sys/kern/vfs_mount.c

   1 /*-
   2  * Copyright (c) 1999-2004 Poul-Henning Kamp
   3  * Copyright (c) 1999 Michael Smith
   4  * Copyright (c) 1989, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  * (c) UNIX System Laboratories, Inc.
   7  * All or some portions of this file are derived from material licensed
   8  * to the University of California by American Telephone and Telegraph
   9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  10  * the permission of UNIX System Laboratories, Inc.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include <sys/param.h>
  41 #include <sys/conf.h>
  42 #include <sys/fcntl.h>
  43 #include <sys/jail.h>
  44 #include <sys/kernel.h>
  45 #include <sys/libkern.h>
  46 #include <sys/malloc.h>
  47 #include <sys/mount.h>
  48 #include <sys/mutex.h>
  49 #include <sys/namei.h>
  50 #include <sys/priv.h>
  51 #include <sys/proc.h>
  52 #include <sys/filedesc.h>
  53 #include <sys/reboot.h>
  54 #include <sys/sbuf.h>
  55 #include <sys/syscallsubr.h>
  56 #include <sys/sysproto.h>
  57 #include <sys/sx.h>
  58 #include <sys/sysctl.h>
  59 #include <sys/sysent.h>
  60 #include <sys/systm.h>
  61 #include <sys/vnode.h>
  62 #include <vm/uma.h>
  63
  64 #include <geom/geom.h>
  65
  66 #include <machine/stdarg.h>
  67
  68 #include <security/audit/audit.h>
  69 #include <security/mac/mac_framework.h>
  70
  71 #define VFS_MOUNTARG_SIZE_MAX   (1024 * 64)
  72
  73 static int      vfs_domount(struct thread *td, const char *fstype, char *fspath,
  74                     uint64_t fsflags, struct vfsoptlist **optlist);
  75 static void     free_mntarg(struct mntarg *ma);
  76
  77 static int      usermount = 0;
  78 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0,
  79     "Unprivileged users may mount and unmount file systems");
  80
  81 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
  82 static uma_zone_t mount_zone;
  83
  84 /* List of mounted filesystems. */
  85 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist);
  86
  87 /* For any iteration/modification of mountlist */
  88 struct mtx mountlist_mtx;
  89 MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF);
  90
  91 /*
  92  * Global opts, taken by all filesystems
  93  */
  94 static const char *global_opts[] = {
  95         "errmsg",
  96         "fstype",
  97         "fspath",
  98         "ro",
  99         "rw",
 100         "nosuid",
 101         "noexec",
 102         NULL
 103 };
 104
 105 static int
 106 mount_init(void *mem, int size, int flags)
 107 {
 108         struct mount *mp;
 109
 110         mp = (struct mount *)mem;
 111         mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
 112         lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0);
 113         return (0);
 114 }
 115
 116 static void
 117 mount_fini(void *mem, int size)
 118 {
 119         struct mount *mp;
 120
 121         mp = (struct mount *)mem;
 122         lockdestroy(&mp->mnt_explock);
 123         mtx_destroy(&mp->mnt_mtx);
 124 }
 125
 126 static void
 127 vfs_mount_init(void *dummy __unused)
 128 {
 129
 130         mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), NULL,
 131             NULL, mount_init, mount_fini, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 132 }
 133 SYSINIT(vfs_mount, SI_SUB_VFS, SI_ORDER_ANY, vfs_mount_init, NULL);
 134
 135 /*
 136  * ---------------------------------------------------------------------
 137  * Functions for building and sanitizing the mount options
 138  */
 139
 140 /* Remove one mount option. */
 141 static void
 142 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt)
 143 {
 144
 145         TAILQ_REMOVE(opts, opt, link);
 146         free(opt->name, M_MOUNT);
 147         if (opt->value != NULL)
 148                 free(opt->value, M_MOUNT);
 149         free(opt, M_MOUNT);
 150 }
 151
 152 /* Release all resources related to the mount options. */
 153 void
 154 vfs_freeopts(struct vfsoptlist *opts)
 155 {
 156         struct vfsopt *opt;
 157
 158         while (!TAILQ_EMPTY(opts)) {
 159                 opt = TAILQ_FIRST(opts);
 160                 vfs_freeopt(opts, opt);
 161         }
 162         free(opts, M_MOUNT);
 163 }
 164
 165 void
 166 vfs_deleteopt(struct vfsoptlist *opts, const char *name)
 167 {
 168         struct vfsopt *opt, *temp;
 169
 170         if (opts == NULL)
 171                 return;
 172         TAILQ_FOREACH_SAFE(opt, opts, link, temp)  {
 173                 if (strcmp(opt->name, name) == 0)
 174                         vfs_freeopt(opts, opt);
 175         }
 176 }
 177
 178 static int
 179 vfs_isopt_ro(const char *opt)
 180 {
 181
 182         if (strcmp(opt, "ro") == 0 || strcmp(opt, "rdonly") == 0 ||
 183             strcmp(opt, "norw") == 0)
 184                 return (1);
 185         return (0);
 186 }
 187
 188 static int
 189 vfs_isopt_rw(const char *opt)
 190 {
 191
 192         if (strcmp(opt, "rw") == 0 || strcmp(opt, "noro") == 0)
 193                 return (1);
 194         return (0);
 195 }
 196
 197 /*
 198  * Check if options are equal (with or without the "no" prefix).
 199  */
 200 static int
 201 vfs_equalopts(const char *opt1, const char *opt2)
 202 {
 203         char *p;
 204
 205         /* "opt" vs. "opt" or "noopt" vs. "noopt" */
 206         if (strcmp(opt1, opt2) == 0)
 207                 return (1);
 208         /* "noopt" vs. "opt" */
 209         if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
 210                 return (1);
 211         /* "opt" vs. "noopt" */
 212         if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
 213                 return (1);
 214         while ((p = strchr(opt1, '.')) != NULL &&
 215             !strncmp(opt1, opt2, ++p - opt1)) {
 216                 opt2 += p - opt1;
 217                 opt1 = p;
 218                 /* "foo.noopt" vs. "foo.opt" */
 219                 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
 220                         return (1);
 221                 /* "foo.opt" vs. "foo.noopt" */
 222                 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
 223                         return (1);
 224         }
 225         /* "ro" / "rdonly" / "norw" / "rw" / "noro" */
 226         if ((vfs_isopt_ro(opt1) || vfs_isopt_rw(opt1)) &&
 227             (vfs_isopt_ro(opt2) || vfs_isopt_rw(opt2)))
 228                 return (1);
 229         return (0);
 230 }
 231
 232 /*
 233  * If a mount option is specified several times,
 234  * (with or without the "no" prefix) only keep
 235  * the last occurrence of it.
 236  */
 237 static void
 238 vfs_sanitizeopts(struct vfsoptlist *opts)
 239 {
 240         struct vfsopt *opt, *opt2, *tmp;
 241
 242         TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) {
 243                 opt2 = TAILQ_PREV(opt, vfsoptlist, link);
 244                 while (opt2 != NULL) {
 245                         if (vfs_equalopts(opt->name, opt2->name)) {
 246                                 tmp = TAILQ_PREV(opt2, vfsoptlist, link);
 247                                 vfs_freeopt(opts, opt2);
 248                                 opt2 = tmp;
 249                         } else {
 250                                 opt2 = TAILQ_PREV(opt2, vfsoptlist, link);
 251                         }
 252                 }
 253         }
 254 }
 255
 256 /*
 257  * Build a linked list of mount options from a struct uio.
 258  */
 259 int
 260 vfs_buildopts(struct uio *auio, struct vfsoptlist **options)
 261 {
 262         struct vfsoptlist *opts;
 263         struct vfsopt *opt;
 264         size_t memused, namelen, optlen;
 265         unsigned int i, iovcnt;
 266         int error;
 267
 268         opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
 269         TAILQ_INIT(opts);
 270         memused = 0;
 271         iovcnt = auio->uio_iovcnt;
 272         for (i = 0; i < iovcnt; i += 2) {
 273                 namelen = auio->uio_iov[i].iov_len;
 274                 optlen = auio->uio_iov[i + 1].iov_len;
 275                 memused += sizeof(struct vfsopt) + optlen + namelen;
 276                 /*
 277                  * Avoid consuming too much memory, and attempts to overflow
 278                  * memused.
 279                  */
 280                 if (memused > VFS_MOUNTARG_SIZE_MAX ||
 281                     optlen > VFS_MOUNTARG_SIZE_MAX ||
 282                     namelen > VFS_MOUNTARG_SIZE_MAX) {
 283                         error = EINVAL;
 284                         goto bad;
 285                 }
 286
 287                 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
 288                 opt->name = malloc(namelen, M_MOUNT, M_WAITOK);
 289                 opt->value = NULL;
 290                 opt->len = 0;
 291                 opt->pos = i / 2;
 292                 opt->seen = 0;
 293
 294                 /*
 295                  * Do this early, so jumps to "bad" will free the current
 296                  * option.
 297                  */
 298                 TAILQ_INSERT_TAIL(opts, opt, link);
 299
 300                 if (auio->uio_segflg == UIO_SYSSPACE) {
 301                         bcopy(auio->uio_iov[i].iov_base, opt->name, namelen);
 302                 } else {
 303                         error = copyin(auio->uio_iov[i].iov_base, opt->name,
 304                             namelen);
 305                         if (error)
 306                                 goto bad;
 307                 }
 308                 /* Ensure names are null-terminated strings. */
 309                 if (namelen == 0 || opt->name[namelen - 1] != '\0') {
 310                         error = EINVAL;
 311                         goto bad;
 312                 }
 313                 if (optlen != 0) {
 314                         opt->len = optlen;
 315                         opt->value = malloc(optlen, M_MOUNT, M_WAITOK);
 316                         if (auio->uio_segflg == UIO_SYSSPACE) {
 317                                 bcopy(auio->uio_iov[i + 1].iov_base, opt->value,
 318                                     optlen);
 319                         } else {
 320                                 error = copyin(auio->uio_iov[i + 1].iov_base,
 321                                     opt->value, optlen);
 322                                 if (error)
 323                                         goto bad;
 324                         }
 325                 }
 326         }
 327         vfs_sanitizeopts(opts);
 328         *options = opts;
 329         return (0);
 330 bad:
 331         vfs_freeopts(opts);
 332         return (error);
 333 }
 334
 335 /*
 336  * Merge the old mount options with the new ones passed
 337  * in the MNT_UPDATE case.
 338  *
 339  * XXX: This function will keep a "nofoo" option in the new
 340  * options.  E.g, if the option's canonical name is "foo",
 341  * "nofoo" ends up in the mount point's active options.
 342  */
 343 static void
 344 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *oldopts)
 345 {
 346         struct vfsopt *opt, *new;
 347
 348         TAILQ_FOREACH(opt, oldopts, link) {
 349                 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
 350                 new->name = strdup(opt->name, M_MOUNT);
 351                 if (opt->len != 0) {
 352                         new->value = malloc(opt->len, M_MOUNT, M_WAITOK);
 353                         bcopy(opt->value, new->value, opt->len);
 354                 } else
 355                         new->value = NULL;
 356                 new->len = opt->len;
 357                 new->seen = opt->seen;
 358                 TAILQ_INSERT_HEAD(toopts, new, link);
 359         }
 360         vfs_sanitizeopts(toopts);
 361 }
 362
 363 /*
 364  * Mount a filesystem.
 365  */
 366 int
 367 sys_nmount(td, uap)
 368         struct thread *td;
 369         struct nmount_args /* {
 370                 struct iovec *iovp;
 371                 unsigned int iovcnt;
 372                 int flags;
 373         } */ *uap;
 374 {
 375         struct uio *auio;
 376         int error;
 377         u_int iovcnt;
 378         uint64_t flags;
 379
 380         /*
 381          * Mount flags are now 64-bits. On 32-bit archtectures only
 382          * 32-bits are passed in, but from here on everything handles
 383          * 64-bit flags correctly.
 384          */
 385         flags = uap->flags;
 386
 387         AUDIT_ARG_FFLAGS(flags);
 388         CTR4(KTR_VFS, "%s: iovp %p with iovcnt %d and flags %d", __func__,
 389             uap->iovp, uap->iovcnt, flags);
 390
 391         /*
 392          * Filter out MNT_ROOTFS.  We do not want clients of nmount() in
 393          * userspace to set this flag, but we must filter it out if we want
 394          * MNT_UPDATE on the root file system to work.
 395          * MNT_ROOTFS should only be set by the kernel when mounting its
 396          * root file system.
 397          */
 398         flags &= ~MNT_ROOTFS;
 399
 400         iovcnt = uap->iovcnt;
 401         /*
 402          * Check that we have an even number of iovec's
 403          * and that we have at least two options.
 404          */
 405         if ((iovcnt & 1) || (iovcnt < 4)) {
 406                 CTR2(KTR_VFS, "%s: failed for invalid iovcnt %d", __func__,
 407                     uap->iovcnt);
 408                 return (EINVAL);
 409         }
 410
 411         error = copyinuio(uap->iovp, iovcnt, &auio);
 412         if (error) {
 413                 CTR2(KTR_VFS, "%s: failed for invalid uio op with %d errno",
 414                     __func__, error);
 415                 return (error);
 416         }
 417         error = vfs_donmount(td, flags, auio);
 418
 419         free(auio, M_IOV);
 420         return (error);
 421 }
 422
 423 /*
 424  * ---------------------------------------------------------------------
 425  * Various utility functions
 426  */
 427
 428 void
 429 vfs_ref(struct mount *mp)
 430 {
 431
 432         CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
 433         MNT_ILOCK(mp);
 434         MNT_REF(mp);
 435         MNT_IUNLOCK(mp);
 436 }
 437
 438 void
 439 vfs_rel(struct mount *mp)
 440 {
 441
 442         CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
 443         MNT_ILOCK(mp);
 444         MNT_REL(mp);
 445         MNT_IUNLOCK(mp);
 446 }
 447
 448 /*
 449  * Allocate and initialize the mount point struct.
 450  */
 451 struct mount *
 452 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath,
 453     struct ucred *cred)
 454 {
 455         struct mount *mp;
 456
 457         mp = uma_zalloc(mount_zone, M_WAITOK);
 458         bzero(&mp->mnt_startzero,
 459             __rangeof(struct mount, mnt_startzero, mnt_endzero));
 460         TAILQ_INIT(&mp->mnt_nvnodelist);
 461         mp->mnt_nvnodelistsize = 0;
 462         TAILQ_INIT(&mp->mnt_activevnodelist);
 463         mp->mnt_activevnodelistsize = 0;
 464         mp->mnt_ref = 0;
 465         (void) vfs_busy(mp, MBF_NOWAIT);
 466         atomic_add_acq_int(&vfsp->vfc_refcount, 1);
 467         mp->mnt_op = vfsp->vfc_vfsops;
 468         mp->mnt_vfc = vfsp;
 469         mp->mnt_stat.f_type = vfsp->vfc_typenum;
 470         mp->mnt_gen++;
 471         strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
 472         mp->mnt_vnodecovered = vp;
 473         mp->mnt_cred = crdup(cred);
 474         mp->mnt_stat.f_owner = cred->cr_uid;
 475         strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN);
 476         mp->mnt_iosize_max = DFLTPHYS;
 477 #ifdef MAC
 478         mac_mount_init(mp);
 479         mac_mount_create(cred, mp);
 480 #endif
 481         arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0);
 482         TAILQ_INIT(&mp->mnt_uppers);
 483         return (mp);
 484 }
 485
 486 /*
 487  * Destroy the mount struct previously allocated by vfs_mount_alloc().
 488  */
 489 void
 490 vfs_mount_destroy(struct mount *mp)
 491 {
 492
 493         MNT_ILOCK(mp);
 494         mp->mnt_kern_flag |= MNTK_REFEXPIRE;
 495         if (mp->mnt_kern_flag & MNTK_MWAIT) {
 496                 mp->mnt_kern_flag &= ~MNTK_MWAIT;
 497                 wakeup(mp);
 498         }
 499         while (mp->mnt_ref)
 500                 msleep(mp, MNT_MTX(mp), PVFS, "mntref", 0);
 501         KASSERT(mp->mnt_ref == 0,
 502             ("%s: invalid refcount in the drain path @ %s:%d", __func__,
 503             __FILE__, __LINE__));
 504         if (mp->mnt_writeopcount != 0)
 505                 panic("vfs_mount_destroy: nonzero writeopcount");
 506         if (mp->mnt_secondary_writes != 0)
 507                 panic("vfs_mount_destroy: nonzero secondary_writes");
 508         atomic_subtract_rel_int(&mp->mnt_vfc->vfc_refcount, 1);
 509         if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) {
 510                 struct vnode *vp;
 511
 512                 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes)
 513                         vprint("", vp);
 514                 panic("unmount: dangling vnode");
 515         }
 516         KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers"));
 517         if (mp->mnt_nvnodelistsize != 0)
 518                 panic("vfs_mount_destroy: nonzero nvnodelistsize");
 519         if (mp->mnt_activevnodelistsize != 0)
 520                 panic("vfs_mount_destroy: nonzero activevnodelistsize");
 521         if (mp->mnt_lockref != 0)
 522                 panic("vfs_mount_destroy: nonzero lock refcount");
 523         MNT_IUNLOCK(mp);
 524 #ifdef MAC
 525         mac_mount_destroy(mp);
 526 #endif
 527         if (mp->mnt_opt != NULL)
 528                 vfs_freeopts(mp->mnt_opt);
 529         crfree(mp->mnt_cred);
 530         uma_zfree(mount_zone, mp);
 531 }
 532
 533 int
 534 vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions)
 535 {
 536         struct vfsoptlist *optlist;
 537         struct vfsopt *opt, *tmp_opt;
 538         char *fstype, *fspath, *errmsg;
 539         int error, fstypelen, fspathlen, errmsg_len, errmsg_pos;
 540
 541         errmsg = fspath = NULL;
 542         errmsg_len = fspathlen = 0;
 543         errmsg_pos = -1;
 544
 545         error = vfs_buildopts(fsoptions, &optlist);
 546         if (error)
 547                 return (error);
 548
 549         if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0)
 550                 errmsg_pos = vfs_getopt_pos(optlist, "errmsg");
 551
 552         /*
 553          * We need these two options before the others,
 554          * and they are mandatory for any filesystem.
 555          * Ensure they are NUL terminated as well.
 556          */
 557         fstypelen = 0;
 558         error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen);
 559         if (error || fstype[fstypelen - 1] != '\0') {
 560                 error = EINVAL;
 561                 if (errmsg != NULL)
 562                         strncpy(errmsg, "Invalid fstype", errmsg_len);
 563                 goto bail;
 564         }
 565         fspathlen = 0;
 566         error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen);
 567         if (error || fspath[fspathlen - 1] != '\0') {
 568                 error = EINVAL;
 569                 if (errmsg != NULL)
 570                         strncpy(errmsg, "Invalid fspath", errmsg_len);
 571                 goto bail;
 572         }
 573
 574         /*
 575          * We need to see if we have the "update" option
 576          * before we call vfs_domount(), since vfs_domount() has special
 577          * logic based on MNT_UPDATE.  This is very important
 578          * when we want to update the root filesystem.
 579          */
 580         TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) {
 581                 if (strcmp(opt->name, "update") == 0) {
 582                         fsflags |= MNT_UPDATE;
 583                         vfs_freeopt(optlist, opt);
 584                 }
 585                 else if (strcmp(opt->name, "async") == 0)
 586                         fsflags |= MNT_ASYNC;
 587                 else if (strcmp(opt->name, "force") == 0) {
 588                         fsflags |= MNT_FORCE;
 589                         vfs_freeopt(optlist, opt);
 590                 }
 591                 else if (strcmp(opt->name, "reload") == 0) {
 592                         fsflags |= MNT_RELOAD;
 593                         vfs_freeopt(optlist, opt);
 594                 }
 595                 else if (strcmp(opt->name, "multilabel") == 0)
 596                         fsflags |= MNT_MULTILABEL;
 597                 else if (strcmp(opt->name, "noasync") == 0)
 598                         fsflags &= ~MNT_ASYNC;
 599                 else if (strcmp(opt->name, "noatime") == 0)
 600                         fsflags |= MNT_NOATIME;
 601                 else if (strcmp(opt->name, "atime") == 0) {
 602                         free(opt->name, M_MOUNT);
 603                         opt->name = strdup("nonoatime", M_MOUNT);
 604                 }
 605                 else if (strcmp(opt->name, "noclusterr") == 0)
 606                         fsflags |= MNT_NOCLUSTERR;
 607                 else if (strcmp(opt->name, "clusterr") == 0) {
 608                         free(opt->name, M_MOUNT);
 609                         opt->name = strdup("nonoclusterr", M_MOUNT);
 610                 }
 611                 else if (strcmp(opt->name, "noclusterw") == 0)
 612                         fsflags |= MNT_NOCLUSTERW;
 613                 else if (strcmp(opt->name, "clusterw") == 0) {
 614                         free(opt->name, M_MOUNT);
 615                         opt->name = strdup("nonoclusterw", M_MOUNT);
 616                 }
 617                 else if (strcmp(opt->name, "noexec") == 0)
 618                         fsflags |= MNT_NOEXEC;
 619                 else if (strcmp(opt->name, "exec") == 0) {
 620                         free(opt->name, M_MOUNT);
 621                         opt->name = strdup("nonoexec", M_MOUNT);
 622                 }
 623                 else if (strcmp(opt->name, "nosuid") == 0)
 624                         fsflags |= MNT_NOSUID;
 625                 else if (strcmp(opt->name, "suid") == 0) {
 626                         free(opt->name, M_MOUNT);
 627                         opt->name = strdup("nonosuid", M_MOUNT);
 628                 }
 629                 else if (strcmp(opt->name, "nosymfollow") == 0)
 630                         fsflags |= MNT_NOSYMFOLLOW;
 631                 else if (strcmp(opt->name, "symfollow") == 0) {
 632                         free(opt->name, M_MOUNT);
 633                         opt->name = strdup("nonosymfollow", M_MOUNT);
 634                 }
 635                 else if (strcmp(opt->name, "noro") == 0)
 636                         fsflags &= ~MNT_RDONLY;
 637                 else if (strcmp(opt->name, "rw") == 0)
 638                         fsflags &= ~MNT_RDONLY;
 639                 else if (strcmp(opt->name, "ro") == 0)
 640                         fsflags |= MNT_RDONLY;
 641                 else if (strcmp(opt->name, "rdonly") == 0) {
 642                         free(opt->name, M_MOUNT);
 643                         opt->name = strdup("ro", M_MOUNT);
 644                         fsflags |= MNT_RDONLY;
 645                 }
 646                 else if (strcmp(opt->name, "suiddir") == 0)
 647                         fsflags |= MNT_SUIDDIR;
 648                 else if (strcmp(opt->name, "sync") == 0)
 649                         fsflags |= MNT_SYNCHRONOUS;
 650                 else if (strcmp(opt->name, "union") == 0)
 651                         fsflags |= MNT_UNION;
 652                 else if (strcmp(opt->name, "automounted") == 0) {
 653                         fsflags |= MNT_AUTOMOUNTED;
 654                         vfs_freeopt(optlist, opt);
 655                 }
 656         }
 657
 658         /*
 659          * Be ultra-paranoid about making sure the type and fspath
 660          * variables will fit in our mp buffers, including the
 661          * terminating NUL.
 662          */
 663         if (fstypelen > MFSNAMELEN || fspathlen > MNAMELEN) {
 664                 error = ENAMETOOLONG;
 665                 goto bail;
 666         }
 667
 668         error = vfs_domount(td, fstype, fspath, fsflags, &optlist);
 669 bail:
 670         /* copyout the errmsg */
 671         if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt)
 672             && errmsg_len > 0 && errmsg != NULL) {
 673                 if (fsoptions->uio_segflg == UIO_SYSSPACE) {
 674                         bcopy(errmsg,
 675                             fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
 676                             fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
 677                 } else {
 678                         copyout(errmsg,
 679                             fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
 680                             fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
 681                 }
 682         }
 683
 684         if (optlist != NULL)
 685                 vfs_freeopts(optlist);
 686         return (error);
 687 }
 688
 689 /*
 690  * Old mount API.
 691  */
 692 #ifndef _SYS_SYSPROTO_H_
 693 struct mount_args {
 694         char    *type;
 695         char    *path;
 696         int     flags;
 697         caddr_t data;
 698 };
 699 #endif
 700 /* ARGSUSED */
 701 int
 702 sys_mount(td, uap)
 703         struct thread *td;
 704         struct mount_args /* {
 705                 char *type;
 706                 char *path;
 707                 int flags;
 708                 caddr_t data;
 709         } */ *uap;
 710 {
 711         char *fstype;
 712         struct vfsconf *vfsp = NULL;
 713         struct mntarg *ma = NULL;
 714         uint64_t flags;
 715         int error;
 716
 717         /*
 718          * Mount flags are now 64-bits. On 32-bit architectures only
 719          * 32-bits are passed in, but from here on everything handles
 720          * 64-bit flags correctly.
 721          */
 722         flags = uap->flags;
 723
 724         AUDIT_ARG_FFLAGS(flags);
 725
 726         /*
 727          * Filter out MNT_ROOTFS.  We do not want clients of mount() in
 728          * userspace to set this flag, but we must filter it out if we want
 729          * MNT_UPDATE on the root file system to work.
 730          * MNT_ROOTFS should only be set by the kernel when mounting its
 731          * root file system.
 732          */
 733         flags &= ~MNT_ROOTFS;
 734
 735         fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK);
 736         error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL);
 737         if (error) {
 738                 free(fstype, M_TEMP);
 739                 return (error);
 740         }
 741
 742         AUDIT_ARG_TEXT(fstype);
 743         vfsp = vfs_byname_kld(fstype, td, &error);
 744         free(fstype, M_TEMP);
 745         if (vfsp == NULL)
 746                 return (ENOENT);
 747         if (vfsp->vfc_vfsops->vfs_cmount == NULL)
 748                 return (EOPNOTSUPP);
 749
 750         ma = mount_argsu(ma, "fstype", uap->type, MFSNAMELEN);
 751         ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN);
 752         ma = mount_argb(ma, flags & MNT_RDONLY, "noro");
 753         ma = mount_argb(ma, !(flags & MNT_NOSUID), "nosuid");
 754         ma = mount_argb(ma, !(flags & MNT_NOEXEC), "noexec");
 755
 756         error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, flags);
 757         return (error);
 758 }
 759
 760 /*
 761  * vfs_domount_first(): first file system mount (not update)
 762  */
 763 static int
 764 vfs_domount_first(
 765         struct thread *td,              /* Calling thread. */
 766         struct vfsconf *vfsp,           /* File system type. */
 767         char *fspath,                   /* Mount path. */
 768         struct vnode *vp,               /* Vnode to be covered. */
 769         uint64_t fsflags,               /* Flags common to all filesystems. */
 770         struct vfsoptlist **optlist     /* Options local to the filesystem. */
 771         )
 772 {
 773         struct vattr va;
 774         struct mount *mp;
 775         struct vnode *newdp;
 776         int error;
 777
 778         ASSERT_VOP_ELOCKED(vp, __func__);
 779         KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here"));
 780
 781         /*
 782          * If the user is not root, ensure that they own the directory
 783          * onto which we are attempting to mount.
 784          */
 785         error = VOP_GETATTR(vp, &va, td->td_ucred);
 786         if (error == 0 && va.va_uid != td->td_ucred->cr_uid)
 787                 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN, 0);
 788         if (error == 0)
 789                 error = vinvalbuf(vp, V_SAVE, 0, 0);
 790         if (error == 0 && vp->v_type != VDIR)
 791                 error = ENOTDIR;
 792         if (error == 0) {
 793                 VI_LOCK(vp);
 794                 if ((vp->v_iflag & VI_MOUNT) == 0 && vp->v_mountedhere == NULL)
 795                         vp->v_iflag |= VI_MOUNT;
 796                 else
 797                         error = EBUSY;
 798                 VI_UNLOCK(vp);
 799         }
 800         if (error != 0) {
 801                 vput(vp);
 802                 return (error);
 803         }
 804         VOP_UNLOCK(vp, 0);
 805
 806         /* Allocate and initialize the filesystem. */
 807         mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred);
 808         /* XXXMAC: pass to vfs_mount_alloc? */
 809         mp->mnt_optnew = *optlist;
 810         /* Set the mount level flags. */
 811         mp->mnt_flag = (fsflags & (MNT_UPDATEMASK | MNT_ROOTFS | MNT_RDONLY));
 812
 813         /*
 814          * Mount the filesystem.
 815          * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
 816          * get.  No freeing of cn_pnbuf.
 817          */
 818         error = VFS_MOUNT(mp);
 819         if (error != 0) {
 820                 vfs_unbusy(mp);
 821                 vfs_mount_destroy(mp);
 822                 VI_LOCK(vp);
 823                 vp->v_iflag &= ~VI_MOUNT;
 824                 VI_UNLOCK(vp);
 825                 vrele(vp);
 826                 return (error);
 827         }
 828
 829         if (mp->mnt_opt != NULL)
 830                 vfs_freeopts(mp->mnt_opt);
 831         mp->mnt_opt = mp->mnt_optnew;
 832         *optlist = NULL;
 833         (void)VFS_STATFS(mp, &mp->mnt_stat);
 834
 835         /*
 836          * Prevent external consumers of mount options from reading mnt_optnew.
 837          */
 838         mp->mnt_optnew = NULL;
 839
 840         MNT_ILOCK(mp);
 841         if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
 842             (mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
 843                 mp->mnt_kern_flag |= MNTK_ASYNC;
 844         else
 845                 mp->mnt_kern_flag &= ~MNTK_ASYNC;
 846         MNT_IUNLOCK(mp);
 847
 848         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 849         cache_purge(vp);
 850         VI_LOCK(vp);
 851         vp->v_iflag &= ~VI_MOUNT;
 852         VI_UNLOCK(vp);
 853         vp->v_mountedhere = mp;
 854         /* Place the new filesystem at the end of the mount list. */
 855         mtx_lock(&mountlist_mtx);
 856         TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
 857         mtx_unlock(&mountlist_mtx);
 858         vfs_event_signal(NULL, VQ_MOUNT, 0);
 859         if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp))
 860                 panic("mount: lost mount");
 861         VOP_UNLOCK(vp, 0);
 862         EVENTHANDLER_INVOKE(vfs_mounted, mp, newdp, td);
 863         VOP_UNLOCK(newdp, 0);
 864         mountcheckdirs(vp, newdp);
 865         vrele(newdp);
 866         if ((mp->mnt_flag & MNT_RDONLY) == 0)
 867                 vfs_allocate_syncvnode(mp);
 868         vfs_unbusy(mp);
 869         return (0);
 870 }
 871
 872 /*
 873  * vfs_domount_update(): update of mounted file system
 874  */
 875 static int
 876 vfs_domount_update(
 877         struct thread *td,              /* Calling thread. */
 878         struct vnode *vp,               /* Mount point vnode. */
 879         uint64_t fsflags,               /* Flags common to all filesystems. */
 880         struct vfsoptlist **optlist     /* Options local to the filesystem. */
 881         )
 882 {
 883         struct oexport_args oexport;
 884         struct export_args export;
 885         struct mount *mp;
 886         int error, export_error;
 887         uint64_t flag;
 888
 889         ASSERT_VOP_ELOCKED(vp, __func__);
 890         KASSERT((fsflags & MNT_UPDATE) != 0, ("MNT_UPDATE should be here"));
 891         mp = vp->v_mount;
 892
 893         if ((vp->v_vflag & VV_ROOT) == 0) {
 894                 if (vfs_copyopt(*optlist, "export", &export, sizeof(export))
 895                     == 0)
 896                         error = EXDEV;
 897                 else
 898                         error = EINVAL;
 899                 vput(vp);
 900                 return (error);
 901         }
 902
 903         /*
 904          * We only allow the filesystem to be reloaded if it
 905          * is currently mounted read-only.
 906          */
 907         flag = mp->mnt_flag;
 908         if ((fsflags & MNT_RELOAD) != 0 && (flag & MNT_RDONLY) == 0) {
 909                 vput(vp);
 910                 return (EOPNOTSUPP);    /* Needs translation */
 911         }
 912         /*
 913          * Only privileged root, or (if MNT_USER is set) the user that
 914          * did the original mount is permitted to update it.
 915          */
 916         error = vfs_suser(mp, td);
 917         if (error != 0) {
 918                 vput(vp);
 919                 return (error);
 920         }
 921         if (vfs_busy(mp, MBF_NOWAIT)) {
 922                 vput(vp);
 923                 return (EBUSY);
 924         }
 925         VI_LOCK(vp);
 926         if ((vp->v_iflag & VI_MOUNT) != 0 || vp->v_mountedhere != NULL) {
 927                 VI_UNLOCK(vp);
 928                 vfs_unbusy(mp);
 929                 vput(vp);
 930                 return (EBUSY);
 931         }
 932         vp->v_iflag |= VI_MOUNT;
 933         VI_UNLOCK(vp);
 934         VOP_UNLOCK(vp, 0);
 935
 936         MNT_ILOCK(mp);
 937         mp->mnt_flag &= ~MNT_UPDATEMASK;
 938         mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE |
 939             MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY);
 940         if ((mp->mnt_flag & MNT_ASYNC) == 0)
 941                 mp->mnt_kern_flag &= ~MNTK_ASYNC;
 942         MNT_IUNLOCK(mp);
 943         mp->mnt_optnew = *optlist;
 944         vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt);
 945
 946         /*
 947          * Mount the filesystem.
 948          * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
 949          * get.  No freeing of cn_pnbuf.
 950          */
 951         error = VFS_MOUNT(mp);
 952
 953         export_error = 0;
 954         if (error == 0) {
 955                 /* Process the export option. */
 956                 if (vfs_copyopt(mp->mnt_optnew, "export", &export,
 957                     sizeof(export)) == 0) {
 958                         export_error = vfs_export(mp, &export);
 959                 } else if (vfs_copyopt(mp->mnt_optnew, "export", &oexport,
 960                     sizeof(oexport)) == 0) {
 961                         export.ex_flags = oexport.ex_flags;
 962                         export.ex_root = oexport.ex_root;
 963                         export.ex_anon = oexport.ex_anon;
 964                         export.ex_addr = oexport.ex_addr;
 965                         export.ex_addrlen = oexport.ex_addrlen;
 966                         export.ex_mask = oexport.ex_mask;
 967                         export.ex_masklen = oexport.ex_masklen;
 968                         export.ex_indexfile = oexport.ex_indexfile;
 969                         export.ex_numsecflavors = 0;
 970                         export_error = vfs_export(mp, &export);
 971                 }
 972         }
 973
 974         MNT_ILOCK(mp);
 975         if (error == 0) {
 976                 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE |
 977                     MNT_SNAPSHOT);
 978         } else {
 979                 /*
 980                  * If we fail, restore old mount flags. MNT_QUOTA is special,
 981                  * because it is not part of MNT_UPDATEMASK, but it could have
 982                  * changed in the meantime if quotactl(2) was called.
 983                  * All in all we want current value of MNT_QUOTA, not the old
 984                  * one.
 985                  */
 986                 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA);
 987         }
 988         if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
 989             (mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
 990                 mp->mnt_kern_flag |= MNTK_ASYNC;
 991         else
 992                 mp->mnt_kern_flag &= ~MNTK_ASYNC;
 993         MNT_IUNLOCK(mp);
 994
 995         if (error != 0)
 996                 goto end;
 997
 998         if (mp->mnt_opt != NULL)
 999                 vfs_freeopts(mp->mnt_opt);
1000         mp->mnt_opt = mp->mnt_optnew;
1001         *optlist = NULL;
1002         (void)VFS_STATFS(mp, &mp->mnt_stat);
1003         /*
1004          * Prevent external consumers of mount options from reading
1005          * mnt_optnew.
1006          */
1007         mp->mnt_optnew = NULL;
1008
1009         if ((mp->mnt_flag & MNT_RDONLY) == 0)
1010                 vfs_allocate_syncvnode(mp);
1011         else
1012                 vfs_deallocate_syncvnode(mp);
1013 end:
1014         vfs_unbusy(mp);
1015         VI_LOCK(vp);
1016         vp->v_iflag &= ~VI_MOUNT;
1017         VI_UNLOCK(vp);
1018         vrele(vp);
1019         return (error != 0 ? error : export_error);
1020 }
1021
1022 /*
1023  * vfs_domount(): actually attempt a filesystem mount.
1024  */
1025 static int
1026 vfs_domount(
1027         struct thread *td,              /* Calling thread. */
1028         const char *fstype,             /* Filesystem type. */
1029         char *fspath,                   /* Mount path. */
1030         uint64_t fsflags,               /* Flags common to all filesystems. */
1031         struct vfsoptlist **optlist     /* Options local to the filesystem. */
1032         )
1033 {
1034         struct vfsconf *vfsp;
1035         struct nameidata nd;
1036         struct vnode *vp;
1037         char *pathbuf;
1038         int error;
1039
1040         /*
1041          * Be ultra-paranoid about making sure the type and fspath
1042          * variables will fit in our mp buffers, including the
1043          * terminating NUL.
1044          */
1045         if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN)
1046                 return (ENAMETOOLONG);
1047
1048         if (jailed(td->td_ucred) || usermount == 0) {
1049                 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0)
1050                         return (error);
1051         }
1052
1053         /*
1054          * Do not allow NFS export or MNT_SUIDDIR by unprivileged users.
1055          */
1056         if (fsflags & MNT_EXPORTED) {
1057                 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED);
1058                 if (error)
1059                         return (error);
1060         }
1061         if (fsflags & MNT_SUIDDIR) {
1062                 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR);
1063                 if (error)
1064                         return (error);
1065         }
1066         /*
1067          * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users.
1068          */
1069         if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) {
1070                 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0)
1071                         fsflags |= MNT_NOSUID | MNT_USER;
1072         }
1073
1074         /* Load KLDs before we lock the covered vnode to avoid reversals. */
1075         vfsp = NULL;
1076         if ((fsflags & MNT_UPDATE) == 0) {
1077                 /* Don't try to load KLDs if we're mounting the root. */
1078                 if (fsflags & MNT_ROOTFS)
1079                         vfsp = vfs_byname(fstype);
1080                 else
1081                         vfsp = vfs_byname_kld(fstype, td, &error);
1082                 if (vfsp == NULL)
1083                         return (ENODEV);
1084                 if (jailed(td->td_ucred) && !(vfsp->vfc_flags & VFCF_JAIL))
1085                         return (EPERM);
1086         }
1087
1088         /*
1089          * Get vnode to be covered or mount point's vnode in case of MNT_UPDATE.
1090          */
1091         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1,
1092             UIO_SYSSPACE, fspath, td);
1093         error = namei(&nd);
1094         if (error != 0)
1095                 return (error);
1096         NDFREE(&nd, NDF_ONLY_PNBUF);
1097         vp = nd.ni_vp;
1098         if ((fsflags & MNT_UPDATE) == 0) {
1099                 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
1100                 strcpy(pathbuf, fspath);
1101                 error = vn_path_to_global_path(td, vp, pathbuf, MNAMELEN);
1102                 /* debug.disablefullpath == 1 results in ENODEV */
1103                 if (error == 0 || error == ENODEV) {
1104                         error = vfs_domount_first(td, vfsp, pathbuf, vp,
1105                             fsflags, optlist);
1106                 }
1107                 free(pathbuf, M_TEMP);
1108         } else
1109                 error = vfs_domount_update(td, vp, fsflags, optlist);
1110
1111         return (error);
1112 }
1113
1114 /*
1115  * Unmount a filesystem.
1116  *
1117  * Note: unmount takes a path to the vnode mounted on as argument, not
1118  * special file (as before).
1119  */
1120 #ifndef _SYS_SYSPROTO_H_
1121 struct unmount_args {
1122         char    *path;
1123         int     flags;
1124 };
1125 #endif
1126 /* ARGSUSED */
1127 int
1128 sys_unmount(struct thread *td, struct unmount_args *uap)
1129 {
1130         struct nameidata nd;
1131         struct mount *mp;
1132         char *pathbuf;
1133         int error, id0, id1;
1134
1135         AUDIT_ARG_VALUE(uap->flags);
1136         if (jailed(td->td_ucred) || usermount == 0) {
1137                 error = priv_check(td, PRIV_VFS_UNMOUNT);
1138                 if (error)
1139                         return (error);
1140         }
1141
1142         pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
1143         error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL);
1144         if (error) {
1145                 free(pathbuf, M_TEMP);
1146                 return (error);
1147         }
1148         if (uap->flags & MNT_BYFSID) {
1149                 AUDIT_ARG_TEXT(pathbuf);
1150                 /* Decode the filesystem ID. */
1151                 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) {
1152                         free(pathbuf, M_TEMP);
1153                         return (EINVAL);
1154                 }
1155
1156                 mtx_lock(&mountlist_mtx);
1157                 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
1158                         if (mp->mnt_stat.f_fsid.val[0] == id0 &&
1159                             mp->mnt_stat.f_fsid.val[1] == id1) {
1160                                 vfs_ref(mp);
1161                                 break;
1162                         }
1163                 }
1164                 mtx_unlock(&mountlist_mtx);
1165         } else {
1166                 /*
1167                  * Try to find global path for path argument.
1168                  */
1169                 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1,
1170                     UIO_SYSSPACE, pathbuf, td);
1171                 if (namei(&nd) == 0) {
1172                         NDFREE(&nd, NDF_ONLY_PNBUF);
1173                         error = vn_path_to_global_path(td, nd.ni_vp, pathbuf,
1174                             MNAMELEN);
1175                         if (error == 0 || error == ENODEV)
1176                                 vput(nd.ni_vp);
1177                 }
1178                 mtx_lock(&mountlist_mtx);
1179                 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
1180                         if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) {
1181                                 vfs_ref(mp);
1182                                 break;
1183                         }
1184                 }
1185                 mtx_unlock(&mountlist_mtx);
1186         }
1187         free(pathbuf, M_TEMP);
1188         if (mp == NULL) {
1189                 /*
1190                  * Previously we returned ENOENT for a nonexistent path and
1191                  * EINVAL for a non-mountpoint.  We cannot tell these apart
1192                  * now, so in the !MNT_BYFSID case return the more likely
1193                  * EINVAL for compatibility.
1194                  */
1195                 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL);
1196         }
1197
1198         /*
1199          * Don't allow unmounting the root filesystem.
1200          */
1201         if (mp->mnt_flag & MNT_ROOTFS) {
1202                 vfs_rel(mp);
1203                 return (EINVAL);
1204         }
1205         error = dounmount(mp, uap->flags, td);
1206         return (error);
1207 }
1208
1209 /*
1210  * Do the actual filesystem unmount.
1211  */
1212 int
1213 dounmount(struct mount *mp, int flags, struct thread *td)
1214 {
1215         struct vnode *coveredvp, *fsrootvp;
1216         int error;
1217         uint64_t async_flag;
1218         int mnt_gen_r;
1219
1220         if ((coveredvp = mp->mnt_vnodecovered) != NULL) {
1221                 mnt_gen_r = mp->mnt_gen;
1222                 VI_LOCK(coveredvp);
1223                 vholdl(coveredvp);
1224                 vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
1225                 vdrop(coveredvp);
1226                 /*
1227                  * Check for mp being unmounted while waiting for the
1228                  * covered vnode lock.
1229                  */
1230                 if (coveredvp->v_mountedhere != mp ||
1231                     coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) {
1232                         VOP_UNLOCK(coveredvp, 0);
1233                         vfs_rel(mp);
1234                         return (EBUSY);
1235                 }
1236         }
1237         /*
1238          * Only privileged root, or (if MNT_USER is set) the user that did the
1239          * original mount is permitted to unmount this filesystem.
1240          */
1241         error = vfs_suser(mp, td);
1242         if (error != 0) {
1243                 if (coveredvp)
1244                         VOP_UNLOCK(coveredvp, 0);
1245                 vfs_rel(mp);
1246                 return (error);
1247         }
1248
1249         vn_start_write(NULL, &mp, V_WAIT | V_MNTREF);
1250         MNT_ILOCK(mp);
1251         if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 ||
1252             !TAILQ_EMPTY(&mp->mnt_uppers)) {
1253                 MNT_IUNLOCK(mp);
1254                 if (coveredvp)
1255                         VOP_UNLOCK(coveredvp, 0);
1256                 vn_finished_write(mp);
1257                 return (EBUSY);
1258         }
1259         mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_NOINSMNTQ;
1260         /* Allow filesystems to detect that a forced unmount is in progress. */
1261         if (flags & MNT_FORCE) {
1262                 mp->mnt_kern_flag |= MNTK_UNMOUNTF;
1263                 MNT_IUNLOCK(mp);
1264                 /*
1265                  * Must be done after setting MNTK_UNMOUNTF and before
1266                  * waiting for mnt_lockref to become 0.
1267                  */
1268                 VFS_PURGE(mp);
1269                 MNT_ILOCK(mp);
1270         }
1271         error = 0;
1272         if (mp->mnt_lockref) {
1273                 mp->mnt_kern_flag |= MNTK_DRAINING;
1274                 error = msleep(&mp->mnt_lockref, MNT_MTX(mp), PVFS,
1275                     "mount drain", 0);
1276         }
1277         MNT_IUNLOCK(mp);
1278         KASSERT(mp->mnt_lockref == 0,
1279             ("%s: invalid lock refcount in the drain path @ %s:%d",
1280             __func__, __FILE__, __LINE__));
1281         KASSERT(error == 0,
1282             ("%s: invalid return value for msleep in the drain path @ %s:%d",
1283             __func__, __FILE__, __LINE__));
1284
1285         if (mp->mnt_flag & MNT_EXPUBLIC)
1286                 vfs_setpublicfs(NULL, NULL, NULL);
1287
1288         vfs_msync(mp, MNT_WAIT);
1289         MNT_ILOCK(mp);
1290         async_flag = mp->mnt_flag & MNT_ASYNC;
1291         mp->mnt_flag &= ~MNT_ASYNC;
1292         mp->mnt_kern_flag &= ~MNTK_ASYNC;
1293         MNT_IUNLOCK(mp);
1294         cache_purgevfs(mp);     /* remove cache entries for this file sys */
1295         vfs_deallocate_syncvnode(mp);
1296         /*
1297          * For forced unmounts, move process cdir/rdir refs on the fs root
1298          * vnode to the covered vnode.  For non-forced unmounts we want
1299          * such references to cause an EBUSY error.
1300          */
1301         if ((flags & MNT_FORCE) &&
1302             VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
1303                 if (mp->mnt_vnodecovered != NULL)
1304                         mountcheckdirs(fsrootvp, mp->mnt_vnodecovered);
1305                 if (fsrootvp == rootvnode) {
1306                         vrele(rootvnode);
1307                         rootvnode = NULL;
1308                 }
1309                 vput(fsrootvp);
1310         }
1311         if ((mp->mnt_flag & MNT_RDONLY) != 0 || (flags & MNT_FORCE) != 0 ||
1312             (error = VFS_SYNC(mp, MNT_WAIT)) == 0)
1313                 error = VFS_UNMOUNT(mp, flags);
1314         vn_finished_write(mp);
1315         /*
1316          * If we failed to flush the dirty blocks for this mount point,
1317          * undo all the cdir/rdir and rootvnode changes we made above.
1318          * Unless we failed to do so because the device is reporting that
1319          * it doesn't exist anymore.
1320          */
1321         if (error && error != ENXIO) {
1322                 if ((flags & MNT_FORCE) &&
1323                     VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
1324                         if (mp->mnt_vnodecovered != NULL)
1325                                 mountcheckdirs(mp->mnt_vnodecovered, fsrootvp);
1326                         if (rootvnode == NULL) {
1327                                 rootvnode = fsrootvp;
1328                                 vref(rootvnode);
1329                         }
1330                         vput(fsrootvp);
1331                 }
1332                 MNT_ILOCK(mp);
1333                 mp->mnt_kern_flag &= ~MNTK_NOINSMNTQ;
1334                 if ((mp->mnt_flag & MNT_RDONLY) == 0) {
1335                         MNT_IUNLOCK(mp);
1336                         vfs_allocate_syncvnode(mp);
1337                         MNT_ILOCK(mp);
1338                 }
1339                 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
1340                 mp->mnt_flag |= async_flag;
1341                 if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
1342                     (mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
1343                         mp->mnt_kern_flag |= MNTK_ASYNC;
1344                 if (mp->mnt_kern_flag & MNTK_MWAIT) {
1345                         mp->mnt_kern_flag &= ~MNTK_MWAIT;
1346                         wakeup(mp);
1347                 }
1348                 MNT_IUNLOCK(mp);
1349                 if (coveredvp)
1350                         VOP_UNLOCK(coveredvp, 0);
1351                 return (error);
1352         }
1353         mtx_lock(&mountlist_mtx);
1354         TAILQ_REMOVE(&mountlist, mp, mnt_list);
1355         mtx_unlock(&mountlist_mtx);
1356         EVENTHANDLER_INVOKE(vfs_unmounted, mp, td);
1357         if (coveredvp != NULL) {
1358                 coveredvp->v_mountedhere = NULL;
1359                 vput(coveredvp);
1360         }
1361         vfs_event_signal(NULL, VQ_UNMOUNT, 0);
1362         if (mp == rootdevmp)
1363                 rootdevmp = NULL;
1364         vfs_mount_destroy(mp);
1365         return (0);
1366 }
1367
1368 /*
1369  * Report errors during filesystem mounting.
1370  */
1371 void
1372 vfs_mount_error(struct mount *mp, const char *fmt, ...)
1373 {
1374         struct vfsoptlist *moptlist = mp->mnt_optnew;
1375         va_list ap;
1376         int error, len;
1377         char *errmsg;
1378
1379         error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len);
1380         if (error || errmsg == NULL || len <= 0)
1381                 return;
1382
1383         va_start(ap, fmt);
1384         vsnprintf(errmsg, (size_t)len, fmt, ap);
1385         va_end(ap);
1386 }
1387
1388 void
1389 vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...)
1390 {
1391         va_list ap;
1392         int error, len;
1393         char *errmsg;
1394
1395         error = vfs_getopt(opts, "errmsg", (void **)&errmsg, &len);
1396         if (error || errmsg == NULL || len <= 0)
1397                 return;
1398
1399         va_start(ap, fmt);
1400         vsnprintf(errmsg, (size_t)len, fmt, ap);
1401         va_end(ap);
1402 }
1403
1404 /*
1405  * ---------------------------------------------------------------------
1406  * Functions for querying mount options/arguments from filesystems.
1407  */
1408
1409 /*
1410  * Check that no unknown options are given
1411  */
1412 int
1413 vfs_filteropt(struct vfsoptlist *opts, const char **legal)
1414 {
1415         struct vfsopt *opt;
1416         char errmsg[255];
1417         const char **t, *p, *q;
1418         int ret = 0;
1419
1420         TAILQ_FOREACH(opt, opts, link) {
1421                 p = opt->name;
1422                 q = NULL;
1423                 if (p[0] == 'n' && p[1] == 'o')
1424                         q = p + 2;
1425                 for(t = global_opts; *t != NULL; t++) {
1426                         if (strcmp(*t, p) == 0)
1427                                 break;
1428                         if (q != NULL) {
1429                                 if (strcmp(*t, q) == 0)
1430                                         break;
1431                         }
1432                 }
1433                 if (*t != NULL)
1434                         continue;
1435                 for(t = legal; *t != NULL; t++) {
1436                         if (strcmp(*t, p) == 0)
1437                                 break;
1438                         if (q != NULL) {
1439                                 if (strcmp(*t, q) == 0)
1440                                         break;
1441                         }
1442                 }
1443                 if (*t != NULL)
1444                         continue;
1445                 snprintf(errmsg, sizeof(errmsg),
1446                     "mount option <%s> is unknown", p);
1447                 ret = EINVAL;
1448         }
1449         if (ret != 0) {
1450                 TAILQ_FOREACH(opt, opts, link) {
1451                         if (strcmp(opt->name, "errmsg") == 0) {
1452                                 strncpy((char *)opt->value, errmsg, opt->len);
1453                                 break;
1454                         }
1455                 }
1456                 if (opt == NULL)
1457                         printf("%s\n", errmsg);
1458         }
1459         return (ret);
1460 }
1461
1462 /*
1463  * Get a mount option by its name.
1464  *
1465  * Return 0 if the option was found, ENOENT otherwise.
1466  * If len is non-NULL it will be filled with the length
1467  * of the option. If buf is non-NULL, it will be filled
1468  * with the address of the option.
1469  */
1470 int
1471 vfs_getopt(opts, name, buf, len)
1472         struct vfsoptlist *opts;
1473         const char *name;
1474         void **buf;
1475         int *len;
1476 {
1477         struct vfsopt *opt;
1478
1479         KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
1480
1481         TAILQ_FOREACH(opt, opts, link) {
1482                 if (strcmp(name, opt->name) == 0) {
1483                         opt->seen = 1;
1484                         if (len != NULL)
1485                                 *len = opt->len;
1486                         if (buf != NULL)
1487                                 *buf = opt->value;
1488                         return (0);
1489                 }
1490         }
1491         return (ENOENT);
1492 }
1493
1494 int
1495 vfs_getopt_pos(struct vfsoptlist *opts, const char *name)
1496 {
1497         struct vfsopt *opt;
1498
1499         if (opts == NULL)
1500                 return (-1);
1501
1502         TAILQ_FOREACH(opt, opts, link) {
1503                 if (strcmp(name, opt->name) == 0) {
1504                         opt->seen = 1;
1505                         return (opt->pos);
1506                 }
1507         }
1508         return (-1);
1509 }
1510
1511 int
1512 vfs_getopt_size(struct vfsoptlist *opts, const char *name, off_t *value)
1513 {
1514         char *opt_value, *vtp;
1515         quad_t iv;
1516         int error, opt_len;
1517
1518         error = vfs_getopt(opts, name, (void **)&opt_value, &opt_len);
1519         if (error != 0)
1520                 return (error);
1521         if (opt_len == 0 || opt_value == NULL)
1522                 return (EINVAL);
1523         if (opt_value[0] == '\0' || opt_value[opt_len - 1] != '\0')
1524                 return (EINVAL);
1525         iv = strtoq(opt_value, &vtp, 0);
1526         if (vtp == opt_value || (vtp[0] != '\0' && vtp[1] != '\0'))
1527                 return (EINVAL);
1528         if (iv < 0)
1529                 return (EINVAL);
1530         switch (vtp[0]) {
1531         case 't':
1532         case 'T':
1533                 iv *= 1024;
1534         case 'g':
1535         case 'G':
1536                 iv *= 1024;
1537         case 'm':
1538         case 'M':
1539                 iv *= 1024;
1540         case 'k':
1541         case 'K':
1542                 iv *= 1024;
1543         case '\0':
1544                 break;
1545         default:
1546                 return (EINVAL);
1547         }
1548         *value = iv;
1549
1550         return (0);
1551 }
1552
1553 char *
1554 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error)
1555 {
1556         struct vfsopt *opt;
1557
1558         *error = 0;
1559         TAILQ_FOREACH(opt, opts, link) {
1560                 if (strcmp(name, opt->name) != 0)
1561                         continue;
1562                 opt->seen = 1;
1563                 if (opt->len == 0 ||
1564                     ((char *)opt->value)[opt->len - 1] != '\0') {
1565                         *error = EINVAL;
1566                         return (NULL);
1567                 }
1568                 return (opt->value);
1569         }
1570         *error = ENOENT;
1571         return (NULL);
1572 }
1573
1574 int
1575 vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w,
1576         uint64_t val)
1577 {
1578         struct vfsopt *opt;
1579
1580         TAILQ_FOREACH(opt, opts, link) {
1581                 if (strcmp(name, opt->name) == 0) {
1582                         opt->seen = 1;
1583                         if (w != NULL)
1584                                 *w |= val;
1585                         return (1);
1586                 }
1587         }
1588         if (w != NULL)
1589                 *w &= ~val;
1590         return (0);
1591 }
1592
1593 int
1594 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...)
1595 {
1596         va_list ap;
1597         struct vfsopt *opt;
1598         int ret;
1599
1600         KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
1601
1602         TAILQ_FOREACH(opt, opts, link) {
1603                 if (strcmp(name, opt->name) != 0)
1604                         continue;
1605                 opt->seen = 1;
1606                 if (opt->len == 0 || opt->value == NULL)
1607                         return (0);
1608                 if (((char *)opt->value)[opt->len - 1] != '\0')
1609                         return (0);
1610                 va_start(ap, fmt);
1611                 ret = vsscanf(opt->value, fmt, ap);
1612                 va_end(ap);
1613                 return (ret);
1614         }
1615         return (0);
1616 }
1617
1618 int
1619 vfs_setopt(struct vfsoptlist *opts, const char *name, void *value, int len)
1620 {
1621         struct vfsopt *opt;
1622
1623         TAILQ_FOREACH(opt, opts, link) {
1624                 if (strcmp(name, opt->name) != 0)
1625                         continue;
1626                 opt->seen = 1;
1627                 if (opt->value == NULL)
1628                         opt->len = len;
1629                 else {
1630                         if (opt->len != len)
1631                                 return (EINVAL);
1632                         bcopy(value, opt->value, len);
1633                 }
1634                 return (0);
1635         }
1636         return (ENOENT);
1637 }
1638
1639 int
1640 vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value, int len)
1641 {
1642         struct vfsopt *opt;
1643
1644         TAILQ_FOREACH(opt, opts, link) {
1645                 if (strcmp(name, opt->name) != 0)
1646                         continue;
1647                 opt->seen = 1;
1648                 if (opt->value == NULL)
1649                         opt->len = len;
1650                 else {
1651                         if (opt->len < len)
1652                                 return (EINVAL);
1653                         opt->len = len;
1654                         bcopy(value, opt->value, len);
1655                 }
1656                 return (0);
1657         }
1658         return (ENOENT);
1659 }
1660
1661 int
1662 vfs_setopts(struct vfsoptlist *opts, const char *name, const char *value)
1663 {
1664         struct vfsopt *opt;
1665
1666         TAILQ_FOREACH(opt, opts, link) {
1667                 if (strcmp(name, opt->name) != 0)
1668                         continue;
1669                 opt->seen = 1;
1670                 if (opt->value == NULL)
1671                         opt->len = strlen(value) + 1;
1672                 else if (strlcpy(opt->value, value, opt->len) >= opt->len)
1673                         return (EINVAL);
1674                 return (0);
1675         }
1676         return (ENOENT);
1677 }
1678
1679 /*
1680  * Find and copy a mount option.
1681  *
1682  * The size of the buffer has to be specified
1683  * in len, if it is not the same length as the
1684  * mount option, EINVAL is returned.
1685  * Returns ENOENT if the option is not found.
1686  */
1687 int
1688 vfs_copyopt(opts, name, dest, len)
1689         struct vfsoptlist *opts;
1690         const char *name;
1691         void *dest;
1692         int len;
1693 {
1694         struct vfsopt *opt;
1695
1696         KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL"));
1697
1698         TAILQ_FOREACH(opt, opts, link) {
1699                 if (strcmp(name, opt->name) == 0) {
1700                         opt->seen = 1;
1701                         if (len != opt->len)
1702                                 return (EINVAL);
1703                         bcopy(opt->value, dest, opt->len);
1704                         return (0);
1705                 }
1706         }
1707         return (ENOENT);
1708 }
1709
1710 int
1711 __vfs_statfs(struct mount *mp, struct statfs *sbp)
1712 {
1713         int error;
1714
1715         error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat);
1716         if (sbp != &mp->mnt_stat)
1717                 *sbp = mp->mnt_stat;
1718         return (error);
1719 }
1720
1721 void
1722 vfs_mountedfrom(struct mount *mp, const char *from)
1723 {
1724
1725         bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname);
1726         strlcpy(mp->mnt_stat.f_mntfromname, from,
1727             sizeof mp->mnt_stat.f_mntfromname);
1728 }
1729
1730 /*
1731  * ---------------------------------------------------------------------
1732  * This is the api for building mount args and mounting filesystems from
1733  * inside the kernel.
1734  *
1735  * The API works by accumulation of individual args.  First error is
1736  * latched.
1737  *
1738  * XXX: should be documented in new manpage kernel_mount(9)
1739  */
1740
1741 /* A memory allocation which must be freed when we are done */
1742 struct mntaarg {
1743         SLIST_ENTRY(mntaarg)    next;
1744 };
1745
1746 /* The header for the mount arguments */
1747 struct mntarg {
1748         struct iovec *v;
1749         int len;
1750         int error;
1751         SLIST_HEAD(, mntaarg)   list;
1752 };
1753
1754 /*
1755  * Add a boolean argument.
1756  *
1757  * flag is the boolean value.
1758  * name must start with "no".
1759  */
1760 struct mntarg *
1761 mount_argb(struct mntarg *ma, int flag, const char *name)
1762 {
1763
1764         KASSERT(name[0] == 'n' && name[1] == 'o',
1765             ("mount_argb(...,%s): name must start with 'no'", name));
1766
1767         return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0));
1768 }
1769
1770 /*
1771  * Add an argument printf style
1772  */
1773 struct mntarg *
1774 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...)
1775 {
1776         va_list ap;
1777         struct mntaarg *maa;
1778         struct sbuf *sb;
1779         int len;
1780
1781         if (ma == NULL) {
1782                 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
1783                 SLIST_INIT(&ma->list);
1784         }
1785         if (ma->error)
1786                 return (ma);
1787
1788         ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
1789             M_MOUNT, M_WAITOK);
1790         ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
1791         ma->v[ma->len].iov_len = strlen(name) + 1;
1792         ma->len++;
1793
1794         sb = sbuf_new_auto();
1795         va_start(ap, fmt);
1796         sbuf_vprintf(sb, fmt, ap);
1797         va_end(ap);
1798         sbuf_finish(sb);
1799         len = sbuf_len(sb) + 1;
1800         maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
1801         SLIST_INSERT_HEAD(&ma->list, maa, next);
1802         bcopy(sbuf_data(sb), maa + 1, len);
1803         sbuf_delete(sb);
1804
1805         ma->v[ma->len].iov_base = maa + 1;
1806         ma->v[ma->len].iov_len = len;
1807         ma->len++;
1808
1809         return (ma);
1810 }
1811
1812 /*
1813  * Add an argument which is a userland string.
1814  */
1815 struct mntarg *
1816 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len)
1817 {
1818         struct mntaarg *maa;
1819         char *tbuf;
1820
1821         if (val == NULL)
1822                 return (ma);
1823         if (ma == NULL) {
1824                 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
1825                 SLIST_INIT(&ma->list);
1826         }
1827         if (ma->error)
1828                 return (ma);
1829         maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
1830         SLIST_INSERT_HEAD(&ma->list, maa, next);
1831         tbuf = (void *)(maa + 1);
1832         ma->error = copyinstr(val, tbuf, len, NULL);
1833         return (mount_arg(ma, name, tbuf, -1));
1834 }
1835
1836 /*
1837  * Plain argument.
1838  *
1839  * If length is -1, treat value as a C string.
1840  */
1841 struct mntarg *
1842 mount_arg(struct mntarg *ma, const char *name, const void *val, int len)
1843 {
1844
1845         if (ma == NULL) {
1846                 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
1847                 SLIST_INIT(&ma->list);
1848         }
1849         if (ma->error)
1850                 return (ma);
1851
1852         ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
1853             M_MOUNT, M_WAITOK);
1854         ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
1855         ma->v[ma->len].iov_len = strlen(name) + 1;
1856         ma->len++;
1857
1858         ma->v[ma->len].iov_base = (void *)(uintptr_t)val;
1859         if (len < 0)
1860                 ma->v[ma->len].iov_len = strlen(val) + 1;
1861         else
1862                 ma->v[ma->len].iov_len = len;
1863         ma->len++;
1864         return (ma);
1865 }
1866
1867 /*
1868  * Free a mntarg structure
1869  */
1870 static void
1871 free_mntarg(struct mntarg *ma)
1872 {
1873         struct mntaarg *maa;
1874
1875         while (!SLIST_EMPTY(&ma->list)) {
1876                 maa = SLIST_FIRST(&ma->list);
1877                 SLIST_REMOVE_HEAD(&ma->list, next);
1878                 free(maa, M_MOUNT);
1879         }
1880         free(ma->v, M_MOUNT);
1881         free(ma, M_MOUNT);
1882 }
1883
1884 /*
1885  * Mount a filesystem
1886  */
1887 int
1888 kernel_mount(struct mntarg *ma, uint64_t flags)
1889 {
1890         struct uio auio;
1891         int error;
1892
1893         KASSERT(ma != NULL, ("kernel_mount NULL ma"));
1894         KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v"));
1895         KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len));
1896
1897         auio.uio_iov = ma->v;
1898         auio.uio_iovcnt = ma->len;
1899         auio.uio_segflg = UIO_SYSSPACE;
1900
1901         error = ma->error;
1902         if (!error)
1903                 error = vfs_donmount(curthread, flags, &auio);
1904         free_mntarg(ma);
1905         return (error);
1906 }
1907
1908 /*
1909  * A printflike function to mount a filesystem.
1910  */
1911 int
1912 kernel_vmount(int flags, ...)
1913 {
1914         struct mntarg *ma = NULL;
1915         va_list ap;
1916         const char *cp;
1917         const void *vp;
1918         int error;
1919
1920         va_start(ap, flags);
1921         for (;;) {
1922                 cp = va_arg(ap, const char *);
1923                 if (cp == NULL)
1924                         break;
1925                 vp = va_arg(ap, const void *);
1926                 ma = mount_arg(ma, cp, vp, (vp != NULL ? -1 : 0));
1927         }
1928         va_end(ap);
1929
1930         error = kernel_mount(ma, flags);
1931         return (error);
1932 }
1933
1934 void
1935 vfs_oexport_conv(const struct oexport_args *oexp, struct export_args *exp)
1936 {
1937
1938         bcopy(oexp, exp, sizeof(*oexp));
1939         exp->ex_numsecflavors = 0;
1940 }