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/9.2/sys/kern/vfs_mountroot.c 252874 2013-07-06 08:51:56Z 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 } 203 204 static int 205 vfs_mountroot_devfs(struct thread *td, struct mount **mpp) 206 { 207 struct vfsoptlist *opts; 208 struct vfsconf *vfsp; 209 struct mount *mp; 210 int error; 211 212 *mpp = NULL; 213 214 vfsp = vfs_byname("devfs"); 215 KASSERT(vfsp != NULL, ("Could not find devfs by name")); 216 if (vfsp == NULL) 217 return (ENOENT); 218 219 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred); 220 221 error = VFS_MOUNT(mp); 222 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error)); 223 if (error) 224 return (error); 225 226 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 227 TAILQ_INIT(opts); 228 mp->mnt_opt = opts; 229 230 mtx_lock(&mountlist_mtx); 231 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 232 mtx_unlock(&mountlist_mtx); 233 234 *mpp = mp; 235 set_rootvnode(); 236 237 error = kern_symlink(td, "/", "dev", UIO_SYSSPACE); 238 if (error) 239 printf("kern_symlink /dev -> / returns %d\n", error); 240 241 return (error); 242 } 243 244 static int 245 vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs) 246 { 247 struct nameidata nd; 248 struct mount *mporoot, *mpnroot; 249 struct vnode *vp, *vporoot, *vpdevfs; 250 char *fspath; 251 int error; 252 253 mpnroot = TAILQ_NEXT(mpdevfs, mnt_list); 254 255 /* Shuffle the mountlist. */ 256 mtx_lock(&mountlist_mtx); 257 mporoot = TAILQ_FIRST(&mountlist); 258 TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list); 259 if (mporoot != mpdevfs) { 260 TAILQ_REMOVE(&mountlist, mpnroot, mnt_list); 261 TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list); 262 } 263 TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list); 264 mtx_unlock(&mountlist_mtx); 265 266 cache_purgevfs(mporoot); 267 if (mporoot != mpdevfs) 268 cache_purgevfs(mpdevfs); 269 270 VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot); 271 272 VI_LOCK(vporoot); 273 vporoot->v_iflag &= ~VI_MOUNT; 274 VI_UNLOCK(vporoot); 275 vporoot->v_mountedhere = NULL; 276 mporoot->mnt_flag &= ~MNT_ROOTFS; 277 mporoot->mnt_vnodecovered = NULL; 278 vput(vporoot); 279 280 /* Set up the new rootvnode, and purge the cache */ 281 mpnroot->mnt_vnodecovered = NULL; 282 set_rootvnode(); 283 cache_purgevfs(rootvnode->v_mount); 284 285 if (mporoot != mpdevfs) { 286 /* Remount old root under /.mount or /mnt */ 287 fspath = "/.mount"; 288 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, 289 fspath, td); 290 error = namei(&nd); 291 if (error) { 292 NDFREE(&nd, NDF_ONLY_PNBUF); 293 fspath = "/mnt"; 294 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, 295 fspath, td); 296 error = namei(&nd); 297 } 298 if (!error) { 299 vp = nd.ni_vp; 300 error = (vp->v_type == VDIR) ? 0 : ENOTDIR; 301 if (!error) 302 error = vinvalbuf(vp, V_SAVE, 0, 0); 303 if (!error) { 304 cache_purge(vp); 305 mporoot->mnt_vnodecovered = vp; 306 vp->v_mountedhere = mporoot; 307 strlcpy(mporoot->mnt_stat.f_mntonname, 308 fspath, MNAMELEN); 309 VOP_UNLOCK(vp, 0); 310 } else 311 vput(vp); 312 } 313 NDFREE(&nd, NDF_ONLY_PNBUF); 314 315 if (error && bootverbose) 316 printf("mountroot: unable to remount previous root " 317 "under /.mount or /mnt (error %d).\n", error); 318 } 319 320 /* Remount devfs under /dev */ 321 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td); 322 error = namei(&nd); 323 if (!error) { 324 vp = nd.ni_vp; 325 error = (vp->v_type == VDIR) ? 0 : ENOTDIR; 326 if (!error) 327 error = vinvalbuf(vp, V_SAVE, 0, 0); 328 if (!error) { 329 vpdevfs = mpdevfs->mnt_vnodecovered; 330 if (vpdevfs != NULL) { 331 cache_purge(vpdevfs); 332 vpdevfs->v_mountedhere = NULL; 333 vrele(vpdevfs); 334 } 335 mpdevfs->mnt_vnodecovered = vp; 336 vp->v_mountedhere = mpdevfs; 337 VOP_UNLOCK(vp, 0); 338 } else 339 vput(vp); 340 } 341 if (error && bootverbose) 342 printf("mountroot: unable to remount devfs under /dev " 343 "(error %d).\n", error); 344 NDFREE(&nd, NDF_ONLY_PNBUF); 345 346 if (mporoot == mpdevfs) { 347 vfs_unbusy(mpdevfs); 348 /* Unlink the no longer needed /dev/dev -> / symlink */ 349 error = kern_unlink(td, "/dev/dev", UIO_SYSSPACE); 350 if (error && bootverbose) 351 printf("mountroot: unable to unlink /dev/dev " 352 "(error %d)\n", error); 353 } 354 355 return (0); 356 } 357 358 /* 359 * Configuration parser. 360 */ 361 362 /* Parser character classes. */ 363 #define CC_WHITESPACE -1 364 #define CC_NONWHITESPACE -2 365 366 /* Parse errors. */ 367 #define PE_EOF -1 368 #define PE_EOL -2 369 370 static __inline int 371 parse_peek(char **conf) 372 { 373 374 return (**conf); 375 } 376 377 static __inline void 378 parse_poke(char **conf, int c) 379 { 380 381 **conf = c; 382 } 383 384 static __inline void 385 parse_advance(char **conf) 386 { 387 388 (*conf)++; 389 } 390 391 static __inline int 392 parse_isspace(int c) 393 { 394 395 return ((c == ' ' || c == '\t' || c == '\n') ? 1 : 0); 396 } 397 398 static int 399 parse_skipto(char **conf, int mc) 400 { 401 int c, match; 402 403 while (1) { 404 c = parse_peek(conf); 405 if (c == 0) 406 return (PE_EOF); 407 switch (mc) { 408 case CC_WHITESPACE: 409 match = (c == ' ' || c == '\t' || c == '\n') ? 1 : 0; 410 break; 411 case CC_NONWHITESPACE: 412 if (c == '\n') 413 return (PE_EOL); 414 match = (c != ' ' && c != '\t') ? 1 : 0; 415 break; 416 default: 417 match = (c == mc) ? 1 : 0; 418 break; 419 } 420 if (match) 421 break; 422 parse_advance(conf); 423 } 424 return (0); 425 } 426 427 static int 428 parse_token(char **conf, char **tok) 429 { 430 char *p; 431 size_t len; 432 int error; 433 434 *tok = NULL; 435 error = parse_skipto(conf, CC_NONWHITESPACE); 436 if (error) 437 return (error); 438 p = *conf; 439 error = parse_skipto(conf, CC_WHITESPACE); 440 len = *conf - p; 441 *tok = malloc(len + 1, M_TEMP, M_WAITOK | M_ZERO); 442 bcopy(p, *tok, len); 443 return (0); 444 } 445 446 static void 447 parse_dir_ask_printenv(const char *var) 448 { 449 char *val; 450 451 val = getenv(var); 452 if (val != NULL) { 453 printf(" %s=%s\n", var, val); 454 freeenv(val); 455 } 456 } 457 458 static int 459 parse_dir_ask(char **conf) 460 { 461 char name[80]; 462 char *mnt; 463 int error; 464 465 printf("\nLoader variables:\n"); 466 parse_dir_ask_printenv("vfs.root.mountfrom"); 467 parse_dir_ask_printenv("vfs.root.mountfrom.options"); 468 469 printf("\nManual root filesystem specification:\n"); 470 printf(" <fstype>:<device> [options]\n"); 471 printf(" Mount <device> using filesystem <fstype>\n"); 472 printf(" and with the specified (optional) option list.\n"); 473 printf("\n"); 474 printf(" eg. ufs:/dev/da0s1a\n"); 475 printf(" zfs:tank\n"); 476 printf(" cd9660:/dev/acd0 ro\n"); 477 printf(" (which is equivalent to: "); 478 printf("mount -t cd9660 -o ro /dev/acd0 /)\n"); 479 printf("\n"); 480 printf(" ? List valid disk boot devices\n"); 481 printf(" . Yield 1 second (for background tasks)\n"); 482 printf(" <empty line> Abort manual input\n"); 483 484 do { 485 error = EINVAL; 486 printf("\nmountroot> "); 487 cngets(name, sizeof(name), GETS_ECHO); 488 if (name[0] == '\0') 489 break; 490 if (name[0] == '?' && name[1] == '\0') { 491 printf("\nList of GEOM managed disk devices:\n "); 492 g_dev_print(); 493 continue; 494 } 495 if (name[0] == '.' && name[1] == '\0') { 496 pause("rmask", hz); 497 continue; 498 } 499 mnt = name; 500 error = parse_mount(&mnt); 501 if (error == -1) 502 printf("Invalid file system specification.\n"); 503 } while (error != 0); 504 505 return (error); 506 } 507 508 static int 509 parse_dir_md(char **conf) 510 { 511 struct stat sb; 512 struct thread *td; 513 struct md_ioctl *mdio; 514 char *path, *tok; 515 int error, fd, len; 516 517 td = curthread; 518 519 error = parse_token(conf, &tok); 520 if (error) 521 return (error); 522 523 len = strlen(tok); 524 mdio = malloc(sizeof(*mdio) + len + 1, M_TEMP, M_WAITOK | M_ZERO); 525 path = (void *)(mdio + 1); 526 bcopy(tok, path, len); 527 free(tok, M_TEMP); 528 529 /* Get file status. */ 530 error = kern_stat(td, path, UIO_SYSSPACE, &sb); 531 if (error) 532 goto out; 533 534 /* Open /dev/mdctl so that we can attach/detach. */ 535 error = kern_open(td, "/dev/" MDCTL_NAME, UIO_SYSSPACE, O_RDWR, 0); 536 if (error) 537 goto out; 538 539 fd = td->td_retval[0]; 540 mdio->md_version = MDIOVERSION; 541 mdio->md_type = MD_VNODE; 542 543 if (root_mount_mddev != -1) { 544 mdio->md_unit = root_mount_mddev; 545 DROP_GIANT(); 546 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio); 547 PICKUP_GIANT(); 548 /* Ignore errors. We don't care. */ 549 root_mount_mddev = -1; 550 } 551 552 mdio->md_file = (void *)(mdio + 1); 553 mdio->md_options = MD_AUTOUNIT | MD_READONLY; 554 mdio->md_mediasize = sb.st_size; 555 mdio->md_unit = 0; 556 DROP_GIANT(); 557 error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio); 558 PICKUP_GIANT(); 559 if (error) 560 goto out; 561 562 if (mdio->md_unit > 9) { 563 printf("rootmount: too many md units\n"); 564 mdio->md_file = NULL; 565 mdio->md_options = 0; 566 mdio->md_mediasize = 0; 567 DROP_GIANT(); 568 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio); 569 PICKUP_GIANT(); 570 /* Ignore errors. We don't care. */ 571 error = ERANGE; 572 goto out; 573 } 574 575 root_mount_mddev = mdio->md_unit; 576 printf(MD_NAME "%u attached to %s\n", root_mount_mddev, mdio->md_file); 577 578 error = kern_close(td, fd); 579 580 out: 581 free(mdio, M_TEMP); 582 return (error); 583 } 584 585 static int 586 parse_dir_onfail(char **conf) 587 { 588 char *action; 589 int error; 590 591 error = parse_token(conf, &action); 592 if (error) 593 return (error); 594 595 if (!strcmp(action, "continue")) 596 root_mount_onfail = A_CONTINUE; 597 else if (!strcmp(action, "panic")) 598 root_mount_onfail = A_PANIC; 599 else if (!strcmp(action, "reboot")) 600 root_mount_onfail = A_REBOOT; 601 else if (!strcmp(action, "retry")) 602 root_mount_onfail = A_RETRY; 603 else { 604 printf("rootmount: %s: unknown action\n", action); 605 error = EINVAL; 606 } 607 608 free(action, M_TEMP); 609 return (0); 610 } 611 612 static int 613 parse_dir_timeout(char **conf) 614 { 615 char *tok, *endtok; 616 long secs; 617 int error; 618 619 error = parse_token(conf, &tok); 620 if (error) 621 return (error); 622 623 secs = strtol(tok, &endtok, 0); 624 error = (secs < 0 || *endtok != '\0') ? EINVAL : 0; 625 if (!error) 626 root_mount_timeout = secs; 627 free(tok, M_TEMP); 628 return (error); 629 } 630 631 static int 632 parse_directive(char **conf) 633 { 634 char *dir; 635 int error; 636 637 error = parse_token(conf, &dir); 638 if (error) 639 return (error); 640 641 if (strcmp(dir, ".ask") == 0) 642 error = parse_dir_ask(conf); 643 else if (strcmp(dir, ".md") == 0) 644 error = parse_dir_md(conf); 645 else if (strcmp(dir, ".onfail") == 0) 646 error = parse_dir_onfail(conf); 647 else if (strcmp(dir, ".timeout") == 0) 648 error = parse_dir_timeout(conf); 649 else { 650 printf("mountroot: invalid directive `%s'\n", dir); 651 /* Ignore the rest of the line. */ 652 (void)parse_skipto(conf, '\n'); 653 error = EINVAL; 654 } 655 free(dir, M_TEMP); 656 return (error); 657 } 658 659 static int 660 parse_mount_dev_present(const char *dev) 661 { 662 struct nameidata nd; 663 int error; 664 665 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, dev, curthread); 666 error = namei(&nd); 667 if (!error) 668 vput(nd.ni_vp); 669 NDFREE(&nd, NDF_ONLY_PNBUF); 670 return (error != 0) ? 0 : 1; 671 } 672 673 #define ERRMSGL 255 674 static int 675 parse_mount(char **conf) 676 { 677 char *errmsg; 678 struct mntarg *ma; 679 char *dev, *fs, *opts, *tok; 680 int delay, error, timeout; 681 682 error = parse_token(conf, &tok); 683 if (error) 684 return (error); 685 fs = tok; 686 error = parse_skipto(&tok, ':'); 687 if (error) { 688 free(fs, M_TEMP); 689 return (error); 690 } 691 parse_poke(&tok, '\0'); 692 parse_advance(&tok); 693 dev = tok; 694 695 if (root_mount_mddev != -1) { 696 /* Handle substitution for the md unit number. */ 697 tok = strstr(dev, "md#"); 698 if (tok != NULL) 699 tok[2] = '' + root_mount_mddev; 700 } 701 702 /* Parse options. */ 703 error = parse_token(conf, &tok); 704 opts = (error == 0) ? tok : NULL; 705 706 printf("Trying to mount root from %s:%s [%s]...\n", fs, dev, 707 (opts != NULL) ? opts : ""); 708 709 errmsg = malloc(ERRMSGL, M_TEMP, M_WAITOK | M_ZERO); 710 711 if (vfs_byname(fs) == NULL) { 712 strlcpy(errmsg, "unknown file system", sizeof(errmsg)); 713 error = ENOENT; 714 goto out; 715 } 716 717 if (strcmp(fs, "zfs") != 0 && dev[0] != '\0' && 718 !parse_mount_dev_present(dev)) { 719 printf("mountroot: waiting for device %s ...\n", dev); 720 delay = hz / 10; 721 timeout = root_mount_timeout * hz; 722 do { 723 pause("rmdev", delay); 724 timeout -= delay; 725 } while (timeout > 0 && !parse_mount_dev_present(dev)); 726 if (timeout <= 0) { 727 error = ENODEV; 728 goto out; 729 } 730 } 731 732 ma = NULL; 733 ma = mount_arg(ma, "fstype", fs, -1); 734 ma = mount_arg(ma, "fspath", "/", -1); 735 ma = mount_arg(ma, "from", dev, -1); 736 ma = mount_arg(ma, "errmsg", errmsg, ERRMSGL); 737 ma = mount_arg(ma, "ro", NULL, 0); 738 ma = parse_mountroot_options(ma, opts); 739 error = kernel_mount(ma, MNT_ROOTFS); 740 741 out: 742 if (error) { 743 printf("Mounting from %s:%s failed with error %d", 744 fs, dev, error); 745 if (errmsg[0] != '\0') 746 printf(": %s", errmsg); 747 printf(".\n"); 748 } 749 free(fs, M_TEMP); 750 free(errmsg, 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 #undef ERRMSGL 757 758 static int 759 vfs_mountroot_parse(struct sbuf *sb, struct mount *mpdevfs) 760 { 761 struct mount *mp; 762 char *conf; 763 int error; 764 765 root_mount_mddev = -1; 766 767 retry: 768 conf = sbuf_data(sb); 769 mp = TAILQ_NEXT(mpdevfs, mnt_list); 770 error = (mp == NULL) ? 0 : EDOOFUS; 771 root_mount_onfail = A_CONTINUE; 772 while (mp == NULL) { 773 error = parse_skipto(&conf, CC_NONWHITESPACE); 774 if (error == PE_EOL) { 775 parse_advance(&conf); 776 continue; 777 } 778 if (error < 0) 779 break; 780 switch (parse_peek(&conf)) { 781 case '#': 782 error = parse_skipto(&conf, '\n'); 783 break; 784 case '.': 785 error = parse_directive(&conf); 786 break; 787 default: 788 error = parse_mount(&conf); 789 break; 790 } 791 if (error < 0) 792 break; 793 /* Ignore any trailing garbage on the line. */ 794 if (parse_peek(&conf) != '\n') { 795 printf("mountroot: advancing to next directive...\n"); 796 (void)parse_skipto(&conf, '\n'); 797 } 798 mp = TAILQ_NEXT(mpdevfs, mnt_list); 799 } 800 if (mp != NULL) 801 return (0); 802 803 /* 804 * We failed to mount (a new) root. 805 */ 806 switch (root_mount_onfail) { 807 case A_CONTINUE: 808 break; 809 case A_PANIC: 810 panic("mountroot: unable to (re-)mount root."); 811 /* NOTREACHED */ 812 case A_RETRY: 813 goto retry; 814 case A_REBOOT: 815 kern_reboot(RB_NOSYNC); 816 /* NOTREACHED */ 817 } 818 819 return (error); 820 } 821 822 static void 823 vfs_mountroot_conf0(struct sbuf *sb) 824 { 825 char *s, *tok, *mnt, *opt; 826 int error; 827 828 sbuf_printf(sb, ".onfail panic\n"); 829 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout); 830 if (boothowto & RB_ASKNAME) 831 sbuf_printf(sb, ".ask\n"); 832 #ifdef ROOTDEVNAME 833 if (boothowto & RB_DFLTROOT) 834 sbuf_printf(sb, "%s\n", ROOTDEVNAME); 835 #endif 836 if (boothowto & RB_CDROM) { 837 sbuf_printf(sb, "cd9660:/dev/cd0 ro\n"); 838 sbuf_printf(sb, ".timeout 0\n"); 839 sbuf_printf(sb, "cd9660:/dev/acd0 ro\n"); 840 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout); 841 } 842 s = getenv("vfs.root.mountfrom"); 843 if (s != NULL) { 844 opt = getenv("vfs.root.mountfrom.options"); 845 tok = s; 846 error = parse_token(&tok, &mnt); 847 while (!error) { 848 sbuf_printf(sb, "%s %s\n", mnt, 849 (opt != NULL) ? opt : ""); 850 free(mnt, M_TEMP); 851 error = parse_token(&tok, &mnt); 852 } 853 if (opt != NULL) 854 freeenv(opt); 855 freeenv(s); 856 } 857 if (rootdevnames[0] != NULL) 858 sbuf_printf(sb, "%s\n", rootdevnames[0]); 859 if (rootdevnames[1] != NULL) 860 sbuf_printf(sb, "%s\n", rootdevnames[1]); 861 #ifdef ROOTDEVNAME 862 if (!(boothowto & RB_DFLTROOT)) 863 sbuf_printf(sb, "%s\n", ROOTDEVNAME); 864 #endif 865 if (!(boothowto & RB_ASKNAME)) 866 sbuf_printf(sb, ".ask\n"); 867 } 868 869 static int 870 vfs_mountroot_readconf(struct thread *td, struct sbuf *sb) 871 { 872 static char buf[128]; 873 struct nameidata nd; 874 off_t ofs; 875 ssize_t resid; 876 int error, flags, len, vfslocked; 877 878 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, 879 "/.mount.conf", td); 880 flags = FREAD; 881 error = vn_open(&nd, &flags, 0, NULL); 882 if (error) 883 return (error); 884 885 vfslocked = NDHASGIANT(&nd); 886 NDFREE(&nd, NDF_ONLY_PNBUF); 887 ofs = 0; 888 len = sizeof(buf) - 1; 889 while (1) { 890 error = vn_rdwr(UIO_READ, nd.ni_vp, buf, len, ofs, 891 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 892 NOCRED, &resid, td); 893 if (error) 894 break; 895 if (resid == len) 896 break; 897 buf[len - resid] = 0; 898 sbuf_printf(sb, "%s", buf); 899 ofs += len - resid; 900 } 901 902 VOP_UNLOCK(nd.ni_vp, 0); 903 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 904 VFS_UNLOCK_GIANT(vfslocked); 905 return (error); 906 } 907 908 static void 909 vfs_mountroot_wait(void) 910 { 911 struct root_hold_token *h; 912 struct timeval lastfail; 913 int curfail; 914 915 curfail = 0; 916 while (1) { 917 DROP_GIANT(); 918 g_waitidle(); 919 PICKUP_GIANT(); 920 mtx_lock(&mountlist_mtx); 921 if (LIST_EMPTY(&root_holds)) { 922 mtx_unlock(&mountlist_mtx); 923 break; 924 } 925 if (ppsratecheck(&lastfail, &curfail, 1)) { 926 printf("Root mount waiting for:"); 927 LIST_FOREACH(h, &root_holds, list) 928 printf(" %s", h->who); 929 printf("\n"); 930 } 931 msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold", 932 hz); 933 } 934 } 935 936 void 937 vfs_mountroot(void) 938 { 939 struct mount *mp; 940 struct sbuf *sb; 941 struct thread *td; 942 time_t timebase; 943 int error; 944 945 td = curthread; 946 947 vfs_mountroot_wait(); 948 949 sb = sbuf_new_auto(); 950 vfs_mountroot_conf0(sb); 951 sbuf_finish(sb); 952 953 error = vfs_mountroot_devfs(td, &mp); 954 while (!error) { 955 error = vfs_mountroot_parse(sb, mp); 956 if (!error) { 957 error = vfs_mountroot_shuffle(td, mp); 958 if (!error) { 959 sbuf_clear(sb); 960 error = vfs_mountroot_readconf(td, sb); 961 sbuf_finish(sb); 962 } 963 } 964 } 965 966 sbuf_delete(sb); 967 968 /* 969 * Iterate over all currently mounted file systems and use 970 * the time stamp found to check and/or initialize the RTC. 971 * Call inittodr() only once and pass it the largest of the 972 * timestamps we encounter. 973 */ 974 timebase = 0; 975 mtx_lock(&mountlist_mtx); 976 mp = TAILQ_FIRST(&mountlist); 977 while (mp != NULL) { 978 if (mp->mnt_time > timebase) 979 timebase = mp->mnt_time; 980 mp = TAILQ_NEXT(mp, mnt_list); 981 } 982 mtx_unlock(&mountlist_mtx); 983 inittodr(timebase); 984 985 /* Keep prison0's root in sync with the global rootvnode. */ 986 mtx_lock(&prison0.pr_mtx); 987 prison0.pr_root = rootvnode; 988 vref(prison0.pr_root); 989 mtx_unlock(&prison0.pr_mtx); 990 991 mtx_lock(&mountlist_mtx); 992 atomic_store_rel_int(&root_mount_complete, 1); 993 wakeup(&root_mount_complete); 994 mtx_unlock(&mountlist_mtx); 995 996 EVENTHANDLER_INVOKE(mountroot); 997 } 998 999 static struct mntarg * 1000 parse_mountroot_options(struct mntarg *ma, const char *options) 1001 { 1002 char *p; 1003 char *name, *name_arg; 1004 char *val, *val_arg; 1005 char *opts; 1006 1007 if (options == NULL || options[0] == '\0') 1008 return (ma); 1009 1010 p = opts = strdup(options, M_MOUNT); 1011 if (opts == NULL) { 1012 return (ma); 1013 } 1014 1015 while((name = strsep(&p, ",")) != NULL) { 1016 if (name[0] == '\0') 1017 break; 1018 1019 val = strchr(name, '='); 1020 if (val != NULL) { 1021 *val = '\0'; 1022 ++val; 1023 } 1024 if( strcmp(name, "rw") == 0 || 1025 strcmp(name, "noro") == 0) { 1026 /* 1027 * The first time we mount the root file system, 1028 * we need to mount 'ro', so We need to ignore 1029 * 'rw' and 'noro' mount options. 1030 */ 1031 continue; 1032 } 1033 name_arg = strdup(name, M_MOUNT); 1034 val_arg = NULL; 1035 if (val != NULL) 1036 val_arg = strdup(val, M_MOUNT); 1037 1038 ma = mount_arg(ma, name_arg, val_arg, 1039 (val_arg != NULL ? -1 : 0)); 1040 } 1041 free(opts, M_MOUNT); 1042 return (ma); 1043 }
Cache object: 544932bf79747228ce879dca29aeec9c
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