u-boot/include/ext4fs.h
Jean-Jacques Hiblot 5efc0686ee fs: ext4: Add support for the creation of symbolic links
Re-use the functions used to write/create a file, to support creation of a
symbolic link.
The difference with a regular file are small:
- The inode mode is flagged with S_IFLNK instead of S_IFREG
- The ext2_dirent's filetype is FILETYPE_SYMLINK instead of FILETYPE_REG
- Instead of storing the content of a file in allocated blocks, the path
to the target is stored. And if the target's path is short enough, no block
is allocated and the target's path is stored in ext2_inode.b.symlink

As with regulars files, if a file/symlink with the same name exits, it is
unlinked first and then re-created.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
[trini: Fix ext4 env code]
Signed-off-by: Tom Rini <trini@konsulko.com>
2019-04-09 20:03:30 -04:00

168 lines
5.4 KiB
C

/*
* (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>
#define EXT4_INDEX_FL 0x00001000 /* Inode uses hash tree index */
#define EXT4_EXTENTS_FL 0x00080000 /* Inode uses extents */
#define EXT4_EXT_MAGIC 0xf30a
#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
#define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM 0x0400
#define EXT4_FEATURE_INCOMPAT_EXTENTS 0x0040
#define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
#define EXT4_INDIRECT_BLOCKS 12
#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(unsigned part_length);
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, disk_partition_t *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,
disk_partition_t *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