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 1.16 2006/05/06 18:48:52 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/disklabel.h> 58 #include <sys/conf.h> 59 #include <sys/cons.h> 60 #include <sys/device.h> 61 #include <sys/namecache.h> 62 #include <sys/paths.h> 63 #include <sys/thread2.h> 64 65 #include "opt_ddb.h" 66 #ifdef DDB 67 #include <ddb/ddb.h> 68 #endif 69 70 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 71 72 #define ROOTNAME "root_device" 73 74 struct vnode *rootvnode; 75 struct namecache *rootncp; 76 77 /* 78 * The root specifiers we will try if RB_CDROM is specified. Note that 79 * the ATA driver will accept acd*a and acd*c, but the SCSI driver 80 * will only accept cd*c, so use 'c'. 81 */ 82 static char *cdrom_rootdevnames[] = { 83 "cd9660:cd0c", 84 "cd9660:acd0c", 85 "cd9660:cd1c", 86 "cd9660:acd1c", 87 NULL 88 }; 89 90 static void vfs_mountroot(void *junk); 91 static int vfs_mountroot_try(const char *mountfrom); 92 static int vfs_mountroot_ask(void); 93 static void gets(char *cp); 94 95 /* legacy find-root code */ 96 char *rootdevnames[2] = {NULL, NULL}; 97 static int setrootbyname(char *name); 98 99 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL); 100 101 /* 102 * Find and mount the root filesystem 103 */ 104 static void 105 vfs_mountroot(void *junk) 106 { 107 int i; 108 dev_t save_rootdev = rootdev; 109 110 /* 111 * The root filesystem information is compiled in, and we are 112 * booted with instructions to use it. 113 */ 114 #ifdef ROOTDEVNAME 115 if ((boothowto & RB_DFLTROOT) && 116 !vfs_mountroot_try(ROOTDEVNAME)) 117 return; 118 #endif 119 /* 120 * We are booted with instructions to prompt for the root filesystem, 121 * or to use the compiled-in default when it doesn't exist. 122 */ 123 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) { 124 if (!vfs_mountroot_ask()) 125 return; 126 } 127 128 /* 129 * We've been given the generic "use CDROM as root" flag. This is 130 * necessary because one media may be used in many different 131 * devices, so we need to search for them. 132 */ 133 if (boothowto & RB_CDROM) { 134 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 135 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 136 return; 137 } 138 } 139 140 /* 141 * Try to use the value read by the loader from /etc/fstab, or 142 * supplied via some other means. This is the preferred 143 * mechanism. 144 */ 145 if (!vfs_mountroot_try(getenv("vfs.root.mountfrom"))) 146 return; 147 148 /* 149 * If a vfs set rootdev, try it (XXX VINUM HACK!) 150 */ 151 if (save_rootdev != NODEV) { 152 rootdev = save_rootdev; 153 if (!vfs_mountroot_try("")) 154 return; 155 } 156 157 /* 158 * Try values that may have been computed by the machine-dependant 159 * legacy code. 160 */ 161 if (rootdevnames[0] && !vfs_mountroot_try(rootdevnames[0])) 162 return; 163 if (rootdevnames[1] && !vfs_mountroot_try(rootdevnames[1])) 164 return; 165 166 /* 167 * If we have a compiled-in default, and haven't already tried it, try 168 * it now. 169 */ 170 #ifdef ROOTDEVNAME 171 if (!(boothowto & RB_DFLTROOT)) 172 if (!vfs_mountroot_try(ROOTDEVNAME)) 173 return; 174 #endif 175 176 /* 177 * Everything so far has failed, prompt on the console if we haven't 178 * already tried that. 179 */ 180 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask()) 181 return; 182 panic("Root mount failed, startup aborted."); 183 } 184 185 /* 186 * Mount (mountfrom) as the root filesystem. 187 */ 188 static int 189 vfs_mountroot_try(const char *mountfrom) 190 { 191 struct mount *mp; 192 char *vfsname, *devname; 193 int error; 194 char patt[32]; 195 196 vfsname = NULL; 197 devname = NULL; 198 mp = NULL; 199 error = EINVAL; 200 201 if (mountfrom == NULL) 202 return(error); /* don't complain */ 203 204 crit_enter(); 205 printf("Mounting root from %s\n", mountfrom); 206 crit_exit(); 207 208 /* parse vfs name and devname */ 209 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 210 devname = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 211 vfsname[0] = devname[0] = 0; 212 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 213 if (sscanf(mountfrom, patt, vfsname, devname) < 1) 214 goto done; 215 216 /* allocate a root mount */ 217 error = vfs_rootmountalloc(vfsname, 218 devname[0] != 0 ? devname : ROOTNAME, &mp); 219 if (error != 0) { 220 printf("Can't allocate root mount for filesystem '%s': %d\n", 221 vfsname, error); 222 goto done; 223 } 224 mp->mnt_flag |= MNT_ROOTFS; 225 226 /* do our best to set rootdev */ 227 if ((devname[0] != 0) && setrootbyname(devname)) 228 printf("setrootbyname failed\n"); 229 230 /* If the root device is a type "memory disk", mount RW */ 231 if (rootdev != NODEV && dev_is_good(rootdev) && 232 (dev_dflags(rootdev) & D_MEMDISK)) { 233 mp->mnt_flag &= ~MNT_RDONLY; 234 } 235 236 error = VFS_MOUNT(mp, NULL, NULL, proc0.p_ucred); 237 238 done: 239 if (vfsname != NULL) 240 free(vfsname, M_MOUNT); 241 if (devname != NULL) 242 free(devname, M_MOUNT); 243 if (error != 0) { 244 if (mp != NULL) { 245 vfs_unbusy(mp); 246 free(mp, M_MOUNT); 247 } 248 printf("Root mount failed: %d\n", error); 249 } else { 250 /* register with list of mounted filesystems */ 251 mountlist_insert(mp, MNTINS_FIRST); 252 253 /* sanity check system clock against root fs timestamp */ 254 inittodr(mp->mnt_time); 255 vfs_unbusy(mp); 256 } 257 return(error); 258 } 259 260 /* 261 * Spin prompting on the console for a suitable root filesystem 262 */ 263 static int 264 vfs_mountroot_ask(void) 265 { 266 char name[128]; 267 int i; 268 dev_t dev; 269 270 for(;;) { 271 printf("\nManual root filesystem specification:\n"); 272 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 273 printf(" eg. ufs:da0s1a\n"); 274 printf(" ? List valid disk boot devices\n"); 275 printf(" <empty line> Abort manual input\n"); 276 printf("\nmountroot> "); 277 gets(name); 278 if (name[0] == 0) 279 return(1); 280 if (name[0] == '?') { 281 printf("Possibly valid devices for 'ufs' root:\n"); 282 for (i = 0; i < NUMCDEVSW; i++) { 283 dev = udev2dev(makeudev(i, 0), 0); 284 if (dev_is_good(dev)) 285 printf(" \"%s\"", dev_dname(dev)); 286 } 287 printf("\n"); 288 continue; 289 } 290 if (!vfs_mountroot_try(name)) 291 return(0); 292 } 293 } 294 295 static void 296 gets(char *cp) 297 { 298 char *lp; 299 int c; 300 301 lp = cp; 302 for (;;) { 303 printf("%c", c = cngetc() & 0177); 304 switch (c) { 305 case -1: 306 case '\n': 307 case '\r': 308 *lp++ = '\0'; 309 return; 310 case '\b': 311 case '\177': 312 if (lp > cp) { 313 printf(" \b"); 314 lp--; 315 } 316 continue; 317 case '#': 318 lp--; 319 if (lp < cp) 320 lp = cp; 321 continue; 322 case '@': 323 case 'u' & 037: 324 lp = cp; 325 printf("%c", '\n'); 326 continue; 327 default: 328 *lp++ = c; 329 } 330 } 331 } 332 333 /* 334 * Convert a given name to the dev_t of the disk-like device 335 * it refers to. 336 */ 337 dev_t 338 getdiskbyname(const char *name) 339 { 340 char *cp; 341 int nlen; 342 int cd, unit, slice, part; 343 dev_t dev; 344 dev_t rdev; 345 346 /* 347 * Get the base name of the device 348 */ 349 if (strncmp(name, __SYS_PATH_DEV, sizeof(__SYS_PATH_DEV) - 1) == 0) 350 name += sizeof(__SYS_PATH_DEV) - 1; 351 cp = __DECONST(char *, name); 352 while (*cp == '/') 353 ++cp; 354 while (*cp >= 'a' && *cp <= 'z') 355 ++cp; 356 if (cp == name) { 357 printf("missing device name\n"); 358 return (NODEV); 359 } 360 nlen = cp - name; 361 362 /* 363 * Get the unit. 364 */ 365 unit = strtol(cp, &cp, 10); 366 if (name + nlen == (const char *)cp || unit < 0 || unit > DKMAXUNIT) { 367 printf("bad unit: %d\n", unit); 368 return (NODEV); 369 } 370 371 /* 372 * Get the slice. Note that if no partition or partition 'a' is 373 * specified, and no slice is specified, we will try both 'ad0a' 374 * (which is what you get when slice is 0), and also 'ad0' (the 375 * whole-disk partition, slice == 1). 376 */ 377 if (*cp == 's') { 378 slice = cp[1] - '0'; 379 if (slice < 1 || slice > 9) { 380 printf("bad slice number\n"); 381 return(NODEV); 382 } 383 ++slice; /* slice #1 starts at 2 */ 384 cp += 2; 385 } else { 386 slice = 0; 387 } 388 389 /* 390 * Get the partition. 391 */ 392 if (*cp >= 'a' && *cp <= 'p') { 393 part = *cp - 'a'; 394 ++cp; 395 } else { 396 part = 0; 397 } 398 399 if (*cp != '\0') { 400 printf("junk after name\n"); 401 return (NODEV); 402 } 403 404 /* 405 * Locate the device 406 */ 407 for (cd = 0; cd < NUMCDEVSW; cd++) { 408 const char *dname; 409 410 dev = udev2dev(makeudev(cd, dkmakeminor(unit, slice, part)), 0); 411 if (dev_is_good(dev) && (dname = dev_dname(dev)) != NULL) { 412 if (strlen(dname) == nlen && 413 strncmp(dname, name, nlen) == 0) { 414 break; 415 } 416 } 417 } 418 if (cd == NUMCDEVSW) { 419 printf("no such device '%*.*s'\n", nlen, nlen, name); 420 return (NODEV); 421 } 422 423 /* 424 * FOUND DEVICE 425 */ 426 rdev = make_sub_dev(dev, dkmakeminor(unit, slice, part)); 427 return(rdev); 428 } 429 430 /* 431 * Set rootdev to match (name), given that we expect it to 432 * refer to a disk-like device. 433 */ 434 static int 435 setrootbyname(char *name) 436 { 437 dev_t diskdev; 438 439 diskdev = getdiskbyname(name); 440 if (diskdev != NODEV) { 441 rootdev = diskdev; 442 return (0); 443 } 444 445 return (1); 446 } 447 448 #ifdef DDB 449 DB_SHOW_COMMAND(disk, db_getdiskbyname) 450 { 451 dev_t dev; 452 453 if (modif[0] == '\0') { 454 db_error("usage: show disk/devicename"); 455 return; 456 } 457 dev = getdiskbyname(modif); 458 if (dev != NODEV) 459 db_printf("dev_t = %p\n", dev); 460 else 461 db_printf("No disk device matched.\n"); 462 } 463 #endif 464