dos33fsprogs/dos33fs-linux2.4/dir.c
Vince Weaver 4f96a4e326 Add dos33fs code
This was a dos33fs filesystem driver for Linux 2.4

It is included for historical reasons.
2016-03-11 14:57:07 -05:00

594 lines
17 KiB
C

/*****************************************************************************
* dir.c
* File and inode operations for directories.
*
* Apple II DOS 3.3 Filesystem Driver for Linux 2.4.x
* Copyright (c) 2001 Vince Weaver
* Copyright (c) 2001 Matt Jensen.
* This program is free software distributed under the terms of the GPL.
*****************************************************************************/
/*= Kernel Includes =========================================================*/
#include <linux/blkdev.h>
/*= DOS 3.3 Includes =======================================================*/
#include "dos33.h"
/*= Forward Declarations ===================================================*/
/* For dos33_dir_inode_operations. */
struct dentry *dos33_lookup(struct inode *,struct dentry *);
int dos33_create(struct inode *,struct dentry *,int);
int dos33_unlink(struct inode *,struct dentry *);
int dos33_rename(struct inode *,struct dentry *,struct inode *,struct dentry *);
/* For dos33_dir_operations. */
int dos33_readdir(struct file *,void *,filldir_t);
/*= VFS Interface Structures ================================================*/
struct inode_operations dos33_dir_inode_operations = {
lookup: dos33_lookup,
create: dos33_create,
unlink: dos33_unlink,
rename: dos33_rename
};
struct file_operations dos33_dir_operations = {
read: generic_read_dir,
readdir: dos33_readdir
/* fsync: file_fsync */
};
/*****************************************************************************
* dos33_new_dir_block()
* Allocate and initialize a new directory block.
*****************************************************************************/
int dos33_expand_dir(struct super_block *sb,u16 block) {
int result = 0;
// u16 new_block = 0;
// struct buffer_head *dir_bh = NULL;
// struct dos33_dir_block *dir = NULL;
DOS33_DEBUG("expand_dir\n");
#if 0
/* Try to allocate a new block. */
new_block = prodos_alloc_block(sb);
if (!new_block) {
result = -ENOSPC;
goto out_cleanup;
}
/* Read the block. */
dir_bh = prodos_bread(sb,new_block);
if (!dir_bh) {
result = -EIO;
goto out_cleanup;
}
dir = (void*)dir_bh->b_data;
/* Initialize the block. */
memset(dir,0,PRODOS_BLOCK_SIZE);
dir->header.prev = cpu_to_le16(block);
dir->header.next = 0;
mark_buffer_dirty(dir_bh);
result = new_block;
out_cleanup:
if (dir_bh) prodos_brelse(dir_bh);
#endif
return result;
}
/*****************************************************************************
* dos33_find_entry()
* Search directory @inode for an entry. If @name is non-NULL, the directory
* is searched for an entry with matching name; if @name is NULL, the
* directory is searched (and possibly expanded) for an unused entry. Zero is
* returned on failure; the found entry's inode number is returned on success.
*****************************************************************************/
unsigned long dos33_find_entry(struct inode *inode,struct qstr *name) {
unsigned long result = 0;
u32 catalog_block = (DOS33_INO_TRACK(inode->i_ino)<<4)+
DOS33_INO_SECTOR(inode->i_ino);
u32 odd=0,entry_num=0;
struct buffer_head *bh = NULL;
struct dos33_catalog_sector *catalog = NULL;
DOS33_DEBUG("find entry: %i %x\n",(int)inode->i_ino,(int)catalog_block);
/* Scan the directory for a matching entry. */
while (catalog_block) {
/* Load next directory block when necessary. */
if (!bh) {
odd=catalog_block%2;
/* Load the block. */
DOS33_DEBUG("==Loading block %x\n",catalog_block);
bh = dos33_bread(inode->i_sb,catalog_block);
if (!bh) {
DOS33_DEBUG("dos33_bread() failed for block %d\n",catalog_block);
goto out_cleanup;
}
/* deal with 256byte sector size */
if (odd) {
catalog = (struct dos33_catalog_sector*)(bh->b_data+256);
}
else {
catalog = (struct dos33_catalog_sector*)(bh->b_data);
}
}
/* Searching for an empty entry. FIX ME */
if (!name) {
DOS33_DEBUG("== no name dir.c FIXME\n");
// result = DOS33_MAKE_INO(0,(cur_block>>4)&0xffff,cur_block&0xf);
goto out_cleanup;
}
else {
int qlen=name->len;
int mismatch=0;
int i;
struct dos33_file_t *file_ent=&catalog->files[entry_num];
/* Do the names match? */
for(i=0;i<qlen;i++) {
if ( name->name[i] != ((file_ent->file_name[i])&0x7f)) mismatch++;
}
/* If they match, return the inode */
if (!mismatch) {
DOS33_DEBUG("==MATCH %s\n",name->name);
result = DOS33_MAKE_INO(0,entry_num,
(catalog_block>>4)&0x7f,
(catalog_block)&0xf);
goto out_cleanup;
}
}
/* Advance to next entry. */
/* For now only handle first 7 files */
if (++entry_num >= 7) {
DOS33_DEBUG("ENDDDDDDDDDDDING\n");
entry_num=0;
catalog_block = ((catalog->next.track)<<4)+catalog->next.sector;
DOS33_DEBUG("== next block %x\n",catalog_block);
/* Release previous block. */
dos33_brelse(bh);
bh = NULL;
}
}
out_cleanup:
if (bh) {
dos33_brelse(bh);
bh = NULL;
}
return result;
}
/*****************************************************************************
* prodos_unlink_all()
* Unlink (delete) all forks of the ProDOS file represented by an @inode.
*****************************************************************************/
#if 0
int dos33_unlink_all(struct inode *inode,struct dos33_dir_entry *ent) {
int result = 0;
const u16 dblk = PRODOS_INO_DBLK(inode->i_ino);
const u8 dent = PRODOS_INO_DENT(inode->i_ino);
u8 dfrk = PRODOS_INO_DFORK(inode->i_ino);
struct buffer_head *ext_bh = NULL;
/* We may have to delete TWO forks. */
if (PRODOS_ISEXTENDED(*ent)) {
struct prodos_ext_key_block *ext_block = NULL;
/* Load the extended directory block. */
ext_bh = prodos_bread(inode->i_sb,PRODOS_I(inode)->i_key);
if (!ext_bh) {
result = -EIO;
goto out_cleanup;
}
ext_block = (void*)ext_bh->b_data;
/* Free the resource fork. */
prodos_free_tree_blocks(inode->i_sb,ext_block->res.stype << 4,
le16_to_cpu(ext_block->res.key_block),
le16_to_cpu(ext_block->res.blocks_used));
/* Free the data fork. */
prodos_free_tree_blocks(inode->i_sb,ext_block->data.stype << 4,
le16_to_cpu(ext_block->data.key_block),
le16_to_cpu(ext_block->data.blocks_used));
/* Release the extended directory block. */
prodos_brelse(ext_bh);
ext_bh = NULL;
/* Free the extended directory block. */
prodos_free_block(inode->i_sb,PRODOS_I(inode)->i_key);
}
/* ...or we may only have to delete one fork. */
else {
prodos_free_tree_blocks(inode->i_sb,PRODOS_I(inode)->i_stype,
le16_to_cpu(ent->key_block),
le16_to_cpu(ent->blocks_used));
}
/* Update this inode. */
inode->i_nlink--;
mark_inode_dirty(inode);
/* Unlink the resource fork inode. */
if (PRODOS_I(inode)->i_stype == PRODOS_STYPE_EXTENDED) {
inode = iget(inode->i_sb,PRODOS_MAKE_INO(dblk,dent,PRODOS_DFORK_RES));
if (inode) {
down(&inode->i_sem);
inode->i_nlink--;
mark_inode_dirty(inode);
up(&inode->i_sem);
iput(inode);
}
}
/* We may have been called on either a data fork inode OR a meta file
inode. Unlink the one upon which we were NOT called (the one we were
called on has, obviously, already been unlinked.) */
dfrk = dfrk == PRODOS_DFORK_META ? PRODOS_DFORK_DATA : PRODOS_DFORK_META;
inode = iget(inode->i_sb,PRODOS_MAKE_INO(dblk,dent,dfrk));
if (inode) {
down(&inode->i_sem);
inode->i_nlink--;
mark_inode_dirty(inode);
up(&inode->i_sem);
iput(inode);
}
/* Mark the directory entry as deleted. */
ent->name[0] &= 0x0f;
result = 1;
out_cleanup:
if (ext_bh) prodos_brelse(ext_bh);
return result;
}
#endif
/*****************************************************************************
* prodos_unlink_res()
* Unlink (delete) the resource fork of the ProDOS file represented by an
* @inode. This is the most involved of the unlink operations. The resource
* fork is deleted and its blocks freed, then the file is collapsed into a
* a regular (non-extended) file by copying the data fork metainformation from
* the extended directory block into the base directory entry itself.
*****************************************************************************/
#if 0
int dos33_unlink_res(struct inode *inode,struct prodos_dir_entry *ent) {
int result = 0;
struct buffer_head *key_bh = NULL;
struct prodos_ext_key_block *key_block = NULL;
/* Need the key block so we can copy data fork info into the dir entry. */
key_bh = prodos_bread(inode->i_sb,PRODOS_I(inode)->i_key);
if (!key_bh) {
result = -EIO;
goto out_cleanup;
}
key_block = (void*)key_bh->b_data;
/* Update the directory entry. Note that we don't have to worry about byte
order since we're copying from one on-disk entry to another. */
ent->name[0] &= 0x0f;
ent->name[0] |= key_block->data.stype << 4;
ent->key_block = key_block->data.key_block;
ent->blocks_used = key_block->data.blocks_used;
memcpy(&ent->eof,&key_block->data.eof,3);
/* TODO: Update the data and meta inodes here (stype, key block, size, blocks used) */
/* Free affected disk blocks. */
prodos_free_tree_blocks(inode->i_sb,key_block->res.stype << 4,
le16_to_cpu(key_block->res.key_block),
le16_to_cpu(key_block->res.blocks_used));
prodos_free_block(inode->i_sb,PRODOS_I(inode)->i_key);
/* The inode is now dirty; also return 1 to cause the directory buffer
to be marked dirty. */
mark_inode_dirty(inode);
result = 1;
out_cleanup:
if (key_bh) prodos_brelse(key_bh);
return result;
}
#endif
/*= Interface Functions =====================================================*/
/*****************************************************************************
* dos33_lookup()
* Search a directory inode for an entry.
*****************************************************************************/
struct dentry *dos33_lookup(struct inode *inode,struct dentry *dentry) {
SHORTCUT struct dos33_sb_info * const psb = DOS33_SB(inode->i_sb);
struct dentry *result = NULL;
unsigned long ino = 0;
DOS33_DEBUG("Lookup\n");
/* Grab directory lock. */
down(&psb->s_dir_lock);
/* Attempt to find matching entry and get its inode number. */
ino = dos33_find_entry(inode,&dentry->d_name);
if (!ino) {
result = ERR_PTR(-ENOENT);
goto out_cleanup;
}
/* Get the inode and set up a dentry. */
inode = iget(inode->i_sb,ino);
if (!inode) {
DOS33_DEBUG("iget() failed for ino 0x%08x",(int)ino);
result = ERR_PTR(-EACCES);
goto out_cleanup;
}
dentry->d_op = &dos33_dentry_operations;
d_add(dentry,inode);
out_cleanup:
up(&psb->s_dir_lock);
return result;
}
/*****************************************************************************
* prodos_create()
* Create a new entry in directory inode @dir. Note that the VFS has already
* checked that the filename is unique within the directory.
*****************************************************************************/
int dos33_create(struct inode *dir,struct dentry *dentry,int mode) {
// SHORTCUT struct prodos_sb_info * psb = PRODOS_SB(dir->i_sb);
int result = 0;
// unsigned long ino = 0;
// struct buffer_head *dir_bh = NULL;
DOS33_DEBUG("create\n");
#if 0
PRODOS_ERROR_0(dir->i_sb,"called");
/* Grab directory lock. */
down(&psb->s_dir_lock);
/* Get an unused "inode" in the directory. */
ino = prodos_find_entry(dir,NULL);
if (!ino) {
result = -ENOSPC;
goto out_cleanup;
}
/* Read the directory block. */
/* dir_bh = prodos_bread(dir->i_sb,PRODOS_INO_DBLK(ino));
if (!dir_bh) {
result = -EIO;
goto out_cleanup;
}*/
result = -EPERM;
out_cleanup:
if (dir_bh) prodos_brelse(dir_bh);
up(&psb->s_dir_lock);
#endif
return result;
}
/*****************************************************************************
* prodos_unlink()
*****************************************************************************/
/* NOTE: The VFS holds the inode->i_zombie semaphore during this call. */
/* The big kernel lock is also held for exactly the duration of this call. */
int dos33_unlink(struct inode *inode,struct dentry *dentry) {
// SHORTCUT struct prodos_sb_info * const psb = PRODOS_SB(inode->i_sb);
// SHORTCUT struct inode * const victim = dentry->d_inode;
int result = 0;
// struct buffer_head *dir_bh = NULL;
// struct prodos_dir_entry *ent = NULL;
DOS33_DEBUG("unlink\n");
#if 0
/* Grab directory lock. */
down(&psb->s_dir_lock);
/* Load the directory block. */
dir_bh = prodos_bread(inode->i_sb,PRODOS_INO_DBLK(victim->i_ino));
if (!dir_bh) {
result = -EIO;
goto out_cleanup;
}
ent = &((struct prodos_dir_block*)dir_bh->b_data)->entries[PRODOS_INO_DENT(victim->i_ino)];
/* Dispatch appropriate unlink function. */
switch (PRODOS_INO_DFORK(victim->i_ino)) {
case PRODOS_DFORK_DATA:
result = prodos_unlink_all(victim,ent);
break;
case PRODOS_DFORK_META:
result = prodos_unlink_all(victim,ent);
break;
case PRODOS_DFORK_RES:
if (!PRODOS_ISEXTENDED(*ent)) {
result = -ENOENT;
goto out_cleanup;
}
result = prodos_unlink_res(victim,ent);
break;
}
/* The prodos_unlink_*() helper returned 1 if it dirtied the dir block. */
if (result == 1) {
mark_buffer_dirty(dir_bh);
result = 0;
}
out_cleanup:
if (dir_bh) prodos_brelse(dir_bh);
up(&psb->s_dir_lock);
#endif
return result;
}
/*****************************************************************************
* prodos_rename()
*****************************************************************************/
int dos33_rename(struct inode *oi,struct dentry *od,struct inode *ni,struct dentry *nd) {
int result = 0;
DOS33_DEBUG("rename\n");
#if 0
/* Our inode number usage prevents all but in-directory renames. */
if (oi != ni) {
result = -EPERM;
goto out_cleanup;
}
result = -EPERM;
out_cleanup:
#endif
return result;
}
/*****************************************************************************
* dos33_readdir()
* Standard file operation; reads a directory and returns its entries via
* the filldir() function supplied by the caller.
*****************************************************************************/
int dos33_readdir(struct file *filp,void *dirent,filldir_t filldir) {
SHORTCUT struct super_block * const sb = filp->f_dentry->d_sb;
SHORTCUT struct inode * const inode = filp->f_dentry->d_inode;
SHORTCUT struct inode * const parent = filp->f_dentry->d_parent->d_inode;
int result = 0;
struct buffer_head *bh = NULL;
struct dos33_catalog_sector *catalog = NULL;
u32 dent=0;
u32 catalog_track = DOS33_INO_TRACK(filp->f_pos);
u32 catalog_sector = DOS33_INO_SECTOR(filp->f_pos);
u32 catalog_block;
u32 odd;
struct dos33_file_t *ent = NULL;
char name[DOS33_MAX_NAME_LEN + 3] = "";
int nlen;
unsigned int ino = 0;
DOS33_DEBUG("readdir\n");
/* Handle the special '.' and '..' entries. */
switch ( (long int)filp->f_pos) {
case 0: /* Add the '.' entry. */
if (filldir(dirent,".",1,0,inode->i_ino,DT_DIR) < 0)
goto out_cleanup;
/* fpos is simply incremented at this point. */
filp->f_pos++;
/* Fall through. */
case 1: /* Add the '..' entry. */
if (filldir(dirent,"..",2,1,parent->i_ino,DT_DIR) < 0)
goto out_cleanup;
/* fpos takes on special format after second entry. */
filp->f_pos = DOS33_MAKE_INO(0,0,
DOS33_INO_TRACK(inode->i_ino),
DOS33_INO_SECTOR(inode->i_ino));
}
/* Grab directory lock. */
down(&DOS33_SB(sb)->s_dir_lock);
/* After the two special entries, filp->f_pos is the "inode number" of the
next file (or fork) in the directory. See the PRODOS_INO_*() and
PRODOS_MAKE_INO() macros for the format of this value. When all entries
have been returned filp->f_pos is set to 3 to signal end-of-directory. */
while (filp->f_pos != 3) {
catalog_block=((catalog_track<<4)+catalog_sector);
odd=catalog_block%2;
DOS33_DEBUG("filp: %x dblk: %x %i %i\n",(int)filp->f_pos,(int)catalog_block,(int)catalog_track,(int)catalog_sector);
/* Load the block if necessary. */
if (!bh) {
bh = dos33_bread(sb,catalog_block);
if (!bh) {
result = -EIO;
goto out_cleanup;
}
/* handle 256 byte sectors */
if (odd) {
catalog = (struct dos33_catalog_sector*)(bh->b_data+256);
}
else {
catalog = (struct dos33_catalog_sector*)bh->b_data;
}
}
ent = &catalog->files[dent];
/* Copy and modify the name as necessary. */
if (ent->file_name[0]!=0) {
memcpy(name,&(ent->file_name),DOS33_MAX_NAME_LEN+1);
nlen=dos33_convert_filename(name);
/* Build inode number. */
ino = DOS33_MAKE_INO(0,dent,catalog_track,
catalog_sector);
/* Finally, attempt to return the entry via filldir(). */
if (filldir(dirent,&name[0],nlen,filp->f_pos,ino,DT_UNKNOWN) < 0)
goto out_cleanup;
}
dent++;
if (dent>6) {
dent=0;
dos33_brelse(bh);
bh=NULL;
catalog_track=(catalog->next.track);
catalog_sector=(catalog->next.sector);
if ((!catalog_track) && (!catalog_sector)) {
filp->f_pos=3;
}
}
}
/* Release remaining resources and return. */
out_cleanup:
if (bh) {
dos33_brelse(bh);
bh = NULL;
}
up(&DOS33_SB(sb)->s_dir_lock);
return result;
}