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>
58 #include <sys/device.h>
60 #include <sys/namecache.h>
61 #include <sys/paths.h>
62 #include <sys/thread2.h>
63 #include <sys/nlookup.h>
64 #include <sys/devfs.h>
65 #include <sys/sysctl.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
[] = {
85 "cd9660:cd0", /* SCSI (including AHCI and SILI) */
86 "cd9660:acd0", /* NATA */
87 "cd9660:cd1", /* SCSI (including AHCI and SILI) */
88 "cd9660:acd1", /* NATA */
89 "cd9660:cd8", /* USB */
90 "cd9660:cd9", /* USB */
94 int vfs_mountroot_devfs(void);
95 static void vfs_mountroot(void *junk
);
96 static int vfs_mountroot_try(const char *mountfrom
);
97 static int vfs_mountroot_ask(void);
98 static int getline(char *cp
, int limit
);
100 /* legacy find-root code */
101 char *rootdevnames
[2] = {NULL
, NULL
};
102 static int setrootbyname(char *name
);
104 SYSINIT(mountroot
, SI_SUB_MOUNT_ROOT
, SI_ORDER_SECOND
, vfs_mountroot
, NULL
);
106 static int wakedelay
= 2; /* delay before mounting root in seconds */
107 TUNABLE_INT("vfs.root.wakedelay", &wakedelay
);
110 * Find and mount the root filesystem
113 vfs_mountroot(void *junk
)
115 cdev_t save_rootdev
= rootdev
;
120 * Make sure all disk devices created so far have also been probed,
121 * and also make sure that the newly created device nodes for
122 * probed disks are ready, too.
124 * Messages can fly around here so get good synchronization
127 * XXX - Delay some more (default: 2s) to help drivers which pickup
128 * devices asynchronously and are not caught by CAM's initial
132 tsleep(&dummy
, 0, "syncer", hz
* wakedelay
);
136 * The root filesystem information is compiled in, and we are
137 * booted with instructions to use it.
140 if ((boothowto
& RB_DFLTROOT
) &&
141 !vfs_mountroot_try(ROOTDEVNAME
))
145 * We are booted with instructions to prompt for the root filesystem,
146 * or to use the compiled-in default when it doesn't exist.
148 if (boothowto
& (RB_DFLTROOT
| RB_ASKNAME
)) {
149 if (!vfs_mountroot_ask())
154 * We've been given the generic "use CDROM as root" flag. This is
155 * necessary because one media may be used in many different
156 * devices, so we need to search for them.
158 if (boothowto
& RB_CDROM
) {
159 for (i
= 0; cdrom_rootdevnames
[i
] != NULL
; i
++) {
160 if (!vfs_mountroot_try(cdrom_rootdevnames
[i
]))
166 * Try to use the value read by the loader from /etc/fstab, or
167 * supplied via some other means. This is the preferred
170 if (!vfs_mountroot_try(kgetenv("vfs.root.mountfrom")))
174 * If a vfs set rootdev, try it (XXX VINUM HACK!)
176 if (save_rootdev
!= NULL
) {
177 rootdev
= save_rootdev
;
178 if (!vfs_mountroot_try(""))
183 * Try values that may have been computed by the machine-dependant
186 if (rootdevnames
[0] && !vfs_mountroot_try(rootdevnames
[0]))
188 if (rootdevnames
[1] && !vfs_mountroot_try(rootdevnames
[1]))
192 * If we have a compiled-in default, and haven't already tried it, try
196 if (!(boothowto
& RB_DFLTROOT
))
197 if (!vfs_mountroot_try(ROOTDEVNAME
))
202 * Everything so far has failed, prompt on the console if we haven't
203 * already tried that.
205 if (!(boothowto
& (RB_DFLTROOT
| RB_ASKNAME
)) && !vfs_mountroot_ask())
207 panic("Root mount failed, startup aborted.");
212 vfs_mountroot_devfs(void)
216 struct nlookupdata nd
;
218 struct vfsconf
*vfsp
;
220 struct ucred
*cred
= proc0
.p_ucred
;
221 const char *devfs_path
, *init_chroot
;
222 char *dev_malloced
= NULL
;
224 if ((init_chroot
= kgetenv("init_chroot")) != NULL
) {
227 l
= strlen(init_chroot
) + sizeof("/dev");
228 dev_malloced
= kmalloc(l
, M_MOUNT
, M_WAITOK
);
229 ksnprintf(dev_malloced
, l
, "%s/dev", init_chroot
);
230 devfs_path
= dev_malloced
;
235 * Lookup the requested path and extract the nch and vnode.
237 error
= nlookup_init_raw(&nd
,
238 devfs_path
, UIO_SYSSPACE
, NLC_FOLLOW
,
242 devfs_debug(DEVFS_DEBUG_DEBUG
, "vfs_mountroot_devfs: nlookup_init is ok...\n");
243 if ((error
= nlookup(&nd
)) == 0) {
244 devfs_debug(DEVFS_DEBUG_DEBUG
, "vfs_mountroot_devfs: nlookup is ok...\n");
245 if (nd
.nl_nch
.ncp
->nc_vp
== NULL
) {
246 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: nlookup: simply not found\n");
251 if (dev_malloced
!= NULL
)
252 kfree(dev_malloced
, M_MOUNT
), dev_malloced
= NULL
;
256 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: nlookup failed, error: %d\n", error
);
261 * Extract the locked+refd ncp and cleanup the nd structure
264 cache_zero(&nd
.nl_nch
);
268 * now we have the locked ref'd nch and unreferenced vnode.
271 if ((error
= vget(vp
, LK_EXCLUSIVE
)) != 0) {
273 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: vget failed\n");
278 if ((error
= vinvalbuf(vp
, V_SAVE
, 0, 0)) != 0) {
281 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: vinvalbuf failed\n");
284 if (vp
->v_type
!= VDIR
) {
287 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: vp is not VDIR\n");
291 vfsp
= vfsconf_find_by_name("devfs");
294 * Allocate and initialize the filesystem.
296 mp
= kmalloc(sizeof(struct mount
), M_MOUNT
, M_ZERO
|M_WAITOK
);
298 vfs_busy(mp
, LK_NOWAIT
);
299 mp
->mnt_op
= vfsp
->vfc_vfsops
;
301 vfsp
->vfc_refcount
++;
302 mp
->mnt_stat
.f_type
= vfsp
->vfc_typenum
;
303 mp
->mnt_flag
|= vfsp
->vfc_flags
& MNT_VISFLAGMASK
;
304 strncpy(mp
->mnt_stat
.f_fstypename
, vfsp
->vfc_name
, MFSNAMELEN
);
305 mp
->mnt_stat
.f_owner
= cred
->cr_uid
;
309 * Mount the filesystem.
311 error
= VFS_MOUNT(mp
, "/dev", NULL
, cred
);
313 vn_lock(vp
, LK_EXCLUSIVE
| LK_RETRY
);
316 * Put the new filesystem on the mount list after root. The mount
317 * point gets its own mnt_ncmountpt (unless the VFS already set one
318 * up) which represents the root of the mount. The lookup code
319 * detects the mount point going forward and checks the root of
320 * the mount going backwards.
322 * It is not necessary to invalidate or purge the vnode underneath
323 * because elements under the mount will be given their own glue
327 if (mp
->mnt_ncmountpt
.ncp
== NULL
) {
329 * allocate, then unlock, but leave the ref intact
331 cache_allocroot(&mp
->mnt_ncmountpt
, mp
, NULL
);
332 cache_unlock(&mp
->mnt_ncmountpt
);
334 mp
->mnt_ncmounton
= nch
; /* inherits ref */
335 nch
.ncp
->nc_flag
|= NCF_ISMOUNTPT
;
337 /* XXX get the root of the fs and cache_setvp(mnt_ncmountpt...) */
338 mountlist_insert(mp
, MNTINS_LAST
);
340 //checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
341 error
= vfs_allocate_syncvnode(mp
);
343 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: vfs_allocate_syncvnode failed\n");
346 error
= VFS_START(mp
, 0);
349 vn_syncer_thr_stop(mp
);
350 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_coherency_ops
);
351 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_journal_ops
);
352 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_norm_ops
);
353 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_spec_ops
);
354 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_fifo_ops
);
355 mp
->mnt_vfc
->vfc_refcount
--;
360 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: mount failed\n");
363 devfs_debug(DEVFS_DEBUG_DEBUG
, "rootmount_devfs done with error: %d\n", error
);
369 * Mount (mountfrom) as the root filesystem.
372 vfs_mountroot_try(const char *mountfrom
)
375 char *vfsname
, *devname
;
388 if (mountfrom
== NULL
)
389 return(error
); /* don't complain */
392 kprintf("Mounting root from %s\n", mountfrom
);
396 /* parse vfs name and devname */
397 vfsname
= kmalloc(MFSNAMELEN
, M_MOUNT
, M_WAITOK
);
398 devname
= kmalloc(MNAMELEN
, M_MOUNT
, M_WAITOK
);
399 mf
= kmalloc(MFSNAMELEN
+MNAMELEN
, M_MOUNT
, M_WAITOK
);
401 for (ep
= cp
; (*ep
!= 0) && (*ep
!= ';'); ep
++);
402 bzero(vfsname
, MFSNAMELEN
);
403 bzero(devname
, MNAMELEN
);
404 bzero(mf
, MFSNAMELEN
+MNAMELEN
);
405 strncpy(mf
, cp
, MFSNAMELEN
+MNAMELEN
);
407 vfsname
[0] = devname
[0] = 0;
408 ksprintf(patt
, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN
, MNAMELEN
);
409 if (ksscanf(mf
, patt
, vfsname
, devname
) < 1)
412 /* allocate a root mount */
413 error
= vfs_rootmountalloc(vfsname
,
414 devname
[0] != 0 ? devname
: ROOTNAME
, &mp
);
416 kprintf("Can't allocate root mount for filesystem '%s': %d\n",
420 mp
->mnt_flag
|= MNT_ROOTFS
;
422 /* do our best to set rootdev */
423 if ((strcmp(vfsname
, "hammer") != 0) && (devname
[0] != 0) &&
424 setrootbyname(devname
))
425 kprintf("setrootbyname failed\n");
427 /* If the root device is a type "memory disk", mount RW */
428 if (rootdev
!= NULL
&& dev_is_good(rootdev
) &&
429 (dev_dflags(rootdev
) & D_MEMDISK
)) {
430 mp
->mnt_flag
&= ~MNT_RDONLY
;
433 error
= VFS_MOUNT(mp
, NULL
, NULL
, proc0
.p_ucred
);
444 kfree(vfsname
, M_MOUNT
);
446 kfree(devname
, M_MOUNT
);
450 /* register with list of mounted filesystems */
451 mountlist_insert(mp
, MNTINS_FIRST
);
453 /* sanity check system clock against root fs timestamp */
454 inittodr(mp
->mnt_time
);
456 /* Get the vnode for '/'. Set p->p_fd->fd_cdir to reference it. */
457 mp
= mountlist_boot_getfirst();
458 if (VFS_ROOT(mp
, &vp
))
459 panic("cannot find root vnode");
460 if (mp
->mnt_ncmountpt
.ncp
== NULL
) {
461 cache_allocroot(&mp
->mnt_ncmountpt
, mp
, vp
);
462 cache_unlock(&mp
->mnt_ncmountpt
); /* leave ref intact */
465 p
->p_fd
->fd_cdir
= vp
;
466 vref(p
->p_fd
->fd_cdir
);
467 p
->p_fd
->fd_rdir
= vp
;
468 vref(p
->p_fd
->fd_rdir
);
469 vfs_cache_setroot(vp
, cache_hold(&mp
->mnt_ncmountpt
));
470 vn_unlock(vp
); /* leave ref intact */
471 cache_copy(&mp
->mnt_ncmountpt
, &p
->p_fd
->fd_ncdir
);
472 cache_copy(&mp
->mnt_ncmountpt
, &p
->p_fd
->fd_nrdir
);
475 if (mp
->mnt_syncer
== NULL
) {
476 error
= vfs_allocate_syncvnode(mp
);
478 kprintf("Warning: no syncer vp for root!\n");
484 vn_syncer_thr_stop(mp
);
488 kprintf("Root mount failed: %d\n", error
);
495 vfs_mountroot_ask_callback(char *name
, cdev_t dev
, bool is_alias
,
498 if (!is_alias
&& dev_is_good(dev
) && (dev_dflags(dev
) & D_DISK
))
499 kprintf(" \"%s\" ", name
);
504 * Spin prompting on the console for a suitable root filesystem
507 vfs_mountroot_ask(void)
512 kprintf("\nManual root filesystem specification:\n");
513 kprintf(" <fstype>:<device> Specify root (e.g. ufs:da0s1a)\n");
514 kprintf(" ? List valid disk boot devices\n");
515 kprintf(" panic Just panic\n");
516 kprintf(" abort Abort manual input\n");
518 kprintf("\nmountroot> ");
520 if (getline(name
, 128) < 0)
524 } else if (name
[0] == '?') {
525 kprintf("Possibly valid devices for root FS:\n");
526 //enumerate all disk devices
527 devfs_scan_callback(vfs_mountroot_ask_callback
, NULL
);
530 } else if (strcmp(name
, "panic") == 0) {
531 panic("panic from console");
532 } else if (strcmp(name
, "abort") == 0) {
534 } else if (vfs_mountroot_try(name
) == 0) {
543 getline(char *cp
, int limit
)
581 if (lp
- cp
>= limit
- 1) {
593 * Convert a given name to the cdev_t of the disk-like device
597 kgetdiskbyname(const char *name
)
602 * Get the base name of the device
604 if (strncmp(name
, __SYS_PATH_DEV
, sizeof(__SYS_PATH_DEV
) - 1) == 0)
605 name
+= sizeof(__SYS_PATH_DEV
) - 1;
610 rdev
= devfs_find_device_by_name("%s", name
);
612 kprintf("no disk named '%s'\n", name
);
621 * Set rootdev to match (name), given that we expect it to
622 * refer to a disk-like device.
625 setrootbyname(char *name
)
629 diskdev
= kgetdiskbyname(name
);
630 if (diskdev
!= NULL
) {
634 /* set to NULL if kgetdiskbyname() fails so that if the first rootdev is
635 * found by fails to mount and the second one isn't found, mountroot_try
636 * doesn't try again with the first one
643 DB_SHOW_COMMAND(disk
, db_getdiskbyname
)
647 if (modif
[0] == '\0') {
648 db_error("usage: show disk/devicename");
651 dev
= kgetdiskbyname(modif
);
653 db_printf("cdev_t = %p\n", dev
);
655 db_printf("No disk device matched.\n");
660 vfs_sysctl_real_root(SYSCTL_HANDLER_ARGS
)
666 real_root
= kgetenv("vfs.root.realroot");
668 if (real_root
== NULL
)
671 len
= strlen(real_root
) + 1;
673 error
= sysctl_handle_string(oidp
, real_root
, len
, req
);
678 SYSCTL_PROC(_vfs
, OID_AUTO
, real_root
,
679 CTLTYPE_STRING
| CTLFLAG_RD
, 0, 0, vfs_sysctl_real_root
,
680 "A", "Real root mount string");