2 * JFFS2 -- Journalling Flash File System, Version 2.
4 * Copyright (C) 2001-2003 Red Hat, Inc.
6 * Created by David Woodhouse <dwmw2@infradead.org>
8 * For licensing information, see the file 'LICENCE' in this directory.
10 * $Id: compr_zlib.c,v 1.32 2005/11/07 11:14:38 gleixner Exp $
14 #if !defined(__KERNEL__) && !defined(__ECOS)
15 #error "The userspace support got too messy and was removed. Update your mkfs.jffs2"
18 #include <linux/config.h>
19 #include <linux/kernel.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/zlib.h>
23 #include <linux/zutil.h>
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?
34 #define STREAM_END_SPACE 12
36 static DECLARE_MUTEX(deflate_sem
);
37 static DECLARE_MUTEX(inflate_sem
);
38 static z_stream inf_strm
, def_strm
;
40 #ifdef __KERNEL__ /* Linux-only */
41 #include <linux/vmalloc.h>
42 #include <linux/init.h>
44 static int __init
alloc_workspaces(void)
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());
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
);
58 D1(printk(KERN_DEBUG
"Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize()));
62 static void free_workspaces(void)
64 vfree(def_strm
.workspace
);
65 vfree(inf_strm
.workspace
);
68 #define alloc_workspaces() (0)
69 #define free_workspaces() do { } while(0)
70 #endif /* __KERNEL__ */
72 static int jffs2_zlib_compress(unsigned char *data_in
,
73 unsigned char *cpage_out
,
74 uint32_t *sourcelen
, uint32_t *dstlen
,
79 if (*dstlen
<= STREAM_END_SPACE
)
84 if (Z_OK
!= zlib_deflateInit(&def_strm
, 3)) {
85 printk(KERN_WARNING
"deflateInit failed\n");
90 def_strm
.next_in
= data_in
;
91 def_strm
.total_in
= 0;
93 def_strm
.next_out
= cpage_out
;
94 def_strm
.total_out
= 0;
96 while (def_strm
.total_out
< *dstlen
- STREAM_END_SPACE
&& def_strm
.total_in
< *sourcelen
) {
97 def_strm
.avail_out
= *dstlen
- (def_strm
.total_out
+ STREAM_END_SPACE
);
98 def_strm
.avail_in
= min((unsigned)(*sourcelen
-def_strm
.total_in
), def_strm
.avail_out
);
99 D1(printk(KERN_DEBUG
"calling deflate with avail_in %d, avail_out %d\n",
100 def_strm
.avail_in
, def_strm
.avail_out
));
101 ret
= zlib_deflate(&def_strm
, Z_PARTIAL_FLUSH
);
102 D1(printk(KERN_DEBUG
"deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n",
103 def_strm
.avail_in
, def_strm
.avail_out
, def_strm
.total_in
, def_strm
.total_out
));
105 D1(printk(KERN_DEBUG
"deflate in loop returned %d\n", ret
));
106 zlib_deflateEnd(&def_strm
);
111 def_strm
.avail_out
+= STREAM_END_SPACE
;
112 def_strm
.avail_in
= 0;
113 ret
= zlib_deflate(&def_strm
, Z_FINISH
);
114 zlib_deflateEnd(&def_strm
);
116 if (ret
!= Z_STREAM_END
) {
117 D1(printk(KERN_DEBUG
"final deflate returned %d\n", ret
));
122 if (def_strm
.total_out
>= def_strm
.total_in
) {
123 D1(printk(KERN_DEBUG
"zlib compressed %ld bytes into %ld; failing\n",
124 def_strm
.total_in
, def_strm
.total_out
));
129 D1(printk(KERN_DEBUG
"zlib compressed %ld bytes into %ld\n",
130 def_strm
.total_in
, def_strm
.total_out
));
132 *dstlen
= def_strm
.total_out
;
133 *sourcelen
= def_strm
.total_in
;
140 static int jffs2_zlib_decompress(unsigned char *data_in
,
141 unsigned char *cpage_out
,
142 uint32_t srclen
, uint32_t destlen
,
146 int wbits
= MAX_WBITS
;
150 inf_strm
.next_in
= data_in
;
151 inf_strm
.avail_in
= srclen
;
152 inf_strm
.total_in
= 0;
154 inf_strm
.next_out
= cpage_out
;
155 inf_strm
.avail_out
= destlen
;
156 inf_strm
.total_out
= 0;
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)) {
164 D2(printk(KERN_DEBUG
"inflate skipping adler32\n"));
165 wbits
= -((data_in
[0] >> 4) + 8);
166 inf_strm
.next_in
+= 2;
167 inf_strm
.avail_in
-= 2;
169 /* Let this remain D1 for now -- it should never happen */
170 D1(printk(KERN_DEBUG
"inflate not skipping adler32\n"));
174 if (Z_OK
!= zlib_inflateInit2(&inf_strm
, wbits
)) {
175 printk(KERN_WARNING
"inflateInit failed\n");
180 while((ret
= zlib_inflate(&inf_strm
, Z_FINISH
)) == Z_OK
)
182 if (ret
!= Z_STREAM_END
) {
183 printk(KERN_NOTICE
"inflate returned %d\n", ret
);
185 zlib_inflateEnd(&inf_strm
);
190 static struct jffs2_compressor jffs2_zlib_comp
= {
191 .priority
= JFFS2_ZLIB_PRIORITY
,
193 .compr
= JFFS2_COMPR_ZLIB
,
194 .compress
= &jffs2_zlib_compress
,
195 .decompress
= &jffs2_zlib_decompress
,
196 #ifdef JFFS2_ZLIB_DISABLED
203 int __init
jffs2_zlib_init(void)
207 ret
= alloc_workspaces();
211 ret
= jffs2_register_compressor(&jffs2_zlib_comp
);
218 void jffs2_zlib_exit(void)
220 jffs2_unregister_compressor(&jffs2_zlib_comp
);