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 $
32 * Locate and mount the root filesystem.
34 * The root filesystem is detailed in the kernel environment variable
35 * vfs.root.mountfrom, which is expected to be in the general format
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
45 #include "opt_rootdevname.h"
47 #include <sys/param.h>
48 #include <sys/kernel.h>
49 #include <sys/systm.h>
51 #include <sys/vnode.h>
52 #include <sys/mount.h>
53 #include <sys/malloc.h>
54 #include <sys/reboot.h>
55 #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 <sys/devfs.h>
66 #include <sys/sysctl.h>
73 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
75 #define ROOTNAME "root_device"
77 struct vnode *rootvnode;
78 struct nchandle rootnch;
81 * The root specifiers we will try if RB_CDROM is specified. Note that
82 * with DEVFS we do not use the compatibility slice's whole-disk 'c'
83 * partition. Instead we just use the whole disk, e.g. cd0 or cd0s0.
85 static char *cdrom_rootdevnames[] = {
86 "cd9660:cd0", /* SCSI (including AHCI and SILI) */
87 "cd9660:acd0", /* NATA */
88 "cd9660:cd1", /* SCSI (including AHCI and SILI) */
89 "cd9660:acd1", /* NATA */
90 "cd9660:cd8", /* USB */
91 "cd9660:cd9", /* USB */
95 int vfs_mountroot_devfs(void);
96 static void vfs_mountroot(void *junk);
97 static int vfs_mountroot_try(const char *mountfrom);
98 static int vfs_mountroot_ask(void);
99 static int get_line(char *cp, int limit);
101 /* legacy find-root code */
102 char *rootdevnames[2] = {NULL, NULL};
103 static int setrootbyname(char *name);
105 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL);
107 static int wakedelay = 2; /* delay before mounting root in seconds */
108 TUNABLE_INT("vfs.root.wakedelay", &wakedelay);
111 * Find and mount the root filesystem
114 vfs_mountroot(void *junk)
116 cdev_t save_rootdev = rootdev;
121 * Make sure all disk devices created so far have also been probed,
122 * and also make sure that the newly created device nodes for
123 * probed disks are ready, too.
125 * Messages can fly around here so get good synchronization
128 * XXX - Delay some more (default: 2s) to help drivers which pickup
129 * devices asynchronously and are not caught by CAM's initial
133 tsleep(&dummy, 0, "syncer", hz * wakedelay);
137 * The root filesystem information is compiled in, and we are
138 * booted with instructions to use it.
141 if ((boothowto & RB_DFLTROOT) &&
142 !vfs_mountroot_try(ROOTDEVNAME))
146 * We are booted with instructions to prompt for the root filesystem,
147 * or to use the compiled-in default when it doesn't exist.
149 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) {
150 if (!vfs_mountroot_ask())
155 * We've been given the generic "use CDROM as root" flag. This is
156 * necessary because one media may be used in many different
157 * devices, so we need to search for them.
159 if (boothowto & RB_CDROM) {
160 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
161 if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
167 * Try to use the value read by the loader from /etc/fstab, or
168 * supplied via some other means. This is the preferred
171 if (!vfs_mountroot_try(kgetenv("vfs.root.mountfrom")))
175 * If a vfs set rootdev, try it (XXX VINUM HACK!)
177 if (save_rootdev != NULL) {
178 rootdev = save_rootdev;
179 if (!vfs_mountroot_try(""))
184 * Try values that may have been computed by the machine-dependant
187 if (rootdevnames[0] && !vfs_mountroot_try(rootdevnames[0]))
189 if (rootdevnames[1] && !vfs_mountroot_try(rootdevnames[1]))
193 * If we have a compiled-in default, and haven't already tried it, try
197 if (!(boothowto & RB_DFLTROOT))
198 if (!vfs_mountroot_try(ROOTDEVNAME))
203 * Everything so far has failed, prompt on the console if we haven't
204 * already tried that.
206 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask())
208 panic("Root mount failed, startup aborted.");
213 vfs_mountroot_devfs(void)
217 struct nlookupdata nd;
219 struct vfsconf *vfsp;
221 struct ucred *cred = proc0.p_ucred;
222 const char *devfs_path, *init_chroot;
223 char *dev_malloced = NULL;
225 if ((init_chroot = kgetenv("init_chroot")) != NULL) {
228 l = strlen(init_chroot) + sizeof("/dev");
229 dev_malloced = kmalloc(l, M_MOUNT, M_WAITOK);
230 ksnprintf(dev_malloced, l, "%s/dev", init_chroot);
231 devfs_path = dev_malloced;
236 * Lookup the requested path and extract the nch and vnode.
238 error = nlookup_init_raw(&nd,
239 devfs_path, UIO_SYSSPACE, NLC_FOLLOW,
243 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup_init is ok...\n");
244 if ((error = nlookup(&nd)) == 0) {
245 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup is ok...\n");
246 if (nd.nl_nch.ncp->nc_vp == NULL) {
247 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup: simply not found\n");
252 if (dev_malloced != NULL)
253 kfree(dev_malloced, M_MOUNT), dev_malloced = NULL;
257 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup failed, error: %d\n", error);
262 * Extract the locked+refd ncp and cleanup the nd structure
265 cache_zero(&nd.nl_nch);
269 * now we have the locked ref'd nch and unreferenced vnode.
272 if ((error = vget(vp, LK_EXCLUSIVE)) != 0) {
274 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vget failed\n");
279 if ((error = vinvalbuf(vp, V_SAVE, 0, 0)) != 0) {
282 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vinvalbuf failed\n");
285 if (vp->v_type != VDIR) {
288 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vp is not VDIR\n");
292 vfsp = vfsconf_find_by_name("devfs");
295 * Allocate and initialize the filesystem.
297 mp = kmalloc(sizeof(struct mount), M_MOUNT, M_ZERO|M_WAITOK);
299 vfs_busy(mp, LK_NOWAIT);
300 mp->mnt_op = vfsp->vfc_vfsops;
302 mp->mnt_pbuf_count = nswbuf_kva / NSWBUF_SPLIT;
303 vfsp->vfc_refcount++;
304 mp->mnt_stat.f_type = vfsp->vfc_typenum;
305 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
306 strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
307 mp->mnt_stat.f_owner = cred->cr_uid;
311 * Mount the filesystem.
313 error = VFS_MOUNT(mp, "/dev", NULL, cred);
315 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
318 * Put the new filesystem on the mount list after root. The mount
319 * point gets its own mnt_ncmountpt (unless the VFS already set one
320 * up) which represents the root of the mount. The lookup code
321 * detects the mount point going forward and checks the root of
322 * the mount going backwards.
324 * It is not necessary to invalidate or purge the vnode underneath
325 * because elements under the mount will be given their own glue
329 if (mp->mnt_ncmountpt.ncp == NULL) {
331 * allocate, then unlock, but leave the ref intact
333 cache_allocroot(&mp->mnt_ncmountpt, mp, NULL);
334 cache_unlock(&mp->mnt_ncmountpt);
337 mp->mnt_ncmounton = nch; /* inherits ref */
339 nch.ncp->nc_flag |= NCF_ISMOUNTPT;
341 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
344 * XXX get the root of the fs and
345 * cache_setvp(mnt_ncmountpt...)
347 mountlist_insert(mp, MNTINS_LAST);
349 //checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
350 error = vfs_allocate_syncvnode(mp);
352 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vfs_allocate_syncvnode failed\n");
355 error = VFS_START(mp, 0);
358 vn_syncer_thr_stop(mp);
359 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
360 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
361 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
362 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
363 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
364 mp->mnt_vfc->vfc_refcount--;
369 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: mount failed\n");
372 devfs_debug(DEVFS_DEBUG_DEBUG, "rootmount_devfs done with error: %d\n", error);
378 * Mount (mountfrom) as the root filesystem.
381 vfs_mountroot_try(const char *mountfrom)
384 char *vfsname, *devname;
397 if (mountfrom == NULL)
398 return(error); /* don't complain */
401 kprintf("Mounting root from %s\n", mountfrom);
405 /* parse vfs name and devname */
406 vfsname = kmalloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
407 devname = kmalloc(MNAMELEN, M_MOUNT, M_WAITOK);
408 mf = kmalloc(MFSNAMELEN+MNAMELEN, M_MOUNT, M_WAITOK);
410 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
411 bzero(vfsname, MFSNAMELEN);
412 bzero(devname, MNAMELEN);
413 bzero(mf, MFSNAMELEN+MNAMELEN);
414 strncpy(mf, cp, MFSNAMELEN+MNAMELEN);
416 vfsname[0] = devname[0] = 0;
417 ksprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
418 if (ksscanf(mf, patt, vfsname, devname) < 1)
421 /* allocate a root mount */
422 error = vfs_rootmountalloc(vfsname,
423 devname[0] != 0 ? devname : ROOTNAME, &mp);
425 kprintf("Can't allocate root mount for filesystem '%s': %d\n",
429 mp->mnt_flag |= MNT_ROOTFS;
431 /* do our best to set rootdev (really just for UFS) */
432 if (strcmp(vfsname, "hammer") != 0 &&
433 strcmp(vfsname, "hammer2") != 0 &&
434 (devname[0] != 0) && setrootbyname(devname)) {
435 kprintf("setrootbyname failed\n");
438 /* If the root device is a type "memory disk", mount RW */
439 if (rootdev != NULL && dev_is_good(rootdev) &&
440 (dev_dflags(rootdev) & D_MEMDISK)) {
441 mp->mnt_flag &= ~MNT_RDONLY;
444 error = VFS_MOUNT(mp, NULL, NULL, proc0.p_ucred);
455 kfree(vfsname, M_MOUNT);
457 kfree(devname, M_MOUNT);
461 /* register with list of mounted filesystems */
462 mountlist_insert(mp, MNTINS_FIRST);
464 /* sanity check system clock against root fs timestamp */
465 inittodr(mp->mnt_time);
467 /* Get the vnode for '/'. Set p->p_fd->fd_cdir to reference it. */
468 mp = mountlist_boot_getfirst();
469 if (VFS_ROOT(mp, &vp))
470 panic("cannot find root vnode");
471 if (mp->mnt_ncmountpt.ncp == NULL) {
472 cache_allocroot(&mp->mnt_ncmountpt, mp, vp);
473 cache_unlock(&mp->mnt_ncmountpt); /* leave ref intact */
476 p->p_fd->fd_cdir = vp;
477 vref(p->p_fd->fd_cdir);
478 p->p_fd->fd_rdir = vp;
479 vref(p->p_fd->fd_rdir);
480 vfs_cache_setroot(vp, cache_hold(&mp->mnt_ncmountpt));
481 vn_unlock(vp); /* leave ref intact */
482 cache_copy(&mp->mnt_ncmountpt, &p->p_fd->fd_ncdir);
483 cache_copy(&mp->mnt_ncmountpt, &p->p_fd->fd_nrdir);
486 if (mp->mnt_syncer == NULL) {
487 error = vfs_allocate_syncvnode(mp);
489 kprintf("Warning: no syncer vp for root!\n");
495 vn_syncer_thr_stop(mp);
499 kprintf("Root mount failed: %d\n", error);
506 vfs_mountroot_ask_callback(char *name, cdev_t dev, bool is_alias,
509 if (!is_alias && dev_is_good(dev) && (dev_dflags(dev) & D_DISK))
510 kprintf(" \"%s\" ", name);
515 * Spin prompting on the console for a suitable root filesystem
518 vfs_mountroot_ask(void)
523 kprintf("\nManual root filesystem specification:\n");
524 kprintf(" <fstype>:<device> Specify root (e.g. ufs:da0s1a)\n");
525 kprintf(" ? List valid disk boot devices\n");
526 kprintf(" panic Just panic\n");
527 kprintf(" abort Abort manual input\n");
529 kprintf("\nmountroot> ");
531 if (get_line(name, 128) < 0)
535 } else if (name[0] == '?') {
536 kprintf("Possibly valid devices for root FS:\n");
537 //enumerate all disk devices
538 devfs_scan_callback(vfs_mountroot_ask_callback, NULL);
541 } else if (strcmp(name, "panic") == 0) {
542 panic("panic from console");
543 } else if (strcmp(name, "abort") == 0) {
545 } else if (vfs_mountroot_try(name) == 0) {
554 get_line(char *cp, int limit)
567 tsleep(&dummy, 0, "cnpoll", hz / 25);
593 /* NOTE: '@' no longer processed here, used for H2 */
598 if (lp - cp >= limit - 1) {
613 * Convert a given name to the cdev_t of the disk-like device
617 kgetdiskbyname(const char *name)
622 * Get the base name of the device
624 if (strncmp(name, __SYS_PATH_DEV, sizeof(__SYS_PATH_DEV) - 1) == 0)
625 name += sizeof(__SYS_PATH_DEV) - 1;
630 rdev = devfs_find_device_by_name("%s", name);
632 kprintf("no disk named '%s'\n", name);
641 * Set rootdev to match (name), given that we expect it to
642 * refer to a disk-like device.
645 setrootbyname(char *name)
649 diskdev = kgetdiskbyname(name);
650 if (diskdev != NULL) {
654 /* set to NULL if kgetdiskbyname() fails so that if the first rootdev is
655 * found by fails to mount and the second one isn't found, mountroot_try
656 * doesn't try again with the first one
663 DB_SHOW_COMMAND(disk, db_getdiskbyname)
667 if (modif[0] == '\0') {
668 db_error("usage: show disk/devicename");
671 dev = kgetdiskbyname(modif);
673 db_printf("cdev_t = %p\n", dev);
675 db_printf("No disk device matched.\n");
680 vfs_sysctl_real_root(SYSCTL_HANDLER_ARGS)
686 real_root = kgetenv("vfs.root.realroot");
688 if (real_root == NULL)
691 len = strlen(real_root) + 1;
693 error = sysctl_handle_string(oidp, real_root, len, req);
698 SYSCTL_PROC(_vfs, OID_AUTO, real_root,
699 CTLTYPE_STRING | CTLFLAG_RD, 0, 0, vfs_sysctl_real_root,
700 "A", "Real root mount string");