1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1994 The Regents of the University of California.
5 * Copyright (c) 1994 Jan-Simon Pendry.
6 * Copyright (c) 2005, 2006 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
7 * Copyright (c) 2006 Daichi Goto <daichi@freebsd.org>
8 * All rights reserved.
9 *
10 * This code is derived from software donated to Berkeley by
11 * Jan-Simon Pendry.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 *    notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 *    notice, this list of conditions and the following disclaimer in the
20 *    documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the University nor the names of its contributors
22 *    may be used to endorse or promote products derived from this software
23 *    without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 *	@(#)union.h	8.9 (Berkeley) 12/10/94
38 * $FreeBSD$
39 */
40
41#ifdef _KERNEL
42
43/* copy method of attr from lower to upper */
44typedef enum _unionfs_copymode {
45	UNIONFS_TRADITIONAL = 0,
46	UNIONFS_TRANSPARENT,
47	UNIONFS_MASQUERADE
48} unionfs_copymode;
49
50/* whiteout policy of upper layer */
51typedef enum _unionfs_whitemode {
52       UNIONFS_WHITE_ALWAYS = 0,
53       UNIONFS_WHITE_WHENNEEDED
54} unionfs_whitemode;
55
56struct unionfs_mount {
57	struct vnode   *um_lowervp;	/* VREFed once */
58	struct vnode   *um_uppervp;	/* VREFed once */
59	struct vnode   *um_rootvp;	/* ROOT vnode */
60	unionfs_copymode um_copymode;
61	unionfs_whitemode um_whitemode;
62	uid_t		um_uid;
63	gid_t		um_gid;
64	u_short		um_udir;
65	u_short		um_ufile;
66};
67
68/* unionfs status list */
69struct unionfs_node_status {
70	LIST_ENTRY(unionfs_node_status) uns_list;	/* Status list */
71	pid_t		uns_pid;		/* current process id */
72	int		uns_node_flag;		/* uns flag */
73	int		uns_lower_opencnt;	/* open count of lower */
74	int		uns_upper_opencnt;	/* open count of upper */
75	int		uns_lower_openmode;	/* open mode of lower */
76	int		uns_readdir_status;	/* read status of readdir */
77};
78
79/* union node status flags */
80#define	UNS_OPENL_4_READDIR	0x01	/* open lower layer for readdir */
81
82/* A cache of vnode references */
83struct unionfs_node {
84	struct vnode   *un_lowervp;		/* lower side vnode */
85	struct vnode   *un_uppervp;		/* upper side vnode */
86	struct vnode   *un_dvp;			/* parent unionfs vnode */
87	struct vnode   *un_vnode;		/* Back pointer */
88	LIST_HEAD(, unionfs_node_status) un_unshead;
89						/* unionfs status head */
90	LIST_HEAD(unionfs_node_hashhead, unionfs_node) *un_hashtbl;
91						/* dir vnode hash table */
92	LIST_ENTRY(unionfs_node)   un_hash;	/* hash list entry */
93	u_long		un_hashmask;		/* bit mask */
94	char           *un_path;		/* path */
95	int		un_flag;		/* unionfs node flag */
96};
97
98/*
99 * unionfs node flags
100 * It needs the vnode with exclusive lock, when changing the un_flag variable.
101 */
102#define UNIONFS_OPENEXTL	0x01	/* openextattr (lower) */
103#define UNIONFS_OPENEXTU	0x02	/* openextattr (upper) */
104
105#define	MOUNTTOUNIONFSMOUNT(mp) ((struct unionfs_mount *)((mp)->mnt_data))
106#define	VTOUNIONFS(vp) ((struct unionfs_node *)(vp)->v_data)
107#define	UNIONFSTOV(xp) ((xp)->un_vnode)
108
109int unionfs_init(struct vfsconf *vfsp);
110int unionfs_uninit(struct vfsconf *vfsp);
111int unionfs_nodeget(struct mount *mp, struct vnode *uppervp, struct vnode *lowervp, struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct thread *td);
112void unionfs_noderem(struct vnode *vp, struct thread *td);
113void unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, struct unionfs_node_status **unspp);
114void unionfs_tryrem_node_status(struct unionfs_node *unp, struct unionfs_node_status *unsp);
115
116int unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td);
117int unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, struct thread *td);
118void unionfs_create_uppervattr_core(struct unionfs_mount *ump, struct vattr *lva, struct vattr *uva, struct thread *td);
119int unionfs_create_uppervattr(struct unionfs_mount *ump, struct vnode *lvp, struct vattr *uva, struct ucred *cred, struct thread *td);
120int unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *duvp, struct unionfs_node *unp, struct componentname *cnp, struct thread *td);
121int unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, struct thread *td, char *path);
122int unionfs_relookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct componentname *cn, struct thread *td, char *path, int pathlen, u_long nameiop);
123int unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, struct thread *td);
124int unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, struct thread *td);
125int unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, struct thread *td);
126
127#ifdef DIAGNOSTIC
128struct vnode   *unionfs_checklowervp(struct vnode *vp, char *fil, int lno);
129struct vnode   *unionfs_checkuppervp(struct vnode *vp, char *fil, int lno);
130#define	UNIONFSVPTOLOWERVP(vp) unionfs_checklowervp((vp), __FILE__, __LINE__)
131#define	UNIONFSVPTOUPPERVP(vp) unionfs_checkuppervp((vp), __FILE__, __LINE__)
132#else
133#define	UNIONFSVPTOLOWERVP(vp) (VTOUNIONFS(vp)->un_lowervp)
134#define	UNIONFSVPTOUPPERVP(vp) (VTOUNIONFS(vp)->un_uppervp)
135#endif
136
137extern struct vop_vector unionfs_vnodeops;
138
139#ifdef MALLOC_DECLARE
140MALLOC_DECLARE(M_UNIONFSNODE);
141MALLOC_DECLARE(M_UNIONFSPATH);
142#endif
143
144#ifdef UNIONFS_DEBUG
145#define UNIONFSDEBUG(format, args...) printf(format ,## args)
146#else
147#define UNIONFSDEBUG(format, args...)
148#endif				/* UNIONFS_DEBUG */
149
150#endif				/* _KERNEL */
151