Index: uspace/lib/ext4/Makefile
===================================================================
--- uspace/lib/ext4/Makefile	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/Makefile	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,42 @@
+#
+# Copyright (c) 2011 Frantisek Princ
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# - Redistributions of source code must retain the above copyright
+#   notice, this list of conditions and the following disclaimer.
+# - Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+# - The name of the author may not be used to endorse or promote products
+#   derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+
+USPACE_PREFIX = ../..
+LIBRARY = libext4
+EXTRA_CFLAGS = -I$(LIBBLOCK_PREFIX)
+LIBS = $(LIBBLOCK_PREFIX)/libblock.a
+
+SOURCES = \
+	libext4_block_group.c \
+	libext4_directory.c \
+	libext4_filesystem.c \
+	libext4_inode.c \
+	libext4_superblock.c
+	
+
+include $(USPACE_PREFIX)/Makefile.common
Index: uspace/lib/ext4/libext4.h
===================================================================
--- uspace/lib/ext4/libext4.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/libext4.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2011 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libext4
+ * @{
+ */ 
+
+#ifndef LIBEXT4_LIBEXT4_H_
+#define LIBEXT4_LIBEXT4_H_
+
+#include "libext4_block_group.h"
+#include "libext4_directory.h"
+#include "libext4_filesystem.h"
+#include "libext4_inode.h"
+#include "libext4_superblock.h"
+
+#endif
+
+/**
+ * @}
+ */
Index: uspace/lib/ext4/libext4_block_group.c
===================================================================
--- uspace/lib/ext4/libext4_block_group.c	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/libext4_block_group.c	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2011 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libext4
+ * @{
+ */ 
+
+/**
+ * @file	libext4_block_group.c
+ * @brief	TODO
+ */
+
+#include "libext4_block_group.h"
+
+
+/**
+ * @}
+ */ 
Index: uspace/lib/ext4/libext4_block_group.h
===================================================================
--- uspace/lib/ext4/libext4_block_group.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/libext4_block_group.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2011 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libext4
+ * @{
+ */ 
+
+#ifndef LIBEXT4_LIBEXT4_BLOCK_GROUP_H_
+#define LIBEXT4_LIBEXT4_BLOCK_GROUP_H_
+
+#include <sys/types.h>
+
+/*
+ * Structure of a blocks group descriptor
+ */
+typedef struct ext4_block_group {
+	uint32_t bg_block_bitmap_lo; // Blocks bitmap block
+	uint32_t bg_inode_bitmap_lo; // Inodes bitmap block
+	uint32_t bg_inode_table_lo; // Inodes table block
+	uint16_t bg_free_blocks_count_lo; // Free blocks count
+	uint16_t bg_free_inodes_count_lo; // Free inodes count
+	uint16_t bg_used_dirs_count_lo; // Directories count
+	uint16_t bg_flags; // EXT4_BG_flags (INODE_UNINIT, etc)
+	uint32_t bg_reserved[2]; // Likely block/inode bitmap checksum
+	uint16_t bg_itable_unused_lo; // Unused inodes count
+	uint16_t bg_checksum; // crc16(sb_uuid+group+desc)
+	uint32_t bg_block_bitmap_hi; // Blocks bitmap block MSB
+	uint32_t bg_inode_bitmap_hi; // Inodes bitmap block MSB
+	uint32_t bg_inode_table_hi; // Inodes table block MSB
+	uint16_t bg_free_blocks_count_hi; // Free blocks count MSB
+	uint16_t bg_free_inodes_count_hi; // Free inodes count MSB
+	uint16_t bg_used_dirs_count_hi; // Directories count MSB
+	uint16_t bg_itable_unused_hi;  // Unused inodes count MSB
+	uint32_t bg_reserved2[3]; // Padding
+} ext4_group_desc_t;
+
+#endif
+
+/**
+ * @}
+ */
Index: uspace/lib/ext4/libext4_directory.c
===================================================================
--- uspace/lib/ext4/libext4_directory.c	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/libext4_directory.c	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2011 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libext4
+ * @{
+ */ 
+
+/**
+ * @file	libext4_directory.c
+ * @brief	TODO
+ */
+
+#include "libext4_directory.h"
+
+
+/**
+ * @}
+ */ 
Index: uspace/lib/ext4/libext4_directory.h
===================================================================
--- uspace/lib/ext4/libext4_directory.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/libext4_directory.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2011 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libext4
+ * @{
+ */ 
+
+#ifndef LIBEXT4_LIBEXT4_DIRECTORY_H_
+#define LIBEXT4_LIBEXT4_DIRECTORY_H_
+
+
+#endif
+
+/**
+ * @}
+ */
Index: uspace/lib/ext4/libext4_filesystem.c
===================================================================
--- uspace/lib/ext4/libext4_filesystem.c	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/libext4_filesystem.c	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2011 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libext4
+ * @{
+ */ 
+
+/**
+ * @file	libext4_filesystem.c
+ * @brief	TODO
+ */
+
+#include <errno.h>
+#include "libext4_filesystem.h"
+
+int ext4_filesystem_init(ext4_filesystem_t *fs, service_id_t service_id)
+{
+	// TODO
+	return EOK;
+}
+
+int ext4_filesystem_check_sanity(ext4_filesystem_t *fs)
+{
+	// TODO
+	return EOK;
+}
+
+int ext4_filesystem_check_flags(ext4_filesystem_t *fs, bool *o_read_only)
+{
+	// TODO
+	return EOK;
+}
+
+void ext4_filesystem_fini(ext4_filesystem_t *fs)
+{
+	// TODO
+}
+
+
+/**
+ * @}
+ */ 
Index: uspace/lib/ext4/libext4_filesystem.h
===================================================================
--- uspace/lib/ext4/libext4_filesystem.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/libext4_filesystem.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2011 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libext4
+ * @{
+ */ 
+
+#ifndef LIBEXT4_LIBEXT4_FILESYSTEM_H_
+#define LIBEXT4_LIBEXT4_FILESYSTEM_H_
+
+#include <libblock.h>
+#include "libext4_superblock.h"
+
+typedef struct ext4_filesystem {
+	service_id_t device;
+	ext4_superblock_t *	superblock;
+} ext4_filesystem_t;
+
+extern int ext4_filesystem_init(ext4_filesystem_t *, service_id_t);
+extern int ext4_filesystem_check_sanity(ext4_filesystem_t *fs);
+extern int ext4_filesystem_check_flags(ext4_filesystem_t *, bool *);
+extern void ext4_filesystem_fini(ext4_filesystem_t *fs);
+
+#endif
+
+/**
+ * @}
+ */
Index: uspace/lib/ext4/libext4_inode.c
===================================================================
--- uspace/lib/ext4/libext4_inode.c	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/libext4_inode.c	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2011 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libext4
+ * @{
+ */ 
+
+/**
+ * @file	libext4_inode.c
+ * @brief	Ext4 inode operations.
+ */
+
+#include "libext4_inode.h"
+
+// TODO check return type
+uint16_t ext4_inode_get_usage_count(ext4_inode_t *inode)
+{
+	// TODO
+	return 0;
+}
+
+
+/**
+ * @}
+ */ 
Index: uspace/lib/ext4/libext4_inode.h
===================================================================
--- uspace/lib/ext4/libext4_inode.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/libext4_inode.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,130 @@
+/*
+ * Copyright (c) 2011 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libext4
+ * @{
+ */ 
+
+#ifndef LIBEXT4_LIBEXT4_INODE_H_
+#define LIBEXT4_LIBEXT4_INODE_H_
+
+#include <libblock.h>
+#include <sys/types.h>
+
+// TODO better constant definition !!!
+#define	EXT4_N_BLOCKS	15
+
+/*
+ * Structure of an inode on the disk
+ */
+typedef struct ext4_inode {
+	uint16_t i_mode; // File mode
+	uint16_t i_uid; // Low 16 bits of owner uid
+	uint32_t i_size_lo; // Size in bytes
+	uint32_t i_atime; // Access time
+	uint32_t i_ctime; // Inode change time
+	uint32_t i_mtime; // Modification time
+	uint32_t i_dtime; // Deletion time
+	uint16_t i_gid; // Low 16 bits of group id
+	uint16_t i_links_count; // Links count
+	uint32_t i_blocks_lo; // Blocks count
+	uint32_t i_flags; // File flags
+
+	/*
+        union {
+                struct {
+                        __le32  l_i_version;
+                } linux1;
+                struct {
+                        __u32  h_i_translator;
+                } hurd1;
+                struct {
+                        __u32  m_i_reserved1;
+                } masix1;
+        } osd1;
+	*/
+	uint32_t unused_osd1; // OS dependent - not used in HelenOS
+
+    uint32_t i_block[EXT4_N_BLOCKS]; // Pointers to blocks
+    uint32_t i_generation; // File version (for NFS)
+    uint32_t i_file_acl_lo; // File ACL
+    uint32_t i_size_high;
+    uint32_t i_obso_faddr; // Obsoleted fragment address
+
+    /*
+        union {
+                struct {
+                        __le16  l_i_blocks_high;
+                        __le16  l_i_file_acl_high;
+                        __le16  l_i_uid_high;
+                        __le16  l_i_gid_high;
+                        __u32   l_i_reserved2;
+                } linux2;
+                struct {
+                        __le16  h_i_reserved1;
+                        __u16   h_i_mode_high;
+                        __u16   h_i_uid_high;
+                        __u16   h_i_gid_high;
+                        __u32   h_i_author;
+                } hurd2;
+                struct {
+                        __le16  h_i_reserved1;
+                        __le16  m_i_file_acl_high;
+                        __u32   m_i_reserved2[2];
+                } masix2;
+        } osd2;
+        */
+
+        uint32_t unused_osd2[3]; // OS dependent - not used in HelenOS
+        uint16_t i_extra_isize;
+        uint16_t i_pad1;
+        uint32_t  i_ctime_extra; // Extra change time (nsec << 2 | epoch)
+        uint32_t i_mtime_extra; // Extra Modification time (nsec << 2 | epoch)
+        uint32_t i_atime_extra; // Extra Access time (nsec << 2 | epoch)
+        uint32_t i_crtime; // File creation time
+        uint32_t i_crtime_extra; // Extra file creation time (nsec << 2 | epoch)
+        uint32_t i_version_hi;   // High 32 bits for 64-bit version
+} __attribute__ ((packed)) ext4_inode_t;
+
+
+// TODO check value
+#define EXT4_INODE_ROOT_INDEX	2
+
+typedef struct ext4_inode_ref {
+	block_t *block; // Reference to a block containing this inode
+	ext4_inode_t *inode;
+	uint32_t index; // Index number of this inode
+} ext4_inode_ref_t;
+
+extern uint16_t ext4_inode_get_usage_count(ext4_inode_t *);
+
+#endif
+
+/**
+ * @}
+ */
Index: uspace/lib/ext4/libext4_superblock.c
===================================================================
--- uspace/lib/ext4/libext4_superblock.c	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/libext4_superblock.c	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2011 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libext4
+ * @{
+ */ 
+
+/**
+ * @file	libext4_superblock.c
+ * @brief	Ext4 superblock operations.
+ */
+
+#include "libext4_superblock.h"
+
+
+/**
+ * @}
+ */ 
Index: uspace/lib/ext4/libext4_superblock.h
===================================================================
--- uspace/lib/ext4/libext4_superblock.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
+++ uspace/lib/ext4/libext4_superblock.h	(revision 54935cf6fe01590e96323ab8738b02418aaba26c)
@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 2011 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libext4
+ * @{
+ */
+
+#ifndef LIBEXT4_LIBEXT4_SUPERBLOCK_H_
+#define LIBEXT4_LIBEXT4_SUPERBLOCK_H_
+
+#include <sys/types.h>
+
+/*
+ * Structure of the super block
+ */
+typedef struct ext4_superblock {
+	uint32_t s_inodes_count; // Inodes count
+	uint32_t s_blocks_count_lo; // Blocks count
+	uint32_t s_r_blocks_count_lo; // Reserved blocks count
+	uint32_t s_free_blocks_count_lo; // Free blocks count
+	uint32_t s_free_inodes_count; // Free inodes count
+	uint32_t s_first_data_block; // First Data Block
+	uint32_t s_log_block_size; // Block size
+	uint32_t s_obso_log_frag_size; // Obsoleted fragment size
+	uint32_t s_blocks_per_group; // Number of blocks per group
+	uint32_t s_obso_frags_per_group; // Obsoleted fragments per group
+	uint32_t s_inodes_per_group; // Number of inodes per group
+	uint32_t s_mtime; // Mount time
+	uint32_t s_wtime; // Write time
+	uint16_t s_mnt_count; // Mount count
+	uint16_t s_max_mnt_count; // Maximal mount count
+	uint16_t s_magic; // Magic signature
+	uint16_t s_state; // File system state
+	uint16_t s_errors; // Behaviour when detecting errors
+	uint16_t s_minor_rev_level; // Minor revision level
+	uint32_t s_lastcheck; // Time of last check
+	uint32_t s_checkinterval; // Maximum time between checks
+	uint32_t s_creator_os; // Creator OS
+	uint32_t s_rev_level; // Revision level
+	uint16_t s_def_resuid; // Default uid for reserved blocks
+	uint16_t s_def_resgid; // Default gid for reserved blocks
+
+	// Fields for EXT4_DYNAMIC_REV superblocks only.
+	uint32_t s_first_ino; // First non-reserved inode
+	uint16_t s_inode_size; // Size of inode structure
+	uint16_t s_block_group_nr; // Block group number of this superblock
+	uint32_t s_feature_compat; // Compatible feature set
+	uint32_t s_feature_incompat; // Incompatible feature set
+	uint32_t s_feature_ro_compat; // Readonly-compatible feature set
+	uint8_t s_uuid[16]; // 128-bit uuid for volume
+	char s_volume_name[16]; // Volume name
+	char s_last_mounted[64]; // Directory where last mounted
+	uint32_t s_algorithm_usage_bitmap; // For compression
+
+	/*
+	 * Performance hints. Directory preallocation should only
+	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
+	 */
+	uint8_t s_prealloc_blocks; // Number of blocks to try to preallocate
+	uint8_t s_prealloc_dir_blocks; // Number to preallocate for dirs
+	uint16_t s_reserved_gdt_blocks; // Per group desc for online growth
+
+	/*
+	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
+	 */
+	uint8_t s_journal_uuid[16]; // UUID of journal superblock
+	uint32_t s_journal_inum; // Inode number of journal file
+	uint32_t s_journal_dev; // Device number of journal file
+	uint32_t s_last_orphan; // Head of list of inodes to delete
+	uint32_t s_hash_seed[4]; // HTREE hash seed
+	uint8_t s_def_hash_version; // Default hash version to use
+	uint8_t s_jnl_backup_type;
+	uint16_t s_desc_size; // Size of group descriptor
+	uint32_t s_default_mount_opts; // Default mount options
+	uint32_t s_first_meta_bg; // First metablock block group
+	uint32_t s_mkfs_time; // When the filesystem was created
+	uint32_t s_jnl_blocks[17]; // Backup of the journal inode
+
+	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
+	uint32_t s_blocks_count_hi; // Blocks count
+	uint32_t s_r_blocks_count_hi; // Reserved blocks count
+	uint32_t s_free_blocks_count_hi; // Free blocks count
+	uint16_t s_min_extra_isize; // All inodes have at least # bytes
+	uint16_t s_want_extra_isize; // New inodes should reserve # bytes
+	uint32_t s_flags; // Miscellaneous flags
+	uint16_t s_raid_stride; // RAID stride
+	uint16_t s_mmp_interval; // # seconds to wait in MMP checking
+	uint64_t s_mmp_block; // Block for multi-mount protection
+	uint32_t s_raid_stripe_width; // blocks on all data disks (N*stride)
+	uint8_t s_log_groups_per_flex; // FLEX_BG group size
+	uint8_t s_reserved_char_pad;
+	uint16_t s_reserved_pad;
+	uint64_t s_kbytes_written; // Number of lifetime kilobytes written
+	uint32_t s_snapshot_inum; // Inode number of active snapshot
+	uint32_t s_snapshot_id; // Sequential ID of active snapshot
+	uint64_t s_snapshot_r_blocks_count; /* reserved blocks for active snapshot's future use */
+	uint32_t s_snapshot_list; // inode number of the head of the on-disk snapshot list
+
+	//#define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
+	uint32_t s_error_count; // number of fs errors
+	uint32_t s_first_error_time; // First time an error happened
+	uint32_t s_first_error_ino; // Inode involved in first error
+	uint64_t s_first_error_block; // block involved of first error
+	uint8_t s_first_error_func[32]; // Function where the error happened
+	uint32_t s_first_error_line; // Line number where error happened
+	uint32_t s_last_error_time; // Most recent time of an error
+	uint32_t s_last_error_ino; // Inode involved in last error
+	uint32_t s_last_error_line; // Line number where error happened
+	uint64_t s_last_error_block;     /* block involved of last error */
+	uint8_t s_last_error_func[32];  /* function where the error happened */
+	//#define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
+	uint8_t s_mount_opts[64];
+	uint32_t s_reserved[112]; // Padding to the end of the block
+
+} __attribute__((packed)) ext4_superblock_t;
+
+
+#endif
+
+/**
+ * @}
+ */
