257 2258 vn_start_write(NULL, &mp, V_WAIT); 2259 MNT_ILOCK(mp); 2260 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 || 2261 (mp->mnt_flag & MNT_UPDATE) != 0 || 2262 !TAILQ_EMPTY(&mp->mnt_uppers)) { 2263 dounmount_cleanup(mp, coveredvp, 0); 2264 return (EBUSY); 2265 } 2266 mp->mnt_kern_flag |= MNTK_UNMOUNT; 2267 rootvp = vfs_cache_root_clear(mp); 2268 if (coveredvp != NULL) 2269 vn_seqc_write_begin(coveredvp); 2270 if (flags & MNT_NONBUSY) { 2271 MNT_IUNLOCK(mp); 2272 error = vfs_check_usecounts(mp); 2273 MNT_ILOCK(mp); 2274 if (error != 0) { 2275 vn_seqc_write_end(coveredvp); 2276 dounmount_cleanup(mp, coveredvp, MNTK_UNMOUNT); 2277 if (rootvp != NULL) { 2278 vn_seqc_write_end(rootvp); 2279 vrele(rootvp); 2280 } 2281 return (error); 2282 } 2283 } 2284 /* Allow filesystems to detect that a forced unmount is in progress. */ 2285 if (flags & MNT_FORCE) { 2286 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 2287 MNT_IUNLOCK(mp); 2288 /* 2289 * Must be done after setting MNTK_UNMOUNTF and before 2290 * waiting for mnt_lockref to become 0. 2291 */ 2292 VFS_PURGE(mp); 2293 MNT_ILOCK(mp); 2294 } 2295 error = 0; 2296 if (mp->mnt_lockref) { 2297 mp->mnt_kern_flag |= MNTK_DRAINING; 2298 error = msleep(&mp->mnt_lockref, MNT_MTX(mp), PVFS, 2299 "mount drain", 0); 2300 } 2301 MNT_IUNLOCK(mp); 2302 KASSERT(mp->mnt_lockref == 0, 2303 ("%s: invalid lock refcount in the drain path @ %s:%d", 2304 __func__, __FILE__, __LINE__)); 2305 KASSERT(error == 0, 2306 ("%s: invalid return value for msleep in the drain path @ %s:%d", 2307 __func__, __FILE__, __LINE__)); 2308 2309 /* 2310 * We want to keep the vnode around so that we can vn_seqc_write_end 2311 * after we are done with unmount. Downgrade our reference to a mere 2312 * hold count so that we don't interefere with anything. 2313 */ 2314 if (rootvp != NULL) { 2315 vhold(rootvp); 2316 vrele(rootvp); 2317 } 2318 2319 if (mp->mnt_flag & MNT_EXPUBLIC) 2320 vfs_setpublicfs(NULL, NULL, NULL); 2321 2322 vfs_periodic(mp, MNT_WAIT); 2323 MNT_ILOCK(mp); 2324 async_flag = mp->mnt_flag & MNT_ASYNC; 2325 mp->mnt_flag &= ~MNT_ASYNC; 2326 mp->mnt_kern_flag &= ~MNTK_ASYNC; 2327 MNT_IUNLOCK(mp); 2328 vfs_deallocate_syncvnode(mp); 2329 error = VFS_UNMOUNT(mp, flags); 2330 vn_finished_write(mp); 2331 vfs_rel(mp); 2332 /* 2333 * If we failed to flush the dirty blocks for this mount point, 2334 * undo all the cdir/rdir and rootvnode changes we made above. 2335 * Unless we failed to do so because the device is reporting that 2336 * it doesn't exist anymore. 2337 */ 2338 if (error && error != ENXIO) { 2339 MNT_ILOCK(mp); 2340 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 2341 MNT_IUNLOCK(mp); 2342 vfs_allocate_syncvnode(mp); 2343 MNT_ILOCK(mp); 2344 } 2345 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 2346 mp->mnt_flag |= async_flag; 2347 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 2348 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 2349 mp->mnt_kern_flag |= MNTK_ASYNC; 2350 if (mp->mnt_kern_flag & MNTK_MWAIT) { 2351 mp->mnt_kern_flag &= ~MNTK_MWAIT; 2352 wakeup(mp); 2353 } 2354 vfs_op_exit_locked(mp); 2355 MNT_IUNLOCK(mp); 2356 if (coveredvp) { 2357 vn_seqc_write_end(coveredvp); 2358 VOP_UNLOCK(coveredvp); 2359 vdrop(coveredvp); 2360 } 2361 if (rootvp != NULL) { 2362 vn_seqc_write_end(rootvp); 2363 vdrop(rootvp); 2364 } 2365 return (error); 2366 } 2367 2368 mtx_lock(&mountlist_mtx); 2369 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2370 mtx_unlock(&mountlist_mtx); 2371 EVENTHANDLER_DIRECT_INVOKE(vfs_unmounted, mp, td); 2372 if (coveredvp != NULL) { 2373 VI_LOCK(coveredvp); 2374 vn_irflag_unset_locked(coveredvp, VIRF_MOUNTPOINT); 2375 coveredvp->v_mountedhere = NULL; 2376 vn_seqc_write_end_locked(coveredvp); 2377 VI_UNLOCK(coveredvp); 2378 VOP_UNLOCK(coveredvp); 2379 vdrop(coveredvp); 2380 } 2381 mount_devctl_event("UNMOUNT", mp, false); 2382 if (rootvp != NULL) { 2383 vn_seqc_write_end(rootvp); 2384 vdrop(rootvp); 2385 } 2386 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 2387 if (rootvnode != NULL && mp == rootvnode->v_mount) { 2388 vrele(rootvnode); 2389 rootvnode = NULL; 2390 } 2391 if (mp == rootdevmp) 2392 rootdevmp = NULL; 2393 if ((flags & MNT_DEFERRED) != 0) 2394 vfs_rel(mp); 2395 vfs_mount_destroy(mp); 2396 return (0); 2397 } 2398 2399 /* 2400 * Report errors during filesystem mounting. 2401 */ 2402 void 2403 vfs_mount_error(struct mount *mp, const char *fmt, ...) 2404 { 2405 struct vfsoptlist *moptlist = mp->mnt_optnew; 2406 va_list ap; 2407 int error, len; 2408 char *errmsg; 2409 2410 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len); 2411 if (error || errmsg == NULL || len <= 0) 2412 return; 2413 2414 va_start(ap, fmt); 2415 vsnprintf(errmsg, (size_t)len, fmt, ap); 2416 va_end(ap); 2417 } 2418 2419 void 2420 vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...) 2421 { 2422 va_list ap; 2423 int error, len; 2424 char *errmsg; 2425 2426 error = vfs_getopt(opts, "errmsg", (void **)&errmsg, &len); 2427 if (error || errmsg == NULL || len <= 0) 2428 return; 2429 2430 va_start(ap, fmt); 2431 vsnprintf(errmsg, (size_t)len, fmt, ap); 2432 va_end(ap); 2433 } 2434 2435 /* 2436 * --------------------------------------------------------------------- 2437 * Functions for querying mount options/arguments from filesystems. 2438 */ 2439 2440 /* 2441 * Check that no unknown options are given 2442 */ 2443 int 2444 vfs_filteropt(struct vfsoptlist *opts, const char **legal) 2445 { 2446 struct vfsopt *opt; 2447 char errmsg[255]; 2448 const char **t, *p, *q; 2449 int ret = 0; 2450 2451 TAILQ_FOREACH(opt, opts, link) { 2452 p = opt->name; 2453 q = NULL; 2454 if (p[0] == 'n' && p[1] == 'o') 2455 q = p + 2; 2456 for(t = global_opts; *t != NULL; t++) { 2457 if (strcmp(*t, p) == 0) 2458 break; 2459 if (q != NULL) { 2460 if (strcmp(*t, q) == 0) 2461 break; 2462 } 2463 } 2464 if (*t != NULL) 2465 continue; 2466 for(t = legal; *t != NULL; t++) { 2467 if (strcmp(*t, p) == 0) 2468 break; 2469 if (q != NULL) { 2470 if (strcmp(*t, q) == 0) 2471 break; 2472 } 2473 } 2474 if (*t != NULL) 2475 continue; 2476 snprintf(errmsg, sizeof(errmsg), 2477 "mount option <%s> is unknown", p); 2478 ret = EINVAL; 2479 } 2480 if (ret != 0) { 2481 TAILQ_FOREACH(opt, opts, link) { 2482 if (strcmp(opt->name, "errmsg") == 0) { 2483 strncpy((char *)opt->value, errmsg, opt->len); 2484 break; 2485 } 2486 } 2487 if (opt == NULL) 2488 printf("%s\n", errmsg); 2489 } 2490 return (ret); 2491 } 2492 2493 /* 2494 * Get a mount option by its name. 2495 * 2496 * Return 0 if the option was found, ENOENT otherwise. 2497 * If len is non-NULL it will be filled with the length 2498 * of the option. If buf is non-NULL, it will be filled 2499 * with the address of the option. 2500 */ 2501 int 2502 vfs_getopt(struct vfsoptlist *opts, const char *name, void **buf, int *len) 2503 { 2504 struct vfsopt *opt; 2505 2506 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 2507 2508 TAILQ_FOREACH(opt, opts, link) { 2509 if (strcmp(name, opt->name) == 0) { 2510 opt->seen = 1; 2511 if (len != NULL) 2512 *len = opt->len; 2513 if (buf != NULL) 2514 *buf = opt->value; 2515 return (0); 2516 } 2517 } 2518 return (ENOENT); 2519 } 2520 2521 int 2522 vfs_getopt_pos(struct vfsoptlist *opts, const char *name) 2523 { 2524 struct vfsopt *opt; 2525 2526 if (opts == NULL) 2527 return (-1); 2528 2529 TAILQ_FOREACH(opt, opts, link) { 2530 if (strcmp(name, opt->name) == 0) { 2531 opt->seen = 1; 2532 return (opt->pos); 2533 } 2534 } 2535 return (-1); 2536 } 2537 2538 int 2539 vfs_getopt_size(struct vfsoptlist *opts, const char *name, off_t *value) 2540 { 2541 char *opt_value, *vtp; 2542 quad_t iv; 2543 int error, opt_len; 2544 2545 error = vfs_getopt(opts, name, (void **)&opt_value, &opt_len); 2546 if (error != 0) 2547 return (error); 2548 if (opt_len == 0 || opt_value == NULL) 2549 return (EINVAL); 2550 if (opt_value[0] == '\0' || opt_value[opt_len - 1] != '\0') 2551 return (EINVAL); 2552 iv = strtoq(opt_value, &vtp, 0); 2553 if (vtp == opt_value || (vtp[0] != '\0' && vtp[1] != '\0')) 2554 return (EINVAL); 2555 if (iv < 0) 2556 return (EINVAL); 2557 switch (vtp[0]) { 2558 case 't': case 'T': 2559 iv *= 1024; 2560 /* FALLTHROUGH */ 2561 case 'g': case 'G': 2562 iv *= 1024; 2563 /* FALLTHROUGH */ 2564 case 'm': case 'M': 2565 iv *= 1024; 2566 /* FALLTHROUGH */ 2567 case 'k': case 'K': 2568 iv *= 1024; 2569 case '\0': 2570 break; 2571 default: 2572 return (EINVAL); 2573 } 2574 *value = iv; 2575 2576 return (0); 2577 } 2578 2579 char * 2580 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 2581 { 2582 struct vfsopt *opt; 2583 2584 *error = 0; 2585 TAILQ_FOREACH(opt, opts, link) { 2586 if (strcmp(name, opt->name) != 0) 2587 continue; 2588 opt->seen = 1; 2589 if (opt->len == 0 || 2590 ((char *)opt->value)[opt->len - 1] != '\0') { 2591 *error = EINVAL; 2592 return (NULL); 2593 } 2594 return (opt->value); 2595 } 2596 *error = ENOENT; 2597 return (NULL); 2598 } 2599 2600 int 2601 vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w, 2602 uint64_t val) 2603 { 2604 struct vfsopt *opt; 2605 2606 TAILQ_FOREACH(opt, opts, link) { 2607 if (strcmp(name, opt->name) == 0) { 2608 opt->seen = 1; 2609 if (w != NULL) 2610 *w |= val; 2611 return (1); 2612 } 2613 } 2614 if (w != NULL) 2615 *w &= ~val; 2616 return (0); 2617 } 2618 2619 int 2620 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 2621 { 2622 va_list ap; 2623 struct vfsopt *opt; 2624 int ret; 2625 2626 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 2627 2628 TAILQ_FOREACH(opt, opts, link) { 2629 if (strcmp(name, opt->name) != 0) 2630 continue; 2631 opt->seen = 1; 2632 if (opt->len == 0 || opt->value == NULL) 2633 return (0); 2634 if (((char *)opt->value)[opt->len - 1] != '\0') 2635 return (0); 2636 va_start(ap, fmt); 2637 ret = vsscanf(opt->value, fmt, ap); 2638 va_end(ap); 2639 return (ret); 2640 } 2641 return (0); 2642 } 2643 2644 int 2645 vfs_setopt(struct vfsoptlist *opts, const char *name, void *value, int len) 2646 { 2647 struct vfsopt *opt; 2648 2649 TAILQ_FOREACH(opt, opts, link) { 2650 if (strcmp(name, opt->name) != 0) 2651 continue; 2652 opt->seen = 1; 2653 if (opt->value == NULL) 2654 opt->len = len; 2655 else { 2656 if (opt->len != len) 2657 return (EINVAL); 2658 bcopy(value, opt->value, len); 2659 } 2660 return (0); 2661 } 2662 return (ENOENT); 2663 } 2664 2665 int 2666 vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value, int len) 2667 { 2668 struct vfsopt *opt; 2669 2670 TAILQ_FOREACH(opt, opts, link) { 2671 if (strcmp(name, opt->name) != 0) 2672 continue; 2673 opt->seen = 1; 2674 if (opt->value == NULL) 2675 opt->len = len; 2676 else { 2677 if (opt->len < len) 2678 return (EINVAL); 2679 opt->len = len; 2680 bcopy(value, opt->value, len); 2681 } 2682 return (0); 2683 } 2684 return (ENOENT); 2685 } 2686 2687 int 2688 vfs_setopts(struct vfsoptlist *opts, const char *name, const char *value) 2689 { 2690 struct vfsopt *opt; 2691 2692 TAILQ_FOREACH(opt, opts, link) { 2693 if (strcmp(name, opt->name) != 0) 2694 continue; 2695 opt->seen = 1; 2696 if (opt->value == NULL) 2697 opt->len = strlen(value) + 1; 2698 else if (strlcpy(opt->value, value, opt->len) >= opt->len) 2699 return (EINVAL); 2700 return (0); 2701 } 2702 return (ENOENT); 2703 } 2704 2705 /* 2706 * Find and copy a mount option. 2707 * 2708 * The size of the buffer has to be specified 2709 * in len, if it is not the same length as the 2710 * mount option, EINVAL is returned. 2711 * Returns ENOENT if the option is not found. 2712 */ 2713 int 2714 vfs_copyopt(struct vfsoptlist *opts, const char *name, void *dest, int len) 2715 { 2716 struct vfsopt *opt; 2717 2718 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 2719 2720 TAILQ_FOREACH(opt, opts, link) { 2721 if (strcmp(name, opt->name) == 0) { 2722 opt->seen = 1; 2723 if (len != opt->len) 2724 return (EINVAL); 2725 bcopy(opt->value, dest, opt->len); 2726 return (0); 2727 } 2728 } 2729 return (ENOENT); 2730 } 2731 2732 int 2733 __vfs_statfs(struct mount *mp, struct statfs *sbp) 2734 { 2735 /* 2736 * Filesystems only fill in part of the structure for updates, we 2737 * have to read the entirety first to get all content. 2738 */ 2739 if (sbp != &mp->mnt_stat) 2740 memcpy(sbp, &mp->mnt_stat, sizeof(*sbp)); 2741 2742 /* 2743 * Set these in case the underlying filesystem fails to do so. 2744 */ 2745 sbp->f_version = STATFS_VERSION; 2746 sbp->f_namemax = NAME_MAX; 2747 sbp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK; 2748 sbp->f_nvnodelistsize = mp->mnt_nvnodelistsize; 2749 2750 return (mp->mnt_op->vfs_statfs(mp, sbp)); 2751 } 2752 2753 void 2754 vfs_mountedfrom(struct mount *mp, const char *from) 2755 { 2756 2757 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 2758 strlcpy(mp->mnt_stat.f_mntfromname, from, 2759 sizeof mp->mnt_stat.f_mntfromname); 2760 } 2761 2762 /* 2763 * --------------------------------------------------------------------- 2764 * This is the api for building mount args and mounting filesystems from 2765 * inside the kernel. 2766 * 2767 * The API works by accumulation of individual args. First error is 2768 * latched. 2769 * 2770 * XXX: should be documented in new manpage kernel_mount(9) 2771 */ 2772 2773 /* A memory allocation which must be freed when we are done */ 2774 struct mntaarg { 2775 SLIST_ENTRY(mntaarg) next; 2776 }; 2777 2778 /* The header for the mount arguments */ 2779 struct mntarg { 2780 struct iovec *v; 2781 int len; 2782 int error; 2783 SLIST_HEAD(, mntaarg) list; 2784 }; 2785 2786 /* 2787 * Add a boolean argument. 2788 * 2789 * flag is the boolean value. 2790 * name must start with "no". 2791 */ 2792 struct mntarg * 2793 mount_argb(struct mntarg *ma, int flag, const char *name) 2794 { 2795 2796 KASSERT(name[0] == 'n' && name[1] == 'o', 2797 ("mount_argb(...,%s): name must start with 'no'", name)); 2798 2799 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 2800 } 2801 2802 /* 2803 * Add an argument printf style 2804 */ 2805 struct mntarg * 2806 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 2807 { 2808 va_list ap; 2809 struct mntaarg *maa; 2810 struct sbuf *sb; 2811 int len; 2812 2813 if (ma == NULL) { 2814 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2815 SLIST_INIT(&ma->list); 2816 } 2817 if (ma->error) 2818 return (ma); 2819 2820 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2821 M_MOUNT, M_WAITOK); 2822 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2823 ma->v[ma->len].iov_len = strlen(name) + 1; 2824 ma->len++; 2825 2826 sb = sbuf_new_auto(); 2827 va_start(ap, fmt); 2828 sbuf_vprintf(sb, fmt, ap); 2829 va_end(ap); 2830 sbuf_finish(sb); 2831 len = sbuf_len(sb) + 1; 2832 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2833 SLIST_INSERT_HEAD(&ma->list, maa, next); 2834 bcopy(sbuf_data(sb), maa + 1, len); 2835 sbuf_delete(sb); 2836 2837 ma->v[ma->len].iov_base = maa + 1; 2838 ma->v[ma->len].iov_len = len; 2839 ma->len++; 2840 2841 return (ma); 2842 } 2843 2844 /* 2845 * Add an argument which is a userland string. 2846 */ 2847 struct mntarg * 2848 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 2849 { 2850 struct mntaarg *maa; 2851 char *tbuf; 2852 2853 if (val == NULL) 2854 return (ma); 2855 if (ma == NULL) { 2856 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2857 SLIST_INIT(&ma->list); 2858 } 2859 if (ma->error) 2860 return (ma); 2861 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2862 SLIST_INSERT_HEAD(&ma->list, maa, next); 2863 tbuf = (void *)(maa + 1); 2864 ma->error = copyinstr(val, tbuf, len, NULL); 2865 return (mount_arg(ma, name, tbuf, -1)); 2866 } 2867 2868 /* 2869 * Plain argument. 2870 * 2871 * If length is -1, treat value as a C string. 2872 */ 2873 struct mntarg * 2874 mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 2875 { 2876 2877 if (ma == NULL) { 2878 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2879 SLIST_INIT(&ma->list); 2880 } 2881 if (ma->error) 2882 return (ma); 2883 2884 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2885 M_MOUNT, M_WAITOK); 2886 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2887 ma->v[ma->len].iov_len = strlen(name) + 1; 2888 ma->len++; 2889 2890 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 2891 if (len < 0) 2892 ma->v[ma->len].iov_len = strlen(val) + 1; 2893 else 2894 ma->v[ma->len].iov_len = len; 2895 ma->len++; 2896 return (ma); 2897 } 2898 2899 /* 2900 * Free a mntarg structure 2901 */ 2902 static void 2903 free_mntarg(struct mntarg *ma) 2904 { 2905 struct mntaarg *maa; 2906 2907 while (!SLIST_EMPTY(&ma->list)) { 2908 maa = SLIST_FIRST(&ma->list); 2909 SLIST_REMOVE_HEAD(&ma->list, next); 2910 free(maa, M_MOUNT); 2911 } 2912 free(ma->v, M_MOUNT); 2913 free(ma, M_MOUNT); 2914 } 2915 2916 /* 2917 * Mount a filesystem 2918 */ 2919 int 2920 kernel_mount(struct mntarg *ma, uint64_t flags) 2921 { 2922 struct uio auio; 2923 int error; 2924 2925 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 2926 KASSERT(ma->error != 0 || ma->v != NULL, ("kernel_mount NULL ma->v")); 2927 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 2928 2929 error = ma->error; 2930 if (error == 0) { 2931 auio.uio_iov = ma->v; 2932 auio.uio_iovcnt = ma->len; 2933 auio.uio_segflg = UIO_SYSSPACE; 2934 error = vfs_donmount(curthread, flags, &auio); 2935 } 2936 free_mntarg(ma); 2937 return (error); 2938 } 2939 2940 /* Map from mount options to printable formats. */ 2941 static struct mntoptnames optnames[] = { 2942 MNTOPT_NAMES 2943 }; 2944 2945 #define DEVCTL_LEN 1024 2946 static void 2947 mount_devctl_event(const char *type, struct mount *mp, bool donew) 2948 { 2949 const uint8_t *cp; 2950 struct mntoptnames *fp; 2951 struct sbuf sb; 2952 struct statfs *sfp = &mp->mnt_stat; 2953 char *buf; 2954 2955 buf = malloc(DEVCTL_LEN, M_MOUNT, M_NOWAIT); 2956 if (buf == NULL) 2957 return; 2958 sbuf_new(&sb, buf, DEVCTL_LEN, SBUF_FIXEDLEN); 2959 sbuf_cpy(&sb, "mount-point=\""); 2960 devctl_safe_quote_sb(&sb, sfp->f_mntonname); 2961 sbuf_cat(&sb, "\" mount-dev=\""); 2962 devctl_safe_quote_sb(&sb, sfp->f_mntfromname); 2963 sbuf_cat(&sb, "\" mount-type=\""); 2964 devctl_safe_quote_sb(&sb, sfp->f_fstypename); 2965 sbuf_cat(&sb, "\" fsid=0x"); 2966 cp = (const uint8_t *)&sfp->f_fsid.val[0]; 2967 for (int i = 0; i < sizeof(sfp->f_fsid); i++) 2968 sbuf_printf(&sb, "%02x", cp[i]); 2969 sbuf_printf(&sb, " owner=%u flags=\"", sfp->f_owner); 2970 for (fp = optnames; fp->o_opt != 0; fp++) { 2971 if ((mp->mnt_flag & fp->o_opt) != 0) { 2972 sbuf_cat(&sb, fp->o_name); 2973 sbuf_putc(&sb, ';'); 2974 } 2975 } 2976 sbuf_putc(&sb, '"'); 2977 sbuf_finish(&sb); 2978 2979 /* 2980 * Options are not published because the form of the options depends on 2981 * the file system and may include binary data. In addition, they don't 2982 * necessarily provide enough useful information to be actionable when 2983 * devd processes them. 2984 */ 2985 2986 if (sbuf_error(&sb) == 0) 2987 devctl_notify("VFS", "FS", type, sbuf_data(&sb)); 2988 sbuf_delete(&sb); 2989 free(buf, M_MOUNT); 2990 } 2991 2992 /* 2993 * Force remount specified mount point to read-only. The argument 2994 * must be busied to avoid parallel unmount attempts. 2995 * 2996 * Intended use is to prevent further writes if some metadata 2997 * inconsistency is detected. Note that the function still flushes 2998 * all cached metadata and data for the mount point, which might be 2999 * not always suitable. 3000 */ 3001 int 3002 vfs_remount_ro(struct mount *mp) 3003 { 3004 struct vfsoptlist *opts; 3005 struct vfsopt *opt; 3006 struct vnode *vp_covered, *rootvp; 3007 int error; 3008 3009 KASSERT(mp->mnt_lockref > 0, 3010 ("vfs_remount_ro: mp %p is not busied", mp)); 3011 KASSERT((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0, 3012 ("vfs_remount_ro: mp %p is being unmounted (and busy?)", mp)); 3013 3014 rootvp = NULL; 3015 vp_covered = mp->mnt_vnodecovered; 3016 error = vget(vp_covered, LK_EXCLUSIVE | LK_NOWAIT); 3017 if (error != 0) 3018 return (error); 3019 VI_LOCK(vp_covered); 3020 if ((vp_covered->v_iflag & VI_MOUNT) != 0) { 3021 VI_UNLOCK(vp_covered); 3022 vput(vp_covered); 3023 return (EBUSY); 3024 } 3025 vp_covered->v_iflag |= VI_MOUNT; 3026 VI_UNLOCK(vp_covered); 3027 vfs_op_enter(mp); 3028 vn_seqc_write_begin(vp_covered); 3029 3030 MNT_ILOCK(mp); 3031 if ((mp->mnt_flag & MNT_RDONLY) != 0) { 3032 MNT_IUNLOCK(mp); 3033 error = EBUSY; 3034 goto out; 3035 } 3036 mp->mnt_flag |= MNT_UPDATE | MNT_FORCE | MNT_RDONLY; 3037 rootvp = vfs_cache_root_clear(mp); 3038 MNT_IUNLOCK(mp); 3039 3040 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK | M_ZERO); 3041 TAILQ_INIT(opts); 3042 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK | M_ZERO); 3043 opt->name = strdup("ro", M_MOUNT); 3044 opt->value = NULL; 3045 TAILQ_INSERT_TAIL(opts, opt, link); 3046 vfs_mergeopts(opts, mp->mnt_opt); 3047 mp->mnt_optnew = opts; 3048 3049 error = VFS_MOUNT(mp); 3050 3051 if (error == 0) { 3052 MNT_ILOCK(mp); 3053 mp->mnt_flag &= ~(MNT_UPDATE | MNT_FORCE); 3054 MNT_IUNLOCK(mp); 3055 vfs_deallocate_syncvnode(mp); 3056 if (mp->mnt_opt != NULL) 3057 vfs_freeopts(mp->mnt_opt); 3058 mp->mnt_opt = mp->mnt_optnew; 3059 } else { 3060 MNT_ILOCK(mp); 3061 mp->mnt_flag &= ~(MNT_UPDATE | MNT_FORCE | MNT_RDONLY); 3062 MNT_IUNLOCK(mp); 3063 vfs_freeopts(mp->mnt_optnew); 3064 } 3065 mp->mnt_optnew = NULL; 3066 3067 out: 3068 vfs_op_exit(mp); 3069 VI_LOCK(vp_covered); 3070 vp_covered->v_iflag &= ~VI_MOUNT; 3071 VI_UNLOCK(vp_covered); 3072 vput(vp_covered); 3073 vn_seqc_write_end(vp_covered); 3074 if (rootvp != NULL) { 3075 vn_seqc_write_end(rootvp); 3076 vrele(rootvp); 3077 } 3078 return (error); 3079 } 3080 3081 /* 3082 * Suspend write operations on all local writeable filesystems. Does 3083 * full sync of them in the process. 3084 * 3085 * Iterate over the mount points in reverse order, suspending most 3086 * recently mounted filesystems first. It handles a case where a 3087 * filesystem mounted from a md(4) vnode-backed device should be 3088 * suspended before the filesystem that owns the vnode. 3089 */ 3090 void 3091 suspend_all_fs(void) 3092 { 3093 struct mount *mp; 3094 int error; 3095 3096 mtx_lock(&mountlist_mtx); 3097 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 3098 error = vfs_busy(mp, MBF_MNTLSTLOCK | MBF_NOWAIT); 3099 if (error != 0) 3100 continue; 3101 if ((mp->mnt_flag & (MNT_RDONLY | MNT_LOCAL)) != MNT_LOCAL || 3102 (mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 3103 mtx_lock(&mountlist_mtx); 3104 vfs_unbusy(mp); 3105 continue; 3106 } 3107 error = vfs_write_suspend(mp, 0); 3108 if (error == 0) { 3109 MNT_ILOCK(mp); 3110 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0); 3111 mp->mnt_kern_flag |= MNTK_SUSPEND_ALL; 3112 MNT_IUNLOCK(mp); 3113 mtx_lock(&mountlist_mtx); 3114 } else { 3115 printf("suspend of %s failed, error %d\n", 3116 mp->mnt_stat.f_mntonname, error); 3117 mtx_lock(&mountlist_mtx); 3118 vfs_unbusy(mp); 3119 } 3120 } 3121 mtx_unlock(&mountlist_mtx); 3122 } 3123 3124 void 3125 resume_all_fs(void) 3126 { 3127 struct mount *mp; 3128 3129 mtx_lock(&mountlist_mtx); 3130 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3131 if ((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0) 3132 continue; 3133 mtx_unlock(&mountlist_mtx); 3134 MNT_ILOCK(mp); 3135 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) != 0); 3136 mp->mnt_kern_flag &= ~MNTK_SUSPEND_ALL; 3137 MNT_IUNLOCK(mp); 3138 vfs_write_resume(mp, 0); 3139 mtx_lock(&mountlist_mtx); 3140 vfs_unbusy(mp); 3141 } 3142 mtx_unlock(&mountlist_mtx); 3143 } 3144