linux/fs/adfs/dir_fplus.c
Russell King 419a6e5e82 fs/adfs: dir: add generic directory reading
Both directory formats code the mechanics of fetching the directory
buffers using their own implementations.  Consolidate these into one
implementation.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-01-20 20:12:41 -05:00

126 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/adfs/dir_fplus.c
*
* Copyright (C) 1997-1999 Russell King
*/
#include "adfs.h"
#include "dir_fplus.h"
static int adfs_fplus_read(struct super_block *sb, u32 indaddr,
unsigned int size, struct adfs_dir *dir)
{
struct adfs_bigdirheader *h;
struct adfs_bigdirtail *t;
unsigned int dirsize;
int ret;
/* Read first buffer */
ret = adfs_dir_read_buffers(sb, indaddr, sb->s_blocksize, dir);
if (ret)
return ret;
h = (struct adfs_bigdirheader *)dir->bhs[0]->b_data;
dirsize = le32_to_cpu(h->bigdirsize);
if (dirsize != size) {
adfs_msg(sb, KERN_WARNING,
"dir %06x header size %X does not match directory size %X",
indaddr, dirsize, size);
}
if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
h->bigdirversion[2] != 0 || size & 2047 ||
h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME)) {
adfs_error(sb, "dir %06x has malformed header", indaddr);
goto out;
}
/* Read remaining buffers */
ret = adfs_dir_read_buffers(sb, indaddr, dirsize, dir);
if (ret)
return ret;
t = (struct adfs_bigdirtail *)
(dir->bhs[dir->nr_buffers - 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) {
adfs_error(sb, "dir %06x has malformed tail", indaddr);
goto out;
}
dir->parent_id = le32_to_cpu(h->bigdirparent);
return 0;
out:
adfs_dir_relse(dir);
return ret;
}
static int
adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
{
struct adfs_bigdirheader *h =
(struct adfs_bigdirheader *) dir->bhs[0]->b_data;
int ret = -ENOENT;
if (fpos <= le32_to_cpu(h->bigdirentries)) {
dir->pos = fpos;
ret = 0;
}
return ret;
}
static int
adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
{
struct adfs_bigdirheader *h =
(struct adfs_bigdirheader *) dir->bhs[0]->b_data;
struct adfs_bigdirentry bde;
unsigned int offset;
int ret;
if (dir->pos >= le32_to_cpu(h->bigdirentries))
return -ENOENT;
offset = offsetof(struct adfs_bigdirheader, bigdirname);
offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
offset += dir->pos * sizeof(struct adfs_bigdirentry);
ret = adfs_dir_copyfrom(&bde, dir, offset,
sizeof(struct adfs_bigdirentry));
if (ret)
return ret;
obj->loadaddr = le32_to_cpu(bde.bigdirload);
obj->execaddr = le32_to_cpu(bde.bigdirexec);
obj->size = le32_to_cpu(bde.bigdirlen);
obj->indaddr = 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);
ret = adfs_dir_copyfrom(obj->name, dir, offset, obj->name_len);
if (ret)
return ret;
adfs_object_fixup(dir, obj);
dir->pos += 1;
return 0;
}
const struct adfs_dir_ops adfs_fplus_dir_ops = {
.read = adfs_fplus_read,
.setpos = adfs_fplus_setpos,
.getnext = adfs_fplus_getnext,
};