ehea: fix skb_frag_size typo
[linux-btrfs-devel.git] / fs / jffs2 / compr_zlib.c
blob5a001020c542a652726e18521429d2d44b6c31d5
1 /*
2 * JFFS2 -- Journalling Flash File System, Version 2.
4 * Copyright © 2001-2007 Red Hat, Inc.
5 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
7 * Created by David Woodhouse <dwmw2@infradead.org>
9 * For licensing information, see the file 'LICENCE' in this directory.
13 #if !defined(__KERNEL__) && !defined(__ECOS)
14 #error "The userspace support got too messy and was removed. Update your mkfs.jffs2"
15 #endif
17 #include <linux/kernel.h>
18 #include <linux/zlib.h>
19 #include <linux/zutil.h>
20 #include "nodelist.h"
21 #include "compr.h"
23 /* Plan: call deflate() with avail_in == *sourcelen,
24 avail_out = *dstlen - 12 and flush == Z_FINISH.
25 If it doesn't manage to finish, call it again with
26 avail_in == 0 and avail_out set to the remaining 12
27 bytes for it to clean up.
28 Q: Is 12 bytes sufficient?
30 #define STREAM_END_SPACE 12
32 static DEFINE_MUTEX(deflate_mutex);
33 static DEFINE_MUTEX(inflate_mutex);
34 static z_stream inf_strm, def_strm;
36 #ifdef __KERNEL__ /* Linux-only */
37 #include <linux/vmalloc.h>
38 #include <linux/init.h>
39 #include <linux/mutex.h>
41 static int __init alloc_workspaces(void)
43 def_strm.workspace = vmalloc(zlib_deflate_workspacesize(MAX_WBITS,
44 MAX_MEM_LEVEL));
45 if (!def_strm.workspace) {
46 printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL));
47 return -ENOMEM;
49 D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL)));
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);
54 return -ENOMEM;
56 D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize()));
57 return 0;
60 static void free_workspaces(void)
62 vfree(def_strm.workspace);
63 vfree(inf_strm.workspace);
65 #else
66 #define alloc_workspaces() (0)
67 #define free_workspaces() do { } while(0)
68 #endif /* __KERNEL__ */
70 static int jffs2_zlib_compress(unsigned char *data_in,
71 unsigned char *cpage_out,
72 uint32_t *sourcelen, uint32_t *dstlen)
74 int ret;
76 if (*dstlen <= STREAM_END_SPACE)
77 return -1;
79 mutex_lock(&deflate_mutex);
81 if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
82 printk(KERN_WARNING "deflateInit failed\n");
83 mutex_unlock(&deflate_mutex);
84 return -1;
87 def_strm.next_in = data_in;
88 def_strm.total_in = 0;
90 def_strm.next_out = cpage_out;
91 def_strm.total_out = 0;
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);
99 D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n",
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);
104 mutex_unlock(&deflate_mutex);
105 return -1;
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);
113 if (ret != Z_STREAM_END) {
114 D1(printk(KERN_DEBUG "final deflate returned %d\n", ret));
115 ret = -1;
116 goto out;
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;
126 D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n",
127 def_strm.total_in, def_strm.total_out));
129 *dstlen = def_strm.total_out;
130 *sourcelen = def_strm.total_in;
131 ret = 0;
132 out:
133 mutex_unlock(&deflate_mutex);
134 return ret;
137 static int jffs2_zlib_decompress(unsigned char *data_in,
138 unsigned char *cpage_out,
139 uint32_t srclen, uint32_t destlen)
141 int ret;
142 int wbits = MAX_WBITS;
144 mutex_lock(&inflate_mutex);
146 inf_strm.next_in = data_in;
147 inf_strm.avail_in = srclen;
148 inf_strm.total_in = 0;
150 inf_strm.next_out = cpage_out;
151 inf_strm.avail_out = destlen;
152 inf_strm.total_out = 0;
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)) {
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"));
170 if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
171 printk(KERN_WARNING "inflateInit failed\n");
172 mutex_unlock(&inflate_mutex);
173 return 1;
176 while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
178 if (ret != Z_STREAM_END) {
179 printk(KERN_NOTICE "inflate returned %d\n", ret);
181 zlib_inflateEnd(&inf_strm);
182 mutex_unlock(&inflate_mutex);
183 return 0;
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
199 int __init jffs2_zlib_init(void)
201 int ret;
203 ret = alloc_workspaces();
204 if (ret)
205 return ret;
207 ret = jffs2_register_compressor(&jffs2_zlib_comp);
208 if (ret)
209 free_workspaces();
211 return ret;
214 void jffs2_zlib_exit(void)
216 jffs2_unregister_compressor(&jffs2_zlib_comp);
217 free_workspaces();