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1da177e4 LT |
1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. | |
3 | * | |
c00c310e | 4 | * Copyright © 2001-2007 Red Hat, Inc. |
1da177e4 LT |
5 | * |
6 | * Created by David Woodhouse <dwmw2@infradead.org> | |
7 | * | |
8 | * For licensing information, see the file 'LICENCE' in this directory. | |
9 | * | |
1da177e4 LT |
10 | */ |
11 | ||
12 | #if !defined(__KERNEL__) && !defined(__ECOS) | |
13 | #error "The userspace support got too messy and was removed. Update your mkfs.jffs2" | |
14 | #endif | |
15 | ||
1da177e4 | 16 | #include <linux/kernel.h> |
1da177e4 LT |
17 | #include <linux/zlib.h> |
18 | #include <linux/zutil.h> | |
1da177e4 LT |
19 | #include "nodelist.h" |
20 | #include "compr.h" | |
21 | ||
182ec4ee TG |
22 | /* Plan: call deflate() with avail_in == *sourcelen, |
23 | avail_out = *dstlen - 12 and flush == Z_FINISH. | |
1da177e4 LT |
24 | If it doesn't manage to finish, call it again with |
25 | avail_in == 0 and avail_out set to the remaining 12 | |
182ec4ee | 26 | bytes for it to clean up. |
1da177e4 LT |
27 | Q: Is 12 bytes sufficient? |
28 | */ | |
29 | #define STREAM_END_SPACE 12 | |
30 | ||
353ab6e9 IM |
31 | static DEFINE_MUTEX(deflate_mutex); |
32 | static DEFINE_MUTEX(inflate_mutex); | |
1da177e4 LT |
33 | static z_stream inf_strm, def_strm; |
34 | ||
35 | #ifdef __KERNEL__ /* Linux-only */ | |
36 | #include <linux/vmalloc.h> | |
37 | #include <linux/init.h> | |
353ab6e9 | 38 | #include <linux/mutex.h> |
1da177e4 LT |
39 | |
40 | static int __init alloc_workspaces(void) | |
41 | { | |
42 | def_strm.workspace = vmalloc(zlib_deflate_workspacesize()); | |
43 | if (!def_strm.workspace) { | |
44 | printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize()); | |
45 | return -ENOMEM; | |
46 | } | |
47 | D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize())); | |
48 | inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); | |
49 | if (!inf_strm.workspace) { | |
50 | printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize()); | |
51 | vfree(def_strm.workspace); | |
52 | return -ENOMEM; | |
53 | } | |
54 | D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize())); | |
55 | return 0; | |
56 | } | |
57 | ||
58 | static void free_workspaces(void) | |
59 | { | |
60 | vfree(def_strm.workspace); | |
61 | vfree(inf_strm.workspace); | |
62 | } | |
63 | #else | |
64 | #define alloc_workspaces() (0) | |
65 | #define free_workspaces() do { } while(0) | |
66 | #endif /* __KERNEL__ */ | |
67 | ||
75c96f85 AB |
68 | static int jffs2_zlib_compress(unsigned char *data_in, |
69 | unsigned char *cpage_out, | |
70 | uint32_t *sourcelen, uint32_t *dstlen, | |
71 | void *model) | |
1da177e4 LT |
72 | { |
73 | int ret; | |
74 | ||
75 | if (*dstlen <= STREAM_END_SPACE) | |
76 | return -1; | |
77 | ||
353ab6e9 | 78 | mutex_lock(&deflate_mutex); |
1da177e4 LT |
79 | |
80 | if (Z_OK != zlib_deflateInit(&def_strm, 3)) { | |
81 | printk(KERN_WARNING "deflateInit failed\n"); | |
353ab6e9 | 82 | mutex_unlock(&deflate_mutex); |
1da177e4 LT |
83 | return -1; |
84 | } | |
85 | ||
86 | def_strm.next_in = data_in; | |
87 | def_strm.total_in = 0; | |
182ec4ee | 88 | |
1da177e4 LT |
89 | def_strm.next_out = cpage_out; |
90 | def_strm.total_out = 0; | |
91 | ||
92 | while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { | |
93 | def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); | |
94 | def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out); | |
95 | D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n", | |
96 | def_strm.avail_in, def_strm.avail_out)); | |
97 | ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); | |
182ec4ee | 98 | D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", |
1da177e4 LT |
99 | def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out)); |
100 | if (ret != Z_OK) { | |
101 | D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret)); | |
102 | zlib_deflateEnd(&def_strm); | |
353ab6e9 | 103 | mutex_unlock(&deflate_mutex); |
1da177e4 LT |
104 | return -1; |
105 | } | |
106 | } | |
107 | def_strm.avail_out += STREAM_END_SPACE; | |
108 | def_strm.avail_in = 0; | |
109 | ret = zlib_deflate(&def_strm, Z_FINISH); | |
110 | zlib_deflateEnd(&def_strm); | |
111 | ||
112 | if (ret != Z_STREAM_END) { | |
113 | D1(printk(KERN_DEBUG "final deflate returned %d\n", ret)); | |
114 | ret = -1; | |
115 | goto out; | |
116 | } | |
117 | ||
118 | if (def_strm.total_out >= def_strm.total_in) { | |
119 | D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n", | |
120 | def_strm.total_in, def_strm.total_out)); | |
121 | ret = -1; | |
122 | goto out; | |
123 | } | |
124 | ||
125 | D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n", | |
126 | def_strm.total_in, def_strm.total_out)); | |
127 | ||
128 | *dstlen = def_strm.total_out; | |
129 | *sourcelen = def_strm.total_in; | |
130 | ret = 0; | |
131 | out: | |
353ab6e9 | 132 | mutex_unlock(&deflate_mutex); |
1da177e4 LT |
133 | return ret; |
134 | } | |
135 | ||
75c96f85 AB |
136 | static int jffs2_zlib_decompress(unsigned char *data_in, |
137 | unsigned char *cpage_out, | |
138 | uint32_t srclen, uint32_t destlen, | |
139 | void *model) | |
1da177e4 LT |
140 | { |
141 | int ret; | |
142 | int wbits = MAX_WBITS; | |
143 | ||
353ab6e9 | 144 | mutex_lock(&inflate_mutex); |
1da177e4 LT |
145 | |
146 | inf_strm.next_in = data_in; | |
147 | inf_strm.avail_in = srclen; | |
148 | inf_strm.total_in = 0; | |
182ec4ee | 149 | |
1da177e4 LT |
150 | inf_strm.next_out = cpage_out; |
151 | inf_strm.avail_out = destlen; | |
152 | inf_strm.total_out = 0; | |
153 | ||
154 | /* If it's deflate, and it's got no preset dictionary, then | |
155 | we can tell zlib to skip the adler32 check. */ | |
156 | if (srclen > 2 && !(data_in[1] & PRESET_DICT) && | |
157 | ((data_in[0] & 0x0f) == Z_DEFLATED) && | |
158 | !(((data_in[0]<<8) + data_in[1]) % 31)) { | |
159 | ||
160 | D2(printk(KERN_DEBUG "inflate skipping adler32\n")); | |
161 | wbits = -((data_in[0] >> 4) + 8); | |
162 | inf_strm.next_in += 2; | |
163 | inf_strm.avail_in -= 2; | |
164 | } else { | |
165 | /* Let this remain D1 for now -- it should never happen */ | |
166 | D1(printk(KERN_DEBUG "inflate not skipping adler32\n")); | |
167 | } | |
168 | ||
169 | ||
170 | if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) { | |
171 | printk(KERN_WARNING "inflateInit failed\n"); | |
353ab6e9 | 172 | mutex_unlock(&inflate_mutex); |
1da177e4 LT |
173 | return 1; |
174 | } | |
175 | ||
176 | while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK) | |
177 | ; | |
178 | if (ret != Z_STREAM_END) { | |
179 | printk(KERN_NOTICE "inflate returned %d\n", ret); | |
180 | } | |
181 | zlib_inflateEnd(&inf_strm); | |
353ab6e9 | 182 | mutex_unlock(&inflate_mutex); |
ef53cb02 | 183 | return 0; |
1da177e4 LT |
184 | } |
185 | ||
186 | static struct jffs2_compressor jffs2_zlib_comp = { | |
187 | .priority = JFFS2_ZLIB_PRIORITY, | |
188 | .name = "zlib", | |
189 | .compr = JFFS2_COMPR_ZLIB, | |
190 | .compress = &jffs2_zlib_compress, | |
191 | .decompress = &jffs2_zlib_decompress, | |
192 | #ifdef JFFS2_ZLIB_DISABLED | |
193 | .disabled = 1, | |
194 | #else | |
195 | .disabled = 0, | |
196 | #endif | |
197 | }; | |
198 | ||
199 | int __init jffs2_zlib_init(void) | |
200 | { | |
201 | int ret; | |
202 | ||
203 | ret = alloc_workspaces(); | |
204 | if (ret) | |
ef53cb02 | 205 | return ret; |
1da177e4 LT |
206 | |
207 | ret = jffs2_register_compressor(&jffs2_zlib_comp); | |
208 | if (ret) | |
ef53cb02 | 209 | free_workspaces(); |
1da177e4 LT |
210 | |
211 | return ret; | |
212 | } | |
213 | ||
214 | void jffs2_zlib_exit(void) | |
215 | { | |
216 | jffs2_unregister_compressor(&jffs2_zlib_comp); | |
217 | free_workspaces(); | |
218 | } |