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 1.7 2004/03/01 06:33:17 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 lwkt_tokref ilock; 181 int s; 182 183 vfsname = NULL; 184 path = NULL; 185 mp = NULL; 186 error = EINVAL; 187 188 if (mountfrom == NULL) 189 return(error); /* don't complain */ 190 191 s = splcam(); /* Overkill, but annoying without it */ 192 printf("Mounting root from %s\n", mountfrom); 193 splx(s); 194 195 /* parse vfs name and path */ 196 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 197 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 198 vfsname[0] = path[0] = 0; 199 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 200 if (sscanf(mountfrom, patt, vfsname, path) < 1) 201 goto done; 202 203 /* allocate a root mount */ 204 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME, 205 &mp); 206 if (error != 0) { 207 printf("Can't allocate root mount for filesystem '%s': %d\n", 208 vfsname, error); 209 goto done; 210 } 211 mp->mnt_flag |= MNT_ROOTFS; 212 213 /* do our best to set rootdev */ 214 if ((path[0] != 0) && setrootbyname(path)) 215 printf("setrootbyname failed\n"); 216 217 /* If the root device is a type "memory disk", mount RW */ 218 if (rootdev != NODEV && dev_dport(rootdev) && 219 (dev_dflags(rootdev) & D_MEMDISK)) { 220 mp->mnt_flag &= ~MNT_RDONLY; 221 } 222 223 error = VFS_MOUNT(mp, NULL, NULL, NULL, td); 224 225 done: 226 if (vfsname != NULL) 227 free(vfsname, M_MOUNT); 228 if (path != NULL) 229 free(path, M_MOUNT); 230 if (error != 0) { 231 if (mp != NULL) { 232 vfs_unbusy(mp, td); 233 free(mp, M_MOUNT); 234 } 235 printf("Root mount failed: %d\n", error); 236 } else { 237 238 /* register with list of mounted filesystems */ 239 lwkt_gettoken(&ilock, &mountlist_token); 240 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 241 lwkt_reltoken(&ilock); 242 243 /* sanity check system clock against root fs timestamp */ 244 inittodr(mp->mnt_time); 245 vfs_unbusy(mp, td); 246 } 247 return(error); 248 } 249 250 /* 251 * Spin prompting on the console for a suitable root filesystem 252 */ 253 static int 254 vfs_mountroot_ask(void) 255 { 256 char name[128]; 257 int i; 258 dev_t dev; 259 260 for(;;) { 261 printf("\nManual root filesystem specification:\n"); 262 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 263 printf(" eg. ufs:%sda0s1a\n", __SYS_PATH_DEV); 264 printf(" ? List valid disk boot devices\n"); 265 printf(" <empty line> Abort manual input\n"); 266 printf("\nmountroot> "); 267 gets(name); 268 if (name[0] == 0) 269 return(1); 270 if (name[0] == '?') { 271 printf("Possibly valid devices for 'ufs' root:\n"); 272 for (i = 0; i < NUMCDEVSW; i++) { 273 dev = makedev(i, 0); 274 if (dev_dport(dev) != NULL) 275 printf(" \"%s\"", dev_dname(dev)); 276 } 277 printf("\n"); 278 continue; 279 } 280 if (!vfs_mountroot_try(name)) 281 return(0); 282 } 283 } 284 285 static void 286 gets(char *cp) 287 { 288 char *lp; 289 int c; 290 291 lp = cp; 292 for (;;) { 293 printf("%c", c = cngetc() & 0177); 294 switch (c) { 295 case -1: 296 case '\n': 297 case '\r': 298 *lp++ = '\0'; 299 return; 300 case '\b': 301 case '\177': 302 if (lp > cp) { 303 printf(" \b"); 304 lp--; 305 } 306 continue; 307 case '#': 308 lp--; 309 if (lp < cp) 310 lp = cp; 311 continue; 312 case '@': 313 case 'u' & 037: 314 lp = cp; 315 printf("%c", '\n'); 316 continue; 317 default: 318 *lp++ = c; 319 } 320 } 321 } 322 323 /* 324 * Convert a given name to the dev_t of the disk-like device 325 * it refers to. 326 */ 327 dev_t 328 getdiskbyname(char *name) { 329 char *cp; 330 int cd, unit, slice, part; 331 dev_t dev; 332 333 slice = 0; 334 part = 0; 335 if (strncmp(name, __SYS_PATH_DEV, sizeof(__SYS_PATH_DEV) - 1) == 0) 336 name += sizeof(__SYS_PATH_DEV) - 1; 337 cp = name; 338 while (*cp != '\0' && (*cp < '0' || *cp > '9') && *cp != '/') 339 cp++; 340 if (cp == name) { 341 printf("missing device name\n"); 342 return (NODEV); 343 } 344 if (*cp == '\0' || *cp == '/') 345 unit = -1; 346 else 347 unit = *cp - '0'; 348 *cp++ = '\0'; 349 for (cd = 0; cd < NUMCDEVSW; cd++) { 350 dev = makedev(cd, 0); 351 if (dev_dport(dev) != NULL && 352 strcmp(dev_dname(dev), name) == 0) 353 goto gotit; 354 } 355 printf("no such device '%s'\n", name); 356 return (NODEV); 357 gotit: 358 if (dev_dmaj(dev) == major(rootdev)) 359 /* driver has already configured rootdev, e. g. vinum */ 360 return (rootdev); 361 if (unit == -1) { 362 printf("missing unit number\n"); 363 return (NODEV); 364 } 365 while (*cp >= '0' && *cp <= '9') 366 unit = 10 * unit + *cp++ - '0'; 367 if (*cp == 's' && cp[1] >= '0' && cp[1] <= '9') { 368 slice = cp[1] - '0' + 1; 369 cp += 2; 370 } 371 if (*cp >= 'a' && *cp <= 'h') { 372 part = *cp - 'a'; 373 cp++; 374 } 375 if (*cp != '\0') { 376 printf("junk after name\n"); 377 return (NODEV); 378 } 379 return (makedev(cd, dkmakeminor(unit, slice, part))); 380 } 381 382 /* 383 * Set rootdev to match (name), given that we expect it to 384 * refer to a disk-like device. 385 */ 386 static int 387 setrootbyname(char *name) 388 { 389 dev_t diskdev; 390 391 diskdev = getdiskbyname(name); 392 if (diskdev != NODEV) { 393 rootdev = diskdev; 394 return (0); 395 } 396 397 return (1); 398 } 399 400 #ifdef DDB 401 DB_SHOW_COMMAND(disk, db_getdiskbyname) 402 { 403 dev_t dev; 404 405 if (modif[0] == '\0') { 406 db_error("usage: show disk/devicename"); 407 return; 408 } 409 dev = getdiskbyname(modif); 410 if (dev != NODEV) 411 db_printf("dev_t = %p\n", dev); 412 else 413 db_printf("No disk device matched.\n"); 414 } 415 #endif 416