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/param.h> 40 #include <sys/conf.h> 41 #include <sys/smp.h> 42 #include <sys/devctl.h> 43 #include <sys/eventhandler.h> 44 #include <sys/fcntl.h> 45 #include <sys/jail.h> 46 #include <sys/kernel.h> 47 #include <sys/ktr.h> 48 #include <sys/libkern.h> 49 #include <sys/limits.h> 50 #include <sys/malloc.h> 51 #include <sys/mount.h> 52 #include <sys/mutex.h> 53 #include <sys/namei.h> 54 #include <sys/priv.h> 55 #include <sys/proc.h> 56 #include <sys/filedesc.h> 57 #include <sys/reboot.h> 58 #include <sys/sbuf.h> 59 #include <sys/stdarg.h> 60 #include <sys/syscallsubr.h> 61 #include <sys/sysproto.h> 62 #include <sys/sx.h> 63 #include <sys/sysctl.h> 64 #include <sys/systm.h> 65 #include <sys/taskqueue.h> 66 #include <sys/vnode.h> 67 #include <vm/uma.h> 68 69 #include <netinet/in.h> 70 #include <net/radix.h> 71 #include <sys/netexport.h> 72 73 #include <geom/geom.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 only_export, bool jail_export, 82 struct vfsoptlist **optlist); 83 static void free_mntarg(struct mntarg *ma); 84 static void pnfsd_waitreplenish(struct mount *mp); 85 86 static int usermount = 0; 87 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 88 "Unprivileged users may mount and unmount file systems"); 89 90 static bool default_autoro = false; 91 SYSCTL_BOOL(_vfs, OID_AUTO, default_autoro, CTLFLAG_RW, &default_autoro, 0, 92 "Retry failed r/w mount as r/o if no explicit ro/rw option is specified"); 93 94 static bool recursive_forced_unmount = false; 95 SYSCTL_BOOL(_vfs, OID_AUTO, recursive_forced_unmount, CTLFLAG_RW, 96 &recursive_forced_unmount, 0, "Recursively unmount stacked upper mounts" 97 " when a file system is forcibly unmounted"); 98 99 static SYSCTL_NODE(_vfs, OID_AUTO, deferred_unmount, 100 CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "deferred unmount controls"); 101 102 static unsigned int deferred_unmount_retry_limit = 10; 103 SYSCTL_UINT(_vfs_deferred_unmount, OID_AUTO, retry_limit, CTLFLAG_RW, 104 &deferred_unmount_retry_limit, 0, 105 "Maximum number of retries for deferred unmount failure"); 106 107 static int deferred_unmount_retry_delay_hz; 108 SYSCTL_INT(_vfs_deferred_unmount, OID_AUTO, retry_delay_hz, CTLFLAG_RW, 109 &deferred_unmount_retry_delay_hz, 0, 110 "Delay in units of [1/kern.hz]s when retrying a failed deferred unmount"); 111 112 static int deferred_unmount_total_retries = 0; 113 SYSCTL_INT(_vfs_deferred_unmount, OID_AUTO, total_retries, CTLFLAG_RD, 114 &deferred_unmount_total_retries, 0, 115 "Total number of retried deferred unmounts"); 116 117 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 118 MALLOC_DEFINE(M_STATFS, "statfs", "statfs structure"); 119 static uma_zone_t mount_zone; 120 121 /* List of mounted filesystems. */ 122 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 123 124 /* For any iteration/modification of mountlist */ 125 struct mtx_padalign __exclusive_cache_line mountlist_mtx; 126 127 EVENTHANDLER_LIST_DEFINE(vfs_mounted); 128 EVENTHANDLER_LIST_DEFINE(vfs_unmounted); 129 130 static void vfs_deferred_unmount(void *arg, int pending); 131 static struct timeout_task deferred_unmount_task; 132 static struct mtx deferred_unmount_lock; 133 MTX_SYSINIT(deferred_unmount, &deferred_unmount_lock, "deferred_unmount", 134 MTX_DEF); 135 static STAILQ_HEAD(, mount) deferred_unmount_list = 136 STAILQ_HEAD_INITIALIZER(deferred_unmount_list); 137 TASKQUEUE_DEFINE_THREAD(deferred_unmount); 138 139 static void mount_devctl_event(const char *type, struct mount *mp, bool donew); 140 141 /* 142 * Global opts, taken by all filesystems 143 */ 144 static const char *global_opts[] = { 145 "errmsg", 146 "fstype", 147 "fspath", 148 "ro", 149 "rw", 150 "nosuid", 151 "noexec", 152 NULL 153 }; 154 155 static int 156 mount_init(void *mem, int size, int flags) 157 { 158 struct mount *mp; 159 160 mp = (struct mount *)mem; 161 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 162 mtx_init(&mp->mnt_listmtx, "struct mount vlist mtx", NULL, MTX_DEF); 163 lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0); 164 lockinit(&mp->mnt_renamelock, PVFS, "rename", 0, 0); 165 mp->mnt_pcpu = uma_zalloc_pcpu(pcpu_zone_16, M_WAITOK | M_ZERO); 166 mp->mnt_ref = 0; 167 mp->mnt_vfs_ops = 1; 168 mp->mnt_rootvnode = NULL; 169 return (0); 170 } 171 172 static void 173 mount_fini(void *mem, int size) 174 { 175 struct mount *mp; 176 177 mp = (struct mount *)mem; 178 uma_zfree_pcpu(pcpu_zone_16, mp->mnt_pcpu); 179 lockdestroy(&mp->mnt_renamelock); 180 lockdestroy(&mp->mnt_explock); 181 mtx_destroy(&mp->mnt_listmtx); 182 mtx_destroy(&mp->mnt_mtx); 183 } 184 185 static void 186 vfs_mount_init(void *dummy __unused) 187 { 188 TIMEOUT_TASK_INIT(taskqueue_deferred_unmount, &deferred_unmount_task, 189 0, vfs_deferred_unmount, NULL); 190 deferred_unmount_retry_delay_hz = hz; 191 mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), NULL, 192 NULL, mount_init, mount_fini, UMA_ALIGN_CACHE, UMA_ZONE_NOFREE); 193 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 194 } 195 SYSINIT(vfs_mount, SI_SUB_VFS, SI_ORDER_ANY, vfs_mount_init, NULL); 196 197 /* 198 * --------------------------------------------------------------------- 199 * Functions for building and sanitizing the mount options 200 */ 201 202 /* Remove one mount option. */ 203 static void 204 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 205 { 206 207 TAILQ_REMOVE(opts, opt, link); 208 free(opt->name, M_MOUNT); 209 if (opt->value != NULL) 210 free(opt->value, M_MOUNT); 211 free(opt, M_MOUNT); 212 } 213 214 /* Release all resources related to the mount options. */ 215 void 216 vfs_freeopts(struct vfsoptlist *opts) 217 { 218 struct vfsopt *opt; 219 220 while (!TAILQ_EMPTY(opts)) { 221 opt = TAILQ_FIRST(opts); 222 vfs_freeopt(opts, opt); 223 } 224 free(opts, M_MOUNT); 225 } 226 227 void 228 vfs_deleteopt(struct vfsoptlist *opts, const char *name) 229 { 230 struct vfsopt *opt, *temp; 231 232 if (opts == NULL) 233 return; 234 TAILQ_FOREACH_SAFE(opt, opts, link, temp) { 235 if (strcmp(opt->name, name) == 0) 236 vfs_freeopt(opts, opt); 237 } 238 } 239 240 static int 241 vfs_isopt_ro(const char *opt) 242 { 243 244 if (strcmp(opt, "ro") == 0 || strcmp(opt, "rdonly") == 0 || 245 strcmp(opt, "norw") == 0) 246 return (1); 247 return (0); 248 } 249 250 static int 251 vfs_isopt_rw(const char *opt) 252 { 253 254 if (strcmp(opt, "rw") == 0 || strcmp(opt, "noro") == 0) 255 return (1); 256 return (0); 257 } 258 259 /* 260 * Check if options are equal (with or without the "no" prefix). 261 */ 262 static int 263 vfs_equalopts(const char *opt1, const char *opt2) 264 { 265 char *p; 266 267 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 268 if (strcmp(opt1, opt2) == 0) 269 return (1); 270 /* "noopt" vs. "opt" */ 271 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 272 return (1); 273 /* "opt" vs. "noopt" */ 274 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 275 return (1); 276 while ((p = strchr(opt1, '.')) != NULL && 277 !strncmp(opt1, opt2, ++p - opt1)) { 278 opt2 += p - opt1; 279 opt1 = p; 280 /* "foo.noopt" vs. "foo.opt" */ 281 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 282 return (1); 283 /* "foo.opt" vs. "foo.noopt" */ 284 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 285 return (1); 286 } 287 /* "ro" / "rdonly" / "norw" / "rw" / "noro" */ 288 if ((vfs_isopt_ro(opt1) || vfs_isopt_rw(opt1)) && 289 (vfs_isopt_ro(opt2) || vfs_isopt_rw(opt2))) 290 return (1); 291 return (0); 292 } 293 294 /* 295 * If a mount option is specified several times, 296 * (with or without the "no" prefix) only keep 297 * the last occurrence of it. 298 */ 299 static void 300 vfs_sanitizeopts(struct vfsoptlist *opts) 301 { 302 struct vfsopt *opt, *opt2, *tmp; 303 304 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 305 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 306 while (opt2 != NULL) { 307 if (vfs_equalopts(opt->name, opt2->name)) { 308 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 309 vfs_freeopt(opts, opt2); 310 opt2 = tmp; 311 } else { 312 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 313 } 314 } 315 } 316 } 317 318 /* 319 * Build a linked list of mount options from a struct uio. 320 */ 321 int 322 vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 323 { 324 struct vfsoptlist *opts; 325 struct vfsopt *opt; 326 size_t memused, namelen, optlen; 327 unsigned int i, iovcnt; 328 int error; 329 330 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 331 TAILQ_INIT(opts); 332 memused = 0; 333 iovcnt = auio->uio_iovcnt; 334 for (i = 0; i < iovcnt; i += 2) { 335 namelen = auio->uio_iov[i].iov_len; 336 optlen = auio->uio_iov[i + 1].iov_len; 337 memused += sizeof(struct vfsopt) + optlen + namelen; 338 /* 339 * Avoid consuming too much memory, and attempts to overflow 340 * memused. 341 */ 342 if (memused > VFS_MOUNTARG_SIZE_MAX || 343 optlen > VFS_MOUNTARG_SIZE_MAX || 344 namelen > VFS_MOUNTARG_SIZE_MAX) { 345 error = EINVAL; 346 goto bad; 347 } 348 349 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 350 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 351 opt->value = NULL; 352 opt->len = 0; 353 opt->pos = i / 2; 354 opt->seen = 0; 355 356 /* 357 * Do this early, so jumps to "bad" will free the current 358 * option. 359 */ 360 TAILQ_INSERT_TAIL(opts, opt, link); 361 362 if (auio->uio_segflg == UIO_SYSSPACE) { 363 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 364 } else { 365 error = copyin(auio->uio_iov[i].iov_base, opt->name, 366 namelen); 367 if (error) 368 goto bad; 369 } 370 /* Ensure names are null-terminated strings. */ 371 if (namelen == 0 || opt->name[namelen - 1] != '\0') { 372 error = EINVAL; 373 goto bad; 374 } 375 if (optlen != 0) { 376 opt->len = optlen; 377 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 378 if (auio->uio_segflg == UIO_SYSSPACE) { 379 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 380 optlen); 381 } else { 382 error = copyin(auio->uio_iov[i + 1].iov_base, 383 opt->value, optlen); 384 if (error) 385 goto bad; 386 } 387 } 388 } 389 vfs_sanitizeopts(opts); 390 *options = opts; 391 return (0); 392 bad: 393 vfs_freeopts(opts); 394 return (error); 395 } 396 397 /* 398 * Merge the old mount options with the new ones passed 399 * in the MNT_UPDATE case. 400 * 401 * XXX: This function will keep a "nofoo" option in the new 402 * options. E.g, if the option's canonical name is "foo", 403 * "nofoo" ends up in the mount point's active options. 404 */ 405 static void 406 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *oldopts) 407 { 408 struct vfsopt *opt, *new; 409 410 TAILQ_FOREACH(opt, oldopts, link) { 411 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 412 new->name = strdup(opt->name, M_MOUNT); 413 if (opt->len != 0) { 414 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 415 bcopy(opt->value, new->value, opt->len); 416 } else 417 new->value = NULL; 418 new->len = opt->len; 419 new->seen = opt->seen; 420 TAILQ_INSERT_HEAD(toopts, new, link); 421 } 422 vfs_sanitizeopts(toopts); 423 } 424 425 /* 426 * Mount a filesystem. 427 */ 428 #ifndef _SYS_SYSPROTO_H_ 429 struct nmount_args { 430 struct iovec *iovp; 431 unsigned int iovcnt; 432 int flags; 433 }; 434 #endif 435 int 436 sys_nmount(struct thread *td, struct nmount_args *uap) 437 { 438 struct uio *auio; 439 int error; 440 u_int iovcnt; 441 uint64_t flags; 442 443 /* 444 * Mount flags are now 64-bits. On 32-bit archtectures only 445 * 32-bits are passed in, but from here on everything handles 446 * 64-bit flags correctly. 447 */ 448 flags = uap->flags; 449 450 AUDIT_ARG_FFLAGS(flags); 451 CTR4(KTR_VFS, "%s: iovp %p with iovcnt %d and flags %d", __func__, 452 uap->iovp, uap->iovcnt, flags); 453 454 /* 455 * Filter out MNT_ROOTFS. We do not want clients of nmount() in 456 * userspace to set this flag, but we must filter it out if we want 457 * MNT_UPDATE on the root file system to work. 458 * MNT_ROOTFS should only be set by the kernel when mounting its 459 * root file system. 460 */ 461 flags &= ~MNT_ROOTFS; 462 463 iovcnt = uap->iovcnt; 464 /* 465 * Check that we have an even number of iovec's 466 * and that we have at least two options. 467 */ 468 if ((iovcnt & 1) || (iovcnt < 4)) { 469 CTR2(KTR_VFS, "%s: failed for invalid iovcnt %d", __func__, 470 uap->iovcnt); 471 return (EINVAL); 472 } 473 474 error = copyinuio(uap->iovp, iovcnt, &auio); 475 if (error) { 476 CTR2(KTR_VFS, "%s: failed for invalid uio op with %d errno", 477 __func__, error); 478 return (error); 479 } 480 error = vfs_donmount(td, flags, auio); 481 482 freeuio(auio); 483 return (error); 484 } 485 486 /* 487 * --------------------------------------------------------------------- 488 * Various utility functions 489 */ 490 491 /* 492 * Get a reference on a mount point from a vnode. 493 * 494 * The vnode is allowed to be passed unlocked and race against dooming. Note in 495 * such case there are no guarantees the referenced mount point will still be 496 * associated with it after the function returns. 497 */ 498 struct mount * 499 vfs_ref_from_vp(struct vnode *vp) 500 { 501 struct mount *mp; 502 struct mount_pcpu *mpcpu; 503 504 mp = atomic_load_ptr(&vp->v_mount); 505 if (__predict_false(mp == NULL)) { 506 return (mp); 507 } 508 if (vfs_op_thread_enter(mp, &mpcpu)) { 509 if (__predict_true(mp == vp->v_mount)) { 510 vfs_mp_count_add_pcpu(mpcpu, ref, 1); 511 vfs_op_thread_exit(mp, mpcpu); 512 } else { 513 vfs_op_thread_exit(mp, mpcpu); 514 mp = NULL; 515 } 516 } else { 517 MNT_ILOCK(mp); 518 if (mp == vp->v_mount) { 519 MNT_REF(mp); 520 MNT_IUNLOCK(mp); 521 } else { 522 MNT_IUNLOCK(mp); 523 mp = NULL; 524 } 525 } 526 return (mp); 527 } 528 529 void 530 vfs_ref(struct mount *mp) 531 { 532 struct mount_pcpu *mpcpu; 533 534 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 535 if (vfs_op_thread_enter(mp, &mpcpu)) { 536 vfs_mp_count_add_pcpu(mpcpu, ref, 1); 537 vfs_op_thread_exit(mp, mpcpu); 538 return; 539 } 540 541 MNT_ILOCK(mp); 542 MNT_REF(mp); 543 MNT_IUNLOCK(mp); 544 } 545 546 /* 547 * Register ump as an upper mount of the mount associated with 548 * vnode vp. This registration will be tracked through 549 * mount_upper_node upper, which should be allocated by the 550 * caller and stored in per-mount data associated with mp. 551 * 552 * If successful, this function will return the mount associated 553 * with vp, and will ensure that it cannot be unmounted until 554 * ump has been unregistered as one of its upper mounts. 555 * 556 * Upon failure this function will return NULL. 557 */ 558 struct mount * 559 vfs_register_upper_from_vp(struct vnode *vp, struct mount *ump, 560 struct mount_upper_node *upper) 561 { 562 struct mount *mp; 563 564 mp = atomic_load_ptr(&vp->v_mount); 565 if (mp == NULL) 566 return (NULL); 567 MNT_ILOCK(mp); 568 if (mp != vp->v_mount || 569 ((mp->mnt_kern_flag & (MNTK_UNMOUNT | MNTK_RECURSE)) != 0)) { 570 MNT_IUNLOCK(mp); 571 return (NULL); 572 } 573 KASSERT(ump != mp, ("upper and lower mounts are identical")); 574 upper->mp = ump; 575 MNT_REF(mp); 576 TAILQ_INSERT_TAIL(&mp->mnt_uppers, upper, mnt_upper_link); 577 MNT_IUNLOCK(mp); 578 return (mp); 579 } 580 581 /* 582 * Register upper mount ump to receive vnode unlink/reclaim 583 * notifications from lower mount mp. This registration will 584 * be tracked through mount_upper_node upper, which should be 585 * allocated by the caller and stored in per-mount data 586 * associated with mp. 587 * 588 * ump must already be registered as an upper mount of mp 589 * through a call to vfs_register_upper_from_vp(). 590 */ 591 void 592 vfs_register_for_notification(struct mount *mp, struct mount *ump, 593 struct mount_upper_node *upper) 594 { 595 upper->mp = ump; 596 MNT_ILOCK(mp); 597 TAILQ_INSERT_TAIL(&mp->mnt_notify, upper, mnt_upper_link); 598 MNT_IUNLOCK(mp); 599 } 600 601 static void 602 vfs_drain_upper_locked(struct mount *mp) 603 { 604 mtx_assert(MNT_MTX(mp), MA_OWNED); 605 while (mp->mnt_upper_pending != 0) { 606 mp->mnt_kern_flag |= MNTK_UPPER_WAITER; 607 msleep(&mp->mnt_uppers, MNT_MTX(mp), 0, "mntupw", 0); 608 } 609 } 610 611 /* 612 * Undo a previous call to vfs_register_for_notification(). 613 * The mount represented by upper must be currently registered 614 * as an upper mount for mp. 615 */ 616 void 617 vfs_unregister_for_notification(struct mount *mp, 618 struct mount_upper_node *upper) 619 { 620 MNT_ILOCK(mp); 621 vfs_drain_upper_locked(mp); 622 TAILQ_REMOVE(&mp->mnt_notify, upper, mnt_upper_link); 623 MNT_IUNLOCK(mp); 624 } 625 626 /* 627 * Undo a previous call to vfs_register_upper_from_vp(). 628 * This must be done before mp can be unmounted. 629 */ 630 void 631 vfs_unregister_upper(struct mount *mp, struct mount_upper_node *upper) 632 { 633 MNT_ILOCK(mp); 634 KASSERT((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0, 635 ("registered upper with pending unmount")); 636 vfs_drain_upper_locked(mp); 637 TAILQ_REMOVE(&mp->mnt_uppers, upper, mnt_upper_link); 638 if ((mp->mnt_kern_flag & MNTK_TASKQUEUE_WAITER) != 0 && 639 TAILQ_EMPTY(&mp->mnt_uppers)) { 640 mp->mnt_kern_flag &= ~MNTK_TASKQUEUE_WAITER; 641 wakeup(&mp->mnt_taskqueue_link); 642 } 643 MNT_REL(mp); 644 MNT_IUNLOCK(mp); 645 } 646 647 void 648 vfs_rel(struct mount *mp) 649 { 650 struct mount_pcpu *mpcpu; 651 652 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 653 if (vfs_op_thread_enter(mp, &mpcpu)) { 654 vfs_mp_count_sub_pcpu(mpcpu, ref, 1); 655 vfs_op_thread_exit(mp, mpcpu); 656 return; 657 } 658 659 MNT_ILOCK(mp); 660 MNT_REL(mp); 661 MNT_IUNLOCK(mp); 662 } 663 664 /* 665 * Allocate and initialize the mount point struct. 666 */ 667 struct mount * 668 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath, 669 struct ucred *cred) 670 { 671 struct mount *mp; 672 673 mp = uma_zalloc(mount_zone, M_WAITOK); 674 bzero(&mp->mnt_startzero, 675 __rangeof(struct mount, mnt_startzero, mnt_endzero)); 676 mp->mnt_kern_flag = 0; 677 mp->mnt_flag = 0; 678 mp->mnt_rootvnode = NULL; 679 mp->mnt_vnodecovered = NULL; 680 mp->mnt_op = NULL; 681 mp->mnt_vfc = NULL; 682 TAILQ_INIT(&mp->mnt_nvnodelist); 683 mp->mnt_nvnodelistsize = 0; 684 TAILQ_INIT(&mp->mnt_lazyvnodelist); 685 mp->mnt_lazyvnodelistsize = 0; 686 MPPASS(mp->mnt_ref == 0 && mp->mnt_lockref == 0 && 687 mp->mnt_writeopcount == 0, mp); 688 MPASSERT(mp->mnt_vfs_ops == 1, mp, 689 ("vfs_ops should be 1 but %d found", mp->mnt_vfs_ops)); 690 (void) vfs_busy(mp, MBF_NOWAIT); 691 mp->mnt_op = vfsp->vfc_vfsops; 692 mp->mnt_vfc = vfsp; 693 mp->mnt_stat.f_type = vfsp->vfc_typenum; 694 mp->mnt_gen++; 695 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 696 mp->mnt_vnodecovered = vp; 697 mp->mnt_cred = crdup(cred); 698 mp->mnt_stat.f_owner = cred->cr_uid; 699 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 700 mp->mnt_iosize_max = DFLTPHYS; 701 #ifdef MAC 702 mac_mount_init(mp); 703 mac_mount_create(cred, mp); 704 #endif 705 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0); 706 mp->mnt_upper_pending = 0; 707 TAILQ_INIT(&mp->mnt_uppers); 708 TAILQ_INIT(&mp->mnt_notify); 709 mp->mnt_taskqueue_flags = 0; 710 mp->mnt_unmount_retries = 0; 711 return (mp); 712 } 713 714 /* 715 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 716 */ 717 void 718 vfs_mount_destroy(struct mount *mp) 719 { 720 721 MPPASS(mp->mnt_vfs_ops != 0, mp); 722 723 vfs_assert_mount_counters(mp); 724 725 MNT_ILOCK(mp); 726 mp->mnt_kern_flag |= MNTK_REFEXPIRE; 727 if (mp->mnt_kern_flag & MNTK_MWAIT) { 728 mp->mnt_kern_flag &= ~MNTK_MWAIT; 729 wakeup(mp); 730 } 731 while (mp->mnt_ref) 732 msleep(mp, MNT_MTX(mp), PVFS, "mntref", 0); 733 KASSERT(mp->mnt_ref == 0, 734 ("%s: invalid refcount in the drain path @ %s:%d", __func__, 735 __FILE__, __LINE__)); 736 MPPASS(mp->mnt_writeopcount == 0, mp); 737 MPPASS(mp->mnt_secondary_writes == 0, mp); 738 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) { 739 struct vnode *vp; 740 741 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) 742 vn_printf(vp, "dangling vnode "); 743 panic("unmount: dangling vnode"); 744 } 745 KASSERT(mp->mnt_upper_pending == 0, ("mnt_upper_pending")); 746 KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers")); 747 KASSERT(TAILQ_EMPTY(&mp->mnt_notify), ("mnt_notify")); 748 MPPASS(mp->mnt_nvnodelistsize == 0, mp); 749 MPPASS(mp->mnt_lazyvnodelistsize == 0, mp); 750 MPPASS(mp->mnt_lockref == 0, mp); 751 MNT_IUNLOCK(mp); 752 753 MPASSERT(mp->mnt_vfs_ops == 1, mp, 754 ("vfs_ops should be 1 but %d found", mp->mnt_vfs_ops)); 755 756 MPASSERT(mp->mnt_rootvnode == NULL, mp, 757 ("mount point still has a root vnode %p", mp->mnt_rootvnode)); 758 759 if (mp->mnt_vnodecovered != NULL) 760 vrele(mp->mnt_vnodecovered); 761 #ifdef MAC 762 mac_mount_destroy(mp); 763 #endif 764 if (mp->mnt_opt != NULL) 765 vfs_freeopts(mp->mnt_opt); 766 if (mp->mnt_exjail != NULL) { 767 atomic_subtract_int(&mp->mnt_exjail->cr_prison->pr_exportcnt, 768 1); 769 crfree(mp->mnt_exjail); 770 } 771 if (mp->mnt_export != NULL) { 772 vfs_free_addrlist(mp->mnt_export); 773 vfs_netexport_release(mp->mnt_export); 774 } 775 vfsconf_lock(); 776 mp->mnt_vfc->vfc_refcount--; 777 vfsconf_unlock(); 778 crfree(mp->mnt_cred); 779 uma_zfree(mount_zone, mp); 780 } 781 782 static bool 783 vfs_should_downgrade_to_ro_mount(uint64_t fsflags, int error) 784 { 785 /* This is an upgrade of an exisiting mount. */ 786 if ((fsflags & MNT_UPDATE) != 0) 787 return (false); 788 /* This is already an R/O mount. */ 789 if ((fsflags & MNT_RDONLY) != 0) 790 return (false); 791 792 switch (error) { 793 case ENODEV: /* generic, geom, ... */ 794 case EACCES: /* cam/scsi, ... */ 795 case EROFS: /* md, mmcsd, ... */ 796 /* 797 * These errors can be returned by the storage layer to signal 798 * that the media is read-only. No harm in the R/O mount 799 * attempt if the error was returned for some other reason. 800 */ 801 return (true); 802 default: 803 return (false); 804 } 805 } 806 807 int 808 vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions) 809 { 810 struct vfsoptlist *optlist; 811 struct vfsopt *opt, *tmp_opt; 812 char *fstype, *fspath, *errmsg; 813 int error, fstypelen, fspathlen, errmsg_len, errmsg_pos; 814 bool autoro, has_nonexport, only_export, jail_export; 815 816 errmsg = fspath = NULL; 817 errmsg_len = fspathlen = 0; 818 errmsg_pos = -1; 819 autoro = default_autoro; 820 821 error = vfs_buildopts(fsoptions, &optlist); 822 if (error) 823 return (error); 824 825 if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0) 826 errmsg_pos = vfs_getopt_pos(optlist, "errmsg"); 827 828 /* 829 * We need these two options before the others, 830 * and they are mandatory for any filesystem. 831 * Ensure they are NUL terminated as well. 832 */ 833 fstypelen = 0; 834 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 835 if (error || fstypelen <= 0 || fstype[fstypelen - 1] != '\0') { 836 error = EINVAL; 837 if (errmsg != NULL) 838 strncpy(errmsg, "Invalid fstype", errmsg_len); 839 goto bail; 840 } 841 fspathlen = 0; 842 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 843 if (error || fspathlen <= 0 || fspath[fspathlen - 1] != '\0') { 844 error = EINVAL; 845 if (errmsg != NULL) 846 strncpy(errmsg, "Invalid fspath", errmsg_len); 847 goto bail; 848 } 849 850 /* 851 * Check to see that "export" is only used with the "update", "fstype", 852 * "fspath", "from" and "errmsg" options when in a vnet jail. 853 * These are the ones used to set/update exports by mountd(8). 854 * If only the above options are set in a jail that can run mountd(8), 855 * then the jail_export argument of vfs_domount() will be true. 856 * When jail_export is true, the vfs_suser() check does not cause 857 * failure, but limits the update to exports only. 858 * This allows mountd(8) running within the vnet jail 859 * to export file systems visible within the jail, but 860 * mounted outside of the jail. 861 */ 862 /* 863 * We need to see if we have the "update" option 864 * before we call vfs_domount(), since vfs_domount() has special 865 * logic based on MNT_UPDATE. This is very important 866 * when we want to update the root filesystem. 867 */ 868 has_nonexport = false; 869 only_export = false; 870 TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) { 871 int do_freeopt = 0; 872 873 if (strcmp(opt->name, "export") != 0 && 874 strcmp(opt->name, "update") != 0 && 875 strcmp(opt->name, "fstype") != 0 && 876 strcmp(opt->name, "fspath") != 0 && 877 strcmp(opt->name, "from") != 0 && 878 strcmp(opt->name, "errmsg") != 0) 879 has_nonexport = true; 880 if (strcmp(opt->name, "update") == 0) { 881 fsflags |= MNT_UPDATE; 882 do_freeopt = 1; 883 } 884 else if (strcmp(opt->name, "async") == 0) 885 fsflags |= MNT_ASYNC; 886 else if (strcmp(opt->name, "force") == 0) { 887 fsflags |= MNT_FORCE; 888 do_freeopt = 1; 889 } 890 else if (strcmp(opt->name, "reload") == 0) { 891 fsflags |= MNT_RELOAD; 892 do_freeopt = 1; 893 } 894 else if (strcmp(opt->name, "multilabel") == 0) 895 fsflags |= MNT_MULTILABEL; 896 else if (strcmp(opt->name, "noasync") == 0) 897 fsflags &= ~MNT_ASYNC; 898 else if (strcmp(opt->name, "noatime") == 0) 899 fsflags |= MNT_NOATIME; 900 else if (strcmp(opt->name, "atime") == 0) { 901 free(opt->name, M_MOUNT); 902 opt->name = strdup("nonoatime", M_MOUNT); 903 } 904 else if (strcmp(opt->name, "noclusterr") == 0) 905 fsflags |= MNT_NOCLUSTERR; 906 else if (strcmp(opt->name, "clusterr") == 0) { 907 free(opt->name, M_MOUNT); 908 opt->name = strdup("nonoclusterr", M_MOUNT); 909 } 910 else if (strcmp(opt->name, "noclusterw") == 0) 911 fsflags |= MNT_NOCLUSTERW; 912 else if (strcmp(opt->name, "clusterw") == 0) { 913 free(opt->name, M_MOUNT); 914 opt->name = strdup("nonoclusterw", M_MOUNT); 915 } 916 else if (strcmp(opt->name, "noexec") == 0) 917 fsflags |= MNT_NOEXEC; 918 else if (strcmp(opt->name, "exec") == 0) { 919 free(opt->name, M_MOUNT); 920 opt->name = strdup("nonoexec", M_MOUNT); 921 } 922 else if (strcmp(opt->name, "nosuid") == 0) 923 fsflags |= MNT_NOSUID; 924 else if (strcmp(opt->name, "suid") == 0) { 925 free(opt->name, M_MOUNT); 926 opt->name = strdup("nonosuid", M_MOUNT); 927 } 928 else if (strcmp(opt->name, "nosymfollow") == 0) 929 fsflags |= MNT_NOSYMFOLLOW; 930 else if (strcmp(opt->name, "symfollow") == 0) { 931 free(opt->name, M_MOUNT); 932 opt->name = strdup("nonosymfollow", M_MOUNT); 933 } 934 else if (strcmp(opt->name, "noro") == 0) { 935 fsflags &= ~MNT_RDONLY; 936 autoro = false; 937 } 938 else if (strcmp(opt->name, "rw") == 0) { 939 fsflags &= ~MNT_RDONLY; 940 autoro = false; 941 } 942 else if (strcmp(opt->name, "ro") == 0) { 943 fsflags |= MNT_RDONLY; 944 autoro = false; 945 } 946 else if (strcmp(opt->name, "rdonly") == 0) { 947 free(opt->name, M_MOUNT); 948 opt->name = strdup("ro", M_MOUNT); 949 fsflags |= MNT_RDONLY; 950 autoro = false; 951 } 952 else if (strcmp(opt->name, "autoro") == 0) { 953 do_freeopt = 1; 954 autoro = true; 955 } 956 else if (strcmp(opt->name, "suiddir") == 0) 957 fsflags |= MNT_SUIDDIR; 958 else if (strcmp(opt->name, "sync") == 0) 959 fsflags |= MNT_SYNCHRONOUS; 960 else if (strcmp(opt->name, "union") == 0) 961 fsflags |= MNT_UNION; 962 else if (strcmp(opt->name, "export") == 0) { 963 fsflags |= MNT_EXPORTED; 964 only_export = true; 965 } else if (strcmp(opt->name, "automounted") == 0) { 966 fsflags |= MNT_AUTOMOUNTED; 967 do_freeopt = 1; 968 } else if (strcmp(opt->name, "nocover") == 0) { 969 fsflags |= MNT_NOCOVER; 970 do_freeopt = 1; 971 } else if (strcmp(opt->name, "cover") == 0) { 972 fsflags &= ~MNT_NOCOVER; 973 do_freeopt = 1; 974 } else if (strcmp(opt->name, "emptydir") == 0) { 975 fsflags |= MNT_EMPTYDIR; 976 do_freeopt = 1; 977 } else if (strcmp(opt->name, "noemptydir") == 0) { 978 fsflags &= ~MNT_EMPTYDIR; 979 do_freeopt = 1; 980 } 981 if (do_freeopt) 982 vfs_freeopt(optlist, opt); 983 } 984 985 /* 986 * Be ultra-paranoid about making sure the type and fspath 987 * variables will fit in our mp buffers, including the 988 * terminating NUL. 989 */ 990 if (fstypelen > MFSNAMELEN || fspathlen > MNAMELEN) { 991 error = ENAMETOOLONG; 992 goto bail; 993 } 994 995 /* 996 * only_export is set to true only if exports are being 997 * updated and nothing else is being updated. 998 */ 999 if (has_nonexport) 1000 only_export = false; 1001 /* 1002 * If only_export is true and the caller is running within a 1003 * vnet prison that can run mountd(8), set jail_export true. 1004 */ 1005 jail_export = false; 1006 if (only_export && jailed(td->td_ucred) && 1007 prison_check_nfsd(td->td_ucred)) 1008 jail_export = true; 1009 1010 error = vfs_domount(td, fstype, fspath, fsflags, only_export, 1011 jail_export, &optlist); 1012 if (error == ENODEV) { 1013 error = EINVAL; 1014 if (errmsg != NULL) 1015 strncpy(errmsg, "Invalid fstype", errmsg_len); 1016 goto bail; 1017 } 1018 1019 /* 1020 * See if we can mount in the read-only mode if the error code suggests 1021 * that it could be possible and the mount options allow for that. 1022 * Never try it if "[no]{ro|rw}" has been explicitly requested and not 1023 * overridden by "autoro". 1024 */ 1025 if (autoro && vfs_should_downgrade_to_ro_mount(fsflags, error)) { 1026 printf("%s: R/W mount failed, possibly R/O media," 1027 " trying R/O mount\n", __func__); 1028 fsflags |= MNT_RDONLY; 1029 error = vfs_domount(td, fstype, fspath, fsflags, only_export, 1030 jail_export, &optlist); 1031 } 1032 bail: 1033 /* copyout the errmsg */ 1034 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt) 1035 && errmsg_len > 0 && errmsg != NULL) { 1036 if (fsoptions->uio_segflg == UIO_SYSSPACE) { 1037 bcopy(errmsg, 1038 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 1039 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 1040 } else { 1041 (void)copyout(errmsg, 1042 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 1043 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 1044 } 1045 } 1046 1047 if (optlist != NULL) 1048 vfs_freeopts(optlist); 1049 return (error); 1050 } 1051 1052 /* 1053 * Old mount API. 1054 */ 1055 #ifndef _SYS_SYSPROTO_H_ 1056 struct mount_args { 1057 char *type; 1058 char *path; 1059 int flags; 1060 caddr_t data; 1061 }; 1062 #endif 1063 /* ARGSUSED */ 1064 int 1065 sys_mount(struct thread *td, struct mount_args *uap) 1066 { 1067 char *fstype; 1068 struct vfsconf *vfsp = NULL; 1069 struct mntarg *ma = NULL; 1070 uint64_t flags; 1071 int error; 1072 1073 /* 1074 * Mount flags are now 64-bits. On 32-bit architectures only 1075 * 32-bits are passed in, but from here on everything handles 1076 * 64-bit flags correctly. 1077 */ 1078 flags = uap->flags; 1079 1080 AUDIT_ARG_FFLAGS(flags); 1081 1082 /* 1083 * Filter out MNT_ROOTFS. We do not want clients of mount() in 1084 * userspace to set this flag, but we must filter it out if we want 1085 * MNT_UPDATE on the root file system to work. 1086 * MNT_ROOTFS should only be set by the kernel when mounting its 1087 * root file system. 1088 */ 1089 flags &= ~MNT_ROOTFS; 1090 1091 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 1092 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 1093 if (error) { 1094 free(fstype, M_TEMP); 1095 return (error); 1096 } 1097 1098 AUDIT_ARG_TEXT(fstype); 1099 vfsp = vfs_byname_kld(fstype, td, &error); 1100 free(fstype, M_TEMP); 1101 if (vfsp == NULL) 1102 return (EINVAL); 1103 if (((vfsp->vfc_flags & VFCF_SBDRY) != 0 && 1104 vfsp->vfc_vfsops_sd->vfs_cmount == NULL) || 1105 ((vfsp->vfc_flags & VFCF_SBDRY) == 0 && 1106 vfsp->vfc_vfsops->vfs_cmount == NULL)) 1107 return (EOPNOTSUPP); 1108 1109 ma = mount_argsu(ma, "fstype", uap->type, MFSNAMELEN); 1110 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 1111 ma = mount_argb(ma, flags & MNT_RDONLY, "noro"); 1112 ma = mount_argb(ma, !(flags & MNT_NOSUID), "nosuid"); 1113 ma = mount_argb(ma, !(flags & MNT_NOEXEC), "noexec"); 1114 1115 if ((vfsp->vfc_flags & VFCF_SBDRY) != 0) 1116 return (vfsp->vfc_vfsops_sd->vfs_cmount(ma, uap->data, flags)); 1117 return (vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, flags)); 1118 } 1119 1120 /* 1121 * vfs_domount_first(): first file system mount (not update) 1122 */ 1123 static int 1124 vfs_domount_first( 1125 struct thread *td, /* Calling thread. */ 1126 struct vfsconf *vfsp, /* File system type. */ 1127 char *fspath, /* Mount path. */ 1128 struct vnode *vp, /* Vnode to be covered. */ 1129 uint64_t fsflags, /* Flags common to all filesystems. */ 1130 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1131 ) 1132 { 1133 struct vattr va; 1134 struct mount *mp; 1135 struct vnode *newdp, *rootvp; 1136 int error, error1; 1137 bool unmounted; 1138 1139 ASSERT_VOP_ELOCKED(vp, __func__); 1140 KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here")); 1141 1142 /* 1143 * If the jail of the calling thread lacks permission for this type of 1144 * file system, or is trying to cover its own root, deny immediately. 1145 */ 1146 if (jailed(td->td_ucred) && (!prison_allow(td->td_ucred, 1147 vfsp->vfc_prison_flag) || vp == td->td_ucred->cr_prison->pr_root)) { 1148 vput(vp); 1149 vfs_unref_vfsconf(vfsp); 1150 return (EPERM); 1151 } 1152 1153 /* 1154 * If the user is not root, ensure that they own the directory 1155 * onto which we are attempting to mount. 1156 */ 1157 error = VOP_GETATTR(vp, &va, td->td_ucred); 1158 if (error == 0 && va.va_uid != td->td_ucred->cr_uid) 1159 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN); 1160 #ifdef MAC 1161 /* 1162 * XXX XNU also has a check_mount_late variant, which takes the 1163 * struct mount instead and gives MAC visibility into, e.g., 1164 * f_mntfromname and other facts. 1165 */ 1166 if (error == 0) { 1167 error = mac_mount_check_mount(td->td_ucred, vp, vfsp, 1168 optlist, fsflags); 1169 } 1170 #endif 1171 if (error == 0) 1172 error = vinvalbuf(vp, V_SAVE, 0, 0); 1173 if (vfsp->vfc_flags & VFCF_FILEMOUNT) { 1174 if (error == 0 && vp->v_type != VDIR && vp->v_type != VREG) 1175 error = EINVAL; 1176 /* 1177 * For file mounts, ensure that there is only one hardlink to the file. 1178 */ 1179 if (error == 0 && vp->v_type == VREG && va.va_nlink != 1) 1180 error = EINVAL; 1181 } else { 1182 if (error == 0 && vp->v_type != VDIR) 1183 error = ENOTDIR; 1184 } 1185 if (error == 0 && (fsflags & MNT_EMPTYDIR) != 0) 1186 error = vn_dir_check_empty(vp); 1187 if (error == 0) { 1188 VI_LOCK(vp); 1189 if ((vp->v_iflag & VI_MOUNT) == 0 && vp->v_mountedhere == NULL) 1190 vp->v_iflag |= VI_MOUNT; 1191 else 1192 error = EBUSY; 1193 VI_UNLOCK(vp); 1194 } 1195 if (error != 0) { 1196 vput(vp); 1197 vfs_unref_vfsconf(vfsp); 1198 return (error); 1199 } 1200 vn_seqc_write_begin(vp); 1201 VOP_UNLOCK(vp); 1202 1203 /* Allocate and initialize the filesystem. */ 1204 mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred); 1205 /* XXXMAC: pass to vfs_mount_alloc? */ 1206 mp->mnt_optnew = *optlist; 1207 /* Set the mount level flags. */ 1208 mp->mnt_flag = (fsflags & 1209 (MNT_UPDATEMASK | MNT_ROOTFS | MNT_RDONLY | MNT_FORCE)); 1210 1211 /* 1212 * Mount the filesystem. 1213 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1214 * get. No freeing of cn_pnbuf. 1215 */ 1216 error1 = 0; 1217 unmounted = true; 1218 if ((error = VFS_MOUNT(mp)) != 0 || 1219 (error1 = VFS_STATFS(mp, &mp->mnt_stat)) != 0 || 1220 (error1 = VFS_ROOT(mp, LK_EXCLUSIVE, &newdp)) != 0) { 1221 rootvp = NULL; 1222 if (error1 != 0) { 1223 MPASS(error == 0); 1224 rootvp = vfs_cache_root_clear(mp); 1225 if (rootvp != NULL) { 1226 vhold(rootvp); 1227 vrele(rootvp); 1228 } 1229 (void)vn_start_write(NULL, &mp, V_WAIT); 1230 MNT_ILOCK(mp); 1231 mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_UNMOUNTF; 1232 MNT_IUNLOCK(mp); 1233 VFS_PURGE(mp); 1234 error = VFS_UNMOUNT(mp, 0); 1235 vn_finished_write(mp); 1236 if (error != 0) { 1237 printf( 1238 "failed post-mount (%d): rollback unmount returned %d\n", 1239 error1, error); 1240 unmounted = false; 1241 } 1242 error = error1; 1243 } 1244 vfs_unbusy(mp); 1245 mp->mnt_vnodecovered = NULL; 1246 if (unmounted) { 1247 /* XXXKIB wait for mnt_lockref drain? */ 1248 vfs_mount_destroy(mp); 1249 } 1250 VI_LOCK(vp); 1251 vp->v_iflag &= ~VI_MOUNT; 1252 VI_UNLOCK(vp); 1253 if (rootvp != NULL) { 1254 vn_seqc_write_end(rootvp); 1255 vdrop(rootvp); 1256 } 1257 vn_seqc_write_end(vp); 1258 vrele(vp); 1259 return (error); 1260 } 1261 vn_seqc_write_begin(newdp); 1262 VOP_UNLOCK(newdp); 1263 1264 if (mp->mnt_opt != NULL) 1265 vfs_freeopts(mp->mnt_opt); 1266 mp->mnt_opt = mp->mnt_optnew; 1267 *optlist = NULL; 1268 1269 /* 1270 * Prevent external consumers of mount options from reading mnt_optnew. 1271 */ 1272 mp->mnt_optnew = NULL; 1273 1274 MNT_ILOCK(mp); 1275 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 1276 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 1277 mp->mnt_kern_flag |= MNTK_ASYNC; 1278 else 1279 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1280 MNT_IUNLOCK(mp); 1281 1282 /* 1283 * VIRF_MOUNTPOINT and v_mountedhere need to be set under the 1284 * vp lock to satisfy vfs_lookup() requirements. 1285 */ 1286 VOP_LOCK(vp, LK_EXCLUSIVE | LK_RETRY); 1287 VI_LOCK(vp); 1288 vn_irflag_set_locked(vp, VIRF_MOUNTPOINT); 1289 vp->v_mountedhere = mp; 1290 VI_UNLOCK(vp); 1291 VOP_UNLOCK(vp); 1292 cache_purge(vp); 1293 1294 /* 1295 * We need to lock both vnodes. 1296 * 1297 * Use vn_lock_pair to avoid establishing an ordering between vnodes 1298 * from different filesystems. 1299 */ 1300 error1 = vn_lock_pair(vp, false, LK_EXCLUSIVE, newdp, false, 1301 LK_EXCLUSIVE); 1302 1303 VI_LOCK(vp); 1304 vp->v_iflag &= ~VI_MOUNT; 1305 VI_UNLOCK(vp); 1306 /* Place the new filesystem at the end of the mount list. */ 1307 mtx_lock(&mountlist_mtx); 1308 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1309 mtx_unlock(&mountlist_mtx); 1310 vfs_event_signal(NULL, VQ_MOUNT, 0); 1311 if (error1 == 0) 1312 VOP_UNLOCK(vp); 1313 else 1314 MPASS(error1 == EDEADLK); 1315 EVENTHANDLER_DIRECT_INVOKE(vfs_mounted, mp, newdp, td); 1316 VOP_UNLOCK(newdp); 1317 mount_devctl_event("MOUNT", mp, false); 1318 mountcheckdirs(vp, newdp); 1319 vn_seqc_write_end(vp); 1320 vn_seqc_write_end(newdp); 1321 vrele(newdp); 1322 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1323 vfs_allocate_syncvnode(mp); 1324 vfs_op_exit(mp); 1325 vfs_unbusy(mp); 1326 return (0); 1327 } 1328 1329 /* 1330 * vfs_domount_update(): update of mounted file system 1331 */ 1332 static int 1333 vfs_domount_update( 1334 struct thread *td, /* Calling thread. */ 1335 struct vnode *vp, /* Mount point vnode. */ 1336 uint64_t fsflags, /* Flags common to all filesystems. */ 1337 bool only_export, /* Got export option. */ 1338 bool jail_export, /* Got export option in vnet prison. */ 1339 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1340 ) 1341 { 1342 struct export_args export; 1343 struct o2export_args o2export; 1344 struct vnode *rootvp; 1345 void *bufp; 1346 struct mount *mp; 1347 int error, export_error, i, len, fsid_up_len; 1348 uint64_t flag, mnt_union; 1349 gid_t *grps; 1350 fsid_t *fsid_up; 1351 bool vfs_suser_failed; 1352 1353 ASSERT_VOP_ELOCKED(vp, __func__); 1354 KASSERT((fsflags & MNT_UPDATE) != 0, ("MNT_UPDATE should be here")); 1355 mp = vp->v_mount; 1356 1357 if ((vp->v_vflag & VV_ROOT) == 0) { 1358 if (vfs_copyopt(*optlist, "export", &export, sizeof(export)) 1359 == 0) 1360 error = EXDEV; 1361 else 1362 error = EINVAL; 1363 vput(vp); 1364 return (error); 1365 } 1366 1367 /* 1368 * We only allow the filesystem to be reloaded if it 1369 * is currently mounted read-only. 1370 */ 1371 flag = mp->mnt_flag; 1372 if ((fsflags & MNT_RELOAD) != 0 && (flag & MNT_RDONLY) == 0) { 1373 vput(vp); 1374 return (EOPNOTSUPP); /* Needs translation */ 1375 } 1376 /* 1377 * Only privileged root, or (if MNT_USER is set) the user that 1378 * did the original mount is permitted to update it. 1379 */ 1380 /* 1381 * For the case of mountd(8) doing exports in a jail, the vfs_suser() 1382 * call does not cause failure. vfs_domount() has already checked 1383 * that "root" is doing this and vfs_suser() will fail when 1384 * the file system has been mounted outside the jail. 1385 * jail_export set true indicates that "export" is not mixed 1386 * with other options that change mount behaviour. 1387 */ 1388 vfs_suser_failed = false; 1389 error = vfs_suser(mp, td); 1390 if (jail_export && error != 0) { 1391 error = 0; 1392 vfs_suser_failed = true; 1393 } 1394 #ifdef MAC 1395 if (error == 0) { 1396 error = mac_mount_check_update(td->td_ucred, mp, optlist, 1397 fsflags); 1398 } 1399 #endif 1400 if (error != 0) { 1401 vput(vp); 1402 return (error); 1403 } 1404 if (vfs_busy(mp, MBF_NOWAIT)) { 1405 vput(vp); 1406 return (EBUSY); 1407 } 1408 VI_LOCK(vp); 1409 if ((vp->v_iflag & VI_MOUNT) != 0 || vp->v_mountedhere != NULL) { 1410 VI_UNLOCK(vp); 1411 vfs_unbusy(mp); 1412 vput(vp); 1413 return (EBUSY); 1414 } 1415 vp->v_iflag |= VI_MOUNT; 1416 VI_UNLOCK(vp); 1417 VOP_UNLOCK(vp); 1418 1419 rootvp = NULL; 1420 vfs_op_enter(mp); 1421 vn_seqc_write_begin(vp); 1422 1423 if (vfs_getopt(*optlist, "fsid", (void **)&fsid_up, 1424 &fsid_up_len) == 0) { 1425 if (fsid_up_len != sizeof(*fsid_up)) { 1426 error = EINVAL; 1427 goto end; 1428 } 1429 if (fsidcmp(fsid_up, &mp->mnt_stat.f_fsid) != 0) { 1430 error = ENOENT; 1431 goto end; 1432 } 1433 vfs_deleteopt(*optlist, "fsid"); 1434 } 1435 1436 mnt_union = 0; 1437 MNT_ILOCK(mp); 1438 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1439 MNT_IUNLOCK(mp); 1440 error = EBUSY; 1441 goto end; 1442 } 1443 if (vfs_suser_failed) { 1444 KASSERT((fsflags & (MNT_EXPORTED | MNT_UPDATE)) == 1445 (MNT_EXPORTED | MNT_UPDATE), 1446 ("%s: jailed export did not set expected fsflags", 1447 __func__)); 1448 /* 1449 * For this case, only MNT_UPDATE and 1450 * MNT_EXPORTED have been set in fsflags 1451 * by the options. Only set MNT_UPDATE, 1452 * since that is the one that would be set 1453 * when set in fsflags, below. 1454 */ 1455 mp->mnt_flag |= MNT_UPDATE; 1456 } else { 1457 mp->mnt_flag &= ~MNT_UPDATEMASK; 1458 if ((mp->mnt_flag & MNT_UNION) == 0 && 1459 (fsflags & MNT_UNION) != 0) { 1460 fsflags &= ~MNT_UNION; 1461 mnt_union = MNT_UNION; 1462 } 1463 mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | 1464 MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY); 1465 if ((mp->mnt_flag & MNT_ASYNC) == 0) 1466 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1467 } 1468 rootvp = vfs_cache_root_clear(mp); 1469 MNT_IUNLOCK(mp); 1470 mp->mnt_optnew = *optlist; 1471 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 1472 1473 /* 1474 * Mount the filesystem. 1475 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1476 * get. No freeing of cn_pnbuf. 1477 */ 1478 /* 1479 * When only updating mount exports, VFS_MOUNT() does not need to 1480 * be called, as indicated by only_export being set true. 1481 * For the case of mountd(8) doing exports from within a vnet jail, 1482 * "from" is typically not set correctly such that VFS_MOUNT() will 1483 * return ENOENT. For ZFS, there is a locking bug which can result in 1484 * deadlock if VFS_MOUNT() is called when extended attributes are 1485 * being updated. 1486 */ 1487 error = 0; 1488 if (!only_export) 1489 error = VFS_MOUNT(mp); 1490 1491 export_error = 0; 1492 /* Process the export option. */ 1493 if (error == 0 && vfs_getopt(mp->mnt_optnew, "export", &bufp, 1494 &len) == 0) { 1495 /* Assume that there is only 1 ABI for each length. */ 1496 switch (len) { 1497 case (sizeof(struct oexport_args)): 1498 bzero(&o2export, sizeof(o2export)); 1499 /* FALLTHROUGH */ 1500 case (sizeof(o2export)): 1501 bcopy(bufp, &o2export, len); 1502 export.ex_flags = (uint64_t)o2export.ex_flags; 1503 export.ex_root = o2export.ex_root; 1504 export.ex_uid = o2export.ex_anon.cr_uid; 1505 export.ex_groups = NULL; 1506 export.ex_ngroups = o2export.ex_anon.cr_ngroups; 1507 if (export.ex_ngroups > 0) { 1508 if (export.ex_ngroups <= XU_NGROUPS) { 1509 export.ex_groups = malloc( 1510 export.ex_ngroups * sizeof(gid_t), 1511 M_TEMP, M_WAITOK); 1512 for (i = 0; i < export.ex_ngroups; i++) 1513 export.ex_groups[i] = 1514 o2export.ex_anon.cr_groups[i]; 1515 } else 1516 export_error = EINVAL; 1517 } else if (export.ex_ngroups < 0) 1518 export_error = EINVAL; 1519 export.ex_addr = o2export.ex_addr; 1520 export.ex_addrlen = o2export.ex_addrlen; 1521 export.ex_mask = o2export.ex_mask; 1522 export.ex_masklen = o2export.ex_masklen; 1523 export.ex_indexfile = o2export.ex_indexfile; 1524 export.ex_numsecflavors = o2export.ex_numsecflavors; 1525 if (export.ex_numsecflavors < MAXSECFLAVORS) { 1526 for (i = 0; i < export.ex_numsecflavors; i++) 1527 export.ex_secflavors[i] = 1528 o2export.ex_secflavors[i]; 1529 } else 1530 export_error = EINVAL; 1531 if (export_error == 0) 1532 export_error = vfs_export(mp, &export, true); 1533 free(export.ex_groups, M_TEMP); 1534 break; 1535 case (sizeof(export)): 1536 bcopy(bufp, &export, len); 1537 grps = NULL; 1538 if (export.ex_ngroups > 0) { 1539 if (export.ex_ngroups <= ngroups_max + 1) { 1540 grps = malloc(export.ex_ngroups * 1541 sizeof(gid_t), M_TEMP, M_WAITOK); 1542 export_error = copyin(export.ex_groups, 1543 grps, export.ex_ngroups * 1544 sizeof(gid_t)); 1545 if (export_error == 0) 1546 export.ex_groups = grps; 1547 } else 1548 export_error = EINVAL; 1549 } else if (export.ex_ngroups == 0) 1550 export.ex_groups = NULL; 1551 else 1552 export_error = EINVAL; 1553 if (export_error == 0) 1554 export_error = vfs_export(mp, &export, true); 1555 free(grps, M_TEMP); 1556 break; 1557 default: 1558 export_error = EINVAL; 1559 break; 1560 } 1561 } 1562 1563 MNT_ILOCK(mp); 1564 if (error == 0) { 1565 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | 1566 MNT_SNAPSHOT); 1567 mp->mnt_flag |= mnt_union; 1568 } else { 1569 /* 1570 * If we fail, restore old mount flags. MNT_QUOTA is special, 1571 * because it is not part of MNT_UPDATEMASK, but it could have 1572 * changed in the meantime if quotactl(2) was called. 1573 * All in all we want current value of MNT_QUOTA, not the old 1574 * one. 1575 */ 1576 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA); 1577 } 1578 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 1579 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 1580 mp->mnt_kern_flag |= MNTK_ASYNC; 1581 else 1582 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1583 MNT_IUNLOCK(mp); 1584 1585 if (error != 0) 1586 goto end; 1587 1588 mount_devctl_event("REMOUNT", mp, true); 1589 if (mp->mnt_opt != NULL) 1590 vfs_freeopts(mp->mnt_opt); 1591 mp->mnt_opt = mp->mnt_optnew; 1592 *optlist = NULL; 1593 (void)VFS_STATFS(mp, &mp->mnt_stat); 1594 /* 1595 * Prevent external consumers of mount options from reading 1596 * mnt_optnew. 1597 */ 1598 mp->mnt_optnew = NULL; 1599 1600 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1601 vfs_allocate_syncvnode(mp); 1602 else 1603 vfs_deallocate_syncvnode(mp); 1604 end: 1605 vfs_op_exit(mp); 1606 if (rootvp != NULL) { 1607 vn_seqc_write_end(rootvp); 1608 vrele(rootvp); 1609 } 1610 vn_seqc_write_end(vp); 1611 vfs_unbusy(mp); 1612 VI_LOCK(vp); 1613 vp->v_iflag &= ~VI_MOUNT; 1614 VI_UNLOCK(vp); 1615 vrele(vp); 1616 return (error != 0 ? error : export_error); 1617 } 1618 1619 /* 1620 * vfs_domount(): actually attempt a filesystem mount. 1621 */ 1622 static int 1623 vfs_domount( 1624 struct thread *td, /* Calling thread. */ 1625 const char *fstype, /* Filesystem type. */ 1626 char *fspath, /* Mount path. */ 1627 uint64_t fsflags, /* Flags common to all filesystems. */ 1628 bool only_export, /* Got export option. */ 1629 bool jail_export, /* Got export option in vnet prison. */ 1630 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1631 ) 1632 { 1633 struct vfsconf *vfsp; 1634 struct nameidata nd; 1635 struct vnode *vp; 1636 char *pathbuf; 1637 int error; 1638 1639 /* 1640 * Be ultra-paranoid about making sure the type and fspath 1641 * variables will fit in our mp buffers, including the 1642 * terminating NUL. 1643 */ 1644 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 1645 return (ENAMETOOLONG); 1646 1647 if (jail_export) { 1648 error = priv_check(td, PRIV_NFS_DAEMON); 1649 if (error) 1650 return (error); 1651 } else if (jailed(td->td_ucred) || usermount == 0) { 1652 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0) 1653 return (error); 1654 } 1655 1656 /* 1657 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 1658 */ 1659 if (fsflags & MNT_EXPORTED) { 1660 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED); 1661 if (error) 1662 return (error); 1663 } 1664 if (fsflags & MNT_SUIDDIR) { 1665 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR); 1666 if (error) 1667 return (error); 1668 } 1669 /* 1670 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users. 1671 */ 1672 if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) { 1673 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0) 1674 fsflags |= MNT_NOSUID | MNT_USER; 1675 } 1676 1677 /* Load KLDs before we lock the covered vnode to avoid reversals. */ 1678 vfsp = NULL; 1679 if ((fsflags & MNT_UPDATE) == 0) { 1680 /* Don't try to load KLDs if we're mounting the root. */ 1681 if (fsflags & MNT_ROOTFS) { 1682 if ((vfsp = vfs_byname(fstype)) == NULL) 1683 return (ENODEV); 1684 } else { 1685 if ((vfsp = vfs_byname_kld(fstype, td, &error)) == NULL) 1686 return (error); 1687 } 1688 } 1689 1690 /* 1691 * Get vnode to be covered or mount point's vnode in case of MNT_UPDATE. 1692 */ 1693 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1 | WANTPARENT, 1694 UIO_SYSSPACE, fspath); 1695 error = namei(&nd); 1696 if (error != 0) 1697 return (error); 1698 vp = nd.ni_vp; 1699 /* 1700 * Don't allow stacking file mounts to work around problems with the way 1701 * that namei sets nd.ni_dvp to vp_crossmp for these. 1702 */ 1703 if (vp->v_type == VREG) 1704 fsflags |= MNT_NOCOVER; 1705 if ((fsflags & MNT_UPDATE) == 0) { 1706 if ((vp->v_vflag & VV_ROOT) != 0 && 1707 (fsflags & MNT_NOCOVER) != 0) { 1708 vput(vp); 1709 error = EBUSY; 1710 goto out; 1711 } 1712 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1713 strcpy(pathbuf, fspath); 1714 /* 1715 * Note: we allow any vnode type here. If the path sanity check 1716 * succeeds, the type will be validated in vfs_domount_first 1717 * above. 1718 */ 1719 if (vp->v_type == VDIR) 1720 error = vn_path_to_global_path(td, vp, pathbuf, 1721 MNAMELEN); 1722 else 1723 error = vn_path_to_global_path_hardlink(td, vp, 1724 nd.ni_dvp, pathbuf, MNAMELEN, 1725 nd.ni_cnd.cn_nameptr, nd.ni_cnd.cn_namelen); 1726 if (error == 0) { 1727 error = vfs_domount_first(td, vfsp, pathbuf, vp, 1728 fsflags, optlist); 1729 } 1730 free(pathbuf, M_TEMP); 1731 } else 1732 error = vfs_domount_update(td, vp, fsflags, only_export, 1733 jail_export, optlist); 1734 1735 out: 1736 NDFREE_PNBUF(&nd); 1737 vrele(nd.ni_dvp); 1738 1739 return (error); 1740 } 1741 1742 /* 1743 * Unmount a filesystem. 1744 * 1745 * Note: unmount takes a path to the vnode mounted on as argument, not 1746 * special file (as before). 1747 */ 1748 #ifndef _SYS_SYSPROTO_H_ 1749 struct unmount_args { 1750 char *path; 1751 int flags; 1752 }; 1753 #endif 1754 /* ARGSUSED */ 1755 int 1756 sys_unmount(struct thread *td, struct unmount_args *uap) 1757 { 1758 1759 return (kern_unmount(td, uap->path, (unsigned)uap->flags)); 1760 } 1761 1762 int 1763 kern_unmount(struct thread *td, const char *path, uint64_t flags) 1764 { 1765 struct nameidata nd; 1766 struct mount *mp; 1767 char *fsidbuf, *pathbuf; 1768 fsid_t fsid; 1769 int error; 1770 1771 AUDIT_ARG_VALUE(flags); 1772 if ((flags & (MNT_DEFERRED | MNT_RECURSE)) != 0) 1773 return (EINVAL); 1774 if (jailed(td->td_ucred) || usermount == 0) { 1775 error = priv_check(td, PRIV_VFS_UNMOUNT); 1776 if (error) 1777 return (error); 1778 } 1779 if (flags & MNT_BYFSID) { 1780 fsidbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1781 error = copyinstr(path, fsidbuf, MNAMELEN, NULL); 1782 if (error) { 1783 free(fsidbuf, M_TEMP); 1784 return (error); 1785 } 1786 1787 AUDIT_ARG_TEXT(fsidbuf); 1788 /* Decode the filesystem ID. */ 1789 if (sscanf(fsidbuf, "FSID:%d:%d", &fsid.val[0], &fsid.val[1]) != 2) { 1790 free(fsidbuf, M_TEMP); 1791 return (EINVAL); 1792 } 1793 1794 mp = vfs_getvfs(&fsid); 1795 free(fsidbuf, M_TEMP); 1796 if (mp == NULL) { 1797 return (ENOENT); 1798 } 1799 } else { 1800 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1801 error = copyinstr(path, pathbuf, MNAMELEN, NULL); 1802 if (error) { 1803 free(pathbuf, M_TEMP); 1804 return (error); 1805 } 1806 1807 /* 1808 * Try to find global path for path argument. 1809 */ 1810 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, 1811 UIO_SYSSPACE, pathbuf); 1812 if (namei(&nd) == 0) { 1813 NDFREE_PNBUF(&nd); 1814 error = vn_path_to_global_path(td, nd.ni_vp, pathbuf, 1815 MNAMELEN); 1816 if (error == 0) 1817 vput(nd.ni_vp); 1818 } 1819 mtx_lock(&mountlist_mtx); 1820 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1821 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) { 1822 vfs_ref(mp); 1823 break; 1824 } 1825 } 1826 mtx_unlock(&mountlist_mtx); 1827 free(pathbuf, M_TEMP); 1828 if (mp == NULL) { 1829 /* 1830 * Previously we returned ENOENT for a nonexistent path and 1831 * EINVAL for a non-mountpoint. We cannot tell these apart 1832 * now, so in the !MNT_BYFSID case return the more likely 1833 * EINVAL for compatibility. 1834 */ 1835 return (EINVAL); 1836 } 1837 } 1838 1839 /* 1840 * Don't allow unmounting the root filesystem. 1841 */ 1842 if (mp->mnt_flag & MNT_ROOTFS) { 1843 vfs_rel(mp); 1844 return (EINVAL); 1845 } 1846 #ifdef MAC 1847 error = mac_mount_check_unmount(td->td_ucred, mp, flags); 1848 if (error != 0) { 1849 vfs_rel(mp); 1850 return (error); 1851 } 1852 #endif 1853 error = dounmount(mp, flags, td); 1854 return (error); 1855 } 1856 1857 /* 1858 * Return error if any of the vnodes, ignoring the root vnode 1859 * and the syncer vnode, have non-zero usecount. 1860 * 1861 * This function is purely advisory - it can return false positives 1862 * and negatives. 1863 */ 1864 static int 1865 vfs_check_usecounts(struct mount *mp) 1866 { 1867 struct vnode *vp, *mvp; 1868 1869 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 1870 if ((vp->v_vflag & VV_ROOT) == 0 && vp->v_type != VNON && 1871 vp->v_usecount != 0) { 1872 VI_UNLOCK(vp); 1873 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 1874 return (EBUSY); 1875 } 1876 VI_UNLOCK(vp); 1877 } 1878 1879 return (0); 1880 } 1881 1882 static void 1883 dounmount_cleanup(struct mount *mp, struct vnode *coveredvp, int mntkflags) 1884 { 1885 1886 mtx_assert(MNT_MTX(mp), MA_OWNED); 1887 mp->mnt_kern_flag &= ~mntkflags; 1888 if ((mp->mnt_kern_flag & MNTK_MWAIT) != 0) { 1889 mp->mnt_kern_flag &= ~MNTK_MWAIT; 1890 wakeup(mp); 1891 } 1892 vfs_op_exit_locked(mp); 1893 MNT_IUNLOCK(mp); 1894 if (coveredvp != NULL) { 1895 VOP_UNLOCK(coveredvp); 1896 vdrop(coveredvp); 1897 } 1898 vn_finished_write(mp); 1899 vfs_rel(mp); 1900 } 1901 1902 /* 1903 * There are various reference counters associated with the mount point. 1904 * Normally it is permitted to modify them without taking the mnt ilock, 1905 * but this behavior can be temporarily disabled if stable value is needed 1906 * or callers are expected to block (e.g. to not allow new users during 1907 * forced unmount). 1908 */ 1909 void 1910 vfs_op_enter(struct mount *mp) 1911 { 1912 struct mount_pcpu *mpcpu; 1913 int cpu; 1914 1915 MNT_ILOCK(mp); 1916 mp->mnt_vfs_ops++; 1917 if (mp->mnt_vfs_ops > 1) { 1918 MNT_IUNLOCK(mp); 1919 return; 1920 } 1921 vfs_op_barrier_wait(mp); 1922 CPU_FOREACH(cpu) { 1923 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1924 1925 mp->mnt_ref += mpcpu->mntp_ref; 1926 mpcpu->mntp_ref = 0; 1927 1928 mp->mnt_lockref += mpcpu->mntp_lockref; 1929 mpcpu->mntp_lockref = 0; 1930 1931 mp->mnt_writeopcount += mpcpu->mntp_writeopcount; 1932 mpcpu->mntp_writeopcount = 0; 1933 } 1934 MPASSERT(mp->mnt_ref > 0 && mp->mnt_lockref >= 0 && 1935 mp->mnt_writeopcount >= 0, mp, 1936 ("invalid count(s): ref %d lockref %d writeopcount %d", 1937 mp->mnt_ref, mp->mnt_lockref, mp->mnt_writeopcount)); 1938 MNT_IUNLOCK(mp); 1939 vfs_assert_mount_counters(mp); 1940 } 1941 1942 void 1943 vfs_op_exit_locked(struct mount *mp) 1944 { 1945 1946 mtx_assert(MNT_MTX(mp), MA_OWNED); 1947 1948 MPASSERT(mp->mnt_vfs_ops > 0, mp, 1949 ("invalid vfs_ops count %d", mp->mnt_vfs_ops)); 1950 MPASSERT(mp->mnt_vfs_ops > 1 || 1951 (mp->mnt_kern_flag & (MNTK_UNMOUNT | MNTK_SUSPEND)) == 0, mp, 1952 ("vfs_ops too low %d in unmount or suspend", mp->mnt_vfs_ops)); 1953 mp->mnt_vfs_ops--; 1954 } 1955 1956 void 1957 vfs_op_exit(struct mount *mp) 1958 { 1959 1960 MNT_ILOCK(mp); 1961 vfs_op_exit_locked(mp); 1962 MNT_IUNLOCK(mp); 1963 } 1964 1965 struct vfs_op_barrier_ipi { 1966 struct mount *mp; 1967 struct smp_rendezvous_cpus_retry_arg srcra; 1968 }; 1969 1970 static void 1971 vfs_op_action_func(void *arg) 1972 { 1973 struct vfs_op_barrier_ipi *vfsopipi; 1974 struct mount *mp; 1975 1976 vfsopipi = __containerof(arg, struct vfs_op_barrier_ipi, srcra); 1977 mp = vfsopipi->mp; 1978 1979 if (!vfs_op_thread_entered(mp)) 1980 smp_rendezvous_cpus_done(arg); 1981 } 1982 1983 static void 1984 vfs_op_wait_func(void *arg, int cpu) 1985 { 1986 struct vfs_op_barrier_ipi *vfsopipi; 1987 struct mount *mp; 1988 struct mount_pcpu *mpcpu; 1989 1990 vfsopipi = __containerof(arg, struct vfs_op_barrier_ipi, srcra); 1991 mp = vfsopipi->mp; 1992 1993 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1994 while (atomic_load_int(&mpcpu->mntp_thread_in_ops)) 1995 cpu_spinwait(); 1996 } 1997 1998 void 1999 vfs_op_barrier_wait(struct mount *mp) 2000 { 2001 struct vfs_op_barrier_ipi vfsopipi; 2002 2003 vfsopipi.mp = mp; 2004 2005 smp_rendezvous_cpus_retry(all_cpus, 2006 smp_no_rendezvous_barrier, 2007 vfs_op_action_func, 2008 smp_no_rendezvous_barrier, 2009 vfs_op_wait_func, 2010 &vfsopipi.srcra); 2011 } 2012 2013 #ifdef DIAGNOSTIC 2014 void 2015 vfs_assert_mount_counters(struct mount *mp) 2016 { 2017 struct mount_pcpu *mpcpu; 2018 int cpu; 2019 2020 if (mp->mnt_vfs_ops == 0) 2021 return; 2022 2023 CPU_FOREACH(cpu) { 2024 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 2025 if (mpcpu->mntp_ref != 0 || 2026 mpcpu->mntp_lockref != 0 || 2027 mpcpu->mntp_writeopcount != 0) 2028 vfs_dump_mount_counters(mp); 2029 } 2030 } 2031 2032 void 2033 vfs_dump_mount_counters(struct mount *mp) 2034 { 2035 struct mount_pcpu *mpcpu; 2036 int ref, lockref, writeopcount; 2037 int cpu; 2038 2039 printf("%s: mp %p vfs_ops %d\n", __func__, mp, mp->mnt_vfs_ops); 2040 2041 printf(" ref : "); 2042 ref = mp->mnt_ref; 2043 CPU_FOREACH(cpu) { 2044 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 2045 printf("%d ", mpcpu->mntp_ref); 2046 ref += mpcpu->mntp_ref; 2047 } 2048 printf("\n"); 2049 printf(" lockref : "); 2050 lockref = mp->mnt_lockref; 2051 CPU_FOREACH(cpu) { 2052 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 2053 printf("%d ", mpcpu->mntp_lockref); 2054 lockref += mpcpu->mntp_lockref; 2055 } 2056 printf("\n"); 2057 printf("writeopcount: "); 2058 writeopcount = mp->mnt_writeopcount; 2059 CPU_FOREACH(cpu) { 2060 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 2061 printf("%d ", mpcpu->mntp_writeopcount); 2062 writeopcount += mpcpu->mntp_writeopcount; 2063 } 2064 printf("\n"); 2065 2066 printf("counter struct total\n"); 2067 printf("ref %-5d %-5d\n", mp->mnt_ref, ref); 2068 printf("lockref %-5d %-5d\n", mp->mnt_lockref, lockref); 2069 printf("writeopcount %-5d %-5d\n", mp->mnt_writeopcount, writeopcount); 2070 2071 panic("invalid counts on struct mount"); 2072 } 2073 #endif 2074 2075 int 2076 vfs_mount_fetch_counter(struct mount *mp, enum mount_counter which) 2077 { 2078 struct mount_pcpu *mpcpu; 2079 int cpu, sum; 2080 2081 switch (which) { 2082 case MNT_COUNT_REF: 2083 sum = mp->mnt_ref; 2084 break; 2085 case MNT_COUNT_LOCKREF: 2086 sum = mp->mnt_lockref; 2087 break; 2088 case MNT_COUNT_WRITEOPCOUNT: 2089 sum = mp->mnt_writeopcount; 2090 break; 2091 } 2092 2093 CPU_FOREACH(cpu) { 2094 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 2095 switch (which) { 2096 case MNT_COUNT_REF: 2097 sum += mpcpu->mntp_ref; 2098 break; 2099 case MNT_COUNT_LOCKREF: 2100 sum += mpcpu->mntp_lockref; 2101 break; 2102 case MNT_COUNT_WRITEOPCOUNT: 2103 sum += mpcpu->mntp_writeopcount; 2104 break; 2105 } 2106 } 2107 return (sum); 2108 } 2109 2110 static bool 2111 deferred_unmount_enqueue(struct mount *mp, uint64_t flags, bool requeue, 2112 int timeout_ticks) 2113 { 2114 bool enqueued; 2115 2116 enqueued = false; 2117 mtx_lock(&deferred_unmount_lock); 2118 if ((mp->mnt_taskqueue_flags & MNT_DEFERRED) == 0 || requeue) { 2119 mp->mnt_taskqueue_flags = flags | MNT_DEFERRED; 2120 STAILQ_INSERT_TAIL(&deferred_unmount_list, mp, 2121 mnt_taskqueue_link); 2122 enqueued = true; 2123 } 2124 mtx_unlock(&deferred_unmount_lock); 2125 2126 if (enqueued) { 2127 taskqueue_enqueue_timeout(taskqueue_deferred_unmount, 2128 &deferred_unmount_task, timeout_ticks); 2129 } 2130 2131 return (enqueued); 2132 } 2133 2134 /* 2135 * Taskqueue handler for processing async/recursive unmounts 2136 */ 2137 static void 2138 vfs_deferred_unmount(void *argi __unused, int pending __unused) 2139 { 2140 STAILQ_HEAD(, mount) local_unmounts; 2141 uint64_t flags; 2142 struct mount *mp, *tmp; 2143 int error; 2144 unsigned int retries; 2145 bool unmounted; 2146 2147 STAILQ_INIT(&local_unmounts); 2148 mtx_lock(&deferred_unmount_lock); 2149 STAILQ_CONCAT(&local_unmounts, &deferred_unmount_list); 2150 mtx_unlock(&deferred_unmount_lock); 2151 2152 STAILQ_FOREACH_SAFE(mp, &local_unmounts, mnt_taskqueue_link, tmp) { 2153 flags = mp->mnt_taskqueue_flags; 2154 KASSERT((flags & MNT_DEFERRED) != 0, 2155 ("taskqueue unmount without MNT_DEFERRED")); 2156 error = dounmount(mp, flags, curthread); 2157 if (error != 0) { 2158 MNT_ILOCK(mp); 2159 unmounted = ((mp->mnt_kern_flag & MNTK_REFEXPIRE) != 0); 2160 MNT_IUNLOCK(mp); 2161 2162 /* 2163 * The deferred unmount thread is the only thread that 2164 * modifies the retry counts, so locking/atomics aren't 2165 * needed here. 2166 */ 2167 retries = (mp->mnt_unmount_retries)++; 2168 deferred_unmount_total_retries++; 2169 if (!unmounted && retries < deferred_unmount_retry_limit) { 2170 deferred_unmount_enqueue(mp, flags, true, 2171 -deferred_unmount_retry_delay_hz); 2172 } else { 2173 if (retries >= deferred_unmount_retry_limit) { 2174 printf("giving up on deferred unmount " 2175 "of %s after %d retries, error %d\n", 2176 mp->mnt_stat.f_mntonname, retries, error); 2177 } 2178 vfs_rel(mp); 2179 } 2180 } 2181 } 2182 } 2183 2184 /* 2185 * Do the actual filesystem unmount. 2186 */ 2187 int 2188 dounmount(struct mount *mp, uint64_t flags, struct thread *td) 2189 { 2190 struct mount_upper_node *upper; 2191 struct vnode *coveredvp, *rootvp; 2192 int error; 2193 uint64_t async_flag; 2194 int mnt_gen_r; 2195 unsigned int retries; 2196 2197 KASSERT((flags & MNT_DEFERRED) == 0 || 2198 (flags & (MNT_RECURSE | MNT_FORCE)) == (MNT_RECURSE | MNT_FORCE), 2199 ("MNT_DEFERRED requires MNT_RECURSE | MNT_FORCE")); 2200 2201 /* 2202 * If the caller has explicitly requested the unmount to be handled by 2203 * the taskqueue and we're not already in taskqueue context, queue 2204 * up the unmount request and exit. This is done prior to any 2205 * credential checks; MNT_DEFERRED should be used only for kernel- 2206 * initiated unmounts and will therefore be processed with the 2207 * (kernel) credentials of the taskqueue thread. Still, callers 2208 * should be sure this is the behavior they want. 2209 */ 2210 if ((flags & MNT_DEFERRED) != 0 && 2211 taskqueue_member(taskqueue_deferred_unmount, curthread) == 0) { 2212 if (!deferred_unmount_enqueue(mp, flags, false, 0)) 2213 vfs_rel(mp); 2214 return (EINPROGRESS); 2215 } 2216 2217 /* 2218 * Only privileged root, or (if MNT_USER is set) the user that did the 2219 * original mount is permitted to unmount this filesystem. 2220 * This check should be made prior to queueing up any recursive 2221 * unmounts of upper filesystems. Those unmounts will be executed 2222 * with kernel thread credentials and are expected to succeed, so 2223 * we must at least ensure the originating context has sufficient 2224 * privilege to unmount the base filesystem before proceeding with 2225 * the uppers. 2226 */ 2227 error = vfs_suser(mp, td); 2228 if (error != 0) { 2229 KASSERT((flags & MNT_DEFERRED) == 0, 2230 ("taskqueue unmount with insufficient privilege")); 2231 vfs_rel(mp); 2232 return (error); 2233 } 2234 2235 if (recursive_forced_unmount && ((flags & MNT_FORCE) != 0)) 2236 flags |= MNT_RECURSE; 2237 2238 if ((flags & MNT_RECURSE) != 0) { 2239 KASSERT((flags & MNT_FORCE) != 0, 2240 ("MNT_RECURSE requires MNT_FORCE")); 2241 2242 MNT_ILOCK(mp); 2243 /* 2244 * Set MNTK_RECURSE to prevent new upper mounts from being 2245 * added, and note that an operation on the uppers list is in 2246 * progress. This will ensure that unregistration from the 2247 * uppers list, and therefore any pending unmount of the upper 2248 * FS, can't complete until after we finish walking the list. 2249 */ 2250 mp->mnt_kern_flag |= MNTK_RECURSE; 2251 mp->mnt_upper_pending++; 2252 TAILQ_FOREACH(upper, &mp->mnt_uppers, mnt_upper_link) { 2253 retries = upper->mp->mnt_unmount_retries; 2254 if (retries > deferred_unmount_retry_limit) { 2255 error = EBUSY; 2256 continue; 2257 } 2258 MNT_IUNLOCK(mp); 2259 2260 vfs_ref(upper->mp); 2261 if (!deferred_unmount_enqueue(upper->mp, flags, 2262 false, 0)) 2263 vfs_rel(upper->mp); 2264 MNT_ILOCK(mp); 2265 } 2266 mp->mnt_upper_pending--; 2267 if ((mp->mnt_kern_flag & MNTK_UPPER_WAITER) != 0 && 2268 mp->mnt_upper_pending == 0) { 2269 mp->mnt_kern_flag &= ~MNTK_UPPER_WAITER; 2270 wakeup(&mp->mnt_uppers); 2271 } 2272 2273 /* 2274 * If we're not on the taskqueue, wait until the uppers list 2275 * is drained before proceeding with unmount. Otherwise, if 2276 * we are on the taskqueue and there are still pending uppers, 2277 * just re-enqueue on the end of the taskqueue. 2278 */ 2279 if ((flags & MNT_DEFERRED) == 0) { 2280 while (error == 0 && !TAILQ_EMPTY(&mp->mnt_uppers)) { 2281 mp->mnt_kern_flag |= MNTK_TASKQUEUE_WAITER; 2282 error = msleep(&mp->mnt_taskqueue_link, 2283 MNT_MTX(mp), PCATCH, "umntqw", 0); 2284 } 2285 if (error != 0) { 2286 MNT_REL(mp); 2287 MNT_IUNLOCK(mp); 2288 return (error); 2289 } 2290 } else if (!TAILQ_EMPTY(&mp->mnt_uppers)) { 2291 MNT_IUNLOCK(mp); 2292 if (error == 0) 2293 deferred_unmount_enqueue(mp, flags, true, 0); 2294 return (error); 2295 } 2296 MNT_IUNLOCK(mp); 2297 KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers not empty")); 2298 } 2299 2300 /* Allow the taskqueue to safely re-enqueue on failure */ 2301 if ((flags & MNT_DEFERRED) != 0) 2302 vfs_ref(mp); 2303 2304 if ((coveredvp = mp->mnt_vnodecovered) != NULL) { 2305 mnt_gen_r = mp->mnt_gen; 2306 VI_LOCK(coveredvp); 2307 vholdl(coveredvp); 2308 vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY); 2309 /* 2310 * Check for mp being unmounted while waiting for the 2311 * covered vnode lock. 2312 */ 2313 if (coveredvp->v_mountedhere != mp || 2314 coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) { 2315 VOP_UNLOCK(coveredvp); 2316 vdrop(coveredvp); 2317 vfs_rel(mp); 2318 return (EBUSY); 2319 } 2320 } 2321 2322 vfs_op_enter(mp); 2323 2324 vn_start_write(NULL, &mp, V_WAIT); 2325 MNT_ILOCK(mp); 2326 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 || 2327 (mp->mnt_flag & MNT_UPDATE) != 0 || 2328 !TAILQ_EMPTY(&mp->mnt_uppers)) { 2329 dounmount_cleanup(mp, coveredvp, 0); 2330 return (EBUSY); 2331 } 2332 mp->mnt_kern_flag |= MNTK_UNMOUNT; 2333 rootvp = vfs_cache_root_clear(mp); 2334 if (coveredvp != NULL) 2335 vn_seqc_write_begin(coveredvp); 2336 if (flags & MNT_NONBUSY) { 2337 MNT_IUNLOCK(mp); 2338 error = vfs_check_usecounts(mp); 2339 MNT_ILOCK(mp); 2340 if (error != 0) { 2341 vn_seqc_write_end(coveredvp); 2342 dounmount_cleanup(mp, coveredvp, MNTK_UNMOUNT); 2343 if (rootvp != NULL) { 2344 vn_seqc_write_end(rootvp); 2345 vrele(rootvp); 2346 } 2347 return (error); 2348 } 2349 } 2350 /* Allow filesystems to detect that a forced unmount is in progress. */ 2351 if (flags & MNT_FORCE) { 2352 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 2353 MNT_IUNLOCK(mp); 2354 /* 2355 * Must be done after setting MNTK_UNMOUNTF and before 2356 * waiting for mnt_lockref to become 0. 2357 */ 2358 VFS_PURGE(mp); 2359 MNT_ILOCK(mp); 2360 } 2361 error = 0; 2362 if (mp->mnt_lockref) { 2363 mp->mnt_kern_flag |= MNTK_DRAINING; 2364 error = msleep(&mp->mnt_lockref, MNT_MTX(mp), PVFS, 2365 "mount drain", 0); 2366 } 2367 MNT_IUNLOCK(mp); 2368 KASSERT(mp->mnt_lockref == 0, 2369 ("%s: invalid lock refcount in the drain path @ %s:%d", 2370 __func__, __FILE__, __LINE__)); 2371 KASSERT(error == 0, 2372 ("%s: invalid return value for msleep in the drain path @ %s:%d", 2373 __func__, __FILE__, __LINE__)); 2374 2375 /* 2376 * We want to keep the vnode around so that we can vn_seqc_write_end 2377 * after we are done with unmount. Downgrade our reference to a mere 2378 * hold count so that we don't interefere with anything. 2379 */ 2380 if (rootvp != NULL) { 2381 vhold(rootvp); 2382 vrele(rootvp); 2383 } 2384 2385 if (mp->mnt_flag & MNT_EXPUBLIC) 2386 vfs_setpublicfs(NULL, NULL, NULL); 2387 2388 vfs_periodic(mp, MNT_WAIT); 2389 MNT_ILOCK(mp); 2390 async_flag = mp->mnt_flag & MNT_ASYNC; 2391 mp->mnt_flag &= ~MNT_ASYNC; 2392 mp->mnt_kern_flag &= ~MNTK_ASYNC; 2393 MNT_IUNLOCK(mp); 2394 2395 /* Wait for any replenish kernel process to terminate. */ 2396 pnfsd_waitreplenish(mp); 2397 2398 vfs_deallocate_syncvnode(mp); 2399 error = VFS_UNMOUNT(mp, flags); 2400 vn_finished_write(mp); 2401 vfs_rel(mp); 2402 /* 2403 * If we failed to flush the dirty blocks for this mount point, 2404 * undo all the cdir/rdir and rootvnode changes we made above. 2405 * Unless we failed to do so because the device is reporting that 2406 * it doesn't exist anymore. 2407 */ 2408 if (error && error != ENXIO) { 2409 MNT_ILOCK(mp); 2410 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 2411 MNT_IUNLOCK(mp); 2412 vfs_allocate_syncvnode(mp); 2413 MNT_ILOCK(mp); 2414 } 2415 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 2416 mp->mnt_flag |= async_flag; 2417 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 2418 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 2419 mp->mnt_kern_flag |= MNTK_ASYNC; 2420 if (mp->mnt_kern_flag & MNTK_MWAIT) { 2421 mp->mnt_kern_flag &= ~MNTK_MWAIT; 2422 wakeup(mp); 2423 } 2424 vfs_op_exit_locked(mp); 2425 MNT_IUNLOCK(mp); 2426 if (coveredvp) { 2427 vn_seqc_write_end(coveredvp); 2428 VOP_UNLOCK(coveredvp); 2429 vdrop(coveredvp); 2430 } 2431 if (rootvp != NULL) { 2432 vn_seqc_write_end(rootvp); 2433 vdrop(rootvp); 2434 } 2435 return (error); 2436 } 2437 2438 mtx_lock(&mountlist_mtx); 2439 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2440 mtx_unlock(&mountlist_mtx); 2441 EVENTHANDLER_DIRECT_INVOKE(vfs_unmounted, mp, td); 2442 if (coveredvp != NULL) { 2443 VI_LOCK(coveredvp); 2444 vn_irflag_unset_locked(coveredvp, VIRF_MOUNTPOINT); 2445 coveredvp->v_mountedhere = NULL; 2446 vn_seqc_write_end_locked(coveredvp); 2447 VI_UNLOCK(coveredvp); 2448 VOP_UNLOCK(coveredvp); 2449 vdrop(coveredvp); 2450 } 2451 mount_devctl_event("UNMOUNT", mp, false); 2452 if (rootvp != NULL) { 2453 vn_seqc_write_end(rootvp); 2454 vdrop(rootvp); 2455 } 2456 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 2457 if (rootvnode != NULL && mp == rootvnode->v_mount) { 2458 vrele(rootvnode); 2459 rootvnode = NULL; 2460 } 2461 if (mp == rootdevmp) 2462 rootdevmp = NULL; 2463 if ((flags & MNT_DEFERRED) != 0) 2464 vfs_rel(mp); 2465 vfs_mount_destroy(mp); 2466 return (0); 2467 } 2468 2469 /* 2470 * Report errors during filesystem mounting. 2471 */ 2472 void 2473 vfs_mount_error(struct mount *mp, const char *fmt, ...) 2474 { 2475 struct vfsoptlist *moptlist = mp->mnt_optnew; 2476 va_list ap; 2477 int error, len; 2478 char *errmsg; 2479 2480 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len); 2481 if (error || errmsg == NULL || len <= 0) 2482 return; 2483 2484 va_start(ap, fmt); 2485 vsnprintf(errmsg, (size_t)len, fmt, ap); 2486 va_end(ap); 2487 } 2488 2489 void 2490 vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...) 2491 { 2492 va_list ap; 2493 int error, len; 2494 char *errmsg; 2495 2496 error = vfs_getopt(opts, "errmsg", (void **)&errmsg, &len); 2497 if (error || errmsg == NULL || len <= 0) 2498 return; 2499 2500 va_start(ap, fmt); 2501 vsnprintf(errmsg, (size_t)len, fmt, ap); 2502 va_end(ap); 2503 } 2504 2505 /* 2506 * --------------------------------------------------------------------- 2507 * Functions for querying mount options/arguments from filesystems. 2508 */ 2509 2510 /* 2511 * Check that no unknown options are given 2512 */ 2513 int 2514 vfs_filteropt(struct vfsoptlist *opts, const char **legal) 2515 { 2516 struct vfsopt *opt; 2517 char errmsg[255]; 2518 const char **t, *p, *q; 2519 int ret = 0; 2520 2521 TAILQ_FOREACH(opt, opts, link) { 2522 p = opt->name; 2523 q = NULL; 2524 if (p[0] == 'n' && p[1] == 'o') 2525 q = p + 2; 2526 for(t = global_opts; *t != NULL; t++) { 2527 if (strcmp(*t, p) == 0) 2528 break; 2529 if (q != NULL) { 2530 if (strcmp(*t, q) == 0) 2531 break; 2532 } 2533 } 2534 if (*t != NULL) 2535 continue; 2536 for(t = legal; *t != NULL; t++) { 2537 if (strcmp(*t, p) == 0) 2538 break; 2539 if (q != NULL) { 2540 if (strcmp(*t, q) == 0) 2541 break; 2542 } 2543 } 2544 if (*t != NULL) 2545 continue; 2546 snprintf(errmsg, sizeof(errmsg), 2547 "mount option <%s> is unknown", p); 2548 ret = EINVAL; 2549 } 2550 if (ret != 0) { 2551 TAILQ_FOREACH(opt, opts, link) { 2552 if (strcmp(opt->name, "errmsg") == 0) { 2553 strncpy((char *)opt->value, errmsg, opt->len); 2554 break; 2555 } 2556 } 2557 if (opt == NULL) 2558 printf("%s\n", errmsg); 2559 } 2560 return (ret); 2561 } 2562 2563 /* 2564 * Get a mount option by its name. 2565 * 2566 * Return 0 if the option was found, ENOENT otherwise. 2567 * If len is non-NULL it will be filled with the length 2568 * of the option. If buf is non-NULL, it will be filled 2569 * with the address of the option. 2570 */ 2571 int 2572 vfs_getopt(struct vfsoptlist *opts, const char *name, void **buf, int *len) 2573 { 2574 struct vfsopt *opt; 2575 2576 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 2577 2578 TAILQ_FOREACH(opt, opts, link) { 2579 if (strcmp(name, opt->name) == 0) { 2580 opt->seen = 1; 2581 if (len != NULL) 2582 *len = opt->len; 2583 if (buf != NULL) 2584 *buf = opt->value; 2585 return (0); 2586 } 2587 } 2588 return (ENOENT); 2589 } 2590 2591 int 2592 vfs_getopt_pos(struct vfsoptlist *opts, const char *name) 2593 { 2594 struct vfsopt *opt; 2595 2596 if (opts == NULL) 2597 return (-1); 2598 2599 TAILQ_FOREACH(opt, opts, link) { 2600 if (strcmp(name, opt->name) == 0) { 2601 opt->seen = 1; 2602 return (opt->pos); 2603 } 2604 } 2605 return (-1); 2606 } 2607 2608 int 2609 vfs_getopt_size(struct vfsoptlist *opts, const char *name, off_t *value) 2610 { 2611 char *opt_value, *vtp; 2612 quad_t iv; 2613 int error, opt_len; 2614 2615 error = vfs_getopt(opts, name, (void **)&opt_value, &opt_len); 2616 if (error != 0) 2617 return (error); 2618 if (opt_len == 0 || opt_value == NULL) 2619 return (EINVAL); 2620 if (opt_value[0] == '\0' || opt_value[opt_len - 1] != '\0') 2621 return (EINVAL); 2622 iv = strtoq(opt_value, &vtp, 0); 2623 if (vtp == opt_value || (vtp[0] != '\0' && vtp[1] != '\0')) 2624 return (EINVAL); 2625 if (iv < 0) 2626 return (EINVAL); 2627 switch (vtp[0]) { 2628 case 't': case 'T': 2629 iv *= 1024; 2630 /* FALLTHROUGH */ 2631 case 'g': case 'G': 2632 iv *= 1024; 2633 /* FALLTHROUGH */ 2634 case 'm': case 'M': 2635 iv *= 1024; 2636 /* FALLTHROUGH */ 2637 case 'k': case 'K': 2638 iv *= 1024; 2639 case '\0': 2640 break; 2641 default: 2642 return (EINVAL); 2643 } 2644 *value = iv; 2645 2646 return (0); 2647 } 2648 2649 char * 2650 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 2651 { 2652 struct vfsopt *opt; 2653 2654 *error = 0; 2655 TAILQ_FOREACH(opt, opts, link) { 2656 if (strcmp(name, opt->name) != 0) 2657 continue; 2658 opt->seen = 1; 2659 if (opt->len == 0 || 2660 ((char *)opt->value)[opt->len - 1] != '\0') { 2661 *error = EINVAL; 2662 return (NULL); 2663 } 2664 return (opt->value); 2665 } 2666 *error = ENOENT; 2667 return (NULL); 2668 } 2669 2670 int 2671 vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w, 2672 uint64_t val) 2673 { 2674 struct vfsopt *opt; 2675 2676 TAILQ_FOREACH(opt, opts, link) { 2677 if (strcmp(name, opt->name) == 0) { 2678 opt->seen = 1; 2679 if (w != NULL) 2680 *w |= val; 2681 return (1); 2682 } 2683 } 2684 if (w != NULL) 2685 *w &= ~val; 2686 return (0); 2687 } 2688 2689 int 2690 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 2691 { 2692 va_list ap; 2693 struct vfsopt *opt; 2694 int ret; 2695 2696 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 2697 2698 TAILQ_FOREACH(opt, opts, link) { 2699 if (strcmp(name, opt->name) != 0) 2700 continue; 2701 opt->seen = 1; 2702 if (opt->len == 0 || opt->value == NULL) 2703 return (0); 2704 if (((char *)opt->value)[opt->len - 1] != '\0') 2705 return (0); 2706 va_start(ap, fmt); 2707 ret = vsscanf(opt->value, fmt, ap); 2708 va_end(ap); 2709 return (ret); 2710 } 2711 return (0); 2712 } 2713 2714 int 2715 vfs_setopt(struct vfsoptlist *opts, const char *name, void *value, int len) 2716 { 2717 struct vfsopt *opt; 2718 2719 TAILQ_FOREACH(opt, opts, link) { 2720 if (strcmp(name, opt->name) != 0) 2721 continue; 2722 opt->seen = 1; 2723 if (opt->value == NULL) 2724 opt->len = len; 2725 else { 2726 if (opt->len != len) 2727 return (EINVAL); 2728 bcopy(value, opt->value, len); 2729 } 2730 return (0); 2731 } 2732 return (ENOENT); 2733 } 2734 2735 int 2736 vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value, int len) 2737 { 2738 struct vfsopt *opt; 2739 2740 TAILQ_FOREACH(opt, opts, link) { 2741 if (strcmp(name, opt->name) != 0) 2742 continue; 2743 opt->seen = 1; 2744 if (opt->value == NULL) 2745 opt->len = len; 2746 else { 2747 if (opt->len < len) 2748 return (EINVAL); 2749 opt->len = len; 2750 bcopy(value, opt->value, len); 2751 } 2752 return (0); 2753 } 2754 return (ENOENT); 2755 } 2756 2757 int 2758 vfs_setopts(struct vfsoptlist *opts, const char *name, const char *value) 2759 { 2760 struct vfsopt *opt; 2761 2762 TAILQ_FOREACH(opt, opts, link) { 2763 if (strcmp(name, opt->name) != 0) 2764 continue; 2765 opt->seen = 1; 2766 if (opt->value == NULL) 2767 opt->len = strlen(value) + 1; 2768 else if (strlcpy(opt->value, value, opt->len) >= opt->len) 2769 return (EINVAL); 2770 return (0); 2771 } 2772 return (ENOENT); 2773 } 2774 2775 /* 2776 * Find and copy a mount option. 2777 * 2778 * The size of the buffer has to be specified 2779 * in len, if it is not the same length as the 2780 * mount option, EINVAL is returned. 2781 * Returns ENOENT if the option is not found. 2782 */ 2783 int 2784 vfs_copyopt(struct vfsoptlist *opts, const char *name, void *dest, int len) 2785 { 2786 struct vfsopt *opt; 2787 2788 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 2789 2790 TAILQ_FOREACH(opt, opts, link) { 2791 if (strcmp(name, opt->name) == 0) { 2792 opt->seen = 1; 2793 if (len != opt->len) 2794 return (EINVAL); 2795 bcopy(opt->value, dest, opt->len); 2796 return (0); 2797 } 2798 } 2799 return (ENOENT); 2800 } 2801 2802 int 2803 __vfs_statfs(struct mount *mp, struct statfs *sbp) 2804 { 2805 /* 2806 * Filesystems only fill in part of the structure for updates, we 2807 * have to read the entirety first to get all content. 2808 */ 2809 if (sbp != &mp->mnt_stat) 2810 memcpy(sbp, &mp->mnt_stat, sizeof(*sbp)); 2811 2812 /* 2813 * Set these in case the underlying filesystem fails to do so. 2814 */ 2815 sbp->f_version = STATFS_VERSION; 2816 sbp->f_namemax = NAME_MAX; 2817 sbp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK; 2818 sbp->f_nvnodelistsize = mp->mnt_nvnodelistsize; 2819 2820 return (mp->mnt_op->vfs_statfs(mp, sbp)); 2821 } 2822 2823 void 2824 vfs_mountedfrom(struct mount *mp, const char *from) 2825 { 2826 2827 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 2828 strlcpy(mp->mnt_stat.f_mntfromname, from, 2829 sizeof mp->mnt_stat.f_mntfromname); 2830 } 2831 2832 /* 2833 * --------------------------------------------------------------------- 2834 * This is the api for building mount args and mounting filesystems from 2835 * inside the kernel. 2836 * 2837 * The API works by accumulation of individual args. First error is 2838 * latched. 2839 * 2840 * XXX: should be documented in new manpage kernel_mount(9) 2841 */ 2842 2843 /* A memory allocation which must be freed when we are done */ 2844 struct mntaarg { 2845 SLIST_ENTRY(mntaarg) next; 2846 }; 2847 2848 /* The header for the mount arguments */ 2849 struct mntarg { 2850 struct iovec *v; 2851 int len; 2852 int error; 2853 SLIST_HEAD(, mntaarg) list; 2854 }; 2855 2856 /* 2857 * Add a boolean argument. 2858 * 2859 * flag is the boolean value. 2860 * name must start with "no". 2861 */ 2862 struct mntarg * 2863 mount_argb(struct mntarg *ma, int flag, const char *name) 2864 { 2865 2866 KASSERT(name[0] == 'n' && name[1] == 'o', 2867 ("mount_argb(...,%s): name must start with 'no'", name)); 2868 2869 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 2870 } 2871 2872 /* 2873 * Add an argument printf style 2874 */ 2875 struct mntarg * 2876 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 2877 { 2878 va_list ap; 2879 struct mntaarg *maa; 2880 struct sbuf *sb; 2881 int len; 2882 2883 if (ma == NULL) { 2884 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2885 SLIST_INIT(&ma->list); 2886 } 2887 if (ma->error) 2888 return (ma); 2889 2890 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2891 M_MOUNT, M_WAITOK); 2892 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2893 ma->v[ma->len].iov_len = strlen(name) + 1; 2894 ma->len++; 2895 2896 sb = sbuf_new_auto(); 2897 va_start(ap, fmt); 2898 sbuf_vprintf(sb, fmt, ap); 2899 va_end(ap); 2900 sbuf_finish(sb); 2901 len = sbuf_len(sb) + 1; 2902 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2903 SLIST_INSERT_HEAD(&ma->list, maa, next); 2904 bcopy(sbuf_data(sb), maa + 1, len); 2905 sbuf_delete(sb); 2906 2907 ma->v[ma->len].iov_base = maa + 1; 2908 ma->v[ma->len].iov_len = len; 2909 ma->len++; 2910 2911 return (ma); 2912 } 2913 2914 /* 2915 * Add an argument which is a userland string. 2916 */ 2917 struct mntarg * 2918 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 2919 { 2920 struct mntaarg *maa; 2921 char *tbuf; 2922 2923 if (val == NULL) 2924 return (ma); 2925 if (ma == NULL) { 2926 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2927 SLIST_INIT(&ma->list); 2928 } 2929 if (ma->error) 2930 return (ma); 2931 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2932 SLIST_INSERT_HEAD(&ma->list, maa, next); 2933 tbuf = (void *)(maa + 1); 2934 ma->error = copyinstr(val, tbuf, len, NULL); 2935 return (mount_arg(ma, name, tbuf, -1)); 2936 } 2937 2938 /* 2939 * Plain argument. 2940 * 2941 * If length is -1, treat value as a C string. 2942 */ 2943 struct mntarg * 2944 mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 2945 { 2946 2947 if (ma == NULL) { 2948 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2949 SLIST_INIT(&ma->list); 2950 } 2951 if (ma->error) 2952 return (ma); 2953 2954 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2955 M_MOUNT, M_WAITOK); 2956 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2957 ma->v[ma->len].iov_len = strlen(name) + 1; 2958 ma->len++; 2959 2960 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 2961 if (len < 0) 2962 ma->v[ma->len].iov_len = strlen(val) + 1; 2963 else 2964 ma->v[ma->len].iov_len = len; 2965 ma->len++; 2966 return (ma); 2967 } 2968 2969 /* 2970 * Free a mntarg structure 2971 */ 2972 static void 2973 free_mntarg(struct mntarg *ma) 2974 { 2975 struct mntaarg *maa; 2976 2977 while (!SLIST_EMPTY(&ma->list)) { 2978 maa = SLIST_FIRST(&ma->list); 2979 SLIST_REMOVE_HEAD(&ma->list, next); 2980 free(maa, M_MOUNT); 2981 } 2982 free(ma->v, M_MOUNT); 2983 free(ma, M_MOUNT); 2984 } 2985 2986 /* 2987 * Mount a filesystem 2988 */ 2989 int 2990 kernel_mount(struct mntarg *ma, uint64_t flags) 2991 { 2992 struct uio auio; 2993 int error; 2994 2995 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 2996 KASSERT(ma->error != 0 || ma->v != NULL, ("kernel_mount NULL ma->v")); 2997 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 2998 2999 error = ma->error; 3000 if (error == 0) { 3001 auio.uio_iov = ma->v; 3002 auio.uio_iovcnt = ma->len; 3003 auio.uio_segflg = UIO_SYSSPACE; 3004 error = vfs_donmount(curthread, flags, &auio); 3005 } 3006 free_mntarg(ma); 3007 return (error); 3008 } 3009 3010 /* Map from mount options to printable formats. */ 3011 static struct mntoptnames optnames[] = { 3012 MNTOPT_NAMES 3013 }; 3014 3015 #define DEVCTL_LEN 1024 3016 static void 3017 mount_devctl_event(const char *type, struct mount *mp, bool donew) 3018 { 3019 const uint8_t *cp; 3020 struct mntoptnames *fp; 3021 struct sbuf sb; 3022 struct statfs *sfp = &mp->mnt_stat; 3023 char *buf; 3024 3025 buf = malloc(DEVCTL_LEN, M_MOUNT, M_NOWAIT); 3026 if (buf == NULL) 3027 return; 3028 sbuf_new(&sb, buf, DEVCTL_LEN, SBUF_FIXEDLEN); 3029 sbuf_cpy(&sb, "mount-point=\""); 3030 devctl_safe_quote_sb(&sb, sfp->f_mntonname); 3031 sbuf_cat(&sb, "\" mount-dev=\""); 3032 devctl_safe_quote_sb(&sb, sfp->f_mntfromname); 3033 sbuf_cat(&sb, "\" mount-type=\""); 3034 devctl_safe_quote_sb(&sb, sfp->f_fstypename); 3035 sbuf_cat(&sb, "\" fsid=0x"); 3036 cp = (const uint8_t *)&sfp->f_fsid.val[0]; 3037 for (int i = 0; i < sizeof(sfp->f_fsid); i++) 3038 sbuf_printf(&sb, "%02x", cp[i]); 3039 sbuf_printf(&sb, " owner=%u flags=\"", sfp->f_owner); 3040 for (fp = optnames; fp->o_opt != 0; fp++) { 3041 if ((mp->mnt_flag & fp->o_opt) != 0) { 3042 sbuf_cat(&sb, fp->o_name); 3043 sbuf_putc(&sb, ';'); 3044 } 3045 } 3046 sbuf_putc(&sb, '"'); 3047 sbuf_finish(&sb); 3048 3049 /* 3050 * Options are not published because the form of the options depends on 3051 * the file system and may include binary data. In addition, they don't 3052 * necessarily provide enough useful information to be actionable when 3053 * devd processes them. 3054 */ 3055 3056 if (sbuf_error(&sb) == 0) 3057 devctl_notify("VFS", "FS", type, sbuf_data(&sb)); 3058 sbuf_delete(&sb); 3059 free(buf, M_MOUNT); 3060 } 3061 3062 /* 3063 * Force remount specified mount point to read-only. The argument 3064 * must be busied to avoid parallel unmount attempts. 3065 * 3066 * Intended use is to prevent further writes if some metadata 3067 * inconsistency is detected. Note that the function still flushes 3068 * all cached metadata and data for the mount point, which might be 3069 * not always suitable. 3070 */ 3071 int 3072 vfs_remount_ro(struct mount *mp) 3073 { 3074 struct vfsoptlist *opts; 3075 struct vfsopt *opt; 3076 struct vnode *vp_covered, *rootvp; 3077 int error; 3078 3079 vfs_op_enter(mp); 3080 KASSERT(mp->mnt_lockref > 0, 3081 ("vfs_remount_ro: mp %p is not busied", mp)); 3082 KASSERT((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0, 3083 ("vfs_remount_ro: mp %p is being unmounted (and busy?)", mp)); 3084 3085 rootvp = NULL; 3086 vp_covered = mp->mnt_vnodecovered; 3087 error = vget(vp_covered, LK_EXCLUSIVE | LK_NOWAIT); 3088 if (error != 0) { 3089 vfs_op_exit(mp); 3090 return (error); 3091 } 3092 VI_LOCK(vp_covered); 3093 if ((vp_covered->v_iflag & VI_MOUNT) != 0) { 3094 VI_UNLOCK(vp_covered); 3095 vput(vp_covered); 3096 vfs_op_exit(mp); 3097 return (EBUSY); 3098 } 3099 vp_covered->v_iflag |= VI_MOUNT; 3100 VI_UNLOCK(vp_covered); 3101 vn_seqc_write_begin(vp_covered); 3102 3103 MNT_ILOCK(mp); 3104 if ((mp->mnt_flag & MNT_RDONLY) != 0) { 3105 MNT_IUNLOCK(mp); 3106 error = EBUSY; 3107 goto out; 3108 } 3109 mp->mnt_flag |= MNT_UPDATE | MNT_FORCE | MNT_RDONLY; 3110 rootvp = vfs_cache_root_clear(mp); 3111 MNT_IUNLOCK(mp); 3112 3113 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK | M_ZERO); 3114 TAILQ_INIT(opts); 3115 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK | M_ZERO); 3116 opt->name = strdup("ro", M_MOUNT); 3117 opt->value = NULL; 3118 TAILQ_INSERT_TAIL(opts, opt, link); 3119 vfs_mergeopts(opts, mp->mnt_opt); 3120 mp->mnt_optnew = opts; 3121 3122 error = VFS_MOUNT(mp); 3123 3124 if (error == 0) { 3125 MNT_ILOCK(mp); 3126 mp->mnt_flag &= ~(MNT_UPDATE | MNT_FORCE); 3127 MNT_IUNLOCK(mp); 3128 vfs_deallocate_syncvnode(mp); 3129 if (mp->mnt_opt != NULL) 3130 vfs_freeopts(mp->mnt_opt); 3131 mp->mnt_opt = mp->mnt_optnew; 3132 } else { 3133 MNT_ILOCK(mp); 3134 mp->mnt_flag &= ~(MNT_UPDATE | MNT_FORCE | MNT_RDONLY); 3135 MNT_IUNLOCK(mp); 3136 vfs_freeopts(mp->mnt_optnew); 3137 } 3138 mp->mnt_optnew = NULL; 3139 3140 out: 3141 vfs_op_exit(mp); 3142 VI_LOCK(vp_covered); 3143 vp_covered->v_iflag &= ~VI_MOUNT; 3144 VI_UNLOCK(vp_covered); 3145 vput(vp_covered); 3146 vn_seqc_write_end(vp_covered); 3147 if (rootvp != NULL) { 3148 vn_seqc_write_end(rootvp); 3149 vrele(rootvp); 3150 } 3151 return (error); 3152 } 3153 3154 /* 3155 * Suspend write operations on all local writeable filesystems. Does 3156 * full sync of them in the process. 3157 * 3158 * Iterate over the mount points in reverse order, suspending most 3159 * recently mounted filesystems first. It handles a case where a 3160 * filesystem mounted from a md(4) vnode-backed device should be 3161 * suspended before the filesystem that owns the vnode. 3162 */ 3163 void 3164 suspend_all_fs(void) 3165 { 3166 struct mount *mp; 3167 int error; 3168 3169 mtx_lock(&mountlist_mtx); 3170 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 3171 error = vfs_busy(mp, MBF_MNTLSTLOCK | MBF_NOWAIT); 3172 if (error != 0) 3173 continue; 3174 if ((mp->mnt_flag & (MNT_RDONLY | MNT_LOCAL)) != MNT_LOCAL || 3175 (mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 3176 mtx_lock(&mountlist_mtx); 3177 vfs_unbusy(mp); 3178 continue; 3179 } 3180 error = vfs_write_suspend(mp, 0); 3181 if (error == 0) { 3182 MNT_ILOCK(mp); 3183 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0); 3184 mp->mnt_kern_flag |= MNTK_SUSPEND_ALL; 3185 MNT_IUNLOCK(mp); 3186 mtx_lock(&mountlist_mtx); 3187 } else { 3188 printf("suspend of %s failed, error %d\n", 3189 mp->mnt_stat.f_mntonname, error); 3190 mtx_lock(&mountlist_mtx); 3191 vfs_unbusy(mp); 3192 } 3193 } 3194 mtx_unlock(&mountlist_mtx); 3195 } 3196 3197 /* 3198 * Clone the mnt_exjail field to a new mount point. 3199 */ 3200 void 3201 vfs_exjail_clone(struct mount *inmp, struct mount *outmp) 3202 { 3203 struct ucred *cr; 3204 struct prison *pr; 3205 3206 MNT_ILOCK(inmp); 3207 cr = inmp->mnt_exjail; 3208 if (cr != NULL) { 3209 crhold(cr); 3210 MNT_IUNLOCK(inmp); 3211 pr = cr->cr_prison; 3212 sx_slock(&allprison_lock); 3213 if (!prison_isalive(pr)) { 3214 sx_sunlock(&allprison_lock); 3215 crfree(cr); 3216 return; 3217 } 3218 MNT_ILOCK(outmp); 3219 if (outmp->mnt_exjail == NULL) { 3220 outmp->mnt_exjail = cr; 3221 atomic_add_int(&pr->pr_exportcnt, 1); 3222 cr = NULL; 3223 } 3224 MNT_IUNLOCK(outmp); 3225 sx_sunlock(&allprison_lock); 3226 if (cr != NULL) 3227 crfree(cr); 3228 } else 3229 MNT_IUNLOCK(inmp); 3230 } 3231 3232 void 3233 resume_all_fs(void) 3234 { 3235 struct mount *mp; 3236 3237 mtx_lock(&mountlist_mtx); 3238 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3239 if ((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0) 3240 continue; 3241 mtx_unlock(&mountlist_mtx); 3242 MNT_ILOCK(mp); 3243 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) != 0); 3244 mp->mnt_kern_flag &= ~MNTK_SUSPEND_ALL; 3245 MNT_IUNLOCK(mp); 3246 vfs_write_resume(mp, 0); 3247 mtx_lock(&mountlist_mtx); 3248 vfs_unbusy(mp); 3249 } 3250 mtx_unlock(&mountlist_mtx); 3251 } 3252 3253 static void 3254 pnfsd_waitreplenish(struct mount *mp) 3255 { 3256 struct netexport *nep; 3257 3258 lockmgr(&mp->mnt_explock, LK_SHARED, NULL); 3259 nep = mp->mnt_export; 3260 if (nep != NULL) { 3261 refcount_acquire(&nep->ne_ref); 3262 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 3263 MNTEXP_LOCK(nep); 3264 if (nep->ne_pnfsnumfile != NULL && 3265 nep->ne_pnfsnumfile != PNFSD_STOPPED) { 3266 nep->ne_pnfsnumfile = PNFSD_STOP; 3267 wakeup(&mp->mnt_export); 3268 while (nep->ne_pnfsnumfile != PNFSD_STOPPED) 3269 (void)msleep(&mp->mnt_explock, MNTEXP_MTX(nep), 3270 PVFS, "pnfsw", hz); 3271 } 3272 MNTEXP_UNLOCK(nep); 3273 vfs_netexport_release(nep); 3274 } else 3275 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 3276 } 3277