NetBSD/sys/miscfs/genfs/layer.h
jmmv 2a3e5eeb7c Apply the NFS exports list rototill patch:
- Remove all NFS related stuff from file system specific code.
- Drop the vfs_checkexp hook and generalize it in the new nfs_check_export
  function, thus removing redundancy from all file systems.
- Move all NFS export-related stuff from kern/vfs_subr.c to the new
  file sys/nfs/nfs_export.c.  The former was becoming large and its code
  is always compiled, regardless of the build options.  Using the latter,
  the code is only compiled in when NFSSERVER is enabled.  While doing this,
  also make some functions in nfs_subs.c conditional to NFSSERVER.
- Add a new command in nfssvc(2), called NFSSVC_SETEXPORTSLIST, that takes a
  path and a set of export entries.  At the moment it can only clear the
  exports list or append entries, one by one, but it is done in a way that
  allows setting the whole set of entries atomically in the future (see the
  comment in mountd_set_exports_list or in doc/TODO).
- Change mountd(8) to use the nfssvc(2) system call instead of mount(2) so
  that it becomes file system agnostic.  In fact, all this whole thing was
  done to remove a 'XXX' block from this utility!
- Change the mount*, newfs and fsck* userland utilities to not deal with NFS
  exports initialization; done internally by the kernel when initializing
  the NFS support for each file system.
- Implement an interface for VFS (called VFS hooks) so that several kernel
  subsystems can run arbitrary code upon receipt of specific VFS events.
  At the moment, this only provides support for unmount and is used to
  destroy NFS exports lists from the file systems being unmounted, though it
  has room for extension.

Thanks go to yamt@, chs@, thorpej@, wrstuden@ and others for their comments
and advice in the development of this patch.
2005-09-23 12:10:31 +00:00

164 lines
6.4 KiB
C

/* $NetBSD: layer.h,v 1.9 2005/09/23 12:10:33 jmmv Exp $ */
/*
* Copyright (c) 1999 National Aeronautics & Space Administration
* All rights reserved.
*
* This software was written by William Studenmund of the
* Numerical Aerospace Simulation Facility, NASA Ames Research Center.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the National Aeronautics & Space Administration
* nor the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NATIONAL AERONAUTICS & SPACE ADMINISTRATION
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE ADMINISTRATION OR CONTRIB-
* UTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: Id: lofs.h,v 1.8 1992/05/30 10:05:43 jsp Exp
* @(#)null.h 8.2 (Berkeley) 1/21/94
*/
#ifndef _MISCFS_GENFS_LAYER_H_
#define _MISCFS_GENFS_LAYER_H_
struct layer_args {
char *target; /* Target of loopback */
struct compat_export_args _pad1; /* compat with old userland tools */
};
#ifdef _KERNEL
struct layer_node;
LIST_HEAD(layer_node_hashhead, layer_node);
struct layer_mount {
struct mount *layerm_vfs;
struct vnode *layerm_rootvp; /* Ref to root layer_node */
u_int layerm_flags; /* mount point layer flags */
u_int layerm_size; /* size of fs's struct node */
enum vtype layerm_tag; /* vtag of our vnodes */
int /* bypass routine for this mount */
(*layerm_bypass)(void *);
int (*layerm_alloc) /* alloc a new layer node */
(struct mount *, struct vnode *,
struct vnode **);
int (**layerm_vnodeop_p) /* ops for our nodes */
(void *);
struct layer_node_hashhead /* head of hash list for layer_nodes */
*layerm_node_hashtbl;
u_long layerm_node_hash; /* hash mask for hash chain */
struct simplelock layerm_hashlock; /* interlock for hash chain. */
};
#define LAYERFS_MFLAGS 0x00000fff /* reserved layer mount flags */
#define LAYERFS_MBYPASSDEBUG 0x00000001
/*
* A cache of vnode references
*/
struct layer_node {
LIST_ENTRY(layer_node) layer_hash; /* Hash list */
struct vnode *layer_lowervp; /* VREFed once */
struct vnode *layer_vnode; /* Back pointer */
unsigned int layer_flags; /* locking, etc. */
};
#define LAYERFS_RESFLAGS 0x00000fff /* flags reserved for layerfs */
#define LAYERFS_REMOVED 0x00000001 /* Did a remove on this node */
/*
* The following macros handle upperfs-specific locking. They are needed
* when the lowerfs does not export a struct lock for locking use by the
* upper layers. These macros are inteded for adjusting the upperfs
* struct lock to reflect changes in the underlying vnode's lock state.
*/
#define LAYERFS_UPPERLOCK(v, f, r) do { \
if ((v)->v_vnlock == NULL) \
r = lockmgr(&(v)->v_lock, (f), &(v)->v_interlock); \
else \
r = 0; \
} while (0)
#define LAYERFS_UPPERUNLOCK(v, f, r) do { \
if ((v)->v_vnlock == NULL) \
r = lockmgr(&(v)->v_lock, (f) | LK_RELEASE, &(v)->v_interlock); \
else \
r = 0; \
} while (0)
#define LAYERFS_UPPERISLOCKED(v, r) do { \
if ((v)->v_vnlock == NULL) \
r = lockstatus(&(v)->v_lock); \
else \
r = -1; \
} while (0)
#define LAYERFS_DO_BYPASS(vp, ap) \
(*MOUNTTOLAYERMOUNT((vp)->v_mount)->layerm_bypass)((ap))
struct vnode *layer_checkvp(struct vnode *vp, const char *fil, int lno);
#define MOUNTTOLAYERMOUNT(mp) ((struct layer_mount *)((mp)->mnt_data))
#define VTOLAYER(vp) ((struct layer_node *)(vp)->v_data)
#define LAYERTOV(xp) ((xp)->layer_vnode)
#ifdef LAYERFS_DIAGNOSTIC
#define LAYERVPTOLOWERVP(vp) layer_checkvp((vp), __FILE__, __LINE__)
extern int layerfs_debug;
#else
#define LAYERVPTOLOWERVP(vp) (VTOLAYER(vp)->layer_lowervp)
#endif
#endif /* _KERNEL */
#endif /* _MISCFS_GENFS_LAYER_H_ */