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 67 #include "opt_ddb.h" 68 #ifdef DDB 69 #include <ddb/ddb.h> 70 #endif 71 72 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 73 74 #define ROOTNAME "root_device" 75 76 struct vnode *rootvnode; 77 struct nchandle rootnch; 78 79 /* 80 * The root specifiers we will try if RB_CDROM is specified. Note that 81 * with DEVFS we do not use the compatibility slice's whole-disk 'c' 82 * partition. Instead we just use the whole disk, e.g. cd0 or cd0s0. 83 */ 84 static char *cdrom_rootdevnames[] = { 85 "cd9660:cd0", /* SCSI (including AHCI and SILI) */ 86 "cd9660:acd0", /* NATA */ 87 "cd9660:cd1", /* SCSI (including AHCI and SILI) */ 88 "cd9660:acd1", /* NATA */ 89 "cd9660:cd8", /* USB */ 90 "cd9660:cd9", /* USB */ 91 NULL 92 }; 93 94 int vfs_mountroot_devfs(void); 95 static void vfs_mountroot(void *junk); 96 static int vfs_mountroot_try(const char *mountfrom); 97 static int vfs_mountroot_ask(void); 98 static int getline(char *cp, int limit); 99 100 /* legacy find-root code */ 101 char *rootdevnames[2] = {NULL, NULL}; 102 static int setrootbyname(char *name); 103 104 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL); 105 106 /* 107 * Find and mount the root filesystem 108 */ 109 static void 110 vfs_mountroot(void *junk) 111 { 112 cdev_t save_rootdev = rootdev; 113 int i; 114 int dummy; 115 116 /* 117 * Make sure all disk devices created so far have also been probed, 118 * and also make sure that the newly created device nodes for 119 * probed disks are ready, too. 120 * 121 * Messages can fly around here so get good synchronization 122 * coverage. 123 * 124 * XXX - Delay an additional 2 seconds to help drivers which pickup 125 * devices asynchronously and are not caught by CAM's initial 126 * probe. 127 */ 128 sync_devs(); 129 tsleep(&dummy, 0, "syncer", hz*2); 130 131 132 /* 133 * The root filesystem information is compiled in, and we are 134 * booted with instructions to use it. 135 */ 136 #ifdef ROOTDEVNAME 137 if ((boothowto & RB_DFLTROOT) && 138 !vfs_mountroot_try(ROOTDEVNAME)) 139 return; 140 #endif 141 /* 142 * We are booted with instructions to prompt for the root filesystem, 143 * or to use the compiled-in default when it doesn't exist. 144 */ 145 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) { 146 if (!vfs_mountroot_ask()) 147 return; 148 } 149 150 /* 151 * We've been given the generic "use CDROM as root" flag. This is 152 * necessary because one media may be used in many different 153 * devices, so we need to search for them. 154 */ 155 if (boothowto & RB_CDROM) { 156 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 157 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 158 return; 159 } 160 } 161 162 /* 163 * Try to use the value read by the loader from /etc/fstab, or 164 * supplied via some other means. This is the preferred 165 * mechanism. 166 */ 167 if (!vfs_mountroot_try(kgetenv("vfs.root.mountfrom"))) 168 return; 169 170 /* 171 * If a vfs set rootdev, try it (XXX VINUM HACK!) 172 */ 173 if (save_rootdev != NULL) { 174 rootdev = save_rootdev; 175 if (!vfs_mountroot_try("")) 176 return; 177 } 178 179 /* 180 * Try values that may have been computed by the machine-dependant 181 * legacy code. 182 */ 183 if (rootdevnames[0] && !vfs_mountroot_try(rootdevnames[0])) 184 return; 185 if (rootdevnames[1] && !vfs_mountroot_try(rootdevnames[1])) 186 return; 187 188 /* 189 * If we have a compiled-in default, and haven't already tried it, try 190 * it now. 191 */ 192 #ifdef ROOTDEVNAME 193 if (!(boothowto & RB_DFLTROOT)) 194 if (!vfs_mountroot_try(ROOTDEVNAME)) 195 return; 196 #endif 197 198 /* 199 * Everything so far has failed, prompt on the console if we haven't 200 * already tried that. 201 */ 202 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask()) 203 return; 204 panic("Root mount failed, startup aborted."); 205 } 206 207 208 int 209 vfs_mountroot_devfs(void) 210 { 211 struct vnode *vp; 212 struct nchandle nch; 213 struct nlookupdata nd; 214 struct mount *mp; 215 struct vfsconf *vfsp; 216 int error; 217 struct ucred *cred = proc0.p_ucred; 218 219 /* 220 * Lookup the requested path and extract the nch and vnode. 221 */ 222 error = nlookup_init_raw(&nd, 223 "/dev", UIO_SYSSPACE, NLC_FOLLOW, 224 cred, &rootnch); 225 226 if (error == 0) { 227 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup_init is ok...\n"); 228 if ((error = nlookup(&nd)) == 0) { 229 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup is ok...\n"); 230 if (nd.nl_nch.ncp->nc_vp == NULL) { 231 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup: simply not found\n"); 232 error = ENOENT; 233 } 234 } 235 } 236 if (error) { 237 nlookup_done(&nd); 238 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup failed, error: %d\n", error); 239 return (error); 240 } 241 242 /* 243 * Extract the locked+refd ncp and cleanup the nd structure 244 */ 245 nch = nd.nl_nch; 246 cache_zero(&nd.nl_nch); 247 nlookup_done(&nd); 248 249 /* 250 * now we have the locked ref'd nch and unreferenced vnode. 251 */ 252 vp = nch.ncp->nc_vp; 253 if ((error = vget(vp, LK_EXCLUSIVE)) != 0) { 254 cache_put(&nch); 255 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vget failed\n"); 256 return (error); 257 } 258 cache_unlock(&nch); 259 260 if ((error = vinvalbuf(vp, V_SAVE, 0, 0)) != 0) { 261 cache_drop(&nch); 262 vput(vp); 263 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vinvalbuf failed\n"); 264 return (error); 265 } 266 if (vp->v_type != VDIR) { 267 cache_drop(&nch); 268 vput(vp); 269 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vp is not VDIR\n"); 270 return (ENOTDIR); 271 } 272 273 vfsp = vfsconf_find_by_name("devfs"); 274 vp->v_flag |= VMOUNT; 275 276 /* 277 * Allocate and initialize the filesystem. 278 */ 279 mp = kmalloc(sizeof(struct mount), M_MOUNT, M_ZERO|M_WAITOK); 280 TAILQ_INIT(&mp->mnt_nvnodelist); 281 TAILQ_INIT(&mp->mnt_reservedvnlist); 282 TAILQ_INIT(&mp->mnt_jlist); 283 mp->mnt_nvnodelistsize = 0; 284 lockinit(&mp->mnt_lock, "vfslock", 0, 0); 285 vfs_busy(mp, LK_NOWAIT); 286 mp->mnt_op = vfsp->vfc_vfsops; 287 mp->mnt_vfc = vfsp; 288 vfsp->vfc_refcount++; 289 mp->mnt_stat.f_type = vfsp->vfc_typenum; 290 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 291 strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 292 mp->mnt_stat.f_owner = cred->cr_uid; 293 mp->mnt_iosize_max = DFLTPHYS; 294 vn_unlock(vp); 295 296 /* 297 * Mount the filesystem. 298 */ 299 error = VFS_MOUNT(mp, "/dev", NULL, cred); 300 301 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 302 303 /* 304 * Put the new filesystem on the mount list after root. The mount 305 * point gets its own mnt_ncmountpt (unless the VFS already set one 306 * up) which represents the root of the mount. The lookup code 307 * detects the mount point going forward and checks the root of 308 * the mount going backwards. 309 * 310 * It is not necessary to invalidate or purge the vnode underneath 311 * because elements under the mount will be given their own glue 312 * namecache record. 313 */ 314 if (!error) { 315 if (mp->mnt_ncmountpt.ncp == NULL) { 316 /* 317 * allocate, then unlock, but leave the ref intact 318 */ 319 cache_allocroot(&mp->mnt_ncmountpt, mp, NULL); 320 cache_unlock(&mp->mnt_ncmountpt); 321 } 322 mp->mnt_ncmounton = nch; /* inherits ref */ 323 nch.ncp->nc_flag |= NCF_ISMOUNTPT; 324 325 /* XXX get the root of the fs and cache_setvp(mnt_ncmountpt...) */ 326 vp->v_flag &= ~VMOUNT; 327 mountlist_insert(mp, MNTINS_LAST); 328 vn_unlock(vp); 329 //checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt); 330 error = vfs_allocate_syncvnode(mp); 331 if (error) { 332 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vfs_allocate_syncvnode failed\n"); 333 } 334 vfs_unbusy(mp); 335 error = VFS_START(mp, 0); 336 vrele(vp); 337 } else { 338 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops); 339 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops); 340 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops); 341 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops); 342 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops); 343 vp->v_flag &= ~VMOUNT; 344 mp->mnt_vfc->vfc_refcount--; 345 vfs_unbusy(mp); 346 kfree(mp, M_MOUNT); 347 cache_drop(&nch); 348 vput(vp); 349 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: mount failed\n"); 350 } 351 352 devfs_debug(DEVFS_DEBUG_DEBUG, "rootmount_devfs done with error: %d\n", error); 353 return (error); 354 } 355 356 357 /* 358 * Mount (mountfrom) as the root filesystem. 359 */ 360 static int 361 vfs_mountroot_try(const char *mountfrom) 362 { 363 struct mount *mp, *mp2; 364 char *vfsname, *devname; 365 int error; 366 char patt[32]; 367 int mountfromlen, len; 368 char *cp, *ep, *mf; 369 370 vfsname = NULL; 371 devname = NULL; 372 mp = NULL; 373 mp2 = NULL; 374 error = EINVAL; 375 376 if (mountfrom == NULL) 377 return(error); /* don't complain */ 378 379 crit_enter(); 380 kprintf("Mounting root from %s\n", mountfrom); 381 crit_exit(); 382 383 mountfromlen = strlen(mountfrom); 384 cp = (char*)mountfrom; 385 /* parse vfs name and devname */ 386 vfsname = kmalloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 387 devname = kmalloc(MNAMELEN, M_MOUNT, M_WAITOK); 388 mf = kmalloc(MFSNAMELEN+MNAMELEN, M_MOUNT, M_WAITOK); 389 for(;;) { 390 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 391 len = ep - cp; 392 bzero(vfsname, MFSNAMELEN); 393 bzero(devname, MNAMELEN); 394 bzero(mf, MFSNAMELEN+MNAMELEN); 395 strncpy(mf, cp, MFSNAMELEN+MNAMELEN); 396 397 vfsname[0] = devname[0] = 0; 398 ksprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 399 if (ksscanf(mf, patt, vfsname, devname) < 1) 400 goto end; 401 402 /* allocate a root mount */ 403 error = vfs_rootmountalloc(vfsname, 404 devname[0] != 0 ? devname : ROOTNAME, &mp); 405 if (error != 0) { 406 kprintf("Can't allocate root mount for filesystem '%s': %d\n", 407 vfsname, error); 408 goto end; 409 } 410 mp->mnt_flag |= MNT_ROOTFS; 411 412 /* do our best to set rootdev */ 413 if ((devname[0] != 0) && setrootbyname(devname)) 414 kprintf("setrootbyname failed\n"); 415 416 /* If the root device is a type "memory disk", mount RW */ 417 if (rootdev != NULL && dev_is_good(rootdev) && 418 (dev_dflags(rootdev) & D_MEMDISK)) { 419 mp->mnt_flag &= ~MNT_RDONLY; 420 } 421 422 error = VFS_MOUNT(mp, NULL, NULL, proc0.p_ucred); 423 424 if (!error) 425 break; 426 end: 427 if(*ep == 0) 428 break; 429 cp = ep + 1; 430 } 431 432 if (vfsname != NULL) 433 kfree(vfsname, M_MOUNT); 434 if (devname != NULL) 435 kfree(devname, M_MOUNT); 436 if (mf != NULL) 437 kfree(mf, M_MOUNT); 438 if (error == 0) { 439 /* register with list of mounted filesystems */ 440 mountlist_insert(mp, MNTINS_FIRST); 441 442 /* sanity check system clock against root fs timestamp */ 443 inittodr(mp->mnt_time); 444 vfs_unbusy(mp); 445 if (mp->mnt_syncer == NULL) { 446 error = vfs_allocate_syncvnode(mp); 447 if (error) 448 kprintf("Warning: no syncer vp for root!\n"); 449 error = 0; 450 } 451 } else { 452 if (mp != NULL) { 453 vfs_unbusy(mp); 454 kfree(mp, M_MOUNT); 455 } 456 kprintf("Root mount failed: %d\n", error); 457 } 458 return(error); 459 } 460 461 462 static void vfs_mountroot_ask_callback(cdev_t); 463 464 /* 465 * Spin prompting on the console for a suitable root filesystem 466 */ 467 468 static int 469 vfs_mountroot_ask(void) 470 { 471 char name[128]; 472 int llimit = 100; 473 474 kprintf("\nManual root filesystem specification:\n"); 475 kprintf(" <fstype>:<device> Specify root (e.g. ufs:da0s1a)\n"); 476 kprintf(" ? List valid disk boot devices\n"); 477 kprintf(" panic Just panic\n"); 478 kprintf(" abort Abort manual input\n"); 479 while (llimit--) { 480 kprintf("\nmountroot> "); 481 482 if (getline(name, 128) < 0) 483 break; 484 if (name[0] == 0) { 485 ; 486 } else if (name[0] == '?') { 487 kprintf("Possibly valid devices for root FS:\n"); 488 //enumerate all disk devices 489 devfs_scan_callback(vfs_mountroot_ask_callback); 490 kprintf("\n"); 491 continue; 492 } else if (strcmp(name, "panic") == 0) { 493 panic("panic from console"); 494 } else if (strcmp(name, "abort") == 0) { 495 break; 496 } else if (vfs_mountroot_try(name) == 0) { 497 return(0); 498 } 499 } 500 return(1); 501 } 502 503 504 static void 505 vfs_mountroot_ask_callback(cdev_t dev) 506 { 507 if (dev_is_good(dev) && (dev_dflags(dev) & D_DISK)) 508 kprintf(" \"%s\" ", dev->si_name); 509 } 510 511 512 static int 513 getline(char *cp, int limit) 514 { 515 char *lp; 516 int c; 517 518 lp = cp; 519 for (;;) { 520 c = cngetc(); 521 522 switch (c) { 523 case -1: 524 return(-1); 525 case '\n': 526 case '\r': 527 kprintf("\n"); 528 *lp++ = '\0'; 529 return(0); 530 case '\b': 531 case '\177': 532 if (lp > cp) { 533 kprintf("\b \b"); 534 lp--; 535 } else { 536 kprintf("%c", 7); 537 } 538 continue; 539 case '#': 540 kprintf("#"); 541 lp--; 542 if (lp < cp) 543 lp = cp; 544 continue; 545 case '@': 546 case 'u' & 037: 547 lp = cp; 548 kprintf("%c", '\n'); 549 continue; 550 default: 551 if (lp - cp >= limit - 1) { 552 kprintf("%c", 7); 553 } else { 554 kprintf("%c", c); 555 *lp++ = c; 556 } 557 continue; 558 } 559 } 560 } 561 562 /* 563 * Convert a given name to the cdev_t of the disk-like device 564 * it refers to. 565 */ 566 struct kdbn_info { 567 const char *name; 568 int nlen; 569 int minor; 570 cdev_t dev; 571 }; 572 573 574 cdev_t 575 kgetdiskbyname(const char *name) 576 { 577 char *cp; 578 cdev_t rdev; 579 580 /* 581 * Get the base name of the device 582 */ 583 if (strncmp(name, __SYS_PATH_DEV, sizeof(__SYS_PATH_DEV) - 1) == 0) 584 name += sizeof(__SYS_PATH_DEV) - 1; 585 cp = __DECONST(char *, name); 586 587 /* 588 * Locate the device 589 */ 590 kprintf("tryroot %s\n", name); 591 rdev = devfs_find_device_by_name(name); 592 if (rdev == NULL) { 593 kprintf("no disk named '%s'\n", name); 594 } 595 /* 596 * FOUND DEVICE 597 */ 598 return(rdev); 599 } 600 601 /* 602 * Set rootdev to match (name), given that we expect it to 603 * refer to a disk-like device. 604 */ 605 static int 606 setrootbyname(char *name) 607 { 608 cdev_t diskdev; 609 610 diskdev = kgetdiskbyname(name); 611 if (diskdev != NULL) { 612 rootdev = diskdev; 613 return (0); 614 } 615 /* set to NULL if kgetdiskbyname() fails so that if the first rootdev is 616 * found by fails to mount and the second one isn't found, mountroot_try 617 * doesn't try again with the first one 618 */ 619 rootdev = NULL; 620 return (1); 621 } 622 623 #ifdef DDB 624 DB_SHOW_COMMAND(disk, db_getdiskbyname) 625 { 626 cdev_t dev; 627 628 if (modif[0] == '\0') { 629 db_error("usage: show disk/devicename"); 630 return; 631 } 632 dev = kgetdiskbyname(modif); 633 if (dev != NULL) 634 db_printf("cdev_t = %p\n", dev); 635 else 636 db_printf("No disk device matched.\n"); 637 } 638 #endif 639