usb-bsd: convert to QOM
[qemu.git] / block / cloop.c
1 /*
2 * QEMU Block driver for CLOOP images
3 *
4 * Copyright (c) 2004 Johannes E. Schindelin
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24 #include "qemu-common.h"
25 #include "block_int.h"
26 #include "module.h"
27 #include <zlib.h>
28
29 typedef struct BDRVCloopState {
30 CoMutex lock;
31 uint32_t block_size;
32 uint32_t n_blocks;
33 uint64_t *offsets;
34 uint32_t sectors_per_block;
35 uint32_t current_block;
36 uint8_t *compressed_block;
37 uint8_t *uncompressed_block;
38 z_stream zstream;
39 } BDRVCloopState;
40
41 static int cloop_probe(const uint8_t *buf, int buf_size, const char *filename)
42 {
43 const char *magic_version_2_0 = "#!/bin/sh\n"
44 "#V2.0 Format\n"
45 "modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1\n";
46 int length = strlen(magic_version_2_0);
47 if (length > buf_size) {
48 length = buf_size;
49 }
50 if (!memcmp(magic_version_2_0, buf, length)) {
51 return 2;
52 }
53 return 0;
54 }
55
56 static int cloop_open(BlockDriverState *bs, int flags)
57 {
58 BDRVCloopState *s = bs->opaque;
59 uint32_t offsets_size, max_compressed_block_size = 1, i;
60
61 bs->read_only = 1;
62
63 /* read header */
64 if (bdrv_pread(bs->file, 128, &s->block_size, 4) < 4) {
65 goto cloop_close;
66 }
67 s->block_size = be32_to_cpu(s->block_size);
68
69 if (bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4) < 4) {
70 goto cloop_close;
71 }
72 s->n_blocks = be32_to_cpu(s->n_blocks);
73
74 /* read offsets */
75 offsets_size = s->n_blocks * sizeof(uint64_t);
76 s->offsets = g_malloc(offsets_size);
77 if (bdrv_pread(bs->file, 128 + 4 + 4, s->offsets, offsets_size) <
78 offsets_size) {
79 goto cloop_close;
80 }
81 for(i=0;i<s->n_blocks;i++) {
82 s->offsets[i] = be64_to_cpu(s->offsets[i]);
83 if (i > 0) {
84 uint32_t size = s->offsets[i] - s->offsets[i - 1];
85 if (size > max_compressed_block_size) {
86 max_compressed_block_size = size;
87 }
88 }
89 }
90
91 /* initialize zlib engine */
92 s->compressed_block = g_malloc(max_compressed_block_size + 1);
93 s->uncompressed_block = g_malloc(s->block_size);
94 if (inflateInit(&s->zstream) != Z_OK) {
95 goto cloop_close;
96 }
97 s->current_block = s->n_blocks;
98
99 s->sectors_per_block = s->block_size/512;
100 bs->total_sectors = s->n_blocks * s->sectors_per_block;
101 qemu_co_mutex_init(&s->lock);
102 return 0;
103
104 cloop_close:
105 return -1;
106 }
107
108 static inline int cloop_read_block(BlockDriverState *bs, int block_num)
109 {
110 BDRVCloopState *s = bs->opaque;
111
112 if (s->current_block != block_num) {
113 int ret;
114 uint32_t bytes = s->offsets[block_num + 1] - s->offsets[block_num];
115
116 ret = bdrv_pread(bs->file, s->offsets[block_num], s->compressed_block,
117 bytes);
118 if (ret != bytes) {
119 return -1;
120 }
121
122 s->zstream.next_in = s->compressed_block;
123 s->zstream.avail_in = bytes;
124 s->zstream.next_out = s->uncompressed_block;
125 s->zstream.avail_out = s->block_size;
126 ret = inflateReset(&s->zstream);
127 if (ret != Z_OK) {
128 return -1;
129 }
130 ret = inflate(&s->zstream, Z_FINISH);
131 if (ret != Z_STREAM_END || s->zstream.total_out != s->block_size) {
132 return -1;
133 }
134
135 s->current_block = block_num;
136 }
137 return 0;
138 }
139
140 static int cloop_read(BlockDriverState *bs, int64_t sector_num,
141 uint8_t *buf, int nb_sectors)
142 {
143 BDRVCloopState *s = bs->opaque;
144 int i;
145
146 for (i = 0; i < nb_sectors; i++) {
147 uint32_t sector_offset_in_block =
148 ((sector_num + i) % s->sectors_per_block),
149 block_num = (sector_num + i) / s->sectors_per_block;
150 if (cloop_read_block(bs, block_num) != 0) {
151 return -1;
152 }
153 memcpy(buf + i * 512,
154 s->uncompressed_block + sector_offset_in_block * 512, 512);
155 }
156 return 0;
157 }
158
159 static coroutine_fn int cloop_co_read(BlockDriverState *bs, int64_t sector_num,
160 uint8_t *buf, int nb_sectors)
161 {
162 int ret;
163 BDRVCloopState *s = bs->opaque;
164 qemu_co_mutex_lock(&s->lock);
165 ret = cloop_read(bs, sector_num, buf, nb_sectors);
166 qemu_co_mutex_unlock(&s->lock);
167 return ret;
168 }
169
170 static void cloop_close(BlockDriverState *bs)
171 {
172 BDRVCloopState *s = bs->opaque;
173 if (s->n_blocks > 0) {
174 g_free(s->offsets);
175 }
176 g_free(s->compressed_block);
177 g_free(s->uncompressed_block);
178 inflateEnd(&s->zstream);
179 }
180
181 static BlockDriver bdrv_cloop = {
182 .format_name = "cloop",
183 .instance_size = sizeof(BDRVCloopState),
184 .bdrv_probe = cloop_probe,
185 .bdrv_open = cloop_open,
186 .bdrv_read = cloop_co_read,
187 .bdrv_close = cloop_close,
188 };
189
190 static void bdrv_cloop_init(void)
191 {
192 bdrv_register(&bdrv_cloop);
193 }
194
195 block_init(bdrv_cloop_init);