/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright 2020 OmniOS Community Edition (OmniOSce) Association.
 */

#ifndef _SYS_FS_NAMENODE_H
#define _SYS_FS_NAMENODE_H

#if defined(_KERNEL)
#include <sys/vnode.h>
#include <sys/vfs_opreg.h>
#endif

#ifdef  __cplusplus
extern "C" {
#endif

/*
 * This structure is used to pass a file descriptor from user
 * level to the kernel. It is first used by fattach() and then
 * be NAMEFS.
 */
struct namefd {
        int fd;
};

#if defined(_KERNEL)
/*
 * Each NAMEFS object is identified by a struct namenode/vnode pair.
 */
struct namenode {
        struct vnode    *nm_vnode;      /* represents mounted file desc. */
        int             nm_flag;        /* flags defined below */
        struct vattr    nm_vattr;       /* attributes of mounted file desc. */
        struct vnode    *nm_filevp;     /* file desc. prior to mounting */
        struct file     *nm_filep;      /* file pointer of nm_filevp */
        struct vnode    *nm_mountpt;    /* mount point prior to mounting */
        struct namenode *nm_nextp;      /* next link in the linked list */
        kmutex_t        nm_lock;        /* protects nm_vattr */
};

/*
 * Valid flags for namenodes.
 */
#define NMNMNT          0x01    /* namenode not mounted */

/*
 * Macros to convert a vnode to a namenode, and vice versa.
 */
#define VTONM(vp) ((struct namenode *)((vp)->v_data))
#define NMTOV(nm) ((nm)->nm_vnode)

#define NM_FILEVP_HASH_SIZE     64
#define NM_FILEVP_HASH_MASK     (NM_FILEVP_HASH_SIZE - 1)
#define NM_FILEVP_HASH_SHIFT    7
#define NM_FILEVP_HASH(vp)      (&nm_filevp_hash[(((uintptr_t)vp) >> \
        NM_FILEVP_HASH_SHIFT) & NM_FILEVP_HASH_MASK])

extern struct namenode *nm_filevp_hash[NM_FILEVP_HASH_SIZE];
extern struct vfs namevfs;

extern int nameinit(int, char *);
extern int nm_unmountall(struct vnode *, struct cred *);
extern void nameinsert(struct namenode *);
extern void nameremove(struct namenode *);
extern struct namenode *namefind(struct vnode *, struct vnode *);
extern uint64_t namenodeno_alloc(void);
extern void namenodeno_free(uint64_t);
extern struct vnodeops *nm_vnodeops;
extern const struct fs_operation_def nm_vnodeops_template[];
extern kmutex_t ntable_lock;

typedef int nm_walk_mounts_f(const struct namenode *, cred_t *, void *);
extern int nm_walk_mounts(const vnode_t *, nm_walk_mounts_f *, cred_t *,
    void *);

#endif /* _KERNEL */

#ifdef  __cplusplus
}
#endif

#endif  /* _SYS_FS_NAMENODE_H */