spapr_pci: perform unplug via the hotplug handler
[qemu/ar7.git] / block / cloop.c
blobdf2b85f7234203d9a457e38f7778b23af895a4cf
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 ret = bdrv_apply_auto_read_only(bs, NULL, errp);
71 if (ret < 0) {
72 return ret;
75 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
76 false, errp);
77 if (!bs->file) {
78 return -EINVAL;
81 /* read header */
82 ret = bdrv_pread(bs->file, 128, &s->block_size, 4);
83 if (ret < 0) {
84 return ret;
86 s->block_size = be32_to_cpu(s->block_size);
87 if (s->block_size % 512) {
88 error_setg(errp, "block_size %" PRIu32 " must be a multiple of 512",
89 s->block_size);
90 return -EINVAL;
92 if (s->block_size == 0) {
93 error_setg(errp, "block_size cannot be zero");
94 return -EINVAL;
97 /* cloop's create_compressed_fs.c warns about block sizes beyond 256 KB but
98 * we can accept more. Prevent ridiculous values like 4 GB - 1 since we
99 * need a buffer this big.
101 if (s->block_size > MAX_BLOCK_SIZE) {
102 error_setg(errp, "block_size %" PRIu32 " must be %u MB or less",
103 s->block_size,
104 MAX_BLOCK_SIZE / (1024 * 1024));
105 return -EINVAL;
108 ret = bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4);
109 if (ret < 0) {
110 return ret;
112 s->n_blocks = be32_to_cpu(s->n_blocks);
114 /* read offsets */
115 if (s->n_blocks > (UINT32_MAX - 1) / sizeof(uint64_t)) {
116 /* Prevent integer overflow */
117 error_setg(errp, "n_blocks %" PRIu32 " must be %zu or less",
118 s->n_blocks,
119 (UINT32_MAX - 1) / sizeof(uint64_t));
120 return -EINVAL;
122 offsets_size = (s->n_blocks + 1) * sizeof(uint64_t);
123 if (offsets_size > 512 * 1024 * 1024) {
124 /* Prevent ridiculous offsets_size which causes memory allocation to
125 * fail or overflows bdrv_pread() size. In practice the 512 MB
126 * offsets[] limit supports 16 TB images at 256 KB block size.
128 error_setg(errp, "image requires too many offsets, "
129 "try increasing block size");
130 return -EINVAL;
133 s->offsets = g_try_malloc(offsets_size);
134 if (s->offsets == NULL) {
135 error_setg(errp, "Could not allocate offsets table");
136 return -ENOMEM;
139 ret = bdrv_pread(bs->file, 128 + 4 + 4, s->offsets, offsets_size);
140 if (ret < 0) {
141 goto fail;
144 for (i = 0; i < s->n_blocks + 1; i++) {
145 uint64_t size;
147 s->offsets[i] = be64_to_cpu(s->offsets[i]);
148 if (i == 0) {
149 continue;
152 if (s->offsets[i] < s->offsets[i - 1]) {
153 error_setg(errp, "offsets not monotonically increasing at "
154 "index %" PRIu32 ", image file is corrupt", i);
155 ret = -EINVAL;
156 goto fail;
159 size = s->offsets[i] - s->offsets[i - 1];
161 /* Compressed blocks should be smaller than the uncompressed block size
162 * but maybe compression performed poorly so the compressed block is
163 * actually bigger. Clamp down on unrealistic values to prevent
164 * ridiculous s->compressed_block allocation.
166 if (size > 2 * MAX_BLOCK_SIZE) {
167 error_setg(errp, "invalid compressed block size at index %" PRIu32
168 ", image file is corrupt", i);
169 ret = -EINVAL;
170 goto fail;
173 if (size > max_compressed_block_size) {
174 max_compressed_block_size = size;
178 /* initialize zlib engine */
179 s->compressed_block = g_try_malloc(max_compressed_block_size + 1);
180 if (s->compressed_block == NULL) {
181 error_setg(errp, "Could not allocate compressed_block");
182 ret = -ENOMEM;
183 goto fail;
186 s->uncompressed_block = g_try_malloc(s->block_size);
187 if (s->uncompressed_block == NULL) {
188 error_setg(errp, "Could not allocate uncompressed_block");
189 ret = -ENOMEM;
190 goto fail;
193 if (inflateInit(&s->zstream) != Z_OK) {
194 ret = -EINVAL;
195 goto fail;
197 s->current_block = s->n_blocks;
199 s->sectors_per_block = s->block_size/512;
200 bs->total_sectors = s->n_blocks * s->sectors_per_block;
201 qemu_co_mutex_init(&s->lock);
202 return 0;
204 fail:
205 g_free(s->offsets);
206 g_free(s->compressed_block);
207 g_free(s->uncompressed_block);
208 return ret;
211 static void cloop_refresh_limits(BlockDriverState *bs, Error **errp)
213 bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */
216 static inline int cloop_read_block(BlockDriverState *bs, int block_num)
218 BDRVCloopState *s = bs->opaque;
220 if (s->current_block != block_num) {
221 int ret;
222 uint32_t bytes = s->offsets[block_num + 1] - s->offsets[block_num];
224 ret = bdrv_pread(bs->file, s->offsets[block_num],
225 s->compressed_block, bytes);
226 if (ret != bytes) {
227 return -1;
230 s->zstream.next_in = s->compressed_block;
231 s->zstream.avail_in = bytes;
232 s->zstream.next_out = s->uncompressed_block;
233 s->zstream.avail_out = s->block_size;
234 ret = inflateReset(&s->zstream);
235 if (ret != Z_OK) {
236 return -1;
238 ret = inflate(&s->zstream, Z_FINISH);
239 if (ret != Z_STREAM_END || s->zstream.total_out != s->block_size) {
240 return -1;
243 s->current_block = block_num;
245 return 0;
248 static int coroutine_fn
249 cloop_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
250 QEMUIOVector *qiov, int flags)
252 BDRVCloopState *s = bs->opaque;
253 uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
254 int nb_sectors = bytes >> BDRV_SECTOR_BITS;
255 int ret, i;
257 assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
258 assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
260 qemu_co_mutex_lock(&s->lock);
262 for (i = 0; i < nb_sectors; i++) {
263 void *data;
264 uint32_t sector_offset_in_block =
265 ((sector_num + i) % s->sectors_per_block),
266 block_num = (sector_num + i) / s->sectors_per_block;
267 if (cloop_read_block(bs, block_num) != 0) {
268 ret = -EIO;
269 goto fail;
272 data = s->uncompressed_block + sector_offset_in_block * 512;
273 qemu_iovec_from_buf(qiov, i * 512, data, 512);
276 ret = 0;
277 fail:
278 qemu_co_mutex_unlock(&s->lock);
280 return ret;
283 static void cloop_close(BlockDriverState *bs)
285 BDRVCloopState *s = bs->opaque;
286 g_free(s->offsets);
287 g_free(s->compressed_block);
288 g_free(s->uncompressed_block);
289 inflateEnd(&s->zstream);
292 static BlockDriver bdrv_cloop = {
293 .format_name = "cloop",
294 .instance_size = sizeof(BDRVCloopState),
295 .bdrv_probe = cloop_probe,
296 .bdrv_open = cloop_open,
297 .bdrv_child_perm = bdrv_format_default_perms,
298 .bdrv_refresh_limits = cloop_refresh_limits,
299 .bdrv_co_preadv = cloop_co_preadv,
300 .bdrv_close = cloop_close,
303 static void bdrv_cloop_init(void)
305 bdrv_register(&bdrv_cloop);
308 block_init(bdrv_cloop_init);