root / block / qcow2.c @ 6377af48
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/*
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* Block driver for the QCOW version 2 format
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*
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* Copyright (c) 2004-2006 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu-common.h" |
25 |
#include "block_int.h" |
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#include "module.h" |
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#include <zlib.h> |
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#include "aes.h" |
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#include "block/qcow2.h" |
30 |
#include "qemu-error.h" |
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#include "qerror.h" |
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#include "trace.h" |
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/*
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Differences with QCOW:
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- Support for multiple incremental snapshots.
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- Memory management by reference counts.
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- Clusters which have a reference count of one have the bit
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QCOW_OFLAG_COPIED to optimize write performance.
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- Size of compressed clusters is stored in sectors to reduce bit usage
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in the cluster offsets.
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- Support for storing additional data (such as the VM state) in the
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snapshots.
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- If a backing store is used, the cluster size is not constrained
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(could be backported to QCOW).
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- L2 tables have always a size of one cluster.
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*/
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|
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|
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typedef struct { |
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uint32_t magic; |
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uint32_t len; |
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} QCowExtension; |
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#define QCOW2_EXT_MAGIC_END 0 |
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#define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA |
57 |
|
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static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) |
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{ |
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const QCowHeader *cow_header = (const void *)buf; |
61 |
|
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if (buf_size >= sizeof(QCowHeader) && |
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be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
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be32_to_cpu(cow_header->version) >= 2)
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return 100; |
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else
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return 0; |
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} |
69 |
|
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|
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/*
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* read qcow2 extension and fill bs
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* start reading from start_offset
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* finish reading upon magic of value 0 or when end_offset reached
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* unknown magic is skipped (future extension this version knows nothing about)
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* return 0 upon success, non-0 otherwise
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*/
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static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, |
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uint64_t end_offset) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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QCowExtension ext; |
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uint64_t offset; |
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int ret;
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|
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#ifdef DEBUG_EXT
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printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
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#endif
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offset = start_offset; |
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while (offset < end_offset) {
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|
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#ifdef DEBUG_EXT
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/* Sanity check */
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if (offset > s->cluster_size)
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printf("qcow2_read_extension: suspicious offset %lu\n", offset);
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printf("attempting to read extended header in offset %lu\n", offset);
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#endif
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|
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if (bdrv_pread(bs->file, offset, &ext, sizeof(ext)) != sizeof(ext)) { |
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fprintf(stderr, "qcow2_read_extension: ERROR: "
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"pread fail from offset %" PRIu64 "\n", |
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offset); |
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return 1; |
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} |
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be32_to_cpus(&ext.magic); |
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be32_to_cpus(&ext.len); |
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offset += sizeof(ext);
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#ifdef DEBUG_EXT
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printf("ext.magic = 0x%x\n", ext.magic);
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#endif
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if (ext.len > end_offset - offset) {
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error_report("Header extension too large");
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return -EINVAL;
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} |
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|
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switch (ext.magic) {
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case QCOW2_EXT_MAGIC_END:
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return 0; |
120 |
|
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case QCOW2_EXT_MAGIC_BACKING_FORMAT:
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if (ext.len >= sizeof(bs->backing_format)) { |
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fprintf(stderr, "ERROR: ext_backing_format: len=%u too large"
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" (>=%zu)\n",
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ext.len, sizeof(bs->backing_format));
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return 2; |
127 |
} |
128 |
if (bdrv_pread(bs->file, offset , bs->backing_format,
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ext.len) != ext.len) |
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return 3; |
131 |
bs->backing_format[ext.len] = '\0';
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#ifdef DEBUG_EXT
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printf("Qcow2: Got format extension %s\n", bs->backing_format);
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#endif
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break;
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|
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default:
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/* unknown magic - save it in case we need to rewrite the header */
|
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{ |
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Qcow2UnknownHeaderExtension *uext; |
141 |
|
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uext = g_malloc0(sizeof(*uext) + ext.len);
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uext->magic = ext.magic; |
144 |
uext->len = ext.len; |
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QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next); |
146 |
|
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ret = bdrv_pread(bs->file, offset , uext->data, uext->len); |
148 |
if (ret < 0) { |
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return ret;
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} |
151 |
} |
152 |
break;
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} |
154 |
|
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offset += ((ext.len + 7) & ~7); |
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} |
157 |
|
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return 0; |
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} |
160 |
|
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static void cleanup_unknown_header_ext(BlockDriverState *bs) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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Qcow2UnknownHeaderExtension *uext, *next; |
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|
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QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { |
167 |
QLIST_REMOVE(uext, next); |
168 |
g_free(uext); |
169 |
} |
170 |
} |
171 |
|
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static void report_unsupported(BlockDriverState *bs, const char *fmt, ...) |
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{ |
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char msg[64]; |
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va_list ap; |
176 |
|
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va_start(ap, fmt); |
178 |
vsnprintf(msg, sizeof(msg), fmt, ap);
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va_end(ap); |
180 |
|
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qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, |
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bs->device_name, "qcow2", msg);
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} |
184 |
|
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static int qcow2_open(BlockDriverState *bs, int flags) |
186 |
{ |
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BDRVQcowState *s = bs->opaque; |
188 |
int len, i, ret = 0; |
189 |
QCowHeader header; |
190 |
uint64_t ext_end; |
191 |
bool writethrough;
|
192 |
|
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ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); |
194 |
if (ret < 0) { |
195 |
goto fail;
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} |
197 |
be32_to_cpus(&header.magic); |
198 |
be32_to_cpus(&header.version); |
199 |
be64_to_cpus(&header.backing_file_offset); |
200 |
be32_to_cpus(&header.backing_file_size); |
201 |
be64_to_cpus(&header.size); |
202 |
be32_to_cpus(&header.cluster_bits); |
203 |
be32_to_cpus(&header.crypt_method); |
204 |
be64_to_cpus(&header.l1_table_offset); |
205 |
be32_to_cpus(&header.l1_size); |
206 |
be64_to_cpus(&header.refcount_table_offset); |
207 |
be32_to_cpus(&header.refcount_table_clusters); |
208 |
be64_to_cpus(&header.snapshots_offset); |
209 |
be32_to_cpus(&header.nb_snapshots); |
210 |
|
211 |
if (header.magic != QCOW_MAGIC) {
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ret = -EINVAL; |
213 |
goto fail;
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214 |
} |
215 |
if (header.version < 2 || header.version > 3) { |
216 |
report_unsupported(bs, "QCOW version %d", header.version);
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ret = -ENOTSUP; |
218 |
goto fail;
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219 |
} |
220 |
|
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s->qcow_version = header.version; |
222 |
|
223 |
/* Initialise version 3 header fields */
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if (header.version == 2) { |
225 |
header.incompatible_features = 0;
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header.compatible_features = 0;
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header.autoclear_features = 0;
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header.refcount_order = 4;
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header.header_length = 72;
|
230 |
} else {
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be64_to_cpus(&header.incompatible_features); |
232 |
be64_to_cpus(&header.compatible_features); |
233 |
be64_to_cpus(&header.autoclear_features); |
234 |
be32_to_cpus(&header.refcount_order); |
235 |
be32_to_cpus(&header.header_length); |
236 |
} |
237 |
|
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if (header.header_length > sizeof(header)) { |
239 |
s->unknown_header_fields_size = header.header_length - sizeof(header);
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s->unknown_header_fields = g_malloc(s->unknown_header_fields_size); |
241 |
ret = bdrv_pread(bs->file, sizeof(header), s->unknown_header_fields,
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s->unknown_header_fields_size); |
243 |
if (ret < 0) { |
244 |
goto fail;
|
245 |
} |
246 |
} |
247 |
|
248 |
/* Handle feature bits */
|
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s->incompatible_features = header.incompatible_features; |
250 |
s->compatible_features = header.compatible_features; |
251 |
s->autoclear_features = header.autoclear_features; |
252 |
|
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if (s->incompatible_features != 0) { |
254 |
report_unsupported(bs, "incompatible features mask %" PRIx64,
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header.incompatible_features); |
256 |
ret = -ENOTSUP; |
257 |
goto fail;
|
258 |
} |
259 |
|
260 |
if (!bs->read_only && s->autoclear_features != 0) { |
261 |
s->autoclear_features = 0;
|
262 |
qcow2_update_header(bs); |
263 |
} |
264 |
|
265 |
/* Check support for various header values */
|
266 |
if (header.refcount_order != 4) { |
267 |
report_unsupported(bs, "%d bit reference counts",
|
268 |
1 << header.refcount_order);
|
269 |
ret = -ENOTSUP; |
270 |
goto fail;
|
271 |
} |
272 |
|
273 |
if (header.cluster_bits < MIN_CLUSTER_BITS ||
|
274 |
header.cluster_bits > MAX_CLUSTER_BITS) { |
275 |
ret = -EINVAL; |
276 |
goto fail;
|
277 |
} |
278 |
if (header.crypt_method > QCOW_CRYPT_AES) {
|
279 |
ret = -EINVAL; |
280 |
goto fail;
|
281 |
} |
282 |
s->crypt_method_header = header.crypt_method; |
283 |
if (s->crypt_method_header) {
|
284 |
bs->encrypted = 1;
|
285 |
} |
286 |
s->cluster_bits = header.cluster_bits; |
287 |
s->cluster_size = 1 << s->cluster_bits;
|
288 |
s->cluster_sectors = 1 << (s->cluster_bits - 9); |
289 |
s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ |
290 |
s->l2_size = 1 << s->l2_bits;
|
291 |
bs->total_sectors = header.size / 512;
|
292 |
s->csize_shift = (62 - (s->cluster_bits - 8)); |
293 |
s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
294 |
s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
295 |
s->refcount_table_offset = header.refcount_table_offset; |
296 |
s->refcount_table_size = |
297 |
header.refcount_table_clusters << (s->cluster_bits - 3);
|
298 |
|
299 |
s->snapshots_offset = header.snapshots_offset; |
300 |
s->nb_snapshots = header.nb_snapshots; |
301 |
|
302 |
/* read the level 1 table */
|
303 |
s->l1_size = header.l1_size; |
304 |
s->l1_vm_state_index = size_to_l1(s, header.size); |
305 |
/* the L1 table must contain at least enough entries to put
|
306 |
header.size bytes */
|
307 |
if (s->l1_size < s->l1_vm_state_index) {
|
308 |
ret = -EINVAL; |
309 |
goto fail;
|
310 |
} |
311 |
s->l1_table_offset = header.l1_table_offset; |
312 |
if (s->l1_size > 0) { |
313 |
s->l1_table = g_malloc0( |
314 |
align_offset(s->l1_size * sizeof(uint64_t), 512)); |
315 |
ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, |
316 |
s->l1_size * sizeof(uint64_t));
|
317 |
if (ret < 0) { |
318 |
goto fail;
|
319 |
} |
320 |
for(i = 0;i < s->l1_size; i++) { |
321 |
be64_to_cpus(&s->l1_table[i]); |
322 |
} |
323 |
} |
324 |
|
325 |
/* alloc L2 table/refcount block cache */
|
326 |
writethrough = ((flags & BDRV_O_CACHE_WB) == 0);
|
327 |
s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE, writethrough); |
328 |
s->refcount_block_cache = qcow2_cache_create(bs, REFCOUNT_CACHE_SIZE, |
329 |
writethrough); |
330 |
|
331 |
s->cluster_cache = g_malloc(s->cluster_size); |
332 |
/* one more sector for decompressed data alignment */
|
333 |
s->cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size |
334 |
+ 512);
|
335 |
s->cluster_cache_offset = -1;
|
336 |
s->flags = flags; |
337 |
|
338 |
ret = qcow2_refcount_init(bs); |
339 |
if (ret != 0) { |
340 |
goto fail;
|
341 |
} |
342 |
|
343 |
QLIST_INIT(&s->cluster_allocs); |
344 |
|
345 |
/* read qcow2 extensions */
|
346 |
if (header.backing_file_offset) {
|
347 |
ext_end = header.backing_file_offset; |
348 |
} else {
|
349 |
ext_end = s->cluster_size; |
350 |
} |
351 |
if (qcow2_read_extensions(bs, header.header_length, ext_end)) {
|
352 |
ret = -EINVAL; |
353 |
goto fail;
|
354 |
} |
355 |
|
356 |
/* read the backing file name */
|
357 |
if (header.backing_file_offset != 0) { |
358 |
len = header.backing_file_size; |
359 |
if (len > 1023) { |
360 |
len = 1023;
|
361 |
} |
362 |
ret = bdrv_pread(bs->file, header.backing_file_offset, |
363 |
bs->backing_file, len); |
364 |
if (ret < 0) { |
365 |
goto fail;
|
366 |
} |
367 |
bs->backing_file[len] = '\0';
|
368 |
} |
369 |
|
370 |
ret = qcow2_read_snapshots(bs); |
371 |
if (ret < 0) { |
372 |
goto fail;
|
373 |
} |
374 |
|
375 |
/* Initialise locks */
|
376 |
qemu_co_mutex_init(&s->lock); |
377 |
|
378 |
#ifdef DEBUG_ALLOC
|
379 |
{ |
380 |
BdrvCheckResult result = {0};
|
381 |
qcow2_check_refcounts(bs, &result); |
382 |
} |
383 |
#endif
|
384 |
return ret;
|
385 |
|
386 |
fail:
|
387 |
g_free(s->unknown_header_fields); |
388 |
cleanup_unknown_header_ext(bs); |
389 |
qcow2_free_snapshots(bs); |
390 |
qcow2_refcount_close(bs); |
391 |
g_free(s->l1_table); |
392 |
if (s->l2_table_cache) {
|
393 |
qcow2_cache_destroy(bs, s->l2_table_cache); |
394 |
} |
395 |
g_free(s->cluster_cache); |
396 |
qemu_vfree(s->cluster_data); |
397 |
return ret;
|
398 |
} |
399 |
|
400 |
static int qcow2_set_key(BlockDriverState *bs, const char *key) |
401 |
{ |
402 |
BDRVQcowState *s = bs->opaque; |
403 |
uint8_t keybuf[16];
|
404 |
int len, i;
|
405 |
|
406 |
memset(keybuf, 0, 16); |
407 |
len = strlen(key); |
408 |
if (len > 16) |
409 |
len = 16;
|
410 |
/* XXX: we could compress the chars to 7 bits to increase
|
411 |
entropy */
|
412 |
for(i = 0;i < len;i++) { |
413 |
keybuf[i] = key[i]; |
414 |
} |
415 |
s->crypt_method = s->crypt_method_header; |
416 |
|
417 |
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
418 |
return -1; |
419 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
420 |
return -1; |
421 |
#if 0
|
422 |
/* test */
|
423 |
{
|
424 |
uint8_t in[16];
|
425 |
uint8_t out[16];
|
426 |
uint8_t tmp[16];
|
427 |
for(i=0;i<16;i++)
|
428 |
in[i] = i;
|
429 |
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
430 |
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
431 |
for(i = 0; i < 16; i++)
|
432 |
printf(" %02x", tmp[i]);
|
433 |
printf("\n");
|
434 |
for(i = 0; i < 16; i++)
|
435 |
printf(" %02x", out[i]);
|
436 |
printf("\n");
|
437 |
}
|
438 |
#endif
|
439 |
return 0; |
440 |
} |
441 |
|
442 |
static int coroutine_fn qcow2_co_is_allocated(BlockDriverState *bs, |
443 |
int64_t sector_num, int nb_sectors, int *pnum) |
444 |
{ |
445 |
BDRVQcowState *s = bs->opaque; |
446 |
uint64_t cluster_offset; |
447 |
int ret;
|
448 |
|
449 |
*pnum = nb_sectors; |
450 |
/* FIXME We can get errors here, but the bdrv_co_is_allocated interface
|
451 |
* can't pass them on today */
|
452 |
qemu_co_mutex_lock(&s->lock); |
453 |
ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
|
454 |
qemu_co_mutex_unlock(&s->lock); |
455 |
if (ret < 0) { |
456 |
*pnum = 0;
|
457 |
} |
458 |
|
459 |
return (cluster_offset != 0); |
460 |
} |
461 |
|
462 |
/* handle reading after the end of the backing file */
|
463 |
int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
|
464 |
int64_t sector_num, int nb_sectors)
|
465 |
{ |
466 |
int n1;
|
467 |
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
468 |
return nb_sectors;
|
469 |
if (sector_num >= bs->total_sectors)
|
470 |
n1 = 0;
|
471 |
else
|
472 |
n1 = bs->total_sectors - sector_num; |
473 |
|
474 |
qemu_iovec_memset_skip(qiov, 0, 512 * (nb_sectors - n1), 512 * n1); |
475 |
|
476 |
return n1;
|
477 |
} |
478 |
|
479 |
static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, |
480 |
int remaining_sectors, QEMUIOVector *qiov)
|
481 |
{ |
482 |
BDRVQcowState *s = bs->opaque; |
483 |
int index_in_cluster, n1;
|
484 |
int ret;
|
485 |
int cur_nr_sectors; /* number of sectors in current iteration */ |
486 |
uint64_t cluster_offset = 0;
|
487 |
uint64_t bytes_done = 0;
|
488 |
QEMUIOVector hd_qiov; |
489 |
uint8_t *cluster_data = NULL;
|
490 |
|
491 |
qemu_iovec_init(&hd_qiov, qiov->niov); |
492 |
|
493 |
qemu_co_mutex_lock(&s->lock); |
494 |
|
495 |
while (remaining_sectors != 0) { |
496 |
|
497 |
/* prepare next request */
|
498 |
cur_nr_sectors = remaining_sectors; |
499 |
if (s->crypt_method) {
|
500 |
cur_nr_sectors = MIN(cur_nr_sectors, |
501 |
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); |
502 |
} |
503 |
|
504 |
ret = qcow2_get_cluster_offset(bs, sector_num << 9,
|
505 |
&cur_nr_sectors, &cluster_offset); |
506 |
if (ret < 0) { |
507 |
goto fail;
|
508 |
} |
509 |
|
510 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
511 |
|
512 |
qemu_iovec_reset(&hd_qiov); |
513 |
qemu_iovec_copy(&hd_qiov, qiov, bytes_done, |
514 |
cur_nr_sectors * 512);
|
515 |
|
516 |
switch (ret) {
|
517 |
case QCOW2_CLUSTER_UNALLOCATED:
|
518 |
|
519 |
if (bs->backing_hd) {
|
520 |
/* read from the base image */
|
521 |
n1 = qcow2_backing_read1(bs->backing_hd, &hd_qiov, |
522 |
sector_num, cur_nr_sectors); |
523 |
if (n1 > 0) { |
524 |
BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); |
525 |
qemu_co_mutex_unlock(&s->lock); |
526 |
ret = bdrv_co_readv(bs->backing_hd, sector_num, |
527 |
n1, &hd_qiov); |
528 |
qemu_co_mutex_lock(&s->lock); |
529 |
if (ret < 0) { |
530 |
goto fail;
|
531 |
} |
532 |
} |
533 |
} else {
|
534 |
/* Note: in this case, no need to wait */
|
535 |
qemu_iovec_memset(&hd_qiov, 0, 512 * cur_nr_sectors); |
536 |
} |
537 |
break;
|
538 |
|
539 |
case QCOW2_CLUSTER_ZERO:
|
540 |
if (s->qcow_version < 3) { |
541 |
ret = -EIO; |
542 |
goto fail;
|
543 |
} |
544 |
qemu_iovec_memset(&hd_qiov, 0, 512 * cur_nr_sectors); |
545 |
break;
|
546 |
|
547 |
case QCOW2_CLUSTER_COMPRESSED:
|
548 |
/* add AIO support for compressed blocks ? */
|
549 |
ret = qcow2_decompress_cluster(bs, cluster_offset); |
550 |
if (ret < 0) { |
551 |
goto fail;
|
552 |
} |
553 |
|
554 |
qemu_iovec_from_buffer(&hd_qiov, |
555 |
s->cluster_cache + index_in_cluster * 512,
|
556 |
512 * cur_nr_sectors);
|
557 |
break;
|
558 |
|
559 |
case QCOW2_CLUSTER_NORMAL:
|
560 |
if ((cluster_offset & 511) != 0) { |
561 |
ret = -EIO; |
562 |
goto fail;
|
563 |
} |
564 |
|
565 |
if (s->crypt_method) {
|
566 |
/*
|
567 |
* For encrypted images, read everything into a temporary
|
568 |
* contiguous buffer on which the AES functions can work.
|
569 |
*/
|
570 |
if (!cluster_data) {
|
571 |
cluster_data = |
572 |
qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
573 |
} |
574 |
|
575 |
assert(cur_nr_sectors <= |
576 |
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); |
577 |
qemu_iovec_reset(&hd_qiov); |
578 |
qemu_iovec_add(&hd_qiov, cluster_data, |
579 |
512 * cur_nr_sectors);
|
580 |
} |
581 |
|
582 |
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); |
583 |
qemu_co_mutex_unlock(&s->lock); |
584 |
ret = bdrv_co_readv(bs->file, |
585 |
(cluster_offset >> 9) + index_in_cluster,
|
586 |
cur_nr_sectors, &hd_qiov); |
587 |
qemu_co_mutex_lock(&s->lock); |
588 |
if (ret < 0) { |
589 |
goto fail;
|
590 |
} |
591 |
if (s->crypt_method) {
|
592 |
qcow2_encrypt_sectors(s, sector_num, cluster_data, |
593 |
cluster_data, cur_nr_sectors, 0, &s->aes_decrypt_key);
|
594 |
qemu_iovec_reset(&hd_qiov); |
595 |
qemu_iovec_copy(&hd_qiov, qiov, bytes_done, |
596 |
cur_nr_sectors * 512);
|
597 |
qemu_iovec_from_buffer(&hd_qiov, cluster_data, |
598 |
512 * cur_nr_sectors);
|
599 |
} |
600 |
break;
|
601 |
|
602 |
default:
|
603 |
g_assert_not_reached(); |
604 |
ret = -EIO; |
605 |
goto fail;
|
606 |
} |
607 |
|
608 |
remaining_sectors -= cur_nr_sectors; |
609 |
sector_num += cur_nr_sectors; |
610 |
bytes_done += cur_nr_sectors * 512;
|
611 |
} |
612 |
ret = 0;
|
613 |
|
614 |
fail:
|
615 |
qemu_co_mutex_unlock(&s->lock); |
616 |
|
617 |
qemu_iovec_destroy(&hd_qiov); |
618 |
qemu_vfree(cluster_data); |
619 |
|
620 |
return ret;
|
621 |
} |
622 |
|
623 |
static void run_dependent_requests(BDRVQcowState *s, QCowL2Meta *m) |
624 |
{ |
625 |
/* Take the request off the list of running requests */
|
626 |
if (m->nb_clusters != 0) { |
627 |
QLIST_REMOVE(m, next_in_flight); |
628 |
} |
629 |
|
630 |
/* Restart all dependent requests */
|
631 |
if (!qemu_co_queue_empty(&m->dependent_requests)) {
|
632 |
qemu_co_mutex_unlock(&s->lock); |
633 |
qemu_co_queue_restart_all(&m->dependent_requests); |
634 |
qemu_co_mutex_lock(&s->lock); |
635 |
} |
636 |
} |
637 |
|
638 |
static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, |
639 |
int64_t sector_num, |
640 |
int remaining_sectors,
|
641 |
QEMUIOVector *qiov) |
642 |
{ |
643 |
BDRVQcowState *s = bs->opaque; |
644 |
int index_in_cluster;
|
645 |
int n_end;
|
646 |
int ret;
|
647 |
int cur_nr_sectors; /* number of sectors in current iteration */ |
648 |
uint64_t cluster_offset; |
649 |
QEMUIOVector hd_qiov; |
650 |
uint64_t bytes_done = 0;
|
651 |
uint8_t *cluster_data = NULL;
|
652 |
QCowL2Meta l2meta = { |
653 |
.nb_clusters = 0,
|
654 |
}; |
655 |
|
656 |
trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num, |
657 |
remaining_sectors); |
658 |
|
659 |
qemu_co_queue_init(&l2meta.dependent_requests); |
660 |
|
661 |
qemu_iovec_init(&hd_qiov, qiov->niov); |
662 |
|
663 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
664 |
|
665 |
qemu_co_mutex_lock(&s->lock); |
666 |
|
667 |
while (remaining_sectors != 0) { |
668 |
|
669 |
trace_qcow2_writev_start_part(qemu_coroutine_self()); |
670 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
671 |
n_end = index_in_cluster + remaining_sectors; |
672 |
if (s->crypt_method &&
|
673 |
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) { |
674 |
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
675 |
} |
676 |
|
677 |
ret = qcow2_alloc_cluster_offset(bs, sector_num << 9,
|
678 |
index_in_cluster, n_end, &cur_nr_sectors, &l2meta); |
679 |
if (ret < 0) { |
680 |
goto fail;
|
681 |
} |
682 |
|
683 |
cluster_offset = l2meta.cluster_offset; |
684 |
assert((cluster_offset & 511) == 0); |
685 |
|
686 |
qemu_iovec_reset(&hd_qiov); |
687 |
qemu_iovec_copy(&hd_qiov, qiov, bytes_done, |
688 |
cur_nr_sectors * 512);
|
689 |
|
690 |
if (s->crypt_method) {
|
691 |
if (!cluster_data) {
|
692 |
cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * |
693 |
s->cluster_size); |
694 |
} |
695 |
|
696 |
assert(hd_qiov.size <= |
697 |
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
698 |
qemu_iovec_to_buffer(&hd_qiov, cluster_data); |
699 |
|
700 |
qcow2_encrypt_sectors(s, sector_num, cluster_data, |
701 |
cluster_data, cur_nr_sectors, 1, &s->aes_encrypt_key);
|
702 |
|
703 |
qemu_iovec_reset(&hd_qiov); |
704 |
qemu_iovec_add(&hd_qiov, cluster_data, |
705 |
cur_nr_sectors * 512);
|
706 |
} |
707 |
|
708 |
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); |
709 |
qemu_co_mutex_unlock(&s->lock); |
710 |
trace_qcow2_writev_data(qemu_coroutine_self(), |
711 |
(cluster_offset >> 9) + index_in_cluster);
|
712 |
ret = bdrv_co_writev(bs->file, |
713 |
(cluster_offset >> 9) + index_in_cluster,
|
714 |
cur_nr_sectors, &hd_qiov); |
715 |
qemu_co_mutex_lock(&s->lock); |
716 |
if (ret < 0) { |
717 |
goto fail;
|
718 |
} |
719 |
|
720 |
ret = qcow2_alloc_cluster_link_l2(bs, &l2meta); |
721 |
if (ret < 0) { |
722 |
goto fail;
|
723 |
} |
724 |
|
725 |
run_dependent_requests(s, &l2meta); |
726 |
|
727 |
remaining_sectors -= cur_nr_sectors; |
728 |
sector_num += cur_nr_sectors; |
729 |
bytes_done += cur_nr_sectors * 512;
|
730 |
trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_nr_sectors); |
731 |
} |
732 |
ret = 0;
|
733 |
|
734 |
fail:
|
735 |
run_dependent_requests(s, &l2meta); |
736 |
|
737 |
qemu_co_mutex_unlock(&s->lock); |
738 |
|
739 |
qemu_iovec_destroy(&hd_qiov); |
740 |
qemu_vfree(cluster_data); |
741 |
trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); |
742 |
|
743 |
return ret;
|
744 |
} |
745 |
|
746 |
static void qcow2_close(BlockDriverState *bs) |
747 |
{ |
748 |
BDRVQcowState *s = bs->opaque; |
749 |
g_free(s->l1_table); |
750 |
|
751 |
qcow2_cache_flush(bs, s->l2_table_cache); |
752 |
qcow2_cache_flush(bs, s->refcount_block_cache); |
753 |
|
754 |
qcow2_cache_destroy(bs, s->l2_table_cache); |
755 |
qcow2_cache_destroy(bs, s->refcount_block_cache); |
756 |
|
757 |
g_free(s->unknown_header_fields); |
758 |
cleanup_unknown_header_ext(bs); |
759 |
|
760 |
g_free(s->cluster_cache); |
761 |
qemu_vfree(s->cluster_data); |
762 |
qcow2_refcount_close(bs); |
763 |
qcow2_free_snapshots(bs); |
764 |
} |
765 |
|
766 |
static void qcow2_invalidate_cache(BlockDriverState *bs) |
767 |
{ |
768 |
BDRVQcowState *s = bs->opaque; |
769 |
int flags = s->flags;
|
770 |
AES_KEY aes_encrypt_key; |
771 |
AES_KEY aes_decrypt_key; |
772 |
uint32_t crypt_method = 0;
|
773 |
|
774 |
/*
|
775 |
* Backing files are read-only which makes all of their metadata immutable,
|
776 |
* that means we don't have to worry about reopening them here.
|
777 |
*/
|
778 |
|
779 |
if (s->crypt_method) {
|
780 |
crypt_method = s->crypt_method; |
781 |
memcpy(&aes_encrypt_key, &s->aes_encrypt_key, sizeof(aes_encrypt_key));
|
782 |
memcpy(&aes_decrypt_key, &s->aes_decrypt_key, sizeof(aes_decrypt_key));
|
783 |
} |
784 |
|
785 |
qcow2_close(bs); |
786 |
|
787 |
memset(s, 0, sizeof(BDRVQcowState)); |
788 |
qcow2_open(bs, flags); |
789 |
|
790 |
if (crypt_method) {
|
791 |
s->crypt_method = crypt_method; |
792 |
memcpy(&s->aes_encrypt_key, &aes_encrypt_key, sizeof(aes_encrypt_key));
|
793 |
memcpy(&s->aes_decrypt_key, &aes_decrypt_key, sizeof(aes_decrypt_key));
|
794 |
} |
795 |
} |
796 |
|
797 |
static size_t header_ext_add(char *buf, uint32_t magic, const void *s, |
798 |
size_t len, size_t buflen) |
799 |
{ |
800 |
QCowExtension *ext_backing_fmt = (QCowExtension*) buf; |
801 |
size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7); |
802 |
|
803 |
if (buflen < ext_len) {
|
804 |
return -ENOSPC;
|
805 |
} |
806 |
|
807 |
*ext_backing_fmt = (QCowExtension) { |
808 |
.magic = cpu_to_be32(magic), |
809 |
.len = cpu_to_be32(len), |
810 |
}; |
811 |
memcpy(buf + sizeof(QCowExtension), s, len);
|
812 |
|
813 |
return ext_len;
|
814 |
} |
815 |
|
816 |
/*
|
817 |
* Updates the qcow2 header, including the variable length parts of it, i.e.
|
818 |
* the backing file name and all extensions. qcow2 was not designed to allow
|
819 |
* such changes, so if we run out of space (we can only use the first cluster)
|
820 |
* this function may fail.
|
821 |
*
|
822 |
* Returns 0 on success, -errno in error cases.
|
823 |
*/
|
824 |
int qcow2_update_header(BlockDriverState *bs)
|
825 |
{ |
826 |
BDRVQcowState *s = bs->opaque; |
827 |
QCowHeader *header; |
828 |
char *buf;
|
829 |
size_t buflen = s->cluster_size; |
830 |
int ret;
|
831 |
uint64_t total_size; |
832 |
uint32_t refcount_table_clusters; |
833 |
size_t header_length; |
834 |
Qcow2UnknownHeaderExtension *uext; |
835 |
|
836 |
buf = qemu_blockalign(bs, buflen); |
837 |
|
838 |
/* Header structure */
|
839 |
header = (QCowHeader*) buf; |
840 |
|
841 |
if (buflen < sizeof(*header)) { |
842 |
ret = -ENOSPC; |
843 |
goto fail;
|
844 |
} |
845 |
|
846 |
header_length = sizeof(*header) + s->unknown_header_fields_size;
|
847 |
total_size = bs->total_sectors * BDRV_SECTOR_SIZE; |
848 |
refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
|
849 |
|
850 |
*header = (QCowHeader) { |
851 |
/* Version 2 fields */
|
852 |
.magic = cpu_to_be32(QCOW_MAGIC), |
853 |
.version = cpu_to_be32(s->qcow_version), |
854 |
.backing_file_offset = 0,
|
855 |
.backing_file_size = 0,
|
856 |
.cluster_bits = cpu_to_be32(s->cluster_bits), |
857 |
.size = cpu_to_be64(total_size), |
858 |
.crypt_method = cpu_to_be32(s->crypt_method_header), |
859 |
.l1_size = cpu_to_be32(s->l1_size), |
860 |
.l1_table_offset = cpu_to_be64(s->l1_table_offset), |
861 |
.refcount_table_offset = cpu_to_be64(s->refcount_table_offset), |
862 |
.refcount_table_clusters = cpu_to_be32(refcount_table_clusters), |
863 |
.nb_snapshots = cpu_to_be32(s->nb_snapshots), |
864 |
.snapshots_offset = cpu_to_be64(s->snapshots_offset), |
865 |
|
866 |
/* Version 3 fields */
|
867 |
.incompatible_features = cpu_to_be64(s->incompatible_features), |
868 |
.compatible_features = cpu_to_be64(s->compatible_features), |
869 |
.autoclear_features = cpu_to_be64(s->autoclear_features), |
870 |
.refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT),
|
871 |
.header_length = cpu_to_be32(header_length), |
872 |
}; |
873 |
|
874 |
/* For older versions, write a shorter header */
|
875 |
switch (s->qcow_version) {
|
876 |
case 2: |
877 |
ret = offsetof(QCowHeader, incompatible_features); |
878 |
break;
|
879 |
case 3: |
880 |
ret = sizeof(*header);
|
881 |
break;
|
882 |
default:
|
883 |
return -EINVAL;
|
884 |
} |
885 |
|
886 |
buf += ret; |
887 |
buflen -= ret; |
888 |
memset(buf, 0, buflen);
|
889 |
|
890 |
/* Preserve any unknown field in the header */
|
891 |
if (s->unknown_header_fields_size) {
|
892 |
if (buflen < s->unknown_header_fields_size) {
|
893 |
ret = -ENOSPC; |
894 |
goto fail;
|
895 |
} |
896 |
|
897 |
memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); |
898 |
buf += s->unknown_header_fields_size; |
899 |
buflen -= s->unknown_header_fields_size; |
900 |
} |
901 |
|
902 |
/* Backing file format header extension */
|
903 |
if (*bs->backing_format) {
|
904 |
ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, |
905 |
bs->backing_format, strlen(bs->backing_format), |
906 |
buflen); |
907 |
if (ret < 0) { |
908 |
goto fail;
|
909 |
} |
910 |
|
911 |
buf += ret; |
912 |
buflen -= ret; |
913 |
} |
914 |
|
915 |
/* Keep unknown header extensions */
|
916 |
QLIST_FOREACH(uext, &s->unknown_header_ext, next) { |
917 |
ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); |
918 |
if (ret < 0) { |
919 |
goto fail;
|
920 |
} |
921 |
|
922 |
buf += ret; |
923 |
buflen -= ret; |
924 |
} |
925 |
|
926 |
/* End of header extensions */
|
927 |
ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); |
928 |
if (ret < 0) { |
929 |
goto fail;
|
930 |
} |
931 |
|
932 |
buf += ret; |
933 |
buflen -= ret; |
934 |
|
935 |
/* Backing file name */
|
936 |
if (*bs->backing_file) {
|
937 |
size_t backing_file_len = strlen(bs->backing_file); |
938 |
|
939 |
if (buflen < backing_file_len) {
|
940 |
ret = -ENOSPC; |
941 |
goto fail;
|
942 |
} |
943 |
|
944 |
strncpy(buf, bs->backing_file, buflen); |
945 |
|
946 |
header->backing_file_offset = cpu_to_be64(buf - ((char*) header));
|
947 |
header->backing_file_size = cpu_to_be32(backing_file_len); |
948 |
} |
949 |
|
950 |
/* Write the new header */
|
951 |
ret = bdrv_pwrite(bs->file, 0, header, s->cluster_size);
|
952 |
if (ret < 0) { |
953 |
goto fail;
|
954 |
} |
955 |
|
956 |
ret = 0;
|
957 |
fail:
|
958 |
qemu_vfree(header); |
959 |
return ret;
|
960 |
} |
961 |
|
962 |
static int qcow2_change_backing_file(BlockDriverState *bs, |
963 |
const char *backing_file, const char *backing_fmt) |
964 |
{ |
965 |
/* Backing file format doesn't make sense without a backing file */
|
966 |
if (backing_fmt && !backing_file) {
|
967 |
return -EINVAL;
|
968 |
} |
969 |
|
970 |
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); |
971 |
pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); |
972 |
|
973 |
return qcow2_update_header(bs);
|
974 |
} |
975 |
|
976 |
static int preallocate(BlockDriverState *bs) |
977 |
{ |
978 |
uint64_t nb_sectors; |
979 |
uint64_t offset; |
980 |
int num;
|
981 |
int ret;
|
982 |
QCowL2Meta meta; |
983 |
|
984 |
nb_sectors = bdrv_getlength(bs) >> 9;
|
985 |
offset = 0;
|
986 |
qemu_co_queue_init(&meta.dependent_requests); |
987 |
meta.cluster_offset = 0;
|
988 |
|
989 |
while (nb_sectors) {
|
990 |
num = MIN(nb_sectors, INT_MAX >> 9);
|
991 |
ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta);
|
992 |
if (ret < 0) { |
993 |
return ret;
|
994 |
} |
995 |
|
996 |
ret = qcow2_alloc_cluster_link_l2(bs, &meta); |
997 |
if (ret < 0) { |
998 |
qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters); |
999 |
return ret;
|
1000 |
} |
1001 |
|
1002 |
/* There are no dependent requests, but we need to remove our request
|
1003 |
* from the list of in-flight requests */
|
1004 |
run_dependent_requests(bs->opaque, &meta); |
1005 |
|
1006 |
/* TODO Preallocate data if requested */
|
1007 |
|
1008 |
nb_sectors -= num; |
1009 |
offset += num << 9;
|
1010 |
} |
1011 |
|
1012 |
/*
|
1013 |
* It is expected that the image file is large enough to actually contain
|
1014 |
* all of the allocated clusters (otherwise we get failing reads after
|
1015 |
* EOF). Extend the image to the last allocated sector.
|
1016 |
*/
|
1017 |
if (meta.cluster_offset != 0) { |
1018 |
uint8_t buf[512];
|
1019 |
memset(buf, 0, 512); |
1020 |
ret = bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1); |
1021 |
if (ret < 0) { |
1022 |
return ret;
|
1023 |
} |
1024 |
} |
1025 |
|
1026 |
return 0; |
1027 |
} |
1028 |
|
1029 |
static int qcow2_create2(const char *filename, int64_t total_size, |
1030 |
const char *backing_file, const char *backing_format, |
1031 |
int flags, size_t cluster_size, int prealloc, |
1032 |
QEMUOptionParameter *options, int version)
|
1033 |
{ |
1034 |
/* Calculate cluster_bits */
|
1035 |
int cluster_bits;
|
1036 |
cluster_bits = ffs(cluster_size) - 1;
|
1037 |
if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS ||
|
1038 |
(1 << cluster_bits) != cluster_size)
|
1039 |
{ |
1040 |
error_report( |
1041 |
"Cluster size must be a power of two between %d and %dk",
|
1042 |
1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); |
1043 |
return -EINVAL;
|
1044 |
} |
1045 |
|
1046 |
/*
|
1047 |
* Open the image file and write a minimal qcow2 header.
|
1048 |
*
|
1049 |
* We keep things simple and start with a zero-sized image. We also
|
1050 |
* do without refcount blocks or a L1 table for now. We'll fix the
|
1051 |
* inconsistency later.
|
1052 |
*
|
1053 |
* We do need a refcount table because growing the refcount table means
|
1054 |
* allocating two new refcount blocks - the seconds of which would be at
|
1055 |
* 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
|
1056 |
* size for any qcow2 image.
|
1057 |
*/
|
1058 |
BlockDriverState* bs; |
1059 |
QCowHeader header; |
1060 |
uint8_t* refcount_table; |
1061 |
int ret;
|
1062 |
|
1063 |
ret = bdrv_create_file(filename, options); |
1064 |
if (ret < 0) { |
1065 |
return ret;
|
1066 |
} |
1067 |
|
1068 |
ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR); |
1069 |
if (ret < 0) { |
1070 |
return ret;
|
1071 |
} |
1072 |
|
1073 |
/* Write the header */
|
1074 |
memset(&header, 0, sizeof(header)); |
1075 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
1076 |
header.version = cpu_to_be32(version); |
1077 |
header.cluster_bits = cpu_to_be32(cluster_bits); |
1078 |
header.size = cpu_to_be64(0);
|
1079 |
header.l1_table_offset = cpu_to_be64(0);
|
1080 |
header.l1_size = cpu_to_be32(0);
|
1081 |
header.refcount_table_offset = cpu_to_be64(cluster_size); |
1082 |
header.refcount_table_clusters = cpu_to_be32(1);
|
1083 |
header.refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT);
|
1084 |
header.header_length = cpu_to_be32(sizeof(header));
|
1085 |
|
1086 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
1087 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
1088 |
} else {
|
1089 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
1090 |
} |
1091 |
|
1092 |
ret = bdrv_pwrite(bs, 0, &header, sizeof(header)); |
1093 |
if (ret < 0) { |
1094 |
goto out;
|
1095 |
} |
1096 |
|
1097 |
/* Write an empty refcount table */
|
1098 |
refcount_table = g_malloc0(cluster_size); |
1099 |
ret = bdrv_pwrite(bs, cluster_size, refcount_table, cluster_size); |
1100 |
g_free(refcount_table); |
1101 |
|
1102 |
if (ret < 0) { |
1103 |
goto out;
|
1104 |
} |
1105 |
|
1106 |
bdrv_close(bs); |
1107 |
|
1108 |
/*
|
1109 |
* And now open the image and make it consistent first (i.e. increase the
|
1110 |
* refcount of the cluster that is occupied by the header and the refcount
|
1111 |
* table)
|
1112 |
*/
|
1113 |
BlockDriver* drv = bdrv_find_format("qcow2");
|
1114 |
assert(drv != NULL);
|
1115 |
ret = bdrv_open(bs, filename, |
1116 |
BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, drv); |
1117 |
if (ret < 0) { |
1118 |
goto out;
|
1119 |
} |
1120 |
|
1121 |
ret = qcow2_alloc_clusters(bs, 2 * cluster_size);
|
1122 |
if (ret < 0) { |
1123 |
goto out;
|
1124 |
|
1125 |
} else if (ret != 0) { |
1126 |
error_report("Huh, first cluster in empty image is already in use?");
|
1127 |
abort(); |
1128 |
} |
1129 |
|
1130 |
/* Okay, now that we have a valid image, let's give it the right size */
|
1131 |
ret = bdrv_truncate(bs, total_size * BDRV_SECTOR_SIZE); |
1132 |
if (ret < 0) { |
1133 |
goto out;
|
1134 |
} |
1135 |
|
1136 |
/* Want a backing file? There you go.*/
|
1137 |
if (backing_file) {
|
1138 |
ret = bdrv_change_backing_file(bs, backing_file, backing_format); |
1139 |
if (ret < 0) { |
1140 |
goto out;
|
1141 |
} |
1142 |
} |
1143 |
|
1144 |
/* And if we're supposed to preallocate metadata, do that now */
|
1145 |
if (prealloc) {
|
1146 |
ret = preallocate(bs); |
1147 |
if (ret < 0) { |
1148 |
goto out;
|
1149 |
} |
1150 |
} |
1151 |
|
1152 |
ret = 0;
|
1153 |
out:
|
1154 |
bdrv_delete(bs); |
1155 |
return ret;
|
1156 |
} |
1157 |
|
1158 |
static int qcow2_create(const char *filename, QEMUOptionParameter *options) |
1159 |
{ |
1160 |
const char *backing_file = NULL; |
1161 |
const char *backing_fmt = NULL; |
1162 |
uint64_t sectors = 0;
|
1163 |
int flags = 0; |
1164 |
size_t cluster_size = DEFAULT_CLUSTER_SIZE; |
1165 |
int prealloc = 0; |
1166 |
int version = 2; |
1167 |
|
1168 |
/* Read out options */
|
1169 |
while (options && options->name) {
|
1170 |
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
1171 |
sectors = options->value.n / 512;
|
1172 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { |
1173 |
backing_file = options->value.s; |
1174 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { |
1175 |
backing_fmt = options->value.s; |
1176 |
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { |
1177 |
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
1178 |
} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { |
1179 |
if (options->value.n) {
|
1180 |
cluster_size = options->value.n; |
1181 |
} |
1182 |
} else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) { |
1183 |
if (!options->value.s || !strcmp(options->value.s, "off")) { |
1184 |
prealloc = 0;
|
1185 |
} else if (!strcmp(options->value.s, "metadata")) { |
1186 |
prealloc = 1;
|
1187 |
} else {
|
1188 |
fprintf(stderr, "Invalid preallocation mode: '%s'\n",
|
1189 |
options->value.s); |
1190 |
return -EINVAL;
|
1191 |
} |
1192 |
} else if (!strcmp(options->name, BLOCK_OPT_COMPAT_LEVEL)) { |
1193 |
if (!options->value.s || !strcmp(options->value.s, "0.10")) { |
1194 |
version = 2;
|
1195 |
} else if (!strcmp(options->value.s, "1.1")) { |
1196 |
version = 3;
|
1197 |
} else {
|
1198 |
fprintf(stderr, "Invalid compatibility level: '%s'\n",
|
1199 |
options->value.s); |
1200 |
return -EINVAL;
|
1201 |
} |
1202 |
} |
1203 |
options++; |
1204 |
} |
1205 |
|
1206 |
if (backing_file && prealloc) {
|
1207 |
fprintf(stderr, "Backing file and preallocation cannot be used at "
|
1208 |
"the same time\n");
|
1209 |
return -EINVAL;
|
1210 |
} |
1211 |
|
1212 |
return qcow2_create2(filename, sectors, backing_file, backing_fmt, flags,
|
1213 |
cluster_size, prealloc, options, version); |
1214 |
} |
1215 |
|
1216 |
static int qcow2_make_empty(BlockDriverState *bs) |
1217 |
{ |
1218 |
#if 0
|
1219 |
/* XXX: not correct */
|
1220 |
BDRVQcowState *s = bs->opaque;
|
1221 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
1222 |
int ret;
|
1223 |
|
1224 |
memset(s->l1_table, 0, l1_length);
|
1225 |
if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
1226 |
return -1;
|
1227 |
ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
|
1228 |
if (ret < 0)
|
1229 |
return ret;
|
1230 |
|
1231 |
l2_cache_reset(bs);
|
1232 |
#endif
|
1233 |
return 0; |
1234 |
} |
1235 |
|
1236 |
static coroutine_fn int qcow2_co_discard(BlockDriverState *bs, |
1237 |
int64_t sector_num, int nb_sectors)
|
1238 |
{ |
1239 |
int ret;
|
1240 |
BDRVQcowState *s = bs->opaque; |
1241 |
|
1242 |
qemu_co_mutex_lock(&s->lock); |
1243 |
ret = qcow2_discard_clusters(bs, sector_num << BDRV_SECTOR_BITS, |
1244 |
nb_sectors); |
1245 |
qemu_co_mutex_unlock(&s->lock); |
1246 |
return ret;
|
1247 |
} |
1248 |
|
1249 |
static int qcow2_truncate(BlockDriverState *bs, int64_t offset) |
1250 |
{ |
1251 |
BDRVQcowState *s = bs->opaque; |
1252 |
int ret, new_l1_size;
|
1253 |
|
1254 |
if (offset & 511) { |
1255 |
error_report("The new size must be a multiple of 512");
|
1256 |
return -EINVAL;
|
1257 |
} |
1258 |
|
1259 |
/* cannot proceed if image has snapshots */
|
1260 |
if (s->nb_snapshots) {
|
1261 |
error_report("Can't resize an image which has snapshots");
|
1262 |
return -ENOTSUP;
|
1263 |
} |
1264 |
|
1265 |
/* shrinking is currently not supported */
|
1266 |
if (offset < bs->total_sectors * 512) { |
1267 |
error_report("qcow2 doesn't support shrinking images yet");
|
1268 |
return -ENOTSUP;
|
1269 |
} |
1270 |
|
1271 |
new_l1_size = size_to_l1(s, offset); |
1272 |
ret = qcow2_grow_l1_table(bs, new_l1_size, true);
|
1273 |
if (ret < 0) { |
1274 |
return ret;
|
1275 |
} |
1276 |
|
1277 |
/* write updated header.size */
|
1278 |
offset = cpu_to_be64(offset); |
1279 |
ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size), |
1280 |
&offset, sizeof(uint64_t));
|
1281 |
if (ret < 0) { |
1282 |
return ret;
|
1283 |
} |
1284 |
|
1285 |
s->l1_vm_state_index = new_l1_size; |
1286 |
return 0; |
1287 |
} |
1288 |
|
1289 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
1290 |
tables to avoid losing bytes in alignment */
|
1291 |
static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, |
1292 |
const uint8_t *buf, int nb_sectors) |
1293 |
{ |
1294 |
BDRVQcowState *s = bs->opaque; |
1295 |
z_stream strm; |
1296 |
int ret, out_len;
|
1297 |
uint8_t *out_buf; |
1298 |
uint64_t cluster_offset; |
1299 |
|
1300 |
if (nb_sectors == 0) { |
1301 |
/* align end of file to a sector boundary to ease reading with
|
1302 |
sector based I/Os */
|
1303 |
cluster_offset = bdrv_getlength(bs->file); |
1304 |
cluster_offset = (cluster_offset + 511) & ~511; |
1305 |
bdrv_truncate(bs->file, cluster_offset); |
1306 |
return 0; |
1307 |
} |
1308 |
|
1309 |
if (nb_sectors != s->cluster_sectors)
|
1310 |
return -EINVAL;
|
1311 |
|
1312 |
out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
1313 |
|
1314 |
/* best compression, small window, no zlib header */
|
1315 |
memset(&strm, 0, sizeof(strm)); |
1316 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
1317 |
Z_DEFLATED, -12,
|
1318 |
9, Z_DEFAULT_STRATEGY);
|
1319 |
if (ret != 0) { |
1320 |
ret = -EINVAL; |
1321 |
goto fail;
|
1322 |
} |
1323 |
|
1324 |
strm.avail_in = s->cluster_size; |
1325 |
strm.next_in = (uint8_t *)buf; |
1326 |
strm.avail_out = s->cluster_size; |
1327 |
strm.next_out = out_buf; |
1328 |
|
1329 |
ret = deflate(&strm, Z_FINISH); |
1330 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
1331 |
deflateEnd(&strm); |
1332 |
ret = -EINVAL; |
1333 |
goto fail;
|
1334 |
} |
1335 |
out_len = strm.next_out - out_buf; |
1336 |
|
1337 |
deflateEnd(&strm); |
1338 |
|
1339 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
1340 |
/* could not compress: write normal cluster */
|
1341 |
ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors); |
1342 |
if (ret < 0) { |
1343 |
goto fail;
|
1344 |
} |
1345 |
} else {
|
1346 |
cluster_offset = qcow2_alloc_compressed_cluster_offset(bs, |
1347 |
sector_num << 9, out_len);
|
1348 |
if (!cluster_offset) {
|
1349 |
ret = -EIO; |
1350 |
goto fail;
|
1351 |
} |
1352 |
cluster_offset &= s->cluster_offset_mask; |
1353 |
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); |
1354 |
ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len); |
1355 |
if (ret < 0) { |
1356 |
goto fail;
|
1357 |
} |
1358 |
} |
1359 |
|
1360 |
ret = 0;
|
1361 |
fail:
|
1362 |
g_free(out_buf); |
1363 |
return ret;
|
1364 |
} |
1365 |
|
1366 |
static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs) |
1367 |
{ |
1368 |
BDRVQcowState *s = bs->opaque; |
1369 |
int ret;
|
1370 |
|
1371 |
qemu_co_mutex_lock(&s->lock); |
1372 |
ret = qcow2_cache_flush(bs, s->l2_table_cache); |
1373 |
if (ret < 0) { |
1374 |
qemu_co_mutex_unlock(&s->lock); |
1375 |
return ret;
|
1376 |
} |
1377 |
|
1378 |
ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
1379 |
if (ret < 0) { |
1380 |
qemu_co_mutex_unlock(&s->lock); |
1381 |
return ret;
|
1382 |
} |
1383 |
qemu_co_mutex_unlock(&s->lock); |
1384 |
|
1385 |
return 0; |
1386 |
} |
1387 |
|
1388 |
static int64_t qcow2_vm_state_offset(BDRVQcowState *s)
|
1389 |
{ |
1390 |
return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
|
1391 |
} |
1392 |
|
1393 |
static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
1394 |
{ |
1395 |
BDRVQcowState *s = bs->opaque; |
1396 |
bdi->cluster_size = s->cluster_size; |
1397 |
bdi->vm_state_offset = qcow2_vm_state_offset(s); |
1398 |
return 0; |
1399 |
} |
1400 |
|
1401 |
|
1402 |
static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result) |
1403 |
{ |
1404 |
return qcow2_check_refcounts(bs, result);
|
1405 |
} |
1406 |
|
1407 |
#if 0
|
1408 |
static void dump_refcounts(BlockDriverState *bs)
|
1409 |
{
|
1410 |
BDRVQcowState *s = bs->opaque;
|
1411 |
int64_t nb_clusters, k, k1, size;
|
1412 |
int refcount;
|
1413 |
|
1414 |
size = bdrv_getlength(bs->file);
|
1415 |
nb_clusters = size_to_clusters(s, size);
|
1416 |
for(k = 0; k < nb_clusters;) {
|
1417 |
k1 = k;
|
1418 |
refcount = get_refcount(bs, k);
|
1419 |
k++;
|
1420 |
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
1421 |
k++;
|
1422 |
printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount,
|
1423 |
k - k1);
|
1424 |
}
|
1425 |
}
|
1426 |
#endif
|
1427 |
|
1428 |
static int qcow2_save_vmstate(BlockDriverState *bs, const uint8_t *buf, |
1429 |
int64_t pos, int size)
|
1430 |
{ |
1431 |
BDRVQcowState *s = bs->opaque; |
1432 |
int growable = bs->growable;
|
1433 |
int ret;
|
1434 |
|
1435 |
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); |
1436 |
bs->growable = 1;
|
1437 |
ret = bdrv_pwrite(bs, qcow2_vm_state_offset(s) + pos, buf, size); |
1438 |
bs->growable = growable; |
1439 |
|
1440 |
return ret;
|
1441 |
} |
1442 |
|
1443 |
static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf, |
1444 |
int64_t pos, int size)
|
1445 |
{ |
1446 |
BDRVQcowState *s = bs->opaque; |
1447 |
int growable = bs->growable;
|
1448 |
int ret;
|
1449 |
|
1450 |
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); |
1451 |
bs->growable = 1;
|
1452 |
ret = bdrv_pread(bs, qcow2_vm_state_offset(s) + pos, buf, size); |
1453 |
bs->growable = growable; |
1454 |
|
1455 |
return ret;
|
1456 |
} |
1457 |
|
1458 |
static QEMUOptionParameter qcow2_create_options[] = {
|
1459 |
{ |
1460 |
.name = BLOCK_OPT_SIZE, |
1461 |
.type = OPT_SIZE, |
1462 |
.help = "Virtual disk size"
|
1463 |
}, |
1464 |
{ |
1465 |
.name = BLOCK_OPT_COMPAT_LEVEL, |
1466 |
.type = OPT_STRING, |
1467 |
.help = "Compatibility level (0.10 or 1.1)"
|
1468 |
}, |
1469 |
{ |
1470 |
.name = BLOCK_OPT_BACKING_FILE, |
1471 |
.type = OPT_STRING, |
1472 |
.help = "File name of a base image"
|
1473 |
}, |
1474 |
{ |
1475 |
.name = BLOCK_OPT_BACKING_FMT, |
1476 |
.type = OPT_STRING, |
1477 |
.help = "Image format of the base image"
|
1478 |
}, |
1479 |
{ |
1480 |
.name = BLOCK_OPT_ENCRYPT, |
1481 |
.type = OPT_FLAG, |
1482 |
.help = "Encrypt the image"
|
1483 |
}, |
1484 |
{ |
1485 |
.name = BLOCK_OPT_CLUSTER_SIZE, |
1486 |
.type = OPT_SIZE, |
1487 |
.help = "qcow2 cluster size",
|
1488 |
.value = { .n = DEFAULT_CLUSTER_SIZE }, |
1489 |
}, |
1490 |
{ |
1491 |
.name = BLOCK_OPT_PREALLOC, |
1492 |
.type = OPT_STRING, |
1493 |
.help = "Preallocation mode (allowed values: off, metadata)"
|
1494 |
}, |
1495 |
{ NULL }
|
1496 |
}; |
1497 |
|
1498 |
static BlockDriver bdrv_qcow2 = {
|
1499 |
.format_name = "qcow2",
|
1500 |
.instance_size = sizeof(BDRVQcowState),
|
1501 |
.bdrv_probe = qcow2_probe, |
1502 |
.bdrv_open = qcow2_open, |
1503 |
.bdrv_close = qcow2_close, |
1504 |
.bdrv_create = qcow2_create, |
1505 |
.bdrv_co_is_allocated = qcow2_co_is_allocated, |
1506 |
.bdrv_set_key = qcow2_set_key, |
1507 |
.bdrv_make_empty = qcow2_make_empty, |
1508 |
|
1509 |
.bdrv_co_readv = qcow2_co_readv, |
1510 |
.bdrv_co_writev = qcow2_co_writev, |
1511 |
.bdrv_co_flush_to_os = qcow2_co_flush_to_os, |
1512 |
|
1513 |
.bdrv_co_discard = qcow2_co_discard, |
1514 |
.bdrv_truncate = qcow2_truncate, |
1515 |
.bdrv_write_compressed = qcow2_write_compressed, |
1516 |
|
1517 |
.bdrv_snapshot_create = qcow2_snapshot_create, |
1518 |
.bdrv_snapshot_goto = qcow2_snapshot_goto, |
1519 |
.bdrv_snapshot_delete = qcow2_snapshot_delete, |
1520 |
.bdrv_snapshot_list = qcow2_snapshot_list, |
1521 |
.bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, |
1522 |
.bdrv_get_info = qcow2_get_info, |
1523 |
|
1524 |
.bdrv_save_vmstate = qcow2_save_vmstate, |
1525 |
.bdrv_load_vmstate = qcow2_load_vmstate, |
1526 |
|
1527 |
.bdrv_change_backing_file = qcow2_change_backing_file, |
1528 |
|
1529 |
.bdrv_invalidate_cache = qcow2_invalidate_cache, |
1530 |
|
1531 |
.create_options = qcow2_create_options, |
1532 |
.bdrv_check = qcow2_check, |
1533 |
}; |
1534 |
|
1535 |
static void bdrv_qcow2_init(void) |
1536 |
{ |
1537 |
bdrv_register(&bdrv_qcow2); |
1538 |
} |
1539 |
|
1540 |
block_init(bdrv_qcow2_init); |