Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_mountroot.c
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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: releng/9.1/sys/kern/vfs_mountroot.c 235407 2012-05-13 17:10:38Z avg $"); 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 suceeds. 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 89 static int parse_mount(char **); 90 static struct mntarg *parse_mountroot_options(struct mntarg *, const char *); 91 92 /* 93 * The vnode of the system's root (/ in the filesystem, without chroot 94 * active.) 95 */ 96 struct vnode *rootvnode; 97 98 char *rootdevnames[2] = {NULL, NULL}; 99 100 struct root_hold_token { 101 const char *who; 102 LIST_ENTRY(root_hold_token) list; 103 }; 104 105 static LIST_HEAD(, root_hold_token) root_holds = 106 LIST_HEAD_INITIALIZER(root_holds); 107 108 enum action { 109 A_CONTINUE, 110 A_PANIC, 111 A_REBOOT, 112 A_RETRY 113 }; 114 115 static enum action root_mount_onfail = A_CONTINUE; 116 117 static int root_mount_mddev; 118 static int root_mount_complete; 119 120 /* By default wait up to 3 seconds for devices to appear. */ 121 static int root_mount_timeout = 3; 122 123 struct root_hold_token * 124 root_mount_hold(const char *identifier) 125 { 126 struct root_hold_token *h; 127 128 if (root_mounted()) 129 return (NULL); 130 131 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK); 132 h->who = identifier; 133 mtx_lock(&mountlist_mtx); 134 LIST_INSERT_HEAD(&root_holds, h, list); 135 mtx_unlock(&mountlist_mtx); 136 return (h); 137 } 138 139 void 140 root_mount_rel(struct root_hold_token *h) 141 { 142 143 if (h == NULL) 144 return; 145 mtx_lock(&mountlist_mtx); 146 LIST_REMOVE(h, list); 147 wakeup(&root_holds); 148 mtx_unlock(&mountlist_mtx); 149 free(h, M_DEVBUF); 150 } 151 152 int 153 root_mounted(void) 154 { 155 156 /* No mutex is acquired here because int stores are atomic. */ 157 return (root_mount_complete); 158 } 159 160 void 161 root_mount_wait(void) 162 { 163 164 /* 165 * Panic on an obvious deadlock - the function can't be called from 166 * a thread which is doing the whole SYSINIT stuff. 167 */ 168 KASSERT(curthread->td_proc->p_pid != 0, 169 ("root_mount_wait: cannot be called from the swapper thread")); 170 mtx_lock(&mountlist_mtx); 171 while (!root_mount_complete) { 172 msleep(&root_mount_complete, &mountlist_mtx, PZERO, "rootwait", 173 hz); 174 } 175 mtx_unlock(&mountlist_mtx); 176 } 177 178 static void 179 set_rootvnode(void) 180 { 181 struct proc *p; 182 183 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode)) 184 panic("Cannot find root vnode"); 185 186 VOP_UNLOCK(rootvnode, 0); 187 188 p = curthread->td_proc; 189 FILEDESC_XLOCK(p->p_fd); 190 191 if (p->p_fd->fd_cdir != NULL) 192 vrele(p->p_fd->fd_cdir); 193 p->p_fd->fd_cdir = rootvnode; 194 VREF(rootvnode); 195 196 if (p->p_fd->fd_rdir != NULL) 197 vrele(p->p_fd->fd_rdir); 198 p->p_fd->fd_rdir = rootvnode; 199 VREF(rootvnode); 200 201 FILEDESC_XUNLOCK(p->p_fd); 202 203 EVENTHANDLER_INVOKE(mountroot); 204 } 205 206 static int 207 vfs_mountroot_devfs(struct thread *td, struct mount **mpp) 208 { 209 struct vfsoptlist *opts; 210 struct vfsconf *vfsp; 211 struct mount *mp; 212 int error; 213 214 *mpp = NULL; 215 216 vfsp = vfs_byname("devfs"); 217 KASSERT(vfsp != NULL, ("Could not find devfs by name")); 218 if (vfsp == NULL) 219 return (ENOENT); 220 221 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred); 222 223 error = VFS_MOUNT(mp); 224 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error)); 225 if (error) 226 return (error); 227 228 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 229 TAILQ_INIT(opts); 230 mp->mnt_opt = opts; 231 232 mtx_lock(&mountlist_mtx); 233 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 234 mtx_unlock(&mountlist_mtx); 235 236 *mpp = mp; 237 set_rootvnode(); 238 239 error = kern_symlink(td, "/", "dev", UIO_SYSSPACE); 240 if (error) 241 printf("kern_symlink /dev -> / returns %d\n", error); 242 243 return (error); 244 } 245 246 static int 247 vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs) 248 { 249 struct nameidata nd; 250 struct mount *mporoot, *mpnroot; 251 struct vnode *vp, *vporoot, *vpdevfs; 252 char *fspath; 253 int error; 254 255 mpnroot = TAILQ_NEXT(mpdevfs, mnt_list); 256 257 /* Shuffle the mountlist. */ 258 mtx_lock(&mountlist_mtx); 259 mporoot = TAILQ_FIRST(&mountlist); 260 TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list); 261 if (mporoot != mpdevfs) { 262 TAILQ_REMOVE(&mountlist, mpnroot, mnt_list); 263 TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list); 264 } 265 TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list); 266 mtx_unlock(&mountlist_mtx); 267 268 cache_purgevfs(mporoot); 269 if (mporoot != mpdevfs) 270 cache_purgevfs(mpdevfs); 271 272 VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot); 273 274 VI_LOCK(vporoot); 275 vporoot->v_iflag &= ~VI_MOUNT; 276 VI_UNLOCK(vporoot); 277 vporoot->v_mountedhere = NULL; 278 mporoot->mnt_flag &= ~MNT_ROOTFS; 279 mporoot->mnt_vnodecovered = NULL; 280 vput(vporoot); 281 282 /* Set up the new rootvnode, and purge the cache */ 283 mpnroot->mnt_vnodecovered = NULL; 284 set_rootvnode(); 285 cache_purgevfs(rootvnode->v_mount); 286 287 if (mporoot != mpdevfs) { 288 /* Remount old root under /.mount or /mnt */ 289 fspath = "/.mount"; 290 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, 291 fspath, td); 292 error = namei(&nd); 293 if (error) { 294 NDFREE(&nd, NDF_ONLY_PNBUF); 295 fspath = "/mnt"; 296 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, 297 fspath, td); 298 error = namei(&nd); 299 } 300 if (!error) { 301 vp = nd.ni_vp; 302 error = (vp->v_type == VDIR) ? 0 : ENOTDIR; 303 if (!error) 304 error = vinvalbuf(vp, V_SAVE, 0, 0); 305 if (!error) { 306 cache_purge(vp); 307 mporoot->mnt_vnodecovered = vp; 308 vp->v_mountedhere = mporoot; 309 strlcpy(mporoot->mnt_stat.f_mntonname, 310 fspath, MNAMELEN); 311 VOP_UNLOCK(vp, 0); 312 } else 313 vput(vp); 314 } 315 NDFREE(&nd, NDF_ONLY_PNBUF); 316 317 if (error && bootverbose) 318 printf("mountroot: unable to remount previous root " 319 "under /.mount or /mnt (error %d).\n", error); 320 } 321 322 /* Remount devfs under /dev */ 323 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td); 324 error = namei(&nd); 325 if (!error) { 326 vp = nd.ni_vp; 327 error = (vp->v_type == VDIR) ? 0 : ENOTDIR; 328 if (!error) 329 error = vinvalbuf(vp, V_SAVE, 0, 0); 330 if (!error) { 331 vpdevfs = mpdevfs->mnt_vnodecovered; 332 if (vpdevfs != NULL) { 333 cache_purge(vpdevfs); 334 vpdevfs->v_mountedhere = NULL; 335 vrele(vpdevfs); 336 } 337 mpdevfs->mnt_vnodecovered = vp; 338 vp->v_mountedhere = mpdevfs; 339 VOP_UNLOCK(vp, 0); 340 } else 341 vput(vp); 342 } 343 if (error && bootverbose) 344 printf("mountroot: unable to remount devfs under /dev " 345 "(error %d).\n", error); 346 NDFREE(&nd, NDF_ONLY_PNBUF); 347 348 if (mporoot == mpdevfs) { 349 vfs_unbusy(mpdevfs); 350 /* Unlink the no longer needed /dev/dev -> / symlink */ 351 error = kern_unlink(td, "/dev/dev", UIO_SYSSPACE); 352 if (error && bootverbose) 353 printf("mountroot: unable to unlink /dev/dev " 354 "(error %d)\n", error); 355 } 356 357 return (0); 358 } 359 360 /* 361 * Configuration parser. 362 */ 363 364 /* Parser character classes. */ 365 #define CC_WHITESPACE -1 366 #define CC_NONWHITESPACE -2 367 368 /* Parse errors. */ 369 #define PE_EOF -1 370 #define PE_EOL -2 371 372 static __inline int 373 parse_peek(char **conf) 374 { 375 376 return (**conf); 377 } 378 379 static __inline void 380 parse_poke(char **conf, int c) 381 { 382 383 **conf = c; 384 } 385 386 static __inline void 387 parse_advance(char **conf) 388 { 389 390 (*conf)++; 391 } 392 393 static __inline int 394 parse_isspace(int c) 395 { 396 397 return ((c == ' ' || c == '\t' || c == '\n') ? 1 : 0); 398 } 399 400 static int 401 parse_skipto(char **conf, int mc) 402 { 403 int c, match; 404 405 while (1) { 406 c = parse_peek(conf); 407 if (c == 0) 408 return (PE_EOF); 409 switch (mc) { 410 case CC_WHITESPACE: 411 match = (c == ' ' || c == '\t' || c == '\n') ? 1 : 0; 412 break; 413 case CC_NONWHITESPACE: 414 if (c == '\n') 415 return (PE_EOL); 416 match = (c != ' ' && c != '\t') ? 1 : 0; 417 break; 418 default: 419 match = (c == mc) ? 1 : 0; 420 break; 421 } 422 if (match) 423 break; 424 parse_advance(conf); 425 } 426 return (0); 427 } 428 429 static int 430 parse_token(char **conf, char **tok) 431 { 432 char *p; 433 size_t len; 434 int error; 435 436 *tok = NULL; 437 error = parse_skipto(conf, CC_NONWHITESPACE); 438 if (error) 439 return (error); 440 p = *conf; 441 error = parse_skipto(conf, CC_WHITESPACE); 442 len = *conf - p; 443 *tok = malloc(len + 1, M_TEMP, M_WAITOK | M_ZERO); 444 bcopy(p, *tok, len); 445 return (0); 446 } 447 448 static void 449 parse_dir_ask_printenv(const char *var) 450 { 451 char *val; 452 453 val = getenv(var); 454 if (val != NULL) { 455 printf(" %s=%s\n", var, val); 456 freeenv(val); 457 } 458 } 459 460 static int 461 parse_dir_ask(char **conf) 462 { 463 char name[80]; 464 char *mnt; 465 int error; 466 467 printf("\nLoader variables:\n"); 468 parse_dir_ask_printenv("vfs.root.mountfrom"); 469 parse_dir_ask_printenv("vfs.root.mountfrom.options"); 470 471 printf("\nManual root filesystem specification:\n"); 472 printf(" <fstype>:<device> [options]\n"); 473 printf(" Mount <device> using filesystem <fstype>\n"); 474 printf(" and with the specified (optional) option list.\n"); 475 printf("\n"); 476 printf(" eg. ufs:/dev/da0s1a\n"); 477 printf(" zfs:tank\n"); 478 printf(" cd9660:/dev/acd0 ro\n"); 479 printf(" (which is equivalent to: "); 480 printf("mount -t cd9660 -o ro /dev/acd0 /)\n"); 481 printf("\n"); 482 printf(" ? List valid disk boot devices\n"); 483 printf(" . Yield 1 second (for background tasks)\n"); 484 printf(" <empty line> Abort manual input\n"); 485 486 do { 487 error = EINVAL; 488 printf("\nmountroot> "); 489 cngets(name, sizeof(name), GETS_ECHO); 490 if (name[0] == '\0') 491 break; 492 if (name[0] == '?' && name[1] == '\0') { 493 printf("\nList of GEOM managed disk devices:\n "); 494 g_dev_print(); 495 continue; 496 } 497 if (name[0] == '.' && name[1] == '\0') { 498 pause("rmask", hz); 499 continue; 500 } 501 mnt = name; 502 error = parse_mount(&mnt); 503 if (error == -1) 504 printf("Invalid file system specification.\n"); 505 } while (error != 0); 506 507 return (error); 508 } 509 510 static int 511 parse_dir_md(char **conf) 512 { 513 struct stat sb; 514 struct thread *td; 515 struct md_ioctl *mdio; 516 char *path, *tok; 517 int error, fd, len; 518 519 td = curthread; 520 521 error = parse_token(conf, &tok); 522 if (error) 523 return (error); 524 525 len = strlen(tok); 526 mdio = malloc(sizeof(*mdio) + len + 1, M_TEMP, M_WAITOK | M_ZERO); 527 path = (void *)(mdio + 1); 528 bcopy(tok, path, len); 529 free(tok, M_TEMP); 530 531 /* Get file status. */ 532 error = kern_stat(td, path, UIO_SYSSPACE, &sb); 533 if (error) 534 goto out; 535 536 /* Open /dev/mdctl so that we can attach/detach. */ 537 error = kern_open(td, "/dev/" MDCTL_NAME, UIO_SYSSPACE, O_RDWR, 0); 538 if (error) 539 goto out; 540 541 fd = td->td_retval[0]; 542 mdio->md_version = MDIOVERSION; 543 mdio->md_type = MD_VNODE; 544 545 if (root_mount_mddev != -1) { 546 mdio->md_unit = root_mount_mddev; 547 DROP_GIANT(); 548 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio); 549 PICKUP_GIANT(); 550 /* Ignore errors. We don't care. */ 551 root_mount_mddev = -1; 552 } 553 554 mdio->md_file = (void *)(mdio + 1); 555 mdio->md_options = MD_AUTOUNIT | MD_READONLY; 556 mdio->md_mediasize = sb.st_size; 557 mdio->md_unit = 0; 558 DROP_GIANT(); 559 error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio); 560 PICKUP_GIANT(); 561 if (error) 562 goto out; 563 564 if (mdio->md_unit > 9) { 565 printf("rootmount: too many md units\n"); 566 mdio->md_file = NULL; 567 mdio->md_options = 0; 568 mdio->md_mediasize = 0; 569 DROP_GIANT(); 570 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio); 571 PICKUP_GIANT(); 572 /* Ignore errors. We don't care. */ 573 error = ERANGE; 574 goto out; 575 } 576 577 root_mount_mddev = mdio->md_unit; 578 printf(MD_NAME "%u attached to %s\n", root_mount_mddev, mdio->md_file); 579 580 error = kern_close(td, fd); 581 582 out: 583 free(mdio, M_TEMP); 584 return (error); 585 } 586 587 static int 588 parse_dir_onfail(char **conf) 589 { 590 char *action; 591 int error; 592 593 error = parse_token(conf, &action); 594 if (error) 595 return (error); 596 597 if (!strcmp(action, "continue")) 598 root_mount_onfail = A_CONTINUE; 599 else if (!strcmp(action, "panic")) 600 root_mount_onfail = A_PANIC; 601 else if (!strcmp(action, "reboot")) 602 root_mount_onfail = A_REBOOT; 603 else if (!strcmp(action, "retry")) 604 root_mount_onfail = A_RETRY; 605 else { 606 printf("rootmount: %s: unknown action\n", action); 607 error = EINVAL; 608 } 609 610 free(action, M_TEMP); 611 return (0); 612 } 613 614 static int 615 parse_dir_timeout(char **conf) 616 { 617 char *tok, *endtok; 618 long secs; 619 int error; 620 621 error = parse_token(conf, &tok); 622 if (error) 623 return (error); 624 625 secs = strtol(tok, &endtok, 0); 626 error = (secs < 0 || *endtok != '\0') ? EINVAL : 0; 627 if (!error) 628 root_mount_timeout = secs; 629 free(tok, M_TEMP); 630 return (error); 631 } 632 633 static int 634 parse_directive(char **conf) 635 { 636 char *dir; 637 int error; 638 639 error = parse_token(conf, &dir); 640 if (error) 641 return (error); 642 643 if (strcmp(dir, ".ask") == 0) 644 error = parse_dir_ask(conf); 645 else if (strcmp(dir, ".md") == 0) 646 error = parse_dir_md(conf); 647 else if (strcmp(dir, ".onfail") == 0) 648 error = parse_dir_onfail(conf); 649 else if (strcmp(dir, ".timeout") == 0) 650 error = parse_dir_timeout(conf); 651 else { 652 printf("mountroot: invalid directive `%s'\n", dir); 653 /* Ignore the rest of the line. */ 654 (void)parse_skipto(conf, '\n'); 655 error = EINVAL; 656 } 657 free(dir, M_TEMP); 658 return (error); 659 } 660 661 static int 662 parse_mount_dev_present(const char *dev) 663 { 664 struct nameidata nd; 665 int error; 666 667 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, dev, curthread); 668 error = namei(&nd); 669 if (!error) 670 vput(nd.ni_vp); 671 NDFREE(&nd, NDF_ONLY_PNBUF); 672 return (error != 0) ? 0 : 1; 673 } 674 675 static int 676 parse_mount(char **conf) 677 { 678 char errmsg[255]; 679 struct mntarg *ma; 680 char *dev, *fs, *opts, *tok; 681 int delay, error, timeout; 682 683 error = parse_token(conf, &tok); 684 if (error) 685 return (error); 686 fs = tok; 687 error = parse_skipto(&tok, ':'); 688 if (error) { 689 free(fs, M_TEMP); 690 return (error); 691 } 692 parse_poke(&tok, '\0'); 693 parse_advance(&tok); 694 dev = tok; 695 696 if (root_mount_mddev != -1) { 697 /* Handle substitution for the md unit number. */ 698 tok = strstr(dev, "md#"); 699 if (tok != NULL) 700 tok[2] = '' + root_mount_mddev; 701 } 702 703 /* Parse options. */ 704 error = parse_token(conf, &tok); 705 opts = (error == 0) ? tok : NULL; 706 707 printf("Trying to mount root from %s:%s [%s]...\n", fs, dev, 708 (opts != NULL) ? opts : ""); 709 710 bzero(errmsg, sizeof(errmsg)); 711 712 if (vfs_byname(fs) == NULL) { 713 strlcpy(errmsg, "unknown file system", sizeof(errmsg)); 714 error = ENOENT; 715 goto out; 716 } 717 718 if (strcmp(fs, "zfs") != 0 && dev[0] != '\0' && 719 !parse_mount_dev_present(dev)) { 720 printf("mountroot: waiting for device %s ...\n", dev); 721 delay = hz / 10; 722 timeout = root_mount_timeout * hz; 723 do { 724 pause("rmdev", delay); 725 timeout -= delay; 726 } while (timeout > 0 && !parse_mount_dev_present(dev)); 727 if (timeout <= 0) { 728 error = ENODEV; 729 goto out; 730 } 731 } 732 733 ma = NULL; 734 ma = mount_arg(ma, "fstype", fs, -1); 735 ma = mount_arg(ma, "fspath", "/", -1); 736 ma = mount_arg(ma, "from", dev, -1); 737 ma = mount_arg(ma, "errmsg", errmsg, sizeof(errmsg)); 738 ma = mount_arg(ma, "ro", NULL, 0); 739 ma = parse_mountroot_options(ma, opts); 740 error = kernel_mount(ma, MNT_ROOTFS); 741 742 out: 743 if (error) { 744 printf("Mounting from %s:%s failed with error %d", 745 fs, dev, error); 746 if (errmsg[0] != '\0') 747 printf(": %s", errmsg); 748 printf(".\n"); 749 } 750 free(fs, M_TEMP); 751 if (opts != NULL) 752 free(opts, M_TEMP); 753 /* kernel_mount can return -1 on error. */ 754 return ((error < 0) ? EDOOFUS : error); 755 } 756 757 static int 758 vfs_mountroot_parse(struct sbuf *sb, struct mount *mpdevfs) 759 { 760 struct mount *mp; 761 char *conf; 762 int error; 763 764 root_mount_mddev = -1; 765 766 retry: 767 conf = sbuf_data(sb); 768 mp = TAILQ_NEXT(mpdevfs, mnt_list); 769 error = (mp == NULL) ? 0 : EDOOFUS; 770 root_mount_onfail = A_CONTINUE; 771 while (mp == NULL) { 772 error = parse_skipto(&conf, CC_NONWHITESPACE); 773 if (error == PE_EOL) { 774 parse_advance(&conf); 775 continue; 776 } 777 if (error < 0) 778 break; 779 switch (parse_peek(&conf)) { 780 case '#': 781 error = parse_skipto(&conf, '\n'); 782 break; 783 case '.': 784 error = parse_directive(&conf); 785 break; 786 default: 787 error = parse_mount(&conf); 788 break; 789 } 790 if (error < 0) 791 break; 792 /* Ignore any trailing garbage on the line. */ 793 if (parse_peek(&conf) != '\n') { 794 printf("mountroot: advancing to next directive...\n"); 795 (void)parse_skipto(&conf, '\n'); 796 } 797 mp = TAILQ_NEXT(mpdevfs, mnt_list); 798 } 799 if (mp != NULL) 800 return (0); 801 802 /* 803 * We failed to mount (a new) root. 804 */ 805 switch (root_mount_onfail) { 806 case A_CONTINUE: 807 break; 808 case A_PANIC: 809 panic("mountroot: unable to (re-)mount root."); 810 /* NOTREACHED */ 811 case A_RETRY: 812 goto retry; 813 case A_REBOOT: 814 kern_reboot(RB_NOSYNC); 815 /* NOTREACHED */ 816 } 817 818 return (error); 819 } 820 821 static void 822 vfs_mountroot_conf0(struct sbuf *sb) 823 { 824 char *s, *tok, *mnt, *opt; 825 int error; 826 827 sbuf_printf(sb, ".onfail panic\n"); 828 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout); 829 if (boothowto & RB_ASKNAME) 830 sbuf_printf(sb, ".ask\n"); 831 #ifdef ROOTDEVNAME 832 if (boothowto & RB_DFLTROOT) 833 sbuf_printf(sb, "%s\n", ROOTDEVNAME); 834 #endif 835 if (boothowto & RB_CDROM) { 836 sbuf_printf(sb, "cd9660:/dev/cd0 ro\n"); 837 sbuf_printf(sb, ".timeout 0\n"); 838 sbuf_printf(sb, "cd9660:/dev/acd0 ro\n"); 839 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout); 840 } 841 s = getenv("vfs.root.mountfrom"); 842 if (s != NULL) { 843 opt = getenv("vfs.root.mountfrom.options"); 844 tok = s; 845 error = parse_token(&tok, &mnt); 846 while (!error) { 847 sbuf_printf(sb, "%s %s\n", mnt, 848 (opt != NULL) ? opt : ""); 849 free(mnt, M_TEMP); 850 error = parse_token(&tok, &mnt); 851 } 852 if (opt != NULL) 853 freeenv(opt); 854 freeenv(s); 855 } 856 if (rootdevnames[0] != NULL) 857 sbuf_printf(sb, "%s\n", rootdevnames[0]); 858 if (rootdevnames[1] != NULL) 859 sbuf_printf(sb, "%s\n", rootdevnames[1]); 860 #ifdef ROOTDEVNAME 861 if (!(boothowto & RB_DFLTROOT)) 862 sbuf_printf(sb, "%s\n", ROOTDEVNAME); 863 #endif 864 if (!(boothowto & RB_ASKNAME)) 865 sbuf_printf(sb, ".ask\n"); 866 } 867 868 static int 869 vfs_mountroot_readconf(struct thread *td, struct sbuf *sb) 870 { 871 static char buf[128]; 872 struct nameidata nd; 873 off_t ofs; 874 ssize_t resid; 875 int error, flags, len, vfslocked; 876 877 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, 878 "/.mount.conf", td); 879 flags = FREAD; 880 error = vn_open(&nd, &flags, 0, NULL); 881 if (error) 882 return (error); 883 884 vfslocked = NDHASGIANT(&nd); 885 NDFREE(&nd, NDF_ONLY_PNBUF); 886 ofs = 0; 887 len = sizeof(buf) - 1; 888 while (1) { 889 error = vn_rdwr(UIO_READ, nd.ni_vp, buf, len, ofs, 890 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 891 NOCRED, &resid, td); 892 if (error) 893 break; 894 if (resid == len) 895 break; 896 buf[len - resid] = 0; 897 sbuf_printf(sb, "%s", buf); 898 ofs += len - resid; 899 } 900 901 VOP_UNLOCK(nd.ni_vp, 0); 902 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 903 VFS_UNLOCK_GIANT(vfslocked); 904 return (error); 905 } 906 907 static void 908 vfs_mountroot_wait(void) 909 { 910 struct root_hold_token *h; 911 struct timeval lastfail; 912 int curfail; 913 914 curfail = 0; 915 while (1) { 916 DROP_GIANT(); 917 g_waitidle(); 918 PICKUP_GIANT(); 919 mtx_lock(&mountlist_mtx); 920 if (LIST_EMPTY(&root_holds)) { 921 mtx_unlock(&mountlist_mtx); 922 break; 923 } 924 if (ppsratecheck(&lastfail, &curfail, 1)) { 925 printf("Root mount waiting for:"); 926 LIST_FOREACH(h, &root_holds, list) 927 printf(" %s", h->who); 928 printf("\n"); 929 } 930 msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold", 931 hz); 932 } 933 } 934 935 void 936 vfs_mountroot(void) 937 { 938 struct mount *mp; 939 struct sbuf *sb; 940 struct thread *td; 941 time_t timebase; 942 int error; 943 944 td = curthread; 945 946 vfs_mountroot_wait(); 947 948 sb = sbuf_new_auto(); 949 vfs_mountroot_conf0(sb); 950 sbuf_finish(sb); 951 952 error = vfs_mountroot_devfs(td, &mp); 953 while (!error) { 954 error = vfs_mountroot_parse(sb, mp); 955 if (!error) { 956 error = vfs_mountroot_shuffle(td, mp); 957 if (!error) { 958 sbuf_clear(sb); 959 error = vfs_mountroot_readconf(td, sb); 960 sbuf_finish(sb); 961 } 962 } 963 } 964 965 sbuf_delete(sb); 966 967 /* 968 * Iterate over all currently mounted file systems and use 969 * the time stamp found to check and/or initialize the RTC. 970 * Call inittodr() only once and pass it the largest of the 971 * timestamps we encounter. 972 */ 973 timebase = 0; 974 mtx_lock(&mountlist_mtx); 975 mp = TAILQ_FIRST(&mountlist); 976 while (mp != NULL) { 977 if (mp->mnt_time > timebase) 978 timebase = mp->mnt_time; 979 mp = TAILQ_NEXT(mp, mnt_list); 980 } 981 mtx_unlock(&mountlist_mtx); 982 inittodr(timebase); 983 984 /* Keep prison0's root in sync with the global rootvnode. */ 985 mtx_lock(&prison0.pr_mtx); 986 prison0.pr_root = rootvnode; 987 vref(prison0.pr_root); 988 mtx_unlock(&prison0.pr_mtx); 989 990 mtx_lock(&mountlist_mtx); 991 atomic_store_rel_int(&root_mount_complete, 1); 992 wakeup(&root_mount_complete); 993 mtx_unlock(&mountlist_mtx); 994 } 995 996 static struct mntarg * 997 parse_mountroot_options(struct mntarg *ma, const char *options) 998 { 999 char *p; 1000 char *name, *name_arg; 1001 char *val, *val_arg; 1002 char *opts; 1003 1004 if (options == NULL || options[0] == '\0') 1005 return (ma); 1006 1007 p = opts = strdup(options, M_MOUNT); 1008 if (opts == NULL) { 1009 return (ma); 1010 } 1011 1012 while((name = strsep(&p, ",")) != NULL) { 1013 if (name[0] == '\0') 1014 break; 1015 1016 val = strchr(name, '='); 1017 if (val != NULL) { 1018 *val = '\0'; 1019 ++val; 1020 } 1021 if( strcmp(name, "rw") == 0 || 1022 strcmp(name, "noro") == 0) { 1023 /* 1024 * The first time we mount the root file system, 1025 * we need to mount 'ro', so We need to ignore 1026 * 'rw' and 'noro' mount options. 1027 */ 1028 continue; 1029 } 1030 name_arg = strdup(name, M_MOUNT); 1031 val_arg = NULL; 1032 if (val != NULL) 1033 val_arg = strdup(val, M_MOUNT); 1034 1035 ma = mount_arg(ma, name_arg, val_arg, 1036 (val_arg != NULL ? -1 : 0)); 1037 } 1038 free(opts, M_MOUNT); 1039 return (ma); 1040 }
Cache object: 687b25147bd3a911407d33e047a8e396
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