9727219460
the reality (remove duplicate one in nullfs, merge some differences from it), KNF, improve and update some comments, add few KASSERT()s, remove unused declarations, avoid double inclusion of headers, misc. No functional changes.
308 lines
8.6 KiB
C
308 lines
8.6 KiB
C
/* $NetBSD: layer_vfsops.c,v 1.33 2010/07/02 03:16:01 rmind Exp $ */
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/*
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* Copyright (c) 1999 National Aeronautics & Space Administration
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* All rights reserved.
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*
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* This software was written by William Studenmund of the
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* Numerical Aerospace Simulation Facility, NASA Ames Research Center.
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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. Neither the name of the National Aeronautics & Space Administration
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* nor the names of its contributors may be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NATIONAL AERONAUTICS & SPACE ADMINISTRATION
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE ADMINISTRATION OR CONTRIB-
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* UTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
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* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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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. 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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* from: Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp
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* from: @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
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* @(#)null_vfsops.c 8.7 (Berkeley) 5/14/95
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*/
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/*
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* Generic layer VFS operations.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: layer_vfsops.c,v 1.33 2010/07/02 03:16:01 rmind Exp $");
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#include <sys/param.h>
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#include <sys/sysctl.h>
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#include <sys/systm.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/kauth.h>
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#include <sys/module.h>
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#include <miscfs/genfs/layer.h>
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#include <miscfs/genfs/layer_extern.h>
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MODULE(MODULE_CLASS_MISC, layerfs, NULL);
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static int
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layerfs_modcmd(modcmd_t cmd, void *arg)
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{
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switch (cmd) {
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case MODULE_CMD_INIT:
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return 0;
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case MODULE_CMD_FINI:
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return 0;
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default:
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return ENOTTY;
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}
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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 on the underlying
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* filesystem will have been called when that filesystem was mounted.
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*/
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int
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layerfs_start(struct mount *mp, int flags)
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{
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#ifdef notyet
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return VFS_START(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, flags);
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#else
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return 0;
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#endif
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}
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int
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layerfs_root(struct mount *mp, struct vnode **vpp)
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{
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struct vnode *vp;
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vp = MOUNTTOLAYERMOUNT(mp)->layerm_rootvp;
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if (vp == NULL) {
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*vpp = NULL;
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return EINVAL;
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}
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/*
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* Return root vnode with locked and with a reference held.
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*/
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vref(vp);
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
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*vpp = vp;
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return 0;
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}
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int
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layerfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg)
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{
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return VFS_QUOTACTL(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, cmd, uid, arg);
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}
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int
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layerfs_statvfs(struct mount *mp, struct statvfs *sbp)
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{
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struct statvfs *sbuf;
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int error;
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sbuf = kmem_zalloc(sizeof(*sbuf), KM_SLEEP);
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if (sbuf == NULL) {
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return ENOMEM;
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}
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error = VFS_STATVFS(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, sbuf);
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if (error) {
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goto done;
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}
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/* Copy across the relevant data and fake the rest. */
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sbp->f_flag = sbuf->f_flag;
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sbp->f_bsize = sbuf->f_bsize;
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sbp->f_frsize = sbuf->f_frsize;
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sbp->f_iosize = sbuf->f_iosize;
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sbp->f_blocks = sbuf->f_blocks;
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sbp->f_bfree = sbuf->f_bfree;
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sbp->f_bavail = sbuf->f_bavail;
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sbp->f_bresvd = sbuf->f_bresvd;
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sbp->f_files = sbuf->f_files;
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sbp->f_ffree = sbuf->f_ffree;
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sbp->f_favail = sbuf->f_favail;
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sbp->f_fresvd = sbuf->f_fresvd;
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sbp->f_namemax = sbuf->f_namemax;
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copy_statvfs_info(sbp, mp);
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done:
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kmem_free(sbuf, sizeof(*sbuf));
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return error;
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}
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int
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layerfs_sync(struct mount *mp, int waitfor,
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kauth_cred_t cred)
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{
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/*
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* XXX - Assumes no data cached at layer.
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*/
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return 0;
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}
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int
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layerfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
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{
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struct vnode *vp;
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int error;
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error = VFS_VGET(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, ino, &vp);
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if (error) {
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*vpp = NULL;
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return error;
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}
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error = layer_node_create(mp, vp, vpp);
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if (error) {
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vput(vp);
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*vpp = NULL;
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return error;
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}
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return 0;
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}
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int
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layerfs_fhtovp(struct mount *mp, struct fid *fidp, struct vnode **vpp)
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{
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struct vnode *vp;
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int error;
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error = VFS_FHTOVP(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, fidp, &vp);
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if (error) {
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return error;
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}
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error = layer_node_create(mp, vp, vpp);
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if (error) {
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vput(vp);
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*vpp = NULL;
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return (error);
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}
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return 0;
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}
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int
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layerfs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
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{
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return VFS_VPTOFH(LAYERVPTOLOWERVP(vp), fhp, fh_size);
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}
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/*
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* layerfs_snapshot - handle a snapshot through a layered file system
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*
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* At present, we do NOT support snapshotting through a layered file
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* system as the ffs implementation changes v_vnlock of the snapshot
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* vnodes to point to one common lock. As there is no way for us to
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* absolutely pass this change up the stack, a layered file system
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* would end up referencing the wrong lock.
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*
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* This routine serves as a central resource for this behavior; all
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* layered file systems don't need to worry about the above. Also, if
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* things get fixed, all layers get the benefit.
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*/
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int
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layerfs_snapshot(struct mount *mp, struct vnode *vp,
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struct timespec *ts)
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{
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return EOPNOTSUPP;
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}
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SYSCTL_SETUP(sysctl_vfs_layerfs_setup, "sysctl vfs.layerfs subtree setup")
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{
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const struct sysctlnode *layerfs_node = NULL;
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sysctl_createv(clog, 0, NULL, NULL,
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CTLFLAG_PERMANENT,
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CTLTYPE_NODE, "vfs", NULL,
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NULL, 0, NULL, 0,
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CTL_VFS, CTL_EOL);
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sysctl_createv(clog, 0, NULL, &layerfs_node,
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CTLFLAG_PERMANENT,
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CTLTYPE_NODE, "layerfs",
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SYSCTL_DESCR("Generic layered file system"),
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NULL, 0, NULL, 0,
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CTL_VFS, CTL_CREATE);
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#ifdef LAYERFS_DIAGNOSTIC
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sysctl_createv(clog, 0, &layerfs_node, NULL,
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CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
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CTLTYPE_INT,
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"debug",
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SYSCTL_DESCR("Verbose debugging messages"),
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NULL, 0, &layerfs_debug, 0,
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CTL_CREATE, CTL_EOL);
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#endif
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/*
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* other subtrees should really be aliases to this, but since
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* they can't tell if layerfs has been instantiated yet, they
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* can't do that...not easily. not yet. :-)
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*/
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}
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int
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layerfs_renamelock_enter(struct mount *mp)
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{
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return VFS_RENAMELOCK_ENTER(MOUNTTOLAYERMOUNT(mp)->layerm_vfs);
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}
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void
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layerfs_renamelock_exit(struct mount *mp)
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{
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VFS_RENAMELOCK_EXIT(MOUNTTOLAYERMOUNT(mp)->layerm_vfs);
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}
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