freebsd-skq/sys/fs/unionfs/union.h
daichi b4e293afdf Added whiteout behavior option. ``-o whiteout=always'' is default mode
(it is established practice) and ``-o whiteout=whenneeded'' is less
disk-space using mode especially for resource restricted environments
like embedded environments. (Contributed by Ed Schouten. Thanks)

Submitted by:   Masanori Ozawa <ozawa@ongs.co.jp> (unionfs developer)
Reviewed by:    jeff, kensmith
Approved by:    re (kensmith)
MFC after:      1 week
2007-10-14 13:55:38 +00:00

143 lines
6.0 KiB
C

/*-
* Copyright (c) 1994 The Regents of the University of California.
* Copyright (c) 1994 Jan-Simon Pendry.
* Copyright (c) 2005, 2006 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
* Copyright (c) 2006 Daichi Goto <daichi@freebsd.org>
* 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.
* 4. 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.
*
* @(#)union.h 8.9 (Berkeley) 12/10/94
* $FreeBSD$
*/
#ifdef _KERNEL
/* copy method of attr from lower to upper */
typedef enum _unionfs_copymode {
UNIONFS_TRADITIONAL = 0,
UNIONFS_TRANSPARENT,
UNIONFS_MASQUERADE
} unionfs_copymode;
/* whiteout policy of upper layer */
typedef enum _unionfs_whitemode {
UNIONFS_WHITE_ALWAYS = 0,
UNIONFS_WHITE_WHENNEEDED
} unionfs_whitemode;
struct unionfs_mount {
struct vnode *um_lowervp; /* VREFed once */
struct vnode *um_uppervp; /* VREFed once */
struct vnode *um_rootvp; /* ROOT vnode */
unionfs_copymode um_copymode;
unionfs_whitemode um_whitemode;
uid_t um_uid;
gid_t um_gid;
u_short um_udir;
u_short um_ufile;
};
/* unionfs status list */
struct unionfs_node_status {
LIST_ENTRY(unionfs_node_status) uns_list; /* Status list */
lwpid_t uns_tid; /* current thread id */
int uns_node_flag; /* uns flag */
int uns_lower_opencnt; /* open count of lower */
int uns_upper_opencnt; /* open count of upper */
int uns_lower_openmode; /* open mode of lower */
int uns_readdir_status; /* read status of readdir */
};
/* union node status flags */
#define UNS_OPENL_4_READDIR 0x01 /* open lower layer for readdir */
/* A cache of vnode references */
struct unionfs_node {
struct vnode *un_lowervp; /* lower side vnode */
struct vnode *un_uppervp; /* upper side vnode */
struct vnode *un_dvp; /* parent unionfs vnode */
struct vnode *un_vnode; /* Back pointer */
LIST_HEAD(, unionfs_node_status) un_unshead; /* unionfs status head */
char *un_path; /* path */
int un_flag; /* unionfs node flag */
};
/*
* unionfs node flags
* It needs the vnode with exclusive lock, when changing the un_flag variable.
*/
#define UNIONFS_OPENEXTL 0x01 /* openextattr (lower) */
#define UNIONFS_OPENEXTU 0x02 /* openextattr (upper) */
#define MOUNTTOUNIONFSMOUNT(mp) ((struct unionfs_mount *)((mp)->mnt_data))
#define VTOUNIONFS(vp) ((struct unionfs_node *)(vp)->v_data)
#define UNIONFSTOV(xp) ((xp)->un_vnode)
int unionfs_init(struct vfsconf *vfsp);
int unionfs_uninit(struct vfsconf *vfsp);
int unionfs_nodeget(struct mount *mp, struct vnode *uppervp, struct vnode *lowervp, struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct thread *td);
void unionfs_noderem(struct vnode *vp, struct thread *td);
void unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, struct unionfs_node_status **unspp);
void unionfs_tryrem_node_status(struct unionfs_node *unp, struct thread *td, struct unionfs_node_status *unsp);
int unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td);
int unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, struct thread *td);
void unionfs_create_uppervattr_core(struct unionfs_mount *ump, struct vattr *lva, struct vattr *uva, struct thread *td);
int unionfs_create_uppervattr(struct unionfs_mount *ump, struct vnode *lvp, struct vattr *uva, struct ucred *cred, struct thread *td);
int unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *duvp, struct unionfs_node *unp, struct componentname *cnp, struct thread *td);
int unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, struct thread *td, char *path);
int unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, struct thread *td);
int unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, struct thread *td);
int unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, struct thread *td);
#ifdef DIAGNOSTIC
struct vnode *unionfs_checklowervp(struct vnode *vp, char *fil, int lno);
struct vnode *unionfs_checkuppervp(struct vnode *vp, char *fil, int lno);
#define UNIONFSVPTOLOWERVP(vp) unionfs_checklowervp((vp), __FILE__, __LINE__)
#define UNIONFSVPTOUPPERVP(vp) unionfs_checkuppervp((vp), __FILE__, __LINE__)
#else
#define UNIONFSVPTOLOWERVP(vp) (VTOUNIONFS(vp)->un_lowervp)
#define UNIONFSVPTOUPPERVP(vp) (VTOUNIONFS(vp)->un_uppervp)
#endif
extern struct vop_vector unionfs_vnodeops;
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_UNIONFSNODE);
MALLOC_DECLARE(M_UNIONFSPATH);
#endif
#ifdef UNIONFS_DEBUG
#define UNIONFSDEBUG(format, args...) printf(format ,## args)
#else
#define UNIONFSDEBUG(format, args...)
#endif /* UNIONFS_DEBUG */
#endif /* _KERNEL */