freebsd-skq/sys/kern/vfs_mount.c
Ian Dowse 318f2fb4bf Add a new mount flag MNT_BYFSID that can be used to unmount a file
system by specifying the file system ID instead of a path. Use this
by default in umount(8). This avoids the need to perform any vnode
operations to look up the mount point, so it makes it possible to
unmount a file system whose root vnode cannot be looked up (e.g.
due to a dead NFS server, or a file system that has become detached
from the hierarchy because an underlying file system was unmounted).
It also provides an unambiguous way to specify which file system is
to be unmunted.

Since the ability to unmount using a path name is retained only for
compatibility, that case now just uses a simple string comparison
of the supplied path against f_mntonname of each mounted file system.

Discussed on:	freebsd-arch
mdoc help from:	ru
2003-07-01 17:40:23 +00:00

1793 lines
42 KiB
C

/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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 REGENTS 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 REGENTS 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.
*
* Copyright (c) 1999 Michael Smith
* All rights reserved.
* Copyright (c) 1999 Poul-Henning Kamp
* All rights reserved.
*
* 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.
*
* 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/cons.h>
#include <sys/kernel.h>
#include <sys/linker.h>
#include <sys/mac.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/filedesc.h>
#include <sys/reboot.h>
#include <sys/sysproto.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <geom/geom.h>
#include <machine/stdarg.h>
#include "opt_rootdevname.h"
#include "opt_ddb.h"
#include "opt_mac.h"
#ifdef DDB
#include <ddb/ddb.h>
#endif
#define ROOTNAME "root_device"
static void checkdirs(struct vnode *olddp, struct vnode *newdp);
static int vfs_nmount(struct thread *td, int, struct uio *);
static int vfs_mountroot_try(char *mountfrom);
static int vfs_mountroot_ask(void);
static void gets(char *cp);
static int usermount = 0; /* if 1, non-root can mount fs. */
SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, "");
MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
/* List of mounted filesystems. */
struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist);
/* For any iteration/modification of mountlist */
struct mtx mountlist_mtx;
/* For any iteration/modification of mnt_vnodelist */
struct mtx mntvnode_mtx;
/*
* 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
*/
/*
* The root specifiers we will try if RB_CDROM is specified.
*/
static char *cdrom_rootdevnames[] = {
"cd9660:cd0a",
"cd9660:acd0a",
"cd9660:wcd0a",
NULL
};
/* legacy find-root code */
char *rootdevnames[2] = {NULL, NULL};
static int setrootbyname(char *name);
dev_t rootdev = NODEV;
/*
* Has to be dynamic as the value of rootdev can change; however, it can't
* change after the root is mounted, so a user process can't access this
* sysctl until after the value is unchangeable.
*/
static int
sysctl_rootdev(SYSCTL_HANDLER_ARGS)
{
int error;
/* _RD prevents this from happening. */
KASSERT(req->newptr == NULL, ("Attempt to change root device name"));
if (rootdev != NODEV)
error = sysctl_handle_string(oidp, rootdev->si_name, 0, req);
else
error = sysctl_handle_string(oidp, "", 0, req);
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, rootdev, CTLTYPE_STRING | CTLFLAG_RD,
0, 0, sysctl_rootdev, "A", "Root file system device");
/* 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);
}
/*
* 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;
int noopt;
TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) {
if (strncmp(opt->name, "no", 2) == 0)
noopt = 1;
else
noopt = 0;
opt2 = TAILQ_PREV(opt, vfsoptlist, link);
while (opt2 != NULL) {
if (strcmp(opt2->name, opt->name) == 0 ||
(noopt && strcmp(opt->name + 2, opt2->name) == 0) ||
(!noopt && strncmp(opt2->name, "no", 2) == 0 &&
strcmp(opt2->name + 2, opt->name) == 0)) {
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;
unsigned int i, iovcnt;
int error, namelen, optlen;
iovcnt = auio->uio_iovcnt;
opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
TAILQ_INIT(opts);
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;
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;
}
opt->len = optlen;
if (optlen != 0) {
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;
}
}
TAILQ_INSERT_TAIL(opts, opt, link);
}
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;
}
}
/*
* New mount API.
*/
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, *needfree;
struct iovec aiov[UIO_SMALLIOV];
unsigned int i;
int error;
u_int iovlen, iovcnt;
iovcnt = uap->iovcnt;
iovlen = iovcnt * sizeof (struct iovec);
/*
* Check that we have an even number of iovec's
* and that we have at least two options.
*/
if ((iovcnt & 1) || (iovcnt < 4) || (iovcnt > UIO_MAXIOV))
return (EINVAL);
if (iovcnt > UIO_SMALLIOV) {
MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK);
needfree = iov;
} else {
iov = aiov;
needfree = NULL;
}
auio.uio_iov = iov;
auio.uio_iovcnt = iovcnt;
auio.uio_segflg = UIO_USERSPACE;
if ((error = copyin(uap->iovp, iov, iovlen)))
goto finish;
for (i = 0; i < iovcnt; i++) {
if (iov->iov_len > MMAXOPTIONLEN) {
error = EINVAL;
goto finish;
}
iov++;
}
error = vfs_nmount(td, uap->flags, &auio);
finish:
if (needfree != NULL)
free(needfree, M_TEMP);
return (error);
}
int
kernel_mount(iovp, iovcnt, flags)
struct iovec *iovp;
unsigned int iovcnt;
int flags;
{
struct uio auio;
int error;
/*
* 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);
auio.uio_iov = iovp;
auio.uio_iovcnt = iovcnt;
auio.uio_segflg = UIO_SYSSPACE;
error = vfs_nmount(curthread, flags, &auio);
return (error);
}
int
kernel_vmount(int flags, ...)
{
struct iovec *iovp;
struct uio auio;
va_list ap;
unsigned int iovcnt, iovlen, len;
const char *cp;
char *buf, *pos;
size_t n;
int error, i;
len = 0;
va_start(ap, flags);
for (iovcnt = 0; (cp = va_arg(ap, const char *)) != NULL; iovcnt++)
len += strlen(cp) + 1;
va_end(ap);
if (iovcnt < 4 || iovcnt & 1)
return (EINVAL);
iovlen = iovcnt * sizeof (struct iovec);
MALLOC(iovp, struct iovec *, iovlen, M_MOUNT, M_WAITOK);
MALLOC(buf, char *, len, M_MOUNT, M_WAITOK);
pos = buf;
va_start(ap, flags);
for (i = 0; i < iovcnt; i++) {
cp = va_arg(ap, const char *);
copystr(cp, pos, len - (pos - buf), &n);
iovp[i].iov_base = pos;
iovp[i].iov_len = n;
pos += n;
}
va_end(ap);
auio.uio_iov = iovp;
auio.uio_iovcnt = iovcnt;
auio.uio_segflg = UIO_SYSSPACE;
error = vfs_nmount(curthread, flags, &auio);
FREE(iovp, M_MOUNT);
FREE(buf, M_MOUNT);
return (error);
}
/*
* vfs_nmount(): actually attempt a filesystem mount.
*/
static int
vfs_nmount(td, fsflags, fsoptions)
struct thread *td;
int fsflags; /* Flags common to all filesystems. */
struct uio *fsoptions; /* Options local to the filesystem. */
{
linker_file_t lf;
struct vnode *vp;
struct mount *mp;
struct vfsconf *vfsp;
struct vfsoptlist *optlist;
char *fstype, *fspath;
int error, flag = 0, kern_flag = 0;
int fstypelen, fspathlen;
struct vattr va;
struct nameidata nd;
error = vfs_buildopts(fsoptions, &optlist);
if (error)
return (error);
/*
* 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;
goto bad;
}
fspathlen = 0;
error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen);
if (error || fspath[fspathlen - 1] != '\0') {
error = EINVAL;
goto bad;
}
/*
* 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 bad;
}
if (usermount == 0) {
error = suser(td);
if (error)
goto bad;
}
/*
* Do not allow NFS export by non-root users.
*/
if (fsflags & MNT_EXPORTED) {
error = suser(td);
if (error)
goto bad;
}
/*
* Silently enforce MNT_NOSUID and MNT_NODEV for non-root users.
*/
if (suser(td))
fsflags |= MNT_NOSUID | MNT_NODEV;
/*
* Get vnode to be covered
*/
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspath, td);
if ((error = namei(&nd)) != 0)
goto bad;
NDFREE(&nd, NDF_ONLY_PNBUF);
vp = nd.ni_vp;
if (fsflags & MNT_UPDATE) {
if ((vp->v_vflag & VV_ROOT) == 0) {
vput(vp);
error = EINVAL;
goto bad;
}
mp = vp->v_mount;
flag = mp->mnt_flag;
kern_flag = mp->mnt_kern_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)) {
vput(vp);
error = EOPNOTSUPP; /* Needs translation */
goto bad;
}
/*
* Only root, or the user that did the original mount is
* permitted to update it.
*/
if (mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
error = suser(td);
if (error) {
vput(vp);
goto bad;
}
}
if (vfs_busy(mp, LK_NOWAIT, 0, td)) {
vput(vp);
error = EBUSY;
goto bad;
}
VI_LOCK(vp);
if ((vp->v_iflag & VI_MOUNT) != 0 ||
vp->v_mountedhere != NULL) {
VI_UNLOCK(vp);
vfs_unbusy(mp, td);
vput(vp);
error = EBUSY;
goto bad;
}
vp->v_iflag |= VI_MOUNT;
VI_UNLOCK(vp);
mp->mnt_flag |= fsflags &
(MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT);
VOP_UNLOCK(vp, 0, td);
mp->mnt_optnew = optlist;
vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt);
goto update;
}
/*
* 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);
goto bad;
}
if (va.va_uid != td->td_ucred->cr_uid) {
error = suser(td);
if (error) {
vput(vp);
goto bad;
}
}
if ((error = vinvalbuf(vp, V_SAVE, td->td_ucred, td, 0, 0)) != 0) {
vput(vp);
goto bad;
}
if (vp->v_type != VDIR) {
vput(vp);
error = ENOTDIR;
goto bad;
}
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (!strcmp(vfsp->vfc_name, fstype))
break;
if (vfsp == NULL) {
/* Only load modules for root (very important!). */
error = suser(td);
if (error) {
vput(vp);
goto bad;
}
error = securelevel_gt(td->td_ucred, 0);
if (error) {
vput(vp);
goto bad;
}
error = linker_load_module(NULL, fstype, NULL, NULL, &lf);
if (error || lf == NULL) {
vput(vp);
if (lf == NULL)
error = ENODEV;
goto bad;
}
lf->userrefs++;
/* Look up again to see if the VFS was loaded. */
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (!strcmp(vfsp->vfc_name, fstype))
break;
if (vfsp == NULL) {
lf->userrefs--;
linker_file_unload(lf);
vput(vp);
error = ENODEV;
goto bad;
}
}
VI_LOCK(vp);
if ((vp->v_iflag & VI_MOUNT) != 0 ||
vp->v_mountedhere != NULL) {
VI_UNLOCK(vp);
vput(vp);
error = EBUSY;
goto bad;
}
vp->v_iflag |= VI_MOUNT;
VI_UNLOCK(vp);
/*
* Allocate and initialize the filesystem.
*/
mp = malloc(sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO);
TAILQ_INIT(&mp->mnt_nvnodelist);
TAILQ_INIT(&mp->mnt_reservedvnlist);
mp->mnt_nvnodelistsize = 0;
lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE);
(void)vfs_busy(mp, LK_NOWAIT, 0, td);
mp->mnt_op = vfsp->vfc_vfsops;
mp->mnt_vfc = vfsp;
vfsp->vfc_refcount++;
mp->mnt_stat.f_type = vfsp->vfc_typenum;
mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
strlcpy(mp->mnt_stat.f_fstypename, fstype, 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
VOP_UNLOCK(vp, 0, td);
mp->mnt_optnew = optlist; /* XXXMAC: should this be above? */
update:
/*
* Check if the fs implements the new VFS_NMOUNT()
* function, since the new system call was used.
*/
if (mp->mnt_op->vfs_mount != NULL) {
printf("%s doesn't support the new mount syscall\n",
mp->mnt_vfc->vfc_name);
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
if (mp->mnt_flag & MNT_UPDATE)
vfs_unbusy(mp, td);
else {
mp->mnt_vfc->vfc_refcount--;
vfs_unbusy(mp, td);
#ifdef MAC
mac_destroy_mount(mp);
#endif
crfree(mp->mnt_cred);
free(mp, M_MOUNT);
}
vrele(vp);
error = EOPNOTSUPP;
goto bad;
}
/*
* Set the mount level flags.
*/
if (fsflags & MNT_RDONLY)
mp->mnt_flag |= MNT_RDONLY;
else if (mp->mnt_flag & MNT_RDONLY)
mp->mnt_kern_flag |= MNTK_WANTRDWR;
mp->mnt_flag &=~ MNT_UPDATEMASK;
mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE);
/*
* Mount the filesystem.
* XXX The final recipients of VFS_MOUNT just overwrite the ndp they
* get. No freeing of cn_pnbuf.
*/
error = VFS_NMOUNT(mp, &nd, td);
if (!error) {
if (mp->mnt_opt != NULL)
vfs_freeopts(mp->mnt_opt);
mp->mnt_opt = mp->mnt_optnew;
}
/*
* Prevent external consumers of mount
* options to read mnt_optnew.
*/
mp->mnt_optnew = NULL;
if (mp->mnt_flag & MNT_UPDATE) {
if (mp->mnt_kern_flag & MNTK_WANTRDWR)
mp->mnt_flag &= ~MNT_RDONLY;
mp->mnt_flag &=~
(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | MNT_SNAPSHOT);
mp->mnt_kern_flag &=~ MNTK_WANTRDWR;
if (error) {
mp->mnt_flag = flag;
mp->mnt_kern_flag = kern_flag;
}
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);
}
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);
if (VFS_ROOT(mp, &newdp))
panic("mount: lost mount");
checkdirs(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 = VFS_START(mp, 0, td)) != 0) {
vrele(vp);
goto bad;
}
} else {
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
mp->mnt_vfc->vfc_refcount--;
vfs_unbusy(mp, td);
#ifdef MAC
mac_destroy_mount(mp);
#endif
crfree(mp->mnt_cred);
free(mp, M_MOUNT);
vput(vp);
goto bad;
}
return (0);
bad:
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;
char *fspath;
int error;
fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK);
fspath = malloc(MNAMELEN, M_TEMP, M_WAITOK);
/*
* vfs_mount() actually takes a kernel string for `type' and
* `path' now, so extract them.
*/
error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL);
if (error == 0)
error = copyinstr(uap->path, fspath, MNAMELEN, NULL);
if (error == 0)
error = vfs_mount(td, fstype, fspath, uap->flags, uap->data);
free(fstype, M_TEMP);
free(fspath, M_TEMP);
return (error);
}
/*
* vfs_mount(): actually attempt a filesystem mount.
*
* This routine is designed to be a "generic" entry point for routines
* that wish to mount a filesystem. All parameters except `fsdata' are
* pointers into kernel space. `fsdata' is currently still a pointer
* into userspace.
*/
int
vfs_mount(td, fstype, fspath, fsflags, fsdata)
struct thread *td;
const char *fstype;
char *fspath;
int fsflags;
void *fsdata;
{
linker_file_t lf;
struct vnode *vp;
struct mount *mp;
struct vfsconf *vfsp;
int error, flag = 0, kern_flag = 0;
struct vattr va;
struct nameidata nd;
/*
* 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 (usermount == 0) {
error = suser(td);
if (error)
return (error);
}
/*
* Do not allow NFS export by non-root users.
*/
if (fsflags & MNT_EXPORTED) {
error = suser(td);
if (error)
return (error);
}
/*
* Silently enforce MNT_NOSUID and MNT_NODEV for non-root users.
*/
if (suser(td))
fsflags |= MNT_NOSUID | MNT_NODEV;
/*
* Get vnode to be covered
*/
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, 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;
flag = mp->mnt_flag;
kern_flag = mp->mnt_kern_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)) {
vput(vp);
return (EOPNOTSUPP); /* Needs translation */
}
/*
* Only root, or the user that did the original mount is
* permitted to update it.
*/
if (mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
error = suser(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);
mp->mnt_flag |= fsflags &
(MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT);
VOP_UNLOCK(vp, 0, td);
goto update;
}
/*
* 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 = suser(td);
if (error) {
vput(vp);
return (error);
}
}
if ((error = vinvalbuf(vp, V_SAVE, td->td_ucred, td, 0, 0)) != 0) {
vput(vp);
return (error);
}
if (vp->v_type != VDIR) {
vput(vp);
return (ENOTDIR);
}
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (!strcmp(vfsp->vfc_name, fstype))
break;
if (vfsp == NULL) {
/* Only load modules for root (very important!). */
error = suser(td);
if (error) {
vput(vp);
return (error);
}
error = securelevel_gt(td->td_ucred, 0);
if (error) {
vput(vp);
return (error);
}
error = linker_load_module(NULL, fstype, NULL, NULL, &lf);
if (error || lf == NULL) {
vput(vp);
if (lf == NULL)
error = ENODEV;
return (error);
}
lf->userrefs++;
/* Look up again to see if the VFS was loaded. */
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (!strcmp(vfsp->vfc_name, fstype))
break;
if (vfsp == NULL) {
lf->userrefs--;
linker_file_unload(lf);
vput(vp);
return (ENODEV);
}
}
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 = malloc(sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO);
TAILQ_INIT(&mp->mnt_nvnodelist);
TAILQ_INIT(&mp->mnt_reservedvnlist);
mp->mnt_nvnodelistsize = 0;
lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE);
(void)vfs_busy(mp, LK_NOWAIT, 0, td);
mp->mnt_op = vfsp->vfc_vfsops;
mp->mnt_vfc = vfsp;
vfsp->vfc_refcount++;
mp->mnt_stat.f_type = vfsp->vfc_typenum;
mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
strlcpy(mp->mnt_stat.f_fstypename, fstype, 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
VOP_UNLOCK(vp, 0, td);
update:
/*
* Check if the fs implements the old VFS_MOUNT()
* function, since the old system call was used.
*/
if (mp->mnt_op->vfs_mount == NULL) {
printf("%s doesn't support the old mount syscall\n",
mp->mnt_vfc->vfc_name);
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
if (mp->mnt_flag & MNT_UPDATE)
vfs_unbusy(mp, td);
else {
mp->mnt_vfc->vfc_refcount--;
vfs_unbusy(mp, td);
#ifdef MAC
mac_destroy_mount(mp);
#endif
crfree(mp->mnt_cred);
free(mp, M_MOUNT);
}
vrele(vp);
return (EOPNOTSUPP);
}
/*
* Set the mount level flags.
*/
if (fsflags & MNT_RDONLY)
mp->mnt_flag |= MNT_RDONLY;
else if (mp->mnt_flag & MNT_RDONLY)
mp->mnt_kern_flag |= MNTK_WANTRDWR;
mp->mnt_flag &=~ MNT_UPDATEMASK;
mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE);
/*
* 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, fspath, fsdata, &nd, td);
if (mp->mnt_flag & MNT_UPDATE) {
if (mp->mnt_kern_flag & MNTK_WANTRDWR)
mp->mnt_flag &= ~MNT_RDONLY;
mp->mnt_flag &=~
(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | MNT_SNAPSHOT);
mp->mnt_kern_flag &=~ MNTK_WANTRDWR;
if (error) {
mp->mnt_flag = flag;
mp->mnt_kern_flag = kern_flag;
}
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);
}
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);
if (VFS_ROOT(mp, &newdp))
panic("mount: lost mount");
checkdirs(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 = VFS_START(mp, 0, td)) != 0)
vrele(vp);
} else {
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
mp->mnt_vfc->vfc_refcount--;
vfs_unbusy(mp, td);
#ifdef MAC
mac_destroy_mount(mp);
#endif
crfree(mp->mnt_cred);
free(mp, M_MOUNT);
vput(vp);
}
return (error);
}
/*
* Scan all active processes to see if any of them have a current
* or root directory of `olddp'. If so, replace them with the new
* mount point.
*/
static void
checkdirs(olddp, newdp)
struct vnode *olddp, *newdp;
{
struct filedesc *fdp;
struct proc *p;
int nrele;
if (vrefcnt(olddp) == 1)
return;
sx_slock(&allproc_lock);
LIST_FOREACH(p, &allproc, p_list) {
mtx_lock(&fdesc_mtx);
fdp = p->p_fd;
if (fdp == NULL) {
mtx_unlock(&fdesc_mtx);
continue;
}
nrele = 0;
FILEDESC_LOCK(fdp);
if (fdp->fd_cdir == olddp) {
VREF(newdp);
fdp->fd_cdir = newdp;
nrele++;
}
if (fdp->fd_rdir == olddp) {
VREF(newdp);
fdp->fd_rdir = newdp;
nrele++;
}
FILEDESC_UNLOCK(fdp);
mtx_unlock(&fdesc_mtx);
while (nrele--)
vrele(olddp);
}
sx_sunlock(&allproc_lock);
if (rootvnode == olddp) {
vrele(rootvnode);
VREF(newdp);
rootvnode = newdp;
}
}
/*
* 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;
pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL);
if (error) {
free(pathbuf, M_TEMP);
return (error);
}
if (uap->flags & MNT_BYFSID) {
/* Decode the filesystem ID. */
if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) {
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)
return (ENOENT);
/*
* Only root, or the user that did the original mount is
* permitted to unmount this filesystem.
*/
if (mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
error = suser(td);
if (error)
return (error);
}
/*
* Don't allow unmounting the root filesystem.
*/
if (mp->mnt_flag & MNT_ROOTFS)
return (EINVAL);
return (dounmount(mp, uap->flags, td));
}
/*
* 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;
mtx_lock(&mountlist_mtx);
if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
mtx_unlock(&mountlist_mtx);
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), &mountlist_mtx, td);
if (error) {
mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
if (mp->mnt_kern_flag & MNTK_MWAIT)
wakeup(mp);
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);
async_flag = mp->mnt_flag & MNT_ASYNC;
mp->mnt_flag &=~ MNT_ASYNC;
cache_purgevfs(mp); /* remove cache entries for this file sys */
if (mp->mnt_syncer != NULL)
vrele(mp->mnt_syncer);
/* Move process cdir/rdir refs on fs root to underlying vnode. */
if (VFS_ROOT(mp, &fsrootvp) == 0) {
if (mp->mnt_vnodecovered != NULL)
checkdirs(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->td_ucred, 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 (VFS_ROOT(mp, &fsrootvp) == 0) {
if (mp->mnt_vnodecovered != NULL)
checkdirs(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);
mtx_lock(&mountlist_mtx);
mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
mp->mnt_flag |= async_flag;
lockmgr(&mp->mnt_lock, LK_RELEASE | LK_INTERLOCK,
&mountlist_mtx, td);
if (mp->mnt_kern_flag & MNTK_MWAIT)
wakeup(mp);
return (error);
}
crfree(mp->mnt_cred);
mtx_lock(&mountlist_mtx);
TAILQ_REMOVE(&mountlist, mp, mnt_list);
if ((coveredvp = mp->mnt_vnodecovered) != NULL)
coveredvp->v_mountedhere = NULL;
mp->mnt_vfc->vfc_refcount--;
if (!TAILQ_EMPTY(&mp->mnt_nvnodelist))
panic("unmount: dangling vnode");
lockmgr(&mp->mnt_lock, LK_RELEASE | LK_INTERLOCK, &mountlist_mtx, td);
lockdestroy(&mp->mnt_lock);
if (coveredvp != NULL)
vrele(coveredvp);
if (mp->mnt_kern_flag & MNTK_MWAIT)
wakeup(mp);
#ifdef MAC
mac_destroy_mount(mp);
#endif
if (mp->mnt_op->vfs_mount == NULL)
vfs_freeopts(mp->mnt_opt);
free(mp, M_MOUNT);
return (0);
}
/*
* Lookup a filesystem type, and if found allocate and initialize
* a mount structure for it.
*
* Devname is usually updated by mount(8) after booting.
*/
int
vfs_rootmountalloc(fstypename, devname, mpp)
char *fstypename;
char *devname;
struct mount **mpp;
{
struct thread *td = curthread; /* XXX */
struct vfsconf *vfsp;
struct mount *mp;
if (fstypename == NULL)
return (ENODEV);
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (!strcmp(vfsp->vfc_name, fstypename))
break;
if (vfsp == NULL)
return (ENODEV);
mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO);
lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE);
(void)vfs_busy(mp, LK_NOWAIT, 0, td);
TAILQ_INIT(&mp->mnt_nvnodelist);
TAILQ_INIT(&mp->mnt_reservedvnlist);
mp->mnt_nvnodelistsize = 0;
mp->mnt_vfc = vfsp;
mp->mnt_op = vfsp->vfc_vfsops;
mp->mnt_flag = MNT_RDONLY;
mp->mnt_vnodecovered = NULLVP;
mp->mnt_cred = crdup(td->td_ucred);
vfsp->vfc_refcount++;
mp->mnt_iosize_max = DFLTPHYS;
mp->mnt_stat.f_type = vfsp->vfc_typenum;
mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
mp->mnt_stat.f_mntonname[0] = '/';
mp->mnt_stat.f_mntonname[1] = 0;
strlcpy(mp->mnt_stat.f_mntfromname, devname, MNAMELEN);
#ifdef MAC
mac_init_mount(mp);
mac_create_mount(td->td_ucred, mp);
#endif
*mpp = mp;
return (0);
}
/*
* Find and mount the root filesystem
*/
void
vfs_mountroot(void)
{
char *cp;
int i, error;
g_waitidle();
/*
* The root filesystem information is compiled in, and we are
* booted with instructions to use it.
*/
#ifdef ROOTDEVNAME
if ((boothowto & RB_DFLTROOT) &&
!vfs_mountroot_try(ROOTDEVNAME))
return;
#endif
/*
* We are booted with instructions to prompt for the root filesystem,
* or to use the compiled-in default when it doesn't exist.
*/
if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) {
if (!vfs_mountroot_ask())
return;
}
/*
* 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.
*/
if ((cp = getenv("vfs.root.mountfrom")) != NULL) {
error = vfs_mountroot_try(cp);
freeenv(cp);
if (!error)
return;
}
/*
* Try values that may have been computed by the machine-dependant
* legacy code.
*/
if (!vfs_mountroot_try(rootdevnames[0]))
return;
if (!vfs_mountroot_try(rootdevnames[1]))
return;
/*
* If we have a compiled-in default, and haven't already tried it, try
* it now.
*/
#ifdef ROOTDEVNAME
if (!(boothowto & RB_DFLTROOT))
if (!vfs_mountroot_try(ROOTDEVNAME))
return;
#endif
/*
* Everything so far has failed, prompt on the console if we haven't
* already tried that.
*/
if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask())
return;
panic("Root mount failed, startup aborted.");
}
/*
* Mount (mountfrom) as the root filesystem.
*/
static int
vfs_mountroot_try(char *mountfrom)
{
struct mount *mp;
char *vfsname, *path;
const char *devname;
int error;
char patt[32];
int s;
vfsname = NULL;
path = NULL;
mp = NULL;
error = EINVAL;
if (mountfrom == NULL)
return(error); /* don't complain */
s = splcam(); /* Overkill, but annoying without it */
printf("Mounting root from %s\n", mountfrom);
splx(s);
/* 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]:%%%zds", MFSNAMELEN, MNAMELEN);
if (sscanf(mountfrom, patt, vfsname, path) < 1)
goto done;
/* allocate a root mount */
error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME,
&mp);
if (error != 0) {
printf("Can't allocate root mount for filesystem '%s': %d\n",
vfsname, error);
goto done;
}
mp->mnt_flag |= MNT_ROOTFS;
/* do our best to set rootdev */
if ((path[0] != 0) && setrootbyname(path))
printf("setrootbyname failed\n");
/* If the root device is a type "memory disk", mount RW */
if (rootdev != NODEV && devsw(rootdev) != NULL) {
devname = devtoname(rootdev);
if (devname[0] == 'm' && devname[1] == 'd')
mp->mnt_flag &= ~MNT_RDONLY;
}
/*
* Set the mount path to be something useful, because the
* filesystem code isn't responsible now for initialising
* f_mntonname unless they want to override the default
* (which is `path'.)
*/
strlcpy(mp->mnt_stat.f_mntonname, "/", MNAMELEN);
error = VFS_MOUNT(mp, NULL, NULL, NULL, curthread);
done:
if (vfsname != NULL)
free(vfsname, M_MOUNT);
if (path != NULL)
free(path, M_MOUNT);
if (error != 0) {
if (mp != NULL) {
vfs_unbusy(mp, curthread);
#ifdef MAC
mac_destroy_mount(mp);
#endif
crfree(mp->mnt_cred);
free(mp, M_MOUNT);
}
printf("Root mount failed: %d\n", error);
} else {
/* register with list of mounted filesystems */
mtx_lock(&mountlist_mtx);
TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
/* sanity check system clock against root fs timestamp */
inittodr(mp->mnt_time);
vfs_unbusy(mp, curthread);
error = VFS_START(mp, 0, curthread);
}
return(error);
}
/*
* Spin prompting on the console for a suitable root filesystem
*/
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(__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);
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);
}
}
/*
* Local helper function for vfs_mountroot_ask.
*/
static void
gets(char *cp)
{
char *lp;
int c;
lp = cp;
for (;;) {
printf("%c", c = cngetc() & 0177);
switch (c) {
case -1:
case '\n':
case '\r':
*lp++ = '\0';
return;
case '\b':
case '\177':
if (lp > cp) {
printf(" \b");
lp--;
}
continue;
case '#':
lp--;
if (lp < cp)
lp = cp;
continue;
case '@':
case 'u' & 037:
lp = cp;
printf("%c", '\n');
continue;
default:
*lp++ = c;
}
}
}
/*
* Convert a given name to the dev_t of the disk-like device
* it refers to.
*/
dev_t
getdiskbyname(char *name) {
char *cp;
dev_t dev;
cp = name;
if (!bcmp(cp, "/dev/", 5))
cp += 5;
dev = NODEV;
EVENTHANDLER_INVOKE(dev_clone, cp, strlen(cp), &dev);
return (dev);
}
/*
* Set rootdev to match (name), given that we expect it to
* refer to a disk-like device.
*/
static int
setrootbyname(char *name)
{
dev_t diskdev;
diskdev = getdiskbyname(name);
if (diskdev != NODEV) {
rootdev = diskdev;
return (0);
}
return (1);
}
/* Show the dev_t for a disk specified by name */
#ifdef DDB
DB_SHOW_COMMAND(disk, db_getdiskbyname)
{
dev_t dev;
if (modif[0] == '\0') {
db_error("usage: show disk/devicename");
return;
}
dev = getdiskbyname(modif);
if (dev != NODEV)
db_printf("dev_t = %p\n", dev);
else
db_printf("No disk device matched.\n");
}
#endif
/*
* 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);
}
/*
* 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);
}