root / block / qcow2.c @ 1de7afc9
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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/block_int.h" |
26 |
#include "qemu/module.h" |
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#include <zlib.h> |
28 |
#include "block/aes.h" |
29 |
#include "block/qcow2.h" |
30 |
#include "qemu/error-report.h" |
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#include "qapi/qmp/qerror.h" |
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#include "trace.h" |
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|
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/*
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Differences with QCOW:
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|
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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; |
55 |
|
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#define QCOW2_EXT_MAGIC_END 0 |
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#define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA |
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#define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 |
59 |
|
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static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) |
61 |
{ |
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const QCowHeader *cow_header = (const void *)buf; |
63 |
|
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if (buf_size >= sizeof(QCowHeader) && |
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be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
66 |
be32_to_cpu(cow_header->version) >= 2)
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return 100; |
68 |
else
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return 0; |
70 |
} |
71 |
|
72 |
|
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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, void **p_feature_table)
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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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|
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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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} |
118 |
|
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switch (ext.magic) {
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case QCOW2_EXT_MAGIC_END:
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return 0; |
122 |
|
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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; |
129 |
} |
130 |
if (bdrv_pread(bs->file, offset , bs->backing_format,
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ext.len) != ext.len) |
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return 3; |
133 |
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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138 |
|
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case QCOW2_EXT_MAGIC_FEATURE_TABLE:
|
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if (p_feature_table != NULL) { |
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void* feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); |
142 |
ret = bdrv_pread(bs->file, offset , feature_table, ext.len); |
143 |
if (ret < 0) { |
144 |
return ret;
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} |
146 |
|
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*p_feature_table = feature_table; |
148 |
} |
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break;
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150 |
|
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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; |
155 |
|
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uext = g_malloc0(sizeof(*uext) + ext.len);
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uext->magic = ext.magic; |
158 |
uext->len = ext.len; |
159 |
QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next); |
160 |
|
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ret = bdrv_pread(bs->file, offset , uext->data, uext->len); |
162 |
if (ret < 0) { |
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return ret;
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} |
165 |
} |
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break;
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167 |
} |
168 |
|
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offset += ((ext.len + 7) & ~7); |
170 |
} |
171 |
|
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return 0; |
173 |
} |
174 |
|
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static void cleanup_unknown_header_ext(BlockDriverState *bs) |
176 |
{ |
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BDRVQcowState *s = bs->opaque; |
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Qcow2UnknownHeaderExtension *uext, *next; |
179 |
|
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QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { |
181 |
QLIST_REMOVE(uext, next); |
182 |
g_free(uext); |
183 |
} |
184 |
} |
185 |
|
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static void GCC_FMT_ATTR(2, 3) report_unsupported(BlockDriverState *bs, |
187 |
const char *fmt, ...) |
188 |
{ |
189 |
char msg[64]; |
190 |
va_list ap; |
191 |
|
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va_start(ap, fmt); |
193 |
vsnprintf(msg, sizeof(msg), fmt, ap);
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va_end(ap); |
195 |
|
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qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, |
197 |
bs->device_name, "qcow2", msg);
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} |
199 |
|
200 |
static void report_unsupported_feature(BlockDriverState *bs, |
201 |
Qcow2Feature *table, uint64_t mask) |
202 |
{ |
203 |
while (table && table->name[0] != '\0') { |
204 |
if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) {
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if (mask & (1 << table->bit)) { |
206 |
report_unsupported(bs, "%.46s",table->name);
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mask &= ~(1 << table->bit);
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208 |
} |
209 |
} |
210 |
table++; |
211 |
} |
212 |
|
213 |
if (mask) {
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report_unsupported(bs, "Unknown incompatible feature: %" PRIx64, mask);
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215 |
} |
216 |
} |
217 |
|
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/*
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* Sets the dirty bit and flushes afterwards if necessary.
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*
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* The incompatible_features bit is only set if the image file header was
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* updated successfully. Therefore it is not required to check the return
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* value of this function.
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*/
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int qcow2_mark_dirty(BlockDriverState *bs)
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{ |
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BDRVQcowState *s = bs->opaque; |
228 |
uint64_t val; |
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int ret;
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230 |
|
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assert(s->qcow_version >= 3);
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|
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if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
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return 0; /* already dirty */ |
235 |
} |
236 |
|
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val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); |
238 |
ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features), |
239 |
&val, sizeof(val));
|
240 |
if (ret < 0) { |
241 |
return ret;
|
242 |
} |
243 |
ret = bdrv_flush(bs->file); |
244 |
if (ret < 0) { |
245 |
return ret;
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246 |
} |
247 |
|
248 |
/* Only treat image as dirty if the header was updated successfully */
|
249 |
s->incompatible_features |= QCOW2_INCOMPAT_DIRTY; |
250 |
return 0; |
251 |
} |
252 |
|
253 |
/*
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254 |
* Clears the dirty bit and flushes before if necessary. Only call this
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255 |
* function when there are no pending requests, it does not guard against
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256 |
* concurrent requests dirtying the image.
|
257 |
*/
|
258 |
static int qcow2_mark_clean(BlockDriverState *bs) |
259 |
{ |
260 |
BDRVQcowState *s = bs->opaque; |
261 |
|
262 |
if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
|
263 |
int ret = bdrv_flush(bs);
|
264 |
if (ret < 0) { |
265 |
return ret;
|
266 |
} |
267 |
|
268 |
s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; |
269 |
return qcow2_update_header(bs);
|
270 |
} |
271 |
return 0; |
272 |
} |
273 |
|
274 |
static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result, |
275 |
BdrvCheckMode fix) |
276 |
{ |
277 |
int ret = qcow2_check_refcounts(bs, result, fix);
|
278 |
if (ret < 0) { |
279 |
return ret;
|
280 |
} |
281 |
|
282 |
if (fix && result->check_errors == 0 && result->corruptions == 0) { |
283 |
return qcow2_mark_clean(bs);
|
284 |
} |
285 |
return ret;
|
286 |
} |
287 |
|
288 |
static int qcow2_open(BlockDriverState *bs, int flags) |
289 |
{ |
290 |
BDRVQcowState *s = bs->opaque; |
291 |
int len, i, ret = 0; |
292 |
QCowHeader header; |
293 |
uint64_t ext_end; |
294 |
|
295 |
ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); |
296 |
if (ret < 0) { |
297 |
goto fail;
|
298 |
} |
299 |
be32_to_cpus(&header.magic); |
300 |
be32_to_cpus(&header.version); |
301 |
be64_to_cpus(&header.backing_file_offset); |
302 |
be32_to_cpus(&header.backing_file_size); |
303 |
be64_to_cpus(&header.size); |
304 |
be32_to_cpus(&header.cluster_bits); |
305 |
be32_to_cpus(&header.crypt_method); |
306 |
be64_to_cpus(&header.l1_table_offset); |
307 |
be32_to_cpus(&header.l1_size); |
308 |
be64_to_cpus(&header.refcount_table_offset); |
309 |
be32_to_cpus(&header.refcount_table_clusters); |
310 |
be64_to_cpus(&header.snapshots_offset); |
311 |
be32_to_cpus(&header.nb_snapshots); |
312 |
|
313 |
if (header.magic != QCOW_MAGIC) {
|
314 |
ret = -EINVAL; |
315 |
goto fail;
|
316 |
} |
317 |
if (header.version < 2 || header.version > 3) { |
318 |
report_unsupported(bs, "QCOW version %d", header.version);
|
319 |
ret = -ENOTSUP; |
320 |
goto fail;
|
321 |
} |
322 |
|
323 |
s->qcow_version = header.version; |
324 |
|
325 |
/* Initialise version 3 header fields */
|
326 |
if (header.version == 2) { |
327 |
header.incompatible_features = 0;
|
328 |
header.compatible_features = 0;
|
329 |
header.autoclear_features = 0;
|
330 |
header.refcount_order = 4;
|
331 |
header.header_length = 72;
|
332 |
} else {
|
333 |
be64_to_cpus(&header.incompatible_features); |
334 |
be64_to_cpus(&header.compatible_features); |
335 |
be64_to_cpus(&header.autoclear_features); |
336 |
be32_to_cpus(&header.refcount_order); |
337 |
be32_to_cpus(&header.header_length); |
338 |
} |
339 |
|
340 |
if (header.header_length > sizeof(header)) { |
341 |
s->unknown_header_fields_size = header.header_length - sizeof(header);
|
342 |
s->unknown_header_fields = g_malloc(s->unknown_header_fields_size); |
343 |
ret = bdrv_pread(bs->file, sizeof(header), s->unknown_header_fields,
|
344 |
s->unknown_header_fields_size); |
345 |
if (ret < 0) { |
346 |
goto fail;
|
347 |
} |
348 |
} |
349 |
|
350 |
if (header.backing_file_offset) {
|
351 |
ext_end = header.backing_file_offset; |
352 |
} else {
|
353 |
ext_end = 1 << header.cluster_bits;
|
354 |
} |
355 |
|
356 |
/* Handle feature bits */
|
357 |
s->incompatible_features = header.incompatible_features; |
358 |
s->compatible_features = header.compatible_features; |
359 |
s->autoclear_features = header.autoclear_features; |
360 |
|
361 |
if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) {
|
362 |
void *feature_table = NULL; |
363 |
qcow2_read_extensions(bs, header.header_length, ext_end, |
364 |
&feature_table); |
365 |
report_unsupported_feature(bs, feature_table, |
366 |
s->incompatible_features & |
367 |
~QCOW2_INCOMPAT_MASK); |
368 |
ret = -ENOTSUP; |
369 |
goto fail;
|
370 |
} |
371 |
|
372 |
/* Check support for various header values */
|
373 |
if (header.refcount_order != 4) { |
374 |
report_unsupported(bs, "%d bit reference counts",
|
375 |
1 << header.refcount_order);
|
376 |
ret = -ENOTSUP; |
377 |
goto fail;
|
378 |
} |
379 |
|
380 |
if (header.cluster_bits < MIN_CLUSTER_BITS ||
|
381 |
header.cluster_bits > MAX_CLUSTER_BITS) { |
382 |
ret = -EINVAL; |
383 |
goto fail;
|
384 |
} |
385 |
if (header.crypt_method > QCOW_CRYPT_AES) {
|
386 |
ret = -EINVAL; |
387 |
goto fail;
|
388 |
} |
389 |
s->crypt_method_header = header.crypt_method; |
390 |
if (s->crypt_method_header) {
|
391 |
bs->encrypted = 1;
|
392 |
} |
393 |
s->cluster_bits = header.cluster_bits; |
394 |
s->cluster_size = 1 << s->cluster_bits;
|
395 |
s->cluster_sectors = 1 << (s->cluster_bits - 9); |
396 |
s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ |
397 |
s->l2_size = 1 << s->l2_bits;
|
398 |
bs->total_sectors = header.size / 512;
|
399 |
s->csize_shift = (62 - (s->cluster_bits - 8)); |
400 |
s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
401 |
s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
402 |
s->refcount_table_offset = header.refcount_table_offset; |
403 |
s->refcount_table_size = |
404 |
header.refcount_table_clusters << (s->cluster_bits - 3);
|
405 |
|
406 |
s->snapshots_offset = header.snapshots_offset; |
407 |
s->nb_snapshots = header.nb_snapshots; |
408 |
|
409 |
/* read the level 1 table */
|
410 |
s->l1_size = header.l1_size; |
411 |
s->l1_vm_state_index = size_to_l1(s, header.size); |
412 |
/* the L1 table must contain at least enough entries to put
|
413 |
header.size bytes */
|
414 |
if (s->l1_size < s->l1_vm_state_index) {
|
415 |
ret = -EINVAL; |
416 |
goto fail;
|
417 |
} |
418 |
s->l1_table_offset = header.l1_table_offset; |
419 |
if (s->l1_size > 0) { |
420 |
s->l1_table = g_malloc0( |
421 |
align_offset(s->l1_size * sizeof(uint64_t), 512)); |
422 |
ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, |
423 |
s->l1_size * sizeof(uint64_t));
|
424 |
if (ret < 0) { |
425 |
goto fail;
|
426 |
} |
427 |
for(i = 0;i < s->l1_size; i++) { |
428 |
be64_to_cpus(&s->l1_table[i]); |
429 |
} |
430 |
} |
431 |
|
432 |
/* alloc L2 table/refcount block cache */
|
433 |
s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE); |
434 |
s->refcount_block_cache = qcow2_cache_create(bs, REFCOUNT_CACHE_SIZE); |
435 |
|
436 |
s->cluster_cache = g_malloc(s->cluster_size); |
437 |
/* one more sector for decompressed data alignment */
|
438 |
s->cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size |
439 |
+ 512);
|
440 |
s->cluster_cache_offset = -1;
|
441 |
s->flags = flags; |
442 |
|
443 |
ret = qcow2_refcount_init(bs); |
444 |
if (ret != 0) { |
445 |
goto fail;
|
446 |
} |
447 |
|
448 |
QLIST_INIT(&s->cluster_allocs); |
449 |
|
450 |
/* read qcow2 extensions */
|
451 |
if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL)) { |
452 |
ret = -EINVAL; |
453 |
goto fail;
|
454 |
} |
455 |
|
456 |
/* read the backing file name */
|
457 |
if (header.backing_file_offset != 0) { |
458 |
len = header.backing_file_size; |
459 |
if (len > 1023) { |
460 |
len = 1023;
|
461 |
} |
462 |
ret = bdrv_pread(bs->file, header.backing_file_offset, |
463 |
bs->backing_file, len); |
464 |
if (ret < 0) { |
465 |
goto fail;
|
466 |
} |
467 |
bs->backing_file[len] = '\0';
|
468 |
} |
469 |
|
470 |
ret = qcow2_read_snapshots(bs); |
471 |
if (ret < 0) { |
472 |
goto fail;
|
473 |
} |
474 |
|
475 |
/* Clear unknown autoclear feature bits */
|
476 |
if (!bs->read_only && s->autoclear_features != 0) { |
477 |
s->autoclear_features = 0;
|
478 |
ret = qcow2_update_header(bs); |
479 |
if (ret < 0) { |
480 |
goto fail;
|
481 |
} |
482 |
} |
483 |
|
484 |
/* Initialise locks */
|
485 |
qemu_co_mutex_init(&s->lock); |
486 |
|
487 |
/* Repair image if dirty */
|
488 |
if (!(flags & BDRV_O_CHECK) && !bs->read_only &&
|
489 |
(s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { |
490 |
BdrvCheckResult result = {0};
|
491 |
|
492 |
ret = qcow2_check(bs, &result, BDRV_FIX_ERRORS); |
493 |
if (ret < 0) { |
494 |
goto fail;
|
495 |
} |
496 |
} |
497 |
|
498 |
#ifdef DEBUG_ALLOC
|
499 |
{ |
500 |
BdrvCheckResult result = {0};
|
501 |
qcow2_check_refcounts(bs, &result, 0);
|
502 |
} |
503 |
#endif
|
504 |
return ret;
|
505 |
|
506 |
fail:
|
507 |
g_free(s->unknown_header_fields); |
508 |
cleanup_unknown_header_ext(bs); |
509 |
qcow2_free_snapshots(bs); |
510 |
qcow2_refcount_close(bs); |
511 |
g_free(s->l1_table); |
512 |
if (s->l2_table_cache) {
|
513 |
qcow2_cache_destroy(bs, s->l2_table_cache); |
514 |
} |
515 |
g_free(s->cluster_cache); |
516 |
qemu_vfree(s->cluster_data); |
517 |
return ret;
|
518 |
} |
519 |
|
520 |
static int qcow2_set_key(BlockDriverState *bs, const char *key) |
521 |
{ |
522 |
BDRVQcowState *s = bs->opaque; |
523 |
uint8_t keybuf[16];
|
524 |
int len, i;
|
525 |
|
526 |
memset(keybuf, 0, 16); |
527 |
len = strlen(key); |
528 |
if (len > 16) |
529 |
len = 16;
|
530 |
/* XXX: we could compress the chars to 7 bits to increase
|
531 |
entropy */
|
532 |
for(i = 0;i < len;i++) { |
533 |
keybuf[i] = key[i]; |
534 |
} |
535 |
s->crypt_method = s->crypt_method_header; |
536 |
|
537 |
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
538 |
return -1; |
539 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
540 |
return -1; |
541 |
#if 0
|
542 |
/* test */
|
543 |
{
|
544 |
uint8_t in[16];
|
545 |
uint8_t out[16];
|
546 |
uint8_t tmp[16];
|
547 |
for(i=0;i<16;i++)
|
548 |
in[i] = i;
|
549 |
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
550 |
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
551 |
for(i = 0; i < 16; i++)
|
552 |
printf(" %02x", tmp[i]);
|
553 |
printf("\n");
|
554 |
for(i = 0; i < 16; i++)
|
555 |
printf(" %02x", out[i]);
|
556 |
printf("\n");
|
557 |
}
|
558 |
#endif
|
559 |
return 0; |
560 |
} |
561 |
|
562 |
/* We have nothing to do for QCOW2 reopen, stubs just return
|
563 |
* success */
|
564 |
static int qcow2_reopen_prepare(BDRVReopenState *state, |
565 |
BlockReopenQueue *queue, Error **errp) |
566 |
{ |
567 |
return 0; |
568 |
} |
569 |
|
570 |
static int coroutine_fn qcow2_co_is_allocated(BlockDriverState *bs, |
571 |
int64_t sector_num, int nb_sectors, int *pnum) |
572 |
{ |
573 |
BDRVQcowState *s = bs->opaque; |
574 |
uint64_t cluster_offset; |
575 |
int ret;
|
576 |
|
577 |
*pnum = nb_sectors; |
578 |
/* FIXME We can get errors here, but the bdrv_co_is_allocated interface
|
579 |
* can't pass them on today */
|
580 |
qemu_co_mutex_lock(&s->lock); |
581 |
ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
|
582 |
qemu_co_mutex_unlock(&s->lock); |
583 |
if (ret < 0) { |
584 |
*pnum = 0;
|
585 |
} |
586 |
|
587 |
return (cluster_offset != 0); |
588 |
} |
589 |
|
590 |
/* handle reading after the end of the backing file */
|
591 |
int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
|
592 |
int64_t sector_num, int nb_sectors)
|
593 |
{ |
594 |
int n1;
|
595 |
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
596 |
return nb_sectors;
|
597 |
if (sector_num >= bs->total_sectors)
|
598 |
n1 = 0;
|
599 |
else
|
600 |
n1 = bs->total_sectors - sector_num; |
601 |
|
602 |
qemu_iovec_memset(qiov, 512 * n1, 0, 512 * (nb_sectors - n1)); |
603 |
|
604 |
return n1;
|
605 |
} |
606 |
|
607 |
static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, |
608 |
int remaining_sectors, QEMUIOVector *qiov)
|
609 |
{ |
610 |
BDRVQcowState *s = bs->opaque; |
611 |
int index_in_cluster, n1;
|
612 |
int ret;
|
613 |
int cur_nr_sectors; /* number of sectors in current iteration */ |
614 |
uint64_t cluster_offset = 0;
|
615 |
uint64_t bytes_done = 0;
|
616 |
QEMUIOVector hd_qiov; |
617 |
uint8_t *cluster_data = NULL;
|
618 |
|
619 |
qemu_iovec_init(&hd_qiov, qiov->niov); |
620 |
|
621 |
qemu_co_mutex_lock(&s->lock); |
622 |
|
623 |
while (remaining_sectors != 0) { |
624 |
|
625 |
/* prepare next request */
|
626 |
cur_nr_sectors = remaining_sectors; |
627 |
if (s->crypt_method) {
|
628 |
cur_nr_sectors = MIN(cur_nr_sectors, |
629 |
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); |
630 |
} |
631 |
|
632 |
ret = qcow2_get_cluster_offset(bs, sector_num << 9,
|
633 |
&cur_nr_sectors, &cluster_offset); |
634 |
if (ret < 0) { |
635 |
goto fail;
|
636 |
} |
637 |
|
638 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
639 |
|
640 |
qemu_iovec_reset(&hd_qiov); |
641 |
qemu_iovec_concat(&hd_qiov, qiov, bytes_done, |
642 |
cur_nr_sectors * 512);
|
643 |
|
644 |
switch (ret) {
|
645 |
case QCOW2_CLUSTER_UNALLOCATED:
|
646 |
|
647 |
if (bs->backing_hd) {
|
648 |
/* read from the base image */
|
649 |
n1 = qcow2_backing_read1(bs->backing_hd, &hd_qiov, |
650 |
sector_num, cur_nr_sectors); |
651 |
if (n1 > 0) { |
652 |
BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); |
653 |
qemu_co_mutex_unlock(&s->lock); |
654 |
ret = bdrv_co_readv(bs->backing_hd, sector_num, |
655 |
n1, &hd_qiov); |
656 |
qemu_co_mutex_lock(&s->lock); |
657 |
if (ret < 0) { |
658 |
goto fail;
|
659 |
} |
660 |
} |
661 |
} else {
|
662 |
/* Note: in this case, no need to wait */
|
663 |
qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors); |
664 |
} |
665 |
break;
|
666 |
|
667 |
case QCOW2_CLUSTER_ZERO:
|
668 |
if (s->qcow_version < 3) { |
669 |
ret = -EIO; |
670 |
goto fail;
|
671 |
} |
672 |
qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors); |
673 |
break;
|
674 |
|
675 |
case QCOW2_CLUSTER_COMPRESSED:
|
676 |
/* add AIO support for compressed blocks ? */
|
677 |
ret = qcow2_decompress_cluster(bs, cluster_offset); |
678 |
if (ret < 0) { |
679 |
goto fail;
|
680 |
} |
681 |
|
682 |
qemu_iovec_from_buf(&hd_qiov, 0,
|
683 |
s->cluster_cache + index_in_cluster * 512,
|
684 |
512 * cur_nr_sectors);
|
685 |
break;
|
686 |
|
687 |
case QCOW2_CLUSTER_NORMAL:
|
688 |
if ((cluster_offset & 511) != 0) { |
689 |
ret = -EIO; |
690 |
goto fail;
|
691 |
} |
692 |
|
693 |
if (s->crypt_method) {
|
694 |
/*
|
695 |
* For encrypted images, read everything into a temporary
|
696 |
* contiguous buffer on which the AES functions can work.
|
697 |
*/
|
698 |
if (!cluster_data) {
|
699 |
cluster_data = |
700 |
qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
701 |
} |
702 |
|
703 |
assert(cur_nr_sectors <= |
704 |
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); |
705 |
qemu_iovec_reset(&hd_qiov); |
706 |
qemu_iovec_add(&hd_qiov, cluster_data, |
707 |
512 * cur_nr_sectors);
|
708 |
} |
709 |
|
710 |
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); |
711 |
qemu_co_mutex_unlock(&s->lock); |
712 |
ret = bdrv_co_readv(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 |
if (s->crypt_method) {
|
720 |
qcow2_encrypt_sectors(s, sector_num, cluster_data, |
721 |
cluster_data, cur_nr_sectors, 0, &s->aes_decrypt_key);
|
722 |
qemu_iovec_from_buf(qiov, bytes_done, |
723 |
cluster_data, 512 * cur_nr_sectors);
|
724 |
} |
725 |
break;
|
726 |
|
727 |
default:
|
728 |
g_assert_not_reached(); |
729 |
ret = -EIO; |
730 |
goto fail;
|
731 |
} |
732 |
|
733 |
remaining_sectors -= cur_nr_sectors; |
734 |
sector_num += cur_nr_sectors; |
735 |
bytes_done += cur_nr_sectors * 512;
|
736 |
} |
737 |
ret = 0;
|
738 |
|
739 |
fail:
|
740 |
qemu_co_mutex_unlock(&s->lock); |
741 |
|
742 |
qemu_iovec_destroy(&hd_qiov); |
743 |
qemu_vfree(cluster_data); |
744 |
|
745 |
return ret;
|
746 |
} |
747 |
|
748 |
static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, |
749 |
int64_t sector_num, |
750 |
int remaining_sectors,
|
751 |
QEMUIOVector *qiov) |
752 |
{ |
753 |
BDRVQcowState *s = bs->opaque; |
754 |
int index_in_cluster;
|
755 |
int n_end;
|
756 |
int ret;
|
757 |
int cur_nr_sectors; /* number of sectors in current iteration */ |
758 |
uint64_t cluster_offset; |
759 |
QEMUIOVector hd_qiov; |
760 |
uint64_t bytes_done = 0;
|
761 |
uint8_t *cluster_data = NULL;
|
762 |
QCowL2Meta *l2meta; |
763 |
|
764 |
trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num, |
765 |
remaining_sectors); |
766 |
|
767 |
qemu_iovec_init(&hd_qiov, qiov->niov); |
768 |
|
769 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
770 |
|
771 |
qemu_co_mutex_lock(&s->lock); |
772 |
|
773 |
while (remaining_sectors != 0) { |
774 |
|
775 |
l2meta = NULL;
|
776 |
|
777 |
trace_qcow2_writev_start_part(qemu_coroutine_self()); |
778 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
779 |
n_end = index_in_cluster + remaining_sectors; |
780 |
if (s->crypt_method &&
|
781 |
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) { |
782 |
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
783 |
} |
784 |
|
785 |
ret = qcow2_alloc_cluster_offset(bs, sector_num << 9,
|
786 |
index_in_cluster, n_end, &cur_nr_sectors, &cluster_offset, &l2meta); |
787 |
if (ret < 0) { |
788 |
goto fail;
|
789 |
} |
790 |
|
791 |
assert((cluster_offset & 511) == 0); |
792 |
|
793 |
qemu_iovec_reset(&hd_qiov); |
794 |
qemu_iovec_concat(&hd_qiov, qiov, bytes_done, |
795 |
cur_nr_sectors * 512);
|
796 |
|
797 |
if (s->crypt_method) {
|
798 |
if (!cluster_data) {
|
799 |
cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * |
800 |
s->cluster_size); |
801 |
} |
802 |
|
803 |
assert(hd_qiov.size <= |
804 |
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
805 |
qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size);
|
806 |
|
807 |
qcow2_encrypt_sectors(s, sector_num, cluster_data, |
808 |
cluster_data, cur_nr_sectors, 1, &s->aes_encrypt_key);
|
809 |
|
810 |
qemu_iovec_reset(&hd_qiov); |
811 |
qemu_iovec_add(&hd_qiov, cluster_data, |
812 |
cur_nr_sectors * 512);
|
813 |
} |
814 |
|
815 |
qemu_co_mutex_unlock(&s->lock); |
816 |
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); |
817 |
trace_qcow2_writev_data(qemu_coroutine_self(), |
818 |
(cluster_offset >> 9) + index_in_cluster);
|
819 |
ret = bdrv_co_writev(bs->file, |
820 |
(cluster_offset >> 9) + index_in_cluster,
|
821 |
cur_nr_sectors, &hd_qiov); |
822 |
qemu_co_mutex_lock(&s->lock); |
823 |
if (ret < 0) { |
824 |
goto fail;
|
825 |
} |
826 |
|
827 |
if (l2meta != NULL) { |
828 |
ret = qcow2_alloc_cluster_link_l2(bs, l2meta); |
829 |
if (ret < 0) { |
830 |
goto fail;
|
831 |
} |
832 |
|
833 |
/* Take the request off the list of running requests */
|
834 |
if (l2meta->nb_clusters != 0) { |
835 |
QLIST_REMOVE(l2meta, next_in_flight); |
836 |
} |
837 |
|
838 |
qemu_co_mutex_unlock(&s->lock); |
839 |
qemu_co_queue_restart_all(&l2meta->dependent_requests); |
840 |
qemu_co_mutex_lock(&s->lock); |
841 |
|
842 |
g_free(l2meta); |
843 |
l2meta = NULL;
|
844 |
} |
845 |
|
846 |
remaining_sectors -= cur_nr_sectors; |
847 |
sector_num += cur_nr_sectors; |
848 |
bytes_done += cur_nr_sectors * 512;
|
849 |
trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_nr_sectors); |
850 |
} |
851 |
ret = 0;
|
852 |
|
853 |
fail:
|
854 |
qemu_co_mutex_unlock(&s->lock); |
855 |
|
856 |
if (l2meta != NULL) { |
857 |
if (l2meta->nb_clusters != 0) { |
858 |
QLIST_REMOVE(l2meta, next_in_flight); |
859 |
} |
860 |
qemu_co_queue_restart_all(&l2meta->dependent_requests); |
861 |
g_free(l2meta); |
862 |
} |
863 |
|
864 |
qemu_iovec_destroy(&hd_qiov); |
865 |
qemu_vfree(cluster_data); |
866 |
trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); |
867 |
|
868 |
return ret;
|
869 |
} |
870 |
|
871 |
static void qcow2_close(BlockDriverState *bs) |
872 |
{ |
873 |
BDRVQcowState *s = bs->opaque; |
874 |
g_free(s->l1_table); |
875 |
|
876 |
qcow2_cache_flush(bs, s->l2_table_cache); |
877 |
qcow2_cache_flush(bs, s->refcount_block_cache); |
878 |
|
879 |
qcow2_mark_clean(bs); |
880 |
|
881 |
qcow2_cache_destroy(bs, s->l2_table_cache); |
882 |
qcow2_cache_destroy(bs, s->refcount_block_cache); |
883 |
|
884 |
g_free(s->unknown_header_fields); |
885 |
cleanup_unknown_header_ext(bs); |
886 |
|
887 |
g_free(s->cluster_cache); |
888 |
qemu_vfree(s->cluster_data); |
889 |
qcow2_refcount_close(bs); |
890 |
qcow2_free_snapshots(bs); |
891 |
} |
892 |
|
893 |
static void qcow2_invalidate_cache(BlockDriverState *bs) |
894 |
{ |
895 |
BDRVQcowState *s = bs->opaque; |
896 |
int flags = s->flags;
|
897 |
AES_KEY aes_encrypt_key; |
898 |
AES_KEY aes_decrypt_key; |
899 |
uint32_t crypt_method = 0;
|
900 |
|
901 |
/*
|
902 |
* Backing files are read-only which makes all of their metadata immutable,
|
903 |
* that means we don't have to worry about reopening them here.
|
904 |
*/
|
905 |
|
906 |
if (s->crypt_method) {
|
907 |
crypt_method = s->crypt_method; |
908 |
memcpy(&aes_encrypt_key, &s->aes_encrypt_key, sizeof(aes_encrypt_key));
|
909 |
memcpy(&aes_decrypt_key, &s->aes_decrypt_key, sizeof(aes_decrypt_key));
|
910 |
} |
911 |
|
912 |
qcow2_close(bs); |
913 |
|
914 |
memset(s, 0, sizeof(BDRVQcowState)); |
915 |
qcow2_open(bs, flags); |
916 |
|
917 |
if (crypt_method) {
|
918 |
s->crypt_method = crypt_method; |
919 |
memcpy(&s->aes_encrypt_key, &aes_encrypt_key, sizeof(aes_encrypt_key));
|
920 |
memcpy(&s->aes_decrypt_key, &aes_decrypt_key, sizeof(aes_decrypt_key));
|
921 |
} |
922 |
} |
923 |
|
924 |
static size_t header_ext_add(char *buf, uint32_t magic, const void *s, |
925 |
size_t len, size_t buflen) |
926 |
{ |
927 |
QCowExtension *ext_backing_fmt = (QCowExtension*) buf; |
928 |
size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7); |
929 |
|
930 |
if (buflen < ext_len) {
|
931 |
return -ENOSPC;
|
932 |
} |
933 |
|
934 |
*ext_backing_fmt = (QCowExtension) { |
935 |
.magic = cpu_to_be32(magic), |
936 |
.len = cpu_to_be32(len), |
937 |
}; |
938 |
memcpy(buf + sizeof(QCowExtension), s, len);
|
939 |
|
940 |
return ext_len;
|
941 |
} |
942 |
|
943 |
/*
|
944 |
* Updates the qcow2 header, including the variable length parts of it, i.e.
|
945 |
* the backing file name and all extensions. qcow2 was not designed to allow
|
946 |
* such changes, so if we run out of space (we can only use the first cluster)
|
947 |
* this function may fail.
|
948 |
*
|
949 |
* Returns 0 on success, -errno in error cases.
|
950 |
*/
|
951 |
int qcow2_update_header(BlockDriverState *bs)
|
952 |
{ |
953 |
BDRVQcowState *s = bs->opaque; |
954 |
QCowHeader *header; |
955 |
char *buf;
|
956 |
size_t buflen = s->cluster_size; |
957 |
int ret;
|
958 |
uint64_t total_size; |
959 |
uint32_t refcount_table_clusters; |
960 |
size_t header_length; |
961 |
Qcow2UnknownHeaderExtension *uext; |
962 |
|
963 |
buf = qemu_blockalign(bs, buflen); |
964 |
|
965 |
/* Header structure */
|
966 |
header = (QCowHeader*) buf; |
967 |
|
968 |
if (buflen < sizeof(*header)) { |
969 |
ret = -ENOSPC; |
970 |
goto fail;
|
971 |
} |
972 |
|
973 |
header_length = sizeof(*header) + s->unknown_header_fields_size;
|
974 |
total_size = bs->total_sectors * BDRV_SECTOR_SIZE; |
975 |
refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
|
976 |
|
977 |
*header = (QCowHeader) { |
978 |
/* Version 2 fields */
|
979 |
.magic = cpu_to_be32(QCOW_MAGIC), |
980 |
.version = cpu_to_be32(s->qcow_version), |
981 |
.backing_file_offset = 0,
|
982 |
.backing_file_size = 0,
|
983 |
.cluster_bits = cpu_to_be32(s->cluster_bits), |
984 |
.size = cpu_to_be64(total_size), |
985 |
.crypt_method = cpu_to_be32(s->crypt_method_header), |
986 |
.l1_size = cpu_to_be32(s->l1_size), |
987 |
.l1_table_offset = cpu_to_be64(s->l1_table_offset), |
988 |
.refcount_table_offset = cpu_to_be64(s->refcount_table_offset), |
989 |
.refcount_table_clusters = cpu_to_be32(refcount_table_clusters), |
990 |
.nb_snapshots = cpu_to_be32(s->nb_snapshots), |
991 |
.snapshots_offset = cpu_to_be64(s->snapshots_offset), |
992 |
|
993 |
/* Version 3 fields */
|
994 |
.incompatible_features = cpu_to_be64(s->incompatible_features), |
995 |
.compatible_features = cpu_to_be64(s->compatible_features), |
996 |
.autoclear_features = cpu_to_be64(s->autoclear_features), |
997 |
.refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT),
|
998 |
.header_length = cpu_to_be32(header_length), |
999 |
}; |
1000 |
|
1001 |
/* For older versions, write a shorter header */
|
1002 |
switch (s->qcow_version) {
|
1003 |
case 2: |
1004 |
ret = offsetof(QCowHeader, incompatible_features); |
1005 |
break;
|
1006 |
case 3: |
1007 |
ret = sizeof(*header);
|
1008 |
break;
|
1009 |
default:
|
1010 |
ret = -EINVAL; |
1011 |
goto fail;
|
1012 |
} |
1013 |
|
1014 |
buf += ret; |
1015 |
buflen -= ret; |
1016 |
memset(buf, 0, buflen);
|
1017 |
|
1018 |
/* Preserve any unknown field in the header */
|
1019 |
if (s->unknown_header_fields_size) {
|
1020 |
if (buflen < s->unknown_header_fields_size) {
|
1021 |
ret = -ENOSPC; |
1022 |
goto fail;
|
1023 |
} |
1024 |
|
1025 |
memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); |
1026 |
buf += s->unknown_header_fields_size; |
1027 |
buflen -= s->unknown_header_fields_size; |
1028 |
} |
1029 |
|
1030 |
/* Backing file format header extension */
|
1031 |
if (*bs->backing_format) {
|
1032 |
ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, |
1033 |
bs->backing_format, strlen(bs->backing_format), |
1034 |
buflen); |
1035 |
if (ret < 0) { |
1036 |
goto fail;
|
1037 |
} |
1038 |
|
1039 |
buf += ret; |
1040 |
buflen -= ret; |
1041 |
} |
1042 |
|
1043 |
/* Feature table */
|
1044 |
Qcow2Feature features[] = { |
1045 |
{ |
1046 |
.type = QCOW2_FEAT_TYPE_INCOMPATIBLE, |
1047 |
.bit = QCOW2_INCOMPAT_DIRTY_BITNR, |
1048 |
.name = "dirty bit",
|
1049 |
}, |
1050 |
{ |
1051 |
.type = QCOW2_FEAT_TYPE_COMPATIBLE, |
1052 |
.bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, |
1053 |
.name = "lazy refcounts",
|
1054 |
}, |
1055 |
}; |
1056 |
|
1057 |
ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, |
1058 |
features, sizeof(features), buflen);
|
1059 |
if (ret < 0) { |
1060 |
goto fail;
|
1061 |
} |
1062 |
buf += ret; |
1063 |
buflen -= ret; |
1064 |
|
1065 |
/* Keep unknown header extensions */
|
1066 |
QLIST_FOREACH(uext, &s->unknown_header_ext, next) { |
1067 |
ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); |
1068 |
if (ret < 0) { |
1069 |
goto fail;
|
1070 |
} |
1071 |
|
1072 |
buf += ret; |
1073 |
buflen -= ret; |
1074 |
} |
1075 |
|
1076 |
/* End of header extensions */
|
1077 |
ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); |
1078 |
if (ret < 0) { |
1079 |
goto fail;
|
1080 |
} |
1081 |
|
1082 |
buf += ret; |
1083 |
buflen -= ret; |
1084 |
|
1085 |
/* Backing file name */
|
1086 |
if (*bs->backing_file) {
|
1087 |
size_t backing_file_len = strlen(bs->backing_file); |
1088 |
|
1089 |
if (buflen < backing_file_len) {
|
1090 |
ret = -ENOSPC; |
1091 |
goto fail;
|
1092 |
} |
1093 |
|
1094 |
/* Using strncpy is ok here, since buf is not NUL-terminated. */
|
1095 |
strncpy(buf, bs->backing_file, buflen); |
1096 |
|
1097 |
header->backing_file_offset = cpu_to_be64(buf - ((char*) header));
|
1098 |
header->backing_file_size = cpu_to_be32(backing_file_len); |
1099 |
} |
1100 |
|
1101 |
/* Write the new header */
|
1102 |
ret = bdrv_pwrite(bs->file, 0, header, s->cluster_size);
|
1103 |
if (ret < 0) { |
1104 |
goto fail;
|
1105 |
} |
1106 |
|
1107 |
ret = 0;
|
1108 |
fail:
|
1109 |
qemu_vfree(header); |
1110 |
return ret;
|
1111 |
} |
1112 |
|
1113 |
static int qcow2_change_backing_file(BlockDriverState *bs, |
1114 |
const char *backing_file, const char *backing_fmt) |
1115 |
{ |
1116 |
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); |
1117 |
pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); |
1118 |
|
1119 |
return qcow2_update_header(bs);
|
1120 |
} |
1121 |
|
1122 |
static int preallocate(BlockDriverState *bs) |
1123 |
{ |
1124 |
uint64_t nb_sectors; |
1125 |
uint64_t offset; |
1126 |
uint64_t host_offset = 0;
|
1127 |
int num;
|
1128 |
int ret;
|
1129 |
QCowL2Meta *meta; |
1130 |
|
1131 |
nb_sectors = bdrv_getlength(bs) >> 9;
|
1132 |
offset = 0;
|
1133 |
|
1134 |
while (nb_sectors) {
|
1135 |
num = MIN(nb_sectors, INT_MAX >> 9);
|
1136 |
ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num,
|
1137 |
&host_offset, &meta); |
1138 |
if (ret < 0) { |
1139 |
return ret;
|
1140 |
} |
1141 |
|
1142 |
ret = qcow2_alloc_cluster_link_l2(bs, meta); |
1143 |
if (ret < 0) { |
1144 |
qcow2_free_any_clusters(bs, meta->alloc_offset, meta->nb_clusters); |
1145 |
return ret;
|
1146 |
} |
1147 |
|
1148 |
/* There are no dependent requests, but we need to remove our request
|
1149 |
* from the list of in-flight requests */
|
1150 |
if (meta != NULL) { |
1151 |
QLIST_REMOVE(meta, next_in_flight); |
1152 |
} |
1153 |
|
1154 |
/* TODO Preallocate data if requested */
|
1155 |
|
1156 |
nb_sectors -= num; |
1157 |
offset += num << 9;
|
1158 |
} |
1159 |
|
1160 |
/*
|
1161 |
* It is expected that the image file is large enough to actually contain
|
1162 |
* all of the allocated clusters (otherwise we get failing reads after
|
1163 |
* EOF). Extend the image to the last allocated sector.
|
1164 |
*/
|
1165 |
if (host_offset != 0) { |
1166 |
uint8_t buf[512];
|
1167 |
memset(buf, 0, 512); |
1168 |
ret = bdrv_write(bs->file, (host_offset >> 9) + num - 1, buf, 1); |
1169 |
if (ret < 0) { |
1170 |
return ret;
|
1171 |
} |
1172 |
} |
1173 |
|
1174 |
return 0; |
1175 |
} |
1176 |
|
1177 |
static int qcow2_create2(const char *filename, int64_t total_size, |
1178 |
const char *backing_file, const char *backing_format, |
1179 |
int flags, size_t cluster_size, int prealloc, |
1180 |
QEMUOptionParameter *options, int version)
|
1181 |
{ |
1182 |
/* Calculate cluster_bits */
|
1183 |
int cluster_bits;
|
1184 |
cluster_bits = ffs(cluster_size) - 1;
|
1185 |
if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS ||
|
1186 |
(1 << cluster_bits) != cluster_size)
|
1187 |
{ |
1188 |
error_report( |
1189 |
"Cluster size must be a power of two between %d and %dk",
|
1190 |
1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); |
1191 |
return -EINVAL;
|
1192 |
} |
1193 |
|
1194 |
/*
|
1195 |
* Open the image file and write a minimal qcow2 header.
|
1196 |
*
|
1197 |
* We keep things simple and start with a zero-sized image. We also
|
1198 |
* do without refcount blocks or a L1 table for now. We'll fix the
|
1199 |
* inconsistency later.
|
1200 |
*
|
1201 |
* We do need a refcount table because growing the refcount table means
|
1202 |
* allocating two new refcount blocks - the seconds of which would be at
|
1203 |
* 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
|
1204 |
* size for any qcow2 image.
|
1205 |
*/
|
1206 |
BlockDriverState* bs; |
1207 |
QCowHeader header; |
1208 |
uint8_t* refcount_table; |
1209 |
int ret;
|
1210 |
|
1211 |
ret = bdrv_create_file(filename, options); |
1212 |
if (ret < 0) { |
1213 |
return ret;
|
1214 |
} |
1215 |
|
1216 |
ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR); |
1217 |
if (ret < 0) { |
1218 |
return ret;
|
1219 |
} |
1220 |
|
1221 |
/* Write the header */
|
1222 |
memset(&header, 0, sizeof(header)); |
1223 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
1224 |
header.version = cpu_to_be32(version); |
1225 |
header.cluster_bits = cpu_to_be32(cluster_bits); |
1226 |
header.size = cpu_to_be64(0);
|
1227 |
header.l1_table_offset = cpu_to_be64(0);
|
1228 |
header.l1_size = cpu_to_be32(0);
|
1229 |
header.refcount_table_offset = cpu_to_be64(cluster_size); |
1230 |
header.refcount_table_clusters = cpu_to_be32(1);
|
1231 |
header.refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT);
|
1232 |
header.header_length = cpu_to_be32(sizeof(header));
|
1233 |
|
1234 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
1235 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
1236 |
} else {
|
1237 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
1238 |
} |
1239 |
|
1240 |
if (flags & BLOCK_FLAG_LAZY_REFCOUNTS) {
|
1241 |
header.compatible_features |= |
1242 |
cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS); |
1243 |
} |
1244 |
|
1245 |
ret = bdrv_pwrite(bs, 0, &header, sizeof(header)); |
1246 |
if (ret < 0) { |
1247 |
goto out;
|
1248 |
} |
1249 |
|
1250 |
/* Write an empty refcount table */
|
1251 |
refcount_table = g_malloc0(cluster_size); |
1252 |
ret = bdrv_pwrite(bs, cluster_size, refcount_table, cluster_size); |
1253 |
g_free(refcount_table); |
1254 |
|
1255 |
if (ret < 0) { |
1256 |
goto out;
|
1257 |
} |
1258 |
|
1259 |
bdrv_close(bs); |
1260 |
|
1261 |
/*
|
1262 |
* And now open the image and make it consistent first (i.e. increase the
|
1263 |
* refcount of the cluster that is occupied by the header and the refcount
|
1264 |
* table)
|
1265 |
*/
|
1266 |
BlockDriver* drv = bdrv_find_format("qcow2");
|
1267 |
assert(drv != NULL);
|
1268 |
ret = bdrv_open(bs, filename, |
1269 |
BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, drv); |
1270 |
if (ret < 0) { |
1271 |
goto out;
|
1272 |
} |
1273 |
|
1274 |
ret = qcow2_alloc_clusters(bs, 2 * cluster_size);
|
1275 |
if (ret < 0) { |
1276 |
goto out;
|
1277 |
|
1278 |
} else if (ret != 0) { |
1279 |
error_report("Huh, first cluster in empty image is already in use?");
|
1280 |
abort(); |
1281 |
} |
1282 |
|
1283 |
/* Okay, now that we have a valid image, let's give it the right size */
|
1284 |
ret = bdrv_truncate(bs, total_size * BDRV_SECTOR_SIZE); |
1285 |
if (ret < 0) { |
1286 |
goto out;
|
1287 |
} |
1288 |
|
1289 |
/* Want a backing file? There you go.*/
|
1290 |
if (backing_file) {
|
1291 |
ret = bdrv_change_backing_file(bs, backing_file, backing_format); |
1292 |
if (ret < 0) { |
1293 |
goto out;
|
1294 |
} |
1295 |
} |
1296 |
|
1297 |
/* And if we're supposed to preallocate metadata, do that now */
|
1298 |
if (prealloc) {
|
1299 |
BDRVQcowState *s = bs->opaque; |
1300 |
qemu_co_mutex_lock(&s->lock); |
1301 |
ret = preallocate(bs); |
1302 |
qemu_co_mutex_unlock(&s->lock); |
1303 |
if (ret < 0) { |
1304 |
goto out;
|
1305 |
} |
1306 |
} |
1307 |
|
1308 |
ret = 0;
|
1309 |
out:
|
1310 |
bdrv_delete(bs); |
1311 |
return ret;
|
1312 |
} |
1313 |
|
1314 |
static int qcow2_create(const char *filename, QEMUOptionParameter *options) |
1315 |
{ |
1316 |
const char *backing_file = NULL; |
1317 |
const char *backing_fmt = NULL; |
1318 |
uint64_t sectors = 0;
|
1319 |
int flags = 0; |
1320 |
size_t cluster_size = DEFAULT_CLUSTER_SIZE; |
1321 |
int prealloc = 0; |
1322 |
int version = 2; |
1323 |
|
1324 |
/* Read out options */
|
1325 |
while (options && options->name) {
|
1326 |
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
1327 |
sectors = options->value.n / 512;
|
1328 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { |
1329 |
backing_file = options->value.s; |
1330 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { |
1331 |
backing_fmt = options->value.s; |
1332 |
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { |
1333 |
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
1334 |
} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { |
1335 |
if (options->value.n) {
|
1336 |
cluster_size = options->value.n; |
1337 |
} |
1338 |
} else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) { |
1339 |
if (!options->value.s || !strcmp(options->value.s, "off")) { |
1340 |
prealloc = 0;
|
1341 |
} else if (!strcmp(options->value.s, "metadata")) { |
1342 |
prealloc = 1;
|
1343 |
} else {
|
1344 |
fprintf(stderr, "Invalid preallocation mode: '%s'\n",
|
1345 |
options->value.s); |
1346 |
return -EINVAL;
|
1347 |
} |
1348 |
} else if (!strcmp(options->name, BLOCK_OPT_COMPAT_LEVEL)) { |
1349 |
if (!options->value.s || !strcmp(options->value.s, "0.10")) { |
1350 |
version = 2;
|
1351 |
} else if (!strcmp(options->value.s, "1.1")) { |
1352 |
version = 3;
|
1353 |
} else {
|
1354 |
fprintf(stderr, "Invalid compatibility level: '%s'\n",
|
1355 |
options->value.s); |
1356 |
return -EINVAL;
|
1357 |
} |
1358 |
} else if (!strcmp(options->name, BLOCK_OPT_LAZY_REFCOUNTS)) { |
1359 |
flags |= options->value.n ? BLOCK_FLAG_LAZY_REFCOUNTS : 0;
|
1360 |
} |
1361 |
options++; |
1362 |
} |
1363 |
|
1364 |
if (backing_file && prealloc) {
|
1365 |
fprintf(stderr, "Backing file and preallocation cannot be used at "
|
1366 |
"the same time\n");
|
1367 |
return -EINVAL;
|
1368 |
} |
1369 |
|
1370 |
if (version < 3 && (flags & BLOCK_FLAG_LAZY_REFCOUNTS)) { |
1371 |
fprintf(stderr, "Lazy refcounts only supported with compatibility "
|
1372 |
"level 1.1 and above (use compat=1.1 or greater)\n");
|
1373 |
return -EINVAL;
|
1374 |
} |
1375 |
|
1376 |
return qcow2_create2(filename, sectors, backing_file, backing_fmt, flags,
|
1377 |
cluster_size, prealloc, options, version); |
1378 |
} |
1379 |
|
1380 |
static int qcow2_make_empty(BlockDriverState *bs) |
1381 |
{ |
1382 |
#if 0
|
1383 |
/* XXX: not correct */
|
1384 |
BDRVQcowState *s = bs->opaque;
|
1385 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
1386 |
int ret;
|
1387 |
|
1388 |
memset(s->l1_table, 0, l1_length);
|
1389 |
if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
1390 |
return -1;
|
1391 |
ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
|
1392 |
if (ret < 0)
|
1393 |
return ret;
|
1394 |
|
1395 |
l2_cache_reset(bs);
|
1396 |
#endif
|
1397 |
return 0; |
1398 |
} |
1399 |
|
1400 |
static coroutine_fn int qcow2_co_write_zeroes(BlockDriverState *bs, |
1401 |
int64_t sector_num, int nb_sectors)
|
1402 |
{ |
1403 |
int ret;
|
1404 |
BDRVQcowState *s = bs->opaque; |
1405 |
|
1406 |
/* Emulate misaligned zero writes */
|
1407 |
if (sector_num % s->cluster_sectors || nb_sectors % s->cluster_sectors) {
|
1408 |
return -ENOTSUP;
|
1409 |
} |
1410 |
|
1411 |
/* Whatever is left can use real zero clusters */
|
1412 |
qemu_co_mutex_lock(&s->lock); |
1413 |
ret = qcow2_zero_clusters(bs, sector_num << BDRV_SECTOR_BITS, |
1414 |
nb_sectors); |
1415 |
qemu_co_mutex_unlock(&s->lock); |
1416 |
|
1417 |
return ret;
|
1418 |
} |
1419 |
|
1420 |
static coroutine_fn int qcow2_co_discard(BlockDriverState *bs, |
1421 |
int64_t sector_num, int nb_sectors)
|
1422 |
{ |
1423 |
int ret;
|
1424 |
BDRVQcowState *s = bs->opaque; |
1425 |
|
1426 |
qemu_co_mutex_lock(&s->lock); |
1427 |
ret = qcow2_discard_clusters(bs, sector_num << BDRV_SECTOR_BITS, |
1428 |
nb_sectors); |
1429 |
qemu_co_mutex_unlock(&s->lock); |
1430 |
return ret;
|
1431 |
} |
1432 |
|
1433 |
static int qcow2_truncate(BlockDriverState *bs, int64_t offset) |
1434 |
{ |
1435 |
BDRVQcowState *s = bs->opaque; |
1436 |
int ret, new_l1_size;
|
1437 |
|
1438 |
if (offset & 511) { |
1439 |
error_report("The new size must be a multiple of 512");
|
1440 |
return -EINVAL;
|
1441 |
} |
1442 |
|
1443 |
/* cannot proceed if image has snapshots */
|
1444 |
if (s->nb_snapshots) {
|
1445 |
error_report("Can't resize an image which has snapshots");
|
1446 |
return -ENOTSUP;
|
1447 |
} |
1448 |
|
1449 |
/* shrinking is currently not supported */
|
1450 |
if (offset < bs->total_sectors * 512) { |
1451 |
error_report("qcow2 doesn't support shrinking images yet");
|
1452 |
return -ENOTSUP;
|
1453 |
} |
1454 |
|
1455 |
new_l1_size = size_to_l1(s, offset); |
1456 |
ret = qcow2_grow_l1_table(bs, new_l1_size, true);
|
1457 |
if (ret < 0) { |
1458 |
return ret;
|
1459 |
} |
1460 |
|
1461 |
/* write updated header.size */
|
1462 |
offset = cpu_to_be64(offset); |
1463 |
ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size), |
1464 |
&offset, sizeof(uint64_t));
|
1465 |
if (ret < 0) { |
1466 |
return ret;
|
1467 |
} |
1468 |
|
1469 |
s->l1_vm_state_index = new_l1_size; |
1470 |
return 0; |
1471 |
} |
1472 |
|
1473 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
1474 |
tables to avoid losing bytes in alignment */
|
1475 |
static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, |
1476 |
const uint8_t *buf, int nb_sectors) |
1477 |
{ |
1478 |
BDRVQcowState *s = bs->opaque; |
1479 |
z_stream strm; |
1480 |
int ret, out_len;
|
1481 |
uint8_t *out_buf; |
1482 |
uint64_t cluster_offset; |
1483 |
|
1484 |
if (nb_sectors == 0) { |
1485 |
/* align end of file to a sector boundary to ease reading with
|
1486 |
sector based I/Os */
|
1487 |
cluster_offset = bdrv_getlength(bs->file); |
1488 |
cluster_offset = (cluster_offset + 511) & ~511; |
1489 |
bdrv_truncate(bs->file, cluster_offset); |
1490 |
return 0; |
1491 |
} |
1492 |
|
1493 |
if (nb_sectors != s->cluster_sectors)
|
1494 |
return -EINVAL;
|
1495 |
|
1496 |
out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
1497 |
|
1498 |
/* best compression, small window, no zlib header */
|
1499 |
memset(&strm, 0, sizeof(strm)); |
1500 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
1501 |
Z_DEFLATED, -12,
|
1502 |
9, Z_DEFAULT_STRATEGY);
|
1503 |
if (ret != 0) { |
1504 |
ret = -EINVAL; |
1505 |
goto fail;
|
1506 |
} |
1507 |
|
1508 |
strm.avail_in = s->cluster_size; |
1509 |
strm.next_in = (uint8_t *)buf; |
1510 |
strm.avail_out = s->cluster_size; |
1511 |
strm.next_out = out_buf; |
1512 |
|
1513 |
ret = deflate(&strm, Z_FINISH); |
1514 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
1515 |
deflateEnd(&strm); |
1516 |
ret = -EINVAL; |
1517 |
goto fail;
|
1518 |
} |
1519 |
out_len = strm.next_out - out_buf; |
1520 |
|
1521 |
deflateEnd(&strm); |
1522 |
|
1523 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
1524 |
/* could not compress: write normal cluster */
|
1525 |
ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors); |
1526 |
if (ret < 0) { |
1527 |
goto fail;
|
1528 |
} |
1529 |
} else {
|
1530 |
cluster_offset = qcow2_alloc_compressed_cluster_offset(bs, |
1531 |
sector_num << 9, out_len);
|
1532 |
if (!cluster_offset) {
|
1533 |
ret = -EIO; |
1534 |
goto fail;
|
1535 |
} |
1536 |
cluster_offset &= s->cluster_offset_mask; |
1537 |
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); |
1538 |
ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len); |
1539 |
if (ret < 0) { |
1540 |
goto fail;
|
1541 |
} |
1542 |
} |
1543 |
|
1544 |
ret = 0;
|
1545 |
fail:
|
1546 |
g_free(out_buf); |
1547 |
return ret;
|
1548 |
} |
1549 |
|
1550 |
static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs) |
1551 |
{ |
1552 |
BDRVQcowState *s = bs->opaque; |
1553 |
int ret;
|
1554 |
|
1555 |
qemu_co_mutex_lock(&s->lock); |
1556 |
ret = qcow2_cache_flush(bs, s->l2_table_cache); |
1557 |
if (ret < 0) { |
1558 |
qemu_co_mutex_unlock(&s->lock); |
1559 |
return ret;
|
1560 |
} |
1561 |
|
1562 |
if (qcow2_need_accurate_refcounts(s)) {
|
1563 |
ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
1564 |
if (ret < 0) { |
1565 |
qemu_co_mutex_unlock(&s->lock); |
1566 |
return ret;
|
1567 |
} |
1568 |
} |
1569 |
qemu_co_mutex_unlock(&s->lock); |
1570 |
|
1571 |
return 0; |
1572 |
} |
1573 |
|
1574 |
static int64_t qcow2_vm_state_offset(BDRVQcowState *s)
|
1575 |
{ |
1576 |
return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
|
1577 |
} |
1578 |
|
1579 |
static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
1580 |
{ |
1581 |
BDRVQcowState *s = bs->opaque; |
1582 |
bdi->cluster_size = s->cluster_size; |
1583 |
bdi->vm_state_offset = qcow2_vm_state_offset(s); |
1584 |
return 0; |
1585 |
} |
1586 |
|
1587 |
#if 0
|
1588 |
static void dump_refcounts(BlockDriverState *bs)
|
1589 |
{
|
1590 |
BDRVQcowState *s = bs->opaque;
|
1591 |
int64_t nb_clusters, k, k1, size;
|
1592 |
int refcount;
|
1593 |
|
1594 |
size = bdrv_getlength(bs->file);
|
1595 |
nb_clusters = size_to_clusters(s, size);
|
1596 |
for(k = 0; k < nb_clusters;) {
|
1597 |
k1 = k;
|
1598 |
refcount = get_refcount(bs, k);
|
1599 |
k++;
|
1600 |
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
1601 |
k++;
|
1602 |
printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount,
|
1603 |
k - k1);
|
1604 |
}
|
1605 |
}
|
1606 |
#endif
|
1607 |
|
1608 |
static int qcow2_save_vmstate(BlockDriverState *bs, const uint8_t *buf, |
1609 |
int64_t pos, int size)
|
1610 |
{ |
1611 |
BDRVQcowState *s = bs->opaque; |
1612 |
int growable = bs->growable;
|
1613 |
int ret;
|
1614 |
|
1615 |
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); |
1616 |
bs->growable = 1;
|
1617 |
ret = bdrv_pwrite(bs, qcow2_vm_state_offset(s) + pos, buf, size); |
1618 |
bs->growable = growable; |
1619 |
|
1620 |
return ret;
|
1621 |
} |
1622 |
|
1623 |
static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf, |
1624 |
int64_t pos, int size)
|
1625 |
{ |
1626 |
BDRVQcowState *s = bs->opaque; |
1627 |
int growable = bs->growable;
|
1628 |
int ret;
|
1629 |
|
1630 |
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); |
1631 |
bs->growable = 1;
|
1632 |
ret = bdrv_pread(bs, qcow2_vm_state_offset(s) + pos, buf, size); |
1633 |
bs->growable = growable; |
1634 |
|
1635 |
return ret;
|
1636 |
} |
1637 |
|
1638 |
static QEMUOptionParameter qcow2_create_options[] = {
|
1639 |
{ |
1640 |
.name = BLOCK_OPT_SIZE, |
1641 |
.type = OPT_SIZE, |
1642 |
.help = "Virtual disk size"
|
1643 |
}, |
1644 |
{ |
1645 |
.name = BLOCK_OPT_COMPAT_LEVEL, |
1646 |
.type = OPT_STRING, |
1647 |
.help = "Compatibility level (0.10 or 1.1)"
|
1648 |
}, |
1649 |
{ |
1650 |
.name = BLOCK_OPT_BACKING_FILE, |
1651 |
.type = OPT_STRING, |
1652 |
.help = "File name of a base image"
|
1653 |
}, |
1654 |
{ |
1655 |
.name = BLOCK_OPT_BACKING_FMT, |
1656 |
.type = OPT_STRING, |
1657 |
.help = "Image format of the base image"
|
1658 |
}, |
1659 |
{ |
1660 |
.name = BLOCK_OPT_ENCRYPT, |
1661 |
.type = OPT_FLAG, |
1662 |
.help = "Encrypt the image"
|
1663 |
}, |
1664 |
{ |
1665 |
.name = BLOCK_OPT_CLUSTER_SIZE, |
1666 |
.type = OPT_SIZE, |
1667 |
.help = "qcow2 cluster size",
|
1668 |
.value = { .n = DEFAULT_CLUSTER_SIZE }, |
1669 |
}, |
1670 |
{ |
1671 |
.name = BLOCK_OPT_PREALLOC, |
1672 |
.type = OPT_STRING, |
1673 |
.help = "Preallocation mode (allowed values: off, metadata)"
|
1674 |
}, |
1675 |
{ |
1676 |
.name = BLOCK_OPT_LAZY_REFCOUNTS, |
1677 |
.type = OPT_FLAG, |
1678 |
.help = "Postpone refcount updates",
|
1679 |
}, |
1680 |
{ NULL }
|
1681 |
}; |
1682 |
|
1683 |
static BlockDriver bdrv_qcow2 = {
|
1684 |
.format_name = "qcow2",
|
1685 |
.instance_size = sizeof(BDRVQcowState),
|
1686 |
.bdrv_probe = qcow2_probe, |
1687 |
.bdrv_open = qcow2_open, |
1688 |
.bdrv_close = qcow2_close, |
1689 |
.bdrv_reopen_prepare = qcow2_reopen_prepare, |
1690 |
.bdrv_create = qcow2_create, |
1691 |
.bdrv_co_is_allocated = qcow2_co_is_allocated, |
1692 |
.bdrv_set_key = qcow2_set_key, |
1693 |
.bdrv_make_empty = qcow2_make_empty, |
1694 |
|
1695 |
.bdrv_co_readv = qcow2_co_readv, |
1696 |
.bdrv_co_writev = qcow2_co_writev, |
1697 |
.bdrv_co_flush_to_os = qcow2_co_flush_to_os, |
1698 |
|
1699 |
.bdrv_co_write_zeroes = qcow2_co_write_zeroes, |
1700 |
.bdrv_co_discard = qcow2_co_discard, |
1701 |
.bdrv_truncate = qcow2_truncate, |
1702 |
.bdrv_write_compressed = qcow2_write_compressed, |
1703 |
|
1704 |
.bdrv_snapshot_create = qcow2_snapshot_create, |
1705 |
.bdrv_snapshot_goto = qcow2_snapshot_goto, |
1706 |
.bdrv_snapshot_delete = qcow2_snapshot_delete, |
1707 |
.bdrv_snapshot_list = qcow2_snapshot_list, |
1708 |
.bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, |
1709 |
.bdrv_get_info = qcow2_get_info, |
1710 |
|
1711 |
.bdrv_save_vmstate = qcow2_save_vmstate, |
1712 |
.bdrv_load_vmstate = qcow2_load_vmstate, |
1713 |
|
1714 |
.bdrv_change_backing_file = qcow2_change_backing_file, |
1715 |
|
1716 |
.bdrv_invalidate_cache = qcow2_invalidate_cache, |
1717 |
|
1718 |
.create_options = qcow2_create_options, |
1719 |
.bdrv_check = qcow2_check, |
1720 |
}; |
1721 |
|
1722 |
static void bdrv_qcow2_init(void) |
1723 |
{ |
1724 |
bdrv_register(&bdrv_qcow2); |
1725 |
} |
1726 |
|
1727 |
block_init(bdrv_qcow2_init); |