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1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. | |
3 | * | |
4 | * Copyright (C) 2001-2003 Red Hat, Inc. | |
5 | * | |
6 | * Created by David Woodhouse <dwmw2@infradead.org> | |
7 | * | |
8 | * For licensing information, see the file 'LICENCE' in this directory. | |
9 | * | |
10 | * $Id: compr_zlib.c,v 1.29 2004/11/16 20:36:11 dwmw2 Exp $ | |
11 | * | |
12 | */ | |
13 | ||
14 | #if !defined(__KERNEL__) && !defined(__ECOS) | |
15 | #error "The userspace support got too messy and was removed. Update your mkfs.jffs2" | |
16 | #endif | |
17 | ||
18 | #include <linux/config.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/zlib.h> | |
22 | #include <linux/zutil.h> | |
23 | #include <asm/semaphore.h> | |
24 | #include "nodelist.h" | |
25 | #include "compr.h" | |
26 | ||
27 | /* Plan: call deflate() with avail_in == *sourcelen, | |
28 | avail_out = *dstlen - 12 and flush == Z_FINISH. | |
29 | If it doesn't manage to finish, call it again with | |
30 | avail_in == 0 and avail_out set to the remaining 12 | |
31 | bytes for it to clean up. | |
32 | Q: Is 12 bytes sufficient? | |
33 | */ | |
34 | #define STREAM_END_SPACE 12 | |
35 | ||
36 | static DECLARE_MUTEX(deflate_sem); | |
37 | static DECLARE_MUTEX(inflate_sem); | |
38 | static z_stream inf_strm, def_strm; | |
39 | ||
40 | #ifdef __KERNEL__ /* Linux-only */ | |
41 | #include <linux/vmalloc.h> | |
42 | #include <linux/init.h> | |
43 | ||
44 | static int __init alloc_workspaces(void) | |
45 | { | |
46 | def_strm.workspace = vmalloc(zlib_deflate_workspacesize()); | |
47 | if (!def_strm.workspace) { | |
48 | printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize()); | |
49 | return -ENOMEM; | |
50 | } | |
51 | D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize())); | |
52 | inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); | |
53 | if (!inf_strm.workspace) { | |
54 | printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize()); | |
55 | vfree(def_strm.workspace); | |
56 | return -ENOMEM; | |
57 | } | |
58 | D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize())); | |
59 | return 0; | |
60 | } | |
61 | ||
62 | static void free_workspaces(void) | |
63 | { | |
64 | vfree(def_strm.workspace); | |
65 | vfree(inf_strm.workspace); | |
66 | } | |
67 | #else | |
68 | #define alloc_workspaces() (0) | |
69 | #define free_workspaces() do { } while(0) | |
70 | #endif /* __KERNEL__ */ | |
71 | ||
72 | int jffs2_zlib_compress(unsigned char *data_in, unsigned char *cpage_out, | |
73 | uint32_t *sourcelen, uint32_t *dstlen, void *model) | |
74 | { | |
75 | int ret; | |
76 | ||
77 | if (*dstlen <= STREAM_END_SPACE) | |
78 | return -1; | |
79 | ||
80 | down(&deflate_sem); | |
81 | ||
82 | if (Z_OK != zlib_deflateInit(&def_strm, 3)) { | |
83 | printk(KERN_WARNING "deflateInit failed\n"); | |
84 | up(&deflate_sem); | |
85 | return -1; | |
86 | } | |
87 | ||
88 | def_strm.next_in = data_in; | |
89 | def_strm.total_in = 0; | |
90 | ||
91 | def_strm.next_out = cpage_out; | |
92 | def_strm.total_out = 0; | |
93 | ||
94 | while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { | |
95 | def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); | |
96 | def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out); | |
97 | D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n", | |
98 | def_strm.avail_in, def_strm.avail_out)); | |
99 | ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); | |
100 | D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", | |
101 | def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out)); | |
102 | if (ret != Z_OK) { | |
103 | D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret)); | |
104 | zlib_deflateEnd(&def_strm); | |
105 | up(&deflate_sem); | |
106 | return -1; | |
107 | } | |
108 | } | |
109 | def_strm.avail_out += STREAM_END_SPACE; | |
110 | def_strm.avail_in = 0; | |
111 | ret = zlib_deflate(&def_strm, Z_FINISH); | |
112 | zlib_deflateEnd(&def_strm); | |
113 | ||
114 | if (ret != Z_STREAM_END) { | |
115 | D1(printk(KERN_DEBUG "final deflate returned %d\n", ret)); | |
116 | ret = -1; | |
117 | goto out; | |
118 | } | |
119 | ||
120 | if (def_strm.total_out >= def_strm.total_in) { | |
121 | D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n", | |
122 | def_strm.total_in, def_strm.total_out)); | |
123 | ret = -1; | |
124 | goto out; | |
125 | } | |
126 | ||
127 | D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n", | |
128 | def_strm.total_in, def_strm.total_out)); | |
129 | ||
130 | *dstlen = def_strm.total_out; | |
131 | *sourcelen = def_strm.total_in; | |
132 | ret = 0; | |
133 | out: | |
134 | up(&deflate_sem); | |
135 | return ret; | |
136 | } | |
137 | ||
138 | int jffs2_zlib_decompress(unsigned char *data_in, unsigned char *cpage_out, | |
139 | uint32_t srclen, uint32_t destlen, void *model) | |
140 | { | |
141 | int ret; | |
142 | int wbits = MAX_WBITS; | |
143 | ||
144 | down(&inflate_sem); | |
145 | ||
146 | inf_strm.next_in = data_in; | |
147 | inf_strm.avail_in = srclen; | |
148 | inf_strm.total_in = 0; | |
149 | ||
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"); | |
172 | up(&inflate_sem); | |
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); | |
182 | up(&inflate_sem); | |
183 | return 0; | |
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) | |
205 | return ret; | |
206 | ||
207 | ret = jffs2_register_compressor(&jffs2_zlib_comp); | |
208 | if (ret) | |
209 | free_workspaces(); | |
210 | ||
211 | return ret; | |
212 | } | |
213 | ||
214 | void jffs2_zlib_exit(void) | |
215 | { | |
216 | jffs2_unregister_compressor(&jffs2_zlib_comp); | |
217 | free_workspaces(); | |
218 | } |