generic-2.6: add 2.6.34 preliminary support (patches)

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@20140 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 7782 insertions, 0 deletions

diff --git a/target/linux/generic-2.6/patches-2.6.34/209-mini_fo.patch b/target/linux/generic-2.6/patches-2.6.34/209-mini_fo.patch
new file mode 100644
index 0000000000..b2625cd269
--- /dev/null
+++ b/target/linux/generic-2.6/patches-2.6.34/209-mini_fo.patch
@@ -0,0 +1,7782 @@
+--- a/fs/Kconfig
++++ b/fs/Kconfig
+@@ -180,6 +180,7 @@ source "fs/ubifs/Kconfig"
+ source "fs/cramfs/Kconfig"
+ source "fs/squashfs/Kconfig"
+ source "fs/freevxfs/Kconfig"
++source "fs/mini_fo/Kconfig"
+ source "fs/minix/Kconfig"
+ source "fs/omfs/Kconfig"
+ source "fs/hpfs/Kconfig"
+--- a/fs/Makefile
++++ b/fs/Makefile
+@@ -77,6 +77,7 @@ obj-$(CONFIG_SQUASHFS)		+= squashfs/
+ obj-y				+= ramfs/
+ obj-$(CONFIG_HUGETLBFS)		+= hugetlbfs/
+ obj-$(CONFIG_CODA_FS)		+= coda/
++obj-$(CONFIG_MINI_FO)		+= mini_fo/
+ obj-$(CONFIG_MINIX_FS)		+= minix/
+ obj-$(CONFIG_FAT_FS)		+= fat/
+ obj-$(CONFIG_BFS_FS)		+= bfs/
+--- /dev/null
++++ b/fs/mini_fo/aux.c
+@@ -0,0 +1,577 @@
++/*
++ * Copyright (c) 1997-2003 Erez Zadok
++ * Copyright (c) 2001-2003 Stony Brook University
++ *
++ * For specific licensing information, see the COPYING file distributed with
++ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
++ *
++ * This Copyright notice must be kept intact and distributed with all
++ * fistgen sources INCLUDING sources generated by fistgen.
++ */
++/*
++ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ */
++/*
++ *  $Id$
++ */
++
++#ifdef HAVE_CONFIG_H
++# include <config.h>
++#endif
++
++#include "fist.h"
++#include "mini_fo.h"
++
++/* check if file exists in storage  */
++int exists_in_storage(dentry_t *dentry)
++{
++	check_mini_fo_dentry(dentry);
++	if(dtost(dentry) == MODIFIED || dtost(dentry) == CREATED || dtost(dentry) == DEL_REWRITTEN)
++		return 1;
++	return 0;
++}
++
++/* check if dentry is in an existing state */
++int is_mini_fo_existant(dentry_t *dentry)
++{
++	check_mini_fo_dentry(dentry);
++
++	if(dtost(dentry) == DELETED || dtost(dentry) == NON_EXISTANT)
++		return 0;
++	else
++		return 1;
++}
++
++/*
++ * This function will create a negative storage dentry for
++ * dentry, what is required for many create like options.
++ * It will create the storage structure if necessary.
++ */
++int get_neg_sto_dentry(dentry_t *dentry)
++{
++	int err = 0;
++	unsigned int len;
++	const unsigned char *name;
++
++	if(!dentry ||
++	   !dtopd(dentry) ||
++	   !(dtost(dentry) == UNMODIFIED ||
++	     dtost(dentry) == NON_EXISTANT ||
++	     dtost(dentry) == DELETED)) {
++		printk(KERN_CRIT "mini_fo: get_neg_sto_dentry: invalid dentry passed.\n");
++		err = -1;
++		goto out;
++	}
++	/* Have we got a neg. dentry already? */
++	if(dtohd2(dentry)) {
++		err = 0;
++		goto out;
++	}
++	if(dtost(dentry->d_parent) == UNMODIFIED) {
++		/* build sto struct */
++		err = build_sto_structure(dentry->d_parent->d_parent, dentry->d_parent);
++		if(err ||
++		   dtost(dentry->d_parent) != MODIFIED) {
++			printk(KERN_CRIT "mini_fo: get_neg_sto_dentry: ERROR building sto structure.\n");
++			err = -1;
++			goto out;
++		}
++	}
++
++	len = dentry->d_name.len;
++	name = dentry->d_name.name;
++
++	dtohd2(dentry) =
++		lookup_one_len(name, dtohd2(dentry->d_parent), len);
++
++ out:
++	return err;
++}
++
++int check_mini_fo_dentry(dentry_t *dentry)
++{
++ 	ASSERT(dentry != NULL);
++	ASSERT(dtopd(dentry) != NULL);
++	ASSERT((dtohd(dentry) != NULL) || (dtohd2(dentry) != NULL));
++
++/* 	if(dtost(dentry) == MODIFIED) { */
++/* 		ASSERT(dentry->d_inode != NULL); */
++/* 		ASSERT(dtohd(dentry) != NULL); */
++/* 		ASSERT(dtohd(dentry)->d_inode != NULL); */
++/* 		ASSERT(dtohd2(dentry) != NULL); */
++/* 		ASSERT(dtohd2(dentry)->d_inode != NULL); */
++/* 	} */
++/* 	else if(dtost(dentry) == UNMODIFIED) { */
++/* 		ASSERT(dentry->d_inode != NULL); */
++/* 		ASSERT( */
++/* 	} */
++	return 0;
++}
++
++int check_mini_fo_file(file_t *file)
++{
++	ASSERT(file != NULL);
++	ASSERT(ftopd(file) != NULL);
++	ASSERT(file->f_dentry != NULL);
++
++	/* violent checking, check depending of state and type
++	 *	if(S_ISDIR(file->f_dentry->d_inode->i_mode)) {}
++	 */
++	ASSERT((ftohf(file) != NULL) || (ftohf2(file) != NULL));
++	return 0;
++}
++
++int check_mini_fo_inode(inode_t *inode)
++{
++	ASSERT(inode != NULL);
++	ASSERT(itopd(inode) != NULL);
++	ASSERT((itohi(inode) != NULL) || (itohi2(inode) != NULL));
++	return 0;
++}
++
++/*
++ * will walk a base path as provided by get_mini_fo_bpath and return
++ * the (hopefully ;-) ) positive dentry of the renamed base dir.
++ *
++ * This does some work of path_init.
++ */
++dentry_t *bpath_walk(super_block_t *sb, char *bpath)
++{
++	int err;
++        struct vfsmount *mnt;
++	struct nameidata nd;
++
++	/* be paranoid */
++	if(!bpath || bpath[0] != '/') {
++		printk(KERN_CRIT "mini_fo: bpath_walk: Invalid string.\n");
++		return NULL;
++	}
++	if(!sb || !stopd(sb)) {
++		printk(KERN_CRIT "mini_fo: bpath_walk: Invalid sb.\n");
++		return NULL;
++	}
++
++	/* fix this: how do I reach this lock?
++	 * read_lock(&current->fs->lock); */
++	mnt = mntget(stopd(sb)->hidden_mnt);
++	/* read_unlock(&current->fs->lock); */
++
++	err = vfs_path_lookup(mnt->mnt_root, mnt, bpath+1, 0, &nd);
++
++	/* validate */
++	if (err || !nd.dentry || !nd.dentry->d_inode) {
++		printk(KERN_CRIT "mini_fo: bpath_walk: path_walk failed.\n");
++		return NULL;
++	}
++	return nd.dentry;
++}
++
++
++/* returns the full path of the basefile incl. its name */
++int get_mini_fo_bpath(dentry_t *dentry, char **bpath, int *bpath_len)
++{
++	char *buf_walker;
++	int len = 0;
++	dentry_t *sky_walker;
++
++	if(!dentry || !dtohd(dentry)) {
++		printk(KERN_CRIT "mini_fo: get_mini_fo_bpath: invalid dentry passed.\n");
++		return -1;
++	}
++	sky_walker = dtohd(dentry);
++
++	do {
++		len += sky_walker->d_name.len + 1 ; /* 1 for '/' */
++		sky_walker = sky_walker->d_parent;
++	} while(sky_walker != stopd(dentry->d_inode->i_sb)->base_dir_dentry);
++
++	/* 1 to oil the loop */
++	*bpath = (char*)  kmalloc(len + 1, GFP_KERNEL);
++	if(!*bpath) {
++		printk(KERN_CRIT "mini_fo: get_mini_fo_bpath: out of mem.\n");
++		return -1;
++	}
++	buf_walker = *bpath+len; /* put it on last char */
++	*buf_walker = '\n';
++	sky_walker = dtohd(dentry);
++
++	do {
++		buf_walker -= sky_walker->d_name.len;
++		strncpy(buf_walker,
++			sky_walker->d_name.name,
++			sky_walker->d_name.len);
++		*(--buf_walker) = '/';
++		sky_walker = sky_walker->d_parent;
++	} while(sky_walker != stopd(dentry->d_inode->i_sb)->base_dir_dentry);
++
++	/* bpath_len doesn't count newline! */
++	*bpath_len = len;
++ 	return 0;
++}
++
++int mini_fo_cp_cont(dentry_t *tgt_dentry, struct vfsmount *tgt_mnt,
++		    dentry_t *src_dentry, struct vfsmount *src_mnt)
++{
++	void *buf;
++	mm_segment_t old_fs;
++	file_t *tgt_file;
++	file_t *src_file;
++	int bytes, len, tmp, err;
++	err = 0;
++
++	if(!(tgt_dentry->d_inode && src_dentry->d_inode)) {
++		printk(KERN_CRIT "mini_fo_cp_cont: ERROR, neg. dentry passed.\n");
++		err = -EINVAL;
++		goto out;
++	}
++
++	dget(tgt_dentry);
++	dget(src_dentry);
++	mntget(tgt_mnt);
++	mntget(src_mnt);
++
++	/* open file write only */
++	tgt_file = dentry_open(tgt_dentry, tgt_mnt, 0x1);
++	if(!tgt_file || IS_ERR(tgt_file)) {
++		printk(KERN_CRIT "mini_fo_cp_cont: ERROR opening target file.\n");
++		err = PTR_ERR(tgt_file);
++		goto out_err;
++	}
++
++	/* open file read only */
++	src_file = dentry_open(src_dentry, src_mnt, 0x0);
++	if(!src_file || IS_ERR(src_file)) {
++		printk(KERN_CRIT "mini_fo_cp_cont: ERROR opening source file.\n");
++		err = PTR_ERR(src_file);
++
++		/* close target file */
++		fput(tgt_file);
++		goto out_err;
++	}
++
++	/* check if the filesystem(s) support read respective write */
++	if(!src_file->f_op->read || !tgt_file->f_op->write) {
++		printk(KERN_CRIT "mini_fo_cp_cont: ERROR, no fs read or write support.\n");
++		err = -EPERM;
++		goto out_close;
++	}
++
++	/* allocate a page for transfering the data */
++	buf = (void *) __get_free_page(GFP_KERNEL);
++	if(!buf) {
++		printk(KERN_CRIT "mini_fo_cp_cont: ERROR, out of kernel mem.\n");
++		goto out_err;
++	}
++
++	tgt_file->f_pos = 0;
++	src_file->f_pos = 0;
++
++	old_fs = get_fs();
++	set_fs(KERNEL_DS);
++
++	/* Doing this I assume that a read operation will return a full
++	 * buffer while there is still data to read, and a less than
++	 * full buffer when all data has been read.
++	 */
++	bytes = len = PAGE_SIZE;
++	while(bytes == len) {
++		bytes = src_file->f_op->read(src_file, buf, len,
++					     &src_file->f_pos);
++		tmp = tgt_file->f_op->write(tgt_file, buf, bytes,
++					    &tgt_file->f_pos);
++		if(tmp != bytes) {
++			printk(KERN_CRIT "mini_fo_cp_cont: ERROR writing.\n");
++			goto out_close_unset;
++		}
++	}
++
++	free_page((unsigned long) buf);
++	set_fs(old_fs);
++	fput(tgt_file);
++	fput(src_file);
++	goto out;
++
++ out_close_unset:
++	free_page((unsigned long) buf);
++	set_fs(old_fs);
++
++ out_close:
++	fput(tgt_file);
++	fput(src_file);
++
++ out_err:
++	dput(tgt_dentry);
++	dput(src_dentry);
++
++	/* mk: not sure if this need to be done */
++	mntput(tgt_mnt);
++	mntput(src_mnt);
++
++ out:
++	return err;
++}
++
++/* mk:
++ * ndl (no-duplicate list) stuff
++ * This is used in mini_fo_readdir, to save the storage directory contents
++ * and later when reading base, match them against the list in order
++ * to avoid duplicates.
++ */
++
++/* add a file specified by name and len to the ndl
++ * Return values: 0 on success, <0 on failure.
++ */
++int ndl_add_entry(struct readdir_data *rd, const char *name, int len)
++{
++	struct ndl_entry *tmp_entry;
++
++	tmp_entry = (struct ndl_entry *)
++		kmalloc(sizeof(struct ndl_entry), GFP_KERNEL);
++	if(!tmp_entry) {
++                printk(KERN_CRIT "mini_fo: ndl_add_entry: out of mem.\n");
++                return -ENOMEM;
++        }
++        tmp_entry->name = (char*) kmalloc(len, GFP_KERNEL);
++        if(!tmp_entry->name) {
++                printk(KERN_CRIT "mini_fo: ndl_add_entry: out of mem.\n");
++                return -ENOMEM;
++        }
++	strncpy(tmp_entry->name, name, len);
++        tmp_entry->len = len;
++
++        list_add(&tmp_entry->list, &rd->ndl_list);
++        rd->ndl_size++;
++        return 0;
++}
++
++/* delete all list entries and free memory */
++void ndl_put_list(struct readdir_data *rd)
++{
++	struct list_head *tmp;
++	struct ndl_entry *tmp_entry;
++
++	if(rd->ndl_size <= 0)
++		return;
++	while(!list_empty(&rd->ndl_list)) {
++		tmp = rd->ndl_list.next;
++                list_del(tmp);
++                tmp_entry = list_entry(tmp, struct ndl_entry, list);
++		kfree(tmp_entry->name);
++                kfree(tmp_entry);
++        }
++	rd->ndl_size = 0;
++}
++
++/* Check if a file specified by name and len is in the ndl
++ * Return value: 0 if not in list, 1 if file is found in ndl.
++ */
++int ndl_check_entry(struct readdir_data *rd, const char *name, int len)
++{
++	struct list_head *tmp;
++	struct ndl_entry *tmp_entry;
++
++	if(rd->ndl_size <= 0)
++		return 0;
++
++	list_for_each(tmp, &rd->ndl_list) {
++                tmp_entry = list_entry(tmp, struct ndl_entry, list);
++                if(tmp_entry->len != len)
++                        continue;
++                if(!strncmp(tmp_entry->name, name, len))
++                        return 1;
++        }
++        return 0;
++}
++
++/* mk:
++ * Recursive function to create corresponding directorys in the storage fs.
++ * The function will build the storage directorys up to dentry.
++ */
++int build_sto_structure(dentry_t *dir, dentry_t *dentry)
++{
++	int err;
++	dentry_t *hidden_sto_dentry;
++	dentry_t *hidden_sto_dir_dentry;
++
++	if(dentry->d_parent != dir) {
++		printk(KERN_CRIT "mini_fo: build_sto_structure: invalid parameter or meta data corruption [1].\n");
++		return 1;
++	}
++
++       	if(dtost(dir) != MODIFIED) {
++		err = build_sto_structure(dir->d_parent, dentry->d_parent);
++		if(err)
++			return err;
++	}
++
++	/* ok, coming back again. */
++	check_mini_fo_dentry(dentry);
++	hidden_sto_dentry = dtohd2(dentry);
++
++	if(!hidden_sto_dentry) {
++		/*
++		 * This is the case after creating the first
++		 * hidden_sto_dentry.
++		 * After one negative storage_dentry, all pointers to
++		 * hidden_storage dentries are set to NULL. We need to
++		 * create the negative dentry before we create the storage
++		 * file.
++		 */
++		unsigned int len;
++		const unsigned char *name;
++		len = dtohd(dentry)->d_name.len;
++		name = dtohd(dentry)->d_name.name;
++		hidden_sto_dentry = lookup_one_len(name, dtohd2(dir), len);
++		dtohd2(dentry) = hidden_sto_dentry;
++	}
++
++	/* was:	hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry); */
++	hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	down(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++	/* lets be safe */
++	if(dtohd2(dir) != hidden_sto_dir_dentry) {
++		printk(KERN_CRIT "mini_fo: build_sto_structure: invalid parameter or meta data corruption [2].\n");
++		return 1;
++	}
++
++	/* check for errors in lock_parent */
++	err = PTR_ERR(hidden_sto_dir_dentry);
++	if(IS_ERR(hidden_sto_dir_dentry)) {
++		printk(KERN_CRIT "mini_fo: build_sto_structure: lock_parent failed.\n");
++		return err;
++	}
++
++	err = vfs_mkdir(hidden_sto_dir_dentry->d_inode,
++			hidden_sto_dentry,
++			dir->d_inode->i_mode);
++
++	if(err) {
++		printk(KERN_CRIT "mini_fo: build_sto_structure: failed to create storage dir [1].\n");
++		/* was: unlock_dir(dir); */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_unlock(&dir->d_inode->i_mutex);
++#else
++		up(&dir->d_inode->i_sem);
++#endif
++		dput(dir);
++		return err;
++	}
++
++	/* everything ok! */
++	if(!dtohd2(dentry)->d_inode) {
++		printk(KERN_CRIT "mini_fo: build_sto_structure: failed to create storage dir [2].\n");
++		/* was: unlock_dir(dir); */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_unlock(&dir->d_inode->i_mutex);
++#else
++		up(&dir->d_inode->i_sem);
++#endif
++		dput(dir);
++		return 1;
++	}
++
++	/* interpose the new inode and set new state */
++	itohi2(dentry->d_inode) = igrab(dtohd2(dentry)->d_inode);
++	dtopd(dentry)->state = MODIFIED;
++
++	/* initalize the wol list */
++	itopd(dentry->d_inode)->deleted_list_size = -1;
++	itopd(dentry->d_inode)->renamed_list_size = -1;
++	meta_build_lists(dentry);
++
++	fist_copy_attr_all(dentry->d_inode, itohi2(dentry->d_inode));
++	fist_copy_attr_timesizes(dir->d_inode,
++				 hidden_sto_dir_dentry->d_inode);
++	dir->d_inode->i_nlink++;
++	/* was: unlock_dir(hidden_sto_dir_dentry); */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++	dput(hidden_sto_dir_dentry);
++	return 0;
++}
++
++
++#if 0 /* unused */
++
++/*
++ * Read "len" bytes from "filename" into "buf".
++ * "buf" is in kernel space.
++ */
++int
++mini_fo_read_file(const char *filename, void *buf, int len)
++{
++    file_t *filp;
++    mm_segment_t oldfs;
++    int bytes;
++    /* Chroot? Maybe NULL isn't right here */
++    filp = filp_open(filename, O_RDONLY, 0);
++    if (!filp || IS_ERR(filp)) {
++	printk("mini_fo_read_file err %d\n", (int) PTR_ERR(filp));
++	return -1;  /* or do something else */
++    }
++
++    if (!filp->f_op->read)
++	return -2;  /* file(system) doesn't allow reads */
++
++    /* now read len bytes from offset 0 */
++    filp->f_pos = 0;		/* start offset */
++    oldfs = get_fs();
++    set_fs(KERNEL_DS);
++    bytes = filp->f_op->read(filp, buf, len, &filp->f_pos);
++    set_fs(oldfs);
++
++    /* close the file */
++    fput(filp);
++
++    return bytes;
++}
++
++
++
++/*
++ * Write "len" bytes from "buf" to "filename"
++ * "buf" is in kernel space.
++ */
++int
++mini_fo_write_file(const char *filename, void *buf, int len)
++{
++    file_t *filp;
++    mm_segment_t oldfs;
++    int bytes;
++				/* Chroot? Maybe NULL isn't right here */
++    filp = filp_open(filename, O_RDWR|O_CREAT, 0640);
++    if (!filp || IS_ERR(filp)) {
++	printk("mini_fo_write_file err %d\n", (int) PTR_ERR(filp));
++	return -1;  /* or do something else */
++    }
++
++    if (!filp->f_op->write)
++	return -2;  /* file(system) doesn't allow writes */
++
++    /* now write len bytes from offset 0 */
++    filp->f_pos = 0;		/* start offset */
++    oldfs = get_fs();
++    set_fs(KERNEL_DS);
++    bytes = filp->f_op->write(filp, buf, len, &filp->f_pos);
++    set_fs(oldfs);
++
++    /* close the file */
++    fput(filp);
++
++    return bytes;
++}
++
++#endif /* unused */
++
+--- /dev/null
++++ b/fs/mini_fo/ChangeLog
+@@ -0,0 +1,281 @@
++2006-01-24  Markus Klotzbuecher  <mk@mary.denx.de>
++
++	* Add tons of ugly ifdefs to Ed L. Cashin's mutex patch to
++          retain backwards compatibility.
++
++2006-01-24  Ed L. Cashin <ecashin@coraid.com>
++
++	* Support for the new mutex infrastructure
++	(7892f2f48d165a34b0b8130c8a195dfd807b8cb6)
++
++2005-10-15  Markus Klotzbuecher  <mk@localhost.localdomain>
++
++	* Bugfix for a serious memory leak in mini_fo_follow_link.
++
++2005-09-21  Markus Klotzbuecher  <mk@mary>
++
++	* new release 0.6.1
++
++	* fix of a compiler warning due to changes in 2.6.13
++
++2005-09-21  Klaus Wenninger  <klaus.wenninger@siemens.com>
++
++	* file.c: readdir: fix for a bug that caused directory entries
++          to show up twice when using storage filesystems such as
++          minixfs or pramfs.
++
++2005-06-30  Eric Lammerts <eric@lammerts.org>
++
++	* fix for an oops when overwriting a binary thats beeing
++          executed.
++
++2005-06-09    <mk@mary>
++
++	* Renamed overlay to mini_fo-overlay.
++
++	* Added mini_fo-merge script to allow merging of storage and base
++	after making modifications.
++
++2005-05-22  root  <mk@mary>
++
++	* Added overlay script that allows to easily mount mini_fo ontop
++	of a given base directory
++
++2005-05-10    <mk@mary>
++
++	* inode.c: xattr functions return -EOPNOSUPP instead of
++          -ENOSUPP, what confuses "ls -l"
++
++	* Changed license from LGPL to GPL.
++
++2005-05-08  root  <mk@mary>
++
++	* Makefile: clean it up and added make install and make
++          uninstall.
++
++2005-05-06    <mk@mary>
++
++	* merged devel branch back to main. [v0-6-0-pre3]
++
++	* removed unused files print.c and fist_ioctl. [devel-0-0-18]
++
++	* ioctl: removed fist_ioctl stuff, that is not needed for
++          now.
++
++2005-05-03    <mk@mary>
++
++	* file.c: simplified mini_fo_open and mini_fo_setattr using
++          new state changing functions. [devel-0-0-17]
++
++	* inode.c: Fixed getattr state bug (see below) in 2.4 function
++          mini_fo_inode revalidate.
++
++	* inode.c: found an other bug in mini_fo_getattr. States are not
++	  reliable in this function, as a file can be opened, unlinked and
++	  the getattr function called. This results in a deleted dentry
++	  with an inode. Fix is to ignore states and simply use the inode
++	  available.
++
++2005-04-29    <mk@mary>
++
++	* file.c: Bugfix and cleanup in fasync and fsync. [devel-0-0-16]
++
++	* file.c: do not use mini_fo_lock so the generic version is
++          used (I guess).
++
++	* inode.c: getattr, never call getattr on lower files, as this
++          will cause the inum to change.
++
++	* inode.c: rename_reg_file renamed to rename_nondir, as it
++          doesn't matter as long it't not a dir. Removed all
++          rename_dev_file etc.
++
++	* tagged as devel-0-0-15
++
++	* inode.c: added support for chosing support for extended
++          attrs at compile time by XATTR define in mini_fo.h .
++
++	* inode.c: fixed mini_fo_getattr to use mini_fo inode and not
++          lower again, what avoids inode number changes that confused
++          rm again. This is the proper solution.
++
++2005-04-24    <mk@mary>
++
++	* all files: updated Copyright notive to 2005. [devel-0-0-14]
++
++	* inode.c: fixed mini_fo_getattr to not change the inode
++          number, even if lower files change.
++
++	* super.c: fixed a bug that caused deleted base file to show
++          up suddenly after some time, or after creating a special
++          file. The problem was that after some time or after special
++          file creating sync_sb_inodes is called by the vfs, that
++          called our mini_fo_put_inode. There was (wrongly) called
++          __meta_put_lists, that nuked the lists, although the inode
++          was going to continue its life. Moving __meta_put_lists to
++          mini_fo_clear_inode, where an inode is really destroyed,
++          solved the problem.
++
++
++2005-04-23    <mk@mary>
++
++	* state.c, aux.c: more cleaning up and
++          simplifications. [devel-0-0-13]
++
++	* inode.c: implemented mini_fo_getattr, that was required for
++          2.6 because inode_revalidate has been remove there, and the
++	  old "du" bug returned.
++
++
++2005-04-20    <mk@mary>
++
++	* aux.c: get_neg_sto_dentry(): allow to be called for dentries
++          in state UNMODIFIED, NON_EXISTANT _and_ DELETED.
++
++2005-04-19    <mk@mary>
++
++	* Fixed a bug under 2.6 that caused files deleted via mini_fo
++          not to be deleted properly and therefore the fs filled up
++          untill no memory was left. [devel-0-0-12]
++
++	* Added basic hard link support. This means that creating
++          hardlinks will work, but existing ones will be treated as
++          individual files. [devel-0-0-11]
++
++2005-04-17    <mk@mary>
++
++	* Bugfixes
++
++2005-04-13  root  <mk@mary>
++
++	* Added file state.c for the state transition
++          functions. Doesn't work very well yet, though...
++
++2005-04-12    <mk@mary>
++
++	* Porting to 2.6 started, which is easier than expected, also
++          due to Olivier previous work.
++
++2005-04-08    <mk@mary>
++
++	* Fixed the bug that caused du to return invalid sizes of
++          directory trees. The problem was that
++          mini_fo_inode_revalidate didn't always copy the attributes
++          from the base inode properly.
++
++2005-04-01  Markus Klotzbuecher  <mk@chasey>
++
++	* Merged devel branch back to main trunk and updated the
++          RELEASE notes. This will be 0-6-0-pre1.
++
++2005-03-31  Markus Klotzbuecher  <mk@chasey>
++
++	* Fixed some bugs in rename_reg_file, that only showed up in
++          the kernel compile test. Kernel compiles cleanly ontop of
++          mini_fo, now also make mrproper etc. work. Seems pretty stable.
++
++2005-03-28  Markus Klotzbuecher  <mk@chasey>
++
++	* Many, many directory renaming bugfixes and a lot of other
++          cleanup. Dir renaming seems to work relatively stable.
++
++2005-03-22  Markus Klotzbuecher  <mk@chasey>
++
++	* Finished implementing lightweight directory renaming. Some
++          basic testing indicates it works fine.
++	  Next is to implement testcases for the testsuite and confirm
++          everything is really working ok.
++
++2005-03-18  Markus Klotzbuecher  <mk@chasey>
++
++	* Finished implementing meta.c stuff required for directory
++          renaming.
++
++2005-03-17  Markus Klotzbuecher  <mk@chasey>
++
++	* Fixed all compile warnings + an extremly old bug that
++          somehow crept in while reworking the wol stuff to the META
++          system. Turning on -Werror again... :-)
++
++	* Fixed some bugs in the new rename_reg_file function.
++
++	* Rewrote mini_fo rename and split it into several
++          subfunctions, that handle the different types
++          seperately. Rewrote the regular file function aswell, as it
++          was implemented somewhat inefficient.
++
++2005-03-16  Markus Klotzbuecher  <mk@chasey>
++
++	* Implemented new META subsystem, removed old WOL stuff in favor
++	  if it.
++
++	* After some basic testing everything seems ok...
++
++2005-03-11  Markus Klotzbuecher  <mk@chasey>
++
++	* Renaming a non regular file caused trouble because I always
++	  tried to copy the contents. Now I only do this for regular
++	  files. mini_fo_rename still isn't implemented properly, renaming
++	  of device files, symlinks etc. results in a empty regular file
++	  instead of the proper type.
++
++	* Directory renaming suddenly works! What a surprise! I guess
++          this is because renaming is implemented as making a copy and
++          removing the original. Still this might not work
++          everywhere...
++
++2005-03-09  Markus Klotzbuecher  <mk@chasey>
++
++	* Bugfix, when a mini_fo directory that exists in storage
++  	  (state: MODIFIED, CREATED and DEL_REWRITTEN) is deleted, a
++  	  possibly existing WOL file contained in it needs to be
++  	  deleted too.
++
++	* Starting cleanup: defined state names in order to get rid of
++          the state numbers.
++
++2005-03-08  Markus Klotzbuecher  <mk@chasey>
++
++	* Makefile fix, fist_ioctl was built against wrong sources if ARCH=um
++
++	* Fixed a bug in dentry.c, mini_fo_d_hash. In state 4 =
++          DEL_REWRITTEN the hash was calculated from the base dentry,
++          which was wrong and and caused assertions in
++          __mini_fo_hidden_dentry to fail.
++
++2005-02-21    <mk@mary>
++
++	* Implemented directory deleting (inode.c)
++
++	* main.c: made mini_fo_parse_options a little more robust.
++
++2004-12-22    <mk@mary>
++
++	* Makefile cleanup and uml stuff, removed unneccessary files
++
++	* Created a new and hopefully more informative README
++
++	* CHANGELOG: created a new CHANGELOG and added old entries reversely
++
++
++2004-10-24 Gleb Natapov <gleb@nbase.co.il>
++
++	* Fix: owner and group where not correctly copied from base to
++          storage.
++
++
++2004-10-05 Gleb Natapov <gleb@nbase.co.il>
++
++	* Implementation of fsync, fasync and lock mini_fo functions.
++
++
++2004-09-29 Bob Lee <bob@pantasys.com>
++
++	* Fix of a serious pointer bug
++
++
++2004-09-28 Gleb Natapov <gleb@nbase.co.il>
++
++	* Implementation of mini_fo_mknod and mini_fo_rename, support
++          for device files.
++
+--- /dev/null
++++ b/fs/mini_fo/dentry.c
+@@ -0,0 +1,244 @@
++/*
++ * Copyright (c) 1997-2003 Erez Zadok
++ * Copyright (c) 2001-2003 Stony Brook University
++ *
++ * For specific licensing information, see the COPYING file distributed with
++ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
++ *
++ * This Copyright notice must be kept intact and distributed with all
++ * fistgen sources INCLUDING sources generated by fistgen.
++ */
++/*
++ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ */
++
++/*
++ *  $Id$
++ */
++
++#ifdef HAVE_CONFIG_H
++# include <config.h>
++#endif
++
++#include "fist.h"
++#include "mini_fo.h"
++
++/*
++ * THIS IS A BOOLEAN FUNCTION: returns 1 if valid, 0 otherwise.
++ */
++STATIC int
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++mini_fo_d_revalidate(dentry_t *dentry, struct nameidata *nd)
++#else
++mini_fo_d_revalidate(dentry_t *dentry, int flags)
++#endif
++{
++	int err1 = 1; /* valid = 1, invalid = 0 */
++	int err2 = 1;
++	dentry_t *hidden_dentry;
++	dentry_t *hidden_sto_dentry;
++
++
++	check_mini_fo_dentry(dentry);
++
++	hidden_dentry  = dtohd(dentry);
++	hidden_sto_dentry = dtohd2(dentry);
++
++	if(hidden_dentry &&
++	   hidden_dentry->d_op &&
++	   hidden_dentry->d_op->d_revalidate) {
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++		err1 = hidden_dentry->d_op->d_revalidate(hidden_dentry, nd);
++#else
++		err1 = hidden_dentry->d_op->d_revalidate(hidden_dentry, flags);
++#endif
++	}
++	if(hidden_sto_dentry &&
++	   hidden_sto_dentry->d_op &&
++	   hidden_sto_dentry->d_op->d_revalidate) {
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++		err2 = hidden_sto_dentry->d_op->d_revalidate(hidden_sto_dentry,
++							     nd);
++#else
++		err2 = hidden_sto_dentry->d_op->d_revalidate(hidden_sto_dentry,
++							     flags);
++#endif
++	}
++
++	/* mk: if one of the lower level dentries are valid,
++	 * the mini_fo dentry is too.
++	 */
++	return (err1 || err2);
++}
++
++
++STATIC int
++mini_fo_d_hash(dentry_t *dentry, qstr_t *name)
++{
++	int err = 0;
++	dentry_t *hidden_dentry;
++	dentry_t *hidden_sto_dentry;
++
++	/* hidden_dentry = mini_fo_hidden_dentry(dentry);
++	 * hidden_sto_dentry = mini_fo_hidden_sto_dentry(dentry); */
++
++	/* state 1, 3, 4, 5: build the hash for the storage dentry */
++	if((dtopd(dentry)->state == MODIFIED) ||
++	   (dtopd(dentry)->state == CREATED) ||
++	   (dtopd(dentry)->state == DEL_REWRITTEN) ||
++	   (dtopd(dentry)->state == DELETED)) {
++		hidden_sto_dentry = dtohd2(dentry);
++		if(hidden_sto_dentry &&
++		   hidden_sto_dentry->d_op &&
++		   hidden_sto_dentry->d_op->d_hash) {
++			err = hidden_sto_dentry->d_op->d_hash(hidden_sto_dentry, name);
++		}
++		goto out;
++	}
++	/* state 2: build the hash for the base dentry */
++	if(dtopd(dentry)->state == UNMODIFIED) {
++		hidden_dentry = dtohd(dentry);
++		if(hidden_dentry &&
++		   hidden_dentry->d_op &&
++		   hidden_dentry->d_op->d_hash) {
++			err = hidden_dentry->d_op->d_hash(hidden_dentry, name);
++		}
++		goto out;
++	}
++	/* state 6: build hash for the dentry that exists */
++	if(dtopd(dentry)->state == NON_EXISTANT) {
++		hidden_sto_dentry = dtohd2(dentry);
++		if(hidden_sto_dentry &&
++		   hidden_sto_dentry->d_op &&
++		   hidden_sto_dentry->d_op->d_hash) {
++			err = hidden_sto_dentry->d_op->d_hash(hidden_sto_dentry, name);
++			goto out;
++		}
++		hidden_dentry = dtohd(dentry);
++		if(hidden_dentry &&
++		   hidden_dentry->d_op &&
++		   hidden_dentry->d_op->d_hash) {
++			err = hidden_dentry->d_op->d_hash(hidden_dentry, name);
++			goto out;
++		}
++	}
++
++	printk(KERN_CRIT "mini_fo: d_hash: invalid state detected.\n");
++
++ out:
++	return err;
++}
++
++
++STATIC int
++mini_fo_d_compare(dentry_t *dentry, qstr_t *a, qstr_t *b)
++{
++	int err;
++	dentry_t *hidden_dentry=NULL;
++
++	/* hidden_dentry = mini_fo_hidden_dentry(dentry); */
++	if(dtohd2(dentry))
++		hidden_dentry = dtohd2(dentry);
++	else if(dtohd(dentry))
++		hidden_dentry = dtohd(dentry);
++
++	if (hidden_dentry && hidden_dentry->d_op && hidden_dentry->d_op->d_compare) {
++		err = hidden_dentry->d_op->d_compare(hidden_dentry, a, b);
++	} else {
++		err = ((a->len != b->len) || memcmp(a->name, b->name, b->len));
++	}
++
++	return err;
++}
++
++
++int
++mini_fo_d_delete(dentry_t *dentry)
++{
++	dentry_t *hidden_dentry;
++	dentry_t *hidden_sto_dentry;
++	int err = 0;
++
++	/* this could be a negative dentry, so check first */
++	if (!dtopd(dentry)) {
++		printk(KERN_CRIT "mini_fo_d_delete: negative dentry passed.\n");
++		goto out;
++	}
++	hidden_dentry = dtohd(dentry);
++	hidden_sto_dentry = dtohd2(dentry);
++
++	if(hidden_dentry) {
++		if(hidden_dentry->d_op &&
++		   hidden_dentry->d_op->d_delete) {
++			err = hidden_dentry->d_op->d_delete(hidden_dentry);
++		}
++	}
++	if(hidden_sto_dentry) {
++		if(hidden_sto_dentry->d_op &&
++		   hidden_sto_dentry->d_op->d_delete) {
++			err = hidden_sto_dentry->d_op->d_delete(hidden_sto_dentry);
++		}
++	}
++
++ out:
++	return err;
++}
++
++
++void
++mini_fo_d_release(dentry_t *dentry)
++{
++	dentry_t *hidden_dentry;
++	dentry_t *hidden_sto_dentry;
++
++
++	/* this could be a negative dentry, so check first */
++	if (!dtopd(dentry)) {
++		printk(KERN_CRIT "mini_fo_d_release: no private data.\n");
++		goto out;
++	}
++	hidden_dentry = dtohd(dentry);
++	hidden_sto_dentry = dtohd2(dentry);
++
++	if(hidden_dentry) {
++		/* decrement hidden dentry's counter and free its inode */
++		dput(hidden_dentry);
++	}
++	if(hidden_sto_dentry) {
++                /* decrement hidden dentry's counter and free its inode */
++		dput(hidden_sto_dentry);
++	}
++
++	/* free private data (mini_fo_dentry_info) here */
++	kfree(dtopd(dentry));
++	__dtopd(dentry) = NULL;	/* just to be safe */
++ out:
++	return;
++}
++
++
++/*
++ * we don't really need mini_fo_d_iput, because dentry_iput will call iput() if
++ * mini_fo_d_iput is not defined. We left this implemented for ease of
++ * tracing/debugging.
++ */
++void
++mini_fo_d_iput(dentry_t *dentry, inode_t *inode)
++{
++	iput(inode);
++}
++
++
++struct dentry_operations mini_fo_dops = {
++	d_revalidate:	mini_fo_d_revalidate,
++	d_hash:		mini_fo_d_hash,
++	d_compare:		mini_fo_d_compare,
++	d_release:		mini_fo_d_release,
++	d_delete:		mini_fo_d_delete,
++	d_iput:		mini_fo_d_iput,
++};
+--- /dev/null
++++ b/fs/mini_fo/file.c
+@@ -0,0 +1,713 @@
++/*
++ * Copyright (c) 1997-2003 Erez Zadok
++ * Copyright (c) 2001-2003 Stony Brook University
++ *
++ * For specific licensing information, see the COPYING file distributed with
++ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
++ *
++ * This Copyright notice must be kept intact and distributed with all
++ * fistgen sources INCLUDING sources generated by fistgen.
++ */
++/*
++ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ */
++
++/*
++ *  $Id$
++ */
++
++#ifdef HAVE_CONFIG_H
++# include <config.h>
++#endif
++
++#include "fist.h"
++#include "mini_fo.h"
++#define ROUND_UP(x) (((x)+sizeof(long)-1) & ~(sizeof(long)-1))
++
++/*******************
++ * File Operations *
++ *******************/
++
++STATIC loff_t
++mini_fo_llseek(file_t *file, loff_t offset, int origin)
++{
++	loff_t err;
++	file_t *hidden_file = NULL;
++
++	if(S_ISDIR(file->f_dentry->d_inode->i_mode)) {
++		/* Check if trying to llseek from a directory */
++		err = -EISDIR;
++		goto out;
++	}
++	if (ftopd(file) != NULL) {
++		if(ftohf2(file)) {
++			hidden_file = ftohf2(file);
++		} else {
++			hidden_file = ftohf(file);
++		}
++	}
++
++	/* always set hidden position to this one */
++	hidden_file->f_pos = file->f_pos;
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++	memcpy(&(hidden_file->f_ra),
++	       &(file->f_ra),
++	       sizeof(struct file_ra_state));
++#else
++	if (file->f_reada) { /* update readahead information if needed */
++		hidden_file->f_reada = file->f_reada;
++		hidden_file->f_ramax = file->f_ramax;
++		hidden_file->f_raend = file->f_raend;
++		hidden_file->f_ralen = file->f_ralen;
++		hidden_file->f_rawin = file->f_rawin;
++	}
++#endif
++	if (hidden_file->f_op && hidden_file->f_op->llseek)
++		err = hidden_file->f_op->llseek(hidden_file, offset, origin);
++	else
++		err = generic_file_llseek(hidden_file, offset, origin);
++
++	if (err < 0)
++		goto out;
++
++	if (err != file->f_pos) {
++		file->f_pos = err;
++		// ION maybe this?
++		// 	file->f_pos = hidden_file->f_pos;
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++		file->f_reada = 0;
++#endif
++		file->f_version++;
++	}
++
++ out:
++	return err;
++}
++
++
++/* mk: fanout capable */
++STATIC ssize_t
++mini_fo_read(file_t *file, char *buf, size_t count, loff_t *ppos)
++{
++	int err = -EINVAL;
++	file_t *hidden_file = NULL;
++	loff_t pos = *ppos;
++
++	if(S_ISDIR(file->f_dentry->d_inode->i_mode)) {
++		/* Check if trying to read from a directory */
++		/* printk(KERN_CRIT "mini_fo_read: ERROR: trying to read data from a directory.\n"); */
++		err = -EISDIR;
++		goto out;
++	}
++
++	if (ftopd(file) != NULL) {
++		if(ftohf2(file)) {
++			hidden_file = ftohf2(file);
++		} else {
++			hidden_file = ftohf(file);
++		}
++	}
++
++	if (!hidden_file->f_op || !hidden_file->f_op->read)
++		goto out;
++
++	err = hidden_file->f_op->read(hidden_file, buf, count, &pos);
++	*ppos = pos;
++
++	if (err >= 0) {
++		/* atime should also be updated for reads of size zero or more */
++		fist_copy_attr_atime(file->f_dentry->d_inode,
++				     hidden_file->f_dentry->d_inode);
++	}
++
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++	/*
++	 * MAJOR HACK
++	 * because pread() does not have any way to tell us that it is
++	 * our caller, then we don't know for sure if we have to update
++	 * the file positions.  This hack relies on read() having passed us
++	 * the "real" pointer of its struct file's f_pos field.
++	 */
++	if (ppos == &file->f_pos)
++		hidden_file->f_pos = *ppos = pos;
++	if (hidden_file->f_reada) { /* update readahead information if needed */
++		file->f_reada = hidden_file->f_reada;
++		file->f_ramax = hidden_file->f_ramax;
++		file->f_raend = hidden_file->f_raend;
++		file->f_ralen = hidden_file->f_ralen;
++		file->f_rawin = hidden_file->f_rawin;
++	}
++#else
++	memcpy(&(file->f_ra),&(hidden_file->f_ra),sizeof(struct file_ra_state));
++#endif
++
++ out:
++	return err;
++}
++
++
++/* this mini_fo_write() does not modify data pages! */
++STATIC ssize_t
++mini_fo_write(file_t *file, const char *buf, size_t count, loff_t *ppos)
++{
++	int err = -EINVAL;
++	file_t *hidden_file = NULL;
++	inode_t *inode;
++	inode_t *hidden_inode;
++	loff_t pos = *ppos;
++
++	/* mk: fan out: */
++	if (ftopd(file) != NULL) {
++		if(ftohf2(file)) {
++			hidden_file = ftohf2(file);
++		} else {
++			/* This is bad! We have no storage file to write to. This
++			 * should never happen because if a file is opened for
++			 * writing, a copy should have been made earlier.
++			 */
++			printk(KERN_CRIT "mini_fo: write : ERROR, no storage file to write.\n");
++			err = -EINVAL;
++			goto out;
++		}
++	}
++
++	inode = file->f_dentry->d_inode;
++	hidden_inode = itohi2(inode);
++	if(!hidden_inode) {
++		printk(KERN_CRIT "mini_fo: write: no sto inode found, not good.\n");
++		goto out;
++	}
++
++	if (!hidden_file->f_op || !hidden_file->f_op->write)
++		goto out;
++
++	/* adjust for append -- seek to the end of the file */
++	if (file->f_flags & O_APPEND)
++		pos = inode->i_size;
++
++	err = hidden_file->f_op->write(hidden_file, buf, count, &pos);
++
++	/*
++	 * copy ctime and mtime from lower layer attributes
++	 * atime is unchanged for both layers
++	 */
++	if (err >= 0)
++		fist_copy_attr_times(inode, hidden_inode);
++
++	*ppos = pos;
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++	/*
++	 * XXX: MAJOR HACK
++	 *
++	 * because pwrite() does not have any way to tell us that it is
++	 * our caller, then we don't know for sure if we have to update
++	 * the file positions.  This hack relies on write() having passed us
++	 * the "real" pointer of its struct file's f_pos field.
++	 */
++	if (ppos == &file->f_pos)
++		hidden_file->f_pos = *ppos = pos;
++#endif
++	/* update this inode's size */
++	if (pos > inode->i_size)
++		inode->i_size = pos;
++
++ out:
++	return err;
++}
++
++/* Global variable to hold a file_t pointer.
++ * This serves to allow mini_fo_filldir function to know which file is
++ * beeing read, which is required for two reasons:
++ *
++ *   - be able to call wol functions in order to avoid listing deleted
++ *     base files.
++ *   - if we're reading a directory which is in state 1, we need to
++ *     maintain a list (in mini_fo_filldir) of which files allready
++ *     have been copied to userspace,to detect files existing in base
++ *     and storage and not list them twice.
++ */
++filldir_t mini_fo_filldir_orig;
++file_t *mini_fo_filldir_file;
++
++/* mainly copied from fs/readdir.c */
++STATIC int
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
++mini_fo_filldir(void * __buf, const char * name, int namlen, loff_t offset,
++		  u64 ino, unsigned int d_type)
++#else
++mini_fo_filldir(void * __buf, const char * name, int namlen, loff_t offset,
++		  ino_t ino, unsigned int d_type)
++#endif
++{
++	struct getdents_callback * buf = (struct getdents_callback *) __buf;
++	file_t* file = mini_fo_filldir_file;
++
++	/* In theses states we filter meta files in storage (WOL) */
++	if(file && (dtopd(file->f_dentry)->state == MODIFIED ||
++		    dtopd(file->f_dentry)->state == CREATED ||
++		    dtopd(file->f_dentry)->state == DEL_REWRITTEN)) {
++
++		int tmp = strlen(META_FILENAME);
++		if(tmp  == namlen) {
++			if(!strncmp(name, META_FILENAME, namlen))
++				return 0;
++		}
++	}
++
++	/* check if we are merging the contents of storage and base */
++	if(file && dtopd(file->f_dentry)->state == MODIFIED) {
++		/* check if we are still reading storage contents, if
++		 * yes, we just save the name of the file for duplicate
++		 * checking later. */
++
++		if(!ftopd(file)->rd.sto_done) {
++			/* put file into ndl list */
++			if(ndl_add_entry(&ftopd(file)->rd, name, namlen))
++				printk(KERN_CRIT "mini_fo_filldir: Error adding to ndl.\n");
++		} else {
++			/* check if file has been deleted */
++			if(meta_check_d_entry(file->f_dentry, name, namlen))
++				return 0;
++
++			/* do duplicate checking */
++			if(ndl_check_entry(&ftopd(file)->rd, name, namlen))
++				return 0;
++		}
++	}
++
++	return mini_fo_filldir_orig(buf, name, namlen, offset, ino, d_type);
++}
++
++
++STATIC int
++mini_fo_readdir(file_t *file, void *dirent, filldir_t filldir)
++{
++	int err = 0;/* mk: ??? -ENOTDIR; */
++	file_t *hidden_file = NULL;
++	file_t *hidden_sto_file = NULL;
++	inode_t *inode;
++	struct getdents_callback *buf;
++	int oldcount;
++
++#if defined(FIST_FILTER_NAME) || defined(FIST_FILTER_SCA)
++	struct mini_fo_getdents_callback buf;
++#endif /* FIST_FILTER_NAME || FIST_FILTER_SCA */
++
++	buf = (struct getdents_callback *) dirent;
++	oldcount = buf->count;
++	inode = file->f_dentry->d_inode;
++	mini_fo_filldir_file = file;
++	mini_fo_filldir_orig = filldir;
++
++	ftopd(file)->rd.sto_done = 0;
++	do {
++		if (ftopd(file) != NULL) {
++			if(ftohf2(file)) {
++				hidden_sto_file = ftohf2(file);
++				err = vfs_readdir(hidden_sto_file, mini_fo_filldir, dirent);
++				file->f_pos = hidden_sto_file->f_pos;
++				if (err > 0)
++					fist_copy_attr_atime(inode, hidden_sto_file->f_dentry->d_inode);
++				/* not finshed yet, we'll be called again */
++				if (buf->count != oldcount)
++					break;
++			}
++
++			ftopd(file)->rd.sto_done = 1;
++
++			if(ftohf(file)) {
++				hidden_file = ftohf(file);
++				err = vfs_readdir(hidden_file, mini_fo_filldir, dirent);
++				file->f_pos = hidden_file->f_pos;
++				if (err > 0)
++					fist_copy_attr_atime(inode, hidden_file->f_dentry->d_inode);
++			}
++
++		}
++	} while (0);
++
++	/* mk:
++	 * we need to check if all the directory data has been copied to userspace,
++	 * or if we will be called again by userspace to complete the operation.
++	 */
++	if(buf->count == oldcount) {
++		ndl_put_list(&ftopd(file)->rd);
++	}
++
++	/* unset this, safe */
++	mini_fo_filldir_file = NULL;
++	return err;
++}
++
++
++STATIC unsigned int
++mini_fo_poll(file_t *file, poll_table *wait)
++{
++	unsigned int mask = DEFAULT_POLLMASK;
++	file_t *hidden_file = NULL;
++
++	if (ftopd(file) != NULL) {
++		if(ftohf2(file)) {
++			hidden_file = ftohf2(file);
++		} else {
++			hidden_file = ftohf(file);
++		}
++	}
++
++	if (!hidden_file->f_op || !hidden_file->f_op->poll)
++		goto out;
++
++	mask = hidden_file->f_op->poll(hidden_file, wait);
++
++ out:
++	return mask;
++}
++
++/* FIST-LITE special version of mmap */
++STATIC int
++mini_fo_mmap(file_t *file, vm_area_t *vma)
++{
++	int err = 0;
++	file_t *hidden_file = NULL;
++
++	/* fanout capability */
++	if (ftopd(file) != NULL) {
++		if(ftohf2(file)) {
++			hidden_file = ftohf2(file);
++		} else {
++			hidden_file = ftohf(file);
++		}
++	}
++
++	ASSERT(hidden_file != NULL);
++	ASSERT(hidden_file->f_op != NULL);
++	ASSERT(hidden_file->f_op->mmap != NULL);
++
++	vma->vm_file = hidden_file;
++	err = hidden_file->f_op->mmap(hidden_file, vma);
++	get_file(hidden_file); /* make sure it doesn't get freed on us */
++	fput(file);	       /* no need to keep extra ref on ours */
++
++	return err;
++}
++
++
++
++STATIC int
++mini_fo_open(inode_t *inode, file_t *file)
++{
++	int err = 0;
++ 	int hidden_flags;
++	file_t *hidden_file = NULL;
++	dentry_t *hidden_dentry = NULL;
++
++	/* fanout stuff */
++	file_t *hidden_sto_file = NULL;
++	dentry_t *hidden_sto_dentry = NULL;
++
++	__ftopd(file) =
++		kmalloc(sizeof(struct mini_fo_file_info), GFP_KERNEL);
++	if (!ftopd(file)) {
++		err = -ENOMEM;
++		goto out;
++	}
++
++	/* init the readdir_helper structure */
++	INIT_LIST_HEAD(&ftopd(file)->rd.ndl_list);
++	ftopd(file)->rd.ndl_size = 0;
++
++	/* In certain paths this could stay uninitalized and cause trouble */
++	ftohf(file) = NULL;
++	ftohf2(file) = NULL;
++	hidden_flags = file->f_flags;
++
++	/* create storage files? */
++	if(dtost(file->f_dentry) == UNMODIFIED) {
++		if(!IS_WRITE_FLAG(file->f_flags)) {
++			hidden_dentry = dtohd(file->f_dentry);
++			dget(hidden_dentry);
++			/* dentry_open will decrement mnt refcnt if err.
++			 * otherwise fput() will do an mntput() for us upon file close. */
++			mntget(stopd(inode->i_sb)->hidden_mnt);
++			hidden_file = dentry_open(hidden_dentry,
++						  stopd(inode->i_sb)->hidden_mnt,
++						  hidden_flags);
++			if (IS_ERR(hidden_file)) {
++				err = PTR_ERR(hidden_file);
++				dput(hidden_dentry);
++				goto out;
++			}
++			ftohf(file) = hidden_file;	/* link two files */
++			goto out;
++		}
++		else {
++			if(S_ISDIR(file->f_dentry->d_inode->i_mode)) {
++				err = dir_unmod_to_mod(file->f_dentry);
++			} else
++				err = nondir_unmod_to_mod(file->f_dentry, 1);
++
++			if (err) {
++				printk("mini_fo_open: ERROR creating storage file.\n");
++				goto out;
++			}
++		}
++	}
++	hidden_sto_dentry = dtohd2(file->f_dentry);
++	dget(hidden_sto_dentry);
++
++	if(dtopd(file->f_dentry)->state == MODIFIED) {
++		/* Directorys are special, interpose on both lower level files */
++		if(S_ISDIR(itohi(inode)->i_mode)) {
++			/* check for invalid file types of lower level files */
++			if(!(S_ISDIR(itohi(inode)->i_mode) && S_ISDIR(itohi2(inode)->i_mode))) {
++				printk(KERN_CRIT "mini_fo_open: meta data corruption detected.\n");
++				dput(hidden_sto_dentry);
++				err = -EINVAL;
++				goto out;
++			}
++
++			/* lower level directorys are ok, open the base file */
++			hidden_dentry = dtohd(file->f_dentry);
++			dget(hidden_dentry);
++
++			mntget(stopd(inode->i_sb)->hidden_mnt);
++			hidden_file = dentry_open(hidden_dentry,
++						  stopd(inode->i_sb)->hidden_mnt,
++						  hidden_flags);
++			if (IS_ERR(hidden_file)) {
++				err = PTR_ERR(hidden_file);
++				dput(hidden_dentry);
++				dput(hidden_sto_dentry);
++				goto out;
++			}
++			ftohf(file) = hidden_file; /* link the two files */
++		}
++	}
++
++	if(!exists_in_storage(file->f_dentry)) {
++		printk(KERN_CRIT "mini_fo_open: invalid file state detected.\n");
++		err = -EINVAL;
++		dput(hidden_sto_dentry);
++
++		/* If the base file has been opened, we need to close it here */
++		if(ftohf(file)) {
++			if (hidden_file->f_op && hidden_file->f_op->flush)
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
++				hidden_file->f_op->flush(hidden_file, NULL);
++#else
++				hidden_file->f_op->flush(hidden_file);
++#endif
++			dput(hidden_dentry);
++		}
++		goto out;
++	}
++
++	/* ok, now we can safely open the storage file */
++	mntget(stopd(inode->i_sb)->hidden_mnt2);
++	hidden_sto_file = dentry_open(hidden_sto_dentry,
++				      stopd(inode->i_sb)->hidden_mnt2,
++				      hidden_flags);
++
++	/* dentry_open dputs the dentry if it fails */
++	if (IS_ERR(hidden_sto_file)) {
++		err = PTR_ERR(hidden_sto_file);
++		/* close base file if open */
++		if(ftohf(file)) {
++			if (hidden_file->f_op && hidden_file->f_op->flush)
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
++				hidden_file->f_op->flush(hidden_file, NULL);
++#else
++				hidden_file->f_op->flush(hidden_file);
++#endif
++			dput(hidden_dentry);
++		}
++		goto out;
++	}
++	ftohf2(file) = hidden_sto_file; /* link storage file */
++
++ out:
++	if (err < 0 && ftopd(file)) {
++		kfree(ftopd(file));
++	}
++	return err;
++}
++
++STATIC int
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
++mini_fo_flush(file_t *file, fl_owner_t id)
++#else
++mini_fo_flush(file_t *file)
++#endif
++{
++	int err1 = 0;		/* assume ok (see open.c:close_fp) */
++	int err2 = 0;
++	file_t *hidden_file = NULL;
++
++	check_mini_fo_file(file);
++
++	/* mk: we don't do any state checking here, as its not worth the time.
++	 * Just flush the lower level files if they exist.
++	 */
++	if(ftopd(file) != NULL) {
++		if(ftohf(file) != NULL) {
++			hidden_file = ftohf(file);
++			if (hidden_file->f_op && hidden_file->f_op->flush)
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
++				err1 = hidden_file->f_op->flush(hidden_file, id);
++#else
++				err1 = hidden_file->f_op->flush(hidden_file);
++#endif
++		}
++		if(ftohf2(file) != NULL) {
++			hidden_file = ftohf2(file);
++			if (hidden_file->f_op && hidden_file->f_op->flush)
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
++				err2 = hidden_file->f_op->flush(hidden_file, id);
++#else
++				err2 = hidden_file->f_op->flush(hidden_file);
++#endif
++		}
++	}
++	return (err1 | err2);
++}
++
++
++STATIC int
++mini_fo_release(inode_t *inode, file_t *file)
++{
++	int err = 0;
++	file_t *hidden_file = NULL;
++
++	if (ftopd(file) != NULL) {
++		if(ftohf(file)) {
++			hidden_file = ftohf(file);
++			fput(hidden_file);
++		}
++		if(ftohf2(file)) {
++			hidden_file = ftohf2(file);
++			fput(hidden_file);
++		}
++		kfree(ftopd(file));
++	}
++	return err;
++}
++
++STATIC int
++mini_fo_fsync(file_t *file, dentry_t *dentry, int datasync)
++{
++	int err1 = 0;
++	int err2 = 0;
++	file_t *hidden_file = NULL;
++	dentry_t *hidden_dentry;
++
++	check_mini_fo_file(file);
++
++	if ((hidden_file = ftohf(file)) != NULL) {
++		hidden_dentry = dtohd(dentry);
++		if (hidden_file->f_op && hidden_file->f_op->fsync) {
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++			mutex_lock(&hidden_dentry->d_inode->i_mutex);
++#else
++			down(&hidden_dentry->d_inode->i_sem);
++#endif
++			err1 = hidden_file->f_op->fsync(hidden_file, hidden_dentry, datasync);
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++			mutex_unlock(&hidden_dentry->d_inode->i_mutex);
++#else
++			up(&hidden_dentry->d_inode->i_sem);
++#endif
++		}
++	}
++
++	if ((hidden_file = ftohf2(file)) != NULL) {
++		hidden_dentry = dtohd2(dentry);
++		if (hidden_file->f_op && hidden_file->f_op->fsync) {
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++			mutex_lock(&hidden_dentry->d_inode->i_mutex);
++#else
++			down(&hidden_dentry->d_inode->i_sem);
++#endif
++			err2 = hidden_file->f_op->fsync(hidden_file, hidden_dentry, datasync);
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++			mutex_unlock(&hidden_dentry->d_inode->i_mutex);
++#else
++			up(&hidden_dentry->d_inode->i_sem);
++#endif
++		}
++	}
++	else
++		goto err;
++
++err:
++	return (err1 || err2);
++}
++
++
++STATIC int
++mini_fo_fasync(int fd, file_t *file, int flag)
++{
++	int err1 = 0;
++	int err2 = 0;
++
++	file_t *hidden_file = NULL;
++
++	check_mini_fo_file(file);
++
++	if((hidden_file = ftohf(file)) != NULL) {
++		err1 = hidden_file->f_op->fasync(fd, hidden_file, flag);
++	}
++	if((hidden_file = ftohf2(file)) != NULL) {
++		err2 = hidden_file->f_op->fasync(fd, hidden_file, flag);
++	}
++
++	return (err1 || err2);
++}
++
++
++
++struct file_operations mini_fo_dir_fops =
++	{
++		read:	generic_read_dir,
++		write:	mini_fo_write,
++		readdir: mini_fo_readdir,
++		poll:	mini_fo_poll,
++		/* ioctl:	mini_fo_ioctl, */
++		mmap:	mini_fo_mmap,
++		open:	mini_fo_open,
++		flush:	mini_fo_flush,
++		release: mini_fo_release,
++		fsync:	mini_fo_fsync,
++		fasync:	mini_fo_fasync,
++		/* not needed lock:	mini_fo_lock, */
++		/* not needed: readv */
++		/* not needed: writev */
++		/* not implemented: sendpage */
++		/* not implemented: get_unmapped_area */
++	};
++
++struct file_operations mini_fo_main_fops =
++	{
++		llseek:	mini_fo_llseek,
++		read:	mini_fo_read,
++		write:	mini_fo_write,
++		readdir: mini_fo_readdir,
++		poll:	mini_fo_poll,
++		/* ioctl:	mini_fo_ioctl, */
++		mmap:	mini_fo_mmap,
++		open:	mini_fo_open,
++		flush:	mini_fo_flush,
++		release: mini_fo_release,
++		fsync:	mini_fo_fsync,
++		fasync:	mini_fo_fasync,
++		/* not needed: lock:	mini_fo_lock, */
++		/* not needed: readv */
++		/* not needed: writev */
++		/* not implemented: sendpage */
++		/* not implemented: get_unmapped_area */
++	};
+--- /dev/null
++++ b/fs/mini_fo/fist.h
+@@ -0,0 +1,254 @@
++/*
++ * Copyright (c) 1997-2003 Erez Zadok
++ * Copyright (c) 2001-2003 Stony Brook University
++ *
++ * For specific licensing information, see the COPYING file distributed with
++ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
++ *
++ * This Copyright notice must be kept intact and distributed with all
++ * fistgen sources INCLUDING sources generated by fistgen.
++ */
++/*
++ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ */
++
++
++/*
++ *  $Id$
++ */
++
++#ifndef __FIST_H_
++#define __FIST_H_
++
++/*
++ * KERNEL ONLY CODE:
++ */
++#ifdef __KERNEL__
++#include <linux/version.h>
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33)
++#include <generated/autoconf.h>
++#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19)
++#include <linux/autoconf.h>
++#else
++#include <linux/config.h>
++#endif
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++#ifdef CONFIG_MODVERSIONS
++# define MODVERSIONS
++# include <linux/modversions.h>
++#endif /* CONFIG_MODVERSIONS */
++#endif /* KERNEL_VERSION < 2.6.0 */
++#include <linux/sched.h>
++#include <linux/kernel.h>
++#include <linux/mm.h>
++#include <linux/string.h>
++#include <linux/stat.h>
++#include <linux/errno.h>
++#include <linux/wait.h>
++#include <linux/limits.h>
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++#include <linux/locks.h>
++#else
++#include <linux/buffer_head.h>
++#include <linux/pagemap.h>
++#include <linux/namei.h>
++#include <linux/module.h>
++#include <linux/mount.h>
++#include <linux/page-flags.h>
++#include <linux/writeback.h>
++#include <linux/statfs.h>
++#endif
++#include <linux/smp.h>
++#include <linux/smp_lock.h>
++#include <linux/file.h>
++#include <linux/slab.h>
++#include <linux/vmalloc.h>
++#include <linux/poll.h>
++#include <linux/list.h>
++#include <linux/init.h>
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20)
++#include <linux/xattr.h>
++#endif
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++#include <linux/security.h>
++#endif
++
++#include <linux/swap.h>
++
++#include <asm/system.h>
++/* #include <asm/segment.h> */
++#include <asm/mman.h>
++#include <linux/seq_file.h>
++
++/*
++ * MACROS:
++ */
++
++/* those mapped to ATTR_* were copied from linux/fs.h */
++#define FA_MODE		ATTR_MODE
++#define FA_UID		ATTR_UID
++#define FA_GID		ATTR_GID
++#define FA_SIZE		ATTR_SIZE
++#define FA_ATIME	ATTR_ATIME
++#define FA_MTIME	ATTR_MTIME
++#define FA_CTIME	ATTR_CTIME
++#define FA_ATIME_SET	ATTR_ATIME_SET
++#define FA_MTIME_SET	ATTR_MTIME_SET
++#define FA_FORCE	ATTR_FORCE
++#define FA_ATTR_FLAGS	ATTR_ATTR_FLAG
++
++/* must be greater than all other ATTR_* flags! */
++#define FA_NLINK	2048
++#define FA_BLKSIZE	4096
++#define FA_BLOCKS	8192
++#define FA_TIMES	(FA_ATIME|FA_MTIME|FA_CTIME)
++#define FA_ALL		0
++
++/* macros to manage changes between kernels */
++#define INODE_DATA(i)	(&(i)->i_data)
++
++#define MIN(x,y) ((x < y) ? (x) : (y))
++#define MAX(x,y) ((x > y) ? (x) : (y))
++#define MAXPATHLEN PATH_MAX
++
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,5)
++# define lookup_one_len(a,b,c) lookup_one(a,b)
++#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(2,4,5) */
++
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,8)
++# define generic_file_llseek default_llseek
++#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(2,4,8) */
++
++#ifndef SEEK_SET
++# define SEEK_SET 0
++#endif /* not SEEK_SET */
++
++#ifndef SEEK_CUR
++# define SEEK_CUR 1
++#endif /* not SEEK_CUR */
++
++#ifndef SEEK_END
++# define SEEK_END 2
++#endif /* not SEEK_END */
++
++#ifndef DEFAULT_POLLMASK
++# define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
++#endif /* not DEFAULT_POLLMASK */
++
++/* XXX: fix this so fistgen generates kfree() code directly */
++#define kfree_s(a,b) kfree(a)
++
++/*
++ * TYPEDEFS:
++ */
++typedef struct dentry dentry_t;
++typedef struct file file_t;
++typedef struct inode inode_t;
++typedef inode_t vnode_t;
++typedef struct page page_t;
++typedef struct qstr qstr_t;
++typedef struct super_block super_block_t;
++typedef super_block_t vfs_t;
++typedef struct vm_area_struct vm_area_t;
++
++
++/*
++ * EXTERNALS:
++ */
++
++#define FPPF(str,page) printk("PPF %s 0x%x/%d: Lck:%d Err:%d Ref:%d Upd:%d Other::%d:%d:%d:%d:\n", \
++		str, \
++		(int) page, \
++		(int) page->index, \
++		(PageLocked(page) ? 1 : 0), \
++		(PageError(page) ? 1 : 0), \
++		(PageReferenced(page) ? 1 : 0), \
++		(Page_Uptodate(page) ? 1 : 0), \
++		(PageDecrAfter(page) ? 1 : 0), \
++		(PageSlab(page) ? 1 : 0), \
++		(PageSwapCache(page) ? 1 : 0), \
++		(PageReserved(page) ? 1 : 0) \
++		)
++#define EZKDBG printk("EZK %s:%d:%s\n",__FILE__,__LINE__,__FUNCTION__)
++#if 0
++# define EZKDBG1 printk("EZK %s:%d\n",__FILE__,__LINE__)
++#else
++# define EZKDBG1
++#endif
++
++extern int fist_get_debug_value(void);
++extern int fist_set_debug_value(int val);
++#if 0 /* mini_fo doesn't need these */
++extern void fist_dprint_internal(int level, char *str,...);
++extern void fist_print_dentry(char *str, const dentry_t *dentry);
++extern void fist_print_inode(char *str, const inode_t *inode);
++extern void fist_print_file(char *str, const file_t *file);
++extern void fist_print_buffer_flags(char *str, struct buffer_head *buffer);
++extern void fist_print_page_flags(char *str, page_t *page);
++extern void fist_print_page_bytes(char *str, page_t *page);
++extern void fist_print_pte_flags(char *str, const page_t *page);
++extern void fist_checkinode(inode_t *inode, char *msg);
++extern void fist_print_sb(char *str, const super_block_t *sb);
++
++/* §$% by mk: special debug functions */
++extern void fist_mk_print_dentry(char *str, const dentry_t *dentry);
++extern void fist_mk_print_inode(char *str, const inode_t *inode);
++
++extern char *add_indent(void);
++extern char *del_indent(void);
++#endif/* mini_fo doesn't need these */
++
++
++#define STATIC
++#define ASSERT(EX)	\
++do {	\
++    if (!(EX)) {	\
++	printk(KERN_CRIT "ASSERTION FAILED: %s at %s:%d (%s)\n", #EX,	\
++	       __FILE__, __LINE__, __FUNCTION__);	\
++	(*((char *)0))=0;	\
++    }	\
++} while (0)
++/* same ASSERT, but tell me who was the caller of the function */
++#define ASSERT2(EX)	\
++do {	\
++    if (!(EX)) {	\
++	printk(KERN_CRIT "ASSERTION FAILED (caller): %s at %s:%d (%s)\n", #EX,	\
++	       file, line, func);	\
++	(*((char *)0))=0;	\
++    }	\
++} while (0)
++
++#if 0 /* mini_fo doesn't need these */
++#define dprintk(format, args...) printk(KERN_DEBUG format, ##args)
++#define fist_dprint(level, str, args...) fist_dprint_internal(level, KERN_DEBUG str, ## args)
++#define print_entry_location() fist_dprint(4, "%sIN:  %s %s:%d\n", add_indent(), __FUNCTION__, __FILE__, __LINE__)
++#define print_exit_location() fist_dprint(4, "%s OUT: %s %s:%d\n", del_indent(), __FUNCTION__, __FILE__, __LINE__)
++#define print_exit_status(status) fist_dprint(4, "%s OUT: %s %s:%d, STATUS: %d\n", del_indent(), __FUNCTION__, __FILE__, __LINE__, status)
++#define print_exit_pointer(status) \
++do { \
++  if (IS_ERR(status)) \
++    fist_dprint(4, "%s OUT: %s %s:%d, RESULT: %ld\n", del_indent(), __FUNCTION__, __FILE__, __LINE__, PTR_ERR(status)); \
++  else \
++    fist_dprint(4, "%s OUT: %s %s:%d, RESULT: 0x%x\n", del_indent(), __FUNCTION__, __FILE__, __LINE__, PTR_ERR(status)); \
++} while (0)
++#endif/* mini_fo doesn't need these */
++
++#endif /* __KERNEL__ */
++
++
++/*
++ * DEFINITIONS FOR USER AND KERNEL CODE:
++ * (Note: ioctl numbers 1--9 are reserved for fistgen, the rest
++ *  are auto-generated automatically based on the user's .fist file.)
++ */
++# define FIST_IOCTL_GET_DEBUG_VALUE	_IOR(0x15, 1, int)
++# define FIST_IOCTL_SET_DEBUG_VALUE	_IOW(0x15, 2, int)
++
++#endif /* not __FIST_H_ */
+--- /dev/null
++++ b/fs/mini_fo/inode.c
+@@ -0,0 +1,1564 @@
++/*
++ * Copyright (c) 1997-2003 Erez Zadok
++ * Copyright (c) 2001-2003 Stony Brook University
++ *
++ * For specific licensing information, see the COPYING file distributed with
++ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
++ *
++ * This Copyright notice must be kept intact and distributed with all
++ * fistgen sources INCLUDING sources generated by fistgen.
++ */
++/*
++ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ */
++
++/*
++ *  $Id$
++ */
++
++#ifdef HAVE_CONFIG_H
++# include <config.h>
++#endif
++
++#include "fist.h"
++#include "mini_fo.h"
++
++STATIC int
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++mini_fo_create(inode_t *dir, dentry_t *dentry, int mode, struct nameidata *nd)
++#else
++mini_fo_create(inode_t *dir, dentry_t *dentry, int mode)
++#endif
++{
++	int err = 0;
++
++	check_mini_fo_dentry(dentry);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++	err = create_sto_reg_file(dentry, mode, nd);
++#else
++	err = create_sto_reg_file(dentry, mode);
++#endif
++	check_mini_fo_dentry(dentry);
++	return err;
++}
++
++
++STATIC dentry_t *
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++mini_fo_lookup(inode_t *dir, dentry_t *dentry, struct nameidata* nd)
++#else
++mini_fo_lookup(inode_t *dir, dentry_t *dentry)
++#endif
++{
++	int err = 0;
++	dentry_t *hidden_dir_dentry;
++	dentry_t *hidden_dentry = NULL;
++
++	dentry_t *hidden_sto_dir_dentry;
++	dentry_t *hidden_sto_dentry = NULL;
++
++	/* whiteout flag */
++	int del_flag = 0;
++	char *bpath = NULL;
++
++	const char *name;
++	unsigned int namelen;
++
++	/* Don't allow lookups of META-files */
++	namelen = strlen(META_FILENAME);
++	if(namelen == dentry->d_name.len) {
++		if(!strncmp(dentry->d_name.name, META_FILENAME, namelen)) {
++			err = -ENOENT;
++			goto out;
++		}
++	}
++
++	hidden_dir_dentry = dtohd(dentry->d_parent);
++	hidden_sto_dir_dentry = dtohd2(dentry->d_parent);
++
++	name = dentry->d_name.name;
++	namelen = dentry->d_name.len;
++
++	/* must initialize dentry operations */
++	dentry->d_op = &mini_fo_dops;
++
++	/* setup the del_flag */
++	del_flag = __meta_check_d_entry(dir, name, namelen);
++	bpath = __meta_check_r_entry(dir, name, namelen);
++
++	/* perform the lookups of base and storage files:
++	 *
++	 * This caused some serious trouble, as a lookup_one_len passing
++	 * a negative dentry oopses. Solution is to only do the lookup
++	 * if the dentry is positive, else we set it to NULL
++	 * More trouble, who said a *_dir_dentry can't be NULL?
++	 */
++	if(bpath) {
++		/* Cross-Interposing (C), yeah! */
++		hidden_dentry = bpath_walk(dir->i_sb, bpath);
++		if(!hidden_dentry || !hidden_dentry->d_inode) {
++			printk(KERN_CRIT "mini_fo_lookup: bpath_walk failed.\n");
++			err= -EINVAL;
++			goto out;
++		}
++
++		/* this can be set up safely without fear of spaghetti
++		 * interposing as it is only used for copying times */
++		hidden_dir_dentry = hidden_dentry->d_parent;
++		kfree(bpath);
++	}
++	else if(hidden_dir_dentry && hidden_dir_dentry->d_inode)
++		hidden_dentry =
++			lookup_one_len(name, hidden_dir_dentry, namelen);
++	else
++		hidden_dentry = NULL;
++
++	if(hidden_sto_dir_dentry && hidden_sto_dir_dentry->d_inode)
++		hidden_sto_dentry =
++			lookup_one_len(name, hidden_sto_dir_dentry, namelen);
++	else
++		hidden_sto_dentry =  NULL;
++
++	/* catch error in lookup */
++	if (IS_ERR(hidden_dentry) || IS_ERR(hidden_sto_dentry)) {
++		/* mk: we need to call dput on the dentry, whose
++		 * lookup_one_len operation failed, in order to avoid
++		 * unmount trouble.
++		 */
++		if(IS_ERR(hidden_dentry)) {
++			printk(KERN_CRIT "mini_fo_lookup: ERR from base dentry, lookup failed.\n");
++			err = PTR_ERR(hidden_dentry);
++		} else {
++			dput(hidden_dentry);
++		}
++		if(IS_ERR(hidden_sto_dentry)) {
++			printk(KERN_CRIT "mini_fo_lookup: ERR from storage dentry, lookup failed.\n");
++			err = PTR_ERR(hidden_sto_dentry);
++		} else {
++			dput(hidden_sto_dentry);
++		}
++		goto out;
++	}
++
++	/* allocate dentry private data */
++	__dtopd(dentry) = (struct mini_fo_dentry_info *)
++		kmalloc(sizeof(struct mini_fo_dentry_info), GFP_KERNEL);
++
++	if (!dtopd(dentry)) {
++		err = -ENOMEM;
++		goto out_dput;
++	}
++
++	/* check for different states of the mini_fo file to be looked up. */
++
++	/* state 1, file has been modified */
++	if(hidden_dentry && hidden_sto_dentry &&
++	   hidden_dentry->d_inode && hidden_sto_dentry->d_inode && !del_flag) {
++
++		/* update parent directory's atime */
++		fist_copy_attr_atime(dir, hidden_sto_dir_dentry->d_inode);
++
++		dtopd(dentry)->state = MODIFIED;
++		dtohd(dentry) = hidden_dentry;
++		dtohd2(dentry) = hidden_sto_dentry;
++
++		err = mini_fo_tri_interpose(hidden_dentry,
++					    hidden_sto_dentry,
++					    dentry, dir->i_sb, 1);
++		if (err) {
++			printk(KERN_CRIT "mini_fo_lookup: error interposing (state1).\n");
++			goto out_free;
++		}
++		goto out;
++	}
++	/* state 2, file is unmodified */
++	if(hidden_dentry && hidden_dentry->d_inode && !del_flag) {
++
++		fist_copy_attr_atime(dir, hidden_dir_dentry->d_inode);
++
++		dtopd(dentry)->state = UNMODIFIED;
++		dtohd(dentry) = hidden_dentry;
++		dtohd2(dentry) = hidden_sto_dentry; /* could be negative */
++
++		err = mini_fo_tri_interpose(hidden_dentry,
++					    hidden_sto_dentry,
++					    dentry, dir->i_sb, 1);
++		if (err) {
++			printk(KERN_CRIT "mini_fo_lookup: error interposing (state2).\n");
++			goto out_free;
++		}
++		goto out;
++	}
++	/* state 3, file has been newly created */
++	if(hidden_sto_dentry && hidden_sto_dentry->d_inode && !del_flag) {
++
++		fist_copy_attr_atime(dir, hidden_sto_dir_dentry->d_inode);
++		dtopd(dentry)->state = CREATED;
++		dtohd(dentry) = hidden_dentry; /* could be negative */
++		dtohd2(dentry) = hidden_sto_dentry;
++
++		err = mini_fo_tri_interpose(hidden_dentry,
++					    hidden_sto_dentry,
++					    dentry, dir->i_sb, 1);
++		if (err) {
++			printk(KERN_CRIT "mini_fo_lookup: error interposing (state3).\n");
++			goto out_free;
++		}
++		goto out;
++	}
++
++	/* state 4, file has deleted and created again. */
++	if(hidden_dentry && hidden_sto_dentry &&
++	   hidden_dentry->d_inode &&
++	   hidden_sto_dentry->d_inode && del_flag) {
++
++		fist_copy_attr_atime(dir, hidden_sto_dir_dentry->d_inode);
++		dtopd(dentry)->state = DEL_REWRITTEN;
++		dtohd(dentry) = NULL;
++		dtohd2(dentry) = hidden_sto_dentry;
++
++		err = mini_fo_tri_interpose(NULL,
++					    hidden_sto_dentry,
++					    dentry, dir->i_sb, 1);
++		if (err) {
++			printk(KERN_CRIT "mini_fo_lookup: error interposing (state4).\n");
++			goto out_free;
++		}
++		/* We will never need this dentry again, as the file has been
++		 * deleted from base */
++		dput(hidden_dentry);
++		goto out;
++	}
++	/* state 5, file has been deleted in base */
++	if(hidden_dentry && hidden_sto_dentry &&
++	   hidden_dentry->d_inode &&
++	   !hidden_sto_dentry->d_inode && del_flag) {
++
++		/* check which parents atime we need for updating */
++		if(hidden_sto_dir_dentry->d_inode)
++			fist_copy_attr_atime(dir,
++					     hidden_sto_dir_dentry->d_inode);
++		else
++			fist_copy_attr_atime(dir,
++					     hidden_dir_dentry->d_inode);
++
++		dtopd(dentry)->state = DELETED;
++		dtohd(dentry) = NULL;
++		dtohd2(dentry) = hidden_sto_dentry;
++
++		/* add negative dentry to dcache to speed up lookups */
++		d_add(dentry, NULL);
++		dput(hidden_dentry);
++		goto out;
++	}
++	/* state 6, file does not exist */
++	if(((hidden_dentry && !hidden_dentry->d_inode) ||
++	    (hidden_sto_dentry && !hidden_sto_dentry->d_inode)) && !del_flag)
++		{
++			/* check which parents atime we need for updating */
++			if(hidden_sto_dir_dentry && hidden_sto_dir_dentry->d_inode)
++				fist_copy_attr_atime(dir, hidden_sto_dir_dentry->d_inode);
++			else
++				fist_copy_attr_atime(dir, hidden_dir_dentry->d_inode);
++
++			dtopd(dentry)->state = NON_EXISTANT;
++			dtohd(dentry) = hidden_dentry;
++			dtohd2(dentry) = hidden_sto_dentry;
++			d_add(dentry, NULL);
++			goto out;
++		}
++
++	/* if we get to here, were in an invalid state. bad. */
++	printk(KERN_CRIT "mini_fo_lookup: ERROR, meta data corruption detected.\n");
++
++	/* end state checking */
++ out_free:
++	d_drop(dentry);		/* so that our bad dentry will get destroyed */
++	kfree(dtopd(dentry));
++	__dtopd(dentry) = NULL;	/* be safe */
++
++ out_dput:
++	if(hidden_dentry)
++		dput(hidden_dentry);
++	if(hidden_sto_dentry)
++		dput(hidden_sto_dentry); /* drops usage count and marks for release */
++
++ out:
++	/* initalize wol if file exists and is directory */
++	if(dentry->d_inode) {
++		if(S_ISDIR(dentry->d_inode->i_mode)) {
++			itopd(dentry->d_inode)->deleted_list_size = -1;
++			itopd(dentry->d_inode)->renamed_list_size = -1;
++			meta_build_lists(dentry);
++		}
++	}
++	return ERR_PTR(err);
++}
++
++
++STATIC int
++mini_fo_link(dentry_t *old_dentry, inode_t *dir, dentry_t *new_dentry)
++{
++	int err;
++	dentry_t *hidden_old_dentry;
++	dentry_t *hidden_new_dentry;
++	dentry_t *hidden_dir_dentry;
++
++
++	check_mini_fo_dentry(old_dentry);
++	check_mini_fo_dentry(new_dentry);
++	check_mini_fo_inode(dir);
++
++	/* no links to directorys and existing targets target allowed */
++	if(S_ISDIR(old_dentry->d_inode->i_mode) ||
++	   is_mini_fo_existant(new_dentry)) {
++		err = -EPERM;
++		goto out;
++	}
++
++	/* bring it directly from unmod to del_rew */
++	if(dtost(old_dentry) == UNMODIFIED) {
++		err = nondir_unmod_to_mod(old_dentry, 1);
++		if(err) {
++			err = -EINVAL;
++			goto out;
++		}
++		err = meta_add_d_entry(old_dentry->d_parent,
++				       old_dentry->d_name.name,
++				       old_dentry->d_name.len);
++		if(err) {
++			err = -EINVAL;
++			goto out;
++		}
++		dput(dtohd(old_dentry));
++		dtohd(old_dentry) = NULL;
++		dtost(old_dentry) = DEL_REWRITTEN;
++	}
++
++	err = get_neg_sto_dentry(new_dentry);
++	if(err) {
++		err = -EINVAL;
++		goto out;
++	}
++
++	hidden_old_dentry = dtohd2(old_dentry);
++	hidden_new_dentry = dtohd2(new_dentry);
++
++	dget(hidden_old_dentry);
++	dget(hidden_new_dentry);
++
++	/* was: hidden_dir_dentry = lock_parent(hidden_new_dentry); */
++	hidden_dir_dentry = dget(hidden_new_dentry->d_parent);
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_lock(&hidden_dir_dentry->d_inode->i_mutex);
++#else
++	down(&hidden_dir_dentry->d_inode->i_sem);
++#endif
++
++	err = vfs_link(hidden_old_dentry,
++		       hidden_dir_dentry->d_inode,
++		       hidden_new_dentry);
++	if (err || !hidden_new_dentry->d_inode)
++		goto out_lock;
++
++	dtost(new_dentry) = CREATED;
++ 	err = mini_fo_tri_interpose(NULL, hidden_new_dentry, new_dentry, dir->i_sb, 0);
++	if (err)
++		goto out_lock;
++
++	fist_copy_attr_timesizes(dir, hidden_new_dentry->d_inode);
++	/* propagate number of hard-links */
++	old_dentry->d_inode->i_nlink = itohi2(old_dentry->d_inode)->i_nlink;
++
++ out_lock:
++	/* was: unlock_dir(hidden_dir_dentry); */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_unlock(&hidden_dir_dentry->d_inode->i_mutex);
++#else
++	up(&hidden_dir_dentry->d_inode->i_sem);
++#endif
++	dput(hidden_dir_dentry);
++
++	dput(hidden_new_dentry);
++	dput(hidden_old_dentry);
++	if (!new_dentry->d_inode)
++		d_drop(new_dentry);
++
++ out:
++	return err;
++}
++
++
++STATIC int
++mini_fo_unlink(inode_t *dir, dentry_t *dentry)
++{
++	int err = 0;
++
++	dget(dentry);
++	if(dtopd(dentry)->state == MODIFIED) {
++		err = nondir_mod_to_del(dentry);
++		goto out;
++	}
++	else if(dtopd(dentry)->state == UNMODIFIED) {
++		err = nondir_unmod_to_del(dentry);
++		goto out;
++	}
++	else if(dtopd(dentry)->state == CREATED) {
++		err = nondir_creat_to_del(dentry);
++		goto out;
++	}
++	else if(dtopd(dentry)->state == DEL_REWRITTEN) {
++		err = nondir_del_rew_to_del(dentry);
++		goto out;
++	}
++
++	printk(KERN_CRIT "mini_fo_unlink: ERROR, invalid state detected.\n");
++
++ out:
++	fist_copy_attr_times(dir, itohi2(dentry->d_parent->d_inode));
++
++	if(!err) {
++		/* is this causing my pain? d_delete(dentry); */
++		d_drop(dentry);
++	}
++
++	dput(dentry);
++	return err;
++}
++
++
++STATIC int
++mini_fo_symlink(inode_t *dir, dentry_t *dentry, const char *symname)
++{
++	int err=0;
++	dentry_t *hidden_sto_dentry;
++	dentry_t *hidden_sto_dir_dentry;
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++        umode_t mode;
++#endif
++
++	/* Fail if the symlink file exists */
++	if(!(dtost(dentry) == DELETED ||
++	     dtost(dentry) == NON_EXISTANT)) {
++		err = -EEXIST;
++		goto out;
++	}
++
++	err = get_neg_sto_dentry(dentry);
++	if(err) {
++		err = -EINVAL;
++		goto out;
++	}
++	hidden_sto_dentry = dtohd2(dentry);
++
++	dget(hidden_sto_dentry);
++	/* was: hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry); */
++	hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	down(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++	mode = S_IALLUGO;
++	err = vfs_symlink(hidden_sto_dir_dentry->d_inode,
++			  hidden_sto_dentry, symname, mode);
++#else
++	err = vfs_symlink(hidden_sto_dir_dentry->d_inode,
++			  hidden_sto_dentry,
++			  symname);
++#endif
++	if (err || !hidden_sto_dentry->d_inode)
++                goto out_lock;
++
++        if(dtost(dentry) == DELETED) {
++                dtost(dentry) = DEL_REWRITTEN;
++                err = mini_fo_tri_interpose(NULL, hidden_sto_dentry, dentry, dir->i_sb, 0);
++                if(err)
++                        goto out_lock;
++        } else if(dtost(dentry) == NON_EXISTANT) {
++                dtost(dentry) = CREATED;
++                err = mini_fo_tri_interpose(dtohd(dentry), hidden_sto_dentry, dentry, dir->i_sb, 0);
++                if(err)
++                        goto out_lock;
++        }
++	fist_copy_attr_timesizes(dir, hidden_sto_dir_dentry->d_inode);
++
++ out_lock:
++        /* was: unlock_dir(hidden_sto_dir_dentry); */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++	dput(hidden_sto_dir_dentry);
++
++        dput(hidden_sto_dentry);
++        if (!dentry->d_inode)
++                d_drop(dentry);
++ out:
++        return err;
++}
++
++STATIC int
++mini_fo_mkdir(inode_t *dir, dentry_t *dentry, int mode)
++{
++	int err;
++
++	err = create_sto_dir(dentry, mode);
++
++	check_mini_fo_dentry(dentry);
++
++	return err;
++}
++
++
++STATIC int
++mini_fo_rmdir(inode_t *dir, dentry_t *dentry)
++{
++	int err = 0;
++
++	dentry_t *hidden_sto_dentry;
++	dentry_t *hidden_sto_dir_dentry;
++	dentry_t *meta_dentry;
++	inode_t *hidden_sto_dir = NULL;
++
++	check_mini_fo_dentry(dentry);
++	check_mini_fo_inode(dir);
++
++	dget(dentry);
++	if(dtopd(dentry)->state == MODIFIED) {
++		/* XXX: disabled, because it does not bother to check files on
++		 * the original filesystem - just a hack, but better than simply
++		 * removing it without testing */
++		err = -EINVAL;
++		goto out;
++
++		hidden_sto_dir = itohi2(dir);
++		hidden_sto_dentry = dtohd2(dentry);
++
++		/* was:hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry); */
++		hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++		down(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++
++		/* Delete an old WOL file contained in the storage dir */
++		meta_dentry = lookup_one_len(META_FILENAME,
++					     hidden_sto_dentry,
++					     strlen(META_FILENAME));
++		if(meta_dentry->d_inode) {
++			err = vfs_unlink(hidden_sto_dentry->d_inode, meta_dentry);
++			dput(meta_dentry);
++			if(!err)
++				d_delete(meta_dentry);
++		}
++
++		err = vfs_rmdir(hidden_sto_dir, hidden_sto_dentry);
++		dput(hidden_sto_dentry);
++		if(!err)
++			d_delete(hidden_sto_dentry);
++
++		/* propagate number of hard-links */
++		dentry->d_inode->i_nlink = itohi2(dentry->d_inode)->i_nlink;
++
++		dput(dtohd(dentry));
++
++		dtohd(dentry) = NULL;
++		dtopd(dentry)->state = DELETED;
++
++		/* carefull with R files */
++		if( __meta_is_r_entry(dir,
++				      dentry->d_name.name,
++				      dentry->d_name.len) == 1) {
++			err = meta_remove_r_entry(dentry->d_parent,
++						  dentry->d_name.name,
++						  dentry->d_name.len);
++			if(err) {
++				printk(KERN_CRIT "mini_fo: rmdir: meta_remove_r_entry failed.\n");
++				goto out;
++			}
++		}
++		else {
++			/* ok, add deleted file to META */
++			meta_add_d_entry(dentry->d_parent,
++					 dentry->d_name.name,
++					 dentry->d_name.len);
++		}
++		/* was: unlock_dir(hidden_sto_dir_dentry); */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++		up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++		dput(hidden_sto_dir_dentry);
++		goto out;
++	}
++	else if(dtopd(dentry)->state == UNMODIFIED) {
++		/* XXX: simply adding it to the delete list here is fscking dangerous!
++		 * as a temporary hack, i will disable rmdir on unmodified directories
++		 * for now.
++		 */
++		err = -EINVAL;
++		goto out;
++
++		err = get_neg_sto_dentry(dentry);
++		if(err) {
++			err = -EINVAL;
++			goto out;
++		}
++
++		/* dput base dentry, this will relase the inode and free the
++		 * dentry, as we will never need it again. */
++		dput(dtohd(dentry));
++		dtohd(dentry) = NULL;
++		dtopd(dentry)->state = DELETED;
++
++		/* add deleted file to META-file */
++		meta_add_d_entry(dentry->d_parent,
++				 dentry->d_name.name,
++				 dentry->d_name.len);
++		goto out;
++	}
++	else if(dtopd(dentry)->state == CREATED) {
++		hidden_sto_dir = itohi2(dir);
++		hidden_sto_dentry = dtohd2(dentry);
++
++		/* was: hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry);*/
++		hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++		down(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++
++		/* Delete an old WOL file contained in the storage dir */
++		meta_dentry = lookup_one_len(META_FILENAME,
++					     hidden_sto_dentry,
++					     strlen(META_FILENAME));
++		if(meta_dentry->d_inode) {
++			/* is this necessary? dget(meta_dentry); */
++			err = vfs_unlink(hidden_sto_dentry->d_inode,
++					 meta_dentry);
++			dput(meta_dentry);
++			if(!err)
++				d_delete(meta_dentry);
++		}
++
++		err = vfs_rmdir(hidden_sto_dir, hidden_sto_dentry);
++		dput(hidden_sto_dentry);
++		if(!err)
++			d_delete(hidden_sto_dentry);
++
++		/* propagate number of hard-links */
++		dentry->d_inode->i_nlink = itohi2(dentry->d_inode)->i_nlink;
++		dtopd(dentry)->state = NON_EXISTANT;
++
++		/* was: unlock_dir(hidden_sto_dir_dentry); */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++		up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++		dput(hidden_sto_dir_dentry);
++
++		goto out;
++	}
++	else if(dtopd(dentry)->state == DEL_REWRITTEN) {
++		hidden_sto_dir = itohi2(dir);
++		hidden_sto_dentry = dtohd2(dentry);
++
++		/* was: hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry);*/
++		hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++		down(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++
++		/* Delete an old WOL file contained in the storage dir */
++		meta_dentry = lookup_one_len(META_FILENAME,
++					     hidden_sto_dentry,
++					     strlen(META_FILENAME));
++		if(meta_dentry->d_inode) {
++			/* is this necessary? dget(meta_dentry); */
++			err = vfs_unlink(hidden_sto_dentry->d_inode,
++					 meta_dentry);
++			dput(meta_dentry);
++			if(!err)
++				d_delete(meta_dentry);
++		}
++
++		err = vfs_rmdir(hidden_sto_dir, hidden_sto_dentry);
++		dput(hidden_sto_dentry);
++		if(!err)
++			d_delete(hidden_sto_dentry);
++
++		/* propagate number of hard-links */
++		dentry->d_inode->i_nlink = itohi2(dentry->d_inode)->i_nlink;
++		dtopd(dentry)->state = DELETED;
++		/* was: unlock_dir(hidden_sto_dir_dentry); */
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++		up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++		dput(hidden_sto_dir_dentry);
++		goto out;
++	}
++
++	printk(KERN_CRIT "mini_fo_rmdir: ERROR, invalid state detected.\n");
++
++ out:
++	if(!err) {
++		d_drop(dentry);
++	}
++
++	fist_copy_attr_times(dir, itohi2(dentry->d_parent->d_inode));
++	dput(dentry);
++
++	return err;
++}
++
++
++STATIC int
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++mini_fo_mknod(inode_t *dir, dentry_t *dentry, int mode, dev_t dev)
++#else
++mini_fo_mknod(inode_t *dir, dentry_t *dentry, int mode, int dev)
++#endif
++{
++	int err = 0;
++
++	check_mini_fo_dentry(dentry);
++
++	err = create_sto_nod(dentry, mode, dev);
++	if(err) {
++		printk(KERN_CRIT "mini_fo_mknod: creating sto nod failed.\n");
++		err = -EINVAL;
++	}
++
++	check_mini_fo_dentry(dentry);
++	return err;
++}
++
++
++STATIC int
++mini_fo_rename(inode_t *old_dir, dentry_t *old_dentry,
++	       inode_t *new_dir, dentry_t *new_dentry)
++{
++	/* dispatch */
++	if(S_ISDIR(old_dentry->d_inode->i_mode))
++		return rename_directory(old_dir, old_dentry, new_dir, new_dentry);
++	return rename_nondir(old_dir, old_dentry, new_dir, new_dentry);
++
++}
++
++int rename_directory(inode_t *old_dir, dentry_t *old_dentry,
++		     inode_t *new_dir, dentry_t *new_dentry)
++{
++	int err, bpath_len;
++	char *bpath;
++
++	dentry_t *hidden_old_dentry;
++	dentry_t *hidden_new_dentry;
++	dentry_t *hidden_old_dir_dentry;
++	dentry_t *hidden_new_dir_dentry;
++
++	err = 0;
++	bpath = NULL;
++	bpath_len = 0;
++
++	/* this is a test, chuck out if it works */
++	if(!(dtopd(new_dentry)->state == DELETED ||
++	     dtopd(new_dentry)->state == NON_EXISTANT)) {
++		printk(KERN_CRIT "mini_fo: rename_directory: \
++                                  uh, ah, new_dentry not negative.\n");
++		/* return -1; */
++	}
++
++	/* state = UNMODIFIED */
++	if(dtopd(old_dentry)->state == UNMODIFIED) {
++		err = dir_unmod_to_mod(old_dentry);
++		if (err)
++			goto out;
++	}
++
++	/* state = MODIFIED */
++	if(dtopd(old_dentry)->state == MODIFIED) {
++		bpath = meta_check_r_entry(old_dentry->d_parent,
++					   old_dentry->d_name.name,
++					   old_dentry->d_name.len);
++		if(bpath) {
++			err = meta_remove_r_entry(old_dentry->d_parent,
++						  old_dentry->d_name.name,
++						  old_dentry->d_name.len);
++			if(err) {
++				printk(KERN_CRIT "mini_fo: rename_directory:\
++                                                   meta_remove_r_entry \
++                                                  failed.\n");
++				goto out;
++			}
++			err = meta_add_r_entry(new_dentry->d_parent,
++					       bpath,
++					       strlen(bpath),
++					       new_dentry->d_name.name,
++					       new_dentry->d_name.len);
++			kfree(bpath);
++		}
++		else {/* wol it */
++			err = meta_add_d_entry(old_dentry->d_parent,
++					       old_dentry->d_name.name,
++					       old_dentry->d_name.len);
++			if (err)
++				goto out;
++			/* put it on rename list */
++			err = get_mini_fo_bpath(old_dentry,
++						&bpath,
++						&bpath_len);
++			if (err)
++				goto out;
++			err = meta_add_r_entry(new_dentry->d_parent,
++					       bpath, bpath_len,
++					       new_dentry->d_name.name,
++					       new_dentry->d_name.len);
++			if (err)
++				goto out;
++		}
++		/* no state change, MODIFIED stays MODIFIED */
++	}
++	/* state = CREATED */
++	if(dtopd(old_dentry)->state == CREATED ||
++	   dtopd(old_dentry)->state == DEL_REWRITTEN) {
++		if(dtohd(old_dentry))
++			dput(dtohd(old_dentry));
++
++		if(dtopd(new_dentry)->state == DELETED) {
++			dtopd(old_dentry)->state = DEL_REWRITTEN;
++			dtohd(old_dentry) = NULL;
++		}
++		else if(dtopd(new_dentry)->state == NON_EXISTANT) {
++			dtopd(old_dentry)->state = CREATED;
++			/* steal new dentry's neg. base dentry */
++			dtohd(old_dentry) = dtohd(new_dentry);
++			dtohd(new_dentry) = NULL;
++		}
++	}
++	if(dtopd(new_dentry)->state == UNMODIFIED ||
++	   dtopd(new_dentry)->state == NON_EXISTANT) {
++		err = get_neg_sto_dentry(new_dentry);
++		if(err)
++			goto out;
++	}
++
++	/* now move sto file */
++	hidden_old_dentry = dtohd2(old_dentry);
++	hidden_new_dentry = dtohd2(new_dentry);
++
++	dget(hidden_old_dentry);
++	dget(hidden_new_dentry);
++
++	hidden_old_dir_dentry = dget(hidden_old_dentry->d_parent);
++	hidden_new_dir_dentry = dget(hidden_new_dentry->d_parent);
++	double_lock(hidden_old_dir_dentry, hidden_new_dir_dentry);
++
++	err = vfs_rename(hidden_old_dir_dentry->d_inode, hidden_old_dentry,
++			 hidden_new_dir_dentry->d_inode, hidden_new_dentry);
++	if(err)
++		goto out_lock;
++
++	fist_copy_attr_all(new_dir, hidden_new_dir_dentry->d_inode);
++	if (new_dir != old_dir)
++		fist_copy_attr_all(old_dir,
++				   hidden_old_dir_dentry->d_inode);
++
++ out_lock:
++	/* double_unlock will dput the new/old parent dentries
++	 * whose refcnts were incremented via get_parent above. */
++	double_unlock(hidden_old_dir_dentry, hidden_new_dir_dentry);
++	dput(hidden_new_dentry);
++	dput(hidden_old_dentry);
++
++ out:
++	return err;
++}
++
++int rename_nondir(inode_t *old_dir, dentry_t *old_dentry,
++		  inode_t *new_dir, dentry_t *new_dentry)
++{
++	int err=0;
++
++	check_mini_fo_dentry(old_dentry);
++	check_mini_fo_dentry(new_dentry);
++	check_mini_fo_inode(old_dir);
++	check_mini_fo_inode(new_dir);
++
++	/* state: UNMODIFIED */
++	if(dtost(old_dentry) == UNMODIFIED) {
++		err = nondir_unmod_to_mod(old_dentry, 1);
++		if(err) {
++			err = -EINVAL;
++			goto out;
++		}
++	}
++
++	/* the easy states */
++	if(exists_in_storage(old_dentry)) {
++
++		dentry_t *hidden_old_dentry;
++		dentry_t *hidden_new_dentry;
++		dentry_t *hidden_old_dir_dentry;
++		dentry_t *hidden_new_dir_dentry;
++
++		/* if old file is MODIFIED, add it to the deleted_list */
++		if(dtopd(old_dentry)->state == MODIFIED) {
++			meta_add_d_entry(old_dentry->d_parent,
++					 old_dentry->d_name.name,
++					 old_dentry->d_name.len);
++
++			dput(dtohd(old_dentry));
++		}
++		/* if old file is CREATED, we only release the base dentry */
++		if(dtopd(old_dentry)->state == CREATED) {
++			if(dtohd(old_dentry))
++				dput(dtohd(old_dentry));
++		}
++
++		/* now setup the new states (depends on new_dentry state) */
++		/* new dentry state =  MODIFIED */
++		if(dtopd(new_dentry)->state == MODIFIED) {
++			meta_add_d_entry(new_dentry->d_parent,
++					 new_dentry->d_name.name,
++					 new_dentry->d_name.len);
++
++			/* new dentry will be d_put'ed later by the vfs
++			 * so don't do it here
++			 * dput(dtohd(new_dentry));
++			 */
++			dtohd(old_dentry) = NULL;
++			dtopd(old_dentry)->state = DEL_REWRITTEN;
++		}
++		/* new dentry state =  UNMODIFIED */
++		else if(dtopd(new_dentry)->state == UNMODIFIED) {
++			if(get_neg_sto_dentry(new_dentry))
++				return -EINVAL;
++
++			meta_add_d_entry(new_dentry->d_parent,
++					 new_dentry->d_name.name,
++					 new_dentry->d_name.len);
++
++			/* is this right??? */
++			/*dput(dtohd(new_dentry));*/
++			dtohd(old_dentry) = NULL;
++			dtopd(old_dentry)->state = DEL_REWRITTEN;
++		}
++		/* new dentry state =  CREATED */
++		else if(dtopd(new_dentry)->state == CREATED) {
++			/* we keep the neg. base dentry (if exists) */
++			dtohd(old_dentry) = dtohd(new_dentry);
++			/* ...and set it to Null, or we'll get
++			 * dcache.c:345 if it gets dput twice... */
++			dtohd(new_dentry) = NULL;
++			dtopd(old_dentry)->state = CREATED;
++		}
++		/* new dentry state =  NON_EXISTANT */
++		else if(dtopd(new_dentry)->state == NON_EXISTANT) {
++			if(get_neg_sto_dentry(new_dentry))
++				return -EINVAL;
++
++			/* we keep the neg. base dentry (if exists) */
++			dtohd(old_dentry) = dtohd(new_dentry);
++			/* ...and set it to Null, or we'll get
++			 * Dr. dcache.c:345 if it gets dput twice... */
++			dtohd(new_dentry) = NULL;
++			dtopd(old_dentry)->state = CREATED;
++		}
++		/* new dentry state =  DEL_REWRITTEN or DELETED */
++		else if(dtopd(new_dentry)->state == DEL_REWRITTEN ||
++			dtopd(new_dentry)->state == DELETED) {
++			dtohd(old_dentry) = NULL;
++			dtopd(old_dentry)->state = DEL_REWRITTEN;
++		}
++		else { /* not possible, uhh, ahh */
++			printk(KERN_CRIT
++			       "mini_fo: rename_reg_file: invalid state detected [1].\n");
++			return -1;
++		}
++
++		/* now we definitely have a sto file */
++		hidden_old_dentry = dtohd2(old_dentry);
++		hidden_new_dentry = dtohd2(new_dentry);
++
++		dget(hidden_old_dentry);
++		dget(hidden_new_dentry);
++
++		hidden_old_dir_dentry = dget(hidden_old_dentry->d_parent);
++		hidden_new_dir_dentry = dget(hidden_new_dentry->d_parent);
++		double_lock(hidden_old_dir_dentry, hidden_new_dir_dentry);
++
++		err = vfs_rename(hidden_old_dir_dentry->d_inode,
++				 hidden_old_dentry,
++				 hidden_new_dir_dentry->d_inode,
++				 hidden_new_dentry);
++		if(err)
++			goto out_lock;
++
++		fist_copy_attr_all(new_dir, hidden_new_dir_dentry->d_inode);
++		if (new_dir != old_dir)
++			fist_copy_attr_all(old_dir, hidden_old_dir_dentry->d_inode);
++
++	out_lock:
++		/* double_unlock will dput the new/old parent dentries
++		 * whose refcnts were incremented via get_parent above.
++		 */
++		double_unlock(hidden_old_dir_dentry, hidden_new_dir_dentry);
++		dput(hidden_new_dentry);
++		dput(hidden_old_dentry);
++	out:
++		return err;
++	}
++	else { /* invalid state */
++		printk(KERN_CRIT "mini_fo: rename_reg_file: ERROR: invalid state detected [2].\n");
++		return -1;
++	}
++}
++
++
++STATIC int
++mini_fo_readlink(dentry_t *dentry, char *buf, int bufsiz)
++{
++	int err=0;
++	dentry_t *hidden_dentry = NULL;
++
++	if(dtohd2(dentry) && dtohd2(dentry)->d_inode) {
++		hidden_dentry = dtohd2(dentry);
++	} else if(dtohd(dentry) && dtohd(dentry)->d_inode) {
++		hidden_dentry = dtohd(dentry);
++	} else {
++		goto out;
++	}
++
++	if (!hidden_dentry->d_inode->i_op ||
++	    !hidden_dentry->d_inode->i_op->readlink) {
++		err = -EINVAL;		goto out;
++	}
++
++	err = hidden_dentry->d_inode->i_op->readlink(hidden_dentry,
++						     buf,
++						     bufsiz);
++	if (err > 0)
++		fist_copy_attr_atime(dentry->d_inode, hidden_dentry->d_inode);
++
++ out:
++	return err;
++}
++
++
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,13)
++static int mini_fo_follow_link(dentry_t *dentry, struct nameidata *nd)
++#else
++static void* mini_fo_follow_link(dentry_t *dentry, struct nameidata *nd)
++#endif
++{
++	char *buf;
++	int len = PAGE_SIZE, err;
++	mm_segment_t old_fs;
++
++	/* in 2.6 this is freed by mini_fo_put_link called by __do_follow_link */
++	buf = kmalloc(len, GFP_KERNEL);
++	if (!buf) {
++		err = -ENOMEM;
++		goto out;
++	}
++
++	/* read the symlink, and then we will follow it */
++	old_fs = get_fs();
++	set_fs(KERNEL_DS);
++	err = dentry->d_inode->i_op->readlink(dentry, buf, len);
++	set_fs(old_fs);
++	if (err < 0) {
++		kfree(buf);
++		buf = NULL;
++		goto out;
++	}
++	buf[err] = 0;
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++        nd_set_link(nd, buf);
++        err = 0;
++#else
++	err = vfs_follow_link(nd, buf);
++#endif
++
++ out:
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++	kfree(buf);
++#endif
++
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,13)
++        return err;
++#else
++        return ERR_PTR(err);
++#endif
++}
++
++STATIC
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,13)
++void mini_fo_put_link(struct dentry *dentry, struct nameidata *nd)
++#else
++void mini_fo_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
++#endif
++{
++        char *link;
++        link = nd_get_link(nd);
++        kfree(link);
++}
++#endif
++
++STATIC int
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++mini_fo_permission(inode_t *inode, int mask, struct nameidata *nd)
++#else
++mini_fo_permission(inode_t *inode, int mask)
++#endif
++{
++	inode_t *hidden_inode;
++	int mode;
++	int err;
++
++	if(itohi2(inode)) {
++		hidden_inode = itohi2(inode);
++	} else {
++		hidden_inode = itohi(inode);
++	}
++	mode = inode->i_mode;
++
++	/* not really needed, as permission handles everything:
++	 *	err = vfs_permission(inode, mask);
++	 *	if (err)
++	 *		goto out;
++	 */
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++	err = permission(hidden_inode, mask, nd);
++#else
++	err = permission(hidden_inode, mask);
++#endif
++
++	/*  out: */
++	return err;
++}
++
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++STATIC int
++mini_fo_inode_revalidate(dentry_t *dentry)
++{
++	int err = 0;
++	dentry_t *hidden_dentry;
++	inode_t *hidden_inode;
++
++	ASSERT(dentry->d_inode);
++	ASSERT(itopd(dentry->d_inode));
++
++	if(itohi2(dentry->d_inode)) {
++                hidden_dentry = dtohd2(dentry);
++		hidden_inode = hidden_dentry->d_inode;
++	} else if(itohi(dentry->d_inode)) {
++                hidden_dentry = dtohd(dentry);
++		hidden_inode = hidden_dentry->d_inode;
++	} else {
++                printk(KERN_CRIT "mini_fo_inode_revalidate: ERROR, invalid state detected.\n");
++                err = -ENOENT;
++                goto out;
++        }
++	if (hidden_inode && hidden_inode->i_op && hidden_inode->i_op->revalidate){
++		err = hidden_inode->i_op->revalidate(hidden_dentry);
++		if (err)
++			goto out;
++	}
++	fist_copy_attr_all(dentry->d_inode, hidden_inode);
++ out:
++	return err;
++}
++#endif
++
++STATIC int
++mini_fo_setattr(dentry_t *dentry, struct iattr *ia)
++{
++	int err = 0;
++
++	check_mini_fo_dentry(dentry);
++
++	if(!is_mini_fo_existant(dentry)) {
++		printk(KERN_CRIT "mini_fo_setattr: ERROR, invalid state detected [1].\n");
++		goto out;
++	}
++
++	if(dtost(dentry) == UNMODIFIED) {
++		if(!IS_COPY_FLAG(ia->ia_valid))
++			goto out; /* we ignore these changes to base */
++
++		if(S_ISDIR(dentry->d_inode->i_mode)) {
++			err = dir_unmod_to_mod(dentry);
++		} else {
++			/* we copy contents if file is not beeing truncated */
++			if(S_ISREG(dentry->d_inode->i_mode) &&
++			   !(ia->ia_size == 0 && (ia->ia_valid & ATTR_SIZE))) {
++				err = nondir_unmod_to_mod(dentry, 1);
++			} else
++				err = nondir_unmod_to_mod(dentry, 0);
++		}
++		if(err) {
++			err = -EINVAL;
++			printk(KERN_CRIT "mini_fo_setattr: ERROR changing states.\n");
++			goto out;
++		}
++	}
++	if(!exists_in_storage(dentry)) {
++		printk(KERN_CRIT "mini_fo_setattr: ERROR, invalid state detected [2].\n");
++		err = -EINVAL;
++		goto out;
++	}
++	ASSERT(dentry->d_inode);
++	ASSERT(dtohd2(dentry));
++	ASSERT(itopd(dentry->d_inode));
++	ASSERT(itohi2(dentry->d_inode));
++
++	err = notify_change(dtohd2(dentry), ia);
++	fist_copy_attr_all(dentry->d_inode, itohi2(dentry->d_inode));
++ out:
++	return err;
++}
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++STATIC int
++mini_fo_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
++{
++	int err = 0;
++        dentry_t *hidden_dentry;
++
++	ASSERT(dentry->d_inode);
++	ASSERT(itopd(dentry->d_inode));
++
++	if(itohi2(dentry->d_inode)) {
++                hidden_dentry = dtohd2(dentry);
++	} else if(itohi(dentry->d_inode)) {
++                hidden_dentry = dtohd(dentry);
++	} else {
++                printk(KERN_CRIT "mini_fo_getattr: ERROR, invalid state detected.\n");
++                err = -ENOENT;
++                goto out;
++        }
++	fist_copy_attr_all(dentry->d_inode, hidden_dentry->d_inode);
++
++	ASSERT(hidden_dentry);
++	ASSERT(hidden_dentry->d_inode);
++	ASSERT(hidden_dentry->d_inode->i_op);
++
++	generic_fillattr(dentry->d_inode, stat);
++	if (!stat->blksize) {
++		struct super_block *s = hidden_dentry->d_inode->i_sb;
++		unsigned blocks;
++		blocks = (stat->size+s->s_blocksize-1) >> s->s_blocksize_bits;
++		stat->blocks = (s->s_blocksize / 512) * blocks;
++		stat->blksize = s->s_blocksize;
++	}
++ out:
++        return err;
++}
++#endif
++
++#if defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20))
++#if 0 /* no xattr_alloc() and xattr_free() */
++/* This is lifted from fs/xattr.c */
++static void *
++xattr_alloc(size_t size, size_t limit)
++{
++	void *ptr;
++
++	if (size > limit)
++		return ERR_PTR(-E2BIG);
++
++	if (!size)	/* size request, no buffer is needed */
++		return NULL;
++	else if (size <= PAGE_SIZE)
++		ptr = kmalloc((unsigned long) size, GFP_KERNEL);
++	else
++		ptr = vmalloc((unsigned long) size);
++	if (!ptr)
++		return ERR_PTR(-ENOMEM);
++	return ptr;
++}
++
++static void
++xattr_free(void *ptr, size_t size)
++{
++	if (!size)	/* size request, no buffer was needed */
++		return;
++	else if (size <= PAGE_SIZE)
++		kfree(ptr);
++	else
++		vfree(ptr);
++}
++#endif /* no xattr_alloc() and xattr_free() */
++
++/* BKL held by caller.
++ * dentry->d_inode->i_sem down
++ */
++STATIC int
++mini_fo_getxattr(struct dentry *dentry, const char *name, void *value, size_t size) {
++	struct dentry *hidden_dentry = NULL;
++	int err = -EOPNOTSUPP;
++	/* Define these anyway so we don't need as much ifdef'ed code. */
++	char *encoded_name = NULL;
++	char *encoded_value = NULL;
++
++	check_mini_fo_dentry(dentry);
++
++	if(exists_in_storage(dentry))
++		hidden_dentry = dtohd2(dentry);
++	else
++		hidden_dentry = dtohd(dentry);
++
++	ASSERT(hidden_dentry);
++	ASSERT(hidden_dentry->d_inode);
++	ASSERT(hidden_dentry->d_inode->i_op);
++
++	if (hidden_dentry->d_inode->i_op->getxattr) {
++		encoded_name = (char *)name;
++		encoded_value = (char *)value;
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_lock(&hidden_dentry->d_inode->i_mutex);
++#else
++		down(&hidden_dentry->d_inode->i_sem);
++#endif
++		/* lock_kernel() already done by caller. */
++		err = hidden_dentry->d_inode->i_op->getxattr(hidden_dentry, encoded_name, encoded_value, size);
++		/* unlock_kernel() will be done by caller. */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_lock(&hidden_dentry->d_inode->i_mutex);
++#else
++		up(&hidden_dentry->d_inode->i_sem);
++#endif
++	}
++	return err;
++}
++
++/* BKL held by caller.
++ * dentry->d_inode->i_sem down
++ */
++STATIC int
++#if ((LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,21) \
++     && LINUX_VERSION_CODE <= KERNEL_VERSION(2,4,23)) \
++     || LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0))
++mini_fo_setxattr(struct dentry *dentry, const char *name,
++		 const void *value, size_t size, int flags)
++#else
++mini_fo_setxattr(struct dentry *dentry, const char *name,
++		 void *value, size_t size, int flags)
++#endif
++
++{
++	struct dentry *hidden_dentry = NULL;
++	int err = -EOPNOTSUPP;
++
++	/* Define these anyway, so we don't have as much ifdef'ed code. */
++	char *encoded_value = NULL;
++	char *encoded_name = NULL;
++
++	check_mini_fo_dentry(dentry);
++
++	if(exists_in_storage(dentry))
++		hidden_dentry = dtohd2(dentry);
++	else
++		hidden_dentry = dtohd(dentry);
++
++	ASSERT(hidden_dentry);
++	ASSERT(hidden_dentry->d_inode);
++	ASSERT(hidden_dentry->d_inode->i_op);
++
++	if (hidden_dentry->d_inode->i_op->setxattr) {
++		encoded_name = (char *)name;
++		encoded_value = (char *)value;
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_lock(&hidden_dentry->d_inode->i_mutex);
++#else
++		down(&hidden_dentry->d_inode->i_sem);
++#endif
++		/* lock_kernel() already done by caller. */
++		err = hidden_dentry->d_inode->i_op->setxattr(hidden_dentry, encoded_name, encoded_value, size, flags);
++		/* unlock_kernel() will be done by caller. */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_unlock(&hidden_dentry->d_inode->i_mutex);
++#else
++		up(&hidden_dentry->d_inode->i_sem);
++#endif
++	}
++	return err;
++}
++
++/* BKL held by caller.
++ * dentry->d_inode->i_sem down
++ */
++STATIC int
++mini_fo_removexattr(struct dentry *dentry, const char *name) {
++	struct dentry *hidden_dentry = NULL;
++	int err = -EOPNOTSUPP;
++	char *encoded_name;
++
++	check_mini_fo_dentry(dentry);
++
++	if(exists_in_storage(dentry))
++		hidden_dentry = dtohd2(dentry);
++	else
++		hidden_dentry = dtohd(dentry);
++
++	ASSERT(hidden_dentry);
++	ASSERT(hidden_dentry->d_inode);
++	ASSERT(hidden_dentry->d_inode->i_op);
++
++	if (hidden_dentry->d_inode->i_op->removexattr) {
++		encoded_name = (char *)name;
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_lock(&hidden_dentry->d_inode->i_mutex);
++#else
++		down(&hidden_dentry->d_inode->i_sem);
++#endif
++		/* lock_kernel() already done by caller. */
++		err = hidden_dentry->d_inode->i_op->removexattr(hidden_dentry, encoded_name);
++		/* unlock_kernel() will be done by caller. */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_unlock(&hidden_dentry->d_inode->i_mutex);
++#else
++		up(&hidden_dentry->d_inode->i_sem);
++#endif
++	}
++	return err;
++}
++
++/* BKL held by caller.
++ * dentry->d_inode->i_sem down
++ */
++STATIC int
++mini_fo_listxattr(struct dentry *dentry, char *list, size_t size) {
++	struct dentry *hidden_dentry = NULL;
++	int err = -EOPNOTSUPP;
++	char *encoded_list = NULL;
++
++	check_mini_fo_dentry(dentry);
++
++	if(exists_in_storage(dentry))
++		hidden_dentry = dtohd2(dentry);
++	else
++		hidden_dentry = dtohd(dentry);
++
++	ASSERT(hidden_dentry);
++	ASSERT(hidden_dentry->d_inode);
++	ASSERT(hidden_dentry->d_inode->i_op);
++
++	if (hidden_dentry->d_inode->i_op->listxattr) {
++		encoded_list = list;
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_lock(&hidden_dentry->d_inode->i_mutex);
++#else
++		down(&hidden_dentry->d_inode->i_sem);
++#endif
++		/* lock_kernel() already done by caller. */
++		err = hidden_dentry->d_inode->i_op->listxattr(hidden_dentry, encoded_list, size);
++		/* unlock_kernel() will be done by caller. */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_unlock(&hidden_dentry->d_inode->i_mutex);
++#else
++		up(&hidden_dentry->d_inode->i_sem);
++#endif
++	}
++	return err;
++}
++# endif /* defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20)) */
++
++struct inode_operations mini_fo_symlink_iops =
++	{
++		readlink:	mini_fo_readlink,
++		follow_link: mini_fo_follow_link,
++		/* mk: permission:	mini_fo_permission, */
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++		revalidate:	mini_fo_inode_revalidate,
++#endif
++		setattr:	mini_fo_setattr,
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++		getattr:	mini_fo_getattr,
++		put_link:       mini_fo_put_link,
++#endif
++
++#if defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20))
++		setxattr:	mini_fo_setxattr,
++		getxattr:	mini_fo_getxattr,
++		listxattr:	mini_fo_listxattr,
++		removexattr: mini_fo_removexattr
++# endif /* defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20)) */
++	};
++
++struct inode_operations mini_fo_dir_iops =
++	{
++		create:	mini_fo_create,
++		lookup:	mini_fo_lookup,
++		link:	mini_fo_link,
++		unlink:	mini_fo_unlink,
++		symlink:	mini_fo_symlink,
++		mkdir:	mini_fo_mkdir,
++		rmdir:	mini_fo_rmdir,
++		mknod:	mini_fo_mknod,
++		rename:	mini_fo_rename,
++		/* no readlink/follow_link for non-symlinks */
++		// off because we have setattr
++		//    truncate:	mini_fo_truncate,
++		/* mk:permission:	mini_fo_permission, */
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++		revalidate:	mini_fo_inode_revalidate,
++#endif
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++		getattr:	mini_fo_getattr,
++#endif
++		setattr:	mini_fo_setattr,
++#if defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20))
++		setxattr:	mini_fo_setxattr,
++		getxattr:	mini_fo_getxattr,
++		listxattr:	mini_fo_listxattr,
++		removexattr: mini_fo_removexattr
++# endif /* XATTR && LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20) */
++	};
++
++struct inode_operations mini_fo_main_iops =
++	{
++		/* permission:	mini_fo_permission, */
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++		revalidate:	mini_fo_inode_revalidate,
++#endif
++		setattr:	mini_fo_setattr,
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++		getattr:	mini_fo_getattr,
++#endif
++#if defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20))
++		setxattr:	mini_fo_setxattr,
++		getxattr:	mini_fo_getxattr,
++		listxattr:	mini_fo_listxattr,
++		removexattr:    mini_fo_removexattr
++# endif /* XATTR && LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20) */
++	};
+--- /dev/null
++++ b/fs/mini_fo/main.c
+@@ -0,0 +1,423 @@
++/*
++ * Copyright (c) 1997-2003 Erez Zadok
++ * Copyright (c) 2001-2003 Stony Brook University
++ *
++ * For specific licensing information, see the COPYING file distributed with
++ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
++ *
++ * This Copyright notice must be kept intact and distributed with all
++ * fistgen sources INCLUDING sources generated by fistgen.
++ */
++/*
++ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ */
++
++/*
++ *  $Id$
++ */
++
++#ifdef HAVE_CONFIG_H
++# include <config.h>
++#endif
++
++#include "fist.h"
++#include "mini_fo.h"
++#include <linux/module.h>
++
++/* This definition must only appear after we include <linux/module.h> */
++#ifndef MODULE_LICENSE
++# define MODULE_LICENSE(bison)
++#endif /* not MODULE_LICENSE */
++
++/*
++ * This is the mini_fo tri interpose function, which extends the
++ * functionality of the regular interpose by interposing a higher
++ * level inode on top of two lower level ones: the base filesystem
++ * inode and the storage filesystem inode.
++ *
++ *  sb we pass is mini_fo's super_block
++ */
++int
++mini_fo_tri_interpose(dentry_t *hidden_dentry,
++		      dentry_t *hidden_sto_dentry,
++		      dentry_t *dentry, super_block_t *sb, int flag)
++{
++	inode_t *hidden_inode = NULL;
++	inode_t *hidden_sto_inode = NULL; /* store corresponding storage inode */
++	int err = 0;
++	inode_t *inode;
++
++	/* Pointer to hidden_sto_inode if exists, else to hidden_inode.
++	 * This is used to copy the attributes of the correct inode. */
++	inode_t *master_inode;
++
++	if(hidden_dentry)
++		hidden_inode = hidden_dentry->d_inode;
++	if(hidden_sto_dentry)
++		hidden_sto_inode = hidden_sto_dentry->d_inode;
++
++	ASSERT(dentry->d_inode == NULL);
++
++	/* mk: One of the inodes associated with the dentrys is likely to
++	 * be NULL, so carefull:
++	 */
++	ASSERT((hidden_inode != NULL) || (hidden_sto_inode != NULL));
++
++	if(hidden_sto_inode)
++		master_inode = hidden_sto_inode;
++	else
++		master_inode = hidden_inode;
++
++	/*
++	 * We allocate our new inode below, by calling iget.
++	 * iget will call our read_inode which will initialize some
++	 * of the new inode's fields
++	 */
++
++	/*
++	 * original: inode = iget(sb, hidden_inode->i_ino);
++	 */
++	inode = iget(sb, iunique(sb, 25));
++	if (!inode) {
++		err = -EACCES;		/* should be impossible??? */
++		goto out;
++	}
++
++	/*
++	 * interpose the inode if not already interposed
++	 *   this is possible if the inode is being reused
++	 * XXX: what happens if we get_empty_inode() but there's another already?
++	 * for now, ASSERT() that this can't happen; fix later.
++	 */
++	if (itohi(inode) != NULL) {
++		printk(KERN_CRIT "mini_fo_tri_interpose: itohi(inode) != NULL.\n");
++	}
++	if (itohi2(inode) != NULL) {
++		printk(KERN_CRIT "mini_fo_tri_interpose: itohi2(inode) != NULL.\n");
++	}
++
++	/* mk: Carefull, igrab can't handle NULL inodes (ok, why should it?), so
++	 * we need to check here:
++	 */
++	if(hidden_inode)
++		itohi(inode) = igrab(hidden_inode);
++	else
++		itohi(inode) = NULL;
++
++	if(hidden_sto_inode)
++		itohi2(inode) = igrab(hidden_sto_inode);
++	else
++		itohi2(inode) = NULL;
++
++
++	/* Use different set of inode ops for symlinks & directories*/
++	if (S_ISLNK(master_inode->i_mode))
++		inode->i_op = &mini_fo_symlink_iops;
++	else if (S_ISDIR(master_inode->i_mode))
++		inode->i_op = &mini_fo_dir_iops;
++
++	/* Use different set of file ops for directories */
++	if (S_ISDIR(master_inode->i_mode))
++		inode->i_fop = &mini_fo_dir_fops;
++
++	/* properly initialize special inodes */
++	if (S_ISBLK(master_inode->i_mode) || S_ISCHR(master_inode->i_mode) ||
++	    S_ISFIFO(master_inode->i_mode) || S_ISSOCK(master_inode->i_mode)) {
++		init_special_inode(inode, master_inode->i_mode, master_inode->i_rdev);
++	}
++
++	/* Fix our inode's address operations to that of the lower inode */
++	if (inode->i_mapping->a_ops != master_inode->i_mapping->a_ops) {
++		inode->i_mapping->a_ops = master_inode->i_mapping->a_ops;
++	}
++
++	/* only (our) lookup wants to do a d_add */
++	if (flag)
++		d_add(dentry, inode);
++	else
++		d_instantiate(dentry, inode);
++
++	ASSERT(dtopd(dentry) != NULL);
++
++	/* all well, copy inode attributes */
++	fist_copy_attr_all(inode, master_inode);
++
++ out:
++	return err;
++}
++
++/* parse mount options "base=" and "sto=" */
++dentry_t *
++mini_fo_parse_options(super_block_t *sb, char *options)
++{
++	dentry_t *hidden_root = ERR_PTR(-EINVAL);
++	dentry_t *hidden_root2 = ERR_PTR(-EINVAL);
++	struct nameidata nd, nd2;
++	char *name, *tmp, *end;
++	int err = 0;
++
++	/* We don't want to go off the end of our arguments later on. */
++	for (end = options; *end; end++);
++
++	while (options < end) {
++		tmp = options;
++		while (*tmp && *tmp != ',')
++			tmp++;
++		*tmp = '\0';
++		if (!strncmp("base=", options, 5)) {
++			name = options + 5;
++			printk(KERN_INFO "mini_fo: using base directory: %s\n", name);
++
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++			if (path_init(name, LOOKUP_FOLLOW, &nd))
++				err = path_walk(name, &nd);
++#else
++			err = path_lookup(name, LOOKUP_FOLLOW, &nd);
++#endif
++			if (err) {
++				printk(KERN_CRIT "mini_fo: error accessing hidden directory '%s'\n", name);
++				hidden_root = ERR_PTR(err);
++				goto out;
++			}
++			hidden_root = nd.dentry;
++			stopd(sb)->base_dir_dentry = nd.dentry;
++			stopd(sb)->hidden_mnt = nd.mnt;
++
++		} else if(!strncmp("sto=", options, 4)) {
++			/* parse the storage dir */
++			name = options + 4;
++			printk(KERN_INFO "mini_fo: using storage directory: %s\n", name);
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++			if(path_init(name, LOOKUP_FOLLOW, &nd2))
++				err = path_walk(name, &nd2);
++#else
++                        err = path_lookup(name, LOOKUP_FOLLOW, &nd2);
++#endif
++			if(err) {
++				printk(KERN_CRIT "mini_fo: error accessing hidden storage directory '%s'\n", name);
++
++				hidden_root2 = ERR_PTR(err);
++				goto out;
++			}
++			hidden_root2 = nd2.dentry;
++			stopd(sb)->storage_dir_dentry = nd2.dentry;
++			stopd(sb)->hidden_mnt2 = nd2.mnt;
++			stohs2(sb) = hidden_root2->d_sb;
++
++			/* validate storage dir, this is done in
++			 * mini_fo_read_super for the base directory.
++			 */
++			if (IS_ERR(hidden_root2)) {
++				printk(KERN_WARNING "mini_fo_parse_options: storage dentry lookup failed (err = %ld)\n", PTR_ERR(hidden_root2));
++				goto out;
++			}
++			if (!hidden_root2->d_inode) {
++				printk(KERN_WARNING "mini_fo_parse_options: no storage dir to interpose on.\n");
++				goto out;
++			}
++			stohs2(sb) = hidden_root2->d_sb;
++		} else {
++			printk(KERN_WARNING "mini_fo: unrecognized option '%s'\n", options);
++			hidden_root = ERR_PTR(-EINVAL);
++			goto out;
++		}
++		options = tmp + 1;
++	}
++
++ out:
++	if(IS_ERR(hidden_root2))
++		return hidden_root2;
++	return hidden_root;
++}
++
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++static int
++#else
++super_block_t *
++#endif
++mini_fo_read_super(super_block_t *sb, void *raw_data, int silent)
++{
++	dentry_t *hidden_root;
++	int err = 0;
++
++	if (!raw_data) {
++		printk(KERN_WARNING "mini_fo_read_super: missing argument\n");
++		err = -EINVAL;
++		goto out;
++	}
++	/*
++	 * Allocate superblock private data
++	 */
++	__stopd(sb) = kmalloc(sizeof(struct mini_fo_sb_info), GFP_KERNEL);
++	if (!stopd(sb)) {
++		printk(KERN_WARNING "%s: out of memory\n", __FUNCTION__);
++		err = -ENOMEM;
++		goto out;
++	}
++	stohs(sb) = NULL;
++
++	hidden_root = mini_fo_parse_options(sb, raw_data);
++	if (IS_ERR(hidden_root)) {
++		printk(KERN_WARNING "mini_fo_read_super: lookup_dentry failed (err = %ld)\n", PTR_ERR(hidden_root));
++		err = PTR_ERR(hidden_root);
++		goto out_free;
++	}
++	if (!hidden_root->d_inode) {
++		printk(KERN_WARNING "mini_fo_read_super: no directory to interpose on\n");
++		goto out_free;
++	}
++	stohs(sb) = hidden_root->d_sb;
++
++	/*
++	 * Linux 2.4.2-ac3 and beyond has code in
++	 * mm/filemap.c:generic_file_write() that requires sb->s_maxbytes
++	 * to be populated.  If not set, all write()s under that sb will
++	 * return 0.
++	 *
++	 * Linux 2.4.4+ automatically sets s_maxbytes to MAX_NON_LFS;
++	 * the filesystem should override it only if it supports LFS.
++	 */
++	/* non-SCA code is good to go with LFS */
++	sb->s_maxbytes = hidden_root->d_sb->s_maxbytes;
++
++	sb->s_op = &mini_fo_sops;
++	/*
++	 * we can't use d_alloc_root if we want to use
++	 * our own interpose function unchanged,
++	 * so we simply replicate *most* of the code in d_alloc_root here
++	 */
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++	sb->s_root = d_alloc(NULL, &(const struct qstr) { "/", 1, 0 });
++#else
++	sb->s_root = d_alloc(NULL, &(const struct qstr){hash: 0, name: "/", len : 1});
++#endif
++	if (IS_ERR(sb->s_root)) {
++		printk(KERN_WARNING "mini_fo_read_super: d_alloc failed\n");
++		err = -ENOMEM;
++		goto out_dput;
++	}
++
++	sb->s_root->d_op = &mini_fo_dops;
++	sb->s_root->d_sb = sb;
++	sb->s_root->d_parent = sb->s_root;
++
++	/* link the upper and lower dentries */
++	__dtopd(sb->s_root) = (struct mini_fo_dentry_info *)
++		kmalloc(sizeof(struct mini_fo_dentry_info), GFP_KERNEL);
++	if (!dtopd(sb->s_root)) {
++		err = -ENOMEM;
++		goto out_dput2;
++	}
++	dtopd(sb->s_root)->state = MODIFIED;
++	dtohd(sb->s_root) = hidden_root;
++
++	/* fanout relevant, interpose on storage root dentry too */
++	dtohd2(sb->s_root) = stopd(sb)->storage_dir_dentry;
++
++	/* ...and call tri-interpose to interpose root dir inodes
++	 * if (mini_fo_interpose(hidden_root, sb->s_root, sb, 0))
++	 */
++	if(mini_fo_tri_interpose(hidden_root, dtohd2(sb->s_root), sb->s_root, sb, 0))
++		goto out_dput2;
++
++	/* initalize the wol list */
++	itopd(sb->s_root->d_inode)->deleted_list_size = -1;
++	itopd(sb->s_root->d_inode)->renamed_list_size = -1;
++	meta_build_lists(sb->s_root);
++
++	goto out;
++
++ out_dput2:
++	dput(sb->s_root);
++ out_dput:
++	dput(hidden_root);
++	dput(dtohd2(sb->s_root)); /* release the hidden_sto_dentry too */
++ out_free:
++	kfree(stopd(sb));
++	__stopd(sb) = NULL;
++ out:
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++        return err;
++#else
++        if (err) {
++		return ERR_PTR(err);
++        } else {
++		return sb;
++        }
++#endif
++}
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
++static int mini_fo_get_sb(struct file_system_type *fs_type,
++					  int flags, const char *dev_name,
++					  void *raw_data, struct vfsmount *mnt)
++{
++	return get_sb_nodev(fs_type, flags, raw_data, mini_fo_read_super, mnt);
++}
++#else
++static struct super_block *mini_fo_get_sb(struct file_system_type *fs_type,
++					  int flags, const char *dev_name,
++					  void *raw_data)
++{
++	return get_sb_nodev(fs_type, flags, raw_data, mini_fo_read_super);
++}
++#endif
++
++void mini_fo_kill_block_super(struct super_block *sb)
++{
++	generic_shutdown_super(sb);
++	/*
++	 *      XXX: BUG: Halcrow: Things get unstable sometime after this point:
++	 *      lib/rwsem-spinlock.c:127: spin_is_locked on uninitialized
++	 *      fs/fs-writeback.c:402: spin_lock(fs/super.c:a0381828) already
++	 *      locked by fs/fs-writeback.c/402
++	 *
++	 *      Apparently, someone's not releasing a lock on sb_lock...
++	 */
++}
++
++static struct file_system_type mini_fo_fs_type = {
++	.owner          = THIS_MODULE,
++	.name           = "mini_fo",
++	.get_sb         = mini_fo_get_sb,
++	.kill_sb        = mini_fo_kill_block_super,
++	.fs_flags       = 0,
++};
++
++
++#else
++static DECLARE_FSTYPE(mini_fo_fs_type, "mini_fo", mini_fo_read_super, 0);
++#endif
++
++static int __init init_mini_fo_fs(void)
++{
++	printk("Registering mini_fo version $Id$\n");
++	return register_filesystem(&mini_fo_fs_type);
++}
++static void __exit exit_mini_fo_fs(void)
++{
++	printk("Unregistering mini_fo version $Id$\n");
++	unregister_filesystem(&mini_fo_fs_type);
++}
++
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++EXPORT_NO_SYMBOLS;
++#endif
++
++MODULE_AUTHOR("Erez Zadok <ezk@cs.sunysb.edu>");
++MODULE_DESCRIPTION("FiST-generated mini_fo filesystem");
++MODULE_LICENSE("GPL");
++
++/* MODULE_PARM(fist_debug_var, "i"); */
++/* MODULE_PARM_DESC(fist_debug_var, "Debug level"); */
++
++module_init(init_mini_fo_fs)
++module_exit(exit_mini_fo_fs)
+--- /dev/null
++++ b/fs/mini_fo/Makefile
+@@ -0,0 +1,17 @@
++#
++# Makefile for mini_fo 2.4 and 2.6 Linux kernels
++#
++# Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++#
++# This program is free software; you can redistribute it and/or
++# modify it under the terms of the GNU General Public License
++# as published by the Free Software Foundation; either version
++# 2 of the License, or (at your option) any later version.
++#
++
++obj-$(CONFIG_MINI_FO) := mini_fo.o
++mini_fo-objs   := meta.o dentry.o file.o inode.o main.o super.o state.o aux.o
++
++# dependencies
++${mini_fo-objs}: mini_fo.h fist.h
++
+--- /dev/null
++++ b/fs/mini_fo/meta.c
+@@ -0,0 +1,1000 @@
++/*
++ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ */
++
++#ifdef HAVE_CONFIG_H
++# include <config.h>
++#endif /* HAVE_CONFIG_H */
++#include "fist.h"
++#include "mini_fo.h"
++
++int meta_build_lists(dentry_t *dentry)
++{
++	struct mini_fo_inode_info *inode_info;
++
++	dentry_t *meta_dentry = 0;
++	file_t *meta_file = 0;
++	mm_segment_t old_fs;
++	void *buf;
++
++	int bytes, len;
++	struct vfsmount *meta_mnt;
++	char *entry;
++
++	inode_info = itopd(dentry->d_inode);
++	if(!(inode_info->deleted_list_size == -1 &&
++	     inode_info->renamed_list_size == -1)) {
++		printk(KERN_CRIT "mini_fo: meta_build_lists: \
++                                  Error, list(s) not virgin.\n");
++		return -1;
++	}
++
++	/* init our meta lists */
++	INIT_LIST_HEAD(&inode_info->deleted_list);
++	inode_info->deleted_list_size = 0;
++
++	INIT_LIST_HEAD(&inode_info->renamed_list);
++	inode_info->renamed_list_size = 0;
++
++  	/* might there be a META-file? */
++	if(dtohd2(dentry) && dtohd2(dentry)->d_inode) {
++		meta_dentry = lookup_one_len(META_FILENAME,
++					     dtohd2(dentry),
++					     strlen(META_FILENAME));
++		if(!meta_dentry->d_inode) {
++			dput(meta_dentry);
++			goto out_ok;
++		}
++		/* $%& err, is this correct? */
++		meta_mnt = stopd(dentry->d_inode->i_sb)->hidden_mnt2;
++		mntget(meta_mnt);
++
++
++		/* open META-file for reading */
++		meta_file = dentry_open(meta_dentry, meta_mnt, 0x0);
++		if(!meta_file || IS_ERR(meta_file)) {
++			printk(KERN_CRIT "mini_fo: meta_build_lists: \
++                                          ERROR opening META file.\n");
++			goto out_err;
++		}
++
++		/* check if fs supports reading */
++		if(!meta_file->f_op->read) {
++			printk(KERN_CRIT "mini_fo: meta_build_lists: \
++                                          ERROR, fs does not support reading.\n");
++			goto out_err_close;
++		}
++
++		/* allocate a page for transfering the data */
++		buf = (void *) __get_free_page(GFP_KERNEL);
++		if(!buf) {
++			printk(KERN_CRIT "mini_fo: meta_build_lists: \
++                                          ERROR, out of mem.\n");
++			goto out_err_close;
++		}
++		meta_file->f_pos = 0;
++		old_fs = get_fs();
++		set_fs(KERNEL_DS);
++		do {
++			char *c;
++			bytes = meta_file->f_op->read(meta_file, buf, PAGE_SIZE, &meta_file->f_pos);
++			if(bytes == PAGE_SIZE) {
++				/* trim a cut off filename and adjust f_pos to get it next time */
++				for(c = (char*) buf+PAGE_SIZE;
++				    *c != '\n';
++				    c--, bytes--, meta_file->f_pos--);
++			}
++			entry = (char *) buf;
++			while(entry < (char *) buf+bytes) {
++
++				char *old_path;
++				char *dir_name;
++				int old_len, new_len;
++
++				/* len without '\n'*/
++				len = (int) (strchr(entry, '\n') - entry);
++				switch (*entry) {
++				case 'D':
++					/* format: "D filename" */
++					meta_list_add_d_entry(dentry,
++							      entry+2,
++							      len-2);
++					break;
++				case 'R':
++					/* format: "R path/xy/dir newDir" */
++					old_path = entry+2;
++					dir_name = strchr(old_path, ' ') + 1;
++					old_len =  dir_name - old_path - 1;
++					new_len = ((int) entry) + len - ((int ) dir_name);
++					meta_list_add_r_entry(dentry,
++							      old_path,
++							      old_len,
++							      dir_name,
++							      new_len);
++					break;
++				default:
++					/* unknown entry type detected */
++					break;
++				}
++				entry += len+1;
++			}
++
++		} while(meta_file->f_pos < meta_dentry->d_inode->i_size);
++
++		free_page((unsigned long) buf);
++		set_fs(old_fs);
++		fput(meta_file);
++	}
++	goto out_ok;
++
++ out_err_close:
++	fput(meta_file);
++ out_err:
++	mntput(meta_mnt);
++	dput(meta_dentry);
++	return -1;
++ out_ok:
++	return 1; /* check this!!! inode_info->wol_size; */
++}
++
++/* cleanups up all lists and free's the mem by dentry */
++int meta_put_lists(dentry_t *dentry)
++{
++	if(!dentry || !dentry->d_inode) {
++		printk("mini_fo: meta_put_lists: invalid dentry passed.\n");
++		return -1;
++	}
++	return __meta_put_lists(dentry->d_inode);
++}
++
++/* cleanups up all lists and free's the mem by inode */
++int __meta_put_lists(inode_t *inode)
++{
++	int err = 0;
++	if(!inode || !itopd(inode)) {
++		printk("mini_fo: __meta_put_lists: invalid inode passed.\n");
++		return -1;
++	}
++	err = __meta_put_d_list(inode);
++	err |= __meta_put_r_list(inode);
++	return err;
++}
++
++int meta_sync_lists(dentry_t *dentry)
++{
++	int err = 0;
++	if(!dentry || !dentry->d_inode) {
++		printk("mini_fo: meta_sync_lists: \
++                        invalid dentry passed.\n");
++		return -1;
++	}
++	err = meta_sync_d_list(dentry, 0);
++	err |= meta_sync_r_list(dentry, 1);
++	return err;
++}
++
++
++/* remove all D entries from the renamed list and free the mem */
++int __meta_put_d_list(inode_t *inode)
++{
++	struct list_head *tmp;
++        struct deleted_entry *del_entry;
++        struct mini_fo_inode_info *inode_info;
++
++	if(!inode || !itopd(inode)) {
++		printk(KERN_CRIT "mini_fo: __meta_put_d_list: \
++                                  invalid inode passed.\n");
++		return -1;
++	}
++	inode_info = itopd(inode);
++
++        /* nuke the DELETED-list */
++        if(inode_info->deleted_list_size <= 0)
++		return 0;
++
++	while(!list_empty(&inode_info->deleted_list)) {
++		tmp = inode_info->deleted_list.next;
++		list_del(tmp);
++		del_entry = list_entry(tmp, struct deleted_entry, list);
++		kfree(del_entry->name);
++		kfree(del_entry);
++	}
++	inode_info->deleted_list_size = 0;
++
++	return 0;
++}
++
++/* remove all R entries from the renamed list and free the mem */
++int __meta_put_r_list(inode_t *inode)
++{
++	struct list_head *tmp;
++	struct renamed_entry *ren_entry;
++        struct mini_fo_inode_info *inode_info;
++
++	if(!inode || !itopd(inode)) {
++		printk(KERN_CRIT "mini_fo: meta_put_r_list: invalid inode.\n");
++		return -1;
++	}
++	inode_info = itopd(inode);
++
++        /* nuke the RENAMED-list */
++        if(inode_info->renamed_list_size <= 0)
++		return 0;
++
++	while(!list_empty(&inode_info->renamed_list)) {
++		tmp = inode_info->renamed_list.next;
++		list_del(tmp);
++		ren_entry = list_entry(tmp, struct renamed_entry, list);
++		kfree(ren_entry->new_name);
++		kfree(ren_entry->old_name);
++		kfree(ren_entry);
++	}
++	inode_info->renamed_list_size = 0;
++
++	return 0;
++}
++
++int meta_add_d_entry(dentry_t *dentry, const char *name, int len)
++{
++	int err = 0;
++	err = meta_list_add_d_entry(dentry, name, len);
++	err |= meta_write_d_entry(dentry,name,len);
++	return err;
++}
++
++/* add a D entry to the deleted list */
++int meta_list_add_d_entry(dentry_t *dentry, const char *name, int len)
++{
++        struct deleted_entry *del_entry;
++        struct mini_fo_inode_info *inode_info;
++
++	if(!dentry || !dentry->d_inode) {
++		printk(KERN_CRIT "mini_fo: meta_list_add_d_entry: \
++                                  invalid dentry passed.\n");
++		return -1;
++	}
++	inode_info = itopd(dentry->d_inode);
++
++        if(inode_info->deleted_list_size < 0)
++                return -1;
++
++        del_entry = (struct deleted_entry *)
++		kmalloc(sizeof(struct deleted_entry), GFP_KERNEL);
++        del_entry->name = (char*) kmalloc(len, GFP_KERNEL);
++        if(!del_entry || !del_entry->name) {
++                printk(KERN_CRIT "mini_fo: meta_list_add_d_entry: \
++                                  out of mem.\n");
++		kfree(del_entry->name);
++		kfree(del_entry);
++                return -ENOMEM;
++        }
++
++        strncpy(del_entry->name, name, len);
++        del_entry->len = len;
++
++        list_add(&del_entry->list, &inode_info->deleted_list);
++        inode_info->deleted_list_size++;
++        return 0;
++}
++
++int meta_add_r_entry(dentry_t *dentry,
++			  const char *old_name, int old_len,
++			  const char *new_name, int new_len)
++{
++	int err = 0;
++	err = meta_list_add_r_entry(dentry,
++				    old_name, old_len,
++				    new_name, new_len);
++	err |= meta_write_r_entry(dentry,
++				  old_name, old_len,
++				  new_name, new_len);
++	return err;
++}
++
++/* add a R entry to the renamed list */
++int meta_list_add_r_entry(dentry_t *dentry,
++			  const char *old_name, int old_len,
++			  const char *new_name, int new_len)
++{
++        struct renamed_entry *ren_entry;
++        struct mini_fo_inode_info *inode_info;
++
++	if(!dentry || !dentry->d_inode) {
++		printk(KERN_CRIT "mini_fo: meta_list_add_r_entry: \
++                                  invalid dentry passed.\n");
++		return -1;
++	}
++	inode_info = itopd(dentry->d_inode);
++
++        if(inode_info->renamed_list_size < 0)
++                return -1;
++
++        ren_entry = (struct renamed_entry *)
++		kmalloc(sizeof(struct renamed_entry), GFP_KERNEL);
++        ren_entry->old_name = (char*) kmalloc(old_len, GFP_KERNEL);
++        ren_entry->new_name = (char*) kmalloc(new_len, GFP_KERNEL);
++
++        if(!ren_entry || !ren_entry->old_name || !ren_entry->new_name) {
++                printk(KERN_CRIT "mini_fo: meta_list_add_r_entry: \
++                                  out of mem.\n");
++		kfree(ren_entry->new_name);
++		kfree(ren_entry->old_name);
++		kfree(ren_entry);
++                return -ENOMEM;
++        }
++
++        strncpy(ren_entry->old_name, old_name, old_len);
++        ren_entry->old_len = old_len;
++        strncpy(ren_entry->new_name, new_name, new_len);
++        ren_entry->new_len = new_len;
++
++        list_add(&ren_entry->list, &inode_info->renamed_list);
++        inode_info->renamed_list_size++;
++        return 0;
++}
++
++
++int meta_remove_r_entry(dentry_t *dentry, const char *name, int len)
++{
++	int err = 0;
++	if(!dentry || !dentry->d_inode) {
++		printk(KERN_CRIT
++		       "mini_fo: meta_remove_r_entry: \
++                        invalid dentry passed.\n");
++		return -1;
++	}
++
++	err = meta_list_remove_r_entry(dentry, name, len);
++	err |= meta_sync_lists(dentry);
++	return err;
++}
++
++int meta_list_remove_r_entry(dentry_t *dentry, const char *name, int len)
++{
++	if(!dentry || !dentry->d_inode) {
++		printk(KERN_CRIT
++		       "mini_fo: meta_list_remove_r_entry: \
++                        invalid dentry passed.\n");
++		return -1;
++	}
++	return __meta_list_remove_r_entry(dentry->d_inode, name, len);
++}
++
++int __meta_list_remove_r_entry(inode_t *inode, const char *name, int len)
++{
++	struct list_head *tmp;
++        struct renamed_entry *ren_entry;
++        struct mini_fo_inode_info *inode_info;
++
++	if(!inode || !itopd(inode))
++		printk(KERN_CRIT
++		       "mini_fo: __meta_list_remove_r_entry: \
++                        invalid inode passed.\n");
++	inode_info = itopd(inode);
++
++        if(inode_info->renamed_list_size < 0)
++                return -1;
++        if(inode_info->renamed_list_size == 0)
++                return 1;
++
++	list_for_each(tmp, &inode_info->renamed_list) {
++		ren_entry = list_entry(tmp, struct renamed_entry, list);
++		if(ren_entry->new_len != len)
++			continue;
++
++		if(!strncmp(ren_entry->new_name, name, len)) {
++			list_del(tmp);
++			kfree(ren_entry->new_name);
++			kfree(ren_entry->old_name);
++			kfree(ren_entry);
++			inode_info->renamed_list_size--;
++			return 0;
++		}
++	}
++	return 1;
++}
++
++
++/* append a single D entry to the meta file */
++int meta_write_d_entry(dentry_t *dentry, const char *name, int len)
++{
++	dentry_t *meta_dentry = 0;
++        file_t *meta_file = 0;
++        mm_segment_t old_fs;
++
++        int bytes, err;
++        struct vfsmount *meta_mnt = 0;
++        char *buf;
++
++	err = 0;
++
++	if(itopd(dentry->d_inode)->deleted_list_size < 0) {
++		err = -1;
++		goto out;
++	}
++
++	if(dtopd(dentry)->state == UNMODIFIED) {
++                err = build_sto_structure(dentry->d_parent, dentry);
++                if(err) {
++                        printk(KERN_CRIT "mini_fo: meta_write_d_entry: \
++                                          build_sto_structure failed.\n");
++			goto out;
++                }
++        }
++	meta_dentry = lookup_one_len(META_FILENAME,
++				     dtohd2(dentry), strlen (META_FILENAME));
++
++	/* We need to create a META-file */
++        if(!meta_dentry->d_inode) {
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++		vfs_create(dtohd2(dentry)->d_inode,
++			   meta_dentry,
++			   S_IRUSR | S_IWUSR,
++			   NULL);
++#else
++                vfs_create(dtohd2(dentry)->d_inode,
++			   meta_dentry,
++			   S_IRUSR | S_IWUSR);
++#endif
++	}
++        /* open META-file for writing */
++        meta_file = dentry_open(meta_dentry, meta_mnt, 0x1);
++        if(!meta_file || IS_ERR(meta_file)) {
++                printk(KERN_CRIT "mini_fo: meta_write_d_entry: \
++                                  ERROR opening meta file.\n");
++                mntput(meta_mnt); /* $%& is this necessary? */
++                dput(meta_dentry);
++		err = -1;
++                goto out;
++        }
++
++        /* check if fs supports writing */
++        if(!meta_file->f_op->write) {
++                printk(KERN_CRIT "mini_fo: meta_write_d_entry: \
++                                  ERROR, fs does not support writing.\n");
++                goto out_err_close;
++        }
++
++	meta_file->f_pos = meta_dentry->d_inode->i_size; /* append */
++        old_fs = get_fs();
++        set_fs(KERNEL_DS);
++
++	/* size: len for name, 1 for \n and 2 for "D " */
++	buf = (char *) kmalloc(len+3, GFP_KERNEL);
++	if (!buf) {
++		printk(KERN_CRIT "mini_fo: meta_write_d_entry: \
++                                  out of mem.\n");
++		return -ENOMEM;
++	}
++
++	buf[0] = 'D';
++	buf[1] = ' ';
++	strncpy(buf+2, name, len);
++	buf[len+2] = '\n';
++	bytes = meta_file->f_op->write(meta_file, buf, len+3,
++				       &meta_file->f_pos);
++	if(bytes != len+3) {
++		printk(KERN_CRIT "mini_fo: meta_write_d_entry: \
++                                  ERROR writing.\n");
++		err = -1;
++	}
++	kfree(buf);
++	set_fs(old_fs);
++
++ out_err_close:
++	fput(meta_file);
++ out:
++	return err;
++}
++
++/* append a single R entry to the meta file */
++int meta_write_r_entry(dentry_t *dentry,
++		       const char *old_name, int old_len,
++		       const char *new_name, int new_len)
++{
++	dentry_t *meta_dentry = 0;
++        file_t *meta_file = 0;
++        mm_segment_t old_fs;
++
++        int bytes, err, buf_len;
++	struct vfsmount *meta_mnt = 0;
++        char *buf;
++
++
++	err = 0;
++
++	if(itopd(dentry->d_inode)->renamed_list_size < 0) {
++		err = -1;
++		goto out;
++	}
++
++	/* build the storage structure? */
++	if(dtopd(dentry)->state == UNMODIFIED) {
++                err = build_sto_structure(dentry->d_parent, dentry);
++                if(err) {
++                        printk(KERN_CRIT "mini_fo: meta_write_r_entry: \
++                                          build_sto_structure failed.\n");
++			goto out;
++                }
++        }
++	meta_dentry = lookup_one_len(META_FILENAME,
++				     dtohd2(dentry),
++				     strlen (META_FILENAME));
++        if(!meta_dentry->d_inode) {
++                /* We need to create a META-file */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++                vfs_create(dtohd2(dentry)->d_inode,
++			   meta_dentry, S_IRUSR | S_IWUSR, NULL);
++#else
++                vfs_create(dtohd2(dentry)->d_inode,
++			   meta_dentry, S_IRUSR | S_IWUSR);
++#endif
++	}
++        /* open META-file for writing */
++        meta_file = dentry_open(meta_dentry, meta_mnt, 0x1);
++        if(!meta_file || IS_ERR(meta_file)) {
++                printk(KERN_CRIT "mini_fo: meta_write_r_entry: \
++                                  ERROR opening meta file.\n");
++                mntput(meta_mnt);
++                dput(meta_dentry);
++		err = -1;
++                goto out;
++        }
++
++        /* check if fs supports writing */
++        if(!meta_file->f_op->write) {
++                printk(KERN_CRIT "mini_fo: meta_write_r_entry: \
++                                  ERROR, fs does not support writing.\n");
++                goto out_err_close;
++        }
++
++	meta_file->f_pos = meta_dentry->d_inode->i_size; /* append */
++        old_fs = get_fs();
++        set_fs(KERNEL_DS);
++
++	/* size: 2 for "R ", old_len+new_len for names, 1 blank+1 \n */
++	buf_len = old_len + new_len + 4;
++	buf = (char *) kmalloc(buf_len, GFP_KERNEL);
++	if (!buf) {
++		printk(KERN_CRIT "mini_fo: meta_write_r_entry: out of mem.\n");
++		return -ENOMEM;
++	}
++
++	buf[0] = 'R';
++	buf[1] = ' ';
++	strncpy(buf + 2, old_name, old_len);
++	buf[old_len + 2] = ' ';
++	strncpy(buf + old_len + 3, new_name, new_len);
++	buf[buf_len -1] = '\n';
++	bytes = meta_file->f_op->write(meta_file, buf, buf_len, &meta_file->f_pos);
++	if(bytes != buf_len) {
++		printk(KERN_CRIT "mini_fo: meta_write_r_entry: ERROR writing.\n");
++		err = -1;
++	}
++
++	kfree(buf);
++	set_fs(old_fs);
++
++ out_err_close:
++	fput(meta_file);
++ out:
++	return err;
++}
++
++/* sync D list to disk, append data if app_flag is 1 */
++/* check the meta_mnt, which seems not to be used (properly)  */
++
++int meta_sync_d_list(dentry_t *dentry, int app_flag)
++{
++	dentry_t *meta_dentry;
++        file_t *meta_file;
++        mm_segment_t old_fs;
++
++        int bytes, err;
++        struct vfsmount *meta_mnt;
++        char *buf;
++
++	struct list_head *tmp;
++        struct deleted_entry *del_entry;
++        struct mini_fo_inode_info *inode_info;
++
++	err = 0;
++	meta_file=0;
++	meta_mnt=0;
++
++	if(!dentry || !dentry->d_inode) {
++		printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
++                                  invalid inode passed.\n");
++		err = -1;
++		goto out;
++	}
++	inode_info = itopd(dentry->d_inode);
++
++        if(inode_info->deleted_list_size < 0) {
++		err = -1;
++		goto out;
++	}
++
++	/* ok, there is something to sync */
++
++	/* build the storage structure? */
++        if(!dtohd2(dentry) && !itohi2(dentry->d_inode)) {
++                err = build_sto_structure(dentry->d_parent, dentry);
++                if(err) {
++                        printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
++                                          build_sto_structure failed.\n");
++			goto out;
++                }
++        }
++	meta_dentry = lookup_one_len(META_FILENAME,
++				     dtohd2(dentry),
++				     strlen(META_FILENAME));
++        if(!meta_dentry->d_inode) {
++                /* We need to create a META-file */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++                vfs_create(dtohd2(dentry)->d_inode,
++			   meta_dentry, S_IRUSR | S_IWUSR, NULL);
++#else
++                vfs_create(dtohd2(dentry)->d_inode,
++			   meta_dentry, S_IRUSR | S_IWUSR);
++#endif
++		app_flag = 0;
++	}
++	/* need we truncate the meta file? */
++	if(!app_flag) {
++		struct iattr newattrs;
++                newattrs.ia_size = 0;
++                newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_lock(&meta_dentry->d_inode->i_mutex);
++#else
++                down(&meta_dentry->d_inode->i_sem);
++#endif
++                err = notify_change(meta_dentry, &newattrs);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_unlock(&meta_dentry->d_inode->i_mutex);
++#else
++                up(&meta_dentry->d_inode->i_sem);
++#endif
++
++                if(err || meta_dentry->d_inode->i_size != 0) {
++                        printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
++                                          ERROR truncating meta file.\n");
++                        goto out_err_close;
++		}
++	}
++
++        /* open META-file for writing */
++        meta_file = dentry_open(meta_dentry, meta_mnt, 0x1);
++        if(!meta_file || IS_ERR(meta_file)) {
++                printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
++                                  ERROR opening meta file.\n");
++		/* we don't mntget so we dont't mntput (for now)
++		 * mntput(meta_mnt);
++		 */
++		dput(meta_dentry);
++		err = -1;
++                goto out;
++        }
++
++        /* check if fs supports writing */
++        if(!meta_file->f_op->write) {
++                printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
++                                  ERROR, fs does not support writing.\n");
++                goto out_err_close;
++        }
++
++	meta_file->f_pos = meta_dentry->d_inode->i_size; /* append */
++        old_fs = get_fs();
++        set_fs(KERNEL_DS);
++
++	/* here we go... */
++        list_for_each(tmp, &inode_info->deleted_list) {
++		del_entry = list_entry(tmp, struct deleted_entry, list);
++
++		/* size: len for name, 1 for \n and 2 for "D " */
++		buf = (char *) kmalloc(del_entry->len+3, GFP_KERNEL);
++		if (!buf) {
++			printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
++                                          out of mem.\n");
++			return -ENOMEM;
++		}
++
++		buf[0] = 'D';
++		buf[1] = ' ';
++		strncpy(buf+2, del_entry->name, del_entry->len);
++		buf[del_entry->len+2] = '\n';
++		bytes = meta_file->f_op->write(meta_file, buf,
++					       del_entry->len+3,
++					       &meta_file->f_pos);
++		if(bytes != del_entry->len+3) {
++			printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
++                                          ERROR writing.\n");
++			err |= -1;
++		}
++		kfree(buf);
++	}
++	set_fs(old_fs);
++
++ out_err_close:
++	fput(meta_file);
++ out:
++	return err;
++
++}
++
++int meta_sync_r_list(dentry_t *dentry, int app_flag)
++{
++	dentry_t *meta_dentry;
++        file_t *meta_file;
++        mm_segment_t old_fs;
++
++        int bytes, err, buf_len;
++        struct vfsmount *meta_mnt;
++        char *buf;
++
++	struct list_head *tmp;
++        struct renamed_entry *ren_entry;
++        struct mini_fo_inode_info *inode_info;
++
++	err = 0;
++	meta_file=0;
++	meta_mnt=0;
++
++	if(!dentry || !dentry->d_inode) {
++		printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
++                                  invalid dentry passed.\n");
++		err = -1;
++		goto out;
++	}
++	inode_info = itopd(dentry->d_inode);
++
++        if(inode_info->deleted_list_size < 0) {
++		err = -1;
++		goto out;
++	}
++
++	/* ok, there is something to sync */
++
++	/* build the storage structure? */
++        if(!dtohd2(dentry) && !itohi2(dentry->d_inode)) {
++                err = build_sto_structure(dentry->d_parent, dentry);
++                if(err) {
++                        printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
++                                          build_sto_structure failed.\n");
++			goto out;
++                }
++        }
++	meta_dentry = lookup_one_len(META_FILENAME,
++				     dtohd2(dentry),
++				     strlen(META_FILENAME));
++        if(!meta_dentry->d_inode) {
++                /* We need to create a META-file */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++                vfs_create(dtohd2(dentry)->d_inode,
++			   meta_dentry, S_IRUSR | S_IWUSR, NULL);
++#else
++                vfs_create(dtohd2(dentry)->d_inode,
++			   meta_dentry, S_IRUSR | S_IWUSR);
++#endif
++		app_flag = 0;
++	}
++	/* need we truncate the meta file? */
++	if(!app_flag) {
++		struct iattr newattrs;
++                newattrs.ia_size = 0;
++                newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_lock(&meta_dentry->d_inode->i_mutex);
++#else
++                down(&meta_dentry->d_inode->i_sem);
++#endif
++                err = notify_change(meta_dentry, &newattrs);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_unlock(&meta_dentry->d_inode->i_mutex);
++#else
++                up(&meta_dentry->d_inode->i_sem);
++#endif
++                if(err || meta_dentry->d_inode->i_size != 0) {
++                        printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
++                                          ERROR truncating meta file.\n");
++                        goto out_err_close;
++		}
++	}
++
++        /* open META-file for writing */
++        meta_file = dentry_open(meta_dentry, meta_mnt, 0x1);
++        if(!meta_file || IS_ERR(meta_file)) {
++                printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
++                                  ERROR opening meta file.\n");
++		/* we don't mntget so we dont't mntput (for now)
++		 * mntput(meta_mnt);
++		 */
++		dput(meta_dentry);
++		err = -1;
++                goto out;
++        }
++
++        /* check if fs supports writing */
++        if(!meta_file->f_op->write) {
++                printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
++                                  ERROR, fs does not support writing.\n");
++                goto out_err_close;
++        }
++
++	meta_file->f_pos = meta_dentry->d_inode->i_size; /* append */
++        old_fs = get_fs();
++        set_fs(KERNEL_DS);
++
++	/* here we go... */
++        list_for_each(tmp, &inode_info->renamed_list) {
++		ren_entry = list_entry(tmp, struct renamed_entry, list);
++		/* size:
++		 * 2 for "R ", old_len+new_len for names, 1 blank+1 \n */
++		buf_len = ren_entry->old_len + ren_entry->new_len + 4;
++		buf = (char *) kmalloc(buf_len, GFP_KERNEL);
++		if (!buf) {
++			printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
++                                          out of mem.\n");
++			return -ENOMEM;
++		}
++		buf[0] = 'R';
++		buf[1] = ' ';
++		strncpy(buf + 2, ren_entry->old_name, ren_entry->old_len);
++		buf[ren_entry->old_len + 2] = ' ';
++		strncpy(buf + ren_entry->old_len + 3,
++			ren_entry->new_name, ren_entry->new_len);
++		buf[buf_len - 1] = '\n';
++		bytes = meta_file->f_op->write(meta_file, buf,
++					       buf_len, &meta_file->f_pos);
++		if(bytes != buf_len) {
++			printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
++                                          ERROR writing.\n");
++			err |= -1;
++		}
++		kfree(buf);
++	}
++	set_fs(old_fs);
++
++ out_err_close:
++	fput(meta_file);
++ out:
++	return err;
++}
++
++int meta_check_d_entry(dentry_t *dentry, const char *name, int len)
++{
++	if(!dentry || !dentry->d_inode)
++		printk(KERN_CRIT "mini_fo: meta_check_d_dentry: \
++                                  invalid dentry passed.\n");
++	return __meta_check_d_entry(dentry->d_inode, name, len);
++}
++
++int __meta_check_d_entry(inode_t *inode, const char *name, int len)
++{
++	struct list_head *tmp;
++        struct deleted_entry *del_entry;
++        struct mini_fo_inode_info *inode_info;
++
++	if(!inode || !itopd(inode))
++		printk(KERN_CRIT "mini_fo: __meta_check_d_dentry: \
++                                  invalid inode passed.\n");
++
++        inode_info = itopd(inode);
++
++        if(inode_info->deleted_list_size <= 0)
++                return 0;
++
++        list_for_each(tmp, &inode_info->deleted_list) {
++		del_entry = list_entry(tmp, struct deleted_entry, list);
++		if(del_entry->len != len)
++			continue;
++
++		if(!strncmp(del_entry->name, name, len))
++			return 1;
++	}
++	return 0;
++}
++
++/*
++ * check if file has been renamed and return path to orig. base dir.
++ * Implements no error return values so far, what of course sucks.
++ * String is null terminated.'
++ */
++char* meta_check_r_entry(dentry_t *dentry, const char *name, int len)
++{
++	if(!dentry || !dentry->d_inode) {
++		printk(KERN_CRIT "mini_fo: meta_check_r_dentry: \
++                                  invalid dentry passed.\n");
++		return NULL;
++	}
++	return __meta_check_r_entry(dentry->d_inode, name, len);
++}
++
++char* __meta_check_r_entry(inode_t *inode, const char *name, int len)
++{
++	struct list_head *tmp;
++        struct renamed_entry *ren_entry;
++        struct mini_fo_inode_info *inode_info;
++	char *old_path;
++
++	if(!inode || !itopd(inode)) {
++		printk(KERN_CRIT "mini_fo: meta_check_r_dentry: \
++                                  invalid inode passed.\n");
++		return NULL;
++	}
++	inode_info = itopd(inode);
++
++        if(inode_info->renamed_list_size <= 0)
++                return NULL;
++
++        list_for_each(tmp, &inode_info->renamed_list) {
++		ren_entry = list_entry(tmp, struct renamed_entry, list);
++		if(ren_entry->new_len != len)
++			continue;
++
++		if(!strncmp(ren_entry->new_name, name, len)) {
++			old_path = (char *)
++				kmalloc(ren_entry->old_len+1, GFP_KERNEL);
++			strncpy(old_path,
++				ren_entry->old_name,
++				ren_entry->old_len);
++			old_path[ren_entry->old_len]='\0';
++			return old_path;
++		}
++	}
++	return NULL;
++}
++
++/*
++ * This version only checks if entry exists and return:
++ *     1 if exists,
++ *     0 if not,
++ *    -1 if error.
++ */
++int meta_is_r_entry(dentry_t *dentry, const char *name, int len)
++{
++	if(!dentry || !dentry->d_inode) {
++		printk(KERN_CRIT "mini_fo: meta_check_r_dentry [2]: \
++                                  invalid dentry passed.\n");
++		return -1;
++	}
++	return __meta_is_r_entry(dentry->d_inode, name, len);
++}
++
++int __meta_is_r_entry(inode_t *inode, const char *name, int len)
++{
++	struct list_head *tmp;
++        struct renamed_entry *ren_entry;
++        struct mini_fo_inode_info *inode_info;
++
++	if(!inode || !itopd(inode)) {
++		printk(KERN_CRIT "mini_fo: meta_check_r_dentry [2]: \
++                                  invalid inode passed.\n");
++		return -1;
++	}
++	inode_info = itopd(inode);
++
++        if(inode_info->renamed_list_size <= 0)
++                return -1;
++
++        list_for_each(tmp, &inode_info->renamed_list) {
++		ren_entry = list_entry(tmp, struct renamed_entry, list);
++		if(ren_entry->new_len != len)
++			continue;
++
++		if(!strncmp(ren_entry->new_name, name, len))
++			return 1;
++	}
++	return 0;
++}
++
+--- /dev/null
++++ b/fs/mini_fo/mini_fo.h
+@@ -0,0 +1,510 @@
++/*
++ * Copyright (c) 1997-2003 Erez Zadok
++ * Copyright (c) 2001-2003 Stony Brook University
++ *
++ * For specific licensing information, see the COPYING file distributed with
++ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
++ *
++ * This Copyright notice must be kept intact and distributed with all
++ * fistgen sources INCLUDING sources generated by fistgen.
++ */
++/*
++ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ */
++
++/*
++ *  $Id$
++ */
++
++#ifndef __MINI_FO_H_
++#define __MINI_FO_H_
++
++#ifdef __KERNEL__
++
++/* META stuff */
++#define META_FILENAME "META_dAfFgHE39ktF3HD2sr"
++
++/* use xattrs? */
++#define XATTR
++
++/* File attributes that when changed, result in a file beeing copied to storage */
++#define COPY_FLAGS ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_SIZE
++
++/*
++ * mini_fo filestates
++ */
++#define MODIFIED       1
++#define UNMODIFIED     2
++#define CREATED        3
++#define DEL_REWRITTEN  4
++#define DELETED        5
++#define NON_EXISTANT   6
++
++/* fist file systems superblock magic */
++# define MINI_FO_SUPER_MAGIC 0xf15f
++
++/*
++ * STRUCTURES:
++ */
++
++/* mini_fo inode data in memory */
++struct mini_fo_inode_info {
++	inode_t *wii_inode;
++	inode_t *wii_inode2; /* pointer to storage inode */
++
++	/* META-data lists */
++	/* deleted list, ex wol */
++	struct list_head deleted_list;
++	int deleted_list_size;
++
++	/* renamed list */
++	struct list_head renamed_list;
++	int renamed_list_size;
++
++	/* add other lists here ... */
++};
++
++/* mini_fo dentry data in memory */
++struct mini_fo_dentry_info {
++	dentry_t *wdi_dentry;
++	dentry_t *wdi_dentry2; /* pointer to  storage dentry */
++	unsigned int state;  /* state of the mini_fo dentry */
++};
++
++
++/* mini_fo super-block data in memory */
++struct mini_fo_sb_info {
++	super_block_t *wsi_sb, *wsi_sb2; /* mk: might point to the same sb */
++	struct vfsmount *hidden_mnt, *hidden_mnt2;
++	dentry_t *base_dir_dentry;
++	dentry_t *storage_dir_dentry;
++	;
++};
++
++/* readdir_data, readdir helper struct */
++struct readdir_data {
++	struct list_head ndl_list; /* linked list head ptr */
++	int ndl_size; /* list size */
++	int sto_done; /* flag to show that the storage dir entries have
++		       * all been read an now follow base entries */
++};
++
++/* file private data. */
++struct mini_fo_file_info {
++	struct file *wfi_file;
++	struct file *wfi_file2; /* pointer to storage file */
++	struct readdir_data rd;
++};
++
++/* struct ndl_entry */
++struct ndl_entry {
++	struct list_head list;
++	char *name;
++	int len;
++};
++
++/********************************
++ *  META-data structures
++ ********************************/
++
++/* deleted entry */
++struct deleted_entry {
++	struct list_head list;
++	char *name;
++	int len;
++};
++
++/* renamed entry */
++struct renamed_entry {
++	struct list_head list;
++	char *old_name;     /* old directory with full path */
++	int old_len;        /* length of above string */
++	char *new_name;     /* new directory name */
++	int new_len;        /* length of above string */
++};
++
++/* attr_change entry */
++struct attr_change_entry {
++	struct list_head list;
++	char *name;
++	int len;
++};
++
++/* link entry */
++struct link_entry {
++	struct list_head list;
++	int links_moved;
++	int inum_base;
++	int inum_sto;
++	char *weird_name;
++	int weird_name_len;
++};
++
++
++/* Some other stuff required for mini_fo_filldir64, copied from
++ * fs/readdir.c
++ */
++
++#define ROUND_UP64(x) (((x)+sizeof(u64)-1) & ~(sizeof(u64)-1))
++#define NAME_OFFSET(de) ((int) ((de)->d_name - (char *) (de)))
++
++
++struct linux_dirent64 {
++        u64             d_ino;
++        s64             d_off;
++        unsigned short  d_reclen;
++        unsigned char   d_type;
++        char            d_name[0];
++};
++
++
++struct getdents_callback64 {
++        struct linux_dirent64 * current_dir;
++        struct linux_dirent64 * previous;
++        int count;
++        int error;
++};
++
++struct linux_dirent {
++	unsigned long   d_ino;
++	unsigned long   d_off;
++	unsigned short  d_reclen;
++	char            d_name[1];
++};
++
++struct getdents_callback {
++	struct linux_dirent * current_dir;
++	struct linux_dirent * previous;
++	int count;
++	int error;
++};
++
++
++/*
++ * MACROS:
++ */
++
++/* file TO private_data */
++# define ftopd(file) ((struct mini_fo_file_info *)((file)->private_data))
++# define __ftopd(file) ((file)->private_data)
++/* file TO hidden_file */
++# define ftohf(file) ((ftopd(file))->wfi_file)
++# define ftohf2(file) ((ftopd(file))->wfi_file2)
++
++/* inode TO private_data */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
++# define itopd(ino) ((struct mini_fo_inode_info *)(ino)->i_private)
++# define __itopd(ino) ((ino)->i_private)
++#else
++# define itopd(ino) ((struct mini_fo_inode_info *)(ino)->u.generic_ip)
++# define __itopd(ino) ((ino)->u.generic_ip)
++#endif
++/* inode TO hidden_inode */
++# define itohi(ino) (itopd(ino)->wii_inode)
++# define itohi2(ino) (itopd(ino)->wii_inode2)
++
++/* superblock TO private_data */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++# define stopd(super) ((struct mini_fo_sb_info *)(super)->s_fs_info)
++# define __stopd(super) ((super)->s_fs_info)
++#else
++# define stopd(super) ((struct mini_fo_sb_info *)(super)->u.generic_sbp)
++# define __stopd(super) ((super)->u.generic_sbp)
++#endif
++
++/* unused? # define vfs2priv stopd */
++/* superblock TO hidden_superblock */
++
++# define stohs(super) (stopd(super)->wsi_sb)
++# define stohs2(super) (stopd(super)->wsi_sb2)
++
++/* dentry TO private_data */
++# define dtopd(dentry) ((struct mini_fo_dentry_info *)(dentry)->d_fsdata)
++# define __dtopd(dentry) ((dentry)->d_fsdata)
++/* dentry TO hidden_dentry */
++# define dtohd(dent) (dtopd(dent)->wdi_dentry)
++# define dtohd2(dent) (dtopd(dent)->wdi_dentry2)
++
++/* dentry to state */
++# define dtost(dent) (dtopd(dent)->state)
++# define sbt(sb) ((sb)->s_type->name)
++
++#define IS_WRITE_FLAG(flag) (flag & (O_RDWR | O_WRONLY | O_APPEND))
++#define IS_COPY_FLAG(flag) (flag & (COPY_FLAGS))
++
++/* macros to simplify non-SCA code */
++#  define MALLOC_PAGE_POINTERS(hidden_pages, num_hidden_pages)
++#  define MALLOC_PAGEDATA_POINTERS(hidden_pages_data, num_hidden_pages)
++#  define FREE_PAGE_POINTERS(hidden_pages, num)
++#  define FREE_PAGEDATA_POINTERS(hidden_pages_data, num)
++#  define FOR_EACH_PAGE
++#  define CURRENT_HIDDEN_PAGE hidden_page
++#  define CURRENT_HIDDEN_PAGEDATA hidden_page_data
++#  define CURRENT_HIDDEN_PAGEINDEX page->index
++
++/*
++ * EXTERNALS:
++ */
++extern struct file_operations mini_fo_main_fops;
++extern struct file_operations mini_fo_dir_fops;
++extern struct inode_operations mini_fo_main_iops;
++extern struct inode_operations mini_fo_dir_iops;
++extern struct inode_operations mini_fo_symlink_iops;
++extern struct super_operations mini_fo_sops;
++extern struct dentry_operations mini_fo_dops;
++extern struct vm_operations_struct mini_fo_shared_vmops;
++extern struct vm_operations_struct mini_fo_private_vmops;
++extern struct address_space_operations mini_fo_aops;
++
++#if 0 /* unused by mini_fo */
++extern int mini_fo_interpose(dentry_t *hidden_dentry, dentry_t *this_dentry, super_block_t *sb, int flag);
++#if defined(FIST_FILTER_DATA) || defined(FIST_FILTER_SCA)
++extern page_t *mini_fo_get1page(file_t *file, int index);
++extern int mini_fo_fill_zeros(file_t *file, page_t *page, unsigned from);
++# endif /* FIST_FILTER_DATA || FIST_FILTER_SCA */
++
++
++#  define mini_fo_hidden_dentry(d) __mini_fo_hidden_dentry(__FILE__,__FUNCTION__,__LINE__,(d))
++#  define mini_fo_hidden_sto_dentry(d) __mini_fo_hidden_sto_dentry(__FILE__,__FUNCTION__,__LINE__,(d))
++
++extern dentry_t *__mini_fo_hidden_dentry(char *file, char *func, int line, dentry_t *this_dentry);
++extern dentry_t *__mini_fo_hidden_sto_dentry(char *file, char *func, int line, dentry_t *this_dentry);
++
++extern int mini_fo_read_file(const char *filename, void *buf, int len);
++extern int mini_fo_write_file(const char *filename, void *buf, int len);
++extern dentry_t *fist_lookup(dentry_t *dir, const char *name, vnode_t **out, uid_t uid, gid_t gid);
++#endif /* unused by mini_fo */
++
++/* state transition functions */
++extern int nondir_unmod_to_mod(dentry_t *dentry, int cp_flag);
++extern int nondir_del_rew_to_del(dentry_t *dentry);
++extern int nondir_creat_to_del(dentry_t *dentry);
++extern int nondir_mod_to_del(dentry_t *dentry);
++extern int nondir_unmod_to_del(dentry_t *dentry);
++
++extern int dir_unmod_to_mod(dentry_t *dentry);
++
++/* rename specials */
++extern int rename_directory(inode_t *old_dir, dentry_t *old_dentry, inode_t *new_dir, dentry_t *new_dentry);
++extern int rename_nondir(inode_t *old_dir, dentry_t *old_dentry, inode_t *new_dir, dentry_t *new_dentry);
++
++/* misc stuff */
++extern int mini_fo_tri_interpose(dentry_t *hidden_dentry,
++				 dentry_t *hidden_sto_dentry,
++				 dentry_t *dentry,
++				 super_block_t *sb, int flag);
++
++extern int mini_fo_cp_cont(dentry_t *tgt_dentry, struct vfsmount *tgt_mnt,
++			   dentry_t *src_dentry, struct vfsmount *src_mnt);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++extern int mini_fo_create(inode_t *dir, dentry_t *dentry, int mode, struct nameidata *nd);
++
++extern int create_sto_nod(dentry_t *dentry, int mode, dev_t dev);
++extern int create_sto_reg_file(dentry_t *dentry, int mode, struct nameidata *nd);
++#else
++extern int mini_fo_create(inode_t *dir, dentry_t *dentry, int mode);
++
++extern int create_sto_nod(dentry_t *dentry, int mode, int dev);
++extern int create_sto_reg_file(dentry_t *dentry, int mode);
++#endif
++
++extern int create_sto_dir(dentry_t *dentry, int mode);
++
++extern int exists_in_storage(dentry_t *dentry);
++extern int is_mini_fo_existant(dentry_t *dentry);
++extern int get_neg_sto_dentry(dentry_t *dentry);
++extern int build_sto_structure(dentry_t *dir, dentry_t *dentry);
++extern int get_mini_fo_bpath(dentry_t *dentry, char **bpath, int *bpath_len);
++extern dentry_t *bpath_walk(super_block_t *sb, char *bpath);
++extern int bpath_put(dentry_t *dentry);
++
++/* check_mini_fo types functions */
++extern int check_mini_fo_dentry(dentry_t *dentry);
++extern int check_mini_fo_file(file_t *file);
++extern int check_mini_fo_inode(inode_t *inode);
++
++/* General meta functions, can be called from outside of meta.c */
++extern int meta_build_lists(dentry_t *dentry);
++extern int meta_put_lists(dentry_t *dentry);
++extern int __meta_put_lists(inode_t *inode);
++
++extern int meta_add_d_entry(dentry_t *dentry, const char *name, int len);
++extern int meta_add_r_entry(dentry_t *dentry,
++			    const char *old_name, int old_len,
++			    const char *new_name, int new_len);
++
++extern int meta_remove_r_entry(dentry_t *dentry, const char *name, int len);
++
++extern int meta_check_d_entry(dentry_t *dentry, const char *name, int len);
++extern int __meta_check_d_entry(inode_t *inode, const char *name, int len);
++
++extern char* meta_check_r_entry(dentry_t *dentry, const char *name, int len);
++extern char* __meta_check_r_entry(inode_t *inode, const char *name, int len);
++extern int meta_is_r_entry(dentry_t *dentry, const char *name, int len);
++extern int __meta_is_r_entry(inode_t *inode, const char *name, int len);
++
++/* Specific meta functions, should be called only inside meta.c */
++extern int __meta_put_d_list(inode_t *inode);
++extern int __meta_put_r_list(inode_t *inode);
++
++extern int meta_list_add_d_entry(dentry_t *dentry,
++				 const char *name, int len);
++extern int meta_list_add_r_entry(dentry_t *dentry,
++				 const char *old_name, int old_len,
++				 const char *new_name, int new_len);
++
++extern int meta_list_remove_r_entry(dentry_t *dentry,
++				    const char *name, int len);
++
++extern int __meta_list_remove_r_entry(inode_t *inode,
++				      const char *name, int len);
++
++extern int meta_write_d_entry(dentry_t *dentry, const char *name, int len);
++extern int meta_write_r_entry(dentry_t *dentry,
++			      const char *old_name, int old_len,
++			      const char *new_name, int new_len);
++
++extern int meta_sync_lists(dentry_t *dentry);
++extern int meta_sync_d_list(dentry_t *dentry, int app_flag);
++extern int meta_sync_r_list(dentry_t *dentry, int app_flag);
++
++/* ndl stuff */
++extern int ndl_add_entry(struct readdir_data *rd, const char *name, int len);
++extern void ndl_put_list(struct readdir_data *rd);
++extern int ndl_check_entry(struct readdir_data *rd,
++			   const char *name, int len);
++
++
++# define copy_inode_size(dst, src) \
++    dst->i_size = src->i_size; \
++    dst->i_blocks = src->i_blocks;
++
++static inline void
++fist_copy_attr_atime(inode_t *dest, const inode_t *src)
++{
++	ASSERT(dest != NULL);
++	ASSERT(src != NULL);
++	dest->i_atime = src->i_atime;
++}
++static inline void
++fist_copy_attr_times(inode_t *dest, const inode_t *src)
++{
++	ASSERT(dest != NULL);
++	ASSERT(src != NULL);
++	dest->i_atime = src->i_atime;
++	dest->i_mtime = src->i_mtime;
++	dest->i_ctime = src->i_ctime;
++}
++static inline void
++fist_copy_attr_timesizes(inode_t *dest, const inode_t *src)
++{
++	ASSERT(dest != NULL);
++	ASSERT(src != NULL);
++	dest->i_atime = src->i_atime;
++	dest->i_mtime = src->i_mtime;
++	dest->i_ctime = src->i_ctime;
++	copy_inode_size(dest, src);
++}
++static inline void
++fist_copy_attr_all(inode_t *dest, const inode_t *src)
++{
++	ASSERT(dest != NULL);
++	ASSERT(src != NULL);
++	dest->i_mode = src->i_mode;
++	dest->i_nlink = src->i_nlink;
++	dest->i_uid = src->i_uid;
++	dest->i_gid = src->i_gid;
++	dest->i_rdev = src->i_rdev;
++	dest->i_atime = src->i_atime;
++	dest->i_mtime = src->i_mtime;
++	dest->i_ctime = src->i_ctime;
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
++	dest->i_blksize = src->i_blksize;
++#endif
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,12)
++	dest->i_blkbits = src->i_blkbits;
++# endif /* linux 2.4.12 and newer */
++	copy_inode_size(dest, src);
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
++	dest->i_attr_flags = src->i_attr_flags;
++#else
++	dest->i_flags = src->i_flags;
++#endif
++}
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++/* copied from linux/fs.h */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++static inline void double_lock(struct dentry *d1, struct dentry *d2)
++{
++	struct mutex *m1 = &d1->d_inode->i_mutex;
++	struct mutex *m2 = &d2->d_inode->i_mutex;
++	if (m1 != m2) {
++		if ((unsigned long) m1 < (unsigned long) m2) {
++			struct mutex *tmp = m2;
++			m2 = m1; m1 = tmp;
++		}
++		mutex_lock(m1);
++	}
++	mutex_lock(m2);
++}
++
++static inline void double_unlock(struct dentry *d1, struct dentry *d2)
++{
++	struct mutex *m1 = &d1->d_inode->i_mutex;
++	struct mutex *m2 = &d2->d_inode->i_mutex;
++	mutex_unlock(m1);
++	if (m1 != m2)
++		mutex_unlock(m2);
++	dput(d1);
++	dput(d2);
++}
++
++#else
++static inline void double_down(struct semaphore *s1, struct semaphore *s2)
++{
++        if (s1 != s2) {
++                if ((unsigned long) s1 < (unsigned long) s2) {
++                        struct semaphore *tmp = s2;
++                        s2 = s1; s1 = tmp;
++                }
++                down(s1);
++        }
++        down(s2);
++}
++
++static inline void double_up(struct semaphore *s1, struct semaphore *s2)
++{
++        up(s1);
++        if (s1 != s2)
++                up(s2);
++}
++
++static inline void double_lock(struct dentry *d1, struct dentry *d2)
++{
++        double_down(&d1->d_inode->i_sem, &d2->d_inode->i_sem);
++}
++
++static inline void double_unlock(struct dentry *d1, struct dentry *d2)
++{
++        double_up(&d1->d_inode->i_sem,&d2->d_inode->i_sem);
++        dput(d1);
++        dput(d2);
++}
++#endif   /* if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16) */
++#endif  /* if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0) */
++#endif /* __KERNEL__ */
++
++/*
++ * Definitions for user and kernel code
++ */
++
++/* ioctls */
++
++#endif	/* not __MINI_FO_H_ */
+--- /dev/null
++++ b/fs/mini_fo/mini_fo-merge
+@@ -0,0 +1,180 @@
++#!/bin/bash
++#
++# Copyright (C) 2005 Markus Klotzbuecher <mk@creamnet.de>
++# This program is free software; you can redistribute it and/or
++# modify it under the terms of the GNU General Public License
++# as published by the Free Software Foundation; either version
++# 2 of the License, or (at your option) any later version.
++#
++
++BASE=
++STO=
++HELP=
++DRYRUN=
++VERBOSE=
++TMP="/tmp/"
++META_NAME="META_dAfFgHE39ktF3HD2sr"
++SKIP_DEL_LIST="skip-delete-list.mini_fo-merge"
++
++COMMAND=
++exec_command()
++{
++    if [ x$DRYRUN == "xset" ]; then
++	echo "  would run: $COMMAND"
++    elif ! [ x$DRYRUN == "xset" ]; then
++	if [ x$VERBOSE == "xset" ]; then
++	    echo "  running: $COMMAND"
++	fi
++	eval $COMMAND
++    fi
++}
++
++usage()
++{
++cat <<EOF
++
++USAGE: $0 -b <base dir> -s <storage dir>
++Version 0.1
++
++This script merges the contents of a mini_fo storage file system back
++to the base file system.
++
++!!! Warning: This will modify the base filesystem and can destroy data
++             if used wrongly.
++
++Options:
++     -b <base dir>
++          the directory of the base file system.
++
++     -s <storage dir>
++          the directory of the storage file system.
++
++     -d   dry run, will not change anything and print the commands that
++          would be executed.
++
++     -t   tmp dir for storing temporary file. default: $TMP
++
++     -v   show what operations are performed.
++
++     -h   displays this message.
++
++EOF
++}
++
++# parse parameters
++while getopts hdvt:b:s: OPTS
++  do
++  case $OPTS in
++      h)  HELP="set";;
++      d)  DRYRUN="set";;
++      v)  VERBOSE="set";;
++      b)  BASE="$OPTARG";;
++      s)  STO="$OPTARG";;
++      t)  TMP="$OPTARG";;
++      ?)  usage
++	  exit 1;;
++  esac
++done
++
++if [ "x$HELP" == "xset" ]; then
++    usage
++    exit -1
++fi
++
++if ! [ -d "$BASE" ] || ! [ -d "$STO" ]; then
++    echo -e "$0:\n Error, -s and/or -b argument missing. type $0 -h for help."
++    exit -1;
++fi
++
++# get full paths
++pushd $STO; STO=`pwd`; popd
++pushd $BASE; BASE=`pwd`; popd
++TMP=${TMP%/}
++
++
++cat<<EOF
++###############################################################################
++# mini_fo-merge
++#
++# base dir:       $BASE
++# storage dir:    $STO
++# meta filename:  $META_NAME
++# dry run:        $DRYRUN
++# verbose:        $VERBOSE
++# tmp files:      $TMP
++###############################################################################
++
++EOF
++
++rm $TMP/$SKIP_DEL_LIST
++
++# first process all renamed dirs
++echo "Merging renamed directories..."
++pushd $STO &> /dev/null
++find . -name $META_NAME -type f -print0  | xargs -0 -e grep  -e '^R ' | tr -s ':R' ' ' | while read ENTRY; do
++    echo "entry: $ENTRY"
++    META_FILE=`echo $ENTRY | cut -d ' ' -f 1`
++    OLD_B_DIR=`echo $ENTRY | cut -d ' ' -f 2 | sed -e 's/\///'`
++    NEW_NAME=`echo $ENTRY | cut -d ' ' -f 3`
++    NEW_B_DIR=`echo $META_FILE | sed -e "s/$META_NAME/$NEW_NAME/" | sed -e 's/^\.\///'`
++    echo "META_FILE: $META_FILE"
++    echo "OLD_B_DIR: $OLD_B_DIR"
++    echo "NEW_NAME: $NEW_NAME"
++    echo  "NEW_B_DIR: $NEW_B_DIR"
++
++    pushd $BASE &> /dev/null
++    # remove an existing dir in storage
++    COMMAND="rm -rf $NEW_B_DIR"; exec_command
++    COMMAND="cp -R $OLD_B_DIR $NEW_B_DIR"; exec_command
++    echo ""
++    popd &> /dev/null
++
++    # remember this dir to exclude it from deleting later
++    echo $NEW_B_DIR >> $TMP/$SKIP_DEL_LIST
++done
++
++# delete all whiteouted files from base
++echo -e "\nDeleting whiteout'ed files from base file system..."
++find . -name $META_NAME -type f -print0  | xargs -0 -e grep  -e '^D ' | sed -e 's/:D//' | while read ENTRY; do
++    META_FILE=`echo $ENTRY | cut -d ' ' -f 1`
++    DEL_NAME=`echo $ENTRY | cut -d ' ' -f 2`
++    DEL_FILE=`echo $META_FILE | sed -e "s/$META_NAME/$DEL_NAME/" | sed -e 's/^\.\///'`
++    grep -x $DEL_FILE $TMP/$SKIP_DEL_LIST &> /dev/null
++    if [ $? -ne 0 ]; then
++	pushd $BASE &> /dev/null
++	COMMAND="rm -rf $DEL_FILE"; exec_command
++	popd &> /dev/null
++    else
++	echo "  excluding: $DEL_FILE as in skip-del-list."
++    fi
++done
++
++# create all dirs and update permissions
++echo -e "\nSetting up directory structures in base file system..."
++find . -type d | sed -e 's/^\.\///' | while read DIR; do
++    PERMS=`stat -c %a $DIR`
++    DIR_UID=`stat -c %u $DIR`
++    DIR_GID=`stat -c %g $DIR`
++    pushd $BASE &> /dev/null
++    if ! [ -d $DIR ]; then
++	COMMAND="mkdir -p $DIR"; exec_command
++    fi
++    COMMAND="chmod $PERMS $DIR"; exec_command
++    COMMAND="chown $DIR_UID:$DIR_GID $DIR"; exec_command
++    popd &> /dev/null
++done
++
++# merge all non-directory files
++echo -e "\nMerging all non-directory files...."
++for i in b c p f l s; do
++    find . -type $i | sed -e 's/^\.\///' | grep -v "$META_NAME" | while read FILE; do
++	pushd $BASE #&> /dev/null
++	COMMAND="cp -df $STO/$FILE $BASE/$FILE"; exec_command
++	popd &> /dev/null
++    done
++done
++popd &> /dev/null
++
++#rm $TMP/$SKIP_DEL_LIST
++
++echo "Done!"
+--- /dev/null
++++ b/fs/mini_fo/mini_fo-overlay
+@@ -0,0 +1,130 @@
++#!/bin/bash
++#
++# Copyright (C) 2005 Markus Klotzbuecher <mk@creamnet.de>
++# This program is free software; you can redistribute it and/or
++# modify it under the terms of the GNU General Public License
++# as published by the Free Software Foundation; either version
++# 2 of the License, or (at your option) any later version.
++#
++
++HELP=
++SUFF=
++MNTP=
++MNT_DIR="/mnt"
++STO=
++STO_DIR="/tmp"
++BASE=
++
++usage()
++{
++cat <<EOF
++
++Usage: $0 [-s suffix] [-d sto_dir_dir] [-m mount point] base_dir
++Version 0.1
++
++This script overlays the given base directory using the mini_fo file
++system. If only the base directory base_dir is given, $0
++will use a storage directory called "sto-<base_dir_name>" in $STO_DIR,
++and mount point "mini_fo-<base_dir_dir>" in $MNT_DIR.
++
++Options:
++     -s <suffix>
++          add given suffix to storage directory and the mount
++          point. This is usefull for overlaying one base directory
++          several times and avoiding conflicts with storage directory
++          names and mount points.
++
++     -d <sto_dir_dir>
++          change the directory in which the storage directory will be
++          created (default is currently "$STO_DIR".
++
++     -m <mount point>
++          use an alternative directory to create the mini_fo
++          mountpoint (default is currently "$MNT_DIR".
++
++     -h   displays this message.
++
++EOF
++exit 1;
++}
++
++while getopts hm:s:d: OPTS
++  do
++  case $OPTS in
++      s)  SUFF="$OPTARG";;
++      d)  STO_DIR="$OPTARG";;
++      m)  MNT_DIR="$OPTARG";;
++      h)  HELP="set";;
++      ?)  usage
++	  exit 1;;
++  esac
++done
++shift $(($OPTIND - 1))
++
++BASE="$1"
++
++if [ "x$HELP" == "xset" ]; then
++    usage
++    exit -1
++fi
++
++# fix suffix
++if [ "x$SUFF" != "x" ]; then
++    SUFF="-$SUFF"
++fi
++
++# kill trailing slashes
++MNT_DIR=${MNT_DIR%/}
++STO_DIR=${STO_DIR%/}
++BASE=${BASE%/}
++
++
++if ! [ -d "$BASE" ]; then
++    echo "invalid base dir $BASE, run $0 -h for help."
++    exit -1
++fi
++
++# check opts
++if ! [ -d "$MNT_DIR" ]; then
++    echo "invalid mount dir $MNT_DIR, run $0 -h for help."
++    exit -1
++fi
++
++if ! [ -d "$STO_DIR" ]; then
++    echo "invalid sto_dir_dir $STO_DIR, run $0 -h for help."
++    exit -1
++fi
++
++MNTP="$MNT_DIR/mini_fo-`basename $BASE`$SUFF"
++STO="$STO_DIR/sto-`basename $BASE`$SUFF"
++
++# create the mount point if it doesn't exist
++mkdir -p $MNTP
++if [ $? -ne 0 ]; then
++    echo "Error, failed to create mount point $MNTP"
++fi
++
++mkdir -p $STO
++if [ $? -ne 0 ]; then
++    echo "Error, failed to create storage dir $STO"
++fi
++
++# check if fs is already mounted
++mount | grep mini_fo | grep $MNTP &> /dev/null
++if [ $? -eq 0 ]; then
++    echo "Error, existing mini_fo mount at $MNTP."
++    exit -1
++fi
++
++mount | grep mini_fo | grep $STO &> /dev/null
++if [ $? -eq 0 ]; then
++    echo "Error, $STO seems to be used already."
++    exit -1
++fi
++
++# mount
++mount -t mini_fo -o base=$BASE,sto=$STO $BASE $MNTP
++
++if [ $? -ne 0 ]; then
++    echo "Error, mounting failed, maybe no permisson to mount?"
++fi
+--- /dev/null
++++ b/fs/mini_fo/mmap.c
+@@ -0,0 +1,637 @@
++/*
++ * Copyright (c) 1997-2003 Erez Zadok
++ * Copyright (c) 2001-2003 Stony Brook University
++ *
++ * For specific licensing information, see the COPYING file distributed with
++ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
++ *
++ * This Copyright notice must be kept intact and distributed with all
++ * fistgen sources INCLUDING sources generated by fistgen.
++ */
++/*
++ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ */
++
++/*
++ *  $Id$
++ */
++
++#ifdef HAVE_CONFIG_H
++# include <config.h>
++#endif /* HAVE_CONFIG_H */
++
++#include "fist.h"
++#include "mini_fo.h"
++
++
++#ifdef FIST_COUNT_WRITES
++/* for counting writes in the middle vs. regular writes */
++unsigned long count_writes = 0, count_writes_middle = 0;
++#endif /* FIST_COUNT_WRITES */
++
++/* forward declaration of commit write and prepare write */
++STATIC int mini_fo_commit_write(file_t *file, page_t *page, unsigned from, unsigned to);
++STATIC int mini_fo_prepare_write(file_t *file, page_t *page, unsigned from, unsigned to);
++
++
++/*
++ * Function for handling creation of holes when lseek-ing past the
++ * end of the file and then writing some data.
++ */
++int
++mini_fo_fill_zeros(file_t* file, page_t *page, unsigned from)
++{
++	int err = 0;
++	dentry_t *dentry = file->f_dentry;
++	inode_t *inode = dentry->d_inode;
++	page_t *tmp_page;
++	int index;
++
++	print_entry_location();
++
++	for (index = inode->i_size >> PAGE_CACHE_SHIFT; index < page->index; index++) {
++		tmp_page = mini_fo_get1page(file, index);
++		if (IS_ERR(tmp_page)) {
++			err = PTR_ERR(tmp_page);
++			goto out;
++		}
++
++		/*
++		 * zero out rest of the contents of the page between the appropriate
++		 * offsets.
++		 */
++		memset((char*)page_address(tmp_page) + (inode->i_size & ~PAGE_CACHE_MASK), 0, PAGE_CACHE_SIZE - (inode->i_size & ~PAGE_CACHE_MASK));
++
++		if (! (err = mini_fo_prepare_write(file, tmp_page, 0, PAGE_CACHE_SIZE)))
++			err = mini_fo_commit_write(file, tmp_page, 0, PAGE_CACHE_SIZE);
++
++		page_cache_release(tmp_page);
++		if (err < 0)
++			goto out;
++		if (current->need_resched)
++			schedule();
++	}
++
++	/* zero out appropriate parts of last page */
++
++	/*
++	 * if the encoding type is block, then adjust the 'from' (where the
++	 * zeroing will start) offset appropriately
++	 */
++	from = from & (~(FIST_ENCODING_BLOCKSIZE - 1));
++
++	if ((from - (inode->i_size & ~PAGE_CACHE_MASK)) > 0) {
++
++		memset((char*)page_address(page) + (inode->i_size & ~PAGE_CACHE_MASK), 0, from - (inode->i_size & ~PAGE_CACHE_MASK));
++		if (! (err = mini_fo_prepare_write(file, page, 0, PAGE_CACHE_SIZE)))
++			err = mini_fo_commit_write(file, page, 0, PAGE_CACHE_SIZE);
++
++		if (err < 0)
++			goto out;
++		if (current->need_resched)
++			schedule();
++	}
++
++ out:
++	print_exit_status(err);
++	return err;
++}
++
++
++
++STATIC int
++mini_fo_writepage(page_t *page)
++{
++	int err = -EIO;
++	inode_t *inode;
++	inode_t *hidden_inode;
++	page_t *hidden_page;
++	char *kaddr, *hidden_kaddr;
++
++	print_entry_location();
++
++	inode = page->mapping->host;
++	hidden_inode = itohi(inode);
++
++	/*
++	 * writepage is called when shared mmap'ed files need to write
++	 * their pages, while prepare/commit_write are called from the
++	 * non-paged write() interface.  (However, in 2.3 the two interfaces
++	 * share the same cache, while in 2.2 they didn't.)
++	 *
++	 * So we pretty much have to duplicate much of what commit_write does.
++	 */
++
++	/* find lower page (returns a locked page) */
++	hidden_page = grab_cache_page(hidden_inode->i_mapping, page->index);
++	if (!hidden_page)
++		goto out;
++
++	/* get page address, and encode it */
++	kaddr = (char *) kmap(page);
++	hidden_kaddr = (char*) kmap(hidden_page);
++	mini_fo_encode_block(kaddr, hidden_kaddr, PAGE_CACHE_SIZE, inode, inode->i_sb, page->index);
++	/* if encode_block could fail, then return error */
++	kunmap(page);
++	kunmap(hidden_page);
++
++	/* call lower writepage (expects locked page) */
++	err = hidden_inode->i_mapping->a_ops->writepage(hidden_page);
++
++	/*
++	 * update mtime and ctime of lower level file system
++	 * mini_fo' mtime and ctime are updated by generic_file_write
++	 */
++	hidden_inode->i_mtime = hidden_inode->i_ctime = CURRENT_TIME;
++
++#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,1)
++	UnlockPage(hidden_page);	/* b/c grab_cache_page locked it */
++# endif /* kernel older than 2.4.1 */
++	page_cache_release(hidden_page); /* b/c grab_cache_page increased refcnt */
++
++	if (err)
++		ClearPageUptodate(page);
++	else
++		SetPageUptodate(page);
++ out:
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,1)
++	UnlockPage(page);
++# endif /* kernel 2.4.1 and newer */
++	print_exit_status(err);
++	return err;
++}
++
++
++/*
++ * get one page from cache or lower f/s, return error otherwise.
++ * returns unlocked, up-to-date page (if ok), with increased refcnt.
++ */
++page_t *
++mini_fo_get1page(file_t *file, int index)
++{
++	page_t *page;
++	dentry_t *dentry;
++	inode_t *inode;
++	struct address_space *mapping;
++	int err;
++
++	print_entry_location();
++
++	dentry = file->f_dentry; /* CPW: Moved below print_entry_location */
++	inode = dentry->d_inode;
++	mapping = inode->i_mapping;
++
++	fist_dprint(8, "%s: read page index %d pid %d\n", __FUNCTION__, index, current->pid);
++	if (index < 0) {
++		printk("%s BUG: index=%d\n", __FUNCTION__, index);
++		page = ERR_PTR(-EIO);
++		goto out;
++	}
++	page = read_cache_page(mapping,
++			       index,
++			       (filler_t *) mapping->a_ops->readpage,
++			       (void *) file);
++	if (IS_ERR(page))
++		goto out;
++	wait_on_page(page);
++	if (!Page_Uptodate(page)) {
++		lock_page(page);
++		err = mapping->a_ops->readpage(file, page);
++		if (err) {
++			page = ERR_PTR(err);
++			goto out;
++		}
++		wait_on_page(page);
++		if (!Page_Uptodate(page)) {
++			page = ERR_PTR(-EIO);
++			goto out;
++		}
++	}
++
++ out:
++	print_exit_pointer(page);
++	return page;
++}
++
++
++/*
++ * get one page from cache or lower f/s, return error otherwise.
++ * similar to get1page, but doesn't guarantee that it will return
++ * an unlocked page.
++ */
++page_t *
++mini_fo_get1page_cached(file_t *file, int index)
++{
++	page_t *page;
++	dentry_t *dentry;
++	inode_t *inode;
++	struct address_space *mapping;
++	int err;
++
++	print_entry_location();
++
++	dentry = file->f_dentry; /* CPW: Moved below print_entry_location */
++	inode = dentry->d_inode;
++	mapping = inode->i_mapping;
++
++	fist_dprint(8, "%s: read page index %d pid %d\n", __FUNCTION__, index, current->pid);
++	if (index < 0) {
++		printk("%s BUG: index=%d\n", __FUNCTION__, index);
++		page = ERR_PTR(-EIO);
++		goto out;
++	}
++	page = read_cache_page(mapping,
++			       index,
++			       (filler_t *) mapping->a_ops->readpage,
++			       (void *) file);
++	if (IS_ERR(page))
++		goto out;
++
++ out:
++	print_exit_pointer(page);
++	return page;
++}
++
++
++/*
++ * readpage is called from generic_page_read and the fault handler.
++ * If your file system uses generic_page_read for the read op, it
++ * must implement readpage.
++ *
++ * Readpage expects a locked page, and must unlock it.
++ */
++STATIC int
++mini_fo_do_readpage(file_t *file, page_t *page)
++{
++	int err = -EIO;
++	dentry_t *dentry;
++	file_t *hidden_file = NULL;
++	dentry_t *hidden_dentry;
++	inode_t *inode;
++	inode_t *hidden_inode;
++	char *page_data;
++	page_t *hidden_page;
++	char *hidden_page_data;
++	int real_size;
++
++	print_entry_location();
++
++	dentry = file->f_dentry; /* CPW: Moved below print_entry_location */
++	if (ftopd(file) != NULL)
++		hidden_file = ftohf(file);
++	hidden_dentry = dtohd(dentry);
++	inode = dentry->d_inode;
++	hidden_inode = itohi(inode);
++
++	fist_dprint(7, "%s: requesting page %d from file %s\n", __FUNCTION__, page->index, dentry->d_name.name);
++
++	MALLOC_PAGE_POINTERS(hidden_pages, num_hidden_pages);
++	MALLOC_PAGEDATA_POINTERS(hidden_pages_data, num_hidden_pages);
++	FOR_EACH_PAGE
++		CURRENT_HIDDEN_PAGE = NULL;
++
++	/* find lower page (returns a locked page) */
++	FOR_EACH_PAGE {
++		fist_dprint(8, "%s: Current page index = %d\n", __FUNCTION__, CURRENT_HIDDEN_PAGEINDEX);
++		CURRENT_HIDDEN_PAGE = read_cache_page(hidden_inode->i_mapping,
++						      CURRENT_HIDDEN_PAGEINDEX,
++						      (filler_t *) hidden_inode->i_mapping->a_ops->readpage,
++						      (void *) hidden_file);
++		if (IS_ERR(CURRENT_HIDDEN_PAGE)) {
++			err = PTR_ERR(CURRENT_HIDDEN_PAGE);
++			CURRENT_HIDDEN_PAGE = NULL;
++			goto out_release;
++		}
++	}
++
++	/*
++	 * wait for the page data to show up
++	 * (signaled by readpage as unlocking the page)
++	 */
++	FOR_EACH_PAGE {
++		wait_on_page(CURRENT_HIDDEN_PAGE);
++		if (!Page_Uptodate(CURRENT_HIDDEN_PAGE)) {
++			/*
++			 * call readpage() again if we returned from wait_on_page with a
++			 * page that's not up-to-date; that can happen when a partial
++			 * page has a few buffers which are ok, but not the whole
++			 * page.
++			 */
++			lock_page(CURRENT_HIDDEN_PAGE);
++			err = hidden_inode->i_mapping->a_ops->readpage(hidden_file,
++								       CURRENT_HIDDEN_PAGE);
++			if (err) {
++				CURRENT_HIDDEN_PAGE = NULL;
++				goto out_release;
++			}
++			wait_on_page(CURRENT_HIDDEN_PAGE);
++			if (!Page_Uptodate(CURRENT_HIDDEN_PAGE)) {
++				err = -EIO;
++				goto out_release;
++			}
++		}
++	}
++
++	/* map pages, get their addresses */
++	page_data = (char *) kmap(page);
++	FOR_EACH_PAGE
++		CURRENT_HIDDEN_PAGEDATA = (char *) kmap(CURRENT_HIDDEN_PAGE);
++
++	/* if decode_block could fail, then return error */
++	err = 0;
++	real_size = hidden_inode->i_size - (page->index << PAGE_CACHE_SHIFT);
++	if (real_size <= 0)
++		memset(page_data, 0, PAGE_CACHE_SIZE);
++	else if (real_size < PAGE_CACHE_SIZE) {
++		mini_fo_decode_block(hidden_page_data, page_data, real_size, inode, inode->i_sb, page->index);
++		memset(page_data + real_size, 0, PAGE_CACHE_SIZE - real_size);
++	} else
++		mini_fo_decode_block(hidden_page_data, page_data, PAGE_CACHE_SIZE, inode, inode->i_sb, page->index);
++
++	FOR_EACH_PAGE
++		kunmap(CURRENT_HIDDEN_PAGE);
++	kunmap(page);
++
++ out_release:
++	FOR_EACH_PAGE
++		if (CURRENT_HIDDEN_PAGE)
++			page_cache_release(CURRENT_HIDDEN_PAGE); /* undo read_cache_page */
++
++	FREE_PAGE_POINTERS(hidden_pages, num_hidden_pages);
++	FREE_PAGEDATA_POINTERS(hidden_pages_data, num_hidden_pages);
++
++ out:
++	if (err == 0)
++		SetPageUptodate(page);
++	else
++		ClearPageUptodate(page);
++
++	print_exit_status(err);
++	return err;
++}
++
++
++STATIC int
++mini_fo_readpage(file_t *file, page_t *page)
++{
++	int err;
++	print_entry_location();
++
++	err = mini_fo_do_readpage(file, page);
++
++	/*
++	 * we have to unlock our page, b/c we _might_ have gotten a locked page.
++	 * but we no longer have to wakeup on our page here, b/c UnlockPage does
++	 * it
++	 */
++	UnlockPage(page);
++
++	print_exit_status(err);
++	return err;
++}
++
++
++STATIC int
++mini_fo_prepare_write(file_t *file, page_t *page, unsigned from, unsigned to)
++{
++	int err = 0;
++
++	print_entry_location();
++
++	/*
++	 * we call kmap(page) only here, and do the kunmap
++	 * and the actual downcalls, including unlockpage and uncache
++	 * in commit_write.
++	 */
++	kmap(page);
++
++	/* fast path for whole page writes */
++	if (from == 0 && to == PAGE_CACHE_SIZE)
++		goto out;
++	/* read the page to "revalidate" our data */
++	/* call the helper function which doesn't unlock the page */
++	if (!Page_Uptodate(page))
++		err = mini_fo_do_readpage(file, page);
++
++ out:
++	print_exit_status(err);
++	return err;
++}
++
++
++
++STATIC int
++mini_fo_commit_write(file_t *file, page_t *page, unsigned from, unsigned to)
++{
++	int err = -ENOMEM;
++	inode_t *inode;
++	inode_t *hidden_inode;
++	page_t *hidden_page;
++	file_t *hidden_file = NULL;
++	loff_t pos;
++	unsigned bytes = to - from;
++	unsigned hidden_from, hidden_to, hidden_bytes;
++
++	print_entry_location();
++
++	inode = page->mapping->host; /* CPW: Moved below print_entry_location */
++	hidden_inode = itohi(inode);
++
++	ASSERT(file != NULL);
++	/*
++	 * here we have a kmapped page, with data from the user copied
++	 * into it.  we need to encode_block it, and then call the lower
++	 * commit_write.  We also need to simulate same behavior of
++	 * generic_file_write, and call prepare_write on the lower f/s first.
++	 */
++#ifdef FIST_COUNT_WRITES
++	count_writes++;
++# endif /* FIST_COUNT_WRITES */
++
++	/* this is append and/or extend -- we can't have holes so fill them in */
++	if (page->index > (hidden_inode->i_size >> PAGE_CACHE_SHIFT)) {
++		page_t *tmp_page;
++		int index;
++		for (index = hidden_inode->i_size >> PAGE_CACHE_SHIFT; index < page->index; index++) {
++			tmp_page = mini_fo_get1page(file, index);
++			if (IS_ERR(tmp_page)) {
++				err = PTR_ERR(tmp_page);
++				goto out;
++			}
++			/* zero out the contents of the page at the appropriate offsets */
++			memset((char*)page_address(tmp_page) + (inode->i_size & ~PAGE_CACHE_MASK), 0, PAGE_CACHE_SIZE - (inode->i_size & ~PAGE_CACHE_MASK));
++			if (!(err = mini_fo_prepare_write(file, tmp_page, 0, PAGE_CACHE_SIZE)))
++				err = mini_fo_commit_write(file, tmp_page, 0, PAGE_CACHE_SIZE);
++			page_cache_release(tmp_page);
++			if (err < 0)
++				goto out;
++			if (current->need_resched)
++				schedule();
++		}
++	}
++
++	if (ftopd(file) != NULL)
++		hidden_file = ftohf(file);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_lock(&hidden_inode->i_mutex);
++#else
++	down(&hidden_inode->i_sem);
++#endif
++	/* find lower page (returns a locked page) */
++	hidden_page = grab_cache_page(hidden_inode->i_mapping, page->index);
++	if (!hidden_page)
++		goto out;
++
++#if FIST_ENCODING_BLOCKSIZE > 1
++#  error encoding_blocksize greater than 1 is not yet supported
++# endif /* FIST_ENCODING_BLOCKSIZE > 1 */
++
++	hidden_from = from & (~(FIST_ENCODING_BLOCKSIZE - 1));
++	hidden_to = ((to + FIST_ENCODING_BLOCKSIZE - 1) & (~(FIST_ENCODING_BLOCKSIZE - 1)));
++	if ((page->index << PAGE_CACHE_SHIFT) + to > hidden_inode->i_size) {
++
++		/*
++		 * if this call to commit_write had introduced holes and the code
++		 * for handling holes was invoked, then the beginning of this page
++		 * must be zeroed out
++		 * zero out bytes from 'size_of_file%pagesize' to 'from'.
++		 */
++		if ((hidden_from - (inode->i_size & ~PAGE_CACHE_MASK)) > 0)
++			memset((char*)page_address(page) + (inode->i_size & ~PAGE_CACHE_MASK), 0, hidden_from - (inode->i_size & ~PAGE_CACHE_MASK));
++
++	}
++	hidden_bytes = hidden_to - hidden_from;
++
++	/* call lower prepare_write */
++	err = -EINVAL;
++	if (hidden_inode->i_mapping &&
++	    hidden_inode->i_mapping->a_ops &&
++	    hidden_inode->i_mapping->a_ops->prepare_write)
++		err = hidden_inode->i_mapping->a_ops->prepare_write(hidden_file,
++								    hidden_page,
++								    hidden_from,
++								    hidden_to);
++	if (err)
++		/* don't leave locked pages behind, esp. on an ENOSPC */
++		goto out_unlock;
++
++	fist_dprint(8, "%s: encoding %d bytes\n", __FUNCTION__, hidden_bytes);
++	mini_fo_encode_block((char *) page_address(page) + hidden_from, (char*) page_address(hidden_page) + hidden_from, hidden_bytes, inode, inode->i_sb, page->index);
++	/* if encode_block could fail, then goto unlock and return error */
++
++	/* call lower commit_write */
++	err = hidden_inode->i_mapping->a_ops->commit_write(hidden_file,
++							   hidden_page,
++							   hidden_from,
++							   hidden_to);
++
++	if (err < 0)
++		goto out_unlock;
++
++	err = bytes;	/* convert error to no. of bytes */
++
++	inode->i_blocks = hidden_inode->i_blocks;
++	/* we may have to update i_size */
++	pos = (page->index << PAGE_CACHE_SHIFT) + to;
++	if (pos > inode->i_size)
++		inode->i_size = pos;
++
++	/*
++	 * update mtime and ctime of lower level file system
++	 * mini_fo' mtime and ctime are updated by generic_file_write
++	 */
++	hidden_inode->i_mtime = hidden_inode->i_ctime = CURRENT_TIME;
++
++	mark_inode_dirty_sync(inode);
++
++ out_unlock:
++	UnlockPage(hidden_page);
++	page_cache_release(hidden_page);
++	kunmap(page);		/* kmap was done in prepare_write */
++ out:
++	/* we must set our page as up-to-date */
++	if (err < 0)
++		ClearPageUptodate(page);
++	else
++		SetPageUptodate(page);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_unlock(&hidden_inode->i_mutex);
++#else
++	up(&hidden_inode->i_sem);
++#endif
++	print_exit_status(err);
++	return err;			/* assume all is ok */
++}
++
++
++STATIC int
++mini_fo_bmap(struct address_space *mapping, long block)
++{
++	int err = 0;
++	inode_t *inode;
++	inode_t *hidden_inode;
++
++	print_entry_location();
++
++	inode = (inode_t *) mapping->host;
++	hidden_inode = itohi(inode);
++
++	if (hidden_inode->i_mapping->a_ops->bmap)
++		err = hidden_inode->i_mapping->a_ops->bmap(hidden_inode->i_mapping, block);
++	print_exit_location();
++	return err;
++}
++
++
++/*
++ * This function is copied verbatim from mm/filemap.c.
++ * XXX: It should be simply moved to some header file instead -- bug Al about it!
++ */
++static inline int sync_page(struct page *page)
++{
++	struct address_space *mapping = page->mapping;
++
++	if (mapping && mapping->a_ops && mapping->a_ops->sync_page)
++		return mapping->a_ops->sync_page(page);
++	return 0;
++}
++
++
++/*
++ * XXX: we may not need this function if not FIST_FILTER_DATA.
++ * FIXME: for FIST_FILTER_SCA, get all lower pages and sync them each.
++ */
++STATIC int
++mini_fo_sync_page(page_t *page)
++{
++	int err = 0;
++	inode_t *inode;
++	inode_t *hidden_inode;
++	page_t *hidden_page;
++
++	print_entry_location();
++
++	inode = page->mapping->host; /* CPW: Moved below print_entry_location */
++	hidden_inode = itohi(inode);
++
++	/* find lower page (returns a locked page) */
++	hidden_page = grab_cache_page(hidden_inode->i_mapping, page->index);
++	if (!hidden_page)
++		goto out;
++
++	err = sync_page(hidden_page);
++
++	UnlockPage(hidden_page);	/* b/c grab_cache_page locked it */
++	page_cache_release(hidden_page); /* b/c grab_cache_page increased refcnt */
++
++ out:
++	print_exit_status(err);
++	return err;
++}
+--- /dev/null
++++ b/fs/mini_fo/README
+@@ -0,0 +1,163 @@
++README for the mini_fo overlay file system
++=========================================
++
++
++WHAT IS MINI_FO?
++----------------
++
++mini_fo is a virtual kernel file system that can make read-only
++file systems writable. This is done by redirecting modifying operations
++to a writeable location called "storage directory", and leaving the
++original data in the "base directory" untouched. When reading, the
++file system merges the modifed and original data so that only the
++newest versions will appear. This occurs transparently to the user,
++who can access the data like on any other read-write file system.
++
++Base and storage directories may be located on the same or on
++different partitions and may be of different file system types. While
++the storage directory obviously needs to be writable, the base may or
++may not be writable, what doesn't matter as it will no be modified
++anyway.
++
++
++WHAT IS GOOD FOR?
++-----------------
++
++The primary purpose of the mini_fo file system is to allow easy
++software updates to embedded systems, that often store their root
++file system in a read-only flash file system, but there are many
++more as for example sandboxing, or for allowing live-cds to
++permanently store information.
++
++
++BUILDING
++--------
++This should be simple. Adjust the Makefile to point to the correct
++kernel headers you want to build the module for. Then:
++
++    # make
++
++should build "mini_fo.o" for a 2.4 kernel or "mini_fo.ko" for a 2.6
++kernel.
++
++If you are building the module for you current kernel, you can install
++the module (as root):
++
++    # make install
++
++or uninstall with
++
++    # make uninstall
++
++
++USING THE FILE SYSTEM
++--------------------
++
++the general mount syntax is:
++
++   mount -t mini_fo -o base=<base directory>,sto=<storage directory>\
++                            <base directory> <mount point>
++
++Example:
++
++You have mounted a cdrom to /mnt/cdrom and want to modifiy some files
++on it:
++
++load the module (as root)
++
++    # insmod mini_fo.o for a 2.4 kernel or
++
++    # insmod mini_fo.ko for a 2.6 kernel
++
++
++create a storage dir in tmp and a mountpoint for mini_fo:
++
++    # mkdir /tmp/sto
++    # mkdir /mnt/mini_fo
++
++and mount the mini_fo file system:
++
++    # mount -t mini_fo -o base=/mnt/cdrom,sto=/tmp/sto /mnt/cdrom /mnt/mini_fo
++
++
++Now the data stored on the cd can be accessed via the mini_fo
++mountpoint just like any read-write file system, files can be modified
++and deleted, new ones can be created and so on. When done unmount the
++file system:
++
++    # unmount /mnt/mini_fo
++
++Note that if the file system is mounted again using the same storage
++file system, of course it will appear in the modified state again. If
++you remount it using an new empty storage directory, it will be
++unmodified. Therefore by executing:
++
++    # cd /tmp/sto
++    # rm -rf *
++
++you can nuke all the changes you made to the original file system. But
++ remember NEVER do this while the mini_fo file system is mounted!
++
++
++Alternatively you can use the mini_fo-overlay bash script, that
++simplifies managing mini_fo mounts. See TOOLS Section.
++
++
++TOOLS
++-----
++
++mini_fo-merge (experimental):
++
++This is a bash script that will merge changes contained in the storage
++directory back to the base directory. This allows mini_fo to function
++as a cache file system by overlaying a slow (network, ...) file system
++and using a fast (ramdisk, ...) as storage. When done, changes can be
++merged back to the (slow) base with mini_fo-merge. See "mini_fo-merge
++-h" for details.
++
++It can be usefull for merging changes back after a successfull test
++(patches, software updates...)
++
++
++mini_fo-overlay:
++
++This bash script simplifies managing one or more mini_fo mounts. For
++overlaying a directory called "basedir1", you can just call:
++
++    # mini_fo-overlay basedir1
++
++This will mount mini_fo with "basedir1" as base, "/tmp/sto-basedir1/"
++as storage to "/mnt/mini_fo-basedir1/". It has more options though,
++type "mini_fo-overlay -h" for details.
++
++
++DOCUMENTATION, REPORTING BUGS, GETTING HELP
++-------------------------------------------
++
++Please visit the mini_fo project page at:
++
++http://www.denx.de/twiki/bin/view/Know/MiniFOHome
++
++
++WARNINGS
++--------
++
++Never modify the base or the storage directorys while the mini_fo
++file system is mounted, or you might crash you system. Simply accessing
++and reading should not cause any trouble.
++
++Exporting a mini_fo mount point via NFS has not been tested, and may
++or may not work.
++
++Check the RELEASE_NOTES for details on bugs and features.
++
++
++
++Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++
++This program is free software; you can redistribute it and/or
++modify it under the terms of the GNU General Public License
++as published by the Free Software Foundation; either version
++2 of the License, or (at your option) any later version.
++
++
+--- /dev/null
++++ b/fs/mini_fo/RELEASE_NOTES
+@@ -0,0 +1,111 @@
++Release:	mini_fo-0.6.1 (v0-6-1)
++Date:		21.09.2005
++
++
++Changes:
++--------
++v0-6-1:
++
++- bugfixes (see ChangeLog)
++
++- two helper scripts "mini_fo_merge" and "mini_fo_overlay" (see
++  README for details).
++
++v0-6-0:
++
++- Support for 2.4 and 2.6 (see Makefile)
++
++- Partial hard link support (creating works as expected, but already
++  existing links in the base file system will be treated as if they
++  were individual files).
++
++- Various bugfixes and cleanups.
++
++
++v0-6-0-pre1:
++
++- This is mini_fo-0-6-0-pre1! This release is a complete rewrite of
++  many vital mini_fo parts such as the old whiteout list code which
++  has been replaced by the new META subsystem.
++
++- Light weight directory renaming implemented. This means if a
++  directory is renamed via the mini_fo filesystem this will no longer
++  result in a complete copy in storage, instead only one empty
++  directory will be created. All base filed contained in the original
++  directory stay there until modified.
++
++- Special files (creating, renaming, deleting etc.) now working.
++
++- Many bugfixes and cleanup, mini_fo is now a lot more stable.
++
++
++v0-5-10:
++
++- Final release of the 0-5-* versions. Next will be a complete rewrite
++  of many features. This release contains several bugfixes related to
++  directory renaming.
++
++
++v0-5-10-pre6:
++
++- Lots of cleanup and several bugfixes related to directory deleting
++
++- Directory renaming suddenly works, what is most likely due to the
++  fact tha that "mv" is smart: if the classic rename doesn't work it
++  will assume that source and target file are on different fs and will
++  copy the directory and try to remove the source directory. Until
++  directory removing wasn't implemented, it would fail to do this and
++  rollback.
++  So, directory renaming works for now, but it doesn't yet do what you
++  would expect from a overlay fs, so use with care.
++
++
++v0-5-10-pre5:
++
++- implemented directory deleting
++- made parsing of mount options more stable
++- New format of mount options! (See README)
++- I can't reproduce the unknown panic with 2.4.25 anymore, so I'll
++  happily assume it never existed!
++
++
++Implemented features:
++---------------------
++
++- creating hard links (see BUGS on already existing hard links)
++- lightweight directory renaming
++- renaming device files, pipes, sockets, etc.
++- creating, renaming, deleting of special files
++- deleting directorys
++- general directory reading (simple "ls" )
++- creating files in existing directorys
++- creating directorys
++- renaming files.
++- reading and writing files (involves opening)
++- appending to files (creates copy in storage)
++- deleting files
++- llseek works too, what allows editors to work
++- persistency (a deleted file stay deleted over remounts)
++- use of symbolic links
++- creating of device files
++
++
++Not (yet) implemented features:
++-------------------------------
++
++- full hard link support.
++
++
++
++BUGS:
++-----
++
++Hard links in the base file system will be treated as individual
++files, not as links to one inode.
++
++The main problem with hard links isn't allowing to create them, but
++their pure existence. If you modify a base hard link, the changes made
++will only show up on this link, the other link will remain in the
++original state. I hope to fix this someday. Please note that this does
++not effect the special hard links '.' and '..', that are handled
++seperately by the lower fs.
+--- /dev/null
++++ b/fs/mini_fo/state.c
+@@ -0,0 +1,620 @@
++/*
++ * Copyright (C) 2005 Markus Klotzbuecher <mk@creamnet.de>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ */
++
++#ifdef HAVE_CONFIG_H
++# include <config.h>
++#endif /* HAVE_CONFIG_H */
++
++#include "fist.h"
++#include "mini_fo.h"
++
++
++/* create the storage file, setup new states */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++int create_sto_reg_file(dentry_t *dentry, int mode, struct nameidata *nd)
++#else
++int create_sto_reg_file(dentry_t *dentry, int mode)
++#endif
++{
++	int err = 0;
++	inode_t *dir;
++	dentry_t *hidden_sto_dentry;
++	dentry_t *hidden_sto_dir_dentry;
++
++	if(exists_in_storage(dentry)) {
++		printk(KERN_CRIT "mini_fo: create_sto_file: wrong type or state.\n");
++		err = -EINVAL;
++		goto out;
++	}
++	err = get_neg_sto_dentry(dentry);
++
++	if (err) {
++		printk(KERN_CRIT "mini_fo: create_sto_file: ERROR getting neg. sto dentry.\n");
++		goto out;
++	}
++
++	dir = dentry->d_parent->d_inode;
++	hidden_sto_dentry = dtohd2(dentry);
++
++	/* lock parent */
++	hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++        down(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++
++	err = PTR_ERR(hidden_sto_dir_dentry);
++        if (IS_ERR(hidden_sto_dir_dentry))
++                goto out;
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++	err = vfs_create(hidden_sto_dir_dentry->d_inode,
++			 hidden_sto_dentry,
++			 mode, nd);
++#else
++	err = vfs_create(hidden_sto_dir_dentry->d_inode,
++			 hidden_sto_dentry,
++			 mode);
++#endif
++        if(err) {
++		printk(KERN_CRIT "mini_fo: create_sto_file: ERROR creating sto file.\n");
++                goto out_lock;
++	}
++
++	if(!dtohd2(dentry)->d_inode) {
++		printk(KERN_CRIT "mini_fo: create_sto_file: ERROR creating sto file [2].\n");
++                err = -EINVAL;
++                goto out_lock;
++        }
++
++        /* interpose the new inode */
++        if(dtost(dentry) == DELETED) {
++                dtost(dentry) = DEL_REWRITTEN;
++                err = mini_fo_tri_interpose(NULL, hidden_sto_dentry, dentry, dir->i_sb, 0);
++                if(err)
++                        goto out_lock;
++        }
++        else if(dtost(dentry) == NON_EXISTANT) {
++                dtost(dentry) = CREATED;
++                err = mini_fo_tri_interpose(dtohd(dentry), hidden_sto_dentry, dentry, dir->i_sb, 0);
++                if(err)
++                        goto out_lock;
++        }
++        else if(dtost(dentry) == UNMODIFIED) {
++                dtost(dentry) = MODIFIED;
++                /* interpose on new inode */
++                if(itohi2(dentry->d_inode) != NULL) {
++                        printk(KERN_CRIT "mini_fo: create_sto_file: invalid inode detected.\n");
++                        err = -EINVAL;
++                        goto out_lock;
++                }
++                itohi2(dentry->d_inode) = igrab(dtohd2(dentry)->d_inode);
++	}
++	fist_copy_attr_timesizes(dentry->d_parent->d_inode,
++				 hidden_sto_dir_dentry->d_inode);
++
++ out_lock:
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++        dput(hidden_sto_dir_dentry);
++ out:
++	return err;
++}
++
++/* create the sto dir, setup states */
++int create_sto_dir(dentry_t *dentry, int mode)
++{
++	int err = 0;
++	inode_t *dir;
++	dentry_t *hidden_sto_dentry;
++        dentry_t *hidden_sto_dir_dentry;
++
++	/* had to take the "!S_ISDIR(mode))" check out, because it failed */
++	if(exists_in_storage(dentry)) {
++                printk(KERN_CRIT "mini_fo: create_sto_dir: wrong type or state.\\
++n");
++                err = -EINVAL;
++                goto out;
++        }
++
++	err = get_neg_sto_dentry(dentry);
++	if(err) {
++		err = -EINVAL;
++		goto out;
++	}
++
++	dir = dentry->d_parent->d_inode;
++	hidden_sto_dentry = dtohd2(dentry);
++
++	/* was: hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry); */
++	hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	down(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++
++	err = PTR_ERR(hidden_sto_dir_dentry);
++	if (IS_ERR(hidden_sto_dir_dentry))
++		goto out;
++
++	err = vfs_mkdir(hidden_sto_dir_dentry->d_inode,
++			hidden_sto_dentry,
++			mode);
++	if(err) {
++		printk(KERN_CRIT "mini_fo: create_sto_dir: ERROR creating sto dir.\n");
++		goto out_lock;
++	}
++
++	if(!dtohd2(dentry)->d_inode) {
++		printk(KERN_CRIT "mini_fo: create_sto_dir: ERROR creating sto dir [2].\n");
++		err = -EINVAL;
++		goto out_lock;
++	}
++
++	/* interpose the new inode */
++	if(dtost(dentry) == DELETED) {
++		dtost(dentry) = DEL_REWRITTEN;
++		err = mini_fo_tri_interpose(NULL, hidden_sto_dentry, dentry, dir->i_sb, 0);
++		if(err)
++			goto out_lock;
++	}
++	else if(dtopd(dentry)->state == NON_EXISTANT) {
++		dtopd(dentry)->state = CREATED;
++		err = mini_fo_tri_interpose(dtohd(dentry), hidden_sto_dentry, dentry, dir->i_sb, 0);
++		if(err)
++			goto out_lock;
++	}
++	else if(dtopd(dentry)->state == UNMODIFIED) {
++		dtopd(dentry)->state = MODIFIED;
++		/* interpose on new inode */
++		if(itohi2(dentry->d_inode) != NULL) {
++			printk(KERN_CRIT "mini_fo:  create_sto_dir: ERROR, invalid inode detected.\n");
++			err = -EINVAL;
++			goto out_lock;
++		}
++		itohi2(dentry->d_inode) = igrab(dtohd2(dentry)->d_inode);
++	}
++
++	fist_copy_attr_timesizes(dir, hidden_sto_dir_dentry->d_inode);
++
++	/* initalize the wol list */
++	itopd(dentry->d_inode)->deleted_list_size = -1;
++	itopd(dentry->d_inode)->renamed_list_size = -1;
++	meta_build_lists(dentry);
++
++
++ out_lock:
++	/* was: unlock_dir(hidden_sto_dir_dentry); */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++	dput(hidden_sto_dir_dentry);
++ out:
++	return err;
++}
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++int create_sto_nod(dentry_t *dentry, int mode, dev_t dev)
++#else
++int create_sto_nod(dentry_t *dentry, int mode, int dev)
++#endif
++{
++	int err = 0;
++	inode_t *dir;
++	dentry_t *hidden_sto_dentry;
++	dentry_t *hidden_sto_dir_dentry;
++
++	if(exists_in_storage(dentry)) {
++		err = -EEXIST;
++		goto out;
++	}
++	err = get_neg_sto_dentry(dentry);
++
++	if (err) {
++                printk(KERN_CRIT "mini_fo: create_sto_nod: ERROR getting neg. sto dentry.\n");
++                goto out;
++        }
++
++	dir = dentry->d_parent->d_inode;
++	hidden_sto_dentry = dtohd2(dentry);
++
++	/* lock parent */
++	hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	down(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++
++	err = PTR_ERR(hidden_sto_dir_dentry);
++	if (IS_ERR(hidden_sto_dir_dentry))
++		goto out;
++
++	err = vfs_mknod(hidden_sto_dir_dentry->d_inode, hidden_sto_dentry, mode, dev);
++	if(err)
++		goto out_lock;
++
++	if(!dtohd2(dentry)->d_inode) {
++		printk(KERN_CRIT "mini_fo: create_sto_nod: creating storage inode failed [1].\n");
++		err = -EINVAL; /* return something indicating failure */
++		goto out_lock;
++	}
++
++	/* interpose the new inode */
++	if(dtost(dentry) == DELETED) {
++		dtost(dentry) = DEL_REWRITTEN;
++		err = mini_fo_tri_interpose(NULL, hidden_sto_dentry, dentry, dir->i_sb, 0);
++		if(err)
++			goto out_lock;
++	}
++	else if(dtost(dentry) == NON_EXISTANT) {
++		dtost(dentry) = CREATED;
++		err = mini_fo_tri_interpose(dtohd(dentry), hidden_sto_dentry, dentry, dir->i_sb, 0);
++		if(err)
++			goto out_lock;
++	}
++	else if(dtost(dentry) == UNMODIFIED) {
++		dtost(dentry) = MODIFIED;
++		/* interpose on new inode */
++		if(itohi2(dentry->d_inode) != NULL) {
++			printk(KERN_CRIT "mini_fo: create_sto_nod: error, invalid inode detected.\n");
++			err = -EINVAL;
++			goto out_lock;
++		}
++		itohi2(dentry->d_inode) = igrab(dtohd2(dentry)->d_inode);
++	}
++
++	fist_copy_attr_timesizes(dir, hidden_sto_dir_dentry->d_inode);
++
++ out_lock:
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++	dput(hidden_sto_dir_dentry);
++ out:
++	return err;
++}
++
++
++/* unimplemented (and possibly not usefull):
++
++   nondir-del_to_del_rew
++   nondir-non_exist_to_creat
++
++   dir-unmod_to_del
++   dir-mod_to_del
++   dir-creat_to_del
++   dir-del_rew_to_del
++   dir-del_to_del_rew
++   dir-non_exist_to_creat
++*/
++
++
++/* bring a file of any type from state UNMODIFIED to MODIFIED */
++int nondir_unmod_to_mod(dentry_t *dentry, int cp_flag)
++{
++	int err = 0;
++	struct vfsmount *tgt_mnt;
++	struct vfsmount *src_mnt;
++	dentry_t *tgt_dentry;
++	dentry_t *src_dentry;
++	dentry_t *hidden_sto_dentry;
++	dentry_t *hidden_sto_dir_dentry;
++
++	check_mini_fo_dentry(dentry);
++
++	if((dtost(dentry) != UNMODIFIED) ||
++	   S_ISDIR(dentry->d_inode->i_mode)) {
++		printk(KERN_CRIT "mini_fo: nondir_unmod_to_mod: \
++                                  wrong type or state.\n");
++		err = -1;
++		goto out;
++	}
++	err = get_neg_sto_dentry(dentry);
++
++	if (err) {
++		printk(KERN_CRIT "mini_fo: nondir_unmod_to_mod: \
++                                  ERROR getting neg. sto dentry.\n");
++		goto out;
++	}
++
++	/* create sto file */
++	hidden_sto_dentry = dtohd2(dentry);
++
++	/* lock parent */
++	hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++        down(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++
++	err = PTR_ERR(hidden_sto_dir_dentry);
++        if (IS_ERR(hidden_sto_dir_dentry))
++                goto out;
++
++	/* handle different types of nondirs */
++	if(S_ISCHR(dentry->d_inode->i_mode) ||
++	   S_ISBLK(dentry->d_inode->i_mode)) {
++		err = vfs_mknod(hidden_sto_dir_dentry->d_inode,
++				hidden_sto_dentry,
++				dtohd(dentry)->d_inode->i_mode,
++				dtohd(dentry)->d_inode->i_rdev);
++	}
++
++	else if(S_ISREG(dentry->d_inode->i_mode)) {
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++		err = vfs_create(hidden_sto_dir_dentry->d_inode,
++				 hidden_sto_dentry,
++				 dtohd(dentry)->d_inode->i_mode, NULL);
++#else
++		err = vfs_create(hidden_sto_dir_dentry->d_inode,
++				 hidden_sto_dentry,
++				 dtohd(dentry)->d_inode->i_mode);
++#endif
++	}
++        if(err) {
++		printk(KERN_CRIT "mini_fo: nondir_unmod_to_mod: \
++                                  ERROR creating sto file.\n");
++                goto out_lock;
++	}
++
++	/* interpose on new inode */
++	if(itohi2(dentry->d_inode) != NULL) {
++		printk(KERN_CRIT "mini_fo: nondir_unmod_to_mod: \
++                                  ERROR, invalid inode detected.\n");
++		err = -EINVAL;
++		goto out_lock;
++	}
++
++	itohi2(dentry->d_inode) = igrab(dtohd2(dentry)->d_inode);
++
++        fist_copy_attr_timesizes(dentry->d_parent->d_inode,
++				 hidden_sto_dir_dentry->d_inode);
++	dtost(dentry) = MODIFIED;
++
++	/* copy contents if regular file and cp_flag = 1 */
++	if((cp_flag == 1) && S_ISREG(dentry->d_inode->i_mode)) {
++
++		/* unlock first */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++		mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++		up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++
++		dput(hidden_sto_dir_dentry);
++
++		tgt_dentry = dtohd2(dentry);
++		tgt_mnt = stopd(dentry->d_inode->i_sb)->hidden_mnt2;
++		src_dentry = dtohd(dentry);
++		src_mnt = stopd(dentry->d_inode->i_sb)->hidden_mnt;
++
++		err = mini_fo_cp_cont(tgt_dentry, tgt_mnt,
++				      src_dentry, src_mnt);
++		if(err) {
++			printk(KERN_CRIT "mini_fo: nondir_unmod_to_mod: \
++                                          ERROR copying contents.\n");
++		}
++		goto out;
++	}
++
++ out_lock:
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++        dput(hidden_sto_dir_dentry);
++ out:
++	return err;
++}
++
++/* this function is currently identical to nondir_creat_to_del */
++int nondir_del_rew_to_del(dentry_t *dentry)
++{
++	return nondir_creat_to_del(dentry);
++}
++
++int nondir_creat_to_del(dentry_t *dentry)
++{
++	int err = 0;
++
++	inode_t *hidden_sto_dir_inode;
++	dentry_t *hidden_sto_dir_dentry;
++	dentry_t *hidden_sto_dentry;
++
++	check_mini_fo_dentry(dentry);
++
++	/* for now this function serves for both state DEL_REWRITTEN and
++	 * CREATED */
++	if(!(dtost(dentry) == CREATED || (dtost(dentry) == DEL_REWRITTEN)) ||
++	   S_ISDIR(dentry->d_inode->i_mode)) {
++		printk(KERN_CRIT "mini_fo: nondir_mod_to_del/del_rew_to_del: \
++                                  wrong type or state.\n");
++		err = -1;
++		goto out;
++	}
++
++	hidden_sto_dir_inode = itohi2(dentry->d_parent->d_inode);
++	hidden_sto_dentry = dtohd2(dentry);
++
++	/* was: hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry);*/
++	hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	down(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++
++	/* avoid destroying the hidden inode if the file is in use */
++	dget(hidden_sto_dentry);
++	err = vfs_unlink(hidden_sto_dir_inode, hidden_sto_dentry);
++	dput(hidden_sto_dentry);
++	if(!err)
++		d_delete(hidden_sto_dentry);
++
++	/* propagate number of hard-links */
++	dentry->d_inode->i_nlink = itohi2(dentry->d_inode)->i_nlink;
++
++	dtost(dentry) = NON_EXISTANT;
++
++	/* was: unlock_dir(hidden_sto_dir_dentry); */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++	dput(hidden_sto_dir_dentry);
++
++ out:
++	return err;
++}
++
++int nondir_mod_to_del(dentry_t *dentry)
++{
++	int err;
++	dentry_t *hidden_sto_dentry;
++	inode_t *hidden_sto_dir_inode;
++	dentry_t *hidden_sto_dir_dentry;
++
++	check_mini_fo_dentry(dentry);
++
++	if(dtost(dentry) != MODIFIED ||
++	   S_ISDIR(dentry->d_inode->i_mode)) {
++		printk(KERN_CRIT "mini_fo: nondir_mod_to_del: \
++                                  wrong type or state.\n");
++		err = -1;
++		goto out;
++	}
++
++	hidden_sto_dir_inode = itohi2(dentry->d_parent->d_inode);
++	hidden_sto_dentry = dtohd2(dentry);
++
++	/* was hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry); */
++	hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	down(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++
++	/* avoid destroying the hidden inode if the file is in use */
++	dget(hidden_sto_dentry);
++	err = vfs_unlink(hidden_sto_dir_inode, hidden_sto_dentry);
++	dput(hidden_sto_dentry);
++	if(!err)
++		d_delete(hidden_sto_dentry);
++
++	/* propagate number of hard-links */
++	dentry->d_inode->i_nlink = itohi2(dentry->d_inode)->i_nlink;
++
++	/* dput base dentry, this will relase the inode and free the
++	 * dentry, as we will never need it again. */
++	dput(dtohd(dentry));
++	dtohd(dentry) = NULL;
++	dtost(dentry) = DELETED;
++
++	/* add deleted file to META-file */
++	meta_add_d_entry(dentry->d_parent,
++			 dentry->d_name.name,
++			 dentry->d_name.len);
++
++	/* was: unlock_dir(hidden_sto_dir_dentry); */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
++	mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
++#else
++	up(&hidden_sto_dir_dentry->d_inode->i_sem);
++#endif
++	dput(hidden_sto_dir_dentry);
++
++ out:
++	return err;
++}
++
++int nondir_unmod_to_del(dentry_t *dentry)
++{
++	int err = 0;
++
++	check_mini_fo_dentry(dentry);
++
++	if(dtost(dentry) != UNMODIFIED ||
++	   S_ISDIR(dentry->d_inode->i_mode)) {
++		printk(KERN_CRIT "mini_fo: nondir_unmod_to_del: \
++                                  wrong type or state.\n");
++		err = -1;
++		goto out;
++	}
++
++	 /* next we have to get a negative dentry for the storage file */
++	err = get_neg_sto_dentry(dentry);
++
++	if(err)
++		goto out;
++
++	/* add deleted file to META lists */
++	err = meta_add_d_entry(dentry->d_parent,
++			       dentry->d_name.name,
++			       dentry->d_name.len);
++
++	if(err)
++		goto out;
++
++	/* dput base dentry, this will relase the inode and free the
++	 * dentry, as we will never need it again. */
++	dput(dtohd(dentry));
++	dtohd(dentry) = NULL;
++	dtost(dentry) = DELETED;
++
++ out:
++	return err;
++}
++
++/* bring a dir from state UNMODIFIED to MODIFIED */
++int dir_unmod_to_mod(dentry_t *dentry)
++{
++	int err;
++
++	check_mini_fo_dentry(dentry);
++
++	if(dtost(dentry) != UNMODIFIED ||
++	   !S_ISDIR(dentry->d_inode->i_mode)) {
++		printk(KERN_CRIT "mini_fo: dir_unmod_to_mod: \
++                                  wrong type or state.\n");
++		err = -1;
++		goto out;
++	}
++
++	/* this creates our dir incl. sto. structure */
++	err = build_sto_structure(dentry->d_parent, dentry);
++	if(err) {
++		printk(KERN_CRIT "mini_fo: dir_unmod_to_mod: \
++                                  build_sto_structure failed.\n");
++		goto out;
++	}
++ out:
++	return err;
++}
++
+--- /dev/null
++++ b/fs/mini_fo/super.c
+@@ -0,0 +1,281 @@
++/*
++ * Copyright (c) 1997-2003 Erez Zadok
++ * Copyright (c) 2001-2003 Stony Brook University
++ *
++ * For specific licensing information, see the COPYING file distributed with
++ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
++ *
++ * This Copyright notice must be kept intact and distributed with all
++ * fistgen sources INCLUDING sources generated by fistgen.
++ */
++/*
++ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ */
++
++/*
++ *  $Id$
++ */
++
++#ifdef HAVE_CONFIG_H
++# include <config.h>
++#endif
++
++#include "fist.h"
++#include "mini_fo.h"
++
++
++STATIC void
++mini_fo_read_inode(inode_t *inode)
++{
++	static struct address_space_operations mini_fo_empty_aops;
++
++	__itopd(inode) = kmalloc(sizeof(struct mini_fo_inode_info), GFP_KERNEL);
++	if (!itopd(inode)) {
++		printk("<0>%s:%s:%d: No kernel memory!\n", __FILE__, __FUNCTION__, __LINE__);
++		ASSERT(NULL);
++	}
++	itohi(inode) = NULL;
++	itohi2(inode) = NULL;
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++	inode->i_version++;
++#else
++	inode->i_version = ++event;	/* increment inode version */
++#endif
++	inode->i_op = &mini_fo_main_iops;
++	inode->i_fop = &mini_fo_main_fops;
++#if 0
++	/*
++	 * XXX: To export a file system via NFS, it has to have the
++	 * FS_REQUIRES_DEV flag, so turn it on.  But should we inherit it from
++	 * the lower file system, or can we allow our file system to be exported
++	 * even if the lower one cannot be natively exported.
++	 */
++	inode->i_sb->s_type->fs_flags |= FS_REQUIRES_DEV;
++	/*
++	 * OK, the above was a hack, which is now turned off because it may
++	 * cause a panic/oops on some systems.  The correct way to export a
++	 * "nodev" filesystem is via using nfs-utils > 1.0 and the "fsid=" export
++	 * parameter, which requires 2.4.20 or later.
++	 */
++#endif
++	/* I don't think ->a_ops is ever allowed to be NULL */
++	inode->i_mapping->a_ops = &mini_fo_empty_aops;
++}
++
++
++#if defined(FIST_DEBUG) || defined(FIST_FILTER_SCA)
++/*
++ * No need to call write_inode() on the lower inode, as it
++ * will have been marked 'dirty' anyway. But we might need
++ * to write some of our own stuff to disk.
++ */
++STATIC void
++mini_fo_write_inode(inode_t *inode, int sync)
++{
++	print_entry_location();
++	print_exit_location();
++}
++#endif /* defined(FIST_DEBUG) || defined(FIST_FILTER_SCA) */
++
++
++STATIC void
++mini_fo_put_inode(inode_t *inode)
++{
++	/*
++	 * This is really funky stuff:
++	 * Basically, if i_count == 1, iput will then decrement it and this inode will be destroyed.
++	 * It is currently holding a reference to the hidden inode.
++	 * Therefore, it needs to release that reference by calling iput on the hidden inode.
++	 * iput() _will_ do it for us (by calling our clear_inode), but _only_ if i_nlink == 0.
++	 * The problem is, NFS keeps i_nlink == 1 for silly_rename'd files.
++	 * So we must for our i_nlink to 0 here to trick iput() into calling our clear_inode.
++	 */
++	if (atomic_read(&inode->i_count) == 1)
++		inode->i_nlink = 0;
++}
++
++
++#if defined(FIST_DEBUG) || defined(FIST_FILTER_SCA)
++/*
++ * we now define delete_inode, because there are two VFS paths that may
++ * destroy an inode: one of them calls clear inode before doing everything
++ * else that's needed, and the other is fine.  This way we truncate the inode
++ * size (and its pages) and then clear our own inode, which will do an iput
++ * on our and the lower inode.
++ */
++STATIC void
++mini_fo_delete_inode(inode_t *inode)
++{
++	print_entry_location();
++
++	fist_checkinode(inode, "mini_fo_delete_inode IN");
++	inode->i_size = 0;		/* every f/s seems to do that */
++	clear_inode(inode);
++
++	print_exit_location();
++}
++#endif /* defined(FIST_DEBUG) || defined(FIST_FILTER_SCA) */
++
++
++/* final actions when unmounting a file system */
++STATIC void
++mini_fo_put_super(super_block_t *sb)
++{
++	if (stopd(sb)) {
++		mntput(stopd(sb)->hidden_mnt);
++		mntput(stopd(sb)->hidden_mnt2);
++
++		/* mk: no! dput(stopd(sb)->base_dir_dentry);
++		   dput(stopd(sb)->storage_dir_dentry); */
++
++		kfree(stopd(sb));
++		__stopd(sb) = NULL;
++	}
++}
++
++
++#ifdef NOT_NEEDED
++/*
++ * This is called in do_umount before put_super.
++ * The superblock lock is not held yet.
++ * We probably do not need to define this or call write_super
++ * on the hidden_sb, because sync_supers() will get to hidden_sb
++ * sooner or later.  But it is also called from file_fsync()...
++ */
++STATIC void
++mini_fo_write_super(super_block_t *sb)
++{
++	return;
++}
++#endif /* NOT_NEEDED */
++
++
++STATIC int
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
++mini_fo_statfs(struct dentry *d, struct kstatfs *buf)
++#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
++mini_fo_statfs(super_block_t *sb, struct kstatfs *buf)
++#else
++mini_fo_statfs(super_block_t *sb, struct statfs *buf)
++#endif
++{
++	int err = 0;
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
++	struct dentry *hidden_d;
++
++	hidden_d = dtohd(d);
++	err = vfs_statfs(hidden_d, buf);
++#else
++	super_block_t *hidden_sb;
++
++	hidden_sb = stohs(sb);
++	err = vfs_statfs(hidden_sb, buf);
++#endif
++
++	return err;
++}
++
++
++/*
++ * XXX: not implemented.  This is not allowed yet.
++ * Should we call this on the hidden_sb?  Probably not.
++ */
++STATIC int
++mini_fo_remount_fs(super_block_t *sb, int *flags, char *data)
++{
++	//printk(KERN_CRIT "mini_fo_remount_fs: WARNING, this function is umimplemented.\n");
++	return -ENOSYS;
++}
++
++
++/*
++ * Called by iput() when the inode reference count reached zero
++ * and the inode is not hashed anywhere.  Used to clear anything
++ * that needs to be, before the inode is completely destroyed and put
++ * on the inode free list.
++ */
++STATIC void
++mini_fo_clear_inode(inode_t *inode)
++{
++	/*
++	 * Decrement a reference to a hidden_inode, which was incremented
++	 * by our read_inode when it was created initially.
++	 */
++
++	/* release the wol_list */
++	if(S_ISDIR(inode->i_mode)) {
++		__meta_put_lists(inode);
++	}
++
++	/* mk: fan out fun */
++	if(itohi(inode))
++		iput(itohi(inode));
++	if(itohi2(inode))
++		iput(itohi2(inode));
++
++	// XXX: why this assertion fails?
++	// because it doesn't like us
++	// ASSERT((inode->i_state & I_DIRTY) == 0);
++	kfree(itopd(inode));
++	__itopd(inode) = NULL;
++}
++
++
++/*
++ * Called in do_umount() if the MNT_FORCE flag was used and this
++ * function is defined.  See comment in linux/fs/super.c:do_umount().
++ * Used only in nfs, to kill any pending RPC tasks, so that subsequent
++ * code can actually succeed and won't leave tasks that need handling.
++ *
++ * PS. I wonder if this is somehow useful to undo damage that was
++ * left in the kernel after a user level file server (such as amd)
++ * dies.
++ */
++STATIC void
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
++mini_fo_umount_begin(struct vfsmount *mnt, int flags)
++{
++	struct vfsmount *hidden_mnt;
++
++	hidden_mnt = stopd(mnt->mnt_sb)->hidden_mnt;
++
++	if (hidden_mnt->mnt_sb->s_op->umount_begin)
++		hidden_mnt->mnt_sb->s_op->umount_begin(hidden_mnt, flags);
++
++}
++#else
++mini_fo_umount_begin(super_block_t *sb)
++{
++	super_block_t *hidden_sb;
++
++	hidden_sb = stohs(sb);
++
++	if (hidden_sb->s_op->umount_begin)
++		hidden_sb->s_op->umount_begin(hidden_sb);
++
++}
++#endif
++
++
++struct super_operations mini_fo_sops =
++{
++	read_inode:		mini_fo_read_inode,
++#if defined(FIST_DEBUG) || defined(FIST_FILTER_SCA)
++	write_inode:	mini_fo_write_inode,
++#endif /* defined(FIST_DEBUG) || defined(FIST_FILTER_SCA) */
++	put_inode:		mini_fo_put_inode,
++#if defined(FIST_DEBUG) || defined(FIST_FILTER_SCA)
++	delete_inode:	mini_fo_delete_inode,
++#endif /* defined(FIST_DEBUG) || defined(FIST_FILTER_SCA) */
++	put_super:		mini_fo_put_super,
++	statfs:		mini_fo_statfs,
++	remount_fs:		mini_fo_remount_fs,
++	clear_inode:	mini_fo_clear_inode,
++	umount_begin:	mini_fo_umount_begin,
++};
+--- /dev/null
++++ b/fs/mini_fo/Kconfig
+@@ -0,0 +1,3 @@
++config MINI_FO
++	tristate "Mini fanout overlay filesystem"
++