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 | |
36 | /* |
37 | * Please switch on @DECMPFS_ENABLE_KDEBUG_TRACES to enable tracepoints. |
38 | * Tracepoints are compiled out by default to eliminate any overhead due to |
39 | * kernel tracing. |
40 | * |
41 | * #define DECMPFS_ENABLE_KDEBUG_TRACES 1 |
42 | */ |
43 | #if DECMPFS_ENABLE_KDEBUG_TRACES |
44 | #define DECMPFS_EMIT_TRACE_ENTRY(D, ...)\ |
45 | KDBG_FILTERED((D) | DBG_FUNC_START, ## __VA_ARGS__) |
46 | #define DECMPFS_EMIT_TRACE_RETURN(D, ...)\ |
47 | KDBG_FILTERED((D) | DBG_FUNC_END, ##__VA_ARGS__) |
48 | #else |
49 | #define DECMPFS_EMIT_TRACE_ENTRY(D, ...) do {} while (0) |
50 | #define DECMPFS_EMIT_TRACE_RETURN(D, ...) do {} while (0) |
51 | #endif /* DECMPFS_ENABLE_KDEBUG_TRACES */ |
52 | |
53 | /* |
54 | * KERNEL_DEBUG related definitions for decmpfs. |
55 | * |
56 | * Please NOTE: The Class DBG_FSYSTEM = 3, and Subclass DBG_DECMP = 0x12, so |
57 | * these debug codes are of the form 0x0312nnnn. |
58 | */ |
59 | #define DECMPDBG_CODE(code) FSDBG_CODE(DBG_DECMP, code) |
60 | |
61 | enum { |
62 | DECMPDBG_DECOMPRESS_FILE = DECMPDBG_CODE(0), /* 0x03120000 */ |
63 | = DECMPDBG_CODE(1), /* 0x03120004 */ |
64 | DECMPDBG_FETCH_UNCOMPRESSED_DATA = DECMPDBG_CODE(2), /* 0x03120008 */ |
65 | DECMPDBG_FREE_COMPRESSED_DATA = DECMPDBG_CODE(4), /* 0x03120010 */ |
66 | DECMPDBG_FILE_IS_COMPRESSED = DECMPDBG_CODE(5), /* 0x03120014 */ |
67 | }; |
68 | |
69 | #define MAX_DECMPFS_XATTR_SIZE 3802 |
70 | |
71 | /* |
72 | NOTE: decmpfs can only be used by thread-safe filesystems |
73 | */ |
74 | |
75 | #define DECMPFS_MAGIC 0x636d7066 /* cmpf */ |
76 | |
77 | #define DECMPFS_XATTR_NAME "com.apple.decmpfs" /* extended attribute to use for decmpfs */ |
78 | |
79 | typedef struct __attribute__((packed)) { |
80 | /* this structure represents the xattr on disk; the fields below are little-endian */ |
81 | uint32_t compression_magic; |
82 | uint32_t compression_type; /* see the enum below */ |
83 | uint64_t uncompressed_size; |
84 | unsigned char attr_bytes[0]; /* the bytes of the attribute after the header */ |
85 | } ; |
86 | |
87 | typedef struct __attribute__((packed)) { |
88 | /* this structure represents the xattr in memory; the fields below are host-endian */ |
89 | uint32_t attr_size; |
90 | uint32_t compression_magic; |
91 | uint32_t compression_type; |
92 | uint64_t uncompressed_size; |
93 | unsigned char attr_bytes[0]; /* the bytes of the attribute after the header */ |
94 | } ; |
95 | |
96 | /* compression_type values */ |
97 | enum { |
98 | CMP_Type1 = 1, /* uncompressed data in xattr */ |
99 | |
100 | /* additional types defined in AppleFSCompression project */ |
101 | |
102 | CMP_MAX = 255 /* Highest compression_type supported */ |
103 | }; |
104 | |
105 | typedef struct { |
106 | void *buf; |
107 | user_ssize_t size; |
108 | } decmpfs_vector; |
109 | |
110 | #ifdef KERNEL |
111 | |
112 | #ifdef XNU_KERNEL_PRIVATE |
113 | |
114 | #include <kern/locks.h> |
115 | |
116 | struct decmpfs_cnode { |
117 | uint8_t cmp_state; |
118 | uint8_t cmp_minimal_xattr; /* if non-zero, this file's com.apple.decmpfs xattr contained only the minimal decmpfs_disk_header */ |
119 | uint32_t cmp_type; |
120 | uint32_t lockcount; |
121 | void *lockowner; /* cnode's lock owner (if a thread is currently holding an exclusive lock) */ |
122 | uint64_t uncompressed_size __attribute__((aligned(8))); |
123 | uint64_t decompression_flags; |
124 | lck_rw_t compressed_data_lock; |
125 | }; |
126 | |
127 | #endif // XNU_KERNEL_PRIVATE |
128 | |
129 | typedef struct decmpfs_cnode decmpfs_cnode; |
130 | |
131 | /* return values from decmpfs_file_is_compressed */ |
132 | enum { |
133 | FILE_TYPE_UNKNOWN = 0, |
134 | FILE_IS_NOT_COMPRESSED = 1, |
135 | FILE_IS_COMPRESSED = 2, |
136 | FILE_IS_CONVERTING = 3 /* file is converting from compressed to decompressed */ |
137 | }; |
138 | |
139 | /* vfs entrypoints */ |
140 | extern vfs_context_t decmpfs_ctx; |
141 | |
142 | /* client filesystem entrypoints */ |
143 | void decmpfs_init(void); |
144 | decmpfs_cnode *decmpfs_cnode_alloc(void); |
145 | void decmpfs_cnode_free(decmpfs_cnode *dp); |
146 | void decmpfs_cnode_init(decmpfs_cnode *cp); |
147 | void decmpfs_cnode_destroy(decmpfs_cnode *cp); |
148 | |
149 | int decmpfs_hides_rsrc(vfs_context_t ctx, decmpfs_cnode *cp); |
150 | int decmpfs_hides_xattr(vfs_context_t ctx, decmpfs_cnode *cp, const char *xattr); |
151 | |
152 | bool decmpfs_trylock_compressed_data(decmpfs_cnode *cp, int exclusive); |
153 | void decmpfs_lock_compressed_data(decmpfs_cnode *cp, int exclusive); |
154 | void decmpfs_unlock_compressed_data(decmpfs_cnode *cp, int exclusive); |
155 | |
156 | uint32_t decmpfs_cnode_get_vnode_state(decmpfs_cnode *cp); |
157 | void decmpfs_cnode_set_vnode_state(decmpfs_cnode *cp, uint32_t state, int skiplock); |
158 | uint64_t decmpfs_cnode_get_vnode_cached_size(decmpfs_cnode *cp); |
159 | uint32_t decmpfs_cnode_cmp_type(decmpfs_cnode *cp); |
160 | |
161 | int decmpfs_file_is_compressed(vnode_t vp, decmpfs_cnode *cp); |
162 | errno_t decmpfs_validate_compressed_file(vnode_t vp, decmpfs_cnode *cp); |
163 | 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 */ |
164 | int decmpfs_free_compressed_data(vnode_t vp, decmpfs_cnode *cp); |
165 | int decmpfs_update_attributes(vnode_t vp, struct vnode_attr *vap); |
166 | /* 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 */ |
167 | errno_t decmpfs_pagein_compressed(struct vnop_pagein_args *ap, int *is_compressed, decmpfs_cnode *cp); |
168 | errno_t decmpfs_read_compressed(struct vnop_read_args *ap, int *is_compressed, decmpfs_cnode *cp); |
169 | |
170 | /* types shared between the kernel and kexts */ |
171 | typedef int (*decmpfs_validate_compressed_file_func)(vnode_t vp, vfs_context_t ctx, decmpfs_header *hdr); |
172 | typedef void (*decmpfs_adjust_fetch_region_func)(vnode_t vp, vfs_context_t ctx, decmpfs_header *hdr, off_t *offset, user_ssize_t *size); |
173 | 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); |
174 | typedef int (*decmpfs_free_compressed_data_func)(vnode_t vp, vfs_context_t ctx, decmpfs_header *hdr); |
175 | 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 |
176 | |
177 | enum { |
178 | DECMPFS_FLAGS_FORCE_FLUSH_ON_DECOMPRESS = 1 << 0, |
179 | }; |
180 | |
181 | /* Versions that are supported for binary compatibility */ |
182 | #define DECMPFS_REGISTRATION_VERSION_V1 1 |
183 | #define DECMPFS_REGISTRATION_VERSION_V3 3 |
184 | |
185 | #define DECMPFS_REGISTRATION_VERSION (DECMPFS_REGISTRATION_VERSION_V3) |
186 | |
187 | typedef struct { |
188 | int decmpfs_registration; |
189 | decmpfs_validate_compressed_file_func validate; |
190 | decmpfs_adjust_fetch_region_func adjust_fetch; |
191 | decmpfs_fetch_uncompressed_data_func fetch; |
192 | decmpfs_free_compressed_data_func free_data; |
193 | decmpfs_get_decompression_flags_func get_flags; |
194 | } decmpfs_registration; |
195 | |
196 | /* hooks for kexts to call */ |
197 | errno_t register_decmpfs_decompressor(uint32_t compression_type, const decmpfs_registration *registration); |
198 | errno_t unregister_decmpfs_decompressor(uint32_t compression_type, decmpfs_registration *registration); |
199 | |
200 | #endif /* KERNEL */ |
201 | |
202 | #endif /* _SYS_DECMPFS_H_ */ |
203 | |