freebsd-dev/sys/fs/unionfs/union_vfsops.c
Pedro F. Giffuni 51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00

509 lines
12 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1994, 1995 The Regents of the University of California.
* Copyright (c) 1994, 1995 Jan-Simon Pendry.
* Copyright (c) 2005, 2006, 2012 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
* Copyright (c) 2006, 2012 Daichi Goto <daichi@freebsd.org>
* All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE 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.
*
* @(#)union_vfsops.c 8.20 (Berkeley) 5/20/95
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kdb.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/stat.h>
#include <fs/unionfs/union.h>
static MALLOC_DEFINE(M_UNIONFSMNT, "UNIONFS mount", "UNIONFS mount structure");
static vfs_fhtovp_t unionfs_fhtovp;
static vfs_checkexp_t unionfs_checkexp;
static vfs_mount_t unionfs_domount;
static vfs_quotactl_t unionfs_quotactl;
static vfs_root_t unionfs_root;
static vfs_sync_t unionfs_sync;
static vfs_statfs_t unionfs_statfs;
static vfs_unmount_t unionfs_unmount;
static vfs_vget_t unionfs_vget;
static vfs_extattrctl_t unionfs_extattrctl;
static struct vfsops unionfs_vfsops;
/*
* Mount unionfs layer.
*/
static int
unionfs_domount(struct mount *mp)
{
int error;
struct vnode *lowerrootvp;
struct vnode *upperrootvp;
struct unionfs_mount *ump;
struct thread *td;
char *target;
char *tmp;
char *ep;
int len;
size_t done;
int below;
uid_t uid;
gid_t gid;
u_short udir;
u_short ufile;
unionfs_copymode copymode;
unionfs_whitemode whitemode;
struct nameidata nd, *ndp;
struct vattr va;
UNIONFSDEBUG("unionfs_mount(mp = %p)\n", (void *)mp);
error = 0;
below = 0;
uid = 0;
gid = 0;
udir = 0;
ufile = 0;
copymode = UNIONFS_TRANSPARENT; /* default */
whitemode = UNIONFS_WHITE_ALWAYS;
ndp = &nd;
td = curthread;
if (mp->mnt_flag & MNT_ROOTFS) {
vfs_mount_error(mp, "Cannot union mount root filesystem");
return (EOPNOTSUPP);
}
/*
* Update is a no operation.
*/
if (mp->mnt_flag & MNT_UPDATE) {
vfs_mount_error(mp, "unionfs does not support mount update");
return (EOPNOTSUPP);
}
/*
* Get argument
*/
error = vfs_getopt(mp->mnt_optnew, "target", (void **)&target, &len);
if (error)
error = vfs_getopt(mp->mnt_optnew, "from", (void **)&target,
&len);
if (error || target[len - 1] != '\0') {
vfs_mount_error(mp, "Invalid target");
return (EINVAL);
}
if (vfs_getopt(mp->mnt_optnew, "below", NULL, NULL) == 0)
below = 1;
if (vfs_getopt(mp->mnt_optnew, "udir", (void **)&tmp, NULL) == 0) {
if (tmp != NULL)
udir = (mode_t)strtol(tmp, &ep, 8);
if (tmp == NULL || *ep) {
vfs_mount_error(mp, "Invalid udir");
return (EINVAL);
}
udir &= S_IRWXU | S_IRWXG | S_IRWXO;
}
if (vfs_getopt(mp->mnt_optnew, "ufile", (void **)&tmp, NULL) == 0) {
if (tmp != NULL)
ufile = (mode_t)strtol(tmp, &ep, 8);
if (tmp == NULL || *ep) {
vfs_mount_error(mp, "Invalid ufile");
return (EINVAL);
}
ufile &= S_IRWXU | S_IRWXG | S_IRWXO;
}
/* check umask, uid and gid */
if (udir == 0 && ufile != 0)
udir = ufile;
if (ufile == 0 && udir != 0)
ufile = udir;
vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY);
error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred);
if (!error) {
if (udir == 0)
udir = va.va_mode;
if (ufile == 0)
ufile = va.va_mode;
uid = va.va_uid;
gid = va.va_gid;
}
VOP_UNLOCK(mp->mnt_vnodecovered, LK_RELEASE);
if (error)
return (error);
if (mp->mnt_cred->cr_ruid == 0) { /* root only */
if (vfs_getopt(mp->mnt_optnew, "uid", (void **)&tmp,
NULL) == 0) {
if (tmp != NULL)
uid = (uid_t)strtol(tmp, &ep, 10);
if (tmp == NULL || *ep) {
vfs_mount_error(mp, "Invalid uid");
return (EINVAL);
}
}
if (vfs_getopt(mp->mnt_optnew, "gid", (void **)&tmp,
NULL) == 0) {
if (tmp != NULL)
gid = (gid_t)strtol(tmp, &ep, 10);
if (tmp == NULL || *ep) {
vfs_mount_error(mp, "Invalid gid");
return (EINVAL);
}
}
if (vfs_getopt(mp->mnt_optnew, "copymode", (void **)&tmp,
NULL) == 0) {
if (tmp == NULL) {
vfs_mount_error(mp, "Invalid copymode");
return (EINVAL);
} else if (strcasecmp(tmp, "traditional") == 0)
copymode = UNIONFS_TRADITIONAL;
else if (strcasecmp(tmp, "transparent") == 0)
copymode = UNIONFS_TRANSPARENT;
else if (strcasecmp(tmp, "masquerade") == 0)
copymode = UNIONFS_MASQUERADE;
else {
vfs_mount_error(mp, "Invalid copymode");
return (EINVAL);
}
}
if (vfs_getopt(mp->mnt_optnew, "whiteout", (void **)&tmp,
NULL) == 0) {
if (tmp == NULL) {
vfs_mount_error(mp, "Invalid whiteout mode");
return (EINVAL);
} else if (strcasecmp(tmp, "always") == 0)
whitemode = UNIONFS_WHITE_ALWAYS;
else if (strcasecmp(tmp, "whenneeded") == 0)
whitemode = UNIONFS_WHITE_WHENNEEDED;
else {
vfs_mount_error(mp, "Invalid whiteout mode");
return (EINVAL);
}
}
}
/* If copymode is UNIONFS_TRADITIONAL, uid/gid is mounted user. */
if (copymode == UNIONFS_TRADITIONAL) {
uid = mp->mnt_cred->cr_ruid;
gid = mp->mnt_cred->cr_rgid;
}
UNIONFSDEBUG("unionfs_mount: uid=%d, gid=%d\n", uid, gid);
UNIONFSDEBUG("unionfs_mount: udir=0%03o, ufile=0%03o\n", udir, ufile);
UNIONFSDEBUG("unionfs_mount: copymode=%d\n", copymode);
/*
* Find upper node
*/
NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, target, td);
if ((error = namei(ndp)))
return (error);
NDFREE(ndp, NDF_ONLY_PNBUF);
/* get root vnodes */
lowerrootvp = mp->mnt_vnodecovered;
upperrootvp = ndp->ni_vp;
/* create unionfs_mount */
ump = (struct unionfs_mount *)malloc(sizeof(struct unionfs_mount),
M_UNIONFSMNT, M_WAITOK | M_ZERO);
/*
* Save reference
*/
if (below) {
VOP_UNLOCK(upperrootvp, LK_RELEASE);
vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY);
ump->um_lowervp = upperrootvp;
ump->um_uppervp = lowerrootvp;
} else {
ump->um_lowervp = lowerrootvp;
ump->um_uppervp = upperrootvp;
}
ump->um_rootvp = NULLVP;
ump->um_uid = uid;
ump->um_gid = gid;
ump->um_udir = udir;
ump->um_ufile = ufile;
ump->um_copymode = copymode;
ump->um_whitemode = whitemode;
mp->mnt_data = ump;
/*
* Copy upper layer's RDONLY flag.
*/
mp->mnt_flag |= ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY;
/*
* Unlock the node
*/
VOP_UNLOCK(ump->um_uppervp, LK_RELEASE);
/*
* Get the unionfs root vnode.
*/
error = unionfs_nodeget(mp, ump->um_uppervp, ump->um_lowervp,
NULLVP, &(ump->um_rootvp), NULL, td);
vrele(upperrootvp);
if (error) {
free(ump, M_UNIONFSMNT);
mp->mnt_data = NULL;
return (error);
}
MNT_ILOCK(mp);
if ((ump->um_lowervp->v_mount->mnt_flag & MNT_LOCAL) &&
(ump->um_uppervp->v_mount->mnt_flag & MNT_LOCAL))
mp->mnt_flag |= MNT_LOCAL;
MNT_IUNLOCK(mp);
/*
* Get new fsid
*/
vfs_getnewfsid(mp);
len = MNAMELEN - 1;
tmp = mp->mnt_stat.f_mntfromname;
copystr((below ? "<below>:" : "<above>:"), tmp, len, &done);
len -= done - 1;
tmp += done - 1;
copystr(target, tmp, len, NULL);
UNIONFSDEBUG("unionfs_mount: from %s, on %s\n",
mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
return (0);
}
/*
* Free reference to unionfs layer
*/
static int
unionfs_unmount(struct mount *mp, int mntflags)
{
struct unionfs_mount *ump;
int error;
int num;
int freeing;
int flags;
UNIONFSDEBUG("unionfs_unmount: mp = %p\n", (void *)mp);
ump = MOUNTTOUNIONFSMOUNT(mp);
flags = 0;
if (mntflags & MNT_FORCE)
flags |= FORCECLOSE;
/* vflush (no need to call vrele) */
for (freeing = 0; (error = vflush(mp, 1, flags, curthread)) != 0;) {
num = mp->mnt_nvnodelistsize;
if (num == freeing)
break;
freeing = num;
}
if (error)
return (error);
free(ump, M_UNIONFSMNT);
mp->mnt_data = NULL;
return (0);
}
static int
unionfs_root(struct mount *mp, int flags, struct vnode **vpp)
{
struct unionfs_mount *ump;
struct vnode *vp;
ump = MOUNTTOUNIONFSMOUNT(mp);
vp = ump->um_rootvp;
UNIONFSDEBUG("unionfs_root: rootvp=%p locked=%x\n",
vp, VOP_ISLOCKED(vp));
vref(vp);
if (flags & LK_TYPE_MASK)
vn_lock(vp, flags);
*vpp = vp;
return (0);
}
static int
unionfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg)
{
struct unionfs_mount *ump;
ump = MOUNTTOUNIONFSMOUNT(mp);
/*
* Writing is always performed to upper vnode.
*/
return (VFS_QUOTACTL(ump->um_uppervp->v_mount, cmd, uid, arg));
}
static int
unionfs_statfs(struct mount *mp, struct statfs *sbp)
{
struct unionfs_mount *ump;
int error;
struct statfs *mstat;
uint64_t lbsize;
ump = MOUNTTOUNIONFSMOUNT(mp);
UNIONFSDEBUG("unionfs_statfs(mp = %p, lvp = %p, uvp = %p)\n",
(void *)mp, (void *)ump->um_lowervp, (void *)ump->um_uppervp);
mstat = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK | M_ZERO);
error = VFS_STATFS(ump->um_lowervp->v_mount, mstat);
if (error) {
free(mstat, M_STATFS);
return (error);
}
/* now copy across the "interesting" information and fake the rest */
sbp->f_blocks = mstat->f_blocks;
sbp->f_files = mstat->f_files;
lbsize = mstat->f_bsize;
error = VFS_STATFS(ump->um_uppervp->v_mount, mstat);
if (error) {
free(mstat, M_STATFS);
return (error);
}
/*
* The FS type etc is copy from upper vfs.
* (write able vfs have priority)
*/
sbp->f_type = mstat->f_type;
sbp->f_flags = mstat->f_flags;
sbp->f_bsize = mstat->f_bsize;
sbp->f_iosize = mstat->f_iosize;
if (mstat->f_bsize != lbsize)
sbp->f_blocks = ((off_t)sbp->f_blocks * lbsize) /
mstat->f_bsize;
sbp->f_blocks += mstat->f_blocks;
sbp->f_bfree = mstat->f_bfree;
sbp->f_bavail = mstat->f_bavail;
sbp->f_files += mstat->f_files;
sbp->f_ffree = mstat->f_ffree;
free(mstat, M_STATFS);
return (0);
}
static int
unionfs_sync(struct mount *mp, int waitfor)
{
/* nothing to do */
return (0);
}
static int
unionfs_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp)
{
return (EOPNOTSUPP);
}
static int
unionfs_fhtovp(struct mount *mp, struct fid *fidp, int flags,
struct vnode **vpp)
{
return (EOPNOTSUPP);
}
static int
unionfs_checkexp(struct mount *mp, struct sockaddr *nam, int *extflagsp,
struct ucred **credanonp, int *numsecflavors, int **secflavors)
{
return (EOPNOTSUPP);
}
static int
unionfs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp,
int namespace, const char *attrname)
{
struct unionfs_mount *ump;
struct unionfs_node *unp;
ump = MOUNTTOUNIONFSMOUNT(mp);
unp = VTOUNIONFS(filename_vp);
if (unp->un_uppervp != NULLVP) {
return (VFS_EXTATTRCTL(ump->um_uppervp->v_mount, cmd,
unp->un_uppervp, namespace, attrname));
} else {
return (VFS_EXTATTRCTL(ump->um_lowervp->v_mount, cmd,
unp->un_lowervp, namespace, attrname));
}
}
static struct vfsops unionfs_vfsops = {
.vfs_checkexp = unionfs_checkexp,
.vfs_extattrctl = unionfs_extattrctl,
.vfs_fhtovp = unionfs_fhtovp,
.vfs_init = unionfs_init,
.vfs_mount = unionfs_domount,
.vfs_quotactl = unionfs_quotactl,
.vfs_root = unionfs_root,
.vfs_statfs = unionfs_statfs,
.vfs_sync = unionfs_sync,
.vfs_uninit = unionfs_uninit,
.vfs_unmount = unionfs_unmount,
.vfs_vget = unionfs_vget,
};
VFS_SET(unionfs_vfsops, unionfs, VFCF_LOOPBACK);