/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2005 Poul-Henning Kamp
 * 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.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */


// Modified to support the Haiku FAT driver.

#ifdef FS_SHELL
#include "sys/types.h"
#include "fssh_api_wrapper.h"
#else
#include <sys/stat.h>
#include <sys/types.h>
#endif

#include "sys/param.h"
#include "sys/systm.h"
#include "sys/buf.h"
#include "sys/mount.h"
#include "sys/namei.h"
#include "sys/vnode.h"

#include "fs/msdosfs/denode.h"
#include "fs/msdosfs/direntry.h"

#include "dosfs.h"


#ifdef USER
#define dprintf printf
#endif


/*! Determine the inode number for a direntry location and return the corresponding node if it is
        constructed.
        @param hash A tentative location-based inode.
        @param arg Pointer to a pre-allocated uint64.
        @param td Ignored in the port.
        @param fn Ignored in the port. In FreeBSD, this is a function pointer that would be passed to
        the VFS and applied to the VFS's list of vnodes to find a match.
        @param arg Pointer to a pre-allocated uint64 that will be set to the final inode number.
        @post *arg is set to the inode number corresponding to hash (which may or may not equal hash).
        *vpp points to the corresponding BSD-style vnode, if that vnode already exists in memory. If
        the node doesn't exist in memory, *vpp is set to NULL.
        The function signature is modified to make hash a uint64 instead of uint32. This is consistent
        with the type passed by deget, and protects against overflow.
        This function never calls get_vnode when the node in question is not already registered with
        the VFS, so it is suitable for use within dosfs_read_vnode.
*/
int
vfs_hash_get(struct mount* mp, uint64 hash, int flags, thread_id td, struct vnode** vpp,
        vfs_hash_cmp_t* fn, void* arg)
{
        uint64* finalInode = arg;
        status_t status = B_OK;
        bool exists = false;
                // Has a node with the same inode number already been constructed?

        status = assign_inode(mp, (ino_t*)&hash);
        if (status != B_OK)
                return B_TO_POSIX_ERROR(status);

        exists = node_exists(mp, hash);
        if (exists == true) {
                // get_vnode will just return a ref (without calling dosfs_read_vnode)
                status = get_vnode(mp->mnt_fsvolume, hash, (void**)vpp);
                if (status != B_OK) {
                        dprintf("FAT vfs_hash_get:  get_vnode failure\n");
                        return B_TO_POSIX_ERROR(status);
                }
                rw_lock_write_lock(&(*vpp)->v_vnlock->haikuRW);
                        // the driver expects the node to be returned locked
        } else {
                // The node needs to be initialized. Returning with a NULL vpp will
                // signal deget() to go through with setting it up.
                *vpp = NULL;
        }

        *finalInode = hash;

        return 0;
}


/*! In FreeBSD, this adds vp to a VFS-level list of nodes. In Haiku, the same thing is
        taken care of automatically by get_vnode.
*/
int
vfs_hash_insert(struct vnode* vp, uint64 hash, int flags, thread_id td, struct vnode** vpp,
        vfs_hash_cmp_t* fn, void* arg)
{
        ASSERT(node_exists(vp->v_mount, hash) == false);

        // This tells the client that there is no existing vnode with the same
        // inode number. This should always be the case under the conditions in which
        // the FAT driver calls this function:  if there was an existing node,
        // deget would have returned early.
        *vpp = NULL;

        return 0;
}


/*! In FreeBSD, this provides the VFS with an updated node hash value based on the new directory
        entry offset when a file is renamed. Not applicable in Haiku.
*/
void
vfs_hash_rehash(struct vnode* vp, uint64 hash)
{
        return;
}