replay: replay BH for IDE trim operation
[qemu/ar7.git] / block / cloop.c
blob2be68987bd9172c52937e159b8d8a38af08dcb0b
1 /*
2 * QEMU Block driver for CLOOP images
4 * Copyright (c) 2004 Johannes E. Schindelin
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:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
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.
24 #include "qemu/osdep.h"
25 #include "qapi/error.h"
26 #include "qemu/error-report.h"
27 #include "qemu-common.h"
28 #include "block/block_int.h"
29 #include "qemu/module.h"
30 #include "qemu/bswap.h"
31 #include <zlib.h>
33 /* Maximum compressed block size */
34 #define MAX_BLOCK_SIZE (64 * 1024 * 1024)
36 typedef struct BDRVCloopState {
37 CoMutex lock;
38 uint32_t block_size;
39 uint32_t n_blocks;
40 uint64_t *offsets;
41 uint32_t sectors_per_block;
42 uint32_t current_block;
43 uint8_t *compressed_block;
44 uint8_t *uncompressed_block;
45 z_stream zstream;
46 } BDRVCloopState;
48 static int cloop_probe(const uint8_t *buf, int buf_size, const char *filename)
50 const char *magic_version_2_0 = "#!/bin/sh\n"
51 "#V2.0 Format\n"
52 "modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1\n";
53 int length = strlen(magic_version_2_0);
54 if (length > buf_size) {
55 length = buf_size;
57 if (!memcmp(magic_version_2_0, buf, length)) {
58 return 2;
60 return 0;
63 static int cloop_open(BlockDriverState *bs, QDict *options, int flags,
64 Error **errp)
66 BDRVCloopState *s = bs->opaque;
67 uint32_t offsets_size, max_compressed_block_size = 1, i;
68 int ret;
70 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
71 false, errp);
72 if (!bs->file) {
73 return -EINVAL;
76 if (!bdrv_is_read_only(bs)) {
77 error_report("Opening cloop images without an explicit read-only=on "
78 "option is deprecated. Future versions will refuse to "
79 "open the image instead of automatically marking the "
80 "image read-only.");
81 ret = bdrv_set_read_only(bs, true, errp);
82 if (ret < 0) {
83 return ret;
87 /* read header */
88 ret = bdrv_pread(bs->file, 128, &s->block_size, 4);
89 if (ret < 0) {
90 return ret;
92 s->block_size = be32_to_cpu(s->block_size);
93 if (s->block_size % 512) {
94 error_setg(errp, "block_size %" PRIu32 " must be a multiple of 512",
95 s->block_size);
96 return -EINVAL;
98 if (s->block_size == 0) {
99 error_setg(errp, "block_size cannot be zero");
100 return -EINVAL;
103 /* cloop's create_compressed_fs.c warns about block sizes beyond 256 KB but
104 * we can accept more. Prevent ridiculous values like 4 GB - 1 since we
105 * need a buffer this big.
107 if (s->block_size > MAX_BLOCK_SIZE) {
108 error_setg(errp, "block_size %" PRIu32 " must be %u MB or less",
109 s->block_size,
110 MAX_BLOCK_SIZE / (1024 * 1024));
111 return -EINVAL;
114 ret = bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4);
115 if (ret < 0) {
116 return ret;
118 s->n_blocks = be32_to_cpu(s->n_blocks);
120 /* read offsets */
121 if (s->n_blocks > (UINT32_MAX - 1) / sizeof(uint64_t)) {
122 /* Prevent integer overflow */
123 error_setg(errp, "n_blocks %" PRIu32 " must be %zu or less",
124 s->n_blocks,
125 (UINT32_MAX - 1) / sizeof(uint64_t));
126 return -EINVAL;
128 offsets_size = (s->n_blocks + 1) * sizeof(uint64_t);
129 if (offsets_size > 512 * 1024 * 1024) {
130 /* Prevent ridiculous offsets_size which causes memory allocation to
131 * fail or overflows bdrv_pread() size. In practice the 512 MB
132 * offsets[] limit supports 16 TB images at 256 KB block size.
134 error_setg(errp, "image requires too many offsets, "
135 "try increasing block size");
136 return -EINVAL;
139 s->offsets = g_try_malloc(offsets_size);
140 if (s->offsets == NULL) {
141 error_setg(errp, "Could not allocate offsets table");
142 return -ENOMEM;
145 ret = bdrv_pread(bs->file, 128 + 4 + 4, s->offsets, offsets_size);
146 if (ret < 0) {
147 goto fail;
150 for (i = 0; i < s->n_blocks + 1; i++) {
151 uint64_t size;
153 s->offsets[i] = be64_to_cpu(s->offsets[i]);
154 if (i == 0) {
155 continue;
158 if (s->offsets[i] < s->offsets[i - 1]) {
159 error_setg(errp, "offsets not monotonically increasing at "
160 "index %" PRIu32 ", image file is corrupt", i);
161 ret = -EINVAL;
162 goto fail;
165 size = s->offsets[i] - s->offsets[i - 1];
167 /* Compressed blocks should be smaller than the uncompressed block size
168 * but maybe compression performed poorly so the compressed block is
169 * actually bigger. Clamp down on unrealistic values to prevent
170 * ridiculous s->compressed_block allocation.
172 if (size > 2 * MAX_BLOCK_SIZE) {
173 error_setg(errp, "invalid compressed block size at index %" PRIu32
174 ", image file is corrupt", i);
175 ret = -EINVAL;
176 goto fail;
179 if (size > max_compressed_block_size) {
180 max_compressed_block_size = size;
184 /* initialize zlib engine */
185 s->compressed_block = g_try_malloc(max_compressed_block_size + 1);
186 if (s->compressed_block == NULL) {
187 error_setg(errp, "Could not allocate compressed_block");
188 ret = -ENOMEM;
189 goto fail;
192 s->uncompressed_block = g_try_malloc(s->block_size);
193 if (s->uncompressed_block == NULL) {
194 error_setg(errp, "Could not allocate uncompressed_block");
195 ret = -ENOMEM;
196 goto fail;
199 if (inflateInit(&s->zstream) != Z_OK) {
200 ret = -EINVAL;
201 goto fail;
203 s->current_block = s->n_blocks;
205 s->sectors_per_block = s->block_size/512;
206 bs->total_sectors = s->n_blocks * s->sectors_per_block;
207 qemu_co_mutex_init(&s->lock);
208 return 0;
210 fail:
211 g_free(s->offsets);
212 g_free(s->compressed_block);
213 g_free(s->uncompressed_block);
214 return ret;
217 static void cloop_refresh_limits(BlockDriverState *bs, Error **errp)
219 bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */
222 static inline int cloop_read_block(BlockDriverState *bs, int block_num)
224 BDRVCloopState *s = bs->opaque;
226 if (s->current_block != block_num) {
227 int ret;
228 uint32_t bytes = s->offsets[block_num + 1] - s->offsets[block_num];
230 ret = bdrv_pread(bs->file, s->offsets[block_num],
231 s->compressed_block, bytes);
232 if (ret != bytes) {
233 return -1;
236 s->zstream.next_in = s->compressed_block;
237 s->zstream.avail_in = bytes;
238 s->zstream.next_out = s->uncompressed_block;
239 s->zstream.avail_out = s->block_size;
240 ret = inflateReset(&s->zstream);
241 if (ret != Z_OK) {
242 return -1;
244 ret = inflate(&s->zstream, Z_FINISH);
245 if (ret != Z_STREAM_END || s->zstream.total_out != s->block_size) {
246 return -1;
249 s->current_block = block_num;
251 return 0;
254 static int coroutine_fn
255 cloop_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
256 QEMUIOVector *qiov, int flags)
258 BDRVCloopState *s = bs->opaque;
259 uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
260 int nb_sectors = bytes >> BDRV_SECTOR_BITS;
261 int ret, i;
263 assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
264 assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
266 qemu_co_mutex_lock(&s->lock);
268 for (i = 0; i < nb_sectors; i++) {
269 void *data;
270 uint32_t sector_offset_in_block =
271 ((sector_num + i) % s->sectors_per_block),
272 block_num = (sector_num + i) / s->sectors_per_block;
273 if (cloop_read_block(bs, block_num) != 0) {
274 ret = -EIO;
275 goto fail;
278 data = s->uncompressed_block + sector_offset_in_block * 512;
279 qemu_iovec_from_buf(qiov, i * 512, data, 512);
282 ret = 0;
283 fail:
284 qemu_co_mutex_unlock(&s->lock);
286 return ret;
289 static void cloop_close(BlockDriverState *bs)
291 BDRVCloopState *s = bs->opaque;
292 g_free(s->offsets);
293 g_free(s->compressed_block);
294 g_free(s->uncompressed_block);
295 inflateEnd(&s->zstream);
298 static BlockDriver bdrv_cloop = {
299 .format_name = "cloop",
300 .instance_size = sizeof(BDRVCloopState),
301 .bdrv_probe = cloop_probe,
302 .bdrv_open = cloop_open,
303 .bdrv_child_perm = bdrv_format_default_perms,
304 .bdrv_refresh_limits = cloop_refresh_limits,
305 .bdrv_co_preadv = cloop_co_preadv,
306 .bdrv_close = cloop_close,
309 static void bdrv_cloop_init(void)
311 bdrv_register(&bdrv_cloop);
314 block_init(bdrv_cloop_init);