463 строки
9.7 KiB
C
463 строки
9.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* linux/fs/adfs/dir_f.c
|
|
*
|
|
* Copyright (C) 1997-1999 Russell King
|
|
*
|
|
* E and F format directory handling
|
|
*/
|
|
#include "adfs.h"
|
|
#include "dir_f.h"
|
|
|
|
static void adfs_f_free(struct adfs_dir *dir);
|
|
|
|
/*
|
|
* Read an (unaligned) value of length 1..4 bytes
|
|
*/
|
|
static inline unsigned int adfs_readval(unsigned char *p, int len)
|
|
{
|
|
unsigned int val = 0;
|
|
|
|
switch (len) {
|
|
case 4: val |= p[3] << 24;
|
|
/* fall through */
|
|
case 3: val |= p[2] << 16;
|
|
/* fall through */
|
|
case 2: val |= p[1] << 8;
|
|
/* fall through */
|
|
default: val |= p[0];
|
|
}
|
|
return val;
|
|
}
|
|
|
|
static inline void adfs_writeval(unsigned char *p, int len, unsigned int val)
|
|
{
|
|
switch (len) {
|
|
case 4: p[3] = val >> 24;
|
|
/* fall through */
|
|
case 3: p[2] = val >> 16;
|
|
/* fall through */
|
|
case 2: p[1] = val >> 8;
|
|
/* fall through */
|
|
default: p[0] = val;
|
|
}
|
|
}
|
|
|
|
#define ror13(v) ((v >> 13) | (v << 19))
|
|
|
|
#define dir_u8(idx) \
|
|
({ int _buf = idx >> blocksize_bits; \
|
|
int _off = idx - (_buf << blocksize_bits);\
|
|
*(u8 *)(bh[_buf]->b_data + _off); \
|
|
})
|
|
|
|
#define dir_u32(idx) \
|
|
({ int _buf = idx >> blocksize_bits; \
|
|
int _off = idx - (_buf << blocksize_bits);\
|
|
*(__le32 *)(bh[_buf]->b_data + _off); \
|
|
})
|
|
|
|
#define bufoff(_bh,_idx) \
|
|
({ int _buf = _idx >> blocksize_bits; \
|
|
int _off = _idx - (_buf << blocksize_bits);\
|
|
(u8 *)(_bh[_buf]->b_data + _off); \
|
|
})
|
|
|
|
/*
|
|
* There are some algorithms that are nice in
|
|
* assembler, but a bitch in C... This is one
|
|
* of them.
|
|
*/
|
|
static u8
|
|
adfs_dir_checkbyte(const struct adfs_dir *dir)
|
|
{
|
|
struct buffer_head * const *bh = dir->bh;
|
|
const int blocksize_bits = dir->sb->s_blocksize_bits;
|
|
union { __le32 *ptr32; u8 *ptr8; } ptr, end;
|
|
u32 dircheck = 0;
|
|
int last = 5 - 26;
|
|
int i = 0;
|
|
|
|
/*
|
|
* Accumulate each word up to the last whole
|
|
* word of the last directory entry. This
|
|
* can spread across several buffer heads.
|
|
*/
|
|
do {
|
|
last += 26;
|
|
do {
|
|
dircheck = le32_to_cpu(dir_u32(i)) ^ ror13(dircheck);
|
|
|
|
i += sizeof(u32);
|
|
} while (i < (last & ~3));
|
|
} while (dir_u8(last) != 0);
|
|
|
|
/*
|
|
* Accumulate the last few bytes. These
|
|
* bytes will be within the same bh.
|
|
*/
|
|
if (i != last) {
|
|
ptr.ptr8 = bufoff(bh, i);
|
|
end.ptr8 = ptr.ptr8 + last - i;
|
|
|
|
do {
|
|
dircheck = *ptr.ptr8++ ^ ror13(dircheck);
|
|
} while (ptr.ptr8 < end.ptr8);
|
|
}
|
|
|
|
/*
|
|
* The directory tail is in the final bh
|
|
* Note that contary to the RISC OS PRMs,
|
|
* the first few bytes are NOT included
|
|
* in the check. All bytes are in the
|
|
* same bh.
|
|
*/
|
|
ptr.ptr8 = bufoff(bh, 2008);
|
|
end.ptr8 = ptr.ptr8 + 36;
|
|
|
|
do {
|
|
__le32 v = *ptr.ptr32++;
|
|
dircheck = le32_to_cpu(v) ^ ror13(dircheck);
|
|
} while (ptr.ptr32 < end.ptr32);
|
|
|
|
return (dircheck ^ (dircheck >> 8) ^ (dircheck >> 16) ^ (dircheck >> 24)) & 0xff;
|
|
}
|
|
|
|
/* Read and check that a directory is valid */
|
|
static int adfs_dir_read(struct super_block *sb, u32 indaddr,
|
|
unsigned int size, struct adfs_dir *dir)
|
|
{
|
|
const unsigned int blocksize_bits = sb->s_blocksize_bits;
|
|
int blk = 0;
|
|
|
|
/*
|
|
* Directories which are not a multiple of 2048 bytes
|
|
* are considered bad v2 [3.6]
|
|
*/
|
|
if (size & 2047)
|
|
goto bad_dir;
|
|
|
|
size >>= blocksize_bits;
|
|
|
|
dir->nr_buffers = 0;
|
|
dir->sb = sb;
|
|
|
|
for (blk = 0; blk < size; blk++) {
|
|
int phys;
|
|
|
|
phys = __adfs_block_map(sb, indaddr, blk);
|
|
if (!phys) {
|
|
adfs_error(sb, "dir %06x has a hole at offset %d",
|
|
indaddr, blk);
|
|
goto release_buffers;
|
|
}
|
|
|
|
dir->bh[blk] = sb_bread(sb, phys);
|
|
if (!dir->bh[blk])
|
|
goto release_buffers;
|
|
}
|
|
|
|
memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
|
|
memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));
|
|
|
|
if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq ||
|
|
memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
|
|
goto bad_dir;
|
|
|
|
if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
|
|
memcmp(&dir->dirhead.startname, "Hugo", 4))
|
|
goto bad_dir;
|
|
|
|
if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
|
|
goto bad_dir;
|
|
|
|
dir->nr_buffers = blk;
|
|
|
|
return 0;
|
|
|
|
bad_dir:
|
|
adfs_error(sb, "dir %06x is corrupted", indaddr);
|
|
release_buffers:
|
|
for (blk -= 1; blk >= 0; blk -= 1)
|
|
brelse(dir->bh[blk]);
|
|
|
|
dir->sb = NULL;
|
|
|
|
return -EIO;
|
|
}
|
|
|
|
/*
|
|
* convert a disk-based directory entry to a Linux ADFS directory entry
|
|
*/
|
|
static inline void
|
|
adfs_dir2obj(struct adfs_dir *dir, struct object_info *obj,
|
|
struct adfs_direntry *de)
|
|
{
|
|
unsigned int name_len;
|
|
|
|
for (name_len = 0; name_len < ADFS_F_NAME_LEN; name_len++) {
|
|
if (de->dirobname[name_len] < ' ')
|
|
break;
|
|
|
|
obj->name[name_len] = de->dirobname[name_len];
|
|
}
|
|
|
|
obj->name_len = name_len;
|
|
obj->indaddr = adfs_readval(de->dirinddiscadd, 3);
|
|
obj->loadaddr = adfs_readval(de->dirload, 4);
|
|
obj->execaddr = adfs_readval(de->direxec, 4);
|
|
obj->size = adfs_readval(de->dirlen, 4);
|
|
obj->attr = de->newdiratts;
|
|
|
|
adfs_object_fixup(dir, obj);
|
|
}
|
|
|
|
/*
|
|
* convert a Linux ADFS directory entry to a disk-based directory entry
|
|
*/
|
|
static inline void
|
|
adfs_obj2dir(struct adfs_direntry *de, struct object_info *obj)
|
|
{
|
|
adfs_writeval(de->dirinddiscadd, 3, obj->indaddr);
|
|
adfs_writeval(de->dirload, 4, obj->loadaddr);
|
|
adfs_writeval(de->direxec, 4, obj->execaddr);
|
|
adfs_writeval(de->dirlen, 4, obj->size);
|
|
de->newdiratts = obj->attr;
|
|
}
|
|
|
|
/*
|
|
* get a directory entry. Note that the caller is responsible
|
|
* for holding the relevant locks.
|
|
*/
|
|
static int
|
|
__adfs_dir_get(struct adfs_dir *dir, int pos, struct object_info *obj)
|
|
{
|
|
struct super_block *sb = dir->sb;
|
|
struct adfs_direntry de;
|
|
int thissize, buffer, offset;
|
|
|
|
buffer = pos >> sb->s_blocksize_bits;
|
|
|
|
if (buffer > dir->nr_buffers)
|
|
return -EINVAL;
|
|
|
|
offset = pos & (sb->s_blocksize - 1);
|
|
thissize = sb->s_blocksize - offset;
|
|
if (thissize > 26)
|
|
thissize = 26;
|
|
|
|
memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
|
|
if (thissize != 26)
|
|
memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
|
|
26 - thissize);
|
|
|
|
if (!de.dirobname[0])
|
|
return -ENOENT;
|
|
|
|
adfs_dir2obj(dir, obj, &de);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
__adfs_dir_put(struct adfs_dir *dir, int pos, struct object_info *obj)
|
|
{
|
|
struct super_block *sb = dir->sb;
|
|
struct adfs_direntry de;
|
|
int thissize, buffer, offset;
|
|
|
|
buffer = pos >> sb->s_blocksize_bits;
|
|
|
|
if (buffer > dir->nr_buffers)
|
|
return -EINVAL;
|
|
|
|
offset = pos & (sb->s_blocksize - 1);
|
|
thissize = sb->s_blocksize - offset;
|
|
if (thissize > 26)
|
|
thissize = 26;
|
|
|
|
/*
|
|
* Get the entry in total
|
|
*/
|
|
memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
|
|
if (thissize != 26)
|
|
memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
|
|
26 - thissize);
|
|
|
|
/*
|
|
* update it
|
|
*/
|
|
adfs_obj2dir(&de, obj);
|
|
|
|
/*
|
|
* Put the new entry back
|
|
*/
|
|
memcpy(dir->bh[buffer]->b_data + offset, &de, thissize);
|
|
if (thissize != 26)
|
|
memcpy(dir->bh[buffer + 1]->b_data, ((char *)&de) + thissize,
|
|
26 - thissize);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* the caller is responsible for holding the necessary
|
|
* locks.
|
|
*/
|
|
static int adfs_dir_find_entry(struct adfs_dir *dir, u32 indaddr)
|
|
{
|
|
int pos, ret;
|
|
|
|
ret = -ENOENT;
|
|
|
|
for (pos = 5; pos < ADFS_NUM_DIR_ENTRIES * 26 + 5; pos += 26) {
|
|
struct object_info obj;
|
|
|
|
if (!__adfs_dir_get(dir, pos, &obj))
|
|
break;
|
|
|
|
if (obj.indaddr == indaddr) {
|
|
ret = pos;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int adfs_f_read(struct super_block *sb, u32 indaddr, unsigned int size,
|
|
struct adfs_dir *dir)
|
|
{
|
|
int ret;
|
|
|
|
if (size != ADFS_NEWDIR_SIZE)
|
|
return -EIO;
|
|
|
|
ret = adfs_dir_read(sb, indaddr, size, dir);
|
|
if (ret)
|
|
adfs_error(sb, "unable to read directory");
|
|
else
|
|
dir->parent_id = adfs_readval(dir->dirtail.new.dirparent, 3);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
adfs_f_setpos(struct adfs_dir *dir, unsigned int fpos)
|
|
{
|
|
if (fpos >= ADFS_NUM_DIR_ENTRIES)
|
|
return -ENOENT;
|
|
|
|
dir->pos = 5 + fpos * 26;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
adfs_f_getnext(struct adfs_dir *dir, struct object_info *obj)
|
|
{
|
|
unsigned int ret;
|
|
|
|
ret = __adfs_dir_get(dir, dir->pos, obj);
|
|
if (ret == 0)
|
|
dir->pos += 26;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
adfs_f_update(struct adfs_dir *dir, struct object_info *obj)
|
|
{
|
|
struct super_block *sb = dir->sb;
|
|
int ret, i;
|
|
|
|
ret = adfs_dir_find_entry(dir, obj->indaddr);
|
|
if (ret < 0) {
|
|
adfs_error(dir->sb, "unable to locate entry to update");
|
|
goto out;
|
|
}
|
|
|
|
__adfs_dir_put(dir, ret, obj);
|
|
|
|
/*
|
|
* Increment directory sequence number
|
|
*/
|
|
dir->bh[0]->b_data[0] += 1;
|
|
dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 6] += 1;
|
|
|
|
ret = adfs_dir_checkbyte(dir);
|
|
/*
|
|
* Update directory check byte
|
|
*/
|
|
dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 1] = ret;
|
|
|
|
#if 1
|
|
{
|
|
const unsigned int blocksize_bits = sb->s_blocksize_bits;
|
|
|
|
memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
|
|
memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));
|
|
|
|
if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq ||
|
|
memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
|
|
goto bad_dir;
|
|
|
|
if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
|
|
memcmp(&dir->dirhead.startname, "Hugo", 4))
|
|
goto bad_dir;
|
|
|
|
if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
|
|
goto bad_dir;
|
|
}
|
|
#endif
|
|
for (i = dir->nr_buffers - 1; i >= 0; i--)
|
|
mark_buffer_dirty(dir->bh[i]);
|
|
|
|
ret = 0;
|
|
out:
|
|
return ret;
|
|
#if 1
|
|
bad_dir:
|
|
adfs_error(dir->sb, "whoops! I broke a directory!");
|
|
return -EIO;
|
|
#endif
|
|
}
|
|
|
|
static int
|
|
adfs_f_sync(struct adfs_dir *dir)
|
|
{
|
|
int err = 0;
|
|
int i;
|
|
|
|
for (i = dir->nr_buffers - 1; i >= 0; i--) {
|
|
struct buffer_head *bh = dir->bh[i];
|
|
sync_dirty_buffer(bh);
|
|
if (buffer_req(bh) && !buffer_uptodate(bh))
|
|
err = -EIO;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static void
|
|
adfs_f_free(struct adfs_dir *dir)
|
|
{
|
|
int i;
|
|
|
|
for (i = dir->nr_buffers - 1; i >= 0; i--) {
|
|
brelse(dir->bh[i]);
|
|
dir->bh[i] = NULL;
|
|
}
|
|
|
|
dir->nr_buffers = 0;
|
|
dir->sb = NULL;
|
|
}
|
|
|
|
const struct adfs_dir_ops adfs_f_dir_ops = {
|
|
.read = adfs_f_read,
|
|
.setpos = adfs_f_setpos,
|
|
.getnext = adfs_f_getnext,
|
|
.update = adfs_f_update,
|
|
.sync = adfs_f_sync,
|
|
.free = adfs_f_free
|
|
};
|