xref: /openbmc/linux/fs/squashfs/squashfs_fs.h (revision b627b4ed)
1 #ifndef SQUASHFS_FS
2 #define SQUASHFS_FS
3 /*
4  * Squashfs
5  *
6  * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
7  * Phillip Lougher <phillip@lougher.demon.co.uk>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * as published by the Free Software Foundation; either version 2,
12  * or (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
22  *
23  * squashfs_fs.h
24  */
25 
26 #define SQUASHFS_CACHED_FRAGMENTS	CONFIG_SQUASHFS_FRAGMENT_CACHE_SIZE
27 #define SQUASHFS_MAJOR			4
28 #define SQUASHFS_MINOR			0
29 #define SQUASHFS_START			0
30 
31 /* size of metadata (inode and directory) blocks */
32 #define SQUASHFS_METADATA_SIZE		8192
33 #define SQUASHFS_METADATA_LOG		13
34 
35 /* default size of data blocks */
36 #define SQUASHFS_FILE_SIZE		131072
37 #define SQUASHFS_FILE_LOG		17
38 
39 #define SQUASHFS_FILE_MAX_SIZE		1048576
40 #define SQUASHFS_FILE_MAX_LOG		20
41 
42 /* Max number of uids and gids */
43 #define SQUASHFS_IDS			65536
44 
45 /* Max length of filename (not 255) */
46 #define SQUASHFS_NAME_LEN		256
47 
48 #define SQUASHFS_INVALID_FRAG		(0xffffffffU)
49 #define SQUASHFS_INVALID_BLK		(-1LL)
50 
51 /* Filesystem flags */
52 #define SQUASHFS_NOI			0
53 #define SQUASHFS_NOD			1
54 #define SQUASHFS_NOF			3
55 #define SQUASHFS_NO_FRAG		4
56 #define SQUASHFS_ALWAYS_FRAG		5
57 #define SQUASHFS_DUPLICATE		6
58 #define SQUASHFS_EXPORT			7
59 
60 #define SQUASHFS_BIT(flag, bit)		((flag >> bit) & 1)
61 
62 #define SQUASHFS_UNCOMPRESSED_INODES(flags)	SQUASHFS_BIT(flags, \
63 						SQUASHFS_NOI)
64 
65 #define SQUASHFS_UNCOMPRESSED_DATA(flags)	SQUASHFS_BIT(flags, \
66 						SQUASHFS_NOD)
67 
68 #define SQUASHFS_UNCOMPRESSED_FRAGMENTS(flags)	SQUASHFS_BIT(flags, \
69 						SQUASHFS_NOF)
70 
71 #define SQUASHFS_NO_FRAGMENTS(flags)		SQUASHFS_BIT(flags, \
72 						SQUASHFS_NO_FRAG)
73 
74 #define SQUASHFS_ALWAYS_FRAGMENTS(flags)	SQUASHFS_BIT(flags, \
75 						SQUASHFS_ALWAYS_FRAG)
76 
77 #define SQUASHFS_DUPLICATES(flags)		SQUASHFS_BIT(flags, \
78 						SQUASHFS_DUPLICATE)
79 
80 #define SQUASHFS_EXPORTABLE(flags)		SQUASHFS_BIT(flags, \
81 						SQUASHFS_EXPORT)
82 
83 /* Max number of types and file types */
84 #define SQUASHFS_DIR_TYPE		1
85 #define SQUASHFS_REG_TYPE		2
86 #define SQUASHFS_SYMLINK_TYPE		3
87 #define SQUASHFS_BLKDEV_TYPE		4
88 #define SQUASHFS_CHRDEV_TYPE		5
89 #define SQUASHFS_FIFO_TYPE		6
90 #define SQUASHFS_SOCKET_TYPE		7
91 #define SQUASHFS_LDIR_TYPE		8
92 #define SQUASHFS_LREG_TYPE		9
93 #define SQUASHFS_LSYMLINK_TYPE		10
94 #define SQUASHFS_LBLKDEV_TYPE		11
95 #define SQUASHFS_LCHRDEV_TYPE		12
96 #define SQUASHFS_LFIFO_TYPE		13
97 #define SQUASHFS_LSOCKET_TYPE		14
98 
99 /* Flag whether block is compressed or uncompressed, bit is set if block is
100  * uncompressed */
101 #define SQUASHFS_COMPRESSED_BIT		(1 << 15)
102 
103 #define SQUASHFS_COMPRESSED_SIZE(B)	(((B) & ~SQUASHFS_COMPRESSED_BIT) ? \
104 		(B) & ~SQUASHFS_COMPRESSED_BIT :  SQUASHFS_COMPRESSED_BIT)
105 
106 #define SQUASHFS_COMPRESSED(B)		(!((B) & SQUASHFS_COMPRESSED_BIT))
107 
108 #define SQUASHFS_COMPRESSED_BIT_BLOCK	(1 << 24)
109 
110 #define SQUASHFS_COMPRESSED_SIZE_BLOCK(B)	((B) & \
111 						~SQUASHFS_COMPRESSED_BIT_BLOCK)
112 
113 #define SQUASHFS_COMPRESSED_BLOCK(B)	(!((B) & SQUASHFS_COMPRESSED_BIT_BLOCK))
114 
115 /*
116  * Inode number ops.  Inodes consist of a compressed block number, and an
117  * uncompressed offset within that block
118  */
119 #define SQUASHFS_INODE_BLK(A)		((unsigned int) ((A) >> 16))
120 
121 #define SQUASHFS_INODE_OFFSET(A)	((unsigned int) ((A) & 0xffff))
122 
123 #define SQUASHFS_MKINODE(A, B)		((long long)(((long long) (A)\
124 					<< 16) + (B)))
125 
126 /* Translate between VFS mode and squashfs mode */
127 #define SQUASHFS_MODE(A)		((A) & 0xfff)
128 
129 /* fragment and fragment table defines */
130 #define SQUASHFS_FRAGMENT_BYTES(A)	\
131 				((A) * sizeof(struct squashfs_fragment_entry))
132 
133 #define SQUASHFS_FRAGMENT_INDEX(A)	(SQUASHFS_FRAGMENT_BYTES(A) / \
134 					SQUASHFS_METADATA_SIZE)
135 
136 #define SQUASHFS_FRAGMENT_INDEX_OFFSET(A)	(SQUASHFS_FRAGMENT_BYTES(A) % \
137 						SQUASHFS_METADATA_SIZE)
138 
139 #define SQUASHFS_FRAGMENT_INDEXES(A)	((SQUASHFS_FRAGMENT_BYTES(A) + \
140 					SQUASHFS_METADATA_SIZE - 1) / \
141 					SQUASHFS_METADATA_SIZE)
142 
143 #define SQUASHFS_FRAGMENT_INDEX_BYTES(A)	(SQUASHFS_FRAGMENT_INDEXES(A) *\
144 						sizeof(u64))
145 
146 /* inode lookup table defines */
147 #define SQUASHFS_LOOKUP_BYTES(A)	((A) * sizeof(u64))
148 
149 #define SQUASHFS_LOOKUP_BLOCK(A)	(SQUASHFS_LOOKUP_BYTES(A) / \
150 					SQUASHFS_METADATA_SIZE)
151 
152 #define SQUASHFS_LOOKUP_BLOCK_OFFSET(A)	(SQUASHFS_LOOKUP_BYTES(A) % \
153 					SQUASHFS_METADATA_SIZE)
154 
155 #define SQUASHFS_LOOKUP_BLOCKS(A)	((SQUASHFS_LOOKUP_BYTES(A) + \
156 					SQUASHFS_METADATA_SIZE - 1) / \
157 					SQUASHFS_METADATA_SIZE)
158 
159 #define SQUASHFS_LOOKUP_BLOCK_BYTES(A)	(SQUASHFS_LOOKUP_BLOCKS(A) *\
160 					sizeof(u64))
161 
162 /* uid/gid lookup table defines */
163 #define SQUASHFS_ID_BYTES(A)		((A) * sizeof(unsigned int))
164 
165 #define SQUASHFS_ID_BLOCK(A)		(SQUASHFS_ID_BYTES(A) / \
166 					SQUASHFS_METADATA_SIZE)
167 
168 #define SQUASHFS_ID_BLOCK_OFFSET(A)	(SQUASHFS_ID_BYTES(A) % \
169 					SQUASHFS_METADATA_SIZE)
170 
171 #define SQUASHFS_ID_BLOCKS(A)		((SQUASHFS_ID_BYTES(A) + \
172 					SQUASHFS_METADATA_SIZE - 1) / \
173 					SQUASHFS_METADATA_SIZE)
174 
175 #define SQUASHFS_ID_BLOCK_BYTES(A)	(SQUASHFS_ID_BLOCKS(A) *\
176 					sizeof(u64))
177 
178 /* cached data constants for filesystem */
179 #define SQUASHFS_CACHED_BLKS		8
180 
181 #define SQUASHFS_MAX_FILE_SIZE_LOG	64
182 
183 #define SQUASHFS_MAX_FILE_SIZE		(1LL << \
184 					(SQUASHFS_MAX_FILE_SIZE_LOG - 2))
185 
186 #define SQUASHFS_MARKER_BYTE		0xff
187 
188 /* meta index cache */
189 #define SQUASHFS_META_INDEXES	(SQUASHFS_METADATA_SIZE / sizeof(unsigned int))
190 #define SQUASHFS_META_ENTRIES	127
191 #define SQUASHFS_META_SLOTS	8
192 
193 struct meta_entry {
194 	u64			data_block;
195 	unsigned int		index_block;
196 	unsigned short		offset;
197 	unsigned short		pad;
198 };
199 
200 struct meta_index {
201 	unsigned int		inode_number;
202 	unsigned int		offset;
203 	unsigned short		entries;
204 	unsigned short		skip;
205 	unsigned short		locked;
206 	unsigned short		pad;
207 	struct meta_entry	meta_entry[SQUASHFS_META_ENTRIES];
208 };
209 
210 
211 /*
212  * definitions for structures on disk
213  */
214 #define ZLIB_COMPRESSION	 1
215 
216 struct squashfs_super_block {
217 	__le32			s_magic;
218 	__le32			inodes;
219 	__le32			mkfs_time;
220 	__le32			block_size;
221 	__le32			fragments;
222 	__le16			compression;
223 	__le16			block_log;
224 	__le16			flags;
225 	__le16			no_ids;
226 	__le16			s_major;
227 	__le16			s_minor;
228 	__le64			root_inode;
229 	__le64			bytes_used;
230 	__le64			id_table_start;
231 	__le64			xattr_table_start;
232 	__le64			inode_table_start;
233 	__le64			directory_table_start;
234 	__le64			fragment_table_start;
235 	__le64			lookup_table_start;
236 };
237 
238 struct squashfs_dir_index {
239 	__le32			index;
240 	__le32			start_block;
241 	__le32			size;
242 	unsigned char		name[0];
243 };
244 
245 struct squashfs_base_inode {
246 	__le16			inode_type;
247 	__le16			mode;
248 	__le16			uid;
249 	__le16			guid;
250 	__le32			mtime;
251 	__le32	 		inode_number;
252 };
253 
254 struct squashfs_ipc_inode {
255 	__le16			inode_type;
256 	__le16			mode;
257 	__le16			uid;
258 	__le16			guid;
259 	__le32			mtime;
260 	__le32	 		inode_number;
261 	__le32			nlink;
262 };
263 
264 struct squashfs_dev_inode {
265 	__le16			inode_type;
266 	__le16			mode;
267 	__le16			uid;
268 	__le16			guid;
269 	__le32			mtime;
270 	__le32	 		inode_number;
271 	__le32			nlink;
272 	__le32			rdev;
273 };
274 
275 struct squashfs_symlink_inode {
276 	__le16			inode_type;
277 	__le16			mode;
278 	__le16			uid;
279 	__le16			guid;
280 	__le32			mtime;
281 	__le32	 		inode_number;
282 	__le32			nlink;
283 	__le32			symlink_size;
284 	char			symlink[0];
285 };
286 
287 struct squashfs_reg_inode {
288 	__le16			inode_type;
289 	__le16			mode;
290 	__le16			uid;
291 	__le16			guid;
292 	__le32			mtime;
293 	__le32	 		inode_number;
294 	__le32			start_block;
295 	__le32			fragment;
296 	__le32			offset;
297 	__le32			file_size;
298 	__le16			block_list[0];
299 };
300 
301 struct squashfs_lreg_inode {
302 	__le16			inode_type;
303 	__le16			mode;
304 	__le16			uid;
305 	__le16			guid;
306 	__le32			mtime;
307 	__le32	 		inode_number;
308 	__le64			start_block;
309 	__le64			file_size;
310 	__le64			sparse;
311 	__le32			nlink;
312 	__le32			fragment;
313 	__le32			offset;
314 	__le32			xattr;
315 	__le16			block_list[0];
316 };
317 
318 struct squashfs_dir_inode {
319 	__le16			inode_type;
320 	__le16			mode;
321 	__le16			uid;
322 	__le16			guid;
323 	__le32			mtime;
324 	__le32	 		inode_number;
325 	__le32			start_block;
326 	__le32			nlink;
327 	__le16			file_size;
328 	__le16			offset;
329 	__le32			parent_inode;
330 };
331 
332 struct squashfs_ldir_inode {
333 	__le16			inode_type;
334 	__le16			mode;
335 	__le16			uid;
336 	__le16			guid;
337 	__le32			mtime;
338 	__le32	 		inode_number;
339 	__le32			nlink;
340 	__le32			file_size;
341 	__le32			start_block;
342 	__le32			parent_inode;
343 	__le16			i_count;
344 	__le16			offset;
345 	__le32			xattr;
346 	struct squashfs_dir_index	index[0];
347 };
348 
349 union squashfs_inode {
350 	struct squashfs_base_inode		base;
351 	struct squashfs_dev_inode		dev;
352 	struct squashfs_symlink_inode		symlink;
353 	struct squashfs_reg_inode		reg;
354 	struct squashfs_lreg_inode		lreg;
355 	struct squashfs_dir_inode		dir;
356 	struct squashfs_ldir_inode		ldir;
357 	struct squashfs_ipc_inode		ipc;
358 };
359 
360 struct squashfs_dir_entry {
361 	__le16			offset;
362 	__le16			inode_number;
363 	__le16			type;
364 	__le16			size;
365 	char			name[0];
366 };
367 
368 struct squashfs_dir_header {
369 	__le32			count;
370 	__le32			start_block;
371 	__le32			inode_number;
372 };
373 
374 struct squashfs_fragment_entry {
375 	__le64			start_block;
376 	__le32			size;
377 	unsigned int		unused;
378 };
379 
380 #endif
381