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.
118 * Messages can fly around here so get good synchronization
124 * The root filesystem information is compiled in, and we are
125 * booted with instructions to use it.
128 if ((boothowto & RB_DFLTROOT) &&
129 !vfs_mountroot_try(ROOTDEVNAME))
133 * We are booted with instructions to prompt for the root filesystem,
134 * or to use the compiled-in default when it doesn't exist.
136 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) {
137 if (!vfs_mountroot_ask())
142 * We've been given the generic "use CDROM as root" flag. This is
143 * necessary because one media may be used in many different
144 * devices, so we need to search for them.
146 if (boothowto & RB_CDROM) {
147 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
148 if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
154 * Try to use the value read by the loader from /etc/fstab, or
155 * supplied via some other means. This is the preferred
158 if (!vfs_mountroot_try(kgetenv("vfs.root.mountfrom")))
162 * If a vfs set rootdev, try it (XXX VINUM HACK!)
164 if (save_rootdev != NULL) {
165 rootdev = save_rootdev;
166 if (!vfs_mountroot_try(""))
171 * Try values that may have been computed by the machine-dependant
174 if (rootdevnames[0] && !vfs_mountroot_try(rootdevnames[0]))
176 if (rootdevnames[1] && !vfs_mountroot_try(rootdevnames[1]))
180 * If we have a compiled-in default, and haven't already tried it, try
184 if (!(boothowto & RB_DFLTROOT))
185 if (!vfs_mountroot_try(ROOTDEVNAME))
190 * Everything so far has failed, prompt on the console if we haven't
191 * already tried that.
193 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask())
195 panic("Root mount failed, startup aborted.");
200 vfs_mountroot_devfs(void)
204 struct nlookupdata nd;
206 struct vfsconf *vfsp;
208 struct ucred *cred = proc0.p_ucred;
211 * Lookup the requested path and extract the nch and vnode.
213 error = nlookup_init_raw(&nd,
214 "/dev", UIO_SYSSPACE, NLC_FOLLOW,
218 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup_init is ok...\n");
219 if ((error = nlookup(&nd)) == 0) {
220 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup is ok...\n");
221 if (nd.nl_nch.ncp->nc_vp == NULL) {
222 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup: simply not found\n");
229 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup failed, error: %d\n", error);
234 * Extract the locked+refd ncp and cleanup the nd structure
237 cache_zero(&nd.nl_nch);
241 * now we have the locked ref'd nch and unreferenced vnode.
244 if ((error = vget(vp, LK_EXCLUSIVE)) != 0) {
246 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vget failed\n");
251 if ((error = vinvalbuf(vp, V_SAVE, 0, 0)) != 0) {
254 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vinvalbuf failed\n");
257 if (vp->v_type != VDIR) {
260 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vp is not VDIR\n");
264 vfsp = vfsconf_find_by_name("devfs");
265 vp->v_flag |= VMOUNT;
268 * Allocate and initialize the filesystem.
270 mp = kmalloc(sizeof(struct mount), M_MOUNT, M_ZERO|M_WAITOK);
271 TAILQ_INIT(&mp->mnt_nvnodelist);
272 TAILQ_INIT(&mp->mnt_reservedvnlist);
273 TAILQ_INIT(&mp->mnt_jlist);
274 mp->mnt_nvnodelistsize = 0;
275 lockinit(&mp->mnt_lock, "vfslock", 0, 0);
276 vfs_busy(mp, LK_NOWAIT);
277 mp->mnt_op = vfsp->vfc_vfsops;
279 vfsp->vfc_refcount++;
280 mp->mnt_stat.f_type = vfsp->vfc_typenum;
281 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
282 strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
283 mp->mnt_stat.f_owner = cred->cr_uid;
284 mp->mnt_iosize_max = DFLTPHYS;
288 * Mount the filesystem.
290 error = VFS_MOUNT(mp, "/dev", NULL, cred);
292 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
295 * Put the new filesystem on the mount list after root. The mount
296 * point gets its own mnt_ncmountpt (unless the VFS already set one
297 * up) which represents the root of the mount. The lookup code
298 * detects the mount point going forward and checks the root of
299 * the mount going backwards.
301 * It is not necessary to invalidate or purge the vnode underneath
302 * because elements under the mount will be given their own glue
306 if (mp->mnt_ncmountpt.ncp == NULL) {
308 * allocate, then unlock, but leave the ref intact
310 cache_allocroot(&mp->mnt_ncmountpt, mp, NULL);
311 cache_unlock(&mp->mnt_ncmountpt);
313 mp->mnt_ncmounton = nch; /* inherits ref */
314 nch.ncp->nc_flag |= NCF_ISMOUNTPT;
316 /* XXX get the root of the fs and cache_setvp(mnt_ncmountpt...) */
317 vp->v_flag &= ~VMOUNT;
318 mountlist_insert(mp, MNTINS_LAST);
320 //checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
321 error = vfs_allocate_syncvnode(mp);
323 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vfs_allocate_syncvnode failed\n");
326 error = VFS_START(mp, 0);
329 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
330 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
331 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
332 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
333 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
334 vp->v_flag &= ~VMOUNT;
335 mp->mnt_vfc->vfc_refcount--;
340 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: mount failed\n");
343 devfs_debug(DEVFS_DEBUG_DEBUG, "rootmount_devfs done with error: %d\n", error);
349 * Mount (mountfrom) as the root filesystem.
352 vfs_mountroot_try(const char *mountfrom)
354 struct mount *mp, *mp2;
355 char *vfsname, *devname;
365 if (mountfrom == NULL)
366 return(error); /* don't complain */
369 kprintf("Mounting root from %s\n", mountfrom);
372 /* parse vfs name and devname */
373 vfsname = kmalloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
374 devname = kmalloc(MNAMELEN, M_MOUNT, M_WAITOK);
375 vfsname[0] = devname[0] = 0;
376 ksprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
377 if (ksscanf(mountfrom, patt, vfsname, devname) < 1)
380 /* allocate a root mount */
381 error = vfs_rootmountalloc(vfsname,
382 devname[0] != 0 ? devname : ROOTNAME, &mp);
384 kprintf("Can't allocate root mount for filesystem '%s': %d\n",
388 mp->mnt_flag |= MNT_ROOTFS;
390 /* do our best to set rootdev */
391 if ((devname[0] != 0) && setrootbyname(devname))
392 kprintf("setrootbyname failed\n");
394 /* If the root device is a type "memory disk", mount RW */
395 if (rootdev != NULL && dev_is_good(rootdev) &&
396 (dev_dflags(rootdev) & D_MEMDISK)) {
397 mp->mnt_flag &= ~MNT_RDONLY;
400 error = VFS_MOUNT(mp, NULL, NULL, proc0.p_ucred);
403 //kprintf("Trying vfs_mountroot_devfs!\n");
404 //vfs_mountroot_devfs();
409 kfree(vfsname, M_MOUNT);
411 kfree(devname, M_MOUNT);
413 /* register with list of mounted filesystems */
414 mountlist_insert(mp, MNTINS_FIRST);
416 /* sanity check system clock against root fs timestamp */
417 inittodr(mp->mnt_time);
419 if (mp->mnt_syncer == NULL) {
420 error = vfs_allocate_syncvnode(mp);
422 kprintf("Warning: no syncer vp for root!\n");
430 kprintf("Root mount failed: %d\n", error);
436 static void vfs_mountroot_ask_callback(cdev_t);
439 * Spin prompting on the console for a suitable root filesystem
443 vfs_mountroot_ask(void)
448 kprintf("\nManual root filesystem specification:\n");
449 kprintf(" <fstype>:<device> Specify root (e.g. ufs:da0s1a)\n");
450 kprintf(" ? List valid disk boot devices\n");
451 kprintf(" panic Just panic\n");
452 kprintf(" abort Abort manual input\n");
454 kprintf("\nmountroot> ");
456 if (getline(name, 128) < 0)
460 } else if (name[0] == '?') {
461 kprintf("Possibly valid devices for root FS:\n");
462 //enumerate all disk devices
463 devfs_scan_callback(vfs_mountroot_ask_callback);
466 } else if (strcmp(name, "panic") == 0) {
467 panic("panic from console");
468 } else if (strcmp(name, "abort") == 0) {
470 } else if (vfs_mountroot_try(name) == 0) {
479 vfs_mountroot_ask_callback(cdev_t dev)
481 if (dev_is_good(dev) && (dev_dflags(dev) & D_DISK))
482 kprintf(" \"%s\" ", dev->si_name);
487 getline(char *cp, int limit)
525 if (lp - cp >= limit - 1) {
537 * Convert a given name to the cdev_t of the disk-like device
549 kgetdiskbyname(const char *name)
555 * Get the base name of the device
557 if (strncmp(name, __SYS_PATH_DEV, sizeof(__SYS_PATH_DEV) - 1) == 0)
558 name += sizeof(__SYS_PATH_DEV) - 1;
559 cp = __DECONST(char *, name);
564 kprintf("tryroot %s\n", name);
565 rdev = devfs_find_device_by_name(name);
567 kprintf("no disk named '%s'\n", name);
576 * Set rootdev to match (name), given that we expect it to
577 * refer to a disk-like device.
580 setrootbyname(char *name)
584 diskdev = kgetdiskbyname(name);
585 if (diskdev != NULL) {
589 /* set to NULL if kgetdiskbyname() fails so that if the first rootdev is
590 * found by fails to mount and the second one isn't found, mountroot_try
591 * doesn't try again with the first one
598 DB_SHOW_COMMAND(disk, db_getdiskbyname)
602 if (modif[0] == '\0') {
603 db_error("usage: show disk/devicename");
606 dev = kgetdiskbyname(modif);
608 db_printf("cdev_t = %p\n", dev);
610 db_printf("No disk device matched.\n");