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 1.6 2003/08/07 21:17:23 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/paths.h> 62 63 #include "opt_ddb.h" 64 #ifdef DDB 65 #include <ddb/ddb.h> 66 #endif 67 68 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 69 70 #define ROOTNAME "root_device" 71 72 struct vnode *rootvnode; 73 74 /* 75 * The root specifiers we will try if RB_CDROM is specified. 76 */ 77 static char *cdrom_rootdevnames[] = { 78 "cd9660:cd0a", 79 "cd9660:acd0a", 80 "cd9660:wcd0a", 81 NULL 82 }; 83 84 static void vfs_mountroot(void *junk); 85 static int vfs_mountroot_try(char *mountfrom); 86 static int vfs_mountroot_ask(void); 87 static void gets(char *cp); 88 89 /* legacy find-root code */ 90 char *rootdevnames[2] = {NULL, NULL}; 91 static int setrootbyname(char *name); 92 93 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL); 94 95 /* 96 * Find and mount the root filesystem 97 */ 98 static void 99 vfs_mountroot(void *junk) 100 { 101 int i; 102 103 /* 104 * The root filesystem information is compiled in, and we are 105 * booted with instructions to use it. 106 */ 107 #ifdef ROOTDEVNAME 108 if ((boothowto & RB_DFLTROOT) && 109 !vfs_mountroot_try(ROOTDEVNAME)) 110 return; 111 #endif 112 /* 113 * We are booted with instructions to prompt for the root filesystem, 114 * or to use the compiled-in default when it doesn't exist. 115 */ 116 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) { 117 if (!vfs_mountroot_ask()) 118 return; 119 } 120 121 /* 122 * We've been given the generic "use CDROM as root" flag. This is 123 * necessary because one media may be used in many different 124 * devices, so we need to search for them. 125 */ 126 if (boothowto & RB_CDROM) { 127 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 128 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 129 return; 130 } 131 } 132 133 /* 134 * Try to use the value read by the loader from /etc/fstab, or 135 * supplied via some other means. This is the preferred 136 * mechanism. 137 */ 138 if (!vfs_mountroot_try(getenv("vfs.root.mountfrom"))) 139 return; 140 141 /* 142 * Try values that may have been computed by the machine-dependant 143 * legacy code. 144 */ 145 if (!vfs_mountroot_try(rootdevnames[0])) 146 return; 147 if (!vfs_mountroot_try(rootdevnames[1])) 148 return; 149 150 /* 151 * If we have a compiled-in default, and haven't already tried it, try 152 * it now. 153 */ 154 #ifdef ROOTDEVNAME 155 if (!(boothowto & RB_DFLTROOT)) 156 if (!vfs_mountroot_try(ROOTDEVNAME)) 157 return; 158 #endif 159 160 /* 161 * Everything so far has failed, prompt on the console if we haven't 162 * already tried that. 163 */ 164 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask()) 165 return; 166 panic("Root mount failed, startup aborted."); 167 } 168 169 /* 170 * Mount (mountfrom) as the root filesystem. 171 */ 172 static int 173 vfs_mountroot_try(char *mountfrom) 174 { 175 struct thread *td = curthread; 176 struct mount *mp; 177 char *vfsname, *path; 178 int error; 179 char patt[32]; 180 int s; 181 182 vfsname = NULL; 183 path = NULL; 184 mp = NULL; 185 error = EINVAL; 186 187 if (mountfrom == NULL) 188 return(error); /* don't complain */ 189 190 s = splcam(); /* Overkill, but annoying without it */ 191 printf("Mounting root from %s\n", mountfrom); 192 splx(s); 193 194 /* parse vfs name and path */ 195 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 196 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 197 vfsname[0] = path[0] = 0; 198 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 199 if (sscanf(mountfrom, patt, vfsname, path) < 1) 200 goto done; 201 202 /* allocate a root mount */ 203 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME, 204 &mp); 205 if (error != 0) { 206 printf("Can't allocate root mount for filesystem '%s': %d\n", 207 vfsname, error); 208 goto done; 209 } 210 mp->mnt_flag |= MNT_ROOTFS; 211 212 /* do our best to set rootdev */ 213 if ((path[0] != 0) && setrootbyname(path)) 214 printf("setrootbyname failed\n"); 215 216 /* If the root device is a type "memory disk", mount RW */ 217 if (rootdev != NODEV && dev_dport(rootdev) && 218 (dev_dflags(rootdev) & D_MEMDISK)) { 219 mp->mnt_flag &= ~MNT_RDONLY; 220 } 221 222 error = VFS_MOUNT(mp, NULL, NULL, NULL, td); 223 224 done: 225 if (vfsname != NULL) 226 free(vfsname, M_MOUNT); 227 if (path != NULL) 228 free(path, M_MOUNT); 229 if (error != 0) { 230 if (mp != NULL) { 231 vfs_unbusy(mp, td); 232 free(mp, M_MOUNT); 233 } 234 printf("Root mount failed: %d\n", error); 235 } else { 236 237 /* register with list of mounted filesystems */ 238 lwkt_gettoken(&mountlist_token); 239 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 240 lwkt_reltoken(&mountlist_token); 241 242 /* sanity check system clock against root fs timestamp */ 243 inittodr(mp->mnt_time); 244 vfs_unbusy(mp, td); 245 } 246 return(error); 247 } 248 249 /* 250 * Spin prompting on the console for a suitable root filesystem 251 */ 252 static int 253 vfs_mountroot_ask(void) 254 { 255 char name[128]; 256 int i; 257 dev_t dev; 258 259 for(;;) { 260 printf("\nManual root filesystem specification:\n"); 261 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 262 printf(" eg. ufs:%sda0s1a\n", __SYS_PATH_DEV); 263 printf(" ? List valid disk boot devices\n"); 264 printf(" <empty line> Abort manual input\n"); 265 printf("\nmountroot> "); 266 gets(name); 267 if (name[0] == 0) 268 return(1); 269 if (name[0] == '?') { 270 printf("Possibly valid devices for 'ufs' root:\n"); 271 for (i = 0; i < NUMCDEVSW; i++) { 272 dev = makedev(i, 0); 273 if (dev_dport(dev) != NULL) 274 printf(" \"%s\"", dev_dname(dev)); 275 } 276 printf("\n"); 277 continue; 278 } 279 if (!vfs_mountroot_try(name)) 280 return(0); 281 } 282 } 283 284 static void 285 gets(char *cp) 286 { 287 char *lp; 288 int c; 289 290 lp = cp; 291 for (;;) { 292 printf("%c", c = cngetc() & 0177); 293 switch (c) { 294 case -1: 295 case '\n': 296 case '\r': 297 *lp++ = '\0'; 298 return; 299 case '\b': 300 case '\177': 301 if (lp > cp) { 302 printf(" \b"); 303 lp--; 304 } 305 continue; 306 case '#': 307 lp--; 308 if (lp < cp) 309 lp = cp; 310 continue; 311 case '@': 312 case 'u' & 037: 313 lp = cp; 314 printf("%c", '\n'); 315 continue; 316 default: 317 *lp++ = c; 318 } 319 } 320 } 321 322 /* 323 * Convert a given name to the dev_t of the disk-like device 324 * it refers to. 325 */ 326 dev_t 327 getdiskbyname(char *name) { 328 char *cp; 329 int cd, unit, slice, part; 330 dev_t dev; 331 332 slice = 0; 333 part = 0; 334 if (strncmp(name, __SYS_PATH_DEV, sizeof(__SYS_PATH_DEV) - 1) == 0) 335 name += sizeof(__SYS_PATH_DEV) - 1; 336 cp = name; 337 while (*cp != '\0' && (*cp < '0' || *cp > '9') && *cp != '/') 338 cp++; 339 if (cp == name) { 340 printf("missing device name\n"); 341 return (NODEV); 342 } 343 if (*cp == '\0' || *cp == '/') 344 unit = -1; 345 else 346 unit = *cp - '0'; 347 *cp++ = '\0'; 348 for (cd = 0; cd < NUMCDEVSW; cd++) { 349 dev = makedev(cd, 0); 350 if (dev_dport(dev) != NULL && 351 strcmp(dev_dname(dev), name) == 0) 352 goto gotit; 353 } 354 printf("no such device '%s'\n", name); 355 return (NODEV); 356 gotit: 357 if (dev_dmaj(dev) == major(rootdev)) 358 /* driver has already configured rootdev, e. g. vinum */ 359 return (rootdev); 360 if (unit == -1) { 361 printf("missing unit number\n"); 362 return (NODEV); 363 } 364 while (*cp >= '0' && *cp <= '9') 365 unit = 10 * unit + *cp++ - '0'; 366 if (*cp == 's' && cp[1] >= '0' && cp[1] <= '9') { 367 slice = cp[1] - '0' + 1; 368 cp += 2; 369 } 370 if (*cp >= 'a' && *cp <= 'h') { 371 part = *cp - 'a'; 372 cp++; 373 } 374 if (*cp != '\0') { 375 printf("junk after name\n"); 376 return (NODEV); 377 } 378 return (makedev(cd, dkmakeminor(unit, slice, part))); 379 } 380 381 /* 382 * Set rootdev to match (name), given that we expect it to 383 * refer to a disk-like device. 384 */ 385 static int 386 setrootbyname(char *name) 387 { 388 dev_t diskdev; 389 390 diskdev = getdiskbyname(name); 391 if (diskdev != NODEV) { 392 rootdev = diskdev; 393 return (0); 394 } 395 396 return (1); 397 } 398 399 #ifdef DDB 400 DB_SHOW_COMMAND(disk, db_getdiskbyname) 401 { 402 dev_t dev; 403 404 if (modif[0] == '\0') { 405 db_error("usage: show disk/devicename"); 406 return; 407 } 408 dev = getdiskbyname(modif); 409 if (dev != NODEV) 410 db_printf("dev_t = %p\n", dev); 411 else 412 db_printf("No disk device matched.\n"); 413 } 414 #endif 415