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, "automounted") == 0) { 928 fsflags |= MNT_AUTOMOUNTED; 929 do_freeopt = 1; 930 } else if (strcmp(opt->name, "nocover") == 0) { 931 fsflags |= MNT_NOCOVER; 932 do_freeopt = 1; 933 } else if (strcmp(opt->name, "cover") == 0) { 934 fsflags &= ~MNT_NOCOVER; 935 do_freeopt = 1; 936 } else if (strcmp(opt->name, "emptydir") == 0) { 937 fsflags |= MNT_EMPTYDIR; 938 do_freeopt = 1; 939 } else if (strcmp(opt->name, "noemptydir") == 0) { 940 fsflags &= ~MNT_EMPTYDIR; 941 do_freeopt = 1; 942 } 943 if (do_freeopt) 944 vfs_freeopt(optlist, opt); 945 } 946 947 /* 948 * Be ultra-paranoid about making sure the type and fspath 949 * variables will fit in our mp buffers, including the 950 * terminating NUL. 951 */ 952 if (fstypelen > MFSNAMELEN || fspathlen > MNAMELEN) { 953 error = ENAMETOOLONG; 954 goto bail; 955 } 956 957 error = vfs_domount(td, fstype, fspath, fsflags, &optlist); 958 if (error == ENOENT) { 959 error = EINVAL; 960 if (errmsg != NULL) 961 strncpy(errmsg, "Invalid fstype", errmsg_len); 962 goto bail; 963 } 964 965 /* 966 * See if we can mount in the read-only mode if the error code suggests 967 * that it could be possible and the mount options allow for that. 968 * Never try it if "[no]{ro|rw}" has been explicitly requested and not 969 * overridden by "autoro". 970 */ 971 if (autoro && vfs_should_downgrade_to_ro_mount(fsflags, error)) { 972 printf("%s: R/W mount failed, possibly R/O media," 973 " trying R/O mount\n", __func__); 974 fsflags |= MNT_RDONLY; 975 error = vfs_domount(td, fstype, fspath, fsflags, &optlist); 976 } 977 bail: 978 /* copyout the errmsg */ 979 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt) 980 && errmsg_len > 0 && errmsg != NULL) { 981 if (fsoptions->uio_segflg == UIO_SYSSPACE) { 982 bcopy(errmsg, 983 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 984 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 985 } else { 986 copyout(errmsg, 987 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 988 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 989 } 990 } 991 992 if (optlist != NULL) 993 vfs_freeopts(optlist); 994 return (error); 995 } 996 997 /* 998 * Old mount API. 999 */ 1000 #ifndef _SYS_SYSPROTO_H_ 1001 struct mount_args { 1002 char *type; 1003 char *path; 1004 int flags; 1005 caddr_t data; 1006 }; 1007 #endif 1008 /* ARGSUSED */ 1009 int 1010 sys_mount(struct thread *td, struct mount_args *uap) 1011 { 1012 char *fstype; 1013 struct vfsconf *vfsp = NULL; 1014 struct mntarg *ma = NULL; 1015 uint64_t flags; 1016 int error; 1017 1018 /* 1019 * Mount flags are now 64-bits. On 32-bit architectures only 1020 * 32-bits are passed in, but from here on everything handles 1021 * 64-bit flags correctly. 1022 */ 1023 flags = uap->flags; 1024 1025 AUDIT_ARG_FFLAGS(flags); 1026 1027 /* 1028 * Filter out MNT_ROOTFS. We do not want clients of mount() in 1029 * userspace to set this flag, but we must filter it out if we want 1030 * MNT_UPDATE on the root file system to work. 1031 * MNT_ROOTFS should only be set by the kernel when mounting its 1032 * root file system. 1033 */ 1034 flags &= ~MNT_ROOTFS; 1035 1036 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 1037 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 1038 if (error) { 1039 free(fstype, M_TEMP); 1040 return (error); 1041 } 1042 1043 AUDIT_ARG_TEXT(fstype); 1044 vfsp = vfs_byname_kld(fstype, td, &error); 1045 free(fstype, M_TEMP); 1046 if (vfsp == NULL) 1047 return (ENOENT); 1048 if (((vfsp->vfc_flags & VFCF_SBDRY) != 0 && 1049 vfsp->vfc_vfsops_sd->vfs_cmount == NULL) || 1050 ((vfsp->vfc_flags & VFCF_SBDRY) == 0 && 1051 vfsp->vfc_vfsops->vfs_cmount == NULL)) 1052 return (EOPNOTSUPP); 1053 1054 ma = mount_argsu(ma, "fstype", uap->type, MFSNAMELEN); 1055 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 1056 ma = mount_argb(ma, flags & MNT_RDONLY, "noro"); 1057 ma = mount_argb(ma, !(flags & MNT_NOSUID), "nosuid"); 1058 ma = mount_argb(ma, !(flags & MNT_NOEXEC), "noexec"); 1059 1060 if ((vfsp->vfc_flags & VFCF_SBDRY) != 0) 1061 return (vfsp->vfc_vfsops_sd->vfs_cmount(ma, uap->data, flags)); 1062 return (vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, flags)); 1063 } 1064 1065 /* 1066 * vfs_domount_first(): first file system mount (not update) 1067 */ 1068 static int 1069 vfs_domount_first( 1070 struct thread *td, /* Calling thread. */ 1071 struct vfsconf *vfsp, /* File system type. */ 1072 char *fspath, /* Mount path. */ 1073 struct vnode *vp, /* Vnode to be covered. */ 1074 uint64_t fsflags, /* Flags common to all filesystems. */ 1075 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1076 ) 1077 { 1078 struct vattr va; 1079 struct mount *mp; 1080 struct vnode *newdp, *rootvp; 1081 int error, error1; 1082 bool unmounted; 1083 1084 ASSERT_VOP_ELOCKED(vp, __func__); 1085 KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here")); 1086 1087 /* 1088 * If the jail of the calling thread lacks permission for this type of 1089 * file system, or is trying to cover its own root, deny immediately. 1090 */ 1091 if (jailed(td->td_ucred) && (!prison_allow(td->td_ucred, 1092 vfsp->vfc_prison_flag) || vp == td->td_ucred->cr_prison->pr_root)) { 1093 vput(vp); 1094 return (EPERM); 1095 } 1096 1097 /* 1098 * If the user is not root, ensure that they own the directory 1099 * onto which we are attempting to mount. 1100 */ 1101 error = VOP_GETATTR(vp, &va, td->td_ucred); 1102 if (error == 0 && va.va_uid != td->td_ucred->cr_uid) 1103 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN); 1104 if (error == 0) 1105 error = vinvalbuf(vp, V_SAVE, 0, 0); 1106 if (error == 0 && vp->v_type != VDIR) 1107 error = ENOTDIR; 1108 if (error == 0 && (fsflags & MNT_EMPTYDIR) != 0) 1109 error = vfs_emptydir(vp); 1110 if (error == 0) { 1111 VI_LOCK(vp); 1112 if ((vp->v_iflag & VI_MOUNT) == 0 && vp->v_mountedhere == NULL) 1113 vp->v_iflag |= VI_MOUNT; 1114 else 1115 error = EBUSY; 1116 VI_UNLOCK(vp); 1117 } 1118 if (error != 0) { 1119 vput(vp); 1120 return (error); 1121 } 1122 vn_seqc_write_begin(vp); 1123 VOP_UNLOCK(vp); 1124 1125 /* Allocate and initialize the filesystem. */ 1126 mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred); 1127 /* XXXMAC: pass to vfs_mount_alloc? */ 1128 mp->mnt_optnew = *optlist; 1129 /* Set the mount level flags. */ 1130 mp->mnt_flag = (fsflags & 1131 (MNT_UPDATEMASK | MNT_ROOTFS | MNT_RDONLY | MNT_FORCE)); 1132 1133 /* 1134 * Mount the filesystem. 1135 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1136 * get. No freeing of cn_pnbuf. 1137 */ 1138 error1 = 0; 1139 unmounted = true; 1140 if ((error = VFS_MOUNT(mp)) != 0 || 1141 (error1 = VFS_STATFS(mp, &mp->mnt_stat)) != 0 || 1142 (error1 = VFS_ROOT(mp, LK_EXCLUSIVE, &newdp)) != 0) { 1143 rootvp = NULL; 1144 if (error1 != 0) { 1145 MPASS(error == 0); 1146 rootvp = vfs_cache_root_clear(mp); 1147 if (rootvp != NULL) { 1148 vhold(rootvp); 1149 vrele(rootvp); 1150 } 1151 (void)vn_start_write(NULL, &mp, V_WAIT); 1152 MNT_ILOCK(mp); 1153 mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_UNMOUNTF; 1154 MNT_IUNLOCK(mp); 1155 VFS_PURGE(mp); 1156 error = VFS_UNMOUNT(mp, 0); 1157 vn_finished_write(mp); 1158 if (error != 0) { 1159 printf( 1160 "failed post-mount (%d): rollback unmount returned %d\n", 1161 error1, error); 1162 unmounted = false; 1163 } 1164 error = error1; 1165 } 1166 vfs_unbusy(mp); 1167 mp->mnt_vnodecovered = NULL; 1168 if (unmounted) { 1169 /* XXXKIB wait for mnt_lockref drain? */ 1170 vfs_mount_destroy(mp); 1171 } 1172 VI_LOCK(vp); 1173 vp->v_iflag &= ~VI_MOUNT; 1174 VI_UNLOCK(vp); 1175 if (rootvp != NULL) { 1176 vn_seqc_write_end(rootvp); 1177 vdrop(rootvp); 1178 } 1179 vn_seqc_write_end(vp); 1180 vrele(vp); 1181 return (error); 1182 } 1183 vn_seqc_write_begin(newdp); 1184 VOP_UNLOCK(newdp); 1185 1186 if (mp->mnt_opt != NULL) 1187 vfs_freeopts(mp->mnt_opt); 1188 mp->mnt_opt = mp->mnt_optnew; 1189 *optlist = NULL; 1190 1191 /* 1192 * Prevent external consumers of mount options from reading mnt_optnew. 1193 */ 1194 mp->mnt_optnew = NULL; 1195 1196 MNT_ILOCK(mp); 1197 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 1198 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 1199 mp->mnt_kern_flag |= MNTK_ASYNC; 1200 else 1201 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1202 MNT_IUNLOCK(mp); 1203 1204 /* 1205 * VIRF_MOUNTPOINT and v_mountedhere need to be set under the 1206 * vp lock to satisfy vfs_lookup() requirements. 1207 */ 1208 VOP_LOCK(vp, LK_EXCLUSIVE | LK_RETRY); 1209 VI_LOCK(vp); 1210 vn_irflag_set_locked(vp, VIRF_MOUNTPOINT); 1211 vp->v_mountedhere = mp; 1212 VI_UNLOCK(vp); 1213 VOP_UNLOCK(vp); 1214 cache_purge(vp); 1215 1216 /* 1217 * We need to lock both vnodes. 1218 * 1219 * Use vn_lock_pair to avoid establishing an ordering between vnodes 1220 * from different filesystems. 1221 */ 1222 vn_lock_pair(vp, false, newdp, false); 1223 1224 VI_LOCK(vp); 1225 vp->v_iflag &= ~VI_MOUNT; 1226 VI_UNLOCK(vp); 1227 /* Place the new filesystem at the end of the mount list. */ 1228 mtx_lock(&mountlist_mtx); 1229 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1230 mtx_unlock(&mountlist_mtx); 1231 vfs_event_signal(NULL, VQ_MOUNT, 0); 1232 VOP_UNLOCK(vp); 1233 EVENTHANDLER_DIRECT_INVOKE(vfs_mounted, mp, newdp, td); 1234 VOP_UNLOCK(newdp); 1235 mount_devctl_event("MOUNT", mp, false); 1236 mountcheckdirs(vp, newdp); 1237 vn_seqc_write_end(vp); 1238 vn_seqc_write_end(newdp); 1239 vrele(newdp); 1240 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1241 vfs_allocate_syncvnode(mp); 1242 vfs_op_exit(mp); 1243 vfs_unbusy(mp); 1244 return (0); 1245 } 1246 1247 /* 1248 * vfs_domount_update(): update of mounted file system 1249 */ 1250 static int 1251 vfs_domount_update( 1252 struct thread *td, /* Calling thread. */ 1253 struct vnode *vp, /* Mount point vnode. */ 1254 uint64_t fsflags, /* Flags common to all filesystems. */ 1255 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1256 ) 1257 { 1258 struct export_args export; 1259 struct o2export_args o2export; 1260 struct vnode *rootvp; 1261 void *bufp; 1262 struct mount *mp; 1263 int error, export_error, i, len; 1264 uint64_t flag; 1265 gid_t *grps; 1266 1267 ASSERT_VOP_ELOCKED(vp, __func__); 1268 KASSERT((fsflags & MNT_UPDATE) != 0, ("MNT_UPDATE should be here")); 1269 mp = vp->v_mount; 1270 1271 if ((vp->v_vflag & VV_ROOT) == 0) { 1272 if (vfs_copyopt(*optlist, "export", &export, sizeof(export)) 1273 == 0) 1274 error = EXDEV; 1275 else 1276 error = EINVAL; 1277 vput(vp); 1278 return (error); 1279 } 1280 1281 /* 1282 * We only allow the filesystem to be reloaded if it 1283 * is currently mounted read-only. 1284 */ 1285 flag = mp->mnt_flag; 1286 if ((fsflags & MNT_RELOAD) != 0 && (flag & MNT_RDONLY) == 0) { 1287 vput(vp); 1288 return (EOPNOTSUPP); /* Needs translation */ 1289 } 1290 /* 1291 * Only privileged root, or (if MNT_USER is set) the user that 1292 * did the original mount is permitted to update it. 1293 */ 1294 error = vfs_suser(mp, td); 1295 if (error != 0) { 1296 vput(vp); 1297 return (error); 1298 } 1299 if (vfs_busy(mp, MBF_NOWAIT)) { 1300 vput(vp); 1301 return (EBUSY); 1302 } 1303 VI_LOCK(vp); 1304 if ((vp->v_iflag & VI_MOUNT) != 0 || vp->v_mountedhere != NULL) { 1305 VI_UNLOCK(vp); 1306 vfs_unbusy(mp); 1307 vput(vp); 1308 return (EBUSY); 1309 } 1310 vp->v_iflag |= VI_MOUNT; 1311 VI_UNLOCK(vp); 1312 VOP_UNLOCK(vp); 1313 1314 vfs_op_enter(mp); 1315 vn_seqc_write_begin(vp); 1316 1317 rootvp = NULL; 1318 MNT_ILOCK(mp); 1319 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1320 MNT_IUNLOCK(mp); 1321 error = EBUSY; 1322 goto end; 1323 } 1324 mp->mnt_flag &= ~MNT_UPDATEMASK; 1325 mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | 1326 MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY); 1327 if ((mp->mnt_flag & MNT_ASYNC) == 0) 1328 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1329 rootvp = vfs_cache_root_clear(mp); 1330 MNT_IUNLOCK(mp); 1331 mp->mnt_optnew = *optlist; 1332 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 1333 1334 /* 1335 * Mount the filesystem. 1336 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1337 * get. No freeing of cn_pnbuf. 1338 */ 1339 error = VFS_MOUNT(mp); 1340 1341 export_error = 0; 1342 /* Process the export option. */ 1343 if (error == 0 && vfs_getopt(mp->mnt_optnew, "export", &bufp, 1344 &len) == 0) { 1345 /* Assume that there is only 1 ABI for each length. */ 1346 switch (len) { 1347 case (sizeof(struct oexport_args)): 1348 bzero(&o2export, sizeof(o2export)); 1349 /* FALLTHROUGH */ 1350 case (sizeof(o2export)): 1351 bcopy(bufp, &o2export, len); 1352 export.ex_flags = (uint64_t)o2export.ex_flags; 1353 export.ex_root = o2export.ex_root; 1354 export.ex_uid = o2export.ex_anon.cr_uid; 1355 export.ex_groups = NULL; 1356 export.ex_ngroups = o2export.ex_anon.cr_ngroups; 1357 if (export.ex_ngroups > 0) { 1358 if (export.ex_ngroups <= XU_NGROUPS) { 1359 export.ex_groups = malloc( 1360 export.ex_ngroups * sizeof(gid_t), 1361 M_TEMP, M_WAITOK); 1362 for (i = 0; i < export.ex_ngroups; i++) 1363 export.ex_groups[i] = 1364 o2export.ex_anon.cr_groups[i]; 1365 } else 1366 export_error = EINVAL; 1367 } else if (export.ex_ngroups < 0) 1368 export_error = EINVAL; 1369 export.ex_addr = o2export.ex_addr; 1370 export.ex_addrlen = o2export.ex_addrlen; 1371 export.ex_mask = o2export.ex_mask; 1372 export.ex_masklen = o2export.ex_masklen; 1373 export.ex_indexfile = o2export.ex_indexfile; 1374 export.ex_numsecflavors = o2export.ex_numsecflavors; 1375 if (export.ex_numsecflavors < MAXSECFLAVORS) { 1376 for (i = 0; i < export.ex_numsecflavors; i++) 1377 export.ex_secflavors[i] = 1378 o2export.ex_secflavors[i]; 1379 } else 1380 export_error = EINVAL; 1381 if (export_error == 0) 1382 export_error = vfs_export(mp, &export); 1383 free(export.ex_groups, M_TEMP); 1384 break; 1385 case (sizeof(export)): 1386 bcopy(bufp, &export, len); 1387 grps = NULL; 1388 if (export.ex_ngroups > 0) { 1389 if (export.ex_ngroups <= NGROUPS_MAX) { 1390 grps = malloc(export.ex_ngroups * 1391 sizeof(gid_t), M_TEMP, M_WAITOK); 1392 export_error = copyin(export.ex_groups, 1393 grps, export.ex_ngroups * 1394 sizeof(gid_t)); 1395 if (export_error == 0) 1396 export.ex_groups = grps; 1397 } else 1398 export_error = EINVAL; 1399 } else if (export.ex_ngroups == 0) 1400 export.ex_groups = NULL; 1401 else 1402 export_error = EINVAL; 1403 if (export_error == 0) 1404 export_error = vfs_export(mp, &export); 1405 free(grps, M_TEMP); 1406 break; 1407 default: 1408 export_error = EINVAL; 1409 break; 1410 } 1411 } 1412 1413 MNT_ILOCK(mp); 1414 if (error == 0) { 1415 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | 1416 MNT_SNAPSHOT); 1417 } else { 1418 /* 1419 * If we fail, restore old mount flags. MNT_QUOTA is special, 1420 * because it is not part of MNT_UPDATEMASK, but it could have 1421 * changed in the meantime if quotactl(2) was called. 1422 * All in all we want current value of MNT_QUOTA, not the old 1423 * one. 1424 */ 1425 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA); 1426 } 1427 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 1428 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 1429 mp->mnt_kern_flag |= MNTK_ASYNC; 1430 else 1431 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1432 MNT_IUNLOCK(mp); 1433 1434 if (error != 0) 1435 goto end; 1436 1437 mount_devctl_event("REMOUNT", mp, true); 1438 if (mp->mnt_opt != NULL) 1439 vfs_freeopts(mp->mnt_opt); 1440 mp->mnt_opt = mp->mnt_optnew; 1441 *optlist = NULL; 1442 (void)VFS_STATFS(mp, &mp->mnt_stat); 1443 /* 1444 * Prevent external consumers of mount options from reading 1445 * mnt_optnew. 1446 */ 1447 mp->mnt_optnew = NULL; 1448 1449 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1450 vfs_allocate_syncvnode(mp); 1451 else 1452 vfs_deallocate_syncvnode(mp); 1453 end: 1454 vfs_op_exit(mp); 1455 if (rootvp != NULL) { 1456 vn_seqc_write_end(rootvp); 1457 vrele(rootvp); 1458 } 1459 vn_seqc_write_end(vp); 1460 vfs_unbusy(mp); 1461 VI_LOCK(vp); 1462 vp->v_iflag &= ~VI_MOUNT; 1463 VI_UNLOCK(vp); 1464 vrele(vp); 1465 return (error != 0 ? error : export_error); 1466 } 1467 1468 /* 1469 * vfs_domount(): actually attempt a filesystem mount. 1470 */ 1471 static int 1472 vfs_domount( 1473 struct thread *td, /* Calling thread. */ 1474 const char *fstype, /* Filesystem type. */ 1475 char *fspath, /* Mount path. */ 1476 uint64_t fsflags, /* Flags common to all filesystems. */ 1477 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1478 ) 1479 { 1480 struct vfsconf *vfsp; 1481 struct nameidata nd; 1482 struct vnode *vp; 1483 char *pathbuf; 1484 int error; 1485 1486 /* 1487 * Be ultra-paranoid about making sure the type and fspath 1488 * variables will fit in our mp buffers, including the 1489 * terminating NUL. 1490 */ 1491 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 1492 return (ENAMETOOLONG); 1493 1494 if (jailed(td->td_ucred) || usermount == 0) { 1495 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0) 1496 return (error); 1497 } 1498 1499 /* 1500 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 1501 */ 1502 if (fsflags & MNT_EXPORTED) { 1503 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED); 1504 if (error) 1505 return (error); 1506 } 1507 if (fsflags & MNT_SUIDDIR) { 1508 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR); 1509 if (error) 1510 return (error); 1511 } 1512 /* 1513 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users. 1514 */ 1515 if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) { 1516 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0) 1517 fsflags |= MNT_NOSUID | MNT_USER; 1518 } 1519 1520 /* Load KLDs before we lock the covered vnode to avoid reversals. */ 1521 vfsp = NULL; 1522 if ((fsflags & MNT_UPDATE) == 0) { 1523 /* Don't try to load KLDs if we're mounting the root. */ 1524 if (fsflags & MNT_ROOTFS) { 1525 if ((vfsp = vfs_byname(fstype)) == NULL) 1526 return (ENODEV); 1527 } else { 1528 if ((vfsp = vfs_byname_kld(fstype, td, &error)) == NULL) 1529 return (error); 1530 } 1531 } 1532 1533 /* 1534 * Get vnode to be covered or mount point's vnode in case of MNT_UPDATE. 1535 */ 1536 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_SYSSPACE, 1537 fspath); 1538 error = namei(&nd); 1539 if (error != 0) 1540 return (error); 1541 NDFREE_PNBUF(&nd); 1542 vp = nd.ni_vp; 1543 if ((fsflags & MNT_UPDATE) == 0) { 1544 if ((vp->v_vflag & VV_ROOT) != 0 && 1545 (fsflags & MNT_NOCOVER) != 0) { 1546 vput(vp); 1547 return (EBUSY); 1548 } 1549 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1550 strcpy(pathbuf, fspath); 1551 error = vn_path_to_global_path(td, vp, pathbuf, MNAMELEN); 1552 if (error == 0) { 1553 error = vfs_domount_first(td, vfsp, pathbuf, vp, 1554 fsflags, optlist); 1555 } 1556 free(pathbuf, M_TEMP); 1557 } else 1558 error = vfs_domount_update(td, vp, fsflags, optlist); 1559 1560 return (error); 1561 } 1562 1563 /* 1564 * Unmount a filesystem. 1565 * 1566 * Note: unmount takes a path to the vnode mounted on as argument, not 1567 * special file (as before). 1568 */ 1569 #ifndef _SYS_SYSPROTO_H_ 1570 struct unmount_args { 1571 char *path; 1572 int flags; 1573 }; 1574 #endif 1575 /* ARGSUSED */ 1576 int 1577 sys_unmount(struct thread *td, struct unmount_args *uap) 1578 { 1579 1580 return (kern_unmount(td, uap->path, uap->flags)); 1581 } 1582 1583 int 1584 kern_unmount(struct thread *td, const char *path, int flags) 1585 { 1586 struct nameidata nd; 1587 struct mount *mp; 1588 char *fsidbuf, *pathbuf; 1589 fsid_t fsid; 1590 int error; 1591 1592 AUDIT_ARG_VALUE(flags); 1593 if (jailed(td->td_ucred) || usermount == 0) { 1594 error = priv_check(td, PRIV_VFS_UNMOUNT); 1595 if (error) 1596 return (error); 1597 } 1598 1599 if (flags & MNT_BYFSID) { 1600 fsidbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1601 error = copyinstr(path, fsidbuf, MNAMELEN, NULL); 1602 if (error) { 1603 free(fsidbuf, M_TEMP); 1604 return (error); 1605 } 1606 1607 AUDIT_ARG_TEXT(fsidbuf); 1608 /* Decode the filesystem ID. */ 1609 if (sscanf(fsidbuf, "FSID:%d:%d", &fsid.val[0], &fsid.val[1]) != 2) { 1610 free(fsidbuf, M_TEMP); 1611 return (EINVAL); 1612 } 1613 1614 mp = vfs_getvfs(&fsid); 1615 free(fsidbuf, M_TEMP); 1616 if (mp == NULL) { 1617 return (ENOENT); 1618 } 1619 } else { 1620 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1621 error = copyinstr(path, pathbuf, MNAMELEN, NULL); 1622 if (error) { 1623 free(pathbuf, M_TEMP); 1624 return (error); 1625 } 1626 1627 /* 1628 * Try to find global path for path argument. 1629 */ 1630 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, 1631 UIO_SYSSPACE, pathbuf); 1632 if (namei(&nd) == 0) { 1633 NDFREE_PNBUF(&nd); 1634 error = vn_path_to_global_path(td, nd.ni_vp, pathbuf, 1635 MNAMELEN); 1636 if (error == 0) 1637 vput(nd.ni_vp); 1638 } 1639 mtx_lock(&mountlist_mtx); 1640 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1641 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) { 1642 vfs_ref(mp); 1643 break; 1644 } 1645 } 1646 mtx_unlock(&mountlist_mtx); 1647 free(pathbuf, M_TEMP); 1648 if (mp == NULL) { 1649 /* 1650 * Previously we returned ENOENT for a nonexistent path and 1651 * EINVAL for a non-mountpoint. We cannot tell these apart 1652 * now, so in the !MNT_BYFSID case return the more likely 1653 * EINVAL for compatibility. 1654 */ 1655 return (EINVAL); 1656 } 1657 } 1658 1659 /* 1660 * Don't allow unmounting the root filesystem. 1661 */ 1662 if (mp->mnt_flag & MNT_ROOTFS) { 1663 vfs_rel(mp); 1664 return (EINVAL); 1665 } 1666 error = dounmount(mp, flags, td); 1667 return (error); 1668 } 1669 1670 /* 1671 * Return error if any of the vnodes, ignoring the root vnode 1672 * and the syncer vnode, have non-zero usecount. 1673 * 1674 * This function is purely advisory - it can return false positives 1675 * and negatives. 1676 */ 1677 static int 1678 vfs_check_usecounts(struct mount *mp) 1679 { 1680 struct vnode *vp, *mvp; 1681 1682 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 1683 if ((vp->v_vflag & VV_ROOT) == 0 && vp->v_type != VNON && 1684 vp->v_usecount != 0) { 1685 VI_UNLOCK(vp); 1686 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 1687 return (EBUSY); 1688 } 1689 VI_UNLOCK(vp); 1690 } 1691 1692 return (0); 1693 } 1694 1695 static void 1696 dounmount_cleanup(struct mount *mp, struct vnode *coveredvp, int mntkflags) 1697 { 1698 1699 mtx_assert(MNT_MTX(mp), MA_OWNED); 1700 mp->mnt_kern_flag &= ~mntkflags; 1701 if ((mp->mnt_kern_flag & MNTK_MWAIT) != 0) { 1702 mp->mnt_kern_flag &= ~MNTK_MWAIT; 1703 wakeup(mp); 1704 } 1705 vfs_op_exit_locked(mp); 1706 MNT_IUNLOCK(mp); 1707 if (coveredvp != NULL) { 1708 VOP_UNLOCK(coveredvp); 1709 vdrop(coveredvp); 1710 } 1711 vn_finished_write(mp); 1712 vfs_rel(mp); 1713 } 1714 1715 /* 1716 * There are various reference counters associated with the mount point. 1717 * Normally it is permitted to modify them without taking the mnt ilock, 1718 * but this behavior can be temporarily disabled if stable value is needed 1719 * or callers are expected to block (e.g. to not allow new users during 1720 * forced unmount). 1721 */ 1722 void 1723 vfs_op_enter(struct mount *mp) 1724 { 1725 struct mount_pcpu *mpcpu; 1726 int cpu; 1727 1728 MNT_ILOCK(mp); 1729 mp->mnt_vfs_ops++; 1730 if (mp->mnt_vfs_ops > 1) { 1731 MNT_IUNLOCK(mp); 1732 return; 1733 } 1734 vfs_op_barrier_wait(mp); 1735 CPU_FOREACH(cpu) { 1736 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1737 1738 mp->mnt_ref += mpcpu->mntp_ref; 1739 mpcpu->mntp_ref = 0; 1740 1741 mp->mnt_lockref += mpcpu->mntp_lockref; 1742 mpcpu->mntp_lockref = 0; 1743 1744 mp->mnt_writeopcount += mpcpu->mntp_writeopcount; 1745 mpcpu->mntp_writeopcount = 0; 1746 } 1747 MPASSERT(mp->mnt_ref > 0 && mp->mnt_lockref >= 0 && 1748 mp->mnt_writeopcount >= 0, mp, 1749 ("invalid count(s): ref %d lockref %d writeopcount %d", 1750 mp->mnt_ref, mp->mnt_lockref, mp->mnt_writeopcount)); 1751 MNT_IUNLOCK(mp); 1752 vfs_assert_mount_counters(mp); 1753 } 1754 1755 void 1756 vfs_op_exit_locked(struct mount *mp) 1757 { 1758 1759 mtx_assert(MNT_MTX(mp), MA_OWNED); 1760 1761 MPASSERT(mp->mnt_vfs_ops > 0, mp, 1762 ("invalid vfs_ops count %d", mp->mnt_vfs_ops)); 1763 MPASSERT(mp->mnt_vfs_ops > 1 || 1764 (mp->mnt_kern_flag & (MNTK_UNMOUNT | MNTK_SUSPEND)) == 0, mp, 1765 ("vfs_ops too low %d in unmount or suspend", mp->mnt_vfs_ops)); 1766 mp->mnt_vfs_ops--; 1767 } 1768 1769 void 1770 vfs_op_exit(struct mount *mp) 1771 { 1772 1773 MNT_ILOCK(mp); 1774 vfs_op_exit_locked(mp); 1775 MNT_IUNLOCK(mp); 1776 } 1777 1778 struct vfs_op_barrier_ipi { 1779 struct mount *mp; 1780 struct smp_rendezvous_cpus_retry_arg srcra; 1781 }; 1782 1783 static void 1784 vfs_op_action_func(void *arg) 1785 { 1786 struct vfs_op_barrier_ipi *vfsopipi; 1787 struct mount *mp; 1788 1789 vfsopipi = __containerof(arg, struct vfs_op_barrier_ipi, srcra); 1790 mp = vfsopipi->mp; 1791 1792 if (!vfs_op_thread_entered(mp)) 1793 smp_rendezvous_cpus_done(arg); 1794 } 1795 1796 static void 1797 vfs_op_wait_func(void *arg, int cpu) 1798 { 1799 struct vfs_op_barrier_ipi *vfsopipi; 1800 struct mount *mp; 1801 struct mount_pcpu *mpcpu; 1802 1803 vfsopipi = __containerof(arg, struct vfs_op_barrier_ipi, srcra); 1804 mp = vfsopipi->mp; 1805 1806 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1807 while (atomic_load_int(&mpcpu->mntp_thread_in_ops)) 1808 cpu_spinwait(); 1809 } 1810 1811 void 1812 vfs_op_barrier_wait(struct mount *mp) 1813 { 1814 struct vfs_op_barrier_ipi vfsopipi; 1815 1816 vfsopipi.mp = mp; 1817 1818 smp_rendezvous_cpus_retry(all_cpus, 1819 smp_no_rendezvous_barrier, 1820 vfs_op_action_func, 1821 smp_no_rendezvous_barrier, 1822 vfs_op_wait_func, 1823 &vfsopipi.srcra); 1824 } 1825 1826 #ifdef DIAGNOSTIC 1827 void 1828 vfs_assert_mount_counters(struct mount *mp) 1829 { 1830 struct mount_pcpu *mpcpu; 1831 int cpu; 1832 1833 if (mp->mnt_vfs_ops == 0) 1834 return; 1835 1836 CPU_FOREACH(cpu) { 1837 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1838 if (mpcpu->mntp_ref != 0 || 1839 mpcpu->mntp_lockref != 0 || 1840 mpcpu->mntp_writeopcount != 0) 1841 vfs_dump_mount_counters(mp); 1842 } 1843 } 1844 1845 void 1846 vfs_dump_mount_counters(struct mount *mp) 1847 { 1848 struct mount_pcpu *mpcpu; 1849 int ref, lockref, writeopcount; 1850 int cpu; 1851 1852 printf("%s: mp %p vfs_ops %d\n", __func__, mp, mp->mnt_vfs_ops); 1853 1854 printf(" ref : "); 1855 ref = mp->mnt_ref; 1856 CPU_FOREACH(cpu) { 1857 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1858 printf("%d ", mpcpu->mntp_ref); 1859 ref += mpcpu->mntp_ref; 1860 } 1861 printf("\n"); 1862 printf(" lockref : "); 1863 lockref = mp->mnt_lockref; 1864 CPU_FOREACH(cpu) { 1865 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1866 printf("%d ", mpcpu->mntp_lockref); 1867 lockref += mpcpu->mntp_lockref; 1868 } 1869 printf("\n"); 1870 printf("writeopcount: "); 1871 writeopcount = mp->mnt_writeopcount; 1872 CPU_FOREACH(cpu) { 1873 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1874 printf("%d ", mpcpu->mntp_writeopcount); 1875 writeopcount += mpcpu->mntp_writeopcount; 1876 } 1877 printf("\n"); 1878 1879 printf("counter struct total\n"); 1880 printf("ref %-5d %-5d\n", mp->mnt_ref, ref); 1881 printf("lockref %-5d %-5d\n", mp->mnt_lockref, lockref); 1882 printf("writeopcount %-5d %-5d\n", mp->mnt_writeopcount, writeopcount); 1883 1884 panic("invalid counts on struct mount"); 1885 } 1886 #endif 1887 1888 int 1889 vfs_mount_fetch_counter(struct mount *mp, enum mount_counter which) 1890 { 1891 struct mount_pcpu *mpcpu; 1892 int cpu, sum; 1893 1894 switch (which) { 1895 case MNT_COUNT_REF: 1896 sum = mp->mnt_ref; 1897 break; 1898 case MNT_COUNT_LOCKREF: 1899 sum = mp->mnt_lockref; 1900 break; 1901 case MNT_COUNT_WRITEOPCOUNT: 1902 sum = mp->mnt_writeopcount; 1903 break; 1904 } 1905 1906 CPU_FOREACH(cpu) { 1907 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1908 switch (which) { 1909 case MNT_COUNT_REF: 1910 sum += mpcpu->mntp_ref; 1911 break; 1912 case MNT_COUNT_LOCKREF: 1913 sum += mpcpu->mntp_lockref; 1914 break; 1915 case MNT_COUNT_WRITEOPCOUNT: 1916 sum += mpcpu->mntp_writeopcount; 1917 break; 1918 } 1919 } 1920 return (sum); 1921 } 1922 1923 static bool 1924 deferred_unmount_enqueue(struct mount *mp, uint64_t flags, bool requeue, 1925 int timeout_ticks) 1926 { 1927 bool enqueued; 1928 1929 enqueued = false; 1930 mtx_lock(&deferred_unmount_lock); 1931 if ((mp->mnt_taskqueue_flags & MNT_DEFERRED) == 0 || requeue) { 1932 mp->mnt_taskqueue_flags = flags | MNT_DEFERRED; 1933 STAILQ_INSERT_TAIL(&deferred_unmount_list, mp, 1934 mnt_taskqueue_link); 1935 enqueued = true; 1936 } 1937 mtx_unlock(&deferred_unmount_lock); 1938 1939 if (enqueued) { 1940 taskqueue_enqueue_timeout(taskqueue_deferred_unmount, 1941 &deferred_unmount_task, timeout_ticks); 1942 } 1943 1944 return (enqueued); 1945 } 1946 1947 /* 1948 * Taskqueue handler for processing async/recursive unmounts 1949 */ 1950 static void 1951 vfs_deferred_unmount(void *argi __unused, int pending __unused) 1952 { 1953 STAILQ_HEAD(, mount) local_unmounts; 1954 uint64_t flags; 1955 struct mount *mp, *tmp; 1956 int error; 1957 unsigned int retries; 1958 bool unmounted; 1959 1960 STAILQ_INIT(&local_unmounts); 1961 mtx_lock(&deferred_unmount_lock); 1962 STAILQ_CONCAT(&local_unmounts, &deferred_unmount_list); 1963 mtx_unlock(&deferred_unmount_lock); 1964 1965 STAILQ_FOREACH_SAFE(mp, &local_unmounts, mnt_taskqueue_link, tmp) { 1966 flags = mp->mnt_taskqueue_flags; 1967 KASSERT((flags & MNT_DEFERRED) != 0, 1968 ("taskqueue unmount without MNT_DEFERRED")); 1969 error = dounmount(mp, flags, curthread); 1970 if (error != 0) { 1971 MNT_ILOCK(mp); 1972 unmounted = ((mp->mnt_kern_flag & MNTK_REFEXPIRE) != 0); 1973 MNT_IUNLOCK(mp); 1974 1975 /* 1976 * The deferred unmount thread is the only thread that 1977 * modifies the retry counts, so locking/atomics aren't 1978 * needed here. 1979 */ 1980 retries = (mp->mnt_unmount_retries)++; 1981 deferred_unmount_total_retries++; 1982 if (!unmounted && retries < deferred_unmount_retry_limit) { 1983 deferred_unmount_enqueue(mp, flags, true, 1984 -deferred_unmount_retry_delay_hz); 1985 } else { 1986 if (retries >= deferred_unmount_retry_limit) { 1987 printf("giving up on deferred unmount " 1988 "of %s after %d retries, error %d\n", 1989 mp->mnt_stat.f_mntonname, retries, error); 1990 } 1991 vfs_rel(mp); 1992 } 1993 } 1994 } 1995 } 1996 1997 /* 1998 * Do the actual filesystem unmount. 1999 */ 2000 int 2001 dounmount(struct mount *mp, uint64_t flags, struct thread *td) 2002 { 2003 struct mount_upper_node *upper; 2004 struct vnode *coveredvp, *rootvp; 2005 int error; 2006 uint64_t async_flag; 2007 int mnt_gen_r; 2008 unsigned int retries; 2009 2010 KASSERT((flags & MNT_DEFERRED) == 0 || 2011 (flags & (MNT_RECURSE | MNT_FORCE)) == (MNT_RECURSE | MNT_FORCE), 2012 ("MNT_DEFERRED requires MNT_RECURSE | MNT_FORCE")); 2013 2014 /* 2015 * If the caller has explicitly requested the unmount to be handled by 2016 * the taskqueue and we're not already in taskqueue context, queue 2017 * up the unmount request and exit. This is done prior to any 2018 * credential checks; MNT_DEFERRED should be used only for kernel- 2019 * initiated unmounts and will therefore be processed with the 2020 * (kernel) credentials of the taskqueue thread. Still, callers 2021 * should be sure this is the behavior they want. 2022 */ 2023 if ((flags & MNT_DEFERRED) != 0 && 2024 taskqueue_member(taskqueue_deferred_unmount, curthread) == 0) { 2025 if (!deferred_unmount_enqueue(mp, flags, false, 0)) 2026 vfs_rel(mp); 2027 return (EINPROGRESS); 2028 } 2029 2030 /* 2031 * Only privileged root, or (if MNT_USER is set) the user that did the 2032 * original mount is permitted to unmount this filesystem. 2033 * This check should be made prior to queueing up any recursive 2034 * unmounts of upper filesystems. Those unmounts will be executed 2035 * with kernel thread credentials and are expected to succeed, so 2036 * we must at least ensure the originating context has sufficient 2037 * privilege to unmount the base filesystem before proceeding with 2038 * the uppers. 2039 */ 2040 error = vfs_suser(mp, td); 2041 if (error != 0) { 2042 KASSERT((flags & MNT_DEFERRED) == 0, 2043 ("taskqueue unmount with insufficient privilege")); 2044 vfs_rel(mp); 2045 return (error); 2046 } 2047 2048 if (recursive_forced_unmount && ((flags & MNT_FORCE) != 0)) 2049 flags |= MNT_RECURSE; 2050 2051 if ((flags & MNT_RECURSE) != 0) { 2052 KASSERT((flags & MNT_FORCE) != 0, 2053 ("MNT_RECURSE requires MNT_FORCE")); 2054 2055 MNT_ILOCK(mp); 2056 /* 2057 * Set MNTK_RECURSE to prevent new upper mounts from being 2058 * added, and note that an operation on the uppers list is in 2059 * progress. This will ensure that unregistration from the 2060 * uppers list, and therefore any pending unmount of the upper 2061 * FS, can't complete until after we finish walking the list. 2062 */ 2063 mp->mnt_kern_flag |= MNTK_RECURSE; 2064 mp->mnt_upper_pending++; 2065 TAILQ_FOREACH(upper, &mp->mnt_uppers, mnt_upper_link) { 2066 retries = upper->mp->mnt_unmount_retries; 2067 if (retries > deferred_unmount_retry_limit) { 2068 error = EBUSY; 2069 continue; 2070 } 2071 MNT_IUNLOCK(mp); 2072 2073 vfs_ref(upper->mp); 2074 if (!deferred_unmount_enqueue(upper->mp, flags, 2075 false, 0)) 2076 vfs_rel(upper->mp); 2077 MNT_ILOCK(mp); 2078 } 2079 mp->mnt_upper_pending--; 2080 if ((mp->mnt_kern_flag & MNTK_UPPER_WAITER) != 0 && 2081 mp->mnt_upper_pending == 0) { 2082 mp->mnt_kern_flag &= ~MNTK_UPPER_WAITER; 2083 wakeup(&mp->mnt_uppers); 2084 } 2085 2086 /* 2087 * If we're not on the taskqueue, wait until the uppers list 2088 * is drained before proceeding with unmount. Otherwise, if 2089 * we are on the taskqueue and there are still pending uppers, 2090 * just re-enqueue on the end of the taskqueue. 2091 */ 2092 if ((flags & MNT_DEFERRED) == 0) { 2093 while (error == 0 && !TAILQ_EMPTY(&mp->mnt_uppers)) { 2094 mp->mnt_kern_flag |= MNTK_TASKQUEUE_WAITER; 2095 error = msleep(&mp->mnt_taskqueue_link, 2096 MNT_MTX(mp), PCATCH, "umntqw", 0); 2097 } 2098 if (error != 0) { 2099 MNT_REL(mp); 2100 MNT_IUNLOCK(mp); 2101 return (error); 2102 } 2103 } else if (!TAILQ_EMPTY(&mp->mnt_uppers)) { 2104 MNT_IUNLOCK(mp); 2105 if (error == 0) 2106 deferred_unmount_enqueue(mp, flags, true, 0); 2107 return (error); 2108 } 2109 MNT_IUNLOCK(mp); 2110 KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers not empty")); 2111 } 2112 2113 /* Allow the taskqueue to safely re-enqueue on failure */ 2114 if ((flags & MNT_DEFERRED) != 0) 2115 vfs_ref(mp); 2116 2117 if ((coveredvp = mp->mnt_vnodecovered) != NULL) { 2118 mnt_gen_r = mp->mnt_gen; 2119 VI_LOCK(coveredvp); 2120 vholdl(coveredvp); 2121 vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY); 2122 /* 2123 * Check for mp being unmounted while waiting for the 2124 * covered vnode lock. 2125 */ 2126 if (coveredvp->v_mountedhere != mp || 2127 coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) { 2128 VOP_UNLOCK(coveredvp); 2129 vdrop(coveredvp); 2130 vfs_rel(mp); 2131 return (EBUSY); 2132 } 2133 } 2134 2135 vfs_op_enter(mp); 2136 2137 vn_start_write(NULL, &mp, V_WAIT); 2138 MNT_ILOCK(mp); 2139 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 || 2140 (mp->mnt_flag & MNT_UPDATE) != 0 || 2141 !TAILQ_EMPTY(&mp->mnt_uppers)) { 2142 dounmount_cleanup(mp, coveredvp, 0); 2143 return (EBUSY); 2144 } 2145 mp->mnt_kern_flag |= MNTK_UNMOUNT; 2146 rootvp = vfs_cache_root_clear(mp); 2147 if (coveredvp != NULL) 2148 vn_seqc_write_begin(coveredvp); 2149 if (flags & MNT_NONBUSY) { 2150 MNT_IUNLOCK(mp); 2151 error = vfs_check_usecounts(mp); 2152 MNT_ILOCK(mp); 2153 if (error != 0) { 2154 vn_seqc_write_end(coveredvp); 2155 dounmount_cleanup(mp, coveredvp, MNTK_UNMOUNT); 2156 if (rootvp != NULL) { 2157 vn_seqc_write_end(rootvp); 2158 vrele(rootvp); 2159 } 2160 return (error); 2161 } 2162 } 2163 /* Allow filesystems to detect that a forced unmount is in progress. */ 2164 if (flags & MNT_FORCE) { 2165 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 2166 MNT_IUNLOCK(mp); 2167 /* 2168 * Must be done after setting MNTK_UNMOUNTF and before 2169 * waiting for mnt_lockref to become 0. 2170 */ 2171 VFS_PURGE(mp); 2172 MNT_ILOCK(mp); 2173 } 2174 error = 0; 2175 if (mp->mnt_lockref) { 2176 mp->mnt_kern_flag |= MNTK_DRAINING; 2177 error = msleep(&mp->mnt_lockref, MNT_MTX(mp), PVFS, 2178 "mount drain", 0); 2179 } 2180 MNT_IUNLOCK(mp); 2181 KASSERT(mp->mnt_lockref == 0, 2182 ("%s: invalid lock refcount in the drain path @ %s:%d", 2183 __func__, __FILE__, __LINE__)); 2184 KASSERT(error == 0, 2185 ("%s: invalid return value for msleep in the drain path @ %s:%d", 2186 __func__, __FILE__, __LINE__)); 2187 2188 /* 2189 * We want to keep the vnode around so that we can vn_seqc_write_end 2190 * after we are done with unmount. Downgrade our reference to a mere 2191 * hold count so that we don't interefere with anything. 2192 */ 2193 if (rootvp != NULL) { 2194 vhold(rootvp); 2195 vrele(rootvp); 2196 } 2197 2198 if (mp->mnt_flag & MNT_EXPUBLIC) 2199 vfs_setpublicfs(NULL, NULL, NULL); 2200 2201 vfs_periodic(mp, MNT_WAIT); 2202 MNT_ILOCK(mp); 2203 async_flag = mp->mnt_flag & MNT_ASYNC; 2204 mp->mnt_flag &= ~MNT_ASYNC; 2205 mp->mnt_kern_flag &= ~MNTK_ASYNC; 2206 MNT_IUNLOCK(mp); 2207 vfs_deallocate_syncvnode(mp); 2208 error = VFS_UNMOUNT(mp, flags); 2209 vn_finished_write(mp); 2210 vfs_rel(mp); 2211 /* 2212 * If we failed to flush the dirty blocks for this mount point, 2213 * undo all the cdir/rdir and rootvnode changes we made above. 2214 * Unless we failed to do so because the device is reporting that 2215 * it doesn't exist anymore. 2216 */ 2217 if (error && error != ENXIO) { 2218 MNT_ILOCK(mp); 2219 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 2220 MNT_IUNLOCK(mp); 2221 vfs_allocate_syncvnode(mp); 2222 MNT_ILOCK(mp); 2223 } 2224 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 2225 mp->mnt_flag |= async_flag; 2226 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 2227 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 2228 mp->mnt_kern_flag |= MNTK_ASYNC; 2229 if (mp->mnt_kern_flag & MNTK_MWAIT) { 2230 mp->mnt_kern_flag &= ~MNTK_MWAIT; 2231 wakeup(mp); 2232 } 2233 vfs_op_exit_locked(mp); 2234 MNT_IUNLOCK(mp); 2235 if (coveredvp) { 2236 vn_seqc_write_end(coveredvp); 2237 VOP_UNLOCK(coveredvp); 2238 vdrop(coveredvp); 2239 } 2240 if (rootvp != NULL) { 2241 vn_seqc_write_end(rootvp); 2242 vdrop(rootvp); 2243 } 2244 return (error); 2245 } 2246 2247 mtx_lock(&mountlist_mtx); 2248 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2249 mtx_unlock(&mountlist_mtx); 2250 EVENTHANDLER_DIRECT_INVOKE(vfs_unmounted, mp, td); 2251 if (coveredvp != NULL) { 2252 VI_LOCK(coveredvp); 2253 vn_irflag_unset_locked(coveredvp, VIRF_MOUNTPOINT); 2254 coveredvp->v_mountedhere = NULL; 2255 vn_seqc_write_end_locked(coveredvp); 2256 VI_UNLOCK(coveredvp); 2257 VOP_UNLOCK(coveredvp); 2258 vdrop(coveredvp); 2259 } 2260 mount_devctl_event("UNMOUNT", mp, false); 2261 if (rootvp != NULL) { 2262 vn_seqc_write_end(rootvp); 2263 vdrop(rootvp); 2264 } 2265 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 2266 if (rootvnode != NULL && mp == rootvnode->v_mount) { 2267 vrele(rootvnode); 2268 rootvnode = NULL; 2269 } 2270 if (mp == rootdevmp) 2271 rootdevmp = NULL; 2272 if ((flags & MNT_DEFERRED) != 0) 2273 vfs_rel(mp); 2274 vfs_mount_destroy(mp); 2275 return (0); 2276 } 2277 2278 /* 2279 * Report errors during filesystem mounting. 2280 */ 2281 void 2282 vfs_mount_error(struct mount *mp, const char *fmt, ...) 2283 { 2284 struct vfsoptlist *moptlist = mp->mnt_optnew; 2285 va_list ap; 2286 int error, len; 2287 char *errmsg; 2288 2289 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len); 2290 if (error || errmsg == NULL || len <= 0) 2291 return; 2292 2293 va_start(ap, fmt); 2294 vsnprintf(errmsg, (size_t)len, fmt, ap); 2295 va_end(ap); 2296 } 2297 2298 void 2299 vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...) 2300 { 2301 va_list ap; 2302 int error, len; 2303 char *errmsg; 2304 2305 error = vfs_getopt(opts, "errmsg", (void **)&errmsg, &len); 2306 if (error || errmsg == NULL || len <= 0) 2307 return; 2308 2309 va_start(ap, fmt); 2310 vsnprintf(errmsg, (size_t)len, fmt, ap); 2311 va_end(ap); 2312 } 2313 2314 /* 2315 * --------------------------------------------------------------------- 2316 * Functions for querying mount options/arguments from filesystems. 2317 */ 2318 2319 /* 2320 * Check that no unknown options are given 2321 */ 2322 int 2323 vfs_filteropt(struct vfsoptlist *opts, const char **legal) 2324 { 2325 struct vfsopt *opt; 2326 char errmsg[255]; 2327 const char **t, *p, *q; 2328 int ret = 0; 2329 2330 TAILQ_FOREACH(opt, opts, link) { 2331 p = opt->name; 2332 q = NULL; 2333 if (p[0] == 'n' && p[1] == 'o') 2334 q = p + 2; 2335 for(t = global_opts; *t != NULL; t++) { 2336 if (strcmp(*t, p) == 0) 2337 break; 2338 if (q != NULL) { 2339 if (strcmp(*t, q) == 0) 2340 break; 2341 } 2342 } 2343 if (*t != NULL) 2344 continue; 2345 for(t = legal; *t != NULL; t++) { 2346 if (strcmp(*t, p) == 0) 2347 break; 2348 if (q != NULL) { 2349 if (strcmp(*t, q) == 0) 2350 break; 2351 } 2352 } 2353 if (*t != NULL) 2354 continue; 2355 snprintf(errmsg, sizeof(errmsg), 2356 "mount option <%s> is unknown", p); 2357 ret = EINVAL; 2358 } 2359 if (ret != 0) { 2360 TAILQ_FOREACH(opt, opts, link) { 2361 if (strcmp(opt->name, "errmsg") == 0) { 2362 strncpy((char *)opt->value, errmsg, opt->len); 2363 break; 2364 } 2365 } 2366 if (opt == NULL) 2367 printf("%s\n", errmsg); 2368 } 2369 return (ret); 2370 } 2371 2372 /* 2373 * Get a mount option by its name. 2374 * 2375 * Return 0 if the option was found, ENOENT otherwise. 2376 * If len is non-NULL it will be filled with the length 2377 * of the option. If buf is non-NULL, it will be filled 2378 * with the address of the option. 2379 */ 2380 int 2381 vfs_getopt(struct vfsoptlist *opts, const char *name, void **buf, int *len) 2382 { 2383 struct vfsopt *opt; 2384 2385 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 2386 2387 TAILQ_FOREACH(opt, opts, link) { 2388 if (strcmp(name, opt->name) == 0) { 2389 opt->seen = 1; 2390 if (len != NULL) 2391 *len = opt->len; 2392 if (buf != NULL) 2393 *buf = opt->value; 2394 return (0); 2395 } 2396 } 2397 return (ENOENT); 2398 } 2399 2400 int 2401 vfs_getopt_pos(struct vfsoptlist *opts, const char *name) 2402 { 2403 struct vfsopt *opt; 2404 2405 if (opts == NULL) 2406 return (-1); 2407 2408 TAILQ_FOREACH(opt, opts, link) { 2409 if (strcmp(name, opt->name) == 0) { 2410 opt->seen = 1; 2411 return (opt->pos); 2412 } 2413 } 2414 return (-1); 2415 } 2416 2417 int 2418 vfs_getopt_size(struct vfsoptlist *opts, const char *name, off_t *value) 2419 { 2420 char *opt_value, *vtp; 2421 quad_t iv; 2422 int error, opt_len; 2423 2424 error = vfs_getopt(opts, name, (void **)&opt_value, &opt_len); 2425 if (error != 0) 2426 return (error); 2427 if (opt_len == 0 || opt_value == NULL) 2428 return (EINVAL); 2429 if (opt_value[0] == '\0' || opt_value[opt_len - 1] != '\0') 2430 return (EINVAL); 2431 iv = strtoq(opt_value, &vtp, 0); 2432 if (vtp == opt_value || (vtp[0] != '\0' && vtp[1] != '\0')) 2433 return (EINVAL); 2434 if (iv < 0) 2435 return (EINVAL); 2436 switch (vtp[0]) { 2437 case 't': case 'T': 2438 iv *= 1024; 2439 /* FALLTHROUGH */ 2440 case 'g': case 'G': 2441 iv *= 1024; 2442 /* FALLTHROUGH */ 2443 case 'm': case 'M': 2444 iv *= 1024; 2445 /* FALLTHROUGH */ 2446 case 'k': case 'K': 2447 iv *= 1024; 2448 case '\0': 2449 break; 2450 default: 2451 return (EINVAL); 2452 } 2453 *value = iv; 2454 2455 return (0); 2456 } 2457 2458 char * 2459 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 2460 { 2461 struct vfsopt *opt; 2462 2463 *error = 0; 2464 TAILQ_FOREACH(opt, opts, link) { 2465 if (strcmp(name, opt->name) != 0) 2466 continue; 2467 opt->seen = 1; 2468 if (opt->len == 0 || 2469 ((char *)opt->value)[opt->len - 1] != '\0') { 2470 *error = EINVAL; 2471 return (NULL); 2472 } 2473 return (opt->value); 2474 } 2475 *error = ENOENT; 2476 return (NULL); 2477 } 2478 2479 int 2480 vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w, 2481 uint64_t val) 2482 { 2483 struct vfsopt *opt; 2484 2485 TAILQ_FOREACH(opt, opts, link) { 2486 if (strcmp(name, opt->name) == 0) { 2487 opt->seen = 1; 2488 if (w != NULL) 2489 *w |= val; 2490 return (1); 2491 } 2492 } 2493 if (w != NULL) 2494 *w &= ~val; 2495 return (0); 2496 } 2497 2498 int 2499 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 2500 { 2501 va_list ap; 2502 struct vfsopt *opt; 2503 int ret; 2504 2505 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 2506 2507 TAILQ_FOREACH(opt, opts, link) { 2508 if (strcmp(name, opt->name) != 0) 2509 continue; 2510 opt->seen = 1; 2511 if (opt->len == 0 || opt->value == NULL) 2512 return (0); 2513 if (((char *)opt->value)[opt->len - 1] != '\0') 2514 return (0); 2515 va_start(ap, fmt); 2516 ret = vsscanf(opt->value, fmt, ap); 2517 va_end(ap); 2518 return (ret); 2519 } 2520 return (0); 2521 } 2522 2523 int 2524 vfs_setopt(struct vfsoptlist *opts, const char *name, void *value, int len) 2525 { 2526 struct vfsopt *opt; 2527 2528 TAILQ_FOREACH(opt, opts, link) { 2529 if (strcmp(name, opt->name) != 0) 2530 continue; 2531 opt->seen = 1; 2532 if (opt->value == NULL) 2533 opt->len = len; 2534 else { 2535 if (opt->len != len) 2536 return (EINVAL); 2537 bcopy(value, opt->value, len); 2538 } 2539 return (0); 2540 } 2541 return (ENOENT); 2542 } 2543 2544 int 2545 vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value, int len) 2546 { 2547 struct vfsopt *opt; 2548 2549 TAILQ_FOREACH(opt, opts, link) { 2550 if (strcmp(name, opt->name) != 0) 2551 continue; 2552 opt->seen = 1; 2553 if (opt->value == NULL) 2554 opt->len = len; 2555 else { 2556 if (opt->len < len) 2557 return (EINVAL); 2558 opt->len = len; 2559 bcopy(value, opt->value, len); 2560 } 2561 return (0); 2562 } 2563 return (ENOENT); 2564 } 2565 2566 int 2567 vfs_setopts(struct vfsoptlist *opts, const char *name, const char *value) 2568 { 2569 struct vfsopt *opt; 2570 2571 TAILQ_FOREACH(opt, opts, link) { 2572 if (strcmp(name, opt->name) != 0) 2573 continue; 2574 opt->seen = 1; 2575 if (opt->value == NULL) 2576 opt->len = strlen(value) + 1; 2577 else if (strlcpy(opt->value, value, opt->len) >= opt->len) 2578 return (EINVAL); 2579 return (0); 2580 } 2581 return (ENOENT); 2582 } 2583 2584 /* 2585 * Find and copy a mount option. 2586 * 2587 * The size of the buffer has to be specified 2588 * in len, if it is not the same length as the 2589 * mount option, EINVAL is returned. 2590 * Returns ENOENT if the option is not found. 2591 */ 2592 int 2593 vfs_copyopt(struct vfsoptlist *opts, const char *name, void *dest, int len) 2594 { 2595 struct vfsopt *opt; 2596 2597 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 2598 2599 TAILQ_FOREACH(opt, opts, link) { 2600 if (strcmp(name, opt->name) == 0) { 2601 opt->seen = 1; 2602 if (len != opt->len) 2603 return (EINVAL); 2604 bcopy(opt->value, dest, opt->len); 2605 return (0); 2606 } 2607 } 2608 return (ENOENT); 2609 } 2610 2611 int 2612 __vfs_statfs(struct mount *mp, struct statfs *sbp) 2613 { 2614 /* 2615 * Filesystems only fill in part of the structure for updates, we 2616 * have to read the entirety first to get all content. 2617 */ 2618 if (sbp != &mp->mnt_stat) 2619 memcpy(sbp, &mp->mnt_stat, sizeof(*sbp)); 2620 2621 /* 2622 * Set these in case the underlying filesystem fails to do so. 2623 */ 2624 sbp->f_version = STATFS_VERSION; 2625 sbp->f_namemax = NAME_MAX; 2626 sbp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK; 2627 sbp->f_nvnodelistsize = mp->mnt_nvnodelistsize; 2628 2629 return (mp->mnt_op->vfs_statfs(mp, sbp)); 2630 } 2631 2632 void 2633 vfs_mountedfrom(struct mount *mp, const char *from) 2634 { 2635 2636 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 2637 strlcpy(mp->mnt_stat.f_mntfromname, from, 2638 sizeof mp->mnt_stat.f_mntfromname); 2639 } 2640 2641 /* 2642 * --------------------------------------------------------------------- 2643 * This is the api for building mount args and mounting filesystems from 2644 * inside the kernel. 2645 * 2646 * The API works by accumulation of individual args. First error is 2647 * latched. 2648 * 2649 * XXX: should be documented in new manpage kernel_mount(9) 2650 */ 2651 2652 /* A memory allocation which must be freed when we are done */ 2653 struct mntaarg { 2654 SLIST_ENTRY(mntaarg) next; 2655 }; 2656 2657 /* The header for the mount arguments */ 2658 struct mntarg { 2659 struct iovec *v; 2660 int len; 2661 int error; 2662 SLIST_HEAD(, mntaarg) list; 2663 }; 2664 2665 /* 2666 * Add a boolean argument. 2667 * 2668 * flag is the boolean value. 2669 * name must start with "no". 2670 */ 2671 struct mntarg * 2672 mount_argb(struct mntarg *ma, int flag, const char *name) 2673 { 2674 2675 KASSERT(name[0] == 'n' && name[1] == 'o', 2676 ("mount_argb(...,%s): name must start with 'no'", name)); 2677 2678 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 2679 } 2680 2681 /* 2682 * Add an argument printf style 2683 */ 2684 struct mntarg * 2685 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 2686 { 2687 va_list ap; 2688 struct mntaarg *maa; 2689 struct sbuf *sb; 2690 int len; 2691 2692 if (ma == NULL) { 2693 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2694 SLIST_INIT(&ma->list); 2695 } 2696 if (ma->error) 2697 return (ma); 2698 2699 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2700 M_MOUNT, M_WAITOK); 2701 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2702 ma->v[ma->len].iov_len = strlen(name) + 1; 2703 ma->len++; 2704 2705 sb = sbuf_new_auto(); 2706 va_start(ap, fmt); 2707 sbuf_vprintf(sb, fmt, ap); 2708 va_end(ap); 2709 sbuf_finish(sb); 2710 len = sbuf_len(sb) + 1; 2711 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2712 SLIST_INSERT_HEAD(&ma->list, maa, next); 2713 bcopy(sbuf_data(sb), maa + 1, len); 2714 sbuf_delete(sb); 2715 2716 ma->v[ma->len].iov_base = maa + 1; 2717 ma->v[ma->len].iov_len = len; 2718 ma->len++; 2719 2720 return (ma); 2721 } 2722 2723 /* 2724 * Add an argument which is a userland string. 2725 */ 2726 struct mntarg * 2727 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 2728 { 2729 struct mntaarg *maa; 2730 char *tbuf; 2731 2732 if (val == NULL) 2733 return (ma); 2734 if (ma == NULL) { 2735 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2736 SLIST_INIT(&ma->list); 2737 } 2738 if (ma->error) 2739 return (ma); 2740 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2741 SLIST_INSERT_HEAD(&ma->list, maa, next); 2742 tbuf = (void *)(maa + 1); 2743 ma->error = copyinstr(val, tbuf, len, NULL); 2744 return (mount_arg(ma, name, tbuf, -1)); 2745 } 2746 2747 /* 2748 * Plain argument. 2749 * 2750 * If length is -1, treat value as a C string. 2751 */ 2752 struct mntarg * 2753 mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 2754 { 2755 2756 if (ma == NULL) { 2757 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2758 SLIST_INIT(&ma->list); 2759 } 2760 if (ma->error) 2761 return (ma); 2762 2763 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2764 M_MOUNT, M_WAITOK); 2765 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2766 ma->v[ma->len].iov_len = strlen(name) + 1; 2767 ma->len++; 2768 2769 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 2770 if (len < 0) 2771 ma->v[ma->len].iov_len = strlen(val) + 1; 2772 else 2773 ma->v[ma->len].iov_len = len; 2774 ma->len++; 2775 return (ma); 2776 } 2777 2778 /* 2779 * Free a mntarg structure 2780 */ 2781 static void 2782 free_mntarg(struct mntarg *ma) 2783 { 2784 struct mntaarg *maa; 2785 2786 while (!SLIST_EMPTY(&ma->list)) { 2787 maa = SLIST_FIRST(&ma->list); 2788 SLIST_REMOVE_HEAD(&ma->list, next); 2789 free(maa, M_MOUNT); 2790 } 2791 free(ma->v, M_MOUNT); 2792 free(ma, M_MOUNT); 2793 } 2794 2795 /* 2796 * Mount a filesystem 2797 */ 2798 int 2799 kernel_mount(struct mntarg *ma, uint64_t flags) 2800 { 2801 struct uio auio; 2802 int error; 2803 2804 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 2805 KASSERT(ma->error != 0 || ma->v != NULL, ("kernel_mount NULL ma->v")); 2806 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 2807 2808 error = ma->error; 2809 if (error == 0) { 2810 auio.uio_iov = ma->v; 2811 auio.uio_iovcnt = ma->len; 2812 auio.uio_segflg = UIO_SYSSPACE; 2813 error = vfs_donmount(curthread, flags, &auio); 2814 } 2815 free_mntarg(ma); 2816 return (error); 2817 } 2818 2819 /* Map from mount options to printable formats. */ 2820 static struct mntoptnames optnames[] = { 2821 MNTOPT_NAMES 2822 }; 2823 2824 #define DEVCTL_LEN 1024 2825 static void 2826 mount_devctl_event(const char *type, struct mount *mp, bool donew) 2827 { 2828 const uint8_t *cp; 2829 struct mntoptnames *fp; 2830 struct sbuf sb; 2831 struct statfs *sfp = &mp->mnt_stat; 2832 char *buf; 2833 2834 buf = malloc(DEVCTL_LEN, M_MOUNT, M_NOWAIT); 2835 if (buf == NULL) 2836 return; 2837 sbuf_new(&sb, buf, DEVCTL_LEN, SBUF_FIXEDLEN); 2838 sbuf_cpy(&sb, "mount-point=\""); 2839 devctl_safe_quote_sb(&sb, sfp->f_mntonname); 2840 sbuf_cat(&sb, "\" mount-dev=\""); 2841 devctl_safe_quote_sb(&sb, sfp->f_mntfromname); 2842 sbuf_cat(&sb, "\" mount-type=\""); 2843 devctl_safe_quote_sb(&sb, sfp->f_fstypename); 2844 sbuf_cat(&sb, "\" fsid=0x"); 2845 cp = (const uint8_t *)&sfp->f_fsid.val[0]; 2846 for (int i = 0; i < sizeof(sfp->f_fsid); i++) 2847 sbuf_printf(&sb, "%02x", cp[i]); 2848 sbuf_printf(&sb, " owner=%u flags=\"", sfp->f_owner); 2849 for (fp = optnames; fp->o_opt != 0; fp++) { 2850 if ((mp->mnt_flag & fp->o_opt) != 0) { 2851 sbuf_cat(&sb, fp->o_name); 2852 sbuf_putc(&sb, ';'); 2853 } 2854 } 2855 sbuf_putc(&sb, '"'); 2856 sbuf_finish(&sb); 2857 2858 /* 2859 * Options are not published because the form of the options depends on 2860 * the file system and may include binary data. In addition, they don't 2861 * necessarily provide enough useful information to be actionable when 2862 * devd processes them. 2863 */ 2864 2865 if (sbuf_error(&sb) == 0) 2866 devctl_notify("VFS", "FS", type, sbuf_data(&sb)); 2867 sbuf_delete(&sb); 2868 free(buf, M_MOUNT); 2869 } 2870 2871 /* 2872 * Force remount specified mount point to read-only. The argument 2873 * must be busied to avoid parallel unmount attempts. 2874 * 2875 * Intended use is to prevent further writes if some metadata 2876 * inconsistency is detected. Note that the function still flushes 2877 * all cached metadata and data for the mount point, which might be 2878 * not always suitable. 2879 */ 2880 int 2881 vfs_remount_ro(struct mount *mp) 2882 { 2883 struct vfsoptlist *opts; 2884 struct vfsopt *opt; 2885 struct vnode *vp_covered, *rootvp; 2886 int error; 2887 2888 KASSERT(mp->mnt_lockref > 0, 2889 ("vfs_remount_ro: mp %p is not busied", mp)); 2890 KASSERT((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0, 2891 ("vfs_remount_ro: mp %p is being unmounted (and busy?)", mp)); 2892 2893 rootvp = NULL; 2894 vp_covered = mp->mnt_vnodecovered; 2895 error = vget(vp_covered, LK_EXCLUSIVE | LK_NOWAIT); 2896 if (error != 0) 2897 return (error); 2898 VI_LOCK(vp_covered); 2899 if ((vp_covered->v_iflag & VI_MOUNT) != 0) { 2900 VI_UNLOCK(vp_covered); 2901 vput(vp_covered); 2902 return (EBUSY); 2903 } 2904 vp_covered->v_iflag |= VI_MOUNT; 2905 VI_UNLOCK(vp_covered); 2906 vfs_op_enter(mp); 2907 vn_seqc_write_begin(vp_covered); 2908 2909 MNT_ILOCK(mp); 2910 if ((mp->mnt_flag & MNT_RDONLY) != 0) { 2911 MNT_IUNLOCK(mp); 2912 error = EBUSY; 2913 goto out; 2914 } 2915 mp->mnt_flag |= MNT_UPDATE | MNT_FORCE | MNT_RDONLY; 2916 rootvp = vfs_cache_root_clear(mp); 2917 MNT_IUNLOCK(mp); 2918 2919 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK | M_ZERO); 2920 TAILQ_INIT(opts); 2921 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK | M_ZERO); 2922 opt->name = strdup("ro", M_MOUNT); 2923 opt->value = NULL; 2924 TAILQ_INSERT_TAIL(opts, opt, link); 2925 vfs_mergeopts(opts, mp->mnt_opt); 2926 mp->mnt_optnew = opts; 2927 2928 error = VFS_MOUNT(mp); 2929 2930 if (error == 0) { 2931 MNT_ILOCK(mp); 2932 mp->mnt_flag &= ~(MNT_UPDATE | MNT_FORCE); 2933 MNT_IUNLOCK(mp); 2934 vfs_deallocate_syncvnode(mp); 2935 if (mp->mnt_opt != NULL) 2936 vfs_freeopts(mp->mnt_opt); 2937 mp->mnt_opt = mp->mnt_optnew; 2938 } else { 2939 MNT_ILOCK(mp); 2940 mp->mnt_flag &= ~(MNT_UPDATE | MNT_FORCE | MNT_RDONLY); 2941 MNT_IUNLOCK(mp); 2942 vfs_freeopts(mp->mnt_optnew); 2943 } 2944 mp->mnt_optnew = NULL; 2945 2946 out: 2947 vfs_op_exit(mp); 2948 VI_LOCK(vp_covered); 2949 vp_covered->v_iflag &= ~VI_MOUNT; 2950 VI_UNLOCK(vp_covered); 2951 vput(vp_covered); 2952 vn_seqc_write_end(vp_covered); 2953 if (rootvp != NULL) { 2954 vn_seqc_write_end(rootvp); 2955 vrele(rootvp); 2956 } 2957 return (error); 2958 } 2959 2960 /* 2961 * Suspend write operations on all local writeable filesystems. Does 2962 * full sync of them in the process. 2963 * 2964 * Iterate over the mount points in reverse order, suspending most 2965 * recently mounted filesystems first. It handles a case where a 2966 * filesystem mounted from a md(4) vnode-backed device should be 2967 * suspended before the filesystem that owns the vnode. 2968 */ 2969 void 2970 suspend_all_fs(void) 2971 { 2972 struct mount *mp; 2973 int error; 2974 2975 mtx_lock(&mountlist_mtx); 2976 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 2977 error = vfs_busy(mp, MBF_MNTLSTLOCK | MBF_NOWAIT); 2978 if (error != 0) 2979 continue; 2980 if ((mp->mnt_flag & (MNT_RDONLY | MNT_LOCAL)) != MNT_LOCAL || 2981 (mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 2982 mtx_lock(&mountlist_mtx); 2983 vfs_unbusy(mp); 2984 continue; 2985 } 2986 error = vfs_write_suspend(mp, 0); 2987 if (error == 0) { 2988 MNT_ILOCK(mp); 2989 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0); 2990 mp->mnt_kern_flag |= MNTK_SUSPEND_ALL; 2991 MNT_IUNLOCK(mp); 2992 mtx_lock(&mountlist_mtx); 2993 } else { 2994 printf("suspend of %s failed, error %d\n", 2995 mp->mnt_stat.f_mntonname, error); 2996 mtx_lock(&mountlist_mtx); 2997 vfs_unbusy(mp); 2998 } 2999 } 3000 mtx_unlock(&mountlist_mtx); 3001 } 3002 3003 void 3004 resume_all_fs(void) 3005 { 3006 struct mount *mp; 3007 3008 mtx_lock(&mountlist_mtx); 3009 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3010 if ((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0) 3011 continue; 3012 mtx_unlock(&mountlist_mtx); 3013 MNT_ILOCK(mp); 3014 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) != 0); 3015 mp->mnt_kern_flag &= ~MNTK_SUSPEND_ALL; 3016 MNT_IUNLOCK(mp); 3017 vfs_write_resume(mp, 0); 3018 mtx_lock(&mountlist_mtx); 3019 vfs_unbusy(mp); 3020 } 3021 mtx_unlock(&mountlist_mtx); 3022 } 3023