root / block / qcow2.c @ d5124c00
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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 "qemu/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 "qapi/qmp/qbool.h" |
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#include "trace.h" |
34 |
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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; |
55 |
} QCowExtension; |
56 |
|
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#define QCOW2_EXT_MAGIC_END 0 |
58 |
#define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA |
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#define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 |
60 |
|
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static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) |
62 |
{ |
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const QCowHeader *cow_header = (const void *)buf; |
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|
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if (buf_size >= sizeof(QCowHeader) && |
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be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
67 |
be32_to_cpu(cow_header->version) >= 2)
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return 100; |
69 |
else
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return 0; |
71 |
} |
72 |
|
73 |
|
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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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#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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} |
119 |
|
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switch (ext.magic) {
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case QCOW2_EXT_MAGIC_END:
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return 0; |
123 |
|
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case QCOW2_EXT_MAGIC_BACKING_FORMAT:
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if (ext.len >= sizeof(bs->backing_format)) { |
126 |
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; |
130 |
} |
131 |
if (bdrv_pread(bs->file, offset , bs->backing_format,
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ext.len) != ext.len) |
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return 3; |
134 |
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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139 |
|
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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)); |
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ret = bdrv_pread(bs->file, offset , feature_table, ext.len); |
144 |
if (ret < 0) { |
145 |
return ret;
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} |
147 |
|
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*p_feature_table = feature_table; |
149 |
} |
150 |
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; |
156 |
|
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uext = g_malloc0(sizeof(*uext) + ext.len);
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uext->magic = ext.magic; |
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uext->len = ext.len; |
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QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next); |
161 |
|
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ret = bdrv_pread(bs->file, offset , uext->data, uext->len); |
163 |
if (ret < 0) { |
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return ret;
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} |
166 |
} |
167 |
break;
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} |
169 |
|
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offset += ((ext.len + 7) & ~7); |
171 |
} |
172 |
|
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return 0; |
174 |
} |
175 |
|
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static void cleanup_unknown_header_ext(BlockDriverState *bs) |
177 |
{ |
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BDRVQcowState *s = bs->opaque; |
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Qcow2UnknownHeaderExtension *uext, *next; |
180 |
|
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QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { |
182 |
QLIST_REMOVE(uext, next); |
183 |
g_free(uext); |
184 |
} |
185 |
} |
186 |
|
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static void GCC_FMT_ATTR(2, 3) report_unsupported(BlockDriverState *bs, |
188 |
const char *fmt, ...) |
189 |
{ |
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char msg[64]; |
191 |
va_list ap; |
192 |
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va_start(ap, fmt); |
194 |
vsnprintf(msg, sizeof(msg), fmt, ap);
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va_end(ap); |
196 |
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qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, |
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bs->device_name, "qcow2", msg);
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} |
200 |
|
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static void report_unsupported_feature(BlockDriverState *bs, |
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Qcow2Feature *table, uint64_t mask) |
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{ |
204 |
while (table && table->name[0] != '\0') { |
205 |
if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) {
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if (mask & (1 << table->bit)) { |
207 |
report_unsupported(bs, "%.46s",table->name);
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mask &= ~(1 << table->bit);
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} |
210 |
} |
211 |
table++; |
212 |
} |
213 |
|
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if (mask) {
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report_unsupported(bs, "Unknown incompatible feature: %" PRIx64, mask);
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216 |
} |
217 |
} |
218 |
|
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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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{ |
228 |
BDRVQcowState *s = bs->opaque; |
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uint64_t val; |
230 |
int ret;
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assert(s->qcow_version >= 3);
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|
234 |
if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
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return 0; /* already dirty */ |
236 |
} |
237 |
|
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val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); |
239 |
ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features), |
240 |
&val, sizeof(val));
|
241 |
if (ret < 0) { |
242 |
return ret;
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243 |
} |
244 |
ret = bdrv_flush(bs->file); |
245 |
if (ret < 0) { |
246 |
return ret;
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247 |
} |
248 |
|
249 |
/* Only treat image as dirty if the header was updated successfully */
|
250 |
s->incompatible_features |= QCOW2_INCOMPAT_DIRTY; |
251 |
return 0; |
252 |
} |
253 |
|
254 |
/*
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255 |
* Clears the dirty bit and flushes before if necessary. Only call this
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256 |
* function when there are no pending requests, it does not guard against
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* concurrent requests dirtying the image.
|
258 |
*/
|
259 |
static int qcow2_mark_clean(BlockDriverState *bs) |
260 |
{ |
261 |
BDRVQcowState *s = bs->opaque; |
262 |
|
263 |
if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
|
264 |
int ret = bdrv_flush(bs);
|
265 |
if (ret < 0) { |
266 |
return ret;
|
267 |
} |
268 |
|
269 |
s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; |
270 |
return qcow2_update_header(bs);
|
271 |
} |
272 |
return 0; |
273 |
} |
274 |
|
275 |
/*
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276 |
* Marks the image as corrupt.
|
277 |
*/
|
278 |
int qcow2_mark_corrupt(BlockDriverState *bs)
|
279 |
{ |
280 |
BDRVQcowState *s = bs->opaque; |
281 |
|
282 |
s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT; |
283 |
return qcow2_update_header(bs);
|
284 |
} |
285 |
|
286 |
/*
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287 |
* Marks the image as consistent, i.e., unsets the corrupt bit, and flushes
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288 |
* before if necessary.
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289 |
*/
|
290 |
int qcow2_mark_consistent(BlockDriverState *bs)
|
291 |
{ |
292 |
BDRVQcowState *s = bs->opaque; |
293 |
|
294 |
if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) {
|
295 |
int ret = bdrv_flush(bs);
|
296 |
if (ret < 0) { |
297 |
return ret;
|
298 |
} |
299 |
|
300 |
s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT; |
301 |
return qcow2_update_header(bs);
|
302 |
} |
303 |
return 0; |
304 |
} |
305 |
|
306 |
static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result, |
307 |
BdrvCheckMode fix) |
308 |
{ |
309 |
int ret = qcow2_check_refcounts(bs, result, fix);
|
310 |
if (ret < 0) { |
311 |
return ret;
|
312 |
} |
313 |
|
314 |
if (fix && result->check_errors == 0 && result->corruptions == 0) { |
315 |
ret = qcow2_mark_clean(bs); |
316 |
if (ret < 0) { |
317 |
return ret;
|
318 |
} |
319 |
return qcow2_mark_consistent(bs);
|
320 |
} |
321 |
return ret;
|
322 |
} |
323 |
|
324 |
static QemuOptsList qcow2_runtime_opts = {
|
325 |
.name = "qcow2",
|
326 |
.head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head), |
327 |
.desc = { |
328 |
{ |
329 |
.name = QCOW2_OPT_LAZY_REFCOUNTS, |
330 |
.type = QEMU_OPT_BOOL, |
331 |
.help = "Postpone refcount updates",
|
332 |
}, |
333 |
{ |
334 |
.name = QCOW2_OPT_DISCARD_REQUEST, |
335 |
.type = QEMU_OPT_BOOL, |
336 |
.help = "Pass guest discard requests to the layer below",
|
337 |
}, |
338 |
{ |
339 |
.name = QCOW2_OPT_DISCARD_SNAPSHOT, |
340 |
.type = QEMU_OPT_BOOL, |
341 |
.help = "Generate discard requests when snapshot related space "
|
342 |
"is freed",
|
343 |
}, |
344 |
{ |
345 |
.name = QCOW2_OPT_DISCARD_OTHER, |
346 |
.type = QEMU_OPT_BOOL, |
347 |
.help = "Generate discard requests when other clusters are freed",
|
348 |
}, |
349 |
{ /* end of list */ }
|
350 |
}, |
351 |
}; |
352 |
|
353 |
static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, |
354 |
Error **errp) |
355 |
{ |
356 |
BDRVQcowState *s = bs->opaque; |
357 |
int len, i, ret = 0; |
358 |
QCowHeader header; |
359 |
QemuOpts *opts; |
360 |
Error *local_err = NULL;
|
361 |
uint64_t ext_end; |
362 |
uint64_t l1_vm_state_index; |
363 |
|
364 |
ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); |
365 |
if (ret < 0) { |
366 |
goto fail;
|
367 |
} |
368 |
be32_to_cpus(&header.magic); |
369 |
be32_to_cpus(&header.version); |
370 |
be64_to_cpus(&header.backing_file_offset); |
371 |
be32_to_cpus(&header.backing_file_size); |
372 |
be64_to_cpus(&header.size); |
373 |
be32_to_cpus(&header.cluster_bits); |
374 |
be32_to_cpus(&header.crypt_method); |
375 |
be64_to_cpus(&header.l1_table_offset); |
376 |
be32_to_cpus(&header.l1_size); |
377 |
be64_to_cpus(&header.refcount_table_offset); |
378 |
be32_to_cpus(&header.refcount_table_clusters); |
379 |
be64_to_cpus(&header.snapshots_offset); |
380 |
be32_to_cpus(&header.nb_snapshots); |
381 |
|
382 |
if (header.magic != QCOW_MAGIC) {
|
383 |
ret = -EMEDIUMTYPE; |
384 |
goto fail;
|
385 |
} |
386 |
if (header.version < 2 || header.version > 3) { |
387 |
report_unsupported(bs, "QCOW version %d", header.version);
|
388 |
ret = -ENOTSUP; |
389 |
goto fail;
|
390 |
} |
391 |
|
392 |
s->qcow_version = header.version; |
393 |
|
394 |
/* Initialise version 3 header fields */
|
395 |
if (header.version == 2) { |
396 |
header.incompatible_features = 0;
|
397 |
header.compatible_features = 0;
|
398 |
header.autoclear_features = 0;
|
399 |
header.refcount_order = 4;
|
400 |
header.header_length = 72;
|
401 |
} else {
|
402 |
be64_to_cpus(&header.incompatible_features); |
403 |
be64_to_cpus(&header.compatible_features); |
404 |
be64_to_cpus(&header.autoclear_features); |
405 |
be32_to_cpus(&header.refcount_order); |
406 |
be32_to_cpus(&header.header_length); |
407 |
} |
408 |
|
409 |
if (header.header_length > sizeof(header)) { |
410 |
s->unknown_header_fields_size = header.header_length - sizeof(header);
|
411 |
s->unknown_header_fields = g_malloc(s->unknown_header_fields_size); |
412 |
ret = bdrv_pread(bs->file, sizeof(header), s->unknown_header_fields,
|
413 |
s->unknown_header_fields_size); |
414 |
if (ret < 0) { |
415 |
goto fail;
|
416 |
} |
417 |
} |
418 |
|
419 |
if (header.backing_file_offset) {
|
420 |
ext_end = header.backing_file_offset; |
421 |
} else {
|
422 |
ext_end = 1 << header.cluster_bits;
|
423 |
} |
424 |
|
425 |
/* Handle feature bits */
|
426 |
s->incompatible_features = header.incompatible_features; |
427 |
s->compatible_features = header.compatible_features; |
428 |
s->autoclear_features = header.autoclear_features; |
429 |
|
430 |
if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) {
|
431 |
void *feature_table = NULL; |
432 |
qcow2_read_extensions(bs, header.header_length, ext_end, |
433 |
&feature_table); |
434 |
report_unsupported_feature(bs, feature_table, |
435 |
s->incompatible_features & |
436 |
~QCOW2_INCOMPAT_MASK); |
437 |
ret = -ENOTSUP; |
438 |
goto fail;
|
439 |
} |
440 |
|
441 |
if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) {
|
442 |
/* Corrupt images may not be written to unless they are being repaired
|
443 |
*/
|
444 |
if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
|
445 |
error_report("qcow2: Image is corrupt; cannot be opened "
|
446 |
"read/write.");
|
447 |
ret = -EACCES; |
448 |
goto fail;
|
449 |
} |
450 |
} |
451 |
|
452 |
/* Check support for various header values */
|
453 |
if (header.refcount_order != 4) { |
454 |
report_unsupported(bs, "%d bit reference counts",
|
455 |
1 << header.refcount_order);
|
456 |
ret = -ENOTSUP; |
457 |
goto fail;
|
458 |
} |
459 |
s->refcount_order = header.refcount_order; |
460 |
|
461 |
if (header.cluster_bits < MIN_CLUSTER_BITS ||
|
462 |
header.cluster_bits > MAX_CLUSTER_BITS) { |
463 |
ret = -EINVAL; |
464 |
goto fail;
|
465 |
} |
466 |
if (header.crypt_method > QCOW_CRYPT_AES) {
|
467 |
ret = -EINVAL; |
468 |
goto fail;
|
469 |
} |
470 |
s->crypt_method_header = header.crypt_method; |
471 |
if (s->crypt_method_header) {
|
472 |
bs->encrypted = 1;
|
473 |
} |
474 |
s->cluster_bits = header.cluster_bits; |
475 |
s->cluster_size = 1 << s->cluster_bits;
|
476 |
s->cluster_sectors = 1 << (s->cluster_bits - 9); |
477 |
s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ |
478 |
s->l2_size = 1 << s->l2_bits;
|
479 |
bs->total_sectors = header.size / 512;
|
480 |
s->csize_shift = (62 - (s->cluster_bits - 8)); |
481 |
s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
482 |
s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
483 |
s->refcount_table_offset = header.refcount_table_offset; |
484 |
s->refcount_table_size = |
485 |
header.refcount_table_clusters << (s->cluster_bits - 3);
|
486 |
|
487 |
s->snapshots_offset = header.snapshots_offset; |
488 |
s->nb_snapshots = header.nb_snapshots; |
489 |
|
490 |
/* read the level 1 table */
|
491 |
s->l1_size = header.l1_size; |
492 |
|
493 |
l1_vm_state_index = size_to_l1(s, header.size); |
494 |
if (l1_vm_state_index > INT_MAX) {
|
495 |
ret = -EFBIG; |
496 |
goto fail;
|
497 |
} |
498 |
s->l1_vm_state_index = l1_vm_state_index; |
499 |
|
500 |
/* the L1 table must contain at least enough entries to put
|
501 |
header.size bytes */
|
502 |
if (s->l1_size < s->l1_vm_state_index) {
|
503 |
ret = -EINVAL; |
504 |
goto fail;
|
505 |
} |
506 |
s->l1_table_offset = header.l1_table_offset; |
507 |
if (s->l1_size > 0) { |
508 |
s->l1_table = g_malloc0( |
509 |
align_offset(s->l1_size * sizeof(uint64_t), 512)); |
510 |
ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, |
511 |
s->l1_size * sizeof(uint64_t));
|
512 |
if (ret < 0) { |
513 |
goto fail;
|
514 |
} |
515 |
for(i = 0;i < s->l1_size; i++) { |
516 |
be64_to_cpus(&s->l1_table[i]); |
517 |
} |
518 |
} |
519 |
|
520 |
/* alloc L2 table/refcount block cache */
|
521 |
s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE); |
522 |
s->refcount_block_cache = qcow2_cache_create(bs, REFCOUNT_CACHE_SIZE); |
523 |
|
524 |
s->cluster_cache = g_malloc(s->cluster_size); |
525 |
/* one more sector for decompressed data alignment */
|
526 |
s->cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size |
527 |
+ 512);
|
528 |
s->cluster_cache_offset = -1;
|
529 |
s->flags = flags; |
530 |
|
531 |
ret = qcow2_refcount_init(bs); |
532 |
if (ret != 0) { |
533 |
goto fail;
|
534 |
} |
535 |
|
536 |
QLIST_INIT(&s->cluster_allocs); |
537 |
QTAILQ_INIT(&s->discards); |
538 |
|
539 |
/* read qcow2 extensions */
|
540 |
if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL)) { |
541 |
ret = -EINVAL; |
542 |
goto fail;
|
543 |
} |
544 |
|
545 |
/* read the backing file name */
|
546 |
if (header.backing_file_offset != 0) { |
547 |
len = header.backing_file_size; |
548 |
if (len > 1023) { |
549 |
len = 1023;
|
550 |
} |
551 |
ret = bdrv_pread(bs->file, header.backing_file_offset, |
552 |
bs->backing_file, len); |
553 |
if (ret < 0) { |
554 |
goto fail;
|
555 |
} |
556 |
bs->backing_file[len] = '\0';
|
557 |
} |
558 |
|
559 |
ret = qcow2_read_snapshots(bs); |
560 |
if (ret < 0) { |
561 |
goto fail;
|
562 |
} |
563 |
|
564 |
/* Clear unknown autoclear feature bits */
|
565 |
if (!bs->read_only && s->autoclear_features != 0) { |
566 |
s->autoclear_features = 0;
|
567 |
ret = qcow2_update_header(bs); |
568 |
if (ret < 0) { |
569 |
goto fail;
|
570 |
} |
571 |
} |
572 |
|
573 |
/* Initialise locks */
|
574 |
qemu_co_mutex_init(&s->lock); |
575 |
|
576 |
/* Repair image if dirty */
|
577 |
if (!(flags & BDRV_O_CHECK) && !bs->read_only &&
|
578 |
(s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { |
579 |
BdrvCheckResult result = {0};
|
580 |
|
581 |
ret = qcow2_check(bs, &result, BDRV_FIX_ERRORS); |
582 |
if (ret < 0) { |
583 |
goto fail;
|
584 |
} |
585 |
} |
586 |
|
587 |
/* Enable lazy_refcounts according to image and command line options */
|
588 |
opts = qemu_opts_create_nofail(&qcow2_runtime_opts); |
589 |
qemu_opts_absorb_qdict(opts, options, &local_err); |
590 |
if (error_is_set(&local_err)) {
|
591 |
qerror_report_err(local_err); |
592 |
error_free(local_err); |
593 |
ret = -EINVAL; |
594 |
goto fail;
|
595 |
} |
596 |
|
597 |
s->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS, |
598 |
(s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)); |
599 |
|
600 |
s->discard_passthrough[QCOW2_DISCARD_NEVER] = false;
|
601 |
s->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true;
|
602 |
s->discard_passthrough[QCOW2_DISCARD_REQUEST] = |
603 |
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST, |
604 |
flags & BDRV_O_UNMAP); |
605 |
s->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] = |
606 |
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true);
|
607 |
s->discard_passthrough[QCOW2_DISCARD_OTHER] = |
608 |
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false);
|
609 |
|
610 |
qemu_opts_del(opts); |
611 |
|
612 |
if (s->use_lazy_refcounts && s->qcow_version < 3) { |
613 |
qerror_report(ERROR_CLASS_GENERIC_ERROR, "Lazy refcounts require "
|
614 |
"a qcow2 image with at least qemu 1.1 compatibility level");
|
615 |
ret = -EINVAL; |
616 |
goto fail;
|
617 |
} |
618 |
|
619 |
#ifdef DEBUG_ALLOC
|
620 |
{ |
621 |
BdrvCheckResult result = {0};
|
622 |
qcow2_check_refcounts(bs, &result, 0);
|
623 |
} |
624 |
#endif
|
625 |
return ret;
|
626 |
|
627 |
fail:
|
628 |
g_free(s->unknown_header_fields); |
629 |
cleanup_unknown_header_ext(bs); |
630 |
qcow2_free_snapshots(bs); |
631 |
qcow2_refcount_close(bs); |
632 |
g_free(s->l1_table); |
633 |
/* else pre-write overlap checks in cache_destroy may crash */
|
634 |
s->l1_table = NULL;
|
635 |
if (s->l2_table_cache) {
|
636 |
qcow2_cache_destroy(bs, s->l2_table_cache); |
637 |
} |
638 |
g_free(s->cluster_cache); |
639 |
qemu_vfree(s->cluster_data); |
640 |
return ret;
|
641 |
} |
642 |
|
643 |
static int qcow2_set_key(BlockDriverState *bs, const char *key) |
644 |
{ |
645 |
BDRVQcowState *s = bs->opaque; |
646 |
uint8_t keybuf[16];
|
647 |
int len, i;
|
648 |
|
649 |
memset(keybuf, 0, 16); |
650 |
len = strlen(key); |
651 |
if (len > 16) |
652 |
len = 16;
|
653 |
/* XXX: we could compress the chars to 7 bits to increase
|
654 |
entropy */
|
655 |
for(i = 0;i < len;i++) { |
656 |
keybuf[i] = key[i]; |
657 |
} |
658 |
s->crypt_method = s->crypt_method_header; |
659 |
|
660 |
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
661 |
return -1; |
662 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
663 |
return -1; |
664 |
#if 0
|
665 |
/* test */
|
666 |
{
|
667 |
uint8_t in[16];
|
668 |
uint8_t out[16];
|
669 |
uint8_t tmp[16];
|
670 |
for(i=0;i<16;i++)
|
671 |
in[i] = i;
|
672 |
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
673 |
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
674 |
for(i = 0; i < 16; i++)
|
675 |
printf(" %02x", tmp[i]);
|
676 |
printf("\n");
|
677 |
for(i = 0; i < 16; i++)
|
678 |
printf(" %02x", out[i]);
|
679 |
printf("\n");
|
680 |
}
|
681 |
#endif
|
682 |
return 0; |
683 |
} |
684 |
|
685 |
/* We have nothing to do for QCOW2 reopen, stubs just return
|
686 |
* success */
|
687 |
static int qcow2_reopen_prepare(BDRVReopenState *state, |
688 |
BlockReopenQueue *queue, Error **errp) |
689 |
{ |
690 |
return 0; |
691 |
} |
692 |
|
693 |
static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs,
|
694 |
int64_t sector_num, int nb_sectors, int *pnum) |
695 |
{ |
696 |
BDRVQcowState *s = bs->opaque; |
697 |
uint64_t cluster_offset; |
698 |
int index_in_cluster, ret;
|
699 |
int64_t status = 0;
|
700 |
|
701 |
*pnum = nb_sectors; |
702 |
qemu_co_mutex_lock(&s->lock); |
703 |
ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
|
704 |
qemu_co_mutex_unlock(&s->lock); |
705 |
if (ret < 0) { |
706 |
return ret;
|
707 |
} |
708 |
|
709 |
if (cluster_offset != 0 && ret != QCOW2_CLUSTER_COMPRESSED && |
710 |
!s->crypt_method) { |
711 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
712 |
cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS); |
713 |
status |= BDRV_BLOCK_OFFSET_VALID | cluster_offset; |
714 |
} |
715 |
if (ret == QCOW2_CLUSTER_ZERO) {
|
716 |
status |= BDRV_BLOCK_ZERO; |
717 |
} else if (ret != QCOW2_CLUSTER_UNALLOCATED) { |
718 |
status |= BDRV_BLOCK_DATA; |
719 |
} |
720 |
return status;
|
721 |
} |
722 |
|
723 |
/* handle reading after the end of the backing file */
|
724 |
int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
|
725 |
int64_t sector_num, int nb_sectors)
|
726 |
{ |
727 |
int n1;
|
728 |
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
729 |
return nb_sectors;
|
730 |
if (sector_num >= bs->total_sectors)
|
731 |
n1 = 0;
|
732 |
else
|
733 |
n1 = bs->total_sectors - sector_num; |
734 |
|
735 |
qemu_iovec_memset(qiov, 512 * n1, 0, 512 * (nb_sectors - n1)); |
736 |
|
737 |
return n1;
|
738 |
} |
739 |
|
740 |
static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, |
741 |
int remaining_sectors, QEMUIOVector *qiov)
|
742 |
{ |
743 |
BDRVQcowState *s = bs->opaque; |
744 |
int index_in_cluster, n1;
|
745 |
int ret;
|
746 |
int cur_nr_sectors; /* number of sectors in current iteration */ |
747 |
uint64_t cluster_offset = 0;
|
748 |
uint64_t bytes_done = 0;
|
749 |
QEMUIOVector hd_qiov; |
750 |
uint8_t *cluster_data = NULL;
|
751 |
|
752 |
qemu_iovec_init(&hd_qiov, qiov->niov); |
753 |
|
754 |
qemu_co_mutex_lock(&s->lock); |
755 |
|
756 |
while (remaining_sectors != 0) { |
757 |
|
758 |
/* prepare next request */
|
759 |
cur_nr_sectors = remaining_sectors; |
760 |
if (s->crypt_method) {
|
761 |
cur_nr_sectors = MIN(cur_nr_sectors, |
762 |
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); |
763 |
} |
764 |
|
765 |
ret = qcow2_get_cluster_offset(bs, sector_num << 9,
|
766 |
&cur_nr_sectors, &cluster_offset); |
767 |
if (ret < 0) { |
768 |
goto fail;
|
769 |
} |
770 |
|
771 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
772 |
|
773 |
qemu_iovec_reset(&hd_qiov); |
774 |
qemu_iovec_concat(&hd_qiov, qiov, bytes_done, |
775 |
cur_nr_sectors * 512);
|
776 |
|
777 |
switch (ret) {
|
778 |
case QCOW2_CLUSTER_UNALLOCATED:
|
779 |
|
780 |
if (bs->backing_hd) {
|
781 |
/* read from the base image */
|
782 |
n1 = qcow2_backing_read1(bs->backing_hd, &hd_qiov, |
783 |
sector_num, cur_nr_sectors); |
784 |
if (n1 > 0) { |
785 |
BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); |
786 |
qemu_co_mutex_unlock(&s->lock); |
787 |
ret = bdrv_co_readv(bs->backing_hd, sector_num, |
788 |
n1, &hd_qiov); |
789 |
qemu_co_mutex_lock(&s->lock); |
790 |
if (ret < 0) { |
791 |
goto fail;
|
792 |
} |
793 |
} |
794 |
} else {
|
795 |
/* Note: in this case, no need to wait */
|
796 |
qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors); |
797 |
} |
798 |
break;
|
799 |
|
800 |
case QCOW2_CLUSTER_ZERO:
|
801 |
qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors); |
802 |
break;
|
803 |
|
804 |
case QCOW2_CLUSTER_COMPRESSED:
|
805 |
/* add AIO support for compressed blocks ? */
|
806 |
ret = qcow2_decompress_cluster(bs, cluster_offset); |
807 |
if (ret < 0) { |
808 |
goto fail;
|
809 |
} |
810 |
|
811 |
qemu_iovec_from_buf(&hd_qiov, 0,
|
812 |
s->cluster_cache + index_in_cluster * 512,
|
813 |
512 * cur_nr_sectors);
|
814 |
break;
|
815 |
|
816 |
case QCOW2_CLUSTER_NORMAL:
|
817 |
if ((cluster_offset & 511) != 0) { |
818 |
ret = -EIO; |
819 |
goto fail;
|
820 |
} |
821 |
|
822 |
if (s->crypt_method) {
|
823 |
/*
|
824 |
* For encrypted images, read everything into a temporary
|
825 |
* contiguous buffer on which the AES functions can work.
|
826 |
*/
|
827 |
if (!cluster_data) {
|
828 |
cluster_data = |
829 |
qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
830 |
} |
831 |
|
832 |
assert(cur_nr_sectors <= |
833 |
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); |
834 |
qemu_iovec_reset(&hd_qiov); |
835 |
qemu_iovec_add(&hd_qiov, cluster_data, |
836 |
512 * cur_nr_sectors);
|
837 |
} |
838 |
|
839 |
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); |
840 |
qemu_co_mutex_unlock(&s->lock); |
841 |
ret = bdrv_co_readv(bs->file, |
842 |
(cluster_offset >> 9) + index_in_cluster,
|
843 |
cur_nr_sectors, &hd_qiov); |
844 |
qemu_co_mutex_lock(&s->lock); |
845 |
if (ret < 0) { |
846 |
goto fail;
|
847 |
} |
848 |
if (s->crypt_method) {
|
849 |
qcow2_encrypt_sectors(s, sector_num, cluster_data, |
850 |
cluster_data, cur_nr_sectors, 0, &s->aes_decrypt_key);
|
851 |
qemu_iovec_from_buf(qiov, bytes_done, |
852 |
cluster_data, 512 * cur_nr_sectors);
|
853 |
} |
854 |
break;
|
855 |
|
856 |
default:
|
857 |
g_assert_not_reached(); |
858 |
ret = -EIO; |
859 |
goto fail;
|
860 |
} |
861 |
|
862 |
remaining_sectors -= cur_nr_sectors; |
863 |
sector_num += cur_nr_sectors; |
864 |
bytes_done += cur_nr_sectors * 512;
|
865 |
} |
866 |
ret = 0;
|
867 |
|
868 |
fail:
|
869 |
qemu_co_mutex_unlock(&s->lock); |
870 |
|
871 |
qemu_iovec_destroy(&hd_qiov); |
872 |
qemu_vfree(cluster_data); |
873 |
|
874 |
return ret;
|
875 |
} |
876 |
|
877 |
static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, |
878 |
int64_t sector_num, |
879 |
int remaining_sectors,
|
880 |
QEMUIOVector *qiov) |
881 |
{ |
882 |
BDRVQcowState *s = bs->opaque; |
883 |
int index_in_cluster;
|
884 |
int n_end;
|
885 |
int ret;
|
886 |
int cur_nr_sectors; /* number of sectors in current iteration */ |
887 |
uint64_t cluster_offset; |
888 |
QEMUIOVector hd_qiov; |
889 |
uint64_t bytes_done = 0;
|
890 |
uint8_t *cluster_data = NULL;
|
891 |
QCowL2Meta *l2meta = NULL;
|
892 |
|
893 |
trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num, |
894 |
remaining_sectors); |
895 |
|
896 |
qemu_iovec_init(&hd_qiov, qiov->niov); |
897 |
|
898 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
899 |
|
900 |
qemu_co_mutex_lock(&s->lock); |
901 |
|
902 |
while (remaining_sectors != 0) { |
903 |
|
904 |
l2meta = NULL;
|
905 |
|
906 |
trace_qcow2_writev_start_part(qemu_coroutine_self()); |
907 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
908 |
n_end = index_in_cluster + remaining_sectors; |
909 |
if (s->crypt_method &&
|
910 |
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) { |
911 |
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
912 |
} |
913 |
|
914 |
ret = qcow2_alloc_cluster_offset(bs, sector_num << 9,
|
915 |
index_in_cluster, n_end, &cur_nr_sectors, &cluster_offset, &l2meta); |
916 |
if (ret < 0) { |
917 |
goto fail;
|
918 |
} |
919 |
|
920 |
assert((cluster_offset & 511) == 0); |
921 |
|
922 |
qemu_iovec_reset(&hd_qiov); |
923 |
qemu_iovec_concat(&hd_qiov, qiov, bytes_done, |
924 |
cur_nr_sectors * 512);
|
925 |
|
926 |
if (s->crypt_method) {
|
927 |
if (!cluster_data) {
|
928 |
cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * |
929 |
s->cluster_size); |
930 |
} |
931 |
|
932 |
assert(hd_qiov.size <= |
933 |
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
934 |
qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size);
|
935 |
|
936 |
qcow2_encrypt_sectors(s, sector_num, cluster_data, |
937 |
cluster_data, cur_nr_sectors, 1, &s->aes_encrypt_key);
|
938 |
|
939 |
qemu_iovec_reset(&hd_qiov); |
940 |
qemu_iovec_add(&hd_qiov, cluster_data, |
941 |
cur_nr_sectors * 512);
|
942 |
} |
943 |
|
944 |
ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, |
945 |
cluster_offset + index_in_cluster * BDRV_SECTOR_SIZE, |
946 |
cur_nr_sectors * BDRV_SECTOR_SIZE); |
947 |
if (ret < 0) { |
948 |
goto fail;
|
949 |
} |
950 |
|
951 |
qemu_co_mutex_unlock(&s->lock); |
952 |
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); |
953 |
trace_qcow2_writev_data(qemu_coroutine_self(), |
954 |
(cluster_offset >> 9) + index_in_cluster);
|
955 |
ret = bdrv_co_writev(bs->file, |
956 |
(cluster_offset >> 9) + index_in_cluster,
|
957 |
cur_nr_sectors, &hd_qiov); |
958 |
qemu_co_mutex_lock(&s->lock); |
959 |
if (ret < 0) { |
960 |
goto fail;
|
961 |
} |
962 |
|
963 |
while (l2meta != NULL) { |
964 |
QCowL2Meta *next; |
965 |
|
966 |
ret = qcow2_alloc_cluster_link_l2(bs, l2meta); |
967 |
if (ret < 0) { |
968 |
goto fail;
|
969 |
} |
970 |
|
971 |
/* Take the request off the list of running requests */
|
972 |
if (l2meta->nb_clusters != 0) { |
973 |
QLIST_REMOVE(l2meta, next_in_flight); |
974 |
} |
975 |
|
976 |
qemu_co_queue_restart_all(&l2meta->dependent_requests); |
977 |
|
978 |
next = l2meta->next; |
979 |
g_free(l2meta); |
980 |
l2meta = next; |
981 |
} |
982 |
|
983 |
remaining_sectors -= cur_nr_sectors; |
984 |
sector_num += cur_nr_sectors; |
985 |
bytes_done += cur_nr_sectors * 512;
|
986 |
trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_nr_sectors); |
987 |
} |
988 |
ret = 0;
|
989 |
|
990 |
fail:
|
991 |
qemu_co_mutex_unlock(&s->lock); |
992 |
|
993 |
while (l2meta != NULL) { |
994 |
QCowL2Meta *next; |
995 |
|
996 |
if (l2meta->nb_clusters != 0) { |
997 |
QLIST_REMOVE(l2meta, next_in_flight); |
998 |
} |
999 |
qemu_co_queue_restart_all(&l2meta->dependent_requests); |
1000 |
|
1001 |
next = l2meta->next; |
1002 |
g_free(l2meta); |
1003 |
l2meta = next; |
1004 |
} |
1005 |
|
1006 |
qemu_iovec_destroy(&hd_qiov); |
1007 |
qemu_vfree(cluster_data); |
1008 |
trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); |
1009 |
|
1010 |
return ret;
|
1011 |
} |
1012 |
|
1013 |
static void qcow2_close(BlockDriverState *bs) |
1014 |
{ |
1015 |
BDRVQcowState *s = bs->opaque; |
1016 |
g_free(s->l1_table); |
1017 |
/* else pre-write overlap checks in cache_destroy may crash */
|
1018 |
s->l1_table = NULL;
|
1019 |
|
1020 |
qcow2_cache_flush(bs, s->l2_table_cache); |
1021 |
qcow2_cache_flush(bs, s->refcount_block_cache); |
1022 |
|
1023 |
qcow2_mark_clean(bs); |
1024 |
|
1025 |
qcow2_cache_destroy(bs, s->l2_table_cache); |
1026 |
qcow2_cache_destroy(bs, s->refcount_block_cache); |
1027 |
|
1028 |
g_free(s->unknown_header_fields); |
1029 |
cleanup_unknown_header_ext(bs); |
1030 |
|
1031 |
g_free(s->cluster_cache); |
1032 |
qemu_vfree(s->cluster_data); |
1033 |
qcow2_refcount_close(bs); |
1034 |
qcow2_free_snapshots(bs); |
1035 |
} |
1036 |
|
1037 |
static void qcow2_invalidate_cache(BlockDriverState *bs) |
1038 |
{ |
1039 |
BDRVQcowState *s = bs->opaque; |
1040 |
int flags = s->flags;
|
1041 |
AES_KEY aes_encrypt_key; |
1042 |
AES_KEY aes_decrypt_key; |
1043 |
uint32_t crypt_method = 0;
|
1044 |
QDict *options; |
1045 |
|
1046 |
/*
|
1047 |
* Backing files are read-only which makes all of their metadata immutable,
|
1048 |
* that means we don't have to worry about reopening them here.
|
1049 |
*/
|
1050 |
|
1051 |
if (s->crypt_method) {
|
1052 |
crypt_method = s->crypt_method; |
1053 |
memcpy(&aes_encrypt_key, &s->aes_encrypt_key, sizeof(aes_encrypt_key));
|
1054 |
memcpy(&aes_decrypt_key, &s->aes_decrypt_key, sizeof(aes_decrypt_key));
|
1055 |
} |
1056 |
|
1057 |
qcow2_close(bs); |
1058 |
|
1059 |
options = qdict_new(); |
1060 |
qdict_put(options, QCOW2_OPT_LAZY_REFCOUNTS, |
1061 |
qbool_from_int(s->use_lazy_refcounts)); |
1062 |
|
1063 |
memset(s, 0, sizeof(BDRVQcowState)); |
1064 |
qcow2_open(bs, options, flags, NULL);
|
1065 |
|
1066 |
QDECREF(options); |
1067 |
|
1068 |
if (crypt_method) {
|
1069 |
s->crypt_method = crypt_method; |
1070 |
memcpy(&s->aes_encrypt_key, &aes_encrypt_key, sizeof(aes_encrypt_key));
|
1071 |
memcpy(&s->aes_decrypt_key, &aes_decrypt_key, sizeof(aes_decrypt_key));
|
1072 |
} |
1073 |
} |
1074 |
|
1075 |
static size_t header_ext_add(char *buf, uint32_t magic, const void *s, |
1076 |
size_t len, size_t buflen) |
1077 |
{ |
1078 |
QCowExtension *ext_backing_fmt = (QCowExtension*) buf; |
1079 |
size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7); |
1080 |
|
1081 |
if (buflen < ext_len) {
|
1082 |
return -ENOSPC;
|
1083 |
} |
1084 |
|
1085 |
*ext_backing_fmt = (QCowExtension) { |
1086 |
.magic = cpu_to_be32(magic), |
1087 |
.len = cpu_to_be32(len), |
1088 |
}; |
1089 |
memcpy(buf + sizeof(QCowExtension), s, len);
|
1090 |
|
1091 |
return ext_len;
|
1092 |
} |
1093 |
|
1094 |
/*
|
1095 |
* Updates the qcow2 header, including the variable length parts of it, i.e.
|
1096 |
* the backing file name and all extensions. qcow2 was not designed to allow
|
1097 |
* such changes, so if we run out of space (we can only use the first cluster)
|
1098 |
* this function may fail.
|
1099 |
*
|
1100 |
* Returns 0 on success, -errno in error cases.
|
1101 |
*/
|
1102 |
int qcow2_update_header(BlockDriverState *bs)
|
1103 |
{ |
1104 |
BDRVQcowState *s = bs->opaque; |
1105 |
QCowHeader *header; |
1106 |
char *buf;
|
1107 |
size_t buflen = s->cluster_size; |
1108 |
int ret;
|
1109 |
uint64_t total_size; |
1110 |
uint32_t refcount_table_clusters; |
1111 |
size_t header_length; |
1112 |
Qcow2UnknownHeaderExtension *uext; |
1113 |
|
1114 |
buf = qemu_blockalign(bs, buflen); |
1115 |
|
1116 |
/* Header structure */
|
1117 |
header = (QCowHeader*) buf; |
1118 |
|
1119 |
if (buflen < sizeof(*header)) { |
1120 |
ret = -ENOSPC; |
1121 |
goto fail;
|
1122 |
} |
1123 |
|
1124 |
header_length = sizeof(*header) + s->unknown_header_fields_size;
|
1125 |
total_size = bs->total_sectors * BDRV_SECTOR_SIZE; |
1126 |
refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
|
1127 |
|
1128 |
*header = (QCowHeader) { |
1129 |
/* Version 2 fields */
|
1130 |
.magic = cpu_to_be32(QCOW_MAGIC), |
1131 |
.version = cpu_to_be32(s->qcow_version), |
1132 |
.backing_file_offset = 0,
|
1133 |
.backing_file_size = 0,
|
1134 |
.cluster_bits = cpu_to_be32(s->cluster_bits), |
1135 |
.size = cpu_to_be64(total_size), |
1136 |
.crypt_method = cpu_to_be32(s->crypt_method_header), |
1137 |
.l1_size = cpu_to_be32(s->l1_size), |
1138 |
.l1_table_offset = cpu_to_be64(s->l1_table_offset), |
1139 |
.refcount_table_offset = cpu_to_be64(s->refcount_table_offset), |
1140 |
.refcount_table_clusters = cpu_to_be32(refcount_table_clusters), |
1141 |
.nb_snapshots = cpu_to_be32(s->nb_snapshots), |
1142 |
.snapshots_offset = cpu_to_be64(s->snapshots_offset), |
1143 |
|
1144 |
/* Version 3 fields */
|
1145 |
.incompatible_features = cpu_to_be64(s->incompatible_features), |
1146 |
.compatible_features = cpu_to_be64(s->compatible_features), |
1147 |
.autoclear_features = cpu_to_be64(s->autoclear_features), |
1148 |
.refcount_order = cpu_to_be32(s->refcount_order), |
1149 |
.header_length = cpu_to_be32(header_length), |
1150 |
}; |
1151 |
|
1152 |
/* For older versions, write a shorter header */
|
1153 |
switch (s->qcow_version) {
|
1154 |
case 2: |
1155 |
ret = offsetof(QCowHeader, incompatible_features); |
1156 |
break;
|
1157 |
case 3: |
1158 |
ret = sizeof(*header);
|
1159 |
break;
|
1160 |
default:
|
1161 |
ret = -EINVAL; |
1162 |
goto fail;
|
1163 |
} |
1164 |
|
1165 |
buf += ret; |
1166 |
buflen -= ret; |
1167 |
memset(buf, 0, buflen);
|
1168 |
|
1169 |
/* Preserve any unknown field in the header */
|
1170 |
if (s->unknown_header_fields_size) {
|
1171 |
if (buflen < s->unknown_header_fields_size) {
|
1172 |
ret = -ENOSPC; |
1173 |
goto fail;
|
1174 |
} |
1175 |
|
1176 |
memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); |
1177 |
buf += s->unknown_header_fields_size; |
1178 |
buflen -= s->unknown_header_fields_size; |
1179 |
} |
1180 |
|
1181 |
/* Backing file format header extension */
|
1182 |
if (*bs->backing_format) {
|
1183 |
ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, |
1184 |
bs->backing_format, strlen(bs->backing_format), |
1185 |
buflen); |
1186 |
if (ret < 0) { |
1187 |
goto fail;
|
1188 |
} |
1189 |
|
1190 |
buf += ret; |
1191 |
buflen -= ret; |
1192 |
} |
1193 |
|
1194 |
/* Feature table */
|
1195 |
Qcow2Feature features[] = { |
1196 |
{ |
1197 |
.type = QCOW2_FEAT_TYPE_INCOMPATIBLE, |
1198 |
.bit = QCOW2_INCOMPAT_DIRTY_BITNR, |
1199 |
.name = "dirty bit",
|
1200 |
}, |
1201 |
{ |
1202 |
.type = QCOW2_FEAT_TYPE_INCOMPATIBLE, |
1203 |
.bit = QCOW2_INCOMPAT_CORRUPT_BITNR, |
1204 |
.name = "corrupt bit",
|
1205 |
}, |
1206 |
{ |
1207 |
.type = QCOW2_FEAT_TYPE_COMPATIBLE, |
1208 |
.bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, |
1209 |
.name = "lazy refcounts",
|
1210 |
}, |
1211 |
}; |
1212 |
|
1213 |
ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, |
1214 |
features, sizeof(features), buflen);
|
1215 |
if (ret < 0) { |
1216 |
goto fail;
|
1217 |
} |
1218 |
buf += ret; |
1219 |
buflen -= ret; |
1220 |
|
1221 |
/* Keep unknown header extensions */
|
1222 |
QLIST_FOREACH(uext, &s->unknown_header_ext, next) { |
1223 |
ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); |
1224 |
if (ret < 0) { |
1225 |
goto fail;
|
1226 |
} |
1227 |
|
1228 |
buf += ret; |
1229 |
buflen -= ret; |
1230 |
} |
1231 |
|
1232 |
/* End of header extensions */
|
1233 |
ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); |
1234 |
if (ret < 0) { |
1235 |
goto fail;
|
1236 |
} |
1237 |
|
1238 |
buf += ret; |
1239 |
buflen -= ret; |
1240 |
|
1241 |
/* Backing file name */
|
1242 |
if (*bs->backing_file) {
|
1243 |
size_t backing_file_len = strlen(bs->backing_file); |
1244 |
|
1245 |
if (buflen < backing_file_len) {
|
1246 |
ret = -ENOSPC; |
1247 |
goto fail;
|
1248 |
} |
1249 |
|
1250 |
/* Using strncpy is ok here, since buf is not NUL-terminated. */
|
1251 |
strncpy(buf, bs->backing_file, buflen); |
1252 |
|
1253 |
header->backing_file_offset = cpu_to_be64(buf - ((char*) header));
|
1254 |
header->backing_file_size = cpu_to_be32(backing_file_len); |
1255 |
} |
1256 |
|
1257 |
/* Write the new header */
|
1258 |
ret = bdrv_pwrite(bs->file, 0, header, s->cluster_size);
|
1259 |
if (ret < 0) { |
1260 |
goto fail;
|
1261 |
} |
1262 |
|
1263 |
ret = 0;
|
1264 |
fail:
|
1265 |
qemu_vfree(header); |
1266 |
return ret;
|
1267 |
} |
1268 |
|
1269 |
static int qcow2_change_backing_file(BlockDriverState *bs, |
1270 |
const char *backing_file, const char *backing_fmt) |
1271 |
{ |
1272 |
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); |
1273 |
pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); |
1274 |
|
1275 |
return qcow2_update_header(bs);
|
1276 |
} |
1277 |
|
1278 |
static int preallocate(BlockDriverState *bs) |
1279 |
{ |
1280 |
uint64_t nb_sectors; |
1281 |
uint64_t offset; |
1282 |
uint64_t host_offset = 0;
|
1283 |
int num;
|
1284 |
int ret;
|
1285 |
QCowL2Meta *meta; |
1286 |
|
1287 |
nb_sectors = bdrv_getlength(bs) >> 9;
|
1288 |
offset = 0;
|
1289 |
|
1290 |
while (nb_sectors) {
|
1291 |
num = MIN(nb_sectors, INT_MAX >> 9);
|
1292 |
ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num,
|
1293 |
&host_offset, &meta); |
1294 |
if (ret < 0) { |
1295 |
return ret;
|
1296 |
} |
1297 |
|
1298 |
ret = qcow2_alloc_cluster_link_l2(bs, meta); |
1299 |
if (ret < 0) { |
1300 |
qcow2_free_any_clusters(bs, meta->alloc_offset, meta->nb_clusters, |
1301 |
QCOW2_DISCARD_NEVER); |
1302 |
return ret;
|
1303 |
} |
1304 |
|
1305 |
/* There are no dependent requests, but we need to remove our request
|
1306 |
* from the list of in-flight requests */
|
1307 |
if (meta != NULL) { |
1308 |
QLIST_REMOVE(meta, next_in_flight); |
1309 |
} |
1310 |
|
1311 |
/* TODO Preallocate data if requested */
|
1312 |
|
1313 |
nb_sectors -= num; |
1314 |
offset += num << 9;
|
1315 |
} |
1316 |
|
1317 |
/*
|
1318 |
* It is expected that the image file is large enough to actually contain
|
1319 |
* all of the allocated clusters (otherwise we get failing reads after
|
1320 |
* EOF). Extend the image to the last allocated sector.
|
1321 |
*/
|
1322 |
if (host_offset != 0) { |
1323 |
uint8_t buf[512];
|
1324 |
memset(buf, 0, 512); |
1325 |
ret = bdrv_write(bs->file, (host_offset >> 9) + num - 1, buf, 1); |
1326 |
if (ret < 0) { |
1327 |
return ret;
|
1328 |
} |
1329 |
} |
1330 |
|
1331 |
return 0; |
1332 |
} |
1333 |
|
1334 |
static int qcow2_create2(const char *filename, int64_t total_size, |
1335 |
const char *backing_file, const char *backing_format, |
1336 |
int flags, size_t cluster_size, int prealloc, |
1337 |
QEMUOptionParameter *options, int version)
|
1338 |
{ |
1339 |
/* Calculate cluster_bits */
|
1340 |
int cluster_bits;
|
1341 |
cluster_bits = ffs(cluster_size) - 1;
|
1342 |
if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS ||
|
1343 |
(1 << cluster_bits) != cluster_size)
|
1344 |
{ |
1345 |
error_report( |
1346 |
"Cluster size must be a power of two between %d and %dk",
|
1347 |
1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); |
1348 |
return -EINVAL;
|
1349 |
} |
1350 |
|
1351 |
/*
|
1352 |
* Open the image file and write a minimal qcow2 header.
|
1353 |
*
|
1354 |
* We keep things simple and start with a zero-sized image. We also
|
1355 |
* do without refcount blocks or a L1 table for now. We'll fix the
|
1356 |
* inconsistency later.
|
1357 |
*
|
1358 |
* We do need a refcount table because growing the refcount table means
|
1359 |
* allocating two new refcount blocks - the seconds of which would be at
|
1360 |
* 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
|
1361 |
* size for any qcow2 image.
|
1362 |
*/
|
1363 |
BlockDriverState* bs; |
1364 |
QCowHeader header; |
1365 |
uint8_t* refcount_table; |
1366 |
int ret;
|
1367 |
|
1368 |
ret = bdrv_create_file(filename, options); |
1369 |
if (ret < 0) { |
1370 |
return ret;
|
1371 |
} |
1372 |
|
1373 |
ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR);
|
1374 |
if (ret < 0) { |
1375 |
return ret;
|
1376 |
} |
1377 |
|
1378 |
/* Write the header */
|
1379 |
memset(&header, 0, sizeof(header)); |
1380 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
1381 |
header.version = cpu_to_be32(version); |
1382 |
header.cluster_bits = cpu_to_be32(cluster_bits); |
1383 |
header.size = cpu_to_be64(0);
|
1384 |
header.l1_table_offset = cpu_to_be64(0);
|
1385 |
header.l1_size = cpu_to_be32(0);
|
1386 |
header.refcount_table_offset = cpu_to_be64(cluster_size); |
1387 |
header.refcount_table_clusters = cpu_to_be32(1);
|
1388 |
header.refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT);
|
1389 |
header.header_length = cpu_to_be32(sizeof(header));
|
1390 |
|
1391 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
1392 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
1393 |
} else {
|
1394 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
1395 |
} |
1396 |
|
1397 |
if (flags & BLOCK_FLAG_LAZY_REFCOUNTS) {
|
1398 |
header.compatible_features |= |
1399 |
cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS); |
1400 |
} |
1401 |
|
1402 |
ret = bdrv_pwrite(bs, 0, &header, sizeof(header)); |
1403 |
if (ret < 0) { |
1404 |
goto out;
|
1405 |
} |
1406 |
|
1407 |
/* Write an empty refcount table */
|
1408 |
refcount_table = g_malloc0(cluster_size); |
1409 |
ret = bdrv_pwrite(bs, cluster_size, refcount_table, cluster_size); |
1410 |
g_free(refcount_table); |
1411 |
|
1412 |
if (ret < 0) { |
1413 |
goto out;
|
1414 |
} |
1415 |
|
1416 |
bdrv_close(bs); |
1417 |
|
1418 |
/*
|
1419 |
* And now open the image and make it consistent first (i.e. increase the
|
1420 |
* refcount of the cluster that is occupied by the header and the refcount
|
1421 |
* table)
|
1422 |
*/
|
1423 |
BlockDriver* drv = bdrv_find_format("qcow2");
|
1424 |
assert(drv != NULL);
|
1425 |
ret = bdrv_open(bs, filename, NULL,
|
1426 |
BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, drv); |
1427 |
if (ret < 0) { |
1428 |
goto out;
|
1429 |
} |
1430 |
|
1431 |
ret = qcow2_alloc_clusters(bs, 2 * cluster_size);
|
1432 |
if (ret < 0) { |
1433 |
goto out;
|
1434 |
|
1435 |
} else if (ret != 0) { |
1436 |
error_report("Huh, first cluster in empty image is already in use?");
|
1437 |
abort(); |
1438 |
} |
1439 |
|
1440 |
/* Okay, now that we have a valid image, let's give it the right size */
|
1441 |
ret = bdrv_truncate(bs, total_size * BDRV_SECTOR_SIZE); |
1442 |
if (ret < 0) { |
1443 |
goto out;
|
1444 |
} |
1445 |
|
1446 |
/* Want a backing file? There you go.*/
|
1447 |
if (backing_file) {
|
1448 |
ret = bdrv_change_backing_file(bs, backing_file, backing_format); |
1449 |
if (ret < 0) { |
1450 |
goto out;
|
1451 |
} |
1452 |
} |
1453 |
|
1454 |
/* And if we're supposed to preallocate metadata, do that now */
|
1455 |
if (prealloc) {
|
1456 |
BDRVQcowState *s = bs->opaque; |
1457 |
qemu_co_mutex_lock(&s->lock); |
1458 |
ret = preallocate(bs); |
1459 |
qemu_co_mutex_unlock(&s->lock); |
1460 |
if (ret < 0) { |
1461 |
goto out;
|
1462 |
} |
1463 |
} |
1464 |
|
1465 |
ret = 0;
|
1466 |
out:
|
1467 |
bdrv_unref(bs); |
1468 |
return ret;
|
1469 |
} |
1470 |
|
1471 |
static int qcow2_create(const char *filename, QEMUOptionParameter *options, |
1472 |
Error **errp) |
1473 |
{ |
1474 |
const char *backing_file = NULL; |
1475 |
const char *backing_fmt = NULL; |
1476 |
uint64_t sectors = 0;
|
1477 |
int flags = 0; |
1478 |
size_t cluster_size = DEFAULT_CLUSTER_SIZE; |
1479 |
int prealloc = 0; |
1480 |
int version = 3; |
1481 |
|
1482 |
/* Read out options */
|
1483 |
while (options && options->name) {
|
1484 |
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
1485 |
sectors = options->value.n / 512;
|
1486 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { |
1487 |
backing_file = options->value.s; |
1488 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { |
1489 |
backing_fmt = options->value.s; |
1490 |
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { |
1491 |
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
1492 |
} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { |
1493 |
if (options->value.n) {
|
1494 |
cluster_size = options->value.n; |
1495 |
} |
1496 |
} else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) { |
1497 |
if (!options->value.s || !strcmp(options->value.s, "off")) { |
1498 |
prealloc = 0;
|
1499 |
} else if (!strcmp(options->value.s, "metadata")) { |
1500 |
prealloc = 1;
|
1501 |
} else {
|
1502 |
fprintf(stderr, "Invalid preallocation mode: '%s'\n",
|
1503 |
options->value.s); |
1504 |
return -EINVAL;
|
1505 |
} |
1506 |
} else if (!strcmp(options->name, BLOCK_OPT_COMPAT_LEVEL)) { |
1507 |
if (!options->value.s) {
|
1508 |
/* keep the default */
|
1509 |
} else if (!strcmp(options->value.s, "0.10")) { |
1510 |
version = 2;
|
1511 |
} else if (!strcmp(options->value.s, "1.1")) { |
1512 |
version = 3;
|
1513 |
} else {
|
1514 |
fprintf(stderr, "Invalid compatibility level: '%s'\n",
|
1515 |
options->value.s); |
1516 |
return -EINVAL;
|
1517 |
} |
1518 |
} else if (!strcmp(options->name, BLOCK_OPT_LAZY_REFCOUNTS)) { |
1519 |
flags |= options->value.n ? BLOCK_FLAG_LAZY_REFCOUNTS : 0;
|
1520 |
} |
1521 |
options++; |
1522 |
} |
1523 |
|
1524 |
if (backing_file && prealloc) {
|
1525 |
fprintf(stderr, "Backing file and preallocation cannot be used at "
|
1526 |
"the same time\n");
|
1527 |
return -EINVAL;
|
1528 |
} |
1529 |
|
1530 |
if (version < 3 && (flags & BLOCK_FLAG_LAZY_REFCOUNTS)) { |
1531 |
fprintf(stderr, "Lazy refcounts only supported with compatibility "
|
1532 |
"level 1.1 and above (use compat=1.1 or greater)\n");
|
1533 |
return -EINVAL;
|
1534 |
} |
1535 |
|
1536 |
return qcow2_create2(filename, sectors, backing_file, backing_fmt, flags,
|
1537 |
cluster_size, prealloc, options, version); |
1538 |
} |
1539 |
|
1540 |
static int qcow2_make_empty(BlockDriverState *bs) |
1541 |
{ |
1542 |
#if 0
|
1543 |
/* XXX: not correct */
|
1544 |
BDRVQcowState *s = bs->opaque;
|
1545 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
1546 |
int ret;
|
1547 |
|
1548 |
memset(s->l1_table, 0, l1_length);
|
1549 |
if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
1550 |
return -1;
|
1551 |
ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
|
1552 |
if (ret < 0)
|
1553 |
return ret;
|
1554 |
|
1555 |
l2_cache_reset(bs);
|
1556 |
#endif
|
1557 |
return 0; |
1558 |
} |
1559 |
|
1560 |
static coroutine_fn int qcow2_co_write_zeroes(BlockDriverState *bs, |
1561 |
int64_t sector_num, int nb_sectors)
|
1562 |
{ |
1563 |
int ret;
|
1564 |
BDRVQcowState *s = bs->opaque; |
1565 |
|
1566 |
/* Emulate misaligned zero writes */
|
1567 |
if (sector_num % s->cluster_sectors || nb_sectors % s->cluster_sectors) {
|
1568 |
return -ENOTSUP;
|
1569 |
} |
1570 |
|
1571 |
/* Whatever is left can use real zero clusters */
|
1572 |
qemu_co_mutex_lock(&s->lock); |
1573 |
ret = qcow2_zero_clusters(bs, sector_num << BDRV_SECTOR_BITS, |
1574 |
nb_sectors); |
1575 |
qemu_co_mutex_unlock(&s->lock); |
1576 |
|
1577 |
return ret;
|
1578 |
} |
1579 |
|
1580 |
static coroutine_fn int qcow2_co_discard(BlockDriverState *bs, |
1581 |
int64_t sector_num, int nb_sectors)
|
1582 |
{ |
1583 |
int ret;
|
1584 |
BDRVQcowState *s = bs->opaque; |
1585 |
|
1586 |
qemu_co_mutex_lock(&s->lock); |
1587 |
ret = qcow2_discard_clusters(bs, sector_num << BDRV_SECTOR_BITS, |
1588 |
nb_sectors, QCOW2_DISCARD_REQUEST); |
1589 |
qemu_co_mutex_unlock(&s->lock); |
1590 |
return ret;
|
1591 |
} |
1592 |
|
1593 |
static int qcow2_truncate(BlockDriverState *bs, int64_t offset) |
1594 |
{ |
1595 |
BDRVQcowState *s = bs->opaque; |
1596 |
int64_t new_l1_size; |
1597 |
int ret;
|
1598 |
|
1599 |
if (offset & 511) { |
1600 |
error_report("The new size must be a multiple of 512");
|
1601 |
return -EINVAL;
|
1602 |
} |
1603 |
|
1604 |
/* cannot proceed if image has snapshots */
|
1605 |
if (s->nb_snapshots) {
|
1606 |
error_report("Can't resize an image which has snapshots");
|
1607 |
return -ENOTSUP;
|
1608 |
} |
1609 |
|
1610 |
/* shrinking is currently not supported */
|
1611 |
if (offset < bs->total_sectors * 512) { |
1612 |
error_report("qcow2 doesn't support shrinking images yet");
|
1613 |
return -ENOTSUP;
|
1614 |
} |
1615 |
|
1616 |
new_l1_size = size_to_l1(s, offset); |
1617 |
ret = qcow2_grow_l1_table(bs, new_l1_size, true);
|
1618 |
if (ret < 0) { |
1619 |
return ret;
|
1620 |
} |
1621 |
|
1622 |
/* write updated header.size */
|
1623 |
offset = cpu_to_be64(offset); |
1624 |
ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size), |
1625 |
&offset, sizeof(uint64_t));
|
1626 |
if (ret < 0) { |
1627 |
return ret;
|
1628 |
} |
1629 |
|
1630 |
s->l1_vm_state_index = new_l1_size; |
1631 |
return 0; |
1632 |
} |
1633 |
|
1634 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
1635 |
tables to avoid losing bytes in alignment */
|
1636 |
static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, |
1637 |
const uint8_t *buf, int nb_sectors) |
1638 |
{ |
1639 |
BDRVQcowState *s = bs->opaque; |
1640 |
z_stream strm; |
1641 |
int ret, out_len;
|
1642 |
uint8_t *out_buf; |
1643 |
uint64_t cluster_offset; |
1644 |
|
1645 |
if (nb_sectors == 0) { |
1646 |
/* align end of file to a sector boundary to ease reading with
|
1647 |
sector based I/Os */
|
1648 |
cluster_offset = bdrv_getlength(bs->file); |
1649 |
cluster_offset = (cluster_offset + 511) & ~511; |
1650 |
bdrv_truncate(bs->file, cluster_offset); |
1651 |
return 0; |
1652 |
} |
1653 |
|
1654 |
if (nb_sectors != s->cluster_sectors) {
|
1655 |
ret = -EINVAL; |
1656 |
|
1657 |
/* Zero-pad last write if image size is not cluster aligned */
|
1658 |
if (sector_num + nb_sectors == bs->total_sectors &&
|
1659 |
nb_sectors < s->cluster_sectors) { |
1660 |
uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size); |
1661 |
memset(pad_buf, 0, s->cluster_size);
|
1662 |
memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE); |
1663 |
ret = qcow2_write_compressed(bs, sector_num, |
1664 |
pad_buf, s->cluster_sectors); |
1665 |
qemu_vfree(pad_buf); |
1666 |
} |
1667 |
return ret;
|
1668 |
} |
1669 |
|
1670 |
out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
1671 |
|
1672 |
/* best compression, small window, no zlib header */
|
1673 |
memset(&strm, 0, sizeof(strm)); |
1674 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
1675 |
Z_DEFLATED, -12,
|
1676 |
9, Z_DEFAULT_STRATEGY);
|
1677 |
if (ret != 0) { |
1678 |
ret = -EINVAL; |
1679 |
goto fail;
|
1680 |
} |
1681 |
|
1682 |
strm.avail_in = s->cluster_size; |
1683 |
strm.next_in = (uint8_t *)buf; |
1684 |
strm.avail_out = s->cluster_size; |
1685 |
strm.next_out = out_buf; |
1686 |
|
1687 |
ret = deflate(&strm, Z_FINISH); |
1688 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
1689 |
deflateEnd(&strm); |
1690 |
ret = -EINVAL; |
1691 |
goto fail;
|
1692 |
} |
1693 |
out_len = strm.next_out - out_buf; |
1694 |
|
1695 |
deflateEnd(&strm); |
1696 |
|
1697 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
1698 |
/* could not compress: write normal cluster */
|
1699 |
|
1700 |
ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, |
1701 |
sector_num * BDRV_SECTOR_SIZE, |
1702 |
s->cluster_sectors * BDRV_SECTOR_SIZE); |
1703 |
if (ret < 0) { |
1704 |
goto fail;
|
1705 |
} |
1706 |
|
1707 |
ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors); |
1708 |
if (ret < 0) { |
1709 |
goto fail;
|
1710 |
} |
1711 |
} else {
|
1712 |
cluster_offset = qcow2_alloc_compressed_cluster_offset(bs, |
1713 |
sector_num << 9, out_len);
|
1714 |
if (!cluster_offset) {
|
1715 |
ret = -EIO; |
1716 |
goto fail;
|
1717 |
} |
1718 |
cluster_offset &= s->cluster_offset_mask; |
1719 |
|
1720 |
ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, |
1721 |
cluster_offset, out_len); |
1722 |
if (ret < 0) { |
1723 |
goto fail;
|
1724 |
} |
1725 |
|
1726 |
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); |
1727 |
ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len); |
1728 |
if (ret < 0) { |
1729 |
goto fail;
|
1730 |
} |
1731 |
} |
1732 |
|
1733 |
ret = 0;
|
1734 |
fail:
|
1735 |
g_free(out_buf); |
1736 |
return ret;
|
1737 |
} |
1738 |
|
1739 |
static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs) |
1740 |
{ |
1741 |
BDRVQcowState *s = bs->opaque; |
1742 |
int ret;
|
1743 |
|
1744 |
qemu_co_mutex_lock(&s->lock); |
1745 |
ret = qcow2_cache_flush(bs, s->l2_table_cache); |
1746 |
if (ret < 0) { |
1747 |
qemu_co_mutex_unlock(&s->lock); |
1748 |
return ret;
|
1749 |
} |
1750 |
|
1751 |
if (qcow2_need_accurate_refcounts(s)) {
|
1752 |
ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
1753 |
if (ret < 0) { |
1754 |
qemu_co_mutex_unlock(&s->lock); |
1755 |
return ret;
|
1756 |
} |
1757 |
} |
1758 |
qemu_co_mutex_unlock(&s->lock); |
1759 |
|
1760 |
return 0; |
1761 |
} |
1762 |
|
1763 |
static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
1764 |
{ |
1765 |
BDRVQcowState *s = bs->opaque; |
1766 |
bdi->cluster_size = s->cluster_size; |
1767 |
bdi->vm_state_offset = qcow2_vm_state_offset(s); |
1768 |
return 0; |
1769 |
} |
1770 |
|
1771 |
#if 0
|
1772 |
static void dump_refcounts(BlockDriverState *bs)
|
1773 |
{
|
1774 |
BDRVQcowState *s = bs->opaque;
|
1775 |
int64_t nb_clusters, k, k1, size;
|
1776 |
int refcount;
|
1777 |
|
1778 |
size = bdrv_getlength(bs->file);
|
1779 |
nb_clusters = size_to_clusters(s, size);
|
1780 |
for(k = 0; k < nb_clusters;) {
|
1781 |
k1 = k;
|
1782 |
refcount = get_refcount(bs, k);
|
1783 |
k++;
|
1784 |
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
1785 |
k++;
|
1786 |
printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount,
|
1787 |
k - k1);
|
1788 |
}
|
1789 |
}
|
1790 |
#endif
|
1791 |
|
1792 |
static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, |
1793 |
int64_t pos) |
1794 |
{ |
1795 |
BDRVQcowState *s = bs->opaque; |
1796 |
int growable = bs->growable;
|
1797 |
int ret;
|
1798 |
|
1799 |
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); |
1800 |
bs->growable = 1;
|
1801 |
ret = bdrv_pwritev(bs, qcow2_vm_state_offset(s) + pos, qiov); |
1802 |
bs->growable = growable; |
1803 |
|
1804 |
return ret;
|
1805 |
} |
1806 |
|
1807 |
static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf, |
1808 |
int64_t pos, int size)
|
1809 |
{ |
1810 |
BDRVQcowState *s = bs->opaque; |
1811 |
int growable = bs->growable;
|
1812 |
bool zero_beyond_eof = bs->zero_beyond_eof;
|
1813 |
int ret;
|
1814 |
|
1815 |
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); |
1816 |
bs->growable = 1;
|
1817 |
bs->zero_beyond_eof = false;
|
1818 |
ret = bdrv_pread(bs, qcow2_vm_state_offset(s) + pos, buf, size); |
1819 |
bs->growable = growable; |
1820 |
bs->zero_beyond_eof = zero_beyond_eof; |
1821 |
|
1822 |
return ret;
|
1823 |
} |
1824 |
|
1825 |
/*
|
1826 |
* Downgrades an image's version. To achieve this, any incompatible features
|
1827 |
* have to be removed.
|
1828 |
*/
|
1829 |
static int qcow2_downgrade(BlockDriverState *bs, int target_version) |
1830 |
{ |
1831 |
BDRVQcowState *s = bs->opaque; |
1832 |
int current_version = s->qcow_version;
|
1833 |
int ret;
|
1834 |
|
1835 |
if (target_version == current_version) {
|
1836 |
return 0; |
1837 |
} else if (target_version > current_version) { |
1838 |
return -EINVAL;
|
1839 |
} else if (target_version != 2) { |
1840 |
return -EINVAL;
|
1841 |
} |
1842 |
|
1843 |
if (s->refcount_order != 4) { |
1844 |
/* we would have to convert the image to a refcount_order == 4 image
|
1845 |
* here; however, since qemu (at the time of writing this) does not
|
1846 |
* support anything different than 4 anyway, there is no point in doing
|
1847 |
* so right now; however, we should error out (if qemu supports this in
|
1848 |
* the future and this code has not been adapted) */
|
1849 |
error_report("qcow2_downgrade: Image refcount orders other than 4 are"
|
1850 |
"currently not supported.");
|
1851 |
return -ENOTSUP;
|
1852 |
} |
1853 |
|
1854 |
/* clear incompatible features */
|
1855 |
if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
|
1856 |
ret = qcow2_mark_clean(bs); |
1857 |
if (ret < 0) { |
1858 |
return ret;
|
1859 |
} |
1860 |
} |
1861 |
|
1862 |
/* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in
|
1863 |
* the first place; if that happens nonetheless, returning -ENOTSUP is the
|
1864 |
* best thing to do anyway */
|
1865 |
|
1866 |
if (s->incompatible_features) {
|
1867 |
return -ENOTSUP;
|
1868 |
} |
1869 |
|
1870 |
/* since we can ignore compatible features, we can set them to 0 as well */
|
1871 |
s->compatible_features = 0;
|
1872 |
/* if lazy refcounts have been used, they have already been fixed through
|
1873 |
* clearing the dirty flag */
|
1874 |
|
1875 |
/* clearing autoclear features is trivial */
|
1876 |
s->autoclear_features = 0;
|
1877 |
|
1878 |
ret = qcow2_expand_zero_clusters(bs); |
1879 |
if (ret < 0) { |
1880 |
return ret;
|
1881 |
} |
1882 |
|
1883 |
s->qcow_version = target_version; |
1884 |
ret = qcow2_update_header(bs); |
1885 |
if (ret < 0) { |
1886 |
s->qcow_version = current_version; |
1887 |
return ret;
|
1888 |
} |
1889 |
return 0; |
1890 |
} |
1891 |
|
1892 |
static int qcow2_amend_options(BlockDriverState *bs, |
1893 |
QEMUOptionParameter *options) |
1894 |
{ |
1895 |
BDRVQcowState *s = bs->opaque; |
1896 |
int old_version = s->qcow_version, new_version = old_version;
|
1897 |
uint64_t new_size = 0;
|
1898 |
const char *backing_file = NULL, *backing_format = NULL; |
1899 |
bool lazy_refcounts = s->use_lazy_refcounts;
|
1900 |
int ret;
|
1901 |
int i;
|
1902 |
|
1903 |
for (i = 0; options[i].name; i++) |
1904 |
{ |
1905 |
if (!options[i].assigned) {
|
1906 |
/* only change explicitly defined options */
|
1907 |
continue;
|
1908 |
} |
1909 |
|
1910 |
if (!strcmp(options[i].name, "compat")) { |
1911 |
if (!options[i].value.s) {
|
1912 |
/* preserve default */
|
1913 |
} else if (!strcmp(options[i].value.s, "0.10")) { |
1914 |
new_version = 2;
|
1915 |
} else if (!strcmp(options[i].value.s, "1.1")) { |
1916 |
new_version = 3;
|
1917 |
} else {
|
1918 |
fprintf(stderr, "Unknown compatibility level %s.\n",
|
1919 |
options[i].value.s); |
1920 |
return -EINVAL;
|
1921 |
} |
1922 |
} else if (!strcmp(options[i].name, "preallocation")) { |
1923 |
fprintf(stderr, "Cannot change preallocation mode.\n");
|
1924 |
return -ENOTSUP;
|
1925 |
} else if (!strcmp(options[i].name, "size")) { |
1926 |
new_size = options[i].value.n; |
1927 |
} else if (!strcmp(options[i].name, "backing_file")) { |
1928 |
backing_file = options[i].value.s; |
1929 |
} else if (!strcmp(options[i].name, "backing_fmt")) { |
1930 |
backing_format = options[i].value.s; |
1931 |
} else if (!strcmp(options[i].name, "encryption")) { |
1932 |
if ((options[i].value.n != !!s->crypt_method)) {
|
1933 |
fprintf(stderr, "Changing the encryption flag is not "
|
1934 |
"supported.\n");
|
1935 |
return -ENOTSUP;
|
1936 |
} |
1937 |
} else if (!strcmp(options[i].name, "cluster_size")) { |
1938 |
if (options[i].value.n != s->cluster_size) {
|
1939 |
fprintf(stderr, "Changing the cluster size is not "
|
1940 |
"supported.\n");
|
1941 |
return -ENOTSUP;
|
1942 |
} |
1943 |
} else if (!strcmp(options[i].name, "lazy_refcounts")) { |
1944 |
lazy_refcounts = options[i].value.n; |
1945 |
} else {
|
1946 |
/* if this assertion fails, this probably means a new option was
|
1947 |
* added without having it covered here */
|
1948 |
assert(false);
|
1949 |
} |
1950 |
} |
1951 |
|
1952 |
if (new_version != old_version) {
|
1953 |
if (new_version > old_version) {
|
1954 |
/* Upgrade */
|
1955 |
s->qcow_version = new_version; |
1956 |
ret = qcow2_update_header(bs); |
1957 |
if (ret < 0) { |
1958 |
s->qcow_version = old_version; |
1959 |
return ret;
|
1960 |
} |
1961 |
} else {
|
1962 |
ret = qcow2_downgrade(bs, new_version); |
1963 |
if (ret < 0) { |
1964 |
return ret;
|
1965 |
} |
1966 |
} |
1967 |
} |
1968 |
|
1969 |
if (backing_file || backing_format) {
|
1970 |
ret = qcow2_change_backing_file(bs, backing_file ?: bs->backing_file, |
1971 |
backing_format ?: bs->backing_format); |
1972 |
if (ret < 0) { |
1973 |
return ret;
|
1974 |
} |
1975 |
} |
1976 |
|
1977 |
if (s->use_lazy_refcounts != lazy_refcounts) {
|
1978 |
if (lazy_refcounts) {
|
1979 |
if (s->qcow_version < 3) { |
1980 |
fprintf(stderr, "Lazy refcounts only supported with compatibility "
|
1981 |
"level 1.1 and above (use compat=1.1 or greater)\n");
|
1982 |
return -EINVAL;
|
1983 |
} |
1984 |
s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; |
1985 |
ret = qcow2_update_header(bs); |
1986 |
if (ret < 0) { |
1987 |
s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; |
1988 |
return ret;
|
1989 |
} |
1990 |
s->use_lazy_refcounts = true;
|
1991 |
} else {
|
1992 |
/* make image clean first */
|
1993 |
ret = qcow2_mark_clean(bs); |
1994 |
if (ret < 0) { |
1995 |
return ret;
|
1996 |
} |
1997 |
/* now disallow lazy refcounts */
|
1998 |
s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; |
1999 |
ret = qcow2_update_header(bs); |
2000 |
if (ret < 0) { |
2001 |
s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; |
2002 |
return ret;
|
2003 |
} |
2004 |
s->use_lazy_refcounts = false;
|
2005 |
} |
2006 |
} |
2007 |
|
2008 |
if (new_size) {
|
2009 |
ret = bdrv_truncate(bs, new_size); |
2010 |
if (ret < 0) { |
2011 |
return ret;
|
2012 |
} |
2013 |
} |
2014 |
|
2015 |
return 0; |
2016 |
} |
2017 |
|
2018 |
static QEMUOptionParameter qcow2_create_options[] = {
|
2019 |
{ |
2020 |
.name = BLOCK_OPT_SIZE, |
2021 |
.type = OPT_SIZE, |
2022 |
.help = "Virtual disk size"
|
2023 |
}, |
2024 |
{ |
2025 |
.name = BLOCK_OPT_COMPAT_LEVEL, |
2026 |
.type = OPT_STRING, |
2027 |
.help = "Compatibility level (0.10 or 1.1)"
|
2028 |
}, |
2029 |
{ |
2030 |
.name = BLOCK_OPT_BACKING_FILE, |
2031 |
.type = OPT_STRING, |
2032 |
.help = "File name of a base image"
|
2033 |
}, |
2034 |
{ |
2035 |
.name = BLOCK_OPT_BACKING_FMT, |
2036 |
.type = OPT_STRING, |
2037 |
.help = "Image format of the base image"
|
2038 |
}, |
2039 |
{ |
2040 |
.name = BLOCK_OPT_ENCRYPT, |
2041 |
.type = OPT_FLAG, |
2042 |
.help = "Encrypt the image"
|
2043 |
}, |
2044 |
{ |
2045 |
.name = BLOCK_OPT_CLUSTER_SIZE, |
2046 |
.type = OPT_SIZE, |
2047 |
.help = "qcow2 cluster size",
|
2048 |
.value = { .n = DEFAULT_CLUSTER_SIZE }, |
2049 |
}, |
2050 |
{ |
2051 |
.name = BLOCK_OPT_PREALLOC, |
2052 |
.type = OPT_STRING, |
2053 |
.help = "Preallocation mode (allowed values: off, metadata)"
|
2054 |
}, |
2055 |
{ |
2056 |
.name = BLOCK_OPT_LAZY_REFCOUNTS, |
2057 |
.type = OPT_FLAG, |
2058 |
.help = "Postpone refcount updates",
|
2059 |
}, |
2060 |
{ NULL }
|
2061 |
}; |
2062 |
|
2063 |
static BlockDriver bdrv_qcow2 = {
|
2064 |
.format_name = "qcow2",
|
2065 |
.instance_size = sizeof(BDRVQcowState),
|
2066 |
.bdrv_probe = qcow2_probe, |
2067 |
.bdrv_open = qcow2_open, |
2068 |
.bdrv_close = qcow2_close, |
2069 |
.bdrv_reopen_prepare = qcow2_reopen_prepare, |
2070 |
.bdrv_create = qcow2_create, |
2071 |
.bdrv_has_zero_init = bdrv_has_zero_init_1, |
2072 |
.bdrv_co_get_block_status = qcow2_co_get_block_status, |
2073 |
.bdrv_set_key = qcow2_set_key, |
2074 |
.bdrv_make_empty = qcow2_make_empty, |
2075 |
|
2076 |
.bdrv_co_readv = qcow2_co_readv, |
2077 |
.bdrv_co_writev = qcow2_co_writev, |
2078 |
.bdrv_co_flush_to_os = qcow2_co_flush_to_os, |
2079 |
|
2080 |
.bdrv_co_write_zeroes = qcow2_co_write_zeroes, |
2081 |
.bdrv_co_discard = qcow2_co_discard, |
2082 |
.bdrv_truncate = qcow2_truncate, |
2083 |
.bdrv_write_compressed = qcow2_write_compressed, |
2084 |
|
2085 |
.bdrv_snapshot_create = qcow2_snapshot_create, |
2086 |
.bdrv_snapshot_goto = qcow2_snapshot_goto, |
2087 |
.bdrv_snapshot_delete = qcow2_snapshot_delete, |
2088 |
.bdrv_snapshot_list = qcow2_snapshot_list, |
2089 |
.bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, |
2090 |
.bdrv_get_info = qcow2_get_info, |
2091 |
|
2092 |
.bdrv_save_vmstate = qcow2_save_vmstate, |
2093 |
.bdrv_load_vmstate = qcow2_load_vmstate, |
2094 |
|
2095 |
.bdrv_change_backing_file = qcow2_change_backing_file, |
2096 |
|
2097 |
.bdrv_invalidate_cache = qcow2_invalidate_cache, |
2098 |
|
2099 |
.create_options = qcow2_create_options, |
2100 |
.bdrv_check = qcow2_check, |
2101 |
.bdrv_amend_options = qcow2_amend_options, |
2102 |
}; |
2103 |
|
2104 |
static void bdrv_qcow2_init(void) |
2105 |
{ |
2106 |
bdrv_register(&bdrv_qcow2); |
2107 |
} |
2108 |
|
2109 |
block_init(bdrv_qcow2_init); |