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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
David Woodhousec00c3102007-04-25 14:16:47 +01004 * Copyright © 2001-2007 Red Hat, Inc.
David Woodhouse6088c052010-08-08 14:15:22 +01005 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
7 * Created by David Woodhouse <dwmw2@infradead.org>
8 *
9 * For licensing information, see the file 'LICENCE' in this directory.
10 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 */
12
13#if !defined(__KERNEL__) && !defined(__ECOS)
14#error "The userspace support got too messy and was removed. Update your mkfs.jffs2"
15#endif
16
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/zlib.h>
19#include <linux/zutil.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include "nodelist.h"
21#include "compr.h"
22
Thomas Gleixner182ec4e2005-11-07 11:16:07 +000023 /* Plan: call deflate() with avail_in == *sourcelen,
24 avail_out = *dstlen - 12 and flush == Z_FINISH.
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 If it doesn't manage to finish, call it again with
26 avail_in == 0 and avail_out set to the remaining 12
Thomas Gleixner182ec4e2005-11-07 11:16:07 +000027 bytes for it to clean up.
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 Q: Is 12 bytes sufficient?
29 */
30#define STREAM_END_SPACE 12
31
Ingo Molnar353ab6e2006-03-26 01:37:12 -080032static DEFINE_MUTEX(deflate_mutex);
33static DEFINE_MUTEX(inflate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070034static z_stream inf_strm, def_strm;
35
36#ifdef __KERNEL__ /* Linux-only */
37#include <linux/vmalloc.h>
38#include <linux/init.h>
Ingo Molnar353ab6e2006-03-26 01:37:12 -080039#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
41static 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
59static 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
Adrian Bunk75c96f82005-05-05 16:16:09 -070069static int jffs2_zlib_compress(unsigned char *data_in,
70 unsigned char *cpage_out,
Mike Frysinger088bd452010-09-22 22:52:33 -040071 uint32_t *sourcelen, uint32_t *dstlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -070072{
73 int ret;
74
75 if (*dstlen <= STREAM_END_SPACE)
76 return -1;
77
Ingo Molnar353ab6e2006-03-26 01:37:12 -080078 mutex_lock(&deflate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
80 if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
81 printk(KERN_WARNING "deflateInit failed\n");
Ingo Molnar353ab6e2006-03-26 01:37:12 -080082 mutex_unlock(&deflate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 return -1;
84 }
85
86 def_strm.next_in = data_in;
87 def_strm.total_in = 0;
Thomas Gleixner182ec4e2005-11-07 11:16:07 +000088
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 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);
Thomas Gleixner182ec4e2005-11-07 11:16:07 +000098 D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 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);
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800103 mutex_unlock(&deflate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 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:
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800132 mutex_unlock(&deflate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 return ret;
134}
135
Adrian Bunk75c96f82005-05-05 16:16:09 -0700136static int jffs2_zlib_decompress(unsigned char *data_in,
137 unsigned char *cpage_out,
Mike Frysinger088bd452010-09-22 22:52:33 -0400138 uint32_t srclen, uint32_t destlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139{
140 int ret;
141 int wbits = MAX_WBITS;
142
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800143 mutex_lock(&inflate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
145 inf_strm.next_in = data_in;
146 inf_strm.avail_in = srclen;
147 inf_strm.total_in = 0;
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 inf_strm.next_out = cpage_out;
150 inf_strm.avail_out = destlen;
151 inf_strm.total_out = 0;
152
153 /* If it's deflate, and it's got no preset dictionary, then
154 we can tell zlib to skip the adler32 check. */
155 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
156 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
157 !(((data_in[0]<<8) + data_in[1]) % 31)) {
158
159 D2(printk(KERN_DEBUG "inflate skipping adler32\n"));
160 wbits = -((data_in[0] >> 4) + 8);
161 inf_strm.next_in += 2;
162 inf_strm.avail_in -= 2;
163 } else {
164 /* Let this remain D1 for now -- it should never happen */
165 D1(printk(KERN_DEBUG "inflate not skipping adler32\n"));
166 }
167
168
169 if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
170 printk(KERN_WARNING "inflateInit failed\n");
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800171 mutex_unlock(&inflate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 return 1;
173 }
174
175 while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
176 ;
177 if (ret != Z_STREAM_END) {
178 printk(KERN_NOTICE "inflate returned %d\n", ret);
179 }
180 zlib_inflateEnd(&inf_strm);
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800181 mutex_unlock(&inflate_mutex);
David Woodhouseef53cb02007-07-10 10:01:22 +0100182 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183}
184
185static struct jffs2_compressor jffs2_zlib_comp = {
186 .priority = JFFS2_ZLIB_PRIORITY,
187 .name = "zlib",
188 .compr = JFFS2_COMPR_ZLIB,
189 .compress = &jffs2_zlib_compress,
190 .decompress = &jffs2_zlib_decompress,
191#ifdef JFFS2_ZLIB_DISABLED
192 .disabled = 1,
193#else
194 .disabled = 0,
195#endif
196};
197
198int __init jffs2_zlib_init(void)
199{
200 int ret;
201
202 ret = alloc_workspaces();
203 if (ret)
David Woodhouseef53cb02007-07-10 10:01:22 +0100204 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
206 ret = jffs2_register_compressor(&jffs2_zlib_comp);
207 if (ret)
David Woodhouseef53cb02007-07-10 10:01:22 +0100208 free_workspaces();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
210 return ret;
211}
212
213void jffs2_zlib_exit(void)
214{
215 jffs2_unregister_compressor(&jffs2_zlib_comp);
216 free_workspaces();
217}