1805 lines
42 KiB
C
1805 lines
42 KiB
C
/*
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* Copyright (c) 1992, 1993, 1994, 1995 Jan-Simon Pendry.
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* Copyright (c) 1992, 1993, 1994, 1995
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Jan-Simon Pendry.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)union_vnops.c 8.32 (Berkeley) 6/23/95
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* $Id: union_vnops.c,v 1.59 1998/12/14 05:00:59 dillon Exp $
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <sys/fcntl.h>
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#include <sys/stat.h>
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#include <sys/kernel.h>
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#include <sys/vnode.h>
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#include <sys/mount.h>
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#include <sys/namei.h>
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#include <sys/malloc.h>
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#include <sys/buf.h>
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#include <sys/lock.h>
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#include <miscfs/union/union.h>
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#define FIXUP(un, p) { \
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if (((un)->un_flags & UN_ULOCK) == 0) { \
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union_fixup(un, p); \
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} \
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}
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static int union_abortop __P((struct vop_abortop_args *ap));
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static int union_access __P((struct vop_access_args *ap));
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static int union_advlock __P((struct vop_advlock_args *ap));
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static int union_bmap __P((struct vop_bmap_args *ap));
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static int union_close __P((struct vop_close_args *ap));
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static int union_create __P((struct vop_create_args *ap));
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static void union_fixup __P((struct union_node *un, struct proc *p));
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static int union_fsync __P((struct vop_fsync_args *ap));
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static int union_getattr __P((struct vop_getattr_args *ap));
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static int union_inactive __P((struct vop_inactive_args *ap));
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static int union_ioctl __P((struct vop_ioctl_args *ap));
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static int union_islocked __P((struct vop_islocked_args *ap));
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static int union_lease __P((struct vop_lease_args *ap));
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static int union_link __P((struct vop_link_args *ap));
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static int union_lock __P((struct vop_lock_args *ap));
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static int union_lookup __P((struct vop_lookup_args *ap));
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static int union_lookup1 __P((struct vnode *udvp, struct vnode **dvpp,
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struct vnode **vpp,
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struct componentname *cnp));
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static int union_mkdir __P((struct vop_mkdir_args *ap));
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static int union_mknod __P((struct vop_mknod_args *ap));
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static int union_mmap __P((struct vop_mmap_args *ap));
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static int union_open __P((struct vop_open_args *ap));
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static int union_pathconf __P((struct vop_pathconf_args *ap));
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static int union_print __P((struct vop_print_args *ap));
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static int union_read __P((struct vop_read_args *ap));
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static int union_readdir __P((struct vop_readdir_args *ap));
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static int union_readlink __P((struct vop_readlink_args *ap));
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static int union_reclaim __P((struct vop_reclaim_args *ap));
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static int union_remove __P((struct vop_remove_args *ap));
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static int union_rename __P((struct vop_rename_args *ap));
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static int union_revoke __P((struct vop_revoke_args *ap));
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static int union_rmdir __P((struct vop_rmdir_args *ap));
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static int union_poll __P((struct vop_poll_args *ap));
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static int union_setattr __P((struct vop_setattr_args *ap));
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static int union_strategy __P((struct vop_strategy_args *ap));
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static int union_symlink __P((struct vop_symlink_args *ap));
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static int union_unlock __P((struct vop_unlock_args *ap));
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static int union_whiteout __P((struct vop_whiteout_args *ap));
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static int union_write __P((struct vop_read_args *ap));
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static void
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union_fixup(un, p)
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struct union_node *un;
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struct proc *p;
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{
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vn_lock(un->un_uppervp, LK_EXCLUSIVE | LK_RETRY, p);
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un->un_flags |= UN_ULOCK;
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}
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static int
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union_lookup1(udvp, dvpp, vpp, cnp)
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struct vnode *udvp;
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struct vnode **dvpp;
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struct vnode **vpp;
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struct componentname *cnp;
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{
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int error;
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struct proc *p = cnp->cn_proc;
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struct vnode *tdvp;
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struct vnode *dvp;
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struct mount *mp;
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dvp = *dvpp;
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/*
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* If stepping up the directory tree, check for going
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* back across the mount point, in which case do what
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* lookup would do by stepping back down the mount
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* hierarchy.
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*/
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if (cnp->cn_flags & ISDOTDOT) {
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while ((dvp != udvp) && (dvp->v_flag & VROOT)) {
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/*
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* Don't do the NOCROSSMOUNT check
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* at this level. By definition,
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* union fs deals with namespaces, not
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* filesystems.
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*/
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tdvp = dvp;
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*dvpp = dvp = dvp->v_mount->mnt_vnodecovered;
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vput(tdvp);
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VREF(dvp);
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vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p);
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}
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}
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error = VOP_LOOKUP(dvp, &tdvp, cnp);
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if (error)
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return (error);
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/*
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* The parent directory will have been unlocked, unless lookup
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* found the last component. In which case, re-lock the node
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* here to allow it to be unlocked again (phew) in union_lookup.
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*/
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if (dvp != tdvp && !(cnp->cn_flags & ISLASTCN))
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vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p);
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dvp = tdvp;
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/*
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* Lastly check if the current node is a mount point in
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* which case walk up the mount hierarchy making sure not to
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* bump into the root of the mount tree (ie. dvp != udvp).
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*/
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while (dvp != udvp && (dvp->v_type == VDIR) &&
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(mp = dvp->v_mountedhere)) {
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if (vfs_busy(mp, 0, 0, p))
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continue;
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error = VFS_ROOT(mp, &tdvp);
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vfs_unbusy(mp, p);
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if (error) {
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vput(dvp);
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return (error);
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}
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vput(dvp);
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dvp = tdvp;
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}
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*vpp = dvp;
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return (0);
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}
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static int
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union_lookup(ap)
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struct vop_lookup_args /* {
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struct vnodeop_desc *a_desc;
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struct vnode *a_dvp;
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struct vnode **a_vpp;
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struct componentname *a_cnp;
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} */ *ap;
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{
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int error;
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int uerror, lerror;
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struct vnode *uppervp, *lowervp;
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struct vnode *upperdvp, *lowerdvp;
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struct vnode *dvp = ap->a_dvp;
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struct union_node *dun = VTOUNION(dvp);
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struct componentname *cnp = ap->a_cnp;
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struct proc *p = cnp->cn_proc;
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int lockparent = cnp->cn_flags & LOCKPARENT;
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struct union_mount *um = MOUNTTOUNIONMOUNT(dvp->v_mount);
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struct ucred *saved_cred = NULL;
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int iswhiteout;
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struct vattr va;
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/*
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* Disallow write attemps to the filesystem mounted read-only.
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*/
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if ((cnp->cn_flags & ISLASTCN) && (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
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(cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME))
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return (EROFS);
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#ifdef notyet
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if (cnp->cn_namelen == 3 &&
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cnp->cn_nameptr[2] == '.' &&
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cnp->cn_nameptr[1] == '.' &&
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cnp->cn_nameptr[0] == '.') {
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dvp = *ap->a_vpp = LOWERVP(ap->a_dvp);
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if (dvp == NULLVP)
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return (ENOENT);
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VREF(dvp);
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vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p);
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if (!lockparent || !(cnp->cn_flags & ISLASTCN))
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VOP_UNLOCK(ap->a_dvp, 0, p);
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return (0);
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}
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#endif
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cnp->cn_flags |= LOCKPARENT;
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upperdvp = dun->un_uppervp;
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lowerdvp = dun->un_lowervp;
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uppervp = NULLVP;
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lowervp = NULLVP;
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iswhiteout = 0;
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if (cnp->cn_flags & ISDOTDOT) {
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if (upperdvp != NULL)
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VREF(upperdvp);
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if (lowerdvp != NULL)
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VREF(lowerdvp);
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}
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/*
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* do the lookup in the upper level.
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* if that level comsumes additional pathnames,
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* then assume that something special is going
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* on and just return that vnode.
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*/
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if (upperdvp != NULLVP) {
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FIXUP(dun, p);
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/*
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* If we're doing `..' in the underlying filesystem,
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* we must drop our lock on the union node before
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* going up the tree in the lower file system--if we block
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* on the lowervp lock, and that's held by someone else
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* coming down the tree and who's waiting for our lock,
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* we would be hosed.
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*/
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if (cnp->cn_flags & ISDOTDOT) {
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/* retain lock on underlying VP: */
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dun->un_flags |= UN_KLOCK;
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VOP_UNLOCK(dvp, 0, p);
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}
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uerror = union_lookup1(um->um_uppervp, &upperdvp,
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&uppervp, cnp);
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/*
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* Disallow write attemps to the filesystem mounted read-only.
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*/
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if (uerror == EJUSTRETURN && (cnp->cn_flags & ISLASTCN) &&
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(dvp->v_mount->mnt_flag & MNT_RDONLY) &&
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(cnp->cn_nameiop == CREATE || cnp->cn_nameiop == RENAME)) {
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if (!lockparent)
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cnp->cn_flags &= ~LOCKPARENT;
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return (EROFS);
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}
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if (cnp->cn_flags & ISDOTDOT) {
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if (dun->un_uppervp == upperdvp) {
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/*
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* We got the underlying bugger back locked...
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* now take back the union node lock. Since we
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* hold the uppervp lock, we can diddle union
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* locking flags at will. :)
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*/
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dun->un_flags |= UN_ULOCK;
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}
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/*
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* If upperdvp got swapped out, it means we did
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* some mount point magic, and we do not have
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* dun->un_uppervp locked currently--so we get it
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* locked here (don't set the UN_ULOCK flag).
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*/
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vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p);
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}
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/*if (uppervp == upperdvp)
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dun->un_flags |= UN_KLOCK;*/
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if (cnp->cn_consume != 0) {
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*ap->a_vpp = uppervp;
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if (!lockparent)
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cnp->cn_flags &= ~LOCKPARENT;
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error = uerror;
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goto out;
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}
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if (uerror == ENOENT || uerror == EJUSTRETURN) {
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if (cnp->cn_flags & ISWHITEOUT) {
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iswhiteout = 1;
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} else if (lowerdvp != NULLVP) {
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lerror = VOP_GETATTR(upperdvp, &va,
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cnp->cn_cred, cnp->cn_proc);
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if (lerror == 0 && (va.va_flags & OPAQUE))
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iswhiteout = 1;
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}
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}
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} else {
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uerror = ENOENT;
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}
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/*
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* in a similar way to the upper layer, do the lookup
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* in the lower layer. this time, if there is some
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* component magic going on, then vput whatever we got
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* back from the upper layer and return the lower vnode
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* instead.
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*/
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if (lowerdvp != NULLVP && !iswhiteout) {
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int nameiop;
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vn_lock(lowerdvp, LK_EXCLUSIVE | LK_RETRY, p);
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/*
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* Only do a LOOKUP on the bottom node, since
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* we won't be making changes to it anyway.
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*/
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nameiop = cnp->cn_nameiop;
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cnp->cn_nameiop = LOOKUP;
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if (um->um_op == UNMNT_BELOW) {
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saved_cred = cnp->cn_cred;
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cnp->cn_cred = um->um_cred;
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}
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/*
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* We shouldn't have to worry about locking interactions
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* between the lower layer and our union layer (w.r.t.
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* `..' processing) because we don't futz with lowervp
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* locks in the union-node instantiation code path.
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*/
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lerror = union_lookup1(um->um_lowervp, &lowerdvp,
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&lowervp, cnp);
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if (um->um_op == UNMNT_BELOW)
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cnp->cn_cred = saved_cred;
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cnp->cn_nameiop = nameiop;
|
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|
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if (lowervp != lowerdvp)
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VOP_UNLOCK(lowerdvp, 0, p);
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|
|
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if (cnp->cn_consume != 0 || lerror == EACCES) {
|
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if (lerror == EACCES)
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lowervp = NULLVP;
|
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if (uppervp != NULLVP) {
|
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if (uppervp == upperdvp)
|
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vrele(uppervp);
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else
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vput(uppervp);
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uppervp = NULLVP;
|
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}
|
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*ap->a_vpp = lowervp;
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if (!lockparent)
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cnp->cn_flags &= ~LOCKPARENT;
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error = lerror;
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goto out;
|
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}
|
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} else {
|
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lerror = ENOENT;
|
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if ((cnp->cn_flags & ISDOTDOT) && dun->un_pvp != NULLVP) {
|
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lowervp = LOWERVP(dun->un_pvp);
|
|
if (lowervp != NULLVP) {
|
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VREF(lowervp);
|
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vn_lock(lowervp, LK_EXCLUSIVE | LK_RETRY, p);
|
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lerror = 0;
|
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}
|
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}
|
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}
|
|
|
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if (!lockparent)
|
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cnp->cn_flags &= ~LOCKPARENT;
|
|
|
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/*
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* at this point, we have uerror and lerror indicating
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* possible errors with the lookups in the upper and lower
|
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* layers. additionally, uppervp and lowervp are (locked)
|
|
* references to existing vnodes in the upper and lower layers.
|
|
*
|
|
* there are now three cases to consider.
|
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* 1. if both layers returned an error, then return whatever
|
|
* error the upper layer generated.
|
|
*
|
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* 2. if the top layer failed and the bottom layer succeeded
|
|
* then two subcases occur.
|
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* a. the bottom vnode is not a directory, in which
|
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* 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
|
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* 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
|
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* vnode referencing whatever the new top layer and
|
|
* whatever the bottom layer returned.
|
|
*/
|
|
|
|
*ap->a_vpp = NULLVP;
|
|
|
|
/* case 1. */
|
|
if ((uerror != 0) && (lerror != 0)) {
|
|
error = uerror;
|
|
goto out;
|
|
}
|
|
|
|
/* case 2. */
|
|
if (uerror != 0 /* && (lerror == 0) */ ) {
|
|
if (lowervp->v_type == VDIR) { /* case 2b. */
|
|
dun->un_flags &= ~UN_ULOCK;
|
|
VOP_UNLOCK(upperdvp, 0, p);
|
|
uerror = union_mkshadow(um, upperdvp, cnp, &uppervp);
|
|
vn_lock(upperdvp, LK_EXCLUSIVE | LK_RETRY, p);
|
|
dun->un_flags |= UN_ULOCK;
|
|
|
|
if (uerror) {
|
|
if (lowervp != NULLVP) {
|
|
vput(lowervp);
|
|
lowervp = NULLVP;
|
|
}
|
|
error = uerror;
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (lowervp != NULLVP)
|
|
VOP_UNLOCK(lowervp, 0, p);
|
|
|
|
error = union_allocvp(ap->a_vpp, dvp->v_mount, dvp, upperdvp, cnp,
|
|
uppervp, lowervp, 1);
|
|
|
|
if (error) {
|
|
if (uppervp != NULLVP)
|
|
vput(uppervp);
|
|
if (lowervp != NULLVP)
|
|
vrele(lowervp);
|
|
} else {
|
|
if (*ap->a_vpp != dvp)
|
|
if (!lockparent || !(cnp->cn_flags & ISLASTCN))
|
|
VOP_UNLOCK(dvp, 0, p);
|
|
#ifdef DIAGNOSTIC
|
|
if (cnp->cn_namelen == 1 &&
|
|
cnp->cn_nameptr[0] == '.' &&
|
|
*ap->a_vpp != dvp) {
|
|
panic("union_lookup returning . (%p) not same as startdir (%p)",
|
|
ap->a_vpp, dvp);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
out:
|
|
if (cnp->cn_flags & ISDOTDOT) {
|
|
if (upperdvp != NULL)
|
|
vrele(upperdvp);
|
|
if (lowerdvp != NULL)
|
|
vrele(lowerdvp);
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
static 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 *dun = VTOUNION(ap->a_dvp);
|
|
struct vnode *dvp = dun->un_uppervp;
|
|
struct componentname *cnp = ap->a_cnp;
|
|
struct proc *p = cnp->cn_proc;
|
|
|
|
if (dvp != NULLVP) {
|
|
struct vnode *vp;
|
|
struct mount *mp;
|
|
int error;
|
|
|
|
FIXUP(dun, p);
|
|
|
|
dun->un_flags |= UN_KLOCK;
|
|
VOP_UNLOCK(ap->a_dvp, 0, p);
|
|
error = VOP_CREATE(dvp, &vp, cnp, ap->a_vap);
|
|
if (error) {
|
|
dun->un_flags |= UN_ULOCK;
|
|
return (error);
|
|
}
|
|
|
|
mp = ap->a_dvp->v_mount;
|
|
VOP_UNLOCK(dvp, 0, p);
|
|
error = union_allocvp(ap->a_vpp, mp, NULLVP, NULLVP, cnp, vp,
|
|
NULLVP, 1);
|
|
if (error)
|
|
vput(vp);
|
|
vn_lock(ap->a_dvp, LK_EXCLUSIVE| LK_RETRY, p);
|
|
return (error);
|
|
}
|
|
|
|
return (EROFS);
|
|
}
|
|
|
|
static int
|
|
union_whiteout(ap)
|
|
struct vop_whiteout_args /* {
|
|
struct vnode *a_dvp;
|
|
struct componentname *a_cnp;
|
|
int a_flags;
|
|
} */ *ap;
|
|
{
|
|
struct union_node *un = VTOUNION(ap->a_dvp);
|
|
struct componentname *cnp = ap->a_cnp;
|
|
struct proc *p = cnp->cn_proc;
|
|
|
|
if (un->un_uppervp == NULLVP)
|
|
return (EOPNOTSUPP);
|
|
|
|
FIXUP(un, p);
|
|
return (VOP_WHITEOUT(un->un_uppervp, cnp, ap->a_flags));
|
|
}
|
|
|
|
static 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 *dun = VTOUNION(ap->a_dvp);
|
|
struct vnode *dvp = dun->un_uppervp;
|
|
struct componentname *cnp = ap->a_cnp;
|
|
struct proc *p = cnp->cn_proc;
|
|
|
|
if (dvp != NULLVP) {
|
|
struct vnode *vp;
|
|
struct mount *mp;
|
|
int error;
|
|
|
|
FIXUP(dun, p);
|
|
|
|
dun->un_flags |= UN_KLOCK;
|
|
VOP_UNLOCK(ap->a_dvp, 0, p);
|
|
error = VOP_MKNOD(dvp, &vp, cnp, ap->a_vap);
|
|
if (error) {
|
|
dun->un_flags |= UN_ULOCK;
|
|
return (error);
|
|
}
|
|
|
|
if (vp != NULLVP) {
|
|
mp = ap->a_dvp->v_mount;
|
|
VOP_UNLOCK(dvp, 0, p);
|
|
error = union_allocvp(ap->a_vpp, mp, NULLVP, NULLVP,
|
|
cnp, vp, NULLVP, 1);
|
|
if (error)
|
|
vput(vp);
|
|
vn_lock(ap->a_dvp, LK_EXCLUSIVE| LK_RETRY, p);
|
|
} else {
|
|
dun->un_flags |= UN_ULOCK;
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
return (EROFS);
|
|
}
|
|
|
|
static 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)) {
|
|
error = union_copyup(un, (mode&O_TRUNC) == 0, cred, p);
|
|
if (error == 0)
|
|
error = VOP_OPEN(un->un_uppervp, mode, cred, p);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Just open the lower vnode
|
|
*/
|
|
un->un_openl++;
|
|
vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY, p);
|
|
error = VOP_OPEN(tvp, mode, cred, p);
|
|
VOP_UNLOCK(tvp, 0, p);
|
|
|
|
return (error);
|
|
}
|
|
|
|
FIXUP(un, p);
|
|
|
|
error = VOP_OPEN(tvp, mode, cred, p);
|
|
|
|
return (error);
|
|
}
|
|
|
|
static 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 ((vp = un->un_uppervp) == NULLVP) {
|
|
#ifdef UNION_DIAGNOSTIC
|
|
if (un->un_openl <= 0)
|
|
panic("union: un_openl cnt");
|
|
#endif
|
|
--un->un_openl;
|
|
vp = un->un_lowervp;
|
|
}
|
|
|
|
ap->a_vp = vp;
|
|
return (VCALL(vp, VOFFSET(vop_close), ap));
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static 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);
|
|
struct proc *p = ap->a_p;
|
|
int error = EACCES;
|
|
struct vnode *vp;
|
|
struct vnode *savedvp;
|
|
|
|
/*
|
|
* Disallow write attempts on filesystems mounted read-only.
|
|
*/
|
|
if (ap->a_mode & VWRITE && (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) {
|
|
switch (ap->a_vp->v_type) {
|
|
case VREG:
|
|
case VDIR:
|
|
case VLNK:
|
|
return (EROFS);
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
if ((vp = un->un_uppervp) != NULLVP) {
|
|
FIXUP(un, p);
|
|
ap->a_vp = vp;
|
|
return (VCALL(vp, VOFFSET(vop_access), ap));
|
|
}
|
|
|
|
if ((vp = un->un_lowervp) != NULLVP) {
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
|
|
savedvp = ap->a_vp;
|
|
ap->a_vp = vp;
|
|
error = VCALL(vp, VOFFSET(vop_access), ap);
|
|
if (error == 0) {
|
|
struct union_mount *um = MOUNTTOUNIONMOUNT(savedvp->v_mount);
|
|
|
|
if (um->um_op == UNMNT_BELOW) {
|
|
ap->a_cred = um->um_cred;
|
|
error = VCALL(vp, VOFFSET(vop_access), ap);
|
|
}
|
|
}
|
|
VOP_UNLOCK(vp, 0, p);
|
|
if (error)
|
|
return (error);
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* We handle getattr only to change the fsid and
|
|
* track object sizes
|
|
*/
|
|
static 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 proc *p = ap->a_p;
|
|
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) {
|
|
/*
|
|
* It's not clear whether VOP_GETATTR is to be
|
|
* called with the vnode locked or not. stat() calls
|
|
* it with (vp) locked, and fstat calls it with
|
|
* (vp) unlocked.
|
|
* In the mean time, compensate here by checking
|
|
* the union_node's lock flag.
|
|
*/
|
|
if (un->un_flags & UN_LOCKED)
|
|
FIXUP(un, p);
|
|
|
|
error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p);
|
|
if (error)
|
|
return (error);
|
|
union_newsize(ap->a_vp, vap->va_size, VNOVAL);
|
|
}
|
|
|
|
if (vp == NULLVP) {
|
|
vp = un->un_lowervp;
|
|
} else if (vp->v_type == VDIR && un->un_lowervp != NULLVP) {
|
|
vp = un->un_lowervp;
|
|
vap = &va;
|
|
} else {
|
|
vp = NULLVP;
|
|
}
|
|
|
|
if (vp != NULLVP) {
|
|
error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p);
|
|
if (error)
|
|
return (error);
|
|
union_newsize(ap->a_vp, VNOVAL, vap->va_size);
|
|
}
|
|
|
|
if ((vap != ap->a_vap) && (vap->va_type == VDIR))
|
|
ap->a_vap->va_nlink += vap->va_nlink;
|
|
|
|
ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
|
|
return (0);
|
|
}
|
|
|
|
static 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);
|
|
struct proc *p = ap->a_p;
|
|
struct vattr *vap = ap->a_vap;
|
|
int error;
|
|
|
|
/*
|
|
* Disallow write attempts on filesystems mounted read-only.
|
|
*/
|
|
if ((ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) &&
|
|
(vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
|
|
vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
|
|
vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL))
|
|
return (EROFS);
|
|
|
|
/*
|
|
* 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)) {
|
|
error = union_copyup(un, (ap->a_vap->va_size != 0),
|
|
ap->a_cred, ap->a_p);
|
|
if (error)
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Try to set attributes in upper layer,
|
|
* otherwise return read-only filesystem error.
|
|
*/
|
|
if (un->un_uppervp != NULLVP) {
|
|
FIXUP(un, p);
|
|
error = VOP_SETATTR(un->un_uppervp, ap->a_vap,
|
|
ap->a_cred, ap->a_p);
|
|
if ((error == 0) && (ap->a_vap->va_size != VNOVAL))
|
|
union_newsize(ap->a_vp, ap->a_vap->va_size, VNOVAL);
|
|
} else {
|
|
error = EROFS;
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
static 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 proc *p = ap->a_uio->uio_procp;
|
|
struct vnode *vp = OTHERVP(ap->a_vp);
|
|
int dolock = (vp == LOWERVP(ap->a_vp));
|
|
|
|
if (dolock)
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
|
|
else
|
|
FIXUP(VTOUNION(ap->a_vp), p);
|
|
error = VOP_READ(vp, ap->a_uio, ap->a_ioflag, ap->a_cred);
|
|
if (dolock)
|
|
VOP_UNLOCK(vp, 0, p);
|
|
|
|
/*
|
|
* XXX
|
|
* perhaps the size of the underlying object has changed under
|
|
* our feet. take advantage of the offset information present
|
|
* in the uio structure.
|
|
*/
|
|
if (error == 0) {
|
|
struct union_node *un = VTOUNION(ap->a_vp);
|
|
off_t cur = ap->a_uio->uio_offset;
|
|
|
|
if (vp == un->un_uppervp) {
|
|
if (cur > un->un_uppersz)
|
|
union_newsize(ap->a_vp, cur, VNOVAL);
|
|
} else {
|
|
if (cur > un->un_lowersz)
|
|
union_newsize(ap->a_vp, VNOVAL, cur);
|
|
}
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
static 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;
|
|
struct union_node *un = VTOUNION(ap->a_vp);
|
|
struct proc *p = ap->a_uio->uio_procp;
|
|
|
|
vp = UPPERVP(ap->a_vp);
|
|
if (vp == NULLVP)
|
|
panic("union: missing upper layer in write");
|
|
|
|
FIXUP(un, p);
|
|
error = VOP_WRITE(vp, ap->a_uio, ap->a_ioflag, ap->a_cred);
|
|
|
|
/*
|
|
* the size of the underlying object may be changed by the
|
|
* write.
|
|
*/
|
|
if (error == 0) {
|
|
off_t cur = ap->a_uio->uio_offset;
|
|
|
|
if (cur > un->un_uppersz)
|
|
union_newsize(ap->a_vp, cur, VNOVAL);
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
union_lease(ap)
|
|
struct vop_lease_args /* {
|
|
struct vnode *a_vp;
|
|
struct proc *a_p;
|
|
struct ucred *a_cred;
|
|
int a_flag;
|
|
} */ *ap;
|
|
{
|
|
register struct vnode *ovp = OTHERVP(ap->a_vp);
|
|
|
|
ap->a_vp = ovp;
|
|
return (VCALL(ovp, VOFFSET(vop_lease), ap));
|
|
}
|
|
|
|
static 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;
|
|
{
|
|
register struct vnode *ovp = OTHERVP(ap->a_vp);
|
|
|
|
ap->a_vp = ovp;
|
|
return (VCALL(ovp, VOFFSET(vop_ioctl), ap));
|
|
}
|
|
|
|
static int
|
|
union_poll(ap)
|
|
struct vop_poll_args /* {
|
|
struct vnode *a_vp;
|
|
int a_events;
|
|
struct ucred *a_cred;
|
|
struct proc *a_p;
|
|
} */ *ap;
|
|
{
|
|
register struct vnode *ovp = OTHERVP(ap->a_vp);
|
|
|
|
ap->a_vp = ovp;
|
|
return (VCALL(ovp, VOFFSET(vop_poll), ap));
|
|
}
|
|
|
|
static int
|
|
union_revoke(ap)
|
|
struct vop_revoke_args /* {
|
|
struct vnode *a_vp;
|
|
int a_flags;
|
|
struct proc *a_p;
|
|
} */ *ap;
|
|
{
|
|
struct vnode *vp = ap->a_vp;
|
|
|
|
if (UPPERVP(vp))
|
|
VOP_REVOKE(UPPERVP(vp), ap->a_flags);
|
|
if (LOWERVP(vp))
|
|
VOP_REVOKE(LOWERVP(vp), ap->a_flags);
|
|
vgone(vp);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
union_mmap(ap)
|
|
struct vop_mmap_args /* {
|
|
struct vnode *a_vp;
|
|
int a_fflags;
|
|
struct ucred *a_cred;
|
|
struct proc *a_p;
|
|
} */ *ap;
|
|
{
|
|
register struct vnode *ovp = OTHERVP(ap->a_vp);
|
|
|
|
ap->a_vp = ovp;
|
|
return (VCALL(ovp, VOFFSET(vop_mmap), ap));
|
|
}
|
|
|
|
static 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 proc *p = ap->a_p;
|
|
struct vnode *targetvp = OTHERVP(ap->a_vp);
|
|
struct union_node *un;
|
|
|
|
if (targetvp != NULLVP) {
|
|
int dolock = (targetvp == LOWERVP(ap->a_vp));
|
|
|
|
un = VTOUNION(ap->a_vp);
|
|
if (dolock)
|
|
vn_lock(targetvp, LK_EXCLUSIVE | LK_RETRY, p);
|
|
else {
|
|
un = VTOUNION(ap->a_vp);
|
|
if ((un->un_flags & UN_ULOCK) == 0 &&
|
|
targetvp->v_data != NULL &&
|
|
((struct lock *)targetvp->v_data)->lk_lockholder
|
|
== curproc->p_pid &&
|
|
VOP_ISLOCKED(targetvp) != 0)
|
|
return 0; /* XXX */
|
|
|
|
FIXUP(un, p);
|
|
}
|
|
|
|
error = VOP_FSYNC(targetvp, ap->a_cred, ap->a_waitfor, p);
|
|
if (dolock)
|
|
VOP_UNLOCK(targetvp, 0, p);
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
union_remove(ap)
|
|
struct vop_remove_args /* {
|
|
struct vnode *a_dvp;
|
|
struct vnode *a_vp;
|
|
struct componentname *a_cnp;
|
|
} */ *ap;
|
|
{
|
|
struct union_node *dun = VTOUNION(ap->a_dvp);
|
|
struct union_node *un = VTOUNION(ap->a_vp);
|
|
struct componentname *cnp = ap->a_cnp;
|
|
struct proc *p = cnp->cn_proc;
|
|
int error;
|
|
|
|
if (dun->un_uppervp == NULLVP)
|
|
panic("union remove: null upper vnode");
|
|
|
|
if (un->un_uppervp != NULLVP) {
|
|
struct vnode *dvp = dun->un_uppervp;
|
|
struct vnode *vp = un->un_uppervp;
|
|
|
|
FIXUP(dun, p);
|
|
dun->un_flags |= UN_KLOCK;
|
|
VOP_UNLOCK(ap->a_dvp, 0, p);
|
|
FIXUP(un, p);
|
|
un->un_flags |= UN_KLOCK;
|
|
VOP_UNLOCK(ap->a_vp, 0, p);
|
|
|
|
if (union_dowhiteout(un, cnp->cn_cred, p))
|
|
cnp->cn_flags |= DOWHITEOUT;
|
|
error = VOP_REMOVE(dvp, vp, cnp);
|
|
#if 0
|
|
/* XXX */
|
|
if (!error)
|
|
union_removed_upper(un);
|
|
#endif
|
|
dun->un_flags |= UN_ULOCK;
|
|
un->un_flags |= UN_ULOCK;
|
|
} else {
|
|
FIXUP(dun, p);
|
|
error = union_mkwhiteout(
|
|
MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount),
|
|
dun->un_uppervp, ap->a_cnp, un->un_path);
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
union_link(ap)
|
|
struct vop_link_args /* {
|
|
struct vnode *a_tdvp;
|
|
struct vnode *a_vp;
|
|
struct componentname *a_cnp;
|
|
} */ *ap;
|
|
{
|
|
struct componentname *cnp = ap->a_cnp;
|
|
struct proc *p = cnp->cn_proc;
|
|
struct union_node *dun = VTOUNION(ap->a_tdvp);
|
|
struct vnode *vp;
|
|
struct vnode *tdvp;
|
|
int error = 0;
|
|
|
|
|
|
if (ap->a_tdvp->v_op != ap->a_vp->v_op) {
|
|
vp = ap->a_vp;
|
|
} else {
|
|
struct union_node *tun = VTOUNION(ap->a_vp);
|
|
if (tun->un_uppervp == NULLVP) {
|
|
vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, p);
|
|
if (dun->un_uppervp == tun->un_dirvp) {
|
|
dun->un_flags &= ~UN_ULOCK;
|
|
VOP_UNLOCK(dun->un_uppervp, 0, p);
|
|
}
|
|
error = union_copyup(tun, 1, cnp->cn_cred, p);
|
|
if (dun->un_uppervp == tun->un_dirvp) {
|
|
vn_lock(dun->un_uppervp,
|
|
LK_EXCLUSIVE | LK_RETRY, p);
|
|
dun->un_flags |= UN_ULOCK;
|
|
}
|
|
VOP_UNLOCK(ap->a_vp, 0, p);
|
|
}
|
|
vp = tun->un_uppervp;
|
|
}
|
|
|
|
tdvp = dun->un_uppervp;
|
|
if (tdvp == NULLVP)
|
|
error = EROFS;
|
|
|
|
if (error)
|
|
return (error);
|
|
|
|
FIXUP(dun, p);
|
|
dun->un_flags |= UN_KLOCK;
|
|
VOP_UNLOCK(ap->a_tdvp, 0, p);
|
|
|
|
error = VOP_LINK(tdvp, vp, cnp);
|
|
|
|
dun->un_flags |= UN_ULOCK;
|
|
|
|
return (error);
|
|
}
|
|
|
|
static 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) {
|
|
/*
|
|
* this should never happen in normal
|
|
* operation but might if there was
|
|
* a problem creating the top-level shadow
|
|
* directory.
|
|
*/
|
|
error = EXDEV;
|
|
goto bad;
|
|
}
|
|
|
|
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) {
|
|
/* XXX: should do a copyup */
|
|
error = EXDEV;
|
|
goto bad;
|
|
}
|
|
|
|
if (un->un_lowervp != NULLVP)
|
|
ap->a_fcnp->cn_flags |= DOWHITEOUT;
|
|
|
|
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) {
|
|
/*
|
|
* this should never happen in normal
|
|
* operation but might if there was
|
|
* a problem creating the top-level shadow
|
|
* directory.
|
|
*/
|
|
error = EXDEV;
|
|
goto bad;
|
|
}
|
|
|
|
tdvp = un->un_uppervp;
|
|
VREF(tdvp);
|
|
un->un_flags |= UN_KLOCK;
|
|
vput(ap->a_tdvp);
|
|
}
|
|
|
|
if (tvp != NULLVP && tvp->v_op == union_vnodeop_p) {
|
|
struct union_node *un = VTOUNION(tvp);
|
|
|
|
tvp = un->un_uppervp;
|
|
if (tvp != NULLVP) {
|
|
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 != NULLVP)
|
|
vput(tvp);
|
|
|
|
return (error);
|
|
}
|
|
|
|
static 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 *dun = VTOUNION(ap->a_dvp);
|
|
struct vnode *dvp = dun->un_uppervp;
|
|
struct componentname *cnp = ap->a_cnp;
|
|
struct proc *p = cnp->cn_proc;
|
|
|
|
if (dvp != NULLVP) {
|
|
struct vnode *vp;
|
|
int error;
|
|
|
|
FIXUP(dun, p);
|
|
dun->un_flags |= UN_KLOCK;
|
|
VOP_UNLOCK(ap->a_dvp, 0, p);
|
|
error = VOP_MKDIR(dvp, &vp, cnp, ap->a_vap);
|
|
if (error) {
|
|
dun->un_flags |= UN_ULOCK;
|
|
return (error);
|
|
}
|
|
|
|
VOP_UNLOCK(dvp, 0, p);
|
|
error = union_allocvp(ap->a_vpp, ap->a_dvp->v_mount, ap->a_dvp,
|
|
NULLVP, cnp, vp, NULLVP, 1);
|
|
if (error)
|
|
vput(vp);
|
|
vn_lock(ap->a_dvp, LK_EXCLUSIVE| LK_RETRY, p);
|
|
|
|
return (error);
|
|
}
|
|
|
|
return (EROFS);
|
|
}
|
|
|
|
static int
|
|
union_rmdir(ap)
|
|
struct vop_rmdir_args /* {
|
|
struct vnode *a_dvp;
|
|
struct vnode *a_vp;
|
|
struct componentname *a_cnp;
|
|
} */ *ap;
|
|
{
|
|
struct union_node *dun = VTOUNION(ap->a_dvp);
|
|
struct union_node *un = VTOUNION(ap->a_vp);
|
|
struct componentname *cnp = ap->a_cnp;
|
|
struct proc *p = cnp->cn_proc;
|
|
int error;
|
|
|
|
if (dun->un_uppervp == NULLVP)
|
|
panic("union rmdir: null upper vnode");
|
|
|
|
if (un->un_uppervp != NULLVP) {
|
|
struct vnode *dvp = dun->un_uppervp;
|
|
struct vnode *vp = un->un_uppervp;
|
|
|
|
FIXUP(dun, p);
|
|
dun->un_flags |= UN_KLOCK;
|
|
VOP_UNLOCK(ap->a_dvp, 0, p);
|
|
FIXUP(un, p);
|
|
un->un_flags |= UN_KLOCK;
|
|
VOP_UNLOCK(ap->a_vp, 0, p);
|
|
|
|
if (union_dowhiteout(un, cnp->cn_cred, p))
|
|
cnp->cn_flags |= DOWHITEOUT;
|
|
error = VOP_RMDIR(dvp, vp, ap->a_cnp);
|
|
#if 0
|
|
/* XXX */
|
|
if (!error)
|
|
union_removed_upper(un);
|
|
#endif
|
|
dun->un_flags |= UN_ULOCK;
|
|
un->un_flags |= UN_ULOCK;
|
|
} else {
|
|
FIXUP(dun, p);
|
|
error = union_mkwhiteout(
|
|
MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount),
|
|
dun->un_uppervp, ap->a_cnp, un->un_path);
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
static 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 *dun = VTOUNION(ap->a_dvp);
|
|
struct vnode *dvp = dun->un_uppervp;
|
|
struct componentname *cnp = ap->a_cnp;
|
|
struct proc *p = cnp->cn_proc;
|
|
|
|
if (dvp != NULLVP) {
|
|
struct vnode *vp;
|
|
int error;
|
|
|
|
FIXUP(dun, p);
|
|
dun->un_flags |= UN_KLOCK;
|
|
VOP_UNLOCK(ap->a_dvp, 0, p);
|
|
error = VOP_SYMLINK(dvp, &vp, cnp, ap->a_vap, ap->a_target);
|
|
dun->un_flags |= UN_ULOCK;
|
|
*ap->a_vpp = NULLVP;
|
|
return (error);
|
|
}
|
|
|
|
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.
|
|
*/
|
|
static int
|
|
union_readdir(ap)
|
|
struct vop_readdir_args /* {
|
|
struct vnode *a_vp;
|
|
struct uio *a_uio;
|
|
struct ucred *a_cred;
|
|
int *a_eofflag;
|
|
u_long *a_cookies;
|
|
int a_ncookies;
|
|
} */ *ap;
|
|
{
|
|
struct union_node *un = VTOUNION(ap->a_vp);
|
|
struct vnode *uvp = un->un_uppervp;
|
|
struct proc *p = ap->a_uio->uio_procp;
|
|
|
|
if (uvp == NULLVP)
|
|
return (0);
|
|
|
|
FIXUP(un, p);
|
|
ap->a_vp = uvp;
|
|
return (VCALL(uvp, VOFFSET(vop_readdir), ap));
|
|
}
|
|
|
|
static int
|
|
union_readlink(ap)
|
|
struct vop_readlink_args /* {
|
|
struct vnode *a_vp;
|
|
struct uio *a_uio;
|
|
struct ucred *a_cred;
|
|
} */ *ap;
|
|
{
|
|
int error;
|
|
struct uio *uio = ap->a_uio;
|
|
struct proc *p = uio->uio_procp;
|
|
struct vnode *vp = OTHERVP(ap->a_vp);
|
|
int dolock = (vp == LOWERVP(ap->a_vp));
|
|
|
|
if (dolock)
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
|
|
else
|
|
FIXUP(VTOUNION(ap->a_vp), p);
|
|
ap->a_vp = vp;
|
|
error = VCALL(vp, VOFFSET(vop_readlink), ap);
|
|
if (dolock)
|
|
VOP_UNLOCK(vp, 0, p);
|
|
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
union_abortop(ap)
|
|
struct vop_abortop_args /* {
|
|
struct vnode *a_dvp;
|
|
struct componentname *a_cnp;
|
|
} */ *ap;
|
|
{
|
|
int error;
|
|
struct componentname *cnp = ap->a_cnp;
|
|
struct proc *p = cnp->cn_proc;
|
|
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)
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
|
|
else
|
|
FIXUP(VTOUNION(ap->a_dvp), p);
|
|
}
|
|
ap->a_dvp = vp;
|
|
error = VCALL(vp, VOFFSET(vop_abortop), ap);
|
|
if (islocked && dolock)
|
|
VOP_UNLOCK(vp, 0, p);
|
|
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
union_inactive(ap)
|
|
struct vop_inactive_args /* {
|
|
struct vnode *a_vp;
|
|
struct proc *a_p;
|
|
} */ *ap;
|
|
{
|
|
struct vnode *vp = ap->a_vp;
|
|
struct proc *p = ap->a_p;
|
|
struct union_node *un = VTOUNION(vp);
|
|
struct vnode **vpp;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
|
|
if (un->un_dircache != 0) {
|
|
for (vpp = un->un_dircache; *vpp != NULLVP; vpp++)
|
|
vrele(*vpp);
|
|
free(un->un_dircache, M_TEMP);
|
|
un->un_dircache = 0;
|
|
}
|
|
|
|
VOP_UNLOCK(vp, 0, p);
|
|
|
|
if ((un->un_flags & UN_CACHED) == 0)
|
|
vgone(vp);
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
union_reclaim(ap)
|
|
struct vop_reclaim_args /* {
|
|
struct vnode *a_vp;
|
|
} */ *ap;
|
|
{
|
|
|
|
union_freevp(ap->a_vp);
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
union_lock(ap)
|
|
struct vop_lock_args *ap;
|
|
{
|
|
struct vnode *vp = ap->a_vp;
|
|
struct proc *p = ap->a_p;
|
|
int flags = ap->a_flags;
|
|
struct union_node *un;
|
|
int error;
|
|
|
|
vop_nolock(ap);
|
|
/*
|
|
* Need to do real lockmgr-style locking here.
|
|
* in the mean time, draining won't work quite right,
|
|
* which could lead to a few race conditions.
|
|
* the following test was here, but is not quite right, we
|
|
* still need to take the lock:
|
|
if ((flags & LK_TYPE_MASK) == LK_DRAIN)
|
|
return (0);
|
|
*/
|
|
flags &= ~LK_INTERLOCK;
|
|
|
|
start:
|
|
un = VTOUNION(vp);
|
|
|
|
if (un->un_uppervp != NULLVP) {
|
|
if (((un->un_flags & UN_ULOCK) == 0) &&
|
|
(vp->v_usecount != 0)) {
|
|
error = vn_lock(un->un_uppervp, flags, p);
|
|
if (error)
|
|
return (error);
|
|
un->un_flags |= UN_ULOCK;
|
|
}
|
|
#ifdef DIAGNOSTIC
|
|
if (un->un_flags & UN_KLOCK) {
|
|
vprint("dangling upper lock", vp);
|
|
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;
|
|
tsleep((caddr_t)&un->un_flags, PINOD, "unionlk2", 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);
|
|
}
|
|
|
|
/*
|
|
* When operations want to vput() a union node yet retain a lock on
|
|
* the upper vnode (say, to do some further operations like link(),
|
|
* mkdir(), ...), they set UN_KLOCK on the union node, then call
|
|
* vput() which calls VOP_UNLOCK() and comes here. union_unlock()
|
|
* unlocks the union node (leaving the upper vnode alone), clears the
|
|
* KLOCK flag, and then returns to vput(). The caller then does whatever
|
|
* is left to do with the upper vnode, and ensures that it gets unlocked.
|
|
*
|
|
* If UN_KLOCK isn't set, then the upper vnode is unlocked here.
|
|
*/
|
|
static int
|
|
union_unlock(ap)
|
|
struct vop_unlock_args /* {
|
|
struct vnode *a_vp;
|
|
int a_flags;
|
|
struct proc *a_p;
|
|
} */ *ap;
|
|
{
|
|
struct union_node *un = VTOUNION(ap->a_vp);
|
|
struct proc *p = ap->a_p;
|
|
|
|
#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, 0, p);
|
|
|
|
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
|
|
vop_nounlock(ap);
|
|
|
|
return (0);
|
|
}
|
|
|
|
static 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;
|
|
int *a_runb;
|
|
} */ *ap;
|
|
{
|
|
int error;
|
|
struct proc *p = curproc; /* XXX */
|
|
struct vnode *vp = OTHERVP(ap->a_vp);
|
|
int dolock = (vp == LOWERVP(ap->a_vp));
|
|
|
|
if (dolock)
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
|
|
else
|
|
FIXUP(VTOUNION(ap->a_vp), p);
|
|
ap->a_vp = vp;
|
|
error = VCALL(vp, VOFFSET(vop_bmap), ap);
|
|
if (dolock)
|
|
VOP_UNLOCK(vp, 0, p);
|
|
|
|
return (error);
|
|
}
|
|
|
|
static 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));
|
|
if (UPPERVP(vp) != NULLVP)
|
|
vprint("union: upper", UPPERVP(vp));
|
|
if (LOWERVP(vp) != NULLVP)
|
|
vprint("union: lower", LOWERVP(vp));
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
union_islocked(ap)
|
|
struct vop_islocked_args /* {
|
|
struct vnode *a_vp;
|
|
} */ *ap;
|
|
{
|
|
|
|
return ((VTOUNION(ap->a_vp)->un_flags & UN_LOCKED) ? 1 : 0);
|
|
}
|
|
|
|
static int
|
|
union_pathconf(ap)
|
|
struct vop_pathconf_args /* {
|
|
struct vnode *a_vp;
|
|
int a_name;
|
|
int *a_retval;
|
|
} */ *ap;
|
|
{
|
|
int error;
|
|
struct proc *p = curproc; /* XXX */
|
|
struct vnode *vp = OTHERVP(ap->a_vp);
|
|
int dolock = (vp == LOWERVP(ap->a_vp));
|
|
|
|
if (dolock)
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
|
|
else
|
|
FIXUP(VTOUNION(ap->a_vp), p);
|
|
ap->a_vp = vp;
|
|
error = VCALL(vp, VOFFSET(vop_pathconf), ap);
|
|
if (dolock)
|
|
VOP_UNLOCK(vp, 0, p);
|
|
|
|
return (error);
|
|
}
|
|
|
|
static 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;
|
|
{
|
|
register struct vnode *ovp = OTHERVP(ap->a_vp);
|
|
|
|
ap->a_vp = ovp;
|
|
return (VCALL(ovp, VOFFSET(vop_advlock), ap));
|
|
}
|
|
|
|
|
|
/*
|
|
* XXX - vop_strategy must be hand coded because it has no
|
|
* vnode in its arguments.
|
|
* This goes away with a merged VM/buffer cache.
|
|
*/
|
|
static int
|
|
union_strategy(ap)
|
|
struct vop_strategy_args /* {
|
|
struct vnode *a_vp;
|
|
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->b_vp, bp);
|
|
bp->b_vp = savedvp;
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Global vfs data structures
|
|
*/
|
|
vop_t **union_vnodeop_p;
|
|
static struct vnodeopv_entry_desc union_vnodeop_entries[] = {
|
|
{ &vop_default_desc, (vop_t *) vop_defaultop },
|
|
{ &vop_abortop_desc, (vop_t *) union_abortop },
|
|
{ &vop_access_desc, (vop_t *) union_access },
|
|
{ &vop_advlock_desc, (vop_t *) union_advlock },
|
|
{ &vop_bmap_desc, (vop_t *) union_bmap },
|
|
{ &vop_close_desc, (vop_t *) union_close },
|
|
{ &vop_create_desc, (vop_t *) union_create },
|
|
{ &vop_fsync_desc, (vop_t *) union_fsync },
|
|
{ &vop_getattr_desc, (vop_t *) union_getattr },
|
|
{ &vop_inactive_desc, (vop_t *) union_inactive },
|
|
{ &vop_ioctl_desc, (vop_t *) union_ioctl },
|
|
{ &vop_islocked_desc, (vop_t *) union_islocked },
|
|
{ &vop_lease_desc, (vop_t *) union_lease },
|
|
{ &vop_link_desc, (vop_t *) union_link },
|
|
{ &vop_lock_desc, (vop_t *) union_lock },
|
|
{ &vop_lookup_desc, (vop_t *) union_lookup },
|
|
{ &vop_mkdir_desc, (vop_t *) union_mkdir },
|
|
{ &vop_mknod_desc, (vop_t *) union_mknod },
|
|
{ &vop_mmap_desc, (vop_t *) union_mmap },
|
|
{ &vop_open_desc, (vop_t *) union_open },
|
|
{ &vop_pathconf_desc, (vop_t *) union_pathconf },
|
|
{ &vop_poll_desc, (vop_t *) union_poll },
|
|
{ &vop_print_desc, (vop_t *) union_print },
|
|
{ &vop_read_desc, (vop_t *) union_read },
|
|
{ &vop_readdir_desc, (vop_t *) union_readdir },
|
|
{ &vop_readlink_desc, (vop_t *) union_readlink },
|
|
{ &vop_reclaim_desc, (vop_t *) union_reclaim },
|
|
{ &vop_remove_desc, (vop_t *) union_remove },
|
|
{ &vop_rename_desc, (vop_t *) union_rename },
|
|
{ &vop_revoke_desc, (vop_t *) union_revoke },
|
|
{ &vop_rmdir_desc, (vop_t *) union_rmdir },
|
|
{ &vop_setattr_desc, (vop_t *) union_setattr },
|
|
{ &vop_strategy_desc, (vop_t *) union_strategy },
|
|
{ &vop_symlink_desc, (vop_t *) union_symlink },
|
|
{ &vop_unlock_desc, (vop_t *) union_unlock },
|
|
{ &vop_whiteout_desc, (vop_t *) union_whiteout },
|
|
{ &vop_write_desc, (vop_t *) union_write },
|
|
{ NULL, NULL }
|
|
};
|
|
static struct vnodeopv_desc union_vnodeop_opv_desc =
|
|
{ &union_vnodeop_p, union_vnodeop_entries };
|
|
|
|
VNODEOP_SET(union_vnodeop_opv_desc);
|