1 /*- 2 * Copyright (c) 1999 Michael Smith 3 * All rights reserved. 4 * Copyright (c) 1999 Poul-Henning Kamp 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD: src/sys/kern/vfs_conf.c,v 1.49.2.5 2003/01/07 11:56:53 joerg Exp $ 29 * $DragonFly: src/sys/kern/vfs_conf.c,v 1.34 2008/05/24 19:08:28 dillon Exp $ 30 */ 31 32 /* 33 * Locate and mount the root filesystem. 34 * 35 * The root filesystem is detailed in the kernel environment variable 36 * vfs.root.mountfrom, which is expected to be in the general format 37 * 38 * <vfsname>:[<path>] 39 * vfsname := the name of a VFS known to the kernel and capable 40 * of being mounted as root 41 * path := disk device name or other data used by the filesystem 42 * to locate its physical store 43 * 44 */ 45 46 #include "opt_rootdevname.h" 47 48 #include <sys/param.h> 49 #include <sys/kernel.h> 50 #include <sys/systm.h> 51 #include <sys/proc.h> 52 #include <sys/vnode.h> 53 #include <sys/mount.h> 54 #include <sys/malloc.h> 55 #include <sys/reboot.h> 56 #include <sys/diskslice.h> 57 #include <sys/conf.h> 58 #include <sys/cons.h> 59 #include <sys/device.h> 60 #include <sys/disk.h> 61 #include <sys/namecache.h> 62 #include <sys/paths.h> 63 #include <sys/thread2.h> 64 #include <sys/nlookup.h> 65 #include <sys/devfs.h> 66 #include <sys/sysctl.h> 67 68 #include "opt_ddb.h" 69 #ifdef DDB 70 #include <ddb/ddb.h> 71 #endif 72 73 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 74 75 #define ROOTNAME "root_device" 76 77 struct vnode *rootvnode; 78 struct nchandle rootnch; 79 80 /* 81 * The root specifiers we will try if RB_CDROM is specified. Note that 82 * with DEVFS we do not use the compatibility slice's whole-disk 'c' 83 * partition. Instead we just use the whole disk, e.g. cd0 or cd0s0. 84 */ 85 static char *cdrom_rootdevnames[] = { 86 "cd9660:cd0", /* SCSI (including AHCI and SILI) */ 87 "cd9660:acd0", /* NATA */ 88 "cd9660:cd1", /* SCSI (including AHCI and SILI) */ 89 "cd9660:acd1", /* NATA */ 90 "cd9660:cd8", /* USB */ 91 "cd9660:cd9", /* USB */ 92 NULL 93 }; 94 95 int vfs_mountroot_devfs(void); 96 static void vfs_mountroot(void *junk); 97 static int vfs_mountroot_try(const char *mountfrom); 98 static int vfs_mountroot_ask(void); 99 static int getline(char *cp, int limit); 100 101 /* legacy find-root code */ 102 char *rootdevnames[2] = {NULL, NULL}; 103 static int setrootbyname(char *name); 104 105 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL); 106 107 /* 108 * Find and mount the root filesystem 109 */ 110 static void 111 vfs_mountroot(void *junk) 112 { 113 cdev_t save_rootdev = rootdev; 114 int i; 115 int dummy; 116 117 /* 118 * Make sure all disk devices created so far have also been probed, 119 * and also make sure that the newly created device nodes for 120 * probed disks are ready, too. 121 * 122 * Messages can fly around here so get good synchronization 123 * coverage. 124 * 125 * XXX - Delay an additional 2 seconds to help drivers which pickup 126 * devices asynchronously and are not caught by CAM's initial 127 * probe. 128 */ 129 sync_devs(); 130 tsleep(&dummy, 0, "syncer", hz*2); 131 132 133 /* 134 * The root filesystem information is compiled in, and we are 135 * booted with instructions to use it. 136 */ 137 #ifdef ROOTDEVNAME 138 if ((boothowto & RB_DFLTROOT) && 139 !vfs_mountroot_try(ROOTDEVNAME)) 140 return; 141 #endif 142 /* 143 * We are booted with instructions to prompt for the root filesystem, 144 * or to use the compiled-in default when it doesn't exist. 145 */ 146 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) { 147 if (!vfs_mountroot_ask()) 148 return; 149 } 150 151 /* 152 * We've been given the generic "use CDROM as root" flag. This is 153 * necessary because one media may be used in many different 154 * devices, so we need to search for them. 155 */ 156 if (boothowto & RB_CDROM) { 157 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 158 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 159 return; 160 } 161 } 162 163 /* 164 * Try to use the value read by the loader from /etc/fstab, or 165 * supplied via some other means. This is the preferred 166 * mechanism. 167 */ 168 if (!vfs_mountroot_try(kgetenv("vfs.root.mountfrom"))) 169 return; 170 171 /* 172 * If a vfs set rootdev, try it (XXX VINUM HACK!) 173 */ 174 if (save_rootdev != NULL) { 175 rootdev = save_rootdev; 176 if (!vfs_mountroot_try("")) 177 return; 178 } 179 180 /* 181 * Try values that may have been computed by the machine-dependant 182 * legacy code. 183 */ 184 if (rootdevnames[0] && !vfs_mountroot_try(rootdevnames[0])) 185 return; 186 if (rootdevnames[1] && !vfs_mountroot_try(rootdevnames[1])) 187 return; 188 189 /* 190 * If we have a compiled-in default, and haven't already tried it, try 191 * it now. 192 */ 193 #ifdef ROOTDEVNAME 194 if (!(boothowto & RB_DFLTROOT)) 195 if (!vfs_mountroot_try(ROOTDEVNAME)) 196 return; 197 #endif 198 199 /* 200 * Everything so far has failed, prompt on the console if we haven't 201 * already tried that. 202 */ 203 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask()) 204 return; 205 panic("Root mount failed, startup aborted."); 206 } 207 208 209 int 210 vfs_mountroot_devfs(void) 211 { 212 struct vnode *vp; 213 struct nchandle nch; 214 struct nlookupdata nd; 215 struct mount *mp; 216 struct vfsconf *vfsp; 217 int error; 218 struct ucred *cred = proc0.p_ucred; 219 const char *devfs_path, *init_chroot; 220 char *dev_malloced = NULL; 221 222 if ((init_chroot = kgetenv("init_chroot")) != NULL) { 223 size_t l; 224 225 l = strlen(init_chroot) + sizeof("/dev"); 226 dev_malloced = kmalloc(l, M_MOUNT, M_WAITOK); 227 ksnprintf(dev_malloced, l, "%s/dev", init_chroot); 228 devfs_path = dev_malloced; 229 } else { 230 devfs_path = "/dev"; 231 } 232 /* 233 * Lookup the requested path and extract the nch and vnode. 234 */ 235 error = nlookup_init_raw(&nd, 236 devfs_path, UIO_SYSSPACE, NLC_FOLLOW, 237 cred, &rootnch); 238 239 if (error == 0) { 240 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup_init is ok...\n"); 241 if ((error = nlookup(&nd)) == 0) { 242 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup is ok...\n"); 243 if (nd.nl_nch.ncp->nc_vp == NULL) { 244 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup: simply not found\n"); 245 error = ENOENT; 246 } 247 } 248 } 249 if (dev_malloced != NULL) 250 kfree(dev_malloced, M_MOUNT), dev_malloced = NULL; 251 devfs_path = NULL; 252 if (error) { 253 nlookup_done(&nd); 254 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup failed, error: %d\n", error); 255 return (error); 256 } 257 258 /* 259 * Extract the locked+refd ncp and cleanup the nd structure 260 */ 261 nch = nd.nl_nch; 262 cache_zero(&nd.nl_nch); 263 nlookup_done(&nd); 264 265 /* 266 * now we have the locked ref'd nch and unreferenced vnode. 267 */ 268 vp = nch.ncp->nc_vp; 269 if ((error = vget(vp, LK_EXCLUSIVE)) != 0) { 270 cache_put(&nch); 271 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vget failed\n"); 272 return (error); 273 } 274 cache_unlock(&nch); 275 276 if ((error = vinvalbuf(vp, V_SAVE, 0, 0)) != 0) { 277 cache_drop(&nch); 278 vput(vp); 279 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vinvalbuf failed\n"); 280 return (error); 281 } 282 if (vp->v_type != VDIR) { 283 cache_drop(&nch); 284 vput(vp); 285 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vp is not VDIR\n"); 286 return (ENOTDIR); 287 } 288 289 vfsp = vfsconf_find_by_name("devfs"); 290 vsetflags(vp, VMOUNT); 291 292 /* 293 * Allocate and initialize the filesystem. 294 */ 295 mp = kmalloc(sizeof(struct mount), M_MOUNT, M_ZERO|M_WAITOK); 296 mount_init(mp); 297 vfs_busy(mp, LK_NOWAIT); 298 mp->mnt_op = vfsp->vfc_vfsops; 299 mp->mnt_vfc = vfsp; 300 vfsp->vfc_refcount++; 301 mp->mnt_stat.f_type = vfsp->vfc_typenum; 302 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 303 strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 304 mp->mnt_stat.f_owner = cred->cr_uid; 305 vn_unlock(vp); 306 307 /* 308 * Mount the filesystem. 309 */ 310 error = VFS_MOUNT(mp, "/dev", NULL, cred); 311 312 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 313 314 /* 315 * Put the new filesystem on the mount list after root. The mount 316 * point gets its own mnt_ncmountpt (unless the VFS already set one 317 * up) which represents the root of the mount. The lookup code 318 * detects the mount point going forward and checks the root of 319 * the mount going backwards. 320 * 321 * It is not necessary to invalidate or purge the vnode underneath 322 * because elements under the mount will be given their own glue 323 * namecache record. 324 */ 325 if (!error) { 326 if (mp->mnt_ncmountpt.ncp == NULL) { 327 /* 328 * allocate, then unlock, but leave the ref intact 329 */ 330 cache_allocroot(&mp->mnt_ncmountpt, mp, NULL); 331 cache_unlock(&mp->mnt_ncmountpt); 332 } 333 mp->mnt_ncmounton = nch; /* inherits ref */ 334 nch.ncp->nc_flag |= NCF_ISMOUNTPT; 335 336 /* XXX get the root of the fs and cache_setvp(mnt_ncmountpt...) */ 337 vclrflags(vp, VMOUNT); 338 mountlist_insert(mp, MNTINS_LAST); 339 vn_unlock(vp); 340 //checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt); 341 error = vfs_allocate_syncvnode(mp); 342 if (error) { 343 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vfs_allocate_syncvnode failed\n"); 344 } 345 vfs_unbusy(mp); 346 error = VFS_START(mp, 0); 347 vrele(vp); 348 } else { 349 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops); 350 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops); 351 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops); 352 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops); 353 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops); 354 vclrflags(vp, VMOUNT); 355 mp->mnt_vfc->vfc_refcount--; 356 vfs_unbusy(mp); 357 kfree(mp, M_MOUNT); 358 cache_drop(&nch); 359 vput(vp); 360 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: mount failed\n"); 361 } 362 363 devfs_debug(DEVFS_DEBUG_DEBUG, "rootmount_devfs done with error: %d\n", error); 364 return (error); 365 } 366 367 368 /* 369 * Mount (mountfrom) as the root filesystem. 370 */ 371 static int 372 vfs_mountroot_try(const char *mountfrom) 373 { 374 struct mount *mp, *mp2; 375 char *vfsname, *devname; 376 int error; 377 char patt[32]; 378 int mountfromlen, len; 379 const char *cp, *ep; 380 char *mf; 381 382 vfsname = NULL; 383 devname = NULL; 384 mp = NULL; 385 mp2 = NULL; 386 error = EINVAL; 387 388 if (mountfrom == NULL) 389 return(error); /* don't complain */ 390 391 crit_enter(); 392 kprintf("Mounting root from %s\n", mountfrom); 393 crit_exit(); 394 395 mountfromlen = strlen(mountfrom); 396 cp = mountfrom; 397 /* parse vfs name and devname */ 398 vfsname = kmalloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 399 devname = kmalloc(MNAMELEN, M_MOUNT, M_WAITOK); 400 mf = kmalloc(MFSNAMELEN+MNAMELEN, M_MOUNT, M_WAITOK); 401 for(;;) { 402 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 403 len = ep - cp; 404 bzero(vfsname, MFSNAMELEN); 405 bzero(devname, MNAMELEN); 406 bzero(mf, MFSNAMELEN+MNAMELEN); 407 strncpy(mf, cp, MFSNAMELEN+MNAMELEN); 408 409 vfsname[0] = devname[0] = 0; 410 ksprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 411 if (ksscanf(mf, patt, vfsname, devname) < 1) 412 goto end; 413 414 /* allocate a root mount */ 415 error = vfs_rootmountalloc(vfsname, 416 devname[0] != 0 ? devname : ROOTNAME, &mp); 417 if (error != 0) { 418 kprintf("Can't allocate root mount for filesystem '%s': %d\n", 419 vfsname, error); 420 goto end; 421 } 422 mp->mnt_flag |= MNT_ROOTFS; 423 424 /* do our best to set rootdev */ 425 if ((strcmp(vfsname, "hammer") != 0) && (devname[0] != 0) && 426 setrootbyname(devname)) 427 kprintf("setrootbyname failed\n"); 428 429 /* If the root device is a type "memory disk", mount RW */ 430 if (rootdev != NULL && dev_is_good(rootdev) && 431 (dev_dflags(rootdev) & D_MEMDISK)) { 432 mp->mnt_flag &= ~MNT_RDONLY; 433 } 434 435 error = VFS_MOUNT(mp, NULL, NULL, proc0.p_ucred); 436 437 if (!error) 438 break; 439 end: 440 if(*ep == 0) 441 break; 442 cp = ep + 1; 443 } 444 445 if (vfsname != NULL) 446 kfree(vfsname, M_MOUNT); 447 if (devname != NULL) 448 kfree(devname, M_MOUNT); 449 if (mf != NULL) 450 kfree(mf, M_MOUNT); 451 if (error == 0) { 452 /* register with list of mounted filesystems */ 453 mountlist_insert(mp, MNTINS_FIRST); 454 455 /* sanity check system clock against root fs timestamp */ 456 inittodr(mp->mnt_time); 457 vfs_unbusy(mp); 458 if (mp->mnt_syncer == NULL) { 459 error = vfs_allocate_syncvnode(mp); 460 if (error) 461 kprintf("Warning: no syncer vp for root!\n"); 462 error = 0; 463 } 464 } else { 465 if (mp != NULL) { 466 vfs_unbusy(mp); 467 kfree(mp, M_MOUNT); 468 } 469 kprintf("Root mount failed: %d\n", error); 470 } 471 return(error); 472 } 473 474 475 static void 476 vfs_mountroot_ask_callback(cdev_t dev, void *arg __unused) 477 { 478 if (dev_is_good(dev) && (dev_dflags(dev) & D_DISK)) 479 kprintf(" \"%s\" ", dev->si_name); 480 } 481 482 483 /* 484 * Spin prompting on the console for a suitable root filesystem 485 */ 486 static int 487 vfs_mountroot_ask(void) 488 { 489 char name[128]; 490 int llimit = 100; 491 492 kprintf("\nManual root filesystem specification:\n"); 493 kprintf(" <fstype>:<device> Specify root (e.g. ufs:da0s1a)\n"); 494 kprintf(" ? List valid disk boot devices\n"); 495 kprintf(" panic Just panic\n"); 496 kprintf(" abort Abort manual input\n"); 497 while (llimit--) { 498 kprintf("\nmountroot> "); 499 500 if (getline(name, 128) < 0) 501 break; 502 if (name[0] == 0) { 503 ; 504 } else if (name[0] == '?') { 505 kprintf("Possibly valid devices for root FS:\n"); 506 //enumerate all disk devices 507 devfs_scan_callback(vfs_mountroot_ask_callback, NULL); 508 kprintf("\n"); 509 continue; 510 } else if (strcmp(name, "panic") == 0) { 511 panic("panic from console"); 512 } else if (strcmp(name, "abort") == 0) { 513 break; 514 } else if (vfs_mountroot_try(name) == 0) { 515 return(0); 516 } 517 } 518 return(1); 519 } 520 521 522 static int 523 getline(char *cp, int limit) 524 { 525 char *lp; 526 int c; 527 528 lp = cp; 529 for (;;) { 530 c = cngetc(); 531 532 switch (c) { 533 case -1: 534 return(-1); 535 case '\n': 536 case '\r': 537 kprintf("\n"); 538 *lp++ = '\0'; 539 return(0); 540 case '\b': 541 case '\177': 542 if (lp > cp) { 543 kprintf("\b \b"); 544 lp--; 545 } else { 546 kprintf("%c", 7); 547 } 548 continue; 549 case '#': 550 kprintf("#"); 551 lp--; 552 if (lp < cp) 553 lp = cp; 554 continue; 555 case '@': 556 case 'u' & 037: 557 lp = cp; 558 kprintf("%c", '\n'); 559 continue; 560 default: 561 if (lp - cp >= limit - 1) { 562 kprintf("%c", 7); 563 } else { 564 kprintf("%c", c); 565 *lp++ = c; 566 } 567 continue; 568 } 569 } 570 } 571 572 /* 573 * Convert a given name to the cdev_t of the disk-like device 574 * it refers to. 575 */ 576 struct kdbn_info { 577 const char *name; 578 int nlen; 579 int minor; 580 cdev_t dev; 581 }; 582 583 584 cdev_t 585 kgetdiskbyname(const char *name) 586 { 587 char *cp; 588 cdev_t rdev; 589 590 /* 591 * Get the base name of the device 592 */ 593 if (strncmp(name, __SYS_PATH_DEV, sizeof(__SYS_PATH_DEV) - 1) == 0) 594 name += sizeof(__SYS_PATH_DEV) - 1; 595 cp = __DECONST(char *, name); 596 597 /* 598 * Locate the device 599 */ 600 kprintf("tryroot %s\n", name); 601 rdev = devfs_find_device_by_name(name); 602 if (rdev == NULL) { 603 kprintf("no disk named '%s'\n", name); 604 } 605 /* 606 * FOUND DEVICE 607 */ 608 return(rdev); 609 } 610 611 /* 612 * Set rootdev to match (name), given that we expect it to 613 * refer to a disk-like device. 614 */ 615 static int 616 setrootbyname(char *name) 617 { 618 cdev_t diskdev; 619 620 diskdev = kgetdiskbyname(name); 621 if (diskdev != NULL) { 622 rootdev = diskdev; 623 return (0); 624 } 625 /* set to NULL if kgetdiskbyname() fails so that if the first rootdev is 626 * found by fails to mount and the second one isn't found, mountroot_try 627 * doesn't try again with the first one 628 */ 629 rootdev = NULL; 630 return (1); 631 } 632 633 #ifdef DDB 634 DB_SHOW_COMMAND(disk, db_getdiskbyname) 635 { 636 cdev_t dev; 637 638 if (modif[0] == '\0') { 639 db_error("usage: show disk/devicename"); 640 return; 641 } 642 dev = kgetdiskbyname(modif); 643 if (dev != NULL) 644 db_printf("cdev_t = %p\n", dev); 645 else 646 db_printf("No disk device matched.\n"); 647 } 648 #endif 649 650 static int 651 vfs_sysctl_real_root(SYSCTL_HANDLER_ARGS) 652 { 653 char *real_root; 654 size_t len; 655 int error; 656 657 real_root = kgetenv("vfs.root.realroot"); 658 659 if (real_root == NULL) 660 real_root = ""; 661 662 len = strlen(real_root) + 1; 663 664 error = sysctl_handle_string(oidp, real_root, len, req); 665 666 return error; 667 } 668 669 SYSCTL_PROC(_vfs, OID_AUTO, real_root, 670 CTLTYPE_STRING | CTLFLAG_RD, 0, 0, vfs_sysctl_real_root, 671 "A", "Real root mount string"); 672