1/*- 2 * Copyright (c) 2010 Marcel Moolenaar 3 * Copyright (c) 1999-2004 Poul-Henning Kamp 4 * Copyright (c) 1999 Michael Smith 5 * Copyright (c) 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38#include "opt_rootdevname.h" 39 40#include <sys/cdefs.h> 41__FBSDID("$FreeBSD: stable/11/sys/kern/vfs_mountroot.c 353717 2019-10-18 03:38:02Z kp $"); 42 43#include <sys/param.h> 44#include <sys/conf.h> 45#include <sys/cons.h> 46#include <sys/fcntl.h> 47#include <sys/jail.h> 48#include <sys/kernel.h> 49#include <sys/malloc.h> 50#include <sys/mdioctl.h> 51#include <sys/mount.h> 52#include <sys/mutex.h> 53#include <sys/namei.h> 54#include <sys/priv.h> 55#include <sys/proc.h> 56#include <sys/filedesc.h> 57#include <sys/reboot.h> 58#include <sys/sbuf.h> 59#include <sys/stat.h> 60#include <sys/syscallsubr.h> 61#include <sys/sysproto.h> 62#include <sys/sx.h> 63#include <sys/sysctl.h> 64#include <sys/sysent.h> 65#include <sys/systm.h> 66#include <sys/vnode.h> 67 68#include <geom/geom.h> 69 70/* 71 * The root filesystem is detailed in the kernel environment variable 72 * vfs.root.mountfrom, which is expected to be in the general format 73 * 74 * <vfsname>:[<path>][ <vfsname>:[<path>] ...] 75 * vfsname := the name of a VFS known to the kernel and capable 76 * of being mounted as root 77 * path := disk device name or other data used by the filesystem 78 * to locate its physical store 79 * 80 * If the environment variable vfs.root.mountfrom is a space separated list, 81 * each list element is tried in turn and the root filesystem will be mounted 82 * from the first one that succeeds. 83 * 84 * The environment variable vfs.root.mountfrom.options is a comma delimited 85 * set of string mount options. These mount options must be parseable 86 * by nmount() in the kernel. 87 */ 88 89static int parse_mount(char **); 90static struct mntarg *parse_mountroot_options(struct mntarg *, const char *); 91static int sysctl_vfs_root_mount_hold(SYSCTL_HANDLER_ARGS); 92static void vfs_mountroot_wait(void); 93static int vfs_mountroot_wait_if_neccessary(const char *fs, const char *dev); 94 95/* 96 * The vnode of the system's root (/ in the filesystem, without chroot 97 * active.) 98 */ 99struct vnode *rootvnode; 100 101/* 102 * Mount of the system's /dev. 103 */ 104struct mount *rootdevmp; 105 106char *rootdevnames[2] = {NULL, NULL}; 107 108struct mtx root_holds_mtx; 109MTX_SYSINIT(root_holds, &root_holds_mtx, "root_holds", MTX_DEF); 110 111struct root_hold_token { 112 const char *who; 113 LIST_ENTRY(root_hold_token) list; 114}; 115 116static LIST_HEAD(, root_hold_token) root_holds = 117 LIST_HEAD_INITIALIZER(root_holds); 118 119enum action { 120 A_CONTINUE, 121 A_PANIC, 122 A_REBOOT, 123 A_RETRY 124}; 125 126static enum action root_mount_onfail = A_CONTINUE; 127 128static int root_mount_mddev; 129static int root_mount_complete; 130 131/* By default wait up to 3 seconds for devices to appear. */ 132static int root_mount_timeout = 3; 133TUNABLE_INT("vfs.mountroot.timeout", &root_mount_timeout); 134 135static int root_mount_always_wait = 0; 136SYSCTL_INT(_vfs, OID_AUTO, root_mount_always_wait, CTLFLAG_RDTUN, 137 &root_mount_always_wait, 0, 138 "Wait for root mount holds even if the root device already exists"); 139 140SYSCTL_PROC(_vfs, OID_AUTO, root_mount_hold, 141 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 142 NULL, 0, sysctl_vfs_root_mount_hold, "A", 143 "List of root mount hold tokens"); 144 145static int 146sysctl_vfs_root_mount_hold(SYSCTL_HANDLER_ARGS) 147{ 148 struct sbuf sb; 149 struct root_hold_token *h; 150 int error; 151 152 sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL); 153 154 mtx_lock(&root_holds_mtx); 155 LIST_FOREACH(h, &root_holds, list) { 156 if (h != LIST_FIRST(&root_holds)) 157 sbuf_putc(&sb, ' '); 158 sbuf_printf(&sb, "%s", h->who); 159 } 160 mtx_unlock(&root_holds_mtx); 161 162 error = sbuf_finish(&sb); 163 if (error == 0) 164 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb)); 165 sbuf_delete(&sb); 166 return (error); 167} 168 169struct root_hold_token * 170root_mount_hold(const char *identifier) 171{ 172 struct root_hold_token *h; 173 174 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK); 175 h->who = identifier; 176 mtx_lock(&root_holds_mtx); 177 LIST_INSERT_HEAD(&root_holds, h, list); 178 mtx_unlock(&root_holds_mtx); 179 return (h); 180} 181 182void 183root_mount_rel(struct root_hold_token *h) 184{ 185 186 if (h == NULL) 187 return; 188 189 mtx_lock(&root_holds_mtx); 190 LIST_REMOVE(h, list); 191 wakeup(&root_holds); 192 mtx_unlock(&root_holds_mtx); 193 free(h, M_DEVBUF); 194} 195 196int 197root_mounted(void) 198{ 199 200 /* No mutex is acquired here because int stores are atomic. */ 201 return (root_mount_complete); 202} 203 204static void 205set_rootvnode(void) 206{ 207 struct proc *p; 208 209 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode)) 210 panic("Cannot find root vnode"); 211 212 VOP_UNLOCK(rootvnode, 0); 213 214 p = curthread->td_proc; 215 FILEDESC_XLOCK(p->p_fd); 216 217 if (p->p_fd->fd_cdir != NULL) 218 vrele(p->p_fd->fd_cdir); 219 p->p_fd->fd_cdir = rootvnode; 220 VREF(rootvnode); 221 222 if (p->p_fd->fd_rdir != NULL) 223 vrele(p->p_fd->fd_rdir); 224 p->p_fd->fd_rdir = rootvnode; 225 VREF(rootvnode); 226 227 FILEDESC_XUNLOCK(p->p_fd); 228} 229 230static int 231vfs_mountroot_devfs(struct thread *td, struct mount **mpp) 232{ 233 struct vfsoptlist *opts; 234 struct vfsconf *vfsp; 235 struct mount *mp; 236 int error; 237 238 *mpp = NULL; 239 240 if (rootdevmp != NULL) { 241 /* 242 * Already have /dev; this happens during rerooting. 243 */ 244 error = vfs_busy(rootdevmp, 0); 245 if (error != 0) 246 return (error); 247 *mpp = rootdevmp; 248 } else { 249 vfsp = vfs_byname("devfs"); 250 KASSERT(vfsp != NULL, ("Could not find devfs by name")); 251 if (vfsp == NULL) 252 return (ENOENT); 253 254 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred); 255 256 error = VFS_MOUNT(mp); 257 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error)); 258 if (error) 259 return (error); 260 261 error = VFS_STATFS(mp, &mp->mnt_stat); 262 KASSERT(error == 0, ("VFS_STATFS(devfs) failed %d", error)); 263 if (error) 264 return (error); 265 266 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 267 TAILQ_INIT(opts); 268 mp->mnt_opt = opts; 269 270 mtx_lock(&mountlist_mtx); 271 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 272 mtx_unlock(&mountlist_mtx); 273 274 *mpp = mp; 275 rootdevmp = mp; 276 } 277 278 set_rootvnode(); 279 280 error = kern_symlinkat(td, "/", AT_FDCWD, "dev", UIO_SYSSPACE); 281 if (error) 282 printf("kern_symlink /dev -> / returns %d\n", error); 283 284 return (error); 285} 286 287static void 288vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs) 289{ 290 struct nameidata nd; 291 struct mount *mporoot, *mpnroot; 292 struct vnode *vp, *vporoot, *vpdevfs; 293 char *fspath; 294 int error; 295 296 mpnroot = TAILQ_NEXT(mpdevfs, mnt_list); 297 298 /* Shuffle the mountlist. */ 299 mtx_lock(&mountlist_mtx); 300 mporoot = TAILQ_FIRST(&mountlist); 301 TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list); 302 if (mporoot != mpdevfs) { 303 TAILQ_REMOVE(&mountlist, mpnroot, mnt_list); 304 TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list); 305 } 306 TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list); 307 mtx_unlock(&mountlist_mtx); 308 309 cache_purgevfs(mporoot, true); 310 if (mporoot != mpdevfs) 311 cache_purgevfs(mpdevfs, true); 312 313 VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot); 314 315 VI_LOCK(vporoot); 316 vporoot->v_iflag &= ~VI_MOUNT; 317 VI_UNLOCK(vporoot); 318 vporoot->v_mountedhere = NULL; 319 mporoot->mnt_flag &= ~MNT_ROOTFS; 320 mporoot->mnt_vnodecovered = NULL; 321 vput(vporoot); 322 323 /* Set up the new rootvnode, and purge the cache */ 324 mpnroot->mnt_vnodecovered = NULL; 325 set_rootvnode(); 326 cache_purgevfs(rootvnode->v_mount, true); 327 328 if (mporoot != mpdevfs) { 329 /* Remount old root under /.mount or /mnt */ 330 fspath = "/.mount"; 331 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, 332 fspath, td); 333 error = namei(&nd); 334 if (error) { 335 NDFREE(&nd, NDF_ONLY_PNBUF); 336 fspath = "/mnt"; 337 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, 338 fspath, td); 339 error = namei(&nd); 340 } 341 if (!error) { 342 vp = nd.ni_vp; 343 error = (vp->v_type == VDIR) ? 0 : ENOTDIR; 344 if (!error) 345 error = vinvalbuf(vp, V_SAVE, 0, 0); 346 if (!error) { 347 cache_purge(vp); 348 mporoot->mnt_vnodecovered = vp; 349 vp->v_mountedhere = mporoot; 350 strlcpy(mporoot->mnt_stat.f_mntonname, 351 fspath, MNAMELEN); 352 VOP_UNLOCK(vp, 0); 353 } else 354 vput(vp); 355 } 356 NDFREE(&nd, NDF_ONLY_PNBUF); 357 358 if (error) 359 printf("mountroot: unable to remount previous root " 360 "under /.mount or /mnt (error %d)\n", error); 361 } 362 363 /* Remount devfs under /dev */ 364 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td); 365 error = namei(&nd); 366 if (!error) { 367 vp = nd.ni_vp; 368 error = (vp->v_type == VDIR) ? 0 : ENOTDIR; 369 if (!error) 370 error = vinvalbuf(vp, V_SAVE, 0, 0); 371 if (!error) { 372 vpdevfs = mpdevfs->mnt_vnodecovered; 373 if (vpdevfs != NULL) { 374 cache_purge(vpdevfs); 375 vpdevfs->v_mountedhere = NULL; 376 vrele(vpdevfs); 377 } 378 mpdevfs->mnt_vnodecovered = vp; 379 vp->v_mountedhere = mpdevfs; 380 VOP_UNLOCK(vp, 0); 381 } else 382 vput(vp); 383 } 384 if (error) 385 printf("mountroot: unable to remount devfs under /dev " 386 "(error %d)\n", error); 387 NDFREE(&nd, NDF_ONLY_PNBUF); 388 389 if (mporoot == mpdevfs) { 390 vfs_unbusy(mpdevfs); 391 /* Unlink the no longer needed /dev/dev -> / symlink */ 392 error = kern_unlinkat(td, AT_FDCWD, "/dev/dev", 393 UIO_SYSSPACE, 0); 394 if (error) 395 printf("mountroot: unable to unlink /dev/dev " 396 "(error %d)\n", error); 397 } 398} 399 400/* 401 * Configuration parser. 402 */ 403 404/* Parser character classes. */ 405#define CC_WHITESPACE -1 406#define CC_NONWHITESPACE -2 407 408/* Parse errors. */ 409#define PE_EOF -1 410#define PE_EOL -2 411 412static __inline int 413parse_peek(char **conf) 414{ 415 416 return (**conf); 417} 418 419static __inline void 420parse_poke(char **conf, int c) 421{ 422 423 **conf = c; 424} 425 426static __inline void 427parse_advance(char **conf) 428{ 429 430 (*conf)++; 431} 432 433static int 434parse_skipto(char **conf, int mc) 435{ 436 int c, match; 437 438 while (1) { 439 c = parse_peek(conf); 440 if (c == 0) 441 return (PE_EOF); 442 switch (mc) { 443 case CC_WHITESPACE: 444 match = (c == ' ' || c == '\t' || c == '\n') ? 1 : 0; 445 break; 446 case CC_NONWHITESPACE: 447 if (c == '\n') 448 return (PE_EOL); 449 match = (c != ' ' && c != '\t') ? 1 : 0; 450 break; 451 default: 452 match = (c == mc) ? 1 : 0; 453 break; 454 } 455 if (match) 456 break; 457 parse_advance(conf); 458 } 459 return (0); 460} 461 462static int 463parse_token(char **conf, char **tok) 464{ 465 char *p; 466 size_t len; 467 int error; 468 469 *tok = NULL; 470 error = parse_skipto(conf, CC_NONWHITESPACE); 471 if (error) 472 return (error); 473 p = *conf; 474 error = parse_skipto(conf, CC_WHITESPACE); 475 len = *conf - p; 476 *tok = malloc(len + 1, M_TEMP, M_WAITOK | M_ZERO); 477 bcopy(p, *tok, len); 478 return (0); 479} 480 481static void 482parse_dir_ask_printenv(const char *var) 483{ 484 char *val; 485 486 val = kern_getenv(var); 487 if (val != NULL) { 488 printf(" %s=%s\n", var, val); 489 freeenv(val); 490 } 491} 492 493static int 494parse_dir_ask(char **conf) 495{ 496 char name[80]; 497 char *mnt; 498 int error; 499 500 vfs_mountroot_wait(); 501 502 printf("\nLoader variables:\n"); 503 parse_dir_ask_printenv("vfs.root.mountfrom"); 504 parse_dir_ask_printenv("vfs.root.mountfrom.options"); 505 506 printf("\nManual root filesystem specification:\n"); 507 printf(" <fstype>:<device> [options]\n"); 508 printf(" Mount <device> using filesystem <fstype>\n"); 509 printf(" and with the specified (optional) option list.\n"); 510 printf("\n"); 511 printf(" eg. ufs:/dev/da0s1a\n"); 512 printf(" zfs:tank\n"); 513 printf(" cd9660:/dev/cd0 ro\n"); 514 printf(" (which is equivalent to: "); 515 printf("mount -t cd9660 -o ro /dev/cd0 /)\n"); 516 printf("\n"); 517 printf(" ? List valid disk boot devices\n"); 518 printf(" . Yield 1 second (for background tasks)\n"); 519 printf(" <empty line> Abort manual input\n"); 520 521 do { 522 error = EINVAL; 523 printf("\nmountroot> "); 524 cngets(name, sizeof(name), GETS_ECHO); 525 if (name[0] == '\0') 526 break; 527 if (name[0] == '?' && name[1] == '\0') { 528 printf("\nList of GEOM managed disk devices:\n "); 529 g_dev_print(); 530 continue; 531 } 532 if (name[0] == '.' && name[1] == '\0') { 533 pause("rmask", hz); 534 continue; 535 } 536 mnt = name; 537 error = parse_mount(&mnt); 538 if (error == -1) 539 printf("Invalid file system specification.\n"); 540 } while (error != 0); 541 542 return (error); 543} 544 545static int 546parse_dir_md(char **conf) 547{ 548 struct stat sb; 549 struct thread *td; 550 struct md_ioctl *mdio; 551 char *path, *tok; 552 int error, fd, len; 553 554 td = curthread; 555 556 error = parse_token(conf, &tok); 557 if (error) 558 return (error); 559 560 len = strlen(tok); 561 mdio = malloc(sizeof(*mdio) + len + 1, M_TEMP, M_WAITOK | M_ZERO); 562 path = (void *)(mdio + 1); 563 bcopy(tok, path, len); 564 free(tok, M_TEMP); 565 566 /* Get file status. */ 567 error = kern_statat(td, 0, AT_FDCWD, path, UIO_SYSSPACE, &sb, NULL); 568 if (error) 569 goto out; 570 571 /* Open /dev/mdctl so that we can attach/detach. */ 572 error = kern_openat(td, AT_FDCWD, "/dev/" MDCTL_NAME, UIO_SYSSPACE, 573 O_RDWR, 0); 574 if (error) 575 goto out; 576 577 fd = td->td_retval[0]; 578 mdio->md_version = MDIOVERSION; 579 mdio->md_type = MD_VNODE; 580 581 if (root_mount_mddev != -1) { 582 mdio->md_unit = root_mount_mddev; 583 DROP_GIANT(); 584 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio); 585 PICKUP_GIANT(); 586 /* Ignore errors. We don't care. */ 587 root_mount_mddev = -1; 588 } 589 590 mdio->md_file = (void *)(mdio + 1); 591 mdio->md_options = MD_AUTOUNIT | MD_READONLY; 592 mdio->md_mediasize = sb.st_size; 593 mdio->md_unit = 0; 594 DROP_GIANT(); 595 error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio); 596 PICKUP_GIANT(); 597 if (error) 598 goto out; 599 600 if (mdio->md_unit > 9) { 601 printf("rootmount: too many md units\n"); 602 mdio->md_file = NULL; 603 mdio->md_options = 0; 604 mdio->md_mediasize = 0; 605 DROP_GIANT(); 606 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio); 607 PICKUP_GIANT(); 608 /* Ignore errors. We don't care. */ 609 error = ERANGE; 610 goto out; 611 } 612 613 root_mount_mddev = mdio->md_unit; 614 printf(MD_NAME "%u attached to %s\n", root_mount_mddev, mdio->md_file); 615 616 error = kern_close(td, fd); 617 618 out: 619 free(mdio, M_TEMP); 620 return (error); 621} 622 623static int 624parse_dir_onfail(char **conf) 625{ 626 char *action; 627 int error; 628 629 error = parse_token(conf, &action); 630 if (error) 631 return (error); 632 633 if (!strcmp(action, "continue")) 634 root_mount_onfail = A_CONTINUE; 635 else if (!strcmp(action, "panic")) 636 root_mount_onfail = A_PANIC; 637 else if (!strcmp(action, "reboot")) 638 root_mount_onfail = A_REBOOT; 639 else if (!strcmp(action, "retry")) 640 root_mount_onfail = A_RETRY; 641 else { 642 printf("rootmount: %s: unknown action\n", action); 643 error = EINVAL; 644 } 645 646 free(action, M_TEMP); 647 return (0); 648} 649 650static int 651parse_dir_timeout(char **conf) 652{ 653 char *tok, *endtok; 654 long secs; 655 int error; 656 657 error = parse_token(conf, &tok); 658 if (error) 659 return (error); 660 661 secs = strtol(tok, &endtok, 0); 662 error = (secs < 0 || *endtok != '\0') ? EINVAL : 0; 663 if (!error) 664 root_mount_timeout = secs; 665 free(tok, M_TEMP); 666 return (error); 667} 668 669static int 670parse_directive(char **conf) 671{ 672 char *dir; 673 int error; 674 675 error = parse_token(conf, &dir); 676 if (error) 677 return (error); 678 679 if (strcmp(dir, ".ask") == 0) 680 error = parse_dir_ask(conf); 681 else if (strcmp(dir, ".md") == 0) 682 error = parse_dir_md(conf); 683 else if (strcmp(dir, ".onfail") == 0) 684 error = parse_dir_onfail(conf); 685 else if (strcmp(dir, ".timeout") == 0) 686 error = parse_dir_timeout(conf); 687 else { 688 printf("mountroot: invalid directive `%s'\n", dir); 689 /* Ignore the rest of the line. */ 690 (void)parse_skipto(conf, '\n'); 691 error = EINVAL; 692 } 693 free(dir, M_TEMP); 694 return (error); 695} 696 697static int 698parse_mount_dev_present(const char *dev) 699{ 700 struct nameidata nd; 701 int error; 702 703 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, dev, curthread); 704 error = namei(&nd); 705 if (!error) 706 vput(nd.ni_vp); 707 NDFREE(&nd, NDF_ONLY_PNBUF); 708 return (error != 0) ? 0 : 1; 709} 710 711#define ERRMSGL 255 712static int 713parse_mount(char **conf) 714{ 715 char *errmsg; 716 struct mntarg *ma; 717 char *dev, *fs, *opts, *tok; 718 int delay, error, timeout; 719 720 error = parse_token(conf, &tok); 721 if (error) 722 return (error); 723 fs = tok; 724 error = parse_skipto(&tok, ':'); 725 if (error) { 726 free(fs, M_TEMP); 727 return (error); 728 } 729 parse_poke(&tok, '\0'); 730 parse_advance(&tok); 731 dev = tok; 732 733 if (root_mount_mddev != -1) { 734 /* Handle substitution for the md unit number. */ 735 tok = strstr(dev, "md#"); 736 if (tok != NULL) 737 tok[2] = '0' + root_mount_mddev; 738 } 739 740 /* Parse options. */ 741 error = parse_token(conf, &tok); 742 opts = (error == 0) ? tok : NULL; 743 744 printf("Trying to mount root from %s:%s [%s]...\n", fs, dev, 745 (opts != NULL) ? opts : ""); 746 747 errmsg = malloc(ERRMSGL, M_TEMP, M_WAITOK | M_ZERO); 748 749 if (vfs_byname(fs) == NULL) { 750 strlcpy(errmsg, "unknown file system", ERRMSGL); 751 error = ENOENT; 752 goto out; 753 } 754 755 error = vfs_mountroot_wait_if_neccessary(fs, dev); 756 if (error != 0) 757 goto out; 758 759 delay = hz / 10; 760 timeout = root_mount_timeout * hz; 761 762 for (;;) { 763 ma = NULL; 764 ma = mount_arg(ma, "fstype", fs, -1); 765 ma = mount_arg(ma, "fspath", "/", -1); 766 ma = mount_arg(ma, "from", dev, -1); 767 ma = mount_arg(ma, "errmsg", errmsg, ERRMSGL); 768 ma = mount_arg(ma, "ro", NULL, 0); 769 ma = parse_mountroot_options(ma, opts); 770 771 error = kernel_mount(ma, MNT_ROOTFS); 772 if (error == 0 || timeout <= 0) 773 break; 774 775 if (root_mount_timeout * hz == timeout || 776 (bootverbose && timeout % hz == 0)) { 777 printf("Mounting from %s:%s failed with error %d; " 778 "retrying for %d more second%s\n", fs, dev, error, 779 timeout / hz, (timeout / hz > 1) ? "s" : ""); 780 } 781 pause("rmretry", delay); 782 timeout -= delay; 783 } 784 out: 785 if (error) { 786 printf("Mounting from %s:%s failed with error %d", 787 fs, dev, error); 788 if (errmsg[0] != '\0') 789 printf(": %s", errmsg); 790 printf(".\n"); 791 } 792 free(fs, M_TEMP); 793 free(errmsg, M_TEMP); 794 if (opts != NULL) 795 free(opts, M_TEMP); 796 /* kernel_mount can return -1 on error. */ 797 return ((error < 0) ? EDOOFUS : error); 798} 799#undef ERRMSGL 800 801static int 802vfs_mountroot_parse(struct sbuf *sb, struct mount *mpdevfs) 803{ 804 struct mount *mp; 805 char *conf; 806 int error; 807 808 root_mount_mddev = -1; 809 810retry: 811 conf = sbuf_data(sb); 812 mp = TAILQ_NEXT(mpdevfs, mnt_list); 813 error = (mp == NULL) ? 0 : EDOOFUS; 814 root_mount_onfail = A_CONTINUE; 815 while (mp == NULL) { 816 error = parse_skipto(&conf, CC_NONWHITESPACE); 817 if (error == PE_EOL) { 818 parse_advance(&conf); 819 continue; 820 } 821 if (error < 0) 822 break; 823 switch (parse_peek(&conf)) { 824 case '#': 825 error = parse_skipto(&conf, '\n'); 826 break; 827 case '.': 828 error = parse_directive(&conf); 829 break; 830 default: 831 error = parse_mount(&conf); 832 if (error == -1) { 833 printf("mountroot: invalid file system " 834 "specification.\n"); 835 error = 0; 836 } 837 break; 838 } 839 if (error < 0) 840 break; 841 /* Ignore any trailing garbage on the line. */ 842 if (parse_peek(&conf) != '\n') { 843 printf("mountroot: advancing to next directive...\n"); 844 (void)parse_skipto(&conf, '\n'); 845 } 846 mp = TAILQ_NEXT(mpdevfs, mnt_list); 847 } 848 if (mp != NULL) 849 return (0); 850 851 /* 852 * We failed to mount (a new) root. 853 */ 854 switch (root_mount_onfail) { 855 case A_CONTINUE: 856 break; 857 case A_PANIC: 858 panic("mountroot: unable to (re-)mount root."); 859 /* NOTREACHED */ 860 case A_RETRY: 861 goto retry; 862 case A_REBOOT: 863 kern_reboot(RB_NOSYNC); 864 /* NOTREACHED */ 865 } 866 867 return (error); 868} 869 870static void 871vfs_mountroot_conf0(struct sbuf *sb) 872{ 873 char *s, *tok, *mnt, *opt; 874 int error; 875 876 sbuf_printf(sb, ".onfail panic\n"); 877 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout); 878 if (boothowto & RB_ASKNAME) 879 sbuf_printf(sb, ".ask\n"); 880#ifdef ROOTDEVNAME 881 if (boothowto & RB_DFLTROOT) 882 sbuf_printf(sb, "%s\n", ROOTDEVNAME); 883#endif 884 if (boothowto & RB_CDROM) { 885 sbuf_printf(sb, "cd9660:/dev/cd0 ro\n"); 886 sbuf_printf(sb, ".timeout 0\n"); 887 sbuf_printf(sb, "cd9660:/dev/cd1 ro\n"); 888 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout); 889 } 890 s = kern_getenv("vfs.root.mountfrom"); 891 if (s != NULL) { 892 opt = kern_getenv("vfs.root.mountfrom.options"); 893 tok = s; 894 error = parse_token(&tok, &mnt); 895 while (!error) { 896 sbuf_printf(sb, "%s %s\n", mnt, 897 (opt != NULL) ? opt : ""); 898 free(mnt, M_TEMP); 899 error = parse_token(&tok, &mnt); 900 } 901 if (opt != NULL) 902 freeenv(opt); 903 freeenv(s); 904 } 905 if (rootdevnames[0] != NULL) 906 sbuf_printf(sb, "%s\n", rootdevnames[0]); 907 if (rootdevnames[1] != NULL) 908 sbuf_printf(sb, "%s\n", rootdevnames[1]); 909#ifdef ROOTDEVNAME 910 if (!(boothowto & RB_DFLTROOT)) 911 sbuf_printf(sb, "%s\n", ROOTDEVNAME); 912#endif 913 if (!(boothowto & RB_ASKNAME)) 914 sbuf_printf(sb, ".ask\n"); 915} 916 917static int 918vfs_mountroot_readconf(struct thread *td, struct sbuf *sb) 919{ 920 static char buf[128]; 921 struct nameidata nd; 922 off_t ofs; 923 ssize_t resid; 924 int error, flags, len; 925 926 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/.mount.conf", td); 927 flags = FREAD; 928 error = vn_open(&nd, &flags, 0, NULL); 929 if (error) 930 return (error); 931 932 NDFREE(&nd, NDF_ONLY_PNBUF); 933 ofs = 0; 934 len = sizeof(buf) - 1; 935 while (1) { 936 error = vn_rdwr(UIO_READ, nd.ni_vp, buf, len, ofs, 937 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 938 NOCRED, &resid, td); 939 if (error) 940 break; 941 if (resid == len) 942 break; 943 buf[len - resid] = 0; 944 sbuf_printf(sb, "%s", buf); 945 ofs += len - resid; 946 } 947 948 VOP_UNLOCK(nd.ni_vp, 0); 949 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 950 return (error); 951} 952 953static void 954vfs_mountroot_wait(void) 955{ 956 struct root_hold_token *h; 957 struct timeval lastfail; 958 int curfail; 959 960 curfail = 0; 961 while (1) { 962 DROP_GIANT(); 963 g_waitidle(); 964 PICKUP_GIANT(); 965 mtx_lock(&root_holds_mtx); 966 if (LIST_EMPTY(&root_holds)) { 967 mtx_unlock(&root_holds_mtx); 968 break; 969 } 970 if (ppsratecheck(&lastfail, &curfail, 1)) { 971 printf("Root mount waiting for:"); 972 LIST_FOREACH(h, &root_holds, list) 973 printf(" %s", h->who); 974 printf("\n"); 975 } 976 msleep(&root_holds, &root_holds_mtx, PZERO | PDROP, "roothold", 977 hz); 978 } 979} 980 981static int 982vfs_mountroot_wait_if_neccessary(const char *fs, const char *dev) 983{ 984 int delay, timeout; 985 986 /* 987 * In case of ZFS and NFS we don't have a way to wait for 988 * specific device. Also do the wait if the user forced that 989 * behaviour by setting vfs.root_mount_always_wait=1. 990 */ 991 if (strcmp(fs, "zfs") == 0 || strstr(fs, "nfs") != NULL || 992 dev[0] == '\0' || root_mount_always_wait != 0) { 993 vfs_mountroot_wait(); 994 return (0); 995 } 996 997 /* 998 * Otherwise, no point in waiting if the device is already there. 999 * Note that we must wait for GEOM to finish reconfiguring itself, 1000 * eg for geom_part(4) to finish tasting. 1001 */ 1002 DROP_GIANT(); 1003 g_waitidle(); 1004 PICKUP_GIANT(); 1005 if (parse_mount_dev_present(dev)) 1006 return (0); 1007 1008 /* 1009 * No luck. Let's wait. This code looks weird, but it's that way 1010 * to behave exactly as it used to work before. 1011 */ 1012 vfs_mountroot_wait(); 1013 printf("mountroot: waiting for device %s...\n", dev); 1014 delay = hz / 10; 1015 timeout = root_mount_timeout * hz; 1016 do { 1017 pause("rmdev", delay); 1018 timeout -= delay; 1019 } while (timeout > 0 && !parse_mount_dev_present(dev)); 1020 1021 if (timeout <= 0) 1022 return (ENODEV); 1023 1024 return (0); 1025} 1026 1027void 1028vfs_mountroot(void) 1029{ 1030 struct mount *mp; 1031 struct sbuf *sb; 1032 struct thread *td; 1033 time_t timebase; 1034 int error; 1035 1036 td = curthread; 1037 1038 sb = sbuf_new_auto(); 1039 vfs_mountroot_conf0(sb); 1040 sbuf_finish(sb); 1041 1042 error = vfs_mountroot_devfs(td, &mp); 1043 while (!error) { 1044 error = vfs_mountroot_parse(sb, mp); 1045 if (!error) { 1046 vfs_mountroot_shuffle(td, mp); 1047 sbuf_clear(sb); 1048 error = vfs_mountroot_readconf(td, sb); 1049 sbuf_finish(sb); 1050 } 1051 } 1052 1053 sbuf_delete(sb); 1054 1055 /* 1056 * Iterate over all currently mounted file systems and use 1057 * the time stamp found to check and/or initialize the RTC. 1058 * Call inittodr() only once and pass it the largest of the 1059 * timestamps we encounter. 1060 */ 1061 timebase = 0; 1062 mtx_lock(&mountlist_mtx); 1063 mp = TAILQ_FIRST(&mountlist); 1064 while (mp != NULL) { 1065 if (mp->mnt_time > timebase) 1066 timebase = mp->mnt_time; 1067 mp = TAILQ_NEXT(mp, mnt_list); 1068 } 1069 mtx_unlock(&mountlist_mtx); 1070 inittodr(timebase); 1071 1072 /* Keep prison0's root in sync with the global rootvnode. */ 1073 mtx_lock(&prison0.pr_mtx); 1074 prison0.pr_root = rootvnode; 1075 vref(prison0.pr_root); 1076 mtx_unlock(&prison0.pr_mtx); 1077 1078 mtx_lock(&root_holds_mtx); 1079 atomic_store_rel_int(&root_mount_complete, 1); 1080 wakeup(&root_mount_complete); 1081 mtx_unlock(&root_holds_mtx); 1082 1083 EVENTHANDLER_INVOKE(mountroot); 1084} 1085 1086static struct mntarg * 1087parse_mountroot_options(struct mntarg *ma, const char *options) 1088{ 1089 char *p; 1090 char *name, *name_arg; 1091 char *val, *val_arg; 1092 char *opts; 1093 1094 if (options == NULL || options[0] == '\0') 1095 return (ma); 1096 1097 p = opts = strdup(options, M_MOUNT); 1098 if (opts == NULL) { 1099 return (ma); 1100 } 1101 1102 while((name = strsep(&p, ",")) != NULL) { 1103 if (name[0] == '\0') 1104 break; 1105 1106 val = strchr(name, '='); 1107 if (val != NULL) { 1108 *val = '\0'; 1109 ++val; 1110 } 1111 if( strcmp(name, "rw") == 0 || 1112 strcmp(name, "noro") == 0) { 1113 /* 1114 * The first time we mount the root file system, 1115 * we need to mount 'ro', so We need to ignore 1116 * 'rw' and 'noro' mount options. 1117 */ 1118 continue; 1119 } 1120 name_arg = strdup(name, M_MOUNT); 1121 val_arg = NULL; 1122 if (val != NULL) 1123 val_arg = strdup(val, M_MOUNT); 1124 1125 ma = mount_arg(ma, name_arg, val_arg, 1126 (val_arg != NULL ? -1 : 0)); 1127 } 1128 free(opts, M_MOUNT); 1129 return (ma); 1130} 1131