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freebsd-skq/sys/kern/vfs_mount.c
Robert Watson acd3428b7d Sweep kernel replacing suser(9) calls with priv(9) calls, assigning 
specific privilege names to a broad range of privileges.  These may
require some future tweaking.

Sponsored by:           nCircle Network Security, Inc.
Obtained from:          TrustedBSD Project
Discussed on:           arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
                        Alex Lyashkov <umka at sevcity dot net>,
                        Skip Ford <skip dot ford at verizon dot net>,
                        Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:42:10 +00:00

2181 lines
51 KiB
C
Raw Blame History

/*-
* 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/clock.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_ddb.h"
#include "opt_mac.h"
#ifdef DDB
#include <ddb/ddb.h>
#endif
#define ROOTNAME "root_device"
#define VFS_MOUNTARG_SIZE_MAX (1024 * 64)
static int vfs_domount(struct thread *td, const char *fstype,
char *fspath, int fsflags, void *fsdata);
static struct mount *vfs_mount_alloc(struct vnode *dvp, struct vfsconf *vfsp,
const char *fspath, struct thread *td);
static int vfs_mountroot_ask(void);
static int vfs_mountroot_try(const char *mountfrom);
static int vfs_donmount(struct thread *td, int fsflags,
struct uio *fsoptions);
static void free_mntarg(struct mntarg *ma);
static void vfs_mount_destroy(struct mount *);
static int vfs_getopt_pos(struct vfsoptlist *opts, const char *name);
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);
TAILQ_HEAD(vfsoptlist, vfsopt);
struct vfsopt {
TAILQ_ENTRY(vfsopt) link;
char *name;
void *value;
int len;
};
/*
* 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",
"rdonly",
"ro",
"rw",
"suid",
"exec",
"update",
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);
#ifdef INVARIANTS
else if (opt->len != 0)
panic("%s: mount option with NULL value but length != 0",
__func__);
#endif
free(opt, M_MOUNT);
}
/* Release all resources related to the mount options. */
static 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);
}
/*
* Check if options are equal (with or without the "no" prefix).
*/
static int
vfs_equalopts(const char *opt1, const char *opt2)
{
/* "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);
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.
*/
static int
vfs_buildopts(struct uio *auio, struct vfsoptlist **options)
{
struct vfsoptlist *opts;
struct vfsopt *opt;
size_t memused;
unsigned int i, iovcnt;
int error, namelen, optlen;
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) {
opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
namelen = auio->uio_iov[i].iov_len;
optlen = auio->uio_iov[i + 1].iov_len;
opt->name = malloc(namelen, M_MOUNT, M_WAITOK);
opt->value = NULL;
opt->len = 0;
/*
* Do this early, so jumps to "bad" will free the current
* option.
*/
TAILQ_INSERT_TAIL(opts, opt, link);
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;
}
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 (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.
*/
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;
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;
struct iovec *iov;
unsigned int i;
int error;
u_int iovcnt;
AUDIT_ARG(fflags, uap->flags);
/* Kick out MNT_ROOTFS early as it is legal internally */
if (uap->flags & MNT_ROOTFS)
return (EINVAL);
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))
return (EINVAL);
error = copyinuio(uap->iovp, iovcnt, &auio);
if (error)
return (error);
iov = auio->uio_iov;
for (i = 0; i < iovcnt; i++) {
if (iov->iov_len > MMAXOPTIONLEN) {
free(auio, M_IOV);
return (EINVAL);
}
iov++;
}
error = vfs_donmount(td, uap->flags, auio);
free(auio, M_IOV);
return (error);
}
/*
* ---------------------------------------------------------------------
* Various utility functions
*/
void
vfs_ref(struct mount *mp)
{
MNT_ILOCK(mp);
MNT_REF(mp);
MNT_IUNLOCK(mp);
}
void
vfs_rel(struct mount *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_lock, PVFS, "vfslock", 0, 0);
return (0);
}
static void
mount_fini(void *mem, int size)
{
struct mount *mp;
mp = (struct mount *)mem;
lockdestroy(&mp->mnt_lock);
mtx_destroy(&mp->mnt_mtx);
}
/*
* Allocate and initialize the mount point struct.
*/
static struct mount *
vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp,
const char *fspath, struct thread *td)
{
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, LK_NOWAIT, 0, td);
mp->mnt_op = vfsp->vfc_vfsops;
mp->mnt_vfc = vfsp;
vfsp->vfc_refcount++; /* XXX Unlocked */
mp->mnt_stat.f_type = vfsp->vfc_typenum;
MNT_ILOCK(mp);
mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
MNT_IUNLOCK(mp);
mp->mnt_gen++;
strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
mp->mnt_vnodecovered = vp;
mp->mnt_cred = crdup(td->td_ucred);
mp->mnt_stat.f_owner = td->td_ucred->cr_uid;
strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN);
mp->mnt_iosize_max = DFLTPHYS;
#ifdef MAC
mac_init_mount(mp);
mac_create_mount(td->td_ucred, mp);
#endif
arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0);
return (mp);
}
/*
* Destroy the mount struct previously allocated by vfs_mount_alloc().
*/
static void
vfs_mount_destroy(struct mount *mp)
{
int i;
MNT_ILOCK(mp);
for (i = 0; mp->mnt_ref && i < 3; i++)
msleep(mp, MNT_MTX(mp), PVFS, "mntref", hz);
/*
* This will always cause a 3 second delay in rebooting due to
* refs on the root mountpoint that never go away. Most of these
* are held by init which never exits.
*/
if (i == 3 && (!rebooting || bootverbose))
printf("Mount point %s had %d dangling refs\n",
mp->mnt_stat.f_mntonname, mp->mnt_ref);
if (mp->mnt_holdcnt != 0) {
printf("Waiting for mount point to be unheld\n");
while (mp->mnt_holdcnt != 0) {
mp->mnt_holdcntwaiters++;
msleep(&mp->mnt_holdcnt, MNT_MTX(mp),
PZERO, "mntdestroy", 0);
mp->mnt_holdcntwaiters--;
}
printf("mount point unheld\n");
}
if (mp->mnt_writeopcount > 0) {
printf("Waiting for mount point write ops\n");
while (mp->mnt_writeopcount > 0) {
mp->mnt_kern_flag |= MNTK_SUSPEND;
msleep(&mp->mnt_writeopcount,
MNT_MTX(mp),
PZERO, "mntdestroy2", 0);
}
printf("mount point write ops completed\n");
}
if (mp->mnt_secondary_writes > 0) {
printf("Waiting for mount point secondary write ops\n");
while (mp->mnt_secondary_writes > 0) {
mp->mnt_kern_flag |= MNTK_SUSPEND;
msleep(&mp->mnt_secondary_writes,
MNT_MTX(mp),
PZERO, "mntdestroy3", 0);
}
printf("mount point secondary write ops completed\n");
}
MNT_IUNLOCK(mp);
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");
}
MNT_ILOCK(mp);
if (mp->mnt_kern_flag & MNTK_MWAIT)
wakeup(mp);
if (mp->mnt_writeopcount != 0)
panic("vfs_mount_destroy: nonzero writeopcount");
if (mp->mnt_secondary_writes != 0)
panic("vfs_mount_destroy: nonzero secondary_writes");
if (mp->mnt_nvnodelistsize != 0)
panic("vfs_mount_destroy: nonzero nvnodelistsize");
mp->mnt_writeopcount = -1000;
mp->mnt_nvnodelistsize = -1000;
mp->mnt_secondary_writes = -1000;
MNT_IUNLOCK(mp);
#ifdef MAC
mac_destroy_mount(mp);
#endif
if (mp->mnt_opt != NULL)
vfs_freeopts(mp->mnt_opt);
crfree(mp->mnt_cred);
uma_zfree(mount_zone, mp);
}
static int
vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions)
{
struct vfsoptlist *optlist;
struct vfsopt *opt, *noro_opt;
char *fstype, *fspath, *errmsg;
int error, fstypelen, fspathlen, errmsg_len, errmsg_pos;
int has_rw, has_noro;
errmsg = NULL;
errmsg_len = 0;
errmsg_pos = -1;
has_rw = 0;
has_noro = 0;
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(opt, optlist, link) {
if (strcmp(opt->name, "update") == 0)
fsflags |= MNT_UPDATE;
else if (strcmp(opt->name, "async") == 0)
fsflags |= MNT_ASYNC;
else if (strcmp(opt->name, "force") == 0)
fsflags |= MNT_FORCE;
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, "noclusterr") == 0)
fsflags |= MNT_NOCLUSTERR;
else if (strcmp(opt->name, "noclusterw") == 0)
fsflags |= MNT_NOCLUSTERW;
else if (strcmp(opt->name, "noexec") == 0)
fsflags |= MNT_NOEXEC;
else if (strcmp(opt->name, "nosuid") == 0)
fsflags |= MNT_NOSUID;
else if (strcmp(opt->name, "nosymfollow") == 0)
fsflags |= MNT_NOSYMFOLLOW;
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 ||
strcmp(opt->name, "rdonly") == 0)
fsflags |= MNT_RDONLY;
else if (strcmp(opt->name, "snapshot") == 0)
fsflags |= MNT_SNAPSHOT;
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;
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);
/* Kick out MNT_ROOTFS early as it is legal internally */
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, td);
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 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))
return (EPERM);
if (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);
}
/*
* 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, LK_NOWAIT, 0, td)) {
vput(vp);
return (EBUSY);
}
VI_LOCK(vp);
if ((vp->v_iflag & VI_MOUNT) != 0 ||
vp->v_mountedhere != NULL) {
VI_UNLOCK(vp);
vfs_unbusy(mp, td);
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, td);
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, td);
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,
SUSER_ALLOWJAIL);
if (error) {
vput(vp);
return (error);
}
}
error = vinvalbuf(vp, V_SAVE, td, 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);
VOP_UNLOCK(vp, 0, td);
/* 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, td);
/*
* 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);
}
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, td);
}
/*
* 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, td);
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, td);
/*
* 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, td))
panic("mount: lost mount");
mountcheckdirs(vp, newdp);
vput(newdp);
VOP_UNLOCK(vp, 0, td);
if ((mp->mnt_flag & MNT_RDONLY) == 0)
error = vfs_allocate_syncvnode(mp);
vfs_unbusy(mp, td);
if (error)
vrele(vp);
} else {
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
vfs_unbusy(mp, td);
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))
return (EPERM);
if (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);
error = vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK, td);
vdrop(coveredvp);
/*
* Check for mp being unmounted while waiting for the
* covered vnode lock.
*/
if (error)
return (error);
if (coveredvp->v_mountedhere != mp ||
coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) {
VOP_UNLOCK(coveredvp, 0, td);
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, td);
return (error);
}
MNT_ILOCK(mp);
if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
MNT_IUNLOCK(mp);
if (coveredvp)
VOP_UNLOCK(coveredvp, 0, td);
return (EBUSY);
}
mp->mnt_kern_flag |= MNTK_UNMOUNT;
/* Allow filesystems to detect that a forced unmount is in progress. */
if (flags & MNT_FORCE)
mp->mnt_kern_flag |= MNTK_UNMOUNTF;
error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK |
((flags & MNT_FORCE) ? 0 : LK_NOWAIT), MNT_MTX(mp), td);
if (error) {
MNT_ILOCK(mp);
mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
if (mp->mnt_kern_flag & MNTK_MWAIT)
wakeup(mp);
MNT_IUNLOCK(mp);
if (coveredvp)
VOP_UNLOCK(coveredvp, 0, td);
return (error);
}
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, td) == 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, td)) == 0) ||
(flags & MNT_FORCE)) {
error = VFS_UNMOUNT(mp, flags, td);
}
vn_finished_write(mp);
if (error) {
/* Undo cdir/rdir and rootvnode changes made above. */
if ((flags & MNT_FORCE) &&
VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) {
if (mp->mnt_vnodecovered != NULL)
mountcheckdirs(mp->mnt_vnodecovered, fsrootvp);
if (rootvnode == NULL) {
rootvnode = fsrootvp;
vref(rootvnode);
}
vput(fsrootvp);
}
if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL)
(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;
lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td);
if (mp->mnt_kern_flag & MNTK_MWAIT)
wakeup(mp);
MNT_IUNLOCK(mp);
if (coveredvp)
VOP_UNLOCK(coveredvp, 0, td);
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);
lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td);
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);
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(&mountlist_mtx);
LIST_INSERT_HEAD(&root_holds, h, list);
mtx_unlock(&mountlist_mtx);
return (h);
}
void
root_mount_rel(struct root_hold_token *h)
{
mtx_lock(&mountlist_mtx);
LIST_REMOVE(h, list);
wakeup(&root_holds);
mtx_unlock(&mountlist_mtx);
free(h, M_DEVBUF);
}
static void
root_mount_wait(void)
{
struct root_hold_token *h;
for (;;) {
DROP_GIANT();
g_waitidle();
PICKUP_GIANT();
mtx_lock(&mountlist_mtx);
if (LIST_EMPTY(&root_holds)) {
mtx_unlock(&mountlist_mtx);
break;
}
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);
}
}
static void
set_rootvnode(struct thread *td)
{
struct proc *p;
if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode, td))
panic("Cannot find root vnode");
p = td->td_proc;
FILEDESC_LOCK(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_UNLOCK(p->p_fd);
VOP_UNLOCK(rootvnode, 0, td);
}
/*
* 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);
error = VFS_MOUNT(mp, td);
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(td);
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, td);
VI_LOCK(dvp);
dvp->v_iflag &= ~VI_MOUNT;
dvp->v_mountedhere = NULL;
VI_UNLOCK(dvp);
/* Set up the real rootvnode, and purge the cache */
TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL;
set_rootvnode(td);
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, td, 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, td);
vput(dvp);
vfs_unbusy(mp, td);
/* 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);
}
/*
* Find and mount the root filesystem
*/
void
vfs_mountroot(void)
{
char *cp;
int error, i, asked = 0;
root_mount_wait();
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())
return;
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))
return;
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]))
return;
}
}
/*
* 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)
return;
}
/*
* Try values that may have been computed by code during boot
*/
if (!vfs_mountroot_try(rootdevnames[0]))
return;
if (!vfs_mountroot_try(rootdevnames[1]))
return;
/*
* If we (still) have a compiled-in default, try it.
*/
if (ctrootdevname != NULL)
if (!vfs_mountroot_try(ctrootdevname))
return;
/*
* Everything so far has failed, prompt on the console if we haven't
* already tried that.
*/
if (!asked)
if (!vfs_mountroot_ask())
return;
panic("Root mount failed, startup aborted.");
}
/*
* 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;
const char **t, *p;
TAILQ_FOREACH(opt, opts, link) {
p = opt->name;
if (p[0] == 'n' && p[1] == 'o')
p += 2;
for(t = global_opts; *t != NULL; t++)
if (!strcmp(*t, p))
break;
if (*t != NULL)
continue;
for(t = legal; *t != NULL; t++)
if (!strcmp(*t, p))
break;
if (*t != NULL)
continue;
printf("mount option <%s> is unknown\n", p);
return (EINVAL);
}
return (0);
}
/*
* 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) {
if (len != NULL)
*len = opt->len;
if (buf != NULL)
*buf = opt->value;
return (0);
}
}
return (ENOENT);
}
static int
vfs_getopt_pos(struct vfsoptlist *opts, const char *name)
{
struct vfsopt *opt;
int i;
if (opts == NULL)
return (-1);
i = 0;
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) == 0)
return (i);
++i;
}
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;
if (((char *)opt->value)[opt->len - 1] != '\0') {
*error = EINVAL;
return (NULL);
}
return (opt->value);
}
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) {
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;
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);
}
/*
* 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) {
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"));
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);
}
mp->mnt_holdcnt++;
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;
mp->mnt_holdcnt--;
if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0)
wakeup(&mp->mnt_holdcnt);
return (NULL);
}
mp->mnt_markercnt++;
(*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;
mp->mnt_markercnt--;
mp->mnt_holdcnt--;
if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0)
wakeup(&mp->mnt_holdcnt);
}
int
__vfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
{
int error;
error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat, td);
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(NULL, NULL, 0, SBUF_AUTOEXTEND);
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, use printf.
*/
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, -1);
}
va_end(ap);
error = kernel_mount(ma, flags);
return (error);
}
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