ac6e464cb2
The ext4 implementation has been taken from U-Boot with some changes: - No global variables to allow for multiple filesystems to be mounted and multiple files to be open. - remove fs internal link following and use the barebox link implementation. - remove write support. This is incomplete in U-Boot, so I decided to skip this for now. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
128 lines
3.8 KiB
C
128 lines
3.8 KiB
C
/*
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* (C) Copyright 2011 - 2012 Samsung Electronics
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* EXT4 filesystem implementation in Uboot by
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* Uma Shankar <uma.shankar@samsung.com>
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* Manjunatha C Achar <a.manjunatha@samsung.com>
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*
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* Ext4 Extent data structures are taken from original ext4 fs code
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* as found in the linux kernel.
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*
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* Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
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* Written by Alex Tomas <alex@clusterfs.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#ifndef __EXT4__
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#define __EXT4__
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#define EXT4_EXTENTS_FL 0x00080000 /* Inode uses extents */
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#define EXT4_EXT_MAGIC 0xf30a
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#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
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#define EXT4_FEATURE_INCOMPAT_EXTENTS 0x0040
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#define EXT4_INDIRECT_BLOCKS 12
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#define EXT4_BG_INODE_UNINIT 0x0001
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#define EXT4_BG_BLOCK_UNINIT 0x0002
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#define EXT4_BG_INODE_ZEROED 0x0004
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/*
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* ext4_inode has i_block array (60 bytes total).
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* The first 12 bytes store ext4_extent_header;
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* the remainder stores an array of ext4_extent.
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*/
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/*
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* This is the extent on-disk structure.
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* It's used at the bottom of the tree.
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*/
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struct ext4_extent {
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__le32 ee_block; /* first logical block extent covers */
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__le16 ee_len; /* number of blocks covered by extent */
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__le16 ee_start_hi; /* high 16 bits of physical block */
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__le32 ee_start_lo; /* low 32 bits of physical block */
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};
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/*
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* This is index on-disk structure.
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* It's used at all the levels except the bottom.
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*/
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struct ext4_extent_idx {
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__le32 ei_block; /* index covers logical blocks from 'block' */
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__le32 ei_leaf_lo; /* pointer to the physical block of the next *
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* level. leaf or next index could be there */
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__le16 ei_leaf_hi; /* high 16 bits of physical block */
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__u16 ei_unused;
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};
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/* Each block (leaves and indexes), even inode-stored has header. */
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struct ext4_extent_header {
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__le16 eh_magic; /* probably will support different formats */
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__le16 eh_entries; /* number of valid entries */
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__le16 eh_max; /* capacity of store in entries */
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__le16 eh_depth; /* has tree real underlying blocks? */
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__le32 eh_generation; /* generation of the tree */
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};
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struct ext_filesystem {
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/* Total Sector of partition */
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uint64_t total_sect;
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/* Block size of partition */
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uint32_t blksz;
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/* Inode size of partition */
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uint32_t inodesz;
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/* Sectors per Block */
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uint32_t sect_perblk;
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/* Group Descriptor Block Number */
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uint32_t gdtable_blkno;
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/* Total block groups of partition */
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uint32_t no_blkgrp;
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/* No of blocks required for bgdtable */
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uint32_t no_blk_pergdt;
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/* Superblock */
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struct ext2_sblock *sb;
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/* Block group descritpor table */
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struct ext2_block_group *bgd;
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char *gdtable;
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/* Block Bitmap Related */
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unsigned char **blk_bmaps;
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long int curr_blkno;
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uint16_t first_pass_bbmap;
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/* Inode Bitmap Related */
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unsigned char **inode_bmaps;
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int curr_inode_no;
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uint16_t first_pass_ibmap;
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/* Journal Related */
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/* Block Device Descriptor */
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struct cdev *cdev;
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struct ext2_data *data;
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struct device_d *dev;
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};
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struct ext2fs_node;
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int ext4fs_open(struct ext2_data *data, const char *filename, struct ext2fs_node **inode);
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int ext4fs_read(char *buf, unsigned len);
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int ext4fs_mount(struct ext_filesystem *fs);
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void ext4fs_umount(struct ext_filesystem *fs);
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char *ext4fs_read_symlink(struct ext2fs_node *node);
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void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot);
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int ext4fs_devread(struct ext_filesystem *fs, int sector, int byte_offset, int byte_len, char *buf);
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long int read_allocated_block(struct ext2fs_node *node, int fileblock);
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#endif
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