Merge tag 'block-5.14-2021-07-24' of git://git.kernel.dk/linux-block
[linux-2.6-microblaze.git] / fs / jffs2 / compr_zlib.c
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2001-2007 Red Hat, Inc.
5  * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6  *
7  * Created by David Woodhouse <dwmw2@infradead.org>
8  *
9  * For licensing information, see the file 'LICENCE' in this directory.
10  *
11  */
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
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19 #include <linux/kernel.h>
20 #include <linux/zlib.h>
21 #include <linux/zutil.h>
22 #include "nodelist.h"
23 #include "compr.h"
24
25         /* Plan: call deflate() with avail_in == *sourcelen,
26                 avail_out = *dstlen - 12 and flush == Z_FINISH.
27                 If it doesn't manage to finish, call it again with
28                 avail_in == 0 and avail_out set to the remaining 12
29                 bytes for it to clean up.
30            Q: Is 12 bytes sufficient?
31         */
32 #define STREAM_END_SPACE 12
33
34 static DEFINE_MUTEX(deflate_mutex);
35 static DEFINE_MUTEX(inflate_mutex);
36 static z_stream inf_strm, def_strm;
37
38 #ifdef __KERNEL__ /* Linux-only */
39 #include <linux/vmalloc.h>
40 #include <linux/init.h>
41 #include <linux/mutex.h>
42
43 static int __init alloc_workspaces(void)
44 {
45         def_strm.workspace = vmalloc(zlib_deflate_workspacesize(MAX_WBITS,
46                                                         MAX_MEM_LEVEL));
47         if (!def_strm.workspace)
48                 return -ENOMEM;
49
50         jffs2_dbg(1, "Allocated %d bytes for deflate workspace\n",
51                   zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL));
52         inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
53         if (!inf_strm.workspace) {
54                 vfree(def_strm.workspace);
55                 return -ENOMEM;
56         }
57         jffs2_dbg(1, "Allocated %d bytes for inflate workspace\n",
58                   zlib_inflate_workspacesize());
59         return 0;
60 }
61
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__ */
71
72 static int jffs2_zlib_compress(unsigned char *data_in,
73                                unsigned char *cpage_out,
74                                uint32_t *sourcelen, uint32_t *dstlen)
75 {
76         int ret;
77
78         if (*dstlen <= STREAM_END_SPACE)
79                 return -1;
80
81         mutex_lock(&deflate_mutex);
82
83         if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
84                 pr_warn("deflateInit failed\n");
85                 mutex_unlock(&deflate_mutex);
86                 return -1;
87         }
88
89         def_strm.next_in = data_in;
90         def_strm.total_in = 0;
91
92         def_strm.next_out = cpage_out;
93         def_strm.total_out = 0;
94
95         while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) {
96                 def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE);
97                 def_strm.avail_in = min_t(unsigned long,
98                         (*sourcelen-def_strm.total_in), def_strm.avail_out);
99                 jffs2_dbg(1, "calling deflate with avail_in %ld, avail_out %ld\n",
100                           def_strm.avail_in, def_strm.avail_out);
101                 ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH);
102                 jffs2_dbg(1, "deflate returned with avail_in %ld, avail_out %ld, total_in %ld, total_out %ld\n",
103                           def_strm.avail_in, def_strm.avail_out,
104                           def_strm.total_in, def_strm.total_out);
105                 if (ret != Z_OK) {
106                         jffs2_dbg(1, "deflate in loop returned %d\n", ret);
107                         zlib_deflateEnd(&def_strm);
108                         mutex_unlock(&deflate_mutex);
109                         return -1;
110                 }
111         }
112         def_strm.avail_out += STREAM_END_SPACE;
113         def_strm.avail_in = 0;
114         ret = zlib_deflate(&def_strm, Z_FINISH);
115         zlib_deflateEnd(&def_strm);
116
117         if (ret != Z_STREAM_END) {
118                 jffs2_dbg(1, "final deflate returned %d\n", ret);
119                 ret = -1;
120                 goto out;
121         }
122
123         if (def_strm.total_out >= def_strm.total_in) {
124                 jffs2_dbg(1, "zlib compressed %ld bytes into %ld; failing\n",
125                           def_strm.total_in, def_strm.total_out);
126                 ret = -1;
127                 goto out;
128         }
129
130         jffs2_dbg(1, "zlib compressed %ld bytes into %ld\n",
131                   def_strm.total_in, def_strm.total_out);
132
133         *dstlen = def_strm.total_out;
134         *sourcelen = def_strm.total_in;
135         ret = 0;
136  out:
137         mutex_unlock(&deflate_mutex);
138         return ret;
139 }
140
141 static int jffs2_zlib_decompress(unsigned char *data_in,
142                                  unsigned char *cpage_out,
143                                  uint32_t srclen, uint32_t destlen)
144 {
145         int ret;
146         int wbits = MAX_WBITS;
147
148         mutex_lock(&inflate_mutex);
149
150         inf_strm.next_in = data_in;
151         inf_strm.avail_in = srclen;
152         inf_strm.total_in = 0;
153
154         inf_strm.next_out = cpage_out;
155         inf_strm.avail_out = destlen;
156         inf_strm.total_out = 0;
157
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)) {
163
164                 jffs2_dbg(2, "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                 jffs2_dbg(1, "inflate not skipping adler32\n");
171         }
172
173
174         if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
175                 pr_warn("inflateInit failed\n");
176                 mutex_unlock(&inflate_mutex);
177                 return 1;
178         }
179
180         while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
181                 ;
182         if (ret != Z_STREAM_END) {
183                 pr_notice("inflate returned %d\n", ret);
184         }
185         zlib_inflateEnd(&inf_strm);
186         mutex_unlock(&inflate_mutex);
187         return 0;
188 }
189
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 };
202
203 int __init jffs2_zlib_init(void)
204 {
205     int ret;
206
207     ret = alloc_workspaces();
208     if (ret)
209             return ret;
210
211     ret = jffs2_register_compressor(&jffs2_zlib_comp);
212     if (ret)
213             free_workspaces();
214
215     return ret;
216 }
217
218 void jffs2_zlib_exit(void)
219 {
220     jffs2_unregister_compressor(&jffs2_zlib_comp);
221     free_workspaces();
222 }