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/malloc.h> 53 #include <sys/mount.h> 54 #include <sys/mutex.h> 55 #include <sys/namei.h> 56 #include <sys/priv.h> 57 #include <sys/proc.h> 58 #include <sys/filedesc.h> 59 #include <sys/reboot.h> 60 #include <sys/sbuf.h> 61 #include <sys/syscallsubr.h> 62 #include <sys/sysproto.h> 63 #include <sys/sx.h> 64 #include <sys/sysctl.h> 65 #include <sys/sysent.h> 66 #include <sys/systm.h> 67 #include <sys/vnode.h> 68 #include <vm/uma.h> 69 70 #include <geom/geom.h> 71 72 #include <machine/stdarg.h> 73 74 #include <security/audit/audit.h> 75 #include <security/mac/mac_framework.h> 76 77 #define VFS_MOUNTARG_SIZE_MAX (1024 * 64) 78 79 static int vfs_domount(struct thread *td, const char *fstype, char *fspath, 80 uint64_t fsflags, struct vfsoptlist **optlist); 81 static void free_mntarg(struct mntarg *ma); 82 83 static int usermount = 0; 84 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 85 "Unprivileged users may mount and unmount file systems"); 86 87 static bool default_autoro = false; 88 SYSCTL_BOOL(_vfs, OID_AUTO, default_autoro, CTLFLAG_RW, &default_autoro, 0, 89 "Retry failed r/w mount as r/o if no explicit ro/rw option is specified"); 90 91 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 92 MALLOC_DEFINE(M_STATFS, "statfs", "statfs structure"); 93 static uma_zone_t mount_zone; 94 95 /* List of mounted filesystems. */ 96 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 97 98 /* For any iteration/modification of mountlist */ 99 struct mtx_padalign __exclusive_cache_line mountlist_mtx; 100 MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF); 101 102 EVENTHANDLER_LIST_DEFINE(vfs_mounted); 103 EVENTHANDLER_LIST_DEFINE(vfs_unmounted); 104 105 static void mount_devctl_event(const char *type, struct mount *mp, bool donew); 106 107 /* 108 * Global opts, taken by all filesystems 109 */ 110 static const char *global_opts[] = { 111 "errmsg", 112 "fstype", 113 "fspath", 114 "ro", 115 "rw", 116 "nosuid", 117 "noexec", 118 NULL 119 }; 120 121 static int 122 mount_init(void *mem, int size, int flags) 123 { 124 struct mount *mp; 125 126 mp = (struct mount *)mem; 127 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 128 mtx_init(&mp->mnt_listmtx, "struct mount vlist mtx", NULL, MTX_DEF); 129 lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0); 130 mp->mnt_thread_in_ops_pcpu = uma_zalloc_pcpu(pcpu_zone_4, 131 M_WAITOK | M_ZERO); 132 mp->mnt_ref_pcpu = uma_zalloc_pcpu(pcpu_zone_4, 133 M_WAITOK | M_ZERO); 134 mp->mnt_lockref_pcpu = uma_zalloc_pcpu(pcpu_zone_4, 135 M_WAITOK | M_ZERO); 136 mp->mnt_writeopcount_pcpu = uma_zalloc_pcpu(pcpu_zone_4, 137 M_WAITOK | M_ZERO); 138 mp->mnt_ref = 0; 139 mp->mnt_vfs_ops = 1; 140 mp->mnt_rootvnode = NULL; 141 return (0); 142 } 143 144 static void 145 mount_fini(void *mem, int size) 146 { 147 struct mount *mp; 148 149 mp = (struct mount *)mem; 150 uma_zfree_pcpu(pcpu_zone_4, mp->mnt_writeopcount_pcpu); 151 uma_zfree_pcpu(pcpu_zone_4, mp->mnt_lockref_pcpu); 152 uma_zfree_pcpu(pcpu_zone_4, mp->mnt_ref_pcpu); 153 uma_zfree_pcpu(pcpu_zone_4, mp->mnt_thread_in_ops_pcpu); 154 lockdestroy(&mp->mnt_explock); 155 mtx_destroy(&mp->mnt_listmtx); 156 mtx_destroy(&mp->mnt_mtx); 157 } 158 159 static void 160 vfs_mount_init(void *dummy __unused) 161 { 162 163 mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), NULL, 164 NULL, mount_init, mount_fini, UMA_ALIGN_CACHE, UMA_ZONE_NOFREE); 165 } 166 SYSINIT(vfs_mount, SI_SUB_VFS, SI_ORDER_ANY, vfs_mount_init, NULL); 167 168 /* 169 * --------------------------------------------------------------------- 170 * Functions for building and sanitizing the mount options 171 */ 172 173 /* Remove one mount option. */ 174 static void 175 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 176 { 177 178 TAILQ_REMOVE(opts, opt, link); 179 free(opt->name, M_MOUNT); 180 if (opt->value != NULL) 181 free(opt->value, M_MOUNT); 182 free(opt, M_MOUNT); 183 } 184 185 /* Release all resources related to the mount options. */ 186 void 187 vfs_freeopts(struct vfsoptlist *opts) 188 { 189 struct vfsopt *opt; 190 191 while (!TAILQ_EMPTY(opts)) { 192 opt = TAILQ_FIRST(opts); 193 vfs_freeopt(opts, opt); 194 } 195 free(opts, M_MOUNT); 196 } 197 198 void 199 vfs_deleteopt(struct vfsoptlist *opts, const char *name) 200 { 201 struct vfsopt *opt, *temp; 202 203 if (opts == NULL) 204 return; 205 TAILQ_FOREACH_SAFE(opt, opts, link, temp) { 206 if (strcmp(opt->name, name) == 0) 207 vfs_freeopt(opts, opt); 208 } 209 } 210 211 static int 212 vfs_isopt_ro(const char *opt) 213 { 214 215 if (strcmp(opt, "ro") == 0 || strcmp(opt, "rdonly") == 0 || 216 strcmp(opt, "norw") == 0) 217 return (1); 218 return (0); 219 } 220 221 static int 222 vfs_isopt_rw(const char *opt) 223 { 224 225 if (strcmp(opt, "rw") == 0 || strcmp(opt, "noro") == 0) 226 return (1); 227 return (0); 228 } 229 230 /* 231 * Check if options are equal (with or without the "no" prefix). 232 */ 233 static int 234 vfs_equalopts(const char *opt1, const char *opt2) 235 { 236 char *p; 237 238 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 239 if (strcmp(opt1, opt2) == 0) 240 return (1); 241 /* "noopt" vs. "opt" */ 242 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 243 return (1); 244 /* "opt" vs. "noopt" */ 245 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 246 return (1); 247 while ((p = strchr(opt1, '.')) != NULL && 248 !strncmp(opt1, opt2, ++p - opt1)) { 249 opt2 += p - opt1; 250 opt1 = p; 251 /* "foo.noopt" vs. "foo.opt" */ 252 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 253 return (1); 254 /* "foo.opt" vs. "foo.noopt" */ 255 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 256 return (1); 257 } 258 /* "ro" / "rdonly" / "norw" / "rw" / "noro" */ 259 if ((vfs_isopt_ro(opt1) || vfs_isopt_rw(opt1)) && 260 (vfs_isopt_ro(opt2) || vfs_isopt_rw(opt2))) 261 return (1); 262 return (0); 263 } 264 265 /* 266 * If a mount option is specified several times, 267 * (with or without the "no" prefix) only keep 268 * the last occurrence of it. 269 */ 270 static void 271 vfs_sanitizeopts(struct vfsoptlist *opts) 272 { 273 struct vfsopt *opt, *opt2, *tmp; 274 275 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 276 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 277 while (opt2 != NULL) { 278 if (vfs_equalopts(opt->name, opt2->name)) { 279 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 280 vfs_freeopt(opts, opt2); 281 opt2 = tmp; 282 } else { 283 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 284 } 285 } 286 } 287 } 288 289 /* 290 * Build a linked list of mount options from a struct uio. 291 */ 292 int 293 vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 294 { 295 struct vfsoptlist *opts; 296 struct vfsopt *opt; 297 size_t memused, namelen, optlen; 298 unsigned int i, iovcnt; 299 int error; 300 301 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 302 TAILQ_INIT(opts); 303 memused = 0; 304 iovcnt = auio->uio_iovcnt; 305 for (i = 0; i < iovcnt; i += 2) { 306 namelen = auio->uio_iov[i].iov_len; 307 optlen = auio->uio_iov[i + 1].iov_len; 308 memused += sizeof(struct vfsopt) + optlen + namelen; 309 /* 310 * Avoid consuming too much memory, and attempts to overflow 311 * memused. 312 */ 313 if (memused > VFS_MOUNTARG_SIZE_MAX || 314 optlen > VFS_MOUNTARG_SIZE_MAX || 315 namelen > VFS_MOUNTARG_SIZE_MAX) { 316 error = EINVAL; 317 goto bad; 318 } 319 320 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 321 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 322 opt->value = NULL; 323 opt->len = 0; 324 opt->pos = i / 2; 325 opt->seen = 0; 326 327 /* 328 * Do this early, so jumps to "bad" will free the current 329 * option. 330 */ 331 TAILQ_INSERT_TAIL(opts, opt, link); 332 333 if (auio->uio_segflg == UIO_SYSSPACE) { 334 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 335 } else { 336 error = copyin(auio->uio_iov[i].iov_base, opt->name, 337 namelen); 338 if (error) 339 goto bad; 340 } 341 /* Ensure names are null-terminated strings. */ 342 if (namelen == 0 || opt->name[namelen - 1] != '\0') { 343 error = EINVAL; 344 goto bad; 345 } 346 if (optlen != 0) { 347 opt->len = optlen; 348 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 349 if (auio->uio_segflg == UIO_SYSSPACE) { 350 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 351 optlen); 352 } else { 353 error = copyin(auio->uio_iov[i + 1].iov_base, 354 opt->value, optlen); 355 if (error) 356 goto bad; 357 } 358 } 359 } 360 vfs_sanitizeopts(opts); 361 *options = opts; 362 return (0); 363 bad: 364 vfs_freeopts(opts); 365 return (error); 366 } 367 368 /* 369 * Merge the old mount options with the new ones passed 370 * in the MNT_UPDATE case. 371 * 372 * XXX: This function will keep a "nofoo" option in the new 373 * options. E.g, if the option's canonical name is "foo", 374 * "nofoo" ends up in the mount point's active options. 375 */ 376 static void 377 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *oldopts) 378 { 379 struct vfsopt *opt, *new; 380 381 TAILQ_FOREACH(opt, oldopts, link) { 382 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 383 new->name = strdup(opt->name, M_MOUNT); 384 if (opt->len != 0) { 385 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 386 bcopy(opt->value, new->value, opt->len); 387 } else 388 new->value = NULL; 389 new->len = opt->len; 390 new->seen = opt->seen; 391 TAILQ_INSERT_HEAD(toopts, new, link); 392 } 393 vfs_sanitizeopts(toopts); 394 } 395 396 /* 397 * Mount a filesystem. 398 */ 399 #ifndef _SYS_SYSPROTO_H_ 400 struct nmount_args { 401 struct iovec *iovp; 402 unsigned int iovcnt; 403 int flags; 404 }; 405 #endif 406 int 407 sys_nmount(struct thread *td, struct nmount_args *uap) 408 { 409 struct uio *auio; 410 int error; 411 u_int iovcnt; 412 uint64_t flags; 413 414 /* 415 * Mount flags are now 64-bits. On 32-bit archtectures only 416 * 32-bits are passed in, but from here on everything handles 417 * 64-bit flags correctly. 418 */ 419 flags = uap->flags; 420 421 AUDIT_ARG_FFLAGS(flags); 422 CTR4(KTR_VFS, "%s: iovp %p with iovcnt %d and flags %d", __func__, 423 uap->iovp, uap->iovcnt, flags); 424 425 /* 426 * Filter out MNT_ROOTFS. We do not want clients of nmount() in 427 * userspace to set this flag, but we must filter it out if we want 428 * MNT_UPDATE on the root file system to work. 429 * MNT_ROOTFS should only be set by the kernel when mounting its 430 * root file system. 431 */ 432 flags &= ~MNT_ROOTFS; 433 434 iovcnt = uap->iovcnt; 435 /* 436 * Check that we have an even number of iovec's 437 * and that we have at least two options. 438 */ 439 if ((iovcnt & 1) || (iovcnt < 4)) { 440 CTR2(KTR_VFS, "%s: failed for invalid iovcnt %d", __func__, 441 uap->iovcnt); 442 return (EINVAL); 443 } 444 445 error = copyinuio(uap->iovp, iovcnt, &auio); 446 if (error) { 447 CTR2(KTR_VFS, "%s: failed for invalid uio op with %d errno", 448 __func__, error); 449 return (error); 450 } 451 error = vfs_donmount(td, flags, auio); 452 453 free(auio, M_IOV); 454 return (error); 455 } 456 457 /* 458 * --------------------------------------------------------------------- 459 * Various utility functions 460 */ 461 462 void 463 vfs_ref(struct mount *mp) 464 { 465 466 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 467 if (vfs_op_thread_enter(mp)) { 468 vfs_mp_count_add_pcpu(mp, ref, 1); 469 vfs_op_thread_exit(mp); 470 return; 471 } 472 473 MNT_ILOCK(mp); 474 MNT_REF(mp); 475 MNT_IUNLOCK(mp); 476 } 477 478 void 479 vfs_rel(struct mount *mp) 480 { 481 482 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 483 if (vfs_op_thread_enter(mp)) { 484 vfs_mp_count_sub_pcpu(mp, ref, 1); 485 vfs_op_thread_exit(mp); 486 return; 487 } 488 489 MNT_ILOCK(mp); 490 MNT_REL(mp); 491 MNT_IUNLOCK(mp); 492 } 493 494 /* 495 * Allocate and initialize the mount point struct. 496 */ 497 struct mount * 498 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath, 499 struct ucred *cred) 500 { 501 struct mount *mp; 502 503 mp = uma_zalloc(mount_zone, M_WAITOK); 504 bzero(&mp->mnt_startzero, 505 __rangeof(struct mount, mnt_startzero, mnt_endzero)); 506 TAILQ_INIT(&mp->mnt_nvnodelist); 507 mp->mnt_nvnodelistsize = 0; 508 TAILQ_INIT(&mp->mnt_lazyvnodelist); 509 mp->mnt_lazyvnodelistsize = 0; 510 if (mp->mnt_ref != 0 || mp->mnt_lockref != 0 || 511 mp->mnt_writeopcount != 0) 512 panic("%s: non-zero counters on new mp %p\n", __func__, mp); 513 if (mp->mnt_vfs_ops != 1) 514 panic("%s: vfs_ops should be 1 but %d found\n", __func__, 515 mp->mnt_vfs_ops); 516 (void) vfs_busy(mp, MBF_NOWAIT); 517 atomic_add_acq_int(&vfsp->vfc_refcount, 1); 518 mp->mnt_op = vfsp->vfc_vfsops; 519 mp->mnt_vfc = vfsp; 520 mp->mnt_stat.f_type = vfsp->vfc_typenum; 521 mp->mnt_gen++; 522 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 523 mp->mnt_vnodecovered = vp; 524 mp->mnt_cred = crdup(cred); 525 mp->mnt_stat.f_owner = cred->cr_uid; 526 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 527 mp->mnt_iosize_max = DFLTPHYS; 528 #ifdef MAC 529 mac_mount_init(mp); 530 mac_mount_create(cred, mp); 531 #endif 532 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0); 533 TAILQ_INIT(&mp->mnt_uppers); 534 return (mp); 535 } 536 537 /* 538 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 539 */ 540 void 541 vfs_mount_destroy(struct mount *mp) 542 { 543 544 if (mp->mnt_vfs_ops == 0) 545 panic("%s: entered with zero vfs_ops\n", __func__); 546 547 vfs_assert_mount_counters(mp); 548 549 MNT_ILOCK(mp); 550 mp->mnt_kern_flag |= MNTK_REFEXPIRE; 551 if (mp->mnt_kern_flag & MNTK_MWAIT) { 552 mp->mnt_kern_flag &= ~MNTK_MWAIT; 553 wakeup(mp); 554 } 555 while (mp->mnt_ref) 556 msleep(mp, MNT_MTX(mp), PVFS, "mntref", 0); 557 KASSERT(mp->mnt_ref == 0, 558 ("%s: invalid refcount in the drain path @ %s:%d", __func__, 559 __FILE__, __LINE__)); 560 if (mp->mnt_writeopcount != 0) 561 panic("vfs_mount_destroy: nonzero writeopcount"); 562 if (mp->mnt_secondary_writes != 0) 563 panic("vfs_mount_destroy: nonzero secondary_writes"); 564 atomic_subtract_rel_int(&mp->mnt_vfc->vfc_refcount, 1); 565 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) { 566 struct vnode *vp; 567 568 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) 569 vn_printf(vp, "dangling vnode "); 570 panic("unmount: dangling vnode"); 571 } 572 KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers")); 573 if (mp->mnt_nvnodelistsize != 0) 574 panic("vfs_mount_destroy: nonzero nvnodelistsize"); 575 if (mp->mnt_lazyvnodelistsize != 0) 576 panic("vfs_mount_destroy: nonzero lazyvnodelistsize"); 577 if (mp->mnt_lockref != 0) 578 panic("vfs_mount_destroy: nonzero lock refcount"); 579 MNT_IUNLOCK(mp); 580 581 if (mp->mnt_vfs_ops != 1) 582 panic("%s: vfs_ops should be 1 but %d found\n", __func__, 583 mp->mnt_vfs_ops); 584 585 if (mp->mnt_rootvnode != NULL) 586 panic("%s: mount point still has a root vnode %p\n", __func__, 587 mp->mnt_rootvnode); 588 589 if (mp->mnt_vnodecovered != NULL) 590 vrele(mp->mnt_vnodecovered); 591 #ifdef MAC 592 mac_mount_destroy(mp); 593 #endif 594 if (mp->mnt_opt != NULL) 595 vfs_freeopts(mp->mnt_opt); 596 crfree(mp->mnt_cred); 597 uma_zfree(mount_zone, mp); 598 } 599 600 static bool 601 vfs_should_downgrade_to_ro_mount(uint64_t fsflags, int error) 602 { 603 /* This is an upgrade of an exisiting mount. */ 604 if ((fsflags & MNT_UPDATE) != 0) 605 return (false); 606 /* This is already an R/O mount. */ 607 if ((fsflags & MNT_RDONLY) != 0) 608 return (false); 609 610 switch (error) { 611 case ENODEV: /* generic, geom, ... */ 612 case EACCES: /* cam/scsi, ... */ 613 case EROFS: /* md, mmcsd, ... */ 614 /* 615 * These errors can be returned by the storage layer to signal 616 * that the media is read-only. No harm in the R/O mount 617 * attempt if the error was returned for some other reason. 618 */ 619 return (true); 620 default: 621 return (false); 622 } 623 } 624 625 int 626 vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions) 627 { 628 struct vfsoptlist *optlist; 629 struct vfsopt *opt, *tmp_opt; 630 char *fstype, *fspath, *errmsg; 631 int error, fstypelen, fspathlen, errmsg_len, errmsg_pos; 632 bool autoro; 633 634 errmsg = fspath = NULL; 635 errmsg_len = fspathlen = 0; 636 errmsg_pos = -1; 637 autoro = default_autoro; 638 639 error = vfs_buildopts(fsoptions, &optlist); 640 if (error) 641 return (error); 642 643 if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0) 644 errmsg_pos = vfs_getopt_pos(optlist, "errmsg"); 645 646 /* 647 * We need these two options before the others, 648 * and they are mandatory for any filesystem. 649 * Ensure they are NUL terminated as well. 650 */ 651 fstypelen = 0; 652 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 653 if (error || fstypelen <= 0 || fstype[fstypelen - 1] != '\0') { 654 error = EINVAL; 655 if (errmsg != NULL) 656 strncpy(errmsg, "Invalid fstype", errmsg_len); 657 goto bail; 658 } 659 fspathlen = 0; 660 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 661 if (error || fspathlen <= 0 || fspath[fspathlen - 1] != '\0') { 662 error = EINVAL; 663 if (errmsg != NULL) 664 strncpy(errmsg, "Invalid fspath", errmsg_len); 665 goto bail; 666 } 667 668 /* 669 * We need to see if we have the "update" option 670 * before we call vfs_domount(), since vfs_domount() has special 671 * logic based on MNT_UPDATE. This is very important 672 * when we want to update the root filesystem. 673 */ 674 TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) { 675 int do_freeopt = 0; 676 677 if (strcmp(opt->name, "update") == 0) { 678 fsflags |= MNT_UPDATE; 679 do_freeopt = 1; 680 } 681 else if (strcmp(opt->name, "async") == 0) 682 fsflags |= MNT_ASYNC; 683 else if (strcmp(opt->name, "force") == 0) { 684 fsflags |= MNT_FORCE; 685 do_freeopt = 1; 686 } 687 else if (strcmp(opt->name, "reload") == 0) { 688 fsflags |= MNT_RELOAD; 689 do_freeopt = 1; 690 } 691 else if (strcmp(opt->name, "multilabel") == 0) 692 fsflags |= MNT_MULTILABEL; 693 else if (strcmp(opt->name, "noasync") == 0) 694 fsflags &= ~MNT_ASYNC; 695 else if (strcmp(opt->name, "noatime") == 0) 696 fsflags |= MNT_NOATIME; 697 else if (strcmp(opt->name, "atime") == 0) { 698 free(opt->name, M_MOUNT); 699 opt->name = strdup("nonoatime", M_MOUNT); 700 } 701 else if (strcmp(opt->name, "noclusterr") == 0) 702 fsflags |= MNT_NOCLUSTERR; 703 else if (strcmp(opt->name, "clusterr") == 0) { 704 free(opt->name, M_MOUNT); 705 opt->name = strdup("nonoclusterr", M_MOUNT); 706 } 707 else if (strcmp(opt->name, "noclusterw") == 0) 708 fsflags |= MNT_NOCLUSTERW; 709 else if (strcmp(opt->name, "clusterw") == 0) { 710 free(opt->name, M_MOUNT); 711 opt->name = strdup("nonoclusterw", M_MOUNT); 712 } 713 else if (strcmp(opt->name, "noexec") == 0) 714 fsflags |= MNT_NOEXEC; 715 else if (strcmp(opt->name, "exec") == 0) { 716 free(opt->name, M_MOUNT); 717 opt->name = strdup("nonoexec", M_MOUNT); 718 } 719 else if (strcmp(opt->name, "nosuid") == 0) 720 fsflags |= MNT_NOSUID; 721 else if (strcmp(opt->name, "suid") == 0) { 722 free(opt->name, M_MOUNT); 723 opt->name = strdup("nonosuid", M_MOUNT); 724 } 725 else if (strcmp(opt->name, "nosymfollow") == 0) 726 fsflags |= MNT_NOSYMFOLLOW; 727 else if (strcmp(opt->name, "symfollow") == 0) { 728 free(opt->name, M_MOUNT); 729 opt->name = strdup("nonosymfollow", M_MOUNT); 730 } 731 else if (strcmp(opt->name, "noro") == 0) { 732 fsflags &= ~MNT_RDONLY; 733 autoro = false; 734 } 735 else if (strcmp(opt->name, "rw") == 0) { 736 fsflags &= ~MNT_RDONLY; 737 autoro = false; 738 } 739 else if (strcmp(opt->name, "ro") == 0) { 740 fsflags |= MNT_RDONLY; 741 autoro = false; 742 } 743 else if (strcmp(opt->name, "rdonly") == 0) { 744 free(opt->name, M_MOUNT); 745 opt->name = strdup("ro", M_MOUNT); 746 fsflags |= MNT_RDONLY; 747 autoro = false; 748 } 749 else if (strcmp(opt->name, "autoro") == 0) { 750 do_freeopt = 1; 751 autoro = true; 752 } 753 else if (strcmp(opt->name, "suiddir") == 0) 754 fsflags |= MNT_SUIDDIR; 755 else if (strcmp(opt->name, "sync") == 0) 756 fsflags |= MNT_SYNCHRONOUS; 757 else if (strcmp(opt->name, "union") == 0) 758 fsflags |= MNT_UNION; 759 else if (strcmp(opt->name, "automounted") == 0) { 760 fsflags |= MNT_AUTOMOUNTED; 761 do_freeopt = 1; 762 } else if (strcmp(opt->name, "nocover") == 0) { 763 fsflags |= MNT_NOCOVER; 764 do_freeopt = 1; 765 } else if (strcmp(opt->name, "cover") == 0) { 766 fsflags &= ~MNT_NOCOVER; 767 do_freeopt = 1; 768 } else if (strcmp(opt->name, "emptydir") == 0) { 769 fsflags |= MNT_EMPTYDIR; 770 do_freeopt = 1; 771 } else if (strcmp(opt->name, "noemptydir") == 0) { 772 fsflags &= ~MNT_EMPTYDIR; 773 do_freeopt = 1; 774 } 775 if (do_freeopt) 776 vfs_freeopt(optlist, opt); 777 } 778 779 /* 780 * Be ultra-paranoid about making sure the type and fspath 781 * variables will fit in our mp buffers, including the 782 * terminating NUL. 783 */ 784 if (fstypelen > MFSNAMELEN || fspathlen > MNAMELEN) { 785 error = ENAMETOOLONG; 786 goto bail; 787 } 788 789 error = vfs_domount(td, fstype, fspath, fsflags, &optlist); 790 791 /* 792 * See if we can mount in the read-only mode if the error code suggests 793 * that it could be possible and the mount options allow for that. 794 * Never try it if "[no]{ro|rw}" has been explicitly requested and not 795 * overridden by "autoro". 796 */ 797 if (autoro && vfs_should_downgrade_to_ro_mount(fsflags, error)) { 798 printf("%s: R/W mount failed, possibly R/O media," 799 " trying R/O mount\n", __func__); 800 fsflags |= MNT_RDONLY; 801 error = vfs_domount(td, fstype, fspath, fsflags, &optlist); 802 } 803 bail: 804 /* copyout the errmsg */ 805 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt) 806 && errmsg_len > 0 && errmsg != NULL) { 807 if (fsoptions->uio_segflg == UIO_SYSSPACE) { 808 bcopy(errmsg, 809 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 810 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 811 } else { 812 copyout(errmsg, 813 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 814 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 815 } 816 } 817 818 if (optlist != NULL) 819 vfs_freeopts(optlist); 820 return (error); 821 } 822 823 /* 824 * Old mount API. 825 */ 826 #ifndef _SYS_SYSPROTO_H_ 827 struct mount_args { 828 char *type; 829 char *path; 830 int flags; 831 caddr_t data; 832 }; 833 #endif 834 /* ARGSUSED */ 835 int 836 sys_mount(struct thread *td, struct mount_args *uap) 837 { 838 char *fstype; 839 struct vfsconf *vfsp = NULL; 840 struct mntarg *ma = NULL; 841 uint64_t flags; 842 int error; 843 844 /* 845 * Mount flags are now 64-bits. On 32-bit architectures only 846 * 32-bits are passed in, but from here on everything handles 847 * 64-bit flags correctly. 848 */ 849 flags = uap->flags; 850 851 AUDIT_ARG_FFLAGS(flags); 852 853 /* 854 * Filter out MNT_ROOTFS. We do not want clients of mount() in 855 * userspace to set this flag, but we must filter it out if we want 856 * MNT_UPDATE on the root file system to work. 857 * MNT_ROOTFS should only be set by the kernel when mounting its 858 * root file system. 859 */ 860 flags &= ~MNT_ROOTFS; 861 862 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 863 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 864 if (error) { 865 free(fstype, M_TEMP); 866 return (error); 867 } 868 869 AUDIT_ARG_TEXT(fstype); 870 vfsp = vfs_byname_kld(fstype, td, &error); 871 free(fstype, M_TEMP); 872 if (vfsp == NULL) 873 return (ENOENT); 874 if (((vfsp->vfc_flags & VFCF_SBDRY) != 0 && 875 vfsp->vfc_vfsops_sd->vfs_cmount == NULL) || 876 ((vfsp->vfc_flags & VFCF_SBDRY) == 0 && 877 vfsp->vfc_vfsops->vfs_cmount == NULL)) 878 return (EOPNOTSUPP); 879 880 ma = mount_argsu(ma, "fstype", uap->type, MFSNAMELEN); 881 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 882 ma = mount_argb(ma, flags & MNT_RDONLY, "noro"); 883 ma = mount_argb(ma, !(flags & MNT_NOSUID), "nosuid"); 884 ma = mount_argb(ma, !(flags & MNT_NOEXEC), "noexec"); 885 886 if ((vfsp->vfc_flags & VFCF_SBDRY) != 0) 887 return (vfsp->vfc_vfsops_sd->vfs_cmount(ma, uap->data, flags)); 888 return (vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, flags)); 889 } 890 891 /* 892 * vfs_domount_first(): first file system mount (not update) 893 */ 894 static int 895 vfs_domount_first( 896 struct thread *td, /* Calling thread. */ 897 struct vfsconf *vfsp, /* File system type. */ 898 char *fspath, /* Mount path. */ 899 struct vnode *vp, /* Vnode to be covered. */ 900 uint64_t fsflags, /* Flags common to all filesystems. */ 901 struct vfsoptlist **optlist /* Options local to the filesystem. */ 902 ) 903 { 904 struct vattr va; 905 struct mount *mp; 906 struct vnode *newdp, *rootvp; 907 int error, error1; 908 909 ASSERT_VOP_ELOCKED(vp, __func__); 910 KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here")); 911 912 if ((fsflags & MNT_EMPTYDIR) != 0) { 913 error = vfs_emptydir(vp); 914 if (error != 0) { 915 vput(vp); 916 return (error); 917 } 918 } 919 920 /* 921 * If the jail of the calling thread lacks permission for this type of 922 * file system, deny immediately. 923 */ 924 if (jailed(td->td_ucred) && !prison_allow(td->td_ucred, 925 vfsp->vfc_prison_flag)) { 926 vput(vp); 927 return (EPERM); 928 } 929 930 /* 931 * If the user is not root, ensure that they own the directory 932 * onto which we are attempting to mount. 933 */ 934 error = VOP_GETATTR(vp, &va, td->td_ucred); 935 if (error == 0 && va.va_uid != td->td_ucred->cr_uid) 936 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN); 937 if (error == 0) 938 error = vinvalbuf(vp, V_SAVE, 0, 0); 939 if (error == 0 && vp->v_type != VDIR) 940 error = ENOTDIR; 941 if (error == 0) { 942 VI_LOCK(vp); 943 if ((vp->v_iflag & VI_MOUNT) == 0 && vp->v_mountedhere == NULL) 944 vp->v_iflag |= VI_MOUNT; 945 else 946 error = EBUSY; 947 VI_UNLOCK(vp); 948 } 949 if (error != 0) { 950 vput(vp); 951 return (error); 952 } 953 vn_seqc_write_begin(vp); 954 VOP_UNLOCK(vp); 955 956 /* Allocate and initialize the filesystem. */ 957 mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred); 958 /* XXXMAC: pass to vfs_mount_alloc? */ 959 mp->mnt_optnew = *optlist; 960 /* Set the mount level flags. */ 961 mp->mnt_flag = (fsflags & (MNT_UPDATEMASK | MNT_ROOTFS | MNT_RDONLY)); 962 963 /* 964 * Mount the filesystem. 965 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 966 * get. No freeing of cn_pnbuf. 967 */ 968 error1 = 0; 969 if ((error = VFS_MOUNT(mp)) != 0 || 970 (error1 = VFS_STATFS(mp, &mp->mnt_stat)) != 0 || 971 (error1 = VFS_ROOT(mp, LK_EXCLUSIVE, &newdp)) != 0) { 972 rootvp = NULL; 973 if (error1 != 0) { 974 error = error1; 975 rootvp = vfs_cache_root_clear(mp); 976 if (rootvp != NULL) { 977 vhold(rootvp); 978 vrele(rootvp); 979 } 980 if ((error1 = VFS_UNMOUNT(mp, 0)) != 0) 981 printf("VFS_UNMOUNT returned %d\n", error1); 982 } 983 vfs_unbusy(mp); 984 mp->mnt_vnodecovered = NULL; 985 vfs_mount_destroy(mp); 986 VI_LOCK(vp); 987 vp->v_iflag &= ~VI_MOUNT; 988 VI_UNLOCK(vp); 989 if (rootvp != NULL) { 990 vn_seqc_write_end(rootvp); 991 vdrop(rootvp); 992 } 993 vn_seqc_write_end(vp); 994 vrele(vp); 995 return (error); 996 } 997 vn_seqc_write_begin(newdp); 998 VOP_UNLOCK(newdp); 999 1000 if (mp->mnt_opt != NULL) 1001 vfs_freeopts(mp->mnt_opt); 1002 mp->mnt_opt = mp->mnt_optnew; 1003 *optlist = NULL; 1004 1005 /* 1006 * Prevent external consumers of mount options from reading mnt_optnew. 1007 */ 1008 mp->mnt_optnew = NULL; 1009 1010 MNT_ILOCK(mp); 1011 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 1012 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 1013 mp->mnt_kern_flag |= MNTK_ASYNC; 1014 else 1015 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1016 MNT_IUNLOCK(mp); 1017 1018 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1019 cache_purge(vp); 1020 VI_LOCK(vp); 1021 vp->v_iflag &= ~VI_MOUNT; 1022 VI_UNLOCK(vp); 1023 vp->v_mountedhere = mp; 1024 /* Place the new filesystem at the end of the mount list. */ 1025 mtx_lock(&mountlist_mtx); 1026 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1027 mtx_unlock(&mountlist_mtx); 1028 vfs_event_signal(NULL, VQ_MOUNT, 0); 1029 vn_lock(newdp, LK_EXCLUSIVE | LK_RETRY); 1030 VOP_UNLOCK(vp); 1031 EVENTHANDLER_DIRECT_INVOKE(vfs_mounted, mp, newdp, td); 1032 VOP_UNLOCK(newdp); 1033 mount_devctl_event("MOUNT", mp, false); 1034 mountcheckdirs(vp, newdp); 1035 vn_seqc_write_end(vp); 1036 vn_seqc_write_end(newdp); 1037 vrele(newdp); 1038 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1039 vfs_allocate_syncvnode(mp); 1040 vfs_op_exit(mp); 1041 vfs_unbusy(mp); 1042 return (0); 1043 } 1044 1045 /* 1046 * vfs_domount_update(): update of mounted file system 1047 */ 1048 static int 1049 vfs_domount_update( 1050 struct thread *td, /* Calling thread. */ 1051 struct vnode *vp, /* Mount point vnode. */ 1052 uint64_t fsflags, /* Flags common to all filesystems. */ 1053 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1054 ) 1055 { 1056 struct export_args export; 1057 struct o2export_args o2export; 1058 struct vnode *rootvp; 1059 void *bufp; 1060 struct mount *mp; 1061 int error, export_error, i, len; 1062 uint64_t flag; 1063 gid_t *grps; 1064 1065 ASSERT_VOP_ELOCKED(vp, __func__); 1066 KASSERT((fsflags & MNT_UPDATE) != 0, ("MNT_UPDATE should be here")); 1067 mp = vp->v_mount; 1068 1069 if ((vp->v_vflag & VV_ROOT) == 0) { 1070 if (vfs_copyopt(*optlist, "export", &export, sizeof(export)) 1071 == 0) 1072 error = EXDEV; 1073 else 1074 error = EINVAL; 1075 vput(vp); 1076 return (error); 1077 } 1078 1079 /* 1080 * We only allow the filesystem to be reloaded if it 1081 * is currently mounted read-only. 1082 */ 1083 flag = mp->mnt_flag; 1084 if ((fsflags & MNT_RELOAD) != 0 && (flag & MNT_RDONLY) == 0) { 1085 vput(vp); 1086 return (EOPNOTSUPP); /* Needs translation */ 1087 } 1088 /* 1089 * Only privileged root, or (if MNT_USER is set) the user that 1090 * did the original mount is permitted to update it. 1091 */ 1092 error = vfs_suser(mp, td); 1093 if (error != 0) { 1094 vput(vp); 1095 return (error); 1096 } 1097 if (vfs_busy(mp, MBF_NOWAIT)) { 1098 vput(vp); 1099 return (EBUSY); 1100 } 1101 VI_LOCK(vp); 1102 if ((vp->v_iflag & VI_MOUNT) != 0 || vp->v_mountedhere != NULL) { 1103 VI_UNLOCK(vp); 1104 vfs_unbusy(mp); 1105 vput(vp); 1106 return (EBUSY); 1107 } 1108 vp->v_iflag |= VI_MOUNT; 1109 VI_UNLOCK(vp); 1110 VOP_UNLOCK(vp); 1111 1112 vfs_op_enter(mp); 1113 vn_seqc_write_begin(vp); 1114 1115 rootvp = NULL; 1116 MNT_ILOCK(mp); 1117 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1118 MNT_IUNLOCK(mp); 1119 error = EBUSY; 1120 goto end; 1121 } 1122 mp->mnt_flag &= ~MNT_UPDATEMASK; 1123 mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | 1124 MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY); 1125 if ((mp->mnt_flag & MNT_ASYNC) == 0) 1126 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1127 rootvp = vfs_cache_root_clear(mp); 1128 MNT_IUNLOCK(mp); 1129 mp->mnt_optnew = *optlist; 1130 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 1131 1132 /* 1133 * Mount the filesystem. 1134 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1135 * get. No freeing of cn_pnbuf. 1136 */ 1137 error = VFS_MOUNT(mp); 1138 1139 export_error = 0; 1140 /* Process the export option. */ 1141 if (error == 0 && vfs_getopt(mp->mnt_optnew, "export", &bufp, 1142 &len) == 0) { 1143 /* Assume that there is only 1 ABI for each length. */ 1144 switch (len) { 1145 case (sizeof(struct oexport_args)): 1146 bzero(&o2export, sizeof(o2export)); 1147 /* FALLTHROUGH */ 1148 case (sizeof(o2export)): 1149 bcopy(bufp, &o2export, len); 1150 export.ex_flags = (uint64_t)o2export.ex_flags; 1151 export.ex_root = o2export.ex_root; 1152 export.ex_uid = o2export.ex_anon.cr_uid; 1153 export.ex_groups = NULL; 1154 export.ex_ngroups = o2export.ex_anon.cr_ngroups; 1155 if (export.ex_ngroups > 0) { 1156 if (export.ex_ngroups <= XU_NGROUPS) { 1157 export.ex_groups = malloc( 1158 export.ex_ngroups * sizeof(gid_t), 1159 M_TEMP, M_WAITOK); 1160 for (i = 0; i < export.ex_ngroups; i++) 1161 export.ex_groups[i] = 1162 o2export.ex_anon.cr_groups[i]; 1163 } else 1164 export_error = EINVAL; 1165 } else if (export.ex_ngroups < 0) 1166 export_error = EINVAL; 1167 export.ex_addr = o2export.ex_addr; 1168 export.ex_addrlen = o2export.ex_addrlen; 1169 export.ex_mask = o2export.ex_mask; 1170 export.ex_masklen = o2export.ex_masklen; 1171 export.ex_indexfile = o2export.ex_indexfile; 1172 export.ex_numsecflavors = o2export.ex_numsecflavors; 1173 if (export.ex_numsecflavors < MAXSECFLAVORS) { 1174 for (i = 0; i < export.ex_numsecflavors; i++) 1175 export.ex_secflavors[i] = 1176 o2export.ex_secflavors[i]; 1177 } else 1178 export_error = EINVAL; 1179 if (export_error == 0) 1180 export_error = vfs_export(mp, &export); 1181 free(export.ex_groups, M_TEMP); 1182 break; 1183 case (sizeof(export)): 1184 bcopy(bufp, &export, len); 1185 grps = NULL; 1186 if (export.ex_ngroups > 0) { 1187 if (export.ex_ngroups <= NGROUPS_MAX) { 1188 grps = malloc(export.ex_ngroups * 1189 sizeof(gid_t), M_TEMP, M_WAITOK); 1190 export_error = copyin(export.ex_groups, 1191 grps, export.ex_ngroups * 1192 sizeof(gid_t)); 1193 if (export_error == 0) 1194 export.ex_groups = grps; 1195 } else 1196 export_error = EINVAL; 1197 } else if (export.ex_ngroups == 0) 1198 export.ex_groups = NULL; 1199 else 1200 export_error = EINVAL; 1201 if (export_error == 0) 1202 export_error = vfs_export(mp, &export); 1203 free(grps, M_TEMP); 1204 break; 1205 default: 1206 export_error = EINVAL; 1207 break; 1208 } 1209 } 1210 1211 MNT_ILOCK(mp); 1212 if (error == 0) { 1213 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | 1214 MNT_SNAPSHOT); 1215 } else { 1216 /* 1217 * If we fail, restore old mount flags. MNT_QUOTA is special, 1218 * because it is not part of MNT_UPDATEMASK, but it could have 1219 * changed in the meantime if quotactl(2) was called. 1220 * All in all we want current value of MNT_QUOTA, not the old 1221 * one. 1222 */ 1223 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA); 1224 } 1225 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 1226 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 1227 mp->mnt_kern_flag |= MNTK_ASYNC; 1228 else 1229 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1230 MNT_IUNLOCK(mp); 1231 1232 if (error != 0) 1233 goto end; 1234 1235 mount_devctl_event("REMOUNT", mp, true); 1236 if (mp->mnt_opt != NULL) 1237 vfs_freeopts(mp->mnt_opt); 1238 mp->mnt_opt = mp->mnt_optnew; 1239 *optlist = NULL; 1240 (void)VFS_STATFS(mp, &mp->mnt_stat); 1241 /* 1242 * Prevent external consumers of mount options from reading 1243 * mnt_optnew. 1244 */ 1245 mp->mnt_optnew = NULL; 1246 1247 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1248 vfs_allocate_syncvnode(mp); 1249 else 1250 vfs_deallocate_syncvnode(mp); 1251 end: 1252 vfs_op_exit(mp); 1253 if (rootvp != NULL) { 1254 vn_seqc_write_end(rootvp); 1255 vrele(rootvp); 1256 } 1257 vn_seqc_write_end(vp); 1258 vfs_unbusy(mp); 1259 VI_LOCK(vp); 1260 vp->v_iflag &= ~VI_MOUNT; 1261 VI_UNLOCK(vp); 1262 vrele(vp); 1263 return (error != 0 ? error : export_error); 1264 } 1265 1266 /* 1267 * vfs_domount(): actually attempt a filesystem mount. 1268 */ 1269 static int 1270 vfs_domount( 1271 struct thread *td, /* Calling thread. */ 1272 const char *fstype, /* Filesystem type. */ 1273 char *fspath, /* Mount path. */ 1274 uint64_t fsflags, /* Flags common to all filesystems. */ 1275 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1276 ) 1277 { 1278 struct vfsconf *vfsp; 1279 struct nameidata nd; 1280 struct vnode *vp; 1281 char *pathbuf; 1282 int error; 1283 1284 /* 1285 * Be ultra-paranoid about making sure the type and fspath 1286 * variables will fit in our mp buffers, including the 1287 * terminating NUL. 1288 */ 1289 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 1290 return (ENAMETOOLONG); 1291 1292 if (jailed(td->td_ucred) || usermount == 0) { 1293 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0) 1294 return (error); 1295 } 1296 1297 /* 1298 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 1299 */ 1300 if (fsflags & MNT_EXPORTED) { 1301 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED); 1302 if (error) 1303 return (error); 1304 } 1305 if (fsflags & MNT_SUIDDIR) { 1306 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR); 1307 if (error) 1308 return (error); 1309 } 1310 /* 1311 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users. 1312 */ 1313 if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) { 1314 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0) 1315 fsflags |= MNT_NOSUID | MNT_USER; 1316 } 1317 1318 /* Load KLDs before we lock the covered vnode to avoid reversals. */ 1319 vfsp = NULL; 1320 if ((fsflags & MNT_UPDATE) == 0) { 1321 /* Don't try to load KLDs if we're mounting the root. */ 1322 if (fsflags & MNT_ROOTFS) 1323 vfsp = vfs_byname(fstype); 1324 else 1325 vfsp = vfs_byname_kld(fstype, td, &error); 1326 if (vfsp == NULL) 1327 return (ENODEV); 1328 } 1329 1330 /* 1331 * Get vnode to be covered or mount point's vnode in case of MNT_UPDATE. 1332 */ 1333 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, 1334 UIO_SYSSPACE, fspath, td); 1335 error = namei(&nd); 1336 if (error != 0) 1337 return (error); 1338 NDFREE(&nd, NDF_ONLY_PNBUF); 1339 vp = nd.ni_vp; 1340 if ((fsflags & MNT_UPDATE) == 0) { 1341 if ((vp->v_vflag & VV_ROOT) != 0 && 1342 (fsflags & MNT_NOCOVER) != 0) { 1343 vput(vp); 1344 return (EBUSY); 1345 } 1346 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1347 strcpy(pathbuf, fspath); 1348 error = vn_path_to_global_path(td, vp, pathbuf, MNAMELEN); 1349 if (error == 0) { 1350 error = vfs_domount_first(td, vfsp, pathbuf, vp, 1351 fsflags, optlist); 1352 } 1353 free(pathbuf, M_TEMP); 1354 } else 1355 error = vfs_domount_update(td, vp, fsflags, optlist); 1356 1357 return (error); 1358 } 1359 1360 /* 1361 * Unmount a filesystem. 1362 * 1363 * Note: unmount takes a path to the vnode mounted on as argument, not 1364 * special file (as before). 1365 */ 1366 #ifndef _SYS_SYSPROTO_H_ 1367 struct unmount_args { 1368 char *path; 1369 int flags; 1370 }; 1371 #endif 1372 /* ARGSUSED */ 1373 int 1374 sys_unmount(struct thread *td, struct unmount_args *uap) 1375 { 1376 1377 return (kern_unmount(td, uap->path, uap->flags)); 1378 } 1379 1380 int 1381 kern_unmount(struct thread *td, const char *path, int flags) 1382 { 1383 struct nameidata nd; 1384 struct mount *mp; 1385 char *pathbuf; 1386 int error, id0, id1; 1387 1388 AUDIT_ARG_VALUE(flags); 1389 if (jailed(td->td_ucred) || usermount == 0) { 1390 error = priv_check(td, PRIV_VFS_UNMOUNT); 1391 if (error) 1392 return (error); 1393 } 1394 1395 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1396 error = copyinstr(path, pathbuf, MNAMELEN, NULL); 1397 if (error) { 1398 free(pathbuf, M_TEMP); 1399 return (error); 1400 } 1401 if (flags & MNT_BYFSID) { 1402 AUDIT_ARG_TEXT(pathbuf); 1403 /* Decode the filesystem ID. */ 1404 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 1405 free(pathbuf, M_TEMP); 1406 return (EINVAL); 1407 } 1408 1409 mtx_lock(&mountlist_mtx); 1410 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1411 if (mp->mnt_stat.f_fsid.val[0] == id0 && 1412 mp->mnt_stat.f_fsid.val[1] == id1) { 1413 vfs_ref(mp); 1414 break; 1415 } 1416 } 1417 mtx_unlock(&mountlist_mtx); 1418 } else { 1419 /* 1420 * Try to find global path for path argument. 1421 */ 1422 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, 1423 UIO_SYSSPACE, pathbuf, td); 1424 if (namei(&nd) == 0) { 1425 NDFREE(&nd, NDF_ONLY_PNBUF); 1426 error = vn_path_to_global_path(td, nd.ni_vp, pathbuf, 1427 MNAMELEN); 1428 if (error == 0) 1429 vput(nd.ni_vp); 1430 } 1431 mtx_lock(&mountlist_mtx); 1432 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1433 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) { 1434 vfs_ref(mp); 1435 break; 1436 } 1437 } 1438 mtx_unlock(&mountlist_mtx); 1439 } 1440 free(pathbuf, M_TEMP); 1441 if (mp == NULL) { 1442 /* 1443 * Previously we returned ENOENT for a nonexistent path and 1444 * EINVAL for a non-mountpoint. We cannot tell these apart 1445 * now, so in the !MNT_BYFSID case return the more likely 1446 * EINVAL for compatibility. 1447 */ 1448 return ((flags & MNT_BYFSID) ? ENOENT : EINVAL); 1449 } 1450 1451 /* 1452 * Don't allow unmounting the root filesystem. 1453 */ 1454 if (mp->mnt_flag & MNT_ROOTFS) { 1455 vfs_rel(mp); 1456 return (EINVAL); 1457 } 1458 error = dounmount(mp, flags, td); 1459 return (error); 1460 } 1461 1462 /* 1463 * Return error if any of the vnodes, ignoring the root vnode 1464 * and the syncer vnode, have non-zero usecount. 1465 * 1466 * This function is purely advisory - it can return false positives 1467 * and negatives. 1468 */ 1469 static int 1470 vfs_check_usecounts(struct mount *mp) 1471 { 1472 struct vnode *vp, *mvp; 1473 1474 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 1475 if ((vp->v_vflag & VV_ROOT) == 0 && vp->v_type != VNON && 1476 vp->v_usecount != 0) { 1477 VI_UNLOCK(vp); 1478 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 1479 return (EBUSY); 1480 } 1481 VI_UNLOCK(vp); 1482 } 1483 1484 return (0); 1485 } 1486 1487 static void 1488 dounmount_cleanup(struct mount *mp, struct vnode *coveredvp, int mntkflags) 1489 { 1490 1491 mtx_assert(MNT_MTX(mp), MA_OWNED); 1492 mp->mnt_kern_flag &= ~mntkflags; 1493 if ((mp->mnt_kern_flag & MNTK_MWAIT) != 0) { 1494 mp->mnt_kern_flag &= ~MNTK_MWAIT; 1495 wakeup(mp); 1496 } 1497 vfs_op_exit_locked(mp); 1498 MNT_IUNLOCK(mp); 1499 if (coveredvp != NULL) { 1500 VOP_UNLOCK(coveredvp); 1501 vdrop(coveredvp); 1502 } 1503 vn_finished_write(mp); 1504 } 1505 1506 /* 1507 * There are various reference counters associated with the mount point. 1508 * Normally it is permitted to modify them without taking the mnt ilock, 1509 * but this behavior can be temporarily disabled if stable value is needed 1510 * or callers are expected to block (e.g. to not allow new users during 1511 * forced unmount). 1512 */ 1513 void 1514 vfs_op_enter(struct mount *mp) 1515 { 1516 int cpu; 1517 1518 MNT_ILOCK(mp); 1519 mp->mnt_vfs_ops++; 1520 if (mp->mnt_vfs_ops > 1) { 1521 MNT_IUNLOCK(mp); 1522 return; 1523 } 1524 vfs_op_barrier_wait(mp); 1525 CPU_FOREACH(cpu) { 1526 mp->mnt_ref += 1527 zpcpu_replace_cpu(mp->mnt_ref_pcpu, 0, cpu); 1528 mp->mnt_lockref += 1529 zpcpu_replace_cpu(mp->mnt_lockref_pcpu, 0, cpu); 1530 mp->mnt_writeopcount += 1531 zpcpu_replace_cpu(mp->mnt_writeopcount_pcpu, 0, cpu); 1532 } 1533 if (mp->mnt_ref <= 0 || mp->mnt_lockref < 0 || mp->mnt_writeopcount < 0) 1534 panic("%s: invalid count(s) on mp %p: ref %d lockref %d writeopcount %d\n", 1535 __func__, mp, mp->mnt_ref, mp->mnt_lockref, mp->mnt_writeopcount); 1536 MNT_IUNLOCK(mp); 1537 vfs_assert_mount_counters(mp); 1538 } 1539 1540 void 1541 vfs_op_exit_locked(struct mount *mp) 1542 { 1543 1544 mtx_assert(MNT_MTX(mp), MA_OWNED); 1545 1546 if (mp->mnt_vfs_ops <= 0) 1547 panic("%s: invalid vfs_ops count %d for mp %p\n", 1548 __func__, mp->mnt_vfs_ops, mp); 1549 mp->mnt_vfs_ops--; 1550 } 1551 1552 void 1553 vfs_op_exit(struct mount *mp) 1554 { 1555 1556 MNT_ILOCK(mp); 1557 vfs_op_exit_locked(mp); 1558 MNT_IUNLOCK(mp); 1559 } 1560 1561 struct vfs_op_barrier_ipi { 1562 struct mount *mp; 1563 struct smp_rendezvous_cpus_retry_arg srcra; 1564 }; 1565 1566 static void 1567 vfs_op_action_func(void *arg) 1568 { 1569 struct vfs_op_barrier_ipi *vfsopipi; 1570 struct mount *mp; 1571 1572 vfsopipi = __containerof(arg, struct vfs_op_barrier_ipi, srcra); 1573 mp = vfsopipi->mp; 1574 1575 if (!vfs_op_thread_entered(mp)) 1576 smp_rendezvous_cpus_done(arg); 1577 } 1578 1579 static void 1580 vfs_op_wait_func(void *arg, int cpu) 1581 { 1582 struct vfs_op_barrier_ipi *vfsopipi; 1583 struct mount *mp; 1584 int *in_op; 1585 1586 vfsopipi = __containerof(arg, struct vfs_op_barrier_ipi, srcra); 1587 mp = vfsopipi->mp; 1588 1589 in_op = zpcpu_get_cpu(mp->mnt_thread_in_ops_pcpu, cpu); 1590 while (atomic_load_int(in_op)) 1591 cpu_spinwait(); 1592 } 1593 1594 void 1595 vfs_op_barrier_wait(struct mount *mp) 1596 { 1597 struct vfs_op_barrier_ipi vfsopipi; 1598 1599 vfsopipi.mp = mp; 1600 1601 smp_rendezvous_cpus_retry(all_cpus, 1602 smp_no_rendezvous_barrier, 1603 vfs_op_action_func, 1604 smp_no_rendezvous_barrier, 1605 vfs_op_wait_func, 1606 &vfsopipi.srcra); 1607 } 1608 1609 #ifdef DIAGNOSTIC 1610 void 1611 vfs_assert_mount_counters(struct mount *mp) 1612 { 1613 int cpu; 1614 1615 if (mp->mnt_vfs_ops == 0) 1616 return; 1617 1618 CPU_FOREACH(cpu) { 1619 if (*zpcpu_get_cpu(mp->mnt_ref_pcpu, cpu) != 0 || 1620 *zpcpu_get_cpu(mp->mnt_lockref_pcpu, cpu) != 0 || 1621 *zpcpu_get_cpu(mp->mnt_writeopcount_pcpu, cpu) != 0) 1622 vfs_dump_mount_counters(mp); 1623 } 1624 } 1625 1626 void 1627 vfs_dump_mount_counters(struct mount *mp) 1628 { 1629 int cpu, *count; 1630 int ref, lockref, writeopcount; 1631 1632 printf("%s: mp %p vfs_ops %d\n", __func__, mp, mp->mnt_vfs_ops); 1633 1634 printf(" ref : "); 1635 ref = mp->mnt_ref; 1636 CPU_FOREACH(cpu) { 1637 count = zpcpu_get_cpu(mp->mnt_ref_pcpu, cpu); 1638 printf("%d ", *count); 1639 ref += *count; 1640 } 1641 printf("\n"); 1642 printf(" lockref : "); 1643 lockref = mp->mnt_lockref; 1644 CPU_FOREACH(cpu) { 1645 count = zpcpu_get_cpu(mp->mnt_lockref_pcpu, cpu); 1646 printf("%d ", *count); 1647 lockref += *count; 1648 } 1649 printf("\n"); 1650 printf("writeopcount: "); 1651 writeopcount = mp->mnt_writeopcount; 1652 CPU_FOREACH(cpu) { 1653 count = zpcpu_get_cpu(mp->mnt_writeopcount_pcpu, cpu); 1654 printf("%d ", *count); 1655 writeopcount += *count; 1656 } 1657 printf("\n"); 1658 1659 printf("counter struct total\n"); 1660 printf("ref %-5d %-5d\n", mp->mnt_ref, ref); 1661 printf("lockref %-5d %-5d\n", mp->mnt_lockref, lockref); 1662 printf("writeopcount %-5d %-5d\n", mp->mnt_writeopcount, writeopcount); 1663 1664 panic("invalid counts on struct mount"); 1665 } 1666 #endif 1667 1668 int 1669 vfs_mount_fetch_counter(struct mount *mp, enum mount_counter which) 1670 { 1671 int *base, *pcpu; 1672 int cpu, sum; 1673 1674 switch (which) { 1675 case MNT_COUNT_REF: 1676 base = &mp->mnt_ref; 1677 pcpu = mp->mnt_ref_pcpu; 1678 break; 1679 case MNT_COUNT_LOCKREF: 1680 base = &mp->mnt_lockref; 1681 pcpu = mp->mnt_lockref_pcpu; 1682 break; 1683 case MNT_COUNT_WRITEOPCOUNT: 1684 base = &mp->mnt_writeopcount; 1685 pcpu = mp->mnt_writeopcount_pcpu; 1686 break; 1687 } 1688 1689 sum = *base; 1690 CPU_FOREACH(cpu) { 1691 sum += *zpcpu_get_cpu(pcpu, cpu); 1692 } 1693 return (sum); 1694 } 1695 1696 /* 1697 * Do the actual filesystem unmount. 1698 */ 1699 int 1700 dounmount(struct mount *mp, int flags, struct thread *td) 1701 { 1702 struct vnode *coveredvp, *rootvp; 1703 int error; 1704 uint64_t async_flag; 1705 int mnt_gen_r; 1706 1707 if ((coveredvp = mp->mnt_vnodecovered) != NULL) { 1708 mnt_gen_r = mp->mnt_gen; 1709 VI_LOCK(coveredvp); 1710 vholdl(coveredvp); 1711 vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY); 1712 /* 1713 * Check for mp being unmounted while waiting for the 1714 * covered vnode lock. 1715 */ 1716 if (coveredvp->v_mountedhere != mp || 1717 coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) { 1718 VOP_UNLOCK(coveredvp); 1719 vdrop(coveredvp); 1720 vfs_rel(mp); 1721 return (EBUSY); 1722 } 1723 } 1724 1725 /* 1726 * Only privileged root, or (if MNT_USER is set) the user that did the 1727 * original mount is permitted to unmount this filesystem. 1728 */ 1729 error = vfs_suser(mp, td); 1730 if (error != 0) { 1731 if (coveredvp != NULL) { 1732 VOP_UNLOCK(coveredvp); 1733 vdrop(coveredvp); 1734 } 1735 vfs_rel(mp); 1736 return (error); 1737 } 1738 1739 vfs_op_enter(mp); 1740 1741 vn_start_write(NULL, &mp, V_WAIT | V_MNTREF); 1742 MNT_ILOCK(mp); 1743 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 || 1744 (mp->mnt_flag & MNT_UPDATE) != 0 || 1745 !TAILQ_EMPTY(&mp->mnt_uppers)) { 1746 dounmount_cleanup(mp, coveredvp, 0); 1747 return (EBUSY); 1748 } 1749 mp->mnt_kern_flag |= MNTK_UNMOUNT; 1750 rootvp = vfs_cache_root_clear(mp); 1751 if (coveredvp != NULL) 1752 vn_seqc_write_begin(coveredvp); 1753 if (flags & MNT_NONBUSY) { 1754 MNT_IUNLOCK(mp); 1755 error = vfs_check_usecounts(mp); 1756 MNT_ILOCK(mp); 1757 if (error != 0) { 1758 vn_seqc_write_end(coveredvp); 1759 dounmount_cleanup(mp, coveredvp, MNTK_UNMOUNT); 1760 if (rootvp != NULL) { 1761 vn_seqc_write_end(rootvp); 1762 vrele(rootvp); 1763 } 1764 return (error); 1765 } 1766 } 1767 /* Allow filesystems to detect that a forced unmount is in progress. */ 1768 if (flags & MNT_FORCE) { 1769 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1770 MNT_IUNLOCK(mp); 1771 /* 1772 * Must be done after setting MNTK_UNMOUNTF and before 1773 * waiting for mnt_lockref to become 0. 1774 */ 1775 VFS_PURGE(mp); 1776 MNT_ILOCK(mp); 1777 } 1778 error = 0; 1779 if (mp->mnt_lockref) { 1780 mp->mnt_kern_flag |= MNTK_DRAINING; 1781 error = msleep(&mp->mnt_lockref, MNT_MTX(mp), PVFS, 1782 "mount drain", 0); 1783 } 1784 MNT_IUNLOCK(mp); 1785 KASSERT(mp->mnt_lockref == 0, 1786 ("%s: invalid lock refcount in the drain path @ %s:%d", 1787 __func__, __FILE__, __LINE__)); 1788 KASSERT(error == 0, 1789 ("%s: invalid return value for msleep in the drain path @ %s:%d", 1790 __func__, __FILE__, __LINE__)); 1791 1792 /* 1793 * We want to keep the vnode around so that we can vn_seqc_write_end 1794 * after we are done with unmount. Downgrade our reference to a mere 1795 * hold count so that we don't interefere with anything. 1796 */ 1797 if (rootvp != NULL) { 1798 vhold(rootvp); 1799 vrele(rootvp); 1800 } 1801 1802 if (mp->mnt_flag & MNT_EXPUBLIC) 1803 vfs_setpublicfs(NULL, NULL, NULL); 1804 1805 vfs_periodic(mp, MNT_WAIT); 1806 MNT_ILOCK(mp); 1807 async_flag = mp->mnt_flag & MNT_ASYNC; 1808 mp->mnt_flag &= ~MNT_ASYNC; 1809 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1810 MNT_IUNLOCK(mp); 1811 vfs_deallocate_syncvnode(mp); 1812 error = VFS_UNMOUNT(mp, flags); 1813 vn_finished_write(mp); 1814 /* 1815 * If we failed to flush the dirty blocks for this mount point, 1816 * undo all the cdir/rdir and rootvnode changes we made above. 1817 * Unless we failed to do so because the device is reporting that 1818 * it doesn't exist anymore. 1819 */ 1820 if (error && error != ENXIO) { 1821 MNT_ILOCK(mp); 1822 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 1823 MNT_IUNLOCK(mp); 1824 vfs_allocate_syncvnode(mp); 1825 MNT_ILOCK(mp); 1826 } 1827 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1828 mp->mnt_flag |= async_flag; 1829 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 1830 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 1831 mp->mnt_kern_flag |= MNTK_ASYNC; 1832 if (mp->mnt_kern_flag & MNTK_MWAIT) { 1833 mp->mnt_kern_flag &= ~MNTK_MWAIT; 1834 wakeup(mp); 1835 } 1836 vfs_op_exit_locked(mp); 1837 MNT_IUNLOCK(mp); 1838 if (coveredvp) { 1839 vn_seqc_write_end(coveredvp); 1840 VOP_UNLOCK(coveredvp); 1841 vdrop(coveredvp); 1842 } 1843 if (rootvp != NULL) { 1844 vn_seqc_write_end(rootvp); 1845 vdrop(rootvp); 1846 } 1847 return (error); 1848 } 1849 mtx_lock(&mountlist_mtx); 1850 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1851 mtx_unlock(&mountlist_mtx); 1852 EVENTHANDLER_DIRECT_INVOKE(vfs_unmounted, mp, td); 1853 if (coveredvp != NULL) { 1854 coveredvp->v_mountedhere = NULL; 1855 vn_seqc_write_end(coveredvp); 1856 VOP_UNLOCK(coveredvp); 1857 vdrop(coveredvp); 1858 } 1859 mount_devctl_event("UNMOUNT", mp, false); 1860 if (rootvp != NULL) { 1861 vn_seqc_write_end(rootvp); 1862 vdrop(rootvp); 1863 } 1864 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 1865 if (rootvnode != NULL && mp == rootvnode->v_mount) { 1866 vrele(rootvnode); 1867 rootvnode = NULL; 1868 } 1869 if (mp == rootdevmp) 1870 rootdevmp = NULL; 1871 vfs_mount_destroy(mp); 1872 return (0); 1873 } 1874 1875 /* 1876 * Report errors during filesystem mounting. 1877 */ 1878 void 1879 vfs_mount_error(struct mount *mp, const char *fmt, ...) 1880 { 1881 struct vfsoptlist *moptlist = mp->mnt_optnew; 1882 va_list ap; 1883 int error, len; 1884 char *errmsg; 1885 1886 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len); 1887 if (error || errmsg == NULL || len <= 0) 1888 return; 1889 1890 va_start(ap, fmt); 1891 vsnprintf(errmsg, (size_t)len, fmt, ap); 1892 va_end(ap); 1893 } 1894 1895 void 1896 vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...) 1897 { 1898 va_list ap; 1899 int error, len; 1900 char *errmsg; 1901 1902 error = vfs_getopt(opts, "errmsg", (void **)&errmsg, &len); 1903 if (error || errmsg == NULL || len <= 0) 1904 return; 1905 1906 va_start(ap, fmt); 1907 vsnprintf(errmsg, (size_t)len, fmt, ap); 1908 va_end(ap); 1909 } 1910 1911 /* 1912 * --------------------------------------------------------------------- 1913 * Functions for querying mount options/arguments from filesystems. 1914 */ 1915 1916 /* 1917 * Check that no unknown options are given 1918 */ 1919 int 1920 vfs_filteropt(struct vfsoptlist *opts, const char **legal) 1921 { 1922 struct vfsopt *opt; 1923 char errmsg[255]; 1924 const char **t, *p, *q; 1925 int ret = 0; 1926 1927 TAILQ_FOREACH(opt, opts, link) { 1928 p = opt->name; 1929 q = NULL; 1930 if (p[0] == 'n' && p[1] == 'o') 1931 q = p + 2; 1932 for(t = global_opts; *t != NULL; t++) { 1933 if (strcmp(*t, p) == 0) 1934 break; 1935 if (q != NULL) { 1936 if (strcmp(*t, q) == 0) 1937 break; 1938 } 1939 } 1940 if (*t != NULL) 1941 continue; 1942 for(t = legal; *t != NULL; t++) { 1943 if (strcmp(*t, p) == 0) 1944 break; 1945 if (q != NULL) { 1946 if (strcmp(*t, q) == 0) 1947 break; 1948 } 1949 } 1950 if (*t != NULL) 1951 continue; 1952 snprintf(errmsg, sizeof(errmsg), 1953 "mount option <%s> is unknown", p); 1954 ret = EINVAL; 1955 } 1956 if (ret != 0) { 1957 TAILQ_FOREACH(opt, opts, link) { 1958 if (strcmp(opt->name, "errmsg") == 0) { 1959 strncpy((char *)opt->value, errmsg, opt->len); 1960 break; 1961 } 1962 } 1963 if (opt == NULL) 1964 printf("%s\n", errmsg); 1965 } 1966 return (ret); 1967 } 1968 1969 /* 1970 * Get a mount option by its name. 1971 * 1972 * Return 0 if the option was found, ENOENT otherwise. 1973 * If len is non-NULL it will be filled with the length 1974 * of the option. If buf is non-NULL, it will be filled 1975 * with the address of the option. 1976 */ 1977 int 1978 vfs_getopt(struct vfsoptlist *opts, const char *name, void **buf, int *len) 1979 { 1980 struct vfsopt *opt; 1981 1982 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1983 1984 TAILQ_FOREACH(opt, opts, link) { 1985 if (strcmp(name, opt->name) == 0) { 1986 opt->seen = 1; 1987 if (len != NULL) 1988 *len = opt->len; 1989 if (buf != NULL) 1990 *buf = opt->value; 1991 return (0); 1992 } 1993 } 1994 return (ENOENT); 1995 } 1996 1997 int 1998 vfs_getopt_pos(struct vfsoptlist *opts, const char *name) 1999 { 2000 struct vfsopt *opt; 2001 2002 if (opts == NULL) 2003 return (-1); 2004 2005 TAILQ_FOREACH(opt, opts, link) { 2006 if (strcmp(name, opt->name) == 0) { 2007 opt->seen = 1; 2008 return (opt->pos); 2009 } 2010 } 2011 return (-1); 2012 } 2013 2014 int 2015 vfs_getopt_size(struct vfsoptlist *opts, const char *name, off_t *value) 2016 { 2017 char *opt_value, *vtp; 2018 quad_t iv; 2019 int error, opt_len; 2020 2021 error = vfs_getopt(opts, name, (void **)&opt_value, &opt_len); 2022 if (error != 0) 2023 return (error); 2024 if (opt_len == 0 || opt_value == NULL) 2025 return (EINVAL); 2026 if (opt_value[0] == '\0' || opt_value[opt_len - 1] != '\0') 2027 return (EINVAL); 2028 iv = strtoq(opt_value, &vtp, 0); 2029 if (vtp == opt_value || (vtp[0] != '\0' && vtp[1] != '\0')) 2030 return (EINVAL); 2031 if (iv < 0) 2032 return (EINVAL); 2033 switch (vtp[0]) { 2034 case 't': case 'T': 2035 iv *= 1024; 2036 /* FALLTHROUGH */ 2037 case 'g': case 'G': 2038 iv *= 1024; 2039 /* FALLTHROUGH */ 2040 case 'm': case 'M': 2041 iv *= 1024; 2042 /* FALLTHROUGH */ 2043 case 'k': case 'K': 2044 iv *= 1024; 2045 case '\0': 2046 break; 2047 default: 2048 return (EINVAL); 2049 } 2050 *value = iv; 2051 2052 return (0); 2053 } 2054 2055 char * 2056 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 2057 { 2058 struct vfsopt *opt; 2059 2060 *error = 0; 2061 TAILQ_FOREACH(opt, opts, link) { 2062 if (strcmp(name, opt->name) != 0) 2063 continue; 2064 opt->seen = 1; 2065 if (opt->len == 0 || 2066 ((char *)opt->value)[opt->len - 1] != '\0') { 2067 *error = EINVAL; 2068 return (NULL); 2069 } 2070 return (opt->value); 2071 } 2072 *error = ENOENT; 2073 return (NULL); 2074 } 2075 2076 int 2077 vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w, 2078 uint64_t val) 2079 { 2080 struct vfsopt *opt; 2081 2082 TAILQ_FOREACH(opt, opts, link) { 2083 if (strcmp(name, opt->name) == 0) { 2084 opt->seen = 1; 2085 if (w != NULL) 2086 *w |= val; 2087 return (1); 2088 } 2089 } 2090 if (w != NULL) 2091 *w &= ~val; 2092 return (0); 2093 } 2094 2095 int 2096 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 2097 { 2098 va_list ap; 2099 struct vfsopt *opt; 2100 int ret; 2101 2102 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 2103 2104 TAILQ_FOREACH(opt, opts, link) { 2105 if (strcmp(name, opt->name) != 0) 2106 continue; 2107 opt->seen = 1; 2108 if (opt->len == 0 || opt->value == NULL) 2109 return (0); 2110 if (((char *)opt->value)[opt->len - 1] != '\0') 2111 return (0); 2112 va_start(ap, fmt); 2113 ret = vsscanf(opt->value, fmt, ap); 2114 va_end(ap); 2115 return (ret); 2116 } 2117 return (0); 2118 } 2119 2120 int 2121 vfs_setopt(struct vfsoptlist *opts, const char *name, void *value, int len) 2122 { 2123 struct vfsopt *opt; 2124 2125 TAILQ_FOREACH(opt, opts, link) { 2126 if (strcmp(name, opt->name) != 0) 2127 continue; 2128 opt->seen = 1; 2129 if (opt->value == NULL) 2130 opt->len = len; 2131 else { 2132 if (opt->len != len) 2133 return (EINVAL); 2134 bcopy(value, opt->value, len); 2135 } 2136 return (0); 2137 } 2138 return (ENOENT); 2139 } 2140 2141 int 2142 vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value, int len) 2143 { 2144 struct vfsopt *opt; 2145 2146 TAILQ_FOREACH(opt, opts, link) { 2147 if (strcmp(name, opt->name) != 0) 2148 continue; 2149 opt->seen = 1; 2150 if (opt->value == NULL) 2151 opt->len = len; 2152 else { 2153 if (opt->len < len) 2154 return (EINVAL); 2155 opt->len = len; 2156 bcopy(value, opt->value, len); 2157 } 2158 return (0); 2159 } 2160 return (ENOENT); 2161 } 2162 2163 int 2164 vfs_setopts(struct vfsoptlist *opts, const char *name, const char *value) 2165 { 2166 struct vfsopt *opt; 2167 2168 TAILQ_FOREACH(opt, opts, link) { 2169 if (strcmp(name, opt->name) != 0) 2170 continue; 2171 opt->seen = 1; 2172 if (opt->value == NULL) 2173 opt->len = strlen(value) + 1; 2174 else if (strlcpy(opt->value, value, opt->len) >= opt->len) 2175 return (EINVAL); 2176 return (0); 2177 } 2178 return (ENOENT); 2179 } 2180 2181 /* 2182 * Find and copy a mount option. 2183 * 2184 * The size of the buffer has to be specified 2185 * in len, if it is not the same length as the 2186 * mount option, EINVAL is returned. 2187 * Returns ENOENT if the option is not found. 2188 */ 2189 int 2190 vfs_copyopt(struct vfsoptlist *opts, const char *name, void *dest, int len) 2191 { 2192 struct vfsopt *opt; 2193 2194 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 2195 2196 TAILQ_FOREACH(opt, opts, link) { 2197 if (strcmp(name, opt->name) == 0) { 2198 opt->seen = 1; 2199 if (len != opt->len) 2200 return (EINVAL); 2201 bcopy(opt->value, dest, opt->len); 2202 return (0); 2203 } 2204 } 2205 return (ENOENT); 2206 } 2207 2208 int 2209 __vfs_statfs(struct mount *mp, struct statfs *sbp) 2210 { 2211 2212 /* 2213 * Filesystems only fill in part of the structure for updates, we 2214 * have to read the entirety first to get all content. 2215 */ 2216 if (sbp != &mp->mnt_stat) 2217 memcpy(sbp, &mp->mnt_stat, sizeof(*sbp)); 2218 2219 /* 2220 * Set these in case the underlying filesystem fails to do so. 2221 */ 2222 sbp->f_version = STATFS_VERSION; 2223 sbp->f_namemax = NAME_MAX; 2224 sbp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK; 2225 2226 return (mp->mnt_op->vfs_statfs(mp, sbp)); 2227 } 2228 2229 void 2230 vfs_mountedfrom(struct mount *mp, const char *from) 2231 { 2232 2233 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 2234 strlcpy(mp->mnt_stat.f_mntfromname, from, 2235 sizeof mp->mnt_stat.f_mntfromname); 2236 } 2237 2238 /* 2239 * --------------------------------------------------------------------- 2240 * This is the api for building mount args and mounting filesystems from 2241 * inside the kernel. 2242 * 2243 * The API works by accumulation of individual args. First error is 2244 * latched. 2245 * 2246 * XXX: should be documented in new manpage kernel_mount(9) 2247 */ 2248 2249 /* A memory allocation which must be freed when we are done */ 2250 struct mntaarg { 2251 SLIST_ENTRY(mntaarg) next; 2252 }; 2253 2254 /* The header for the mount arguments */ 2255 struct mntarg { 2256 struct iovec *v; 2257 int len; 2258 int error; 2259 SLIST_HEAD(, mntaarg) list; 2260 }; 2261 2262 /* 2263 * Add a boolean argument. 2264 * 2265 * flag is the boolean value. 2266 * name must start with "no". 2267 */ 2268 struct mntarg * 2269 mount_argb(struct mntarg *ma, int flag, const char *name) 2270 { 2271 2272 KASSERT(name[0] == 'n' && name[1] == 'o', 2273 ("mount_argb(...,%s): name must start with 'no'", name)); 2274 2275 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 2276 } 2277 2278 /* 2279 * Add an argument printf style 2280 */ 2281 struct mntarg * 2282 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 2283 { 2284 va_list ap; 2285 struct mntaarg *maa; 2286 struct sbuf *sb; 2287 int len; 2288 2289 if (ma == NULL) { 2290 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2291 SLIST_INIT(&ma->list); 2292 } 2293 if (ma->error) 2294 return (ma); 2295 2296 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2297 M_MOUNT, M_WAITOK); 2298 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2299 ma->v[ma->len].iov_len = strlen(name) + 1; 2300 ma->len++; 2301 2302 sb = sbuf_new_auto(); 2303 va_start(ap, fmt); 2304 sbuf_vprintf(sb, fmt, ap); 2305 va_end(ap); 2306 sbuf_finish(sb); 2307 len = sbuf_len(sb) + 1; 2308 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2309 SLIST_INSERT_HEAD(&ma->list, maa, next); 2310 bcopy(sbuf_data(sb), maa + 1, len); 2311 sbuf_delete(sb); 2312 2313 ma->v[ma->len].iov_base = maa + 1; 2314 ma->v[ma->len].iov_len = len; 2315 ma->len++; 2316 2317 return (ma); 2318 } 2319 2320 /* 2321 * Add an argument which is a userland string. 2322 */ 2323 struct mntarg * 2324 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 2325 { 2326 struct mntaarg *maa; 2327 char *tbuf; 2328 2329 if (val == NULL) 2330 return (ma); 2331 if (ma == NULL) { 2332 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2333 SLIST_INIT(&ma->list); 2334 } 2335 if (ma->error) 2336 return (ma); 2337 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2338 SLIST_INSERT_HEAD(&ma->list, maa, next); 2339 tbuf = (void *)(maa + 1); 2340 ma->error = copyinstr(val, tbuf, len, NULL); 2341 return (mount_arg(ma, name, tbuf, -1)); 2342 } 2343 2344 /* 2345 * Plain argument. 2346 * 2347 * If length is -1, treat value as a C string. 2348 */ 2349 struct mntarg * 2350 mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 2351 { 2352 2353 if (ma == NULL) { 2354 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2355 SLIST_INIT(&ma->list); 2356 } 2357 if (ma->error) 2358 return (ma); 2359 2360 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2361 M_MOUNT, M_WAITOK); 2362 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2363 ma->v[ma->len].iov_len = strlen(name) + 1; 2364 ma->len++; 2365 2366 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 2367 if (len < 0) 2368 ma->v[ma->len].iov_len = strlen(val) + 1; 2369 else 2370 ma->v[ma->len].iov_len = len; 2371 ma->len++; 2372 return (ma); 2373 } 2374 2375 /* 2376 * Free a mntarg structure 2377 */ 2378 static void 2379 free_mntarg(struct mntarg *ma) 2380 { 2381 struct mntaarg *maa; 2382 2383 while (!SLIST_EMPTY(&ma->list)) { 2384 maa = SLIST_FIRST(&ma->list); 2385 SLIST_REMOVE_HEAD(&ma->list, next); 2386 free(maa, M_MOUNT); 2387 } 2388 free(ma->v, M_MOUNT); 2389 free(ma, M_MOUNT); 2390 } 2391 2392 /* 2393 * Mount a filesystem 2394 */ 2395 int 2396 kernel_mount(struct mntarg *ma, uint64_t flags) 2397 { 2398 struct uio auio; 2399 int error; 2400 2401 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 2402 KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v")); 2403 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 2404 2405 auio.uio_iov = ma->v; 2406 auio.uio_iovcnt = ma->len; 2407 auio.uio_segflg = UIO_SYSSPACE; 2408 2409 error = ma->error; 2410 if (!error) 2411 error = vfs_donmount(curthread, flags, &auio); 2412 free_mntarg(ma); 2413 return (error); 2414 } 2415 2416 /* 2417 * A printflike function to mount a filesystem. 2418 */ 2419 int 2420 kernel_vmount(int flags, ...) 2421 { 2422 struct mntarg *ma = NULL; 2423 va_list ap; 2424 const char *cp; 2425 const void *vp; 2426 int error; 2427 2428 va_start(ap, flags); 2429 for (;;) { 2430 cp = va_arg(ap, const char *); 2431 if (cp == NULL) 2432 break; 2433 vp = va_arg(ap, const void *); 2434 ma = mount_arg(ma, cp, vp, (vp != NULL ? -1 : 0)); 2435 } 2436 va_end(ap); 2437 2438 error = kernel_mount(ma, flags); 2439 return (error); 2440 } 2441 2442 /* Map from mount options to printable formats. */ 2443 static struct mntoptnames optnames[] = { 2444 MNTOPT_NAMES 2445 }; 2446 2447 static void 2448 mount_devctl_event_mntopt(struct sbuf *sb, const char *what, struct vfsoptlist *opts) 2449 { 2450 struct vfsopt *opt; 2451 2452 if (opts == NULL || TAILQ_EMPTY(opts)) 2453 return; 2454 sbuf_printf(sb, " %s=\"", what); 2455 TAILQ_FOREACH(opt, opts, link) { 2456 if (opt->name[0] == '\0' || (opt->len > 0 && *(char *)opt->value == '\0')) 2457 continue; 2458 devctl_safe_quote_sb(sb, opt->name); 2459 if (opt->len > 0) { 2460 sbuf_putc(sb, '='); 2461 devctl_safe_quote_sb(sb, opt->value); 2462 } 2463 sbuf_putc(sb, ';'); 2464 } 2465 sbuf_putc(sb, '"'); 2466 } 2467 2468 #define DEVCTL_LEN 1024 2469 static void 2470 mount_devctl_event(const char *type, struct mount *mp, bool donew) 2471 { 2472 const uint8_t *cp; 2473 struct mntoptnames *fp; 2474 struct sbuf sb; 2475 struct statfs *sfp = &mp->mnt_stat; 2476 char *buf; 2477 2478 buf = malloc(DEVCTL_LEN, M_MOUNT, M_NOWAIT); 2479 if (buf == NULL) 2480 return; 2481 sbuf_new(&sb, buf, DEVCTL_LEN, SBUF_FIXEDLEN); 2482 sbuf_cpy(&sb, "mount-point=\""); 2483 devctl_safe_quote_sb(&sb, sfp->f_mntonname); 2484 sbuf_cat(&sb, "\" mount-dev=\""); 2485 devctl_safe_quote_sb(&sb, sfp->f_mntfromname); 2486 sbuf_cat(&sb, "\" mount-type=\""); 2487 devctl_safe_quote_sb(&sb, sfp->f_fstypename); 2488 sbuf_cat(&sb, "\" fsid=0x"); 2489 cp = (const uint8_t *)&sfp->f_fsid.val[0]; 2490 for (int i = 0; i < sizeof(sfp->f_fsid); i++) 2491 sbuf_printf(&sb, "%02x", cp[i]); 2492 sbuf_printf(&sb, " owner=%u flags=\"", sfp->f_owner); 2493 for (fp = optnames; fp->o_opt != 0; fp++) { 2494 if ((mp->mnt_flag & fp->o_opt) != 0) { 2495 sbuf_cat(&sb, fp->o_name); 2496 sbuf_putc(&sb, ';'); 2497 } 2498 } 2499 sbuf_putc(&sb, '"'); 2500 mount_devctl_event_mntopt(&sb, "opt", mp->mnt_opt); 2501 if (donew) 2502 mount_devctl_event_mntopt(&sb, "optnew", mp->mnt_optnew); 2503 sbuf_finish(&sb); 2504 2505 if (sbuf_error(&sb) == 0) 2506 devctl_notify("VFS", "FS", type, sbuf_data(&sb)); 2507 sbuf_delete(&sb); 2508 free(buf, M_MOUNT); 2509 } 2510 2511 /* 2512 * Suspend write operations on all local writeable filesystems. Does 2513 * full sync of them in the process. 2514 * 2515 * Iterate over the mount points in reverse order, suspending most 2516 * recently mounted filesystems first. It handles a case where a 2517 * filesystem mounted from a md(4) vnode-backed device should be 2518 * suspended before the filesystem that owns the vnode. 2519 */ 2520 void 2521 suspend_all_fs(void) 2522 { 2523 struct mount *mp; 2524 int error; 2525 2526 mtx_lock(&mountlist_mtx); 2527 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 2528 error = vfs_busy(mp, MBF_MNTLSTLOCK | MBF_NOWAIT); 2529 if (error != 0) 2530 continue; 2531 if ((mp->mnt_flag & (MNT_RDONLY | MNT_LOCAL)) != MNT_LOCAL || 2532 (mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 2533 mtx_lock(&mountlist_mtx); 2534 vfs_unbusy(mp); 2535 continue; 2536 } 2537 error = vfs_write_suspend(mp, 0); 2538 if (error == 0) { 2539 MNT_ILOCK(mp); 2540 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0); 2541 mp->mnt_kern_flag |= MNTK_SUSPEND_ALL; 2542 MNT_IUNLOCK(mp); 2543 mtx_lock(&mountlist_mtx); 2544 } else { 2545 printf("suspend of %s failed, error %d\n", 2546 mp->mnt_stat.f_mntonname, error); 2547 mtx_lock(&mountlist_mtx); 2548 vfs_unbusy(mp); 2549 } 2550 } 2551 mtx_unlock(&mountlist_mtx); 2552 } 2553 2554 void 2555 resume_all_fs(void) 2556 { 2557 struct mount *mp; 2558 2559 mtx_lock(&mountlist_mtx); 2560 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 2561 if ((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0) 2562 continue; 2563 mtx_unlock(&mountlist_mtx); 2564 MNT_ILOCK(mp); 2565 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) != 0); 2566 mp->mnt_kern_flag &= ~MNTK_SUSPEND_ALL; 2567 MNT_IUNLOCK(mp); 2568 vfs_write_resume(mp, 0); 2569 mtx_lock(&mountlist_mtx); 2570 vfs_unbusy(mp); 2571 } 2572 mtx_unlock(&mountlist_mtx); 2573 } 2574