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freebsd/sys/kern/vfs_mountroot.c

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/*-
* Copyright (c) 2010 Marcel Moolenaar
* Copyright (c) 1999-2004 Poul-Henning Kamp
* Copyright (c) 1999 Michael Smith
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "opt_rootdevname.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/fcntl.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mdioctl.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/filedesc.h>
#include <sys/reboot.h>
2011-07-11 05:17:46 +00:00
#include <sys/sbuf.h>
#include <sys/stat.h>
#include <sys/syscallsubr.h>
#include <sys/sysproto.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <geom/geom.h>
/*
* The root filesystem is detailed in the kernel environment variable
* vfs.root.mountfrom, which is expected to be in the general format
*
* <vfsname>:[<path>][ <vfsname>:[<path>] ...]
* vfsname := the name of a VFS known to the kernel and capable
* of being mounted as root
* path := disk device name or other data used by the filesystem
* to locate its physical store
*
* If the environment variable vfs.root.mountfrom is a space separated list,
* each list element is tried in turn and the root filesystem will be mounted
* from the first one that suceeds.
*
* The environment variable vfs.root.mountfrom.options is a comma delimited
* set of string mount options. These mount options must be parseable
* by nmount() in the kernel.
*/
static int parse_mount(char **);
static struct mntarg *parse_mountroot_options(struct mntarg *, const char *);
/*
* The vnode of the system's root (/ in the filesystem, without chroot
* active.)
*/
struct vnode *rootvnode;
/*
* Mount of the system's /dev.
*/
struct mount *rootdevmp;
char *rootdevnames[2] = {NULL, NULL};
struct mtx root_holds_mtx;
MTX_SYSINIT(root_holds, &root_holds_mtx, "root_holds", MTX_DEF);
struct root_hold_token {
const char *who;
LIST_ENTRY(root_hold_token) list;
};
static LIST_HEAD(, root_hold_token) root_holds =
LIST_HEAD_INITIALIZER(root_holds);
enum action {
A_CONTINUE,
A_PANIC,
A_REBOOT,
A_RETRY
};
static enum action root_mount_onfail = A_CONTINUE;
static int root_mount_mddev;
static int root_mount_complete;
/* By default wait up to 3 seconds for devices to appear. */
static int root_mount_timeout = 3;
2013-08-03 04:25:25 +00:00
TUNABLE_INT("vfs.mountroot.timeout", &root_mount_timeout);
struct root_hold_token *
root_mount_hold(const char *identifier)
{
struct root_hold_token *h;
if (root_mounted())
return (NULL);
h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
h->who = identifier;
mtx_lock(&root_holds_mtx);
LIST_INSERT_HEAD(&root_holds, h, list);
mtx_unlock(&root_holds_mtx);
return (h);
}
void
root_mount_rel(struct root_hold_token *h)
{
if (h == NULL)
return;
mtx_lock(&root_holds_mtx);
LIST_REMOVE(h, list);
wakeup(&root_holds);
mtx_unlock(&root_holds_mtx);
free(h, M_DEVBUF);
}
int
root_mounted(void)
{
/* No mutex is acquired here because int stores are atomic. */
return (root_mount_complete);
}
void
root_mount_wait(void)
{
/*
* Panic on an obvious deadlock - the function can't be called from
* a thread which is doing the whole SYSINIT stuff.
*/
KASSERT(curthread->td_proc->p_pid != 0,
("root_mount_wait: cannot be called from the swapper thread"));
mtx_lock(&root_holds_mtx);
while (!root_mount_complete) {
msleep(&root_mount_complete, &root_holds_mtx, PZERO, "rootwait",
hz);
}
mtx_unlock(&root_holds_mtx);
}
static void
set_rootvnode(void)
{
struct proc *p;
if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
panic("Cannot find root vnode");
VOP_UNLOCK(rootvnode, 0);
p = curthread->td_proc;
FILEDESC_XLOCK(p->p_fd);
if (p->p_fd->fd_cdir != NULL)
vrele(p->p_fd->fd_cdir);
p->p_fd->fd_cdir = rootvnode;
VREF(rootvnode);
if (p->p_fd->fd_rdir != NULL)
vrele(p->p_fd->fd_rdir);
p->p_fd->fd_rdir = rootvnode;
VREF(rootvnode);
FILEDESC_XUNLOCK(p->p_fd);
}
static int
vfs_mountroot_devfs(struct thread *td, struct mount **mpp)
{
struct vfsoptlist *opts;
struct vfsconf *vfsp;
struct mount *mp;
int error;
*mpp = NULL;
if (rootdevmp != NULL) {
/*
* Already have /dev; this happens during rerooting.
*/
error = vfs_busy(rootdevmp, 0);
if (error != 0)
return (error);
*mpp = rootdevmp;
} else {
vfsp = vfs_byname("devfs");
KASSERT(vfsp != NULL, ("Could not find devfs by name"));
if (vfsp == NULL)
return (ENOENT);
mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
error = VFS_MOUNT(mp);
KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
if (error)
return (error);
opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
TAILQ_INIT(opts);
mp->mnt_opt = opts;
mtx_lock(&mountlist_mtx);
TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
*mpp = mp;
rootdevmp = mp;
}
set_rootvnode();
error = kern_symlinkat(td, "/", AT_FDCWD, "dev", UIO_SYSSPACE);
if (error)
printf("kern_symlink /dev -> / returns %d\n", error);
return (error);
}
static int
vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs)
{
struct nameidata nd;
struct mount *mporoot, *mpnroot;
struct vnode *vp, *vporoot, *vpdevfs;
char *fspath;
int error;
mpnroot = TAILQ_NEXT(mpdevfs, mnt_list);
/* Shuffle the mountlist. */
mtx_lock(&mountlist_mtx);
mporoot = TAILQ_FIRST(&mountlist);
TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list);
if (mporoot != mpdevfs) {
TAILQ_REMOVE(&mountlist, mpnroot, mnt_list);
TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list);
}
TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list);
mtx_unlock(&mountlist_mtx);
cache_purgevfs(mporoot);
if (mporoot != mpdevfs)
cache_purgevfs(mpdevfs);
VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot);
VI_LOCK(vporoot);
vporoot->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vporoot);
vporoot->v_mountedhere = NULL;
mporoot->mnt_flag &= ~MNT_ROOTFS;
mporoot->mnt_vnodecovered = NULL;
vput(vporoot);
/* Set up the new rootvnode, and purge the cache */
mpnroot->mnt_vnodecovered = NULL;
set_rootvnode();
cache_purgevfs(rootvnode->v_mount);
if (mporoot != mpdevfs) {
/* Remount old root under /.mount or /mnt */
fspath = "/.mount";
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
fspath, td);
error = namei(&nd);
if (error) {
NDFREE(&nd, NDF_ONLY_PNBUF);
fspath = "/mnt";
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
fspath, td);
error = namei(&nd);
}
if (!error) {
vp = nd.ni_vp;
error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
if (!error)
error = vinvalbuf(vp, V_SAVE, 0, 0);
if (!error) {
cache_purge(vp);
mporoot->mnt_vnodecovered = vp;
vp->v_mountedhere = mporoot;
strlcpy(mporoot->mnt_stat.f_mntonname,
fspath, MNAMELEN);
VOP_UNLOCK(vp, 0);
} else
vput(vp);
}
NDFREE(&nd, NDF_ONLY_PNBUF);
if (error && bootverbose)
printf("mountroot: unable to remount previous root "
"under /.mount or /mnt (error %d).\n", error);
}
/* Remount devfs under /dev */
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
error = namei(&nd);
if (!error) {
vp = nd.ni_vp;
error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
if (!error)
error = vinvalbuf(vp, V_SAVE, 0, 0);
if (!error) {
vpdevfs = mpdevfs->mnt_vnodecovered;
if (vpdevfs != NULL) {
cache_purge(vpdevfs);
vpdevfs->v_mountedhere = NULL;
vrele(vpdevfs);
}
mpdevfs->mnt_vnodecovered = vp;
vp->v_mountedhere = mpdevfs;
VOP_UNLOCK(vp, 0);
} else
vput(vp);
}
if (error && bootverbose)
printf("mountroot: unable to remount devfs under /dev "
"(error %d).\n", error);
NDFREE(&nd, NDF_ONLY_PNBUF);
if (mporoot == mpdevfs) {
vfs_unbusy(mpdevfs);
/* Unlink the no longer needed /dev/dev -> / symlink */
error = kern_unlinkat(td, AT_FDCWD, "/dev/dev",
UIO_SYSSPACE, 0);
if (error && bootverbose)
printf("mountroot: unable to unlink /dev/dev "
"(error %d)\n", error);
}
return (0);
}
/*
* Configuration parser.
*/
/* Parser character classes. */
#define CC_WHITESPACE -1
#define CC_NONWHITESPACE -2
/* Parse errors. */
#define PE_EOF -1
#define PE_EOL -2
static __inline int
parse_peek(char **conf)
{
return (**conf);
}
static __inline void
parse_poke(char **conf, int c)
{
**conf = c;
}
static __inline void
parse_advance(char **conf)
{
(*conf)++;
}
static int
parse_skipto(char **conf, int mc)
{
int c, match;
while (1) {
c = parse_peek(conf);
if (c == 0)
return (PE_EOF);
switch (mc) {
case CC_WHITESPACE:
match = (c == ' ' || c == '\t' || c == '\n') ? 1 : 0;
break;
case CC_NONWHITESPACE:
if (c == '\n')
return (PE_EOL);
match = (c != ' ' && c != '\t') ? 1 : 0;
break;
default:
match = (c == mc) ? 1 : 0;
break;
}
if (match)
break;
parse_advance(conf);
}
return (0);
}
static int
parse_token(char **conf, char **tok)
{
char *p;
size_t len;
int error;
*tok = NULL;
error = parse_skipto(conf, CC_NONWHITESPACE);
if (error)
return (error);
p = *conf;
error = parse_skipto(conf, CC_WHITESPACE);
len = *conf - p;
*tok = malloc(len + 1, M_TEMP, M_WAITOK | M_ZERO);
bcopy(p, *tok, len);
return (0);
}
static void
parse_dir_ask_printenv(const char *var)
{
char *val;
val = kern_getenv(var);
if (val != NULL) {
printf(" %s=%s\n", var, val);
freeenv(val);
}
}
static int
parse_dir_ask(char **conf)
{
char name[80];
char *mnt;
int error;
printf("\nLoader variables:\n");
parse_dir_ask_printenv("vfs.root.mountfrom");
parse_dir_ask_printenv("vfs.root.mountfrom.options");
printf("\nManual root filesystem specification:\n");
printf(" <fstype>:<device> [options]\n");
printf(" Mount <device> using filesystem <fstype>\n");
printf(" and with the specified (optional) option list.\n");
printf("\n");
printf(" eg. ufs:/dev/da0s1a\n");
printf(" zfs:tank\n");
printf(" cd9660:/dev/acd0 ro\n");
printf(" (which is equivalent to: ");
printf("mount -t cd9660 -o ro /dev/acd0 /)\n");
printf("\n");
printf(" ? List valid disk boot devices\n");
printf(" . Yield 1 second (for background tasks)\n");
printf(" <empty line> Abort manual input\n");
do {
error = EINVAL;
printf("\nmountroot> ");
cngets(name, sizeof(name), GETS_ECHO);
if (name[0] == '\0')
break;
if (name[0] == '?' && name[1] == '\0') {
printf("\nList of GEOM managed disk devices:\n ");
g_dev_print();
continue;
}
if (name[0] == '.' && name[1] == '\0') {
pause("rmask", hz);
continue;
}
mnt = name;
error = parse_mount(&mnt);
if (error == -1)
printf("Invalid file system specification.\n");
} while (error != 0);
return (error);
}
static int
parse_dir_md(char **conf)
{
struct stat sb;
struct thread *td;
struct md_ioctl *mdio;
char *path, *tok;
int error, fd, len;
td = curthread;
error = parse_token(conf, &tok);
if (error)
return (error);
len = strlen(tok);
mdio = malloc(sizeof(*mdio) + len + 1, M_TEMP, M_WAITOK | M_ZERO);
path = (void *)(mdio + 1);
bcopy(tok, path, len);
free(tok, M_TEMP);
/* Get file status. */
error = kern_statat(td, 0, AT_FDCWD, path, UIO_SYSSPACE, &sb, NULL);
if (error)
goto out;
/* Open /dev/mdctl so that we can attach/detach. */
error = kern_openat(td, AT_FDCWD, "/dev/" MDCTL_NAME, UIO_SYSSPACE,
O_RDWR, 0);
if (error)
goto out;
fd = td->td_retval[0];
mdio->md_version = MDIOVERSION;
mdio->md_type = MD_VNODE;
if (root_mount_mddev != -1) {
mdio->md_unit = root_mount_mddev;
DROP_GIANT();
error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
PICKUP_GIANT();
/* Ignore errors. We don't care. */
root_mount_mddev = -1;
}
mdio->md_file = (void *)(mdio + 1);
mdio->md_options = MD_AUTOUNIT | MD_READONLY;
mdio->md_mediasize = sb.st_size;
mdio->md_unit = 0;
DROP_GIANT();
error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio);
PICKUP_GIANT();
if (error)
goto out;
if (mdio->md_unit > 9) {
printf("rootmount: too many md units\n");
mdio->md_file = NULL;
mdio->md_options = 0;
mdio->md_mediasize = 0;
DROP_GIANT();
error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
PICKUP_GIANT();
/* Ignore errors. We don't care. */
error = ERANGE;
goto out;
}
root_mount_mddev = mdio->md_unit;
printf(MD_NAME "%u attached to %s\n", root_mount_mddev, mdio->md_file);
error = kern_close(td, fd);
out:
free(mdio, M_TEMP);
return (error);
}
static int
parse_dir_onfail(char **conf)
{
char *action;
int error;
error = parse_token(conf, &action);
if (error)
return (error);
if (!strcmp(action, "continue"))
root_mount_onfail = A_CONTINUE;
else if (!strcmp(action, "panic"))
root_mount_onfail = A_PANIC;
else if (!strcmp(action, "reboot"))
root_mount_onfail = A_REBOOT;
else if (!strcmp(action, "retry"))
root_mount_onfail = A_RETRY;
else {
printf("rootmount: %s: unknown action\n", action);
error = EINVAL;
}
free(action, M_TEMP);
return (0);
}
static int
parse_dir_timeout(char **conf)
{
char *tok, *endtok;
long secs;
int error;
error = parse_token(conf, &tok);
if (error)
return (error);
secs = strtol(tok, &endtok, 0);
error = (secs < 0 || *endtok != '\0') ? EINVAL : 0;
if (!error)
root_mount_timeout = secs;
free(tok, M_TEMP);
return (error);
}
static int
parse_directive(char **conf)
{
char *dir;
int error;
error = parse_token(conf, &dir);
if (error)
return (error);
if (strcmp(dir, ".ask") == 0)
error = parse_dir_ask(conf);
else if (strcmp(dir, ".md") == 0)
error = parse_dir_md(conf);
else if (strcmp(dir, ".onfail") == 0)
error = parse_dir_onfail(conf);
else if (strcmp(dir, ".timeout") == 0)
error = parse_dir_timeout(conf);
else {
printf("mountroot: invalid directive `%s'\n", dir);
/* Ignore the rest of the line. */
(void)parse_skipto(conf, '\n');
error = EINVAL;
}
free(dir, M_TEMP);
return (error);
}
static int
parse_mount_dev_present(const char *dev)
{
struct nameidata nd;
int error;
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, dev, curthread);
error = namei(&nd);
if (!error)
vput(nd.ni_vp);
NDFREE(&nd, NDF_ONLY_PNBUF);
return (error != 0) ? 0 : 1;
}
#define ERRMSGL 255
static int
parse_mount(char **conf)
{
char *errmsg;
struct mntarg *ma;
char *dev, *fs, *opts, *tok;
int delay, error, timeout;
error = parse_token(conf, &tok);
if (error)
return (error);
fs = tok;
error = parse_skipto(&tok, ':');
if (error) {
free(fs, M_TEMP);
return (error);
}
parse_poke(&tok, '\0');
parse_advance(&tok);
dev = tok;
if (root_mount_mddev != -1) {
/* Handle substitution for the md unit number. */
tok = strstr(dev, "md#");
if (tok != NULL)
tok[2] = '0' + root_mount_mddev;
}
/* Parse options. */
error = parse_token(conf, &tok);
opts = (error == 0) ? tok : NULL;
printf("Trying to mount root from %s:%s [%s]...\n", fs, dev,
(opts != NULL) ? opts : "");
errmsg = malloc(ERRMSGL, M_TEMP, M_WAITOK | M_ZERO);
if (vfs_byname(fs) == NULL) {
strlcpy(errmsg, "unknown file system", ERRMSGL);
error = ENOENT;
goto out;
}
Changes to allow using BOOTP_NFSROOT and mounting an nfs root filesystem other than the one specified by the BOOTP server. This configures NFS using the BOOTP protocol while also respecting other root-path options such as setting vfs.root.mountfrom in the environment or using the RB_DFLTROOT boot option. It allows you to override the root path provided by the server, or to supply a root path when the server provides IP configuration but no root path info. This maintains the historical BOOTP_NFSROOT behavior of panicking on a failure to mount the root path provided by the server, unless you've provided an alternative via the ROOTDEVNAME kernel option or by setting vfs.root.mountfrom. The behavior of panicking when given no other options is preserved because it amounts to a bit of a retry loop that could eventually recover from a transient network or server problem. The user can now override the root path from loader(8) even if the kernel is compiled with BOOTP_NFSROOT. If vfs.root.mountfrom is set in the environment it is used unconditionally -- it always overrides the BOOTP info. If it begins with [old]nfs: then the BOOTP code uses it instead of the server-provided info. If it specifies some other filesystem then the bootp code will not panic like it used to and the code in vfs_mountroot.c will invoke the right filesystem to do the mount. If the kernel is compiled with the ROOTDEVNAME option, then that name is used by the BOOTP code if either * The server doesn't provide a pathname. * The boothowto flags include RB_DFLTROOT. The latter allows the user to compile in alternate path in ROOTDEVNAME such as ufs:/dev/da0s1a and boot from that path by setting boot_dftlroot=1 in loader(8) or using the '-r' option in boot(8). The one thing not provided here is automatic failover from a server-provided path to a compiled-in one without the user manually requesting that. The code just isn't currently structured in a way that makes that possible with a lot of rewrite. I think the ability to set vfs.root.mountfrom and to use ROOTDEVNAME automatically when the server doesn't provide a name covers the most common needs. A set of patches submitted by Lars Eggert provided the part I couldn't figure out by myself when I tried to do this last year; many thanks. Reviewed by: rodrigc
2013-07-31 19:14:00 +00:00
if (strcmp(fs, "zfs") != 0 && strstr(fs, "nfs") == NULL &&
dev[0] != '\0' && !parse_mount_dev_present(dev)) {
printf("mountroot: waiting for device %s ...\n", dev);
delay = hz / 10;
timeout = root_mount_timeout * hz;
do {
pause("rmdev", delay);
timeout -= delay;
} while (timeout > 0 && !parse_mount_dev_present(dev));
if (timeout <= 0) {
error = ENODEV;
goto out;
}
}
ma = NULL;
ma = mount_arg(ma, "fstype", fs, -1);
ma = mount_arg(ma, "fspath", "/", -1);
ma = mount_arg(ma, "from", dev, -1);
ma = mount_arg(ma, "errmsg", errmsg, ERRMSGL);
ma = mount_arg(ma, "ro", NULL, 0);
ma = parse_mountroot_options(ma, opts);
error = kernel_mount(ma, MNT_ROOTFS);
out:
if (error) {
printf("Mounting from %s:%s failed with error %d",
fs, dev, error);
if (errmsg[0] != '\0')
printf(": %s", errmsg);
printf(".\n");
}
free(fs, M_TEMP);
free(errmsg, M_TEMP);
if (opts != NULL)
free(opts, M_TEMP);
/* kernel_mount can return -1 on error. */
return ((error < 0) ? EDOOFUS : error);
}
#undef ERRMSGL
static int
vfs_mountroot_parse(struct sbuf *sb, struct mount *mpdevfs)
{
struct mount *mp;
char *conf;
int error;
root_mount_mddev = -1;
retry:
conf = sbuf_data(sb);
mp = TAILQ_NEXT(mpdevfs, mnt_list);
error = (mp == NULL) ? 0 : EDOOFUS;
root_mount_onfail = A_CONTINUE;
while (mp == NULL) {
error = parse_skipto(&conf, CC_NONWHITESPACE);
if (error == PE_EOL) {
parse_advance(&conf);
continue;
}
if (error < 0)
break;
switch (parse_peek(&conf)) {
case '#':
error = parse_skipto(&conf, '\n');
break;
case '.':
error = parse_directive(&conf);
break;
default:
error = parse_mount(&conf);
if (error == -1) {
printf("mountroot: invalid file system "
"specification.\n");
error = 0;
}
break;
}
if (error < 0)
break;
/* Ignore any trailing garbage on the line. */
if (parse_peek(&conf) != '\n') {
printf("mountroot: advancing to next directive...\n");
(void)parse_skipto(&conf, '\n');
}
mp = TAILQ_NEXT(mpdevfs, mnt_list);
}
if (mp != NULL)
return (0);
/*
* We failed to mount (a new) root.
*/
switch (root_mount_onfail) {
case A_CONTINUE:
break;
case A_PANIC:
panic("mountroot: unable to (re-)mount root.");
/* NOTREACHED */
case A_RETRY:
goto retry;
case A_REBOOT:
kern_reboot(RB_NOSYNC);
/* NOTREACHED */
}
return (error);
}
static void
vfs_mountroot_conf0(struct sbuf *sb)
{
char *s, *tok, *mnt, *opt;
int error;
sbuf_printf(sb, ".onfail panic\n");
sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
if (boothowto & RB_ASKNAME)
sbuf_printf(sb, ".ask\n");
#ifdef ROOTDEVNAME
if (boothowto & RB_DFLTROOT)
sbuf_printf(sb, "%s\n", ROOTDEVNAME);
#endif
if (boothowto & RB_CDROM) {
sbuf_printf(sb, "cd9660:/dev/cd0 ro\n");
sbuf_printf(sb, ".timeout 0\n");
sbuf_printf(sb, "cd9660:/dev/acd0 ro\n");
sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
}
s = kern_getenv("vfs.root.mountfrom");
if (s != NULL) {
opt = kern_getenv("vfs.root.mountfrom.options");
tok = s;
error = parse_token(&tok, &mnt);
while (!error) {
sbuf_printf(sb, "%s %s\n", mnt,
(opt != NULL) ? opt : "");
free(mnt, M_TEMP);
error = parse_token(&tok, &mnt);
}
if (opt != NULL)
freeenv(opt);
freeenv(s);
}
if (rootdevnames[0] != NULL)
sbuf_printf(sb, "%s\n", rootdevnames[0]);
if (rootdevnames[1] != NULL)
sbuf_printf(sb, "%s\n", rootdevnames[1]);
#ifdef ROOTDEVNAME
if (!(boothowto & RB_DFLTROOT))
sbuf_printf(sb, "%s\n", ROOTDEVNAME);
#endif
if (!(boothowto & RB_ASKNAME))
sbuf_printf(sb, ".ask\n");
}
static int
vfs_mountroot_readconf(struct thread *td, struct sbuf *sb)
{
static char buf[128];
struct nameidata nd;
off_t ofs;
ssize_t resid;
int error, flags, len;
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/.mount.conf", td);
flags = FREAD;
error = vn_open(&nd, &flags, 0, NULL);
if (error)
return (error);
NDFREE(&nd, NDF_ONLY_PNBUF);
ofs = 0;
len = sizeof(buf) - 1;
while (1) {
error = vn_rdwr(UIO_READ, nd.ni_vp, buf, len, ofs,
UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
NOCRED, &resid, td);
if (error)
break;
if (resid == len)
break;
buf[len - resid] = 0;
sbuf_printf(sb, "%s", buf);
ofs += len - resid;
}
VOP_UNLOCK(nd.ni_vp, 0);
vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
return (error);
}
static void
vfs_mountroot_wait(void)
{
struct root_hold_token *h;
struct timeval lastfail;
int curfail;
curfail = 0;
while (1) {
DROP_GIANT();
g_waitidle();
PICKUP_GIANT();
mtx_lock(&root_holds_mtx);
if (LIST_EMPTY(&root_holds)) {
mtx_unlock(&root_holds_mtx);
break;
}
if (ppsratecheck(&lastfail, &curfail, 1)) {
printf("Root mount waiting for:");
LIST_FOREACH(h, &root_holds, list)
printf(" %s", h->who);
printf("\n");
}
msleep(&root_holds, &root_holds_mtx, PZERO | PDROP, "roothold",
hz);
}
}
void
vfs_mountroot(void)
{
struct mount *mp;
struct sbuf *sb;
struct thread *td;
time_t timebase;
int error;
td = curthread;
vfs_mountroot_wait();
sb = sbuf_new_auto();
vfs_mountroot_conf0(sb);
sbuf_finish(sb);
error = vfs_mountroot_devfs(td, &mp);
while (!error) {
error = vfs_mountroot_parse(sb, mp);
if (!error) {
error = vfs_mountroot_shuffle(td, mp);
if (!error) {
sbuf_clear(sb);
error = vfs_mountroot_readconf(td, sb);
sbuf_finish(sb);
}
}
}
sbuf_delete(sb);
/*
* Iterate over all currently mounted file systems and use
* the time stamp found to check and/or initialize the RTC.
* Call inittodr() only once and pass it the largest of the
* timestamps we encounter.
*/
timebase = 0;
mtx_lock(&mountlist_mtx);
mp = TAILQ_FIRST(&mountlist);
while (mp != NULL) {
if (mp->mnt_time > timebase)
timebase = mp->mnt_time;
mp = TAILQ_NEXT(mp, mnt_list);
}
mtx_unlock(&mountlist_mtx);
inittodr(timebase);
/* Keep prison0's root in sync with the global rootvnode. */
mtx_lock(&prison0.pr_mtx);
prison0.pr_root = rootvnode;
vref(prison0.pr_root);
mtx_unlock(&prison0.pr_mtx);
mtx_lock(&root_holds_mtx);
atomic_store_rel_int(&root_mount_complete, 1);
wakeup(&root_mount_complete);
mtx_unlock(&root_holds_mtx);
EVENTHANDLER_INVOKE(mountroot);
}
static struct mntarg *
parse_mountroot_options(struct mntarg *ma, const char *options)
{
char *p;
char *name, *name_arg;
char *val, *val_arg;
char *opts;
if (options == NULL || options[0] == '\0')
return (ma);
p = opts = strdup(options, M_MOUNT);
if (opts == NULL) {
return (ma);
}
while((name = strsep(&p, ",")) != NULL) {
if (name[0] == '\0')
break;
val = strchr(name, '=');
if (val != NULL) {
*val = '\0';
++val;
}
if( strcmp(name, "rw") == 0 ||
strcmp(name, "noro") == 0) {
/*
* The first time we mount the root file system,
* we need to mount 'ro', so We need to ignore
* 'rw' and 'noro' mount options.
*/
continue;
}
name_arg = strdup(name, M_MOUNT);
val_arg = NULL;
if (val != NULL)
val_arg = strdup(val, M_MOUNT);
ma = mount_arg(ma, name_arg, val_arg,
(val_arg != NULL ? -1 : 0));
}
free(opts, M_MOUNT);
return (ma);
}