Viewing file:  dir_fplus.c (4.33 KB) -rw-r--r--
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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
};
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