diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c
new file mode 100644
index 0000000..aa92d6b
--- /dev/null
+++ b/fs/qnx4/inode.c
@@ -0,0 +1,603 @@
+/*
+ * QNX4 file system, Linux implementation.
+ *
+ * Version : 0.2.1
+ *
+ * Using parts of the xiafs filesystem.
+ *
+ * History :
+ *
+ * 01-06-1998 by Richard Frowijn : first release.
+ * 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc.
+ * 30-06-1998 by Frank Denis : first step to write inodes.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/qnx4_fs.h>
+#include <linux/init.h>
+#include <linux/highuid.h>
+#include <linux/smp_lock.h>
+#include <linux/pagemap.h>
+#include <linux/buffer_head.h>
+#include <linux/vfs.h>
+#include <asm/uaccess.h>
+
+#define QNX4_VERSION  4
+#define QNX4_BMNAME   ".bitmap"
+
+static struct super_operations qnx4_sops;
+
+#ifdef CONFIG_QNX4FS_RW
+
+int qnx4_sync_inode(struct inode *inode)
+{
+	int err = 0;
+# if 0
+	struct buffer_head *bh;
+
+   	bh = qnx4_update_inode(inode);
+	if (bh && buffer_dirty(bh))
+	{
+		sync_dirty_buffer(bh);
+		if (buffer_req(bh) && !buffer_uptodate(bh))
+		{
+			printk ("IO error syncing qnx4 inode [%s:%08lx]\n",
+				inode->i_sb->s_id, inode->i_ino);
+			err = -1;
+		}
+	        brelse (bh);
+	} else if (!bh) {
+		err = -1;
+	}
+# endif
+
+	return err;
+}
+
+static void qnx4_delete_inode(struct inode *inode)
+{
+	QNX4DEBUG(("qnx4: deleting inode [%lu]\n", (unsigned long) inode->i_ino));
+	inode->i_size = 0;
+	qnx4_truncate(inode);
+	lock_kernel();
+	qnx4_free_inode(inode);
+	unlock_kernel();
+}
+
+static void qnx4_write_super(struct super_block *sb)
+{
+	lock_kernel();
+	QNX4DEBUG(("qnx4: write_super\n"));
+	sb->s_dirt = 0;
+	unlock_kernel();
+}
+
+static int qnx4_write_inode(struct inode *inode, int unused)
+{
+	struct qnx4_inode_entry *raw_inode;
+	int block, ino;
+	struct buffer_head *bh;
+	ino = inode->i_ino;
+
+	QNX4DEBUG(("qnx4: write inode 1.\n"));
+	if (inode->i_nlink == 0) {
+		return 0;
+	}
+	if (!ino) {
+		printk("qnx4: bad inode number on dev %s: %d is out of range\n",
+		       inode->i_sb->s_id, ino);
+		return -EIO;
+	}
+	QNX4DEBUG(("qnx4: write inode 2.\n"));
+	block = ino / QNX4_INODES_PER_BLOCK;
+	lock_kernel();
+	if (!(bh = sb_bread(inode->i_sb, block))) {
+		printk("qnx4: major problem: unable to read inode from dev "
+		       "%s\n", inode->i_sb->s_id);
+		unlock_kernel();
+		return -EIO;
+	}
+	raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
+	    (ino % QNX4_INODES_PER_BLOCK);
+	raw_inode->di_mode  = cpu_to_le16(inode->i_mode);
+	raw_inode->di_uid   = cpu_to_le16(fs_high2lowuid(inode->i_uid));
+	raw_inode->di_gid   = cpu_to_le16(fs_high2lowgid(inode->i_gid));
+	raw_inode->di_nlink = cpu_to_le16(inode->i_nlink);
+	raw_inode->di_size  = cpu_to_le32(inode->i_size);
+	raw_inode->di_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
+	raw_inode->di_atime = cpu_to_le32(inode->i_atime.tv_sec);
+	raw_inode->di_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
+	raw_inode->di_first_xtnt.xtnt_size = cpu_to_le32(inode->i_blocks);
+	mark_buffer_dirty(bh);
+	brelse(bh);
+	unlock_kernel();
+	return 0;
+}
+
+#endif
+
+static void qnx4_put_super(struct super_block *sb);
+static struct inode *qnx4_alloc_inode(struct super_block *sb);
+static void qnx4_destroy_inode(struct inode *inode);
+static void qnx4_read_inode(struct inode *);
+static int qnx4_remount(struct super_block *sb, int *flags, char *data);
+static int qnx4_statfs(struct super_block *, struct kstatfs *);
+
+static struct super_operations qnx4_sops =
+{
+	.alloc_inode	= qnx4_alloc_inode,
+	.destroy_inode	= qnx4_destroy_inode,
+	.read_inode	= qnx4_read_inode,
+	.put_super	= qnx4_put_super,
+	.statfs		= qnx4_statfs,
+	.remount_fs	= qnx4_remount,
+#ifdef CONFIG_QNX4FS_RW
+	.write_inode	= qnx4_write_inode,
+	.delete_inode	= qnx4_delete_inode,
+	.write_super	= qnx4_write_super,
+#endif
+};
+
+static int qnx4_remount(struct super_block *sb, int *flags, char *data)
+{
+	struct qnx4_sb_info *qs;
+
+	qs = qnx4_sb(sb);
+	qs->Version = QNX4_VERSION;
+#ifndef CONFIG_QNX4FS_RW
+	*flags |= MS_RDONLY;
+#endif
+	if (*flags & MS_RDONLY) {
+		return 0;
+	}
+
+	mark_buffer_dirty(qs->sb_buf);
+
+	return 0;
+}
+
+static struct buffer_head *qnx4_getblk(struct inode *inode, int nr,
+				       int create)
+{
+	struct buffer_head *result = NULL;
+
+	if ( nr >= 0 )
+		nr = qnx4_block_map( inode, nr );
+	if (nr) {
+		result = sb_getblk(inode->i_sb, nr);
+		return result;
+	}
+	if (!create) {
+		return NULL;
+	}
+#if 0
+	tmp = qnx4_new_block(inode->i_sb);
+	if (!tmp) {
+		return NULL;
+	}
+	result = sb_getblk(inode->i_sb, tmp);
+	if (tst) {
+		qnx4_free_block(inode->i_sb, tmp);
+		brelse(result);
+		goto repeat;
+	}
+	tst = tmp;
+#endif
+	inode->i_ctime = CURRENT_TIME_SEC;
+	mark_inode_dirty(inode);
+	return result;
+}
+
+struct buffer_head *qnx4_bread(struct inode *inode, int block, int create)
+{
+	struct buffer_head *bh;
+
+	bh = qnx4_getblk(inode, block, create);
+	if (!bh || buffer_uptodate(bh)) {
+		return bh;
+	}
+	ll_rw_block(READ, 1, &bh);
+	wait_on_buffer(bh);
+	if (buffer_uptodate(bh)) {
+		return bh;
+	}
+	brelse(bh);
+
+	return NULL;
+}
+
+static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
+{
+	unsigned long phys;
+
+	QNX4DEBUG(("qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
+
+	phys = qnx4_block_map( inode, iblock );
+	if ( phys ) {
+		// logical block is before EOF
+		map_bh(bh, inode->i_sb, phys);
+	} else if ( create ) {
+		// to be done.
+	}
+	return 0;
+}
+
+unsigned long qnx4_block_map( struct inode *inode, long iblock )
+{
+	int ix;
+	long offset, i_xblk;
+	unsigned long block = 0;
+	struct buffer_head *bh = NULL;
+	struct qnx4_xblk *xblk = NULL;
+	struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
+	qnx4_nxtnt_t nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
+
+	if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
+		// iblock is in the first extent. This is easy.
+		block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
+	} else {
+		// iblock is beyond first extent. We have to follow the extent chain.
+		i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
+		offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
+		ix = 0;
+		while ( --nxtnt > 0 ) {
+			if ( ix == 0 ) {
+				// read next xtnt block.
+				bh = sb_bread(inode->i_sb, i_xblk - 1);
+				if ( !bh ) {
+					QNX4DEBUG(("qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
+					return -EIO;
+				}
+				xblk = (struct qnx4_xblk*)bh->b_data;
+				if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
+					QNX4DEBUG(("qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
+					return -EIO;
+				}
+			}
+			if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
+				// got it!
+				block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
+				break;
+			}
+			offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
+			if ( ++ix >= xblk->xblk_num_xtnts ) {
+				i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
+				ix = 0;
+				brelse( bh );
+				bh = NULL;
+			}
+		}
+		if ( bh )
+			brelse( bh );
+	}
+
+	QNX4DEBUG(("qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
+	return block;
+}
+
+static int qnx4_statfs(struct super_block *sb, struct kstatfs *buf)
+{
+	lock_kernel();
+
+	buf->f_type    = sb->s_magic;
+	buf->f_bsize   = sb->s_blocksize;
+	buf->f_blocks  = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
+	buf->f_bfree   = qnx4_count_free_blocks(sb);
+	buf->f_bavail  = buf->f_bfree;
+	buf->f_namelen = QNX4_NAME_MAX;
+
+	unlock_kernel();
+
+	return 0;
+}
+
+/*
+ * Check the root directory of the filesystem to make sure
+ * it really _is_ a qnx4 filesystem, and to check the size
+ * of the directory entry.
+ */
+static const char *qnx4_checkroot(struct super_block *sb)
+{
+	struct buffer_head *bh;
+	struct qnx4_inode_entry *rootdir;
+	int rd, rl;
+	int i, j;
+	int found = 0;
+
+	if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') {
+		return "no qnx4 filesystem (no root dir).";
+	} else {
+		QNX4DEBUG(("QNX4 filesystem found on dev %s.\n", sb->s_id));
+		rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
+		rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
+		for (j = 0; j < rl; j++) {
+			bh = sb_bread(sb, rd + j);	/* root dir, first block */
+			if (bh == NULL) {
+				return "unable to read root entry.";
+			}
+			for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
+				rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE);
+				if (rootdir->di_fname != NULL) {
+					QNX4DEBUG(("Rootdir entry found : [%s]\n", rootdir->di_fname));
+					if (!strncmp(rootdir->di_fname, QNX4_BMNAME, sizeof QNX4_BMNAME)) {
+						found = 1;
+						qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
+						if (!qnx4_sb(sb)->BitMap) {
+							brelse (bh);
+							return "not enough memory for bitmap inode";
+						}
+						memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) );	/* keep bitmap inode known */
+						break;
+					}
+				}
+			}
+			brelse(bh);
+			if (found != 0) {
+				break;
+			}
+		}
+		if (found == 0) {
+			return "bitmap file not found.";
+		}
+	}
+	return NULL;
+}
+
+static int qnx4_fill_super(struct super_block *s, void *data, int silent)
+{
+	struct buffer_head *bh;
+	struct inode *root;
+	const char *errmsg;
+	struct qnx4_sb_info *qs;
+
+	qs = kmalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
+	if (!qs)
+		return -ENOMEM;
+	s->s_fs_info = qs;
+	memset(qs, 0, sizeof(struct qnx4_sb_info));
+
+	sb_set_blocksize(s, QNX4_BLOCK_SIZE);
+
+	/* Check the superblock signature. Since the qnx4 code is
+	   dangerous, we should leave as quickly as possible
+	   if we don't belong here... */
+	bh = sb_bread(s, 1);
+	if (!bh) {
+		printk("qnx4: unable to read the superblock\n");
+		goto outnobh;
+	}
+	if ( le32_to_cpu( *(__u32*)bh->b_data ) != QNX4_SUPER_MAGIC ) {
+		if (!silent)
+			printk("qnx4: wrong fsid in superblock.\n");
+		goto out;
+	}
+	s->s_op = &qnx4_sops;
+	s->s_magic = QNX4_SUPER_MAGIC;
+#ifndef CONFIG_QNX4FS_RW
+	s->s_flags |= MS_RDONLY;	/* Yup, read-only yet */
+#endif
+	qnx4_sb(s)->sb_buf = bh;
+	qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
+
+
+ 	/* check before allocating dentries, inodes, .. */
+	errmsg = qnx4_checkroot(s);
+	if (errmsg != NULL) {
+ 		if (!silent)
+ 			printk("qnx4: %s\n", errmsg);
+		goto out;
+	}
+
+ 	/* does root not have inode number QNX4_ROOT_INO ?? */
+ 	root = iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
+ 	if (!root) {
+ 		printk("qnx4: get inode failed\n");
+ 		goto out;
+ 	}
+
+ 	s->s_root = d_alloc_root(root);
+ 	if (s->s_root == NULL)
+ 		goto outi;
+
+	brelse(bh);
+
+	return 0;
+
+      outi:
+	iput(root);
+      out:
+	brelse(bh);
+      outnobh:
+	kfree(qs);
+	s->s_fs_info = NULL;
+	return -EINVAL;
+}
+
+static void qnx4_put_super(struct super_block *sb)
+{
+	struct qnx4_sb_info *qs = qnx4_sb(sb);
+	kfree( qs->BitMap );
+	kfree( qs );
+	sb->s_fs_info = NULL;
+	return;
+}
+
+static int qnx4_writepage(struct page *page, struct writeback_control *wbc)
+{
+	return block_write_full_page(page,qnx4_get_block, wbc);
+}
+static int qnx4_readpage(struct file *file, struct page *page)
+{
+	return block_read_full_page(page,qnx4_get_block);
+}
+static int qnx4_prepare_write(struct file *file, struct page *page,
+			      unsigned from, unsigned to)
+{
+	struct qnx4_inode_info *qnx4_inode = qnx4_i(page->mapping->host);
+	return cont_prepare_write(page, from, to, qnx4_get_block,
+				  &qnx4_inode->mmu_private);
+}
+static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
+{
+	return generic_block_bmap(mapping,block,qnx4_get_block);
+}
+static struct address_space_operations qnx4_aops = {
+	.readpage	= qnx4_readpage,
+	.writepage	= qnx4_writepage,
+	.sync_page	= block_sync_page,
+	.prepare_write	= qnx4_prepare_write,
+	.commit_write	= generic_commit_write,
+	.bmap		= qnx4_bmap
+};
+
+static void qnx4_read_inode(struct inode *inode)
+{
+	struct buffer_head *bh;
+	struct qnx4_inode_entry *raw_inode;
+	int block, ino;
+	struct super_block *sb = inode->i_sb;
+	struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
+
+	ino = inode->i_ino;
+	inode->i_mode = 0;
+
+	QNX4DEBUG(("Reading inode : [%d]\n", ino));
+	if (!ino) {
+		printk("qnx4: bad inode number on dev %s: %d is out of range\n",
+		       sb->s_id, ino);
+		return;
+	}
+	block = ino / QNX4_INODES_PER_BLOCK;
+
+	if (!(bh = sb_bread(sb, block))) {
+		printk("qnx4: major problem: unable to read inode from dev "
+		       "%s\n", sb->s_id);
+		return;
+	}
+	raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
+	    (ino % QNX4_INODES_PER_BLOCK);
+
+	inode->i_mode    = le16_to_cpu(raw_inode->di_mode);
+	inode->i_uid     = (uid_t)le16_to_cpu(raw_inode->di_uid);
+	inode->i_gid     = (gid_t)le16_to_cpu(raw_inode->di_gid);
+	inode->i_nlink   = le16_to_cpu(raw_inode->di_nlink);
+	inode->i_size    = le32_to_cpu(raw_inode->di_size);
+	inode->i_mtime.tv_sec   = le32_to_cpu(raw_inode->di_mtime);
+	inode->i_mtime.tv_nsec = 0;
+	inode->i_atime.tv_sec   = le32_to_cpu(raw_inode->di_atime);
+	inode->i_atime.tv_nsec = 0;
+	inode->i_ctime.tv_sec   = le32_to_cpu(raw_inode->di_ctime);
+	inode->i_ctime.tv_nsec = 0;
+	inode->i_blocks  = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
+	inode->i_blksize = QNX4_DIR_ENTRY_SIZE;
+
+	memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
+	if (S_ISREG(inode->i_mode)) {
+		inode->i_op = &qnx4_file_inode_operations;
+		inode->i_fop = &qnx4_file_operations;
+		inode->i_mapping->a_ops = &qnx4_aops;
+		qnx4_i(inode)->mmu_private = inode->i_size;
+	} else if (S_ISDIR(inode->i_mode)) {
+		inode->i_op = &qnx4_dir_inode_operations;
+		inode->i_fop = &qnx4_dir_operations;
+	} else if (S_ISLNK(inode->i_mode)) {
+		inode->i_op = &page_symlink_inode_operations;
+		inode->i_mapping->a_ops = &qnx4_aops;
+		qnx4_i(inode)->mmu_private = inode->i_size;
+	} else
+		printk("qnx4: bad inode %d on dev %s\n",ino,sb->s_id);
+	brelse(bh);
+}
+
+static kmem_cache_t *qnx4_inode_cachep;
+
+static struct inode *qnx4_alloc_inode(struct super_block *sb)
+{
+	struct qnx4_inode_info *ei;
+	ei = kmem_cache_alloc(qnx4_inode_cachep, SLAB_KERNEL);
+	if (!ei)
+		return NULL;
+	return &ei->vfs_inode;
+}
+
+static void qnx4_destroy_inode(struct inode *inode)
+{
+	kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
+}
+
+static void init_once(void *foo, kmem_cache_t * cachep,
+		      unsigned long flags)
+{
+	struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
+
+	if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) ==
+	    SLAB_CTOR_CONSTRUCTOR)
+		inode_init_once(&ei->vfs_inode);
+}
+
+static int init_inodecache(void)
+{
+	qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
+					     sizeof(struct qnx4_inode_info),
+					     0, SLAB_RECLAIM_ACCOUNT,
+					     init_once, NULL);
+	if (qnx4_inode_cachep == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	if (kmem_cache_destroy(qnx4_inode_cachep))
+		printk(KERN_INFO
+		       "qnx4_inode_cache: not all structures were freed\n");
+}
+
+static struct super_block *qnx4_get_sb(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	return get_sb_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
+}
+
+static struct file_system_type qnx4_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "qnx4",
+	.get_sb		= qnx4_get_sb,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+
+static int __init init_qnx4_fs(void)
+{
+	int err;
+
+	err = init_inodecache();
+	if (err)
+		return err;
+
+	err = register_filesystem(&qnx4_fs_type);
+	if (err) {
+		destroy_inodecache();
+		return err;
+	}
+
+	printk("QNX4 filesystem 0.2.3 registered.\n");
+	return 0;
+}
+
+static void __exit exit_qnx4_fs(void)
+{
+	unregister_filesystem(&qnx4_fs_type);
+	destroy_inodecache();
+}
+
+module_init(init_qnx4_fs)
+module_exit(exit_qnx4_fs)
+MODULE_LICENSE("GPL");
+