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freebsd-skq/sys/kern/vfs_mount.c
jamie a013e0afcb Add hierarchical jails. A jail may further virtualize its environment 
by creating a child jail, which is visible to that jail and to any
parent jails.  Child jails may be restricted more than their parents,
but never less.  Jail names reflect this hierarchy, being MIB-style
dot-separated strings.

Every thread now points to a jail, the default being prison0, which
contains information about the physical system.  Prison0's root
directory is the same as rootvnode; its hostname is the same as the
global hostname, and its securelevel replaces the global securelevel.
Note that the variable "securelevel" has actually gone away, which
should not cause any problems for code that properly uses
securelevel_gt() and securelevel_ge().

Some jail-related permissions that were kept in global variables and
set via sysctls are now per-jail settings.  The sysctls still exist for
backward compatibility, used only by the now-deprecated jail(2) system
call.

Approved by:	bz (mentor)
2009-05-27 14:11:23 +00:00

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/*-
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/libkern.h>
#include <sys/malloc.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/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 <vm/uma.h>
#include <geom/geom.h>
#include <machine/stdarg.h>
#include <security/audit/audit.h>
#include <security/mac/mac_framework.h>
#include "opt_rootdevname.h"
#include "opt_mac.h"
#define ROOTNAME "root_device"
#define VFS_MOUNTARG_SIZE_MAX (1024 * 64)
static void set_rootvnode(void);
static int vfs_domount(struct thread *td, const char *fstype,
char *fspath, int fsflags, void *fsdata);
static int vfs_mountroot_ask(void);
static int vfs_mountroot_try(const char *mountfrom);
static void free_mntarg(struct mntarg *ma);
static int usermount = 0;
SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0,
"Unprivileged users may mount and unmount file systems");
MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
static uma_zone_t mount_zone;
/* List of mounted filesystems. */
struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist);
/* For any iteration/modification of mountlist */
struct mtx mountlist_mtx;
MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF);
/*
* The vnode of the system's root (/ in the filesystem, without chroot
* active.)
*/
struct vnode *rootvnode;
/*
* 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 := 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
*/
/*
* Global opts, taken by all filesystems
*/
static const char *global_opts[] = {
"errmsg",
"fstype",
"fspath",
"ro",
"rw",
"nosuid",
"noexec",
NULL
};
/*
* The root specifiers we will try if RB_CDROM is specified.
*/
static char *cdrom_rootdevnames[] = {
"cd9660:cd0",
"cd9660:acd0",
NULL
};
/* legacy find-root code */
char *rootdevnames[2] = {NULL, NULL};
#ifndef ROOTDEVNAME
# define ROOTDEVNAME NULL
#endif
static const char *ctrootdevname = ROOTDEVNAME;
/*
* ---------------------------------------------------------------------
* Functions for building and sanitizing the mount options
*/
/* Remove one mount option. */
static void
vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt)
{
TAILQ_REMOVE(opts, opt, link);
free(opt->name, M_MOUNT);
if (opt->value != NULL)
free(opt->value, M_MOUNT);
free(opt, M_MOUNT);
}
/* Release all resources related to the mount options. */
void
vfs_freeopts(struct vfsoptlist *opts)
{
struct vfsopt *opt;
while (!TAILQ_EMPTY(opts)) {
opt = TAILQ_FIRST(opts);
vfs_freeopt(opts, opt);
}
free(opts, M_MOUNT);
}
void
vfs_deleteopt(struct vfsoptlist *opts, const char *name)
{
struct vfsopt *opt, *temp;
if (opts == NULL)
return;
TAILQ_FOREACH_SAFE(opt, opts, link, temp) {
if (strcmp(opt->name, name) == 0)
vfs_freeopt(opts, opt);
}
}
/*
* Check if options are equal (with or without the "no" prefix).
*/
static int
vfs_equalopts(const char *opt1, const char *opt2)
{
char *p;
/* "opt" vs. "opt" or "noopt" vs. "noopt" */
if (strcmp(opt1, opt2) == 0)
return (1);
/* "noopt" vs. "opt" */
if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
return (1);
/* "opt" vs. "noopt" */
if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
return (1);
while ((p = strchr(opt1, '.')) != NULL &&
!strncmp(opt1, opt2, ++p - opt1)) {
opt2 += p - opt1;
opt1 = p;
/* "foo.noopt" vs. "foo.opt" */
if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
return (1);
/* "foo.opt" vs. "foo.noopt" */
if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
return (1);
}
return (0);
}
/*
* If a mount option is specified several times,
* (with or without the "no" prefix) only keep
* the last occurence of it.
*/
static void
vfs_sanitizeopts(struct vfsoptlist *opts)
{
struct vfsopt *opt, *opt2, *tmp;
TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) {
opt2 = TAILQ_PREV(opt, vfsoptlist, link);
while (opt2 != NULL) {
if (vfs_equalopts(opt->name, opt2->name)) {
tmp = TAILQ_PREV(opt2, vfsoptlist, link);
vfs_freeopt(opts, opt2);
opt2 = tmp;
} else {
opt2 = TAILQ_PREV(opt2, vfsoptlist, link);
}
}
}
}
/*
* Build a linked list of mount options from a struct uio.
*/
int
vfs_buildopts(struct uio *auio, struct vfsoptlist **options)
{
struct vfsoptlist *opts;
struct vfsopt *opt;
size_t memused, namelen, optlen;
unsigned int i, iovcnt;
int error;
opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
TAILQ_INIT(opts);
memused = 0;
iovcnt = auio->uio_iovcnt;
for (i = 0; i < iovcnt; i += 2) {
namelen = auio->uio_iov[i].iov_len;
optlen = auio->uio_iov[i + 1].iov_len;
memused += sizeof(struct vfsopt) + optlen + namelen;
/*
* Avoid consuming too much memory, and attempts to overflow
* memused.
*/
if (memused > VFS_MOUNTARG_SIZE_MAX ||
optlen > VFS_MOUNTARG_SIZE_MAX ||
namelen > VFS_MOUNTARG_SIZE_MAX) {
error = EINVAL;
goto bad;
}
opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
opt->name = malloc(namelen, M_MOUNT, M_WAITOK);
opt->value = NULL;
opt->len = 0;
opt->pos = i / 2;
opt->seen = 0;
/*
* Do this early, so jumps to "bad" will free the current
* option.
*/
TAILQ_INSERT_TAIL(opts, opt, link);
if (auio->uio_segflg == UIO_SYSSPACE) {
bcopy(auio->uio_iov[i].iov_base, opt->name, namelen);
} else {
error = copyin(auio->uio_iov[i].iov_base, opt->name,
namelen);
if (error)
goto bad;
}
/* Ensure names are null-terminated strings. */
if (namelen == 0 || opt->name[namelen - 1] != '\0') {
error = EINVAL;
goto bad;
}
if (optlen != 0) {
opt->len = optlen;
opt->value = malloc(optlen, M_MOUNT, M_WAITOK);
if (auio->uio_segflg == UIO_SYSSPACE) {
bcopy(auio->uio_iov[i + 1].iov_base, opt->value,
optlen);
} else {
error = copyin(auio->uio_iov[i + 1].iov_base,
opt->value, optlen);
if (error)
goto bad;
}
}
}
vfs_sanitizeopts(opts);
*options = opts;
return (0);
bad:
vfs_freeopts(opts);
return (error);
}
/*
* Merge the old mount options with the new ones passed
* in the MNT_UPDATE case.
*
* XXX This function will keep a "nofoo" option in the
* new options if there is no matching "foo" option
* to be cancelled in the old options. This is a bug
* if the option's canonical name is "foo". E.g., "noro"
* shouldn't end up in the mount point's active options,
* but it can.
*/
static void
vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts)
{
struct vfsopt *opt, *opt2, *new;
TAILQ_FOREACH(opt, opts, link) {
/*
* Check that this option hasn't been redefined
* nor cancelled with a "no" mount option.
*/
opt2 = TAILQ_FIRST(toopts);
while (opt2 != NULL) {
if (strcmp(opt2->name, opt->name) == 0)
goto next;
if (strncmp(opt2->name, "no", 2) == 0 &&
strcmp(opt2->name + 2, opt->name) == 0) {
vfs_freeopt(toopts, opt2);
goto next;
}
opt2 = TAILQ_NEXT(opt2, link);
}
/* We want this option, duplicate it. */
new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK);
strcpy(new->name, opt->name);
if (opt->len != 0) {
new->value = malloc(opt->len, M_MOUNT, M_WAITOK);
bcopy(opt->value, new->value, opt->len);
} else {
new->value = NULL;
}
new->len = opt->len;
new->seen = opt->seen;
TAILQ_INSERT_TAIL(toopts, new, link);
next:
continue;
}
}
/*
* Mount a filesystem.
*/
int
nmount(td, uap)
struct thread *td;
struct nmount_args /* {
struct iovec *iovp;
unsigned int iovcnt;
int flags;
} */ *uap;
{
struct uio *auio;
int error;
u_int iovcnt;
AUDIT_ARG(fflags, uap->flags);
CTR4(KTR_VFS, "%s: iovp %p with iovcnt %d and flags %d", __func__,
uap->iovp, uap->iovcnt, uap->flags);
/*
* Filter out MNT_ROOTFS. We do not want clients of nmount() in
* userspace to set this flag, but we must filter it out if we want
* MNT_UPDATE on the root file system to work.
* MNT_ROOTFS should only be set in the kernel in vfs_mountroot_try().
*/
uap->flags &= ~MNT_ROOTFS;
iovcnt = uap->iovcnt;
/*
* Check that we have an even number of iovec's
* and that we have at least two options.
*/
if ((iovcnt & 1) || (iovcnt < 4)) {
CTR2(KTR_VFS, "%s: failed for invalid iovcnt %d", __func__,
uap->iovcnt);
return (EINVAL);
}
error = copyinuio(uap->iovp, iovcnt, &auio);
if (error) {
CTR2(KTR_VFS, "%s: failed for invalid uio op with %d errno",
__func__, error);
return (error);
}
error = vfs_donmount(td, uap->flags, auio);
free(auio, M_IOV);
return (error);
}
/*
* ---------------------------------------------------------------------
* Various utility functions
*/
void
vfs_ref(struct mount *mp)
{
CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
MNT_ILOCK(mp);
MNT_REF(mp);
MNT_IUNLOCK(mp);
}
void
vfs_rel(struct mount *mp)
{
CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
MNT_ILOCK(mp);
MNT_REL(mp);
MNT_IUNLOCK(mp);
}
static int
mount_init(void *mem, int size, int flags)
{
struct mount *mp;
mp = (struct mount *)mem;
mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0);
return (0);
}
static void
mount_fini(void *mem, int size)
{
struct mount *mp;
mp = (struct mount *)mem;
lockdestroy(&mp->mnt_explock);
mtx_destroy(&mp->mnt_mtx);
}
/*
* Allocate and initialize the mount point struct.
*/
struct mount *
vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath,
struct ucred *cred)
{
struct mount *mp;
mp = uma_zalloc(mount_zone, M_WAITOK);
bzero(&mp->mnt_startzero,
__rangeof(struct mount, mnt_startzero, mnt_endzero));
TAILQ_INIT(&mp->mnt_nvnodelist);
mp->mnt_nvnodelistsize = 0;
mp->mnt_ref = 0;
(void) vfs_busy(mp, MBF_NOWAIT);
mp->mnt_op = vfsp->vfc_vfsops;
mp->mnt_vfc = vfsp;
vfsp->vfc_refcount++; /* XXX Unlocked */
mp->mnt_stat.f_type = vfsp->vfc_typenum;
mp->mnt_gen++;
strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
mp->mnt_vnodecovered = vp;
mp->mnt_cred = crdup(cred);
mp->mnt_stat.f_owner = cred->cr_uid;
strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN);
mp->mnt_iosize_max = DFLTPHYS;
#ifdef MAC
mac_mount_init(mp);
mac_mount_create(cred, mp);
#endif
arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0);
return (mp);
}
/*
* Destroy the mount struct previously allocated by vfs_mount_alloc().
*/
void
vfs_mount_destroy(struct mount *mp)
{
MNT_ILOCK(mp);
mp->mnt_kern_flag |= MNTK_REFEXPIRE;
if (mp->mnt_kern_flag & MNTK_MWAIT) {
mp->mnt_kern_flag &= ~MNTK_MWAIT;
wakeup(mp);
}
while (mp->mnt_ref)
msleep(mp, MNT_MTX(mp), PVFS, "mntref", 0);
KASSERT(mp->mnt_ref == 0,
("%s: invalid refcount in the drain path @ %s:%d", __func__,
__FILE__, __LINE__));
if (mp->mnt_writeopcount != 0)
panic("vfs_mount_destroy: nonzero writeopcount");
if (mp->mnt_secondary_writes != 0)
panic("vfs_mount_destroy: nonzero secondary_writes");
mp->mnt_vfc->vfc_refcount--;
if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) {
struct vnode *vp;
TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes)
vprint("", vp);
panic("unmount: dangling vnode");
}
if (mp->mnt_nvnodelistsize != 0)
panic("vfs_mount_destroy: nonzero nvnodelistsize");
if (mp->mnt_lockref != 0)
panic("vfs_mount_destroy: nonzero lock refcount");
MNT_IUNLOCK(mp);
#ifdef MAC
mac_mount_destroy(mp);
#endif
if (mp->mnt_opt != NULL)
vfs_freeopts(mp->mnt_opt);
crfree(mp->mnt_cred);
uma_zfree(mount_zone, mp);
}
int
vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions)
{
struct vfsoptlist *optlist;
struct vfsopt *opt, *noro_opt, *tmp_opt;
char *fstype, *fspath, *errmsg;
int error, fstypelen, fspathlen, errmsg_len, errmsg_pos;
int has_rw, has_noro;
errmsg = fspath = NULL;
errmsg_len = has_noro = has_rw = fspathlen = 0;
errmsg_pos = -1;
error = vfs_buildopts(fsoptions, &optlist);
if (error)
return (error);
if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0)
errmsg_pos = vfs_getopt_pos(optlist, "errmsg");
/*
* We need these two options before the others,
* and they are mandatory for any filesystem.
* Ensure they are NUL terminated as well.
*/
fstypelen = 0;
error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen);
if (error || fstype[fstypelen - 1] != '\0') {
error = EINVAL;
if (errmsg != NULL)
strncpy(errmsg, "Invalid fstype", errmsg_len);
goto bail;
}
fspathlen = 0;
error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen);
if (error || fspath[fspathlen - 1] != '\0') {
error = EINVAL;
if (errmsg != NULL)
strncpy(errmsg, "Invalid fspath", errmsg_len);
goto bail;
}
/*
* We need to see if we have the "update" option
* before we call vfs_domount(), since vfs_domount() has special
* logic based on MNT_UPDATE. This is very important
* when we want to update the root filesystem.
*/
TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) {
if (strcmp(opt->name, "update") == 0) {
fsflags |= MNT_UPDATE;
vfs_freeopt(optlist, opt);
}
else if (strcmp(opt->name, "async") == 0)
fsflags |= MNT_ASYNC;
else if (strcmp(opt->name, "force") == 0) {
fsflags |= MNT_FORCE;
vfs_freeopt(optlist, opt);
}
else if (strcmp(opt->name, "reload") == 0) {
fsflags |= MNT_RELOAD;
vfs_freeopt(optlist, opt);
}
else if (strcmp(opt->name, "multilabel") == 0)
fsflags |= MNT_MULTILABEL;
else if (strcmp(opt->name, "noasync") == 0)
fsflags &= ~MNT_ASYNC;
else if (strcmp(opt->name, "noatime") == 0)
fsflags |= MNT_NOATIME;
else if (strcmp(opt->name, "atime") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonoatime", M_MOUNT);
}
else if (strcmp(opt->name, "noclusterr") == 0)
fsflags |= MNT_NOCLUSTERR;
else if (strcmp(opt->name, "clusterr") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonoclusterr", M_MOUNT);
}
else if (strcmp(opt->name, "noclusterw") == 0)
fsflags |= MNT_NOCLUSTERW;
else if (strcmp(opt->name, "clusterw") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonoclusterw", M_MOUNT);
}
else if (strcmp(opt->name, "noexec") == 0)
fsflags |= MNT_NOEXEC;
else if (strcmp(opt->name, "exec") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonoexec", M_MOUNT);
}
else if (strcmp(opt->name, "nosuid") == 0)
fsflags |= MNT_NOSUID;
else if (strcmp(opt->name, "suid") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonosuid", M_MOUNT);
}
else if (strcmp(opt->name, "nosymfollow") == 0)
fsflags |= MNT_NOSYMFOLLOW;
else if (strcmp(opt->name, "symfollow") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonosymfollow", M_MOUNT);
}
else if (strcmp(opt->name, "noro") == 0) {
fsflags &= ~MNT_RDONLY;
has_noro = 1;
}
else if (strcmp(opt->name, "rw") == 0) {
fsflags &= ~MNT_RDONLY;
has_rw = 1;
}
else if (strcmp(opt->name, "ro") == 0)
fsflags |= MNT_RDONLY;
else if (strcmp(opt->name, "rdonly") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("ro", M_MOUNT);
fsflags |= MNT_RDONLY;
}
else if (strcmp(opt->name, "suiddir") == 0)
fsflags |= MNT_SUIDDIR;
else if (strcmp(opt->name, "sync") == 0)
fsflags |= MNT_SYNCHRONOUS;
else if (strcmp(opt->name, "union") == 0)
fsflags |= MNT_UNION;
}
/*
* If "rw" was specified as a mount option, and we
* are trying to update a mount-point from "ro" to "rw",
* we need a mount option "noro", since in vfs_mergeopts(),
* "noro" will cancel "ro", but "rw" will not do anything.
*/
if (has_rw && !has_noro) {
noro_opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
noro_opt->name = strdup("noro", M_MOUNT);
noro_opt->value = NULL;
noro_opt->len = 0;
noro_opt->pos = -1;
noro_opt->seen = 1;
TAILQ_INSERT_TAIL(optlist, noro_opt, link);
}
/*
* Be ultra-paranoid about making sure the type and fspath
* variables will fit in our mp buffers, including the
* terminating NUL.
*/
if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) {
error = ENAMETOOLONG;
goto bail;
}
mtx_lock(&Giant);
error = vfs_domount(td, fstype, fspath, fsflags, optlist);
mtx_unlock(&Giant);
bail:
/* copyout the errmsg */
if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt)
&& errmsg_len > 0 && errmsg != NULL) {
if (fsoptions->uio_segflg == UIO_SYSSPACE) {
bcopy(errmsg,
fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
} else {
copyout(errmsg,
fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
}
}
if (error != 0)
vfs_freeopts(optlist);
return (error);
}
/*
* Old mount API.
*/
#ifndef _SYS_SYSPROTO_H_
struct mount_args {
char *type;
char *path;
int flags;
caddr_t data;
};
#endif
/* ARGSUSED */
int
mount(td, uap)
struct thread *td;
struct mount_args /* {
char *type;
char *path;
int flags;
caddr_t data;
} */ *uap;
{
char *fstype;
struct vfsconf *vfsp = NULL;
struct mntarg *ma = NULL;
int error;
AUDIT_ARG(fflags, uap->flags);
/*
* Filter out MNT_ROOTFS. We do not want clients of mount() in
* userspace to set this flag, but we must filter it out if we want
* MNT_UPDATE on the root file system to work.
* MNT_ROOTFS should only be set in the kernel in vfs_mountroot_try().
*/
uap->flags &= ~MNT_ROOTFS;
fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK);
error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL);
if (error) {
free(fstype, M_TEMP);
return (error);
}
AUDIT_ARG(text, fstype);
mtx_lock(&Giant);
vfsp = vfs_byname_kld(fstype, td, &error);
free(fstype, M_TEMP);
if (vfsp == NULL) {
mtx_unlock(&Giant);
return (ENOENT);
}
if (vfsp->vfc_vfsops->vfs_cmount == NULL) {
mtx_unlock(&Giant);
return (EOPNOTSUPP);
}
ma = mount_argsu(ma, "fstype", uap->type, MNAMELEN);
ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN);
ma = mount_argb(ma, uap->flags & MNT_RDONLY, "noro");
ma = mount_argb(ma, !(uap->flags & MNT_NOSUID), "nosuid");
ma = mount_argb(ma, !(uap->flags & MNT_NOEXEC), "noexec");
error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, uap->flags);
mtx_unlock(&Giant);
return (error);
}
/*
* vfs_domount(): actually attempt a filesystem mount.
*/
static int
vfs_domount(
struct thread *td, /* Calling thread. */
const char *fstype, /* Filesystem type. */
char *fspath, /* Mount path. */
int fsflags, /* Flags common to all filesystems. */
void *fsdata /* Options local to the filesystem. */
)
{
struct vnode *vp;
struct mount *mp;
struct vfsconf *vfsp;
struct oexport_args oexport;
struct export_args export;
int error, flag = 0;
struct vattr va;
struct nameidata nd;
mtx_assert(&Giant, MA_OWNED);
/*
* Be ultra-paranoid about making sure the type and fspath
* variables will fit in our mp buffers, including the
* terminating NUL.
*/
if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN)
return (ENAMETOOLONG);
if (jailed(td->td_ucred) || usermount == 0) {
if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0)
return (error);
}
/*
* Do not allow NFS export or MNT_SUIDDIR by unprivileged users.
*/
if (fsflags & MNT_EXPORTED) {
error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED);
if (error)
return (error);
}
if (fsflags & MNT_SUIDDIR) {
error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR);
if (error)
return (error);
}
/*
* Silently enforce MNT_NOSUID and MNT_USER for unprivileged users.
*/
if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) {
if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0)
fsflags |= MNT_NOSUID | MNT_USER;
}
/* Load KLDs before we lock the covered vnode to avoid reversals. */
vfsp = NULL;
if ((fsflags & MNT_UPDATE) == 0) {
/* Don't try to load KLDs if we're mounting the root. */
if (fsflags & MNT_ROOTFS)
vfsp = vfs_byname(fstype);
else
vfsp = vfs_byname_kld(fstype, td, &error);
if (vfsp == NULL)
return (ENODEV);
if (jailed(td->td_ucred) && !(vfsp->vfc_flags & VFCF_JAIL))
return (EPERM);
}
/*
* Get vnode to be covered
*/
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_SYSSPACE,
fspath, td);
if ((error = namei(&nd)) != 0)
return (error);
NDFREE(&nd, NDF_ONLY_PNBUF);
vp = nd.ni_vp;
if (fsflags & MNT_UPDATE) {
if ((vp->v_vflag & VV_ROOT) == 0) {
vput(vp);
return (EINVAL);
}
mp = vp->v_mount;
MNT_ILOCK(mp);
flag = mp->mnt_flag;
/*
* We only allow the filesystem to be reloaded if it
* is currently mounted read-only.
*/
if ((fsflags & MNT_RELOAD) &&
((mp->mnt_flag & MNT_RDONLY) == 0)) {
MNT_IUNLOCK(mp);
vput(vp);
return (EOPNOTSUPP); /* Needs translation */
}
MNT_IUNLOCK(mp);
/*
* Only privileged root, or (if MNT_USER is set) the user that
* did the original mount is permitted to update it.
*/
error = vfs_suser(mp, td);
if (error) {
vput(vp);
return (error);
}
if (vfs_busy(mp, MBF_NOWAIT)) {
vput(vp);
return (EBUSY);
}
VI_LOCK(vp);
if ((vp->v_iflag & VI_MOUNT) != 0 ||
vp->v_mountedhere != NULL) {
VI_UNLOCK(vp);
vfs_unbusy(mp);
vput(vp);
return (EBUSY);
}
vp->v_iflag |= VI_MOUNT;
VI_UNLOCK(vp);
MNT_ILOCK(mp);
mp->mnt_flag |= fsflags &
(MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT | MNT_ROOTFS);
MNT_IUNLOCK(mp);
VOP_UNLOCK(vp, 0);
mp->mnt_optnew = fsdata;
vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt);
} else {
/*
* If the user is not root, ensure that they own the directory
* onto which we are attempting to mount.
*/
error = VOP_GETATTR(vp, &va, td->td_ucred);
if (error) {
vput(vp);
return (error);
}
if (va.va_uid != td->td_ucred->cr_uid) {
error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN,
0);
if (error) {
vput(vp);
return (error);
}
}
error = vinvalbuf(vp, V_SAVE, 0, 0);
if (error != 0) {
vput(vp);
return (error);
}
if (vp->v_type != VDIR) {
vput(vp);
return (ENOTDIR);
}
VI_LOCK(vp);
if ((vp->v_iflag & VI_MOUNT) != 0 ||
vp->v_mountedhere != NULL) {
VI_UNLOCK(vp);
vput(vp);
return (EBUSY);
}
vp->v_iflag |= VI_MOUNT;
VI_UNLOCK(vp);
/*
* Allocate and initialize the filesystem.
*/
mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred);
VOP_UNLOCK(vp, 0);
/* XXXMAC: pass to vfs_mount_alloc? */
mp->mnt_optnew = fsdata;
}
/*
* Set the mount level flags.
*/
MNT_ILOCK(mp);
mp->mnt_flag = (mp->mnt_flag & ~MNT_UPDATEMASK) |
(fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS |
MNT_RDONLY));
if ((mp->mnt_flag & MNT_ASYNC) == 0)
mp->mnt_kern_flag &= ~MNTK_ASYNC;
MNT_IUNLOCK(mp);
/*
* Mount the filesystem.
* XXX The final recipients of VFS_MOUNT just overwrite the ndp they
* get. No freeing of cn_pnbuf.
*/
error = VFS_MOUNT(mp);
/*
* Process the export option only if we are
* updating mount options.
*/
if (!error && (fsflags & MNT_UPDATE)) {
if (vfs_copyopt(mp->mnt_optnew, "export", &export,
sizeof(export)) == 0)
error = vfs_export(mp, &export);
else if (vfs_copyopt(mp->mnt_optnew, "export", &oexport,
sizeof(oexport)) == 0) {
export.ex_flags = oexport.ex_flags;
export.ex_root = oexport.ex_root;
export.ex_anon = oexport.ex_anon;
export.ex_addr = oexport.ex_addr;
export.ex_addrlen = oexport.ex_addrlen;
export.ex_mask = oexport.ex_mask;
export.ex_masklen = oexport.ex_masklen;
export.ex_indexfile = oexport.ex_indexfile;
export.ex_numsecflavors = 0;
error = vfs_export(mp, &export);
}
}
if (!error) {
if (mp->mnt_opt != NULL)
vfs_freeopts(mp->mnt_opt);
mp->mnt_opt = mp->mnt_optnew;
(void)VFS_STATFS(mp, &mp->mnt_stat);
}
/*
* Prevent external consumers of mount options from reading
* mnt_optnew.
*/
mp->mnt_optnew = NULL;
if (mp->mnt_flag & MNT_UPDATE) {
MNT_ILOCK(mp);
if (error)
mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) |
(flag & ~MNT_QUOTA);
else
mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD |
MNT_FORCE | MNT_SNAPSHOT);
if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0)
mp->mnt_kern_flag |= MNTK_ASYNC;
else
mp->mnt_kern_flag &= ~MNTK_ASYNC;
MNT_IUNLOCK(mp);
if ((mp->mnt_flag & MNT_RDONLY) == 0) {
if (mp->mnt_syncer == NULL)
error = vfs_allocate_syncvnode(mp);
} else {
if (mp->mnt_syncer != NULL)
vrele(mp->mnt_syncer);
mp->mnt_syncer = NULL;
}
vfs_unbusy(mp);
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
vrele(vp);
return (error);
}
MNT_ILOCK(mp);
if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0)
mp->mnt_kern_flag |= MNTK_ASYNC;
else
mp->mnt_kern_flag &= ~MNTK_ASYNC;
MNT_IUNLOCK(mp);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
/*
* Put the new filesystem on the mount list after root.
*/
cache_purge(vp);
if (!error) {
struct vnode *newdp;
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
vp->v_mountedhere = mp;
mtx_lock(&mountlist_mtx);
TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
vfs_event_signal(NULL, VQ_MOUNT, 0);
if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp))
panic("mount: lost mount");
mountcheckdirs(vp, newdp);
vput(newdp);
VOP_UNLOCK(vp, 0);
if ((mp->mnt_flag & MNT_RDONLY) == 0)
error = vfs_allocate_syncvnode(mp);
vfs_unbusy(mp);
if (error)
vrele(vp);
} else {
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
vfs_unbusy(mp);
vfs_mount_destroy(mp);
vput(vp);
}
return (error);
}
/*
* Unmount a filesystem.
*
* Note: unmount takes a path to the vnode mounted on as argument, not
* special file (as before).
*/
#ifndef _SYS_SYSPROTO_H_
struct unmount_args {
char *path;
int flags;
};
#endif
/* ARGSUSED */
int
unmount(td, uap)
struct thread *td;
register struct unmount_args /* {
char *path;
int flags;
} */ *uap;
{
struct mount *mp;
char *pathbuf;
int error, id0, id1;
if (jailed(td->td_ucred) || usermount == 0) {
error = priv_check(td, PRIV_VFS_UNMOUNT);
if (error)
return (error);
}
pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL);
if (error) {
free(pathbuf, M_TEMP);
return (error);
}
AUDIT_ARG(upath, td, pathbuf, ARG_UPATH1);
mtx_lock(&Giant);
if (uap->flags & MNT_BYFSID) {
/* Decode the filesystem ID. */
if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) {
mtx_unlock(&Giant);
free(pathbuf, M_TEMP);
return (EINVAL);
}
mtx_lock(&mountlist_mtx);
TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
if (mp->mnt_stat.f_fsid.val[0] == id0 &&
mp->mnt_stat.f_fsid.val[1] == id1)
break;
}
mtx_unlock(&mountlist_mtx);
} else {
mtx_lock(&mountlist_mtx);
TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0)
break;
}
mtx_unlock(&mountlist_mtx);
}
free(pathbuf, M_TEMP);
if (mp == NULL) {
/*
* Previously we returned ENOENT for a nonexistent path and
* EINVAL for a non-mountpoint. We cannot tell these apart
* now, so in the !MNT_BYFSID case return the more likely
* EINVAL for compatibility.
*/
mtx_unlock(&Giant);
return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL);
}
/*
* Don't allow unmounting the root filesystem.
*/
if (mp->mnt_flag & MNT_ROOTFS) {
mtx_unlock(&Giant);
return (EINVAL);
}
error = dounmount(mp, uap->flags, td);
mtx_unlock(&Giant);
return (error);
}
/*
* Do the actual filesystem unmount.
*/
int
dounmount(mp, flags, td)
struct mount *mp;
int flags;
struct thread *td;
{
struct vnode *coveredvp, *fsrootvp;
int error;
int async_flag;
int mnt_gen_r;
mtx_assert(&Giant, MA_OWNED);
if ((coveredvp = mp->mnt_vnodecovered) != NULL) {
mnt_gen_r = mp->mnt_gen;
VI_LOCK(coveredvp);
vholdl(coveredvp);
vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
vdrop(coveredvp);
/*
* Check for mp being unmounted while waiting for the
* covered vnode lock.
*/
if (coveredvp->v_mountedhere != mp ||
coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) {
VOP_UNLOCK(coveredvp, 0);
return (EBUSY);
}
}
/*
* Only privileged root, or (if MNT_USER is set) the user that did the
* original mount is permitted to unmount this filesystem.
*/
error = vfs_suser(mp, td);
if (error) {
if (coveredvp)
VOP_UNLOCK(coveredvp, 0);
return (error);
}
MNT_ILOCK(mp);
if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
MNT_IUNLOCK(mp);
if (coveredvp)
VOP_UNLOCK(coveredvp, 0);
return (EBUSY);
}
mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_NOINSMNTQ;
/* Allow filesystems to detect that a forced unmount is in progress. */
if (flags & MNT_FORCE)
mp->mnt_kern_flag |= MNTK_UNMOUNTF;
error = 0;
if (mp->mnt_lockref) {
if ((flags & MNT_FORCE) == 0) {
mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_NOINSMNTQ |
MNTK_UNMOUNTF);
if (mp->mnt_kern_flag & MNTK_MWAIT) {
mp->mnt_kern_flag &= ~MNTK_MWAIT;
wakeup(mp);
}
MNT_IUNLOCK(mp);
if (coveredvp)
VOP_UNLOCK(coveredvp, 0);
return (EBUSY);
}
mp->mnt_kern_flag |= MNTK_DRAINING;
error = msleep(&mp->mnt_lockref, MNT_MTX(mp), PVFS,
"mount drain", 0);
}
MNT_IUNLOCK(mp);
KASSERT(mp->mnt_lockref == 0,
("%s: invalid lock refcount in the drain path @ %s:%d",
__func__, __FILE__, __LINE__));
KASSERT(error == 0,
("%s: invalid return value for msleep in the drain path @ %s:%d",
__func__, __FILE__, __LINE__));
vn_start_write(NULL, &mp, V_WAIT);
if (mp->mnt_flag & MNT_EXPUBLIC)
vfs_setpublicfs(NULL, NULL, NULL);
vfs_msync(mp, MNT_WAIT);
MNT_ILOCK(mp);
async_flag = mp->mnt_flag & MNT_ASYNC;
mp->mnt_flag &= ~MNT_ASYNC;
mp->mnt_kern_flag &= ~MNTK_ASYNC;
MNT_IUNLOCK(mp);
cache_purgevfs(mp); /* remove cache entries for this file sys */
if (mp->mnt_syncer != NULL)
vrele(mp->mnt_syncer);
/*
* For forced unmounts, move process cdir/rdir refs on the fs root
* vnode to the covered vnode. For non-forced unmounts we want
* such references to cause an EBUSY error.
*/
if ((flags & MNT_FORCE) &&
VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
if (mp->mnt_vnodecovered != NULL)
mountcheckdirs(fsrootvp, mp->mnt_vnodecovered);
if (fsrootvp == rootvnode) {
vrele(rootvnode);
rootvnode = NULL;
}
vput(fsrootvp);
}
if (((mp->mnt_flag & MNT_RDONLY) ||
(error = VFS_SYNC(mp, MNT_WAIT)) == 0) || (flags & MNT_FORCE) != 0)
error = VFS_UNMOUNT(mp, flags);
vn_finished_write(mp);
/*
* If we failed to flush the dirty blocks for this mount point,
* undo all the cdir/rdir and rootvnode changes we made above.
* Unless we failed to do so because the device is reporting that
* it doesn't exist anymore.
*/
if (error && error != ENXIO) {
if ((flags & MNT_FORCE) &&
VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
if (mp->mnt_vnodecovered != NULL)
mountcheckdirs(mp->mnt_vnodecovered, fsrootvp);
if (rootvnode == NULL) {
rootvnode = fsrootvp;
vref(rootvnode);
}
vput(fsrootvp);
}
MNT_ILOCK(mp);
mp->mnt_kern_flag &= ~MNTK_NOINSMNTQ;
if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) {
MNT_IUNLOCK(mp);
(void) vfs_allocate_syncvnode(mp);
MNT_ILOCK(mp);
}
mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
mp->mnt_flag |= async_flag;
if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0)
mp->mnt_kern_flag |= MNTK_ASYNC;
if (mp->mnt_kern_flag & MNTK_MWAIT) {
mp->mnt_kern_flag &= ~MNTK_MWAIT;
wakeup(mp);
}
MNT_IUNLOCK(mp);
if (coveredvp)
VOP_UNLOCK(coveredvp, 0);
return (error);
}
mtx_lock(&mountlist_mtx);
TAILQ_REMOVE(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
if (coveredvp != NULL) {
coveredvp->v_mountedhere = NULL;
vput(coveredvp);
}
vfs_event_signal(NULL, VQ_UNMOUNT, 0);
vfs_mount_destroy(mp);
return (0);
}
/*
* ---------------------------------------------------------------------
* Mounting of root filesystem
*
*/
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);
static int root_mount_complete;
/*
* Hold root mount.
*/
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(&mountlist_mtx);
LIST_INSERT_HEAD(&root_holds, h, list);
mtx_unlock(&mountlist_mtx);
return (h);
}
/*
* Release root mount.
*/
void
root_mount_rel(struct root_hold_token *h)
{
if (h == NULL)
return;
mtx_lock(&mountlist_mtx);
LIST_REMOVE(h, list);
wakeup(&root_holds);
mtx_unlock(&mountlist_mtx);
free(h, M_DEVBUF);
}
/*
* Wait for all subsystems to release root mount.
*/
static void
root_mount_prepare(void)
{
struct root_hold_token *h;
struct timeval lastfail;
int curfail = 0;
for (;;) {
DROP_GIANT();
g_waitidle();
PICKUP_GIANT();
mtx_lock(&mountlist_mtx);
if (LIST_EMPTY(&root_holds)) {
mtx_unlock(&mountlist_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, &mountlist_mtx, PZERO | PDROP, "roothold",
hz);
}
}
/*
* Root was mounted, share the good news.
*/
static void
root_mount_done(void)
{
/* 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);
/*
* Use a mutex to prevent the wakeup being missed and waiting for
* an extra 1 second sleep.
*/
mtx_lock(&mountlist_mtx);
root_mount_complete = 1;
wakeup(&root_mount_complete);
mtx_unlock(&mountlist_mtx);
}
/*
* Return true if root is already mounted.
*/
int
root_mounted(void)
{
/* No mutex is acquired here because int stores are atomic. */
return (root_mount_complete);
}
/*
* Wait until root is mounted.
*/
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(&mountlist_mtx);
while (!root_mount_complete) {
msleep(&root_mount_complete, &mountlist_mtx, PZERO, "rootwait",
hz);
}
mtx_unlock(&mountlist_mtx);
}
static void
set_rootvnode()
{
struct proc *p;
if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
panic("Cannot find root vnode");
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);
VOP_UNLOCK(rootvnode, 0);
EVENTHANDLER_INVOKE(mountroot);
}
/*
* Mount /devfs as our root filesystem, but do not put it on the mountlist
* yet. Create a /dev -> / symlink so that absolute pathnames will lookup.
*/
static void
devfs_first(void)
{
struct thread *td = curthread;
struct vfsoptlist *opts;
struct vfsconf *vfsp;
struct mount *mp = NULL;
int error;
vfsp = vfs_byname("devfs");
KASSERT(vfsp != NULL, ("Could not find devfs by name"));
if (vfsp == NULL)
return;
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;
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);
set_rootvnode();
error = kern_symlink(td, "/", "dev", UIO_SYSSPACE);
if (error)
printf("kern_symlink /dev -> / returns %d\n", error);
}
/*
* Surgically move our devfs to be mounted on /dev.
*/
static void
devfs_fixup(struct thread *td)
{
struct nameidata nd;
int error;
struct vnode *vp, *dvp;
struct mount *mp;
/* Remove our devfs mount from the mountlist and purge the cache */
mtx_lock(&mountlist_mtx);
mp = TAILQ_FIRST(&mountlist);
TAILQ_REMOVE(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
cache_purgevfs(mp);
VFS_ROOT(mp, LK_EXCLUSIVE, &dvp);
VI_LOCK(dvp);
dvp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(dvp);
dvp->v_mountedhere = NULL;
/* Set up the real rootvnode, and purge the cache */
TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL;
set_rootvnode();
cache_purgevfs(rootvnode->v_mount);
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
error = namei(&nd);
if (error) {
printf("Lookup of /dev for devfs, error: %d\n", error);
return;
}
NDFREE(&nd, NDF_ONLY_PNBUF);
vp = nd.ni_vp;
if (vp->v_type != VDIR) {
vput(vp);
}
error = vinvalbuf(vp, V_SAVE, 0, 0);
if (error) {
vput(vp);
}
cache_purge(vp);
mp->mnt_vnodecovered = vp;
vp->v_mountedhere = mp;
mtx_lock(&mountlist_mtx);
TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
VOP_UNLOCK(vp, 0);
vput(dvp);
vfs_unbusy(mp);
/* Unlink the no longer needed /dev/dev -> / symlink */
kern_unlink(td, "/dev/dev", UIO_SYSSPACE);
}
/*
* Report errors during filesystem mounting.
*/
void
vfs_mount_error(struct mount *mp, const char *fmt, ...)
{
struct vfsoptlist *moptlist = mp->mnt_optnew;
va_list ap;
int error, len;
char *errmsg;
error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len);
if (error || errmsg == NULL || len <= 0)
return;
va_start(ap, fmt);
vsnprintf(errmsg, (size_t)len, fmt, ap);
va_end(ap);
}
void
vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...)
{
va_list ap;
int error, len;
char *errmsg;
error = vfs_getopt(opts, "errmsg", (void **)&errmsg, &len);
if (error || errmsg == NULL || len <= 0)
return;
va_start(ap, fmt);
vsnprintf(errmsg, (size_t)len, fmt, ap);
va_end(ap);
}
/*
* Find and mount the root filesystem
*/
void
vfs_mountroot(void)
{
char *cp;
int error, i, asked = 0;
root_mount_prepare();
mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount),
NULL, NULL, mount_init, mount_fini,
UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
devfs_first();
/*
* We are booted with instructions to prompt for the root filesystem.
*/
if (boothowto & RB_ASKNAME) {
if (!vfs_mountroot_ask())
goto mounted;
asked = 1;
}
/*
* The root filesystem information is compiled in, and we are
* booted with instructions to use it.
*/
if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) {
if (!vfs_mountroot_try(ctrootdevname))
goto mounted;
ctrootdevname = NULL;
}
/*
* We've been given the generic "use CDROM as root" flag. This is
* necessary because one media may be used in many different
* devices, so we need to search for them.
*/
if (boothowto & RB_CDROM) {
for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
goto mounted;
}
}
/*
* Try to use the value read by the loader from /etc/fstab, or
* supplied via some other means. This is the preferred
* mechanism.
*/
cp = getenv("vfs.root.mountfrom");
if (cp != NULL) {
error = vfs_mountroot_try(cp);
freeenv(cp);
if (!error)
goto mounted;
}
/*
* Try values that may have been computed by code during boot
*/
if (!vfs_mountroot_try(rootdevnames[0]))
goto mounted;
if (!vfs_mountroot_try(rootdevnames[1]))
goto mounted;
/*
* If we (still) have a compiled-in default, try it.
*/
if (ctrootdevname != NULL)
if (!vfs_mountroot_try(ctrootdevname))
goto mounted;
/*
* Everything so far has failed, prompt on the console if we haven't
* already tried that.
*/
if (!asked)
if (!vfs_mountroot_ask())
goto mounted;
panic("Root mount failed, startup aborted.");
mounted:
root_mount_done();
}
/*
* Mount (mountfrom) as the root filesystem.
*/
static int
vfs_mountroot_try(const char *mountfrom)
{
struct mount *mp;
char *vfsname, *path;
time_t timebase;
int error;
char patt[32];
vfsname = NULL;
path = NULL;
mp = NULL;
error = EINVAL;
if (mountfrom == NULL)
return (error); /* don't complain */
printf("Trying to mount root from %s\n", mountfrom);
/* parse vfs name and path */
vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
path = malloc(MNAMELEN, M_MOUNT, M_WAITOK);
vfsname[0] = path[0] = 0;
sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
if (sscanf(mountfrom, patt, vfsname, path) < 1)
goto out;
if (path[0] == '\0')
strcpy(path, ROOTNAME);
error = kernel_vmount(
MNT_RDONLY | MNT_ROOTFS,
"fstype", vfsname,
"fspath", "/",
"from", path,
NULL);
if (error == 0) {
/*
* We mount devfs prior to mounting the / FS, so the first
* entry will typically be devfs.
*/
mp = TAILQ_FIRST(&mountlist);
KASSERT(mp != NULL, ("%s: mountlist is empty", __func__));
/*
* Iterate over all currently mounted file systems and use
* the time stamp found to check and/or initialize the RTC.
* Typically devfs has no time stamp and the only other FS
* is the actual / FS.
* Call inittodr() only once and pass it the largest of the
* timestamps we encounter.
*/
timebase = 0;
do {
if (mp->mnt_time > timebase)
timebase = mp->mnt_time;
mp = TAILQ_NEXT(mp, mnt_list);
} while (mp != NULL);
inittodr(timebase);
devfs_fixup(curthread);
}
out:
free(path, M_MOUNT);
free(vfsname, M_MOUNT);
return (error);
}
/*
* ---------------------------------------------------------------------
* Interactive root filesystem selection code.
*/
static int
vfs_mountroot_ask(void)
{
char name[128];
for(;;) {
printf("\nManual root filesystem specification:\n");
printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n");
#if defined(__amd64__) || defined(__i386__) || defined(__ia64__)
printf(" eg. ufs:da0s1a\n");
#else
printf(" eg. ufs:/dev/da0a\n");
#endif
printf(" ? List valid disk boot devices\n");
printf(" <empty line> Abort manual input\n");
printf("\nmountroot> ");
gets(name, sizeof(name), 1);
if (name[0] == '\0')
return (1);
if (name[0] == '?') {
printf("\nList of GEOM managed disk devices:\n ");
g_dev_print();
continue;
}
if (!vfs_mountroot_try(name))
return (0);
}
}
/*
* ---------------------------------------------------------------------
* Functions for querying mount options/arguments from filesystems.
*/
/*
* Check that no unknown options are given
*/
int
vfs_filteropt(struct vfsoptlist *opts, const char **legal)
{
struct vfsopt *opt;
char errmsg[255];
const char **t, *p, *q;
int ret = 0;
TAILQ_FOREACH(opt, opts, link) {
p = opt->name;
q = NULL;
if (p[0] == 'n' && p[1] == 'o')
q = p + 2;
for(t = global_opts; *t != NULL; t++) {
if (strcmp(*t, p) == 0)
break;
if (q != NULL) {
if (strcmp(*t, q) == 0)
break;
}
}
if (*t != NULL)
continue;
for(t = legal; *t != NULL; t++) {
if (strcmp(*t, p) == 0)
break;
if (q != NULL) {
if (strcmp(*t, q) == 0)
break;
}
}
if (*t != NULL)
continue;
snprintf(errmsg, sizeof(errmsg),
"mount option <%s> is unknown", p);
printf("%s\n", errmsg);
ret = EINVAL;
}
if (ret != 0) {
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(opt->name, "errmsg") == 0) {
strncpy((char *)opt->value, errmsg, opt->len);
}
}
}
return (ret);
}
/*
* Get a mount option by its name.
*
* Return 0 if the option was found, ENOENT otherwise.
* If len is non-NULL it will be filled with the length
* of the option. If buf is non-NULL, it will be filled
* with the address of the option.
*/
int
vfs_getopt(opts, name, buf, len)
struct vfsoptlist *opts;
const char *name;
void **buf;
int *len;
{
struct vfsopt *opt;
KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) == 0) {
opt->seen = 1;
if (len != NULL)
*len = opt->len;
if (buf != NULL)
*buf = opt->value;
return (0);
}
}
return (ENOENT);
}
int
vfs_getopt_pos(struct vfsoptlist *opts, const char *name)
{
struct vfsopt *opt;
if (opts == NULL)
return (-1);
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) == 0) {
opt->seen = 1;
return (opt->pos);
}
}
return (-1);
}
char *
vfs_getopts(struct vfsoptlist *opts, const char *name, int *error)
{
struct vfsopt *opt;
*error = 0;
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) != 0)
continue;
opt->seen = 1;
if (opt->len == 0 ||
((char *)opt->value)[opt->len - 1] != '\0') {
*error = EINVAL;
return (NULL);
}
return (opt->value);
}
*error = ENOENT;
return (NULL);
}
int
vfs_flagopt(struct vfsoptlist *opts, const char *name, u_int *w, u_int val)
{
struct vfsopt *opt;
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) == 0) {
opt->seen = 1;
if (w != NULL)
*w |= val;
return (1);
}
}
if (w != NULL)
*w &= ~val;
return (0);
}
int
vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...)
{
va_list ap;
struct vfsopt *opt;
int ret;
KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) != 0)
continue;
opt->seen = 1;
if (opt->len == 0 || opt->value == NULL)
return (0);
if (((char *)opt->value)[opt->len - 1] != '\0')
return (0);
va_start(ap, fmt);
ret = vsscanf(opt->value, fmt, ap);
va_end(ap);
return (ret);
}
return (0);
}
int
vfs_setopt(struct vfsoptlist *opts, const char *name, void *value, int len)
{
struct vfsopt *opt;
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) != 0)
continue;
opt->seen = 1;
if (opt->value == NULL)
opt->len = len;
else {
if (opt->len != len)
return (EINVAL);
bcopy(value, opt->value, len);
}
return (0);
}
return (ENOENT);
}
int
vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value, int len)
{
struct vfsopt *opt;
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) != 0)
continue;
opt->seen = 1;
if (opt->value == NULL)
opt->len = len;
else {
if (opt->len < len)
return (EINVAL);
opt->len = len;
bcopy(value, opt->value, len);
}
return (0);
}
return (ENOENT);
}
int
vfs_setopts(struct vfsoptlist *opts, const char *name, const char *value)
{
struct vfsopt *opt;
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) != 0)
continue;
opt->seen = 1;
if (opt->value == NULL)
opt->len = strlen(value) + 1;
else if (strlcpy(opt->value, value, opt->len) >= opt->len)
return (EINVAL);
return (0);
}
return (ENOENT);
}
/*
* Find and copy a mount option.
*
* The size of the buffer has to be specified
* in len, if it is not the same length as the
* mount option, EINVAL is returned.
* Returns ENOENT if the option is not found.
*/
int
vfs_copyopt(opts, name, dest, len)
struct vfsoptlist *opts;
const char *name;
void *dest;
int len;
{
struct vfsopt *opt;
KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL"));
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) == 0) {
opt->seen = 1;
if (len != opt->len)
return (EINVAL);
bcopy(opt->value, dest, opt->len);
return (0);
}
}
return (ENOENT);
}
/*
* This is a helper function for filesystems to traverse their
* vnodes. See MNT_VNODE_FOREACH() in sys/mount.h
*/
struct vnode *
__mnt_vnode_next(struct vnode **mvp, struct mount *mp)
{
struct vnode *vp;
mtx_assert(MNT_MTX(mp), MA_OWNED);
KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
if ((*mvp)->v_yield++ == 500) {
MNT_IUNLOCK(mp);
(*mvp)->v_yield = 0;
uio_yield();
MNT_ILOCK(mp);
}
vp = TAILQ_NEXT(*mvp, v_nmntvnodes);
while (vp != NULL && vp->v_type == VMARKER)
vp = TAILQ_NEXT(vp, v_nmntvnodes);
/* Check if we are done */
if (vp == NULL) {
__mnt_vnode_markerfree(mvp, mp);
return (NULL);
}
TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
return (vp);
}
struct vnode *
__mnt_vnode_first(struct vnode **mvp, struct mount *mp)
{
struct vnode *vp;
mtx_assert(MNT_MTX(mp), MA_OWNED);
vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
while (vp != NULL && vp->v_type == VMARKER)
vp = TAILQ_NEXT(vp, v_nmntvnodes);
/* Check if we are done */
if (vp == NULL) {
*mvp = NULL;
return (NULL);
}
MNT_REF(mp);
MNT_IUNLOCK(mp);
*mvp = (struct vnode *) malloc(sizeof(struct vnode),
M_VNODE_MARKER,
M_WAITOK | M_ZERO);
MNT_ILOCK(mp);
(*mvp)->v_type = VMARKER;
vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
while (vp != NULL && vp->v_type == VMARKER)
vp = TAILQ_NEXT(vp, v_nmntvnodes);
/* Check if we are done */
if (vp == NULL) {
MNT_IUNLOCK(mp);
free(*mvp, M_VNODE_MARKER);
MNT_ILOCK(mp);
*mvp = NULL;
MNT_REL(mp);
return (NULL);
}
(*mvp)->v_mount = mp;
TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
return (vp);
}
void
__mnt_vnode_markerfree(struct vnode **mvp, struct mount *mp)
{
if (*mvp == NULL)
return;
mtx_assert(MNT_MTX(mp), MA_OWNED);
KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
MNT_IUNLOCK(mp);
free(*mvp, M_VNODE_MARKER);
MNT_ILOCK(mp);
*mvp = NULL;
MNT_REL(mp);
}
int
__vfs_statfs(struct mount *mp, struct statfs *sbp)
{
int error;
error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat);
if (sbp != &mp->mnt_stat)
*sbp = mp->mnt_stat;
return (error);
}
void
vfs_mountedfrom(struct mount *mp, const char *from)
{
bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname);
strlcpy(mp->mnt_stat.f_mntfromname, from,
sizeof mp->mnt_stat.f_mntfromname);
}
/*
* ---------------------------------------------------------------------
* This is the api for building mount args and mounting filesystems from
* inside the kernel.
*
* The API works by accumulation of individual args. First error is
* latched.
*
* XXX: should be documented in new manpage kernel_mount(9)
*/
/* A memory allocation which must be freed when we are done */
struct mntaarg {
SLIST_ENTRY(mntaarg) next;
};
/* The header for the mount arguments */
struct mntarg {
struct iovec *v;
int len;
int error;
SLIST_HEAD(, mntaarg) list;
};
/*
* Add a boolean argument.
*
* flag is the boolean value.
* name must start with "no".
*/
struct mntarg *
mount_argb(struct mntarg *ma, int flag, const char *name)
{
KASSERT(name[0] == 'n' && name[1] == 'o',
("mount_argb(...,%s): name must start with 'no'", name));
return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0));
}
/*
* Add an argument printf style
*/
struct mntarg *
mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...)
{
va_list ap;
struct mntaarg *maa;
struct sbuf *sb;
int len;
if (ma == NULL) {
ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
SLIST_INIT(&ma->list);
}
if (ma->error)
return (ma);
ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
M_MOUNT, M_WAITOK);
ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
ma->v[ma->len].iov_len = strlen(name) + 1;
ma->len++;
sb = sbuf_new_auto();
va_start(ap, fmt);
sbuf_vprintf(sb, fmt, ap);
va_end(ap);
sbuf_finish(sb);
len = sbuf_len(sb) + 1;
maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
SLIST_INSERT_HEAD(&ma->list, maa, next);
bcopy(sbuf_data(sb), maa + 1, len);
sbuf_delete(sb);
ma->v[ma->len].iov_base = maa + 1;
ma->v[ma->len].iov_len = len;
ma->len++;
return (ma);
}
/*
* Add an argument which is a userland string.
*/
struct mntarg *
mount_argsu(struct mntarg *ma, const char *name, const void *val, int len)
{
struct mntaarg *maa;
char *tbuf;
if (val == NULL)
return (ma);
if (ma == NULL) {
ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
SLIST_INIT(&ma->list);
}
if (ma->error)
return (ma);
maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
SLIST_INSERT_HEAD(&ma->list, maa, next);
tbuf = (void *)(maa + 1);
ma->error = copyinstr(val, tbuf, len, NULL);
return (mount_arg(ma, name, tbuf, -1));
}
/*
* Plain argument.
*
* If length is -1, treat value as a C string.
*/
struct mntarg *
mount_arg(struct mntarg *ma, const char *name, const void *val, int len)
{
if (ma == NULL) {
ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
SLIST_INIT(&ma->list);
}
if (ma->error)
return (ma);
ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
M_MOUNT, M_WAITOK);
ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
ma->v[ma->len].iov_len = strlen(name) + 1;
ma->len++;
ma->v[ma->len].iov_base = (void *)(uintptr_t)val;
if (len < 0)
ma->v[ma->len].iov_len = strlen(val) + 1;
else
ma->v[ma->len].iov_len = len;
ma->len++;
return (ma);
}
/*
* Free a mntarg structure
*/
static void
free_mntarg(struct mntarg *ma)
{
struct mntaarg *maa;
while (!SLIST_EMPTY(&ma->list)) {
maa = SLIST_FIRST(&ma->list);
SLIST_REMOVE_HEAD(&ma->list, next);
free(maa, M_MOUNT);
}
free(ma->v, M_MOUNT);
free(ma, M_MOUNT);
}
/*
* Mount a filesystem
*/
int
kernel_mount(struct mntarg *ma, int flags)
{
struct uio auio;
int error;
KASSERT(ma != NULL, ("kernel_mount NULL ma"));
KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v"));
KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len));
auio.uio_iov = ma->v;
auio.uio_iovcnt = ma->len;
auio.uio_segflg = UIO_SYSSPACE;
error = ma->error;
if (!error)
error = vfs_donmount(curthread, flags, &auio);
free_mntarg(ma);
return (error);
}
/*
* A printflike function to mount a filesystem.
*/
int
kernel_vmount(int flags, ...)
{
struct mntarg *ma = NULL;
va_list ap;
const char *cp;
const void *vp;
int error;
va_start(ap, flags);
for (;;) {
cp = va_arg(ap, const char *);
if (cp == NULL)
break;
vp = va_arg(ap, const void *);
ma = mount_arg(ma, cp, vp, (vp != NULL ? -1 : 0));
}
va_end(ap);
error = kernel_mount(ma, flags);
return (error);
}
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