root / block / qcow2.c @ f7d0fe02
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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" |
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#include "block_int.h" |
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#include "module.h" |
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#include <zlib.h> |
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#include "aes.h" |
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#include "block/qcow2.h" |
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|
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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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//#define DEBUG_ALLOC
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//#define DEBUG_ALLOC2
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//#define DEBUG_EXT
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|
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|
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typedef struct { |
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uint32_t magic; |
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uint32_t len; |
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} QCowExtension; |
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#define QCOW_EXT_MAGIC_END 0 |
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#define QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA |
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|
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|
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typedef struct __attribute__((packed)) QCowSnapshotHeader { |
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/* header is 8 byte aligned */
|
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uint64_t l1_table_offset; |
63 |
|
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uint32_t l1_size; |
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uint16_t id_str_size; |
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uint16_t name_size; |
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|
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uint32_t date_sec; |
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uint32_t date_nsec; |
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|
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uint64_t vm_clock_nsec; |
72 |
|
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uint32_t vm_state_size; |
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uint32_t extra_data_size; /* for extension */
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/* extra data follows */
|
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/* id_str follows */
|
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/* name follows */
|
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} QCowSnapshotHeader; |
79 |
|
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|
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static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset); |
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static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
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uint8_t *buf, int nb_sectors);
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static int qcow_read_snapshots(BlockDriverState *bs); |
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static void qcow_free_snapshots(BlockDriverState *bs); |
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|
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static int qcow_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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|
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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) == QCOW_VERSION) |
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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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|
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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 qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset, |
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uint64_t end_offset) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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QCowExtension ext; |
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uint64_t offset; |
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|
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#ifdef DEBUG_EXT
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printf("qcow_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
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#endif
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offset = start_offset; |
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while (offset < end_offset) {
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|
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#ifdef DEBUG_EXT
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/* Sanity check */
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if (offset > s->cluster_size)
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printf("qcow_handle_extension: suspicious offset %lu\n", offset);
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printf("attemting 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(s->hd, offset, &ext, sizeof(ext)) != sizeof(ext)) { |
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fprintf(stderr, "qcow_handle_extension: ERROR: pread fail from offset %llu\n",
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(unsigned long long)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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switch (ext.magic) {
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case QCOW_EXT_MAGIC_END:
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return 0; |
142 |
|
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case QCOW_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(s->hd, 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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offset += ((ext.len + 7) & ~7); |
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break;
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default:
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/* unknown magic -- just skip it */
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offset += ((ext.len + 7) & ~7); |
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break;
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} |
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} |
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return 0; |
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} |
169 |
|
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|
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static int qcow_open(BlockDriverState *bs, const char *filename, int flags) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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int len, i, shift, ret;
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QCowHeader header; |
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uint64_t ext_end; |
177 |
|
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/* Performance is terrible right now with cache=writethrough due mainly
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* to reference count updates. If the user does not explicitly specify
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* a caching type, force to writeback caching.
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*/
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if ((flags & BDRV_O_CACHE_DEF)) {
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flags |= BDRV_O_CACHE_WB; |
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flags &= ~BDRV_O_CACHE_DEF; |
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} |
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ret = bdrv_file_open(&s->hd, filename, flags); |
187 |
if (ret < 0) |
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return ret;
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if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) |
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goto fail;
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be32_to_cpus(&header.magic); |
192 |
be32_to_cpus(&header.version); |
193 |
be64_to_cpus(&header.backing_file_offset); |
194 |
be32_to_cpus(&header.backing_file_size); |
195 |
be64_to_cpus(&header.size); |
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be32_to_cpus(&header.cluster_bits); |
197 |
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); |
203 |
be32_to_cpus(&header.nb_snapshots); |
204 |
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if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION)
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goto fail;
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if (header.size <= 1 || |
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header.cluster_bits < MIN_CLUSTER_BITS || |
209 |
header.cluster_bits > MAX_CLUSTER_BITS) |
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goto fail;
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if (header.crypt_method > QCOW_CRYPT_AES)
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goto fail;
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s->crypt_method_header = header.crypt_method; |
214 |
if (s->crypt_method_header)
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bs->encrypted = 1;
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s->cluster_bits = header.cluster_bits; |
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s->cluster_size = 1 << s->cluster_bits;
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s->cluster_sectors = 1 << (s->cluster_bits - 9); |
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s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ |
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s->l2_size = 1 << s->l2_bits;
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bs->total_sectors = header.size / 512;
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s->csize_shift = (62 - (s->cluster_bits - 8)); |
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s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
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s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
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s->refcount_table_offset = header.refcount_table_offset; |
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s->refcount_table_size = |
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header.refcount_table_clusters << (s->cluster_bits - 3);
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|
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s->snapshots_offset = header.snapshots_offset; |
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s->nb_snapshots = header.nb_snapshots; |
231 |
|
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/* read the level 1 table */
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s->l1_size = header.l1_size; |
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shift = s->cluster_bits + s->l2_bits; |
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s->l1_vm_state_index = (header.size + (1LL << shift) - 1) >> shift; |
236 |
/* the L1 table must contain at least enough entries to put
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header.size bytes */
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if (s->l1_size < s->l1_vm_state_index)
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goto fail;
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s->l1_table_offset = header.l1_table_offset; |
241 |
s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
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if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != |
243 |
s->l1_size * sizeof(uint64_t))
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goto fail;
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for(i = 0;i < s->l1_size; i++) { |
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be64_to_cpus(&s->l1_table[i]); |
247 |
} |
248 |
/* alloc L2 cache */
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s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
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s->cluster_cache = qemu_malloc(s->cluster_size); |
251 |
/* one more sector for decompressed data alignment */
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s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size |
253 |
+ 512);
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s->cluster_cache_offset = -1;
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255 |
|
256 |
if (refcount_init(bs) < 0) |
257 |
goto fail;
|
258 |
|
259 |
/* read qcow2 extensions */
|
260 |
if (header.backing_file_offset)
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ext_end = header.backing_file_offset; |
262 |
else
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ext_end = s->cluster_size; |
264 |
if (qcow_read_extensions(bs, sizeof(header), ext_end)) |
265 |
goto fail;
|
266 |
|
267 |
/* read the backing file name */
|
268 |
if (header.backing_file_offset != 0) { |
269 |
len = header.backing_file_size; |
270 |
if (len > 1023) |
271 |
len = 1023;
|
272 |
if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len)
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273 |
goto fail;
|
274 |
bs->backing_file[len] = '\0';
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275 |
} |
276 |
if (qcow_read_snapshots(bs) < 0) |
277 |
goto fail;
|
278 |
|
279 |
#ifdef DEBUG_ALLOC
|
280 |
check_refcounts(bs); |
281 |
#endif
|
282 |
return 0; |
283 |
|
284 |
fail:
|
285 |
qcow_free_snapshots(bs); |
286 |
refcount_close(bs); |
287 |
qemu_free(s->l1_table); |
288 |
qemu_free(s->l2_cache); |
289 |
qemu_free(s->cluster_cache); |
290 |
qemu_free(s->cluster_data); |
291 |
bdrv_delete(s->hd); |
292 |
return -1; |
293 |
} |
294 |
|
295 |
static int qcow_set_key(BlockDriverState *bs, const char *key) |
296 |
{ |
297 |
BDRVQcowState *s = bs->opaque; |
298 |
uint8_t keybuf[16];
|
299 |
int len, i;
|
300 |
|
301 |
memset(keybuf, 0, 16); |
302 |
len = strlen(key); |
303 |
if (len > 16) |
304 |
len = 16;
|
305 |
/* XXX: we could compress the chars to 7 bits to increase
|
306 |
entropy */
|
307 |
for(i = 0;i < len;i++) { |
308 |
keybuf[i] = key[i]; |
309 |
} |
310 |
s->crypt_method = s->crypt_method_header; |
311 |
|
312 |
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
313 |
return -1; |
314 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
315 |
return -1; |
316 |
#if 0
|
317 |
/* test */
|
318 |
{
|
319 |
uint8_t in[16];
|
320 |
uint8_t out[16];
|
321 |
uint8_t tmp[16];
|
322 |
for(i=0;i<16;i++)
|
323 |
in[i] = i;
|
324 |
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
325 |
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
326 |
for(i = 0; i < 16; i++)
|
327 |
printf(" %02x", tmp[i]);
|
328 |
printf("\n");
|
329 |
for(i = 0; i < 16; i++)
|
330 |
printf(" %02x", out[i]);
|
331 |
printf("\n");
|
332 |
}
|
333 |
#endif
|
334 |
return 0; |
335 |
} |
336 |
|
337 |
/* The crypt function is compatible with the linux cryptoloop
|
338 |
algorithm for < 4 GB images. NOTE: out_buf == in_buf is
|
339 |
supported */
|
340 |
static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
341 |
uint8_t *out_buf, const uint8_t *in_buf,
|
342 |
int nb_sectors, int enc, |
343 |
const AES_KEY *key)
|
344 |
{ |
345 |
union {
|
346 |
uint64_t ll[2];
|
347 |
uint8_t b[16];
|
348 |
} ivec; |
349 |
int i;
|
350 |
|
351 |
for(i = 0; i < nb_sectors; i++) { |
352 |
ivec.ll[0] = cpu_to_le64(sector_num);
|
353 |
ivec.ll[1] = 0; |
354 |
AES_cbc_encrypt(in_buf, out_buf, 512, key,
|
355 |
ivec.b, enc); |
356 |
sector_num++; |
357 |
in_buf += 512;
|
358 |
out_buf += 512;
|
359 |
} |
360 |
} |
361 |
|
362 |
static int copy_sectors(BlockDriverState *bs, uint64_t start_sect, |
363 |
uint64_t cluster_offset, int n_start, int n_end) |
364 |
{ |
365 |
BDRVQcowState *s = bs->opaque; |
366 |
int n, ret;
|
367 |
|
368 |
n = n_end - n_start; |
369 |
if (n <= 0) |
370 |
return 0; |
371 |
ret = qcow_read(bs, start_sect + n_start, s->cluster_data, n); |
372 |
if (ret < 0) |
373 |
return ret;
|
374 |
if (s->crypt_method) {
|
375 |
encrypt_sectors(s, start_sect + n_start, |
376 |
s->cluster_data, |
377 |
s->cluster_data, n, 1,
|
378 |
&s->aes_encrypt_key); |
379 |
} |
380 |
ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start,
|
381 |
s->cluster_data, n); |
382 |
if (ret < 0) |
383 |
return ret;
|
384 |
return 0; |
385 |
} |
386 |
|
387 |
void l2_cache_reset(BlockDriverState *bs)
|
388 |
{ |
389 |
BDRVQcowState *s = bs->opaque; |
390 |
|
391 |
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
392 |
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
393 |
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
394 |
} |
395 |
|
396 |
static inline int l2_cache_new_entry(BlockDriverState *bs) |
397 |
{ |
398 |
BDRVQcowState *s = bs->opaque; |
399 |
uint32_t min_count; |
400 |
int min_index, i;
|
401 |
|
402 |
/* find a new entry in the least used one */
|
403 |
min_index = 0;
|
404 |
min_count = 0xffffffff;
|
405 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
406 |
if (s->l2_cache_counts[i] < min_count) {
|
407 |
min_count = s->l2_cache_counts[i]; |
408 |
min_index = i; |
409 |
} |
410 |
} |
411 |
return min_index;
|
412 |
} |
413 |
|
414 |
static int64_t align_offset(int64_t offset, int n) |
415 |
{ |
416 |
offset = (offset + n - 1) & ~(n - 1); |
417 |
return offset;
|
418 |
} |
419 |
|
420 |
static int grow_l1_table(BlockDriverState *bs, int min_size) |
421 |
{ |
422 |
BDRVQcowState *s = bs->opaque; |
423 |
int new_l1_size, new_l1_size2, ret, i;
|
424 |
uint64_t *new_l1_table; |
425 |
uint64_t new_l1_table_offset; |
426 |
uint8_t data[12];
|
427 |
|
428 |
new_l1_size = s->l1_size; |
429 |
if (min_size <= new_l1_size)
|
430 |
return 0; |
431 |
while (min_size > new_l1_size) {
|
432 |
new_l1_size = (new_l1_size * 3 + 1) / 2; |
433 |
} |
434 |
#ifdef DEBUG_ALLOC2
|
435 |
printf("grow l1_table from %d to %d\n", s->l1_size, new_l1_size);
|
436 |
#endif
|
437 |
|
438 |
new_l1_size2 = sizeof(uint64_t) * new_l1_size;
|
439 |
new_l1_table = qemu_mallocz(new_l1_size2); |
440 |
memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
|
441 |
|
442 |
/* write new table (align to cluster) */
|
443 |
new_l1_table_offset = alloc_clusters(bs, new_l1_size2); |
444 |
|
445 |
for(i = 0; i < s->l1_size; i++) |
446 |
new_l1_table[i] = cpu_to_be64(new_l1_table[i]); |
447 |
ret = bdrv_pwrite(s->hd, new_l1_table_offset, new_l1_table, new_l1_size2); |
448 |
if (ret != new_l1_size2)
|
449 |
goto fail;
|
450 |
for(i = 0; i < s->l1_size; i++) |
451 |
new_l1_table[i] = be64_to_cpu(new_l1_table[i]); |
452 |
|
453 |
/* set new table */
|
454 |
cpu_to_be32w((uint32_t*)data, new_l1_size); |
455 |
cpu_to_be64w((uint64_t*)(data + 4), new_l1_table_offset);
|
456 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_size), data,
|
457 |
sizeof(data)) != sizeof(data)) |
458 |
goto fail;
|
459 |
qemu_free(s->l1_table); |
460 |
free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t));
|
461 |
s->l1_table_offset = new_l1_table_offset; |
462 |
s->l1_table = new_l1_table; |
463 |
s->l1_size = new_l1_size; |
464 |
return 0; |
465 |
fail:
|
466 |
qemu_free(s->l1_table); |
467 |
return -EIO;
|
468 |
} |
469 |
|
470 |
/*
|
471 |
* seek_l2_table
|
472 |
*
|
473 |
* seek l2_offset in the l2_cache table
|
474 |
* if not found, return NULL,
|
475 |
* if found,
|
476 |
* increments the l2 cache hit count of the entry,
|
477 |
* if counter overflow, divide by two all counters
|
478 |
* return the pointer to the l2 cache entry
|
479 |
*
|
480 |
*/
|
481 |
|
482 |
static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset)
|
483 |
{ |
484 |
int i, j;
|
485 |
|
486 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
487 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
488 |
/* increment the hit count */
|
489 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
490 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
491 |
s->l2_cache_counts[j] >>= 1;
|
492 |
} |
493 |
} |
494 |
return s->l2_cache + (i << s->l2_bits);
|
495 |
} |
496 |
} |
497 |
return NULL; |
498 |
} |
499 |
|
500 |
/*
|
501 |
* l2_load
|
502 |
*
|
503 |
* Loads a L2 table into memory. If the table is in the cache, the cache
|
504 |
* is used; otherwise the L2 table is loaded from the image file.
|
505 |
*
|
506 |
* Returns a pointer to the L2 table on success, or NULL if the read from
|
507 |
* the image file failed.
|
508 |
*/
|
509 |
|
510 |
static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset)
|
511 |
{ |
512 |
BDRVQcowState *s = bs->opaque; |
513 |
int min_index;
|
514 |
uint64_t *l2_table; |
515 |
|
516 |
/* seek if the table for the given offset is in the cache */
|
517 |
|
518 |
l2_table = seek_l2_table(s, l2_offset); |
519 |
if (l2_table != NULL) |
520 |
return l2_table;
|
521 |
|
522 |
/* not found: load a new entry in the least used one */
|
523 |
|
524 |
min_index = l2_cache_new_entry(bs); |
525 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
526 |
if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
527 |
s->l2_size * sizeof(uint64_t))
|
528 |
return NULL; |
529 |
s->l2_cache_offsets[min_index] = l2_offset; |
530 |
s->l2_cache_counts[min_index] = 1;
|
531 |
|
532 |
return l2_table;
|
533 |
} |
534 |
|
535 |
/*
|
536 |
* l2_allocate
|
537 |
*
|
538 |
* Allocate a new l2 entry in the file. If l1_index points to an already
|
539 |
* used entry in the L2 table (i.e. we are doing a copy on write for the L2
|
540 |
* table) copy the contents of the old L2 table into the newly allocated one.
|
541 |
* Otherwise the new table is initialized with zeros.
|
542 |
*
|
543 |
*/
|
544 |
|
545 |
static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index) |
546 |
{ |
547 |
BDRVQcowState *s = bs->opaque; |
548 |
int min_index;
|
549 |
uint64_t old_l2_offset, tmp; |
550 |
uint64_t *l2_table, l2_offset; |
551 |
|
552 |
old_l2_offset = s->l1_table[l1_index]; |
553 |
|
554 |
/* allocate a new l2 entry */
|
555 |
|
556 |
l2_offset = alloc_clusters(bs, s->l2_size * sizeof(uint64_t));
|
557 |
|
558 |
/* update the L1 entry */
|
559 |
|
560 |
s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; |
561 |
|
562 |
tmp = cpu_to_be64(l2_offset | QCOW_OFLAG_COPIED); |
563 |
if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), |
564 |
&tmp, sizeof(tmp)) != sizeof(tmp)) |
565 |
return NULL; |
566 |
|
567 |
/* allocate a new entry in the l2 cache */
|
568 |
|
569 |
min_index = l2_cache_new_entry(bs); |
570 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
571 |
|
572 |
if (old_l2_offset == 0) { |
573 |
/* if there was no old l2 table, clear the new table */
|
574 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
575 |
} else {
|
576 |
/* if there was an old l2 table, read it from the disk */
|
577 |
if (bdrv_pread(s->hd, old_l2_offset,
|
578 |
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
579 |
s->l2_size * sizeof(uint64_t))
|
580 |
return NULL; |
581 |
} |
582 |
/* write the l2 table to the file */
|
583 |
if (bdrv_pwrite(s->hd, l2_offset,
|
584 |
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
585 |
s->l2_size * sizeof(uint64_t))
|
586 |
return NULL; |
587 |
|
588 |
/* update the l2 cache entry */
|
589 |
|
590 |
s->l2_cache_offsets[min_index] = l2_offset; |
591 |
s->l2_cache_counts[min_index] = 1;
|
592 |
|
593 |
return l2_table;
|
594 |
} |
595 |
|
596 |
static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, |
597 |
uint64_t *l2_table, uint64_t start, uint64_t mask) |
598 |
{ |
599 |
int i;
|
600 |
uint64_t offset = be64_to_cpu(l2_table[0]) & ~mask;
|
601 |
|
602 |
if (!offset)
|
603 |
return 0; |
604 |
|
605 |
for (i = start; i < start + nb_clusters; i++)
|
606 |
if (offset + i * cluster_size != (be64_to_cpu(l2_table[i]) & ~mask))
|
607 |
break;
|
608 |
|
609 |
return (i - start);
|
610 |
} |
611 |
|
612 |
static int count_contiguous_free_clusters(uint64_t nb_clusters, uint64_t *l2_table) |
613 |
{ |
614 |
int i = 0; |
615 |
|
616 |
while(nb_clusters-- && l2_table[i] == 0) |
617 |
i++; |
618 |
|
619 |
return i;
|
620 |
} |
621 |
|
622 |
/*
|
623 |
* get_cluster_offset
|
624 |
*
|
625 |
* For a given offset of the disk image, return cluster offset in
|
626 |
* qcow2 file.
|
627 |
*
|
628 |
* on entry, *num is the number of contiguous clusters we'd like to
|
629 |
* access following offset.
|
630 |
*
|
631 |
* on exit, *num is the number of contiguous clusters we can read.
|
632 |
*
|
633 |
* Return 1, if the offset is found
|
634 |
* Return 0, otherwise.
|
635 |
*
|
636 |
*/
|
637 |
|
638 |
static uint64_t get_cluster_offset(BlockDriverState *bs,
|
639 |
uint64_t offset, int *num)
|
640 |
{ |
641 |
BDRVQcowState *s = bs->opaque; |
642 |
int l1_index, l2_index;
|
643 |
uint64_t l2_offset, *l2_table, cluster_offset; |
644 |
int l1_bits, c;
|
645 |
int index_in_cluster, nb_available, nb_needed, nb_clusters;
|
646 |
|
647 |
index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1); |
648 |
nb_needed = *num + index_in_cluster; |
649 |
|
650 |
l1_bits = s->l2_bits + s->cluster_bits; |
651 |
|
652 |
/* compute how many bytes there are between the offset and
|
653 |
* the end of the l1 entry
|
654 |
*/
|
655 |
|
656 |
nb_available = (1 << l1_bits) - (offset & ((1 << l1_bits) - 1)); |
657 |
|
658 |
/* compute the number of available sectors */
|
659 |
|
660 |
nb_available = (nb_available >> 9) + index_in_cluster;
|
661 |
|
662 |
if (nb_needed > nb_available) {
|
663 |
nb_needed = nb_available; |
664 |
} |
665 |
|
666 |
cluster_offset = 0;
|
667 |
|
668 |
/* seek the the l2 offset in the l1 table */
|
669 |
|
670 |
l1_index = offset >> l1_bits; |
671 |
if (l1_index >= s->l1_size)
|
672 |
goto out;
|
673 |
|
674 |
l2_offset = s->l1_table[l1_index]; |
675 |
|
676 |
/* seek the l2 table of the given l2 offset */
|
677 |
|
678 |
if (!l2_offset)
|
679 |
goto out;
|
680 |
|
681 |
/* load the l2 table in memory */
|
682 |
|
683 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
684 |
l2_table = l2_load(bs, l2_offset); |
685 |
if (l2_table == NULL) |
686 |
return 0; |
687 |
|
688 |
/* find the cluster offset for the given disk offset */
|
689 |
|
690 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
691 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
692 |
nb_clusters = size_to_clusters(s, nb_needed << 9);
|
693 |
|
694 |
if (!cluster_offset) {
|
695 |
/* how many empty clusters ? */
|
696 |
c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]); |
697 |
} else {
|
698 |
/* how many allocated clusters ? */
|
699 |
c = count_contiguous_clusters(nb_clusters, s->cluster_size, |
700 |
&l2_table[l2_index], 0, QCOW_OFLAG_COPIED);
|
701 |
} |
702 |
|
703 |
nb_available = (c * s->cluster_sectors); |
704 |
out:
|
705 |
if (nb_available > nb_needed)
|
706 |
nb_available = nb_needed; |
707 |
|
708 |
*num = nb_available - index_in_cluster; |
709 |
|
710 |
return cluster_offset & ~QCOW_OFLAG_COPIED;
|
711 |
} |
712 |
|
713 |
/*
|
714 |
* free_any_clusters
|
715 |
*
|
716 |
* free clusters according to its type: compressed or not
|
717 |
*
|
718 |
*/
|
719 |
|
720 |
static void free_any_clusters(BlockDriverState *bs, |
721 |
uint64_t cluster_offset, int nb_clusters)
|
722 |
{ |
723 |
BDRVQcowState *s = bs->opaque; |
724 |
|
725 |
/* free the cluster */
|
726 |
|
727 |
if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
728 |
int nb_csectors;
|
729 |
nb_csectors = ((cluster_offset >> s->csize_shift) & |
730 |
s->csize_mask) + 1;
|
731 |
free_clusters(bs, (cluster_offset & s->cluster_offset_mask) & ~511,
|
732 |
nb_csectors * 512);
|
733 |
return;
|
734 |
} |
735 |
|
736 |
free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits); |
737 |
|
738 |
return;
|
739 |
} |
740 |
|
741 |
/*
|
742 |
* get_cluster_table
|
743 |
*
|
744 |
* for a given disk offset, load (and allocate if needed)
|
745 |
* the l2 table.
|
746 |
*
|
747 |
* the l2 table offset in the qcow2 file and the cluster index
|
748 |
* in the l2 table are given to the caller.
|
749 |
*
|
750 |
*/
|
751 |
|
752 |
static int get_cluster_table(BlockDriverState *bs, uint64_t offset, |
753 |
uint64_t **new_l2_table, |
754 |
uint64_t *new_l2_offset, |
755 |
int *new_l2_index)
|
756 |
{ |
757 |
BDRVQcowState *s = bs->opaque; |
758 |
int l1_index, l2_index, ret;
|
759 |
uint64_t l2_offset, *l2_table; |
760 |
|
761 |
/* seek the the l2 offset in the l1 table */
|
762 |
|
763 |
l1_index = offset >> (s->l2_bits + s->cluster_bits); |
764 |
if (l1_index >= s->l1_size) {
|
765 |
ret = grow_l1_table(bs, l1_index + 1);
|
766 |
if (ret < 0) |
767 |
return 0; |
768 |
} |
769 |
l2_offset = s->l1_table[l1_index]; |
770 |
|
771 |
/* seek the l2 table of the given l2 offset */
|
772 |
|
773 |
if (l2_offset & QCOW_OFLAG_COPIED) {
|
774 |
/* load the l2 table in memory */
|
775 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
776 |
l2_table = l2_load(bs, l2_offset); |
777 |
if (l2_table == NULL) |
778 |
return 0; |
779 |
} else {
|
780 |
if (l2_offset)
|
781 |
free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t));
|
782 |
l2_table = l2_allocate(bs, l1_index); |
783 |
if (l2_table == NULL) |
784 |
return 0; |
785 |
l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED; |
786 |
} |
787 |
|
788 |
/* find the cluster offset for the given disk offset */
|
789 |
|
790 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
791 |
|
792 |
*new_l2_table = l2_table; |
793 |
*new_l2_offset = l2_offset; |
794 |
*new_l2_index = l2_index; |
795 |
|
796 |
return 1; |
797 |
} |
798 |
|
799 |
/*
|
800 |
* alloc_compressed_cluster_offset
|
801 |
*
|
802 |
* For a given offset of the disk image, return cluster offset in
|
803 |
* qcow2 file.
|
804 |
*
|
805 |
* If the offset is not found, allocate a new compressed cluster.
|
806 |
*
|
807 |
* Return the cluster offset if successful,
|
808 |
* Return 0, otherwise.
|
809 |
*
|
810 |
*/
|
811 |
|
812 |
static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs,
|
813 |
uint64_t offset, |
814 |
int compressed_size)
|
815 |
{ |
816 |
BDRVQcowState *s = bs->opaque; |
817 |
int l2_index, ret;
|
818 |
uint64_t l2_offset, *l2_table, cluster_offset; |
819 |
int nb_csectors;
|
820 |
|
821 |
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
822 |
if (ret == 0) |
823 |
return 0; |
824 |
|
825 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
826 |
if (cluster_offset & QCOW_OFLAG_COPIED)
|
827 |
return cluster_offset & ~QCOW_OFLAG_COPIED;
|
828 |
|
829 |
if (cluster_offset)
|
830 |
free_any_clusters(bs, cluster_offset, 1);
|
831 |
|
832 |
cluster_offset = alloc_bytes(bs, compressed_size); |
833 |
nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) - |
834 |
(cluster_offset >> 9);
|
835 |
|
836 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
837 |
((uint64_t)nb_csectors << s->csize_shift); |
838 |
|
839 |
/* update L2 table */
|
840 |
|
841 |
/* compressed clusters never have the copied flag */
|
842 |
|
843 |
l2_table[l2_index] = cpu_to_be64(cluster_offset); |
844 |
if (bdrv_pwrite(s->hd,
|
845 |
l2_offset + l2_index * sizeof(uint64_t),
|
846 |
l2_table + l2_index, |
847 |
sizeof(uint64_t)) != sizeof(uint64_t)) |
848 |
return 0; |
849 |
|
850 |
return cluster_offset;
|
851 |
} |
852 |
|
853 |
typedef struct QCowL2Meta |
854 |
{ |
855 |
uint64_t offset; |
856 |
int n_start;
|
857 |
int nb_available;
|
858 |
int nb_clusters;
|
859 |
} QCowL2Meta; |
860 |
|
861 |
static int alloc_cluster_link_l2(BlockDriverState *bs, uint64_t cluster_offset, |
862 |
QCowL2Meta *m) |
863 |
{ |
864 |
BDRVQcowState *s = bs->opaque; |
865 |
int i, j = 0, l2_index, ret; |
866 |
uint64_t *old_cluster, start_sect, l2_offset, *l2_table; |
867 |
|
868 |
if (m->nb_clusters == 0) |
869 |
return 0; |
870 |
|
871 |
old_cluster = qemu_malloc(m->nb_clusters * sizeof(uint64_t));
|
872 |
|
873 |
/* copy content of unmodified sectors */
|
874 |
start_sect = (m->offset & ~(s->cluster_size - 1)) >> 9; |
875 |
if (m->n_start) {
|
876 |
ret = copy_sectors(bs, start_sect, cluster_offset, 0, m->n_start);
|
877 |
if (ret < 0) |
878 |
goto err;
|
879 |
} |
880 |
|
881 |
if (m->nb_available & (s->cluster_sectors - 1)) { |
882 |
uint64_t end = m->nb_available & ~(uint64_t)(s->cluster_sectors - 1);
|
883 |
ret = copy_sectors(bs, start_sect + end, cluster_offset + (end << 9),
|
884 |
m->nb_available - end, s->cluster_sectors); |
885 |
if (ret < 0) |
886 |
goto err;
|
887 |
} |
888 |
|
889 |
ret = -EIO; |
890 |
/* update L2 table */
|
891 |
if (!get_cluster_table(bs, m->offset, &l2_table, &l2_offset, &l2_index))
|
892 |
goto err;
|
893 |
|
894 |
for (i = 0; i < m->nb_clusters; i++) { |
895 |
/* if two concurrent writes happen to the same unallocated cluster
|
896 |
* each write allocates separate cluster and writes data concurrently.
|
897 |
* The first one to complete updates l2 table with pointer to its
|
898 |
* cluster the second one has to do RMW (which is done above by
|
899 |
* copy_sectors()), update l2 table with its cluster pointer and free
|
900 |
* old cluster. This is what this loop does */
|
901 |
if(l2_table[l2_index + i] != 0) |
902 |
old_cluster[j++] = l2_table[l2_index + i]; |
903 |
|
904 |
l2_table[l2_index + i] = cpu_to_be64((cluster_offset + |
905 |
(i << s->cluster_bits)) | QCOW_OFLAG_COPIED); |
906 |
} |
907 |
|
908 |
if (bdrv_pwrite(s->hd, l2_offset + l2_index * sizeof(uint64_t), |
909 |
l2_table + l2_index, m->nb_clusters * sizeof(uint64_t)) !=
|
910 |
m->nb_clusters * sizeof(uint64_t))
|
911 |
goto err;
|
912 |
|
913 |
for (i = 0; i < j; i++) |
914 |
free_any_clusters(bs, be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED, |
915 |
1);
|
916 |
|
917 |
ret = 0;
|
918 |
err:
|
919 |
qemu_free(old_cluster); |
920 |
return ret;
|
921 |
} |
922 |
|
923 |
/*
|
924 |
* alloc_cluster_offset
|
925 |
*
|
926 |
* For a given offset of the disk image, return cluster offset in
|
927 |
* qcow2 file.
|
928 |
*
|
929 |
* If the offset is not found, allocate a new cluster.
|
930 |
*
|
931 |
* Return the cluster offset if successful,
|
932 |
* Return 0, otherwise.
|
933 |
*
|
934 |
*/
|
935 |
|
936 |
static uint64_t alloc_cluster_offset(BlockDriverState *bs,
|
937 |
uint64_t offset, |
938 |
int n_start, int n_end, |
939 |
int *num, QCowL2Meta *m)
|
940 |
{ |
941 |
BDRVQcowState *s = bs->opaque; |
942 |
int l2_index, ret;
|
943 |
uint64_t l2_offset, *l2_table, cluster_offset; |
944 |
int nb_clusters, i = 0; |
945 |
|
946 |
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
947 |
if (ret == 0) |
948 |
return 0; |
949 |
|
950 |
nb_clusters = size_to_clusters(s, n_end << 9);
|
951 |
|
952 |
nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); |
953 |
|
954 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
955 |
|
956 |
/* We keep all QCOW_OFLAG_COPIED clusters */
|
957 |
|
958 |
if (cluster_offset & QCOW_OFLAG_COPIED) {
|
959 |
nb_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size, |
960 |
&l2_table[l2_index], 0, 0); |
961 |
|
962 |
cluster_offset &= ~QCOW_OFLAG_COPIED; |
963 |
m->nb_clusters = 0;
|
964 |
|
965 |
goto out;
|
966 |
} |
967 |
|
968 |
/* for the moment, multiple compressed clusters are not managed */
|
969 |
|
970 |
if (cluster_offset & QCOW_OFLAG_COMPRESSED)
|
971 |
nb_clusters = 1;
|
972 |
|
973 |
/* how many available clusters ? */
|
974 |
|
975 |
while (i < nb_clusters) {
|
976 |
i += count_contiguous_clusters(nb_clusters - i, s->cluster_size, |
977 |
&l2_table[l2_index], i, 0);
|
978 |
|
979 |
if(be64_to_cpu(l2_table[l2_index + i]))
|
980 |
break;
|
981 |
|
982 |
i += count_contiguous_free_clusters(nb_clusters - i, |
983 |
&l2_table[l2_index + i]); |
984 |
|
985 |
cluster_offset = be64_to_cpu(l2_table[l2_index + i]); |
986 |
|
987 |
if ((cluster_offset & QCOW_OFLAG_COPIED) ||
|
988 |
(cluster_offset & QCOW_OFLAG_COMPRESSED)) |
989 |
break;
|
990 |
} |
991 |
nb_clusters = i; |
992 |
|
993 |
/* allocate a new cluster */
|
994 |
|
995 |
cluster_offset = alloc_clusters(bs, nb_clusters * s->cluster_size); |
996 |
|
997 |
/* save info needed for meta data update */
|
998 |
m->offset = offset; |
999 |
m->n_start = n_start; |
1000 |
m->nb_clusters = nb_clusters; |
1001 |
|
1002 |
out:
|
1003 |
m->nb_available = MIN(nb_clusters << (s->cluster_bits - 9), n_end);
|
1004 |
|
1005 |
*num = m->nb_available - n_start; |
1006 |
|
1007 |
return cluster_offset;
|
1008 |
} |
1009 |
|
1010 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
1011 |
int nb_sectors, int *pnum) |
1012 |
{ |
1013 |
uint64_t cluster_offset; |
1014 |
|
1015 |
*pnum = nb_sectors; |
1016 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, pnum);
|
1017 |
|
1018 |
return (cluster_offset != 0); |
1019 |
} |
1020 |
|
1021 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
1022 |
const uint8_t *buf, int buf_size) |
1023 |
{ |
1024 |
z_stream strm1, *strm = &strm1; |
1025 |
int ret, out_len;
|
1026 |
|
1027 |
memset(strm, 0, sizeof(*strm)); |
1028 |
|
1029 |
strm->next_in = (uint8_t *)buf; |
1030 |
strm->avail_in = buf_size; |
1031 |
strm->next_out = out_buf; |
1032 |
strm->avail_out = out_buf_size; |
1033 |
|
1034 |
ret = inflateInit2(strm, -12);
|
1035 |
if (ret != Z_OK)
|
1036 |
return -1; |
1037 |
ret = inflate(strm, Z_FINISH); |
1038 |
out_len = strm->next_out - out_buf; |
1039 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
1040 |
out_len != out_buf_size) { |
1041 |
inflateEnd(strm); |
1042 |
return -1; |
1043 |
} |
1044 |
inflateEnd(strm); |
1045 |
return 0; |
1046 |
} |
1047 |
|
1048 |
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) |
1049 |
{ |
1050 |
int ret, csize, nb_csectors, sector_offset;
|
1051 |
uint64_t coffset; |
1052 |
|
1053 |
coffset = cluster_offset & s->cluster_offset_mask; |
1054 |
if (s->cluster_cache_offset != coffset) {
|
1055 |
nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
|
1056 |
sector_offset = coffset & 511;
|
1057 |
csize = nb_csectors * 512 - sector_offset;
|
1058 |
ret = bdrv_read(s->hd, coffset >> 9, s->cluster_data, nb_csectors);
|
1059 |
if (ret < 0) { |
1060 |
return -1; |
1061 |
} |
1062 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
1063 |
s->cluster_data + sector_offset, csize) < 0) {
|
1064 |
return -1; |
1065 |
} |
1066 |
s->cluster_cache_offset = coffset; |
1067 |
} |
1068 |
return 0; |
1069 |
} |
1070 |
|
1071 |
/* handle reading after the end of the backing file */
|
1072 |
static int backing_read1(BlockDriverState *bs, |
1073 |
int64_t sector_num, uint8_t *buf, int nb_sectors)
|
1074 |
{ |
1075 |
int n1;
|
1076 |
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
1077 |
return nb_sectors;
|
1078 |
if (sector_num >= bs->total_sectors)
|
1079 |
n1 = 0;
|
1080 |
else
|
1081 |
n1 = bs->total_sectors - sector_num; |
1082 |
memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1)); |
1083 |
return n1;
|
1084 |
} |
1085 |
|
1086 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
1087 |
uint8_t *buf, int nb_sectors)
|
1088 |
{ |
1089 |
BDRVQcowState *s = bs->opaque; |
1090 |
int ret, index_in_cluster, n, n1;
|
1091 |
uint64_t cluster_offset; |
1092 |
|
1093 |
while (nb_sectors > 0) { |
1094 |
n = nb_sectors; |
1095 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, &n);
|
1096 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
1097 |
if (!cluster_offset) {
|
1098 |
if (bs->backing_hd) {
|
1099 |
/* read from the base image */
|
1100 |
n1 = backing_read1(bs->backing_hd, sector_num, buf, n); |
1101 |
if (n1 > 0) { |
1102 |
ret = bdrv_read(bs->backing_hd, sector_num, buf, n1); |
1103 |
if (ret < 0) |
1104 |
return -1; |
1105 |
} |
1106 |
} else {
|
1107 |
memset(buf, 0, 512 * n); |
1108 |
} |
1109 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1110 |
if (decompress_cluster(s, cluster_offset) < 0) |
1111 |
return -1; |
1112 |
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); |
1113 |
} else {
|
1114 |
ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
1115 |
if (ret != n * 512) |
1116 |
return -1; |
1117 |
if (s->crypt_method) {
|
1118 |
encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
1119 |
&s->aes_decrypt_key); |
1120 |
} |
1121 |
} |
1122 |
nb_sectors -= n; |
1123 |
sector_num += n; |
1124 |
buf += n * 512;
|
1125 |
} |
1126 |
return 0; |
1127 |
} |
1128 |
|
1129 |
typedef struct QCowAIOCB { |
1130 |
BlockDriverAIOCB common; |
1131 |
int64_t sector_num; |
1132 |
QEMUIOVector *qiov; |
1133 |
uint8_t *buf; |
1134 |
void *orig_buf;
|
1135 |
int nb_sectors;
|
1136 |
int n;
|
1137 |
uint64_t cluster_offset; |
1138 |
uint8_t *cluster_data; |
1139 |
BlockDriverAIOCB *hd_aiocb; |
1140 |
struct iovec hd_iov;
|
1141 |
QEMUIOVector hd_qiov; |
1142 |
QEMUBH *bh; |
1143 |
QCowL2Meta l2meta; |
1144 |
} QCowAIOCB; |
1145 |
|
1146 |
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) |
1147 |
{ |
1148 |
QCowAIOCB *acb = (QCowAIOCB *)blockacb; |
1149 |
if (acb->hd_aiocb)
|
1150 |
bdrv_aio_cancel(acb->hd_aiocb); |
1151 |
qemu_aio_release(acb); |
1152 |
} |
1153 |
|
1154 |
static AIOPool qcow_aio_pool = {
|
1155 |
.aiocb_size = sizeof(QCowAIOCB),
|
1156 |
.cancel = qcow_aio_cancel, |
1157 |
}; |
1158 |
|
1159 |
static void qcow_aio_read_cb(void *opaque, int ret); |
1160 |
static void qcow_aio_read_bh(void *opaque) |
1161 |
{ |
1162 |
QCowAIOCB *acb = opaque; |
1163 |
qemu_bh_delete(acb->bh); |
1164 |
acb->bh = NULL;
|
1165 |
qcow_aio_read_cb(opaque, 0);
|
1166 |
} |
1167 |
|
1168 |
static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb) |
1169 |
{ |
1170 |
if (acb->bh)
|
1171 |
return -EIO;
|
1172 |
|
1173 |
acb->bh = qemu_bh_new(cb, acb); |
1174 |
if (!acb->bh)
|
1175 |
return -EIO;
|
1176 |
|
1177 |
qemu_bh_schedule(acb->bh); |
1178 |
|
1179 |
return 0; |
1180 |
} |
1181 |
|
1182 |
static void qcow_aio_read_cb(void *opaque, int ret) |
1183 |
{ |
1184 |
QCowAIOCB *acb = opaque; |
1185 |
BlockDriverState *bs = acb->common.bs; |
1186 |
BDRVQcowState *s = bs->opaque; |
1187 |
int index_in_cluster, n1;
|
1188 |
|
1189 |
acb->hd_aiocb = NULL;
|
1190 |
if (ret < 0) |
1191 |
goto done;
|
1192 |
|
1193 |
/* post process the read buffer */
|
1194 |
if (!acb->cluster_offset) {
|
1195 |
/* nothing to do */
|
1196 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1197 |
/* nothing to do */
|
1198 |
} else {
|
1199 |
if (s->crypt_method) {
|
1200 |
encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, |
1201 |
acb->n, 0,
|
1202 |
&s->aes_decrypt_key); |
1203 |
} |
1204 |
} |
1205 |
|
1206 |
acb->nb_sectors -= acb->n; |
1207 |
acb->sector_num += acb->n; |
1208 |
acb->buf += acb->n * 512;
|
1209 |
|
1210 |
if (acb->nb_sectors == 0) { |
1211 |
/* request completed */
|
1212 |
ret = 0;
|
1213 |
goto done;
|
1214 |
} |
1215 |
|
1216 |
/* prepare next AIO request */
|
1217 |
acb->n = acb->nb_sectors; |
1218 |
acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, &acb->n);
|
1219 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
1220 |
|
1221 |
if (!acb->cluster_offset) {
|
1222 |
if (bs->backing_hd) {
|
1223 |
/* read from the base image */
|
1224 |
n1 = backing_read1(bs->backing_hd, acb->sector_num, |
1225 |
acb->buf, acb->n); |
1226 |
if (n1 > 0) { |
1227 |
acb->hd_iov.iov_base = (void *)acb->buf;
|
1228 |
acb->hd_iov.iov_len = acb->n * 512;
|
1229 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
1230 |
acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num, |
1231 |
&acb->hd_qiov, acb->n, |
1232 |
qcow_aio_read_cb, acb); |
1233 |
if (acb->hd_aiocb == NULL) |
1234 |
goto done;
|
1235 |
} else {
|
1236 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
1237 |
if (ret < 0) |
1238 |
goto done;
|
1239 |
} |
1240 |
} else {
|
1241 |
/* Note: in this case, no need to wait */
|
1242 |
memset(acb->buf, 0, 512 * acb->n); |
1243 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
1244 |
if (ret < 0) |
1245 |
goto done;
|
1246 |
} |
1247 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1248 |
/* add AIO support for compressed blocks ? */
|
1249 |
if (decompress_cluster(s, acb->cluster_offset) < 0) |
1250 |
goto done;
|
1251 |
memcpy(acb->buf, |
1252 |
s->cluster_cache + index_in_cluster * 512, 512 * acb->n); |
1253 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
1254 |
if (ret < 0) |
1255 |
goto done;
|
1256 |
} else {
|
1257 |
if ((acb->cluster_offset & 511) != 0) { |
1258 |
ret = -EIO; |
1259 |
goto done;
|
1260 |
} |
1261 |
|
1262 |
acb->hd_iov.iov_base = (void *)acb->buf;
|
1263 |
acb->hd_iov.iov_len = acb->n * 512;
|
1264 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
1265 |
acb->hd_aiocb = bdrv_aio_readv(s->hd, |
1266 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
1267 |
&acb->hd_qiov, acb->n, qcow_aio_read_cb, acb); |
1268 |
if (acb->hd_aiocb == NULL) |
1269 |
goto done;
|
1270 |
} |
1271 |
|
1272 |
return;
|
1273 |
done:
|
1274 |
if (acb->qiov->niov > 1) { |
1275 |
qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size); |
1276 |
qemu_vfree(acb->orig_buf); |
1277 |
} |
1278 |
acb->common.cb(acb->common.opaque, ret); |
1279 |
qemu_aio_release(acb); |
1280 |
} |
1281 |
|
1282 |
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
|
1283 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
1284 |
BlockDriverCompletionFunc *cb, void *opaque, int is_write) |
1285 |
{ |
1286 |
QCowAIOCB *acb; |
1287 |
|
1288 |
acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque); |
1289 |
if (!acb)
|
1290 |
return NULL; |
1291 |
acb->hd_aiocb = NULL;
|
1292 |
acb->sector_num = sector_num; |
1293 |
acb->qiov = qiov; |
1294 |
if (qiov->niov > 1) { |
1295 |
acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size); |
1296 |
if (is_write)
|
1297 |
qemu_iovec_to_buffer(qiov, acb->buf); |
1298 |
} else {
|
1299 |
acb->buf = (uint8_t *)qiov->iov->iov_base; |
1300 |
} |
1301 |
acb->nb_sectors = nb_sectors; |
1302 |
acb->n = 0;
|
1303 |
acb->cluster_offset = 0;
|
1304 |
acb->l2meta.nb_clusters = 0;
|
1305 |
return acb;
|
1306 |
} |
1307 |
|
1308 |
static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
|
1309 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
1310 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1311 |
{ |
1312 |
QCowAIOCB *acb; |
1313 |
|
1314 |
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
|
1315 |
if (!acb)
|
1316 |
return NULL; |
1317 |
|
1318 |
qcow_aio_read_cb(acb, 0);
|
1319 |
return &acb->common;
|
1320 |
} |
1321 |
|
1322 |
static void qcow_aio_write_cb(void *opaque, int ret) |
1323 |
{ |
1324 |
QCowAIOCB *acb = opaque; |
1325 |
BlockDriverState *bs = acb->common.bs; |
1326 |
BDRVQcowState *s = bs->opaque; |
1327 |
int index_in_cluster;
|
1328 |
const uint8_t *src_buf;
|
1329 |
int n_end;
|
1330 |
|
1331 |
acb->hd_aiocb = NULL;
|
1332 |
|
1333 |
if (ret < 0) |
1334 |
goto done;
|
1335 |
|
1336 |
if (alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta) < 0) { |
1337 |
free_any_clusters(bs, acb->cluster_offset, acb->l2meta.nb_clusters); |
1338 |
goto done;
|
1339 |
} |
1340 |
|
1341 |
acb->nb_sectors -= acb->n; |
1342 |
acb->sector_num += acb->n; |
1343 |
acb->buf += acb->n * 512;
|
1344 |
|
1345 |
if (acb->nb_sectors == 0) { |
1346 |
/* request completed */
|
1347 |
ret = 0;
|
1348 |
goto done;
|
1349 |
} |
1350 |
|
1351 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
1352 |
n_end = index_in_cluster + acb->nb_sectors; |
1353 |
if (s->crypt_method &&
|
1354 |
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) |
1355 |
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
1356 |
|
1357 |
acb->cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9,
|
1358 |
index_in_cluster, |
1359 |
n_end, &acb->n, &acb->l2meta); |
1360 |
if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) { |
1361 |
ret = -EIO; |
1362 |
goto done;
|
1363 |
} |
1364 |
if (s->crypt_method) {
|
1365 |
if (!acb->cluster_data) {
|
1366 |
acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * |
1367 |
s->cluster_size); |
1368 |
} |
1369 |
encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, |
1370 |
acb->n, 1, &s->aes_encrypt_key);
|
1371 |
src_buf = acb->cluster_data; |
1372 |
} else {
|
1373 |
src_buf = acb->buf; |
1374 |
} |
1375 |
acb->hd_iov.iov_base = (void *)src_buf;
|
1376 |
acb->hd_iov.iov_len = acb->n * 512;
|
1377 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
1378 |
acb->hd_aiocb = bdrv_aio_writev(s->hd, |
1379 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
1380 |
&acb->hd_qiov, acb->n, |
1381 |
qcow_aio_write_cb, acb); |
1382 |
if (acb->hd_aiocb == NULL) |
1383 |
goto done;
|
1384 |
|
1385 |
return;
|
1386 |
|
1387 |
done:
|
1388 |
if (acb->qiov->niov > 1) |
1389 |
qemu_vfree(acb->orig_buf); |
1390 |
acb->common.cb(acb->common.opaque, ret); |
1391 |
qemu_aio_release(acb); |
1392 |
} |
1393 |
|
1394 |
static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
|
1395 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
1396 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1397 |
{ |
1398 |
BDRVQcowState *s = bs->opaque; |
1399 |
QCowAIOCB *acb; |
1400 |
|
1401 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
1402 |
|
1403 |
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
|
1404 |
if (!acb)
|
1405 |
return NULL; |
1406 |
|
1407 |
qcow_aio_write_cb(acb, 0);
|
1408 |
return &acb->common;
|
1409 |
} |
1410 |
|
1411 |
static void qcow_close(BlockDriverState *bs) |
1412 |
{ |
1413 |
BDRVQcowState *s = bs->opaque; |
1414 |
qemu_free(s->l1_table); |
1415 |
qemu_free(s->l2_cache); |
1416 |
qemu_free(s->cluster_cache); |
1417 |
qemu_free(s->cluster_data); |
1418 |
refcount_close(bs); |
1419 |
bdrv_delete(s->hd); |
1420 |
} |
1421 |
|
1422 |
static int get_bits_from_size(size_t size) |
1423 |
{ |
1424 |
int res = 0; |
1425 |
|
1426 |
if (size == 0) { |
1427 |
return -1; |
1428 |
} |
1429 |
|
1430 |
while (size != 1) { |
1431 |
/* Not a power of two */
|
1432 |
if (size & 1) { |
1433 |
return -1; |
1434 |
} |
1435 |
|
1436 |
size >>= 1;
|
1437 |
res++; |
1438 |
} |
1439 |
|
1440 |
return res;
|
1441 |
} |
1442 |
|
1443 |
static int qcow_create2(const char *filename, int64_t total_size, |
1444 |
const char *backing_file, const char *backing_format, |
1445 |
int flags, size_t cluster_size)
|
1446 |
{ |
1447 |
|
1448 |
int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
|
1449 |
int ref_clusters, backing_format_len = 0; |
1450 |
QCowHeader header; |
1451 |
uint64_t tmp, offset; |
1452 |
QCowCreateState s1, *s = &s1; |
1453 |
QCowExtension ext_bf = {0, 0}; |
1454 |
|
1455 |
|
1456 |
memset(s, 0, sizeof(*s)); |
1457 |
|
1458 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
1459 |
if (fd < 0) |
1460 |
return -1; |
1461 |
memset(&header, 0, sizeof(header)); |
1462 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
1463 |
header.version = cpu_to_be32(QCOW_VERSION); |
1464 |
header.size = cpu_to_be64(total_size * 512);
|
1465 |
header_size = sizeof(header);
|
1466 |
backing_filename_len = 0;
|
1467 |
if (backing_file) {
|
1468 |
if (backing_format) {
|
1469 |
ext_bf.magic = QCOW_EXT_MAGIC_BACKING_FORMAT; |
1470 |
backing_format_len = strlen(backing_format); |
1471 |
ext_bf.len = (backing_format_len + 7) & ~7; |
1472 |
header_size += ((sizeof(ext_bf) + ext_bf.len + 7) & ~7); |
1473 |
} |
1474 |
header.backing_file_offset = cpu_to_be64(header_size); |
1475 |
backing_filename_len = strlen(backing_file); |
1476 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
1477 |
header_size += backing_filename_len; |
1478 |
} |
1479 |
|
1480 |
/* Cluster size */
|
1481 |
s->cluster_bits = get_bits_from_size(cluster_size); |
1482 |
if (s->cluster_bits < MIN_CLUSTER_BITS ||
|
1483 |
s->cluster_bits > MAX_CLUSTER_BITS) |
1484 |
{ |
1485 |
fprintf(stderr, "Cluster size must be a power of two between "
|
1486 |
"%d and %dk\n",
|
1487 |
1 << MIN_CLUSTER_BITS,
|
1488 |
1 << (MAX_CLUSTER_BITS - 10)); |
1489 |
return -EINVAL;
|
1490 |
} |
1491 |
s->cluster_size = 1 << s->cluster_bits;
|
1492 |
|
1493 |
header.cluster_bits = cpu_to_be32(s->cluster_bits); |
1494 |
header_size = (header_size + 7) & ~7; |
1495 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
1496 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
1497 |
} else {
|
1498 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
1499 |
} |
1500 |
l2_bits = s->cluster_bits - 3;
|
1501 |
shift = s->cluster_bits + l2_bits; |
1502 |
l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift); |
1503 |
offset = align_offset(header_size, s->cluster_size); |
1504 |
s->l1_table_offset = offset; |
1505 |
header.l1_table_offset = cpu_to_be64(s->l1_table_offset); |
1506 |
header.l1_size = cpu_to_be32(l1_size); |
1507 |
offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
|
1508 |
|
1509 |
s->refcount_table = qemu_mallocz(s->cluster_size); |
1510 |
|
1511 |
s->refcount_table_offset = offset; |
1512 |
header.refcount_table_offset = cpu_to_be64(offset); |
1513 |
header.refcount_table_clusters = cpu_to_be32(1);
|
1514 |
offset += s->cluster_size; |
1515 |
s->refcount_block_offset = offset; |
1516 |
|
1517 |
/* count how many refcount blocks needed */
|
1518 |
tmp = offset >> s->cluster_bits; |
1519 |
ref_clusters = (tmp >> (s->cluster_bits - REFCOUNT_SHIFT)) + 1;
|
1520 |
for (i=0; i < ref_clusters; i++) { |
1521 |
s->refcount_table[i] = cpu_to_be64(offset); |
1522 |
offset += s->cluster_size; |
1523 |
} |
1524 |
|
1525 |
s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size); |
1526 |
|
1527 |
/* update refcounts */
|
1528 |
create_refcount_update(s, 0, header_size);
|
1529 |
create_refcount_update(s, s->l1_table_offset, l1_size * sizeof(uint64_t));
|
1530 |
create_refcount_update(s, s->refcount_table_offset, s->cluster_size); |
1531 |
create_refcount_update(s, s->refcount_block_offset, ref_clusters * s->cluster_size); |
1532 |
|
1533 |
/* write all the data */
|
1534 |
write(fd, &header, sizeof(header));
|
1535 |
if (backing_file) {
|
1536 |
if (backing_format_len) {
|
1537 |
char zero[16]; |
1538 |
int d = ext_bf.len - backing_format_len;
|
1539 |
|
1540 |
memset(zero, 0, sizeof(zero)); |
1541 |
cpu_to_be32s(&ext_bf.magic); |
1542 |
cpu_to_be32s(&ext_bf.len); |
1543 |
write(fd, &ext_bf, sizeof(ext_bf));
|
1544 |
write(fd, backing_format, backing_format_len); |
1545 |
if (d>0) { |
1546 |
write(fd, zero, d); |
1547 |
} |
1548 |
} |
1549 |
write(fd, backing_file, backing_filename_len); |
1550 |
} |
1551 |
lseek(fd, s->l1_table_offset, SEEK_SET); |
1552 |
tmp = 0;
|
1553 |
for(i = 0;i < l1_size; i++) { |
1554 |
write(fd, &tmp, sizeof(tmp));
|
1555 |
} |
1556 |
lseek(fd, s->refcount_table_offset, SEEK_SET); |
1557 |
write(fd, s->refcount_table, s->cluster_size); |
1558 |
|
1559 |
lseek(fd, s->refcount_block_offset, SEEK_SET); |
1560 |
write(fd, s->refcount_block, ref_clusters * s->cluster_size); |
1561 |
|
1562 |
qemu_free(s->refcount_table); |
1563 |
qemu_free(s->refcount_block); |
1564 |
close(fd); |
1565 |
return 0; |
1566 |
} |
1567 |
|
1568 |
static int qcow_create(const char *filename, QEMUOptionParameter *options) |
1569 |
{ |
1570 |
const char *backing_file = NULL; |
1571 |
const char *backing_fmt = NULL; |
1572 |
uint64_t sectors = 0;
|
1573 |
int flags = 0; |
1574 |
size_t cluster_size = 65536;
|
1575 |
|
1576 |
/* Read out options */
|
1577 |
while (options && options->name) {
|
1578 |
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
1579 |
sectors = options->value.n / 512;
|
1580 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { |
1581 |
backing_file = options->value.s; |
1582 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { |
1583 |
backing_fmt = options->value.s; |
1584 |
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { |
1585 |
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
1586 |
} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { |
1587 |
if (options->value.n) {
|
1588 |
cluster_size = options->value.n; |
1589 |
} |
1590 |
} |
1591 |
options++; |
1592 |
} |
1593 |
|
1594 |
return qcow_create2(filename, sectors, backing_file, backing_fmt, flags,
|
1595 |
cluster_size); |
1596 |
} |
1597 |
|
1598 |
static int qcow_make_empty(BlockDriverState *bs) |
1599 |
{ |
1600 |
#if 0
|
1601 |
/* XXX: not correct */
|
1602 |
BDRVQcowState *s = bs->opaque;
|
1603 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
1604 |
int ret;
|
1605 |
|
1606 |
memset(s->l1_table, 0, l1_length);
|
1607 |
if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
1608 |
return -1;
|
1609 |
ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length);
|
1610 |
if (ret < 0)
|
1611 |
return ret;
|
1612 |
|
1613 |
l2_cache_reset(bs);
|
1614 |
#endif
|
1615 |
return 0; |
1616 |
} |
1617 |
|
1618 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
1619 |
tables to avoid losing bytes in alignment */
|
1620 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
1621 |
const uint8_t *buf, int nb_sectors) |
1622 |
{ |
1623 |
BDRVQcowState *s = bs->opaque; |
1624 |
z_stream strm; |
1625 |
int ret, out_len;
|
1626 |
uint8_t *out_buf; |
1627 |
uint64_t cluster_offset; |
1628 |
|
1629 |
if (nb_sectors == 0) { |
1630 |
/* align end of file to a sector boundary to ease reading with
|
1631 |
sector based I/Os */
|
1632 |
cluster_offset = bdrv_getlength(s->hd); |
1633 |
cluster_offset = (cluster_offset + 511) & ~511; |
1634 |
bdrv_truncate(s->hd, cluster_offset); |
1635 |
return 0; |
1636 |
} |
1637 |
|
1638 |
if (nb_sectors != s->cluster_sectors)
|
1639 |
return -EINVAL;
|
1640 |
|
1641 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
1642 |
|
1643 |
/* best compression, small window, no zlib header */
|
1644 |
memset(&strm, 0, sizeof(strm)); |
1645 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
1646 |
Z_DEFLATED, -12,
|
1647 |
9, Z_DEFAULT_STRATEGY);
|
1648 |
if (ret != 0) { |
1649 |
qemu_free(out_buf); |
1650 |
return -1; |
1651 |
} |
1652 |
|
1653 |
strm.avail_in = s->cluster_size; |
1654 |
strm.next_in = (uint8_t *)buf; |
1655 |
strm.avail_out = s->cluster_size; |
1656 |
strm.next_out = out_buf; |
1657 |
|
1658 |
ret = deflate(&strm, Z_FINISH); |
1659 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
1660 |
qemu_free(out_buf); |
1661 |
deflateEnd(&strm); |
1662 |
return -1; |
1663 |
} |
1664 |
out_len = strm.next_out - out_buf; |
1665 |
|
1666 |
deflateEnd(&strm); |
1667 |
|
1668 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
1669 |
/* could not compress: write normal cluster */
|
1670 |
bdrv_write(bs, sector_num, buf, s->cluster_sectors); |
1671 |
} else {
|
1672 |
cluster_offset = alloc_compressed_cluster_offset(bs, sector_num << 9,
|
1673 |
out_len); |
1674 |
if (!cluster_offset)
|
1675 |
return -1; |
1676 |
cluster_offset &= s->cluster_offset_mask; |
1677 |
if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
|
1678 |
qemu_free(out_buf); |
1679 |
return -1; |
1680 |
} |
1681 |
} |
1682 |
|
1683 |
qemu_free(out_buf); |
1684 |
return 0; |
1685 |
} |
1686 |
|
1687 |
static void qcow_flush(BlockDriverState *bs) |
1688 |
{ |
1689 |
BDRVQcowState *s = bs->opaque; |
1690 |
bdrv_flush(s->hd); |
1691 |
} |
1692 |
|
1693 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
1694 |
{ |
1695 |
BDRVQcowState *s = bs->opaque; |
1696 |
bdi->cluster_size = s->cluster_size; |
1697 |
bdi->vm_state_offset = (int64_t)s->l1_vm_state_index << |
1698 |
(s->cluster_bits + s->l2_bits); |
1699 |
return 0; |
1700 |
} |
1701 |
|
1702 |
/*********************************************************/
|
1703 |
/* snapshot support */
|
1704 |
|
1705 |
|
1706 |
static void qcow_free_snapshots(BlockDriverState *bs) |
1707 |
{ |
1708 |
BDRVQcowState *s = bs->opaque; |
1709 |
int i;
|
1710 |
|
1711 |
for(i = 0; i < s->nb_snapshots; i++) { |
1712 |
qemu_free(s->snapshots[i].name); |
1713 |
qemu_free(s->snapshots[i].id_str); |
1714 |
} |
1715 |
qemu_free(s->snapshots); |
1716 |
s->snapshots = NULL;
|
1717 |
s->nb_snapshots = 0;
|
1718 |
} |
1719 |
|
1720 |
static int qcow_read_snapshots(BlockDriverState *bs) |
1721 |
{ |
1722 |
BDRVQcowState *s = bs->opaque; |
1723 |
QCowSnapshotHeader h; |
1724 |
QCowSnapshot *sn; |
1725 |
int i, id_str_size, name_size;
|
1726 |
int64_t offset; |
1727 |
uint32_t extra_data_size; |
1728 |
|
1729 |
if (!s->nb_snapshots) {
|
1730 |
s->snapshots = NULL;
|
1731 |
s->snapshots_size = 0;
|
1732 |
return 0; |
1733 |
} |
1734 |
|
1735 |
offset = s->snapshots_offset; |
1736 |
s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot));
|
1737 |
for(i = 0; i < s->nb_snapshots; i++) { |
1738 |
offset = align_offset(offset, 8);
|
1739 |
if (bdrv_pread(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
1740 |
goto fail;
|
1741 |
offset += sizeof(h);
|
1742 |
sn = s->snapshots + i; |
1743 |
sn->l1_table_offset = be64_to_cpu(h.l1_table_offset); |
1744 |
sn->l1_size = be32_to_cpu(h.l1_size); |
1745 |
sn->vm_state_size = be32_to_cpu(h.vm_state_size); |
1746 |
sn->date_sec = be32_to_cpu(h.date_sec); |
1747 |
sn->date_nsec = be32_to_cpu(h.date_nsec); |
1748 |
sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec); |
1749 |
extra_data_size = be32_to_cpu(h.extra_data_size); |
1750 |
|
1751 |
id_str_size = be16_to_cpu(h.id_str_size); |
1752 |
name_size = be16_to_cpu(h.name_size); |
1753 |
|
1754 |
offset += extra_data_size; |
1755 |
|
1756 |
sn->id_str = qemu_malloc(id_str_size + 1);
|
1757 |
if (bdrv_pread(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
1758 |
goto fail;
|
1759 |
offset += id_str_size; |
1760 |
sn->id_str[id_str_size] = '\0';
|
1761 |
|
1762 |
sn->name = qemu_malloc(name_size + 1);
|
1763 |
if (bdrv_pread(s->hd, offset, sn->name, name_size) != name_size)
|
1764 |
goto fail;
|
1765 |
offset += name_size; |
1766 |
sn->name[name_size] = '\0';
|
1767 |
} |
1768 |
s->snapshots_size = offset - s->snapshots_offset; |
1769 |
return 0; |
1770 |
fail:
|
1771 |
qcow_free_snapshots(bs); |
1772 |
return -1; |
1773 |
} |
1774 |
|
1775 |
/* add at the end of the file a new list of snapshots */
|
1776 |
static int qcow_write_snapshots(BlockDriverState *bs) |
1777 |
{ |
1778 |
BDRVQcowState *s = bs->opaque; |
1779 |
QCowSnapshot *sn; |
1780 |
QCowSnapshotHeader h; |
1781 |
int i, name_size, id_str_size, snapshots_size;
|
1782 |
uint64_t data64; |
1783 |
uint32_t data32; |
1784 |
int64_t offset, snapshots_offset; |
1785 |
|
1786 |
/* compute the size of the snapshots */
|
1787 |
offset = 0;
|
1788 |
for(i = 0; i < s->nb_snapshots; i++) { |
1789 |
sn = s->snapshots + i; |
1790 |
offset = align_offset(offset, 8);
|
1791 |
offset += sizeof(h);
|
1792 |
offset += strlen(sn->id_str); |
1793 |
offset += strlen(sn->name); |
1794 |
} |
1795 |
snapshots_size = offset; |
1796 |
|
1797 |
snapshots_offset = alloc_clusters(bs, snapshots_size); |
1798 |
offset = snapshots_offset; |
1799 |
|
1800 |
for(i = 0; i < s->nb_snapshots; i++) { |
1801 |
sn = s->snapshots + i; |
1802 |
memset(&h, 0, sizeof(h)); |
1803 |
h.l1_table_offset = cpu_to_be64(sn->l1_table_offset); |
1804 |
h.l1_size = cpu_to_be32(sn->l1_size); |
1805 |
h.vm_state_size = cpu_to_be32(sn->vm_state_size); |
1806 |
h.date_sec = cpu_to_be32(sn->date_sec); |
1807 |
h.date_nsec = cpu_to_be32(sn->date_nsec); |
1808 |
h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec); |
1809 |
|
1810 |
id_str_size = strlen(sn->id_str); |
1811 |
name_size = strlen(sn->name); |
1812 |
h.id_str_size = cpu_to_be16(id_str_size); |
1813 |
h.name_size = cpu_to_be16(name_size); |
1814 |
offset = align_offset(offset, 8);
|
1815 |
if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
1816 |
goto fail;
|
1817 |
offset += sizeof(h);
|
1818 |
if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
1819 |
goto fail;
|
1820 |
offset += id_str_size; |
1821 |
if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size)
|
1822 |
goto fail;
|
1823 |
offset += name_size; |
1824 |
} |
1825 |
|
1826 |
/* update the various header fields */
|
1827 |
data64 = cpu_to_be64(snapshots_offset); |
1828 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset),
|
1829 |
&data64, sizeof(data64)) != sizeof(data64)) |
1830 |
goto fail;
|
1831 |
data32 = cpu_to_be32(s->nb_snapshots); |
1832 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots),
|
1833 |
&data32, sizeof(data32)) != sizeof(data32)) |
1834 |
goto fail;
|
1835 |
|
1836 |
/* free the old snapshot table */
|
1837 |
free_clusters(bs, s->snapshots_offset, s->snapshots_size); |
1838 |
s->snapshots_offset = snapshots_offset; |
1839 |
s->snapshots_size = snapshots_size; |
1840 |
return 0; |
1841 |
fail:
|
1842 |
return -1; |
1843 |
} |
1844 |
|
1845 |
static void find_new_snapshot_id(BlockDriverState *bs, |
1846 |
char *id_str, int id_str_size) |
1847 |
{ |
1848 |
BDRVQcowState *s = bs->opaque; |
1849 |
QCowSnapshot *sn; |
1850 |
int i, id, id_max = 0; |
1851 |
|
1852 |
for(i = 0; i < s->nb_snapshots; i++) { |
1853 |
sn = s->snapshots + i; |
1854 |
id = strtoul(sn->id_str, NULL, 10); |
1855 |
if (id > id_max)
|
1856 |
id_max = id; |
1857 |
} |
1858 |
snprintf(id_str, id_str_size, "%d", id_max + 1); |
1859 |
} |
1860 |
|
1861 |
static int find_snapshot_by_id(BlockDriverState *bs, const char *id_str) |
1862 |
{ |
1863 |
BDRVQcowState *s = bs->opaque; |
1864 |
int i;
|
1865 |
|
1866 |
for(i = 0; i < s->nb_snapshots; i++) { |
1867 |
if (!strcmp(s->snapshots[i].id_str, id_str))
|
1868 |
return i;
|
1869 |
} |
1870 |
return -1; |
1871 |
} |
1872 |
|
1873 |
static int find_snapshot_by_id_or_name(BlockDriverState *bs, const char *name) |
1874 |
{ |
1875 |
BDRVQcowState *s = bs->opaque; |
1876 |
int i, ret;
|
1877 |
|
1878 |
ret = find_snapshot_by_id(bs, name); |
1879 |
if (ret >= 0) |
1880 |
return ret;
|
1881 |
for(i = 0; i < s->nb_snapshots; i++) { |
1882 |
if (!strcmp(s->snapshots[i].name, name))
|
1883 |
return i;
|
1884 |
} |
1885 |
return -1; |
1886 |
} |
1887 |
|
1888 |
/* if no id is provided, a new one is constructed */
|
1889 |
static int qcow_snapshot_create(BlockDriverState *bs, |
1890 |
QEMUSnapshotInfo *sn_info) |
1891 |
{ |
1892 |
BDRVQcowState *s = bs->opaque; |
1893 |
QCowSnapshot *snapshots1, sn1, *sn = &sn1; |
1894 |
int i, ret;
|
1895 |
uint64_t *l1_table = NULL;
|
1896 |
|
1897 |
memset(sn, 0, sizeof(*sn)); |
1898 |
|
1899 |
if (sn_info->id_str[0] == '\0') { |
1900 |
/* compute a new id */
|
1901 |
find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
|
1902 |
} |
1903 |
|
1904 |
/* check that the ID is unique */
|
1905 |
if (find_snapshot_by_id(bs, sn_info->id_str) >= 0) |
1906 |
return -ENOENT;
|
1907 |
|
1908 |
sn->id_str = qemu_strdup(sn_info->id_str); |
1909 |
if (!sn->id_str)
|
1910 |
goto fail;
|
1911 |
sn->name = qemu_strdup(sn_info->name); |
1912 |
if (!sn->name)
|
1913 |
goto fail;
|
1914 |
sn->vm_state_size = sn_info->vm_state_size; |
1915 |
sn->date_sec = sn_info->date_sec; |
1916 |
sn->date_nsec = sn_info->date_nsec; |
1917 |
sn->vm_clock_nsec = sn_info->vm_clock_nsec; |
1918 |
|
1919 |
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
|
1920 |
if (ret < 0) |
1921 |
goto fail;
|
1922 |
|
1923 |
/* create the L1 table of the snapshot */
|
1924 |
sn->l1_table_offset = alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
|
1925 |
sn->l1_size = s->l1_size; |
1926 |
|
1927 |
l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
|
1928 |
for(i = 0; i < s->l1_size; i++) { |
1929 |
l1_table[i] = cpu_to_be64(s->l1_table[i]); |
1930 |
} |
1931 |
if (bdrv_pwrite(s->hd, sn->l1_table_offset,
|
1932 |
l1_table, s->l1_size * sizeof(uint64_t)) !=
|
1933 |
(s->l1_size * sizeof(uint64_t)))
|
1934 |
goto fail;
|
1935 |
qemu_free(l1_table); |
1936 |
l1_table = NULL;
|
1937 |
|
1938 |
snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot)); |
1939 |
if (s->snapshots) {
|
1940 |
memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot));
|
1941 |
qemu_free(s->snapshots); |
1942 |
} |
1943 |
s->snapshots = snapshots1; |
1944 |
s->snapshots[s->nb_snapshots++] = *sn; |
1945 |
|
1946 |
if (qcow_write_snapshots(bs) < 0) |
1947 |
goto fail;
|
1948 |
#ifdef DEBUG_ALLOC
|
1949 |
check_refcounts(bs); |
1950 |
#endif
|
1951 |
return 0; |
1952 |
fail:
|
1953 |
qemu_free(sn->name); |
1954 |
qemu_free(l1_table); |
1955 |
return -1; |
1956 |
} |
1957 |
|
1958 |
/* copy the snapshot 'snapshot_name' into the current disk image */
|
1959 |
static int qcow_snapshot_goto(BlockDriverState *bs, |
1960 |
const char *snapshot_id) |
1961 |
{ |
1962 |
BDRVQcowState *s = bs->opaque; |
1963 |
QCowSnapshot *sn; |
1964 |
int i, snapshot_index, l1_size2;
|
1965 |
|
1966 |
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
1967 |
if (snapshot_index < 0) |
1968 |
return -ENOENT;
|
1969 |
sn = &s->snapshots[snapshot_index]; |
1970 |
|
1971 |
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1) < 0) |
1972 |
goto fail;
|
1973 |
|
1974 |
if (grow_l1_table(bs, sn->l1_size) < 0) |
1975 |
goto fail;
|
1976 |
|
1977 |
s->l1_size = sn->l1_size; |
1978 |
l1_size2 = s->l1_size * sizeof(uint64_t);
|
1979 |
/* copy the snapshot l1 table to the current l1 table */
|
1980 |
if (bdrv_pread(s->hd, sn->l1_table_offset,
|
1981 |
s->l1_table, l1_size2) != l1_size2) |
1982 |
goto fail;
|
1983 |
if (bdrv_pwrite(s->hd, s->l1_table_offset,
|
1984 |
s->l1_table, l1_size2) != l1_size2) |
1985 |
goto fail;
|
1986 |
for(i = 0;i < s->l1_size; i++) { |
1987 |
be64_to_cpus(&s->l1_table[i]); |
1988 |
} |
1989 |
|
1990 |
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1) < 0) |
1991 |
goto fail;
|
1992 |
|
1993 |
#ifdef DEBUG_ALLOC
|
1994 |
check_refcounts(bs); |
1995 |
#endif
|
1996 |
return 0; |
1997 |
fail:
|
1998 |
return -EIO;
|
1999 |
} |
2000 |
|
2001 |
static int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) |
2002 |
{ |
2003 |
BDRVQcowState *s = bs->opaque; |
2004 |
QCowSnapshot *sn; |
2005 |
int snapshot_index, ret;
|
2006 |
|
2007 |
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
2008 |
if (snapshot_index < 0) |
2009 |
return -ENOENT;
|
2010 |
sn = &s->snapshots[snapshot_index]; |
2011 |
|
2012 |
ret = update_snapshot_refcount(bs, sn->l1_table_offset, sn->l1_size, -1);
|
2013 |
if (ret < 0) |
2014 |
return ret;
|
2015 |
/* must update the copied flag on the current cluster offsets */
|
2016 |
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0);
|
2017 |
if (ret < 0) |
2018 |
return ret;
|
2019 |
free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t));
|
2020 |
|
2021 |
qemu_free(sn->id_str); |
2022 |
qemu_free(sn->name); |
2023 |
memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn)); |
2024 |
s->nb_snapshots--; |
2025 |
ret = qcow_write_snapshots(bs); |
2026 |
if (ret < 0) { |
2027 |
/* XXX: restore snapshot if error ? */
|
2028 |
return ret;
|
2029 |
} |
2030 |
#ifdef DEBUG_ALLOC
|
2031 |
check_refcounts(bs); |
2032 |
#endif
|
2033 |
return 0; |
2034 |
} |
2035 |
|
2036 |
static int qcow_snapshot_list(BlockDriverState *bs, |
2037 |
QEMUSnapshotInfo **psn_tab) |
2038 |
{ |
2039 |
BDRVQcowState *s = bs->opaque; |
2040 |
QEMUSnapshotInfo *sn_tab, *sn_info; |
2041 |
QCowSnapshot *sn; |
2042 |
int i;
|
2043 |
|
2044 |
if (!s->nb_snapshots) {
|
2045 |
*psn_tab = NULL;
|
2046 |
return s->nb_snapshots;
|
2047 |
} |
2048 |
|
2049 |
sn_tab = qemu_mallocz(s->nb_snapshots * sizeof(QEMUSnapshotInfo));
|
2050 |
for(i = 0; i < s->nb_snapshots; i++) { |
2051 |
sn_info = sn_tab + i; |
2052 |
sn = s->snapshots + i; |
2053 |
pstrcpy(sn_info->id_str, sizeof(sn_info->id_str),
|
2054 |
sn->id_str); |
2055 |
pstrcpy(sn_info->name, sizeof(sn_info->name),
|
2056 |
sn->name); |
2057 |
sn_info->vm_state_size = sn->vm_state_size; |
2058 |
sn_info->date_sec = sn->date_sec; |
2059 |
sn_info->date_nsec = sn->date_nsec; |
2060 |
sn_info->vm_clock_nsec = sn->vm_clock_nsec; |
2061 |
} |
2062 |
*psn_tab = sn_tab; |
2063 |
return s->nb_snapshots;
|
2064 |
} |
2065 |
|
2066 |
static int qcow_check(BlockDriverState *bs) |
2067 |
{ |
2068 |
return check_refcounts(bs);
|
2069 |
} |
2070 |
|
2071 |
#if 0
|
2072 |
static void dump_refcounts(BlockDriverState *bs)
|
2073 |
{
|
2074 |
BDRVQcowState *s = bs->opaque;
|
2075 |
int64_t nb_clusters, k, k1, size;
|
2076 |
int refcount;
|
2077 |
|
2078 |
size = bdrv_getlength(s->hd);
|
2079 |
nb_clusters = size_to_clusters(s, size);
|
2080 |
for(k = 0; k < nb_clusters;) {
|
2081 |
k1 = k;
|
2082 |
refcount = get_refcount(bs, k);
|
2083 |
k++;
|
2084 |
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
2085 |
k++;
|
2086 |
printf("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1);
|
2087 |
}
|
2088 |
}
|
2089 |
#endif
|
2090 |
|
2091 |
static int qcow_put_buffer(BlockDriverState *bs, const uint8_t *buf, |
2092 |
int64_t pos, int size)
|
2093 |
{ |
2094 |
int growable = bs->growable;
|
2095 |
|
2096 |
bs->growable = 1;
|
2097 |
bdrv_pwrite(bs, pos, buf, size); |
2098 |
bs->growable = growable; |
2099 |
|
2100 |
return size;
|
2101 |
} |
2102 |
|
2103 |
static int qcow_get_buffer(BlockDriverState *bs, uint8_t *buf, |
2104 |
int64_t pos, int size)
|
2105 |
{ |
2106 |
int growable = bs->growable;
|
2107 |
int ret;
|
2108 |
|
2109 |
bs->growable = 1;
|
2110 |
ret = bdrv_pread(bs, pos, buf, size); |
2111 |
bs->growable = growable; |
2112 |
|
2113 |
return ret;
|
2114 |
} |
2115 |
|
2116 |
static QEMUOptionParameter qcow_create_options[] = {
|
2117 |
{ |
2118 |
.name = BLOCK_OPT_SIZE, |
2119 |
.type = OPT_SIZE, |
2120 |
.help = "Virtual disk size"
|
2121 |
}, |
2122 |
{ |
2123 |
.name = BLOCK_OPT_BACKING_FILE, |
2124 |
.type = OPT_STRING, |
2125 |
.help = "File name of a base image"
|
2126 |
}, |
2127 |
{ |
2128 |
.name = BLOCK_OPT_BACKING_FMT, |
2129 |
.type = OPT_STRING, |
2130 |
.help = "Image format of the base image"
|
2131 |
}, |
2132 |
{ |
2133 |
.name = BLOCK_OPT_ENCRYPT, |
2134 |
.type = OPT_FLAG, |
2135 |
.help = "Encrypt the image"
|
2136 |
}, |
2137 |
{ |
2138 |
.name = BLOCK_OPT_CLUSTER_SIZE, |
2139 |
.type = OPT_SIZE, |
2140 |
.help = "qcow2 cluster size"
|
2141 |
}, |
2142 |
{ NULL }
|
2143 |
}; |
2144 |
|
2145 |
static BlockDriver bdrv_qcow2 = {
|
2146 |
.format_name = "qcow2",
|
2147 |
.instance_size = sizeof(BDRVQcowState),
|
2148 |
.bdrv_probe = qcow_probe, |
2149 |
.bdrv_open = qcow_open, |
2150 |
.bdrv_close = qcow_close, |
2151 |
.bdrv_create = qcow_create, |
2152 |
.bdrv_flush = qcow_flush, |
2153 |
.bdrv_is_allocated = qcow_is_allocated, |
2154 |
.bdrv_set_key = qcow_set_key, |
2155 |
.bdrv_make_empty = qcow_make_empty, |
2156 |
|
2157 |
.bdrv_aio_readv = qcow_aio_readv, |
2158 |
.bdrv_aio_writev = qcow_aio_writev, |
2159 |
.bdrv_write_compressed = qcow_write_compressed, |
2160 |
|
2161 |
.bdrv_snapshot_create = qcow_snapshot_create, |
2162 |
.bdrv_snapshot_goto = qcow_snapshot_goto, |
2163 |
.bdrv_snapshot_delete = qcow_snapshot_delete, |
2164 |
.bdrv_snapshot_list = qcow_snapshot_list, |
2165 |
.bdrv_get_info = qcow_get_info, |
2166 |
|
2167 |
.bdrv_put_buffer = qcow_put_buffer, |
2168 |
.bdrv_get_buffer = qcow_get_buffer, |
2169 |
|
2170 |
.create_options = qcow_create_options, |
2171 |
.bdrv_check = qcow_check, |
2172 |
}; |
2173 |
|
2174 |
static void bdrv_qcow2_init(void) |
2175 |
{ |
2176 |
bdrv_register(&bdrv_qcow2); |
2177 |
} |
2178 |
|
2179 |
block_init(bdrv_qcow2_init); |