1826 lines
54 KiB
C
1826 lines
54 KiB
C
/*
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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"
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#include "block/block_int.h"
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#include "qemu/module.h"
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#include <zlib.h>
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#include "qemu/aes.h"
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#include "block/qcow2.h"
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#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"
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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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typedef struct {
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uint32_t magic;
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uint32_t len;
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} QCowExtension;
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#define QCOW2_EXT_MAGIC_END 0
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#define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
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#define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
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static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
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{
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const QCowHeader *cow_header = (const void *)buf;
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if (buf_size >= sizeof(QCowHeader) &&
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be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
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be32_to_cpu(cow_header->version) >= 2)
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return 100;
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else
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return 0;
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}
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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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#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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printf("attempting to read extended header in offset %lu\n", offset);
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#endif
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if (bdrv_pread(bs->file, offset, &ext, sizeof(ext)) != sizeof(ext)) {
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fprintf(stderr, "qcow2_read_extension: ERROR: "
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"pread fail from offset %" PRIu64 "\n",
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offset);
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return 1;
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}
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be32_to_cpus(&ext.magic);
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be32_to_cpus(&ext.len);
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offset += sizeof(ext);
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#ifdef DEBUG_EXT
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printf("ext.magic = 0x%x\n", ext.magic);
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#endif
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if (ext.len > end_offset - offset) {
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error_report("Header extension too large");
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return -EINVAL;
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}
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switch (ext.magic) {
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case QCOW2_EXT_MAGIC_END:
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return 0;
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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;
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}
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if (bdrv_pread(bs->file, offset , bs->backing_format,
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ext.len) != ext.len)
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return 3;
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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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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);
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if (ret < 0) {
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return ret;
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}
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*p_feature_table = feature_table;
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}
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break;
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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;
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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);
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ret = bdrv_pread(bs->file, offset , uext->data, uext->len);
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if (ret < 0) {
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return ret;
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}
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}
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break;
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}
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offset += ((ext.len + 7) & ~7);
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}
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return 0;
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}
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static void cleanup_unknown_header_ext(BlockDriverState *bs)
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{
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BDRVQcowState *s = bs->opaque;
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Qcow2UnknownHeaderExtension *uext, *next;
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QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) {
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QLIST_REMOVE(uext, next);
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g_free(uext);
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}
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}
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static void GCC_FMT_ATTR(2, 3) report_unsupported(BlockDriverState *bs,
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const char *fmt, ...)
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{
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char msg[64];
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va_list ap;
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va_start(ap, fmt);
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vsnprintf(msg, sizeof(msg), fmt, ap);
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va_end(ap);
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qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
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bs->device_name, "qcow2", msg);
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}
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static void report_unsupported_feature(BlockDriverState *bs,
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Qcow2Feature *table, uint64_t mask)
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{
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while (table && table->name[0] != '\0') {
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if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) {
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if (mask & (1 << table->bit)) {
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report_unsupported(bs, "%.46s",table->name);
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mask &= ~(1 << table->bit);
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}
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}
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table++;
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}
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if (mask) {
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report_unsupported(bs, "Unknown incompatible feature: %" PRIx64, mask);
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}
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}
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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;
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uint64_t val;
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int ret;
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assert(s->qcow_version >= 3);
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if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
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return 0; /* already dirty */
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}
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val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY);
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ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features),
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&val, sizeof(val));
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if (ret < 0) {
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return ret;
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}
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ret = bdrv_flush(bs->file);
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if (ret < 0) {
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return ret;
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}
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/* Only treat image as dirty if the header was updated successfully */
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s->incompatible_features |= QCOW2_INCOMPAT_DIRTY;
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return 0;
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}
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/*
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* Clears the dirty bit and flushes before if necessary. Only call this
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* function when there are no pending requests, it does not guard against
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* concurrent requests dirtying the image.
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*/
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static int qcow2_mark_clean(BlockDriverState *bs)
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{
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BDRVQcowState *s = bs->opaque;
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if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
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int ret = bdrv_flush(bs);
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if (ret < 0) {
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return ret;
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}
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s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY;
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return qcow2_update_header(bs);
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}
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return 0;
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}
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static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result,
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BdrvCheckMode fix)
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{
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int ret = qcow2_check_refcounts(bs, result, fix);
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if (ret < 0) {
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return ret;
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}
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if (fix && result->check_errors == 0 && result->corruptions == 0) {
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return qcow2_mark_clean(bs);
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}
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return ret;
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}
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static QemuOptsList qcow2_runtime_opts = {
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.name = "qcow2",
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.head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head),
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.desc = {
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{
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.name = "lazy_refcounts",
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.type = QEMU_OPT_BOOL,
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.help = "Postpone refcount updates",
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},
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{
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.name = QCOW2_OPT_DISCARD_REQUEST,
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.type = QEMU_OPT_BOOL,
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.help = "Pass guest discard requests to the layer below",
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},
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{
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.name = QCOW2_OPT_DISCARD_SNAPSHOT,
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.type = QEMU_OPT_BOOL,
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.help = "Generate discard requests when snapshot related space "
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"is freed",
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},
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{
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.name = QCOW2_OPT_DISCARD_OTHER,
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.type = QEMU_OPT_BOOL,
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.help = "Generate discard requests when other clusters are freed",
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},
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{ /* end of list */ }
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},
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};
|
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static int qcow2_open(BlockDriverState *bs, QDict *options, int flags)
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{
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BDRVQcowState *s = bs->opaque;
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int len, i, ret = 0;
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QCowHeader header;
|
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QemuOpts *opts;
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Error *local_err = NULL;
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uint64_t ext_end;
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uint64_t l1_vm_state_index;
|
|
|
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ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
be32_to_cpus(&header.magic);
|
|
be32_to_cpus(&header.version);
|
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be64_to_cpus(&header.backing_file_offset);
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be32_to_cpus(&header.backing_file_size);
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be64_to_cpus(&header.size);
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be32_to_cpus(&header.cluster_bits);
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be32_to_cpus(&header.crypt_method);
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be64_to_cpus(&header.l1_table_offset);
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be32_to_cpus(&header.l1_size);
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be64_to_cpus(&header.refcount_table_offset);
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be32_to_cpus(&header.refcount_table_clusters);
|
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be64_to_cpus(&header.snapshots_offset);
|
|
be32_to_cpus(&header.nb_snapshots);
|
|
|
|
if (header.magic != QCOW_MAGIC) {
|
|
ret = -EMEDIUMTYPE;
|
|
goto fail;
|
|
}
|
|
if (header.version < 2 || header.version > 3) {
|
|
report_unsupported(bs, "QCOW version %d", header.version);
|
|
ret = -ENOTSUP;
|
|
goto fail;
|
|
}
|
|
|
|
s->qcow_version = header.version;
|
|
|
|
/* Initialise version 3 header fields */
|
|
if (header.version == 2) {
|
|
header.incompatible_features = 0;
|
|
header.compatible_features = 0;
|
|
header.autoclear_features = 0;
|
|
header.refcount_order = 4;
|
|
header.header_length = 72;
|
|
} else {
|
|
be64_to_cpus(&header.incompatible_features);
|
|
be64_to_cpus(&header.compatible_features);
|
|
be64_to_cpus(&header.autoclear_features);
|
|
be32_to_cpus(&header.refcount_order);
|
|
be32_to_cpus(&header.header_length);
|
|
}
|
|
|
|
if (header.header_length > sizeof(header)) {
|
|
s->unknown_header_fields_size = header.header_length - sizeof(header);
|
|
s->unknown_header_fields = g_malloc(s->unknown_header_fields_size);
|
|
ret = bdrv_pread(bs->file, sizeof(header), s->unknown_header_fields,
|
|
s->unknown_header_fields_size);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
if (header.backing_file_offset) {
|
|
ext_end = header.backing_file_offset;
|
|
} else {
|
|
ext_end = 1 << header.cluster_bits;
|
|
}
|
|
|
|
/* Handle feature bits */
|
|
s->incompatible_features = header.incompatible_features;
|
|
s->compatible_features = header.compatible_features;
|
|
s->autoclear_features = header.autoclear_features;
|
|
|
|
if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) {
|
|
void *feature_table = NULL;
|
|
qcow2_read_extensions(bs, header.header_length, ext_end,
|
|
&feature_table);
|
|
report_unsupported_feature(bs, feature_table,
|
|
s->incompatible_features &
|
|
~QCOW2_INCOMPAT_MASK);
|
|
ret = -ENOTSUP;
|
|
goto fail;
|
|
}
|
|
|
|
/* Check support for various header values */
|
|
if (header.refcount_order != 4) {
|
|
report_unsupported(bs, "%d bit reference counts",
|
|
1 << header.refcount_order);
|
|
ret = -ENOTSUP;
|
|
goto fail;
|
|
}
|
|
|
|
if (header.cluster_bits < MIN_CLUSTER_BITS ||
|
|
header.cluster_bits > MAX_CLUSTER_BITS) {
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
if (header.crypt_method > QCOW_CRYPT_AES) {
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
s->crypt_method_header = header.crypt_method;
|
|
if (s->crypt_method_header) {
|
|
bs->encrypted = 1;
|
|
}
|
|
s->cluster_bits = header.cluster_bits;
|
|
s->cluster_size = 1 << s->cluster_bits;
|
|
s->cluster_sectors = 1 << (s->cluster_bits - 9);
|
|
s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */
|
|
s->l2_size = 1 << s->l2_bits;
|
|
bs->total_sectors = header.size / 512;
|
|
s->csize_shift = (62 - (s->cluster_bits - 8));
|
|
s->csize_mask = (1 << (s->cluster_bits - 8)) - 1;
|
|
s->cluster_offset_mask = (1LL << s->csize_shift) - 1;
|
|
s->refcount_table_offset = header.refcount_table_offset;
|
|
s->refcount_table_size =
|
|
header.refcount_table_clusters << (s->cluster_bits - 3);
|
|
|
|
s->snapshots_offset = header.snapshots_offset;
|
|
s->nb_snapshots = header.nb_snapshots;
|
|
|
|
/* read the level 1 table */
|
|
s->l1_size = header.l1_size;
|
|
|
|
l1_vm_state_index = size_to_l1(s, header.size);
|
|
if (l1_vm_state_index > INT_MAX) {
|
|
ret = -EFBIG;
|
|
goto fail;
|
|
}
|
|
s->l1_vm_state_index = l1_vm_state_index;
|
|
|
|
/* the L1 table must contain at least enough entries to put
|
|
header.size bytes */
|
|
if (s->l1_size < s->l1_vm_state_index) {
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
s->l1_table_offset = header.l1_table_offset;
|
|
if (s->l1_size > 0) {
|
|
s->l1_table = g_malloc0(
|
|
align_offset(s->l1_size * sizeof(uint64_t), 512));
|
|
ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table,
|
|
s->l1_size * sizeof(uint64_t));
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
for(i = 0;i < s->l1_size; i++) {
|
|
be64_to_cpus(&s->l1_table[i]);
|
|
}
|
|
}
|
|
|
|
/* alloc L2 table/refcount block cache */
|
|
s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE);
|
|
s->refcount_block_cache = qcow2_cache_create(bs, REFCOUNT_CACHE_SIZE);
|
|
|
|
s->cluster_cache = g_malloc(s->cluster_size);
|
|
/* one more sector for decompressed data alignment */
|
|
s->cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size
|
|
+ 512);
|
|
s->cluster_cache_offset = -1;
|
|
s->flags = flags;
|
|
|
|
ret = qcow2_refcount_init(bs);
|
|
if (ret != 0) {
|
|
goto fail;
|
|
}
|
|
|
|
QLIST_INIT(&s->cluster_allocs);
|
|
QTAILQ_INIT(&s->discards);
|
|
|
|
/* read qcow2 extensions */
|
|
if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL)) {
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
/* read the backing file name */
|
|
if (header.backing_file_offset != 0) {
|
|
len = header.backing_file_size;
|
|
if (len > 1023) {
|
|
len = 1023;
|
|
}
|
|
ret = bdrv_pread(bs->file, header.backing_file_offset,
|
|
bs->backing_file, len);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
bs->backing_file[len] = '\0';
|
|
}
|
|
|
|
ret = qcow2_read_snapshots(bs);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
/* Clear unknown autoclear feature bits */
|
|
if (!bs->read_only && s->autoclear_features != 0) {
|
|
s->autoclear_features = 0;
|
|
ret = qcow2_update_header(bs);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
/* Initialise locks */
|
|
qemu_co_mutex_init(&s->lock);
|
|
|
|
/* Repair image if dirty */
|
|
if (!(flags & BDRV_O_CHECK) && !bs->read_only &&
|
|
(s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) {
|
|
BdrvCheckResult result = {0};
|
|
|
|
ret = qcow2_check(bs, &result, BDRV_FIX_ERRORS);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
/* Enable lazy_refcounts according to image and command line options */
|
|
opts = qemu_opts_create_nofail(&qcow2_runtime_opts);
|
|
qemu_opts_absorb_qdict(opts, options, &local_err);
|
|
if (error_is_set(&local_err)) {
|
|
qerror_report_err(local_err);
|
|
error_free(local_err);
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
s->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS,
|
|
(s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS));
|
|
|
|
s->discard_passthrough[QCOW2_DISCARD_NEVER] = false;
|
|
s->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true;
|
|
s->discard_passthrough[QCOW2_DISCARD_REQUEST] =
|
|
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST,
|
|
flags & BDRV_O_UNMAP);
|
|
s->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] =
|
|
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true);
|
|
s->discard_passthrough[QCOW2_DISCARD_OTHER] =
|
|
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false);
|
|
|
|
qemu_opts_del(opts);
|
|
|
|
if (s->use_lazy_refcounts && s->qcow_version < 3) {
|
|
qerror_report(ERROR_CLASS_GENERIC_ERROR, "Lazy refcounts require "
|
|
"a qcow2 image with at least qemu 1.1 compatibility level");
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
#ifdef DEBUG_ALLOC
|
|
{
|
|
BdrvCheckResult result = {0};
|
|
qcow2_check_refcounts(bs, &result, 0);
|
|
}
|
|
#endif
|
|
return ret;
|
|
|
|
fail:
|
|
g_free(s->unknown_header_fields);
|
|
cleanup_unknown_header_ext(bs);
|
|
qcow2_free_snapshots(bs);
|
|
qcow2_refcount_close(bs);
|
|
g_free(s->l1_table);
|
|
if (s->l2_table_cache) {
|
|
qcow2_cache_destroy(bs, s->l2_table_cache);
|
|
}
|
|
g_free(s->cluster_cache);
|
|
qemu_vfree(s->cluster_data);
|
|
return ret;
|
|
}
|
|
|
|
static int qcow2_set_key(BlockDriverState *bs, const char *key)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
uint8_t keybuf[16];
|
|
int len, i;
|
|
|
|
memset(keybuf, 0, 16);
|
|
len = strlen(key);
|
|
if (len > 16)
|
|
len = 16;
|
|
/* XXX: we could compress the chars to 7 bits to increase
|
|
entropy */
|
|
for(i = 0;i < len;i++) {
|
|
keybuf[i] = key[i];
|
|
}
|
|
s->crypt_method = s->crypt_method_header;
|
|
|
|
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
|
|
return -1;
|
|
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0)
|
|
return -1;
|
|
#if 0
|
|
/* test */
|
|
{
|
|
uint8_t in[16];
|
|
uint8_t out[16];
|
|
uint8_t tmp[16];
|
|
for(i=0;i<16;i++)
|
|
in[i] = i;
|
|
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
|
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
|
for(i = 0; i < 16; i++)
|
|
printf(" %02x", tmp[i]);
|
|
printf("\n");
|
|
for(i = 0; i < 16; i++)
|
|
printf(" %02x", out[i]);
|
|
printf("\n");
|
|
}
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/* We have nothing to do for QCOW2 reopen, stubs just return
|
|
* success */
|
|
static int qcow2_reopen_prepare(BDRVReopenState *state,
|
|
BlockReopenQueue *queue, Error **errp)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int coroutine_fn qcow2_co_is_allocated(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, int *pnum)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
uint64_t cluster_offset;
|
|
int ret;
|
|
|
|
*pnum = nb_sectors;
|
|
/* FIXME We can get errors here, but the bdrv_co_is_allocated interface
|
|
* can't pass them on today */
|
|
qemu_co_mutex_lock(&s->lock);
|
|
ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
if (ret < 0) {
|
|
*pnum = 0;
|
|
}
|
|
|
|
return (cluster_offset != 0) || (ret == QCOW2_CLUSTER_ZERO);
|
|
}
|
|
|
|
/* handle reading after the end of the backing file */
|
|
int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
|
|
int64_t sector_num, int nb_sectors)
|
|
{
|
|
int n1;
|
|
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
|
return nb_sectors;
|
|
if (sector_num >= bs->total_sectors)
|
|
n1 = 0;
|
|
else
|
|
n1 = bs->total_sectors - sector_num;
|
|
|
|
qemu_iovec_memset(qiov, 512 * n1, 0, 512 * (nb_sectors - n1));
|
|
|
|
return n1;
|
|
}
|
|
|
|
static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num,
|
|
int remaining_sectors, QEMUIOVector *qiov)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int index_in_cluster, n1;
|
|
int ret;
|
|
int cur_nr_sectors; /* number of sectors in current iteration */
|
|
uint64_t cluster_offset = 0;
|
|
uint64_t bytes_done = 0;
|
|
QEMUIOVector hd_qiov;
|
|
uint8_t *cluster_data = NULL;
|
|
|
|
qemu_iovec_init(&hd_qiov, qiov->niov);
|
|
|
|
qemu_co_mutex_lock(&s->lock);
|
|
|
|
while (remaining_sectors != 0) {
|
|
|
|
/* prepare next request */
|
|
cur_nr_sectors = remaining_sectors;
|
|
if (s->crypt_method) {
|
|
cur_nr_sectors = MIN(cur_nr_sectors,
|
|
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors);
|
|
}
|
|
|
|
ret = qcow2_get_cluster_offset(bs, sector_num << 9,
|
|
&cur_nr_sectors, &cluster_offset);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
|
|
|
qemu_iovec_reset(&hd_qiov);
|
|
qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
|
|
cur_nr_sectors * 512);
|
|
|
|
switch (ret) {
|
|
case QCOW2_CLUSTER_UNALLOCATED:
|
|
|
|
if (bs->backing_hd) {
|
|
/* read from the base image */
|
|
n1 = qcow2_backing_read1(bs->backing_hd, &hd_qiov,
|
|
sector_num, cur_nr_sectors);
|
|
if (n1 > 0) {
|
|
BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
ret = bdrv_co_readv(bs->backing_hd, sector_num,
|
|
n1, &hd_qiov);
|
|
qemu_co_mutex_lock(&s->lock);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
}
|
|
} else {
|
|
/* Note: in this case, no need to wait */
|
|
qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors);
|
|
}
|
|
break;
|
|
|
|
case QCOW2_CLUSTER_ZERO:
|
|
qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors);
|
|
break;
|
|
|
|
case QCOW2_CLUSTER_COMPRESSED:
|
|
/* add AIO support for compressed blocks ? */
|
|
ret = qcow2_decompress_cluster(bs, cluster_offset);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
qemu_iovec_from_buf(&hd_qiov, 0,
|
|
s->cluster_cache + index_in_cluster * 512,
|
|
512 * cur_nr_sectors);
|
|
break;
|
|
|
|
case QCOW2_CLUSTER_NORMAL:
|
|
if ((cluster_offset & 511) != 0) {
|
|
ret = -EIO;
|
|
goto fail;
|
|
}
|
|
|
|
if (s->crypt_method) {
|
|
/*
|
|
* For encrypted images, read everything into a temporary
|
|
* contiguous buffer on which the AES functions can work.
|
|
*/
|
|
if (!cluster_data) {
|
|
cluster_data =
|
|
qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
|
|
}
|
|
|
|
assert(cur_nr_sectors <=
|
|
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors);
|
|
qemu_iovec_reset(&hd_qiov);
|
|
qemu_iovec_add(&hd_qiov, cluster_data,
|
|
512 * cur_nr_sectors);
|
|
}
|
|
|
|
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
ret = bdrv_co_readv(bs->file,
|
|
(cluster_offset >> 9) + index_in_cluster,
|
|
cur_nr_sectors, &hd_qiov);
|
|
qemu_co_mutex_lock(&s->lock);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
if (s->crypt_method) {
|
|
qcow2_encrypt_sectors(s, sector_num, cluster_data,
|
|
cluster_data, cur_nr_sectors, 0, &s->aes_decrypt_key);
|
|
qemu_iovec_from_buf(qiov, bytes_done,
|
|
cluster_data, 512 * cur_nr_sectors);
|
|
}
|
|
break;
|
|
|
|
default:
|
|
g_assert_not_reached();
|
|
ret = -EIO;
|
|
goto fail;
|
|
}
|
|
|
|
remaining_sectors -= cur_nr_sectors;
|
|
sector_num += cur_nr_sectors;
|
|
bytes_done += cur_nr_sectors * 512;
|
|
}
|
|
ret = 0;
|
|
|
|
fail:
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
|
|
qemu_iovec_destroy(&hd_qiov);
|
|
qemu_vfree(cluster_data);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,
|
|
int64_t sector_num,
|
|
int remaining_sectors,
|
|
QEMUIOVector *qiov)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int index_in_cluster;
|
|
int n_end;
|
|
int ret;
|
|
int cur_nr_sectors; /* number of sectors in current iteration */
|
|
uint64_t cluster_offset;
|
|
QEMUIOVector hd_qiov;
|
|
uint64_t bytes_done = 0;
|
|
uint8_t *cluster_data = NULL;
|
|
QCowL2Meta *l2meta = NULL;
|
|
|
|
trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num,
|
|
remaining_sectors);
|
|
|
|
qemu_iovec_init(&hd_qiov, qiov->niov);
|
|
|
|
s->cluster_cache_offset = -1; /* disable compressed cache */
|
|
|
|
qemu_co_mutex_lock(&s->lock);
|
|
|
|
while (remaining_sectors != 0) {
|
|
|
|
l2meta = NULL;
|
|
|
|
trace_qcow2_writev_start_part(qemu_coroutine_self());
|
|
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
|
n_end = index_in_cluster + remaining_sectors;
|
|
if (s->crypt_method &&
|
|
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) {
|
|
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
|
|
}
|
|
|
|
ret = qcow2_alloc_cluster_offset(bs, sector_num << 9,
|
|
index_in_cluster, n_end, &cur_nr_sectors, &cluster_offset, &l2meta);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
assert((cluster_offset & 511) == 0);
|
|
|
|
qemu_iovec_reset(&hd_qiov);
|
|
qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
|
|
cur_nr_sectors * 512);
|
|
|
|
if (s->crypt_method) {
|
|
if (!cluster_data) {
|
|
cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS *
|
|
s->cluster_size);
|
|
}
|
|
|
|
assert(hd_qiov.size <=
|
|
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
|
|
qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size);
|
|
|
|
qcow2_encrypt_sectors(s, sector_num, cluster_data,
|
|
cluster_data, cur_nr_sectors, 1, &s->aes_encrypt_key);
|
|
|
|
qemu_iovec_reset(&hd_qiov);
|
|
qemu_iovec_add(&hd_qiov, cluster_data,
|
|
cur_nr_sectors * 512);
|
|
}
|
|
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
|
|
trace_qcow2_writev_data(qemu_coroutine_self(),
|
|
(cluster_offset >> 9) + index_in_cluster);
|
|
ret = bdrv_co_writev(bs->file,
|
|
(cluster_offset >> 9) + index_in_cluster,
|
|
cur_nr_sectors, &hd_qiov);
|
|
qemu_co_mutex_lock(&s->lock);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
while (l2meta != NULL) {
|
|
QCowL2Meta *next;
|
|
|
|
ret = qcow2_alloc_cluster_link_l2(bs, l2meta);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
/* Take the request off the list of running requests */
|
|
if (l2meta->nb_clusters != 0) {
|
|
QLIST_REMOVE(l2meta, next_in_flight);
|
|
}
|
|
|
|
qemu_co_queue_restart_all(&l2meta->dependent_requests);
|
|
|
|
next = l2meta->next;
|
|
g_free(l2meta);
|
|
l2meta = next;
|
|
}
|
|
|
|
remaining_sectors -= cur_nr_sectors;
|
|
sector_num += cur_nr_sectors;
|
|
bytes_done += cur_nr_sectors * 512;
|
|
trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_nr_sectors);
|
|
}
|
|
ret = 0;
|
|
|
|
fail:
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
|
|
while (l2meta != NULL) {
|
|
QCowL2Meta *next;
|
|
|
|
if (l2meta->nb_clusters != 0) {
|
|
QLIST_REMOVE(l2meta, next_in_flight);
|
|
}
|
|
qemu_co_queue_restart_all(&l2meta->dependent_requests);
|
|
|
|
next = l2meta->next;
|
|
g_free(l2meta);
|
|
l2meta = next;
|
|
}
|
|
|
|
qemu_iovec_destroy(&hd_qiov);
|
|
qemu_vfree(cluster_data);
|
|
trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void qcow2_close(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
g_free(s->l1_table);
|
|
|
|
qcow2_cache_flush(bs, s->l2_table_cache);
|
|
qcow2_cache_flush(bs, s->refcount_block_cache);
|
|
|
|
qcow2_mark_clean(bs);
|
|
|
|
qcow2_cache_destroy(bs, s->l2_table_cache);
|
|
qcow2_cache_destroy(bs, s->refcount_block_cache);
|
|
|
|
g_free(s->unknown_header_fields);
|
|
cleanup_unknown_header_ext(bs);
|
|
|
|
g_free(s->cluster_cache);
|
|
qemu_vfree(s->cluster_data);
|
|
qcow2_refcount_close(bs);
|
|
qcow2_free_snapshots(bs);
|
|
}
|
|
|
|
static void qcow2_invalidate_cache(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int flags = s->flags;
|
|
AES_KEY aes_encrypt_key;
|
|
AES_KEY aes_decrypt_key;
|
|
uint32_t crypt_method = 0;
|
|
QDict *options;
|
|
|
|
/*
|
|
* Backing files are read-only which makes all of their metadata immutable,
|
|
* that means we don't have to worry about reopening them here.
|
|
*/
|
|
|
|
if (s->crypt_method) {
|
|
crypt_method = s->crypt_method;
|
|
memcpy(&aes_encrypt_key, &s->aes_encrypt_key, sizeof(aes_encrypt_key));
|
|
memcpy(&aes_decrypt_key, &s->aes_decrypt_key, sizeof(aes_decrypt_key));
|
|
}
|
|
|
|
qcow2_close(bs);
|
|
|
|
options = qdict_new();
|
|
qdict_put(options, QCOW2_OPT_LAZY_REFCOUNTS,
|
|
qbool_from_int(s->use_lazy_refcounts));
|
|
|
|
memset(s, 0, sizeof(BDRVQcowState));
|
|
qcow2_open(bs, options, flags);
|
|
|
|
QDECREF(options);
|
|
|
|
if (crypt_method) {
|
|
s->crypt_method = crypt_method;
|
|
memcpy(&s->aes_encrypt_key, &aes_encrypt_key, sizeof(aes_encrypt_key));
|
|
memcpy(&s->aes_decrypt_key, &aes_decrypt_key, sizeof(aes_decrypt_key));
|
|
}
|
|
}
|
|
|
|
static size_t header_ext_add(char *buf, uint32_t magic, const void *s,
|
|
size_t len, size_t buflen)
|
|
{
|
|
QCowExtension *ext_backing_fmt = (QCowExtension*) buf;
|
|
size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7);
|
|
|
|
if (buflen < ext_len) {
|
|
return -ENOSPC;
|
|
}
|
|
|
|
*ext_backing_fmt = (QCowExtension) {
|
|
.magic = cpu_to_be32(magic),
|
|
.len = cpu_to_be32(len),
|
|
};
|
|
memcpy(buf + sizeof(QCowExtension), s, len);
|
|
|
|
return ext_len;
|
|
}
|
|
|
|
/*
|
|
* Updates the qcow2 header, including the variable length parts of it, i.e.
|
|
* the backing file name and all extensions. qcow2 was not designed to allow
|
|
* such changes, so if we run out of space (we can only use the first cluster)
|
|
* this function may fail.
|
|
*
|
|
* Returns 0 on success, -errno in error cases.
|
|
*/
|
|
int qcow2_update_header(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowHeader *header;
|
|
char *buf;
|
|
size_t buflen = s->cluster_size;
|
|
int ret;
|
|
uint64_t total_size;
|
|
uint32_t refcount_table_clusters;
|
|
size_t header_length;
|
|
Qcow2UnknownHeaderExtension *uext;
|
|
|
|
buf = qemu_blockalign(bs, buflen);
|
|
|
|
/* Header structure */
|
|
header = (QCowHeader*) buf;
|
|
|
|
if (buflen < sizeof(*header)) {
|
|
ret = -ENOSPC;
|
|
goto fail;
|
|
}
|
|
|
|
header_length = sizeof(*header) + s->unknown_header_fields_size;
|
|
total_size = bs->total_sectors * BDRV_SECTOR_SIZE;
|
|
refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
|
|
|
|
*header = (QCowHeader) {
|
|
/* Version 2 fields */
|
|
.magic = cpu_to_be32(QCOW_MAGIC),
|
|
.version = cpu_to_be32(s->qcow_version),
|
|
.backing_file_offset = 0,
|
|
.backing_file_size = 0,
|
|
.cluster_bits = cpu_to_be32(s->cluster_bits),
|
|
.size = cpu_to_be64(total_size),
|
|
.crypt_method = cpu_to_be32(s->crypt_method_header),
|
|
.l1_size = cpu_to_be32(s->l1_size),
|
|
.l1_table_offset = cpu_to_be64(s->l1_table_offset),
|
|
.refcount_table_offset = cpu_to_be64(s->refcount_table_offset),
|
|
.refcount_table_clusters = cpu_to_be32(refcount_table_clusters),
|
|
.nb_snapshots = cpu_to_be32(s->nb_snapshots),
|
|
.snapshots_offset = cpu_to_be64(s->snapshots_offset),
|
|
|
|
/* Version 3 fields */
|
|
.incompatible_features = cpu_to_be64(s->incompatible_features),
|
|
.compatible_features = cpu_to_be64(s->compatible_features),
|
|
.autoclear_features = cpu_to_be64(s->autoclear_features),
|
|
.refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT),
|
|
.header_length = cpu_to_be32(header_length),
|
|
};
|
|
|
|
/* For older versions, write a shorter header */
|
|
switch (s->qcow_version) {
|
|
case 2:
|
|
ret = offsetof(QCowHeader, incompatible_features);
|
|
break;
|
|
case 3:
|
|
ret = sizeof(*header);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
buf += ret;
|
|
buflen -= ret;
|
|
memset(buf, 0, buflen);
|
|
|
|
/* Preserve any unknown field in the header */
|
|
if (s->unknown_header_fields_size) {
|
|
if (buflen < s->unknown_header_fields_size) {
|
|
ret = -ENOSPC;
|
|
goto fail;
|
|
}
|
|
|
|
memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size);
|
|
buf += s->unknown_header_fields_size;
|
|
buflen -= s->unknown_header_fields_size;
|
|
}
|
|
|
|
/* Backing file format header extension */
|
|
if (*bs->backing_format) {
|
|
ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT,
|
|
bs->backing_format, strlen(bs->backing_format),
|
|
buflen);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
buf += ret;
|
|
buflen -= ret;
|
|
}
|
|
|
|
/* Feature table */
|
|
Qcow2Feature features[] = {
|
|
{
|
|
.type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
|
|
.bit = QCOW2_INCOMPAT_DIRTY_BITNR,
|
|
.name = "dirty bit",
|
|
},
|
|
{
|
|
.type = QCOW2_FEAT_TYPE_COMPATIBLE,
|
|
.bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
|
|
.name = "lazy refcounts",
|
|
},
|
|
};
|
|
|
|
ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE,
|
|
features, sizeof(features), buflen);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
buf += ret;
|
|
buflen -= ret;
|
|
|
|
/* Keep unknown header extensions */
|
|
QLIST_FOREACH(uext, &s->unknown_header_ext, next) {
|
|
ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
buf += ret;
|
|
buflen -= ret;
|
|
}
|
|
|
|
/* End of header extensions */
|
|
ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
buf += ret;
|
|
buflen -= ret;
|
|
|
|
/* Backing file name */
|
|
if (*bs->backing_file) {
|
|
size_t backing_file_len = strlen(bs->backing_file);
|
|
|
|
if (buflen < backing_file_len) {
|
|
ret = -ENOSPC;
|
|
goto fail;
|
|
}
|
|
|
|
/* Using strncpy is ok here, since buf is not NUL-terminated. */
|
|
strncpy(buf, bs->backing_file, buflen);
|
|
|
|
header->backing_file_offset = cpu_to_be64(buf - ((char*) header));
|
|
header->backing_file_size = cpu_to_be32(backing_file_len);
|
|
}
|
|
|
|
/* Write the new header */
|
|
ret = bdrv_pwrite(bs->file, 0, header, s->cluster_size);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
ret = 0;
|
|
fail:
|
|
qemu_vfree(header);
|
|
return ret;
|
|
}
|
|
|
|
static int qcow2_change_backing_file(BlockDriverState *bs,
|
|
const char *backing_file, const char *backing_fmt)
|
|
{
|
|
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
|
|
pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
|
|
|
|
return qcow2_update_header(bs);
|
|
}
|
|
|
|
static int preallocate(BlockDriverState *bs)
|
|
{
|
|
uint64_t nb_sectors;
|
|
uint64_t offset;
|
|
uint64_t host_offset = 0;
|
|
int num;
|
|
int ret;
|
|
QCowL2Meta *meta;
|
|
|
|
nb_sectors = bdrv_getlength(bs) >> 9;
|
|
offset = 0;
|
|
|
|
while (nb_sectors) {
|
|
num = MIN(nb_sectors, INT_MAX >> 9);
|
|
ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num,
|
|
&host_offset, &meta);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
ret = qcow2_alloc_cluster_link_l2(bs, meta);
|
|
if (ret < 0) {
|
|
qcow2_free_any_clusters(bs, meta->alloc_offset, meta->nb_clusters,
|
|
QCOW2_DISCARD_NEVER);
|
|
return ret;
|
|
}
|
|
|
|
/* There are no dependent requests, but we need to remove our request
|
|
* from the list of in-flight requests */
|
|
if (meta != NULL) {
|
|
QLIST_REMOVE(meta, next_in_flight);
|
|
}
|
|
|
|
/* TODO Preallocate data if requested */
|
|
|
|
nb_sectors -= num;
|
|
offset += num << 9;
|
|
}
|
|
|
|
/*
|
|
* It is expected that the image file is large enough to actually contain
|
|
* all of the allocated clusters (otherwise we get failing reads after
|
|
* EOF). Extend the image to the last allocated sector.
|
|
*/
|
|
if (host_offset != 0) {
|
|
uint8_t buf[512];
|
|
memset(buf, 0, 512);
|
|
ret = bdrv_write(bs->file, (host_offset >> 9) + num - 1, buf, 1);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int qcow2_create2(const char *filename, int64_t total_size,
|
|
const char *backing_file, const char *backing_format,
|
|
int flags, size_t cluster_size, int prealloc,
|
|
QEMUOptionParameter *options, int version)
|
|
{
|
|
/* Calculate cluster_bits */
|
|
int cluster_bits;
|
|
cluster_bits = ffs(cluster_size) - 1;
|
|
if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS ||
|
|
(1 << cluster_bits) != cluster_size)
|
|
{
|
|
error_report(
|
|
"Cluster size must be a power of two between %d and %dk",
|
|
1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10));
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Open the image file and write a minimal qcow2 header.
|
|
*
|
|
* We keep things simple and start with a zero-sized image. We also
|
|
* do without refcount blocks or a L1 table for now. We'll fix the
|
|
* inconsistency later.
|
|
*
|
|
* We do need a refcount table because growing the refcount table means
|
|
* allocating two new refcount blocks - the seconds of which would be at
|
|
* 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
|
|
* size for any qcow2 image.
|
|
*/
|
|
BlockDriverState* bs;
|
|
QCowHeader header;
|
|
uint8_t* refcount_table;
|
|
int ret;
|
|
|
|
ret = bdrv_create_file(filename, options);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
/* Write the header */
|
|
memset(&header, 0, sizeof(header));
|
|
header.magic = cpu_to_be32(QCOW_MAGIC);
|
|
header.version = cpu_to_be32(version);
|
|
header.cluster_bits = cpu_to_be32(cluster_bits);
|
|
header.size = cpu_to_be64(0);
|
|
header.l1_table_offset = cpu_to_be64(0);
|
|
header.l1_size = cpu_to_be32(0);
|
|
header.refcount_table_offset = cpu_to_be64(cluster_size);
|
|
header.refcount_table_clusters = cpu_to_be32(1);
|
|
header.refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT);
|
|
header.header_length = cpu_to_be32(sizeof(header));
|
|
|
|
if (flags & BLOCK_FLAG_ENCRYPT) {
|
|
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
|
|
} else {
|
|
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
|
|
}
|
|
|
|
if (flags & BLOCK_FLAG_LAZY_REFCOUNTS) {
|
|
header.compatible_features |=
|
|
cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS);
|
|
}
|
|
|
|
ret = bdrv_pwrite(bs, 0, &header, sizeof(header));
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
/* Write an empty refcount table */
|
|
refcount_table = g_malloc0(cluster_size);
|
|
ret = bdrv_pwrite(bs, cluster_size, refcount_table, cluster_size);
|
|
g_free(refcount_table);
|
|
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
bdrv_close(bs);
|
|
|
|
/*
|
|
* And now open the image and make it consistent first (i.e. increase the
|
|
* refcount of the cluster that is occupied by the header and the refcount
|
|
* table)
|
|
*/
|
|
BlockDriver* drv = bdrv_find_format("qcow2");
|
|
assert(drv != NULL);
|
|
ret = bdrv_open(bs, filename, NULL,
|
|
BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, drv);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
ret = qcow2_alloc_clusters(bs, 2 * cluster_size);
|
|
if (ret < 0) {
|
|
goto out;
|
|
|
|
} else if (ret != 0) {
|
|
error_report("Huh, first cluster in empty image is already in use?");
|
|
abort();
|
|
}
|
|
|
|
/* Okay, now that we have a valid image, let's give it the right size */
|
|
ret = bdrv_truncate(bs, total_size * BDRV_SECTOR_SIZE);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
/* Want a backing file? There you go.*/
|
|
if (backing_file) {
|
|
ret = bdrv_change_backing_file(bs, backing_file, backing_format);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* And if we're supposed to preallocate metadata, do that now */
|
|
if (prealloc) {
|
|
BDRVQcowState *s = bs->opaque;
|
|
qemu_co_mutex_lock(&s->lock);
|
|
ret = preallocate(bs);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
out:
|
|
bdrv_delete(bs);
|
|
return ret;
|
|
}
|
|
|
|
static int qcow2_create(const char *filename, QEMUOptionParameter *options)
|
|
{
|
|
const char *backing_file = NULL;
|
|
const char *backing_fmt = NULL;
|
|
uint64_t sectors = 0;
|
|
int flags = 0;
|
|
size_t cluster_size = DEFAULT_CLUSTER_SIZE;
|
|
int prealloc = 0;
|
|
int version = 2;
|
|
|
|
/* Read out options */
|
|
while (options && options->name) {
|
|
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
|
sectors = options->value.n / 512;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
|
|
backing_file = options->value.s;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) {
|
|
backing_fmt = options->value.s;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
|
|
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
|
|
if (options->value.n) {
|
|
cluster_size = options->value.n;
|
|
}
|
|
} else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) {
|
|
if (!options->value.s || !strcmp(options->value.s, "off")) {
|
|
prealloc = 0;
|
|
} else if (!strcmp(options->value.s, "metadata")) {
|
|
prealloc = 1;
|
|
} else {
|
|
fprintf(stderr, "Invalid preallocation mode: '%s'\n",
|
|
options->value.s);
|
|
return -EINVAL;
|
|
}
|
|
} else if (!strcmp(options->name, BLOCK_OPT_COMPAT_LEVEL)) {
|
|
if (!options->value.s || !strcmp(options->value.s, "0.10")) {
|
|
version = 2;
|
|
} else if (!strcmp(options->value.s, "1.1")) {
|
|
version = 3;
|
|
} else {
|
|
fprintf(stderr, "Invalid compatibility level: '%s'\n",
|
|
options->value.s);
|
|
return -EINVAL;
|
|
}
|
|
} else if (!strcmp(options->name, BLOCK_OPT_LAZY_REFCOUNTS)) {
|
|
flags |= options->value.n ? BLOCK_FLAG_LAZY_REFCOUNTS : 0;
|
|
}
|
|
options++;
|
|
}
|
|
|
|
if (backing_file && prealloc) {
|
|
fprintf(stderr, "Backing file and preallocation cannot be used at "
|
|
"the same time\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (version < 3 && (flags & BLOCK_FLAG_LAZY_REFCOUNTS)) {
|
|
fprintf(stderr, "Lazy refcounts only supported with compatibility "
|
|
"level 1.1 and above (use compat=1.1 or greater)\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
return qcow2_create2(filename, sectors, backing_file, backing_fmt, flags,
|
|
cluster_size, prealloc, options, version);
|
|
}
|
|
|
|
static int qcow2_make_empty(BlockDriverState *bs)
|
|
{
|
|
#if 0
|
|
/* XXX: not correct */
|
|
BDRVQcowState *s = bs->opaque;
|
|
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
|
int ret;
|
|
|
|
memset(s->l1_table, 0, l1_length);
|
|
if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
|
return -1;
|
|
ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
l2_cache_reset(bs);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
static coroutine_fn int qcow2_co_write_zeroes(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors)
|
|
{
|
|
int ret;
|
|
BDRVQcowState *s = bs->opaque;
|
|
|
|
/* Emulate misaligned zero writes */
|
|
if (sector_num % s->cluster_sectors || nb_sectors % s->cluster_sectors) {
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
/* Whatever is left can use real zero clusters */
|
|
qemu_co_mutex_lock(&s->lock);
|
|
ret = qcow2_zero_clusters(bs, sector_num << BDRV_SECTOR_BITS,
|
|
nb_sectors);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static coroutine_fn int qcow2_co_discard(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors)
|
|
{
|
|
int ret;
|
|
BDRVQcowState *s = bs->opaque;
|
|
|
|
qemu_co_mutex_lock(&s->lock);
|
|
ret = qcow2_discard_clusters(bs, sector_num << BDRV_SECTOR_BITS,
|
|
nb_sectors);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
return ret;
|
|
}
|
|
|
|
static int qcow2_truncate(BlockDriverState *bs, int64_t offset)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int64_t new_l1_size;
|
|
int ret;
|
|
|
|
if (offset & 511) {
|
|
error_report("The new size must be a multiple of 512");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* cannot proceed if image has snapshots */
|
|
if (s->nb_snapshots) {
|
|
error_report("Can't resize an image which has snapshots");
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
/* shrinking is currently not supported */
|
|
if (offset < bs->total_sectors * 512) {
|
|
error_report("qcow2 doesn't support shrinking images yet");
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
new_l1_size = size_to_l1(s, offset);
|
|
ret = qcow2_grow_l1_table(bs, new_l1_size, true);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
/* write updated header.size */
|
|
offset = cpu_to_be64(offset);
|
|
ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size),
|
|
&offset, sizeof(uint64_t));
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
s->l1_vm_state_index = new_l1_size;
|
|
return 0;
|
|
}
|
|
|
|
/* XXX: put compressed sectors first, then all the cluster aligned
|
|
tables to avoid losing bytes in alignment */
|
|
static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num,
|
|
const uint8_t *buf, int nb_sectors)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
z_stream strm;
|
|
int ret, out_len;
|
|
uint8_t *out_buf;
|
|
uint64_t cluster_offset;
|
|
|
|
if (nb_sectors == 0) {
|
|
/* align end of file to a sector boundary to ease reading with
|
|
sector based I/Os */
|
|
cluster_offset = bdrv_getlength(bs->file);
|
|
cluster_offset = (cluster_offset + 511) & ~511;
|
|
bdrv_truncate(bs->file, cluster_offset);
|
|
return 0;
|
|
}
|
|
|
|
if (nb_sectors != s->cluster_sectors) {
|
|
ret = -EINVAL;
|
|
|
|
/* Zero-pad last write if image size is not cluster aligned */
|
|
if (sector_num + nb_sectors == bs->total_sectors &&
|
|
nb_sectors < s->cluster_sectors) {
|
|
uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size);
|
|
memset(pad_buf, 0, s->cluster_size);
|
|
memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE);
|
|
ret = qcow2_write_compressed(bs, sector_num,
|
|
pad_buf, s->cluster_sectors);
|
|
qemu_vfree(pad_buf);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
|
|
|
|
/* best compression, small window, no zlib header */
|
|
memset(&strm, 0, sizeof(strm));
|
|
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
|
|
Z_DEFLATED, -12,
|
|
9, Z_DEFAULT_STRATEGY);
|
|
if (ret != 0) {
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
strm.avail_in = s->cluster_size;
|
|
strm.next_in = (uint8_t *)buf;
|
|
strm.avail_out = s->cluster_size;
|
|
strm.next_out = out_buf;
|
|
|
|
ret = deflate(&strm, Z_FINISH);
|
|
if (ret != Z_STREAM_END && ret != Z_OK) {
|
|
deflateEnd(&strm);
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
out_len = strm.next_out - out_buf;
|
|
|
|
deflateEnd(&strm);
|
|
|
|
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
|
/* could not compress: write normal cluster */
|
|
ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
} else {
|
|
cluster_offset = qcow2_alloc_compressed_cluster_offset(bs,
|
|
sector_num << 9, out_len);
|
|
if (!cluster_offset) {
|
|
ret = -EIO;
|
|
goto fail;
|
|
}
|
|
cluster_offset &= s->cluster_offset_mask;
|
|
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
|
|
ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
fail:
|
|
g_free(out_buf);
|
|
return ret;
|
|
}
|
|
|
|
static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int ret;
|
|
|
|
qemu_co_mutex_lock(&s->lock);
|
|
ret = qcow2_cache_flush(bs, s->l2_table_cache);
|
|
if (ret < 0) {
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
return ret;
|
|
}
|
|
|
|
if (qcow2_need_accurate_refcounts(s)) {
|
|
ret = qcow2_cache_flush(bs, s->refcount_block_cache);
|
|
if (ret < 0) {
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
return ret;
|
|
}
|
|
}
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int64_t qcow2_vm_state_offset(BDRVQcowState *s)
|
|
{
|
|
return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
|
|
}
|
|
|
|
static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
bdi->cluster_size = s->cluster_size;
|
|
bdi->vm_state_offset = qcow2_vm_state_offset(s);
|
|
return 0;
|
|
}
|
|
|
|
#if 0
|
|
static void dump_refcounts(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int64_t nb_clusters, k, k1, size;
|
|
int refcount;
|
|
|
|
size = bdrv_getlength(bs->file);
|
|
nb_clusters = size_to_clusters(s, size);
|
|
for(k = 0; k < nb_clusters;) {
|
|
k1 = k;
|
|
refcount = get_refcount(bs, k);
|
|
k++;
|
|
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
|
k++;
|
|
printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount,
|
|
k - k1);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
|
|
int64_t pos)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int growable = bs->growable;
|
|
int ret;
|
|
|
|
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
|
|
bs->growable = 1;
|
|
ret = bdrv_pwritev(bs, qcow2_vm_state_offset(s) + pos, qiov);
|
|
bs->growable = growable;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf,
|
|
int64_t pos, int size)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int growable = bs->growable;
|
|
int ret;
|
|
|
|
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
|
|
bs->growable = 1;
|
|
ret = bdrv_pread(bs, qcow2_vm_state_offset(s) + pos, buf, size);
|
|
bs->growable = growable;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static QEMUOptionParameter qcow2_create_options[] = {
|
|
{
|
|
.name = BLOCK_OPT_SIZE,
|
|
.type = OPT_SIZE,
|
|
.help = "Virtual disk size"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_COMPAT_LEVEL,
|
|
.type = OPT_STRING,
|
|
.help = "Compatibility level (0.10 or 1.1)"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_BACKING_FILE,
|
|
.type = OPT_STRING,
|
|
.help = "File name of a base image"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_BACKING_FMT,
|
|
.type = OPT_STRING,
|
|
.help = "Image format of the base image"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_ENCRYPT,
|
|
.type = OPT_FLAG,
|
|
.help = "Encrypt the image"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_CLUSTER_SIZE,
|
|
.type = OPT_SIZE,
|
|
.help = "qcow2 cluster size",
|
|
.value = { .n = DEFAULT_CLUSTER_SIZE },
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_PREALLOC,
|
|
.type = OPT_STRING,
|
|
.help = "Preallocation mode (allowed values: off, metadata)"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_LAZY_REFCOUNTS,
|
|
.type = OPT_FLAG,
|
|
.help = "Postpone refcount updates",
|
|
},
|
|
{ NULL }
|
|
};
|
|
|
|
static BlockDriver bdrv_qcow2 = {
|
|
.format_name = "qcow2",
|
|
.instance_size = sizeof(BDRVQcowState),
|
|
.bdrv_probe = qcow2_probe,
|
|
.bdrv_open = qcow2_open,
|
|
.bdrv_close = qcow2_close,
|
|
.bdrv_reopen_prepare = qcow2_reopen_prepare,
|
|
.bdrv_create = qcow2_create,
|
|
.bdrv_has_zero_init = bdrv_has_zero_init_1,
|
|
.bdrv_co_is_allocated = qcow2_co_is_allocated,
|
|
.bdrv_set_key = qcow2_set_key,
|
|
.bdrv_make_empty = qcow2_make_empty,
|
|
|
|
.bdrv_co_readv = qcow2_co_readv,
|
|
.bdrv_co_writev = qcow2_co_writev,
|
|
.bdrv_co_flush_to_os = qcow2_co_flush_to_os,
|
|
|
|
.bdrv_co_write_zeroes = qcow2_co_write_zeroes,
|
|
.bdrv_co_discard = qcow2_co_discard,
|
|
.bdrv_truncate = qcow2_truncate,
|
|
.bdrv_write_compressed = qcow2_write_compressed,
|
|
|
|
.bdrv_snapshot_create = qcow2_snapshot_create,
|
|
.bdrv_snapshot_goto = qcow2_snapshot_goto,
|
|
.bdrv_snapshot_delete = qcow2_snapshot_delete,
|
|
.bdrv_snapshot_list = qcow2_snapshot_list,
|
|
.bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp,
|
|
.bdrv_get_info = qcow2_get_info,
|
|
|
|
.bdrv_save_vmstate = qcow2_save_vmstate,
|
|
.bdrv_load_vmstate = qcow2_load_vmstate,
|
|
|
|
.bdrv_change_backing_file = qcow2_change_backing_file,
|
|
|
|
.bdrv_invalidate_cache = qcow2_invalidate_cache,
|
|
|
|
.create_options = qcow2_create_options,
|
|
.bdrv_check = qcow2_check,
|
|
};
|
|
|
|
static void bdrv_qcow2_init(void)
|
|
{
|
|
bdrv_register(&bdrv_qcow2);
|
|
}
|
|
|
|
block_init(bdrv_qcow2_init);
|