/*      $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 */
}

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