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 <sys/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
[] = {
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
);
107 * Find and mount the root filesystem
110 vfs_mountroot(void *junk
)
112 cdev_t save_rootdev
= rootdev
;
117 * Make sure all disk devices created so far have also been probed,
118 * and also make sure that the newly created device nodes for
119 * probed disks are ready, too.
121 * Messages can fly around here so get good synchronization
124 * XXX - Delay an additional 2 seconds to help drivers which pickup
125 * devices asynchronously and are not caught by CAM's initial
129 tsleep(&dummy
, 0, "syncer", hz
*2);
133 * The root filesystem information is compiled in, and we are
134 * booted with instructions to use it.
137 if ((boothowto
& RB_DFLTROOT
) &&
138 !vfs_mountroot_try(ROOTDEVNAME
))
142 * We are booted with instructions to prompt for the root filesystem,
143 * or to use the compiled-in default when it doesn't exist.
145 if (boothowto
& (RB_DFLTROOT
| RB_ASKNAME
)) {
146 if (!vfs_mountroot_ask())
151 * We've been given the generic "use CDROM as root" flag. This is
152 * necessary because one media may be used in many different
153 * devices, so we need to search for them.
155 if (boothowto
& RB_CDROM
) {
156 for (i
= 0; cdrom_rootdevnames
[i
] != NULL
; i
++) {
157 if (!vfs_mountroot_try(cdrom_rootdevnames
[i
]))
163 * Try to use the value read by the loader from /etc/fstab, or
164 * supplied via some other means. This is the preferred
167 if (!vfs_mountroot_try(kgetenv("vfs.root.mountfrom")))
171 * If a vfs set rootdev, try it (XXX VINUM HACK!)
173 if (save_rootdev
!= NULL
) {
174 rootdev
= save_rootdev
;
175 if (!vfs_mountroot_try(""))
180 * Try values that may have been computed by the machine-dependant
183 if (rootdevnames
[0] && !vfs_mountroot_try(rootdevnames
[0]))
185 if (rootdevnames
[1] && !vfs_mountroot_try(rootdevnames
[1]))
189 * If we have a compiled-in default, and haven't already tried it, try
193 if (!(boothowto
& RB_DFLTROOT
))
194 if (!vfs_mountroot_try(ROOTDEVNAME
))
199 * Everything so far has failed, prompt on the console if we haven't
200 * already tried that.
202 if (!(boothowto
& (RB_DFLTROOT
| RB_ASKNAME
)) && !vfs_mountroot_ask())
204 panic("Root mount failed, startup aborted.");
209 vfs_mountroot_devfs(void)
213 struct nlookupdata nd
;
215 struct vfsconf
*vfsp
;
217 struct ucred
*cred
= proc0
.p_ucred
;
220 * Lookup the requested path and extract the nch and vnode.
222 error
= nlookup_init_raw(&nd
,
223 "/dev", UIO_SYSSPACE
, NLC_FOLLOW
,
227 devfs_debug(DEVFS_DEBUG_DEBUG
, "vfs_mountroot_devfs: nlookup_init is ok...\n");
228 if ((error
= nlookup(&nd
)) == 0) {
229 devfs_debug(DEVFS_DEBUG_DEBUG
, "vfs_mountroot_devfs: nlookup is ok...\n");
230 if (nd
.nl_nch
.ncp
->nc_vp
== NULL
) {
231 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: nlookup: simply not found\n");
238 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: nlookup failed, error: %d\n", error
);
243 * Extract the locked+refd ncp and cleanup the nd structure
246 cache_zero(&nd
.nl_nch
);
250 * now we have the locked ref'd nch and unreferenced vnode.
253 if ((error
= vget(vp
, LK_EXCLUSIVE
)) != 0) {
255 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: vget failed\n");
260 if ((error
= vinvalbuf(vp
, V_SAVE
, 0, 0)) != 0) {
263 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: vinvalbuf failed\n");
266 if (vp
->v_type
!= VDIR
) {
269 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: vp is not VDIR\n");
273 vfsp
= vfsconf_find_by_name("devfs");
274 vsetflags(vp
, VMOUNT
);
277 * Allocate and initialize the filesystem.
279 mp
= kmalloc(sizeof(struct mount
), M_MOUNT
, M_ZERO
|M_WAITOK
);
281 vfs_busy(mp
, LK_NOWAIT
);
282 mp
->mnt_op
= vfsp
->vfc_vfsops
;
284 vfsp
->vfc_refcount
++;
285 mp
->mnt_stat
.f_type
= vfsp
->vfc_typenum
;
286 mp
->mnt_flag
|= vfsp
->vfc_flags
& MNT_VISFLAGMASK
;
287 strncpy(mp
->mnt_stat
.f_fstypename
, vfsp
->vfc_name
, MFSNAMELEN
);
288 mp
->mnt_stat
.f_owner
= cred
->cr_uid
;
292 * Mount the filesystem.
294 error
= VFS_MOUNT(mp
, "/dev", NULL
, cred
);
296 vn_lock(vp
, LK_EXCLUSIVE
| LK_RETRY
);
299 * Put the new filesystem on the mount list after root. The mount
300 * point gets its own mnt_ncmountpt (unless the VFS already set one
301 * up) which represents the root of the mount. The lookup code
302 * detects the mount point going forward and checks the root of
303 * the mount going backwards.
305 * It is not necessary to invalidate or purge the vnode underneath
306 * because elements under the mount will be given their own glue
310 if (mp
->mnt_ncmountpt
.ncp
== NULL
) {
312 * allocate, then unlock, but leave the ref intact
314 cache_allocroot(&mp
->mnt_ncmountpt
, mp
, NULL
);
315 cache_unlock(&mp
->mnt_ncmountpt
);
317 mp
->mnt_ncmounton
= nch
; /* inherits ref */
318 nch
.ncp
->nc_flag
|= NCF_ISMOUNTPT
;
320 /* XXX get the root of the fs and cache_setvp(mnt_ncmountpt...) */
321 vclrflags(vp
, VMOUNT
);
322 mountlist_insert(mp
, MNTINS_LAST
);
324 //checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
325 error
= vfs_allocate_syncvnode(mp
);
327 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: vfs_allocate_syncvnode failed\n");
330 error
= VFS_START(mp
, 0);
333 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_coherency_ops
);
334 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_journal_ops
);
335 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_norm_ops
);
336 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_spec_ops
);
337 vfs_rm_vnodeops(mp
, NULL
, &mp
->mnt_vn_fifo_ops
);
338 vclrflags(vp
, VMOUNT
);
339 mp
->mnt_vfc
->vfc_refcount
--;
344 devfs_debug(DEVFS_DEBUG_SHOW
, "vfs_mountroot_devfs: mount failed\n");
347 devfs_debug(DEVFS_DEBUG_DEBUG
, "rootmount_devfs done with error: %d\n", error
);
353 * Mount (mountfrom) as the root filesystem.
356 vfs_mountroot_try(const char *mountfrom
)
358 struct mount
*mp
, *mp2
;
359 char *vfsname
, *devname
;
362 int mountfromlen
, len
;
372 if (mountfrom
== NULL
)
373 return(error
); /* don't complain */
376 kprintf("Mounting root from %s\n", mountfrom
);
379 mountfromlen
= strlen(mountfrom
);
381 /* parse vfs name and devname */
382 vfsname
= kmalloc(MFSNAMELEN
, M_MOUNT
, M_WAITOK
);
383 devname
= kmalloc(MNAMELEN
, M_MOUNT
, M_WAITOK
);
384 mf
= kmalloc(MFSNAMELEN
+MNAMELEN
, M_MOUNT
, M_WAITOK
);
386 for (ep
= cp
; (*ep
!= 0) && (*ep
!= ';'); ep
++);
388 bzero(vfsname
, MFSNAMELEN
);
389 bzero(devname
, MNAMELEN
);
390 bzero(mf
, MFSNAMELEN
+MNAMELEN
);
391 strncpy(mf
, cp
, MFSNAMELEN
+MNAMELEN
);
393 vfsname
[0] = devname
[0] = 0;
394 ksprintf(patt
, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN
, MNAMELEN
);
395 if (ksscanf(mf
, patt
, vfsname
, devname
) < 1)
398 /* allocate a root mount */
399 error
= vfs_rootmountalloc(vfsname
,
400 devname
[0] != 0 ? devname
: ROOTNAME
, &mp
);
402 kprintf("Can't allocate root mount for filesystem '%s': %d\n",
406 mp
->mnt_flag
|= MNT_ROOTFS
;
408 /* do our best to set rootdev */
409 if ((strcmp(vfsname
, "hammer") != 0) && (devname
[0] != 0) &&
410 setrootbyname(devname
))
411 kprintf("setrootbyname failed\n");
413 /* If the root device is a type "memory disk", mount RW */
414 if (rootdev
!= NULL
&& dev_is_good(rootdev
) &&
415 (dev_dflags(rootdev
) & D_MEMDISK
)) {
416 mp
->mnt_flag
&= ~MNT_RDONLY
;
419 error
= VFS_MOUNT(mp
, NULL
, NULL
, proc0
.p_ucred
);
430 kfree(vfsname
, M_MOUNT
);
432 kfree(devname
, M_MOUNT
);
436 /* register with list of mounted filesystems */
437 mountlist_insert(mp
, MNTINS_FIRST
);
439 /* sanity check system clock against root fs timestamp */
440 inittodr(mp
->mnt_time
);
442 if (mp
->mnt_syncer
== NULL
) {
443 error
= vfs_allocate_syncvnode(mp
);
445 kprintf("Warning: no syncer vp for root!\n");
453 kprintf("Root mount failed: %d\n", error
);
459 static void vfs_mountroot_ask_callback(cdev_t
);
462 * Spin prompting on the console for a suitable root filesystem
466 vfs_mountroot_ask(void)
471 kprintf("\nManual root filesystem specification:\n");
472 kprintf(" <fstype>:<device> Specify root (e.g. ufs:da0s1a)\n");
473 kprintf(" ? List valid disk boot devices\n");
474 kprintf(" panic Just panic\n");
475 kprintf(" abort Abort manual input\n");
477 kprintf("\nmountroot> ");
479 if (getline(name
, 128) < 0)
483 } else if (name
[0] == '?') {
484 kprintf("Possibly valid devices for root FS:\n");
485 //enumerate all disk devices
486 devfs_scan_callback(vfs_mountroot_ask_callback
);
489 } else if (strcmp(name
, "panic") == 0) {
490 panic("panic from console");
491 } else if (strcmp(name
, "abort") == 0) {
493 } else if (vfs_mountroot_try(name
) == 0) {
502 vfs_mountroot_ask_callback(cdev_t dev
)
504 if (dev_is_good(dev
) && (dev_dflags(dev
) & D_DISK
))
505 kprintf(" \"%s\" ", dev
->si_name
);
510 getline(char *cp
, int limit
)
548 if (lp
- cp
>= limit
- 1) {
560 * Convert a given name to the cdev_t of the disk-like device
572 kgetdiskbyname(const char *name
)
578 * Get the base name of the device
580 if (strncmp(name
, __SYS_PATH_DEV
, sizeof(__SYS_PATH_DEV
) - 1) == 0)
581 name
+= sizeof(__SYS_PATH_DEV
) - 1;
582 cp
= __DECONST(char *, name
);
587 kprintf("tryroot %s\n", name
);
588 rdev
= devfs_find_device_by_name(name
);
590 kprintf("no disk named '%s'\n", name
);
599 * Set rootdev to match (name), given that we expect it to
600 * refer to a disk-like device.
603 setrootbyname(char *name
)
607 diskdev
= kgetdiskbyname(name
);
608 if (diskdev
!= NULL
) {
612 /* set to NULL if kgetdiskbyname() fails so that if the first rootdev is
613 * found by fails to mount and the second one isn't found, mountroot_try
614 * doesn't try again with the first one
621 DB_SHOW_COMMAND(disk
, db_getdiskbyname
)
625 if (modif
[0] == '\0') {
626 db_error("usage: show disk/devicename");
629 dev
= kgetdiskbyname(modif
);
631 db_printf("cdev_t = %p\n", dev
);
633 db_printf("No disk device matched.\n");