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/kernel.h> 49 #include <sys/systm.h> 50 #include <sys/vnode.h> 51 #include <sys/mount.h> 52 #include <sys/malloc.h> 53 #include <sys/reboot.h> 54 #include <sys/diskslice.h> 55 #include <sys/disklabel.h> 56 #include <sys/conf.h> 57 #include <sys/cons.h> 58 #include <paths.h> 59 60 #include "opt_ddb.h" 61 #ifdef DDB 62 #include <ddb/ddb.h> 63 #endif 64 65 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 66 67 #define ROOTNAME "root_device" 68 69 struct vnode *rootvnode; 70 71 /* 72 * The root specifiers we will try if RB_CDROM is specified. 73 */ 74 static char *cdrom_rootdevnames[] = { 75 "cd9660:cd0a", 76 "cd9660:acd0a", 77 "cd9660:wcd0a", 78 NULL 79 }; 80 81 static void vfs_mountroot(void *junk); 82 static int vfs_mountroot_try(char *mountfrom); 83 static int vfs_mountroot_ask(void); 84 static void gets(char *cp); 85 86 /* legacy find-root code */ 87 char *rootdevnames[2] = {NULL, NULL}; 88 static int setrootbyname(char *name); 89 90 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL); 91 92 /* 93 * Find and mount the root filesystem 94 */ 95 static void 96 vfs_mountroot(void *junk) 97 { 98 int i; 99 100 /* 101 * The root filesystem information is compiled in, and we are 102 * booted with instructions to use it. 103 */ 104 #ifdef ROOTDEVNAME 105 if ((boothowto & RB_DFLTROOT) && 106 !vfs_mountroot_try(ROOTDEVNAME)) 107 return; 108 #endif 109 /* 110 * We are booted with instructions to prompt for the root filesystem, 111 * or to use the compiled-in default when it doesn't exist. 112 */ 113 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) { 114 if (!vfs_mountroot_ask()) 115 return; 116 } 117 118 /* 119 * We've been given the generic "use CDROM as root" flag. This is 120 * necessary because one media may be used in many different 121 * devices, so we need to search for them. 122 */ 123 if (boothowto & RB_CDROM) { 124 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 125 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 126 return; 127 } 128 } 129 130 /* 131 * Try to use the value read by the loader from /etc/fstab, or 132 * supplied via some other means. This is the preferred 133 * mechanism. 134 */ 135 if (!vfs_mountroot_try(getenv("vfs.root.mountfrom"))) 136 return; 137 138 /* 139 * Try values that may have been computed by the machine-dependant 140 * legacy code. 141 */ 142 if (!vfs_mountroot_try(rootdevnames[0])) 143 return; 144 if (!vfs_mountroot_try(rootdevnames[1])) 145 return; 146 147 /* 148 * If we have a compiled-in default, and haven't already tried it, try 149 * it now. 150 */ 151 #ifdef ROOTDEVNAME 152 if (!(boothowto & RB_DFLTROOT)) 153 if (!vfs_mountroot_try(ROOTDEVNAME)) 154 return; 155 #endif 156 157 /* 158 * Everything so far has failed, prompt on the console if we haven't 159 * already tried that. 160 */ 161 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask()) 162 return; 163 panic("Root mount failed, startup aborted."); 164 } 165 166 /* 167 * Mount (mountfrom) as the root filesystem. 168 */ 169 static int 170 vfs_mountroot_try(char *mountfrom) 171 { 172 struct mount *mp; 173 char *vfsname, *path; 174 int error; 175 char patt[32]; 176 int s; 177 178 vfsname = NULL; 179 path = NULL; 180 mp = NULL; 181 error = EINVAL; 182 183 if (mountfrom == NULL) 184 return(error); /* don't complain */ 185 186 s = splcam(); /* Overkill, but annoying without it */ 187 printf("Mounting root from %s\n", mountfrom); 188 splx(s); 189 190 /* parse vfs name and path */ 191 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 192 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 193 vfsname[0] = path[0] = 0; 194 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 195 if (sscanf(mountfrom, patt, vfsname, path) < 1) 196 goto done; 197 198 /* allocate a root mount */ 199 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME, 200 &mp); 201 if (error != 0) { 202 printf("Can't allocate root mount for filesystem '%s': %d\n", 203 vfsname, error); 204 goto done; 205 } 206 mp->mnt_flag |= MNT_ROOTFS; 207 208 /* do our best to set rootdev */ 209 if ((path[0] != 0) && setrootbyname(path)) 210 printf("setrootbyname failed\n"); 211 212 /* If the root device is a type "memory disk", mount RW */ 213 if (rootdev != NODEV && devsw(rootdev) && 214 (devsw(rootdev)->d_flags & D_MEMDISK)) 215 mp->mnt_flag &= ~MNT_RDONLY; 216 217 error = VFS_MOUNT(mp, NULL, NULL, NULL, curproc); 218 219 done: 220 if (vfsname != NULL) 221 free(vfsname, M_MOUNT); 222 if (path != NULL) 223 free(path, M_MOUNT); 224 if (error != 0) { 225 if (mp != NULL) { 226 vfs_unbusy(mp, curproc); 227 free(mp, M_MOUNT); 228 } 229 printf("Root mount failed: %d\n", error); 230 } else { 231 232 /* register with list of mounted filesystems */ 233 mtx_enter(&mountlist_mtx, MTX_DEF); 234 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 235 mtx_exit(&mountlist_mtx, MTX_DEF); 236 237 /* sanity check system clock against root filesystem timestamp */ 238 inittodr(mp->mnt_time); 239 vfs_unbusy(mp, curproc); 240 } 241 return(error); 242 } 243 244 /* 245 * Spin prompting on the console for a suitable root filesystem 246 */ 247 static int 248 vfs_mountroot_ask(void) 249 { 250 char name[128]; 251 int i; 252 dev_t dev; 253 254 for(;;) { 255 printf("\nManual root filesystem specification:\n"); 256 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 257 printf(" eg. ufs:%sda0s1a\n", _PATH_DEV); 258 printf(" ? List valid disk boot devices\n"); 259 printf(" <empty line> Abort manual input\n"); 260 printf("\nmountroot> "); 261 gets(name); 262 if (name[0] == 0) 263 return(1); 264 if (name[0] == '?') { 265 printf("Possibly valid devices for 'ufs' root:\n"); 266 for (i = 0; i < NUMCDEVSW; i++) { 267 dev = makedev(i, 0); 268 if (devsw(dev) != NULL) 269 printf(" \"%s\"", devsw(dev)->d_name); 270 } 271 printf("\n"); 272 continue; 273 } 274 if (!vfs_mountroot_try(name)) 275 return(0); 276 } 277 } 278 279 static void 280 gets(char *cp) 281 { 282 char *lp; 283 int c; 284 285 lp = cp; 286 for (;;) { 287 printf("%c", c = cngetc() & 0177); 288 switch (c) { 289 case -1: 290 case '\n': 291 case '\r': 292 *lp++ = '\0'; 293 return; 294 case '\b': 295 case '\177': 296 if (lp > cp) { 297 printf(" \b"); 298 lp--; 299 } 300 continue; 301 case '#': 302 lp--; 303 if (lp < cp) 304 lp = cp; 305 continue; 306 case '@': 307 case 'u' & 037: 308 lp = cp; 309 printf("%c", '\n'); 310 continue; 311 default: 312 *lp++ = c; 313 } 314 } 315 } 316 317 /* 318 * Convert a given name to the dev_t of the disk-like device 319 * it refers to. 320 */ 321 dev_t 322 getdiskbyname(char *name) { 323 char *cp; 324 dev_t dev; 325 326 cp = name; 327 if (!bcmp(cp, "/dev/", 5)) 328 cp += 5; 329 330 dev = NODEV; 331 EVENTHANDLER_INVOKE(dev_clone, cp, strlen(cp), &dev); 332 return (dev); 333 } 334 335 /* 336 * Set rootdev to match (name), given that we expect it to 337 * refer to a disk-like device. 338 */ 339 static int 340 setrootbyname(char *name) 341 { 342 dev_t diskdev; 343 344 diskdev = getdiskbyname(name); 345 if (diskdev != NODEV) { 346 rootdev = diskdev; 347 return (0); 348 } 349 350 return (1); 351 } 352 353 #ifdef DDB 354 DB_SHOW_COMMAND(disk, db_getdiskbyname) 355 { 356 dev_t dev; 357 358 if (modif[0] == '\0') { 359 db_error("usage: show disk/devicename"); 360 return; 361 } 362 dev = getdiskbyname(modif); 363 if (dev != NODEV) 364 db_printf("dev_t = %p\n", dev); 365 else 366 db_printf("No disk device matched.\n"); 367 } 368 #endif 369