2674 lines
82 KiB
C
2674 lines
82 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_int.h"
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#include <zlib.h>
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#include "aes.h"
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#include <assert.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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//#define DEBUG_ALLOC
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//#define DEBUG_ALLOC2
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#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
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#define QCOW_VERSION 2
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#define QCOW_CRYPT_NONE 0
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#define QCOW_CRYPT_AES 1
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#define QCOW_MAX_CRYPT_CLUSTERS 32
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/* indicate that the refcount of the referenced cluster is exactly one. */
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#define QCOW_OFLAG_COPIED (1LL << 63)
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/* indicate that the cluster is compressed (they never have the copied flag) */
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#define QCOW_OFLAG_COMPRESSED (1LL << 62)
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#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */
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typedef struct QCowHeader {
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uint32_t magic;
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uint32_t version;
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uint64_t backing_file_offset;
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uint32_t backing_file_size;
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uint32_t cluster_bits;
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uint64_t size; /* in bytes */
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uint32_t crypt_method;
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uint32_t l1_size; /* XXX: save number of clusters instead ? */
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uint64_t l1_table_offset;
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uint64_t refcount_table_offset;
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uint32_t refcount_table_clusters;
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uint32_t nb_snapshots;
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uint64_t snapshots_offset;
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} QCowHeader;
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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;
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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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uint32_t date_sec;
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uint32_t date_nsec;
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uint64_t vm_clock_nsec;
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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;
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#define L2_CACHE_SIZE 16
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typedef struct QCowSnapshot {
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uint64_t l1_table_offset;
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uint32_t l1_size;
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char *id_str;
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char *name;
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uint32_t vm_state_size;
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uint32_t date_sec;
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uint32_t date_nsec;
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uint64_t vm_clock_nsec;
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} QCowSnapshot;
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typedef struct BDRVQcowState {
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BlockDriverState *hd;
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int cluster_bits;
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int cluster_size;
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int cluster_sectors;
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int l2_bits;
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int l2_size;
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int l1_size;
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int l1_vm_state_index;
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int csize_shift;
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int csize_mask;
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uint64_t cluster_offset_mask;
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uint64_t l1_table_offset;
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uint64_t *l1_table;
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uint64_t *l2_cache;
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uint64_t l2_cache_offsets[L2_CACHE_SIZE];
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uint32_t l2_cache_counts[L2_CACHE_SIZE];
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uint8_t *cluster_cache;
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uint8_t *cluster_data;
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uint64_t cluster_cache_offset;
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uint64_t *refcount_table;
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uint64_t refcount_table_offset;
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uint32_t refcount_table_size;
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uint64_t refcount_block_cache_offset;
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uint16_t *refcount_block_cache;
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int64_t free_cluster_index;
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int64_t free_byte_offset;
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uint32_t crypt_method; /* current crypt method, 0 if no key yet */
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uint32_t crypt_method_header;
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AES_KEY aes_encrypt_key;
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AES_KEY aes_decrypt_key;
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int64_t highest_alloc; /* highest cluester allocated (in clusters) */
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int64_t nc_free; /* num of free clusters below highest_alloc */
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uint64_t snapshots_offset;
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int snapshots_size;
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int nb_snapshots;
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QCowSnapshot *snapshots;
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} BDRVQcowState;
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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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static int refcount_init(BlockDriverState *bs);
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static void refcount_close(BlockDriverState *bs);
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static int get_refcount(BlockDriverState *bs, int64_t cluster_index);
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static int update_cluster_refcount(BlockDriverState *bs,
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int64_t cluster_index,
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int addend);
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static void update_refcount(BlockDriverState *bs,
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int64_t offset, int64_t length,
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int addend);
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static int64_t alloc_clusters(BlockDriverState *bs, int64_t size);
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static int64_t alloc_bytes(BlockDriverState *bs, int size);
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static void free_clusters(BlockDriverState *bs,
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int64_t offset, int64_t size);
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#ifdef DEBUG_ALLOC
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static void check_refcounts(BlockDriverState *bs);
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#endif
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static void scan_refcount(BlockDriverState *bs, int64_t *high, int64_t *free);
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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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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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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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/* 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);
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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);
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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);
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be32_to_cpus(&header.nb_snapshots);
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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 < 9 ||
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header.cluster_bits > 16)
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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;
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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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s->snapshots_offset = header.snapshots_offset;
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s->nb_snapshots = header.nb_snapshots;
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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;
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/* 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;
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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)) !=
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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]);
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}
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/* 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);
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/* one more sector for decompressed data alignment */
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s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size
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+ 512);
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s->cluster_cache_offset = -1;
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if (refcount_init(bs) < 0)
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goto fail;
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scan_refcount(bs, &s->highest_alloc, &s->nc_free);
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/* read the backing file name */
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if (header.backing_file_offset != 0) {
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len = header.backing_file_size;
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if (len > 1023)
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len = 1023;
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if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len)
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goto fail;
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bs->backing_file[len] = '\0';
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}
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if (qcow_read_snapshots(bs) < 0)
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goto fail;
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#ifdef DEBUG_ALLOC
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check_refcounts(bs);
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#endif
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return 0;
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fail:
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qcow_free_snapshots(bs);
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refcount_close(bs);
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qemu_free(s->l1_table);
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qemu_free(s->l2_cache);
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qemu_free(s->cluster_cache);
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qemu_free(s->cluster_data);
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bdrv_delete(s->hd);
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return -1;
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}
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static int qcow_set_key(BlockDriverState *bs, const char *key)
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{
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BDRVQcowState *s = bs->opaque;
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uint8_t keybuf[16];
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int len, i;
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memset(keybuf, 0, 16);
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len = strlen(key);
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if (len > 16)
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len = 16;
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/* XXX: we could compress the chars to 7 bits to increase
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entropy */
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for(i = 0;i < len;i++) {
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keybuf[i] = key[i];
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}
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s->crypt_method = s->crypt_method_header;
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|
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if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
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return -1;
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if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0)
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return -1;
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#if 0
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/* test */
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{
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uint8_t in[16];
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uint8_t out[16];
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uint8_t tmp[16];
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for(i=0;i<16;i++)
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in[i] = i;
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AES_encrypt(in, tmp, &s->aes_encrypt_key);
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AES_decrypt(tmp, out, &s->aes_decrypt_key);
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for(i = 0; i < 16; i++)
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printf(" %02x", tmp[i]);
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printf("\n");
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for(i = 0; i < 16; i++)
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printf(" %02x", out[i]);
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printf("\n");
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}
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#endif
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return 0;
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}
|
|
|
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/* The crypt function is compatible with the linux cryptoloop
|
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algorithm for < 4 GB images. NOTE: out_buf == in_buf is
|
|
supported */
|
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static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
|
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uint8_t *out_buf, const uint8_t *in_buf,
|
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int nb_sectors, int enc,
|
|
const AES_KEY *key)
|
|
{
|
|
union {
|
|
uint64_t ll[2];
|
|
uint8_t b[16];
|
|
} ivec;
|
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int i;
|
|
|
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for(i = 0; i < nb_sectors; i++) {
|
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ivec.ll[0] = cpu_to_le64(sector_num);
|
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ivec.ll[1] = 0;
|
|
AES_cbc_encrypt(in_buf, out_buf, 512, key,
|
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ivec.b, enc);
|
|
sector_num++;
|
|
in_buf += 512;
|
|
out_buf += 512;
|
|
}
|
|
}
|
|
|
|
static int copy_sectors(BlockDriverState *bs, uint64_t start_sect,
|
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uint64_t cluster_offset, int n_start, int n_end)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int n, ret;
|
|
|
|
n = n_end - n_start;
|
|
if (n <= 0)
|
|
return 0;
|
|
ret = qcow_read(bs, start_sect + n_start, s->cluster_data, n);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (s->crypt_method) {
|
|
encrypt_sectors(s, start_sect + n_start,
|
|
s->cluster_data,
|
|
s->cluster_data, n, 1,
|
|
&s->aes_encrypt_key);
|
|
}
|
|
ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start,
|
|
s->cluster_data, n);
|
|
if (ret < 0)
|
|
return ret;
|
|
return 0;
|
|
}
|
|
|
|
static void l2_cache_reset(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
|
|
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
|
|
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
|
|
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
|
|
}
|
|
|
|
static inline int l2_cache_new_entry(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
uint32_t min_count;
|
|
int min_index, i;
|
|
|
|
/* find a new entry in the least used one */
|
|
min_index = 0;
|
|
min_count = 0xffffffff;
|
|
for(i = 0; i < L2_CACHE_SIZE; i++) {
|
|
if (s->l2_cache_counts[i] < min_count) {
|
|
min_count = s->l2_cache_counts[i];
|
|
min_index = i;
|
|
}
|
|
}
|
|
return min_index;
|
|
}
|
|
|
|
static int64_t align_offset(int64_t offset, int n)
|
|
{
|
|
offset = (offset + n - 1) & ~(n - 1);
|
|
return offset;
|
|
}
|
|
|
|
static int grow_l1_table(BlockDriverState *bs, int min_size)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int new_l1_size, new_l1_size2, ret, i;
|
|
uint64_t *new_l1_table;
|
|
uint64_t new_l1_table_offset;
|
|
uint8_t data[12];
|
|
|
|
new_l1_size = s->l1_size;
|
|
if (min_size <= new_l1_size)
|
|
return 0;
|
|
while (min_size > new_l1_size) {
|
|
new_l1_size = (new_l1_size * 3 + 1) / 2;
|
|
}
|
|
#ifdef DEBUG_ALLOC2
|
|
printf("grow l1_table from %d to %d\n", s->l1_size, new_l1_size);
|
|
#endif
|
|
|
|
new_l1_size2 = sizeof(uint64_t) * new_l1_size;
|
|
new_l1_table = qemu_mallocz(new_l1_size2);
|
|
memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
|
|
|
|
/* write new table (align to cluster) */
|
|
new_l1_table_offset = alloc_clusters(bs, new_l1_size2);
|
|
|
|
for(i = 0; i < s->l1_size; i++)
|
|
new_l1_table[i] = cpu_to_be64(new_l1_table[i]);
|
|
ret = bdrv_pwrite(s->hd, new_l1_table_offset, new_l1_table, new_l1_size2);
|
|
if (ret != new_l1_size2)
|
|
goto fail;
|
|
for(i = 0; i < s->l1_size; i++)
|
|
new_l1_table[i] = be64_to_cpu(new_l1_table[i]);
|
|
|
|
/* set new table */
|
|
cpu_to_be32w((uint32_t*)data, new_l1_size);
|
|
cpu_to_be64w((uint64_t*)(data + 4), new_l1_table_offset);
|
|
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_size), data,
|
|
sizeof(data)) != sizeof(data))
|
|
goto fail;
|
|
qemu_free(s->l1_table);
|
|
free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t));
|
|
s->l1_table_offset = new_l1_table_offset;
|
|
s->l1_table = new_l1_table;
|
|
s->l1_size = new_l1_size;
|
|
return 0;
|
|
fail:
|
|
qemu_free(s->l1_table);
|
|
return -EIO;
|
|
}
|
|
|
|
/*
|
|
* seek_l2_table
|
|
*
|
|
* seek l2_offset in the l2_cache table
|
|
* if not found, return NULL,
|
|
* if found,
|
|
* increments the l2 cache hit count of the entry,
|
|
* if counter overflow, divide by two all counters
|
|
* return the pointer to the l2 cache entry
|
|
*
|
|
*/
|
|
|
|
static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset)
|
|
{
|
|
int i, j;
|
|
|
|
for(i = 0; i < L2_CACHE_SIZE; i++) {
|
|
if (l2_offset == s->l2_cache_offsets[i]) {
|
|
/* increment the hit count */
|
|
if (++s->l2_cache_counts[i] == 0xffffffff) {
|
|
for(j = 0; j < L2_CACHE_SIZE; j++) {
|
|
s->l2_cache_counts[j] >>= 1;
|
|
}
|
|
}
|
|
return s->l2_cache + (i << s->l2_bits);
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* l2_load
|
|
*
|
|
* Loads a L2 table into memory. If the table is in the cache, the cache
|
|
* is used; otherwise the L2 table is loaded from the image file.
|
|
*
|
|
* Returns a pointer to the L2 table on success, or NULL if the read from
|
|
* the image file failed.
|
|
*/
|
|
|
|
static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int min_index;
|
|
uint64_t *l2_table;
|
|
|
|
/* seek if the table for the given offset is in the cache */
|
|
|
|
l2_table = seek_l2_table(s, l2_offset);
|
|
if (l2_table != NULL)
|
|
return l2_table;
|
|
|
|
/* not found: load a new entry in the least used one */
|
|
|
|
min_index = l2_cache_new_entry(bs);
|
|
l2_table = s->l2_cache + (min_index << s->l2_bits);
|
|
if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) !=
|
|
s->l2_size * sizeof(uint64_t))
|
|
return NULL;
|
|
s->l2_cache_offsets[min_index] = l2_offset;
|
|
s->l2_cache_counts[min_index] = 1;
|
|
|
|
return l2_table;
|
|
}
|
|
|
|
/*
|
|
* l2_allocate
|
|
*
|
|
* Allocate a new l2 entry in the file. If l1_index points to an already
|
|
* used entry in the L2 table (i.e. we are doing a copy on write for the L2
|
|
* table) copy the contents of the old L2 table into the newly allocated one.
|
|
* Otherwise the new table is initialized with zeros.
|
|
*
|
|
*/
|
|
|
|
static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int min_index;
|
|
uint64_t old_l2_offset, tmp;
|
|
uint64_t *l2_table, l2_offset;
|
|
|
|
old_l2_offset = s->l1_table[l1_index];
|
|
|
|
/* allocate a new l2 entry */
|
|
|
|
l2_offset = alloc_clusters(bs, s->l2_size * sizeof(uint64_t));
|
|
|
|
/* update the L1 entry */
|
|
|
|
s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED;
|
|
|
|
tmp = cpu_to_be64(l2_offset | QCOW_OFLAG_COPIED);
|
|
if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp),
|
|
&tmp, sizeof(tmp)) != sizeof(tmp))
|
|
return NULL;
|
|
|
|
/* allocate a new entry in the l2 cache */
|
|
|
|
min_index = l2_cache_new_entry(bs);
|
|
l2_table = s->l2_cache + (min_index << s->l2_bits);
|
|
|
|
if (old_l2_offset == 0) {
|
|
/* if there was no old l2 table, clear the new table */
|
|
memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
|
|
} else {
|
|
/* if there was an old l2 table, read it from the disk */
|
|
if (bdrv_pread(s->hd, old_l2_offset,
|
|
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
|
s->l2_size * sizeof(uint64_t))
|
|
return NULL;
|
|
}
|
|
/* write the l2 table to the file */
|
|
if (bdrv_pwrite(s->hd, l2_offset,
|
|
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
|
s->l2_size * sizeof(uint64_t))
|
|
return NULL;
|
|
|
|
/* update the l2 cache entry */
|
|
|
|
s->l2_cache_offsets[min_index] = l2_offset;
|
|
s->l2_cache_counts[min_index] = 1;
|
|
|
|
return l2_table;
|
|
}
|
|
|
|
static int size_to_clusters(BDRVQcowState *s, int64_t size)
|
|
{
|
|
return (size + (s->cluster_size - 1)) >> s->cluster_bits;
|
|
}
|
|
|
|
static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size,
|
|
uint64_t *l2_table, uint64_t start, uint64_t mask)
|
|
{
|
|
int i;
|
|
uint64_t offset = be64_to_cpu(l2_table[0]) & ~mask;
|
|
|
|
if (!offset)
|
|
return 0;
|
|
|
|
for (i = start; i < start + nb_clusters; i++)
|
|
if (offset + i * cluster_size != (be64_to_cpu(l2_table[i]) & ~mask))
|
|
break;
|
|
|
|
return (i - start);
|
|
}
|
|
|
|
static int count_contiguous_free_clusters(uint64_t nb_clusters, uint64_t *l2_table)
|
|
{
|
|
int i = 0;
|
|
|
|
while(nb_clusters-- && l2_table[i] == 0)
|
|
i++;
|
|
|
|
return i;
|
|
}
|
|
|
|
/*
|
|
* get_cluster_offset
|
|
*
|
|
* For a given offset of the disk image, return cluster offset in
|
|
* qcow2 file.
|
|
*
|
|
* on entry, *num is the number of contiguous clusters we'd like to
|
|
* access following offset.
|
|
*
|
|
* on exit, *num is the number of contiguous clusters we can read.
|
|
*
|
|
* Return 1, if the offset is found
|
|
* Return 0, otherwise.
|
|
*
|
|
*/
|
|
|
|
static uint64_t get_cluster_offset(BlockDriverState *bs,
|
|
uint64_t offset, int *num)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int l1_index, l2_index;
|
|
uint64_t l2_offset, *l2_table, cluster_offset;
|
|
int l1_bits, c;
|
|
int index_in_cluster, nb_available, nb_needed, nb_clusters;
|
|
|
|
index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1);
|
|
nb_needed = *num + index_in_cluster;
|
|
|
|
l1_bits = s->l2_bits + s->cluster_bits;
|
|
|
|
/* compute how many bytes there are between the offset and
|
|
* the end of the l1 entry
|
|
*/
|
|
|
|
nb_available = (1 << l1_bits) - (offset & ((1 << l1_bits) - 1));
|
|
|
|
/* compute the number of available sectors */
|
|
|
|
nb_available = (nb_available >> 9) + index_in_cluster;
|
|
|
|
cluster_offset = 0;
|
|
|
|
/* seek the the l2 offset in the l1 table */
|
|
|
|
l1_index = offset >> l1_bits;
|
|
if (l1_index >= s->l1_size)
|
|
goto out;
|
|
|
|
l2_offset = s->l1_table[l1_index];
|
|
|
|
/* seek the l2 table of the given l2 offset */
|
|
|
|
if (!l2_offset)
|
|
goto out;
|
|
|
|
/* load the l2 table in memory */
|
|
|
|
l2_offset &= ~QCOW_OFLAG_COPIED;
|
|
l2_table = l2_load(bs, l2_offset);
|
|
if (l2_table == NULL)
|
|
return 0;
|
|
|
|
/* find the cluster offset for the given disk offset */
|
|
|
|
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
|
cluster_offset = be64_to_cpu(l2_table[l2_index]);
|
|
nb_clusters = size_to_clusters(s, nb_needed << 9);
|
|
|
|
if (!cluster_offset) {
|
|
/* how many empty clusters ? */
|
|
c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]);
|
|
} else {
|
|
/* how many allocated clusters ? */
|
|
c = count_contiguous_clusters(nb_clusters, s->cluster_size,
|
|
&l2_table[l2_index], 0, QCOW_OFLAG_COPIED);
|
|
}
|
|
|
|
nb_available = (c * s->cluster_sectors);
|
|
out:
|
|
if (nb_available > nb_needed)
|
|
nb_available = nb_needed;
|
|
|
|
*num = nb_available - index_in_cluster;
|
|
|
|
return cluster_offset & ~QCOW_OFLAG_COPIED;
|
|
}
|
|
|
|
/*
|
|
* free_any_clusters
|
|
*
|
|
* free clusters according to its type: compressed or not
|
|
*
|
|
*/
|
|
|
|
static void free_any_clusters(BlockDriverState *bs,
|
|
uint64_t cluster_offset, int nb_clusters)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
|
|
/* free the cluster */
|
|
|
|
if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
|
int nb_csectors;
|
|
nb_csectors = ((cluster_offset >> s->csize_shift) &
|
|
s->csize_mask) + 1;
|
|
free_clusters(bs, (cluster_offset & s->cluster_offset_mask) & ~511,
|
|
nb_csectors * 512);
|
|
return;
|
|
}
|
|
|
|
free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits);
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* get_cluster_table
|
|
*
|
|
* for a given disk offset, load (and allocate if needed)
|
|
* the l2 table.
|
|
*
|
|
* the l2 table offset in the qcow2 file and the cluster index
|
|
* in the l2 table are given to the caller.
|
|
*
|
|
*/
|
|
|
|
static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
|
|
uint64_t **new_l2_table,
|
|
uint64_t *new_l2_offset,
|
|
int *new_l2_index)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int l1_index, l2_index, ret;
|
|
uint64_t l2_offset, *l2_table;
|
|
|
|
/* seek the the l2 offset in the l1 table */
|
|
|
|
l1_index = offset >> (s->l2_bits + s->cluster_bits);
|
|
if (l1_index >= s->l1_size) {
|
|
ret = grow_l1_table(bs, l1_index + 1);
|
|
if (ret < 0)
|
|
return 0;
|
|
}
|
|
l2_offset = s->l1_table[l1_index];
|
|
|
|
/* seek the l2 table of the given l2 offset */
|
|
|
|
if (l2_offset & QCOW_OFLAG_COPIED) {
|
|
/* load the l2 table in memory */
|
|
l2_offset &= ~QCOW_OFLAG_COPIED;
|
|
l2_table = l2_load(bs, l2_offset);
|
|
if (l2_table == NULL)
|
|
return 0;
|
|
} else {
|
|
if (l2_offset)
|
|
free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t));
|
|
l2_table = l2_allocate(bs, l1_index);
|
|
if (l2_table == NULL)
|
|
return 0;
|
|
l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED;
|
|
}
|
|
|
|
/* find the cluster offset for the given disk offset */
|
|
|
|
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
|
|
|
*new_l2_table = l2_table;
|
|
*new_l2_offset = l2_offset;
|
|
*new_l2_index = l2_index;
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* alloc_compressed_cluster_offset
|
|
*
|
|
* For a given offset of the disk image, return cluster offset in
|
|
* qcow2 file.
|
|
*
|
|
* If the offset is not found, allocate a new compressed cluster.
|
|
*
|
|
* Return the cluster offset if successful,
|
|
* Return 0, otherwise.
|
|
*
|
|
*/
|
|
|
|
static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs,
|
|
uint64_t offset,
|
|
int compressed_size)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int l2_index, ret;
|
|
uint64_t l2_offset, *l2_table, cluster_offset;
|
|
int nb_csectors;
|
|
|
|
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index);
|
|
if (ret == 0)
|
|
return 0;
|
|
|
|
cluster_offset = be64_to_cpu(l2_table[l2_index]);
|
|
if (cluster_offset & QCOW_OFLAG_COPIED)
|
|
return cluster_offset & ~QCOW_OFLAG_COPIED;
|
|
|
|
if (cluster_offset)
|
|
free_any_clusters(bs, cluster_offset, 1);
|
|
|
|
cluster_offset = alloc_bytes(bs, compressed_size);
|
|
nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) -
|
|
(cluster_offset >> 9);
|
|
|
|
cluster_offset |= QCOW_OFLAG_COMPRESSED |
|
|
((uint64_t)nb_csectors << s->csize_shift);
|
|
|
|
/* update L2 table */
|
|
|
|
/* compressed clusters never have the copied flag */
|
|
|
|
l2_table[l2_index] = cpu_to_be64(cluster_offset);
|
|
if (bdrv_pwrite(s->hd,
|
|
l2_offset + l2_index * sizeof(uint64_t),
|
|
l2_table + l2_index,
|
|
sizeof(uint64_t)) != sizeof(uint64_t))
|
|
return 0;
|
|
|
|
return cluster_offset;
|
|
}
|
|
|
|
typedef struct QCowL2Meta
|
|
{
|
|
uint64_t offset;
|
|
int n_start;
|
|
int nb_available;
|
|
int nb_clusters;
|
|
} QCowL2Meta;
|
|
|
|
static int alloc_cluster_link_l2(BlockDriverState *bs, uint64_t cluster_offset,
|
|
QCowL2Meta *m)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int i, j = 0, l2_index, ret;
|
|
uint64_t *old_cluster, start_sect, l2_offset, *l2_table;
|
|
|
|
if (m->nb_clusters == 0)
|
|
return 0;
|
|
|
|
old_cluster = qemu_malloc(m->nb_clusters * sizeof(uint64_t));
|
|
|
|
/* copy content of unmodified sectors */
|
|
start_sect = (m->offset & ~(s->cluster_size - 1)) >> 9;
|
|
if (m->n_start) {
|
|
ret = copy_sectors(bs, start_sect, cluster_offset, 0, m->n_start);
|
|
if (ret < 0)
|
|
goto err;
|
|
}
|
|
|
|
if (m->nb_available & (s->cluster_sectors - 1)) {
|
|
uint64_t end = m->nb_available & ~(uint64_t)(s->cluster_sectors - 1);
|
|
ret = copy_sectors(bs, start_sect + end, cluster_offset + (end << 9),
|
|
m->nb_available - end, s->cluster_sectors);
|
|
if (ret < 0)
|
|
goto err;
|
|
}
|
|
|
|
ret = -EIO;
|
|
/* update L2 table */
|
|
if (!get_cluster_table(bs, m->offset, &l2_table, &l2_offset, &l2_index))
|
|
goto err;
|
|
|
|
for (i = 0; i < m->nb_clusters; i++) {
|
|
if(l2_table[l2_index + i] != 0)
|
|
old_cluster[j++] = l2_table[l2_index + i];
|
|
|
|
l2_table[l2_index + i] = cpu_to_be64((cluster_offset +
|
|
(i << s->cluster_bits)) | QCOW_OFLAG_COPIED);
|
|
}
|
|
|
|
if (bdrv_pwrite(s->hd, l2_offset + l2_index * sizeof(uint64_t),
|
|
l2_table + l2_index, m->nb_clusters * sizeof(uint64_t)) !=
|
|
m->nb_clusters * sizeof(uint64_t))
|
|
goto err;
|
|
|
|
for (i = 0; i < j; i++)
|
|
free_any_clusters(bs, old_cluster[i], 1);
|
|
|
|
ret = 0;
|
|
err:
|
|
qemu_free(old_cluster);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* alloc_cluster_offset
|
|
*
|
|
* For a given offset of the disk image, return cluster offset in
|
|
* qcow2 file.
|
|
*
|
|
* If the offset is not found, allocate a new cluster.
|
|
*
|
|
* Return the cluster offset if successful,
|
|
* Return 0, otherwise.
|
|
*
|
|
*/
|
|
|
|
static uint64_t alloc_cluster_offset(BlockDriverState *bs,
|
|
uint64_t offset,
|
|
int n_start, int n_end,
|
|
int *num, QCowL2Meta *m)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int l2_index, ret;
|
|
uint64_t l2_offset, *l2_table, cluster_offset;
|
|
int nb_clusters, i = 0;
|
|
|
|
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index);
|
|
if (ret == 0)
|
|
return 0;
|
|
|
|
nb_clusters = size_to_clusters(s, n_end << 9);
|
|
|
|
nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
|
|
|
|
cluster_offset = be64_to_cpu(l2_table[l2_index]);
|
|
|
|
/* We keep all QCOW_OFLAG_COPIED clusters */
|
|
|
|
if (cluster_offset & QCOW_OFLAG_COPIED) {
|
|
nb_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size,
|
|
&l2_table[l2_index], 0, 0);
|
|
|
|
cluster_offset &= ~QCOW_OFLAG_COPIED;
|
|
m->nb_clusters = 0;
|
|
|
|
goto out;
|
|
}
|
|
|
|
/* for the moment, multiple compressed clusters are not managed */
|
|
|
|
if (cluster_offset & QCOW_OFLAG_COMPRESSED)
|
|
nb_clusters = 1;
|
|
|
|
/* how many available clusters ? */
|
|
|
|
while (i < nb_clusters) {
|
|
i += count_contiguous_clusters(nb_clusters - i, s->cluster_size,
|
|
&l2_table[l2_index], i, 0);
|
|
|
|
if(be64_to_cpu(l2_table[l2_index + i]))
|
|
break;
|
|
|
|
i += count_contiguous_free_clusters(nb_clusters - i,
|
|
&l2_table[l2_index + i]);
|
|
|
|
cluster_offset = be64_to_cpu(l2_table[l2_index + i]);
|
|
|
|
if ((cluster_offset & QCOW_OFLAG_COPIED) ||
|
|
(cluster_offset & QCOW_OFLAG_COMPRESSED))
|
|
break;
|
|
}
|
|
nb_clusters = i;
|
|
|
|
/* allocate a new cluster */
|
|
|
|
cluster_offset = alloc_clusters(bs, nb_clusters * s->cluster_size);
|
|
|
|
/* save info needed for meta data update */
|
|
m->offset = offset;
|
|
m->n_start = n_start;
|
|
m->nb_clusters = nb_clusters;
|
|
|
|
out:
|
|
m->nb_available = MIN(nb_clusters << (s->cluster_bits - 9), n_end);
|
|
|
|
*num = m->nb_available - n_start;
|
|
|
|
return cluster_offset;
|
|
}
|
|
|
|
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, int *pnum)
|
|
{
|
|
uint64_t cluster_offset;
|
|
|
|
*pnum = nb_sectors;
|
|
cluster_offset = get_cluster_offset(bs, sector_num << 9, pnum);
|
|
|
|
return (cluster_offset != 0);
|
|
}
|
|
|
|
static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
|
|
const uint8_t *buf, int buf_size)
|
|
{
|
|
z_stream strm1, *strm = &strm1;
|
|
int ret, out_len;
|
|
|
|
memset(strm, 0, sizeof(*strm));
|
|
|
|
strm->next_in = (uint8_t *)buf;
|
|
strm->avail_in = buf_size;
|
|
strm->next_out = out_buf;
|
|
strm->avail_out = out_buf_size;
|
|
|
|
ret = inflateInit2(strm, -12);
|
|
if (ret != Z_OK)
|
|
return -1;
|
|
ret = inflate(strm, Z_FINISH);
|
|
out_len = strm->next_out - out_buf;
|
|
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
|
out_len != out_buf_size) {
|
|
inflateEnd(strm);
|
|
return -1;
|
|
}
|
|
inflateEnd(strm);
|
|
return 0;
|
|
}
|
|
|
|
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset)
|
|
{
|
|
int ret, csize, nb_csectors, sector_offset;
|
|
uint64_t coffset;
|
|
|
|
coffset = cluster_offset & s->cluster_offset_mask;
|
|
if (s->cluster_cache_offset != coffset) {
|
|
nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
|
|
sector_offset = coffset & 511;
|
|
csize = nb_csectors * 512 - sector_offset;
|
|
ret = bdrv_read(s->hd, coffset >> 9, s->cluster_data, nb_csectors);
|
|
if (ret < 0) {
|
|
return -1;
|
|
}
|
|
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
|
s->cluster_data + sector_offset, csize) < 0) {
|
|
return -1;
|
|
}
|
|
s->cluster_cache_offset = coffset;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* handle reading after the end of the backing file */
|
|
static int backing_read1(BlockDriverState *bs,
|
|
int64_t sector_num, uint8_t *buf, 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;
|
|
memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1));
|
|
return n1;
|
|
}
|
|
|
|
static int qcow_read(BlockDriverState *bs, int64_t sector_num,
|
|
uint8_t *buf, int nb_sectors)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int ret, index_in_cluster, n, n1;
|
|
uint64_t cluster_offset;
|
|
|
|
while (nb_sectors > 0) {
|
|
n = nb_sectors;
|
|
cluster_offset = get_cluster_offset(bs, sector_num << 9, &n);
|
|
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
|
if (!cluster_offset) {
|
|
if (bs->backing_hd) {
|
|
/* read from the base image */
|
|
n1 = backing_read1(bs->backing_hd, sector_num, buf, n);
|
|
if (n1 > 0) {
|
|
ret = bdrv_read(bs->backing_hd, sector_num, buf, n1);
|
|
if (ret < 0)
|
|
return -1;
|
|
}
|
|
} else {
|
|
memset(buf, 0, 512 * n);
|
|
}
|
|
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
|
if (decompress_cluster(s, cluster_offset) < 0)
|
|
return -1;
|
|
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n);
|
|
} else {
|
|
ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512);
|
|
if (ret != n * 512)
|
|
return -1;
|
|
if (s->crypt_method) {
|
|
encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
|
&s->aes_decrypt_key);
|
|
}
|
|
}
|
|
nb_sectors -= n;
|
|
sector_num += n;
|
|
buf += n * 512;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int qcow_write(BlockDriverState *bs, int64_t sector_num,
|
|
const uint8_t *buf, int nb_sectors)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int ret, index_in_cluster, n;
|
|
uint64_t cluster_offset;
|
|
int n_end;
|
|
QCowL2Meta l2meta;
|
|
|
|
while (nb_sectors > 0) {
|
|
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
|
n_end = index_in_cluster + nb_sectors;
|
|
if (s->crypt_method &&
|
|
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors)
|
|
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
|
|
cluster_offset = alloc_cluster_offset(bs, sector_num << 9,
|
|
index_in_cluster,
|
|
n_end, &n, &l2meta);
|
|
if (!cluster_offset)
|
|
return -1;
|
|
if (s->crypt_method) {
|
|
encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1,
|
|
&s->aes_encrypt_key);
|
|
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512,
|
|
s->cluster_data, n * 512);
|
|
} else {
|
|
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512);
|
|
}
|
|
if (ret != n * 512 || alloc_cluster_link_l2(bs, cluster_offset, &l2meta) < 0) {
|
|
free_any_clusters(bs, cluster_offset, l2meta.nb_clusters);
|
|
return -1;
|
|
}
|
|
nb_sectors -= n;
|
|
sector_num += n;
|
|
buf += n * 512;
|
|
}
|
|
s->cluster_cache_offset = -1; /* disable compressed cache */
|
|
return 0;
|
|
}
|
|
|
|
typedef struct QCowAIOCB {
|
|
BlockDriverAIOCB common;
|
|
int64_t sector_num;
|
|
uint8_t *buf;
|
|
int nb_sectors;
|
|
int n;
|
|
uint64_t cluster_offset;
|
|
uint8_t *cluster_data;
|
|
BlockDriverAIOCB *hd_aiocb;
|
|
QEMUBH *bh;
|
|
QCowL2Meta l2meta;
|
|
} QCowAIOCB;
|
|
|
|
static void qcow_aio_read_cb(void *opaque, int ret);
|
|
static void qcow_aio_read_bh(void *opaque)
|
|
{
|
|
QCowAIOCB *acb = opaque;
|
|
qemu_bh_delete(acb->bh);
|
|
acb->bh = NULL;
|
|
qcow_aio_read_cb(opaque, 0);
|
|
}
|
|
|
|
static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb)
|
|
{
|
|
if (acb->bh)
|
|
return -EIO;
|
|
|
|
acb->bh = qemu_bh_new(cb, acb);
|
|
if (!acb->bh)
|
|
return -EIO;
|
|
|
|
qemu_bh_schedule(acb->bh);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void qcow_aio_read_cb(void *opaque, int ret)
|
|
{
|
|
QCowAIOCB *acb = opaque;
|
|
BlockDriverState *bs = acb->common.bs;
|
|
BDRVQcowState *s = bs->opaque;
|
|
int index_in_cluster, n1;
|
|
|
|
acb->hd_aiocb = NULL;
|
|
if (ret < 0) {
|
|
fail:
|
|
acb->common.cb(acb->common.opaque, ret);
|
|
qemu_aio_release(acb);
|
|
return;
|
|
}
|
|
|
|
/* post process the read buffer */
|
|
if (!acb->cluster_offset) {
|
|
/* nothing to do */
|
|
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
|
/* nothing to do */
|
|
} else {
|
|
if (s->crypt_method) {
|
|
encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf,
|
|
acb->n, 0,
|
|
&s->aes_decrypt_key);
|
|
}
|
|
}
|
|
|
|
acb->nb_sectors -= acb->n;
|
|
acb->sector_num += acb->n;
|
|
acb->buf += acb->n * 512;
|
|
|
|
if (acb->nb_sectors == 0) {
|
|
/* request completed */
|
|
acb->common.cb(acb->common.opaque, 0);
|
|
qemu_aio_release(acb);
|
|
return;
|
|
}
|
|
|
|
/* prepare next AIO request */
|
|
acb->n = acb->nb_sectors;
|
|
acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, &acb->n);
|
|
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
|
|
|
if (!acb->cluster_offset) {
|
|
if (bs->backing_hd) {
|
|
/* read from the base image */
|
|
n1 = backing_read1(bs->backing_hd, acb->sector_num,
|
|
acb->buf, acb->n);
|
|
if (n1 > 0) {
|
|
acb->hd_aiocb = bdrv_aio_read(bs->backing_hd, acb->sector_num,
|
|
acb->buf, acb->n, qcow_aio_read_cb, acb);
|
|
if (acb->hd_aiocb == NULL)
|
|
goto fail;
|
|
} else {
|
|
ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
|
|
if (ret < 0)
|
|
goto fail;
|
|
}
|
|
} else {
|
|
/* Note: in this case, no need to wait */
|
|
memset(acb->buf, 0, 512 * acb->n);
|
|
ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
|
|
if (ret < 0)
|
|
goto fail;
|
|
}
|
|
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
|
/* add AIO support for compressed blocks ? */
|
|
if (decompress_cluster(s, acb->cluster_offset) < 0)
|
|
goto fail;
|
|
memcpy(acb->buf,
|
|
s->cluster_cache + index_in_cluster * 512, 512 * acb->n);
|
|
ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
|
|
if (ret < 0)
|
|
goto fail;
|
|
} else {
|
|
if ((acb->cluster_offset & 511) != 0) {
|
|
ret = -EIO;
|
|
goto fail;
|
|
}
|
|
acb->hd_aiocb = bdrv_aio_read(s->hd,
|
|
(acb->cluster_offset >> 9) + index_in_cluster,
|
|
acb->buf, acb->n, qcow_aio_read_cb, acb);
|
|
if (acb->hd_aiocb == NULL)
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
|
|
int64_t sector_num, uint8_t *buf, int nb_sectors,
|
|
BlockDriverCompletionFunc *cb, void *opaque)
|
|
{
|
|
QCowAIOCB *acb;
|
|
|
|
acb = qemu_aio_get(bs, cb, opaque);
|
|
if (!acb)
|
|
return NULL;
|
|
acb->hd_aiocb = NULL;
|
|
acb->sector_num = sector_num;
|
|
acb->buf = buf;
|
|
acb->nb_sectors = nb_sectors;
|
|
acb->n = 0;
|
|
acb->cluster_offset = 0;
|
|
acb->l2meta.nb_clusters = 0;
|
|
return acb;
|
|
}
|
|
|
|
static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs,
|
|
int64_t sector_num, uint8_t *buf, int nb_sectors,
|
|
BlockDriverCompletionFunc *cb, void *opaque)
|
|
{
|
|
QCowAIOCB *acb;
|
|
|
|
acb = qcow_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque);
|
|
if (!acb)
|
|
return NULL;
|
|
|
|
qcow_aio_read_cb(acb, 0);
|
|
return &acb->common;
|
|
}
|
|
|
|
static void qcow_aio_write_cb(void *opaque, int ret)
|
|
{
|
|
QCowAIOCB *acb = opaque;
|
|
BlockDriverState *bs = acb->common.bs;
|
|
BDRVQcowState *s = bs->opaque;
|
|
int index_in_cluster;
|
|
const uint8_t *src_buf;
|
|
int n_end;
|
|
|
|
acb->hd_aiocb = NULL;
|
|
|
|
if (ret < 0) {
|
|
fail:
|
|
acb->common.cb(acb->common.opaque, ret);
|
|
qemu_aio_release(acb);
|
|
return;
|
|
}
|
|
|
|
if (alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta) < 0) {
|
|
free_any_clusters(bs, acb->cluster_offset, acb->l2meta.nb_clusters);
|
|
goto fail;
|
|
}
|
|
|
|
acb->nb_sectors -= acb->n;
|
|
acb->sector_num += acb->n;
|
|
acb->buf += acb->n * 512;
|
|
|
|
if (acb->nb_sectors == 0) {
|
|
/* request completed */
|
|
acb->common.cb(acb->common.opaque, 0);
|
|
qemu_aio_release(acb);
|
|
return;
|
|
}
|
|
|
|
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
|
n_end = index_in_cluster + acb->nb_sectors;
|
|
if (s->crypt_method &&
|
|
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors)
|
|
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
|
|
|
|
acb->cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9,
|
|
index_in_cluster,
|
|
n_end, &acb->n, &acb->l2meta);
|
|
if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) {
|
|
ret = -EIO;
|
|
goto fail;
|
|
}
|
|
if (s->crypt_method) {
|
|
if (!acb->cluster_data) {
|
|
acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS *
|
|
s->cluster_size);
|
|
}
|
|
encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf,
|
|
acb->n, 1, &s->aes_encrypt_key);
|
|
src_buf = acb->cluster_data;
|
|
} else {
|
|
src_buf = acb->buf;
|
|
}
|
|
acb->hd_aiocb = bdrv_aio_write(s->hd,
|
|
(acb->cluster_offset >> 9) + index_in_cluster,
|
|
src_buf, acb->n,
|
|
qcow_aio_write_cb, acb);
|
|
if (acb->hd_aiocb == NULL)
|
|
goto fail;
|
|
}
|
|
|
|
static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs,
|
|
int64_t sector_num, const uint8_t *buf, int nb_sectors,
|
|
BlockDriverCompletionFunc *cb, void *opaque)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowAIOCB *acb;
|
|
|
|
s->cluster_cache_offset = -1; /* disable compressed cache */
|
|
|
|
acb = qcow_aio_setup(bs, sector_num, (uint8_t*)buf, nb_sectors, cb, opaque);
|
|
if (!acb)
|
|
return NULL;
|
|
|
|
qcow_aio_write_cb(acb, 0);
|
|
return &acb->common;
|
|
}
|
|
|
|
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb)
|
|
{
|
|
QCowAIOCB *acb = (QCowAIOCB *)blockacb;
|
|
if (acb->hd_aiocb)
|
|
bdrv_aio_cancel(acb->hd_aiocb);
|
|
qemu_aio_release(acb);
|
|
}
|
|
|
|
static void qcow_close(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
qemu_free(s->l1_table);
|
|
qemu_free(s->l2_cache);
|
|
qemu_free(s->cluster_cache);
|
|
qemu_free(s->cluster_data);
|
|
refcount_close(bs);
|
|
bdrv_delete(s->hd);
|
|
}
|
|
|
|
/* XXX: use std qcow open function ? */
|
|
typedef struct QCowCreateState {
|
|
int cluster_size;
|
|
int cluster_bits;
|
|
uint16_t *refcount_block;
|
|
uint64_t *refcount_table;
|
|
int64_t l1_table_offset;
|
|
int64_t refcount_table_offset;
|
|
int64_t refcount_block_offset;
|
|
} QCowCreateState;
|
|
|
|
static void create_refcount_update(QCowCreateState *s,
|
|
int64_t offset, int64_t size)
|
|
{
|
|
int refcount;
|
|
int64_t start, last, cluster_offset;
|
|
uint16_t *p;
|
|
|
|
start = offset & ~(s->cluster_size - 1);
|
|
last = (offset + size - 1) & ~(s->cluster_size - 1);
|
|
for(cluster_offset = start; cluster_offset <= last;
|
|
cluster_offset += s->cluster_size) {
|
|
p = &s->refcount_block[cluster_offset >> s->cluster_bits];
|
|
refcount = be16_to_cpu(*p);
|
|
refcount++;
|
|
*p = cpu_to_be16(refcount);
|
|
}
|
|
}
|
|
|
|
static int qcow_create(const char *filename, int64_t total_size,
|
|
const char *backing_file, int flags)
|
|
{
|
|
int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
|
|
QCowHeader header;
|
|
uint64_t tmp, offset;
|
|
QCowCreateState s1, *s = &s1;
|
|
|
|
memset(s, 0, sizeof(*s));
|
|
|
|
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
|
if (fd < 0)
|
|
return -1;
|
|
memset(&header, 0, sizeof(header));
|
|
header.magic = cpu_to_be32(QCOW_MAGIC);
|
|
header.version = cpu_to_be32(QCOW_VERSION);
|
|
header.size = cpu_to_be64(total_size * 512);
|
|
header_size = sizeof(header);
|
|
backing_filename_len = 0;
|
|
if (backing_file) {
|
|
header.backing_file_offset = cpu_to_be64(header_size);
|
|
backing_filename_len = strlen(backing_file);
|
|
header.backing_file_size = cpu_to_be32(backing_filename_len);
|
|
header_size += backing_filename_len;
|
|
}
|
|
s->cluster_bits = 12; /* 4 KB clusters */
|
|
s->cluster_size = 1 << s->cluster_bits;
|
|
header.cluster_bits = cpu_to_be32(s->cluster_bits);
|
|
header_size = (header_size + 7) & ~7;
|
|
if (flags & BLOCK_FLAG_ENCRYPT) {
|
|
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
|
|
} else {
|
|
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
|
|
}
|
|
l2_bits = s->cluster_bits - 3;
|
|
shift = s->cluster_bits + l2_bits;
|
|
l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift);
|
|
offset = align_offset(header_size, s->cluster_size);
|
|
s->l1_table_offset = offset;
|
|
header.l1_table_offset = cpu_to_be64(s->l1_table_offset);
|
|
header.l1_size = cpu_to_be32(l1_size);
|
|
offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
|
|
|
|
s->refcount_table = qemu_mallocz(s->cluster_size);
|
|
s->refcount_block = qemu_mallocz(s->cluster_size);
|
|
|
|
s->refcount_table_offset = offset;
|
|
header.refcount_table_offset = cpu_to_be64(offset);
|
|
header.refcount_table_clusters = cpu_to_be32(1);
|
|
offset += s->cluster_size;
|
|
|
|
s->refcount_table[0] = cpu_to_be64(offset);
|
|
s->refcount_block_offset = offset;
|
|
offset += s->cluster_size;
|
|
|
|
/* update refcounts */
|
|
create_refcount_update(s, 0, header_size);
|
|
create_refcount_update(s, s->l1_table_offset, l1_size * sizeof(uint64_t));
|
|
create_refcount_update(s, s->refcount_table_offset, s->cluster_size);
|
|
create_refcount_update(s, s->refcount_block_offset, s->cluster_size);
|
|
|
|
/* write all the data */
|
|
write(fd, &header, sizeof(header));
|
|
if (backing_file) {
|
|
write(fd, backing_file, backing_filename_len);
|
|
}
|
|
lseek(fd, s->l1_table_offset, SEEK_SET);
|
|
tmp = 0;
|
|
for(i = 0;i < l1_size; i++) {
|
|
write(fd, &tmp, sizeof(tmp));
|
|
}
|
|
lseek(fd, s->refcount_table_offset, SEEK_SET);
|
|
write(fd, s->refcount_table, s->cluster_size);
|
|
|
|
lseek(fd, s->refcount_block_offset, SEEK_SET);
|
|
write(fd, s->refcount_block, s->cluster_size);
|
|
|
|
qemu_free(s->refcount_table);
|
|
qemu_free(s->refcount_block);
|
|
close(fd);
|
|
return 0;
|
|
}
|
|
|
|
static int qcow_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(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
|
return -1;
|
|
ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
l2_cache_reset(bs);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/* XXX: put compressed sectors first, then all the cluster aligned
|
|
tables to avoid losing bytes in alignment */
|
|
static int qcow_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(s->hd);
|
|
cluster_offset = (cluster_offset + 511) & ~511;
|
|
bdrv_truncate(s->hd, cluster_offset);
|
|
return 0;
|
|
}
|
|
|
|
if (nb_sectors != s->cluster_sectors)
|
|
return -EINVAL;
|
|
|
|
out_buf = qemu_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) {
|
|
qemu_free(out_buf);
|
|
return -1;
|
|
}
|
|
|
|
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) {
|
|
qemu_free(out_buf);
|
|
deflateEnd(&strm);
|
|
return -1;
|
|
}
|
|
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 */
|
|
qcow_write(bs, sector_num, buf, s->cluster_sectors);
|
|
} else {
|
|
cluster_offset = alloc_compressed_cluster_offset(bs, sector_num << 9,
|
|
out_len);
|
|
if (!cluster_offset)
|
|
return -1;
|
|
cluster_offset &= s->cluster_offset_mask;
|
|
if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
|
|
qemu_free(out_buf);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
qemu_free(out_buf);
|
|
return 0;
|
|
}
|
|
|
|
static void qcow_flush(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
bdrv_flush(s->hd);
|
|
}
|
|
|
|
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
bdi->cluster_size = s->cluster_size;
|
|
bdi->vm_state_offset = (int64_t)s->l1_vm_state_index <<
|
|
(s->cluster_bits + s->l2_bits);
|
|
bdi->highest_alloc = s->highest_alloc << s->cluster_bits;
|
|
bdi->num_free_bytes = s->nc_free << s->cluster_bits;
|
|
return 0;
|
|
}
|
|
|
|
/*********************************************************/
|
|
/* snapshot support */
|
|
|
|
/* update the refcounts of snapshots and the copied flag */
|
|
static int update_snapshot_refcount(BlockDriverState *bs,
|
|
int64_t l1_table_offset,
|
|
int l1_size,
|
|
int addend)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated;
|
|
int64_t old_offset, old_l2_offset;
|
|
int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount;
|
|
|
|
l2_cache_reset(bs);
|
|
|
|
l2_table = NULL;
|
|
l1_table = NULL;
|
|
l1_size2 = l1_size * sizeof(uint64_t);
|
|
l1_allocated = 0;
|
|
if (l1_table_offset != s->l1_table_offset) {
|
|
l1_table = qemu_malloc(l1_size2);
|
|
l1_allocated = 1;
|
|
if (bdrv_pread(s->hd, l1_table_offset,
|
|
l1_table, l1_size2) != l1_size2)
|
|
goto fail;
|
|
for(i = 0;i < l1_size; i++)
|
|
be64_to_cpus(&l1_table[i]);
|
|
} else {
|
|
assert(l1_size == s->l1_size);
|
|
l1_table = s->l1_table;
|
|
l1_allocated = 0;
|
|
}
|
|
|
|
l2_size = s->l2_size * sizeof(uint64_t);
|
|
l2_table = qemu_malloc(l2_size);
|
|
l1_modified = 0;
|
|
for(i = 0; i < l1_size; i++) {
|
|
l2_offset = l1_table[i];
|
|
if (l2_offset) {
|
|
old_l2_offset = l2_offset;
|
|
l2_offset &= ~QCOW_OFLAG_COPIED;
|
|
l2_modified = 0;
|
|
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
|
|
goto fail;
|
|
for(j = 0; j < s->l2_size; j++) {
|
|
offset = be64_to_cpu(l2_table[j]);
|
|
if (offset != 0) {
|
|
old_offset = offset;
|
|
offset &= ~QCOW_OFLAG_COPIED;
|
|
if (offset & QCOW_OFLAG_COMPRESSED) {
|
|
nb_csectors = ((offset >> s->csize_shift) &
|
|
s->csize_mask) + 1;
|
|
if (addend != 0)
|
|
update_refcount(bs, (offset & s->cluster_offset_mask) & ~511,
|
|
nb_csectors * 512, addend);
|
|
/* compressed clusters are never modified */
|
|
refcount = 2;
|
|
} else {
|
|
if (addend != 0) {
|
|
refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend);
|
|
} else {
|
|
refcount = get_refcount(bs, offset >> s->cluster_bits);
|
|
}
|
|
}
|
|
|
|
if (refcount == 1) {
|
|
offset |= QCOW_OFLAG_COPIED;
|
|
}
|
|
if (offset != old_offset) {
|
|
l2_table[j] = cpu_to_be64(offset);
|
|
l2_modified = 1;
|
|
}
|
|
}
|
|
}
|
|
if (l2_modified) {
|
|
if (bdrv_pwrite(s->hd,
|
|
l2_offset, l2_table, l2_size) != l2_size)
|
|
goto fail;
|
|
}
|
|
|
|
if (addend != 0) {
|
|
refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend);
|
|
} else {
|
|
refcount = get_refcount(bs, l2_offset >> s->cluster_bits);
|
|
}
|
|
if (refcount == 1) {
|
|
l2_offset |= QCOW_OFLAG_COPIED;
|
|
}
|
|
if (l2_offset != old_l2_offset) {
|
|
l1_table[i] = l2_offset;
|
|
l1_modified = 1;
|
|
}
|
|
}
|
|
}
|
|
if (l1_modified) {
|
|
for(i = 0; i < l1_size; i++)
|
|
cpu_to_be64s(&l1_table[i]);
|
|
if (bdrv_pwrite(s->hd, l1_table_offset, l1_table,
|
|
l1_size2) != l1_size2)
|
|
goto fail;
|
|
for(i = 0; i < l1_size; i++)
|
|
be64_to_cpus(&l1_table[i]);
|
|
}
|
|
if (l1_allocated)
|
|
qemu_free(l1_table);
|
|
qemu_free(l2_table);
|
|
return 0;
|
|
fail:
|
|
if (l1_allocated)
|
|
qemu_free(l1_table);
|
|
qemu_free(l2_table);
|
|
return -EIO;
|
|
}
|
|
|
|
static void qcow_free_snapshots(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int i;
|
|
|
|
for(i = 0; i < s->nb_snapshots; i++) {
|
|
qemu_free(s->snapshots[i].name);
|
|
qemu_free(s->snapshots[i].id_str);
|
|
}
|
|
qemu_free(s->snapshots);
|
|
s->snapshots = NULL;
|
|
s->nb_snapshots = 0;
|
|
}
|
|
|
|
static int qcow_read_snapshots(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowSnapshotHeader h;
|
|
QCowSnapshot *sn;
|
|
int i, id_str_size, name_size;
|
|
int64_t offset;
|
|
uint32_t extra_data_size;
|
|
|
|
if (!s->nb_snapshots) {
|
|
s->snapshots = NULL;
|
|
s->snapshots_size = 0;
|
|
return 0;
|
|
}
|
|
|
|
offset = s->snapshots_offset;
|
|
s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot));
|
|
for(i = 0; i < s->nb_snapshots; i++) {
|
|
offset = align_offset(offset, 8);
|
|
if (bdrv_pread(s->hd, offset, &h, sizeof(h)) != sizeof(h))
|
|
goto fail;
|
|
offset += sizeof(h);
|
|
sn = s->snapshots + i;
|
|
sn->l1_table_offset = be64_to_cpu(h.l1_table_offset);
|
|
sn->l1_size = be32_to_cpu(h.l1_size);
|
|
sn->vm_state_size = be32_to_cpu(h.vm_state_size);
|
|
sn->date_sec = be32_to_cpu(h.date_sec);
|
|
sn->date_nsec = be32_to_cpu(h.date_nsec);
|
|
sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec);
|
|
extra_data_size = be32_to_cpu(h.extra_data_size);
|
|
|
|
id_str_size = be16_to_cpu(h.id_str_size);
|
|
name_size = be16_to_cpu(h.name_size);
|
|
|
|
offset += extra_data_size;
|
|
|
|
sn->id_str = qemu_malloc(id_str_size + 1);
|
|
if (bdrv_pread(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
|
goto fail;
|
|
offset += id_str_size;
|
|
sn->id_str[id_str_size] = '\0';
|
|
|
|
sn->name = qemu_malloc(name_size + 1);
|
|
if (bdrv_pread(s->hd, offset, sn->name, name_size) != name_size)
|
|
goto fail;
|
|
offset += name_size;
|
|
sn->name[name_size] = '\0';
|
|
}
|
|
s->snapshots_size = offset - s->snapshots_offset;
|
|
return 0;
|
|
fail:
|
|
qcow_free_snapshots(bs);
|
|
return -1;
|
|
}
|
|
|
|
/* add at the end of the file a new list of snapshots */
|
|
static int qcow_write_snapshots(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowSnapshot *sn;
|
|
QCowSnapshotHeader h;
|
|
int i, name_size, id_str_size, snapshots_size;
|
|
uint64_t data64;
|
|
uint32_t data32;
|
|
int64_t offset, snapshots_offset;
|
|
|
|
/* compute the size of the snapshots */
|
|
offset = 0;
|
|
for(i = 0; i < s->nb_snapshots; i++) {
|
|
sn = s->snapshots + i;
|
|
offset = align_offset(offset, 8);
|
|
offset += sizeof(h);
|
|
offset += strlen(sn->id_str);
|
|
offset += strlen(sn->name);
|
|
}
|
|
snapshots_size = offset;
|
|
|
|
snapshots_offset = alloc_clusters(bs, snapshots_size);
|
|
offset = snapshots_offset;
|
|
|
|
for(i = 0; i < s->nb_snapshots; i++) {
|
|
sn = s->snapshots + i;
|
|
memset(&h, 0, sizeof(h));
|
|
h.l1_table_offset = cpu_to_be64(sn->l1_table_offset);
|
|
h.l1_size = cpu_to_be32(sn->l1_size);
|
|
h.vm_state_size = cpu_to_be32(sn->vm_state_size);
|
|
h.date_sec = cpu_to_be32(sn->date_sec);
|
|
h.date_nsec = cpu_to_be32(sn->date_nsec);
|
|
h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec);
|
|
|
|
id_str_size = strlen(sn->id_str);
|
|
name_size = strlen(sn->name);
|
|
h.id_str_size = cpu_to_be16(id_str_size);
|
|
h.name_size = cpu_to_be16(name_size);
|
|
offset = align_offset(offset, 8);
|
|
if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h))
|
|
goto fail;
|
|
offset += sizeof(h);
|
|
if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
|
goto fail;
|
|
offset += id_str_size;
|
|
if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size)
|
|
goto fail;
|
|
offset += name_size;
|
|
}
|
|
|
|
/* update the various header fields */
|
|
data64 = cpu_to_be64(snapshots_offset);
|
|
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset),
|
|
&data64, sizeof(data64)) != sizeof(data64))
|
|
goto fail;
|
|
data32 = cpu_to_be32(s->nb_snapshots);
|
|
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots),
|
|
&data32, sizeof(data32)) != sizeof(data32))
|
|
goto fail;
|
|
|
|
/* free the old snapshot table */
|
|
free_clusters(bs, s->snapshots_offset, s->snapshots_size);
|
|
s->snapshots_offset = snapshots_offset;
|
|
s->snapshots_size = snapshots_size;
|
|
return 0;
|
|
fail:
|
|
return -1;
|
|
}
|
|
|
|
static void find_new_snapshot_id(BlockDriverState *bs,
|
|
char *id_str, int id_str_size)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowSnapshot *sn;
|
|
int i, id, id_max = 0;
|
|
|
|
for(i = 0; i < s->nb_snapshots; i++) {
|
|
sn = s->snapshots + i;
|
|
id = strtoul(sn->id_str, NULL, 10);
|
|
if (id > id_max)
|
|
id_max = id;
|
|
}
|
|
snprintf(id_str, id_str_size, "%d", id_max + 1);
|
|
}
|
|
|
|
static int find_snapshot_by_id(BlockDriverState *bs, const char *id_str)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int i;
|
|
|
|
for(i = 0; i < s->nb_snapshots; i++) {
|
|
if (!strcmp(s->snapshots[i].id_str, id_str))
|
|
return i;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static int find_snapshot_by_id_or_name(BlockDriverState *bs, const char *name)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int i, ret;
|
|
|
|
ret = find_snapshot_by_id(bs, name);
|
|
if (ret >= 0)
|
|
return ret;
|
|
for(i = 0; i < s->nb_snapshots; i++) {
|
|
if (!strcmp(s->snapshots[i].name, name))
|
|
return i;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/* if no id is provided, a new one is constructed */
|
|
static int qcow_snapshot_create(BlockDriverState *bs,
|
|
QEMUSnapshotInfo *sn_info)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowSnapshot *snapshots1, sn1, *sn = &sn1;
|
|
int i, ret;
|
|
uint64_t *l1_table = NULL;
|
|
|
|
memset(sn, 0, sizeof(*sn));
|
|
|
|
if (sn_info->id_str[0] == '\0') {
|
|
/* compute a new id */
|
|
find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
|
|
}
|
|
|
|
/* check that the ID is unique */
|
|
if (find_snapshot_by_id(bs, sn_info->id_str) >= 0)
|
|
return -ENOENT;
|
|
|
|
sn->id_str = qemu_strdup(sn_info->id_str);
|
|
if (!sn->id_str)
|
|
goto fail;
|
|
sn->name = qemu_strdup(sn_info->name);
|
|
if (!sn->name)
|
|
goto fail;
|
|
sn->vm_state_size = sn_info->vm_state_size;
|
|
sn->date_sec = sn_info->date_sec;
|
|
sn->date_nsec = sn_info->date_nsec;
|
|
sn->vm_clock_nsec = sn_info->vm_clock_nsec;
|
|
|
|
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
|
|
if (ret < 0)
|
|
goto fail;
|
|
|
|
/* create the L1 table of the snapshot */
|
|
sn->l1_table_offset = alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
|
|
sn->l1_size = s->l1_size;
|
|
|
|
l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
|
|
for(i = 0; i < s->l1_size; i++) {
|
|
l1_table[i] = cpu_to_be64(s->l1_table[i]);
|
|
}
|
|
if (bdrv_pwrite(s->hd, sn->l1_table_offset,
|
|
l1_table, s->l1_size * sizeof(uint64_t)) !=
|
|
(s->l1_size * sizeof(uint64_t)))
|
|
goto fail;
|
|
qemu_free(l1_table);
|
|
l1_table = NULL;
|
|
|
|
snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot));
|
|
if (s->snapshots) {
|
|
memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot));
|
|
qemu_free(s->snapshots);
|
|
}
|
|
s->snapshots = snapshots1;
|
|
s->snapshots[s->nb_snapshots++] = *sn;
|
|
|
|
if (qcow_write_snapshots(bs) < 0)
|
|
goto fail;
|
|
#ifdef DEBUG_ALLOC
|
|
check_refcounts(bs);
|
|
#endif
|
|
return 0;
|
|
fail:
|
|
qemu_free(sn->name);
|
|
qemu_free(l1_table);
|
|
return -1;
|
|
}
|
|
|
|
/* copy the snapshot 'snapshot_name' into the current disk image */
|
|
static int qcow_snapshot_goto(BlockDriverState *bs,
|
|
const char *snapshot_id)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowSnapshot *sn;
|
|
int i, snapshot_index, l1_size2;
|
|
|
|
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id);
|
|
if (snapshot_index < 0)
|
|
return -ENOENT;
|
|
sn = &s->snapshots[snapshot_index];
|
|
|
|
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1) < 0)
|
|
goto fail;
|
|
|
|
if (grow_l1_table(bs, sn->l1_size) < 0)
|
|
goto fail;
|
|
|
|
s->l1_size = sn->l1_size;
|
|
l1_size2 = s->l1_size * sizeof(uint64_t);
|
|
/* copy the snapshot l1 table to the current l1 table */
|
|
if (bdrv_pread(s->hd, sn->l1_table_offset,
|
|
s->l1_table, l1_size2) != l1_size2)
|
|
goto fail;
|
|
if (bdrv_pwrite(s->hd, s->l1_table_offset,
|
|
s->l1_table, l1_size2) != l1_size2)
|
|
goto fail;
|
|
for(i = 0;i < s->l1_size; i++) {
|
|
be64_to_cpus(&s->l1_table[i]);
|
|
}
|
|
|
|
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1) < 0)
|
|
goto fail;
|
|
|
|
#ifdef DEBUG_ALLOC
|
|
check_refcounts(bs);
|
|
#endif
|
|
return 0;
|
|
fail:
|
|
return -EIO;
|
|
}
|
|
|
|
static int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowSnapshot *sn;
|
|
int snapshot_index, ret;
|
|
|
|
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id);
|
|
if (snapshot_index < 0)
|
|
return -ENOENT;
|
|
sn = &s->snapshots[snapshot_index];
|
|
|
|
ret = update_snapshot_refcount(bs, sn->l1_table_offset, sn->l1_size, -1);
|
|
if (ret < 0)
|
|
return ret;
|
|
/* must update the copied flag on the current cluster offsets */
|
|
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0);
|
|
if (ret < 0)
|
|
return ret;
|
|
free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t));
|
|
|
|
qemu_free(sn->id_str);
|
|
qemu_free(sn->name);
|
|
memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn));
|
|
s->nb_snapshots--;
|
|
ret = qcow_write_snapshots(bs);
|
|
if (ret < 0) {
|
|
/* XXX: restore snapshot if error ? */
|
|
return ret;
|
|
}
|
|
#ifdef DEBUG_ALLOC
|
|
check_refcounts(bs);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
static int qcow_snapshot_list(BlockDriverState *bs,
|
|
QEMUSnapshotInfo **psn_tab)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QEMUSnapshotInfo *sn_tab, *sn_info;
|
|
QCowSnapshot *sn;
|
|
int i;
|
|
|
|
sn_tab = qemu_mallocz(s->nb_snapshots * sizeof(QEMUSnapshotInfo));
|
|
for(i = 0; i < s->nb_snapshots; i++) {
|
|
sn_info = sn_tab + i;
|
|
sn = s->snapshots + i;
|
|
pstrcpy(sn_info->id_str, sizeof(sn_info->id_str),
|
|
sn->id_str);
|
|
pstrcpy(sn_info->name, sizeof(sn_info->name),
|
|
sn->name);
|
|
sn_info->vm_state_size = sn->vm_state_size;
|
|
sn_info->date_sec = sn->date_sec;
|
|
sn_info->date_nsec = sn->date_nsec;
|
|
sn_info->vm_clock_nsec = sn->vm_clock_nsec;
|
|
}
|
|
*psn_tab = sn_tab;
|
|
return s->nb_snapshots;
|
|
}
|
|
|
|
/*********************************************************/
|
|
/* refcount handling */
|
|
|
|
static int refcount_init(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int ret, refcount_table_size2, i;
|
|
|
|
s->refcount_block_cache = qemu_malloc(s->cluster_size);
|
|
refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t);
|
|
s->refcount_table = qemu_malloc(refcount_table_size2);
|
|
if (s->refcount_table_size > 0) {
|
|
ret = bdrv_pread(s->hd, s->refcount_table_offset,
|
|
s->refcount_table, refcount_table_size2);
|
|
if (ret != refcount_table_size2)
|
|
goto fail;
|
|
for(i = 0; i < s->refcount_table_size; i++)
|
|
be64_to_cpus(&s->refcount_table[i]);
|
|
}
|
|
return 0;
|
|
fail:
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static void refcount_close(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
qemu_free(s->refcount_block_cache);
|
|
qemu_free(s->refcount_table);
|
|
}
|
|
|
|
|
|
static int load_refcount_block(BlockDriverState *bs,
|
|
int64_t refcount_block_offset)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int ret;
|
|
ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache,
|
|
s->cluster_size);
|
|
if (ret != s->cluster_size)
|
|
return -EIO;
|
|
s->refcount_block_cache_offset = refcount_block_offset;
|
|
return 0;
|
|
}
|
|
|
|
static void scan_refcount(BlockDriverState *bs, int64_t *high, int64_t *free)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int64_t refcnt_index, cluster_index, cluster_end, h = 0, f = 0;
|
|
int64_t tail = 0; /* do not count last consecutive free entries */
|
|
|
|
for (refcnt_index=0; refcnt_index < s->refcount_table_size; refcnt_index++){
|
|
if (s->refcount_table[refcnt_index] == 0) {
|
|
f += 1 << (s->cluster_bits - REFCOUNT_SHIFT);
|
|
tail += 1 << (s->cluster_bits - REFCOUNT_SHIFT);
|
|
continue;
|
|
}
|
|
cluster_index = refcnt_index << (s->cluster_bits - REFCOUNT_SHIFT);
|
|
cluster_end = (refcnt_index + 1) << (s->cluster_bits - REFCOUNT_SHIFT);
|
|
for ( ; cluster_index < cluster_end; cluster_index++) {
|
|
if (get_refcount(bs, cluster_index) == 0) {
|
|
f++;
|
|
tail++;
|
|
}
|
|
else {
|
|
h = cluster_index;
|
|
tail = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
f -= tail;
|
|
if (free)
|
|
*free = f;
|
|
if (high)
|
|
*high = (h+1);
|
|
}
|
|
|
|
static int get_refcount(BlockDriverState *bs, int64_t cluster_index)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int refcount_table_index, block_index;
|
|
int64_t refcount_block_offset;
|
|
|
|
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
|
|
if (refcount_table_index >= s->refcount_table_size)
|
|
return 0;
|
|
refcount_block_offset = s->refcount_table[refcount_table_index];
|
|
if (!refcount_block_offset)
|
|
return 0;
|
|
if (refcount_block_offset != s->refcount_block_cache_offset) {
|
|
/* better than nothing: return allocated if read error */
|
|
if (load_refcount_block(bs, refcount_block_offset) < 0)
|
|
return 1;
|
|
}
|
|
block_index = cluster_index &
|
|
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
|
|
return be16_to_cpu(s->refcount_block_cache[block_index]);
|
|
}
|
|
|
|
/* return < 0 if error */
|
|
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int i, nb_clusters;
|
|
|
|
nb_clusters = size_to_clusters(s, size);
|
|
retry:
|
|
for(i = 0; i < nb_clusters; i++) {
|
|
int64_t i = s->free_cluster_index++;
|
|
if (get_refcount(bs, i) != 0)
|
|
goto retry;
|
|
}
|
|
#ifdef DEBUG_ALLOC2
|
|
printf("alloc_clusters: size=%lld -> %lld\n",
|
|
size,
|
|
(s->free_cluster_index - nb_clusters) << s->cluster_bits);
|
|
#endif
|
|
|
|
if (s->highest_alloc < s->free_cluster_index) {
|
|
s->nc_free += (s->free_cluster_index - s->highest_alloc);
|
|
s->highest_alloc = s->free_cluster_index;
|
|
}
|
|
|
|
return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
|
|
}
|
|
|
|
static int64_t alloc_clusters(BlockDriverState *bs, int64_t size)
|
|
{
|
|
int64_t offset;
|
|
|
|
offset = alloc_clusters_noref(bs, size);
|
|
update_refcount(bs, offset, size, 1);
|
|
return offset;
|
|
}
|
|
|
|
/* only used to allocate compressed sectors. We try to allocate
|
|
contiguous sectors. size must be <= cluster_size */
|
|
static int64_t alloc_bytes(BlockDriverState *bs, int size)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int64_t offset, cluster_offset;
|
|
int free_in_cluster;
|
|
|
|
assert(size > 0 && size <= s->cluster_size);
|
|
if (s->free_byte_offset == 0) {
|
|
s->free_byte_offset = alloc_clusters(bs, s->cluster_size);
|
|
}
|
|
redo:
|
|
free_in_cluster = s->cluster_size -
|
|
(s->free_byte_offset & (s->cluster_size - 1));
|
|
if (size <= free_in_cluster) {
|
|
/* enough space in current cluster */
|
|
offset = s->free_byte_offset;
|
|
s->free_byte_offset += size;
|
|
free_in_cluster -= size;
|
|
if (free_in_cluster == 0)
|
|
s->free_byte_offset = 0;
|
|
if ((offset & (s->cluster_size - 1)) != 0)
|
|
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
|
} else {
|
|
offset = alloc_clusters(bs, s->cluster_size);
|
|
cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1);
|
|
if ((cluster_offset + s->cluster_size) == offset) {
|
|
/* we are lucky: contiguous data */
|
|
offset = s->free_byte_offset;
|
|
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
|
s->free_byte_offset += size;
|
|
} else {
|
|
s->free_byte_offset = offset;
|
|
goto redo;
|
|
}
|
|
}
|
|
return offset;
|
|
}
|
|
|
|
static void free_clusters(BlockDriverState *bs,
|
|
int64_t offset, int64_t size)
|
|
{
|
|
update_refcount(bs, offset, size, -1);
|
|
}
|
|
|
|
static int grow_refcount_table(BlockDriverState *bs, int min_size)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int new_table_size, new_table_size2, refcount_table_clusters, i, ret;
|
|
uint64_t *new_table;
|
|
int64_t table_offset;
|
|
uint8_t data[12];
|
|
int old_table_size;
|
|
int64_t old_table_offset;
|
|
|
|
if (min_size <= s->refcount_table_size)
|
|
return 0;
|
|
/* compute new table size */
|
|
refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
|
|
for(;;) {
|
|
if (refcount_table_clusters == 0) {
|
|
refcount_table_clusters = 1;
|
|
} else {
|
|
refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2;
|
|
}
|
|
new_table_size = refcount_table_clusters << (s->cluster_bits - 3);
|
|
if (min_size <= new_table_size)
|
|
break;
|
|
}
|
|
#ifdef DEBUG_ALLOC2
|
|
printf("grow_refcount_table from %d to %d\n",
|
|
s->refcount_table_size,
|
|
new_table_size);
|
|
#endif
|
|
new_table_size2 = new_table_size * sizeof(uint64_t);
|
|
new_table = qemu_mallocz(new_table_size2);
|
|
memcpy(new_table, s->refcount_table,
|
|
s->refcount_table_size * sizeof(uint64_t));
|
|
for(i = 0; i < s->refcount_table_size; i++)
|
|
cpu_to_be64s(&new_table[i]);
|
|
/* Note: we cannot update the refcount now to avoid recursion */
|
|
table_offset = alloc_clusters_noref(bs, new_table_size2);
|
|
ret = bdrv_pwrite(s->hd, table_offset, new_table, new_table_size2);
|
|
if (ret != new_table_size2)
|
|
goto fail;
|
|
for(i = 0; i < s->refcount_table_size; i++)
|
|
be64_to_cpus(&new_table[i]);
|
|
|
|
cpu_to_be64w((uint64_t*)data, table_offset);
|
|
cpu_to_be32w((uint32_t*)(data + 8), refcount_table_clusters);
|
|
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset),
|
|
data, sizeof(data)) != sizeof(data))
|
|
goto fail;
|
|
qemu_free(s->refcount_table);
|
|
old_table_offset = s->refcount_table_offset;
|
|
old_table_size = s->refcount_table_size;
|
|
s->refcount_table = new_table;
|
|
s->refcount_table_size = new_table_size;
|
|
s->refcount_table_offset = table_offset;
|
|
|
|
update_refcount(bs, table_offset, new_table_size2, 1);
|
|
free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t));
|
|
return 0;
|
|
fail:
|
|
free_clusters(bs, table_offset, new_table_size2);
|
|
qemu_free(new_table);
|
|
return -EIO;
|
|
}
|
|
|
|
/* addend must be 1 or -1 */
|
|
/* XXX: cache several refcount block clusters ? */
|
|
static int update_cluster_refcount(BlockDriverState *bs,
|
|
int64_t cluster_index,
|
|
int addend)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int64_t offset, refcount_block_offset;
|
|
int ret, refcount_table_index, block_index, refcount;
|
|
uint64_t data64;
|
|
|
|
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
|
|
if (refcount_table_index >= s->refcount_table_size) {
|
|
if (addend < 0)
|
|
return -EINVAL;
|
|
ret = grow_refcount_table(bs, refcount_table_index + 1);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
refcount_block_offset = s->refcount_table[refcount_table_index];
|
|
if (!refcount_block_offset) {
|
|
if (addend < 0)
|
|
return -EINVAL;
|
|
/* create a new refcount block */
|
|
/* Note: we cannot update the refcount now to avoid recursion */
|
|
offset = alloc_clusters_noref(bs, s->cluster_size);
|
|
memset(s->refcount_block_cache, 0, s->cluster_size);
|
|
ret = bdrv_pwrite(s->hd, offset, s->refcount_block_cache, s->cluster_size);
|
|
if (ret != s->cluster_size)
|
|
return -EINVAL;
|
|
s->refcount_table[refcount_table_index] = offset;
|
|
data64 = cpu_to_be64(offset);
|
|
ret = bdrv_pwrite(s->hd, s->refcount_table_offset +
|
|
refcount_table_index * sizeof(uint64_t),
|
|
&data64, sizeof(data64));
|
|
if (ret != sizeof(data64))
|
|
return -EINVAL;
|
|
|
|
refcount_block_offset = offset;
|
|
s->refcount_block_cache_offset = offset;
|
|
update_refcount(bs, offset, s->cluster_size, 1);
|
|
} else {
|
|
if (refcount_block_offset != s->refcount_block_cache_offset) {
|
|
if (load_refcount_block(bs, refcount_block_offset) < 0)
|
|
return -EIO;
|
|
}
|
|
}
|
|
/* we can update the count and save it */
|
|
block_index = cluster_index &
|
|
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
|
|
refcount = be16_to_cpu(s->refcount_block_cache[block_index]);
|
|
|
|
if (refcount == 1 && addend == -1)
|
|
s->nc_free += 1;
|
|
else if (refcount == 0 && addend == 1)
|
|
s->nc_free -= 1;
|
|
|
|
refcount += addend;
|
|
if (refcount < 0 || refcount > 0xffff)
|
|
return -EINVAL;
|
|
if (refcount == 0 && cluster_index < s->free_cluster_index) {
|
|
s->free_cluster_index = cluster_index;
|
|
}
|
|
s->refcount_block_cache[block_index] = cpu_to_be16(refcount);
|
|
if (bdrv_pwrite(s->hd,
|
|
refcount_block_offset + (block_index << REFCOUNT_SHIFT),
|
|
&s->refcount_block_cache[block_index], 2) != 2)
|
|
return -EIO;
|
|
return refcount;
|
|
}
|
|
|
|
static void update_refcount(BlockDriverState *bs,
|
|
int64_t offset, int64_t length,
|
|
int addend)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int64_t start, last, cluster_offset;
|
|
|
|
#ifdef DEBUG_ALLOC2
|
|
printf("update_refcount: offset=%lld size=%lld addend=%d\n",
|
|
offset, length, addend);
|
|
#endif
|
|
if (length <= 0)
|
|
return;
|
|
start = offset & ~(s->cluster_size - 1);
|
|
last = (offset + length - 1) & ~(s->cluster_size - 1);
|
|
for(cluster_offset = start; cluster_offset <= last;
|
|
cluster_offset += s->cluster_size) {
|
|
update_cluster_refcount(bs, cluster_offset >> s->cluster_bits, addend);
|
|
}
|
|
}
|
|
|
|
#ifdef DEBUG_ALLOC
|
|
static void inc_refcounts(BlockDriverState *bs,
|
|
uint16_t *refcount_table,
|
|
int refcount_table_size,
|
|
int64_t offset, int64_t size)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int64_t start, last, cluster_offset;
|
|
int k;
|
|
|
|
if (size <= 0)
|
|
return;
|
|
|
|
start = offset & ~(s->cluster_size - 1);
|
|
last = (offset + size - 1) & ~(s->cluster_size - 1);
|
|
for(cluster_offset = start; cluster_offset <= last;
|
|
cluster_offset += s->cluster_size) {
|
|
k = cluster_offset >> s->cluster_bits;
|
|
if (k < 0 || k >= refcount_table_size) {
|
|
printf("ERROR: invalid cluster offset=0x%llx\n", cluster_offset);
|
|
} else {
|
|
if (++refcount_table[k] == 0) {
|
|
printf("ERROR: overflow cluster offset=0x%llx\n", cluster_offset);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static int check_refcounts_l1(BlockDriverState *bs,
|
|
uint16_t *refcount_table,
|
|
int refcount_table_size,
|
|
int64_t l1_table_offset, int l1_size,
|
|
int check_copied)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2;
|
|
int l2_size, i, j, nb_csectors, refcount;
|
|
|
|
l2_table = NULL;
|
|
l1_size2 = l1_size * sizeof(uint64_t);
|
|
|
|
inc_refcounts(bs, refcount_table, refcount_table_size,
|
|
l1_table_offset, l1_size2);
|
|
|
|
l1_table = qemu_malloc(l1_size2);
|
|
if (bdrv_pread(s->hd, l1_table_offset,
|
|
l1_table, l1_size2) != l1_size2)
|
|
goto fail;
|
|
for(i = 0;i < l1_size; i++)
|
|
be64_to_cpus(&l1_table[i]);
|
|
|
|
l2_size = s->l2_size * sizeof(uint64_t);
|
|
l2_table = qemu_malloc(l2_size);
|
|
for(i = 0; i < l1_size; i++) {
|
|
l2_offset = l1_table[i];
|
|
if (l2_offset) {
|
|
if (check_copied) {
|
|
refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits);
|
|
if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) {
|
|
printf("ERROR OFLAG_COPIED: l2_offset=%llx refcount=%d\n",
|
|
l2_offset, refcount);
|
|
}
|
|
}
|
|
l2_offset &= ~QCOW_OFLAG_COPIED;
|
|
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
|
|
goto fail;
|
|
for(j = 0; j < s->l2_size; j++) {
|
|
offset = be64_to_cpu(l2_table[j]);
|
|
if (offset != 0) {
|
|
if (offset & QCOW_OFLAG_COMPRESSED) {
|
|
if (offset & QCOW_OFLAG_COPIED) {
|
|
printf("ERROR: cluster %lld: copied flag must never be set for compressed clusters\n",
|
|
offset >> s->cluster_bits);
|
|
offset &= ~QCOW_OFLAG_COPIED;
|
|
}
|
|
nb_csectors = ((offset >> s->csize_shift) &
|
|
s->csize_mask) + 1;
|
|
offset &= s->cluster_offset_mask;
|
|
inc_refcounts(bs, refcount_table,
|
|
refcount_table_size,
|
|
offset & ~511, nb_csectors * 512);
|
|
} else {
|
|
if (check_copied) {
|
|
refcount = get_refcount(bs, (offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits);
|
|
if ((refcount == 1) != ((offset & QCOW_OFLAG_COPIED) != 0)) {
|
|
printf("ERROR OFLAG_COPIED: offset=%llx refcount=%d\n",
|
|
offset, refcount);
|
|
}
|
|
}
|
|
offset &= ~QCOW_OFLAG_COPIED;
|
|
inc_refcounts(bs, refcount_table,
|
|
refcount_table_size,
|
|
offset, s->cluster_size);
|
|
}
|
|
}
|
|
}
|
|
inc_refcounts(bs, refcount_table,
|
|
refcount_table_size,
|
|
l2_offset,
|
|
s->cluster_size);
|
|
}
|
|
}
|
|
qemu_free(l1_table);
|
|
qemu_free(l2_table);
|
|
return 0;
|
|
fail:
|
|
printf("ERROR: I/O error in check_refcounts_l1\n");
|
|
qemu_free(l1_table);
|
|
qemu_free(l2_table);
|
|
return -EIO;
|
|
}
|
|
|
|
static void check_refcounts(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int64_t size;
|
|
int nb_clusters, refcount1, refcount2, i;
|
|
QCowSnapshot *sn;
|
|
uint16_t *refcount_table;
|
|
|
|
size = bdrv_getlength(s->hd);
|
|
nb_clusters = size_to_clusters(s, size);
|
|
refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t));
|
|
|
|
/* header */
|
|
inc_refcounts(bs, refcount_table, nb_clusters,
|
|
0, s->cluster_size);
|
|
|
|
check_refcounts_l1(bs, refcount_table, nb_clusters,
|
|
s->l1_table_offset, s->l1_size, 1);
|
|
|
|
/* snapshots */
|
|
for(i = 0; i < s->nb_snapshots; i++) {
|
|
sn = s->snapshots + i;
|
|
check_refcounts_l1(bs, refcount_table, nb_clusters,
|
|
sn->l1_table_offset, sn->l1_size, 0);
|
|
}
|
|
inc_refcounts(bs, refcount_table, nb_clusters,
|
|
s->snapshots_offset, s->snapshots_size);
|
|
|
|
/* refcount data */
|
|
inc_refcounts(bs, refcount_table, nb_clusters,
|
|
s->refcount_table_offset,
|
|
s->refcount_table_size * sizeof(uint64_t));
|
|
for(i = 0; i < s->refcount_table_size; i++) {
|
|
int64_t offset;
|
|
offset = s->refcount_table[i];
|
|
if (offset != 0) {
|
|
inc_refcounts(bs, refcount_table, nb_clusters,
|
|
offset, s->cluster_size);
|
|
}
|
|
}
|
|
|
|
/* compare ref counts */
|
|
for(i = 0; i < nb_clusters; i++) {
|
|
refcount1 = get_refcount(bs, i);
|
|
refcount2 = refcount_table[i];
|
|
if (refcount1 != refcount2)
|
|
printf("ERROR cluster %d refcount=%d reference=%d\n",
|
|
i, refcount1, refcount2);
|
|
}
|
|
|
|
qemu_free(refcount_table);
|
|
}
|
|
|
|
#if 0
|
|
static void dump_refcounts(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int64_t nb_clusters, k, k1, size;
|
|
int refcount;
|
|
|
|
size = bdrv_getlength(s->hd);
|
|
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("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1);
|
|
}
|
|
}
|
|
#endif
|
|
#endif
|
|
|
|
BlockDriver bdrv_qcow2 = {
|
|
"qcow2",
|
|
sizeof(BDRVQcowState),
|
|
qcow_probe,
|
|
qcow_open,
|
|
NULL,
|
|
NULL,
|
|
qcow_close,
|
|
qcow_create,
|
|
qcow_flush,
|
|
qcow_is_allocated,
|
|
qcow_set_key,
|
|
qcow_make_empty,
|
|
|
|
.bdrv_aio_read = qcow_aio_read,
|
|
.bdrv_aio_write = qcow_aio_write,
|
|
.bdrv_aio_cancel = qcow_aio_cancel,
|
|
.aiocb_size = sizeof(QCowAIOCB),
|
|
.bdrv_write_compressed = qcow_write_compressed,
|
|
|
|
.bdrv_snapshot_create = qcow_snapshot_create,
|
|
.bdrv_snapshot_goto = qcow_snapshot_goto,
|
|
.bdrv_snapshot_delete = qcow_snapshot_delete,
|
|
.bdrv_snapshot_list = qcow_snapshot_list,
|
|
.bdrv_get_info = qcow_get_info,
|
|
};
|