6753c74560
fix for layered-file-removal. It will work for the case of accessing and deleting a file through the layered file system. Accessing via the layer and deleting on the underlying still won't work, nor will accessing via complicated structures (like two umap layers over a given file systems). We still need VOP_UPCALL(), but this is better than things were before. This patch has been discussed off & on for a while. This incarnation was tested by hannken at netbsd dot org.
164 lines
6.4 KiB
C
164 lines
6.4 KiB
C
/* $NetBSD: layer.h,v 1.6 2004/05/28 18:55:20 wrstuden 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
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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.h,v 1.8 1992/05/30 10:05:43 jsp Exp
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* @(#)null.h 8.2 (Berkeley) 1/21/94
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*/
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#ifndef _MISCFS_GENFS_LAYER_H_
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#define _MISCFS_GENFS_LAYER_H_
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struct layer_args {
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char *target; /* Target of loopback */
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struct export_args export; /* network export info */
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};
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#ifdef _KERNEL
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struct layer_node;
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LIST_HEAD(layer_node_hashhead, layer_node);
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struct layer_mount {
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struct mount *layerm_vfs;
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struct vnode *layerm_rootvp; /* Ref to root layer_node */
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struct netexport layerm_export; /* export info */
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u_int layerm_flags; /* mount point layer flags */
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u_int layerm_size; /* size of fs's struct node */
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enum vtype layerm_tag; /* vtag of our vnodes */
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int /* bypass routine for this mount */
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(*layerm_bypass) __P((void *));
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int (*layerm_alloc) /* alloc a new layer node */
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__P((struct mount *, struct vnode *,
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struct vnode **));
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int (**layerm_vnodeop_p) /* ops for our nodes */
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__P((void *));
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struct layer_node_hashhead /* head of hash list for layer_nodes */
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*layerm_node_hashtbl;
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u_long layerm_node_hash; /* hash mask for hash chain */
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struct simplelock layerm_hashlock; /* interlock for hash chain. */
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};
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#define LAYERFS_MFLAGS 0x00000fff /* reserved layer mount flags */
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#define LAYERFS_MBYPASSDEBUG 0x00000001
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/*
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* A cache of vnode references
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*/
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struct layer_node {
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LIST_ENTRY(layer_node) layer_hash; /* Hash list */
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struct vnode *layer_lowervp; /* VREFed once */
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struct vnode *layer_vnode; /* Back pointer */
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unsigned int layer_flags; /* locking, etc. */
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};
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#define LAYERFS_RESFLAGS 0x00000fff /* flags reserved for layerfs */
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#define LAYERFS_REMOVED 0x00000001 /* Did a remove on this node */
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/*
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* The following macros handle upperfs-specific locking. They are needed
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* when the lowerfs does not export a struct lock for locking use by the
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* upper layers. These macros are inteded for adjusting the upperfs
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* struct lock to reflect changes in the underlying vnode's lock state.
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*/
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#define LAYERFS_UPPERLOCK(v, f, r) do { \
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if ((v)->v_vnlock == NULL) \
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r = lockmgr(&(v)->v_lock, (f), &(v)->v_interlock); \
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else \
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r = 0; \
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} while (0)
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#define LAYERFS_UPPERUNLOCK(v, f, r) do { \
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if ((v)->v_vnlock == NULL) \
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r = lockmgr(&(v)->v_lock, (f) | LK_RELEASE, &(v)->v_interlock); \
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else \
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r = 0; \
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} while (0)
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#define LAYERFS_UPPERISLOCKED(v, r) do { \
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if ((v)->v_vnlock == NULL) \
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r = lockstatus(&(v)->v_lock); \
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else \
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r = -1; \
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} while (0)
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#define LAYERFS_DO_BYPASS(vp, ap) \
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(*MOUNTTOLAYERMOUNT((vp)->v_mount)->layerm_bypass)((ap))
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extern struct vnode *layer_checkvp __P((struct vnode *vp, char *fil, int lno));
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#define MOUNTTOLAYERMOUNT(mp) ((struct layer_mount *)((mp)->mnt_data))
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#define VTOLAYER(vp) ((struct layer_node *)(vp)->v_data)
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#define LAYERTOV(xp) ((xp)->layer_vnode)
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#ifdef LAYERFS_DIAGNOSTIC
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#define LAYERVPTOLOWERVP(vp) layer_checkvp((vp), __FILE__, __LINE__)
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#else
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#define LAYERVPTOLOWERVP(vp) (VTOLAYER(vp)->layer_lowervp)
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#endif
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#endif /* _KERNEL */
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#endif /* _MISCFS_GENFS_LAYER_H_ */
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