freebsd-dev/sys/kern/vfs_mountroot.c
Konstantin Belousov 4f77f48884 Implement O_BENEATH and AT_BENEATH.
Flags prevent open(2) and *at(2) vfs syscalls name lookup from
escaping the starting directory.  Supposedly the interface is similar
to the same proposed Linux flags.

Reviewed by:	jilles (code, previous version of manpages), 0mp (manpages)
Discussed with:	allanjude, emaste, jonathan
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D17547
2018-10-25 22:16:34 +00:00

1132 lines
26 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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.
* 3. 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>
#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 succeeds.
*
* 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 *);
static int sysctl_vfs_root_mount_hold(SYSCTL_HANDLER_ARGS);
static void vfs_mountroot_wait(void);
static int vfs_mountroot_wait_if_neccessary(const char *fs, const char *dev);
/*
* 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;
TUNABLE_INT("vfs.mountroot.timeout", &root_mount_timeout);
static int root_mount_always_wait = 0;
SYSCTL_INT(_vfs, OID_AUTO, root_mount_always_wait, CTLFLAG_RDTUN,
&root_mount_always_wait, 0,
"Wait for root mount holds even if the root device already exists");
SYSCTL_PROC(_vfs, OID_AUTO, root_mount_hold,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
NULL, 0, sysctl_vfs_root_mount_hold, "A",
"List of root mount hold tokens");
static int
sysctl_vfs_root_mount_hold(SYSCTL_HANDLER_ARGS)
{
struct sbuf sb;
struct root_hold_token *h;
int error;
sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL);
mtx_lock(&root_holds_mtx);
LIST_FOREACH(h, &root_holds, list) {
if (h != LIST_FIRST(&root_holds))
sbuf_putc(&sb, ' ');
sbuf_printf(&sb, "%s", h->who);
}
mtx_unlock(&root_holds_mtx);
error = sbuf_finish(&sb);
if (error == 0)
error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
sbuf_delete(&sb);
return (error);
}
struct root_hold_token *
root_mount_hold(const char *identifier)
{
struct root_hold_token *h;
h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
h->who = identifier;
mtx_lock(&root_holds_mtx);
TSHOLD("root mount");
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);
TSRELEASE("root mount");
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);
}
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 void
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, true);
if (mporoot != mpdevfs)
cache_purgevfs(mpdevfs, true);
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, true);
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)
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)
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, 0);
if (error)
printf("mountroot: unable to unlink /dev/dev "
"(error %d)\n", error);
}
}
/*
* 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;
vfs_mountroot_wait();
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:zroot/ROOT/default\n");
printf(" cd9660:/dev/cd0 ro\n");
printf(" (which is equivalent to: ");
printf("mount -t cd9660 -o ro /dev/cd0 /)\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;
(void)kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
/* 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;
error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio);
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;
error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
/* 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;
}
error = vfs_mountroot_wait_if_neccessary(fs, dev);
if (error != 0)
goto out;
delay = hz / 10;
timeout = root_mount_timeout * hz;
for (;;) {
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);
if (error == 0 || timeout <= 0)
break;
if (root_mount_timeout * hz == timeout ||
(bootverbose && timeout % hz == 0)) {
printf("Mounting from %s:%s failed with error %d; "
"retrying for %d more second%s\n", fs, dev, error,
timeout / hz, (timeout / hz > 1) ? "s" : "");
}
pause("rmretry", delay);
timeout -= delay;
}
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/cd1 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;
TSENTER();
curfail = 0;
while (1) {
g_waitidle();
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");
}
TSWAIT("root mount");
msleep(&root_holds, &root_holds_mtx, PZERO | PDROP, "roothold",
hz);
TSUNWAIT("root mount");
}
TSEXIT();
}
static int
vfs_mountroot_wait_if_neccessary(const char *fs, const char *dev)
{
int delay, timeout;
/*
* In case of ZFS and NFS we don't have a way to wait for
* specific device. Also do the wait if the user forced that
* behaviour by setting vfs.root_mount_always_wait=1.
*/
if (strcmp(fs, "zfs") == 0 || strstr(fs, "nfs") != NULL ||
dev[0] == '\0' || root_mount_always_wait != 0) {
vfs_mountroot_wait();
return (0);
}
/*
* Otherwise, no point in waiting if the device is already there.
* Note that we must wait for GEOM to finish reconfiguring itself,
* eg for geom_part(4) to finish tasting.
*/
g_waitidle();
if (parse_mount_dev_present(dev))
return (0);
/*
* No luck. Let's wait. This code looks weird, but it's that way
* to behave exactly as it used to work before.
*/
vfs_mountroot_wait();
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)
return (ENODEV);
return (0);
}
void
vfs_mountroot(void)
{
struct mount *mp;
struct sbuf *sb;
struct thread *td;
time_t timebase;
int error;
mtx_assert(&Giant, MA_NOTOWNED);
TSENTER();
td = curthread;
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) {
vfs_mountroot_shuffle(td, mp);
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);
TSEXIT();
}
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);
}