1 | /* |
2 | * Copyright (c) 2008 Apple Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
9 | * compliance with the License. The rights granted to you under the License |
10 | * may not be used to create, or enable the creation or redistribution of, |
11 | * unlawful or unlicensed copies of an Apple operating system, or to |
12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
18 | * The Original Code and all software distributed under the License are |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
23 | * Please see the License for the specific language governing rights and |
24 | * limitations under the License. |
25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | #ifndef _SYS_DECMPFS_H_ |
29 | #define _SYS_DECMPFS_H_ 1 |
30 | |
31 | #include <stdbool.h> |
32 | #include <sys/kdebug.h> |
33 | #include <sys/kernel_types.h> |
34 | #include <sys/vnode.h> |
35 | #include <sys/cdefs.h> |
36 | |
37 | __BEGIN_DECLS |
38 | /* |
39 | * Please switch on @DECMPFS_ENABLE_KDEBUG_TRACES to enable tracepoints. |
40 | * Tracepoints are compiled out by default to eliminate any overhead due to |
41 | * kernel tracing. |
42 | * |
43 | * #define DECMPFS_ENABLE_KDEBUG_TRACES 1 |
44 | */ |
45 | #if DECMPFS_ENABLE_KDEBUG_TRACES |
46 | #define DECMPFS_EMIT_TRACE_ENTRY(D, ...) \ |
47 | KDBG_FILTERED((D) | DBG_FUNC_START, ## __VA_ARGS__) |
48 | #define DECMPFS_EMIT_TRACE_RETURN(D, ...) \ |
49 | KDBG_FILTERED((D) | DBG_FUNC_END, ##__VA_ARGS__) |
50 | #else |
51 | #define DECMPFS_EMIT_TRACE_ENTRY(D, ...) do {} while (0) |
52 | #define DECMPFS_EMIT_TRACE_RETURN(D, ...) do {} while (0) |
53 | #endif /* DECMPFS_ENABLE_KDEBUG_TRACES */ |
54 | |
55 | /* |
56 | * KERNEL_DEBUG related definitions for decmpfs. |
57 | * |
58 | * Please NOTE: The Class DBG_FSYSTEM = 3, and Subclass DBG_DECMP = 0x12, so |
59 | * these debug codes are of the form 0x0312nnnn. |
60 | */ |
61 | #define DECMPDBG_CODE(code) FSDBG_CODE(DBG_DECMP, code) |
62 | |
63 | enum { |
64 | DECMPDBG_DECOMPRESS_FILE = DECMPDBG_CODE(0),/* 0x03120000 */ |
65 | = DECMPDBG_CODE(1),/* 0x03120004 */ |
66 | DECMPDBG_FETCH_UNCOMPRESSED_DATA = DECMPDBG_CODE(2),/* 0x03120008 */ |
67 | DECMPDBG_FREE_COMPRESSED_DATA = DECMPDBG_CODE(4),/* 0x03120010 */ |
68 | DECMPDBG_FILE_IS_COMPRESSED = DECMPDBG_CODE(5),/* 0x03120014 */ |
69 | }; |
70 | |
71 | #define MAX_DECMPFS_XATTR_SIZE 3802 |
72 | |
73 | /* |
74 | * NOTE: decmpfs can only be used by thread-safe filesystems |
75 | */ |
76 | |
77 | #define DECMPFS_MAGIC 0x636d7066 /* cmpf */ |
78 | |
79 | #define DECMPFS_XATTR_NAME "com.apple.decmpfs" /* extended attribute to use for decmpfs */ |
80 | |
81 | /* |
82 | * This single field is to be interpreted differently depending on the |
83 | * corresponding item type. |
84 | * For regular files: it is a 64bits-encoded logical size |
85 | * For directories: it is a 64bits-encoded number of children (ie st_nlink - 2) |
86 | * For packages: it is 40bits encoded size and 24bits number of children at root |
87 | */ |
88 | typedef struct __attribute__((packed)) { |
89 | uint64_t value; |
90 | } decmpfs_raw_item_size; |
91 | |
92 | #define DECMPFS_PKG_SIZE_MASK 0x000000ffffffffffULL |
93 | #define DECMPFS_PKG_COUNT_MASK 0xffffff |
94 | #define DECMPFS_PKG_CHLD_COUNT_SHIFT 40 |
95 | |
96 | #define DECMPFS_PKG_SIZE(x) ((x).value & DECMPFS_PKG_SIZE_MASK) |
97 | #define DECMPFS_PKG_CHLD_COUNT(x) ((uint32_t)(((x).value >> DECMPFS_PKG_CHLD_COUNT_SHIFT) & DECMPFS_PKG_COUNT_MASK)) |
98 | #define DECMPFS_PKG_VALUE_FROM_SIZE_COUNT(size, count) \ |
99 | (((size) & DECMPFS_PKG_SIZE_MASK) | ((uint64_t)(count) << DECMPFS_PKG_CHLD_COUNT_SHIFT)) |
100 | |
101 | /* Dataless file or directory */ |
102 | #define DATALESS_CMPFS_TYPE 0x80000001 |
103 | |
104 | /* Dataless package, with number of root children and total size encoded on disk */ |
105 | #define DATALESS_PKG_CMPFS_TYPE 0x80000002 |
106 | |
107 | |
108 | static inline bool |
109 | decmpfs_type_is_dataless(uint32_t cmp_type) |
110 | { |
111 | return cmp_type == DATALESS_CMPFS_TYPE || cmp_type == DATALESS_PKG_CMPFS_TYPE; |
112 | } |
113 | |
114 | typedef struct __attribute__((packed)) { |
115 | /* this structure represents the xattr on disk; the fields below are little-endian */ |
116 | uint32_t ; |
117 | uint32_t ; /* see the enum below */ |
118 | union { |
119 | uint64_t uncompressed_size; /* compatility accessor */ |
120 | decmpfs_raw_item_size _size; |
121 | }; |
122 | unsigned char [0]; /* the bytes of the attribute after the header */ |
123 | } ; |
124 | |
125 | typedef struct __attribute__((packed)) { |
126 | /* this structure represents the xattr in memory; the fields below are host-endian */ |
127 | uint32_t ; |
128 | uint32_t ; |
129 | uint32_t ; |
130 | union { |
131 | /* |
132 | * although uncompressed_size remains available for backward-compatibility reasons |
133 | * the uncompressed size and nchildren should be accessed using the inline helpers |
134 | * below |
135 | */ |
136 | uint64_t uncompressed_size; |
137 | decmpfs_raw_item_size _size; |
138 | }; |
139 | unsigned char [0]; /* the bytes of the attribute after the header */ |
140 | } ; |
141 | |
142 | static inline uint64_t |
143 | decmpfs_get_uncompressed_size(const decmpfs_header *hdr) |
144 | { |
145 | if (hdr->compression_magic == DECMPFS_MAGIC && hdr->compression_type == DATALESS_PKG_CMPFS_TYPE) { |
146 | return DECMPFS_PKG_SIZE(hdr->_size); |
147 | } |
148 | |
149 | return hdr->uncompressed_size; |
150 | } |
151 | |
152 | static inline uint32_t |
153 | decmpfs_get_directory_entries(const decmpfs_header *hdr) |
154 | { |
155 | if (hdr->compression_magic == DECMPFS_MAGIC && hdr->compression_type == DATALESS_PKG_CMPFS_TYPE) { |
156 | return DECMPFS_PKG_CHLD_COUNT(hdr->_size); |
157 | } |
158 | |
159 | return (uint32_t)hdr->uncompressed_size; |
160 | } |
161 | |
162 | /* compression_type values */ |
163 | enum { |
164 | CMP_Type1 = 1,/* uncompressed data in xattr */ |
165 | |
166 | /* additional types defined in AppleFSCompression project */ |
167 | |
168 | CMP_MAX = 255/* Highest compression_type supported */ |
169 | }; |
170 | |
171 | typedef struct { |
172 | void *buf; |
173 | user_ssize_t size; |
174 | } decmpfs_vector; |
175 | |
176 | __END_DECLS |
177 | |
178 | #ifdef KERNEL |
179 | |
180 | #ifdef XNU_KERNEL_PRIVATE |
181 | |
182 | #include <kern/locks.h> |
183 | |
184 | __BEGIN_DECLS |
185 | |
186 | struct decmpfs_cnode { |
187 | uint8_t cmp_state; |
188 | uint8_t cmp_minimal_xattr; /* if non-zero, this file's com.apple.decmpfs xattr contained only the minimal decmpfs_disk_header */ |
189 | uint32_t cmp_type; |
190 | uint32_t lockcount; |
191 | void *lockowner; /* cnode's lock owner (if a thread is currently holding an exclusive lock) */ |
192 | uint64_t uncompressed_size __attribute__((aligned(8))); |
193 | uint64_t nchildren __attribute__((aligned(8))); /* for dataless directories (incl. packages) */ |
194 | uint64_t total_size __attribute__((aligned(8)));/* for dataless directories (incl. packages) */ |
195 | uint64_t decompression_flags; |
196 | lck_rw_t compressed_data_lock; |
197 | }; |
198 | |
199 | __END_DECLS |
200 | |
201 | #endif // XNU_KERNEL_PRIVATE |
202 | |
203 | __BEGIN_DECLS |
204 | |
205 | typedef struct decmpfs_cnode decmpfs_cnode; |
206 | |
207 | /* return values from decmpfs_file_is_compressed */ |
208 | enum { |
209 | FILE_TYPE_UNKNOWN = 0, |
210 | FILE_IS_NOT_COMPRESSED = 1, |
211 | FILE_IS_COMPRESSED = 2, |
212 | FILE_IS_CONVERTING = 3/* file is converting from compressed to decompressed */ |
213 | }; |
214 | |
215 | /* vfs entrypoints */ |
216 | extern vfs_context_t decmpfs_ctx; |
217 | |
218 | /* client filesystem entrypoints */ |
219 | void decmpfs_init(void); |
220 | decmpfs_cnode *decmpfs_cnode_alloc(void); |
221 | void decmpfs_cnode_free(decmpfs_cnode *dp); |
222 | void decmpfs_cnode_init(decmpfs_cnode *cp); |
223 | void decmpfs_cnode_destroy(decmpfs_cnode *cp); |
224 | |
225 | int decmpfs_hides_rsrc(vfs_context_t ctx, decmpfs_cnode *cp); |
226 | int decmpfs_hides_xattr(vfs_context_t ctx, decmpfs_cnode *cp, const char *xattr); |
227 | |
228 | bool decmpfs_trylock_compressed_data(decmpfs_cnode *cp, int exclusive); |
229 | void decmpfs_lock_compressed_data(decmpfs_cnode *cp, int exclusive); |
230 | void decmpfs_unlock_compressed_data(decmpfs_cnode *cp, int exclusive); |
231 | |
232 | uint32_t decmpfs_cnode_get_vnode_state(decmpfs_cnode *cp); |
233 | void decmpfs_cnode_set_vnode_state(decmpfs_cnode *cp, uint32_t state, int skiplock); |
234 | uint64_t decmpfs_cnode_get_vnode_cached_size(decmpfs_cnode *cp); |
235 | uint64_t decmpfs_cnode_get_vnode_cached_nchildren(decmpfs_cnode *cp); |
236 | uint64_t decmpfs_cnode_get_vnode_cached_total_size(decmpfs_cnode *cp); |
237 | void decmpfs_cnode_set_vnode_cached_size(decmpfs_cnode *cp, uint64_t size); |
238 | void decmpfs_cnode_set_vnode_cached_nchildren(decmpfs_cnode *cp, uint64_t nchildren); |
239 | void decmpfs_cnode_set_vnode_cached_total_size(decmpfs_cnode *cp, uint64_t total_sz); |
240 | uint32_t decmpfs_cnode_cmp_type(decmpfs_cnode *cp); |
241 | |
242 | int decmpfs_file_is_compressed(vnode_t vp, decmpfs_cnode *cp); |
243 | errno_t decmpfs_validate_compressed_file(vnode_t vp, decmpfs_cnode *cp); |
244 | int decmpfs_decompress_file(vnode_t vp, decmpfs_cnode *cp, off_t toSize, int truncate_okay, int skiplock); /* if toSize == -1, decompress the entire file */ |
245 | int decmpfs_free_compressed_data(vnode_t vp, decmpfs_cnode *cp); |
246 | int decmpfs_update_attributes(vnode_t vp, struct vnode_attr *vap); |
247 | /* the following two routines will set *is_compressed to 0 if the file was converted from compressed to decompressed before data could be fetched from the decompressor */ |
248 | errno_t decmpfs_pagein_compressed(struct vnop_pagein_args *ap, int *is_compressed, decmpfs_cnode *cp); |
249 | errno_t decmpfs_read_compressed(struct vnop_read_args *ap, int *is_compressed, decmpfs_cnode *cp); |
250 | |
251 | /* types shared between the kernel and kexts */ |
252 | typedef int (*decmpfs_validate_compressed_file_func)(vnode_t vp, vfs_context_t ctx, decmpfs_header *hdr); |
253 | typedef void (*decmpfs_adjust_fetch_region_func)(vnode_t vp, vfs_context_t ctx, decmpfs_header *hdr, off_t *offset, user_ssize_t *size); |
254 | typedef int (*decmpfs_fetch_uncompressed_data_func)(vnode_t vp, vfs_context_t ctx, decmpfs_header *hdr, off_t offset, user_ssize_t size, int nvec, decmpfs_vector *vec, uint64_t *bytes_read); |
255 | typedef int (*decmpfs_free_compressed_data_func)(vnode_t vp, vfs_context_t ctx, decmpfs_header *hdr); |
256 | typedef uint64_t (*decmpfs_get_decompression_flags_func)(vnode_t vp, vfs_context_t ctx, decmpfs_header *hdr); // returns flags from the DECMPFS_FLAGS enumeration below |
257 | |
258 | enum { |
259 | DECMPFS_FLAGS_FORCE_FLUSH_ON_DECOMPRESS = 1 << 0, |
260 | }; |
261 | |
262 | /* Versions that are supported for binary compatibility */ |
263 | #define DECMPFS_REGISTRATION_VERSION_V1 1 |
264 | #define DECMPFS_REGISTRATION_VERSION_V3 3 |
265 | |
266 | #define DECMPFS_REGISTRATION_VERSION (DECMPFS_REGISTRATION_VERSION_V3) |
267 | |
268 | typedef struct { |
269 | int decmpfs_registration; |
270 | decmpfs_validate_compressed_file_func validate; |
271 | decmpfs_adjust_fetch_region_func adjust_fetch; |
272 | decmpfs_fetch_uncompressed_data_func fetch; |
273 | decmpfs_free_compressed_data_func free_data; |
274 | decmpfs_get_decompression_flags_func get_flags; |
275 | } decmpfs_registration; |
276 | |
277 | /* hooks for kexts to call */ |
278 | errno_t register_decmpfs_decompressor(uint32_t compression_type, const decmpfs_registration *registration); |
279 | errno_t unregister_decmpfs_decompressor(uint32_t compression_type, decmpfs_registration *registration); |
280 | |
281 | __END_DECLS |
282 | #endif /* KERNEL */ |
283 | |
284 | #endif /* _SYS_DECMPFS_H_ */ |
285 | |