freebsd-dev/sys/fs/unionfs/union_vfsops.c
Mark Johnston 5f34e93c58 Check suspendability on the mountpoint returned by VOP_GETWRITEMOUNT.
This obviates the need for a MNTK_SUSPENDABLE flag, since passthrough
filesystems like nullfs and unionfs no longer need to inherit this
information from their lower layer(s). This change also restores the
pre-r273336 behaviour of using the presence of a susp_clean VFS method to
request suspension support.

Reviewed by:	kib, mjg
Differential Revision:	https://reviews.freebsd.org/D2937
2015-07-05 22:37:33 +00:00

499 lines
12 KiB
C

/*-
* 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.
* 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.
*
* @(#)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);
bzero(&mstat, sizeof(mstat));
error = VFS_STATFS(ump->um_lowervp->v_mount, &mstat);
if (error)
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)
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;
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);