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 "opt_rootdevname.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/kernel.h> 50 #include <sys/lock.h> 51 #include <sys/mutex.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/proc.h> 61 62 #include "opt_ddb.h" 63 64 #ifdef DDB 65 #include <ddb/ddb.h> 66 #endif 67 68 #include <paths.h> 69 70 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 71 72 #define ROOTNAME "root_device" 73 74 /* 75 * The vnode of the system's root (/ in the filesystem, without chroot 76 * active.) 77 */ 78 struct vnode *rootvnode; 79 80 /* 81 * The root specifiers we will try if RB_CDROM is specified. 82 */ 83 static char *cdrom_rootdevnames[] = { 84 "cd9660:cd0a", 85 "cd9660:acd0a", 86 "cd9660:wcd0a", 87 NULL 88 }; 89 90 static int vfs_mountroot_try(char *mountfrom); 91 static int vfs_mountroot_ask(void); 92 static void gets(char *cp); 93 94 /* legacy find-root code */ 95 char *rootdevnames[2] = {NULL, NULL}; 96 static int setrootbyname(char *name); 97 dev_t rootdev = NODEV; 98 99 /* 100 * Find and mount the root filesystem 101 */ 102 void 103 vfs_mountroot(void *foo __unused) 104 { 105 char *cp; 106 int i, error; 107 108 /* 109 * The root filesystem information is compiled in, and we are 110 * booted with instructions to use it. 111 */ 112 #ifdef ROOTDEVNAME 113 if ((boothowto & RB_DFLTROOT) && 114 !vfs_mountroot_try(ROOTDEVNAME)) 115 return; 116 #endif 117 /* 118 * We are booted with instructions to prompt for the root filesystem, 119 * or to use the compiled-in default when it doesn't exist. 120 */ 121 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) { 122 if (!vfs_mountroot_ask()) 123 return; 124 } 125 126 /* 127 * We've been given the generic "use CDROM as root" flag. This is 128 * necessary because one media may be used in many different 129 * devices, so we need to search for them. 130 */ 131 if (boothowto & RB_CDROM) { 132 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 133 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 134 return; 135 } 136 } 137 138 /* 139 * Try to use the value read by the loader from /etc/fstab, or 140 * supplied via some other means. This is the preferred 141 * mechanism. 142 */ 143 if ((cp = getenv("vfs.root.mountfrom")) != NULL) { 144 error = vfs_mountroot_try(cp); 145 freeenv(cp); 146 if (!error) 147 return; 148 } 149 150 /* 151 * Try values that may have been computed by the machine-dependant 152 * legacy code. 153 */ 154 if (!vfs_mountroot_try(rootdevnames[0])) 155 return; 156 if (!vfs_mountroot_try(rootdevnames[1])) 157 return; 158 159 /* 160 * If we have a compiled-in default, and haven't already tried it, try 161 * it now. 162 */ 163 #ifdef ROOTDEVNAME 164 if (!(boothowto & RB_DFLTROOT)) 165 if (!vfs_mountroot_try(ROOTDEVNAME)) 166 return; 167 #endif 168 169 /* 170 * Everything so far has failed, prompt on the console if we haven't 171 * already tried that. 172 */ 173 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask()) 174 return; 175 panic("Root mount failed, startup aborted."); 176 } 177 178 /* 179 * Mount (mountfrom) as the root filesystem. 180 */ 181 static int 182 vfs_mountroot_try(char *mountfrom) 183 { 184 struct mount *mp; 185 char *vfsname, *path; 186 int error; 187 char patt[32]; 188 int s; 189 190 vfsname = NULL; 191 path = NULL; 192 mp = NULL; 193 error = EINVAL; 194 195 if (mountfrom == NULL) 196 return(error); /* don't complain */ 197 198 s = splcam(); /* Overkill, but annoying without it */ 199 printf("Mounting root from %s\n", mountfrom); 200 splx(s); 201 202 /* parse vfs name and path */ 203 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 204 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 205 vfsname[0] = path[0] = 0; 206 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 207 if (sscanf(mountfrom, patt, vfsname, path) < 1) 208 goto done; 209 210 /* allocate a root mount */ 211 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME, 212 &mp); 213 if (error != 0) { 214 printf("Can't allocate root mount for filesystem '%s': %d\n", 215 vfsname, error); 216 goto done; 217 } 218 mp->mnt_flag |= MNT_ROOTFS; 219 220 /* do our best to set rootdev */ 221 if ((path[0] != 0) && setrootbyname(path)) 222 printf("setrootbyname failed\n"); 223 224 /* If the root device is a type "memory disk", mount RW */ 225 if (rootdev != NODEV && devsw(rootdev) && 226 (devsw(rootdev)->d_flags & D_MEMDISK)) 227 mp->mnt_flag &= ~MNT_RDONLY; 228 229 /* 230 * Set the mount path to be something useful, because the 231 * filesystem code isn't responsible now for initialising 232 * f_mntonname unless they want to override the default 233 * (which is `path'.) 234 */ 235 strncpy(mp->mnt_stat.f_mntonname, "/", MNAMELEN); 236 237 error = VFS_MOUNT(mp, NULL, NULL, NULL, curthread); 238 239 done: 240 if (vfsname != NULL) 241 free(vfsname, M_MOUNT); 242 if (path != NULL) 243 free(path, M_MOUNT); 244 if (error != 0) { 245 if (mp != NULL) { 246 vfs_unbusy(mp, curthread); 247 free(mp, M_MOUNT); 248 } 249 printf("Root mount failed: %d\n", error); 250 } else { 251 252 /* register with list of mounted filesystems */ 253 mtx_lock(&mountlist_mtx); 254 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 255 mtx_unlock(&mountlist_mtx); 256 257 /* sanity check system clock against root filesystem timestamp */ 258 inittodr(mp->mnt_time); 259 vfs_unbusy(mp, curthread); 260 } 261 return(error); 262 } 263 264 /* 265 * Spin prompting on the console for a suitable root filesystem 266 */ 267 static int 268 vfs_mountroot_ask(void) 269 { 270 char name[128]; 271 int i; 272 dev_t dev; 273 274 for(;;) { 275 printf("\nManual root filesystem specification:\n"); 276 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 277 #if defined(__i386__) || defined(__ia64__) 278 printf(" eg. ufs:da0s1a\n"); 279 #else 280 printf(" eg. ufs:da0a\n"); 281 #endif 282 printf(" ? List valid disk boot devices\n"); 283 printf(" <empty line> Abort manual input\n"); 284 printf("\nmountroot> "); 285 gets(name); 286 if (name[0] == 0) 287 return(1); 288 if (name[0] == '?') { 289 printf("Possibly valid devices for 'ufs' root:\n"); 290 for (i = 0; i < NUMCDEVSW; i++) { 291 dev = makedev(i, 0); 292 if (devsw(dev) != NULL) 293 printf(" \"%s\"", devsw(dev)->d_name); 294 } 295 printf("\n"); 296 continue; 297 } 298 if (!vfs_mountroot_try(name)) 299 return(0); 300 } 301 } 302 303 /* 304 * Local helper function for vfs_mountroot_ask. 305 */ 306 static void 307 gets(char *cp) 308 { 309 char *lp; 310 int c; 311 312 lp = cp; 313 for (;;) { 314 printf("%c", c = cngetc() & 0177); 315 switch (c) { 316 case -1: 317 case '\n': 318 case '\r': 319 *lp++ = '\0'; 320 return; 321 case '\b': 322 case '\177': 323 if (lp > cp) { 324 printf(" \b"); 325 lp--; 326 } 327 continue; 328 case '#': 329 lp--; 330 if (lp < cp) 331 lp = cp; 332 continue; 333 case '@': 334 case 'u' & 037: 335 lp = cp; 336 printf("%c", '\n'); 337 continue; 338 default: 339 *lp++ = c; 340 } 341 } 342 } 343 344 /* 345 * Convert a given name to the dev_t of the disk-like device 346 * it refers to. 347 */ 348 dev_t 349 getdiskbyname(char *name) { 350 char *cp; 351 dev_t dev; 352 353 cp = name; 354 if (!bcmp(cp, "/dev/", 5)) 355 cp += 5; 356 357 dev = NODEV; 358 EVENTHANDLER_INVOKE(dev_clone, cp, strlen(cp), &dev); 359 return (dev); 360 } 361 362 /* 363 * Set rootdev to match (name), given that we expect it to 364 * refer to a disk-like device. 365 */ 366 static int 367 setrootbyname(char *name) 368 { 369 dev_t diskdev; 370 371 diskdev = getdiskbyname(name); 372 if (diskdev != NODEV) { 373 rootdev = diskdev; 374 return (0); 375 } 376 377 return (1); 378 } 379 380 /* Show the dev_t for a disk specified by name */ 381 #ifdef DDB 382 DB_SHOW_COMMAND(disk, db_getdiskbyname) 383 { 384 dev_t dev; 385 386 if (modif[0] == '\0') { 387 db_error("usage: show disk/devicename"); 388 return; 389 } 390 dev = getdiskbyname(modif); 391 if (dev != NODEV) 392 db_printf("dev_t = %p\n", dev); 393 else 394 db_printf("No disk device matched.\n"); 395 } 396 #endif 397