vfs_mountroot.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    1 /*-
    2  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 2010 Marcel Moolenaar
    5  * Copyright (c) 1999-2004 Poul-Henning Kamp
    6  * Copyright (c) 1999 Michael Smith
    7  * Copyright (c) 1989, 1993
    8  *      The Regents of the University of California.  All rights reserved.
    9  * (c) UNIX System Laboratories, Inc.
   10  * All or some portions of this file are derived from material licensed
   11  * to the University of California by American Telephone and Telegraph
   12  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
   13  * the permission of UNIX System Laboratories, Inc.
   14  *
   15  * Redistribution and use in source and binary forms, with or without
   16  * modification, are permitted provided that the following conditions
   17  * are met:
   18  * 1. Redistributions of source code must retain the above copyright
   19  *    notice, this list of conditions and the following disclaimer.
   20  * 2. Redistributions in binary form must reproduce the above copyright
   21  *    notice, this list of conditions and the following disclaimer in the
   22  *    documentation and/or other materials provided with the distribution.
   23  * 3. Neither the name of the University nor the names of its contributors
   24  *    may be used to endorse or promote products derived from this software
   25  *    without specific prior written permission.
   26  *
   27  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   37  * SUCH DAMAGE.
   38  */
   39 
   40 #include "opt_rootdevname.h"
   41 
   42 #include <sys/cdefs.h>
   43 __FBSDID("$FreeBSD$");
   44 
   45 #include <sys/param.h>
   46 #include <sys/conf.h>
   47 #include <sys/cons.h>
   48 #include <sys/eventhandler.h>
   49 #include <sys/fcntl.h>
   50 #include <sys/jail.h>
   51 #include <sys/kernel.h>
   52 #include <sys/malloc.h>
   53 #include <sys/mdioctl.h>
   54 #include <sys/mount.h>
   55 #include <sys/mutex.h>
   56 #include <sys/namei.h>
   57 #include <sys/priv.h>
   58 #include <sys/proc.h>
   59 #include <sys/filedesc.h>
   60 #include <sys/reboot.h>
   61 #include <sys/sbuf.h>
   62 #include <sys/stat.h>
   63 #include <sys/syscallsubr.h>
   64 #include <sys/sysproto.h>
   65 #include <sys/sx.h>
   66 #include <sys/sysctl.h>
   67 #include <sys/sysent.h>
   68 #include <sys/systm.h>
   69 #include <sys/vnode.h>
   70 
   71 #include <geom/geom.h>
   72 
   73 /*
   74  * The root filesystem is detailed in the kernel environment variable
   75  * vfs.root.mountfrom, which is expected to be in the general format
   76  *
   77  * <vfsname>:[<path>][  <vfsname>:[<path>] ...]
   78  * vfsname   := the name of a VFS known to the kernel and capable
   79  *              of being mounted as root
   80  * path      := disk device name or other data used by the filesystem
   81  *              to locate its physical store
   82  *
   83  * If the environment variable vfs.root.mountfrom is a space separated list,
   84  * each list element is tried in turn and the root filesystem will be mounted
   85  * from the first one that succeeds.
   86  *
   87  * The environment variable vfs.root.mountfrom.options is a comma delimited
   88  * set of string mount options.  These mount options must be parseable
   89  * by nmount() in the kernel.
   90  */
   91 
   92 static int parse_mount(char **);
   93 static struct mntarg *parse_mountroot_options(struct mntarg *, const char *);
   94 static int sysctl_vfs_root_mount_hold(SYSCTL_HANDLER_ARGS);
   95 static void vfs_mountroot_wait(void);
   96 static int vfs_mountroot_wait_if_neccessary(const char *fs, const char *dev);
   97 
   98 /*
   99  * The vnode of the system's root (/ in the filesystem, without chroot
  100  * active.)
  101  */
  102 struct vnode *rootvnode;
  103 
  104 /*
  105  * Mount of the system's /dev.
  106  */
  107 struct mount *rootdevmp;
  108 
  109 char *rootdevnames[2] = {NULL, NULL};
  110 
  111 struct mtx root_holds_mtx;
  112 MTX_SYSINIT(root_holds, &root_holds_mtx, "root_holds", MTX_DEF);
  113 
  114 static TAILQ_HEAD(, root_hold_token)    root_holds =
  115     TAILQ_HEAD_INITIALIZER(root_holds);
  116 
  117 enum action {
  118         A_CONTINUE,
  119         A_PANIC,
  120         A_REBOOT,
  121         A_RETRY
  122 };
  123 
  124 enum rh_flags {
  125         RH_FREE,
  126         RH_ALLOC,
  127         RH_ARG,
  128 };
  129 
  130 static enum action root_mount_onfail = A_CONTINUE;
  131 
  132 static int root_mount_mddev;
  133 static int root_mount_complete;
  134 
  135 /* By default wait up to 3 seconds for devices to appear. */
  136 static int root_mount_timeout = 3;
  137 TUNABLE_INT("vfs.mountroot.timeout", &root_mount_timeout);
  138 
  139 static int root_mount_always_wait = 0;
  140 SYSCTL_INT(_vfs, OID_AUTO, root_mount_always_wait, CTLFLAG_RDTUN,
  141     &root_mount_always_wait, 0,
  142     "Wait for root mount holds even if the root device already exists");
  143 
  144 SYSCTL_PROC(_vfs, OID_AUTO, root_mount_hold,
  145     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
  146     NULL, 0, sysctl_vfs_root_mount_hold, "A",
  147     "List of root mount hold tokens");
  148 
  149 static int
  150 sysctl_vfs_root_mount_hold(SYSCTL_HANDLER_ARGS)
  151 {
  152         struct sbuf sb;
  153         struct root_hold_token *h;
  154         int error;
  155 
  156         sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL);
  157 
  158         mtx_lock(&root_holds_mtx);
  159         TAILQ_FOREACH(h, &root_holds, list) {
  160                 if (h != TAILQ_FIRST(&root_holds))
  161                         sbuf_putc(&sb, ' ');
  162                 sbuf_printf(&sb, "%s", h->who);
  163         }
  164         mtx_unlock(&root_holds_mtx);
  165 
  166         error = sbuf_finish(&sb);
  167         if (error == 0)
  168                 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
  169         sbuf_delete(&sb);
  170         return (error);
  171 }
  172 
  173 struct root_hold_token *
  174 root_mount_hold(const char *identifier)
  175 {
  176         struct root_hold_token *h;
  177 
  178         h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
  179         h->flags = RH_ALLOC;
  180         h->who = identifier;
  181         mtx_lock(&root_holds_mtx);
  182         TSHOLD("root mount");
  183         TAILQ_INSERT_TAIL(&root_holds, h, list);
  184         mtx_unlock(&root_holds_mtx);
  185         return (h);
  186 }
  187 
  188 void
  189 root_mount_hold_token(const char *identifier, struct root_hold_token *h)
  190 {
  191 #ifdef INVARIANTS
  192         struct root_hold_token *t;
  193 #endif
  194 
  195         h->flags = RH_ARG;
  196         h->who = identifier;
  197         mtx_lock(&root_holds_mtx);
  198 #ifdef INVARIANTS
  199         TAILQ_FOREACH(t, &root_holds, list) {
  200                 if (t == h) {
  201                         panic("Duplicate mount hold by '%s' on %p",
  202                             identifier, h);
  203                 }
  204         }
  205 #endif
  206         TSHOLD("root mount");
  207         TAILQ_INSERT_TAIL(&root_holds, h, list);
  208         mtx_unlock(&root_holds_mtx);
  209 }
  210 
  211 void
  212 root_mount_rel(struct root_hold_token *h)
  213 {
  214 
  215         if (h == NULL || h->flags == RH_FREE)
  216                 return;
  217 
  218         mtx_lock(&root_holds_mtx);
  219         TAILQ_REMOVE(&root_holds, h, list);
  220         TSRELEASE("root mount");
  221         wakeup(&root_holds);
  222         mtx_unlock(&root_holds_mtx);
  223         if (h->flags == RH_ALLOC) {
  224                 free(h, M_DEVBUF);
  225         } else
  226                 h->flags = RH_FREE;
  227 }
  228 
  229 int
  230 root_mounted(void)
  231 {
  232 
  233         /* No mutex is acquired here because int stores are atomic. */
  234         return (root_mount_complete);
  235 }
  236 
  237 static void
  238 set_rootvnode(void)
  239 {
  240 
  241         if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
  242                 panic("set_rootvnode: Cannot find root vnode");
  243 
  244         VOP_UNLOCK(rootvnode);
  245 
  246         pwd_set_rootvnode();
  247 }
  248 
  249 static int
  250 vfs_mountroot_devfs(struct thread *td, struct mount **mpp)
  251 {
  252         struct vfsoptlist *opts;
  253         struct vfsconf *vfsp;
  254         struct mount *mp;
  255         int error;
  256 
  257         *mpp = NULL;
  258 
  259         if (rootdevmp != NULL) {
  260                 /*
  261                  * Already have /dev; this happens during rerooting.
  262                  */
  263                 error = vfs_busy(rootdevmp, 0);
  264                 if (error != 0)
  265                         return (error);
  266                 *mpp = rootdevmp;
  267         } else {
  268                 vfsp = vfs_byname("devfs");
  269                 KASSERT(vfsp != NULL, ("Could not find devfs by name"));
  270                 if (vfsp == NULL)
  271                         return (ENOENT);
  272 
  273                 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
  274 
  275                 error = VFS_MOUNT(mp);
  276                 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
  277                 if (error)
  278                         return (error);
  279 
  280                 error = VFS_STATFS(mp, &mp->mnt_stat);
  281                 KASSERT(error == 0, ("VFS_STATFS(devfs) failed %d", error));
  282                 if (error)
  283                         return (error);
  284 
  285                 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
  286                 TAILQ_INIT(opts);
  287                 mp->mnt_opt = opts;
  288 
  289                 mtx_lock(&mountlist_mtx);
  290                 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
  291                 mtx_unlock(&mountlist_mtx);
  292 
  293                 *mpp = mp;
  294                 rootdevmp = mp;
  295                 vfs_op_exit(mp);
  296         }
  297 
  298         set_rootvnode();
  299 
  300         error = kern_symlinkat(td, "/", AT_FDCWD, "dev", UIO_SYSSPACE);
  301         if (error)
  302                 printf("kern_symlink /dev -> / returns %d\n", error);
  303 
  304         return (error);
  305 }
  306 
  307 static void
  308 vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs)
  309 {
  310         struct nameidata nd;
  311         struct mount *mporoot, *mpnroot;
  312         struct vnode *vp, *vporoot, *vpdevfs;
  313         char *fspath;
  314         int error;
  315 
  316         mpnroot = TAILQ_NEXT(mpdevfs, mnt_list);
  317 
  318         /* Shuffle the mountlist. */
  319         mtx_lock(&mountlist_mtx);
  320         mporoot = TAILQ_FIRST(&mountlist);
  321         TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list);
  322         if (mporoot != mpdevfs) {
  323                 TAILQ_REMOVE(&mountlist, mpnroot, mnt_list);
  324                 TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list);
  325         }
  326         TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list);
  327         mtx_unlock(&mountlist_mtx);
  328 
  329         cache_purgevfs(mporoot);
  330         if (mporoot != mpdevfs)
  331                 cache_purgevfs(mpdevfs);
  332 
  333         if (VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot))
  334                 panic("vfs_mountroot_shuffle: Cannot find root vnode");
  335 
  336         VI_LOCK(vporoot);
  337         vporoot->v_iflag &= ~VI_MOUNT;
  338         vn_irflag_unset_locked(vporoot, VIRF_MOUNTPOINT);
  339         vporoot->v_mountedhere = NULL;
  340         VI_UNLOCK(vporoot);
  341         mporoot->mnt_flag &= ~MNT_ROOTFS;
  342         mporoot->mnt_vnodecovered = NULL;
  343         vput(vporoot);
  344 
  345         /* Set up the new rootvnode, and purge the cache */
  346         mpnroot->mnt_vnodecovered = NULL;
  347         set_rootvnode();
  348         cache_purgevfs(rootvnode->v_mount);
  349 
  350         if (mporoot != mpdevfs) {
  351                 /* Remount old root under /.mount or /mnt */
  352                 fspath = "/.mount";
  353                 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
  354                     fspath, td);
  355                 error = namei(&nd);
  356                 if (error) {
  357                         NDFREE(&nd, NDF_ONLY_PNBUF);
  358                         fspath = "/mnt";
  359                         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
  360                             fspath, td);
  361                         error = namei(&nd);
  362                 }
  363                 if (!error) {
  364                         vp = nd.ni_vp;
  365                         error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
  366                         if (!error)
  367                                 error = vinvalbuf(vp, V_SAVE, 0, 0);
  368                         if (!error) {
  369                                 cache_purge(vp);
  370                                 VI_LOCK(vp);
  371                                 mporoot->mnt_vnodecovered = vp;
  372                                 vn_irflag_set_locked(vp, VIRF_MOUNTPOINT);
  373                                 vp->v_mountedhere = mporoot;
  374                                 strlcpy(mporoot->mnt_stat.f_mntonname,
  375                                     fspath, MNAMELEN);
  376                                 VI_UNLOCK(vp);
  377                                 VOP_UNLOCK(vp);
  378                         } else
  379                                 vput(vp);
  380                 }
  381                 NDFREE(&nd, NDF_ONLY_PNBUF);
  382 
  383                 if (error)
  384                         printf("mountroot: unable to remount previous root "
  385                             "under /.mount or /mnt (error %d)\n", error);
  386         }
  387 
  388         /* Remount devfs under /dev */
  389         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
  390         error = namei(&nd);
  391         if (!error) {
  392                 vp = nd.ni_vp;
  393                 error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
  394                 if (!error)
  395                         error = vinvalbuf(vp, V_SAVE, 0, 0);
  396                 if (!error) {
  397                         vpdevfs = mpdevfs->mnt_vnodecovered;
  398                         if (vpdevfs != NULL) {
  399                                 cache_purge(vpdevfs);
  400                                 VI_LOCK(vpdevfs);
  401                                 vn_irflag_unset_locked(vpdevfs, VIRF_MOUNTPOINT);
  402                                 vpdevfs->v_mountedhere = NULL;
  403                                 VI_UNLOCK(vpdevfs);
  404                                 vrele(vpdevfs);
  405                         }
  406                         VI_LOCK(vp);
  407                         mpdevfs->mnt_vnodecovered = vp;
  408                         vn_irflag_set_locked(vp, VIRF_MOUNTPOINT);
  409                         vp->v_mountedhere = mpdevfs;
  410                         VI_UNLOCK(vp);
  411                         VOP_UNLOCK(vp);
  412                 } else
  413                         vput(vp);
  414         }
  415         if (error)
  416                 printf("mountroot: unable to remount devfs under /dev "
  417                     "(error %d)\n", error);
  418         NDFREE(&nd, NDF_ONLY_PNBUF);
  419 
  420         if (mporoot == mpdevfs) {
  421                 vfs_unbusy(mpdevfs);
  422                 /* Unlink the no longer needed /dev/dev -> / symlink */
  423                 error = kern_funlinkat(td, AT_FDCWD, "/dev/dev", FD_NONE,
  424                     UIO_SYSSPACE, 0, 0);
  425                 if (error)
  426                         printf("mountroot: unable to unlink /dev/dev "
  427                             "(error %d)\n", error);
  428         }
  429 }
  430 
  431 /*
  432  * Configuration parser.
  433  */
  434 
  435 /* Parser character classes. */
  436 #define CC_WHITESPACE           -1
  437 #define CC_NONWHITESPACE        -2
  438 
  439 /* Parse errors. */
  440 #define PE_EOF                  -1
  441 #define PE_EOL                  -2
  442 
  443 static __inline int
  444 parse_peek(char **conf)
  445 {
  446 
  447         return (**conf);
  448 }
  449 
  450 static __inline void
  451 parse_poke(char **conf, int c)
  452 {
  453 
  454         **conf = c;
  455 }
  456 
  457 static __inline void
  458 parse_advance(char **conf)
  459 {
  460 
  461         (*conf)++;
  462 }
  463 
  464 static int
  465 parse_skipto(char **conf, int mc)
  466 {
  467         int c, match;
  468 
  469         while (1) {
  470                 c = parse_peek(conf);
  471                 if (c == 0)
  472                         return (PE_EOF);
  473                 switch (mc) {
  474                 case CC_WHITESPACE:
  475                         match = (c == ' ' || c == '\t' || c == '\n') ? 1 : 0;
  476                         break;
  477                 case CC_NONWHITESPACE:
  478                         if (c == '\n')
  479                                 return (PE_EOL);
  480                         match = (c != ' ' && c != '\t') ? 1 : 0;
  481                         break;
  482                 default:
  483                         match = (c == mc) ? 1 : 0;
  484                         break;
  485                 }
  486                 if (match)
  487                         break;
  488                 parse_advance(conf);
  489         }
  490         return (0);
  491 }
  492 
  493 static int
  494 parse_token(char **conf, char **tok)
  495 {
  496         char *p;
  497         size_t len;
  498         int error;
  499 
  500         *tok = NULL;
  501         error = parse_skipto(conf, CC_NONWHITESPACE);
  502         if (error)
  503                 return (error);
  504         p = *conf;
  505         error = parse_skipto(conf, CC_WHITESPACE);
  506         len = *conf - p;
  507         *tok = malloc(len + 1, M_TEMP, M_WAITOK | M_ZERO);
  508         bcopy(p, *tok, len);
  509         return (0);
  510 }
  511 
  512 static void
  513 parse_dir_ask_printenv(const char *var)
  514 {
  515         char *val;
  516 
  517         val = kern_getenv(var);
  518         if (val != NULL) {
  519                 printf("  %s=%s\n", var, val);
  520                 freeenv(val);
  521         }
  522 }
  523 
  524 static int
  525 parse_dir_ask(char **conf)
  526 {
  527         char name[80];
  528         char *mnt;
  529         int error;
  530 
  531         vfs_mountroot_wait();
  532 
  533         printf("\nLoader variables:\n");
  534         parse_dir_ask_printenv("vfs.root.mountfrom");
  535         parse_dir_ask_printenv("vfs.root.mountfrom.options");
  536 
  537         printf("\nManual root filesystem specification:\n");
  538         printf("  <fstype>:<device> [options]\n");
  539         printf("      Mount <device> using filesystem <fstype>\n");
  540         printf("      and with the specified (optional) option list.\n");
  541         printf("\n");
  542         printf("    eg. ufs:/dev/da0s1a\n");
  543         printf("        zfs:zroot/ROOT/default\n");
  544         printf("        cd9660:/dev/cd0 ro\n");
  545         printf("          (which is equivalent to: ");
  546         printf("mount -t cd9660 -o ro /dev/cd0 /)\n");
  547         printf("\n");
  548         printf("  ?               List valid disk boot devices\n");
  549         printf("  .               Yield 1 second (for background tasks)\n");
  550         printf("  <empty line>    Abort manual input\n");
  551 
  552         do {
  553                 error = EINVAL;
  554                 printf("\nmountroot> ");
  555                 cngets(name, sizeof(name), GETS_ECHO);
  556                 if (name[0] == '\0')
  557                         break;
  558                 if (name[0] == '?' && name[1] == '\0') {
  559                         printf("\nList of GEOM managed disk devices:\n  ");
  560                         g_dev_print();
  561                         continue;
  562                 }
  563                 if (name[0] == '.' && name[1] == '\0') {
  564                         pause("rmask", hz);
  565                         continue;
  566                 }
  567                 mnt = name;
  568                 error = parse_mount(&mnt);
  569                 if (error == -1)
  570                         printf("Invalid file system specification.\n");
  571         } while (error != 0);
  572 
  573         return (error);
  574 }
  575 
  576 static int
  577 parse_dir_md(char **conf)
  578 {
  579         struct stat sb;
  580         struct thread *td;
  581         struct md_ioctl *mdio;
  582         char *path, *tok;
  583         int error, fd, len;
  584 
  585         td = curthread;
  586         fd = -1;
  587 
  588         error = parse_token(conf, &tok);
  589         if (error)
  590                 return (error);
  591 
  592         len = strlen(tok);
  593         mdio = malloc(sizeof(*mdio) + len + 1, M_TEMP, M_WAITOK | M_ZERO);
  594         path = (void *)(mdio + 1);
  595         bcopy(tok, path, len);
  596         free(tok, M_TEMP);
  597 
  598         /* Get file status. */
  599         error = kern_statat(td, 0, AT_FDCWD, path, UIO_SYSSPACE, &sb, NULL);
  600         if (error)
  601                 goto out;
  602 
  603         /* Open /dev/mdctl so that we can attach/detach. */
  604         error = kern_openat(td, AT_FDCWD, "/dev/" MDCTL_NAME, UIO_SYSSPACE,
  605             O_RDWR, 0);
  606         if (error)
  607                 goto out;
  608 
  609         fd = td->td_retval[0];
  610         mdio->md_version = MDIOVERSION;
  611         mdio->md_type = MD_VNODE;
  612 
  613         if (root_mount_mddev != -1) {
  614                 mdio->md_unit = root_mount_mddev;
  615                 (void)kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
  616                 /* Ignore errors. We don't care. */
  617                 root_mount_mddev = -1;
  618         }
  619 
  620         mdio->md_file = (void *)(mdio + 1);
  621         mdio->md_options = MD_AUTOUNIT | MD_READONLY;
  622         mdio->md_mediasize = sb.st_size;
  623         mdio->md_unit = 0;
  624         error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio);
  625         if (error)
  626                 goto out;
  627 
  628         if (mdio->md_unit > 9) {
  629                 printf("rootmount: too many md units\n");
  630                 mdio->md_file = NULL;
  631                 mdio->md_options = 0;
  632                 mdio->md_mediasize = 0;
  633                 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
  634                 /* Ignore errors. We don't care. */
  635                 error = ERANGE;
  636                 goto out;
  637         }
  638 
  639         root_mount_mddev = mdio->md_unit;
  640         printf(MD_NAME "%u attached to %s\n", root_mount_mddev, mdio->md_file);
  641 
  642  out:
  643         if (fd >= 0)
  644                 (void)kern_close(td, fd);
  645         free(mdio, M_TEMP);
  646         return (error);
  647 }
  648 
  649 static int
  650 parse_dir_onfail(char **conf)
  651 {
  652         char *action;
  653         int error;
  654 
  655         error = parse_token(conf, &action);
  656         if (error)
  657                 return (error);
  658 
  659         if (!strcmp(action, "continue"))
  660                 root_mount_onfail = A_CONTINUE;
  661         else if (!strcmp(action, "panic"))
  662                 root_mount_onfail = A_PANIC;
  663         else if (!strcmp(action, "reboot"))
  664                 root_mount_onfail = A_REBOOT;
  665         else if (!strcmp(action, "retry"))
  666                 root_mount_onfail = A_RETRY;
  667         else {
  668                 printf("rootmount: %s: unknown action\n", action);
  669                 error = EINVAL;
  670         }
  671 
  672         free(action, M_TEMP);
  673         return (0);
  674 }
  675 
  676 static int
  677 parse_dir_timeout(char **conf)
  678 {
  679         char *tok, *endtok;
  680         long secs;
  681         int error;
  682 
  683         error = parse_token(conf, &tok);
  684         if (error)
  685                 return (error);
  686 
  687         secs = strtol(tok, &endtok, 0);
  688         error = (secs < 0 || *endtok != '\0') ? EINVAL : 0;
  689         if (!error)
  690                 root_mount_timeout = secs;
  691         free(tok, M_TEMP);
  692         return (error);
  693 }
  694 
  695 static int
  696 parse_directive(char **conf)
  697 {
  698         char *dir;
  699         int error;
  700 
  701         error = parse_token(conf, &dir);
  702         if (error)
  703                 return (error);
  704 
  705         if (strcmp(dir, ".ask") == 0)
  706                 error = parse_dir_ask(conf);
  707         else if (strcmp(dir, ".md") == 0)
  708                 error = parse_dir_md(conf);
  709         else if (strcmp(dir, ".onfail") == 0)
  710                 error = parse_dir_onfail(conf);
  711         else if (strcmp(dir, ".timeout") == 0)
  712                 error = parse_dir_timeout(conf);
  713         else {
  714                 printf("mountroot: invalid directive `%s'\n", dir);
  715                 /* Ignore the rest of the line. */
  716                 (void)parse_skipto(conf, '\n');
  717                 error = EINVAL;
  718         }
  719         free(dir, M_TEMP);
  720         return (error);
  721 }
  722 
  723 static int
  724 parse_mount_dev_present(const char *dev)
  725 {
  726         struct nameidata nd;
  727         int error;
  728 
  729         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, dev, curthread);
  730         error = namei(&nd);
  731         if (!error)
  732                 vput(nd.ni_vp);
  733         NDFREE(&nd, NDF_ONLY_PNBUF);
  734         return (error != 0) ? 0 : 1;
  735 }
  736 
  737 #define ERRMSGL 255
  738 static int
  739 parse_mount(char **conf)
  740 {
  741         char *errmsg;
  742         struct mntarg *ma;
  743         char *dev, *fs, *opts, *tok;
  744         int delay, error, timeout;
  745 
  746         error = parse_token(conf, &tok);
  747         if (error)
  748                 return (error);
  749         fs = tok;
  750         error = parse_skipto(&tok, ':');
  751         if (error) {
  752                 free(fs, M_TEMP);
  753                 return (error);
  754         }
  755         parse_poke(&tok, '\0');
  756         parse_advance(&tok);
  757         dev = tok;
  758 
  759         if (root_mount_mddev != -1) {
  760                 /* Handle substitution for the md unit number. */
  761                 tok = strstr(dev, "md#");
  762                 if (tok != NULL)
  763                         tok[2] = '' + root_mount_mddev;
  764         }
  765 
  766         /* Parse options. */
  767         error = parse_token(conf, &tok);
  768         opts = (error == 0) ? tok : NULL;
  769 
  770         printf("Trying to mount root from %s:%s [%s]...\n", fs, dev,
  771             (opts != NULL) ? opts : "");
  772 
  773         errmsg = malloc(ERRMSGL, M_TEMP, M_WAITOK | M_ZERO);
  774 
  775         if (vfs_byname(fs) == NULL) {
  776                 strlcpy(errmsg, "unknown file system", ERRMSGL);
  777                 error = ENOENT;
  778                 goto out;
  779         }
  780 
  781         error = vfs_mountroot_wait_if_neccessary(fs, dev);
  782         if (error != 0)
  783                 goto out;
  784 
  785         delay = hz / 10;
  786         timeout = root_mount_timeout * hz;
  787 
  788         for (;;) {
  789                 ma = NULL;
  790                 ma = mount_arg(ma, "fstype", fs, -1);
  791                 ma = mount_arg(ma, "fspath", "/", -1);
  792                 ma = mount_arg(ma, "from", dev, -1);
  793                 ma = mount_arg(ma, "errmsg", errmsg, ERRMSGL);
  794                 ma = mount_arg(ma, "ro", NULL, 0);
  795                 ma = parse_mountroot_options(ma, opts);
  796 
  797                 error = kernel_mount(ma, MNT_ROOTFS);
  798                 if (error == 0 || timeout <= 0)
  799                         break;
  800 
  801                 if (root_mount_timeout * hz == timeout ||
  802                     (bootverbose && timeout % hz == 0)) {
  803                         printf("Mounting from %s:%s failed with error %d; "
  804                             "retrying for %d more second%s\n", fs, dev, error,
  805                             timeout / hz, (timeout / hz > 1) ? "s" : "");
  806                 }
  807                 pause("rmretry", delay);
  808                 timeout -= delay;
  809         }
  810  out:
  811         if (error) {
  812                 printf("Mounting from %s:%s failed with error %d",
  813                     fs, dev, error);
  814                 if (errmsg[0] != '\0')
  815                         printf(": %s", errmsg);
  816                 printf(".\n");
  817         }
  818         free(fs, M_TEMP);
  819         free(errmsg, M_TEMP);
  820         if (opts != NULL)
  821                 free(opts, M_TEMP);
  822         /* kernel_mount can return -1 on error. */
  823         return ((error < 0) ? EDOOFUS : error);
  824 }
  825 #undef ERRMSGL
  826 
  827 static int
  828 vfs_mountroot_parse(struct sbuf *sb, struct mount *mpdevfs)
  829 {
  830         struct mount *mp;
  831         char *conf;
  832         int error;
  833 
  834         root_mount_mddev = -1;
  835 
  836 retry:
  837         conf = sbuf_data(sb);
  838         mp = TAILQ_NEXT(mpdevfs, mnt_list);
  839         error = (mp == NULL) ? 0 : EDOOFUS;
  840         root_mount_onfail = A_CONTINUE;
  841         while (mp == NULL) {
  842                 error = parse_skipto(&conf, CC_NONWHITESPACE);
  843                 if (error == PE_EOL) {
  844                         parse_advance(&conf);
  845                         continue;
  846                 }
  847                 if (error < 0)
  848                         break;
  849                 switch (parse_peek(&conf)) {
  850                 case '#':
  851                         error = parse_skipto(&conf, '\n');
  852                         break;
  853                 case '.':
  854                         error = parse_directive(&conf);
  855                         break;
  856                 default:
  857                         error = parse_mount(&conf);
  858                         if (error == -1) {
  859                                 printf("mountroot: invalid file system "
  860                                     "specification.\n");
  861                                 error = 0;
  862                         }
  863                         break;
  864                 }
  865                 if (error < 0)
  866                         break;
  867                 /* Ignore any trailing garbage on the line. */
  868                 if (parse_peek(&conf) != '\n') {
  869                         printf("mountroot: advancing to next directive...\n");
  870                         (void)parse_skipto(&conf, '\n');
  871                 }
  872                 mp = TAILQ_NEXT(mpdevfs, mnt_list);
  873         }
  874         if (mp != NULL)
  875                 return (0);
  876 
  877         /*
  878          * We failed to mount (a new) root.
  879          */
  880         switch (root_mount_onfail) {
  881         case A_CONTINUE:
  882                 break;
  883         case A_PANIC:
  884                 panic("mountroot: unable to (re-)mount root.");
  885                 /* NOTREACHED */
  886         case A_RETRY:
  887                 goto retry;
  888         case A_REBOOT:
  889                 kern_reboot(RB_NOSYNC);
  890                 /* NOTREACHED */
  891         }
  892 
  893         return (error);
  894 }
  895 
  896 static void
  897 vfs_mountroot_conf0(struct sbuf *sb)
  898 {
  899         char *s, *tok, *mnt, *opt;
  900         int error;
  901 
  902         sbuf_printf(sb, ".onfail panic\n");
  903         sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
  904         if (boothowto & RB_ASKNAME)
  905                 sbuf_printf(sb, ".ask\n");
  906 #ifdef ROOTDEVNAME
  907         if (boothowto & RB_DFLTROOT)
  908                 sbuf_printf(sb, "%s\n", ROOTDEVNAME);
  909 #endif
  910         if (boothowto & RB_CDROM) {
  911                 sbuf_printf(sb, "cd9660:/dev/cd0 ro\n");
  912                 sbuf_printf(sb, ".timeout 0\n");
  913                 sbuf_printf(sb, "cd9660:/dev/cd1 ro\n");
  914                 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
  915         }
  916         s = kern_getenv("vfs.root.mountfrom");
  917         if (s != NULL) {
  918                 opt = kern_getenv("vfs.root.mountfrom.options");
  919                 tok = s;
  920                 error = parse_token(&tok, &mnt);
  921                 while (!error) {
  922                         sbuf_printf(sb, "%s %s\n", mnt,
  923                             (opt != NULL) ? opt : "");
  924                         free(mnt, M_TEMP);
  925                         error = parse_token(&tok, &mnt);
  926                 }
  927                 if (opt != NULL)
  928                         freeenv(opt);
  929                 freeenv(s);
  930         }
  931         if (rootdevnames[0] != NULL)
  932                 sbuf_printf(sb, "%s\n", rootdevnames[0]);
  933         if (rootdevnames[1] != NULL)
  934                 sbuf_printf(sb, "%s\n", rootdevnames[1]);
  935 #ifdef ROOTDEVNAME
  936         if (!(boothowto & RB_DFLTROOT))
  937                 sbuf_printf(sb, "%s\n", ROOTDEVNAME);
  938 #endif
  939         if (!(boothowto & RB_ASKNAME))
  940                 sbuf_printf(sb, ".ask\n");
  941 }
  942 
  943 static int
  944 vfs_mountroot_readconf(struct thread *td, struct sbuf *sb)
  945 {
  946         static char buf[128];
  947         struct nameidata nd;
  948         off_t ofs;
  949         ssize_t resid;
  950         int error, flags, len;
  951 
  952         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/.mount.conf", td);
  953         flags = FREAD;
  954         error = vn_open(&nd, &flags, 0, NULL);
  955         if (error)
  956                 return (error);
  957 
  958         NDFREE(&nd, NDF_ONLY_PNBUF);
  959         ofs = 0;
  960         len = sizeof(buf) - 1;
  961         while (1) {
  962                 error = vn_rdwr(UIO_READ, nd.ni_vp, buf, len, ofs,
  963                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
  964                     NOCRED, &resid, td);
  965                 if (error)
  966                         break;
  967                 if (resid == len)
  968                         break;
  969                 buf[len - resid] = 0;
  970                 sbuf_printf(sb, "%s", buf);
  971                 ofs += len - resid;
  972         }
  973 
  974         VOP_UNLOCK(nd.ni_vp);
  975         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
  976         return (error);
  977 }
  978 
  979 static void
  980 vfs_mountroot_wait(void)
  981 {
  982         struct root_hold_token *h;
  983         struct timeval lastfail;
  984         int curfail;
  985 
  986         TSENTER();
  987 
  988         curfail = 0;
  989         lastfail.tv_sec = 0;
  990         while (1) {
  991                 g_waitidle();
  992                 mtx_lock(&root_holds_mtx);
  993                 if (TAILQ_EMPTY(&root_holds)) {
  994                         mtx_unlock(&root_holds_mtx);
  995                         break;
  996                 }
  997                 if (ppsratecheck(&lastfail, &curfail, 1)) {
  998                         printf("Root mount waiting for:");
  999                         TAILQ_FOREACH(h, &root_holds, list)
 1000                                 printf(" %s", h->who);
 1001                         printf("\n");
 1002                 }
 1003                 TSWAIT("root mount");
 1004                 msleep(&root_holds, &root_holds_mtx, PZERO | PDROP, "roothold",
 1005                     hz);
 1006                 TSUNWAIT("root mount");
 1007         }
 1008 
 1009         TSEXIT();
 1010 }
 1011 
 1012 static int
 1013 vfs_mountroot_wait_if_neccessary(const char *fs, const char *dev)
 1014 {
 1015         int delay, timeout;
 1016 
 1017         /*
 1018          * In case of ZFS and NFS we don't have a way to wait for
 1019          * specific device.  Also do the wait if the user forced that
 1020          * behaviour by setting vfs.root_mount_always_wait=1.
 1021          */
 1022         if (strcmp(fs, "zfs") == 0 || strstr(fs, "nfs") != NULL ||
 1023             dev[0] == '\0' || root_mount_always_wait != 0) {
 1024                 vfs_mountroot_wait();
 1025                 return (0);
 1026         }
 1027 
 1028         /*
 1029          * Otherwise, no point in waiting if the device is already there.
 1030          * Note that we must wait for GEOM to finish reconfiguring itself,
 1031          * eg for geom_part(4) to finish tasting.
 1032          */
 1033         g_waitidle();
 1034         if (parse_mount_dev_present(dev))
 1035                 return (0);
 1036 
 1037         /*
 1038          * No luck.  Let's wait.  This code looks weird, but it's that way
 1039          * to behave exactly as it used to work before.
 1040          */
 1041         vfs_mountroot_wait();
 1042         printf("mountroot: waiting for device %s...\n", dev);
 1043         delay = hz / 10;
 1044         timeout = root_mount_timeout * hz;
 1045         do {
 1046                 pause("rmdev", delay);
 1047                 timeout -= delay;
 1048         } while (timeout > 0 && !parse_mount_dev_present(dev));
 1049 
 1050         if (timeout <= 0)
 1051                 return (ENODEV);
 1052 
 1053         return (0);
 1054 }
 1055 
 1056 void
 1057 vfs_mountroot(void)
 1058 {
 1059         struct mount *mp;
 1060         struct sbuf *sb;
 1061         struct thread *td;
 1062         time_t timebase;
 1063         int error;
 1064 
 1065         mtx_assert(&Giant, MA_NOTOWNED);
 1066 
 1067         TSENTER();
 1068 
 1069         td = curthread;
 1070 
 1071         sb = sbuf_new_auto();
 1072         vfs_mountroot_conf0(sb);
 1073         sbuf_finish(sb);
 1074 
 1075         error = vfs_mountroot_devfs(td, &mp);
 1076         while (!error) {
 1077                 error = vfs_mountroot_parse(sb, mp);
 1078                 if (!error) {
 1079                         vfs_mountroot_shuffle(td, mp);
 1080                         sbuf_clear(sb);
 1081                         error = vfs_mountroot_readconf(td, sb);
 1082                         sbuf_finish(sb);
 1083                 }
 1084         }
 1085 
 1086         sbuf_delete(sb);
 1087 
 1088         /*
 1089          * Iterate over all currently mounted file systems and use
 1090          * the time stamp found to check and/or initialize the RTC.
 1091          * Call inittodr() only once and pass it the largest of the
 1092          * timestamps we encounter.
 1093          */
 1094         timebase = 0;
 1095         mtx_lock(&mountlist_mtx);
 1096         mp = TAILQ_FIRST(&mountlist);
 1097         while (mp != NULL) {
 1098                 if (mp->mnt_time > timebase)
 1099                         timebase = mp->mnt_time;
 1100                 mp = TAILQ_NEXT(mp, mnt_list);
 1101         }
 1102         mtx_unlock(&mountlist_mtx);
 1103         inittodr(timebase);
 1104 
 1105         /* Keep prison0's root in sync with the global rootvnode. */
 1106         mtx_lock(&prison0.pr_mtx);
 1107         prison0.pr_root = rootvnode;
 1108         vref(prison0.pr_root);
 1109         mtx_unlock(&prison0.pr_mtx);
 1110 
 1111         mtx_lock(&root_holds_mtx);
 1112         atomic_store_rel_int(&root_mount_complete, 1);
 1113         wakeup(&root_mount_complete);
 1114         mtx_unlock(&root_holds_mtx);
 1115 
 1116         EVENTHANDLER_INVOKE(mountroot);
 1117 
 1118         TSEXIT();
 1119 }
 1120 
 1121 static struct mntarg *
 1122 parse_mountroot_options(struct mntarg *ma, const char *options)
 1123 {
 1124         char *p;
 1125         char *name, *name_arg;
 1126         char *val, *val_arg;
 1127         char *opts;
 1128 
 1129         if (options == NULL || options[0] == '\0')
 1130                 return (ma);
 1131 
 1132         p = opts = strdup(options, M_MOUNT);
 1133         if (opts == NULL) {
 1134                 return (ma);
 1135         }
 1136 
 1137         while((name = strsep(&p, ",")) != NULL) {
 1138                 if (name[0] == '\0')
 1139                         break;
 1140 
 1141                 val = strchr(name, '=');
 1142                 if (val != NULL) {
 1143                         *val = '\0';
 1144                         ++val;
 1145                 }
 1146                 if( strcmp(name, "rw") == 0 ||
 1147                     strcmp(name, "noro") == 0) {
 1148                         /*
 1149                          * The first time we mount the root file system,
 1150                          * we need to mount 'ro', so We need to ignore
 1151                          * 'rw' and 'noro' mount options.
 1152                          */
 1153                         continue;
 1154                 }
 1155                 name_arg = strdup(name, M_MOUNT);
 1156                 val_arg = NULL;
 1157                 if (val != NULL)
 1158                         val_arg = strdup(val, M_MOUNT);
 1159 
 1160                 ma = mount_arg(ma, name_arg, val_arg,
 1161                     (val_arg != NULL ? -1 : 0));
 1162         }
 1163         free(opts, M_MOUNT);
 1164         return (ma);
 1165 }
Cache object: bddd73227e6498ee4d63e33c5794e23a
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/kern/vfs_mountroot.c

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