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/sysent.h> 67 #include <sys/systm.h> 68 #include <sys/taskqueue.h> 69 #include <sys/vnode.h> 70 #include <vm/uma.h> 71 72 #include <geom/geom.h> 73 74 #include <machine/stdarg.h> 75 76 #include <security/audit/audit.h> 77 #include <security/mac/mac_framework.h> 78 79 #define VFS_MOUNTARG_SIZE_MAX (1024 * 64) 80 81 static int vfs_domount(struct thread *td, const char *fstype, char *fspath, 82 uint64_t fsflags, struct vfsoptlist **optlist); 83 static void free_mntarg(struct mntarg *ma); 84 85 static int usermount = 0; 86 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 87 "Unprivileged users may mount and unmount file systems"); 88 89 static bool default_autoro = false; 90 SYSCTL_BOOL(_vfs, OID_AUTO, default_autoro, CTLFLAG_RW, &default_autoro, 0, 91 "Retry failed r/w mount as r/o if no explicit ro/rw option is specified"); 92 93 static bool recursive_forced_unmount = false; 94 SYSCTL_BOOL(_vfs, OID_AUTO, recursive_forced_unmount, CTLFLAG_RW, 95 &recursive_forced_unmount, 0, "Recursively unmount stacked upper mounts" 96 " when a file system is forcibly unmounted"); 97 98 static SYSCTL_NODE(_vfs, OID_AUTO, deferred_unmount, 99 CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "deferred unmount controls"); 100 101 static unsigned int deferred_unmount_retry_limit = 10; 102 SYSCTL_UINT(_vfs_deferred_unmount, OID_AUTO, retry_limit, CTLFLAG_RW, 103 &deferred_unmount_retry_limit, 0, 104 "Maximum number of retries for deferred unmount failure"); 105 106 static int deferred_unmount_retry_delay_hz; 107 SYSCTL_INT(_vfs_deferred_unmount, OID_AUTO, retry_delay_hz, CTLFLAG_RW, 108 &deferred_unmount_retry_delay_hz, 0, 109 "Delay in units of [1/kern.hz]s when retrying a failed deferred unmount"); 110 111 static int deferred_unmount_total_retries = 0; 112 SYSCTL_INT(_vfs_deferred_unmount, OID_AUTO, total_retries, CTLFLAG_RD, 113 &deferred_unmount_total_retries, 0, 114 "Total number of retried deferred unmounts"); 115 116 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 117 MALLOC_DEFINE(M_STATFS, "statfs", "statfs structure"); 118 static uma_zone_t mount_zone; 119 120 /* List of mounted filesystems. */ 121 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 122 123 /* For any iteration/modification of mountlist */ 124 struct mtx_padalign __exclusive_cache_line mountlist_mtx; 125 126 EVENTHANDLER_LIST_DEFINE(vfs_mounted); 127 EVENTHANDLER_LIST_DEFINE(vfs_unmounted); 128 129 static void vfs_deferred_unmount(void *arg, int pending); 130 static struct timeout_task deferred_unmount_task; 131 static struct mtx deferred_unmount_lock; 132 MTX_SYSINIT(deferred_unmount, &deferred_unmount_lock, "deferred_unmount", 133 MTX_DEF); 134 static STAILQ_HEAD(, mount) deferred_unmount_list = 135 STAILQ_HEAD_INITIALIZER(deferred_unmount_list); 136 TASKQUEUE_DEFINE_THREAD(deferred_unmount); 137 138 static void mount_devctl_event(const char *type, struct mount *mp, bool donew); 139 140 /* 141 * Global opts, taken by all filesystems 142 */ 143 static const char *global_opts[] = { 144 "errmsg", 145 "fstype", 146 "fspath", 147 "ro", 148 "rw", 149 "nosuid", 150 "noexec", 151 NULL 152 }; 153 154 static int 155 mount_init(void *mem, int size, int flags) 156 { 157 struct mount *mp; 158 159 mp = (struct mount *)mem; 160 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 161 mtx_init(&mp->mnt_listmtx, "struct mount vlist mtx", NULL, MTX_DEF); 162 lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0); 163 mp->mnt_pcpu = uma_zalloc_pcpu(pcpu_zone_16, M_WAITOK | M_ZERO); 164 mp->mnt_ref = 0; 165 mp->mnt_vfs_ops = 1; 166 mp->mnt_rootvnode = NULL; 167 return (0); 168 } 169 170 static void 171 mount_fini(void *mem, int size) 172 { 173 struct mount *mp; 174 175 mp = (struct mount *)mem; 176 uma_zfree_pcpu(pcpu_zone_16, mp->mnt_pcpu); 177 lockdestroy(&mp->mnt_explock); 178 mtx_destroy(&mp->mnt_listmtx); 179 mtx_destroy(&mp->mnt_mtx); 180 } 181 182 static void 183 vfs_mount_init(void *dummy __unused) 184 { 185 TIMEOUT_TASK_INIT(taskqueue_deferred_unmount, &deferred_unmount_task, 186 0, vfs_deferred_unmount, NULL); 187 deferred_unmount_retry_delay_hz = hz; 188 mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), NULL, 189 NULL, mount_init, mount_fini, UMA_ALIGN_CACHE, UMA_ZONE_NOFREE); 190 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 191 } 192 SYSINIT(vfs_mount, SI_SUB_VFS, SI_ORDER_ANY, vfs_mount_init, NULL); 193 194 /* 195 * --------------------------------------------------------------------- 196 * Functions for building and sanitizing the mount options 197 */ 198 199 /* Remove one mount option. */ 200 static void 201 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 202 { 203 204 TAILQ_REMOVE(opts, opt, link); 205 free(opt->name, M_MOUNT); 206 if (opt->value != NULL) 207 free(opt->value, M_MOUNT); 208 free(opt, M_MOUNT); 209 } 210 211 /* Release all resources related to the mount options. */ 212 void 213 vfs_freeopts(struct vfsoptlist *opts) 214 { 215 struct vfsopt *opt; 216 217 while (!TAILQ_EMPTY(opts)) { 218 opt = TAILQ_FIRST(opts); 219 vfs_freeopt(opts, opt); 220 } 221 free(opts, M_MOUNT); 222 } 223 224 void 225 vfs_deleteopt(struct vfsoptlist *opts, const char *name) 226 { 227 struct vfsopt *opt, *temp; 228 229 if (opts == NULL) 230 return; 231 TAILQ_FOREACH_SAFE(opt, opts, link, temp) { 232 if (strcmp(opt->name, name) == 0) 233 vfs_freeopt(opts, opt); 234 } 235 } 236 237 static int 238 vfs_isopt_ro(const char *opt) 239 { 240 241 if (strcmp(opt, "ro") == 0 || strcmp(opt, "rdonly") == 0 || 242 strcmp(opt, "norw") == 0) 243 return (1); 244 return (0); 245 } 246 247 static int 248 vfs_isopt_rw(const char *opt) 249 { 250 251 if (strcmp(opt, "rw") == 0 || strcmp(opt, "noro") == 0) 252 return (1); 253 return (0); 254 } 255 256 /* 257 * Check if options are equal (with or without the "no" prefix). 258 */ 259 static int 260 vfs_equalopts(const char *opt1, const char *opt2) 261 { 262 char *p; 263 264 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 265 if (strcmp(opt1, opt2) == 0) 266 return (1); 267 /* "noopt" vs. "opt" */ 268 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 269 return (1); 270 /* "opt" vs. "noopt" */ 271 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 272 return (1); 273 while ((p = strchr(opt1, '.')) != NULL && 274 !strncmp(opt1, opt2, ++p - opt1)) { 275 opt2 += p - opt1; 276 opt1 = p; 277 /* "foo.noopt" vs. "foo.opt" */ 278 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 279 return (1); 280 /* "foo.opt" vs. "foo.noopt" */ 281 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 282 return (1); 283 } 284 /* "ro" / "rdonly" / "norw" / "rw" / "noro" */ 285 if ((vfs_isopt_ro(opt1) || vfs_isopt_rw(opt1)) && 286 (vfs_isopt_ro(opt2) || vfs_isopt_rw(opt2))) 287 return (1); 288 return (0); 289 } 290 291 /* 292 * If a mount option is specified several times, 293 * (with or without the "no" prefix) only keep 294 * the last occurrence of it. 295 */ 296 static void 297 vfs_sanitizeopts(struct vfsoptlist *opts) 298 { 299 struct vfsopt *opt, *opt2, *tmp; 300 301 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 302 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 303 while (opt2 != NULL) { 304 if (vfs_equalopts(opt->name, opt2->name)) { 305 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 306 vfs_freeopt(opts, opt2); 307 opt2 = tmp; 308 } else { 309 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 310 } 311 } 312 } 313 } 314 315 /* 316 * Build a linked list of mount options from a struct uio. 317 */ 318 int 319 vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 320 { 321 struct vfsoptlist *opts; 322 struct vfsopt *opt; 323 size_t memused, namelen, optlen; 324 unsigned int i, iovcnt; 325 int error; 326 327 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 328 TAILQ_INIT(opts); 329 memused = 0; 330 iovcnt = auio->uio_iovcnt; 331 for (i = 0; i < iovcnt; i += 2) { 332 namelen = auio->uio_iov[i].iov_len; 333 optlen = auio->uio_iov[i + 1].iov_len; 334 memused += sizeof(struct vfsopt) + optlen + namelen; 335 /* 336 * Avoid consuming too much memory, and attempts to overflow 337 * memused. 338 */ 339 if (memused > VFS_MOUNTARG_SIZE_MAX || 340 optlen > VFS_MOUNTARG_SIZE_MAX || 341 namelen > VFS_MOUNTARG_SIZE_MAX) { 342 error = EINVAL; 343 goto bad; 344 } 345 346 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 347 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 348 opt->value = NULL; 349 opt->len = 0; 350 opt->pos = i / 2; 351 opt->seen = 0; 352 353 /* 354 * Do this early, so jumps to "bad" will free the current 355 * option. 356 */ 357 TAILQ_INSERT_TAIL(opts, opt, link); 358 359 if (auio->uio_segflg == UIO_SYSSPACE) { 360 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 361 } else { 362 error = copyin(auio->uio_iov[i].iov_base, opt->name, 363 namelen); 364 if (error) 365 goto bad; 366 } 367 /* Ensure names are null-terminated strings. */ 368 if (namelen == 0 || opt->name[namelen - 1] != '\0') { 369 error = EINVAL; 370 goto bad; 371 } 372 if (optlen != 0) { 373 opt->len = optlen; 374 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 375 if (auio->uio_segflg == UIO_SYSSPACE) { 376 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 377 optlen); 378 } else { 379 error = copyin(auio->uio_iov[i + 1].iov_base, 380 opt->value, optlen); 381 if (error) 382 goto bad; 383 } 384 } 385 } 386 vfs_sanitizeopts(opts); 387 *options = opts; 388 return (0); 389 bad: 390 vfs_freeopts(opts); 391 return (error); 392 } 393 394 /* 395 * Merge the old mount options with the new ones passed 396 * in the MNT_UPDATE case. 397 * 398 * XXX: This function will keep a "nofoo" option in the new 399 * options. E.g, if the option's canonical name is "foo", 400 * "nofoo" ends up in the mount point's active options. 401 */ 402 static void 403 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *oldopts) 404 { 405 struct vfsopt *opt, *new; 406 407 TAILQ_FOREACH(opt, oldopts, link) { 408 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 409 new->name = strdup(opt->name, M_MOUNT); 410 if (opt->len != 0) { 411 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 412 bcopy(opt->value, new->value, opt->len); 413 } else 414 new->value = NULL; 415 new->len = opt->len; 416 new->seen = opt->seen; 417 TAILQ_INSERT_HEAD(toopts, new, link); 418 } 419 vfs_sanitizeopts(toopts); 420 } 421 422 /* 423 * Mount a filesystem. 424 */ 425 #ifndef _SYS_SYSPROTO_H_ 426 struct nmount_args { 427 struct iovec *iovp; 428 unsigned int iovcnt; 429 int flags; 430 }; 431 #endif 432 int 433 sys_nmount(struct thread *td, struct nmount_args *uap) 434 { 435 struct uio *auio; 436 int error; 437 u_int iovcnt; 438 uint64_t flags; 439 440 /* 441 * Mount flags are now 64-bits. On 32-bit archtectures only 442 * 32-bits are passed in, but from here on everything handles 443 * 64-bit flags correctly. 444 */ 445 flags = uap->flags; 446 447 AUDIT_ARG_FFLAGS(flags); 448 CTR4(KTR_VFS, "%s: iovp %p with iovcnt %d and flags %d", __func__, 449 uap->iovp, uap->iovcnt, flags); 450 451 /* 452 * Filter out MNT_ROOTFS. We do not want clients of nmount() in 453 * userspace to set this flag, but we must filter it out if we want 454 * MNT_UPDATE on the root file system to work. 455 * MNT_ROOTFS should only be set by the kernel when mounting its 456 * root file system. 457 */ 458 flags &= ~MNT_ROOTFS; 459 460 iovcnt = uap->iovcnt; 461 /* 462 * Check that we have an even number of iovec's 463 * and that we have at least two options. 464 */ 465 if ((iovcnt & 1) || (iovcnt < 4)) { 466 CTR2(KTR_VFS, "%s: failed for invalid iovcnt %d", __func__, 467 uap->iovcnt); 468 return (EINVAL); 469 } 470 471 error = copyinuio(uap->iovp, iovcnt, &auio); 472 if (error) { 473 CTR2(KTR_VFS, "%s: failed for invalid uio op with %d errno", 474 __func__, error); 475 return (error); 476 } 477 error = vfs_donmount(td, flags, auio); 478 479 free(auio, M_IOV); 480 return (error); 481 } 482 483 /* 484 * --------------------------------------------------------------------- 485 * Various utility functions 486 */ 487 488 /* 489 * Get a reference on a mount point from a vnode. 490 * 491 * The vnode is allowed to be passed unlocked and race against dooming. Note in 492 * such case there are no guarantees the referenced mount point will still be 493 * associated with it after the function returns. 494 */ 495 struct mount * 496 vfs_ref_from_vp(struct vnode *vp) 497 { 498 struct mount *mp; 499 struct mount_pcpu *mpcpu; 500 501 mp = atomic_load_ptr(&vp->v_mount); 502 if (__predict_false(mp == NULL)) { 503 return (mp); 504 } 505 if (vfs_op_thread_enter(mp, mpcpu)) { 506 if (__predict_true(mp == vp->v_mount)) { 507 vfs_mp_count_add_pcpu(mpcpu, ref, 1); 508 vfs_op_thread_exit(mp, mpcpu); 509 } else { 510 vfs_op_thread_exit(mp, mpcpu); 511 mp = NULL; 512 } 513 } else { 514 MNT_ILOCK(mp); 515 if (mp == vp->v_mount) { 516 MNT_REF(mp); 517 MNT_IUNLOCK(mp); 518 } else { 519 MNT_IUNLOCK(mp); 520 mp = NULL; 521 } 522 } 523 return (mp); 524 } 525 526 void 527 vfs_ref(struct mount *mp) 528 { 529 struct mount_pcpu *mpcpu; 530 531 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 532 if (vfs_op_thread_enter(mp, mpcpu)) { 533 vfs_mp_count_add_pcpu(mpcpu, ref, 1); 534 vfs_op_thread_exit(mp, mpcpu); 535 return; 536 } 537 538 MNT_ILOCK(mp); 539 MNT_REF(mp); 540 MNT_IUNLOCK(mp); 541 } 542 543 /* 544 * Register ump as an upper mount of the mount associated with 545 * vnode vp. This registration will be tracked through 546 * mount_upper_node upper, which should be allocated by the 547 * caller and stored in per-mount data associated with mp. 548 * 549 * If successful, this function will return the mount associated 550 * with vp, and will ensure that it cannot be unmounted until 551 * ump has been unregistered as one of its upper mounts. 552 * 553 * Upon failure this function will return NULL. 554 */ 555 struct mount * 556 vfs_register_upper_from_vp(struct vnode *vp, struct mount *ump, 557 struct mount_upper_node *upper) 558 { 559 struct mount *mp; 560 561 mp = atomic_load_ptr(&vp->v_mount); 562 if (mp == NULL) 563 return (NULL); 564 MNT_ILOCK(mp); 565 if (mp != vp->v_mount || 566 ((mp->mnt_kern_flag & (MNTK_UNMOUNT | MNTK_RECURSE)) != 0)) { 567 MNT_IUNLOCK(mp); 568 return (NULL); 569 } 570 KASSERT(ump != mp, ("upper and lower mounts are identical")); 571 upper->mp = ump; 572 MNT_REF(mp); 573 TAILQ_INSERT_TAIL(&mp->mnt_uppers, upper, mnt_upper_link); 574 MNT_IUNLOCK(mp); 575 return (mp); 576 } 577 578 /* 579 * Register upper mount ump to receive vnode unlink/reclaim 580 * notifications from lower mount mp. This registration will 581 * be tracked through mount_upper_node upper, which should be 582 * allocated by the caller and stored in per-mount data 583 * associated with mp. 584 * 585 * ump must already be registered as an upper mount of mp 586 * through a call to vfs_register_upper_from_vp(). 587 */ 588 void 589 vfs_register_for_notification(struct mount *mp, struct mount *ump, 590 struct mount_upper_node *upper) 591 { 592 upper->mp = ump; 593 MNT_ILOCK(mp); 594 TAILQ_INSERT_TAIL(&mp->mnt_notify, upper, mnt_upper_link); 595 MNT_IUNLOCK(mp); 596 } 597 598 static void 599 vfs_drain_upper_locked(struct mount *mp) 600 { 601 mtx_assert(MNT_MTX(mp), MA_OWNED); 602 while (mp->mnt_upper_pending != 0) { 603 mp->mnt_kern_flag |= MNTK_UPPER_WAITER; 604 msleep(&mp->mnt_uppers, MNT_MTX(mp), 0, "mntupw", 0); 605 } 606 } 607 608 /* 609 * Undo a previous call to vfs_register_for_notification(). 610 * The mount represented by upper must be currently registered 611 * as an upper mount for mp. 612 */ 613 void 614 vfs_unregister_for_notification(struct mount *mp, 615 struct mount_upper_node *upper) 616 { 617 MNT_ILOCK(mp); 618 vfs_drain_upper_locked(mp); 619 TAILQ_REMOVE(&mp->mnt_notify, upper, mnt_upper_link); 620 MNT_IUNLOCK(mp); 621 } 622 623 /* 624 * Undo a previous call to vfs_register_upper_from_vp(). 625 * This must be done before mp can be unmounted. 626 */ 627 void 628 vfs_unregister_upper(struct mount *mp, struct mount_upper_node *upper) 629 { 630 MNT_ILOCK(mp); 631 KASSERT((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0, 632 ("registered upper with pending unmount")); 633 vfs_drain_upper_locked(mp); 634 TAILQ_REMOVE(&mp->mnt_uppers, upper, mnt_upper_link); 635 if ((mp->mnt_kern_flag & MNTK_TASKQUEUE_WAITER) != 0 && 636 TAILQ_EMPTY(&mp->mnt_uppers)) { 637 mp->mnt_kern_flag &= ~MNTK_TASKQUEUE_WAITER; 638 wakeup(&mp->mnt_taskqueue_link); 639 } 640 MNT_REL(mp); 641 MNT_IUNLOCK(mp); 642 } 643 644 void 645 vfs_rel(struct mount *mp) 646 { 647 struct mount_pcpu *mpcpu; 648 649 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 650 if (vfs_op_thread_enter(mp, mpcpu)) { 651 vfs_mp_count_sub_pcpu(mpcpu, ref, 1); 652 vfs_op_thread_exit(mp, mpcpu); 653 return; 654 } 655 656 MNT_ILOCK(mp); 657 MNT_REL(mp); 658 MNT_IUNLOCK(mp); 659 } 660 661 /* 662 * Allocate and initialize the mount point struct. 663 */ 664 struct mount * 665 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath, 666 struct ucred *cred) 667 { 668 struct mount *mp; 669 670 mp = uma_zalloc(mount_zone, M_WAITOK); 671 bzero(&mp->mnt_startzero, 672 __rangeof(struct mount, mnt_startzero, mnt_endzero)); 673 mp->mnt_kern_flag = 0; 674 mp->mnt_flag = 0; 675 mp->mnt_rootvnode = NULL; 676 mp->mnt_vnodecovered = NULL; 677 mp->mnt_op = NULL; 678 mp->mnt_vfc = NULL; 679 TAILQ_INIT(&mp->mnt_nvnodelist); 680 mp->mnt_nvnodelistsize = 0; 681 TAILQ_INIT(&mp->mnt_lazyvnodelist); 682 mp->mnt_lazyvnodelistsize = 0; 683 if (mp->mnt_ref != 0 || mp->mnt_lockref != 0 || 684 mp->mnt_writeopcount != 0) 685 panic("%s: non-zero counters on new mp %p\n", __func__, mp); 686 if (mp->mnt_vfs_ops != 1) 687 panic("%s: vfs_ops should be 1 but %d found\n", __func__, 688 mp->mnt_vfs_ops); 689 (void) vfs_busy(mp, MBF_NOWAIT); 690 atomic_add_acq_int(&vfsp->vfc_refcount, 1); 691 mp->mnt_op = vfsp->vfc_vfsops; 692 mp->mnt_vfc = vfsp; 693 mp->mnt_stat.f_type = vfsp->vfc_typenum; 694 mp->mnt_gen++; 695 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 696 mp->mnt_vnodecovered = vp; 697 mp->mnt_cred = crdup(cred); 698 mp->mnt_stat.f_owner = cred->cr_uid; 699 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 700 mp->mnt_iosize_max = DFLTPHYS; 701 #ifdef MAC 702 mac_mount_init(mp); 703 mac_mount_create(cred, mp); 704 #endif 705 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0); 706 mp->mnt_upper_pending = 0; 707 TAILQ_INIT(&mp->mnt_uppers); 708 TAILQ_INIT(&mp->mnt_notify); 709 mp->mnt_taskqueue_flags = 0; 710 mp->mnt_unmount_retries = 0; 711 return (mp); 712 } 713 714 /* 715 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 716 */ 717 void 718 vfs_mount_destroy(struct mount *mp) 719 { 720 721 if (mp->mnt_vfs_ops == 0) 722 panic("%s: entered with zero vfs_ops\n", __func__); 723 724 vfs_assert_mount_counters(mp); 725 726 MNT_ILOCK(mp); 727 mp->mnt_kern_flag |= MNTK_REFEXPIRE; 728 if (mp->mnt_kern_flag & MNTK_MWAIT) { 729 mp->mnt_kern_flag &= ~MNTK_MWAIT; 730 wakeup(mp); 731 } 732 while (mp->mnt_ref) 733 msleep(mp, MNT_MTX(mp), PVFS, "mntref", 0); 734 KASSERT(mp->mnt_ref == 0, 735 ("%s: invalid refcount in the drain path @ %s:%d", __func__, 736 __FILE__, __LINE__)); 737 if (mp->mnt_writeopcount != 0) 738 panic("vfs_mount_destroy: nonzero writeopcount"); 739 if (mp->mnt_secondary_writes != 0) 740 panic("vfs_mount_destroy: nonzero secondary_writes"); 741 atomic_subtract_rel_int(&mp->mnt_vfc->vfc_refcount, 1); 742 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) { 743 struct vnode *vp; 744 745 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) 746 vn_printf(vp, "dangling vnode "); 747 panic("unmount: dangling vnode"); 748 } 749 KASSERT(mp->mnt_upper_pending == 0, ("mnt_upper_pending")); 750 KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers")); 751 KASSERT(TAILQ_EMPTY(&mp->mnt_notify), ("mnt_notify")); 752 if (mp->mnt_nvnodelistsize != 0) 753 panic("vfs_mount_destroy: nonzero nvnodelistsize"); 754 if (mp->mnt_lazyvnodelistsize != 0) 755 panic("vfs_mount_destroy: nonzero lazyvnodelistsize"); 756 if (mp->mnt_lockref != 0) 757 panic("vfs_mount_destroy: nonzero lock refcount"); 758 MNT_IUNLOCK(mp); 759 760 if (mp->mnt_vfs_ops != 1) 761 panic("%s: vfs_ops should be 1 but %d found\n", __func__, 762 mp->mnt_vfs_ops); 763 764 if (mp->mnt_rootvnode != NULL) 765 panic("%s: mount point still has a root vnode %p\n", __func__, 766 mp->mnt_rootvnode); 767 768 if (mp->mnt_vnodecovered != NULL) 769 vrele(mp->mnt_vnodecovered); 770 #ifdef MAC 771 mac_mount_destroy(mp); 772 #endif 773 if (mp->mnt_opt != NULL) 774 vfs_freeopts(mp->mnt_opt); 775 crfree(mp->mnt_cred); 776 uma_zfree(mount_zone, mp); 777 } 778 779 static bool 780 vfs_should_downgrade_to_ro_mount(uint64_t fsflags, int error) 781 { 782 /* This is an upgrade of an exisiting mount. */ 783 if ((fsflags & MNT_UPDATE) != 0) 784 return (false); 785 /* This is already an R/O mount. */ 786 if ((fsflags & MNT_RDONLY) != 0) 787 return (false); 788 789 switch (error) { 790 case ENODEV: /* generic, geom, ... */ 791 case EACCES: /* cam/scsi, ... */ 792 case EROFS: /* md, mmcsd, ... */ 793 /* 794 * These errors can be returned by the storage layer to signal 795 * that the media is read-only. No harm in the R/O mount 796 * attempt if the error was returned for some other reason. 797 */ 798 return (true); 799 default: 800 return (false); 801 } 802 } 803 804 int 805 vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions) 806 { 807 struct vfsoptlist *optlist; 808 struct vfsopt *opt, *tmp_opt; 809 char *fstype, *fspath, *errmsg; 810 int error, fstypelen, fspathlen, errmsg_len, errmsg_pos; 811 bool autoro; 812 813 errmsg = fspath = NULL; 814 errmsg_len = fspathlen = 0; 815 errmsg_pos = -1; 816 autoro = default_autoro; 817 818 error = vfs_buildopts(fsoptions, &optlist); 819 if (error) 820 return (error); 821 822 if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0) 823 errmsg_pos = vfs_getopt_pos(optlist, "errmsg"); 824 825 /* 826 * We need these two options before the others, 827 * and they are mandatory for any filesystem. 828 * Ensure they are NUL terminated as well. 829 */ 830 fstypelen = 0; 831 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 832 if (error || fstypelen <= 0 || fstype[fstypelen - 1] != '\0') { 833 error = EINVAL; 834 if (errmsg != NULL) 835 strncpy(errmsg, "Invalid fstype", errmsg_len); 836 goto bail; 837 } 838 fspathlen = 0; 839 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 840 if (error || fspathlen <= 0 || fspath[fspathlen - 1] != '\0') { 841 error = EINVAL; 842 if (errmsg != NULL) 843 strncpy(errmsg, "Invalid fspath", errmsg_len); 844 goto bail; 845 } 846 847 /* 848 * We need to see if we have the "update" option 849 * before we call vfs_domount(), since vfs_domount() has special 850 * logic based on MNT_UPDATE. This is very important 851 * when we want to update the root filesystem. 852 */ 853 TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) { 854 int do_freeopt = 0; 855 856 if (strcmp(opt->name, "update") == 0) { 857 fsflags |= MNT_UPDATE; 858 do_freeopt = 1; 859 } 860 else if (strcmp(opt->name, "async") == 0) 861 fsflags |= MNT_ASYNC; 862 else if (strcmp(opt->name, "force") == 0) { 863 fsflags |= MNT_FORCE; 864 do_freeopt = 1; 865 } 866 else if (strcmp(opt->name, "reload") == 0) { 867 fsflags |= MNT_RELOAD; 868 do_freeopt = 1; 869 } 870 else if (strcmp(opt->name, "multilabel") == 0) 871 fsflags |= MNT_MULTILABEL; 872 else if (strcmp(opt->name, "noasync") == 0) 873 fsflags &= ~MNT_ASYNC; 874 else if (strcmp(opt->name, "noatime") == 0) 875 fsflags |= MNT_NOATIME; 876 else if (strcmp(opt->name, "atime") == 0) { 877 free(opt->name, M_MOUNT); 878 opt->name = strdup("nonoatime", M_MOUNT); 879 } 880 else if (strcmp(opt->name, "noclusterr") == 0) 881 fsflags |= MNT_NOCLUSTERR; 882 else if (strcmp(opt->name, "clusterr") == 0) { 883 free(opt->name, M_MOUNT); 884 opt->name = strdup("nonoclusterr", M_MOUNT); 885 } 886 else if (strcmp(opt->name, "noclusterw") == 0) 887 fsflags |= MNT_NOCLUSTERW; 888 else if (strcmp(opt->name, "clusterw") == 0) { 889 free(opt->name, M_MOUNT); 890 opt->name = strdup("nonoclusterw", M_MOUNT); 891 } 892 else if (strcmp(opt->name, "noexec") == 0) 893 fsflags |= MNT_NOEXEC; 894 else if (strcmp(opt->name, "exec") == 0) { 895 free(opt->name, M_MOUNT); 896 opt->name = strdup("nonoexec", M_MOUNT); 897 } 898 else if (strcmp(opt->name, "nosuid") == 0) 899 fsflags |= MNT_NOSUID; 900 else if (strcmp(opt->name, "suid") == 0) { 901 free(opt->name, M_MOUNT); 902 opt->name = strdup("nonosuid", M_MOUNT); 903 } 904 else if (strcmp(opt->name, "nosymfollow") == 0) 905 fsflags |= MNT_NOSYMFOLLOW; 906 else if (strcmp(opt->name, "symfollow") == 0) { 907 free(opt->name, M_MOUNT); 908 opt->name = strdup("nonosymfollow", M_MOUNT); 909 } 910 else if (strcmp(opt->name, "noro") == 0) { 911 fsflags &= ~MNT_RDONLY; 912 autoro = false; 913 } 914 else if (strcmp(opt->name, "rw") == 0) { 915 fsflags &= ~MNT_RDONLY; 916 autoro = false; 917 } 918 else if (strcmp(opt->name, "ro") == 0) { 919 fsflags |= MNT_RDONLY; 920 autoro = false; 921 } 922 else if (strcmp(opt->name, "rdonly") == 0) { 923 free(opt->name, M_MOUNT); 924 opt->name = strdup("ro", M_MOUNT); 925 fsflags |= MNT_RDONLY; 926 autoro = false; 927 } 928 else if (strcmp(opt->name, "autoro") == 0) { 929 do_freeopt = 1; 930 autoro = true; 931 } 932 else if (strcmp(opt->name, "suiddir") == 0) 933 fsflags |= MNT_SUIDDIR; 934 else if (strcmp(opt->name, "sync") == 0) 935 fsflags |= MNT_SYNCHRONOUS; 936 else if (strcmp(opt->name, "union") == 0) 937 fsflags |= MNT_UNION; 938 else if (strcmp(opt->name, "automounted") == 0) { 939 fsflags |= MNT_AUTOMOUNTED; 940 do_freeopt = 1; 941 } else if (strcmp(opt->name, "nocover") == 0) { 942 fsflags |= MNT_NOCOVER; 943 do_freeopt = 1; 944 } else if (strcmp(opt->name, "cover") == 0) { 945 fsflags &= ~MNT_NOCOVER; 946 do_freeopt = 1; 947 } else if (strcmp(opt->name, "emptydir") == 0) { 948 fsflags |= MNT_EMPTYDIR; 949 do_freeopt = 1; 950 } else if (strcmp(opt->name, "noemptydir") == 0) { 951 fsflags &= ~MNT_EMPTYDIR; 952 do_freeopt = 1; 953 } 954 if (do_freeopt) 955 vfs_freeopt(optlist, opt); 956 } 957 958 /* 959 * Be ultra-paranoid about making sure the type and fspath 960 * variables will fit in our mp buffers, including the 961 * terminating NUL. 962 */ 963 if (fstypelen > MFSNAMELEN || fspathlen > MNAMELEN) { 964 error = ENAMETOOLONG; 965 goto bail; 966 } 967 968 error = vfs_domount(td, fstype, fspath, fsflags, &optlist); 969 if (error == ENOENT) { 970 error = EINVAL; 971 if (errmsg != NULL) 972 strncpy(errmsg, "Invalid fstype", errmsg_len); 973 goto bail; 974 } 975 976 /* 977 * See if we can mount in the read-only mode if the error code suggests 978 * that it could be possible and the mount options allow for that. 979 * Never try it if "[no]{ro|rw}" has been explicitly requested and not 980 * overridden by "autoro". 981 */ 982 if (autoro && vfs_should_downgrade_to_ro_mount(fsflags, error)) { 983 printf("%s: R/W mount failed, possibly R/O media," 984 " trying R/O mount\n", __func__); 985 fsflags |= MNT_RDONLY; 986 error = vfs_domount(td, fstype, fspath, fsflags, &optlist); 987 } 988 bail: 989 /* copyout the errmsg */ 990 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt) 991 && errmsg_len > 0 && errmsg != NULL) { 992 if (fsoptions->uio_segflg == UIO_SYSSPACE) { 993 bcopy(errmsg, 994 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 995 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 996 } else { 997 copyout(errmsg, 998 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 999 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 1000 } 1001 } 1002 1003 if (optlist != NULL) 1004 vfs_freeopts(optlist); 1005 return (error); 1006 } 1007 1008 /* 1009 * Old mount API. 1010 */ 1011 #ifndef _SYS_SYSPROTO_H_ 1012 struct mount_args { 1013 char *type; 1014 char *path; 1015 int flags; 1016 caddr_t data; 1017 }; 1018 #endif 1019 /* ARGSUSED */ 1020 int 1021 sys_mount(struct thread *td, struct mount_args *uap) 1022 { 1023 char *fstype; 1024 struct vfsconf *vfsp = NULL; 1025 struct mntarg *ma = NULL; 1026 uint64_t flags; 1027 int error; 1028 1029 /* 1030 * Mount flags are now 64-bits. On 32-bit architectures only 1031 * 32-bits are passed in, but from here on everything handles 1032 * 64-bit flags correctly. 1033 */ 1034 flags = uap->flags; 1035 1036 AUDIT_ARG_FFLAGS(flags); 1037 1038 /* 1039 * Filter out MNT_ROOTFS. We do not want clients of mount() in 1040 * userspace to set this flag, but we must filter it out if we want 1041 * MNT_UPDATE on the root file system to work. 1042 * MNT_ROOTFS should only be set by the kernel when mounting its 1043 * root file system. 1044 */ 1045 flags &= ~MNT_ROOTFS; 1046 1047 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 1048 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 1049 if (error) { 1050 free(fstype, M_TEMP); 1051 return (error); 1052 } 1053 1054 AUDIT_ARG_TEXT(fstype); 1055 vfsp = vfs_byname_kld(fstype, td, &error); 1056 free(fstype, M_TEMP); 1057 if (vfsp == NULL) 1058 return (ENOENT); 1059 if (((vfsp->vfc_flags & VFCF_SBDRY) != 0 && 1060 vfsp->vfc_vfsops_sd->vfs_cmount == NULL) || 1061 ((vfsp->vfc_flags & VFCF_SBDRY) == 0 && 1062 vfsp->vfc_vfsops->vfs_cmount == NULL)) 1063 return (EOPNOTSUPP); 1064 1065 ma = mount_argsu(ma, "fstype", uap->type, MFSNAMELEN); 1066 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 1067 ma = mount_argb(ma, flags & MNT_RDONLY, "noro"); 1068 ma = mount_argb(ma, !(flags & MNT_NOSUID), "nosuid"); 1069 ma = mount_argb(ma, !(flags & MNT_NOEXEC), "noexec"); 1070 1071 if ((vfsp->vfc_flags & VFCF_SBDRY) != 0) 1072 return (vfsp->vfc_vfsops_sd->vfs_cmount(ma, uap->data, flags)); 1073 return (vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, flags)); 1074 } 1075 1076 /* 1077 * vfs_domount_first(): first file system mount (not update) 1078 */ 1079 static int 1080 vfs_domount_first( 1081 struct thread *td, /* Calling thread. */ 1082 struct vfsconf *vfsp, /* File system type. */ 1083 char *fspath, /* Mount path. */ 1084 struct vnode *vp, /* Vnode to be covered. */ 1085 uint64_t fsflags, /* Flags common to all filesystems. */ 1086 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1087 ) 1088 { 1089 struct vattr va; 1090 struct mount *mp; 1091 struct vnode *newdp, *rootvp; 1092 int error, error1; 1093 bool unmounted; 1094 1095 ASSERT_VOP_ELOCKED(vp, __func__); 1096 KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here")); 1097 1098 /* 1099 * If the jail of the calling thread lacks permission for this type of 1100 * file system, or is trying to cover its own root, deny immediately. 1101 */ 1102 if (jailed(td->td_ucred) && (!prison_allow(td->td_ucred, 1103 vfsp->vfc_prison_flag) || vp == td->td_ucred->cr_prison->pr_root)) { 1104 vput(vp); 1105 return (EPERM); 1106 } 1107 1108 /* 1109 * If the user is not root, ensure that they own the directory 1110 * onto which we are attempting to mount. 1111 */ 1112 error = VOP_GETATTR(vp, &va, td->td_ucred); 1113 if (error == 0 && va.va_uid != td->td_ucred->cr_uid) 1114 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN); 1115 if (error == 0) 1116 error = vinvalbuf(vp, V_SAVE, 0, 0); 1117 if (error == 0 && vp->v_type != VDIR) 1118 error = ENOTDIR; 1119 if (error == 0 && (fsflags & MNT_EMPTYDIR) != 0) 1120 error = vfs_emptydir(vp); 1121 if (error == 0) { 1122 VI_LOCK(vp); 1123 if ((vp->v_iflag & VI_MOUNT) == 0 && vp->v_mountedhere == NULL) 1124 vp->v_iflag |= VI_MOUNT; 1125 else 1126 error = EBUSY; 1127 VI_UNLOCK(vp); 1128 } 1129 if (error != 0) { 1130 vput(vp); 1131 return (error); 1132 } 1133 vn_seqc_write_begin(vp); 1134 VOP_UNLOCK(vp); 1135 1136 /* Allocate and initialize the filesystem. */ 1137 mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred); 1138 /* XXXMAC: pass to vfs_mount_alloc? */ 1139 mp->mnt_optnew = *optlist; 1140 /* Set the mount level flags. */ 1141 mp->mnt_flag = (fsflags & (MNT_UPDATEMASK | MNT_ROOTFS | MNT_RDONLY)); 1142 1143 /* 1144 * Mount the filesystem. 1145 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1146 * get. No freeing of cn_pnbuf. 1147 */ 1148 error1 = 0; 1149 unmounted = true; 1150 if ((error = VFS_MOUNT(mp)) != 0 || 1151 (error1 = VFS_STATFS(mp, &mp->mnt_stat)) != 0 || 1152 (error1 = VFS_ROOT(mp, LK_EXCLUSIVE, &newdp)) != 0) { 1153 rootvp = NULL; 1154 if (error1 != 0) { 1155 MPASS(error == 0); 1156 rootvp = vfs_cache_root_clear(mp); 1157 if (rootvp != NULL) { 1158 vhold(rootvp); 1159 vrele(rootvp); 1160 } 1161 (void)vn_start_write(NULL, &mp, V_WAIT); 1162 MNT_ILOCK(mp); 1163 mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_UNMOUNTF; 1164 MNT_IUNLOCK(mp); 1165 VFS_PURGE(mp); 1166 error = VFS_UNMOUNT(mp, 0); 1167 vn_finished_write(mp); 1168 if (error != 0) { 1169 printf( 1170 "failed post-mount (%d): rollback unmount returned %d\n", 1171 error1, error); 1172 unmounted = false; 1173 } 1174 error = error1; 1175 } 1176 vfs_unbusy(mp); 1177 mp->mnt_vnodecovered = NULL; 1178 if (unmounted) { 1179 /* XXXKIB wait for mnt_lockref drain? */ 1180 vfs_mount_destroy(mp); 1181 } 1182 VI_LOCK(vp); 1183 vp->v_iflag &= ~VI_MOUNT; 1184 VI_UNLOCK(vp); 1185 if (rootvp != NULL) { 1186 vn_seqc_write_end(rootvp); 1187 vdrop(rootvp); 1188 } 1189 vn_seqc_write_end(vp); 1190 vrele(vp); 1191 return (error); 1192 } 1193 vn_seqc_write_begin(newdp); 1194 VOP_UNLOCK(newdp); 1195 1196 if (mp->mnt_opt != NULL) 1197 vfs_freeopts(mp->mnt_opt); 1198 mp->mnt_opt = mp->mnt_optnew; 1199 *optlist = NULL; 1200 1201 /* 1202 * Prevent external consumers of mount options from reading mnt_optnew. 1203 */ 1204 mp->mnt_optnew = NULL; 1205 1206 MNT_ILOCK(mp); 1207 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 1208 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 1209 mp->mnt_kern_flag |= MNTK_ASYNC; 1210 else 1211 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1212 MNT_IUNLOCK(mp); 1213 1214 VI_LOCK(vp); 1215 vn_irflag_set_locked(vp, VIRF_MOUNTPOINT); 1216 vp->v_mountedhere = mp; 1217 VI_UNLOCK(vp); 1218 cache_purge(vp); 1219 1220 /* 1221 * We need to lock both vnodes. 1222 * 1223 * Use vn_lock_pair to avoid establishing an ordering between vnodes 1224 * from different filesystems. 1225 */ 1226 vn_lock_pair(vp, false, newdp, false); 1227 1228 VI_LOCK(vp); 1229 vp->v_iflag &= ~VI_MOUNT; 1230 VI_UNLOCK(vp); 1231 /* Place the new filesystem at the end of the mount list. */ 1232 mtx_lock(&mountlist_mtx); 1233 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1234 mtx_unlock(&mountlist_mtx); 1235 vfs_event_signal(NULL, VQ_MOUNT, 0); 1236 VOP_UNLOCK(vp); 1237 EVENTHANDLER_DIRECT_INVOKE(vfs_mounted, mp, newdp, td); 1238 VOP_UNLOCK(newdp); 1239 mount_devctl_event("MOUNT", mp, false); 1240 mountcheckdirs(vp, newdp); 1241 vn_seqc_write_end(vp); 1242 vn_seqc_write_end(newdp); 1243 vrele(newdp); 1244 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1245 vfs_allocate_syncvnode(mp); 1246 vfs_op_exit(mp); 1247 vfs_unbusy(mp); 1248 return (0); 1249 } 1250 1251 /* 1252 * vfs_domount_update(): update of mounted file system 1253 */ 1254 static int 1255 vfs_domount_update( 1256 struct thread *td, /* Calling thread. */ 1257 struct vnode *vp, /* Mount point vnode. */ 1258 uint64_t fsflags, /* Flags common to all filesystems. */ 1259 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1260 ) 1261 { 1262 struct export_args export; 1263 struct o2export_args o2export; 1264 struct vnode *rootvp; 1265 void *bufp; 1266 struct mount *mp; 1267 int error, export_error, i, len; 1268 uint64_t flag; 1269 gid_t *grps; 1270 1271 ASSERT_VOP_ELOCKED(vp, __func__); 1272 KASSERT((fsflags & MNT_UPDATE) != 0, ("MNT_UPDATE should be here")); 1273 mp = vp->v_mount; 1274 1275 if ((vp->v_vflag & VV_ROOT) == 0) { 1276 if (vfs_copyopt(*optlist, "export", &export, sizeof(export)) 1277 == 0) 1278 error = EXDEV; 1279 else 1280 error = EINVAL; 1281 vput(vp); 1282 return (error); 1283 } 1284 1285 /* 1286 * We only allow the filesystem to be reloaded if it 1287 * is currently mounted read-only. 1288 */ 1289 flag = mp->mnt_flag; 1290 if ((fsflags & MNT_RELOAD) != 0 && (flag & MNT_RDONLY) == 0) { 1291 vput(vp); 1292 return (EOPNOTSUPP); /* Needs translation */ 1293 } 1294 /* 1295 * Only privileged root, or (if MNT_USER is set) the user that 1296 * did the original mount is permitted to update it. 1297 */ 1298 error = vfs_suser(mp, td); 1299 if (error != 0) { 1300 vput(vp); 1301 return (error); 1302 } 1303 if (vfs_busy(mp, MBF_NOWAIT)) { 1304 vput(vp); 1305 return (EBUSY); 1306 } 1307 VI_LOCK(vp); 1308 if ((vp->v_iflag & VI_MOUNT) != 0 || vp->v_mountedhere != NULL) { 1309 VI_UNLOCK(vp); 1310 vfs_unbusy(mp); 1311 vput(vp); 1312 return (EBUSY); 1313 } 1314 vp->v_iflag |= VI_MOUNT; 1315 VI_UNLOCK(vp); 1316 VOP_UNLOCK(vp); 1317 1318 vfs_op_enter(mp); 1319 vn_seqc_write_begin(vp); 1320 1321 rootvp = NULL; 1322 MNT_ILOCK(mp); 1323 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1324 MNT_IUNLOCK(mp); 1325 error = EBUSY; 1326 goto end; 1327 } 1328 mp->mnt_flag &= ~MNT_UPDATEMASK; 1329 mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | 1330 MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY); 1331 if ((mp->mnt_flag & MNT_ASYNC) == 0) 1332 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1333 rootvp = vfs_cache_root_clear(mp); 1334 MNT_IUNLOCK(mp); 1335 mp->mnt_optnew = *optlist; 1336 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 1337 1338 /* 1339 * Mount the filesystem. 1340 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1341 * get. No freeing of cn_pnbuf. 1342 */ 1343 error = VFS_MOUNT(mp); 1344 1345 export_error = 0; 1346 /* Process the export option. */ 1347 if (error == 0 && vfs_getopt(mp->mnt_optnew, "export", &bufp, 1348 &len) == 0) { 1349 /* Assume that there is only 1 ABI for each length. */ 1350 switch (len) { 1351 case (sizeof(struct oexport_args)): 1352 bzero(&o2export, sizeof(o2export)); 1353 /* FALLTHROUGH */ 1354 case (sizeof(o2export)): 1355 bcopy(bufp, &o2export, len); 1356 export.ex_flags = (uint64_t)o2export.ex_flags; 1357 export.ex_root = o2export.ex_root; 1358 export.ex_uid = o2export.ex_anon.cr_uid; 1359 export.ex_groups = NULL; 1360 export.ex_ngroups = o2export.ex_anon.cr_ngroups; 1361 if (export.ex_ngroups > 0) { 1362 if (export.ex_ngroups <= XU_NGROUPS) { 1363 export.ex_groups = malloc( 1364 export.ex_ngroups * sizeof(gid_t), 1365 M_TEMP, M_WAITOK); 1366 for (i = 0; i < export.ex_ngroups; i++) 1367 export.ex_groups[i] = 1368 o2export.ex_anon.cr_groups[i]; 1369 } else 1370 export_error = EINVAL; 1371 } else if (export.ex_ngroups < 0) 1372 export_error = EINVAL; 1373 export.ex_addr = o2export.ex_addr; 1374 export.ex_addrlen = o2export.ex_addrlen; 1375 export.ex_mask = o2export.ex_mask; 1376 export.ex_masklen = o2export.ex_masklen; 1377 export.ex_indexfile = o2export.ex_indexfile; 1378 export.ex_numsecflavors = o2export.ex_numsecflavors; 1379 if (export.ex_numsecflavors < MAXSECFLAVORS) { 1380 for (i = 0; i < export.ex_numsecflavors; i++) 1381 export.ex_secflavors[i] = 1382 o2export.ex_secflavors[i]; 1383 } else 1384 export_error = EINVAL; 1385 if (export_error == 0) 1386 export_error = vfs_export(mp, &export); 1387 free(export.ex_groups, M_TEMP); 1388 break; 1389 case (sizeof(export)): 1390 bcopy(bufp, &export, len); 1391 grps = NULL; 1392 if (export.ex_ngroups > 0) { 1393 if (export.ex_ngroups <= NGROUPS_MAX) { 1394 grps = malloc(export.ex_ngroups * 1395 sizeof(gid_t), M_TEMP, M_WAITOK); 1396 export_error = copyin(export.ex_groups, 1397 grps, export.ex_ngroups * 1398 sizeof(gid_t)); 1399 if (export_error == 0) 1400 export.ex_groups = grps; 1401 } else 1402 export_error = EINVAL; 1403 } else if (export.ex_ngroups == 0) 1404 export.ex_groups = NULL; 1405 else 1406 export_error = EINVAL; 1407 if (export_error == 0) 1408 export_error = vfs_export(mp, &export); 1409 free(grps, M_TEMP); 1410 break; 1411 default: 1412 export_error = EINVAL; 1413 break; 1414 } 1415 } 1416 1417 MNT_ILOCK(mp); 1418 if (error == 0) { 1419 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | 1420 MNT_SNAPSHOT); 1421 } else { 1422 /* 1423 * If we fail, restore old mount flags. MNT_QUOTA is special, 1424 * because it is not part of MNT_UPDATEMASK, but it could have 1425 * changed in the meantime if quotactl(2) was called. 1426 * All in all we want current value of MNT_QUOTA, not the old 1427 * one. 1428 */ 1429 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA); 1430 } 1431 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 1432 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 1433 mp->mnt_kern_flag |= MNTK_ASYNC; 1434 else 1435 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1436 MNT_IUNLOCK(mp); 1437 1438 if (error != 0) 1439 goto end; 1440 1441 mount_devctl_event("REMOUNT", mp, true); 1442 if (mp->mnt_opt != NULL) 1443 vfs_freeopts(mp->mnt_opt); 1444 mp->mnt_opt = mp->mnt_optnew; 1445 *optlist = NULL; 1446 (void)VFS_STATFS(mp, &mp->mnt_stat); 1447 /* 1448 * Prevent external consumers of mount options from reading 1449 * mnt_optnew. 1450 */ 1451 mp->mnt_optnew = NULL; 1452 1453 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1454 vfs_allocate_syncvnode(mp); 1455 else 1456 vfs_deallocate_syncvnode(mp); 1457 end: 1458 vfs_op_exit(mp); 1459 if (rootvp != NULL) { 1460 vn_seqc_write_end(rootvp); 1461 vrele(rootvp); 1462 } 1463 vn_seqc_write_end(vp); 1464 vfs_unbusy(mp); 1465 VI_LOCK(vp); 1466 vp->v_iflag &= ~VI_MOUNT; 1467 VI_UNLOCK(vp); 1468 vrele(vp); 1469 return (error != 0 ? error : export_error); 1470 } 1471 1472 /* 1473 * vfs_domount(): actually attempt a filesystem mount. 1474 */ 1475 static int 1476 vfs_domount( 1477 struct thread *td, /* Calling thread. */ 1478 const char *fstype, /* Filesystem type. */ 1479 char *fspath, /* Mount path. */ 1480 uint64_t fsflags, /* Flags common to all filesystems. */ 1481 struct vfsoptlist **optlist /* Options local to the filesystem. */ 1482 ) 1483 { 1484 struct vfsconf *vfsp; 1485 struct nameidata nd; 1486 struct vnode *vp; 1487 char *pathbuf; 1488 int error; 1489 1490 /* 1491 * Be ultra-paranoid about making sure the type and fspath 1492 * variables will fit in our mp buffers, including the 1493 * terminating NUL. 1494 */ 1495 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 1496 return (ENAMETOOLONG); 1497 1498 if (jailed(td->td_ucred) || usermount == 0) { 1499 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0) 1500 return (error); 1501 } 1502 1503 /* 1504 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 1505 */ 1506 if (fsflags & MNT_EXPORTED) { 1507 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED); 1508 if (error) 1509 return (error); 1510 } 1511 if (fsflags & MNT_SUIDDIR) { 1512 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR); 1513 if (error) 1514 return (error); 1515 } 1516 /* 1517 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users. 1518 */ 1519 if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) { 1520 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0) 1521 fsflags |= MNT_NOSUID | MNT_USER; 1522 } 1523 1524 /* Load KLDs before we lock the covered vnode to avoid reversals. */ 1525 vfsp = NULL; 1526 if ((fsflags & MNT_UPDATE) == 0) { 1527 /* Don't try to load KLDs if we're mounting the root. */ 1528 if (fsflags & MNT_ROOTFS) { 1529 if ((vfsp = vfs_byname(fstype)) == NULL) 1530 return (ENODEV); 1531 } else { 1532 if ((vfsp = vfs_byname_kld(fstype, td, &error)) == NULL) 1533 return (error); 1534 } 1535 } 1536 1537 /* 1538 * Get vnode to be covered or mount point's vnode in case of MNT_UPDATE. 1539 */ 1540 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, 1541 UIO_SYSSPACE, fspath, td); 1542 error = namei(&nd); 1543 if (error != 0) 1544 return (error); 1545 NDFREE(&nd, NDF_ONLY_PNBUF); 1546 vp = nd.ni_vp; 1547 if ((fsflags & MNT_UPDATE) == 0) { 1548 if ((vp->v_vflag & VV_ROOT) != 0 && 1549 (fsflags & MNT_NOCOVER) != 0) { 1550 vput(vp); 1551 return (EBUSY); 1552 } 1553 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1554 strcpy(pathbuf, fspath); 1555 error = vn_path_to_global_path(td, vp, pathbuf, MNAMELEN); 1556 if (error == 0) { 1557 error = vfs_domount_first(td, vfsp, pathbuf, vp, 1558 fsflags, optlist); 1559 } 1560 free(pathbuf, M_TEMP); 1561 } else 1562 error = vfs_domount_update(td, vp, fsflags, optlist); 1563 1564 return (error); 1565 } 1566 1567 /* 1568 * Unmount a filesystem. 1569 * 1570 * Note: unmount takes a path to the vnode mounted on as argument, not 1571 * special file (as before). 1572 */ 1573 #ifndef _SYS_SYSPROTO_H_ 1574 struct unmount_args { 1575 char *path; 1576 int flags; 1577 }; 1578 #endif 1579 /* ARGSUSED */ 1580 int 1581 sys_unmount(struct thread *td, struct unmount_args *uap) 1582 { 1583 1584 return (kern_unmount(td, uap->path, uap->flags)); 1585 } 1586 1587 int 1588 kern_unmount(struct thread *td, const char *path, int flags) 1589 { 1590 struct nameidata nd; 1591 struct mount *mp; 1592 char *fsidbuf, *pathbuf; 1593 fsid_t fsid; 1594 int error; 1595 1596 AUDIT_ARG_VALUE(flags); 1597 if (jailed(td->td_ucred) || usermount == 0) { 1598 error = priv_check(td, PRIV_VFS_UNMOUNT); 1599 if (error) 1600 return (error); 1601 } 1602 1603 if (flags & MNT_BYFSID) { 1604 fsidbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1605 error = copyinstr(path, fsidbuf, MNAMELEN, NULL); 1606 if (error) { 1607 free(fsidbuf, M_TEMP); 1608 return (error); 1609 } 1610 1611 AUDIT_ARG_TEXT(fsidbuf); 1612 /* Decode the filesystem ID. */ 1613 if (sscanf(fsidbuf, "FSID:%d:%d", &fsid.val[0], &fsid.val[1]) != 2) { 1614 free(fsidbuf, M_TEMP); 1615 return (EINVAL); 1616 } 1617 1618 mp = vfs_getvfs(&fsid); 1619 free(fsidbuf, M_TEMP); 1620 if (mp == NULL) { 1621 return (ENOENT); 1622 } 1623 } else { 1624 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1625 error = copyinstr(path, pathbuf, MNAMELEN, NULL); 1626 if (error) { 1627 free(pathbuf, M_TEMP); 1628 return (error); 1629 } 1630 1631 /* 1632 * Try to find global path for path argument. 1633 */ 1634 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, 1635 UIO_SYSSPACE, pathbuf, td); 1636 if (namei(&nd) == 0) { 1637 NDFREE(&nd, NDF_ONLY_PNBUF); 1638 error = vn_path_to_global_path(td, nd.ni_vp, pathbuf, 1639 MNAMELEN); 1640 if (error == 0) 1641 vput(nd.ni_vp); 1642 } 1643 mtx_lock(&mountlist_mtx); 1644 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1645 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) { 1646 vfs_ref(mp); 1647 break; 1648 } 1649 } 1650 mtx_unlock(&mountlist_mtx); 1651 free(pathbuf, M_TEMP); 1652 if (mp == NULL) { 1653 /* 1654 * Previously we returned ENOENT for a nonexistent path and 1655 * EINVAL for a non-mountpoint. We cannot tell these apart 1656 * now, so in the !MNT_BYFSID case return the more likely 1657 * EINVAL for compatibility. 1658 */ 1659 return (EINVAL); 1660 } 1661 } 1662 1663 /* 1664 * Don't allow unmounting the root filesystem. 1665 */ 1666 if (mp->mnt_flag & MNT_ROOTFS) { 1667 vfs_rel(mp); 1668 return (EINVAL); 1669 } 1670 error = dounmount(mp, flags, td); 1671 return (error); 1672 } 1673 1674 /* 1675 * Return error if any of the vnodes, ignoring the root vnode 1676 * and the syncer vnode, have non-zero usecount. 1677 * 1678 * This function is purely advisory - it can return false positives 1679 * and negatives. 1680 */ 1681 static int 1682 vfs_check_usecounts(struct mount *mp) 1683 { 1684 struct vnode *vp, *mvp; 1685 1686 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 1687 if ((vp->v_vflag & VV_ROOT) == 0 && vp->v_type != VNON && 1688 vp->v_usecount != 0) { 1689 VI_UNLOCK(vp); 1690 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 1691 return (EBUSY); 1692 } 1693 VI_UNLOCK(vp); 1694 } 1695 1696 return (0); 1697 } 1698 1699 static void 1700 dounmount_cleanup(struct mount *mp, struct vnode *coveredvp, int mntkflags) 1701 { 1702 1703 mtx_assert(MNT_MTX(mp), MA_OWNED); 1704 mp->mnt_kern_flag &= ~mntkflags; 1705 if ((mp->mnt_kern_flag & MNTK_MWAIT) != 0) { 1706 mp->mnt_kern_flag &= ~MNTK_MWAIT; 1707 wakeup(mp); 1708 } 1709 vfs_op_exit_locked(mp); 1710 MNT_IUNLOCK(mp); 1711 if (coveredvp != NULL) { 1712 VOP_UNLOCK(coveredvp); 1713 vdrop(coveredvp); 1714 } 1715 vn_finished_write(mp); 1716 } 1717 1718 /* 1719 * There are various reference counters associated with the mount point. 1720 * Normally it is permitted to modify them without taking the mnt ilock, 1721 * but this behavior can be temporarily disabled if stable value is needed 1722 * or callers are expected to block (e.g. to not allow new users during 1723 * forced unmount). 1724 */ 1725 void 1726 vfs_op_enter(struct mount *mp) 1727 { 1728 struct mount_pcpu *mpcpu; 1729 int cpu; 1730 1731 MNT_ILOCK(mp); 1732 mp->mnt_vfs_ops++; 1733 if (mp->mnt_vfs_ops > 1) { 1734 MNT_IUNLOCK(mp); 1735 return; 1736 } 1737 vfs_op_barrier_wait(mp); 1738 CPU_FOREACH(cpu) { 1739 mpcpu = vfs_mount_pcpu_remote(mp, cpu); 1740 1741 mp->mnt_ref += mpcpu->mntp_ref; 1742 mpcpu->mntp_ref = 0; 1743 1744 mp->mnt_lockref += mpcpu->mntp_lockref; 1745 mpcpu->mntp_lockref = 0; 1746 1747 mp->mnt_writeopcount += mpcpu->mntp_writeopcount; 1748 mpcpu->mntp_writeopcount = 0; 1749 } 1750 if (mp->mnt_ref <= 0 || mp->mnt_lockref < 0 || mp->mnt_writeopcount < 0) 1751 panic("%s: invalid count(s) on mp %p: ref %d lockref %d writeopcount %d\n", 1752 __func__, mp, mp->mnt_ref, mp->mnt_lockref, mp->mnt_writeopcount); 1753 MNT_IUNLOCK(mp); 1754 vfs_assert_mount_counters(mp); 1755 } 1756 1757 void 1758 vfs_op_exit_locked(struct mount *mp) 1759 { 1760 1761 mtx_assert(MNT_MTX(mp), MA_OWNED); 1762 1763 if (mp->mnt_vfs_ops <= 0) 1764 panic("%s: invalid vfs_ops count %d for mp %p\n", 1765 __func__, mp->mnt_vfs_ops, mp); 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 | V_MNTREF); 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 /* 2211 * If we failed to flush the dirty blocks for this mount point, 2212 * undo all the cdir/rdir and rootvnode changes we made above. 2213 * Unless we failed to do so because the device is reporting that 2214 * it doesn't exist anymore. 2215 */ 2216 if (error && error != ENXIO) { 2217 MNT_ILOCK(mp); 2218 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 2219 MNT_IUNLOCK(mp); 2220 vfs_allocate_syncvnode(mp); 2221 MNT_ILOCK(mp); 2222 } 2223 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 2224 mp->mnt_flag |= async_flag; 2225 if ((mp->mnt_flag & MNT_ASYNC) != 0 && 2226 (mp->mnt_kern_flag & MNTK_NOASYNC) == 0) 2227 mp->mnt_kern_flag |= MNTK_ASYNC; 2228 if (mp->mnt_kern_flag & MNTK_MWAIT) { 2229 mp->mnt_kern_flag &= ~MNTK_MWAIT; 2230 wakeup(mp); 2231 } 2232 vfs_op_exit_locked(mp); 2233 MNT_IUNLOCK(mp); 2234 if (coveredvp) { 2235 vn_seqc_write_end(coveredvp); 2236 VOP_UNLOCK(coveredvp); 2237 vdrop(coveredvp); 2238 } 2239 if (rootvp != NULL) { 2240 vn_seqc_write_end(rootvp); 2241 vdrop(rootvp); 2242 } 2243 return (error); 2244 } 2245 2246 mtx_lock(&mountlist_mtx); 2247 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2248 mtx_unlock(&mountlist_mtx); 2249 EVENTHANDLER_DIRECT_INVOKE(vfs_unmounted, mp, td); 2250 if (coveredvp != NULL) { 2251 VI_LOCK(coveredvp); 2252 vn_irflag_unset_locked(coveredvp, VIRF_MOUNTPOINT); 2253 coveredvp->v_mountedhere = NULL; 2254 vn_seqc_write_end_locked(coveredvp); 2255 VI_UNLOCK(coveredvp); 2256 VOP_UNLOCK(coveredvp); 2257 vdrop(coveredvp); 2258 } 2259 mount_devctl_event("UNMOUNT", mp, false); 2260 if (rootvp != NULL) { 2261 vn_seqc_write_end(rootvp); 2262 vdrop(rootvp); 2263 } 2264 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 2265 if (rootvnode != NULL && mp == rootvnode->v_mount) { 2266 vrele(rootvnode); 2267 rootvnode = NULL; 2268 } 2269 if (mp == rootdevmp) 2270 rootdevmp = NULL; 2271 if ((flags & MNT_DEFERRED) != 0) 2272 vfs_rel(mp); 2273 vfs_mount_destroy(mp); 2274 return (0); 2275 } 2276 2277 /* 2278 * Report errors during filesystem mounting. 2279 */ 2280 void 2281 vfs_mount_error(struct mount *mp, const char *fmt, ...) 2282 { 2283 struct vfsoptlist *moptlist = mp->mnt_optnew; 2284 va_list ap; 2285 int error, len; 2286 char *errmsg; 2287 2288 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len); 2289 if (error || errmsg == NULL || len <= 0) 2290 return; 2291 2292 va_start(ap, fmt); 2293 vsnprintf(errmsg, (size_t)len, fmt, ap); 2294 va_end(ap); 2295 } 2296 2297 void 2298 vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...) 2299 { 2300 va_list ap; 2301 int error, len; 2302 char *errmsg; 2303 2304 error = vfs_getopt(opts, "errmsg", (void **)&errmsg, &len); 2305 if (error || errmsg == NULL || len <= 0) 2306 return; 2307 2308 va_start(ap, fmt); 2309 vsnprintf(errmsg, (size_t)len, fmt, ap); 2310 va_end(ap); 2311 } 2312 2313 /* 2314 * --------------------------------------------------------------------- 2315 * Functions for querying mount options/arguments from filesystems. 2316 */ 2317 2318 /* 2319 * Check that no unknown options are given 2320 */ 2321 int 2322 vfs_filteropt(struct vfsoptlist *opts, const char **legal) 2323 { 2324 struct vfsopt *opt; 2325 char errmsg[255]; 2326 const char **t, *p, *q; 2327 int ret = 0; 2328 2329 TAILQ_FOREACH(opt, opts, link) { 2330 p = opt->name; 2331 q = NULL; 2332 if (p[0] == 'n' && p[1] == 'o') 2333 q = p + 2; 2334 for(t = global_opts; *t != NULL; t++) { 2335 if (strcmp(*t, p) == 0) 2336 break; 2337 if (q != NULL) { 2338 if (strcmp(*t, q) == 0) 2339 break; 2340 } 2341 } 2342 if (*t != NULL) 2343 continue; 2344 for(t = legal; *t != NULL; t++) { 2345 if (strcmp(*t, p) == 0) 2346 break; 2347 if (q != NULL) { 2348 if (strcmp(*t, q) == 0) 2349 break; 2350 } 2351 } 2352 if (*t != NULL) 2353 continue; 2354 snprintf(errmsg, sizeof(errmsg), 2355 "mount option <%s> is unknown", p); 2356 ret = EINVAL; 2357 } 2358 if (ret != 0) { 2359 TAILQ_FOREACH(opt, opts, link) { 2360 if (strcmp(opt->name, "errmsg") == 0) { 2361 strncpy((char *)opt->value, errmsg, opt->len); 2362 break; 2363 } 2364 } 2365 if (opt == NULL) 2366 printf("%s\n", errmsg); 2367 } 2368 return (ret); 2369 } 2370 2371 /* 2372 * Get a mount option by its name. 2373 * 2374 * Return 0 if the option was found, ENOENT otherwise. 2375 * If len is non-NULL it will be filled with the length 2376 * of the option. If buf is non-NULL, it will be filled 2377 * with the address of the option. 2378 */ 2379 int 2380 vfs_getopt(struct vfsoptlist *opts, const char *name, void **buf, int *len) 2381 { 2382 struct vfsopt *opt; 2383 2384 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 2385 2386 TAILQ_FOREACH(opt, opts, link) { 2387 if (strcmp(name, opt->name) == 0) { 2388 opt->seen = 1; 2389 if (len != NULL) 2390 *len = opt->len; 2391 if (buf != NULL) 2392 *buf = opt->value; 2393 return (0); 2394 } 2395 } 2396 return (ENOENT); 2397 } 2398 2399 int 2400 vfs_getopt_pos(struct vfsoptlist *opts, const char *name) 2401 { 2402 struct vfsopt *opt; 2403 2404 if (opts == NULL) 2405 return (-1); 2406 2407 TAILQ_FOREACH(opt, opts, link) { 2408 if (strcmp(name, opt->name) == 0) { 2409 opt->seen = 1; 2410 return (opt->pos); 2411 } 2412 } 2413 return (-1); 2414 } 2415 2416 int 2417 vfs_getopt_size(struct vfsoptlist *opts, const char *name, off_t *value) 2418 { 2419 char *opt_value, *vtp; 2420 quad_t iv; 2421 int error, opt_len; 2422 2423 error = vfs_getopt(opts, name, (void **)&opt_value, &opt_len); 2424 if (error != 0) 2425 return (error); 2426 if (opt_len == 0 || opt_value == NULL) 2427 return (EINVAL); 2428 if (opt_value[0] == '\0' || opt_value[opt_len - 1] != '\0') 2429 return (EINVAL); 2430 iv = strtoq(opt_value, &vtp, 0); 2431 if (vtp == opt_value || (vtp[0] != '\0' && vtp[1] != '\0')) 2432 return (EINVAL); 2433 if (iv < 0) 2434 return (EINVAL); 2435 switch (vtp[0]) { 2436 case 't': case 'T': 2437 iv *= 1024; 2438 /* FALLTHROUGH */ 2439 case 'g': case 'G': 2440 iv *= 1024; 2441 /* FALLTHROUGH */ 2442 case 'm': case 'M': 2443 iv *= 1024; 2444 /* FALLTHROUGH */ 2445 case 'k': case 'K': 2446 iv *= 1024; 2447 case '\0': 2448 break; 2449 default: 2450 return (EINVAL); 2451 } 2452 *value = iv; 2453 2454 return (0); 2455 } 2456 2457 char * 2458 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 2459 { 2460 struct vfsopt *opt; 2461 2462 *error = 0; 2463 TAILQ_FOREACH(opt, opts, link) { 2464 if (strcmp(name, opt->name) != 0) 2465 continue; 2466 opt->seen = 1; 2467 if (opt->len == 0 || 2468 ((char *)opt->value)[opt->len - 1] != '\0') { 2469 *error = EINVAL; 2470 return (NULL); 2471 } 2472 return (opt->value); 2473 } 2474 *error = ENOENT; 2475 return (NULL); 2476 } 2477 2478 int 2479 vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w, 2480 uint64_t val) 2481 { 2482 struct vfsopt *opt; 2483 2484 TAILQ_FOREACH(opt, opts, link) { 2485 if (strcmp(name, opt->name) == 0) { 2486 opt->seen = 1; 2487 if (w != NULL) 2488 *w |= val; 2489 return (1); 2490 } 2491 } 2492 if (w != NULL) 2493 *w &= ~val; 2494 return (0); 2495 } 2496 2497 int 2498 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 2499 { 2500 va_list ap; 2501 struct vfsopt *opt; 2502 int ret; 2503 2504 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 2505 2506 TAILQ_FOREACH(opt, opts, link) { 2507 if (strcmp(name, opt->name) != 0) 2508 continue; 2509 opt->seen = 1; 2510 if (opt->len == 0 || opt->value == NULL) 2511 return (0); 2512 if (((char *)opt->value)[opt->len - 1] != '\0') 2513 return (0); 2514 va_start(ap, fmt); 2515 ret = vsscanf(opt->value, fmt, ap); 2516 va_end(ap); 2517 return (ret); 2518 } 2519 return (0); 2520 } 2521 2522 int 2523 vfs_setopt(struct vfsoptlist *opts, const char *name, void *value, int len) 2524 { 2525 struct vfsopt *opt; 2526 2527 TAILQ_FOREACH(opt, opts, link) { 2528 if (strcmp(name, opt->name) != 0) 2529 continue; 2530 opt->seen = 1; 2531 if (opt->value == NULL) 2532 opt->len = len; 2533 else { 2534 if (opt->len != len) 2535 return (EINVAL); 2536 bcopy(value, opt->value, len); 2537 } 2538 return (0); 2539 } 2540 return (ENOENT); 2541 } 2542 2543 int 2544 vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value, int len) 2545 { 2546 struct vfsopt *opt; 2547 2548 TAILQ_FOREACH(opt, opts, link) { 2549 if (strcmp(name, opt->name) != 0) 2550 continue; 2551 opt->seen = 1; 2552 if (opt->value == NULL) 2553 opt->len = len; 2554 else { 2555 if (opt->len < len) 2556 return (EINVAL); 2557 opt->len = len; 2558 bcopy(value, opt->value, len); 2559 } 2560 return (0); 2561 } 2562 return (ENOENT); 2563 } 2564 2565 int 2566 vfs_setopts(struct vfsoptlist *opts, const char *name, const char *value) 2567 { 2568 struct vfsopt *opt; 2569 2570 TAILQ_FOREACH(opt, opts, link) { 2571 if (strcmp(name, opt->name) != 0) 2572 continue; 2573 opt->seen = 1; 2574 if (opt->value == NULL) 2575 opt->len = strlen(value) + 1; 2576 else if (strlcpy(opt->value, value, opt->len) >= opt->len) 2577 return (EINVAL); 2578 return (0); 2579 } 2580 return (ENOENT); 2581 } 2582 2583 /* 2584 * Find and copy a mount option. 2585 * 2586 * The size of the buffer has to be specified 2587 * in len, if it is not the same length as the 2588 * mount option, EINVAL is returned. 2589 * Returns ENOENT if the option is not found. 2590 */ 2591 int 2592 vfs_copyopt(struct vfsoptlist *opts, const char *name, void *dest, int len) 2593 { 2594 struct vfsopt *opt; 2595 2596 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 2597 2598 TAILQ_FOREACH(opt, opts, link) { 2599 if (strcmp(name, opt->name) == 0) { 2600 opt->seen = 1; 2601 if (len != opt->len) 2602 return (EINVAL); 2603 bcopy(opt->value, dest, opt->len); 2604 return (0); 2605 } 2606 } 2607 return (ENOENT); 2608 } 2609 2610 int 2611 __vfs_statfs(struct mount *mp, struct statfs *sbp) 2612 { 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 2628 return (mp->mnt_op->vfs_statfs(mp, sbp)); 2629 } 2630 2631 void 2632 vfs_mountedfrom(struct mount *mp, const char *from) 2633 { 2634 2635 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 2636 strlcpy(mp->mnt_stat.f_mntfromname, from, 2637 sizeof mp->mnt_stat.f_mntfromname); 2638 } 2639 2640 /* 2641 * --------------------------------------------------------------------- 2642 * This is the api for building mount args and mounting filesystems from 2643 * inside the kernel. 2644 * 2645 * The API works by accumulation of individual args. First error is 2646 * latched. 2647 * 2648 * XXX: should be documented in new manpage kernel_mount(9) 2649 */ 2650 2651 /* A memory allocation which must be freed when we are done */ 2652 struct mntaarg { 2653 SLIST_ENTRY(mntaarg) next; 2654 }; 2655 2656 /* The header for the mount arguments */ 2657 struct mntarg { 2658 struct iovec *v; 2659 int len; 2660 int error; 2661 SLIST_HEAD(, mntaarg) list; 2662 }; 2663 2664 /* 2665 * Add a boolean argument. 2666 * 2667 * flag is the boolean value. 2668 * name must start with "no". 2669 */ 2670 struct mntarg * 2671 mount_argb(struct mntarg *ma, int flag, const char *name) 2672 { 2673 2674 KASSERT(name[0] == 'n' && name[1] == 'o', 2675 ("mount_argb(...,%s): name must start with 'no'", name)); 2676 2677 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 2678 } 2679 2680 /* 2681 * Add an argument printf style 2682 */ 2683 struct mntarg * 2684 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 2685 { 2686 va_list ap; 2687 struct mntaarg *maa; 2688 struct sbuf *sb; 2689 int len; 2690 2691 if (ma == NULL) { 2692 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2693 SLIST_INIT(&ma->list); 2694 } 2695 if (ma->error) 2696 return (ma); 2697 2698 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2699 M_MOUNT, M_WAITOK); 2700 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2701 ma->v[ma->len].iov_len = strlen(name) + 1; 2702 ma->len++; 2703 2704 sb = sbuf_new_auto(); 2705 va_start(ap, fmt); 2706 sbuf_vprintf(sb, fmt, ap); 2707 va_end(ap); 2708 sbuf_finish(sb); 2709 len = sbuf_len(sb) + 1; 2710 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2711 SLIST_INSERT_HEAD(&ma->list, maa, next); 2712 bcopy(sbuf_data(sb), maa + 1, len); 2713 sbuf_delete(sb); 2714 2715 ma->v[ma->len].iov_base = maa + 1; 2716 ma->v[ma->len].iov_len = len; 2717 ma->len++; 2718 2719 return (ma); 2720 } 2721 2722 /* 2723 * Add an argument which is a userland string. 2724 */ 2725 struct mntarg * 2726 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 2727 { 2728 struct mntaarg *maa; 2729 char *tbuf; 2730 2731 if (val == NULL) 2732 return (ma); 2733 if (ma == NULL) { 2734 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2735 SLIST_INIT(&ma->list); 2736 } 2737 if (ma->error) 2738 return (ma); 2739 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2740 SLIST_INSERT_HEAD(&ma->list, maa, next); 2741 tbuf = (void *)(maa + 1); 2742 ma->error = copyinstr(val, tbuf, len, NULL); 2743 return (mount_arg(ma, name, tbuf, -1)); 2744 } 2745 2746 /* 2747 * Plain argument. 2748 * 2749 * If length is -1, treat value as a C string. 2750 */ 2751 struct mntarg * 2752 mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 2753 { 2754 2755 if (ma == NULL) { 2756 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2757 SLIST_INIT(&ma->list); 2758 } 2759 if (ma->error) 2760 return (ma); 2761 2762 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2763 M_MOUNT, M_WAITOK); 2764 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2765 ma->v[ma->len].iov_len = strlen(name) + 1; 2766 ma->len++; 2767 2768 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 2769 if (len < 0) 2770 ma->v[ma->len].iov_len = strlen(val) + 1; 2771 else 2772 ma->v[ma->len].iov_len = len; 2773 ma->len++; 2774 return (ma); 2775 } 2776 2777 /* 2778 * Free a mntarg structure 2779 */ 2780 static void 2781 free_mntarg(struct mntarg *ma) 2782 { 2783 struct mntaarg *maa; 2784 2785 while (!SLIST_EMPTY(&ma->list)) { 2786 maa = SLIST_FIRST(&ma->list); 2787 SLIST_REMOVE_HEAD(&ma->list, next); 2788 free(maa, M_MOUNT); 2789 } 2790 free(ma->v, M_MOUNT); 2791 free(ma, M_MOUNT); 2792 } 2793 2794 /* 2795 * Mount a filesystem 2796 */ 2797 int 2798 kernel_mount(struct mntarg *ma, uint64_t flags) 2799 { 2800 struct uio auio; 2801 int error; 2802 2803 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 2804 KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v")); 2805 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 2806 2807 auio.uio_iov = ma->v; 2808 auio.uio_iovcnt = ma->len; 2809 auio.uio_segflg = UIO_SYSSPACE; 2810 2811 error = ma->error; 2812 if (!error) 2813 error = vfs_donmount(curthread, flags, &auio); 2814 free_mntarg(ma); 2815 return (error); 2816 } 2817 2818 /* 2819 * A printflike function to mount a filesystem. 2820 */ 2821 int 2822 kernel_vmount(int flags, ...) 2823 { 2824 struct mntarg *ma = NULL; 2825 va_list ap; 2826 const char *cp; 2827 const void *vp; 2828 int error; 2829 2830 va_start(ap, flags); 2831 for (;;) { 2832 cp = va_arg(ap, const char *); 2833 if (cp == NULL) 2834 break; 2835 vp = va_arg(ap, const void *); 2836 ma = mount_arg(ma, cp, vp, (vp != NULL ? -1 : 0)); 2837 } 2838 va_end(ap); 2839 2840 error = kernel_mount(ma, flags); 2841 return (error); 2842 } 2843 2844 /* Map from mount options to printable formats. */ 2845 static struct mntoptnames optnames[] = { 2846 MNTOPT_NAMES 2847 }; 2848 2849 #define DEVCTL_LEN 1024 2850 static void 2851 mount_devctl_event(const char *type, struct mount *mp, bool donew) 2852 { 2853 const uint8_t *cp; 2854 struct mntoptnames *fp; 2855 struct sbuf sb; 2856 struct statfs *sfp = &mp->mnt_stat; 2857 char *buf; 2858 2859 buf = malloc(DEVCTL_LEN, M_MOUNT, M_NOWAIT); 2860 if (buf == NULL) 2861 return; 2862 sbuf_new(&sb, buf, DEVCTL_LEN, SBUF_FIXEDLEN); 2863 sbuf_cpy(&sb, "mount-point=\""); 2864 devctl_safe_quote_sb(&sb, sfp->f_mntonname); 2865 sbuf_cat(&sb, "\" mount-dev=\""); 2866 devctl_safe_quote_sb(&sb, sfp->f_mntfromname); 2867 sbuf_cat(&sb, "\" mount-type=\""); 2868 devctl_safe_quote_sb(&sb, sfp->f_fstypename); 2869 sbuf_cat(&sb, "\" fsid=0x"); 2870 cp = (const uint8_t *)&sfp->f_fsid.val[0]; 2871 for (int i = 0; i < sizeof(sfp->f_fsid); i++) 2872 sbuf_printf(&sb, "%02x", cp[i]); 2873 sbuf_printf(&sb, " owner=%u flags=\"", sfp->f_owner); 2874 for (fp = optnames; fp->o_opt != 0; fp++) { 2875 if ((mp->mnt_flag & fp->o_opt) != 0) { 2876 sbuf_cat(&sb, fp->o_name); 2877 sbuf_putc(&sb, ';'); 2878 } 2879 } 2880 sbuf_putc(&sb, '"'); 2881 sbuf_finish(&sb); 2882 2883 /* 2884 * Options are not published because the form of the options depends on 2885 * the file system and may include binary data. In addition, they don't 2886 * necessarily provide enough useful information to be actionable when 2887 * devd processes them. 2888 */ 2889 2890 if (sbuf_error(&sb) == 0) 2891 devctl_notify("VFS", "FS", type, sbuf_data(&sb)); 2892 sbuf_delete(&sb); 2893 free(buf, M_MOUNT); 2894 } 2895 2896 /* 2897 * Suspend write operations on all local writeable filesystems. Does 2898 * full sync of them in the process. 2899 * 2900 * Iterate over the mount points in reverse order, suspending most 2901 * recently mounted filesystems first. It handles a case where a 2902 * filesystem mounted from a md(4) vnode-backed device should be 2903 * suspended before the filesystem that owns the vnode. 2904 */ 2905 void 2906 suspend_all_fs(void) 2907 { 2908 struct mount *mp; 2909 int error; 2910 2911 mtx_lock(&mountlist_mtx); 2912 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 2913 error = vfs_busy(mp, MBF_MNTLSTLOCK | MBF_NOWAIT); 2914 if (error != 0) 2915 continue; 2916 if ((mp->mnt_flag & (MNT_RDONLY | MNT_LOCAL)) != MNT_LOCAL || 2917 (mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 2918 mtx_lock(&mountlist_mtx); 2919 vfs_unbusy(mp); 2920 continue; 2921 } 2922 error = vfs_write_suspend(mp, 0); 2923 if (error == 0) { 2924 MNT_ILOCK(mp); 2925 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0); 2926 mp->mnt_kern_flag |= MNTK_SUSPEND_ALL; 2927 MNT_IUNLOCK(mp); 2928 mtx_lock(&mountlist_mtx); 2929 } else { 2930 printf("suspend of %s failed, error %d\n", 2931 mp->mnt_stat.f_mntonname, error); 2932 mtx_lock(&mountlist_mtx); 2933 vfs_unbusy(mp); 2934 } 2935 } 2936 mtx_unlock(&mountlist_mtx); 2937 } 2938 2939 void 2940 resume_all_fs(void) 2941 { 2942 struct mount *mp; 2943 2944 mtx_lock(&mountlist_mtx); 2945 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 2946 if ((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0) 2947 continue; 2948 mtx_unlock(&mountlist_mtx); 2949 MNT_ILOCK(mp); 2950 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) != 0); 2951 mp->mnt_kern_flag &= ~MNTK_SUSPEND_ALL; 2952 MNT_IUNLOCK(mp); 2953 vfs_write_resume(mp, 0); 2954 mtx_lock(&mountlist_mtx); 2955 vfs_unbusy(mp); 2956 } 2957 mtx_unlock(&mountlist_mtx); 2958 } 2959