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 1.2 2003/06/17 04:28:42 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 <paths.h> 61 62 #include "opt_ddb.h" 63 #ifdef DDB 64 #include <ddb/ddb.h> 65 #endif 66 67 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 68 69 #define ROOTNAME "root_device" 70 71 struct vnode *rootvnode; 72 73 /* 74 * The root specifiers we will try if RB_CDROM is specified. 75 */ 76 static char *cdrom_rootdevnames[] = { 77 "cd9660:cd0a", 78 "cd9660:acd0a", 79 "cd9660:wcd0a", 80 NULL 81 }; 82 83 static void vfs_mountroot(void *junk); 84 static int vfs_mountroot_try(char *mountfrom); 85 static int vfs_mountroot_ask(void); 86 static void gets(char *cp); 87 88 /* legacy find-root code */ 89 char *rootdevnames[2] = {NULL, NULL}; 90 static int setrootbyname(char *name); 91 92 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL); 93 94 /* 95 * Find and mount the root filesystem 96 */ 97 static void 98 vfs_mountroot(void *junk) 99 { 100 int i; 101 102 /* 103 * The root filesystem information is compiled in, and we are 104 * booted with instructions to use it. 105 */ 106 #ifdef ROOTDEVNAME 107 if ((boothowto & RB_DFLTROOT) && 108 !vfs_mountroot_try(ROOTDEVNAME)) 109 return; 110 #endif 111 /* 112 * We are booted with instructions to prompt for the root filesystem, 113 * or to use the compiled-in default when it doesn't exist. 114 */ 115 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) { 116 if (!vfs_mountroot_ask()) 117 return; 118 } 119 120 /* 121 * We've been given the generic "use CDROM as root" flag. This is 122 * necessary because one media may be used in many different 123 * devices, so we need to search for them. 124 */ 125 if (boothowto & RB_CDROM) { 126 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 127 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 128 return; 129 } 130 } 131 132 /* 133 * Try to use the value read by the loader from /etc/fstab, or 134 * supplied via some other means. This is the preferred 135 * mechanism. 136 */ 137 if (!vfs_mountroot_try(getenv("vfs.root.mountfrom"))) 138 return; 139 140 /* 141 * Try values that may have been computed by the machine-dependant 142 * legacy code. 143 */ 144 if (!vfs_mountroot_try(rootdevnames[0])) 145 return; 146 if (!vfs_mountroot_try(rootdevnames[1])) 147 return; 148 149 /* 150 * If we have a compiled-in default, and haven't already tried it, try 151 * it now. 152 */ 153 #ifdef ROOTDEVNAME 154 if (!(boothowto & RB_DFLTROOT)) 155 if (!vfs_mountroot_try(ROOTDEVNAME)) 156 return; 157 #endif 158 159 /* 160 * Everything so far has failed, prompt on the console if we haven't 161 * already tried that. 162 */ 163 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask()) 164 return; 165 panic("Root mount failed, startup aborted."); 166 } 167 168 /* 169 * Mount (mountfrom) as the root filesystem. 170 */ 171 static int 172 vfs_mountroot_try(char *mountfrom) 173 { 174 struct mount *mp; 175 char *vfsname, *path; 176 int error; 177 char patt[32]; 178 int s; 179 180 vfsname = NULL; 181 path = NULL; 182 mp = NULL; 183 error = EINVAL; 184 185 if (mountfrom == NULL) 186 return(error); /* don't complain */ 187 188 s = splcam(); /* Overkill, but annoying without it */ 189 printf("Mounting root from %s\n", mountfrom); 190 splx(s); 191 192 /* parse vfs name and path */ 193 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 194 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 195 vfsname[0] = path[0] = 0; 196 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 197 if (sscanf(mountfrom, patt, vfsname, path) < 1) 198 goto done; 199 200 /* allocate a root mount */ 201 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME, 202 &mp); 203 if (error != 0) { 204 printf("Can't allocate root mount for filesystem '%s': %d\n", 205 vfsname, error); 206 goto done; 207 } 208 mp->mnt_flag |= MNT_ROOTFS; 209 210 /* do our best to set rootdev */ 211 if ((path[0] != 0) && setrootbyname(path)) 212 printf("setrootbyname failed\n"); 213 214 /* If the root device is a type "memory disk", mount RW */ 215 if (rootdev != NODEV && devsw(rootdev) && 216 (devsw(rootdev)->d_flags & D_MEMDISK)) 217 mp->mnt_flag &= ~MNT_RDONLY; 218 219 error = VFS_MOUNT(mp, NULL, NULL, NULL, curproc); 220 221 done: 222 if (vfsname != NULL) 223 free(vfsname, M_MOUNT); 224 if (path != NULL) 225 free(path, M_MOUNT); 226 if (error != 0) { 227 if (mp != NULL) { 228 vfs_unbusy(mp, curproc); 229 free(mp, M_MOUNT); 230 } 231 printf("Root mount failed: %d\n", error); 232 } else { 233 234 /* register with list of mounted filesystems */ 235 simple_lock(&mountlist_slock); 236 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 237 simple_unlock(&mountlist_slock); 238 239 /* sanity check system clock against root filesystem timestamp */ 240 inittodr(mp->mnt_time); 241 vfs_unbusy(mp, curproc); 242 } 243 return(error); 244 } 245 246 /* 247 * Spin prompting on the console for a suitable root filesystem 248 */ 249 static int 250 vfs_mountroot_ask(void) 251 { 252 char name[128]; 253 int i; 254 dev_t dev; 255 256 for(;;) { 257 printf("\nManual root filesystem specification:\n"); 258 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 259 printf(" eg. ufs:%sda0s1a\n", _PATH_DEV); 260 printf(" ? List valid disk boot devices\n"); 261 printf(" <empty line> Abort manual input\n"); 262 printf("\nmountroot> "); 263 gets(name); 264 if (name[0] == 0) 265 return(1); 266 if (name[0] == '?') { 267 printf("Possibly valid devices for 'ufs' root:\n"); 268 for (i = 0; i < NUMCDEVSW; i++) { 269 dev = makedev(i, 0); 270 if (devsw(dev) != NULL) 271 printf(" \"%s\"", devsw(dev)->d_name); 272 } 273 printf("\n"); 274 continue; 275 } 276 if (!vfs_mountroot_try(name)) 277 return(0); 278 } 279 } 280 281 static void 282 gets(char *cp) 283 { 284 char *lp; 285 int c; 286 287 lp = cp; 288 for (;;) { 289 printf("%c", c = cngetc() & 0177); 290 switch (c) { 291 case -1: 292 case '\n': 293 case '\r': 294 *lp++ = '\0'; 295 return; 296 case '\b': 297 case '\177': 298 if (lp > cp) { 299 printf(" \b"); 300 lp--; 301 } 302 continue; 303 case '#': 304 lp--; 305 if (lp < cp) 306 lp = cp; 307 continue; 308 case '@': 309 case 'u' & 037: 310 lp = cp; 311 printf("%c", '\n'); 312 continue; 313 default: 314 *lp++ = c; 315 } 316 } 317 } 318 319 /* 320 * Convert a given name to the dev_t of the disk-like device 321 * it refers to. 322 */ 323 dev_t 324 getdiskbyname(char *name) { 325 char *cp; 326 int cd, unit, slice, part; 327 dev_t dev; 328 329 slice = 0; 330 part = 0; 331 if (strncmp(name, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) 332 name += sizeof(_PATH_DEV) - 1; 333 cp = name; 334 while (*cp != '\0' && (*cp < '0' || *cp > '9') && *cp != '/') 335 cp++; 336 if (cp == name) { 337 printf("missing device name\n"); 338 return (NODEV); 339 } 340 if (*cp == '\0' || *cp == '/') 341 unit = -1; 342 else 343 unit = *cp - '0'; 344 *cp++ = '\0'; 345 for (cd = 0; cd < NUMCDEVSW; cd++) { 346 dev = makedev(cd, 0); 347 if (devsw(dev) != NULL && 348 strcmp(devsw(dev)->d_name, name) == 0) 349 goto gotit; 350 } 351 printf("no such device '%s'\n", name); 352 return (NODEV); 353 gotit: 354 if (devsw(dev)->d_maj == major(rootdev)) 355 /* driver has already configured rootdev, e. g. vinum */ 356 return (rootdev); 357 if (unit == -1) { 358 printf("missing unit number\n"); 359 return (NODEV); 360 } 361 while (*cp >= '0' && *cp <= '9') 362 unit = 10 * unit + *cp++ - '0'; 363 if (*cp == 's' && cp[1] >= '0' && cp[1] <= '9') { 364 slice = cp[1] - '0' + 1; 365 cp += 2; 366 } 367 if (*cp >= 'a' && *cp <= 'h') { 368 part = *cp - 'a'; 369 cp++; 370 } 371 if (*cp != '\0') { 372 printf("junk after name\n"); 373 return (NODEV); 374 } 375 return (makedev(cd, dkmakeminor(unit, slice, part))); 376 } 377 378 /* 379 * Set rootdev to match (name), given that we expect it to 380 * refer to a disk-like device. 381 */ 382 static int 383 setrootbyname(char *name) 384 { 385 dev_t diskdev; 386 387 diskdev = getdiskbyname(name); 388 if (diskdev != NODEV) { 389 rootdev = diskdev; 390 return (0); 391 } 392 393 return (1); 394 } 395 396 #ifdef DDB 397 DB_SHOW_COMMAND(disk, db_getdiskbyname) 398 { 399 dev_t dev; 400 401 if (modif[0] == '\0') { 402 db_error("usage: show disk/devicename"); 403 return; 404 } 405 dev = getdiskbyname(modif); 406 if (dev != NODEV) 407 db_printf("dev_t = %p\n", dev); 408 else 409 db_printf("No disk device matched.\n"); 410 } 411 #endif 412