1 /*
2  * (C) Copyright 2011 - 2012 Samsung Electronics
3  * EXT4 filesystem implementation in Uboot by
4  * Uma Shankar <uma.shankar@samsung.com>
5  * Manjunatha C Achar <a.manjunatha@samsung.com>
6  *
7  * Ext4 Extent data structures are taken from  original ext4 fs code
8  * as found in the linux kernel.
9  *
10  * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
11  * Written by Alex Tomas <alex@clusterfs.com>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License version 2 as
15  * published by the Free Software Foundation.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25  */
26 
27 #ifndef __EXT4__
28 #define __EXT4__
29 #include <ext_common.h>
30 #include <fs.h>
31 
32 struct disk_partition;
33 
34 #define EXT4_INDEX_FL		0x00001000 /* Inode uses hash tree index */
35 #define EXT4_TOPDIR_FL		0x00020000 /* Top of directory hierarchies*/
36 #define EXT4_EXTENTS_FL		0x00080000 /* Inode uses extents */
37 #define EXT4_EXT_MAGIC			0xf30a
38 
39 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER  0x0001
40 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE    0x0002
41 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR     0x0004
42 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE     0x0008
43 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM      0x0010
44 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK     0x0020
45 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE   0x0040
46 #define EXT4_FEATURE_RO_COMPAT_QUOTA         0x0100
47 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC      0x0200
48 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM 0x0400
49 
50 #define EXT4_FEATURE_INCOMPAT_FILETYPE  0x0002
51 #define EXT4_FEATURE_INCOMPAT_RECOVER   0x0004
52 #define EXT4_FEATURE_INCOMPAT_EXTENTS	0x0040
53 #define EXT4_FEATURE_INCOMPAT_64BIT	0x0080
54 #define EXT4_FEATURE_INCOMPAT_MMP       0x0100
55 #define EXT4_FEATURE_INCOMPAT_FLEX_BG   0x0200
56 #define EXT4_FEATURE_INCOMPAT_CSUM_SEED 0x2000
57 #define EXT4_FEATURE_INCOMPAT_ENCRYPT   0x10000
58 
59 #define EXT4_INDIRECT_BLOCKS		12
60 
61 /*
62  * Incompat features supported by this implementation.
63  */
64 #define EXT4_FEATURE_INCOMPAT_SUPP (EXT4_FEATURE_INCOMPAT_FILETYPE | \
65 				   EXT4_FEATURE_INCOMPAT_RECOVER | \
66 				   EXT4_FEATURE_INCOMPAT_EXTENTS | \
67 				   EXT4_FEATURE_INCOMPAT_64BIT | \
68 				   EXT4_FEATURE_INCOMPAT_FLEX_BG)
69 
70 /*
71  * Incompat features supported by this implementation only in a lazy
72  * way, good enough for reading files.
73  *
74  * - Multi mount protection (mmp) is not supported, but for read-only
75  *   we get away with it.
76  * - Same for metadata_csum_seed and metadata_csum.
77  * - The implementation has also no clue about fscrypt, but it can read
78  *   unencrypted files. Reading encrypted files will read garbage.
79  */
80 #define EXT4_FEATURE_INCOMPAT_SUPP_LAZY_RO (EXT4_FEATURE_INCOMPAT_MMP | \
81 					   EXT4_FEATURE_INCOMPAT_CSUM_SEED | \
82 					   EXT4_FEATURE_INCOMPAT_ENCRYPT)
83 
84 /*
85  * Read-only compat features we support.
86  * If unknown ro compat features are detected, writing to the fs is denied.
87  */
88 #define EXT4_FEATURE_RO_COMPAT_SUPP (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER | \
89 				    EXT4_FEATURE_RO_COMPAT_LARGE_FILE | \
90 				    EXT4_FEATURE_RO_COMPAT_HUGE_FILE | \
91 				    EXT4_FEATURE_RO_COMPAT_GDT_CSUM | \
92 				    EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
93 				    EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)
94 
95 #define EXT4_BG_INODE_UNINIT		0x0001
96 #define EXT4_BG_BLOCK_UNINIT		0x0002
97 #define EXT4_BG_INODE_ZEROED		0x0004
98 
99 /*
100  * ext4_inode has i_block array (60 bytes total).
101  * The first 12 bytes store ext4_extent_header;
102  * the remainder stores an array of ext4_extent.
103  */
104 
105 /*
106  * This is the extent on-disk structure.
107  * It's used at the bottom of the tree.
108  */
109 struct ext4_extent {
110 	__le32	ee_block;	/* first logical block extent covers */
111 	__le16	ee_len;		/* number of blocks covered by extent */
112 	__le16	ee_start_hi;	/* high 16 bits of physical block */
113 	__le32	ee_start_lo;	/* low 32 bits of physical block */
114 };
115 
116 /*
117  * This is index on-disk structure.
118  * It's used at all the levels except the bottom.
119  */
120 struct ext4_extent_idx {
121 	__le32	ei_block;	/* index covers logical blocks from 'block' */
122 	__le32	ei_leaf_lo;	/* pointer to the physical block of the next *
123 				 * level. leaf or next index could be there */
124 	__le16	ei_leaf_hi;	/* high 16 bits of physical block */
125 	__u16	ei_unused;
126 };
127 
128 /* Each block (leaves and indexes), even inode-stored has header. */
129 struct ext4_extent_header {
130 	__le16	eh_magic;	/* probably will support different formats */
131 	__le16	eh_entries;	/* number of valid entries */
132 	__le16	eh_max;		/* capacity of store in entries */
133 	__le16	eh_depth;	/* has tree real underlying blocks? */
134 	__le32	eh_generation;	/* generation of the tree */
135 };
136 
137 struct ext_filesystem {
138 	/* Total Sector of partition */
139 	uint64_t total_sect;
140 	/* Block size  of partition */
141 	uint32_t blksz;
142 	/* Inode size of partition */
143 	uint32_t inodesz;
144 	/* Sectors per Block */
145 	uint32_t sect_perblk;
146 	/* Group Descriptor size */
147 	uint16_t gdsize;
148 	/* Group Descriptor Block Number */
149 	uint32_t gdtable_blkno;
150 	/* Total block groups of partition */
151 	uint32_t no_blkgrp;
152 	/* No of blocks required for bgdtable */
153 	uint32_t no_blk_pergdt;
154 	/* Superblock */
155 	struct ext2_sblock *sb;
156 	/* Block group descritpor table */
157 	char *gdtable;
158 
159 	/* Block Bitmap Related */
160 	unsigned char **blk_bmaps;
161 	long int curr_blkno;
162 	uint16_t first_pass_bbmap;
163 
164 	/* Inode Bitmap Related */
165 	unsigned char **inode_bmaps;
166 	int curr_inode_no;
167 	uint16_t first_pass_ibmap;
168 
169 	/* Journal Related */
170 
171 	/* Block Device Descriptor */
172 	struct blk_desc *dev_desc;
173 };
174 
175 struct ext_block_cache {
176 	char *buf;
177 	lbaint_t block;
178 	int size;
179 };
180 
181 extern struct ext2_data *ext4fs_root;
182 extern struct ext2fs_node *ext4fs_file;
183 
184 #if defined(CONFIG_EXT4_WRITE)
185 extern struct ext2_inode *g_parent_inode;
186 extern int gd_index;
187 extern int gindex;
188 
189 int ext4fs_init(void);
190 void ext4fs_deinit(void);
191 int ext4fs_filename_unlink(char *filename);
192 int ext4fs_write(const char *fname, const char *buffer,
193 				 unsigned long sizebytes, int type);
194 int ext4_write_file(const char *filename, void *buf, loff_t offset, loff_t len,
195 		    loff_t *actwrite);
196 int ext4fs_create_link(const char *target, const char *fname);
197 #endif
198 
199 struct ext_filesystem *get_fs(void);
200 int ext4fs_open(const char *filename, loff_t *len);
201 int ext4fs_read(char *buf, loff_t offset, loff_t len, loff_t *actread);
202 int ext4fs_mount(void);
203 void ext4fs_close(void);
204 void ext4fs_reinit_global(void);
205 int ext4fs_ls(const char *dirname);
206 int ext4fs_exists(const char *filename);
207 int ext4fs_size(const char *filename, loff_t *size);
208 void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot);
209 int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf);
210 void ext4fs_set_blk_dev(struct blk_desc *rbdd, struct disk_partition *info);
211 long int read_allocated_block(struct ext2_inode *inode, int fileblock,
212 			      struct ext_block_cache *cache);
213 int ext4fs_probe(struct blk_desc *fs_dev_desc,
214 		 struct disk_partition *fs_partition);
215 int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
216 		   loff_t *actread);
217 int ext4_read_superblock(char *buffer);
218 int ext4fs_uuid(char *uuid_str);
219 void ext_cache_init(struct ext_block_cache *cache);
220 void ext_cache_fini(struct ext_block_cache *cache);
221 int ext_cache_read(struct ext_block_cache *cache, lbaint_t block, int size);
222 int ext4fs_opendir(const char *dirname, struct fs_dir_stream **dirsp);
223 int ext4fs_readdir(struct fs_dir_stream *dirs, struct fs_dirent **dentp);
224 void ext4fs_closedir(struct fs_dir_stream *dirs);
225 #endif
226