/* $NetBSD: vnode.c,v 1.16 2020/04/03 19:36:33 joerg Exp $ */
/*-
 * Copyright (c) 2003 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Konrad E. Schroder <perseant@hhhh.org>.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/buf.h>
#include <sys/mount.h>
#include <sys/queue.h>

#define VU_DIROP 0x01000000 /* XXX XXX from sys/vnode.h */
#define vnode uvnode
#include <ufs/lfs/lfs.h>
#include <ufs/lfs/lfs_inode.h>
#undef vnode

#include <assert.h>
#include <err.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <util.h>

#include "bufcache.h"
#include "extern.h"
#include "kernelops.h"

struct uvnodelst vnodelist;
struct uvnodelst getvnodelist[VNODE_HASH_MAX];
struct vgrlst    vgrlist;

int nvnodes;

/* Convert between inode pointers and vnode pointers. */
#ifndef VTOI
#define VTOI(vp)        ((struct inode *)(vp)->v_data)
#endif

/*
 * Raw device uvnode ops
 */

int
raw_vop_strategy(struct ubuf * bp)
{
        if (bp->b_flags & B_READ) {
                return kops.ko_pread(bp->b_vp->v_fd, bp->b_data, bp->b_bcount,
                    bp->b_blkno * dev_bsize);
        } else {
                return kops.ko_pwrite(bp->b_vp->v_fd, bp->b_data, bp->b_bcount,
                    bp->b_blkno * dev_bsize);
        }
}

int
raw_vop_bwrite(struct ubuf * bp)
{
        bp->b_flags &= ~(B_READ | B_DELWRI | B_DONE | B_ERROR);
        raw_vop_strategy(bp);
        brelse(bp, 0);
        return 0;
}

int
raw_vop_bmap(struct uvnode * vp, daddr_t lbn, daddr_t * daddrp)
{
        *daddrp = lbn;
        return 0;
}

/* Register a fs-specific vget function */
void
register_vget(void *fs, struct uvnode *func(void *, ino_t))
{
        struct vget_reg *vgr;

        vgr = emalloc(sizeof(*vgr));
        vgr->vgr_fs = fs;
        vgr->vgr_func = func;
        LIST_INSERT_HEAD(&vgrlist, vgr, vgr_list);
}

static struct uvnode *
VFS_VGET(void *fs, ino_t ino)
{
        struct vget_reg *vgr;

        LIST_FOREACH(vgr, &vgrlist, vgr_list) {
                if (vgr->vgr_fs == fs)
                        return vgr->vgr_func(fs, ino);
        }
        return NULL;
}

void
vnode_destroy(struct uvnode *tossvp)
{
        struct ubuf *bp;

        --nvnodes;
        LIST_REMOVE(tossvp, v_getvnodes);
        LIST_REMOVE(tossvp, v_mntvnodes);
        while ((bp = LIST_FIRST(&tossvp->v_dirtyblkhd)) != NULL) {
                LIST_REMOVE(bp, b_vnbufs);
                bremfree(bp);
                buf_destroy(bp);
        }
        while ((bp = LIST_FIRST(&tossvp->v_cleanblkhd)) != NULL) {
                LIST_REMOVE(bp, b_vnbufs);
                bremfree(bp);
                buf_destroy(bp);
        }
        free(VTOI(tossvp)->inode_ext.lfs);
        free(VTOI(tossvp)->i_din);
        memset(VTOI(tossvp), 0, sizeof(struct inode));
        free(tossvp->v_data);
        memset(tossvp, 0, sizeof(*tossvp));
        free(tossvp);
}

int hits, misses;

/*
 * Find a vnode in the cache; if not present, get it from the
 * filesystem-specific vget routine.
 */
struct uvnode *
vget(void *fs, ino_t ino)
{
        struct uvnode *vp, *tossvp;
        int hash;

        /* Look in the uvnode cache */
        tossvp = NULL;
        hash = ((unsigned long)fs + ino) & (VNODE_HASH_MAX - 1);
        LIST_FOREACH(vp, &getvnodelist[hash], v_getvnodes) {
                if (vp->v_fs != fs)
                        continue;
                if (VTOI(vp)->i_number == ino) {
                        /* Move to the front of the list */
                        LIST_REMOVE(vp, v_getvnodes);
                        LIST_INSERT_HEAD(&getvnodelist[hash], vp, v_getvnodes);
                        ++hits;
                        break;
                }
                if (LIST_EMPTY(&vp->v_dirtyblkhd) &&
                    vp->v_usecount == 0 &&
                    !(vp->v_uflag & VU_DIROP))
                        tossvp = vp;
        }
        /* Don't let vnode list grow arbitrarily */
        if (nvnodes > VNODE_CACHE_SIZE && tossvp) {
                vnode_destroy(tossvp);
        }
        if (vp)
                return vp;

        ++misses;
        return VFS_VGET(fs, ino);
}

void
vfs_init(void)
{
        int i;

        nvnodes = 0;
        LIST_INIT(&vnodelist);
        for (i = 0; i < VNODE_HASH_MAX; i++)
                LIST_INIT(&getvnodelist[i]);
        LIST_INIT(&vgrlist);
}