34bdbbd0de
a complement to all ops that return a vpp, VFS_VRELE. This is initially only for file systems that implement the following ops that do a WILLRELE: vop_create, vop_whiteout, vop_mknod, vop_remove, vop_link, vop_rename, vop_mkdir, vop_rmdir, vop_symlink This is initial DNA that doesn't do anything yet. VFS_VRELE is implemented but not called. A default vfs_vrele was created for fs implementations that use the standard vnode management routines. VFS_VRELE implementations were made for the following file systems: Standard (vfs_vrele) ffs mfs nfs msdosfs devfs ext2fs Custom union umapfs Just EOPNOTSUPP fdesc procfs kernfs portal cd9660 These implementations may change as VOP changes are implemented. In the next phase, in the vop implementations calls to vrele and the vrele part of vput will be moved to the top layer vfs_vnops and made visible to all layers. vput will be replaced by unlock in these cases. Unlocking will still be done in the per fs layer but the refcount decrement will be triggered at the top because it doesn't hurt to hold a vnode reference a little longer. This will have minimal impact on the structure of the existing code. This will only be done for vnode arguments that are released by the various fs vop implementations. Wider use of VFS_VRELE will likely require restructuring of the code. Reviewed by: phk, dyson, terry et. al. Submitted by: Michael Hancock <michaelh@cet.co.jp>
448 lines
11 KiB
C
448 lines
11 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 1.24 1998/02/06 12:13:40 eivind 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 "opt_debug_nullfs.h"
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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_vrele __P((struct mount *mp, struct vnode *vp));
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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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/*
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* Complement to all vpp returning ops.
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* XXX - initially only to get rid of WILLRELE.
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*/
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/* ARGSUSED */
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static int
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nullfs_vrele(mp, vp)
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struct mount *mp;
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struct vnode *vp;
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{
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int error = 0;
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error = VFS_VRELE(MOUNTTONULLMOUNT(mp)->nullm_vfs,
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NULLVPTOLOWERVP(vp));
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vrele(vp);
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return (error);
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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_vrele,
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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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