xref: /freebsd/sys/fs/fdescfs/fdesc.h (revision e9ac41698b2f322d55ccf9da50a3596edb2c1800)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software donated to Berkeley by
8  * Jan-Simon Pendry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #ifndef _FS_FDESC_H_
36 #define _FS_FDESC_H_
37 
38 /* Private mount flags for fdescfs. */
39 #define FMNT_UNMOUNTF	0x01
40 #define FMNT_LINRDLNKF	0x02
41 #define	FMNT_NODUP	0x04
42 #define FMNT_RDLNKF	0x08
43 
44 struct fdescmount {
45 	struct vnode	*f_root;	/* Root node */
46 	int flags;
47 };
48 
49 #define FD_ROOT		1
50 #define FD_DESC		3
51 
52 typedef enum {
53 	Froot,
54 	Fdesc
55 } fdntype;
56 
57 struct fdescnode {
58 	LIST_ENTRY(fdescnode) fd_hash;	/* Hash list */
59 	struct vnode	*fd_vnode;	/* Back ptr to vnode */
60 	fdntype		fd_type;	/* Type of this node */
61 	unsigned	fd_fd;		/* Fd to be dup'ed */
62 	int		fd_ix;		/* filesystem index */
63 };
64 
65 extern struct mtx fdesc_hashmtx;
66 #define VFSTOFDESC(mp)	((struct fdescmount *)((mp)->mnt_data))
67 #define	VTOFDESC(vp) ((struct fdescnode *)(vp)->v_data)
68 
69 extern vfs_init_t fdesc_init;
70 extern vfs_uninit_t fdesc_uninit;
71 extern int fdesc_allocvp(fdntype, unsigned, int, struct mount *,
72     struct vnode **);
73 #endif /* !_FS_FDESC_H_ */
74