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 getline(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 vfsp
->vfc_refcount
++;
303 mp
->mnt_stat
.f_type
= vfsp
->vfc_typenum
;
304 mp
->mnt_flag
|= vfsp
->vfc_flags
& MNT_VISFLAGMASK
;
305 strncpy(mp
->mnt_stat
.f_fstypename
, vfsp
->vfc_name
, MFSNAMELEN
);
306 mp
->mnt_stat
.f_owner
= cred
->cr_uid
;
310 * Mount the filesystem.
312 error
= VFS_MOUNT(mp
, "/dev", NULL
, cred
);
314 vn_lock(vp
, LK_EXCLUSIVE
| LK_RETRY
);
317 * Put the new filesystem on the mount list after root. The mount
318 * point gets its own mnt_ncmountpt (unless the VFS already set one
319 * up) which represents the root of the mount. The lookup code
320 * detects the mount point going forward and checks the root of
321 * the mount going backwards.
323 * It is not necessary to invalidate or purge the vnode underneath
324 * because elements under the mount will be given their own glue
328 if (mp
->mnt_ncmountpt
.ncp
== NULL
) {
330 * allocate, then unlock, but leave the ref intact
332 cache_allocroot(&mp
->mnt_ncmountpt
, mp
, NULL
);
333 cache_unlock(&mp
->mnt_ncmountpt
);
336 mp
->mnt_ncmounton
= nch
; /* inherits ref */
338 nch
.ncp
->nc_flag
|= NCF_ISMOUNTPT
;
340 vn_lock(vp
, LK_EXCLUSIVE
| LK_RETRY
);
343 * XXX get the root of the fs and
344 * cache_setvp(mnt_ncmountpt...)
346 mountlist_insert(mp
, MNTINS_LAST
);
348 //checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
349 error
= vfs_allocate_syncvnode(mp
);
351 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: vfs_allocate_syncvnode failed\n");
354 error
= VFS_START(mp
, 0);
357 vn_syncer_thr_stop(mp
);
358 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_coherency_ops
);
359 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_journal_ops
);
360 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_norm_ops
);
361 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_spec_ops
);
362 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_fifo_ops
);
363 mp
->mnt_vfc
->vfc_refcount
--;
368 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: mount failed\n");
371 devfs_debug(DEVFS_DEBUG_DEBUG
, "rootmount_devfs done with error: %d\n", error
);
377 * Mount (mountfrom) as the root filesystem.
380 vfs_mountroot_try(const char *mountfrom
)
383 char *vfsname
, *devname
;
396 if (mountfrom
== NULL
)
397 return(error
); /* don't complain */
400 kprintf("Mounting root from %s\n", mountfrom
);
404 /* parse vfs name and devname */
405 vfsname
= kmalloc(MFSNAMELEN
, M_MOUNT
, M_WAITOK
);
406 devname
= kmalloc(MNAMELEN
, M_MOUNT
, M_WAITOK
);
407 mf
= kmalloc(MFSNAMELEN
+MNAMELEN
, M_MOUNT
, M_WAITOK
);
409 for (ep
= cp
; (*ep
!= 0) && (*ep
!= ';'); ep
++);
410 bzero(vfsname
, MFSNAMELEN
);
411 bzero(devname
, MNAMELEN
);
412 bzero(mf
, MFSNAMELEN
+MNAMELEN
);
413 strncpy(mf
, cp
, MFSNAMELEN
+MNAMELEN
);
415 vfsname
[0] = devname
[0] = 0;
416 ksprintf(patt
, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN
, MNAMELEN
);
417 if (ksscanf(mf
, patt
, vfsname
, devname
) < 1)
420 /* allocate a root mount */
421 error
= vfs_rootmountalloc(vfsname
,
422 devname
[0] != 0 ? devname
: ROOTNAME
, &mp
);
424 kprintf("Can't allocate root mount for filesystem '%s': %d\n",
428 mp
->mnt_flag
|= MNT_ROOTFS
;
430 /* do our best to set rootdev (really just for UFS) */
431 if (strcmp(vfsname
, "hammer") != 0 &&
432 strcmp(vfsname
, "hammer2") != 0 &&
433 (devname
[0] != 0) && setrootbyname(devname
)) {
434 kprintf("setrootbyname failed\n");
437 /* If the root device is a type "memory disk", mount RW */
438 if (rootdev
!= NULL
&& dev_is_good(rootdev
) &&
439 (dev_dflags(rootdev
) & D_MEMDISK
)) {
440 mp
->mnt_flag
&= ~MNT_RDONLY
;
443 error
= VFS_MOUNT(mp
, NULL
, NULL
, proc0
.p_ucred
);
454 kfree(vfsname
, M_MOUNT
);
456 kfree(devname
, M_MOUNT
);
460 /* register with list of mounted filesystems */
461 mountlist_insert(mp
, MNTINS_FIRST
);
463 /* sanity check system clock against root fs timestamp */
464 inittodr(mp
->mnt_time
);
466 /* Get the vnode for '/'. Set p->p_fd->fd_cdir to reference it. */
467 mp
= mountlist_boot_getfirst();
468 if (VFS_ROOT(mp
, &vp
))
469 panic("cannot find root vnode");
470 if (mp
->mnt_ncmountpt
.ncp
== NULL
) {
471 cache_allocroot(&mp
->mnt_ncmountpt
, mp
, vp
);
472 cache_unlock(&mp
->mnt_ncmountpt
); /* leave ref intact */
475 p
->p_fd
->fd_cdir
= vp
;
476 vref(p
->p_fd
->fd_cdir
);
477 p
->p_fd
->fd_rdir
= vp
;
478 vref(p
->p_fd
->fd_rdir
);
479 vfs_cache_setroot(vp
, cache_hold(&mp
->mnt_ncmountpt
));
480 vn_unlock(vp
); /* leave ref intact */
481 cache_copy(&mp
->mnt_ncmountpt
, &p
->p_fd
->fd_ncdir
);
482 cache_copy(&mp
->mnt_ncmountpt
, &p
->p_fd
->fd_nrdir
);
485 if (mp
->mnt_syncer
== NULL
) {
486 error
= vfs_allocate_syncvnode(mp
);
488 kprintf("Warning: no syncer vp for root!\n");
494 vn_syncer_thr_stop(mp
);
498 kprintf("Root mount failed: %d\n", error
);
505 vfs_mountroot_ask_callback(char *name
, cdev_t dev
, bool is_alias
,
508 if (!is_alias
&& dev_is_good(dev
) && (dev_dflags(dev
) & D_DISK
))
509 kprintf(" \"%s\" ", name
);
514 * Spin prompting on the console for a suitable root filesystem
517 vfs_mountroot_ask(void)
522 kprintf("\nManual root filesystem specification:\n");
523 kprintf(" <fstype>:<device> Specify root (e.g. ufs:da0s1a)\n");
524 kprintf(" ? List valid disk boot devices\n");
525 kprintf(" panic Just panic\n");
526 kprintf(" abort Abort manual input\n");
528 kprintf("\nmountroot> ");
530 if (getline(name
, 128) < 0)
534 } else if (name
[0] == '?') {
535 kprintf("Possibly valid devices for root FS:\n");
536 //enumerate all disk devices
537 devfs_scan_callback(vfs_mountroot_ask_callback
, NULL
);
540 } else if (strcmp(name
, "panic") == 0) {
541 panic("panic from console");
542 } else if (strcmp(name
, "abort") == 0) {
544 } else if (vfs_mountroot_try(name
) == 0) {
553 getline(char *cp
, int limit
)
566 tsleep(&dummy
, 0, "cnpoll", hz
/ 25);
592 /* NOTE: '@' no longer processed here, used for H2 */
597 if (lp
- cp
>= limit
- 1) {
612 * Convert a given name to the cdev_t of the disk-like device
616 kgetdiskbyname(const char *name
)
621 * Get the base name of the device
623 if (strncmp(name
, __SYS_PATH_DEV
, sizeof(__SYS_PATH_DEV
) - 1) == 0)
624 name
+= sizeof(__SYS_PATH_DEV
) - 1;
629 rdev
= devfs_find_device_by_name("%s", name
);
631 kprintf("no disk named '%s'\n", name
);
640 * Set rootdev to match (name), given that we expect it to
641 * refer to a disk-like device.
644 setrootbyname(char *name
)
648 diskdev
= kgetdiskbyname(name
);
649 if (diskdev
!= NULL
) {
653 /* set to NULL if kgetdiskbyname() fails so that if the first rootdev is
654 * found by fails to mount and the second one isn't found, mountroot_try
655 * doesn't try again with the first one
662 DB_SHOW_COMMAND(disk
, db_getdiskbyname
)
666 if (modif
[0] == '\0') {
667 db_error("usage: show disk/devicename");
670 dev
= kgetdiskbyname(modif
);
672 db_printf("cdev_t = %p\n", dev
);
674 db_printf("No disk device matched.\n");
679 vfs_sysctl_real_root(SYSCTL_HANDLER_ARGS
)
685 real_root
= kgetenv("vfs.root.realroot");
687 if (real_root
== NULL
)
690 len
= strlen(real_root
) + 1;
692 error
= sysctl_handle_string(oidp
, real_root
, len
, req
);
697 SYSCTL_PROC(_vfs
, OID_AUTO
, real_root
,
698 CTLTYPE_STRING
| CTLFLAG_RD
, 0, 0, vfs_sysctl_real_root
,
699 "A", "Real root mount string");