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90833c99de
freebsd/sys/kern/vfs_mount.c
Jeff Roberson 25b286d6db - Use standard locking functions in syncer's opv 
- vput instead of vrele syncer vnodes in vfs_mount
 - Add vop_lookup_{pre,post} to verify locking in VOP_LOOKUP
2002-07-09 19:54:20 +00:00

1618 lines
38 KiB
C
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/*
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/kernel.h>
#include <sys/linker.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/proc.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 <machine/stdarg.h>
#include "opt_rootdevname.h"
#include "opt_ddb.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;
/*
* 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);
TAILQ_REMOVE(opts, opt, link);
free(opt->name, M_MOUNT);
free(opt->value, M_MOUNT);
free(opt, M_MOUNT);
}
free(opts, M_MOUNT);
}
/*
* 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 = malloc(optlen, M_MOUNT, M_WAITOK);
opt->len = optlen;
if (auio->uio_segflg == UIO_SYSSPACE) {
bcopy(auio->uio_iov[i].iov_base, opt->name, namelen);
bcopy(auio->uio_iov[i + 1].iov_base, opt->value,
optlen);
} else {
error = copyin(auio->uio_iov[i].iov_base, opt->name,
namelen);
if (!error)
error = copyin(auio->uio_iov[i + 1].iov_base,
opt->value, optlen);
if (error)
goto bad;
}
TAILQ_INSERT_TAIL(opts, opt, link);
}
*options = opts;
return (0);
bad:
vfs_freeopts(opts);
return (error);
}
/*
* New mount API.
*/
int
nmount(td, uap)
struct thread *td;
struct nmount_args /* {
syscallarg(struct iovec *) iovp;
syscallarg(unsigned int) iovcnt;
syscallarg(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 = SCARG(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, SCARG(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_flag & VROOT) == 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_stat.f_owner != 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;
}
mtx_lock(&vp->v_interlock);
if ((vp->v_flag & VMOUNT) != 0 || vp->v_mountedhere != NULL) {
mtx_unlock(&vp->v_interlock);
vfs_unbusy(mp, td);
vput(vp);
error = EBUSY;
goto bad;
}
vp->v_flag |= VMOUNT;
mtx_unlock(&vp->v_interlock);
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);
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_file(fstype, &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;
}
}
mtx_lock(&vp->v_interlock);
if ((vp->v_flag & VMOUNT) != 0 ||
vp->v_mountedhere != NULL) {
mtx_unlock(&vp->v_interlock);
vput(vp);
error = EBUSY;
goto bad;
}
vp->v_flag |= VMOUNT;
mtx_unlock(&vp->v_interlock);
/*
* 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);
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;
strncpy(mp->mnt_stat.f_fstypename, fstype, MFSNAMELEN);
mp->mnt_vnodecovered = vp;
mp->mnt_stat.f_owner = td->td_ucred->cr_uid;
strncpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN);
mp->mnt_iosize_max = DFLTPHYS;
VOP_UNLOCK(vp, 0, td);
update:
mp->mnt_optnew = optlist;
/*
* 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);
mtx_lock(&vp->v_interlock);
vp->v_flag &= ~VMOUNT;
mtx_unlock(&vp->v_interlock);
if (mp->mnt_flag & MNT_UPDATE)
vfs_unbusy(mp, td);
else {
mp->mnt_vfc->vfc_refcount--;
vfs_unbusy(mp, td);
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)
vput(mp->mnt_syncer);
mp->mnt_syncer = NULL;
}
vfs_unbusy(mp, td);
mtx_lock(&vp->v_interlock);
vp->v_flag &= ~VMOUNT;
mtx_unlock(&vp->v_interlock);
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;
mtx_lock(&vp->v_interlock);
vp->v_flag &= ~VMOUNT;
vp->v_mountedhere = mp;
mtx_unlock(&vp->v_interlock);
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 {
mtx_lock(&vp->v_interlock);
vp->v_flag &= ~VMOUNT;
mtx_unlock(&vp->v_interlock);
mp->mnt_vfc->vfc_refcount--;
vfs_unbusy(mp, td);
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 /* {
syscallarg(char *) type;
syscallarg(char *) path;
syscallarg(int) flags;
syscallarg(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(SCARG(uap, type), fstype, MFSNAMELEN, NULL);
if (error)
goto finish;
error = copyinstr(SCARG(uap, path), fspath, MNAMELEN, NULL);
if (error)
goto finish;
error = vfs_mount(td, fstype, fspath, SCARG(uap, flags),
SCARG(uap, data));
finish:
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_flag & VROOT) == 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_stat.f_owner != 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);
}
mtx_lock(&vp->v_interlock);
if ((vp->v_flag & VMOUNT) != 0 || vp->v_mountedhere != NULL) {
mtx_unlock(&vp->v_interlock);
vfs_unbusy(mp, td);
vput(vp);
return (EBUSY);
}
vp->v_flag |= VMOUNT;
mtx_unlock(&vp->v_interlock);
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_file(fstype, &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);
}
}
mtx_lock(&vp->v_interlock);
if ((vp->v_flag & VMOUNT) != 0 ||
vp->v_mountedhere != NULL) {
mtx_unlock(&vp->v_interlock);
vput(vp);
return (EBUSY);
}
vp->v_flag |= VMOUNT;
mtx_unlock(&vp->v_interlock);
/*
* 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);
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;
strncpy(mp->mnt_stat.f_fstypename, fstype, MFSNAMELEN);
mp->mnt_vnodecovered = vp;
mp->mnt_stat.f_owner = td->td_ucred->cr_uid;
strncpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN);
mp->mnt_iosize_max = DFLTPHYS;
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);
mtx_lock(&vp->v_interlock);
vp->v_flag &= ~VMOUNT;
mtx_unlock(&vp->v_interlock);
if (mp->mnt_flag & MNT_UPDATE)
vfs_unbusy(mp, td);
else {
mp->mnt_vfc->vfc_refcount--;
vfs_unbusy(mp, td);
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)
vput(mp->mnt_syncer);
mp->mnt_syncer = NULL;
}
vfs_unbusy(mp, td);
mtx_lock(&vp->v_interlock);
vp->v_flag &= ~VMOUNT;
mtx_unlock(&vp->v_interlock);
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;
mtx_lock(&vp->v_interlock);
vp->v_flag &= ~VMOUNT;
vp->v_mountedhere = mp;
mtx_unlock(&vp->v_interlock);
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 {
mtx_lock(&vp->v_interlock);
vp->v_flag &= ~VMOUNT;
mtx_unlock(&vp->v_interlock);
mp->mnt_vfc->vfc_refcount--;
vfs_unbusy(mp, td);
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 (olddp->v_usecount == 1)
return;
sx_slock(&allproc_lock);
LIST_FOREACH(p, &allproc, p_list) {
PROC_LOCK(p);
fdp = p->p_fd;
if (fdp == NULL) {
PROC_UNLOCK(p);
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);
PROC_UNLOCK(p);
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 /* {
syscallarg(char *) path;
syscallarg(int) flags;
} */ *uap;
{
register struct vnode *vp;
struct mount *mp;
int error;
struct nameidata nd;
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
SCARG(uap, path), td);
if ((error = namei(&nd)) != 0)
return (error);
vp = nd.ni_vp;
NDFREE(&nd, NDF_ONLY_PNBUF);
mp = vp->v_mount;
/*
* Only root, or the user that did the original mount is
* permitted to unmount this filesystem.
*/
if (mp->mnt_stat.f_owner != td->td_ucred->cr_uid) {
error = suser(td);
if (error) {
vput(vp);
return (error);
}
}
/*
* Don't allow unmounting the root filesystem.
*/
if (mp->mnt_flag & MNT_ROOTFS) {
vput(vp);
return (EINVAL);
}
/*
* Must be the root of the filesystem
*/
if ((vp->v_flag & VROOT) == 0) {
vput(vp);
return (EINVAL);
}
vput(vp);
return (dounmount(mp, SCARG(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)
vput(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);
}
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);
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_vfc = vfsp;
mp->mnt_op = vfsp->vfc_vfsops;
mp->mnt_flag = MNT_RDONLY;
mp->mnt_vnodecovered = NULLVP;
vfsp->vfc_refcount++;
mp->mnt_iosize_max = DFLTPHYS;
mp->mnt_stat.f_type = vfsp->vfc_typenum;
mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
mp->mnt_stat.f_mntonname[0] = '/';
mp->mnt_stat.f_mntonname[1] = 0;
(void) copystr(devname, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 0);
*mpp = mp;
return (0);
}
/*
* Find and mount the root filesystem
*/
void
vfs_mountroot(void)
{
char *cp;
int i, error;
/*
* 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;
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]:%%%ds", 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) &&
(devsw(rootdev)->d_flags & D_MEMDISK))
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'.)
*/
strncpy(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);
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];
int i;
dev_t dev;
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: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("Possibly valid devices for 'ufs' root:\n");
for (i = 0; i < NUMCDEVSW; i++) {
dev = makedev(i, 0);
if (devsw(dev) != NULL)
printf(" \"%s\"", devsw(dev)->d_name);
}
printf("\n");
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;
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;
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);
}
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