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