2 * Copyright (c) 1999 Michael Smith
4 * Copyright (c) 1999 Poul-Henning Kamp
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
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 1.34 2008/05/24 19:08:28 dillon Exp $
33 * Locate and mount the root filesystem.
35 * The root filesystem is detailed in the kernel environment variable
36 * vfs.root.mountfrom, which is expected to be in the general format
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
46 #include "opt_rootdevname.h"
48 #include <sys/param.h>
49 #include <sys/kernel.h>
50 #include <sys/systm.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>
59 #include <sys/device.h>
61 #include <sys/namecache.h>
62 #include <sys/paths.h>
63 #include <sys/thread2.h>
64 #include <sys/nlookup.h>
65 #include <vfs/devfs/devfs.h>
72 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
74 #define ROOTNAME "root_device"
76 struct vnode *rootvnode;
77 struct nchandle rootnch;
80 * The root specifiers we will try if RB_CDROM is specified. Note that
81 * with DEVFS we do not use the compatibility slice's whole-disk 'c'
82 * partition. Instead we just use the whole disk, e.g. cd0 or cd0s0.
84 static char *cdrom_rootdevnames[] = {
92 int vfs_mountroot_devfs(void);
93 static void vfs_mountroot(void *junk);
94 static int vfs_mountroot_try(const char *mountfrom);
95 static int vfs_mountroot_ask(void);
96 static int getline(char *cp, int limit);
98 /* legacy find-root code */
99 char *rootdevnames[2] = {NULL, NULL};
100 static int setrootbyname(char *name);
102 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL);
105 * Find and mount the root filesystem
108 vfs_mountroot(void *junk)
111 cdev_t save_rootdev = rootdev;
114 * Make sure all disk devices created so far have also been probed,
115 * and also make sure that the newly created device nodes for
116 * probed disks are ready, too.
122 * The root filesystem information is compiled in, and we are
123 * booted with instructions to use it.
126 if ((boothowto & RB_DFLTROOT) &&
127 !vfs_mountroot_try(ROOTDEVNAME))
131 * We are booted with instructions to prompt for the root filesystem,
132 * or to use the compiled-in default when it doesn't exist.
134 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) {
135 if (!vfs_mountroot_ask())
140 * We've been given the generic "use CDROM as root" flag. This is
141 * necessary because one media may be used in many different
142 * devices, so we need to search for them.
144 if (boothowto & RB_CDROM) {
145 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
146 if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
152 * Try to use the value read by the loader from /etc/fstab, or
153 * supplied via some other means. This is the preferred
156 if (!vfs_mountroot_try(kgetenv("vfs.root.mountfrom")))
160 * If a vfs set rootdev, try it (XXX VINUM HACK!)
162 if (save_rootdev != NULL) {
163 rootdev = save_rootdev;
164 if (!vfs_mountroot_try(""))
169 * Try values that may have been computed by the machine-dependant
172 if (rootdevnames[0] && !vfs_mountroot_try(rootdevnames[0]))
174 if (rootdevnames[1] && !vfs_mountroot_try(rootdevnames[1]))
178 * If we have a compiled-in default, and haven't already tried it, try
182 if (!(boothowto & RB_DFLTROOT))
183 if (!vfs_mountroot_try(ROOTDEVNAME))
188 * Everything so far has failed, prompt on the console if we haven't
189 * already tried that.
191 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask())
193 panic("Root mount failed, startup aborted.");
198 vfs_mountroot_devfs(void)
202 struct nlookupdata nd;
204 struct vfsconf *vfsp;
206 struct ucred *cred = proc0.p_ucred;
209 * Lookup the requested path and extract the nch and vnode.
211 error = nlookup_init_raw(&nd,
212 "/dev", UIO_SYSSPACE, NLC_FOLLOW,
216 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup_init is ok...\n");
217 if ((error = nlookup(&nd)) == 0) {
218 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup is ok...\n");
219 if (nd.nl_nch.ncp->nc_vp == NULL) {
220 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup: simply not found\n");
227 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup failed, error: %d\n", error);
232 * Extract the locked+refd ncp and cleanup the nd structure
235 cache_zero(&nd.nl_nch);
239 * now we have the locked ref'd nch and unreferenced vnode.
242 if ((error = vget(vp, LK_EXCLUSIVE)) != 0) {
244 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vget failed\n");
249 if ((error = vinvalbuf(vp, V_SAVE, 0, 0)) != 0) {
252 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vinvalbuf failed\n");
255 if (vp->v_type != VDIR) {
258 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vp is not VDIR\n");
262 vfsp = vfsconf_find_by_name("devfs");
263 vp->v_flag |= VMOUNT;
266 * Allocate and initialize the filesystem.
268 mp = kmalloc(sizeof(struct mount), M_MOUNT, M_ZERO|M_WAITOK);
269 TAILQ_INIT(&mp->mnt_nvnodelist);
270 TAILQ_INIT(&mp->mnt_reservedvnlist);
271 TAILQ_INIT(&mp->mnt_jlist);
272 mp->mnt_nvnodelistsize = 0;
273 lockinit(&mp->mnt_lock, "vfslock", 0, 0);
274 vfs_busy(mp, LK_NOWAIT);
275 mp->mnt_op = vfsp->vfc_vfsops;
277 vfsp->vfc_refcount++;
278 mp->mnt_stat.f_type = vfsp->vfc_typenum;
279 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
280 strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
281 mp->mnt_stat.f_owner = cred->cr_uid;
282 mp->mnt_iosize_max = DFLTPHYS;
286 * Mount the filesystem.
288 error = VFS_MOUNT(mp, "/dev", NULL, cred);
290 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
293 * Put the new filesystem on the mount list after root. The mount
294 * point gets its own mnt_ncmountpt (unless the VFS already set one
295 * up) which represents the root of the mount. The lookup code
296 * detects the mount point going forward and checks the root of
297 * the mount going backwards.
299 * It is not necessary to invalidate or purge the vnode underneath
300 * because elements under the mount will be given their own glue
304 if (mp->mnt_ncmountpt.ncp == NULL) {
306 * allocate, then unlock, but leave the ref intact
308 cache_allocroot(&mp->mnt_ncmountpt, mp, NULL);
309 cache_unlock(&mp->mnt_ncmountpt);
311 mp->mnt_ncmounton = nch; /* inherits ref */
312 nch.ncp->nc_flag |= NCF_ISMOUNTPT;
314 /* XXX get the root of the fs and cache_setvp(mnt_ncmountpt...) */
315 vp->v_flag &= ~VMOUNT;
316 mountlist_insert(mp, MNTINS_LAST);
318 //checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
319 error = vfs_allocate_syncvnode(mp);
321 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vfs_allocate_syncvnode failed\n");
324 error = VFS_START(mp, 0);
327 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
328 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
329 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
330 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
331 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
332 vp->v_flag &= ~VMOUNT;
333 mp->mnt_vfc->vfc_refcount--;
338 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: mount failed\n");
341 devfs_debug(DEVFS_DEBUG_DEBUG, "rootmount_devfs done with error: %d\n", error);
347 * Mount (mountfrom) as the root filesystem.
350 vfs_mountroot_try(const char *mountfrom)
352 struct mount *mp, *mp2;
353 char *vfsname, *devname;
363 if (mountfrom == NULL)
364 return(error); /* don't complain */
367 kprintf("Mounting root from %s\n", mountfrom);
370 /* parse vfs name and devname */
371 vfsname = kmalloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
372 devname = kmalloc(MNAMELEN, M_MOUNT, M_WAITOK);
373 vfsname[0] = devname[0] = 0;
374 ksprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
375 if (ksscanf(mountfrom, patt, vfsname, devname) < 1)
378 /* allocate a root mount */
379 error = vfs_rootmountalloc(vfsname,
380 devname[0] != 0 ? devname : ROOTNAME, &mp);
382 kprintf("Can't allocate root mount for filesystem '%s': %d\n",
386 mp->mnt_flag |= MNT_ROOTFS;
388 /* do our best to set rootdev */
389 if ((devname[0] != 0) && setrootbyname(devname))
390 kprintf("setrootbyname failed\n");
392 /* If the root device is a type "memory disk", mount RW */
393 if (rootdev != NULL && dev_is_good(rootdev) &&
394 (dev_dflags(rootdev) & D_MEMDISK)) {
395 mp->mnt_flag &= ~MNT_RDONLY;
398 error = VFS_MOUNT(mp, NULL, NULL, proc0.p_ucred);
401 //kprintf("Trying vfs_mountroot_devfs!\n");
402 //vfs_mountroot_devfs();
407 kfree(vfsname, M_MOUNT);
409 kfree(devname, M_MOUNT);
411 /* register with list of mounted filesystems */
412 mountlist_insert(mp, MNTINS_FIRST);
414 /* sanity check system clock against root fs timestamp */
415 inittodr(mp->mnt_time);
417 if (mp->mnt_syncer == NULL) {
418 error = vfs_allocate_syncvnode(mp);
420 kprintf("Warning: no syncer vp for root!\n");
428 kprintf("Root mount failed: %d\n", error);
434 static void vfs_mountroot_ask_callback(cdev_t);
437 * Spin prompting on the console for a suitable root filesystem
441 vfs_mountroot_ask(void)
446 kprintf("\nManual root filesystem specification:\n");
447 kprintf(" <fstype>:<device> Specify root (e.g. ufs:da0s1a)\n");
448 kprintf(" ? List valid disk boot devices\n");
449 kprintf(" panic Just panic\n");
450 kprintf(" abort Abort manual input\n");
452 kprintf("\nmountroot> ");
454 if (getline(name, 128) < 0)
458 } else if (name[0] == '?') {
459 kprintf("Possibly valid devices for root FS:\n");
460 //enumerate all disk devices
461 devfs_scan_callback(vfs_mountroot_ask_callback);
464 } else if (strcmp(name, "panic") == 0) {
465 panic("panic from console");
466 } else if (strcmp(name, "abort") == 0) {
468 } else if (vfs_mountroot_try(name) == 0) {
477 vfs_mountroot_ask_callback(cdev_t dev)
479 if (dev_is_good(dev) && (dev_dflags(dev) & D_DISK))
480 kprintf(" \"%s\" ", dev->si_name);
485 getline(char *cp, int limit)
523 if (lp - cp >= limit - 1) {
535 * Convert a given name to the cdev_t of the disk-like device
547 kgetdiskbyname(const char *name)
553 * Get the base name of the device
555 if (strncmp(name, __SYS_PATH_DEV, sizeof(__SYS_PATH_DEV) - 1) == 0)
556 name += sizeof(__SYS_PATH_DEV) - 1;
557 cp = __DECONST(char *, name);
562 kprintf("tryroot %s\n", name);
563 rdev = devfs_find_device_by_name(name);
565 kprintf("no disk named '%s'\n", name);
574 * Set rootdev to match (name), given that we expect it to
575 * refer to a disk-like device.
578 setrootbyname(char *name)
582 diskdev = kgetdiskbyname(name);
583 if (diskdev != NULL) {
587 /* set to NULL if kgetdiskbyname() fails so that if the first rootdev is
588 * found by fails to mount and the second one isn't found, mountroot_try
589 * doesn't try again with the first one
596 DB_SHOW_COMMAND(disk, db_getdiskbyname)
600 if (modif[0] == '\0') {
601 db_error("usage: show disk/devicename");
604 dev = kgetdiskbyname(modif);
606 db_printf("cdev_t = %p\n", dev);
608 db_printf("No disk device matched.\n");