tests: virtio-9p: rename PCI configuration test
[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/osdep.h"
25 #include "qapi/error.h"
26 #include "qemu-common.h"
27 #include "block/block_int.h"
28 #include "qemu/module.h"
29 #include "qemu/bswap.h"
30 #include <zlib.h>
31
32 /* Maximum compressed block size */
33 #define MAX_BLOCK_SIZE (64 * 1024 * 1024)
34
35 typedef struct BDRVCloopState {
36 CoMutex lock;
37 uint32_t block_size;
38 uint32_t n_blocks;
39 uint64_t *offsets;
40 uint32_t sectors_per_block;
41 uint32_t current_block;
42 uint8_t *compressed_block;
43 uint8_t *uncompressed_block;
44 z_stream zstream;
45 } BDRVCloopState;
46
47 static int cloop_probe(const uint8_t *buf, int buf_size, const char *filename)
48 {
49 const char *magic_version_2_0 = "#!/bin/sh\n"
50 "#V2.0 Format\n"
51 "modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1\n";
52 int length = strlen(magic_version_2_0);
53 if (length > buf_size) {
54 length = buf_size;
55 }
56 if (!memcmp(magic_version_2_0, buf, length)) {
57 return 2;
58 }
59 return 0;
60 }
61
62 static int cloop_open(BlockDriverState *bs, QDict *options, int flags,
63 Error **errp)
64 {
65 BDRVCloopState *s = bs->opaque;
66 uint32_t offsets_size, max_compressed_block_size = 1, i;
67 int ret;
68
69 bs->read_only = true;
70
71 /* read header */
72 ret = bdrv_pread(bs->file, 128, &s->block_size, 4);
73 if (ret < 0) {
74 return ret;
75 }
76 s->block_size = be32_to_cpu(s->block_size);
77 if (s->block_size % 512) {
78 error_setg(errp, "block_size %" PRIu32 " must be a multiple of 512",
79 s->block_size);
80 return -EINVAL;
81 }
82 if (s->block_size == 0) {
83 error_setg(errp, "block_size cannot be zero");
84 return -EINVAL;
85 }
86
87 /* cloop's create_compressed_fs.c warns about block sizes beyond 256 KB but
88 * we can accept more. Prevent ridiculous values like 4 GB - 1 since we
89 * need a buffer this big.
90 */
91 if (s->block_size > MAX_BLOCK_SIZE) {
92 error_setg(errp, "block_size %" PRIu32 " must be %u MB or less",
93 s->block_size,
94 MAX_BLOCK_SIZE / (1024 * 1024));
95 return -EINVAL;
96 }
97
98 ret = bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4);
99 if (ret < 0) {
100 return ret;
101 }
102 s->n_blocks = be32_to_cpu(s->n_blocks);
103
104 /* read offsets */
105 if (s->n_blocks > (UINT32_MAX - 1) / sizeof(uint64_t)) {
106 /* Prevent integer overflow */
107 error_setg(errp, "n_blocks %" PRIu32 " must be %zu or less",
108 s->n_blocks,
109 (UINT32_MAX - 1) / sizeof(uint64_t));
110 return -EINVAL;
111 }
112 offsets_size = (s->n_blocks + 1) * sizeof(uint64_t);
113 if (offsets_size > 512 * 1024 * 1024) {
114 /* Prevent ridiculous offsets_size which causes memory allocation to
115 * fail or overflows bdrv_pread() size. In practice the 512 MB
116 * offsets[] limit supports 16 TB images at 256 KB block size.
117 */
118 error_setg(errp, "image requires too many offsets, "
119 "try increasing block size");
120 return -EINVAL;
121 }
122
123 s->offsets = g_try_malloc(offsets_size);
124 if (s->offsets == NULL) {
125 error_setg(errp, "Could not allocate offsets table");
126 return -ENOMEM;
127 }
128
129 ret = bdrv_pread(bs->file, 128 + 4 + 4, s->offsets, offsets_size);
130 if (ret < 0) {
131 goto fail;
132 }
133
134 for (i = 0; i < s->n_blocks + 1; i++) {
135 uint64_t size;
136
137 s->offsets[i] = be64_to_cpu(s->offsets[i]);
138 if (i == 0) {
139 continue;
140 }
141
142 if (s->offsets[i] < s->offsets[i - 1]) {
143 error_setg(errp, "offsets not monotonically increasing at "
144 "index %" PRIu32 ", image file is corrupt", i);
145 ret = -EINVAL;
146 goto fail;
147 }
148
149 size = s->offsets[i] - s->offsets[i - 1];
150
151 /* Compressed blocks should be smaller than the uncompressed block size
152 * but maybe compression performed poorly so the compressed block is
153 * actually bigger. Clamp down on unrealistic values to prevent
154 * ridiculous s->compressed_block allocation.
155 */
156 if (size > 2 * MAX_BLOCK_SIZE) {
157 error_setg(errp, "invalid compressed block size at index %" PRIu32
158 ", image file is corrupt", i);
159 ret = -EINVAL;
160 goto fail;
161 }
162
163 if (size > max_compressed_block_size) {
164 max_compressed_block_size = size;
165 }
166 }
167
168 /* initialize zlib engine */
169 s->compressed_block = g_try_malloc(max_compressed_block_size + 1);
170 if (s->compressed_block == NULL) {
171 error_setg(errp, "Could not allocate compressed_block");
172 ret = -ENOMEM;
173 goto fail;
174 }
175
176 s->uncompressed_block = g_try_malloc(s->block_size);
177 if (s->uncompressed_block == NULL) {
178 error_setg(errp, "Could not allocate uncompressed_block");
179 ret = -ENOMEM;
180 goto fail;
181 }
182
183 if (inflateInit(&s->zstream) != Z_OK) {
184 ret = -EINVAL;
185 goto fail;
186 }
187 s->current_block = s->n_blocks;
188
189 s->sectors_per_block = s->block_size/512;
190 bs->total_sectors = s->n_blocks * s->sectors_per_block;
191 qemu_co_mutex_init(&s->lock);
192 return 0;
193
194 fail:
195 g_free(s->offsets);
196 g_free(s->compressed_block);
197 g_free(s->uncompressed_block);
198 return ret;
199 }
200
201 static void cloop_refresh_limits(BlockDriverState *bs, Error **errp)
202 {
203 bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */
204 }
205
206 static inline int cloop_read_block(BlockDriverState *bs, int block_num)
207 {
208 BDRVCloopState *s = bs->opaque;
209
210 if (s->current_block != block_num) {
211 int ret;
212 uint32_t bytes = s->offsets[block_num + 1] - s->offsets[block_num];
213
214 ret = bdrv_pread(bs->file, s->offsets[block_num],
215 s->compressed_block, bytes);
216 if (ret != bytes) {
217 return -1;
218 }
219
220 s->zstream.next_in = s->compressed_block;
221 s->zstream.avail_in = bytes;
222 s->zstream.next_out = s->uncompressed_block;
223 s->zstream.avail_out = s->block_size;
224 ret = inflateReset(&s->zstream);
225 if (ret != Z_OK) {
226 return -1;
227 }
228 ret = inflate(&s->zstream, Z_FINISH);
229 if (ret != Z_STREAM_END || s->zstream.total_out != s->block_size) {
230 return -1;
231 }
232
233 s->current_block = block_num;
234 }
235 return 0;
236 }
237
238 static int coroutine_fn
239 cloop_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
240 QEMUIOVector *qiov, int flags)
241 {
242 BDRVCloopState *s = bs->opaque;
243 uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
244 int nb_sectors = bytes >> BDRV_SECTOR_BITS;
245 int ret, i;
246
247 assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
248 assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
249
250 qemu_co_mutex_lock(&s->lock);
251
252 for (i = 0; i < nb_sectors; i++) {
253 void *data;
254 uint32_t sector_offset_in_block =
255 ((sector_num + i) % s->sectors_per_block),
256 block_num = (sector_num + i) / s->sectors_per_block;
257 if (cloop_read_block(bs, block_num) != 0) {
258 ret = -EIO;
259 goto fail;
260 }
261
262 data = s->uncompressed_block + sector_offset_in_block * 512;
263 qemu_iovec_from_buf(qiov, i * 512, data, 512);
264 }
265
266 ret = 0;
267 fail:
268 qemu_co_mutex_unlock(&s->lock);
269
270 return ret;
271 }
272
273 static void cloop_close(BlockDriverState *bs)
274 {
275 BDRVCloopState *s = bs->opaque;
276 g_free(s->offsets);
277 g_free(s->compressed_block);
278 g_free(s->uncompressed_block);
279 inflateEnd(&s->zstream);
280 }
281
282 static BlockDriver bdrv_cloop = {
283 .format_name = "cloop",
284 .instance_size = sizeof(BDRVCloopState),
285 .bdrv_probe = cloop_probe,
286 .bdrv_open = cloop_open,
287 .bdrv_refresh_limits = cloop_refresh_limits,
288 .bdrv_co_preadv = cloop_co_preadv,
289 .bdrv_close = cloop_close,
290 };
291
292 static void bdrv_cloop_init(void)
293 {
294 bdrv_register(&bdrv_cloop);
295 }
296
297 block_init(bdrv_cloop_init);