/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2001 Dag-Erling Smørgrav
 * All rights reserved.
 *
 * 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
 *    in this position and unchanged.
 * 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

#include <sys/cdefs.h>
#include "opt_pseudofs.h"

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/systm.h>

#include <fs/pseudofs/pseudofs.h>
#include <fs/pseudofs/pseudofs_internal.h>

/*
 * Initialize fileno bitmap
 */
void
pfs_fileno_init(struct pfs_info *pi)
{

        mtx_init(&pi->pi_mutex, "pfs_fileno", NULL, MTX_DEF);
        pi->pi_unrhdr = new_unrhdr(3, INT_MAX / NO_PID, &pi->pi_mutex);
}

/*
 * Tear down fileno bitmap
 */
void
pfs_fileno_uninit(struct pfs_info *pi)
{

        delete_unrhdr(pi->pi_unrhdr);
        pi->pi_unrhdr = NULL;
        mtx_destroy(&pi->pi_mutex);
}

/*
 * Allocate a file number
 */
void
pfs_fileno_alloc(struct pfs_node *pn)
{

        if (pn->pn_parent)
                PFS_TRACE(("%s/%s", pn->pn_parent->pn_name, pn->pn_name));
        else
                PFS_TRACE(("%s", pn->pn_name));
        pfs_assert_not_owned(pn);

        switch (pn->pn_type) {
        case pfstype_root:
                /* root must always be 2 */
                pn->pn_fileno = 2;
                break;
        case pfstype_dir:
        case pfstype_file:
        case pfstype_symlink:
        case pfstype_procdir:
                pn->pn_fileno = alloc_unr(pn->pn_info->pi_unrhdr);
                break;
        case pfstype_this:
                KASSERT(pn->pn_parent != NULL,
                    ("%s(): pfstype_this node has no parent", __func__));
                pn->pn_fileno = pn->pn_parent->pn_fileno;
                break;
        case pfstype_parent:
                KASSERT(pn->pn_parent != NULL,
                    ("%s(): pfstype_parent node has no parent", __func__));
                if (pn->pn_parent->pn_type == pfstype_root) {
                        pn->pn_fileno = pn->pn_parent->pn_fileno;
                        break;
                }
                KASSERT(pn->pn_parent->pn_parent != NULL,
                    ("%s(): pfstype_parent node has no grandparent", __func__));
                pn->pn_fileno = pn->pn_parent->pn_parent->pn_fileno;
                break;
        case pfstype_none:
                KASSERT(0,
                    ("%s(): pfstype_none node", __func__));
                break;
        }

#if 0
        printf("%s(): %s: ", __func__, pn->pn_info->pi_name);
        if (pn->pn_parent) {
                if (pn->pn_parent->pn_parent) {
                        printf("%s/", pn->pn_parent->pn_parent->pn_name);
                }
                printf("%s/", pn->pn_parent->pn_name);
        }
        printf("%s -> %d\n", pn->pn_name, pn->pn_fileno);
#endif
}

/*
 * Release a file number
 */
void
pfs_fileno_free(struct pfs_node *pn)
{

        pfs_assert_not_owned(pn);

        switch (pn->pn_type) {
        case pfstype_root:
                /* not allocated from unrhdr */
                return;
        case pfstype_dir:
        case pfstype_file:
        case pfstype_symlink:
        case pfstype_procdir:
                free_unr(pn->pn_info->pi_unrhdr, pn->pn_fileno);
                break;
        case pfstype_this:
        case pfstype_parent:
                /* ignore these, as they don't "own" their file number */
                break;
        case pfstype_none:
                KASSERT(0,
                    ("pfs_fileno_free() called for pfstype_none node"));
                break;
        }
}