ia64/linux-2.6.18-xen.hg

view fs/jffs2/compr_zlib.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
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 1.32 2005/11/07 11:14:38 gleixner Exp $
11 *
12 */
14 #if !defined(__KERNEL__) && !defined(__ECOS)
15 #error "The userspace support got too messy and was removed. Update your mkfs.jffs2"
16 #endif
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/slab.h>
21 #include <linux/zlib.h>
22 #include <linux/zutil.h>
23 #include "nodelist.h"
24 #include "compr.h"
26 /* Plan: call deflate() with avail_in == *sourcelen,
27 avail_out = *dstlen - 12 and flush == Z_FINISH.
28 If it doesn't manage to finish, call it again with
29 avail_in == 0 and avail_out set to the remaining 12
30 bytes for it to clean up.
31 Q: Is 12 bytes sufficient?
32 */
33 #define STREAM_END_SPACE 12
35 static DEFINE_MUTEX(deflate_mutex);
36 static DEFINE_MUTEX(inflate_mutex);
37 static z_stream inf_strm, def_strm;
39 #ifdef __KERNEL__ /* Linux-only */
40 #include <linux/vmalloc.h>
41 #include <linux/init.h>
42 #include <linux/mutex.h>
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 }
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__ */
72 static int jffs2_zlib_compress(unsigned char *data_in,
73 unsigned char *cpage_out,
74 uint32_t *sourcelen, uint32_t *dstlen,
75 void *model)
76 {
77 int ret;
79 if (*dstlen <= STREAM_END_SPACE)
80 return -1;
82 mutex_lock(&deflate_mutex);
84 if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
85 printk(KERN_WARNING "deflateInit failed\n");
86 mutex_unlock(&deflate_mutex);
87 return -1;
88 }
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));
104 if (ret != Z_OK) {
105 D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret));
106 zlib_deflateEnd(&def_strm);
107 mutex_unlock(&deflate_mutex);
108 return -1;
109 }
110 }
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));
118 ret = -1;
119 goto out;
120 }
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));
125 ret = -1;
126 goto out;
127 }
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;
134 ret = 0;
135 out:
136 mutex_unlock(&deflate_mutex);
137 return ret;
138 }
140 static int jffs2_zlib_decompress(unsigned char *data_in,
141 unsigned char *cpage_out,
142 uint32_t srclen, uint32_t destlen,
143 void *model)
144 {
145 int ret;
146 int wbits = MAX_WBITS;
148 mutex_lock(&inflate_mutex);
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;
168 } else {
169 /* Let this remain D1 for now -- it should never happen */
170 D1(printk(KERN_DEBUG "inflate not skipping adler32\n"));
171 }
174 if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
175 printk(KERN_WARNING "inflateInit failed\n");
176 mutex_unlock(&inflate_mutex);
177 return 1;
178 }
180 while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
181 ;
182 if (ret != Z_STREAM_END) {
183 printk(KERN_NOTICE "inflate returned %d\n", ret);
184 }
185 zlib_inflateEnd(&inf_strm);
186 mutex_unlock(&inflate_mutex);
187 return 0;
188 }
190 static struct jffs2_compressor jffs2_zlib_comp = {
191 .priority = JFFS2_ZLIB_PRIORITY,
192 .name = "zlib",
193 .compr = JFFS2_COMPR_ZLIB,
194 .compress = &jffs2_zlib_compress,
195 .decompress = &jffs2_zlib_decompress,
196 #ifdef JFFS2_ZLIB_DISABLED
197 .disabled = 1,
198 #else
199 .disabled = 0,
200 #endif
201 };
203 int __init jffs2_zlib_init(void)
204 {
205 int ret;
207 ret = alloc_workspaces();
208 if (ret)
209 return ret;
211 ret = jffs2_register_compressor(&jffs2_zlib_comp);
212 if (ret)
213 free_workspaces();
215 return ret;
216 }
218 void jffs2_zlib_exit(void)
219 {
220 jffs2_unregister_compressor(&jffs2_zlib_comp);
221 free_workspaces();
222 }