fdesc.h

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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.
 */

#ifndef _FS_FDESC_H_
#define _FS_FDESC_H_

/* Private mount flags for fdescfs. */
#define FMNT_UNMOUNTF	0x01
#define FMNT_LINRDLNKF	0x02
#define	FMNT_NODUP	0x04
#define FMNT_RDLNKF	0x08

struct fdescmount {
	struct vnode	*f_root;	/* Root node */
	int flags;
};

#define FD_ROOT		1
#define FD_DESC		3

typedef enum {
	Froot,
	Fdesc
} fdntype;

struct fdescnode {
	LIST_ENTRY(fdescnode) fd_hash;	/* Hash list */
	struct vnode	*fd_vnode;	/* Back ptr to vnode */
	fdntype		fd_type;	/* Type of this node */
	unsigned	fd_fd;		/* Fd to be dup'ed */
	int		fd_ix;		/* filesystem index */
};

extern struct mtx fdesc_hashmtx;
#define VFSTOFDESC(mp)	((struct fdescmount *)((mp)->mnt_data))
#define	VTOFDESC(vp) ((struct fdescnode *)(vp)->v_data)

extern vfs_init_t fdesc_init;
extern vfs_uninit_t fdesc_uninit;
extern int fdesc_allocvp(fdntype, unsigned, int, struct mount *,
    struct vnode **);
#endif /* !_FS_FDESC_H_ */