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