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 * $FreeBSD$ 29 */ 30 31 /* 32 * Locate and mount the root filesystem. 33 * 34 * The root filesystem is detailed in the kernel environment variable 35 * vfs.root.mountfrom, which is expected to be in the general format 36 * 37 * <vfsname>:[<path>] 38 * vfsname := the name of a VFS known to the kernel and capable 39 * of being mounted as root 40 * path := disk device name or other data used by the filesystem 41 * to locate its physical store 42 * 43 */ 44 45 #include <sys/param.h> 46 #include <sys/kernel.h> 47 #include <sys/systm.h> 48 #include <sys/proc.h> 49 #include <sys/vnode.h> 50 #include <sys/mount.h> 51 #include <sys/malloc.h> 52 #include <sys/reboot.h> 53 #include <sys/diskslice.h> 54 #include <sys/disklabel.h> 55 #include <sys/conf.h> 56 #include <sys/cons.h> 57 58 #include "opt_ddb.h" 59 #ifdef DDB 60 #include <ddb/ddb.h> 61 #endif 62 63 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 64 65 #define ROOTNAME "root_device" 66 67 struct vnode *rootvnode; 68 69 /* 70 * The root specifiers we will try if RB_CDROM is specified. 71 */ 72 static char *cdrom_rootdevnames[] = { 73 "cd9660:cd0a", 74 "cd9660:acd0a", 75 "cd9660:wcd0a", 76 NULL 77 }; 78 79 static void vfs_mountroot(void *junk); 80 static int vfs_mountroot_try(char *mountfrom); 81 static int vfs_mountroot_ask(void); 82 static void gets(char *cp); 83 84 /* legacy find-root code */ 85 char *rootdevnames[2] = {NULL, NULL}; 86 static int setrootbyname(char *name); 87 88 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL); 89 90 /* 91 * Find and mount the root filesystem 92 */ 93 static void 94 vfs_mountroot(void *junk) 95 { 96 int i; 97 98 /* 99 * The root filesystem information is compiled in, and we are 100 * booted with instructions to use it. 101 */ 102 #ifdef ROOTDEVNAME 103 if ((boothowto & RB_DFLTROOT) && 104 !vfs_mountroot_try(ROOTDEVNAME)) 105 return; 106 #endif 107 /* 108 * We are booted with instructions to prompt for the root filesystem, 109 * or to use the compiled-in default when it doesn't exist. 110 */ 111 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) { 112 if (!vfs_mountroot_ask()) 113 return; 114 } 115 116 /* 117 * We've been given the generic "use CDROM as root" flag. This is 118 * necessary because one media may be used in many different 119 * devices, so we need to search for them. 120 */ 121 if (boothowto & RB_CDROM) { 122 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 123 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 124 return; 125 } 126 } 127 128 /* 129 * Try to use the value read by the loader from /etc/fstab, or 130 * supplied via some other means. This is the preferred 131 * mechanism. 132 */ 133 if (!vfs_mountroot_try(getenv("vfs.root.mountfrom"))) 134 return; 135 136 /* 137 * Try values that may have been computed by the machine-dependant 138 * legacy code. 139 */ 140 if (!vfs_mountroot_try(rootdevnames[0])) 141 return; 142 if (!vfs_mountroot_try(rootdevnames[1])) 143 return; 144 145 /* 146 * If we have a compiled-in default, and haven't already tried it, try 147 * it now. 148 */ 149 #ifdef ROOTDEVNAME 150 if (!(boothowto & RB_DFLTROOT)) 151 if (!vfs_mountroot_try(ROOTDEVNAME)) 152 return; 153 #endif 154 155 /* 156 * Everything so far has failed, prompt on the console if we haven't 157 * already tried that. 158 */ 159 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask()) 160 return; 161 panic("Root mount failed, startup aborted."); 162 } 163 164 /* 165 * Mount (mountfrom) as the root filesystem. 166 */ 167 static int 168 vfs_mountroot_try(char *mountfrom) 169 { 170 struct mount *mp; 171 char *vfsname, *path; 172 int error; 173 char patt[32]; 174 int s; 175 176 vfsname = NULL; 177 path = NULL; 178 mp = NULL; 179 error = EINVAL; 180 181 if (mountfrom == NULL) 182 return(error); /* don't complain */ 183 184 s = splcam(); /* Overkill, but annoying without it */ 185 printf("Mounting root from %s\n", mountfrom); 186 splx(s); 187 188 /* parse vfs name and path */ 189 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 190 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 191 vfsname[0] = path[0] = 0; 192 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 193 if (sscanf(mountfrom, patt, vfsname, path) < 1) 194 goto done; 195 196 /* allocate a root mount */ 197 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME, 198 &mp); 199 if (error != 0) { 200 printf("Can't allocate root mount for filesystem '%s': %d\n", 201 vfsname, error); 202 goto done; 203 } 204 mp->mnt_flag |= MNT_ROOTFS; 205 206 /* do our best to set rootdev */ 207 if ((path[0] != 0) && setrootbyname(path)) 208 printf("setrootbyname failed\n"); 209 210 /* If the root device is a type "memory disk", mount RW */ 211 if (rootdev != NODEV && devsw(rootdev) && 212 (devsw(rootdev)->d_flags & D_MEMDISK)) 213 mp->mnt_flag &= ~MNT_RDONLY; 214 215 error = VFS_MOUNT(mp, NULL, NULL, NULL, curproc); 216 217 done: 218 if (vfsname != NULL) 219 free(vfsname, M_MOUNT); 220 if (path != NULL) 221 free(path, M_MOUNT); 222 if (error != 0) { 223 if (mp != NULL) { 224 vfs_unbusy(mp, curproc); 225 free(mp, M_MOUNT); 226 } 227 printf("Root mount failed: %d\n", error); 228 } else { 229 230 /* register with list of mounted filesystems */ 231 simple_lock(&mountlist_slock); 232 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 233 simple_unlock(&mountlist_slock); 234 235 /* sanity check system clock against root filesystem timestamp */ 236 inittodr(mp->mnt_time); 237 vfs_unbusy(mp, curproc); 238 } 239 return(error); 240 } 241 242 /* 243 * Spin prompting on the console for a suitable root filesystem 244 */ 245 static int 246 vfs_mountroot_ask(void) 247 { 248 char name[128]; 249 int i; 250 dev_t dev; 251 252 for(;;) { 253 printf("\nManual root filesystem specification:\n"); 254 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 255 printf(" eg. ufs:/dev/da0s1a\n"); 256 printf(" ? List valid disk boot devices\n"); 257 printf(" <empty line> Abort manual input\n"); 258 printf("\nmountroot> "); 259 gets(name); 260 if (name[0] == 0) 261 return(1); 262 if (name[0] == '?') { 263 printf("Possibly valid devices for 'ufs' root:\n"); 264 for (i = 0; i < NUMCDEVSW; i++) { 265 dev = makedev(i, 0); 266 if (devsw(dev) != NULL) 267 printf(" \"%s\"", devsw(dev)->d_name); 268 } 269 printf("\n"); 270 continue; 271 } 272 if (!vfs_mountroot_try(name)) 273 return(0); 274 } 275 } 276 277 static void 278 gets(char *cp) 279 { 280 char *lp; 281 int c; 282 283 lp = cp; 284 for (;;) { 285 printf("%c", c = cngetc() & 0177); 286 switch (c) { 287 case -1: 288 case '\n': 289 case '\r': 290 *lp++ = '\0'; 291 return; 292 case '\b': 293 case '\177': 294 if (lp > cp) { 295 printf(" \b"); 296 lp--; 297 } 298 continue; 299 case '#': 300 lp--; 301 if (lp < cp) 302 lp = cp; 303 continue; 304 case '@': 305 case 'u' & 037: 306 lp = cp; 307 printf("%c", '\n'); 308 continue; 309 default: 310 *lp++ = c; 311 } 312 } 313 } 314 315 /* 316 * Convert a given name to the dev_t of the disk-like device 317 * it refers to. 318 */ 319 dev_t 320 getdiskbyname(char *name) { 321 char *cp; 322 int cd, unit, slice, part; 323 dev_t dev; 324 325 slice = 0; 326 part = 0; 327 cp = rindex(name, '/'); 328 if (cp != NULL) { 329 name = cp + 1; 330 } 331 cp = name; 332 while (cp != '\0' && (*cp < '0' || *cp > '9')) 333 cp++; 334 if (cp == name) { 335 printf("missing device name\n"); 336 return (NODEV); 337 } 338 if (*cp == '\0') { 339 printf("missing unit number\n"); 340 return (NODEV); 341 } 342 unit = *cp - '0'; 343 *cp++ = '\0'; 344 for (cd = 0; cd < NUMCDEVSW; cd++) { 345 dev = makedev(cd, 0); 346 if (devsw(dev) != NULL && 347 strcmp(devsw(dev)->d_name, name) == 0) 348 goto gotit; 349 } 350 printf("no such device '%s'\n", name); 351 return (NODEV); 352 gotit: 353 while (*cp >= '0' && *cp <= '9') 354 unit += 10 * unit + *cp++ - '0'; 355 if (*cp == 's' && cp[1] >= '0' && cp[1] <= '9') { 356 slice = cp[1] - '0' + 1; 357 cp += 2; 358 } 359 if (*cp >= 'a' && *cp <= 'h') { 360 part = *cp - 'a'; 361 cp++; 362 } 363 if (*cp != '\0') { 364 printf("junk after name\n"); 365 return (NODEV); 366 } 367 return (makedev(cd, dkmakeminor(unit, slice, part))); 368 } 369 370 /* 371 * Set rootdev to match (name), given that we expect it to 372 * refer to a disk-like device. 373 */ 374 static int 375 setrootbyname(char *name) 376 { 377 dev_t diskdev; 378 379 diskdev = getdiskbyname(name); 380 if (diskdev != NODEV) { 381 rootdev = diskdev; 382 return (0); 383 } 384 385 return (1); 386 } 387 388 #ifdef DDB 389 DB_SHOW_COMMAND(disk, db_getdiskbyname) 390 { 391 dev_t dev; 392 393 if (modif[0] == '\0') { 394 db_error("usage: show disk/devicename"); 395 return; 396 } 397 dev = getdiskbyname(modif); 398 if (dev != NODEV) 399 db_printf("dev_t = %p\n", dev); 400 else 401 db_printf("No disk device matched.\n"); 402 } 403 #endif 404