/*
* Copyright (c) 1992, 1993, 1994 The Regents of the University of California.
* Copyright (c) 1992, 1993, 1994 Jan-Simon Pendry.
* All rights reserved.
*
* This code is derived from software contributed 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. 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.
*
* @(#)union_vnops.c 8.6 (Berkeley) 2/17/94
* $Id: union_vnops.c,v 1.8 1994/11/04 14:41:46 davidg Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/types.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/buf.h>
#include <sys/queue.h>
#include <miscfs/union/union.h>
/* FIXUP throws the lock on the uppervp vnode if the union_node is already
* locked and the uppervp vnode is not. Before, this was thrown regardless
* of the state of the union_node which resulted in locked vnodes which
* were never unlocked (since the union would never be unlocked).
*/
#define FIXUP(un) { \
if (((un)->un_flags & (UN_LOCKED|UN_ULOCK)) == UN_LOCKED) { \
union_fixup(un); \
} \
}
static void
union_fixup(un)
struct union_node *un;
{
VOP_LOCK(un->un_uppervp);
un->un_flags |= UN_ULOCK;
}
static int
union_lookup1(udvp, dvp, vpp, cnp)
struct vnode *udvp;
struct vnode *dvp;
struct vnode **vpp;
struct componentname *cnp;
{
int error;
struct vnode *tdvp;
struct mount *mp;
/*
* If stepping up the directory tree, check for going
* back across the mount point, in which case do what
* lookup would do by stepping back down the mount
* hierarchy.
*/
if (cnp->cn_flags & ISDOTDOT) {
for (;;) {
/*
* Don't do the NOCROSSMOUNT check
* at this level. By definition,
* union fs deals with namespaces, not
* filesystems.
*/
if ((dvp->v_flag & VROOT) == 0)
break;
tdvp = dvp;
dvp = dvp->v_mount->mnt_vnodecovered;
vput(tdvp);
VREF(dvp);
VOP_LOCK(dvp);
}
}
error = VOP_LOOKUP(dvp, &tdvp, cnp);
if (error)
return (error);
/*
* The parent directory will have been unlocked, unless lookup
* found the last component. In which case, re-lock the node
* here to allow it to be unlocked again (phew) in union_lookup.
*/
if (dvp != tdvp && !(cnp->cn_flags & ISLASTCN))
VOP_LOCK(dvp);
dvp = tdvp;
/*
* Lastly check if the current node is a mount point in
* which case walk up the mount hierarchy making sure not to
* bump into the root of the mount tree (ie. dvp != udvp).
*/
while (dvp != udvp && (dvp->v_type == VDIR) &&
(mp = dvp->v_mountedhere)) {
if (mp->mnt_flag & MNT_MLOCK) {
mp->mnt_flag |= MNT_MWAIT;
(void) tsleep((caddr_t) mp, PVFS, "unlkup", 0);
continue;
}
error = VFS_ROOT(mp, &tdvp);
if (error) {
vput(dvp);
return (error);
}
vput(dvp);
dvp = tdvp;
}
*vpp = dvp;
return (0);
}
int
union_lookup(ap)
struct vop_lookup_args /* {
struct vnodeop_desc *a_desc;
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
} */ *ap;
{
int error;
int uerror, lerror;
struct vnode *uppervp, *lowervp;
struct vnode *upperdvp, *lowerdvp;
struct vnode *dvp = ap->a_dvp;
struct union_node *dun = VTOUNION(dvp);
struct componentname *cnp = ap->a_cnp;
int lockparent = cnp->cn_flags & LOCKPARENT;
struct union_mount *um = MOUNTTOUNIONMOUNT(dvp->v_mount);
struct ucred *saved_cred = 0;
cnp->cn_flags |= LOCKPARENT;
upperdvp = dun->un_uppervp;
lowerdvp = dun->un_lowervp;
uppervp = NULLVP;
lowervp = NULLVP;
/*
* do the lookup in the upper level.
* if that level comsumes additional pathnames,
* then assume that something special is going
* on and just return that vnode.
*/
if (upperdvp) {
FIXUP(dun);
uerror = union_lookup1(um->um_uppervp, upperdvp,
&uppervp, cnp);
/*if (uppervp == upperdvp)
dun->un_flags |= UN_KLOCK;*/
if (cnp->cn_consume != 0) {
*ap->a_vpp = uppervp;
if (!lockparent)
cnp->cn_flags &= ~LOCKPARENT;
return (uerror);
}
} else {
uerror = ENOENT;
}
/*
* in a similar way to the upper layer, do the lookup
* in the lower layer. this time, if there is some
* component magic going on, then vput whatever we got
* back from the upper layer and return the lower vnode
* instead.
*/
if (lowerdvp) {
int nameiop;
VOP_LOCK(lowerdvp);
/*
* Only do a LOOKUP on the bottom node, since
* we won't be making changes to it anyway.
*/
nameiop = cnp->cn_nameiop;
cnp->cn_nameiop = LOOKUP;
if (um->um_op == UNMNT_BELOW) {
saved_cred = cnp->cn_cred;
cnp->cn_cred = um->um_cred;
}
lerror = union_lookup1(um->um_lowervp, lowerdvp,
&lowervp, cnp);
if (um->um_op == UNMNT_BELOW)
cnp->cn_cred = saved_cred;
cnp->cn_nameiop = nameiop;
if (lowervp != lowerdvp)
VOP_UNLOCK(lowerdvp);
if (cnp->cn_consume != 0) {
if (uppervp) {
if (uppervp == upperdvp)
vrele(uppervp);
else
vput(uppervp);
uppervp = NULLVP;
}
*ap->a_vpp = lowervp;
if (!lockparent)
cnp->cn_flags &= ~LOCKPARENT;
return (lerror);
}
} else {
lerror = ENOENT;
}
if (!lockparent)
cnp->cn_flags &= ~LOCKPARENT;
/*
* at this point, we have uerror and lerror indicating
* possible errors with the lookups in the upper and lower
* layers. additionally, uppervp and lowervp are (locked)
* references to existing vnodes in the upper and lower layers.
*
* there are now three cases to consider.
* 1. if both layers returned an error, then return whatever
* error the upper layer generated.
*
* 2. if the top layer failed and the bottom layer succeeded
* then two subcases occur.
* a. the bottom vnode is not a directory, in which
* case just return a new union vnode referencing
* an empty top layer and the existing bottom layer.
* b. the bottom vnode is a directory, in which case
* create a new directory in the top-level and
* continue as in case 3.
*
* 3. if the top layer succeeded then return a new union
* vnode referencing whatever the new top layer and
* whatever the bottom layer returned.
*/
*ap->a_vpp = NULLVP;
/* case 1. */
if ((uerror != 0) && (lerror != 0)) {
return (uerror);
}
/* case 2. */
if (uerror != 0 /* && (lerror == 0) */ ) {
if (lowervp->v_type == VDIR) { /* case 2b. */
dun->un_flags &= ~UN_ULOCK;
VOP_UNLOCK(upperdvp);
uerror = union_mkshadow(um, upperdvp, cnp, &uppervp);
VOP_LOCK(upperdvp);
dun->un_flags |= UN_ULOCK;
if (uerror) {
if (lowervp) {
vput(lowervp);
lowervp = NULLVP;
}
return (uerror);
}
}
}
if (lowervp)
VOP_UNLOCK(lowervp);
error = union_allocvp(ap->a_vpp, dvp->v_mount, dvp, upperdvp, cnp,
uppervp, lowervp);
if (error) {
if (uppervp)
vput(uppervp);
if (lowervp)
vrele(lowervp);
} else {
if (*ap->a_vpp != dvp)
if (!lockparent || !(cnp->cn_flags & ISLASTCN))
VOP_UNLOCK(dvp);
}
return (error);
}
int
union_create(ap)
struct vop_create_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
} */ *ap;
{
struct union_node *un = VTOUNION(ap->a_dvp);
struct vnode *dvp = un->un_uppervp;
if (dvp) {
int error;
struct vnode *vp;
FIXUP(un);
VREF(dvp);
un->un_flags |= UN_KLOCK;
vput(ap->a_dvp);
error = VOP_CREATE(dvp, &vp, ap->a_cnp, ap->a_vap);
if (error)
return (error);
error = union_allocvp(
ap->a_vpp,
ap->a_dvp->v_mount,
ap->a_dvp,
NULLVP,
ap->a_cnp,
vp,
NULLVP);
if (error)
vput(vp);
return (error);
}
vput(ap->a_dvp);
return (EROFS);
}
int
union_mknod(ap)
struct vop_mknod_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
} */ *ap;
{
struct union_node *un = VTOUNION(ap->a_dvp);
struct vnode *dvp = un->un_uppervp;
if (dvp) {
int error;
struct vnode *vp;
FIXUP(un);
VREF(dvp);
un->un_flags |= UN_KLOCK;
vput(ap->a_dvp);
error = VOP_MKNOD(dvp, &vp, ap->a_cnp, ap->a_vap);
if (error)
return (error);
if (vp) {
error = union_allocvp(
ap->a_vpp,
ap->a_dvp->v_mount,
ap->a_dvp,
NULLVP,
ap->a_cnp,
vp,
NULLVP);
if (error)
vput(vp);
}
return (error);
}
vput(ap->a_dvp);
return (EROFS);
}
int
union_open(ap)
struct vop_open_args /* {
struct vnodeop_desc *a_desc;
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct union_node *un = VTOUNION(ap->a_vp);
struct vnode *tvp;
int mode = ap->a_mode;
struct ucred *cred = ap->a_cred;
struct proc *p = ap->a_p;
int error;
/*
* If there is an existing upper vp then simply open that.
*/
tvp = un->un_uppervp;
if (tvp == NULLVP) {
/*
* If the lower vnode is being opened for writing, then
* copy the file contents to the upper vnode and open that,
* otherwise can simply open the lower vnode.
*/
tvp = un->un_lowervp;
if ((ap->a_mode & FWRITE) && (tvp->v_type == VREG)) {
struct vnode *vp;
int i;
/*
* Open the named file in the upper layer. Note that
* the file may have come into existence *since* the
* lookup was done, since the upper layer may really
* be a loopback mount of some other filesystem...
* so open the file with exclusive create and barf if
* it already exists.
* XXX - perhaps should re-lookup the node (once more
* with feeling) and simply open that. Who knows.
*/
error = union_vn_create(&vp, un, p);
if (error)
return (error);
/* at this point, uppervp is locked */
union_newupper(un, vp);
un->un_flags |= UN_ULOCK;
/*
* Now, if the file is being opened with truncation,
* then the (new) upper vnode is ready to fly,
* otherwise the data from the lower vnode must be
* copied to the upper layer first. This only works
* for regular files (check is made above).
*/
if ((mode & O_TRUNC) == 0) {
/*
* XXX - should not ignore errors
* from VOP_CLOSE
*/
VOP_LOCK(tvp);
error = VOP_OPEN(tvp, FREAD, cred, p);
if (error == 0) {
error = union_copyfile(p, cred,
tvp, un->un_uppervp);
VOP_UNLOCK(tvp);
(void) VOP_CLOSE(tvp, FREAD);
} else {
VOP_UNLOCK(tvp);
}
#ifdef UNION_DIAGNOSTIC
if (!error)
uprintf("union: copied up %s\n",
un->un_path);
#endif
}
un->un_flags &= ~UN_ULOCK;
VOP_UNLOCK(un->un_uppervp);
union_vn_close(un->un_uppervp, FWRITE, cred, p);
VOP_LOCK(un->un_uppervp);
un->un_flags |= UN_ULOCK;
/*
* Subsequent IOs will go to the top layer, so
* call close on the lower vnode and open on the
* upper vnode to ensure that the filesystem keeps
* its references counts right. This doesn't do
* the right thing with (cred) and (FREAD) though.
* Ignoring error returns is not righ, either.
*/
for (i = 0; i < un->un_openl; i++) {
(void) VOP_CLOSE(tvp, FREAD);
(void) VOP_OPEN(un->un_uppervp, FREAD, cred, p);
}
un->un_openl = 0;
if (error == 0)
error = VOP_OPEN(un->un_uppervp, mode, cred, p);
return (error);
}
/*
* Just open the lower vnode
*/
un->un_openl++;
VOP_LOCK(tvp);
error = VOP_OPEN(tvp, mode, cred, p);
VOP_UNLOCK(tvp);
return (error);
}
FIXUP(un);
error = VOP_OPEN(tvp, mode, cred, p);
return (error);
}
int
union_close(ap)
struct vop_close_args /* {
struct vnode *a_vp;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct union_node *un = VTOUNION(ap->a_vp);
struct vnode *vp;
if (un->un_uppervp) {
vp = un->un_uppervp;
} else {
#ifdef UNION_DIAGNOSTIC
if (un->un_openl <= 0)
panic("union: un_openl cnt");
#endif
--un->un_openl;
vp = un->un_lowervp;
}
return (VOP_CLOSE(vp, ap->a_fflag, ap->a_cred, ap->a_p));
}
/*
* Check access permission on the union vnode.
* The access check being enforced is to check
* against both the underlying vnode, and any
* copied vnode. This ensures that no additional
* file permissions are given away simply because
* the user caused an implicit file copy.
*/
int
union_access(ap)
struct vop_access_args /* {
struct vnodeop_desc *a_desc;
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct union_node *un = VTOUNION(ap->a_vp);
int error = EACCES;
struct vnode *vp;
vp = un->un_uppervp;
if (vp) {
FIXUP(un);
return (VOP_ACCESS(vp, ap->a_mode, ap->a_cred, ap->a_p));
}
vp = un->un_lowervp;
if (vp) {
VOP_LOCK(vp);
error = VOP_ACCESS(vp, ap->a_mode, ap->a_cred, ap->a_p);
if (error == 0) {
struct union_mount *um = MOUNTTOUNIONMOUNT(vp->v_mount);
if (um->um_op == UNMNT_BELOW)
error = VOP_ACCESS(vp, ap->a_mode,
um->um_cred, ap->a_p);
}
VOP_UNLOCK(vp);
if (error)
return (error);
}
return (error);
}
/*
* We handle getattr only to change the fsid.
*/
int
union_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
int error;
struct union_node *un = VTOUNION(ap->a_vp);
struct vnode *vp = un->un_uppervp;
struct vattr *vap;
struct vattr va;
/*
* Some programs walk the filesystem hierarchy by counting
* links to directories to avoid stat'ing all the time.
* This means the link count on directories needs to be "correct".
* The only way to do that is to call getattr on both layers
* and fix up the link count. The link count will not necessarily
* be accurate but will be large enough to defeat the tree walkers.
*/
vap = ap->a_vap;
vp = un->un_uppervp;
if (vp != NULLVP) {
FIXUP(un);
error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p);
if (error)
return (error);
}
if (vp == NULLVP) {
vp = un->un_lowervp;
} else if (vp->v_type == VDIR) {
vp = un->un_lowervp;
vap = &va;
} else {
vp = NULLVP;
}
if (vp != NULLVP) {
VOP_LOCK(vp);
error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p);
VOP_UNLOCK(vp);
if (error)
return (error);
}
if ((vap != ap->a_vap) && (vap->va_type == VDIR))
ap->a_vap->va_nlink += vap->va_nlink;
vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
return (0);
}
int
union_setattr(ap)
struct vop_setattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct union_node *un = VTOUNION(ap->a_vp);
int error;
/*
* Handle case of truncating lower object to zero size,
* by creating a zero length upper object. This is to
* handle the case of open with O_TRUNC and O_CREAT.
*/
if ((un->un_uppervp == NULLVP) &&
/* assert(un->un_lowervp != NULLVP) */
(un->un_lowervp->v_type == VREG) &&
(ap->a_vap->va_size == 0)) {
struct vnode *vp;
error = union_vn_create(&vp, un, ap->a_p);
if (error)
return (error);
/* at this point, uppervp is locked */
union_newupper(un, vp);
VOP_UNLOCK(vp);
union_vn_close(un->un_uppervp, FWRITE, ap->a_cred, ap->a_p);
VOP_LOCK(vp);
un->un_flags |= UN_ULOCK;
}
/*
* Try to set attributes in upper layer,
* otherwise return read-only filesystem error.
*/
if (un->un_uppervp != NULLVP) {
FIXUP(un);
error = VOP_SETATTR(un->un_uppervp, ap->a_vap,
ap->a_cred, ap->a_p);
} else {
error = EROFS;
}
return (error);
}
int
union_read(ap)
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
int error;
struct vnode *vp = OTHERVP(ap->a_vp);
int dolock = (vp == LOWERVP(ap->a_vp));
if (dolock)
VOP_LOCK(vp);
else
FIXUP(VTOUNION(ap->a_vp));
error = VOP_READ(vp, ap->a_uio, ap->a_ioflag, ap->a_cred);
if (dolock)
VOP_UNLOCK(vp);
return (error);
}
int
union_write(ap)
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
int error;
struct vnode *vp = OTHERVP(ap->a_vp);
int dolock = (vp == LOWERVP(ap->a_vp));
if (dolock)
VOP_LOCK(vp);
else
FIXUP(VTOUNION(ap->a_vp));
error = VOP_WRITE(vp, ap->a_uio, ap->a_ioflag, ap->a_cred);
if (dolock)
VOP_UNLOCK(vp);
return (error);
}
int
union_ioctl(ap)
struct vop_ioctl_args /* {
struct vnode *a_vp;
int a_command;
caddr_t a_data;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
return (VOP_IOCTL(OTHERVP(ap->a_vp), ap->a_command, ap->a_data,
ap->a_fflag, ap->a_cred, ap->a_p));
}
int
union_select(ap)
struct vop_select_args /* {
struct vnode *a_vp;
int a_which;
int a_fflags;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
return (VOP_SELECT(OTHERVP(ap->a_vp), ap->a_which, ap->a_fflags,
ap->a_cred, ap->a_p));
}
int
union_mmap(ap)
struct vop_mmap_args /* {
struct vnode *a_vp;
int a_fflags;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
return (VOP_MMAP(OTHERVP(ap->a_vp), ap->a_fflags,
ap->a_cred, ap->a_p));
}
int
union_fsync(ap)
struct vop_fsync_args /* {
struct vnode *a_vp;
struct ucred *a_cred;
int a_waitfor;
struct proc *a_p;
} */ *ap;
{
int error = 0;
struct vnode *targetvp = OTHERVP(ap->a_vp);
if (targetvp) {
int dolock = (targetvp == LOWERVP(ap->a_vp));
if (dolock)
VOP_LOCK(targetvp);
else
FIXUP(VTOUNION(ap->a_vp));
error = VOP_FSYNC(targetvp, ap->a_cred,
ap->a_waitfor, ap->a_p);
if (dolock)
VOP_UNLOCK(targetvp);
}
return (error);
}
int
union_seek(ap)
struct vop_seek_args /* {
struct vnode *a_vp;
off_t a_oldoff;
off_t a_newoff;
struct ucred *a_cred;
} */ *ap;
{
return (VOP_SEEK(OTHERVP(ap->a_vp), ap->a_oldoff, ap->a_newoff, ap->a_cred));
}
int
union_remove(ap)
struct vop_remove_args /* {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */ *ap;
{
int error;
struct union_node *dun = VTOUNION(ap->a_dvp);
struct union_node *un = VTOUNION(ap->a_vp);
if (dun->un_uppervp && un->un_uppervp) {
struct vnode *dvp = dun->un_uppervp;
struct vnode *vp = un->un_uppervp;
FIXUP(dun);
VREF(dvp);
dun->un_flags |= UN_KLOCK;
vput(ap->a_dvp);
FIXUP(un);
VREF(vp);
un->un_flags |= UN_KLOCK;
vput(ap->a_vp);
error = VOP_REMOVE(dvp, vp, ap->a_cnp);
if (!error)
union_removed_upper(un);
/*
* XXX: should create a whiteout here
*/
} else {
/*
* XXX: should create a whiteout here
*/
vput(ap->a_dvp);
vput(ap->a_vp);
error = EROFS;
}
return (error);
}
int
union_link(ap)
struct vop_link_args /* {
struct vnode *a_vp;
struct vnode *a_tdvp;
struct componentname *a_cnp;
} */ *ap;
{
int error;
struct union_node *dun = VTOUNION(ap->a_vp);
struct union_node *un = VTOUNION(ap->a_tdvp);
if (dun->un_uppervp && un->un_uppervp) {
struct vnode *dvp = dun->un_uppervp;
struct vnode *vp = un->un_uppervp;
FIXUP(dun);
VREF(dvp);
dun->un_flags |= UN_KLOCK;
vput(ap->a_vp);
FIXUP(un);
VREF(vp);
vrele(ap->a_tdvp);
error = VOP_LINK(vp, dvp, ap->a_cnp);
} else {
/*
* XXX: need to copy to upper layer
* and do the link there.
*/
vput(ap->a_vp);
vrele(ap->a_tdvp);
error = EROFS;
}
return (error);
}
int
union_rename(ap)
struct vop_rename_args /* {
struct vnode *a_fdvp;
struct vnode *a_fvp;
struct componentname *a_fcnp;
struct vnode *a_tdvp;
struct vnode *a_tvp;
struct componentname *a_tcnp;
} */ *ap;
{
int error;
struct vnode *fdvp = ap->a_fdvp;
struct vnode *fvp = ap->a_fvp;
struct vnode *tdvp = ap->a_tdvp;
struct vnode *tvp = ap->a_tvp;
if (fdvp->v_op == union_vnodeop_p) { /* always true */
struct union_node *un = VTOUNION(fdvp);
if (un->un_uppervp == NULLVP) {
error = EROFS;
goto bad;
}
FIXUP(un);
fdvp = un->un_uppervp;
VREF(fdvp);
vrele(ap->a_fdvp);
}
if (fvp->v_op == union_vnodeop_p) { /* always true */
struct union_node *un = VTOUNION(fvp);
if (un->un_uppervp == NULLVP) {
error = EROFS;
goto bad;
}
FIXUP(un);
fvp = un->un_uppervp;
VREF(fvp);
vrele(ap->a_fvp);
}
if (tdvp->v_op == union_vnodeop_p) {
struct union_node *un = VTOUNION(tdvp);
if (un->un_uppervp == NULLVP) {
error = EROFS;
goto bad;
}
tdvp = un->un_uppervp;
VREF(tdvp);
un->un_flags |= UN_KLOCK;
vput(ap->a_tdvp);
}
if (tvp && tvp->v_op == union_vnodeop_p) {
struct union_node *un = VTOUNION(tvp);
if (un->un_uppervp == NULLVP) {
error = EROFS;
goto bad;
}
tvp = un->un_uppervp;
VREF(tvp);
un->un_flags |= UN_KLOCK;
vput(ap->a_tvp);
}
return (VOP_RENAME(fdvp, fvp, ap->a_fcnp, tdvp, tvp, ap->a_tcnp));
bad:
vrele(fdvp);
vrele(fvp);
vput(tdvp);
if (tvp)
vput(tvp);
return (error);
}
int
union_mkdir(ap)
struct vop_mkdir_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
} */ *ap;
{
struct union_node *un = VTOUNION(ap->a_dvp);
struct vnode *dvp = un->un_uppervp;
if (dvp) {
int error;
struct vnode *vp;
FIXUP(un);
VREF(dvp);
un->un_flags |= UN_KLOCK;
vput(ap->a_dvp);
error = VOP_MKDIR(dvp, &vp, ap->a_cnp, ap->a_vap);
if (error)
return (error);
error = union_allocvp(
ap->a_vpp,
ap->a_dvp->v_mount,
ap->a_dvp,
NULLVP,
ap->a_cnp,
vp,
NULLVP);
if (error)
vput(vp);
return (error);
}
vput(ap->a_dvp);
return (EROFS);
}
int
union_rmdir(ap)
struct vop_rmdir_args /* {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */ *ap;
{
int error;
struct union_node *dun = VTOUNION(ap->a_dvp);
struct union_node *un = VTOUNION(ap->a_vp);
if (dun->un_uppervp && un->un_uppervp) {
struct vnode *dvp = dun->un_uppervp;
struct vnode *vp = un->un_uppervp;
FIXUP(dun);
VREF(dvp);
dun->un_flags |= UN_KLOCK;
vput(ap->a_dvp);
FIXUP(un);
VREF(vp);
un->un_flags |= UN_KLOCK;
vput(ap->a_vp);
error = VOP_RMDIR(dvp, vp, ap->a_cnp);
if (!error)
union_removed_upper(un);
/*
* XXX: should create a whiteout here
*/
} else {
/*
* XXX: should create a whiteout here
*/
vput(ap->a_dvp);
vput(ap->a_vp);
error = EROFS;
}
return (error);
}
int
union_symlink(ap)
struct vop_symlink_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
char *a_target;
} */ *ap;
{
struct union_node *un = VTOUNION(ap->a_dvp);
struct vnode *dvp = un->un_uppervp;
if (dvp) {
int error;
struct vnode *vp;
FIXUP(un);
VREF(dvp);
un->un_flags |= UN_KLOCK;
vput(ap->a_dvp);
error = VOP_SYMLINK(dvp, &vp, ap->a_cnp,
ap->a_vap, ap->a_target);
*ap->a_vpp = NULLVP;
return (error);
}
vput(ap->a_dvp);
return (EROFS);
}
/*
* union_readdir works in concert with getdirentries and
* readdir(3) to provide a list of entries in the unioned
* directories. getdirentries is responsible for walking
* down the union stack. readdir(3) is responsible for
* eliminating duplicate names from the returned data stream.
*/
int
union_readdir(ap)
struct vop_readdir_args /* {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
} */ *ap;
{
int error = 0;
struct union_node *un = VTOUNION(ap->a_vp);
if (un->un_uppervp) {
FIXUP(un);
error = VOP_READDIR(un->un_uppervp, ap->a_uio, ap->a_cred, NULL, NULL, NULL);
}
return (error);
}
int
union_readlink(ap)
struct vop_readlink_args /* {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
} */ *ap;
{
int error;
struct vnode *vp = OTHERVP(ap->a_vp);
int dolock = (vp == LOWERVP(ap->a_vp));
if (dolock)
VOP_LOCK(vp);
else
FIXUP(VTOUNION(ap->a_vp));
error = VOP_READLINK(vp, ap->a_uio, ap->a_cred);
if (dolock)
VOP_UNLOCK(vp);
return (error);
}
int
union_abortop(ap)
struct vop_abortop_args /* {
struct vnode *a_dvp;
struct componentname *a_cnp;
} */ *ap;
{
int error;
struct vnode *vp = OTHERVP(ap->a_dvp);
struct union_node *un = VTOUNION(ap->a_dvp);
int islocked = un->un_flags & UN_LOCKED;
int dolock = (vp == LOWERVP(ap->a_dvp));
if (islocked) {
if (dolock)
VOP_LOCK(vp);
else
FIXUP(VTOUNION(ap->a_dvp));
}
error = VOP_ABORTOP(vp, ap->a_cnp);
if (islocked && dolock)
VOP_UNLOCK(vp);
return (error);
}
int
union_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
} */ *ap;
{
/*
* Do nothing (and _don't_ bypass).
* Wait to vrele lowervp until reclaim,
* so that until then our union_node is in the
* cache and reusable.
*
* NEEDSWORK: Someday, consider inactive'ing
* the lowervp and then trying to reactivate it
* with capabilities (v_id)
* like they do in the name lookup cache code.
* That's too much work for now.
*/
#ifdef UNION_DIAGNOSTIC
struct union_node *un = VTOUNION(ap->a_vp);
if (un->un_flags & UN_LOCKED)
panic("union: inactivating locked node");
#endif
return (0);
}
int
union_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
union_freevp(ap->a_vp);
return (0);
}
int
union_lock(ap)
struct vop_lock_args *ap;
{
struct vnode *vp = ap->a_vp;
struct union_node *un;
start:
while (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
(void) tsleep((caddr_t)vp, PINOD, "unnlk1", 0);
}
un = VTOUNION(vp);
if (un->un_uppervp) {
if ((un->un_flags & UN_ULOCK) == 0) {
un->un_flags |= UN_ULOCK;
VOP_LOCK(un->un_uppervp);
}
#ifdef DIAGNOSTIC
if (un->un_flags & UN_KLOCK)
panic("union: dangling upper lock");
#endif
}
if (un->un_flags & UN_LOCKED) {
#ifdef DIAGNOSTIC
if (curproc && un->un_pid == curproc->p_pid &&
un->un_pid > -1 && curproc->p_pid > -1)
panic("union: locking against myself");
#endif
un->un_flags |= UN_WANT;
(void) tsleep((caddr_t) &un->un_flags, PINOD, "unnlk2", 0);
goto start;
}
#ifdef DIAGNOSTIC
if (curproc)
un->un_pid = curproc->p_pid;
else
un->un_pid = -1;
#endif
un->un_flags |= UN_LOCKED;
return (0);
}
int
union_unlock(ap)
struct vop_lock_args *ap;
{
struct union_node *un = VTOUNION(ap->a_vp);
#ifdef DIAGNOSTIC
if ((un->un_flags & UN_LOCKED) == 0)
panic("union: unlock unlocked node");
if (curproc && un->un_pid != curproc->p_pid &&
curproc->p_pid > -1 && un->un_pid > -1)
panic("union: unlocking other process's union node");
#endif
un->un_flags &= ~UN_LOCKED;
if ((un->un_flags & (UN_ULOCK|UN_KLOCK)) == UN_ULOCK)
VOP_UNLOCK(un->un_uppervp);
un->un_flags &= ~(UN_ULOCK|UN_KLOCK);
if (un->un_flags & UN_WANT) {
un->un_flags &= ~UN_WANT;
wakeup((caddr_t) &un->un_flags);
}
#ifdef DIAGNOSTIC
un->un_pid = 0;
#endif
return (0);
}
int
union_bmap(ap)
struct vop_bmap_args /* {
struct vnode *a_vp;
daddr_t a_bn;
struct vnode **a_vpp;
daddr_t *a_bnp;
int *a_runp;
} */ *ap;
{
int error;
struct vnode *vp = OTHERVP(ap->a_vp);
int dolock = (vp == LOWERVP(ap->a_vp));
if (dolock)
VOP_LOCK(vp);
else
FIXUP(VTOUNION(ap->a_vp));
error = VOP_BMAP(vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp);
if (dolock)
VOP_UNLOCK(vp);
return (error);
}
int
union_print(ap)
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
printf("\ttag VT_UNION, vp=%p, uppervp=%p, lowervp=%p\n",
vp, UPPERVP(vp), LOWERVP(vp));
return (0);
}
int
union_islocked(ap)
struct vop_islocked_args /* {
struct vnode *a_vp;
} */ *ap;
{
return ((VTOUNION(ap->a_vp)->un_flags & UN_LOCKED) ? 1 : 0);
}
int
union_pathconf(ap)
struct vop_pathconf_args /* {
struct vnode *a_vp;
int a_name;
int *a_retval;
} */ *ap;
{
int error;
struct vnode *vp = OTHERVP(ap->a_vp);
int dolock = (vp == LOWERVP(ap->a_vp));
if (dolock)
VOP_LOCK(vp);
else
FIXUP(VTOUNION(ap->a_vp));
error = VOP_PATHCONF(vp, ap->a_name, ap->a_retval);
if (dolock)
VOP_UNLOCK(vp);
return (error);
}
int
union_advlock(ap)
struct vop_advlock_args /* {
struct vnode *a_vp;
caddr_t a_id;
int a_op;
struct flock *a_fl;
int a_flags;
} */ *ap;
{
return (VOP_ADVLOCK(OTHERVP(ap->a_vp), ap->a_id, ap->a_op,
ap->a_fl, ap->a_flags));
}
/*
* XXX - vop_strategy must be hand coded because it has no
* vnode in its arguments.
* This goes away with a merged VM/buffer cache.
*/
int
union_strategy(ap)
struct vop_strategy_args /* {
struct buf *a_bp;
} */ *ap;
{
struct buf *bp = ap->a_bp;
int error;
struct vnode *savedvp;
savedvp = bp->b_vp;
bp->b_vp = OTHERVP(bp->b_vp);
#ifdef DIAGNOSTIC
if (bp->b_vp == NULLVP)
panic("union_strategy: nil vp");
if (((bp->b_flags & B_READ) == 0) &&
(bp->b_vp == LOWERVP(savedvp)))
panic("union_strategy: writing to lowervp");
#endif
error = VOP_STRATEGY(bp);
bp->b_vp = savedvp;
return (error);
}
/*
* Global vfs data structures
*/
int (**union_vnodeop_p)();
struct vnodeopv_entry_desc union_vnodeop_entries[] = {
{ &vop_default_desc, vn_default_error },
{ &vop_lookup_desc, union_lookup }, /* lookup */
{ &vop_create_desc, union_create }, /* create */
{ &vop_mknod_desc, union_mknod }, /* mknod */
{ &vop_open_desc, union_open }, /* open */
{ &vop_close_desc, union_close }, /* close */
{ &vop_access_desc, union_access }, /* access */
{ &vop_getattr_desc, union_getattr }, /* getattr */
{ &vop_setattr_desc, union_setattr }, /* setattr */
{ &vop_read_desc, union_read }, /* read */
{ &vop_write_desc, union_write }, /* write */
{ &vop_ioctl_desc, union_ioctl }, /* ioctl */
{ &vop_select_desc, union_select }, /* select */
{ &vop_mmap_desc, union_mmap }, /* mmap */
{ &vop_fsync_desc, union_fsync }, /* fsync */
{ &vop_seek_desc, union_seek }, /* seek */
{ &vop_remove_desc, union_remove }, /* remove */
{ &vop_link_desc, union_link }, /* link */
{ &vop_rename_desc, union_rename }, /* rename */
{ &vop_mkdir_desc, union_mkdir }, /* mkdir */
{ &vop_rmdir_desc, union_rmdir }, /* rmdir */
{ &vop_symlink_desc, union_symlink }, /* symlink */
{ &vop_readdir_desc, union_readdir }, /* readdir */
{ &vop_readlink_desc, union_readlink }, /* readlink */
{ &vop_abortop_desc, union_abortop }, /* abortop */
{ &vop_inactive_desc, union_inactive }, /* inactive */
{ &vop_reclaim_desc, union_reclaim }, /* reclaim */
{ &vop_lock_desc, union_lock }, /* lock */
{ &vop_unlock_desc, union_unlock }, /* unlock */
{ &vop_bmap_desc, union_bmap }, /* bmap */
{ &vop_strategy_desc, union_strategy }, /* strategy */
{ &vop_print_desc, union_print }, /* print */
{ &vop_islocked_desc, union_islocked }, /* islocked */
{ &vop_pathconf_desc, union_pathconf }, /* pathconf */
{ &vop_advlock_desc, union_advlock }, /* advlock */
#ifdef notdef
{ &vop_blkatoff_desc, union_blkatoff }, /* blkatoff */
{ &vop_valloc_desc, union_valloc }, /* valloc */
{ &vop_vfree_desc, union_vfree }, /* vfree */
{ &vop_truncate_desc, union_truncate }, /* truncate */
{ &vop_update_desc, union_update }, /* update */
{ &vop_bwrite_desc, union_bwrite }, /* bwrite */
#endif
{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
};
struct vnodeopv_desc union_vnodeop_opv_desc =
{ &union_vnodeop_p, union_vnodeop_entries };
VNODEOP_SET(union_vnodeop_opv_desc);
