/*      $NetBSD: v7fs_superblock.c,v 1.2 2011/07/18 21:51:49 apb Exp $  */

/*-
 * Copyright (c) 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by UCHIYAMA Yasushi.
 *
 * 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.
 */

#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: v7fs_superblock.c,v 1.2 2011/07/18 21:51:49 apb Exp $");
#if defined _KERNEL_OPT
#include "opt_v7fs.h"
#endif

#ifdef _KERNEL
#include <sys/systm.h>
#include <sys/param.h>  /* errno */
#else
#include <stdio.h>
#include <string.h>
#include <errno.h>
#endif

#include "v7fs.h"
#include "v7fs_impl.h"
#include "v7fs_endian.h"
#include "v7fs_superblock.h"
#include "v7fs_inode.h"
#include "v7fs_datablock.h"

#ifdef V7FS_SUPERBLOCK_DEBUG
#define DPRINTF(fmt, args...)   printf("%s: " fmt, __func__, ##args)
#define DPRINTF_(fmt, args...)  printf(fmt, ##args)
#else
#define DPRINTF(fmt, args...)   ((void)0)
#define DPRINTF_(fmt, args...)  ((void)0)
#endif

static void v7fs_superblock_endian_convert(struct v7fs_self *,
    struct v7fs_superblock *, struct v7fs_superblock *);
static int v7fs_superblock_sanity(struct v7fs_self *);

/* Load superblock from disk. */
int
v7fs_superblock_load(struct v7fs_self *fs)
{
        struct v7fs_superblock *disksb;
        void *buf;
        int error;

        if (!(buf = scratch_read(fs, V7FS_SUPERBLOCK_SECTOR)))
                return EIO;
        disksb = (struct v7fs_superblock *)buf;
        v7fs_superblock_endian_convert(fs, &fs->superblock, disksb);
        scratch_free(fs, buf);

        if ((error = v7fs_superblock_sanity(fs)))
                return error;

        return 0;
}

/* Writeback superblock to disk. */
int
v7fs_superblock_writeback(struct v7fs_self *fs)
{
        struct v7fs_superblock *memsb = &fs->superblock;
        struct v7fs_superblock *disksb;
        void *buf;
        int error = 0;

        if (!memsb->modified)
                return 0;

        if (!(buf = scratch_read(fs, V7FS_SUPERBLOCK_SECTOR)))
                return EIO;
        disksb = (struct v7fs_superblock *)buf;
        v7fs_superblock_endian_convert(fs, disksb, memsb);
        if (!fs->io.write(fs->io.cookie, buf, V7FS_SUPERBLOCK_SECTOR))
                error = EIO;
        scratch_free(fs, buf);

        memsb->modified = 0;
        DPRINTF("done. %d\n", error);

        return error;
}

/* Check endian mismatch. */
static int
v7fs_superblock_sanity(struct v7fs_self *fs)
{
        const struct v7fs_superblock *sb = &fs->superblock;
        void *buf = 0;

        if ((sb->volume_size < 128) || /* smaller than 64KB. */
            (sb->datablock_start_sector > sb->volume_size) ||
            (sb->nfreeinode > V7FS_MAX_FREEINODE) ||
            (sb->nfreeblock > V7FS_MAX_FREEBLOCK) ||
            (sb->update_time < 0) ||
            (sb->total_freeblock > sb->volume_size) ||
            ((sb->nfreeinode == 0) && (sb->nfreeblock == 0) &&
                (sb->total_freeblock == 0) && (sb->total_freeinode == 0)) ||
            (!(buf = scratch_read(fs, sb->volume_size - 1)))) {
                DPRINTF("invalid super block.\n");
                return EINVAL;
        }
        if (buf)
                scratch_free(fs, buf);

        return 0;
}

/* Fill free block to superblock cache. */
int
v7fs_freeblock_update(struct v7fs_self *fs, v7fs_daddr_t blk)
{
        /* Assume superblock is locked by caller. */
        struct v7fs_superblock *sb = &fs->superblock;
        struct v7fs_freeblock *fb;
        void *buf;
        int error;

        /* Read next freeblock table from disk. */
        if (!datablock_number_sanity(fs, blk) || !(buf = scratch_read(fs, blk)))
                return EIO;

        /* Update in-core superblock freelist. */
        fb = (struct v7fs_freeblock *)buf;
        if ((error = v7fs_freeblock_endian_convert(fs, fb))) {
                scratch_free(fs, buf);
                return error;
        }
        DPRINTF("freeblock table#%d, nfree=%d\n", blk, fb->nfreeblock);

        memcpy(sb->freeblock, fb->freeblock, sizeof(blk) * fb->nfreeblock);
        sb->nfreeblock = fb->nfreeblock;
        sb->modified = true;
        scratch_free(fs, buf);

        return 0;
}

int
v7fs_freeblock_endian_convert(struct v7fs_self *fs __unused,
    struct v7fs_freeblock *fb __unused)
{
#ifdef V7FS_EI
        int i;
        int16_t nfree;

        nfree = V7FS_VAL16(fs, fb->nfreeblock);
        if (nfree <= 0 || nfree > V7FS_MAX_FREEBLOCK) {
                DPRINTF("invalid freeblock list. %d (max=%d)\n", nfree,
                    V7FS_MAX_FREEBLOCK);
                return ENOSPC;
        }
        fb->nfreeblock = nfree;

        for (i = 0; i < nfree; i++) {
                fb->freeblock[i] = V7FS_VAL32(fs, fb->freeblock[i]);
        }
#endif /* V7FS_EI */

        return 0;
}

/* Fill free inode to superblock cache. */
int
v7fs_freeinode_update(struct v7fs_self *fs)
{
        /* Assume superblock is locked by caller. */
        struct v7fs_superblock *sb = &fs->superblock;
        v7fs_ino_t *freeinode = sb->freeinode;
        size_t i, j, k;
        v7fs_ino_t ino;

        /* Loop over all inode list. */
        for (i = V7FS_ILIST_SECTOR, ino = 1/* inode start from 1*/, k = 0;
            i < sb->datablock_start_sector; i++) {
                struct v7fs_inode_diskimage *di;
                void *buf;
                if (!(buf = scratch_read(fs, i))) {
                        DPRINTF("block %zu I/O error.\n", i);
                        ino += V7FS_INODE_PER_BLOCK;
                        continue;
                }
                di = (struct v7fs_inode_diskimage *)buf;

                for (j = 0;
                    (j < V7FS_INODE_PER_BLOCK) && (k < V7FS_MAX_FREEINODE);
                    j++, di++, ino++) {
                        if (v7fs_inode_allocated(di))
                                continue;
                        DPRINTF("free inode%d\n", ino);
                        freeinode[k++] = ino;
                }
                scratch_free(fs, buf);
        }
        sb->nfreeinode = k;

        return 0;
}

static void
v7fs_superblock_endian_convert(struct v7fs_self *fs __unused,
    struct v7fs_superblock *to,  struct v7fs_superblock *from)
{
#ifdef V7FS_EI
#define conv16(m)       (to->m = V7FS_VAL16(fs, from->m))
#define conv32(m)       (to->m = V7FS_VAL32(fs, from->m))
        int i;

        conv16(datablock_start_sector);
        conv32(volume_size);
        conv16(nfreeblock);
        v7fs_daddr_t *dfrom = from->freeblock;
        v7fs_daddr_t *dto = to->freeblock;
        for (i = 0; i < V7FS_MAX_FREEBLOCK; i++, dfrom++, dto++)
                *dto = V7FS_VAL32(fs, *dfrom);

        conv16(nfreeinode);
        v7fs_ino_t *ifrom = from->freeinode;
        v7fs_ino_t *ito = to->freeinode;
        for (i = 0; i < V7FS_MAX_FREEINODE; i++, ifrom++, ito++)
                *ito = V7FS_VAL16(fs, *ifrom);

        conv32(update_time);
        conv32(total_freeblock);
        conv16(total_freeinode);
#undef conv16
#undef conv32
#else /* V7FS_EI */
        memcpy(to, from , sizeof(*to));
#endif /* V7FS_EI */
}