Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging
[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/block_int.h"
26 #include "qemu/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, QDict *options, int flags,
57 Error **errp)
58 {
59 BDRVCloopState *s = bs->opaque;
60 uint32_t offsets_size, max_compressed_block_size = 1, i;
61 int ret;
62
63 bs->read_only = 1;
64
65 /* read header */
66 ret = bdrv_pread(bs->file, 128, &s->block_size, 4);
67 if (ret < 0) {
68 return ret;
69 }
70 s->block_size = be32_to_cpu(s->block_size);
71
72 ret = bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4);
73 if (ret < 0) {
74 return ret;
75 }
76 s->n_blocks = be32_to_cpu(s->n_blocks);
77
78 /* read offsets */
79 offsets_size = s->n_blocks * sizeof(uint64_t);
80 s->offsets = g_malloc(offsets_size);
81
82 ret = bdrv_pread(bs->file, 128 + 4 + 4, s->offsets, offsets_size);
83 if (ret < 0) {
84 goto fail;
85 }
86
87 for(i=0;i<s->n_blocks;i++) {
88 s->offsets[i] = be64_to_cpu(s->offsets[i]);
89 if (i > 0) {
90 uint32_t size = s->offsets[i] - s->offsets[i - 1];
91 if (size > max_compressed_block_size) {
92 max_compressed_block_size = size;
93 }
94 }
95 }
96
97 /* initialize zlib engine */
98 s->compressed_block = g_malloc(max_compressed_block_size + 1);
99 s->uncompressed_block = g_malloc(s->block_size);
100 if (inflateInit(&s->zstream) != Z_OK) {
101 ret = -EINVAL;
102 goto fail;
103 }
104 s->current_block = s->n_blocks;
105
106 s->sectors_per_block = s->block_size/512;
107 bs->total_sectors = s->n_blocks * s->sectors_per_block;
108 qemu_co_mutex_init(&s->lock);
109 return 0;
110
111 fail:
112 g_free(s->offsets);
113 g_free(s->compressed_block);
114 g_free(s->uncompressed_block);
115 return ret;
116 }
117
118 static inline int cloop_read_block(BlockDriverState *bs, int block_num)
119 {
120 BDRVCloopState *s = bs->opaque;
121
122 if (s->current_block != block_num) {
123 int ret;
124 uint32_t bytes = s->offsets[block_num + 1] - s->offsets[block_num];
125
126 ret = bdrv_pread(bs->file, s->offsets[block_num], s->compressed_block,
127 bytes);
128 if (ret != bytes) {
129 return -1;
130 }
131
132 s->zstream.next_in = s->compressed_block;
133 s->zstream.avail_in = bytes;
134 s->zstream.next_out = s->uncompressed_block;
135 s->zstream.avail_out = s->block_size;
136 ret = inflateReset(&s->zstream);
137 if (ret != Z_OK) {
138 return -1;
139 }
140 ret = inflate(&s->zstream, Z_FINISH);
141 if (ret != Z_STREAM_END || s->zstream.total_out != s->block_size) {
142 return -1;
143 }
144
145 s->current_block = block_num;
146 }
147 return 0;
148 }
149
150 static int cloop_read(BlockDriverState *bs, int64_t sector_num,
151 uint8_t *buf, int nb_sectors)
152 {
153 BDRVCloopState *s = bs->opaque;
154 int i;
155
156 for (i = 0; i < nb_sectors; i++) {
157 uint32_t sector_offset_in_block =
158 ((sector_num + i) % s->sectors_per_block),
159 block_num = (sector_num + i) / s->sectors_per_block;
160 if (cloop_read_block(bs, block_num) != 0) {
161 return -1;
162 }
163 memcpy(buf + i * 512,
164 s->uncompressed_block + sector_offset_in_block * 512, 512);
165 }
166 return 0;
167 }
168
169 static coroutine_fn int cloop_co_read(BlockDriverState *bs, int64_t sector_num,
170 uint8_t *buf, int nb_sectors)
171 {
172 int ret;
173 BDRVCloopState *s = bs->opaque;
174 qemu_co_mutex_lock(&s->lock);
175 ret = cloop_read(bs, sector_num, buf, nb_sectors);
176 qemu_co_mutex_unlock(&s->lock);
177 return ret;
178 }
179
180 static void cloop_close(BlockDriverState *bs)
181 {
182 BDRVCloopState *s = bs->opaque;
183 if (s->n_blocks > 0) {
184 g_free(s->offsets);
185 }
186 g_free(s->compressed_block);
187 g_free(s->uncompressed_block);
188 inflateEnd(&s->zstream);
189 }
190
191 static BlockDriver bdrv_cloop = {
192 .format_name = "cloop",
193 .instance_size = sizeof(BDRVCloopState),
194 .bdrv_probe = cloop_probe,
195 .bdrv_open = cloop_open,
196 .bdrv_read = cloop_co_read,
197 .bdrv_close = cloop_close,
198 };
199
200 static void bdrv_cloop_init(void)
201 {
202 bdrv_register(&bdrv_cloop);
203 }
204
205 block_init(bdrv_cloop_init);