1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. |
3 | * |
4 | * Copyright © 2001-2007 Red Hat, Inc. |
5 | * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org> |
6 | * |
7 | * Created by David Woodhouse <dwmw2@infradead.org> |
8 | * |
9 | * For licensing information, see the file 'LICENCE' in this directory. |
10 | * |
11 | */ |
12 | |
13 | #if !defined(__KERNEL__) && !defined(__ECOS) |
14 | #error "The userspace support got too messy and was removed. Update your mkfs.jffs2" |
15 | #endif |
16 | |
17 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
18 | |
19 | #include <linux/kernel.h> |
20 | #include <linux/zlib.h> |
21 | #include <linux/zutil.h> |
22 | #include "nodelist.h" |
23 | #include "compr.h" |
24 | |
25 | /* Plan: call deflate() with avail_in == *sourcelen, |
26 | avail_out = *dstlen - 12 and flush == Z_FINISH. |
27 | If it doesn't manage to finish, call it again with |
28 | avail_in == 0 and avail_out set to the remaining 12 |
29 | bytes for it to clean up. |
30 | Q: Is 12 bytes sufficient? |
31 | */ |
32 | #define STREAM_END_SPACE 12 |
33 | |
34 | static DEFINE_MUTEX(deflate_mutex); |
35 | static DEFINE_MUTEX(inflate_mutex); |
36 | static z_stream inf_strm, def_strm; |
37 | |
38 | #ifdef __KERNEL__ /* Linux-only */ |
39 | #include <linux/vmalloc.h> |
40 | #include <linux/init.h> |
41 | #include <linux/mutex.h> |
42 | |
43 | static int __init alloc_workspaces(void) |
44 | { |
45 | def_strm.workspace = vmalloc(size: zlib_deflate_workspacesize(MAX_WBITS, |
46 | MAX_MEM_LEVEL)); |
47 | if (!def_strm.workspace) |
48 | return -ENOMEM; |
49 | |
50 | jffs2_dbg(1, "Allocated %d bytes for deflate workspace\n" , |
51 | zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL)); |
52 | inf_strm.workspace = vmalloc(size: zlib_inflate_workspacesize()); |
53 | if (!inf_strm.workspace) { |
54 | vfree(addr: def_strm.workspace); |
55 | return -ENOMEM; |
56 | } |
57 | jffs2_dbg(1, "Allocated %d bytes for inflate workspace\n" , |
58 | zlib_inflate_workspacesize()); |
59 | return 0; |
60 | } |
61 | |
62 | static void free_workspaces(void) |
63 | { |
64 | vfree(addr: def_strm.workspace); |
65 | vfree(addr: inf_strm.workspace); |
66 | } |
67 | #else |
68 | #define alloc_workspaces() (0) |
69 | #define free_workspaces() do { } while(0) |
70 | #endif /* __KERNEL__ */ |
71 | |
72 | static int jffs2_zlib_compress(unsigned char *data_in, |
73 | unsigned char *cpage_out, |
74 | uint32_t *sourcelen, uint32_t *dstlen) |
75 | { |
76 | int ret; |
77 | |
78 | if (*dstlen <= STREAM_END_SPACE) |
79 | return -1; |
80 | |
81 | mutex_lock(&deflate_mutex); |
82 | |
83 | if (Z_OK != zlib_deflateInit(&def_strm, 3)) { |
84 | pr_warn("deflateInit failed\n" ); |
85 | mutex_unlock(lock: &deflate_mutex); |
86 | return -1; |
87 | } |
88 | |
89 | def_strm.next_in = data_in; |
90 | def_strm.total_in = 0; |
91 | |
92 | def_strm.next_out = cpage_out; |
93 | def_strm.total_out = 0; |
94 | |
95 | while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { |
96 | def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); |
97 | def_strm.avail_in = min_t(unsigned long, |
98 | (*sourcelen-def_strm.total_in), def_strm.avail_out); |
99 | jffs2_dbg(1, "calling deflate with avail_in %ld, avail_out %ld\n" , |
100 | def_strm.avail_in, def_strm.avail_out); |
101 | ret = zlib_deflate(strm: &def_strm, Z_PARTIAL_FLUSH); |
102 | jffs2_dbg(1, "deflate returned with avail_in %ld, avail_out %ld, total_in %ld, total_out %ld\n" , |
103 | def_strm.avail_in, def_strm.avail_out, |
104 | def_strm.total_in, def_strm.total_out); |
105 | if (ret != Z_OK) { |
106 | jffs2_dbg(1, "deflate in loop returned %d\n" , ret); |
107 | zlib_deflateEnd(strm: &def_strm); |
108 | mutex_unlock(lock: &deflate_mutex); |
109 | return -1; |
110 | } |
111 | } |
112 | def_strm.avail_out += STREAM_END_SPACE; |
113 | def_strm.avail_in = 0; |
114 | ret = zlib_deflate(strm: &def_strm, Z_FINISH); |
115 | zlib_deflateEnd(strm: &def_strm); |
116 | |
117 | if (ret != Z_STREAM_END) { |
118 | jffs2_dbg(1, "final deflate returned %d\n" , ret); |
119 | ret = -1; |
120 | goto out; |
121 | } |
122 | |
123 | if (def_strm.total_out >= def_strm.total_in) { |
124 | jffs2_dbg(1, "zlib compressed %ld bytes into %ld; failing\n" , |
125 | def_strm.total_in, def_strm.total_out); |
126 | ret = -1; |
127 | goto out; |
128 | } |
129 | |
130 | jffs2_dbg(1, "zlib compressed %ld bytes into %ld\n" , |
131 | def_strm.total_in, def_strm.total_out); |
132 | |
133 | *dstlen = def_strm.total_out; |
134 | *sourcelen = def_strm.total_in; |
135 | ret = 0; |
136 | out: |
137 | mutex_unlock(lock: &deflate_mutex); |
138 | return ret; |
139 | } |
140 | |
141 | static int jffs2_zlib_decompress(unsigned char *data_in, |
142 | unsigned char *cpage_out, |
143 | uint32_t srclen, uint32_t destlen) |
144 | { |
145 | int ret; |
146 | int wbits = MAX_WBITS; |
147 | |
148 | mutex_lock(&inflate_mutex); |
149 | |
150 | inf_strm.next_in = data_in; |
151 | inf_strm.avail_in = srclen; |
152 | inf_strm.total_in = 0; |
153 | |
154 | inf_strm.next_out = cpage_out; |
155 | inf_strm.avail_out = destlen; |
156 | inf_strm.total_out = 0; |
157 | |
158 | /* If it's deflate, and it's got no preset dictionary, then |
159 | we can tell zlib to skip the adler32 check. */ |
160 | if (srclen > 2 && !(data_in[1] & PRESET_DICT) && |
161 | ((data_in[0] & 0x0f) == Z_DEFLATED) && |
162 | !(((data_in[0]<<8) + data_in[1]) % 31)) { |
163 | |
164 | jffs2_dbg(2, "inflate skipping adler32\n" ); |
165 | wbits = -((data_in[0] >> 4) + 8); |
166 | inf_strm.next_in += 2; |
167 | inf_strm.avail_in -= 2; |
168 | } else { |
169 | /* Let this remain D1 for now -- it should never happen */ |
170 | jffs2_dbg(1, "inflate not skipping adler32\n" ); |
171 | } |
172 | |
173 | |
174 | if (Z_OK != zlib_inflateInit2(strm: &inf_strm, windowBits: wbits)) { |
175 | pr_warn("inflateInit failed\n" ); |
176 | mutex_unlock(lock: &inflate_mutex); |
177 | return 1; |
178 | } |
179 | |
180 | while((ret = zlib_inflate(strm: &inf_strm, Z_FINISH)) == Z_OK) |
181 | ; |
182 | if (ret != Z_STREAM_END) { |
183 | pr_notice("inflate returned %d\n" , ret); |
184 | } |
185 | zlib_inflateEnd(strm: &inf_strm); |
186 | mutex_unlock(lock: &inflate_mutex); |
187 | return 0; |
188 | } |
189 | |
190 | static struct jffs2_compressor jffs2_zlib_comp = { |
191 | .priority = JFFS2_ZLIB_PRIORITY, |
192 | .name = "zlib" , |
193 | .compr = JFFS2_COMPR_ZLIB, |
194 | .compress = &jffs2_zlib_compress, |
195 | .decompress = &jffs2_zlib_decompress, |
196 | #ifdef JFFS2_ZLIB_DISABLED |
197 | .disabled = 1, |
198 | #else |
199 | .disabled = 0, |
200 | #endif |
201 | }; |
202 | |
203 | int __init jffs2_zlib_init(void) |
204 | { |
205 | int ret; |
206 | |
207 | ret = alloc_workspaces(); |
208 | if (ret) |
209 | return ret; |
210 | |
211 | ret = jffs2_register_compressor(comp: &jffs2_zlib_comp); |
212 | if (ret) |
213 | free_workspaces(); |
214 | |
215 | return ret; |
216 | } |
217 | |
218 | void jffs2_zlib_exit(void) |
219 | { |
220 | jffs2_unregister_compressor(comp: &jffs2_zlib_comp); |
221 | free_workspaces(); |
222 | } |
223 | |