include/ext4fs.h

/*
 * (C) Copyright 2011 - 2012 Samsung Electronics
 * EXT4 filesystem implementation in Uboot by
 * Uma Shankar <uma.shankar@samsung.com>
 * Manjunatha C Achar <a.manjunatha@samsung.com>
 *
 * Ext4 Extent data structures are taken from  original ext4 fs code
 * as found in the linux kernel.
 *
 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
 * Written by Alex Tomas <alex@clusterfs.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef __EXT4__
#define __EXT4__
#include <ext_common.h>

struct disk_partition;

#define EXT4_INDEX_FL		0x00001000 /* Inode uses hash tree index */
#define EXT4_TOPDIR_FL		0x00020000 /* Top of directory hierarchies*/
#define EXT4_EXTENTS_FL		0x00080000 /* Inode uses extents */
#define EXT4_EXT_MAGIC			0xf30a

#define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER  0x0001
#define EXT4_FEATURE_RO_COMPAT_LARGE_FILE    0x0002
#define EXT4_FEATURE_RO_COMPAT_BTREE_DIR     0x0004
#define EXT4_FEATURE_RO_COMPAT_HUGE_FILE     0x0008
#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM      0x0010
#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK     0x0020
#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE   0x0040
#define EXT4_FEATURE_RO_COMPAT_QUOTA         0x0100
#define EXT4_FEATURE_RO_COMPAT_BIGALLOC      0x0200
#define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM 0x0400

#define EXT4_FEATURE_INCOMPAT_FILETYPE  0x0002
#define EXT4_FEATURE_INCOMPAT_RECOVER   0x0004
#define EXT4_FEATURE_INCOMPAT_EXTENTS	0x0040
#define EXT4_FEATURE_INCOMPAT_64BIT	0x0080
#define EXT4_FEATURE_INCOMPAT_MMP       0x0100
#define EXT4_FEATURE_INCOMPAT_FLEX_BG   0x0200
#define EXT4_FEATURE_INCOMPAT_CSUM_SEED 0x2000
#define EXT4_FEATURE_INCOMPAT_ENCRYPT   0x10000

#define EXT4_INDIRECT_BLOCKS		12

/*
 * Incompat features supported by this implementation.
 */
#define EXT4_FEATURE_INCOMPAT_SUPP (EXT4_FEATURE_INCOMPAT_FILETYPE | \
				   EXT4_FEATURE_INCOMPAT_RECOVER | \
				   EXT4_FEATURE_INCOMPAT_EXTENTS | \
				   EXT4_FEATURE_INCOMPAT_64BIT | \
				   EXT4_FEATURE_INCOMPAT_FLEX_BG)

/*
 * Incompat features supported by this implementation only in a lazy
 * way, good enough for reading files.
 *
 * - Multi mount protection (mmp) is not supported, but for read-only
 *   we get away with it.
 * - Same for metadata_csum_seed and metadata_csum.
 * - The implementation has also no clue about fscrypt, but it can read
 *   unencrypted files. Reading encrypted files will read garbage.
 */
#define EXT4_FEATURE_INCOMPAT_SUPP_LAZY_RO (EXT4_FEATURE_INCOMPAT_MMP | \
					   EXT4_FEATURE_INCOMPAT_CSUM_SEED | \
					   EXT4_FEATURE_INCOMPAT_ENCRYPT)

/*
 * Read-only compat features we support.
 * If unknown ro compat features are detected, writing to the fs is denied.
 */
#define EXT4_FEATURE_RO_COMPAT_SUPP (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER | \
				    EXT4_FEATURE_RO_COMPAT_LARGE_FILE | \
				    EXT4_FEATURE_RO_COMPAT_HUGE_FILE | \
				    EXT4_FEATURE_RO_COMPAT_GDT_CSUM | \
				    EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
				    EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)

#define EXT4_BG_INODE_UNINIT		0x0001
#define EXT4_BG_BLOCK_UNINIT		0x0002
#define EXT4_BG_INODE_ZEROED		0x0004

/*
 * ext4_inode has i_block array (60 bytes total).
 * The first 12 bytes store ext4_extent_header;
 * the remainder stores an array of ext4_extent.
 */

/*
 * This is the extent on-disk structure.
 * It's used at the bottom of the tree.
 */
struct ext4_extent {
	__le32	ee_block;	/* first logical block extent covers */
	__le16	ee_len;		/* number of blocks covered by extent */
	__le16	ee_start_hi;	/* high 16 bits of physical block */
	__le32	ee_start_lo;	/* low 32 bits of physical block */
};

/*
 * This is index on-disk structure.
 * It's used at all the levels except the bottom.
 */
struct ext4_extent_idx {
	__le32	ei_block;	/* index covers logical blocks from 'block' */
	__le32	ei_leaf_lo;	/* pointer to the physical block of the next *
				 * level. leaf or next index could be there */
	__le16	ei_leaf_hi;	/* high 16 bits of physical block */
	__u16	ei_unused;
};

/* Each block (leaves and indexes), even inode-stored has header. */
struct ext4_extent_header {
	__le16	eh_magic;	/* probably will support different formats */
	__le16	eh_entries;	/* number of valid entries */
	__le16	eh_max;		/* capacity of store in entries */
	__le16	eh_depth;	/* has tree real underlying blocks? */
	__le32	eh_generation;	/* generation of the tree */
};

struct ext_filesystem {
	/* Total Sector of partition */
	uint64_t total_sect;
	/* Block size  of partition */
	uint32_t blksz;
	/* Inode size of partition */
	uint32_t inodesz;
	/* Sectors per Block */
	uint32_t sect_perblk;
	/* Group Descriptor size */
	uint16_t gdsize;
	/* Group Descriptor Block Number */
	uint32_t gdtable_blkno;
	/* Total block groups of partition */
	uint32_t no_blkgrp;
	/* No of blocks required for bgdtable */
	uint32_t no_blk_pergdt;
	/* Superblock */
	struct ext2_sblock *sb;
	/* Block group descritpor table */
	char *gdtable;

	/* Block Bitmap Related */
	unsigned char **blk_bmaps;
	long int curr_blkno;
	uint16_t first_pass_bbmap;

	/* Inode Bitmap Related */
	unsigned char **inode_bmaps;
	int curr_inode_no;
	uint16_t first_pass_ibmap;

	/* Journal Related */

	/* Block Device Descriptor */
	struct blk_desc *dev_desc;
};

struct ext_block_cache {
	char *buf;
	lbaint_t block;
	int size;
};

extern struct ext2_data *ext4fs_root;
extern struct ext2fs_node *ext4fs_file;

#if defined(CONFIG_EXT4_WRITE)
extern struct ext2_inode *g_parent_inode;
extern int gd_index;
extern int gindex;

int ext4fs_init(void);
void ext4fs_deinit(void);
int ext4fs_filename_unlink(char *filename);
int ext4fs_write(const char *fname, const char *buffer,
				 unsigned long sizebytes, int type);
int ext4_write_file(const char *filename, void *buf, loff_t offset, loff_t len,
		    loff_t *actwrite);
int ext4fs_create_link(const char *target, const char *fname);
#endif

struct ext_filesystem *get_fs(void);
int ext4fs_open(const char *filename, loff_t *len);
int ext4fs_read(char *buf, loff_t offset, loff_t len, loff_t *actread);
int ext4fs_mount(void);
void ext4fs_close(void);
void ext4fs_reinit_global(void);
int ext4fs_ls(const char *dirname);
int ext4fs_exists(const char *filename);
int ext4fs_size(const char *filename, loff_t *size);
void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot);
int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf);
void ext4fs_set_blk_dev(struct blk_desc *rbdd, struct disk_partition *info);
long int read_allocated_block(struct ext2_inode *inode, int fileblock,
			      struct ext_block_cache *cache);
int ext4fs_probe(struct blk_desc *fs_dev_desc,
		 struct disk_partition *fs_partition);
int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
		   loff_t *actread);
int ext4_read_superblock(char *buffer);
int ext4fs_uuid(char *uuid_str);
void ext_cache_init(struct ext_block_cache *cache);
void ext_cache_fini(struct ext_block_cache *cache);
int ext_cache_read(struct ext_block_cache *cache, lbaint_t block, int size);
#endif