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/*

 *  linux/fs/adfs/dir_fplus.c

 *

 *  Copyright (C) 1997-1999 Russell King

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#include <linux/version.h>

#include <linux/errno.h>

#include <linux/fs.h>

#include <linux/adfs_fs.h>

#include <linux/sched.h>

#include <linux/stat.h>

#include <linux/spinlock.h>

#include "adfs.h"

#include "dir_fplus.h"

static int

adfs_fplus_read(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir)

{

        struct adfs_bigdirheader *h;

        struct adfs_bigdirtail *t;

        unsigned long block;

        unsigned int blk, size;

        int i, ret = -EIO;

        dir->nr_buffers = 0;

        block = __adfs_block_map(sb, id, 0);

        if (!block) {

                adfs_error(sb, "dir object %X has a hole at offset 0", id);

                goto out;

        }

        dir->bh[0] = sb_bread(sb, block);

        if (!dir->bh[0])

                goto out;

        dir->nr_buffers += 1;

        h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;

        size = le32_to_cpu(h->bigdirsize);

        if (size != sz) {

                printk(KERN_WARNING "adfs: adfs_fplus_read: directory header size\n"

                                " does not match directory size\n");

        }

        if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||

            h->bigdirversion[2] != 0 || size & 2047 ||

            h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME))

                goto out;

        size >>= sb->s_blocksize_bits;

        for (blk = 1; blk < size; blk++) {

                block = __adfs_block_map(sb, id, blk);

                if (!block) {

                        adfs_error(sb, "dir object %X has a hole at offset %d", id, blk);

                        goto out;

                }

                dir->bh[blk] = sb_bread(sb, block);

                if (!dir->bh[blk])

                        goto out;

                dir->nr_buffers = blk;

        }

        t = (struct adfs_bigdirtail *)(dir->bh[size - 1]->b_data + (sb->s_blocksize - 8));

        if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||

            t->bigdirendmasseq != h->startmasseq ||

            t->reserved[0] != 0 || t->reserved[1] != 0)

                goto out;

        dir->parent_id = le32_to_cpu(h->bigdirparent);

        dir->sb = sb;

        return 0;

out:

        for (i = 0; i < dir->nr_buffers; i++)

                brelse(dir->bh[i]);

        dir->sb = NULL;

        return ret;

}

static int

adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)

{

        struct adfs_bigdirheader *h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;

        int ret = -ENOENT;

        if (fpos <= le32_to_cpu(h->bigdirentries)) {

                dir->pos = fpos;

                ret = 0;

        }

        return ret;

}

static void

dir_memcpy(struct adfs_dir *dir, unsigned int offset, void *to, int len)

{

        struct super_block *sb = dir->sb;

        unsigned int buffer, partial, remainder;

        buffer = offset >> sb->s_blocksize_bits;

        offset &= sb->s_blocksize - 1;

        partial = sb->s_blocksize - offset;

        if (partial >= len)

                memcpy(to, dir->bh[buffer]->b_data + offset, len);

        else {

                char *c = (char *)to;

                remainder = len - partial;

                memcpy(c, dir->bh[buffer]->b_data + offset, partial);

                memcpy(c + partial, dir->bh[buffer + 1]->b_data, remainder);

        }

}

static int

adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)

{

        struct adfs_bigdirheader *h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;

        struct adfs_bigdirentry bde;

        unsigned int offset;

        int i, ret = -ENOENT;

        if (dir->pos >= le32_to_cpu(h->bigdirentries))

                goto out;

        offset = offsetof(struct adfs_bigdirheader, bigdirname);

        offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);

        offset += dir->pos * sizeof(struct adfs_bigdirentry);

        dir_memcpy(dir, offset, &bde, sizeof(struct adfs_bigdirentry));

        obj->loadaddr = le32_to_cpu(bde.bigdirload);

        obj->execaddr = le32_to_cpu(bde.bigdirexec);

        obj->size     = le32_to_cpu(bde.bigdirlen);

        obj->file_id  = le32_to_cpu(bde.bigdirindaddr);

        obj->attr     = le32_to_cpu(bde.bigdirattr);

        obj->name_len = le32_to_cpu(bde.bigdirobnamelen);

        offset = offsetof(struct adfs_bigdirheader, bigdirname);

        offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);

        offset += le32_to_cpu(h->bigdirentries) * sizeof(struct adfs_bigdirentry);

        offset += le32_to_cpu(bde.bigdirobnameptr);

        dir_memcpy(dir, offset, obj->name, obj->name_len);

        for (i = 0; i < obj->name_len; i++)

                if (obj->name[i] == '/')

                        obj->name[i] = '.';

        dir->pos += 1;

        ret = 0;

out:

        return ret;

}

static void

adfs_fplus_free(struct adfs_dir *dir)

{

        int i;

        for (i = 0; i < dir->nr_buffers; i++)

                brelse(dir->bh[i]);

        dir->sb = NULL;

}

struct adfs_dir_ops adfs_fplus_dir_ops = {

        adfs_fplus_read,

        adfs_fplus_setpos,

        adfs_fplus_getnext,

        NULL,

        NULL,

        NULL,

        adfs_fplus_free

};