426 lines
10 KiB
C
426 lines
10 KiB
C
/*
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* Copyright (c) 1992, 1993, 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 donated 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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* @(#)null_vfsops.c 8.2 (Berkeley) 1/21/94
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*
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* @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
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* $Id: null_vfsops.c,v 1.20 1997/10/12 20:24:50 phk Exp $
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*/
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/*
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* Null Layer
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* (See null_vnops.c for a description of what this does.)
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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/kernel.h>
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#include <sys/proc.h>
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#include <sys/malloc.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 <miscfs/nullfs/null.h>
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static MALLOC_DEFINE(M_NULLFSMNT, "NULLFS mount", "NULLFS mount structure");
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static int nullfs_fhtovp __P((struct mount *mp, struct fid *fidp,
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struct sockaddr *nam, struct vnode **vpp,
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int *exflagsp, struct ucred **credanonp));
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static int nullfs_mount __P((struct mount *mp, char *path, caddr_t data,
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struct nameidata *ndp, struct proc *p));
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static int nullfs_quotactl __P((struct mount *mp, int cmd, uid_t uid,
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caddr_t arg, struct proc *p));
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static int nullfs_root __P((struct mount *mp, struct vnode **vpp));
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static int nullfs_start __P((struct mount *mp, int flags, struct proc *p));
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static int nullfs_statfs __P((struct mount *mp, struct statfs *sbp,
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struct proc *p));
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static int nullfs_sync __P((struct mount *mp, int waitfor,
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struct ucred *cred, struct proc *p));
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static int nullfs_unmount __P((struct mount *mp, int mntflags,
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struct proc *p));
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static int nullfs_vget __P((struct mount *mp, ino_t ino,
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struct vnode **vpp));
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static int nullfs_vptofh __P((struct vnode *vp, struct fid *fhp));
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/*
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* Mount null layer
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*/
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static int
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nullfs_mount(mp, path, data, ndp, p)
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struct mount *mp;
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char *path;
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caddr_t data;
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struct nameidata *ndp;
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struct proc *p;
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{
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int error = 0;
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struct null_args args;
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struct vnode *lowerrootvp, *vp;
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struct vnode *nullm_rootvp;
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struct null_mount *xmp;
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u_int size;
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int isvnunlocked = 0;
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#ifdef NULLFS_DIAGNOSTIC
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printf("nullfs_mount(mp = %x)\n", mp);
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#endif
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/*
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* Update is a no-op
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*/
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if (mp->mnt_flag & MNT_UPDATE) {
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return (EOPNOTSUPP);
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/* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/
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}
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/*
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* Get argument
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*/
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error = copyin(data, (caddr_t)&args, sizeof(struct null_args));
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if (error)
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return (error);
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/*
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* Unlock lower node to avoid deadlock.
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* (XXX) VOP_ISLOCKED is needed?
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*/
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if ((mp->mnt_vnodecovered->v_op == null_vnodeop_p) &&
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VOP_ISLOCKED(mp->mnt_vnodecovered)) {
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VOP_UNLOCK(mp->mnt_vnodecovered, 0, p);
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isvnunlocked = 1;
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}
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/*
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* Find lower node
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*/
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NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
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UIO_USERSPACE, args.target, p);
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error = namei(ndp);
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/*
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* Re-lock vnode.
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*/
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if (isvnunlocked && !VOP_ISLOCKED(mp->mnt_vnodecovered))
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vn_lock(mp->mnt_vnodecovered, LK_EXCLUSIVE | LK_RETRY, p);
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if (error)
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return (error);
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/*
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* Sanity check on lower vnode
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*/
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lowerrootvp = ndp->ni_vp;
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vrele(ndp->ni_dvp);
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ndp->ni_dvp = NULLVP;
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/*
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* Check multi null mount to avoid `lock against myself' panic.
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*/
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if (lowerrootvp == VTONULL(mp->mnt_vnodecovered)->null_lowervp) {
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#ifdef DIAGNOSTIC
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printf("nullfs_mount: multi null mount?\n");
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#endif
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return (EDEADLK);
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}
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xmp = (struct null_mount *) malloc(sizeof(struct null_mount),
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M_NULLFSMNT, M_WAITOK); /* XXX */
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/*
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* Save reference to underlying FS
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*/
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xmp->nullm_vfs = lowerrootvp->v_mount;
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/*
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* Save reference. Each mount also holds
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* a reference on the root vnode.
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*/
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error = null_node_create(mp, lowerrootvp, &vp);
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/*
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* Unlock the node (either the lower or the alias)
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*/
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VOP_UNLOCK(vp, 0, p);
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/*
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* Make sure the node alias worked
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*/
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if (error) {
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vrele(lowerrootvp);
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free(xmp, M_NULLFSMNT); /* XXX */
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return (error);
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}
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/*
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* Keep a held reference to the root vnode.
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* It is vrele'd in nullfs_unmount.
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*/
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nullm_rootvp = vp;
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nullm_rootvp->v_flag |= VROOT;
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xmp->nullm_rootvp = nullm_rootvp;
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if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
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mp->mnt_flag |= MNT_LOCAL;
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mp->mnt_data = (qaddr_t) xmp;
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vfs_getnewfsid(mp);
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(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
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bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
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(void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
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&size);
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bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
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(void)nullfs_statfs(mp, &mp->mnt_stat, p);
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#ifdef NULLFS_DIAGNOSTIC
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printf("nullfs_mount: lower %s, alias at %s\n",
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mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
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#endif
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return (0);
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}
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/*
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* VFS start. Nothing needed here - the start routine
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* on the underlying filesystem will have been called
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* when that filesystem was mounted.
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*/
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static int
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nullfs_start(mp, flags, p)
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struct mount *mp;
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int flags;
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struct proc *p;
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{
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return (0);
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/* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */
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}
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/*
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* Free reference to null layer
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*/
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static int
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nullfs_unmount(mp, mntflags, p)
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struct mount *mp;
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int mntflags;
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struct proc *p;
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{
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struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
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int error;
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int flags = 0;
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#ifdef NULLFS_DIAGNOSTIC
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printf("nullfs_unmount(mp = %x)\n", mp);
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#endif
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if (mntflags & MNT_FORCE)
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flags |= FORCECLOSE;
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/*
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* Clear out buffer cache. I don't think we
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* ever get anything cached at this level at the
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* moment, but who knows...
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*/
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#if 0
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mntflushbuf(mp, 0);
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if (mntinvalbuf(mp, 1))
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return (EBUSY);
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#endif
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if (nullm_rootvp->v_usecount > 1)
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return (EBUSY);
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error = vflush(mp, nullm_rootvp, flags);
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if (error)
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return (error);
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#ifdef NULLFS_DIAGNOSTIC
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vprint("alias root of lower", nullm_rootvp);
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#endif
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/*
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* Release reference on underlying root vnode
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*/
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vrele(nullm_rootvp);
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/*
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* And blow it away for future re-use
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*/
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vgone(nullm_rootvp);
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/*
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* Finally, throw away the null_mount structure
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*/
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free(mp->mnt_data, M_NULLFSMNT); /* XXX */
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mp->mnt_data = 0;
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return 0;
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}
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static int
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nullfs_root(mp, vpp)
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struct mount *mp;
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struct vnode **vpp;
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{
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struct proc *p = curproc; /* XXX */
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struct vnode *vp;
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#ifdef NULLFS_DIAGNOSTIC
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printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp,
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MOUNTTONULLMOUNT(mp)->nullm_rootvp,
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NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
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);
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#endif
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/*
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* Return locked reference to root.
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*/
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vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
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VREF(vp);
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if (VOP_ISLOCKED(vp)) {
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/*
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* XXX
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* Should we check type of node?
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*/
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#ifdef DIAGNOSTIC
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printf("nullfs_root: multi null mount?\n");
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#endif
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vrele(vp);
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return (EDEADLK);
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} else
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
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*vpp = vp;
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return 0;
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}
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static int
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nullfs_quotactl(mp, cmd, uid, arg, p)
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struct mount *mp;
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int cmd;
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uid_t uid;
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caddr_t arg;
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struct proc *p;
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{
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return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p);
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}
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static int
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nullfs_statfs(mp, sbp, p)
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struct mount *mp;
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struct statfs *sbp;
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struct proc *p;
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{
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int error;
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struct statfs mstat;
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#ifdef NULLFS_DIAGNOSTIC
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printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp,
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MOUNTTONULLMOUNT(mp)->nullm_rootvp,
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NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
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);
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#endif
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bzero(&mstat, sizeof(mstat));
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error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p);
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if (error)
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return (error);
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/* now copy across the "interesting" information and fake the rest */
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sbp->f_type = mstat.f_type;
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sbp->f_flags = mstat.f_flags;
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sbp->f_bsize = mstat.f_bsize;
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sbp->f_iosize = mstat.f_iosize;
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sbp->f_blocks = mstat.f_blocks;
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sbp->f_bfree = mstat.f_bfree;
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sbp->f_bavail = mstat.f_bavail;
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sbp->f_files = mstat.f_files;
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sbp->f_ffree = mstat.f_ffree;
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if (sbp != &mp->mnt_stat) {
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bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
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bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
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bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
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}
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return (0);
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}
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static int
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nullfs_sync(mp, waitfor, cred, p)
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struct mount *mp;
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int waitfor;
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struct ucred *cred;
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struct proc *p;
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{
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/*
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* XXX - Assumes no data cached at null layer.
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*/
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return (0);
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}
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static int
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nullfs_vget(mp, ino, vpp)
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struct mount *mp;
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ino_t ino;
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struct vnode **vpp;
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{
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return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp);
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}
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static int
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nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
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struct mount *mp;
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struct fid *fidp;
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struct sockaddr *nam;
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struct vnode **vpp;
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int *exflagsp;
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struct ucred**credanonp;
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{
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return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam,
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vpp, exflagsp, credanonp);
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}
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static int
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nullfs_vptofh(vp, fhp)
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struct vnode *vp;
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struct fid *fhp;
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{
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return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp);
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}
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static struct vfsops null_vfsops = {
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nullfs_mount,
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nullfs_start,
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nullfs_unmount,
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nullfs_root,
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nullfs_quotactl,
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nullfs_statfs,
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nullfs_sync,
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nullfs_vget,
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nullfs_fhtovp,
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nullfs_vptofh,
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nullfs_init,
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};
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VFS_SET(null_vfsops, null, MOUNT_NULL, VFCF_LOOPBACK);
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