Commit | Line | Data |
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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 LT |
16 | #include <linux/kernel.h> |
17 | #include <linux/slab.h> | |
18 | #include <linux/zlib.h> | |
19 | #include <linux/zutil.h> | |
1da177e4 LT |
20 | #include "nodelist.h" |
21 | #include "compr.h" | |
22 | ||
182ec4ee TG |
23 | /* Plan: call deflate() with avail_in == *sourcelen, |
24 | avail_out = *dstlen - 12 and flush == Z_FINISH. | |
1da177e4 LT |
25 | If it doesn't manage to finish, call it again with |
26 | avail_in == 0 and avail_out set to the remaining 12 | |
182ec4ee | 27 | bytes for it to clean up. |
1da177e4 LT |
28 | Q: Is 12 bytes sufficient? |
29 | */ | |
30 | #define STREAM_END_SPACE 12 | |
31 | ||
353ab6e9 IM |
32 | static DEFINE_MUTEX(deflate_mutex); |
33 | static DEFINE_MUTEX(inflate_mutex); | |
1da177e4 LT |
34 | static z_stream inf_strm, def_strm; |
35 | ||
36 | #ifdef __KERNEL__ /* Linux-only */ | |
37 | #include <linux/vmalloc.h> | |
38 | #include <linux/init.h> | |
353ab6e9 | 39 | #include <linux/mutex.h> |
1da177e4 LT |
40 | |
41 | static int __init alloc_workspaces(void) | |
42 | { | |
43 | def_strm.workspace = vmalloc(zlib_deflate_workspacesize()); | |
44 | if (!def_strm.workspace) { | |
45 | printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize()); | |
46 | return -ENOMEM; | |
47 | } | |
48 | D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize())); | |
49 | inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); | |
50 | if (!inf_strm.workspace) { | |
51 | printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize()); | |
52 | vfree(def_strm.workspace); | |
53 | return -ENOMEM; | |
54 | } | |
55 | D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize())); | |
56 | return 0; | |
57 | } | |
58 | ||
59 | static void free_workspaces(void) | |
60 | { | |
61 | vfree(def_strm.workspace); | |
62 | vfree(inf_strm.workspace); | |
63 | } | |
64 | #else | |
65 | #define alloc_workspaces() (0) | |
66 | #define free_workspaces() do { } while(0) | |
67 | #endif /* __KERNEL__ */ | |
68 | ||
75c96f85 AB |
69 | static int jffs2_zlib_compress(unsigned char *data_in, |
70 | unsigned char *cpage_out, | |
71 | uint32_t *sourcelen, uint32_t *dstlen, | |
72 | void *model) | |
1da177e4 LT |
73 | { |
74 | int ret; | |
75 | ||
76 | if (*dstlen <= STREAM_END_SPACE) | |
77 | return -1; | |
78 | ||
353ab6e9 | 79 | mutex_lock(&deflate_mutex); |
1da177e4 LT |
80 | |
81 | if (Z_OK != zlib_deflateInit(&def_strm, 3)) { | |
82 | printk(KERN_WARNING "deflateInit failed\n"); | |
353ab6e9 | 83 | mutex_unlock(&deflate_mutex); |
1da177e4 LT |
84 | return -1; |
85 | } | |
86 | ||
87 | def_strm.next_in = data_in; | |
88 | def_strm.total_in = 0; | |
182ec4ee | 89 | |
1da177e4 LT |
90 | def_strm.next_out = cpage_out; |
91 | def_strm.total_out = 0; | |
92 | ||
93 | while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { | |
94 | def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); | |
95 | def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out); | |
96 | D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n", | |
97 | def_strm.avail_in, def_strm.avail_out)); | |
98 | ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); | |
182ec4ee | 99 | D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", |
1da177e4 LT |
100 | def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out)); |
101 | if (ret != Z_OK) { | |
102 | D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret)); | |
103 | zlib_deflateEnd(&def_strm); | |
353ab6e9 | 104 | mutex_unlock(&deflate_mutex); |
1da177e4 LT |
105 | return -1; |
106 | } | |
107 | } | |
108 | def_strm.avail_out += STREAM_END_SPACE; | |
109 | def_strm.avail_in = 0; | |
110 | ret = zlib_deflate(&def_strm, Z_FINISH); | |
111 | zlib_deflateEnd(&def_strm); | |
112 | ||
113 | if (ret != Z_STREAM_END) { | |
114 | D1(printk(KERN_DEBUG "final deflate returned %d\n", ret)); | |
115 | ret = -1; | |
116 | goto out; | |
117 | } | |
118 | ||
119 | if (def_strm.total_out >= def_strm.total_in) { | |
120 | D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n", | |
121 | def_strm.total_in, def_strm.total_out)); | |
122 | ret = -1; | |
123 | goto out; | |
124 | } | |
125 | ||
126 | D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n", | |
127 | def_strm.total_in, def_strm.total_out)); | |
128 | ||
129 | *dstlen = def_strm.total_out; | |
130 | *sourcelen = def_strm.total_in; | |
131 | ret = 0; | |
132 | out: | |
353ab6e9 | 133 | mutex_unlock(&deflate_mutex); |
1da177e4 LT |
134 | return ret; |
135 | } | |
136 | ||
75c96f85 AB |
137 | static int jffs2_zlib_decompress(unsigned char *data_in, |
138 | unsigned char *cpage_out, | |
139 | uint32_t srclen, uint32_t destlen, | |
140 | void *model) | |
1da177e4 LT |
141 | { |
142 | int ret; | |
143 | int wbits = MAX_WBITS; | |
144 | ||
353ab6e9 | 145 | mutex_lock(&inflate_mutex); |
1da177e4 LT |
146 | |
147 | inf_strm.next_in = data_in; | |
148 | inf_strm.avail_in = srclen; | |
149 | inf_strm.total_in = 0; | |
182ec4ee | 150 | |
1da177e4 LT |
151 | inf_strm.next_out = cpage_out; |
152 | inf_strm.avail_out = destlen; | |
153 | inf_strm.total_out = 0; | |
154 | ||
155 | /* If it's deflate, and it's got no preset dictionary, then | |
156 | we can tell zlib to skip the adler32 check. */ | |
157 | if (srclen > 2 && !(data_in[1] & PRESET_DICT) && | |
158 | ((data_in[0] & 0x0f) == Z_DEFLATED) && | |
159 | !(((data_in[0]<<8) + data_in[1]) % 31)) { | |
160 | ||
161 | D2(printk(KERN_DEBUG "inflate skipping adler32\n")); | |
162 | wbits = -((data_in[0] >> 4) + 8); | |
163 | inf_strm.next_in += 2; | |
164 | inf_strm.avail_in -= 2; | |
165 | } else { | |
166 | /* Let this remain D1 for now -- it should never happen */ | |
167 | D1(printk(KERN_DEBUG "inflate not skipping adler32\n")); | |
168 | } | |
169 | ||
170 | ||
171 | if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) { | |
172 | printk(KERN_WARNING "inflateInit failed\n"); | |
353ab6e9 | 173 | mutex_unlock(&inflate_mutex); |
1da177e4 LT |
174 | return 1; |
175 | } | |
176 | ||
177 | while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK) | |
178 | ; | |
179 | if (ret != Z_STREAM_END) { | |
180 | printk(KERN_NOTICE "inflate returned %d\n", ret); | |
181 | } | |
182 | zlib_inflateEnd(&inf_strm); | |
353ab6e9 | 183 | mutex_unlock(&inflate_mutex); |
ef53cb02 | 184 | return 0; |
1da177e4 LT |
185 | } |
186 | ||
187 | static struct jffs2_compressor jffs2_zlib_comp = { | |
188 | .priority = JFFS2_ZLIB_PRIORITY, | |
189 | .name = "zlib", | |
190 | .compr = JFFS2_COMPR_ZLIB, | |
191 | .compress = &jffs2_zlib_compress, | |
192 | .decompress = &jffs2_zlib_decompress, | |
193 | #ifdef JFFS2_ZLIB_DISABLED | |
194 | .disabled = 1, | |
195 | #else | |
196 | .disabled = 0, | |
197 | #endif | |
198 | }; | |
199 | ||
200 | int __init jffs2_zlib_init(void) | |
201 | { | |
202 | int ret; | |
203 | ||
204 | ret = alloc_workspaces(); | |
205 | if (ret) | |
ef53cb02 | 206 | return ret; |
1da177e4 LT |
207 | |
208 | ret = jffs2_register_compressor(&jffs2_zlib_comp); | |
209 | if (ret) | |
ef53cb02 | 210 | free_workspaces(); |
1da177e4 LT |
211 | |
212 | return ret; | |
213 | } | |
214 | ||
215 | void jffs2_zlib_exit(void) | |
216 | { | |
217 | jffs2_unregister_compressor(&jffs2_zlib_comp); | |
218 | free_workspaces(); | |
219 | } |