2 * JFFS2 -- Journalling Flash File System, Version 2.
4 * Copyright (C) 2001-2003 Red Hat, Inc.
6 * Created by David Woodhouse <dwmw2@redhat.com>
8 * For licensing information, see the file 'LICENCE' in this directory.
10 * $Id: compr_zlib.c,v 1.24 2003/10/04 08:33:06 dwmw2 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/vmalloc.h>
21 #include <linux/init.h>
22 #include <linux/slab.h>
23 #include <linux/zlib.h>
24 #include <linux/zutil.h>
25 #include <asm/semaphore.h>
28 /* Plan: call deflate() with avail_in == *sourcelen,
29 avail_out = *dstlen - 12 and flush == Z_FINISH.
30 If it doesn't manage to finish, call it again with
31 avail_in == 0 and avail_out set to the remaining 12
32 bytes for it to clean up.
33 Q: Is 12 bytes sufficient?
35 #define STREAM_END_SPACE 12
37 static DECLARE_MUTEX(deflate_sem);
38 static DECLARE_MUTEX(inflate_sem);
39 static z_stream inf_strm, def_strm;
41 #ifdef __KERNEL__ /* Linux-only */
42 int __init jffs2_zlib_init(void)
44 def_strm.workspace = vmalloc(zlib_deflate_workspacesize());
45 if (!def_strm.workspace) {
46 printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize());
49 D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize()));
50 inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
51 if (!inf_strm.workspace) {
52 printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize());
53 vfree(def_strm.workspace);
56 D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize()));
60 void jffs2_zlib_exit(void)
62 vfree(def_strm.workspace);
63 vfree(inf_strm.workspace);
65 #endif /* __KERNEL__ */
67 int jffs2_zlib_compress(unsigned char *data_in, unsigned char *cpage_out,
68 uint32_t *sourcelen, uint32_t *dstlen)
72 if (*dstlen <= STREAM_END_SPACE)
77 if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
78 printk(KERN_WARNING "deflateInit failed\n");
83 def_strm.next_in = data_in;
84 def_strm.total_in = 0;
86 def_strm.next_out = cpage_out;
87 def_strm.total_out = 0;
89 while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) {
90 def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE);
91 def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out);
92 D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n",
93 def_strm.avail_in, def_strm.avail_out));
94 ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH);
95 D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n",
96 def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out));
98 D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret));
99 zlib_deflateEnd(&def_strm);
104 def_strm.avail_out += STREAM_END_SPACE;
105 def_strm.avail_in = 0;
106 ret = zlib_deflate(&def_strm, Z_FINISH);
107 zlib_deflateEnd(&def_strm);
109 if (ret != Z_STREAM_END) {
110 D1(printk(KERN_DEBUG "final deflate returned %d\n", ret));
115 if (def_strm.total_out >= def_strm.total_in) {
116 D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n",
117 def_strm.total_in, def_strm.total_out));
122 D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n",
123 def_strm.total_in, def_strm.total_out));
125 *dstlen = def_strm.total_out;
126 *sourcelen = def_strm.total_in;
133 void jffs2_zlib_decompress(unsigned char *data_in, unsigned char *cpage_out,
134 uint32_t srclen, uint32_t destlen)
137 int wbits = MAX_WBITS;
141 inf_strm.next_in = data_in;
142 inf_strm.avail_in = srclen;
143 inf_strm.total_in = 0;
145 inf_strm.next_out = cpage_out;
146 inf_strm.avail_out = destlen;
147 inf_strm.total_out = 0;
149 /* If it's deflate, and it's got no preset dictionary, then
150 we can tell zlib to skip the adler32 check. */
151 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
152 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
153 !(((data_in[0]<<8) + data_in[1]) % 31)) {
155 D2(printk(KERN_DEBUG "inflate skipping adler32\n"));
156 wbits = -((data_in[0] >> 4) + 8);
157 inf_strm.next_in += 2;
158 inf_strm.avail_in -= 2;
160 /* Let this remain D1 for now -- it should never happen */
161 D1(printk(KERN_DEBUG "inflate not skipping adler32\n"));
165 if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
166 printk(KERN_WARNING "inflateInit failed\n");
171 while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
173 if (ret != Z_STREAM_END) {
174 printk(KERN_NOTICE "inflate returned %d\n", ret);
176 zlib_inflateEnd(&inf_strm);