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FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_mount.c

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    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: head/sys/kern/vfs_mount.c 234482 2012-04-20 06:50:44Z mckusick $");
   39 
   40 #include "opt_vfs_allow_nonmpsafe.h"
   41 
   42 #include <sys/param.h>
   43 #include <sys/conf.h>
   44 #include <sys/fcntl.h>
   45 #include <sys/jail.h>
   46 #include <sys/kernel.h>
   47 #include <sys/libkern.h>
   48 #include <sys/malloc.h>
   49 #include <sys/mount.h>
   50 #include <sys/mutex.h>
   51 #include <sys/namei.h>
   52 #include <sys/priv.h>
   53 #include <sys/proc.h>
   54 #include <sys/filedesc.h>
   55 #include <sys/reboot.h>
   56 #include <sys/sbuf.h>
   57 #include <sys/syscallsubr.h>
   58 #include <sys/sysproto.h>
   59 #include <sys/sx.h>
   60 #include <sys/sysctl.h>
   61 #include <sys/sysent.h>
   62 #include <sys/systm.h>
   63 #include <sys/vnode.h>
   64 #include <vm/uma.h>
   65 
   66 #include <geom/geom.h>
   67 
   68 #include <machine/stdarg.h>
   69 
   70 #include <security/audit/audit.h>
   71 #include <security/mac/mac_framework.h>
   72 
   73 #define VFS_MOUNTARG_SIZE_MAX   (1024 * 64)
   74 
   75 static int      vfs_domount(struct thread *td, const char *fstype, char *fspath,
   76                     uint64_t fsflags, struct vfsoptlist **optlist);
   77 static void     free_mntarg(struct mntarg *ma);
   78 
   79 static int      usermount = 0;
   80 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0,
   81     "Unprivileged users may mount and unmount file systems");
   82 
   83 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
   84 static uma_zone_t mount_zone;
   85 
   86 /* List of mounted filesystems. */
   87 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist);
   88 
   89 /* For any iteration/modification of mountlist */
   90 struct mtx mountlist_mtx;
   91 MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF);
   92 
   93 /*
   94  * Global opts, taken by all filesystems
   95  */
   96 static const char *global_opts[] = {
   97         "errmsg",
   98         "fstype",
   99         "fspath",
  100         "ro",
  101         "rw",
  102         "nosuid",
  103         "noexec",
  104         NULL
  105 };
  106 
  107 static int
  108 mount_init(void *mem, int size, int flags)
  109 {
  110         struct mount *mp;
  111 
  112         mp = (struct mount *)mem;
  113         mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
  114         lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0);
  115         return (0);
  116 }
  117 
  118 static void
  119 mount_fini(void *mem, int size)
  120 {
  121         struct mount *mp;
  122 
  123         mp = (struct mount *)mem;
  124         lockdestroy(&mp->mnt_explock);
  125         mtx_destroy(&mp->mnt_mtx);
  126 }
  127 
  128 static void
  129 vfs_mount_init(void *dummy __unused)
  130 {
  131 
  132         mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), NULL,
  133             NULL, mount_init, mount_fini, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
  134 }
  135 SYSINIT(vfs_mount, SI_SUB_VFS, SI_ORDER_ANY, vfs_mount_init, NULL);
  136 
  137 /*
  138  * ---------------------------------------------------------------------
  139  * Functions for building and sanitizing the mount options
  140  */
  141 
  142 /* Remove one mount option. */
  143 static void
  144 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt)
  145 {
  146 
  147         TAILQ_REMOVE(opts, opt, link);
  148         free(opt->name, M_MOUNT);
  149         if (opt->value != NULL)
  150                 free(opt->value, M_MOUNT);
  151         free(opt, M_MOUNT);
  152 }
  153 
  154 /* Release all resources related to the mount options. */
  155 void
  156 vfs_freeopts(struct vfsoptlist *opts)
  157 {
  158         struct vfsopt *opt;
  159 
  160         while (!TAILQ_EMPTY(opts)) {
  161                 opt = TAILQ_FIRST(opts);
  162                 vfs_freeopt(opts, opt);
  163         }
  164         free(opts, M_MOUNT);
  165 }
  166 
  167 void
  168 vfs_deleteopt(struct vfsoptlist *opts, const char *name)
  169 {
  170         struct vfsopt *opt, *temp;
  171 
  172         if (opts == NULL)
  173                 return;
  174         TAILQ_FOREACH_SAFE(opt, opts, link, temp)  {
  175                 if (strcmp(opt->name, name) == 0)
  176                         vfs_freeopt(opts, opt);
  177         }
  178 }
  179 
  180 static int
  181 vfs_isopt_ro(const char *opt)
  182 {
  183 
  184         if (strcmp(opt, "ro") == 0 || strcmp(opt, "rdonly") == 0 ||
  185             strcmp(opt, "norw") == 0)
  186                 return (1);
  187         return (0);
  188 }
  189 
  190 static int
  191 vfs_isopt_rw(const char *opt)
  192 {
  193 
  194         if (strcmp(opt, "rw") == 0 || strcmp(opt, "noro") == 0)
  195                 return (1);
  196         return (0);
  197 }
  198 
  199 /*
  200  * Check if options are equal (with or without the "no" prefix).
  201  */
  202 static int
  203 vfs_equalopts(const char *opt1, const char *opt2)
  204 {
  205         char *p;
  206 
  207         /* "opt" vs. "opt" or "noopt" vs. "noopt" */
  208         if (strcmp(opt1, opt2) == 0)
  209                 return (1);
  210         /* "noopt" vs. "opt" */
  211         if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
  212                 return (1);
  213         /* "opt" vs. "noopt" */
  214         if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
  215                 return (1);
  216         while ((p = strchr(opt1, '.')) != NULL &&
  217             !strncmp(opt1, opt2, ++p - opt1)) {
  218                 opt2 += p - opt1;
  219                 opt1 = p;
  220                 /* "foo.noopt" vs. "foo.opt" */
  221                 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
  222                         return (1);
  223                 /* "foo.opt" vs. "foo.noopt" */
  224                 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
  225                         return (1);
  226         }
  227         /* "ro" / "rdonly" / "norw" / "rw" / "noro" */
  228         if ((vfs_isopt_ro(opt1) || vfs_isopt_rw(opt1)) &&
  229             (vfs_isopt_ro(opt2) || vfs_isopt_rw(opt2)))
  230                 return (1);
  231         return (0);
  232 }
  233 
  234 /*
  235  * If a mount option is specified several times,
  236  * (with or without the "no" prefix) only keep
  237  * the last occurence of it.
  238  */
  239 static void
  240 vfs_sanitizeopts(struct vfsoptlist *opts)
  241 {
  242         struct vfsopt *opt, *opt2, *tmp;
  243 
  244         TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) {
  245                 opt2 = TAILQ_PREV(opt, vfsoptlist, link);
  246                 while (opt2 != NULL) {
  247                         if (vfs_equalopts(opt->name, opt2->name)) {
  248                                 tmp = TAILQ_PREV(opt2, vfsoptlist, link);
  249                                 vfs_freeopt(opts, opt2);
  250                                 opt2 = tmp;
  251                         } else {
  252                                 opt2 = TAILQ_PREV(opt2, vfsoptlist, link);
  253                         }
  254                 }
  255         }
  256 }
  257 
  258 /*
  259  * Build a linked list of mount options from a struct uio.
  260  */
  261 int
  262 vfs_buildopts(struct uio *auio, struct vfsoptlist **options)
  263 {
  264         struct vfsoptlist *opts;
  265         struct vfsopt *opt;
  266         size_t memused, namelen, optlen;
  267         unsigned int i, iovcnt;
  268         int error;
  269 
  270         opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
  271         TAILQ_INIT(opts);
  272         memused = 0;
  273         iovcnt = auio->uio_iovcnt;
  274         for (i = 0; i < iovcnt; i += 2) {
  275                 namelen = auio->uio_iov[i].iov_len;
  276                 optlen = auio->uio_iov[i + 1].iov_len;
  277                 memused += sizeof(struct vfsopt) + optlen + namelen;
  278                 /*
  279                  * Avoid consuming too much memory, and attempts to overflow
  280                  * memused.
  281                  */
  282                 if (memused > VFS_MOUNTARG_SIZE_MAX ||
  283                     optlen > VFS_MOUNTARG_SIZE_MAX ||
  284                     namelen > VFS_MOUNTARG_SIZE_MAX) {
  285                         error = EINVAL;
  286                         goto bad;
  287                 }
  288 
  289                 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
  290                 opt->name = malloc(namelen, M_MOUNT, M_WAITOK);
  291                 opt->value = NULL;
  292                 opt->len = 0;
  293                 opt->pos = i / 2;
  294                 opt->seen = 0;
  295 
  296                 /*
  297                  * Do this early, so jumps to "bad" will free the current
  298                  * option.
  299                  */
  300                 TAILQ_INSERT_TAIL(opts, opt, link);
  301 
  302                 if (auio->uio_segflg == UIO_SYSSPACE) {
  303                         bcopy(auio->uio_iov[i].iov_base, opt->name, namelen);
  304                 } else {
  305                         error = copyin(auio->uio_iov[i].iov_base, opt->name,
  306                             namelen);
  307                         if (error)
  308                                 goto bad;
  309                 }
  310                 /* Ensure names are null-terminated strings. */
  311                 if (namelen == 0 || opt->name[namelen - 1] != '\0') {
  312                         error = EINVAL;
  313                         goto bad;
  314                 }
  315                 if (optlen != 0) {
  316                         opt->len = optlen;
  317                         opt->value = malloc(optlen, M_MOUNT, M_WAITOK);
  318                         if (auio->uio_segflg == UIO_SYSSPACE) {
  319                                 bcopy(auio->uio_iov[i + 1].iov_base, opt->value,
  320                                     optlen);
  321                         } else {
  322                                 error = copyin(auio->uio_iov[i + 1].iov_base,
  323                                     opt->value, optlen);
  324                                 if (error)
  325                                         goto bad;
  326                         }
  327                 }
  328         }
  329         vfs_sanitizeopts(opts);
  330         *options = opts;
  331         return (0);
  332 bad:
  333         vfs_freeopts(opts);
  334         return (error);
  335 }
  336 
  337 /*
  338  * Merge the old mount options with the new ones passed
  339  * in the MNT_UPDATE case.
  340  *
  341  * XXX: This function will keep a "nofoo" option in the new
  342  * options.  E.g, if the option's canonical name is "foo",
  343  * "nofoo" ends up in the mount point's active options.
  344  */
  345 static void
  346 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *oldopts)
  347 {
  348         struct vfsopt *opt, *new;
  349 
  350         TAILQ_FOREACH(opt, oldopts, link) {
  351                 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
  352                 new->name = strdup(opt->name, M_MOUNT);
  353                 if (opt->len != 0) {
  354                         new->value = malloc(opt->len, M_MOUNT, M_WAITOK);
  355                         bcopy(opt->value, new->value, opt->len);
  356                 } else
  357                         new->value = NULL;
  358                 new->len = opt->len;
  359                 new->seen = opt->seen;
  360                 TAILQ_INSERT_HEAD(toopts, new, link);
  361         }
  362         vfs_sanitizeopts(toopts);
  363 }
  364 
  365 /*
  366  * Mount a filesystem.
  367  */
  368 int
  369 sys_nmount(td, uap)
  370         struct thread *td;
  371         struct nmount_args /* {
  372                 struct iovec *iovp;
  373                 unsigned int iovcnt;
  374                 int flags;
  375         } */ *uap;
  376 {
  377         struct uio *auio;
  378         int error;
  379         u_int iovcnt;
  380         uint64_t flags;
  381 
  382         /*
  383          * Mount flags are now 64-bits. On 32-bit archtectures only
  384          * 32-bits are passed in, but from here on everything handles
  385          * 64-bit flags correctly.
  386          */
  387         flags = uap->flags;
  388 
  389         AUDIT_ARG_FFLAGS(flags);
  390         CTR4(KTR_VFS, "%s: iovp %p with iovcnt %d and flags %d", __func__,
  391             uap->iovp, uap->iovcnt, flags);
  392 
  393         /*
  394          * Filter out MNT_ROOTFS.  We do not want clients of nmount() in
  395          * userspace to set this flag, but we must filter it out if we want
  396          * MNT_UPDATE on the root file system to work.
  397          * MNT_ROOTFS should only be set by the kernel when mounting its
  398          * root file system.
  399          */
  400         flags &= ~MNT_ROOTFS;
  401 
  402         iovcnt = uap->iovcnt;
  403         /*
  404          * Check that we have an even number of iovec's
  405          * and that we have at least two options.
  406          */
  407         if ((iovcnt & 1) || (iovcnt < 4)) {
  408                 CTR2(KTR_VFS, "%s: failed for invalid iovcnt %d", __func__,
  409                     uap->iovcnt);
  410                 return (EINVAL);
  411         }
  412 
  413         error = copyinuio(uap->iovp, iovcnt, &auio);
  414         if (error) {
  415                 CTR2(KTR_VFS, "%s: failed for invalid uio op with %d errno",
  416                     __func__, error);
  417                 return (error);
  418         }
  419         error = vfs_donmount(td, flags, auio);
  420 
  421         free(auio, M_IOV);
  422         return (error);
  423 }
  424 
  425 /*
  426  * ---------------------------------------------------------------------
  427  * Various utility functions
  428  */
  429 
  430 void
  431 vfs_ref(struct mount *mp)
  432 {
  433 
  434         CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
  435         MNT_ILOCK(mp);
  436         MNT_REF(mp);
  437         MNT_IUNLOCK(mp);
  438 }
  439 
  440 void
  441 vfs_rel(struct mount *mp)
  442 {
  443 
  444         CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
  445         MNT_ILOCK(mp);
  446         MNT_REL(mp);
  447         MNT_IUNLOCK(mp);
  448 }
  449 
  450 /*
  451  * Allocate and initialize the mount point struct.
  452  */
  453 struct mount *
  454 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath,
  455     struct ucred *cred)
  456 {
  457         struct mount *mp;
  458 
  459         mp = uma_zalloc(mount_zone, M_WAITOK);
  460         bzero(&mp->mnt_startzero,
  461             __rangeof(struct mount, mnt_startzero, mnt_endzero));
  462         TAILQ_INIT(&mp->mnt_nvnodelist);
  463         mp->mnt_nvnodelistsize = 0;
  464         TAILQ_INIT(&mp->mnt_activevnodelist);
  465         mp->mnt_activevnodelistsize = 0;
  466         mp->mnt_ref = 0;
  467         (void) vfs_busy(mp, MBF_NOWAIT);
  468         mp->mnt_op = vfsp->vfc_vfsops;
  469         mp->mnt_vfc = vfsp;
  470         vfsp->vfc_refcount++;   /* XXX Unlocked */
  471         mp->mnt_stat.f_type = vfsp->vfc_typenum;
  472         mp->mnt_gen++;
  473         strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
  474         mp->mnt_vnodecovered = vp;
  475         mp->mnt_cred = crdup(cred);
  476         mp->mnt_stat.f_owner = cred->cr_uid;
  477         strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN);
  478         mp->mnt_iosize_max = DFLTPHYS;
  479 #ifdef MAC
  480         mac_mount_init(mp);
  481         mac_mount_create(cred, mp);
  482 #endif
  483         arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0);
  484         return (mp);
  485 }
  486 
  487 /*
  488  * Destroy the mount struct previously allocated by vfs_mount_alloc().
  489  */
  490 void
  491 vfs_mount_destroy(struct mount *mp)
  492 {
  493 
  494         MNT_ILOCK(mp);
  495         mp->mnt_kern_flag |= MNTK_REFEXPIRE;
  496         if (mp->mnt_kern_flag & MNTK_MWAIT) {
  497                 mp->mnt_kern_flag &= ~MNTK_MWAIT;
  498                 wakeup(mp);
  499         }
  500         while (mp->mnt_ref)
  501                 msleep(mp, MNT_MTX(mp), PVFS, "mntref", 0);
  502         KASSERT(mp->mnt_ref == 0,
  503             ("%s: invalid refcount in the drain path @ %s:%d", __func__,
  504             __FILE__, __LINE__));
  505         if (mp->mnt_writeopcount != 0)
  506                 panic("vfs_mount_destroy: nonzero writeopcount");
  507         if (mp->mnt_secondary_writes != 0)
  508                 panic("vfs_mount_destroy: nonzero secondary_writes");
  509         mp->mnt_vfc->vfc_refcount--;
  510         if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) {
  511                 struct vnode *vp;
  512 
  513                 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes)
  514                         vprint("", vp);
  515                 panic("unmount: dangling vnode");
  516         }
  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         }
  653 
  654         /*
  655          * Be ultra-paranoid about making sure the type and fspath
  656          * variables will fit in our mp buffers, including the
  657          * terminating NUL.
  658          */
  659         if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) {
  660                 error = ENAMETOOLONG;
  661                 goto bail;
  662         }
  663 
  664         error = vfs_domount(td, fstype, fspath, fsflags, &optlist);
  665 bail:
  666         /* copyout the errmsg */
  667         if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt)
  668             && errmsg_len > 0 && errmsg != NULL) {
  669                 if (fsoptions->uio_segflg == UIO_SYSSPACE) {
  670                         bcopy(errmsg,
  671                             fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
  672                             fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
  673                 } else {
  674                         copyout(errmsg,
  675                             fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
  676                             fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
  677                 }
  678         }
  679 
  680         if (optlist != NULL)
  681                 vfs_freeopts(optlist);
  682         return (error);
  683 }
  684 
  685 /*
  686  * Old mount API.
  687  */
  688 #ifndef _SYS_SYSPROTO_H_
  689 struct mount_args {
  690         char    *type;
  691         char    *path;
  692         int     flags;
  693         caddr_t data;
  694 };
  695 #endif
  696 /* ARGSUSED */
  697 int
  698 sys_mount(td, uap)
  699         struct thread *td;
  700         struct mount_args /* {
  701                 char *type;
  702                 char *path;
  703                 int flags;
  704                 caddr_t data;
  705         } */ *uap;
  706 {
  707         char *fstype;
  708         struct vfsconf *vfsp = NULL;
  709         struct mntarg *ma = NULL;
  710         uint64_t flags;
  711         int error;
  712 
  713         /*
  714          * Mount flags are now 64-bits. On 32-bit archtectures only
  715          * 32-bits are passed in, but from here on everything handles
  716          * 64-bit flags correctly.
  717          */
  718         flags = uap->flags;
  719 
  720         AUDIT_ARG_FFLAGS(flags);
  721 
  722         /*
  723          * Filter out MNT_ROOTFS.  We do not want clients of mount() in
  724          * userspace to set this flag, but we must filter it out if we want
  725          * MNT_UPDATE on the root file system to work.
  726          * MNT_ROOTFS should only be set by the kernel when mounting its
  727          * root file system.
  728          */
  729         flags &= ~MNT_ROOTFS;
  730 
  731         fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK);
  732         error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL);
  733         if (error) {
  734                 free(fstype, M_TEMP);
  735                 return (error);
  736         }
  737 
  738         AUDIT_ARG_TEXT(fstype);
  739         mtx_lock(&Giant);
  740         vfsp = vfs_byname_kld(fstype, td, &error);
  741         free(fstype, M_TEMP);
  742         if (vfsp == NULL) {
  743                 mtx_unlock(&Giant);
  744                 return (ENOENT);
  745         }
  746         if (vfsp->vfc_vfsops->vfs_cmount == NULL) {
  747                 mtx_unlock(&Giant);
  748                 return (EOPNOTSUPP);
  749         }
  750 
  751         ma = mount_argsu(ma, "fstype", uap->type, MNAMELEN);
  752         ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN);
  753         ma = mount_argb(ma, flags & MNT_RDONLY, "noro");
  754         ma = mount_argb(ma, !(flags & MNT_NOSUID), "nosuid");
  755         ma = mount_argb(ma, !(flags & MNT_NOEXEC), "noexec");
  756 
  757         error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, flags);
  758         mtx_unlock(&Giant);
  759         return (error);
  760 }
  761 
  762 /*
  763  * vfs_domount_first(): first file system mount (not update)
  764  */
  765 static int
  766 vfs_domount_first(
  767         struct thread *td,              /* Calling thread. */
  768         struct vfsconf *vfsp,           /* File system type. */
  769         char *fspath,                   /* Mount path. */
  770         struct vnode *vp,               /* Vnode to be covered. */
  771         uint64_t fsflags,               /* Flags common to all filesystems. */
  772         struct vfsoptlist **optlist     /* Options local to the filesystem. */
  773         )
  774 {
  775         struct vattr va;
  776         struct mount *mp;
  777         struct vnode *newdp;
  778         int error;
  779 
  780         mtx_assert(&Giant, MA_OWNED);
  781         ASSERT_VOP_ELOCKED(vp, __func__);
  782         KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here"));
  783 
  784         /*
  785          * If the user is not root, ensure that they own the directory
  786          * onto which we are attempting to mount.
  787          */
  788         error = VOP_GETATTR(vp, &va, td->td_ucred);
  789         if (error == 0 && va.va_uid != td->td_ucred->cr_uid)
  790                 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN, 0);
  791         if (error == 0)
  792                 error = vinvalbuf(vp, V_SAVE, 0, 0);
  793         if (error == 0 && vp->v_type != VDIR)
  794                 error = ENOTDIR;
  795         if (error == 0) {
  796                 VI_LOCK(vp);
  797                 if ((vp->v_iflag & VI_MOUNT) == 0 && vp->v_mountedhere == NULL)
  798                         vp->v_iflag |= VI_MOUNT;
  799                 else
  800                         error = EBUSY;
  801                 VI_UNLOCK(vp);
  802         }
  803         if (error != 0) {
  804                 vput(vp);
  805                 return (error);
  806         }
  807         VOP_UNLOCK(vp, 0);
  808 
  809         /* Allocate and initialize the filesystem. */
  810         mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred);
  811         /* XXXMAC: pass to vfs_mount_alloc? */
  812         mp->mnt_optnew = *optlist;
  813         /* Set the mount level flags. */
  814         mp->mnt_flag = (fsflags & (MNT_UPDATEMASK | MNT_ROOTFS | MNT_RDONLY));
  815 
  816         /*
  817          * Mount the filesystem.
  818          * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
  819          * get.  No freeing of cn_pnbuf.
  820          */
  821         error = VFS_MOUNT(mp);
  822 #ifndef VFS_ALLOW_NONMPSAFE
  823         if (error == 0 && VFS_NEEDSGIANT(mp)) {
  824                 (void)VFS_UNMOUNT(mp, fsflags);
  825                 error = ENXIO;
  826                 printf("%s: Mounting non-MPSAFE fs (%s) is disabled\n",
  827                     __func__, mp->mnt_vfc->vfc_name);
  828         }
  829 #endif
  830         if (error != 0) {
  831                 vfs_unbusy(mp);
  832                 vfs_mount_destroy(mp);
  833                 VI_LOCK(vp);
  834                 vp->v_iflag &= ~VI_MOUNT;
  835                 VI_UNLOCK(vp);
  836                 vrele(vp);
  837                 return (error);
  838         }
  839 #ifdef VFS_ALLOW_NONMPSAFE
  840         if (VFS_NEEDSGIANT(mp))
  841                 printf("%s: Mounting non-MPSAFE fs (%s) is deprecated\n",
  842                     __func__, mp->mnt_vfc->vfc_name);
  843 #endif
  844 
  845         if (mp->mnt_opt != NULL)
  846                 vfs_freeopts(mp->mnt_opt);
  847         mp->mnt_opt = mp->mnt_optnew;
  848         *optlist = NULL;
  849         (void)VFS_STATFS(mp, &mp->mnt_stat);
  850 
  851         /*
  852          * Prevent external consumers of mount options from reading mnt_optnew.
  853          */
  854         mp->mnt_optnew = NULL;
  855 
  856         MNT_ILOCK(mp);
  857         if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
  858             (mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
  859                 mp->mnt_kern_flag |= MNTK_ASYNC;
  860         else
  861                 mp->mnt_kern_flag &= ~MNTK_ASYNC;
  862         MNT_IUNLOCK(mp);
  863 
  864         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
  865         cache_purge(vp);
  866         VI_LOCK(vp);
  867         vp->v_iflag &= ~VI_MOUNT;
  868         VI_UNLOCK(vp);
  869         vp->v_mountedhere = mp;
  870         /* Place the new filesystem at the end of the mount list. */
  871         mtx_lock(&mountlist_mtx);
  872         TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
  873         mtx_unlock(&mountlist_mtx);
  874         vfs_event_signal(NULL, VQ_MOUNT, 0);
  875         if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp))
  876                 panic("mount: lost mount");
  877         VOP_UNLOCK(newdp, 0);
  878         VOP_UNLOCK(vp, 0);
  879         mountcheckdirs(vp, newdp);
  880         vrele(newdp);
  881         if ((mp->mnt_flag & MNT_RDONLY) == 0)
  882                 vfs_allocate_syncvnode(mp);
  883         vfs_unbusy(mp);
  884         return (0);
  885 }
  886 
  887 /*
  888  * vfs_domount_update(): update of mounted file system
  889  */
  890 static int
  891 vfs_domount_update(
  892         struct thread *td,              /* Calling thread. */
  893         struct vnode *vp,               /* Mount point vnode. */
  894         uint64_t fsflags,               /* Flags common to all filesystems. */
  895         struct vfsoptlist **optlist     /* Options local to the filesystem. */
  896         )
  897 {
  898         struct oexport_args oexport;
  899         struct export_args export;
  900         struct mount *mp;
  901         int error, export_error;
  902         uint64_t flag;
  903 
  904         mtx_assert(&Giant, MA_OWNED);
  905         ASSERT_VOP_ELOCKED(vp, __func__);
  906         KASSERT((fsflags & MNT_UPDATE) != 0, ("MNT_UPDATE should be here"));
  907 
  908         if ((vp->v_vflag & VV_ROOT) == 0) {
  909                 vput(vp);
  910                 return (EINVAL);
  911         }
  912         mp = vp->v_mount;
  913         /*
  914          * We only allow the filesystem to be reloaded if it
  915          * is currently mounted read-only.
  916          */
  917         flag = mp->mnt_flag;
  918         if ((fsflags & MNT_RELOAD) != 0 && (flag & MNT_RDONLY) == 0) {
  919                 vput(vp);
  920                 return (EOPNOTSUPP);    /* Needs translation */
  921         }
  922         /*
  923          * Only privileged root, or (if MNT_USER is set) the user that
  924          * did the original mount is permitted to update it.
  925          */
  926         error = vfs_suser(mp, td);
  927         if (error != 0) {
  928                 vput(vp);
  929                 return (error);
  930         }
  931         if (vfs_busy(mp, MBF_NOWAIT)) {
  932                 vput(vp);
  933                 return (EBUSY);
  934         }
  935         VI_LOCK(vp);
  936         if ((vp->v_iflag & VI_MOUNT) != 0 || vp->v_mountedhere != NULL) {
  937                 VI_UNLOCK(vp);
  938                 vfs_unbusy(mp);
  939                 vput(vp);
  940                 return (EBUSY);
  941         }
  942         vp->v_iflag |= VI_MOUNT;
  943         VI_UNLOCK(vp);
  944         VOP_UNLOCK(vp, 0);
  945 
  946         MNT_ILOCK(mp);
  947         mp->mnt_flag &= ~MNT_UPDATEMASK;
  948         mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE |
  949             MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY);
  950         if ((mp->mnt_flag & MNT_ASYNC) == 0)
  951                 mp->mnt_kern_flag &= ~MNTK_ASYNC;
  952         MNT_IUNLOCK(mp);
  953         mp->mnt_optnew = *optlist;
  954         vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt);
  955 
  956         /*
  957          * Mount the filesystem.
  958          * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
  959          * get.  No freeing of cn_pnbuf.
  960          */
  961         error = VFS_MOUNT(mp);
  962 
  963         export_error = 0;
  964         if (error == 0) {
  965                 /* Process the export option. */
  966                 if (vfs_copyopt(mp->mnt_optnew, "export", &export,
  967                     sizeof(export)) == 0) {
  968                         export_error = vfs_export(mp, &export);
  969                 } else if (vfs_copyopt(mp->mnt_optnew, "export", &oexport,
  970                     sizeof(oexport)) == 0) {
  971                         export.ex_flags = oexport.ex_flags;
  972                         export.ex_root = oexport.ex_root;
  973                         export.ex_anon = oexport.ex_anon;
  974                         export.ex_addr = oexport.ex_addr;
  975                         export.ex_addrlen = oexport.ex_addrlen;
  976                         export.ex_mask = oexport.ex_mask;
  977                         export.ex_masklen = oexport.ex_masklen;
  978                         export.ex_indexfile = oexport.ex_indexfile;
  979                         export.ex_numsecflavors = 0;
  980                         export_error = vfs_export(mp, &export);
  981                 }
  982         }
  983 
  984         MNT_ILOCK(mp);
  985         if (error == 0) {
  986                 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE |
  987                     MNT_SNAPSHOT);
  988         } else {
  989                 /*
  990                  * If we fail, restore old mount flags. MNT_QUOTA is special,
  991                  * because it is not part of MNT_UPDATEMASK, but it could have
  992                  * changed in the meantime if quotactl(2) was called.
  993                  * All in all we want current value of MNT_QUOTA, not the old
  994                  * one.
  995                  */
  996                 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA);
  997         }
  998         if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
  999             (mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
 1000                 mp->mnt_kern_flag |= MNTK_ASYNC;
 1001         else
 1002                 mp->mnt_kern_flag &= ~MNTK_ASYNC;
 1003         MNT_IUNLOCK(mp);
 1004 
 1005         if (error != 0)
 1006                 goto end;
 1007 
 1008         if (mp->mnt_opt != NULL)
 1009                 vfs_freeopts(mp->mnt_opt);
 1010         mp->mnt_opt = mp->mnt_optnew;
 1011         *optlist = NULL;
 1012         (void)VFS_STATFS(mp, &mp->mnt_stat);
 1013         /*
 1014          * Prevent external consumers of mount options from reading
 1015          * mnt_optnew.
 1016          */
 1017         mp->mnt_optnew = NULL;
 1018 
 1019         if ((mp->mnt_flag & MNT_RDONLY) == 0)
 1020                 vfs_allocate_syncvnode(mp);
 1021         else
 1022                 vfs_deallocate_syncvnode(mp);
 1023 end:
 1024         vfs_unbusy(mp);
 1025         VI_LOCK(vp);
 1026         vp->v_iflag &= ~VI_MOUNT;
 1027         VI_UNLOCK(vp);
 1028         vrele(vp);
 1029         return (error != 0 ? error : export_error);
 1030 }
 1031 
 1032 /*
 1033  * vfs_domount(): actually attempt a filesystem mount.
 1034  */
 1035 static int
 1036 vfs_domount(
 1037         struct thread *td,              /* Calling thread. */
 1038         const char *fstype,             /* Filesystem type. */
 1039         char *fspath,                   /* Mount path. */
 1040         uint64_t fsflags,               /* Flags common to all filesystems. */
 1041         struct vfsoptlist **optlist     /* Options local to the filesystem. */
 1042         )
 1043 {
 1044         struct vfsconf *vfsp;
 1045         struct nameidata nd;
 1046         struct vnode *vp;
 1047         char *pathbuf;
 1048         int error;
 1049 
 1050         /*
 1051          * Be ultra-paranoid about making sure the type and fspath
 1052          * variables will fit in our mp buffers, including the
 1053          * terminating NUL.
 1054          */
 1055         if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN)
 1056                 return (ENAMETOOLONG);
 1057 
 1058         if (jailed(td->td_ucred) || usermount == 0) {
 1059                 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0)
 1060                         return (error);
 1061         }
 1062 
 1063         /*
 1064          * Do not allow NFS export or MNT_SUIDDIR by unprivileged users.
 1065          */
 1066         if (fsflags & MNT_EXPORTED) {
 1067                 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED);
 1068                 if (error)
 1069                         return (error);
 1070         }
 1071         if (fsflags & MNT_SUIDDIR) {
 1072                 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR);
 1073                 if (error)
 1074                         return (error);
 1075         }
 1076         /*
 1077          * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users.
 1078          */
 1079         if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) {
 1080                 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0)
 1081                         fsflags |= MNT_NOSUID | MNT_USER;
 1082         }
 1083 
 1084         /* Load KLDs before we lock the covered vnode to avoid reversals. */
 1085         vfsp = NULL;
 1086         if ((fsflags & MNT_UPDATE) == 0) {
 1087                 /* Don't try to load KLDs if we're mounting the root. */
 1088                 if (fsflags & MNT_ROOTFS)
 1089                         vfsp = vfs_byname(fstype);
 1090                 else
 1091                         vfsp = vfs_byname_kld(fstype, td, &error);
 1092                 if (vfsp == NULL)
 1093                         return (ENODEV);
 1094                 if (jailed(td->td_ucred) && !(vfsp->vfc_flags & VFCF_JAIL))
 1095                         return (EPERM);
 1096         }
 1097 
 1098         /*
 1099          * Get vnode to be covered or mount point's vnode in case of MNT_UPDATE.
 1100          */
 1101         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | MPSAFE | AUDITVNODE1,
 1102             UIO_SYSSPACE, fspath, td);
 1103         error = namei(&nd);
 1104         if (error != 0)
 1105                 return (error);
 1106         if (!NDHASGIANT(&nd))
 1107                 mtx_lock(&Giant);
 1108         NDFREE(&nd, NDF_ONLY_PNBUF);
 1109         vp = nd.ni_vp;
 1110         if ((fsflags & MNT_UPDATE) == 0) {
 1111                 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
 1112                 strcpy(pathbuf, fspath);
 1113                 error = vn_path_to_global_path(td, vp, pathbuf, MNAMELEN);
 1114                 /* debug.disablefullpath == 1 results in ENODEV */
 1115                 if (error == 0 || error == ENODEV) {
 1116                         error = vfs_domount_first(td, vfsp, pathbuf, vp,
 1117                             fsflags, optlist);
 1118                 }
 1119                 free(pathbuf, M_TEMP);
 1120         } else
 1121                 error = vfs_domount_update(td, vp, fsflags, optlist);
 1122         mtx_unlock(&Giant);
 1123 
 1124         ASSERT_VI_UNLOCKED(vp, __func__);
 1125         ASSERT_VOP_UNLOCKED(vp, __func__);
 1126 
 1127         return (error);
 1128 }
 1129 
 1130 /*
 1131  * Unmount a filesystem.
 1132  *
 1133  * Note: unmount takes a path to the vnode mounted on as argument, not
 1134  * special file (as before).
 1135  */
 1136 #ifndef _SYS_SYSPROTO_H_
 1137 struct unmount_args {
 1138         char    *path;
 1139         int     flags;
 1140 };
 1141 #endif
 1142 /* ARGSUSED */
 1143 int
 1144 sys_unmount(td, uap)
 1145         struct thread *td;
 1146         register struct unmount_args /* {
 1147                 char *path;
 1148                 int flags;
 1149         } */ *uap;
 1150 {
 1151         struct nameidata nd;
 1152         struct mount *mp;
 1153         char *pathbuf;
 1154         int error, id0, id1, vfslocked;
 1155 
 1156         AUDIT_ARG_VALUE(uap->flags);
 1157         if (jailed(td->td_ucred) || usermount == 0) {
 1158                 error = priv_check(td, PRIV_VFS_UNMOUNT);
 1159                 if (error)
 1160                         return (error);
 1161         }
 1162 
 1163         pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
 1164         error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL);
 1165         if (error) {
 1166                 free(pathbuf, M_TEMP);
 1167                 return (error);
 1168         }
 1169         mtx_lock(&Giant);
 1170         if (uap->flags & MNT_BYFSID) {
 1171                 AUDIT_ARG_TEXT(pathbuf);
 1172                 /* Decode the filesystem ID. */
 1173                 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) {
 1174                         mtx_unlock(&Giant);
 1175                         free(pathbuf, M_TEMP);
 1176                         return (EINVAL);
 1177                 }
 1178 
 1179                 mtx_lock(&mountlist_mtx);
 1180                 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
 1181                         if (mp->mnt_stat.f_fsid.val[0] == id0 &&
 1182                             mp->mnt_stat.f_fsid.val[1] == id1)
 1183                                 break;
 1184                 }
 1185                 mtx_unlock(&mountlist_mtx);
 1186         } else {
 1187                 AUDIT_ARG_UPATH1(td, pathbuf);
 1188                 /*
 1189                  * Try to find global path for path argument.
 1190                  */
 1191                 NDINIT(&nd, LOOKUP,
 1192                     FOLLOW | LOCKLEAF | MPSAFE | AUDITVNODE1,
 1193                     UIO_SYSSPACE, pathbuf, td);
 1194                 if (namei(&nd) == 0) {
 1195                         vfslocked = NDHASGIANT(&nd);
 1196                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1197                         error = vn_path_to_global_path(td, nd.ni_vp, pathbuf,
 1198                             MNAMELEN);
 1199                         if (error == 0 || error == ENODEV)
 1200                                 vput(nd.ni_vp);
 1201                         VFS_UNLOCK_GIANT(vfslocked);
 1202                 }
 1203                 mtx_lock(&mountlist_mtx);
 1204                 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
 1205                         if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0)
 1206                                 break;
 1207                 }
 1208                 mtx_unlock(&mountlist_mtx);
 1209         }
 1210         free(pathbuf, M_TEMP);
 1211         if (mp == NULL) {
 1212                 /*
 1213                  * Previously we returned ENOENT for a nonexistent path and
 1214                  * EINVAL for a non-mountpoint.  We cannot tell these apart
 1215                  * now, so in the !MNT_BYFSID case return the more likely
 1216                  * EINVAL for compatibility.
 1217                  */
 1218                 mtx_unlock(&Giant);
 1219                 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL);
 1220         }
 1221 
 1222         /*
 1223          * Don't allow unmounting the root filesystem.
 1224          */
 1225         if (mp->mnt_flag & MNT_ROOTFS) {
 1226                 mtx_unlock(&Giant);
 1227                 return (EINVAL);
 1228         }
 1229         error = dounmount(mp, uap->flags, td);
 1230         mtx_unlock(&Giant);
 1231         return (error);
 1232 }
 1233 
 1234 /*
 1235  * Do the actual filesystem unmount.
 1236  */
 1237 int
 1238 dounmount(mp, flags, td)
 1239         struct mount *mp;
 1240         int flags;
 1241         struct thread *td;
 1242 {
 1243         struct vnode *coveredvp, *fsrootvp;
 1244         int error;
 1245         uint64_t async_flag;
 1246         int mnt_gen_r;
 1247 
 1248         mtx_assert(&Giant, MA_OWNED);
 1249 
 1250         if ((coveredvp = mp->mnt_vnodecovered) != NULL) {
 1251                 mnt_gen_r = mp->mnt_gen;
 1252                 VI_LOCK(coveredvp);
 1253                 vholdl(coveredvp);
 1254                 vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
 1255                 vdrop(coveredvp);
 1256                 /*
 1257                  * Check for mp being unmounted while waiting for the
 1258                  * covered vnode lock.
 1259                  */
 1260                 if (coveredvp->v_mountedhere != mp ||
 1261                     coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) {
 1262                         VOP_UNLOCK(coveredvp, 0);
 1263                         return (EBUSY);
 1264                 }
 1265         }
 1266         /*
 1267          * Only privileged root, or (if MNT_USER is set) the user that did the
 1268          * original mount is permitted to unmount this filesystem.
 1269          */
 1270         error = vfs_suser(mp, td);
 1271         if (error) {
 1272                 if (coveredvp)
 1273                         VOP_UNLOCK(coveredvp, 0);
 1274                 return (error);
 1275         }
 1276 
 1277         MNT_ILOCK(mp);
 1278         if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
 1279                 MNT_IUNLOCK(mp);
 1280                 if (coveredvp)
 1281                         VOP_UNLOCK(coveredvp, 0);
 1282                 return (EBUSY);
 1283         }
 1284         mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_NOINSMNTQ;
 1285         /* Allow filesystems to detect that a forced unmount is in progress. */
 1286         if (flags & MNT_FORCE)
 1287                 mp->mnt_kern_flag |= MNTK_UNMOUNTF;
 1288         error = 0;
 1289         if (mp->mnt_lockref) {
 1290                 mp->mnt_kern_flag |= MNTK_DRAINING;
 1291                 error = msleep(&mp->mnt_lockref, MNT_MTX(mp), PVFS,
 1292                     "mount drain", 0);
 1293         }
 1294         MNT_IUNLOCK(mp);
 1295         KASSERT(mp->mnt_lockref == 0,
 1296             ("%s: invalid lock refcount in the drain path @ %s:%d",
 1297             __func__, __FILE__, __LINE__));
 1298         KASSERT(error == 0,
 1299             ("%s: invalid return value for msleep in the drain path @ %s:%d",
 1300             __func__, __FILE__, __LINE__));
 1301         vn_start_write(NULL, &mp, V_WAIT);
 1302 
 1303         if (mp->mnt_flag & MNT_EXPUBLIC)
 1304                 vfs_setpublicfs(NULL, NULL, NULL);
 1305 
 1306         vfs_msync(mp, MNT_WAIT);
 1307         MNT_ILOCK(mp);
 1308         async_flag = mp->mnt_flag & MNT_ASYNC;
 1309         mp->mnt_flag &= ~MNT_ASYNC;
 1310         mp->mnt_kern_flag &= ~MNTK_ASYNC;
 1311         MNT_IUNLOCK(mp);
 1312         cache_purgevfs(mp);     /* remove cache entries for this file sys */
 1313         vfs_deallocate_syncvnode(mp);
 1314         /*
 1315          * For forced unmounts, move process cdir/rdir refs on the fs root
 1316          * vnode to the covered vnode.  For non-forced unmounts we want
 1317          * such references to cause an EBUSY error.
 1318          */
 1319         if ((flags & MNT_FORCE) &&
 1320             VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
 1321                 if (mp->mnt_vnodecovered != NULL)
 1322                         mountcheckdirs(fsrootvp, mp->mnt_vnodecovered);
 1323                 if (fsrootvp == rootvnode) {
 1324                         vrele(rootvnode);
 1325                         rootvnode = NULL;
 1326                 }
 1327                 vput(fsrootvp);
 1328         }
 1329         if (((mp->mnt_flag & MNT_RDONLY) ||
 1330              (error = VFS_SYNC(mp, MNT_WAIT)) == 0) || (flags & MNT_FORCE) != 0)
 1331                 error = VFS_UNMOUNT(mp, flags);
 1332         vn_finished_write(mp);
 1333         /*
 1334          * If we failed to flush the dirty blocks for this mount point,
 1335          * undo all the cdir/rdir and rootvnode changes we made above.
 1336          * Unless we failed to do so because the device is reporting that
 1337          * it doesn't exist anymore.
 1338          */
 1339         if (error && error != ENXIO) {
 1340                 if ((flags & MNT_FORCE) &&
 1341                     VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
 1342                         if (mp->mnt_vnodecovered != NULL)
 1343                                 mountcheckdirs(mp->mnt_vnodecovered, fsrootvp);
 1344                         if (rootvnode == NULL) {
 1345                                 rootvnode = fsrootvp;
 1346                                 vref(rootvnode);
 1347                         }
 1348                         vput(fsrootvp);
 1349                 }
 1350                 MNT_ILOCK(mp);
 1351                 mp->mnt_kern_flag &= ~MNTK_NOINSMNTQ;
 1352                 if ((mp->mnt_flag & MNT_RDONLY) == 0) {
 1353                         MNT_IUNLOCK(mp);
 1354                         vfs_allocate_syncvnode(mp);
 1355                         MNT_ILOCK(mp);
 1356                 }
 1357                 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
 1358                 mp->mnt_flag |= async_flag;
 1359                 if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
 1360                     (mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
 1361                         mp->mnt_kern_flag |= MNTK_ASYNC;
 1362                 if (mp->mnt_kern_flag & MNTK_MWAIT) {
 1363                         mp->mnt_kern_flag &= ~MNTK_MWAIT;
 1364                         wakeup(mp);
 1365                 }
 1366                 MNT_IUNLOCK(mp);
 1367                 if (coveredvp)
 1368                         VOP_UNLOCK(coveredvp, 0);
 1369                 return (error);
 1370         }
 1371         mtx_lock(&mountlist_mtx);
 1372         TAILQ_REMOVE(&mountlist, mp, mnt_list);
 1373         mtx_unlock(&mountlist_mtx);
 1374         if (coveredvp != NULL) {
 1375                 coveredvp->v_mountedhere = NULL;
 1376                 vput(coveredvp);
 1377         }
 1378         vfs_event_signal(NULL, VQ_UNMOUNT, 0);
 1379         vfs_mount_destroy(mp);
 1380         return (0);
 1381 }
 1382 
 1383 /*
 1384  * Report errors during filesystem mounting.
 1385  */
 1386 void
 1387 vfs_mount_error(struct mount *mp, const char *fmt, ...)
 1388 {
 1389         struct vfsoptlist *moptlist = mp->mnt_optnew;
 1390         va_list ap;
 1391         int error, len;
 1392         char *errmsg;
 1393 
 1394         error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len);
 1395         if (error || errmsg == NULL || len <= 0)
 1396                 return;
 1397 
 1398         va_start(ap, fmt);
 1399         vsnprintf(errmsg, (size_t)len, fmt, ap);
 1400         va_end(ap);
 1401 }
 1402 
 1403 void
 1404 vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...)
 1405 {
 1406         va_list ap;
 1407         int error, len;
 1408         char *errmsg;
 1409 
 1410         error = vfs_getopt(opts, "errmsg", (void **)&errmsg, &len);
 1411         if (error || errmsg == NULL || len <= 0)
 1412                 return;
 1413 
 1414         va_start(ap, fmt);
 1415         vsnprintf(errmsg, (size_t)len, fmt, ap);
 1416         va_end(ap);
 1417 }
 1418 
 1419 /*
 1420  * ---------------------------------------------------------------------
 1421  * Functions for querying mount options/arguments from filesystems.
 1422  */
 1423 
 1424 /*
 1425  * Check that no unknown options are given
 1426  */
 1427 int
 1428 vfs_filteropt(struct vfsoptlist *opts, const char **legal)
 1429 {
 1430         struct vfsopt *opt;
 1431         char errmsg[255];
 1432         const char **t, *p, *q;
 1433         int ret = 0;
 1434 
 1435         TAILQ_FOREACH(opt, opts, link) {
 1436                 p = opt->name;
 1437                 q = NULL;
 1438                 if (p[0] == 'n' && p[1] == 'o')
 1439                         q = p + 2;
 1440                 for(t = global_opts; *t != NULL; t++) {
 1441                         if (strcmp(*t, p) == 0)
 1442                                 break;
 1443                         if (q != NULL) {
 1444                                 if (strcmp(*t, q) == 0)
 1445                                         break;
 1446                         }
 1447                 }
 1448                 if (*t != NULL)
 1449                         continue;
 1450                 for(t = legal; *t != NULL; t++) {
 1451                         if (strcmp(*t, p) == 0)
 1452                                 break;
 1453                         if (q != NULL) {
 1454                                 if (strcmp(*t, q) == 0)
 1455                                         break;
 1456                         }
 1457                 }
 1458                 if (*t != NULL)
 1459                         continue;
 1460                 snprintf(errmsg, sizeof(errmsg),
 1461                     "mount option <%s> is unknown", p);
 1462                 ret = EINVAL;
 1463         }
 1464         if (ret != 0) {
 1465                 TAILQ_FOREACH(opt, opts, link) {
 1466                         if (strcmp(opt->name, "errmsg") == 0) {
 1467                                 strncpy((char *)opt->value, errmsg, opt->len);
 1468                                 break;
 1469                         }
 1470                 }
 1471                 if (opt == NULL)
 1472                         printf("%s\n", errmsg);
 1473         }
 1474         return (ret);
 1475 }
 1476 
 1477 /*
 1478  * Get a mount option by its name.
 1479  *
 1480  * Return 0 if the option was found, ENOENT otherwise.
 1481  * If len is non-NULL it will be filled with the length
 1482  * of the option. If buf is non-NULL, it will be filled
 1483  * with the address of the option.
 1484  */
 1485 int
 1486 vfs_getopt(opts, name, buf, len)
 1487         struct vfsoptlist *opts;
 1488         const char *name;
 1489         void **buf;
 1490         int *len;
 1491 {
 1492         struct vfsopt *opt;
 1493 
 1494         KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
 1495 
 1496         TAILQ_FOREACH(opt, opts, link) {
 1497                 if (strcmp(name, opt->name) == 0) {
 1498                         opt->seen = 1;
 1499                         if (len != NULL)
 1500                                 *len = opt->len;
 1501                         if (buf != NULL)
 1502                                 *buf = opt->value;
 1503                         return (0);
 1504                 }
 1505         }
 1506         return (ENOENT);
 1507 }
 1508 
 1509 int
 1510 vfs_getopt_pos(struct vfsoptlist *opts, const char *name)
 1511 {
 1512         struct vfsopt *opt;
 1513 
 1514         if (opts == NULL)
 1515                 return (-1);
 1516 
 1517         TAILQ_FOREACH(opt, opts, link) {
 1518                 if (strcmp(name, opt->name) == 0) {
 1519                         opt->seen = 1;
 1520                         return (opt->pos);
 1521                 }
 1522         }
 1523         return (-1);
 1524 }
 1525 
 1526 int
 1527 vfs_getopt_size(struct vfsoptlist *opts, const char *name, off_t *value)
 1528 {
 1529         char *opt_value, *vtp;
 1530         quad_t iv;
 1531         int error, opt_len;
 1532 
 1533         error = vfs_getopt(opts, name, (void **)&opt_value, &opt_len);
 1534         if (error != 0)
 1535                 return (error);
 1536         if (opt_len == 0 || opt_value == NULL)
 1537                 return (EINVAL);
 1538         if (opt_value[0] == '\0' || opt_value[opt_len - 1] != '\0')
 1539                 return (EINVAL);
 1540         iv = strtoq(opt_value, &vtp, 0);
 1541         if (vtp == opt_value || (vtp[0] != '\0' && vtp[1] != '\0'))
 1542                 return (EINVAL);
 1543         if (iv < 0)
 1544                 return (EINVAL);
 1545         switch (vtp[0]) {
 1546         case 't':
 1547         case 'T':
 1548                 iv *= 1024;
 1549         case 'g':
 1550         case 'G':
 1551                 iv *= 1024;
 1552         case 'm':
 1553         case 'M':
 1554                 iv *= 1024;
 1555         case 'k':
 1556         case 'K':
 1557                 iv *= 1024;
 1558         case '\0':
 1559                 break;
 1560         default:
 1561                 return (EINVAL);
 1562         }
 1563         *value = iv;
 1564 
 1565         return (0);
 1566 }
 1567 
 1568 char *
 1569 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error)
 1570 {
 1571         struct vfsopt *opt;
 1572 
 1573         *error = 0;
 1574         TAILQ_FOREACH(opt, opts, link) {
 1575                 if (strcmp(name, opt->name) != 0)
 1576                         continue;
 1577                 opt->seen = 1;
 1578                 if (opt->len == 0 ||
 1579                     ((char *)opt->value)[opt->len - 1] != '\0') {
 1580                         *error = EINVAL;
 1581                         return (NULL);
 1582                 }
 1583                 return (opt->value);
 1584         }
 1585         *error = ENOENT;
 1586         return (NULL);
 1587 }
 1588 
 1589 int
 1590 vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w,
 1591         uint64_t val)
 1592 {
 1593         struct vfsopt *opt;
 1594 
 1595         TAILQ_FOREACH(opt, opts, link) {
 1596                 if (strcmp(name, opt->name) == 0) {
 1597                         opt->seen = 1;
 1598                         if (w != NULL)
 1599                                 *w |= val;
 1600                         return (1);
 1601                 }
 1602         }
 1603         if (w != NULL)
 1604                 *w &= ~val;
 1605         return (0);
 1606 }
 1607 
 1608 int
 1609 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...)
 1610 {
 1611         va_list ap;
 1612         struct vfsopt *opt;
 1613         int ret;
 1614 
 1615         KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
 1616 
 1617         TAILQ_FOREACH(opt, opts, link) {
 1618                 if (strcmp(name, opt->name) != 0)
 1619                         continue;
 1620                 opt->seen = 1;
 1621                 if (opt->len == 0 || opt->value == NULL)
 1622                         return (0);
 1623                 if (((char *)opt->value)[opt->len - 1] != '\0')
 1624                         return (0);
 1625                 va_start(ap, fmt);
 1626                 ret = vsscanf(opt->value, fmt, ap);
 1627                 va_end(ap);
 1628                 return (ret);
 1629         }
 1630         return (0);
 1631 }
 1632 
 1633 int
 1634 vfs_setopt(struct vfsoptlist *opts, const char *name, void *value, int len)
 1635 {
 1636         struct vfsopt *opt;
 1637 
 1638         TAILQ_FOREACH(opt, opts, link) {
 1639                 if (strcmp(name, opt->name) != 0)
 1640                         continue;
 1641                 opt->seen = 1;
 1642                 if (opt->value == NULL)
 1643                         opt->len = len;
 1644                 else {
 1645                         if (opt->len != len)
 1646                                 return (EINVAL);
 1647                         bcopy(value, opt->value, len);
 1648                 }
 1649                 return (0);
 1650         }
 1651         return (ENOENT);
 1652 }
 1653 
 1654 int
 1655 vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value, int len)
 1656 {
 1657         struct vfsopt *opt;
 1658 
 1659         TAILQ_FOREACH(opt, opts, link) {
 1660                 if (strcmp(name, opt->name) != 0)
 1661                         continue;
 1662                 opt->seen = 1;
 1663                 if (opt->value == NULL)
 1664                         opt->len = len;
 1665                 else {
 1666                         if (opt->len < len)
 1667                                 return (EINVAL);
 1668                         opt->len = len;
 1669                         bcopy(value, opt->value, len);
 1670                 }
 1671                 return (0);
 1672         }
 1673         return (ENOENT);
 1674 }
 1675 
 1676 int
 1677 vfs_setopts(struct vfsoptlist *opts, const char *name, const char *value)
 1678 {
 1679         struct vfsopt *opt;
 1680 
 1681         TAILQ_FOREACH(opt, opts, link) {
 1682                 if (strcmp(name, opt->name) != 0)
 1683                         continue;
 1684                 opt->seen = 1;
 1685                 if (opt->value == NULL)
 1686                         opt->len = strlen(value) + 1;
 1687                 else if (strlcpy(opt->value, value, opt->len) >= opt->len)
 1688                         return (EINVAL);
 1689                 return (0);
 1690         }
 1691         return (ENOENT);
 1692 }
 1693 
 1694 /*
 1695  * Find and copy a mount option.
 1696  *
 1697  * The size of the buffer has to be specified
 1698  * in len, if it is not the same length as the
 1699  * mount option, EINVAL is returned.
 1700  * Returns ENOENT if the option is not found.
 1701  */
 1702 int
 1703 vfs_copyopt(opts, name, dest, len)
 1704         struct vfsoptlist *opts;
 1705         const char *name;
 1706         void *dest;
 1707         int len;
 1708 {
 1709         struct vfsopt *opt;
 1710 
 1711         KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL"));
 1712 
 1713         TAILQ_FOREACH(opt, opts, link) {
 1714                 if (strcmp(name, opt->name) == 0) {
 1715                         opt->seen = 1;
 1716                         if (len != opt->len)
 1717                                 return (EINVAL);
 1718                         bcopy(opt->value, dest, opt->len);
 1719                         return (0);
 1720                 }
 1721         }
 1722         return (ENOENT);
 1723 }
 1724 
 1725 /*
 1726  * These are helper functions for filesystems to traverse all
 1727  * their vnodes.  See MNT_VNODE_FOREACH() in sys/mount.h.
 1728  *
 1729  * This interface has been deprecated in favor of MNT_VNODE_FOREACH_ALL.
 1730  */
 1731 
 1732 MALLOC_DECLARE(M_VNODE_MARKER);
 1733 
 1734 struct vnode *
 1735 __mnt_vnode_next(struct vnode **mvp, struct mount *mp)
 1736 {
 1737         struct vnode *vp;
 1738 
 1739         mtx_assert(MNT_MTX(mp), MA_OWNED);
 1740 
 1741         KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
 1742         if (should_yield()) {
 1743                 MNT_IUNLOCK(mp);
 1744                 kern_yield(PRI_UNCHANGED);
 1745                 MNT_ILOCK(mp);
 1746         }
 1747         vp = TAILQ_NEXT(*mvp, v_nmntvnodes);
 1748         while (vp != NULL && vp->v_type == VMARKER)
 1749                 vp = TAILQ_NEXT(vp, v_nmntvnodes);
 1750 
 1751         /* Check if we are done */
 1752         if (vp == NULL) {
 1753                 __mnt_vnode_markerfree(mvp, mp);
 1754                 return (NULL);
 1755         }
 1756         TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
 1757         TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
 1758         return (vp);
 1759 }
 1760 
 1761 struct vnode *
 1762 __mnt_vnode_first(struct vnode **mvp, struct mount *mp)
 1763 {
 1764         struct vnode *vp;
 1765 
 1766         mtx_assert(MNT_MTX(mp), MA_OWNED);
 1767 
 1768         vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
 1769         while (vp != NULL && vp->v_type == VMARKER)
 1770                 vp = TAILQ_NEXT(vp, v_nmntvnodes);
 1771 
 1772         /* Check if we are done */
 1773         if (vp == NULL) {
 1774                 *mvp = NULL;
 1775                 return (NULL);
 1776         }
 1777         MNT_REF(mp);
 1778         MNT_IUNLOCK(mp);
 1779         *mvp = (struct vnode *) malloc(sizeof(struct vnode),
 1780                                        M_VNODE_MARKER,
 1781                                        M_WAITOK | M_ZERO);
 1782         MNT_ILOCK(mp);
 1783         (*mvp)->v_type = VMARKER;
 1784 
 1785         vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
 1786         while (vp != NULL && vp->v_type == VMARKER)
 1787                 vp = TAILQ_NEXT(vp, v_nmntvnodes);
 1788 
 1789         /* Check if we are done */
 1790         if (vp == NULL) {
 1791                 MNT_IUNLOCK(mp);
 1792                 free(*mvp, M_VNODE_MARKER);
 1793                 MNT_ILOCK(mp);
 1794                 *mvp = NULL;
 1795                 MNT_REL(mp);
 1796                 return (NULL);
 1797         }
 1798         (*mvp)->v_mount = mp;
 1799         TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
 1800         return (vp);
 1801 }
 1802 
 1803 
 1804 void
 1805 __mnt_vnode_markerfree(struct vnode **mvp, struct mount *mp)
 1806 {
 1807 
 1808         if (*mvp == NULL)
 1809                 return;
 1810 
 1811         mtx_assert(MNT_MTX(mp), MA_OWNED);
 1812 
 1813         KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
 1814         TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
 1815         MNT_IUNLOCK(mp);
 1816         free(*mvp, M_VNODE_MARKER);
 1817         MNT_ILOCK(mp);
 1818         *mvp = NULL;
 1819         MNT_REL(mp);
 1820 }
 1821 
 1822 int
 1823 __vfs_statfs(struct mount *mp, struct statfs *sbp)
 1824 {
 1825         int error;
 1826 
 1827         error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat);
 1828         if (sbp != &mp->mnt_stat)
 1829                 *sbp = mp->mnt_stat;
 1830         return (error);
 1831 }
 1832 
 1833 void
 1834 vfs_mountedfrom(struct mount *mp, const char *from)
 1835 {
 1836 
 1837         bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname);
 1838         strlcpy(mp->mnt_stat.f_mntfromname, from,
 1839             sizeof mp->mnt_stat.f_mntfromname);
 1840 }
 1841 
 1842 /*
 1843  * ---------------------------------------------------------------------
 1844  * This is the api for building mount args and mounting filesystems from
 1845  * inside the kernel.
 1846  *
 1847  * The API works by accumulation of individual args.  First error is
 1848  * latched.
 1849  *
 1850  * XXX: should be documented in new manpage kernel_mount(9)
 1851  */
 1852 
 1853 /* A memory allocation which must be freed when we are done */
 1854 struct mntaarg {
 1855         SLIST_ENTRY(mntaarg)    next;
 1856 };
 1857 
 1858 /* The header for the mount arguments */
 1859 struct mntarg {
 1860         struct iovec *v;
 1861         int len;
 1862         int error;
 1863         SLIST_HEAD(, mntaarg)   list;
 1864 };
 1865 
 1866 /*
 1867  * Add a boolean argument.
 1868  *
 1869  * flag is the boolean value.
 1870  * name must start with "no".
 1871  */
 1872 struct mntarg *
 1873 mount_argb(struct mntarg *ma, int flag, const char *name)
 1874 {
 1875 
 1876         KASSERT(name[0] == 'n' && name[1] == 'o',
 1877             ("mount_argb(...,%s): name must start with 'no'", name));
 1878 
 1879         return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0));
 1880 }
 1881 
 1882 /*
 1883  * Add an argument printf style
 1884  */
 1885 struct mntarg *
 1886 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...)
 1887 {
 1888         va_list ap;
 1889         struct mntaarg *maa;
 1890         struct sbuf *sb;
 1891         int len;
 1892 
 1893         if (ma == NULL) {
 1894                 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
 1895                 SLIST_INIT(&ma->list);
 1896         }
 1897         if (ma->error)
 1898                 return (ma);
 1899 
 1900         ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
 1901             M_MOUNT, M_WAITOK);
 1902         ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
 1903         ma->v[ma->len].iov_len = strlen(name) + 1;
 1904         ma->len++;
 1905 
 1906         sb = sbuf_new_auto();
 1907         va_start(ap, fmt);
 1908         sbuf_vprintf(sb, fmt, ap);
 1909         va_end(ap);
 1910         sbuf_finish(sb);
 1911         len = sbuf_len(sb) + 1;
 1912         maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
 1913         SLIST_INSERT_HEAD(&ma->list, maa, next);
 1914         bcopy(sbuf_data(sb), maa + 1, len);
 1915         sbuf_delete(sb);
 1916 
 1917         ma->v[ma->len].iov_base = maa + 1;
 1918         ma->v[ma->len].iov_len = len;
 1919         ma->len++;
 1920 
 1921         return (ma);
 1922 }
 1923 
 1924 /*
 1925  * Add an argument which is a userland string.
 1926  */
 1927 struct mntarg *
 1928 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len)
 1929 {
 1930         struct mntaarg *maa;
 1931         char *tbuf;
 1932 
 1933         if (val == NULL)
 1934                 return (ma);
 1935         if (ma == NULL) {
 1936                 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
 1937                 SLIST_INIT(&ma->list);
 1938         }
 1939         if (ma->error)
 1940                 return (ma);
 1941         maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
 1942         SLIST_INSERT_HEAD(&ma->list, maa, next);
 1943         tbuf = (void *)(maa + 1);
 1944         ma->error = copyinstr(val, tbuf, len, NULL);
 1945         return (mount_arg(ma, name, tbuf, -1));
 1946 }
 1947 
 1948 /*
 1949  * Plain argument.
 1950  *
 1951  * If length is -1, treat value as a C string.
 1952  */
 1953 struct mntarg *
 1954 mount_arg(struct mntarg *ma, const char *name, const void *val, int len)
 1955 {
 1956 
 1957         if (ma == NULL) {
 1958                 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
 1959                 SLIST_INIT(&ma->list);
 1960         }
 1961         if (ma->error)
 1962                 return (ma);
 1963 
 1964         ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
 1965             M_MOUNT, M_WAITOK);
 1966         ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
 1967         ma->v[ma->len].iov_len = strlen(name) + 1;
 1968         ma->len++;
 1969 
 1970         ma->v[ma->len].iov_base = (void *)(uintptr_t)val;
 1971         if (len < 0)
 1972                 ma->v[ma->len].iov_len = strlen(val) + 1;
 1973         else
 1974                 ma->v[ma->len].iov_len = len;
 1975         ma->len++;
 1976         return (ma);
 1977 }
 1978 
 1979 /*
 1980  * Free a mntarg structure
 1981  */
 1982 static void
 1983 free_mntarg(struct mntarg *ma)
 1984 {
 1985         struct mntaarg *maa;
 1986 
 1987         while (!SLIST_EMPTY(&ma->list)) {
 1988                 maa = SLIST_FIRST(&ma->list);
 1989                 SLIST_REMOVE_HEAD(&ma->list, next);
 1990                 free(maa, M_MOUNT);
 1991         }
 1992         free(ma->v, M_MOUNT);
 1993         free(ma, M_MOUNT);
 1994 }
 1995 
 1996 /*
 1997  * Mount a filesystem
 1998  */
 1999 int
 2000 kernel_mount(struct mntarg *ma, uint64_t flags)
 2001 {
 2002         struct uio auio;
 2003         int error;
 2004 
 2005         KASSERT(ma != NULL, ("kernel_mount NULL ma"));
 2006         KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v"));
 2007         KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len));
 2008 
 2009         auio.uio_iov = ma->v;
 2010         auio.uio_iovcnt = ma->len;
 2011         auio.uio_segflg = UIO_SYSSPACE;
 2012 
 2013         error = ma->error;
 2014         if (!error)
 2015                 error = vfs_donmount(curthread, flags, &auio);
 2016         free_mntarg(ma);
 2017         return (error);
 2018 }
 2019 
 2020 /*
 2021  * A printflike function to mount a filesystem.
 2022  */
 2023 int
 2024 kernel_vmount(int flags, ...)
 2025 {
 2026         struct mntarg *ma = NULL;
 2027         va_list ap;
 2028         const char *cp;
 2029         const void *vp;
 2030         int error;
 2031 
 2032         va_start(ap, flags);
 2033         for (;;) {
 2034                 cp = va_arg(ap, const char *);
 2035                 if (cp == NULL)
 2036                         break;
 2037                 vp = va_arg(ap, const void *);
 2038                 ma = mount_arg(ma, cp, vp, (vp != NULL ? -1 : 0));
 2039         }
 2040         va_end(ap);
 2041 
 2042         error = kernel_mount(ma, flags);
 2043         return (error);
 2044 }
 2045 
 2046 void
 2047 vfs_oexport_conv(const struct oexport_args *oexp, struct export_args *exp)
 2048 {
 2049 
 2050         bcopy(oexp, exp, sizeof(*oexp));
 2051         exp->ex_numsecflavors = 0;
 2052 }

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