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/*
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* Block driver for the QCOW version 2 format
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*
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* Copyright (c) 2004-2006 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu-common.h" |
25 |
#include "block_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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/*
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Differences with QCOW:
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- Support for multiple incremental snapshots.
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- Memory management by reference counts.
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- Clusters which have a reference count of one have the bit
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QCOW_OFLAG_COPIED to optimize write performance.
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- Size of compressed clusters is stored in sectors to reduce bit usage
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in the cluster offsets.
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- Support for storing additional data (such as the VM state) in the
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snapshots.
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- If a backing store is used, the cluster size is not constrained
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(could be backported to QCOW).
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- L2 tables have always a size of one cluster.
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*/
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|
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//#define DEBUG_ALLOC
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//#define DEBUG_ALLOC2
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#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) |
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#define QCOW_VERSION 2 |
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|
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#define QCOW_CRYPT_NONE 0 |
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#define QCOW_CRYPT_AES 1 |
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|
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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) |
59 |
|
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#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */ |
61 |
|
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#ifndef offsetof
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#define offsetof(type, field) ((size_t) &((type *)0)->field) |
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#endif
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|
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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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|
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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; |
85 |
|
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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; |
89 |
|
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uint32_t date_sec; |
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uint32_t date_nsec; |
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|
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uint64_t vm_clock_nsec; |
94 |
|
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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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|
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#define L2_CACHE_SIZE 16 |
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|
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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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|
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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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|
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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; |
143 |
|
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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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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; |
153 |
|
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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 int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
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{ |
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const QCowHeader *cow_header = (const void *)buf; |
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|
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if (buf_size >= sizeof(QCowHeader) && |
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be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
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be32_to_cpu(cow_header->version) == QCOW_VERSION) |
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return 100; |
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else
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return 0; |
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} |
187 |
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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; |
193 |
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ret = bdrv_file_open(&s->hd, filename, flags); |
195 |
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); |
200 |
be32_to_cpus(&header.version); |
201 |
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); |
205 |
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; |
225 |
s->cluster_size = 1 << s->cluster_bits;
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s->cluster_sectors = 1 << (s->cluster_bits - 9); |
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s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ |
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s->l2_size = 1 << s->l2_bits;
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bs->total_sectors = header.size / 512;
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s->csize_shift = (62 - (s->cluster_bits - 8)); |
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s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
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s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
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s->refcount_table_offset = header.refcount_table_offset; |
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s->refcount_table_size = |
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header.refcount_table_clusters << (s->cluster_bits - 3);
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|
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s->snapshots_offset = header.snapshots_offset; |
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s->nb_snapshots = header.nb_snapshots; |
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|
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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; |
249 |
s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
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if (!s->l1_table)
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goto fail;
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if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != |
253 |
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]); |
257 |
} |
258 |
/* 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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260 |
if (!s->l2_cache)
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goto fail;
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262 |
s->cluster_cache = qemu_malloc(s->cluster_size); |
263 |
if (!s->cluster_cache)
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goto fail;
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265 |
/* one more sector for decompressed data alignment */
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s->cluster_data = qemu_malloc(s->cluster_size + 512);
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267 |
if (!s->cluster_data)
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goto fail;
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269 |
s->cluster_cache_offset = -1;
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270 |
|
271 |
if (refcount_init(bs) < 0) |
272 |
goto fail;
|
273 |
|
274 |
/* read the backing file name */
|
275 |
if (header.backing_file_offset != 0) { |
276 |
len = header.backing_file_size; |
277 |
if (len > 1023) |
278 |
len = 1023;
|
279 |
if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len)
|
280 |
goto fail;
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281 |
bs->backing_file[len] = '\0';
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282 |
} |
283 |
if (qcow_read_snapshots(bs) < 0) |
284 |
goto fail;
|
285 |
|
286 |
#ifdef DEBUG_ALLOC
|
287 |
check_refcounts(bs); |
288 |
#endif
|
289 |
return 0; |
290 |
|
291 |
fail:
|
292 |
qcow_free_snapshots(bs); |
293 |
refcount_close(bs); |
294 |
qemu_free(s->l1_table); |
295 |
qemu_free(s->l2_cache); |
296 |
qemu_free(s->cluster_cache); |
297 |
qemu_free(s->cluster_data); |
298 |
bdrv_delete(s->hd); |
299 |
return -1; |
300 |
} |
301 |
|
302 |
static int qcow_set_key(BlockDriverState *bs, const char *key) |
303 |
{ |
304 |
BDRVQcowState *s = bs->opaque; |
305 |
uint8_t keybuf[16];
|
306 |
int len, i;
|
307 |
|
308 |
memset(keybuf, 0, 16); |
309 |
len = strlen(key); |
310 |
if (len > 16) |
311 |
len = 16;
|
312 |
/* XXX: we could compress the chars to 7 bits to increase
|
313 |
entropy */
|
314 |
for(i = 0;i < len;i++) { |
315 |
keybuf[i] = key[i]; |
316 |
} |
317 |
s->crypt_method = s->crypt_method_header; |
318 |
|
319 |
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
320 |
return -1; |
321 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
322 |
return -1; |
323 |
#if 0
|
324 |
/* test */
|
325 |
{
|
326 |
uint8_t in[16];
|
327 |
uint8_t out[16];
|
328 |
uint8_t tmp[16];
|
329 |
for(i=0;i<16;i++)
|
330 |
in[i] = i;
|
331 |
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
332 |
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
333 |
for(i = 0; i < 16; i++)
|
334 |
printf(" %02x", tmp[i]);
|
335 |
printf("\n");
|
336 |
for(i = 0; i < 16; i++)
|
337 |
printf(" %02x", out[i]);
|
338 |
printf("\n");
|
339 |
}
|
340 |
#endif
|
341 |
return 0; |
342 |
} |
343 |
|
344 |
/* The crypt function is compatible with the linux cryptoloop
|
345 |
algorithm for < 4 GB images. NOTE: out_buf == in_buf is
|
346 |
supported */
|
347 |
static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
348 |
uint8_t *out_buf, const uint8_t *in_buf,
|
349 |
int nb_sectors, int enc, |
350 |
const AES_KEY *key)
|
351 |
{ |
352 |
union {
|
353 |
uint64_t ll[2];
|
354 |
uint8_t b[16];
|
355 |
} ivec; |
356 |
int i;
|
357 |
|
358 |
for(i = 0; i < nb_sectors; i++) { |
359 |
ivec.ll[0] = cpu_to_le64(sector_num);
|
360 |
ivec.ll[1] = 0; |
361 |
AES_cbc_encrypt(in_buf, out_buf, 512, key,
|
362 |
ivec.b, enc); |
363 |
sector_num++; |
364 |
in_buf += 512;
|
365 |
out_buf += 512;
|
366 |
} |
367 |
} |
368 |
|
369 |
static int copy_sectors(BlockDriverState *bs, uint64_t start_sect, |
370 |
uint64_t cluster_offset, int n_start, int n_end) |
371 |
{ |
372 |
BDRVQcowState *s = bs->opaque; |
373 |
int n, ret;
|
374 |
|
375 |
n = n_end - n_start; |
376 |
if (n <= 0) |
377 |
return 0; |
378 |
ret = qcow_read(bs, start_sect + n_start, s->cluster_data, n); |
379 |
if (ret < 0) |
380 |
return ret;
|
381 |
if (s->crypt_method) {
|
382 |
encrypt_sectors(s, start_sect + n_start, |
383 |
s->cluster_data, |
384 |
s->cluster_data, n, 1,
|
385 |
&s->aes_encrypt_key); |
386 |
} |
387 |
ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start,
|
388 |
s->cluster_data, n); |
389 |
if (ret < 0) |
390 |
return ret;
|
391 |
return 0; |
392 |
} |
393 |
|
394 |
static void l2_cache_reset(BlockDriverState *bs) |
395 |
{ |
396 |
BDRVQcowState *s = bs->opaque; |
397 |
|
398 |
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
399 |
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
400 |
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
401 |
} |
402 |
|
403 |
static inline int l2_cache_new_entry(BlockDriverState *bs) |
404 |
{ |
405 |
BDRVQcowState *s = bs->opaque; |
406 |
uint32_t min_count; |
407 |
int min_index, i;
|
408 |
|
409 |
/* find a new entry in the least used one */
|
410 |
min_index = 0;
|
411 |
min_count = 0xffffffff;
|
412 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
413 |
if (s->l2_cache_counts[i] < min_count) {
|
414 |
min_count = s->l2_cache_counts[i]; |
415 |
min_index = i; |
416 |
} |
417 |
} |
418 |
return min_index;
|
419 |
} |
420 |
|
421 |
static int64_t align_offset(int64_t offset, int n) |
422 |
{ |
423 |
offset = (offset + n - 1) & ~(n - 1); |
424 |
return offset;
|
425 |
} |
426 |
|
427 |
static int grow_l1_table(BlockDriverState *bs, int min_size) |
428 |
{ |
429 |
BDRVQcowState *s = bs->opaque; |
430 |
int new_l1_size, new_l1_size2, ret, i;
|
431 |
uint64_t *new_l1_table; |
432 |
uint64_t new_l1_table_offset; |
433 |
uint64_t data64; |
434 |
uint32_t data32; |
435 |
|
436 |
new_l1_size = s->l1_size; |
437 |
if (min_size <= new_l1_size)
|
438 |
return 0; |
439 |
while (min_size > new_l1_size) {
|
440 |
new_l1_size = (new_l1_size * 3 + 1) / 2; |
441 |
} |
442 |
#ifdef DEBUG_ALLOC2
|
443 |
printf("grow l1_table from %d to %d\n", s->l1_size, new_l1_size);
|
444 |
#endif
|
445 |
|
446 |
new_l1_size2 = sizeof(uint64_t) * new_l1_size;
|
447 |
new_l1_table = qemu_mallocz(new_l1_size2); |
448 |
if (!new_l1_table)
|
449 |
return -ENOMEM;
|
450 |
memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
|
451 |
|
452 |
/* write new table (align to cluster) */
|
453 |
new_l1_table_offset = alloc_clusters(bs, new_l1_size2); |
454 |
|
455 |
for(i = 0; i < s->l1_size; i++) |
456 |
new_l1_table[i] = cpu_to_be64(new_l1_table[i]); |
457 |
ret = bdrv_pwrite(s->hd, new_l1_table_offset, new_l1_table, new_l1_size2); |
458 |
if (ret != new_l1_size2)
|
459 |
goto fail;
|
460 |
for(i = 0; i < s->l1_size; i++) |
461 |
new_l1_table[i] = be64_to_cpu(new_l1_table[i]); |
462 |
|
463 |
/* set new table */
|
464 |
data64 = cpu_to_be64(new_l1_table_offset); |
465 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_table_offset),
|
466 |
&data64, sizeof(data64)) != sizeof(data64)) |
467 |
goto fail;
|
468 |
data32 = cpu_to_be32(new_l1_size); |
469 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_size),
|
470 |
&data32, sizeof(data32)) != sizeof(data32)) |
471 |
goto fail;
|
472 |
qemu_free(s->l1_table); |
473 |
free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t));
|
474 |
s->l1_table_offset = new_l1_table_offset; |
475 |
s->l1_table = new_l1_table; |
476 |
s->l1_size = new_l1_size; |
477 |
return 0; |
478 |
fail:
|
479 |
qemu_free(s->l1_table); |
480 |
return -EIO;
|
481 |
} |
482 |
|
483 |
/*
|
484 |
* seek_l2_table
|
485 |
*
|
486 |
* seek l2_offset in the l2_cache table
|
487 |
* if not found, return NULL,
|
488 |
* if found,
|
489 |
* increments the l2 cache hit count of the entry,
|
490 |
* if counter overflow, divide by two all counters
|
491 |
* return the pointer to the l2 cache entry
|
492 |
*
|
493 |
*/
|
494 |
|
495 |
static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset)
|
496 |
{ |
497 |
int i, j;
|
498 |
|
499 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
500 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
501 |
/* increment the hit count */
|
502 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
503 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
504 |
s->l2_cache_counts[j] >>= 1;
|
505 |
} |
506 |
} |
507 |
return s->l2_cache + (i << s->l2_bits);
|
508 |
} |
509 |
} |
510 |
return NULL; |
511 |
} |
512 |
|
513 |
/*
|
514 |
* l2_load
|
515 |
*
|
516 |
* Loads a L2 table into memory. If the table is in the cache, the cache
|
517 |
* is used; otherwise the L2 table is loaded from the image file.
|
518 |
*
|
519 |
* Returns a pointer to the L2 table on success, or NULL if the read from
|
520 |
* the image file failed.
|
521 |
*/
|
522 |
|
523 |
static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset)
|
524 |
{ |
525 |
BDRVQcowState *s = bs->opaque; |
526 |
int min_index;
|
527 |
uint64_t *l2_table; |
528 |
|
529 |
/* seek if the table for the given offset is in the cache */
|
530 |
|
531 |
l2_table = seek_l2_table(s, l2_offset); |
532 |
if (l2_table != NULL) |
533 |
return l2_table;
|
534 |
|
535 |
/* not found: load a new entry in the least used one */
|
536 |
|
537 |
min_index = l2_cache_new_entry(bs); |
538 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
539 |
if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
540 |
s->l2_size * sizeof(uint64_t))
|
541 |
return NULL; |
542 |
s->l2_cache_offsets[min_index] = l2_offset; |
543 |
s->l2_cache_counts[min_index] = 1;
|
544 |
|
545 |
return l2_table;
|
546 |
} |
547 |
|
548 |
/*
|
549 |
* l2_allocate
|
550 |
*
|
551 |
* Allocate a new l2 entry in the file. If l1_index points to an already
|
552 |
* used entry in the L2 table (i.e. we are doing a copy on write for the L2
|
553 |
* table) copy the contents of the old L2 table into the newly allocated one.
|
554 |
* Otherwise the new table is initialized with zeros.
|
555 |
*
|
556 |
*/
|
557 |
|
558 |
static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index) |
559 |
{ |
560 |
BDRVQcowState *s = bs->opaque; |
561 |
int min_index;
|
562 |
uint64_t old_l2_offset, tmp; |
563 |
uint64_t *l2_table, l2_offset; |
564 |
|
565 |
old_l2_offset = s->l1_table[l1_index]; |
566 |
|
567 |
/* allocate a new l2 entry */
|
568 |
|
569 |
l2_offset = alloc_clusters(bs, s->l2_size * sizeof(uint64_t));
|
570 |
|
571 |
/* update the L1 entry */
|
572 |
|
573 |
s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; |
574 |
|
575 |
tmp = cpu_to_be64(l2_offset | QCOW_OFLAG_COPIED); |
576 |
if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), |
577 |
&tmp, sizeof(tmp)) != sizeof(tmp)) |
578 |
return NULL; |
579 |
|
580 |
/* allocate a new entry in the l2 cache */
|
581 |
|
582 |
min_index = l2_cache_new_entry(bs); |
583 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
584 |
|
585 |
if (old_l2_offset == 0) { |
586 |
/* if there was no old l2 table, clear the new table */
|
587 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
588 |
} else {
|
589 |
/* if there was an old l2 table, read it from the disk */
|
590 |
if (bdrv_pread(s->hd, old_l2_offset,
|
591 |
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
592 |
s->l2_size * sizeof(uint64_t))
|
593 |
return NULL; |
594 |
} |
595 |
/* write the l2 table to the file */
|
596 |
if (bdrv_pwrite(s->hd, l2_offset,
|
597 |
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
598 |
s->l2_size * sizeof(uint64_t))
|
599 |
return NULL; |
600 |
|
601 |
/* update the l2 cache entry */
|
602 |
|
603 |
s->l2_cache_offsets[min_index] = l2_offset; |
604 |
s->l2_cache_counts[min_index] = 1;
|
605 |
|
606 |
return l2_table;
|
607 |
} |
608 |
|
609 |
/*
|
610 |
* get_cluster_offset
|
611 |
*
|
612 |
* For a given offset of the disk image, return cluster offset in
|
613 |
* qcow2 file.
|
614 |
*
|
615 |
* Return 1, if the offset is found
|
616 |
* Return 0, otherwise.
|
617 |
*
|
618 |
*/
|
619 |
|
620 |
static uint64_t get_cluster_offset(BlockDriverState *bs, uint64_t offset)
|
621 |
{ |
622 |
BDRVQcowState *s = bs->opaque; |
623 |
int l1_index, l2_index;
|
624 |
uint64_t l2_offset, *l2_table, cluster_offset; |
625 |
|
626 |
/* seek the the l2 offset in the l1 table */
|
627 |
|
628 |
l1_index = offset >> (s->l2_bits + s->cluster_bits); |
629 |
if (l1_index >= s->l1_size)
|
630 |
return 0; |
631 |
|
632 |
l2_offset = s->l1_table[l1_index]; |
633 |
|
634 |
/* seek the l2 table of the given l2 offset */
|
635 |
|
636 |
if (!l2_offset)
|
637 |
return 0; |
638 |
|
639 |
/* load the l2 table in memory */
|
640 |
|
641 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
642 |
l2_table = l2_load(bs, l2_offset); |
643 |
if (l2_table == NULL) |
644 |
return 0; |
645 |
|
646 |
/* find the cluster offset for the given disk offset */
|
647 |
|
648 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
649 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
650 |
|
651 |
return cluster_offset & ~QCOW_OFLAG_COPIED;
|
652 |
} |
653 |
|
654 |
/*
|
655 |
* alloc_cluster_offset
|
656 |
*
|
657 |
* For a given offset of the disk image, return cluster offset in
|
658 |
* qcow2 file.
|
659 |
*
|
660 |
* If the offset is not found, allocate a new cluster.
|
661 |
*
|
662 |
* Return the cluster offset if successful,
|
663 |
* Return 0, otherwise.
|
664 |
*
|
665 |
*/
|
666 |
|
667 |
static uint64_t alloc_cluster_offset(BlockDriverState *bs,
|
668 |
uint64_t offset, |
669 |
int compressed_size,
|
670 |
int n_start, int n_end) |
671 |
{ |
672 |
BDRVQcowState *s = bs->opaque; |
673 |
int l1_index, l2_index, ret;
|
674 |
uint64_t l2_offset, *l2_table, cluster_offset; |
675 |
|
676 |
/* seek the the l2 offset in the l1 table */
|
677 |
|
678 |
l1_index = offset >> (s->l2_bits + s->cluster_bits); |
679 |
if (l1_index >= s->l1_size) {
|
680 |
ret = grow_l1_table(bs, l1_index + 1);
|
681 |
if (ret < 0) |
682 |
return 0; |
683 |
} |
684 |
l2_offset = s->l1_table[l1_index]; |
685 |
|
686 |
/* seek the l2 table of the given l2 offset */
|
687 |
|
688 |
if (l2_offset & QCOW_OFLAG_COPIED) {
|
689 |
/* load the l2 table in memory */
|
690 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
691 |
l2_table = l2_load(bs, l2_offset); |
692 |
if (l2_table == NULL) |
693 |
return 0; |
694 |
} else {
|
695 |
if (l2_offset)
|
696 |
free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t));
|
697 |
l2_table = l2_allocate(bs, l1_index); |
698 |
if (l2_table == NULL) |
699 |
return 0; |
700 |
l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED; |
701 |
} |
702 |
|
703 |
/* find the cluster offset for the given disk offset */
|
704 |
|
705 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
706 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
707 |
|
708 |
if (cluster_offset & QCOW_OFLAG_COPIED)
|
709 |
return cluster_offset & ~QCOW_OFLAG_COPIED;
|
710 |
|
711 |
if (cluster_offset) {
|
712 |
/* free the cluster */
|
713 |
if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
714 |
int nb_csectors;
|
715 |
nb_csectors = ((cluster_offset >> s->csize_shift) & |
716 |
s->csize_mask) + 1;
|
717 |
free_clusters(bs, (cluster_offset & s->cluster_offset_mask) & ~511,
|
718 |
nb_csectors * 512);
|
719 |
} else {
|
720 |
free_clusters(bs, cluster_offset, s->cluster_size); |
721 |
} |
722 |
} |
723 |
|
724 |
if (compressed_size) {
|
725 |
int nb_csectors;
|
726 |
|
727 |
cluster_offset = alloc_bytes(bs, compressed_size); |
728 |
nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) - |
729 |
(cluster_offset >> 9);
|
730 |
|
731 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
732 |
((uint64_t)nb_csectors << s->csize_shift); |
733 |
|
734 |
/* update L2 table */
|
735 |
|
736 |
/* compressed clusters never have the copied flag */
|
737 |
|
738 |
l2_table[l2_index] = cpu_to_be64(cluster_offset); |
739 |
if (bdrv_pwrite(s->hd,
|
740 |
l2_offset + l2_index * sizeof(uint64_t),
|
741 |
l2_table + l2_index, |
742 |
sizeof(uint64_t)) != sizeof(uint64_t)) |
743 |
return 0; |
744 |
|
745 |
return cluster_offset;
|
746 |
} |
747 |
|
748 |
/* allocate a new cluster */
|
749 |
|
750 |
cluster_offset = alloc_clusters(bs, s->cluster_size); |
751 |
|
752 |
/* we must initialize the cluster content which won't be
|
753 |
written */
|
754 |
|
755 |
if ((n_end - n_start) < s->cluster_sectors) {
|
756 |
uint64_t start_sect; |
757 |
|
758 |
start_sect = (offset & ~(s->cluster_size - 1)) >> 9; |
759 |
ret = copy_sectors(bs, start_sect, |
760 |
cluster_offset, 0, n_start);
|
761 |
if (ret < 0) |
762 |
return 0; |
763 |
ret = copy_sectors(bs, start_sect, |
764 |
cluster_offset, n_end, s->cluster_sectors); |
765 |
if (ret < 0) |
766 |
return 0; |
767 |
} |
768 |
|
769 |
/* update L2 table */
|
770 |
|
771 |
l2_table[l2_index] = cpu_to_be64(cluster_offset | QCOW_OFLAG_COPIED); |
772 |
if (bdrv_pwrite(s->hd,
|
773 |
l2_offset + l2_index * sizeof(uint64_t),
|
774 |
l2_table + l2_index, |
775 |
sizeof(uint64_t)) != sizeof(uint64_t)) |
776 |
return 0; |
777 |
|
778 |
return cluster_offset;
|
779 |
} |
780 |
|
781 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
782 |
int nb_sectors, int *pnum) |
783 |
{ |
784 |
BDRVQcowState *s = bs->opaque; |
785 |
int index_in_cluster, n;
|
786 |
uint64_t cluster_offset; |
787 |
|
788 |
cluster_offset = get_cluster_offset(bs, sector_num << 9);
|
789 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
790 |
n = s->cluster_sectors - index_in_cluster; |
791 |
if (n > nb_sectors)
|
792 |
n = nb_sectors; |
793 |
*pnum = n; |
794 |
return (cluster_offset != 0); |
795 |
} |
796 |
|
797 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
798 |
const uint8_t *buf, int buf_size) |
799 |
{ |
800 |
z_stream strm1, *strm = &strm1; |
801 |
int ret, out_len;
|
802 |
|
803 |
memset(strm, 0, sizeof(*strm)); |
804 |
|
805 |
strm->next_in = (uint8_t *)buf; |
806 |
strm->avail_in = buf_size; |
807 |
strm->next_out = out_buf; |
808 |
strm->avail_out = out_buf_size; |
809 |
|
810 |
ret = inflateInit2(strm, -12);
|
811 |
if (ret != Z_OK)
|
812 |
return -1; |
813 |
ret = inflate(strm, Z_FINISH); |
814 |
out_len = strm->next_out - out_buf; |
815 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
816 |
out_len != out_buf_size) { |
817 |
inflateEnd(strm); |
818 |
return -1; |
819 |
} |
820 |
inflateEnd(strm); |
821 |
return 0; |
822 |
} |
823 |
|
824 |
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) |
825 |
{ |
826 |
int ret, csize, nb_csectors, sector_offset;
|
827 |
uint64_t coffset; |
828 |
|
829 |
coffset = cluster_offset & s->cluster_offset_mask; |
830 |
if (s->cluster_cache_offset != coffset) {
|
831 |
nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
|
832 |
sector_offset = coffset & 511;
|
833 |
csize = nb_csectors * 512 - sector_offset;
|
834 |
ret = bdrv_read(s->hd, coffset >> 9, s->cluster_data, nb_csectors);
|
835 |
if (ret < 0) { |
836 |
return -1; |
837 |
} |
838 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
839 |
s->cluster_data + sector_offset, csize) < 0) {
|
840 |
return -1; |
841 |
} |
842 |
s->cluster_cache_offset = coffset; |
843 |
} |
844 |
return 0; |
845 |
} |
846 |
|
847 |
/* handle reading after the end of the backing file */
|
848 |
static int backing_read1(BlockDriverState *bs, |
849 |
int64_t sector_num, uint8_t *buf, int nb_sectors)
|
850 |
{ |
851 |
int n1;
|
852 |
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
853 |
return nb_sectors;
|
854 |
if (sector_num >= bs->total_sectors)
|
855 |
n1 = 0;
|
856 |
else
|
857 |
n1 = bs->total_sectors - sector_num; |
858 |
memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1)); |
859 |
return n1;
|
860 |
} |
861 |
|
862 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
863 |
uint8_t *buf, int nb_sectors)
|
864 |
{ |
865 |
BDRVQcowState *s = bs->opaque; |
866 |
int ret, index_in_cluster, n, n1;
|
867 |
uint64_t cluster_offset; |
868 |
|
869 |
while (nb_sectors > 0) { |
870 |
cluster_offset = get_cluster_offset(bs, sector_num << 9);
|
871 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
872 |
n = s->cluster_sectors - index_in_cluster; |
873 |
if (n > nb_sectors)
|
874 |
n = nb_sectors; |
875 |
if (!cluster_offset) {
|
876 |
if (bs->backing_hd) {
|
877 |
/* read from the base image */
|
878 |
n1 = backing_read1(bs->backing_hd, sector_num, buf, n); |
879 |
if (n1 > 0) { |
880 |
ret = bdrv_read(bs->backing_hd, sector_num, buf, n1); |
881 |
if (ret < 0) |
882 |
return -1; |
883 |
} |
884 |
} else {
|
885 |
memset(buf, 0, 512 * n); |
886 |
} |
887 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
888 |
if (decompress_cluster(s, cluster_offset) < 0) |
889 |
return -1; |
890 |
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); |
891 |
} else {
|
892 |
ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
893 |
if (ret != n * 512) |
894 |
return -1; |
895 |
if (s->crypt_method) {
|
896 |
encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
897 |
&s->aes_decrypt_key); |
898 |
} |
899 |
} |
900 |
nb_sectors -= n; |
901 |
sector_num += n; |
902 |
buf += n * 512;
|
903 |
} |
904 |
return 0; |
905 |
} |
906 |
|
907 |
static int qcow_write(BlockDriverState *bs, int64_t sector_num, |
908 |
const uint8_t *buf, int nb_sectors) |
909 |
{ |
910 |
BDRVQcowState *s = bs->opaque; |
911 |
int ret, index_in_cluster, n;
|
912 |
uint64_t cluster_offset; |
913 |
|
914 |
while (nb_sectors > 0) { |
915 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
916 |
n = s->cluster_sectors - index_in_cluster; |
917 |
if (n > nb_sectors)
|
918 |
n = nb_sectors; |
919 |
cluster_offset = alloc_cluster_offset(bs, sector_num << 9, 0, |
920 |
index_in_cluster, |
921 |
index_in_cluster + n); |
922 |
if (!cluster_offset)
|
923 |
return -1; |
924 |
if (s->crypt_method) {
|
925 |
encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1,
|
926 |
&s->aes_encrypt_key); |
927 |
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512,
|
928 |
s->cluster_data, n * 512);
|
929 |
} else {
|
930 |
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
931 |
} |
932 |
if (ret != n * 512) |
933 |
return -1; |
934 |
nb_sectors -= n; |
935 |
sector_num += n; |
936 |
buf += n * 512;
|
937 |
} |
938 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
939 |
return 0; |
940 |
} |
941 |
|
942 |
typedef struct QCowAIOCB { |
943 |
BlockDriverAIOCB common; |
944 |
int64_t sector_num; |
945 |
uint8_t *buf; |
946 |
int nb_sectors;
|
947 |
int n;
|
948 |
uint64_t cluster_offset; |
949 |
uint8_t *cluster_data; |
950 |
BlockDriverAIOCB *hd_aiocb; |
951 |
} QCowAIOCB; |
952 |
|
953 |
static void qcow_aio_read_cb(void *opaque, int ret) |
954 |
{ |
955 |
QCowAIOCB *acb = opaque; |
956 |
BlockDriverState *bs = acb->common.bs; |
957 |
BDRVQcowState *s = bs->opaque; |
958 |
int index_in_cluster, n1;
|
959 |
|
960 |
acb->hd_aiocb = NULL;
|
961 |
if (ret < 0) { |
962 |
fail:
|
963 |
acb->common.cb(acb->common.opaque, ret); |
964 |
qemu_aio_release(acb); |
965 |
return;
|
966 |
} |
967 |
|
968 |
redo:
|
969 |
/* post process the read buffer */
|
970 |
if (!acb->cluster_offset) {
|
971 |
/* nothing to do */
|
972 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
973 |
/* nothing to do */
|
974 |
} else {
|
975 |
if (s->crypt_method) {
|
976 |
encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, |
977 |
acb->n, 0,
|
978 |
&s->aes_decrypt_key); |
979 |
} |
980 |
} |
981 |
|
982 |
acb->nb_sectors -= acb->n; |
983 |
acb->sector_num += acb->n; |
984 |
acb->buf += acb->n * 512;
|
985 |
|
986 |
if (acb->nb_sectors == 0) { |
987 |
/* request completed */
|
988 |
acb->common.cb(acb->common.opaque, 0);
|
989 |
qemu_aio_release(acb); |
990 |
return;
|
991 |
} |
992 |
|
993 |
/* prepare next AIO request */
|
994 |
acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9);
|
995 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
996 |
acb->n = s->cluster_sectors - index_in_cluster; |
997 |
if (acb->n > acb->nb_sectors)
|
998 |
acb->n = acb->nb_sectors; |
999 |
|
1000 |
if (!acb->cluster_offset) {
|
1001 |
if (bs->backing_hd) {
|
1002 |
/* read from the base image */
|
1003 |
n1 = backing_read1(bs->backing_hd, acb->sector_num, |
1004 |
acb->buf, acb->n); |
1005 |
if (n1 > 0) { |
1006 |
acb->hd_aiocb = bdrv_aio_read(bs->backing_hd, acb->sector_num, |
1007 |
acb->buf, acb->n, qcow_aio_read_cb, acb); |
1008 |
if (acb->hd_aiocb == NULL) |
1009 |
goto fail;
|
1010 |
} else {
|
1011 |
goto redo;
|
1012 |
} |
1013 |
} else {
|
1014 |
/* Note: in this case, no need to wait */
|
1015 |
memset(acb->buf, 0, 512 * acb->n); |
1016 |
goto redo;
|
1017 |
} |
1018 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1019 |
/* add AIO support for compressed blocks ? */
|
1020 |
if (decompress_cluster(s, acb->cluster_offset) < 0) |
1021 |
goto fail;
|
1022 |
memcpy(acb->buf, |
1023 |
s->cluster_cache + index_in_cluster * 512, 512 * acb->n); |
1024 |
goto redo;
|
1025 |
} else {
|
1026 |
if ((acb->cluster_offset & 511) != 0) { |
1027 |
ret = -EIO; |
1028 |
goto fail;
|
1029 |
} |
1030 |
acb->hd_aiocb = bdrv_aio_read(s->hd, |
1031 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
1032 |
acb->buf, acb->n, qcow_aio_read_cb, acb); |
1033 |
if (acb->hd_aiocb == NULL) |
1034 |
goto fail;
|
1035 |
} |
1036 |
} |
1037 |
|
1038 |
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
|
1039 |
int64_t sector_num, uint8_t *buf, int nb_sectors,
|
1040 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1041 |
{ |
1042 |
QCowAIOCB *acb; |
1043 |
|
1044 |
acb = qemu_aio_get(bs, cb, opaque); |
1045 |
if (!acb)
|
1046 |
return NULL; |
1047 |
acb->hd_aiocb = NULL;
|
1048 |
acb->sector_num = sector_num; |
1049 |
acb->buf = buf; |
1050 |
acb->nb_sectors = nb_sectors; |
1051 |
acb->n = 0;
|
1052 |
acb->cluster_offset = 0;
|
1053 |
return acb;
|
1054 |
} |
1055 |
|
1056 |
static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs,
|
1057 |
int64_t sector_num, uint8_t *buf, int nb_sectors,
|
1058 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1059 |
{ |
1060 |
QCowAIOCB *acb; |
1061 |
|
1062 |
acb = qcow_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque); |
1063 |
if (!acb)
|
1064 |
return NULL; |
1065 |
|
1066 |
qcow_aio_read_cb(acb, 0);
|
1067 |
return &acb->common;
|
1068 |
} |
1069 |
|
1070 |
static void qcow_aio_write_cb(void *opaque, int ret) |
1071 |
{ |
1072 |
QCowAIOCB *acb = opaque; |
1073 |
BlockDriverState *bs = acb->common.bs; |
1074 |
BDRVQcowState *s = bs->opaque; |
1075 |
int index_in_cluster;
|
1076 |
uint64_t cluster_offset; |
1077 |
const uint8_t *src_buf;
|
1078 |
|
1079 |
acb->hd_aiocb = NULL;
|
1080 |
|
1081 |
if (ret < 0) { |
1082 |
fail:
|
1083 |
acb->common.cb(acb->common.opaque, ret); |
1084 |
qemu_aio_release(acb); |
1085 |
return;
|
1086 |
} |
1087 |
|
1088 |
acb->nb_sectors -= acb->n; |
1089 |
acb->sector_num += acb->n; |
1090 |
acb->buf += acb->n * 512;
|
1091 |
|
1092 |
if (acb->nb_sectors == 0) { |
1093 |
/* request completed */
|
1094 |
acb->common.cb(acb->common.opaque, 0);
|
1095 |
qemu_aio_release(acb); |
1096 |
return;
|
1097 |
} |
1098 |
|
1099 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
1100 |
acb->n = s->cluster_sectors - index_in_cluster; |
1101 |
if (acb->n > acb->nb_sectors)
|
1102 |
acb->n = acb->nb_sectors; |
1103 |
cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9, 0, |
1104 |
index_in_cluster, |
1105 |
index_in_cluster + acb->n); |
1106 |
if (!cluster_offset || (cluster_offset & 511) != 0) { |
1107 |
ret = -EIO; |
1108 |
goto fail;
|
1109 |
} |
1110 |
if (s->crypt_method) {
|
1111 |
if (!acb->cluster_data) {
|
1112 |
acb->cluster_data = qemu_mallocz(s->cluster_size); |
1113 |
if (!acb->cluster_data) {
|
1114 |
ret = -ENOMEM; |
1115 |
goto fail;
|
1116 |
} |
1117 |
} |
1118 |
encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, |
1119 |
acb->n, 1, &s->aes_encrypt_key);
|
1120 |
src_buf = acb->cluster_data; |
1121 |
} else {
|
1122 |
src_buf = acb->buf; |
1123 |
} |
1124 |
acb->hd_aiocb = bdrv_aio_write(s->hd, |
1125 |
(cluster_offset >> 9) + index_in_cluster,
|
1126 |
src_buf, acb->n, |
1127 |
qcow_aio_write_cb, acb); |
1128 |
if (acb->hd_aiocb == NULL) |
1129 |
goto fail;
|
1130 |
} |
1131 |
|
1132 |
static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs,
|
1133 |
int64_t sector_num, const uint8_t *buf, int nb_sectors, |
1134 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1135 |
{ |
1136 |
BDRVQcowState *s = bs->opaque; |
1137 |
QCowAIOCB *acb; |
1138 |
|
1139 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
1140 |
|
1141 |
acb = qcow_aio_setup(bs, sector_num, (uint8_t*)buf, nb_sectors, cb, opaque); |
1142 |
if (!acb)
|
1143 |
return NULL; |
1144 |
|
1145 |
qcow_aio_write_cb(acb, 0);
|
1146 |
return &acb->common;
|
1147 |
} |
1148 |
|
1149 |
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) |
1150 |
{ |
1151 |
QCowAIOCB *acb = (QCowAIOCB *)blockacb; |
1152 |
if (acb->hd_aiocb)
|
1153 |
bdrv_aio_cancel(acb->hd_aiocb); |
1154 |
qemu_aio_release(acb); |
1155 |
} |
1156 |
|
1157 |
static void qcow_close(BlockDriverState *bs) |
1158 |
{ |
1159 |
BDRVQcowState *s = bs->opaque; |
1160 |
qemu_free(s->l1_table); |
1161 |
qemu_free(s->l2_cache); |
1162 |
qemu_free(s->cluster_cache); |
1163 |
qemu_free(s->cluster_data); |
1164 |
refcount_close(bs); |
1165 |
bdrv_delete(s->hd); |
1166 |
} |
1167 |
|
1168 |
/* XXX: use std qcow open function ? */
|
1169 |
typedef struct QCowCreateState { |
1170 |
int cluster_size;
|
1171 |
int cluster_bits;
|
1172 |
uint16_t *refcount_block; |
1173 |
uint64_t *refcount_table; |
1174 |
int64_t l1_table_offset; |
1175 |
int64_t refcount_table_offset; |
1176 |
int64_t refcount_block_offset; |
1177 |
} QCowCreateState; |
1178 |
|
1179 |
static void create_refcount_update(QCowCreateState *s, |
1180 |
int64_t offset, int64_t size) |
1181 |
{ |
1182 |
int refcount;
|
1183 |
int64_t start, last, cluster_offset; |
1184 |
uint16_t *p; |
1185 |
|
1186 |
start = offset & ~(s->cluster_size - 1);
|
1187 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
1188 |
for(cluster_offset = start; cluster_offset <= last;
|
1189 |
cluster_offset += s->cluster_size) { |
1190 |
p = &s->refcount_block[cluster_offset >> s->cluster_bits]; |
1191 |
refcount = be16_to_cpu(*p); |
1192 |
refcount++; |
1193 |
*p = cpu_to_be16(refcount); |
1194 |
} |
1195 |
} |
1196 |
|
1197 |
static int qcow_create(const char *filename, int64_t total_size, |
1198 |
const char *backing_file, int flags) |
1199 |
{ |
1200 |
int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
|
1201 |
QCowHeader header; |
1202 |
uint64_t tmp, offset; |
1203 |
QCowCreateState s1, *s = &s1; |
1204 |
|
1205 |
memset(s, 0, sizeof(*s)); |
1206 |
|
1207 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
1208 |
if (fd < 0) |
1209 |
return -1; |
1210 |
memset(&header, 0, sizeof(header)); |
1211 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
1212 |
header.version = cpu_to_be32(QCOW_VERSION); |
1213 |
header.size = cpu_to_be64(total_size * 512);
|
1214 |
header_size = sizeof(header);
|
1215 |
backing_filename_len = 0;
|
1216 |
if (backing_file) {
|
1217 |
header.backing_file_offset = cpu_to_be64(header_size); |
1218 |
backing_filename_len = strlen(backing_file); |
1219 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
1220 |
header_size += backing_filename_len; |
1221 |
} |
1222 |
s->cluster_bits = 12; /* 4 KB clusters */ |
1223 |
s->cluster_size = 1 << s->cluster_bits;
|
1224 |
header.cluster_bits = cpu_to_be32(s->cluster_bits); |
1225 |
header_size = (header_size + 7) & ~7; |
1226 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
1227 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
1228 |
} else {
|
1229 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
1230 |
} |
1231 |
l2_bits = s->cluster_bits - 3;
|
1232 |
shift = s->cluster_bits + l2_bits; |
1233 |
l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift); |
1234 |
offset = align_offset(header_size, s->cluster_size); |
1235 |
s->l1_table_offset = offset; |
1236 |
header.l1_table_offset = cpu_to_be64(s->l1_table_offset); |
1237 |
header.l1_size = cpu_to_be32(l1_size); |
1238 |
offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
|
1239 |
|
1240 |
s->refcount_table = qemu_mallocz(s->cluster_size); |
1241 |
if (!s->refcount_table)
|
1242 |
goto fail;
|
1243 |
s->refcount_block = qemu_mallocz(s->cluster_size); |
1244 |
if (!s->refcount_block)
|
1245 |
goto fail;
|
1246 |
|
1247 |
s->refcount_table_offset = offset; |
1248 |
header.refcount_table_offset = cpu_to_be64(offset); |
1249 |
header.refcount_table_clusters = cpu_to_be32(1);
|
1250 |
offset += s->cluster_size; |
1251 |
|
1252 |
s->refcount_table[0] = cpu_to_be64(offset);
|
1253 |
s->refcount_block_offset = offset; |
1254 |
offset += s->cluster_size; |
1255 |
|
1256 |
/* update refcounts */
|
1257 |
create_refcount_update(s, 0, header_size);
|
1258 |
create_refcount_update(s, s->l1_table_offset, l1_size * sizeof(uint64_t));
|
1259 |
create_refcount_update(s, s->refcount_table_offset, s->cluster_size); |
1260 |
create_refcount_update(s, s->refcount_block_offset, s->cluster_size); |
1261 |
|
1262 |
/* write all the data */
|
1263 |
write(fd, &header, sizeof(header));
|
1264 |
if (backing_file) {
|
1265 |
write(fd, backing_file, backing_filename_len); |
1266 |
} |
1267 |
lseek(fd, s->l1_table_offset, SEEK_SET); |
1268 |
tmp = 0;
|
1269 |
for(i = 0;i < l1_size; i++) { |
1270 |
write(fd, &tmp, sizeof(tmp));
|
1271 |
} |
1272 |
lseek(fd, s->refcount_table_offset, SEEK_SET); |
1273 |
write(fd, s->refcount_table, s->cluster_size); |
1274 |
|
1275 |
lseek(fd, s->refcount_block_offset, SEEK_SET); |
1276 |
write(fd, s->refcount_block, s->cluster_size); |
1277 |
|
1278 |
qemu_free(s->refcount_table); |
1279 |
qemu_free(s->refcount_block); |
1280 |
close(fd); |
1281 |
return 0; |
1282 |
fail:
|
1283 |
qemu_free(s->refcount_table); |
1284 |
qemu_free(s->refcount_block); |
1285 |
close(fd); |
1286 |
return -ENOMEM;
|
1287 |
} |
1288 |
|
1289 |
static int qcow_make_empty(BlockDriverState *bs) |
1290 |
{ |
1291 |
#if 0
|
1292 |
/* XXX: not correct */
|
1293 |
BDRVQcowState *s = bs->opaque;
|
1294 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
1295 |
int ret;
|
1296 |
|
1297 |
memset(s->l1_table, 0, l1_length);
|
1298 |
if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
1299 |
return -1;
|
1300 |
ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length);
|
1301 |
if (ret < 0)
|
1302 |
return ret;
|
1303 |
|
1304 |
l2_cache_reset(bs);
|
1305 |
#endif
|
1306 |
return 0; |
1307 |
} |
1308 |
|
1309 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
1310 |
tables to avoid losing bytes in alignment */
|
1311 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
1312 |
const uint8_t *buf, int nb_sectors) |
1313 |
{ |
1314 |
BDRVQcowState *s = bs->opaque; |
1315 |
z_stream strm; |
1316 |
int ret, out_len;
|
1317 |
uint8_t *out_buf; |
1318 |
uint64_t cluster_offset; |
1319 |
|
1320 |
if (nb_sectors == 0) { |
1321 |
/* align end of file to a sector boundary to ease reading with
|
1322 |
sector based I/Os */
|
1323 |
cluster_offset = bdrv_getlength(s->hd); |
1324 |
cluster_offset = (cluster_offset + 511) & ~511; |
1325 |
bdrv_truncate(s->hd, cluster_offset); |
1326 |
return 0; |
1327 |
} |
1328 |
|
1329 |
if (nb_sectors != s->cluster_sectors)
|
1330 |
return -EINVAL;
|
1331 |
|
1332 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
1333 |
if (!out_buf)
|
1334 |
return -ENOMEM;
|
1335 |
|
1336 |
/* best compression, small window, no zlib header */
|
1337 |
memset(&strm, 0, sizeof(strm)); |
1338 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
1339 |
Z_DEFLATED, -12,
|
1340 |
9, Z_DEFAULT_STRATEGY);
|
1341 |
if (ret != 0) { |
1342 |
qemu_free(out_buf); |
1343 |
return -1; |
1344 |
} |
1345 |
|
1346 |
strm.avail_in = s->cluster_size; |
1347 |
strm.next_in = (uint8_t *)buf; |
1348 |
strm.avail_out = s->cluster_size; |
1349 |
strm.next_out = out_buf; |
1350 |
|
1351 |
ret = deflate(&strm, Z_FINISH); |
1352 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
1353 |
qemu_free(out_buf); |
1354 |
deflateEnd(&strm); |
1355 |
return -1; |
1356 |
} |
1357 |
out_len = strm.next_out - out_buf; |
1358 |
|
1359 |
deflateEnd(&strm); |
1360 |
|
1361 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
1362 |
/* could not compress: write normal cluster */
|
1363 |
qcow_write(bs, sector_num, buf, s->cluster_sectors); |
1364 |
} else {
|
1365 |
cluster_offset = alloc_cluster_offset(bs, sector_num << 9,
|
1366 |
out_len, 0, 0); |
1367 |
cluster_offset &= s->cluster_offset_mask; |
1368 |
if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
|
1369 |
qemu_free(out_buf); |
1370 |
return -1; |
1371 |
} |
1372 |
} |
1373 |
|
1374 |
qemu_free(out_buf); |
1375 |
return 0; |
1376 |
} |
1377 |
|
1378 |
static void qcow_flush(BlockDriverState *bs) |
1379 |
{ |
1380 |
BDRVQcowState *s = bs->opaque; |
1381 |
bdrv_flush(s->hd); |
1382 |
} |
1383 |
|
1384 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
1385 |
{ |
1386 |
BDRVQcowState *s = bs->opaque; |
1387 |
bdi->cluster_size = s->cluster_size; |
1388 |
bdi->vm_state_offset = (int64_t)s->l1_vm_state_index << |
1389 |
(s->cluster_bits + s->l2_bits); |
1390 |
return 0; |
1391 |
} |
1392 |
|
1393 |
/*********************************************************/
|
1394 |
/* snapshot support */
|
1395 |
|
1396 |
/* update the refcounts of snapshots and the copied flag */
|
1397 |
static int update_snapshot_refcount(BlockDriverState *bs, |
1398 |
int64_t l1_table_offset, |
1399 |
int l1_size,
|
1400 |
int addend)
|
1401 |
{ |
1402 |
BDRVQcowState *s = bs->opaque; |
1403 |
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; |
1404 |
int64_t old_offset, old_l2_offset; |
1405 |
int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount;
|
1406 |
|
1407 |
l2_cache_reset(bs); |
1408 |
|
1409 |
l2_table = NULL;
|
1410 |
l1_table = NULL;
|
1411 |
l1_size2 = l1_size * sizeof(uint64_t);
|
1412 |
l1_allocated = 0;
|
1413 |
if (l1_table_offset != s->l1_table_offset) {
|
1414 |
l1_table = qemu_malloc(l1_size2); |
1415 |
if (!l1_table)
|
1416 |
goto fail;
|
1417 |
l1_allocated = 1;
|
1418 |
if (bdrv_pread(s->hd, l1_table_offset,
|
1419 |
l1_table, l1_size2) != l1_size2) |
1420 |
goto fail;
|
1421 |
for(i = 0;i < l1_size; i++) |
1422 |
be64_to_cpus(&l1_table[i]); |
1423 |
} else {
|
1424 |
assert(l1_size == s->l1_size); |
1425 |
l1_table = s->l1_table; |
1426 |
l1_allocated = 0;
|
1427 |
} |
1428 |
|
1429 |
l2_size = s->l2_size * sizeof(uint64_t);
|
1430 |
l2_table = qemu_malloc(l2_size); |
1431 |
if (!l2_table)
|
1432 |
goto fail;
|
1433 |
l1_modified = 0;
|
1434 |
for(i = 0; i < l1_size; i++) { |
1435 |
l2_offset = l1_table[i]; |
1436 |
if (l2_offset) {
|
1437 |
old_l2_offset = l2_offset; |
1438 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
1439 |
l2_modified = 0;
|
1440 |
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
|
1441 |
goto fail;
|
1442 |
for(j = 0; j < s->l2_size; j++) { |
1443 |
offset = be64_to_cpu(l2_table[j]); |
1444 |
if (offset != 0) { |
1445 |
old_offset = offset; |
1446 |
offset &= ~QCOW_OFLAG_COPIED; |
1447 |
if (offset & QCOW_OFLAG_COMPRESSED) {
|
1448 |
nb_csectors = ((offset >> s->csize_shift) & |
1449 |
s->csize_mask) + 1;
|
1450 |
if (addend != 0) |
1451 |
update_refcount(bs, (offset & s->cluster_offset_mask) & ~511,
|
1452 |
nb_csectors * 512, addend);
|
1453 |
/* compressed clusters are never modified */
|
1454 |
refcount = 2;
|
1455 |
} else {
|
1456 |
if (addend != 0) { |
1457 |
refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend); |
1458 |
} else {
|
1459 |
refcount = get_refcount(bs, offset >> s->cluster_bits); |
1460 |
} |
1461 |
} |
1462 |
|
1463 |
if (refcount == 1) { |
1464 |
offset |= QCOW_OFLAG_COPIED; |
1465 |
} |
1466 |
if (offset != old_offset) {
|
1467 |
l2_table[j] = cpu_to_be64(offset); |
1468 |
l2_modified = 1;
|
1469 |
} |
1470 |
} |
1471 |
} |
1472 |
if (l2_modified) {
|
1473 |
if (bdrv_pwrite(s->hd,
|
1474 |
l2_offset, l2_table, l2_size) != l2_size) |
1475 |
goto fail;
|
1476 |
} |
1477 |
|
1478 |
if (addend != 0) { |
1479 |
refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); |
1480 |
} else {
|
1481 |
refcount = get_refcount(bs, l2_offset >> s->cluster_bits); |
1482 |
} |
1483 |
if (refcount == 1) { |
1484 |
l2_offset |= QCOW_OFLAG_COPIED; |
1485 |
} |
1486 |
if (l2_offset != old_l2_offset) {
|
1487 |
l1_table[i] = l2_offset; |
1488 |
l1_modified = 1;
|
1489 |
} |
1490 |
} |
1491 |
} |
1492 |
if (l1_modified) {
|
1493 |
for(i = 0; i < l1_size; i++) |
1494 |
cpu_to_be64s(&l1_table[i]); |
1495 |
if (bdrv_pwrite(s->hd, l1_table_offset, l1_table,
|
1496 |
l1_size2) != l1_size2) |
1497 |
goto fail;
|
1498 |
for(i = 0; i < l1_size; i++) |
1499 |
be64_to_cpus(&l1_table[i]); |
1500 |
} |
1501 |
if (l1_allocated)
|
1502 |
qemu_free(l1_table); |
1503 |
qemu_free(l2_table); |
1504 |
return 0; |
1505 |
fail:
|
1506 |
if (l1_allocated)
|
1507 |
qemu_free(l1_table); |
1508 |
qemu_free(l2_table); |
1509 |
return -EIO;
|
1510 |
} |
1511 |
|
1512 |
static void qcow_free_snapshots(BlockDriverState *bs) |
1513 |
{ |
1514 |
BDRVQcowState *s = bs->opaque; |
1515 |
int i;
|
1516 |
|
1517 |
for(i = 0; i < s->nb_snapshots; i++) { |
1518 |
qemu_free(s->snapshots[i].name); |
1519 |
qemu_free(s->snapshots[i].id_str); |
1520 |
} |
1521 |
qemu_free(s->snapshots); |
1522 |
s->snapshots = NULL;
|
1523 |
s->nb_snapshots = 0;
|
1524 |
} |
1525 |
|
1526 |
static int qcow_read_snapshots(BlockDriverState *bs) |
1527 |
{ |
1528 |
BDRVQcowState *s = bs->opaque; |
1529 |
QCowSnapshotHeader h; |
1530 |
QCowSnapshot *sn; |
1531 |
int i, id_str_size, name_size;
|
1532 |
int64_t offset; |
1533 |
uint32_t extra_data_size; |
1534 |
|
1535 |
offset = s->snapshots_offset; |
1536 |
s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot));
|
1537 |
if (!s->snapshots)
|
1538 |
goto fail;
|
1539 |
for(i = 0; i < s->nb_snapshots; i++) { |
1540 |
offset = align_offset(offset, 8);
|
1541 |
if (bdrv_pread(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
1542 |
goto fail;
|
1543 |
offset += sizeof(h);
|
1544 |
sn = s->snapshots + i; |
1545 |
sn->l1_table_offset = be64_to_cpu(h.l1_table_offset); |
1546 |
sn->l1_size = be32_to_cpu(h.l1_size); |
1547 |
sn->vm_state_size = be32_to_cpu(h.vm_state_size); |
1548 |
sn->date_sec = be32_to_cpu(h.date_sec); |
1549 |
sn->date_nsec = be32_to_cpu(h.date_nsec); |
1550 |
sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec); |
1551 |
extra_data_size = be32_to_cpu(h.extra_data_size); |
1552 |
|
1553 |
id_str_size = be16_to_cpu(h.id_str_size); |
1554 |
name_size = be16_to_cpu(h.name_size); |
1555 |
|
1556 |
offset += extra_data_size; |
1557 |
|
1558 |
sn->id_str = qemu_malloc(id_str_size + 1);
|
1559 |
if (!sn->id_str)
|
1560 |
goto fail;
|
1561 |
if (bdrv_pread(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
1562 |
goto fail;
|
1563 |
offset += id_str_size; |
1564 |
sn->id_str[id_str_size] = '\0';
|
1565 |
|
1566 |
sn->name = qemu_malloc(name_size + 1);
|
1567 |
if (!sn->name)
|
1568 |
goto fail;
|
1569 |
if (bdrv_pread(s->hd, offset, sn->name, name_size) != name_size)
|
1570 |
goto fail;
|
1571 |
offset += name_size; |
1572 |
sn->name[name_size] = '\0';
|
1573 |
} |
1574 |
s->snapshots_size = offset - s->snapshots_offset; |
1575 |
return 0; |
1576 |
fail:
|
1577 |
qcow_free_snapshots(bs); |
1578 |
return -1; |
1579 |
} |
1580 |
|
1581 |
/* add at the end of the file a new list of snapshots */
|
1582 |
static int qcow_write_snapshots(BlockDriverState *bs) |
1583 |
{ |
1584 |
BDRVQcowState *s = bs->opaque; |
1585 |
QCowSnapshot *sn; |
1586 |
QCowSnapshotHeader h; |
1587 |
int i, name_size, id_str_size, snapshots_size;
|
1588 |
uint64_t data64; |
1589 |
uint32_t data32; |
1590 |
int64_t offset, snapshots_offset; |
1591 |
|
1592 |
/* compute the size of the snapshots */
|
1593 |
offset = 0;
|
1594 |
for(i = 0; i < s->nb_snapshots; i++) { |
1595 |
sn = s->snapshots + i; |
1596 |
offset = align_offset(offset, 8);
|
1597 |
offset += sizeof(h);
|
1598 |
offset += strlen(sn->id_str); |
1599 |
offset += strlen(sn->name); |
1600 |
} |
1601 |
snapshots_size = offset; |
1602 |
|
1603 |
snapshots_offset = alloc_clusters(bs, snapshots_size); |
1604 |
offset = snapshots_offset; |
1605 |
|
1606 |
for(i = 0; i < s->nb_snapshots; i++) { |
1607 |
sn = s->snapshots + i; |
1608 |
memset(&h, 0, sizeof(h)); |
1609 |
h.l1_table_offset = cpu_to_be64(sn->l1_table_offset); |
1610 |
h.l1_size = cpu_to_be32(sn->l1_size); |
1611 |
h.vm_state_size = cpu_to_be32(sn->vm_state_size); |
1612 |
h.date_sec = cpu_to_be32(sn->date_sec); |
1613 |
h.date_nsec = cpu_to_be32(sn->date_nsec); |
1614 |
h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec); |
1615 |
|
1616 |
id_str_size = strlen(sn->id_str); |
1617 |
name_size = strlen(sn->name); |
1618 |
h.id_str_size = cpu_to_be16(id_str_size); |
1619 |
h.name_size = cpu_to_be16(name_size); |
1620 |
offset = align_offset(offset, 8);
|
1621 |
if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
1622 |
goto fail;
|
1623 |
offset += sizeof(h);
|
1624 |
if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
1625 |
goto fail;
|
1626 |
offset += id_str_size; |
1627 |
if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size)
|
1628 |
goto fail;
|
1629 |
offset += name_size; |
1630 |
} |
1631 |
|
1632 |
/* update the various header fields */
|
1633 |
data64 = cpu_to_be64(snapshots_offset); |
1634 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset),
|
1635 |
&data64, sizeof(data64)) != sizeof(data64)) |
1636 |
goto fail;
|
1637 |
data32 = cpu_to_be32(s->nb_snapshots); |
1638 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots),
|
1639 |
&data32, sizeof(data32)) != sizeof(data32)) |
1640 |
goto fail;
|
1641 |
|
1642 |
/* free the old snapshot table */
|
1643 |
free_clusters(bs, s->snapshots_offset, s->snapshots_size); |
1644 |
s->snapshots_offset = snapshots_offset; |
1645 |
s->snapshots_size = snapshots_size; |
1646 |
return 0; |
1647 |
fail:
|
1648 |
return -1; |
1649 |
} |
1650 |
|
1651 |
static void find_new_snapshot_id(BlockDriverState *bs, |
1652 |
char *id_str, int id_str_size) |
1653 |
{ |
1654 |
BDRVQcowState *s = bs->opaque; |
1655 |
QCowSnapshot *sn; |
1656 |
int i, id, id_max = 0; |
1657 |
|
1658 |
for(i = 0; i < s->nb_snapshots; i++) { |
1659 |
sn = s->snapshots + i; |
1660 |
id = strtoul(sn->id_str, NULL, 10); |
1661 |
if (id > id_max)
|
1662 |
id_max = id; |
1663 |
} |
1664 |
snprintf(id_str, id_str_size, "%d", id_max + 1); |
1665 |
} |
1666 |
|
1667 |
static int find_snapshot_by_id(BlockDriverState *bs, const char *id_str) |
1668 |
{ |
1669 |
BDRVQcowState *s = bs->opaque; |
1670 |
int i;
|
1671 |
|
1672 |
for(i = 0; i < s->nb_snapshots; i++) { |
1673 |
if (!strcmp(s->snapshots[i].id_str, id_str))
|
1674 |
return i;
|
1675 |
} |
1676 |
return -1; |
1677 |
} |
1678 |
|
1679 |
static int find_snapshot_by_id_or_name(BlockDriverState *bs, const char *name) |
1680 |
{ |
1681 |
BDRVQcowState *s = bs->opaque; |
1682 |
int i, ret;
|
1683 |
|
1684 |
ret = find_snapshot_by_id(bs, name); |
1685 |
if (ret >= 0) |
1686 |
return ret;
|
1687 |
for(i = 0; i < s->nb_snapshots; i++) { |
1688 |
if (!strcmp(s->snapshots[i].name, name))
|
1689 |
return i;
|
1690 |
} |
1691 |
return -1; |
1692 |
} |
1693 |
|
1694 |
/* if no id is provided, a new one is constructed */
|
1695 |
static int qcow_snapshot_create(BlockDriverState *bs, |
1696 |
QEMUSnapshotInfo *sn_info) |
1697 |
{ |
1698 |
BDRVQcowState *s = bs->opaque; |
1699 |
QCowSnapshot *snapshots1, sn1, *sn = &sn1; |
1700 |
int i, ret;
|
1701 |
uint64_t *l1_table = NULL;
|
1702 |
|
1703 |
memset(sn, 0, sizeof(*sn)); |
1704 |
|
1705 |
if (sn_info->id_str[0] == '\0') { |
1706 |
/* compute a new id */
|
1707 |
find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
|
1708 |
} |
1709 |
|
1710 |
/* check that the ID is unique */
|
1711 |
if (find_snapshot_by_id(bs, sn_info->id_str) >= 0) |
1712 |
return -ENOENT;
|
1713 |
|
1714 |
sn->id_str = qemu_strdup(sn_info->id_str); |
1715 |
if (!sn->id_str)
|
1716 |
goto fail;
|
1717 |
sn->name = qemu_strdup(sn_info->name); |
1718 |
if (!sn->name)
|
1719 |
goto fail;
|
1720 |
sn->vm_state_size = sn_info->vm_state_size; |
1721 |
sn->date_sec = sn_info->date_sec; |
1722 |
sn->date_nsec = sn_info->date_nsec; |
1723 |
sn->vm_clock_nsec = sn_info->vm_clock_nsec; |
1724 |
|
1725 |
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
|
1726 |
if (ret < 0) |
1727 |
goto fail;
|
1728 |
|
1729 |
/* create the L1 table of the snapshot */
|
1730 |
sn->l1_table_offset = alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
|
1731 |
sn->l1_size = s->l1_size; |
1732 |
|
1733 |
l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
|
1734 |
if (!l1_table)
|
1735 |
goto fail;
|
1736 |
for(i = 0; i < s->l1_size; i++) { |
1737 |
l1_table[i] = cpu_to_be64(s->l1_table[i]); |
1738 |
} |
1739 |
if (bdrv_pwrite(s->hd, sn->l1_table_offset,
|
1740 |
l1_table, s->l1_size * sizeof(uint64_t)) !=
|
1741 |
(s->l1_size * sizeof(uint64_t)))
|
1742 |
goto fail;
|
1743 |
qemu_free(l1_table); |
1744 |
l1_table = NULL;
|
1745 |
|
1746 |
snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot)); |
1747 |
if (!snapshots1)
|
1748 |
goto fail;
|
1749 |
memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot));
|
1750 |
s->snapshots = snapshots1; |
1751 |
s->snapshots[s->nb_snapshots++] = *sn; |
1752 |
|
1753 |
if (qcow_write_snapshots(bs) < 0) |
1754 |
goto fail;
|
1755 |
#ifdef DEBUG_ALLOC
|
1756 |
check_refcounts(bs); |
1757 |
#endif
|
1758 |
return 0; |
1759 |
fail:
|
1760 |
qemu_free(sn->name); |
1761 |
qemu_free(l1_table); |
1762 |
return -1; |
1763 |
} |
1764 |
|
1765 |
/* copy the snapshot 'snapshot_name' into the current disk image */
|
1766 |
static int qcow_snapshot_goto(BlockDriverState *bs, |
1767 |
const char *snapshot_id) |
1768 |
{ |
1769 |
BDRVQcowState *s = bs->opaque; |
1770 |
QCowSnapshot *sn; |
1771 |
int i, snapshot_index, l1_size2;
|
1772 |
|
1773 |
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
1774 |
if (snapshot_index < 0) |
1775 |
return -ENOENT;
|
1776 |
sn = &s->snapshots[snapshot_index]; |
1777 |
|
1778 |
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1) < 0) |
1779 |
goto fail;
|
1780 |
|
1781 |
if (grow_l1_table(bs, sn->l1_size) < 0) |
1782 |
goto fail;
|
1783 |
|
1784 |
s->l1_size = sn->l1_size; |
1785 |
l1_size2 = s->l1_size * sizeof(uint64_t);
|
1786 |
/* copy the snapshot l1 table to the current l1 table */
|
1787 |
if (bdrv_pread(s->hd, sn->l1_table_offset,
|
1788 |
s->l1_table, l1_size2) != l1_size2) |
1789 |
goto fail;
|
1790 |
if (bdrv_pwrite(s->hd, s->l1_table_offset,
|
1791 |
s->l1_table, l1_size2) != l1_size2) |
1792 |
goto fail;
|
1793 |
for(i = 0;i < s->l1_size; i++) { |
1794 |
be64_to_cpus(&s->l1_table[i]); |
1795 |
} |
1796 |
|
1797 |
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1) < 0) |
1798 |
goto fail;
|
1799 |
|
1800 |
#ifdef DEBUG_ALLOC
|
1801 |
check_refcounts(bs); |
1802 |
#endif
|
1803 |
return 0; |
1804 |
fail:
|
1805 |
return -EIO;
|
1806 |
} |
1807 |
|
1808 |
static int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) |
1809 |
{ |
1810 |
BDRVQcowState *s = bs->opaque; |
1811 |
QCowSnapshot *sn; |
1812 |
int snapshot_index, ret;
|
1813 |
|
1814 |
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
1815 |
if (snapshot_index < 0) |
1816 |
return -ENOENT;
|
1817 |
sn = &s->snapshots[snapshot_index]; |
1818 |
|
1819 |
ret = update_snapshot_refcount(bs, sn->l1_table_offset, sn->l1_size, -1);
|
1820 |
if (ret < 0) |
1821 |
return ret;
|
1822 |
/* must update the copied flag on the current cluster offsets */
|
1823 |
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0);
|
1824 |
if (ret < 0) |
1825 |
return ret;
|
1826 |
free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t));
|
1827 |
|
1828 |
qemu_free(sn->id_str); |
1829 |
qemu_free(sn->name); |
1830 |
memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn)); |
1831 |
s->nb_snapshots--; |
1832 |
ret = qcow_write_snapshots(bs); |
1833 |
if (ret < 0) { |
1834 |
/* XXX: restore snapshot if error ? */
|
1835 |
return ret;
|
1836 |
} |
1837 |
#ifdef DEBUG_ALLOC
|
1838 |
check_refcounts(bs); |
1839 |
#endif
|
1840 |
return 0; |
1841 |
} |
1842 |
|
1843 |
static int qcow_snapshot_list(BlockDriverState *bs, |
1844 |
QEMUSnapshotInfo **psn_tab) |
1845 |
{ |
1846 |
BDRVQcowState *s = bs->opaque; |
1847 |
QEMUSnapshotInfo *sn_tab, *sn_info; |
1848 |
QCowSnapshot *sn; |
1849 |
int i;
|
1850 |
|
1851 |
sn_tab = qemu_mallocz(s->nb_snapshots * sizeof(QEMUSnapshotInfo));
|
1852 |
if (!sn_tab)
|
1853 |
goto fail;
|
1854 |
for(i = 0; i < s->nb_snapshots; i++) { |
1855 |
sn_info = sn_tab + i; |
1856 |
sn = s->snapshots + i; |
1857 |
pstrcpy(sn_info->id_str, sizeof(sn_info->id_str),
|
1858 |
sn->id_str); |
1859 |
pstrcpy(sn_info->name, sizeof(sn_info->name),
|
1860 |
sn->name); |
1861 |
sn_info->vm_state_size = sn->vm_state_size; |
1862 |
sn_info->date_sec = sn->date_sec; |
1863 |
sn_info->date_nsec = sn->date_nsec; |
1864 |
sn_info->vm_clock_nsec = sn->vm_clock_nsec; |
1865 |
} |
1866 |
*psn_tab = sn_tab; |
1867 |
return s->nb_snapshots;
|
1868 |
fail:
|
1869 |
qemu_free(sn_tab); |
1870 |
*psn_tab = NULL;
|
1871 |
return -ENOMEM;
|
1872 |
} |
1873 |
|
1874 |
/*********************************************************/
|
1875 |
/* refcount handling */
|
1876 |
|
1877 |
static int refcount_init(BlockDriverState *bs) |
1878 |
{ |
1879 |
BDRVQcowState *s = bs->opaque; |
1880 |
int ret, refcount_table_size2, i;
|
1881 |
|
1882 |
s->refcount_block_cache = qemu_malloc(s->cluster_size); |
1883 |
if (!s->refcount_block_cache)
|
1884 |
goto fail;
|
1885 |
refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t);
|
1886 |
s->refcount_table = qemu_malloc(refcount_table_size2); |
1887 |
if (!s->refcount_table)
|
1888 |
goto fail;
|
1889 |
if (s->refcount_table_size > 0) { |
1890 |
ret = bdrv_pread(s->hd, s->refcount_table_offset, |
1891 |
s->refcount_table, refcount_table_size2); |
1892 |
if (ret != refcount_table_size2)
|
1893 |
goto fail;
|
1894 |
for(i = 0; i < s->refcount_table_size; i++) |
1895 |
be64_to_cpus(&s->refcount_table[i]); |
1896 |
} |
1897 |
return 0; |
1898 |
fail:
|
1899 |
return -ENOMEM;
|
1900 |
} |
1901 |
|
1902 |
static void refcount_close(BlockDriverState *bs) |
1903 |
{ |
1904 |
BDRVQcowState *s = bs->opaque; |
1905 |
qemu_free(s->refcount_block_cache); |
1906 |
qemu_free(s->refcount_table); |
1907 |
} |
1908 |
|
1909 |
|
1910 |
static int load_refcount_block(BlockDriverState *bs, |
1911 |
int64_t refcount_block_offset) |
1912 |
{ |
1913 |
BDRVQcowState *s = bs->opaque; |
1914 |
int ret;
|
1915 |
ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache, |
1916 |
s->cluster_size); |
1917 |
if (ret != s->cluster_size)
|
1918 |
return -EIO;
|
1919 |
s->refcount_block_cache_offset = refcount_block_offset; |
1920 |
return 0; |
1921 |
} |
1922 |
|
1923 |
static int get_refcount(BlockDriverState *bs, int64_t cluster_index) |
1924 |
{ |
1925 |
BDRVQcowState *s = bs->opaque; |
1926 |
int refcount_table_index, block_index;
|
1927 |
int64_t refcount_block_offset; |
1928 |
|
1929 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
1930 |
if (refcount_table_index >= s->refcount_table_size)
|
1931 |
return 0; |
1932 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
1933 |
if (!refcount_block_offset)
|
1934 |
return 0; |
1935 |
if (refcount_block_offset != s->refcount_block_cache_offset) {
|
1936 |
/* better than nothing: return allocated if read error */
|
1937 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
1938 |
return 1; |
1939 |
} |
1940 |
block_index = cluster_index & |
1941 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
1942 |
return be16_to_cpu(s->refcount_block_cache[block_index]);
|
1943 |
} |
1944 |
|
1945 |
/* return < 0 if error */
|
1946 |
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
|
1947 |
{ |
1948 |
BDRVQcowState *s = bs->opaque; |
1949 |
int i, nb_clusters;
|
1950 |
|
1951 |
nb_clusters = (size + s->cluster_size - 1) >> s->cluster_bits;
|
1952 |
for(;;) {
|
1953 |
if (get_refcount(bs, s->free_cluster_index) == 0) { |
1954 |
s->free_cluster_index++; |
1955 |
for(i = 1; i < nb_clusters; i++) { |
1956 |
if (get_refcount(bs, s->free_cluster_index) != 0) |
1957 |
goto not_found;
|
1958 |
s->free_cluster_index++; |
1959 |
} |
1960 |
#ifdef DEBUG_ALLOC2
|
1961 |
printf("alloc_clusters: size=%lld -> %lld\n",
|
1962 |
size, |
1963 |
(s->free_cluster_index - nb_clusters) << s->cluster_bits); |
1964 |
#endif
|
1965 |
return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
|
1966 |
} else {
|
1967 |
not_found:
|
1968 |
s->free_cluster_index++; |
1969 |
} |
1970 |
} |
1971 |
} |
1972 |
|
1973 |
static int64_t alloc_clusters(BlockDriverState *bs, int64_t size)
|
1974 |
{ |
1975 |
int64_t offset; |
1976 |
|
1977 |
offset = alloc_clusters_noref(bs, size); |
1978 |
update_refcount(bs, offset, size, 1);
|
1979 |
return offset;
|
1980 |
} |
1981 |
|
1982 |
/* only used to allocate compressed sectors. We try to allocate
|
1983 |
contiguous sectors. size must be <= cluster_size */
|
1984 |
static int64_t alloc_bytes(BlockDriverState *bs, int size) |
1985 |
{ |
1986 |
BDRVQcowState *s = bs->opaque; |
1987 |
int64_t offset, cluster_offset; |
1988 |
int free_in_cluster;
|
1989 |
|
1990 |
assert(size > 0 && size <= s->cluster_size);
|
1991 |
if (s->free_byte_offset == 0) { |
1992 |
s->free_byte_offset = alloc_clusters(bs, s->cluster_size); |
1993 |
} |
1994 |
redo:
|
1995 |
free_in_cluster = s->cluster_size - |
1996 |
(s->free_byte_offset & (s->cluster_size - 1));
|
1997 |
if (size <= free_in_cluster) {
|
1998 |
/* enough space in current cluster */
|
1999 |
offset = s->free_byte_offset; |
2000 |
s->free_byte_offset += size; |
2001 |
free_in_cluster -= size; |
2002 |
if (free_in_cluster == 0) |
2003 |
s->free_byte_offset = 0;
|
2004 |
if ((offset & (s->cluster_size - 1)) != 0) |
2005 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
2006 |
} else {
|
2007 |
offset = alloc_clusters(bs, s->cluster_size); |
2008 |
cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1);
|
2009 |
if ((cluster_offset + s->cluster_size) == offset) {
|
2010 |
/* we are lucky: contiguous data */
|
2011 |
offset = s->free_byte_offset; |
2012 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
2013 |
s->free_byte_offset += size; |
2014 |
} else {
|
2015 |
s->free_byte_offset = offset; |
2016 |
goto redo;
|
2017 |
} |
2018 |
} |
2019 |
return offset;
|
2020 |
} |
2021 |
|
2022 |
static void free_clusters(BlockDriverState *bs, |
2023 |
int64_t offset, int64_t size) |
2024 |
{ |
2025 |
update_refcount(bs, offset, size, -1);
|
2026 |
} |
2027 |
|
2028 |
static int grow_refcount_table(BlockDriverState *bs, int min_size) |
2029 |
{ |
2030 |
BDRVQcowState *s = bs->opaque; |
2031 |
int new_table_size, new_table_size2, refcount_table_clusters, i, ret;
|
2032 |
uint64_t *new_table; |
2033 |
int64_t table_offset; |
2034 |
uint64_t data64; |
2035 |
uint32_t data32; |
2036 |
int old_table_size;
|
2037 |
int64_t old_table_offset; |
2038 |
|
2039 |
if (min_size <= s->refcount_table_size)
|
2040 |
return 0; |
2041 |
/* compute new table size */
|
2042 |
refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
|
2043 |
for(;;) {
|
2044 |
if (refcount_table_clusters == 0) { |
2045 |
refcount_table_clusters = 1;
|
2046 |
} else {
|
2047 |
refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; |
2048 |
} |
2049 |
new_table_size = refcount_table_clusters << (s->cluster_bits - 3);
|
2050 |
if (min_size <= new_table_size)
|
2051 |
break;
|
2052 |
} |
2053 |
#ifdef DEBUG_ALLOC2
|
2054 |
printf("grow_refcount_table from %d to %d\n",
|
2055 |
s->refcount_table_size, |
2056 |
new_table_size); |
2057 |
#endif
|
2058 |
new_table_size2 = new_table_size * sizeof(uint64_t);
|
2059 |
new_table = qemu_mallocz(new_table_size2); |
2060 |
if (!new_table)
|
2061 |
return -ENOMEM;
|
2062 |
memcpy(new_table, s->refcount_table, |
2063 |
s->refcount_table_size * sizeof(uint64_t));
|
2064 |
for(i = 0; i < s->refcount_table_size; i++) |
2065 |
cpu_to_be64s(&new_table[i]); |
2066 |
/* Note: we cannot update the refcount now to avoid recursion */
|
2067 |
table_offset = alloc_clusters_noref(bs, new_table_size2); |
2068 |
ret = bdrv_pwrite(s->hd, table_offset, new_table, new_table_size2); |
2069 |
if (ret != new_table_size2)
|
2070 |
goto fail;
|
2071 |
for(i = 0; i < s->refcount_table_size; i++) |
2072 |
be64_to_cpus(&new_table[i]); |
2073 |
|
2074 |
data64 = cpu_to_be64(table_offset); |
2075 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset),
|
2076 |
&data64, sizeof(data64)) != sizeof(data64)) |
2077 |
goto fail;
|
2078 |
data32 = cpu_to_be32(refcount_table_clusters); |
2079 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_clusters),
|
2080 |
&data32, sizeof(data32)) != sizeof(data32)) |
2081 |
goto fail;
|
2082 |
qemu_free(s->refcount_table); |
2083 |
old_table_offset = s->refcount_table_offset; |
2084 |
old_table_size = s->refcount_table_size; |
2085 |
s->refcount_table = new_table; |
2086 |
s->refcount_table_size = new_table_size; |
2087 |
s->refcount_table_offset = table_offset; |
2088 |
|
2089 |
update_refcount(bs, table_offset, new_table_size2, 1);
|
2090 |
free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t));
|
2091 |
return 0; |
2092 |
fail:
|
2093 |
free_clusters(bs, table_offset, new_table_size2); |
2094 |
qemu_free(new_table); |
2095 |
return -EIO;
|
2096 |
} |
2097 |
|
2098 |
/* addend must be 1 or -1 */
|
2099 |
/* XXX: cache several refcount block clusters ? */
|
2100 |
static int update_cluster_refcount(BlockDriverState *bs, |
2101 |
int64_t cluster_index, |
2102 |
int addend)
|
2103 |
{ |
2104 |
BDRVQcowState *s = bs->opaque; |
2105 |
int64_t offset, refcount_block_offset; |
2106 |
int ret, refcount_table_index, block_index, refcount;
|
2107 |
uint64_t data64; |
2108 |
|
2109 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
2110 |
if (refcount_table_index >= s->refcount_table_size) {
|
2111 |
if (addend < 0) |
2112 |
return -EINVAL;
|
2113 |
ret = grow_refcount_table(bs, refcount_table_index + 1);
|
2114 |
if (ret < 0) |
2115 |
return ret;
|
2116 |
} |
2117 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
2118 |
if (!refcount_block_offset) {
|
2119 |
if (addend < 0) |
2120 |
return -EINVAL;
|
2121 |
/* create a new refcount block */
|
2122 |
/* Note: we cannot update the refcount now to avoid recursion */
|
2123 |
offset = alloc_clusters_noref(bs, s->cluster_size); |
2124 |
memset(s->refcount_block_cache, 0, s->cluster_size);
|
2125 |
ret = bdrv_pwrite(s->hd, offset, s->refcount_block_cache, s->cluster_size); |
2126 |
if (ret != s->cluster_size)
|
2127 |
return -EINVAL;
|
2128 |
s->refcount_table[refcount_table_index] = offset; |
2129 |
data64 = cpu_to_be64(offset); |
2130 |
ret = bdrv_pwrite(s->hd, s->refcount_table_offset + |
2131 |
refcount_table_index * sizeof(uint64_t),
|
2132 |
&data64, sizeof(data64));
|
2133 |
if (ret != sizeof(data64)) |
2134 |
return -EINVAL;
|
2135 |
|
2136 |
refcount_block_offset = offset; |
2137 |
s->refcount_block_cache_offset = offset; |
2138 |
update_refcount(bs, offset, s->cluster_size, 1);
|
2139 |
} else {
|
2140 |
if (refcount_block_offset != s->refcount_block_cache_offset) {
|
2141 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
2142 |
return -EIO;
|
2143 |
} |
2144 |
} |
2145 |
/* we can update the count and save it */
|
2146 |
block_index = cluster_index & |
2147 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
2148 |
refcount = be16_to_cpu(s->refcount_block_cache[block_index]); |
2149 |
refcount += addend; |
2150 |
if (refcount < 0 || refcount > 0xffff) |
2151 |
return -EINVAL;
|
2152 |
if (refcount == 0 && cluster_index < s->free_cluster_index) { |
2153 |
s->free_cluster_index = cluster_index; |
2154 |
} |
2155 |
s->refcount_block_cache[block_index] = cpu_to_be16(refcount); |
2156 |
if (bdrv_pwrite(s->hd,
|
2157 |
refcount_block_offset + (block_index << REFCOUNT_SHIFT), |
2158 |
&s->refcount_block_cache[block_index], 2) != 2) |
2159 |
return -EIO;
|
2160 |
return refcount;
|
2161 |
} |
2162 |
|
2163 |
static void update_refcount(BlockDriverState *bs, |
2164 |
int64_t offset, int64_t length, |
2165 |
int addend)
|
2166 |
{ |
2167 |
BDRVQcowState *s = bs->opaque; |
2168 |
int64_t start, last, cluster_offset; |
2169 |
|
2170 |
#ifdef DEBUG_ALLOC2
|
2171 |
printf("update_refcount: offset=%lld size=%lld addend=%d\n",
|
2172 |
offset, length, addend); |
2173 |
#endif
|
2174 |
if (length <= 0) |
2175 |
return;
|
2176 |
start = offset & ~(s->cluster_size - 1);
|
2177 |
last = (offset + length - 1) & ~(s->cluster_size - 1); |
2178 |
for(cluster_offset = start; cluster_offset <= last;
|
2179 |
cluster_offset += s->cluster_size) { |
2180 |
update_cluster_refcount(bs, cluster_offset >> s->cluster_bits, addend); |
2181 |
} |
2182 |
} |
2183 |
|
2184 |
#ifdef DEBUG_ALLOC
|
2185 |
static void inc_refcounts(BlockDriverState *bs, |
2186 |
uint16_t *refcount_table, |
2187 |
int refcount_table_size,
|
2188 |
int64_t offset, int64_t size) |
2189 |
{ |
2190 |
BDRVQcowState *s = bs->opaque; |
2191 |
int64_t start, last, cluster_offset; |
2192 |
int k;
|
2193 |
|
2194 |
if (size <= 0) |
2195 |
return;
|
2196 |
|
2197 |
start = offset & ~(s->cluster_size - 1);
|
2198 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
2199 |
for(cluster_offset = start; cluster_offset <= last;
|
2200 |
cluster_offset += s->cluster_size) { |
2201 |
k = cluster_offset >> s->cluster_bits; |
2202 |
if (k < 0 || k >= refcount_table_size) { |
2203 |
printf("ERROR: invalid cluster offset=0x%llx\n", cluster_offset);
|
2204 |
} else {
|
2205 |
if (++refcount_table[k] == 0) { |
2206 |
printf("ERROR: overflow cluster offset=0x%llx\n", cluster_offset);
|
2207 |
} |
2208 |
} |
2209 |
} |
2210 |
} |
2211 |
|
2212 |
static int check_refcounts_l1(BlockDriverState *bs, |
2213 |
uint16_t *refcount_table, |
2214 |
int refcount_table_size,
|
2215 |
int64_t l1_table_offset, int l1_size,
|
2216 |
int check_copied)
|
2217 |
{ |
2218 |
BDRVQcowState *s = bs->opaque; |
2219 |
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2; |
2220 |
int l2_size, i, j, nb_csectors, refcount;
|
2221 |
|
2222 |
l2_table = NULL;
|
2223 |
l1_size2 = l1_size * sizeof(uint64_t);
|
2224 |
|
2225 |
inc_refcounts(bs, refcount_table, refcount_table_size, |
2226 |
l1_table_offset, l1_size2); |
2227 |
|
2228 |
l1_table = qemu_malloc(l1_size2); |
2229 |
if (!l1_table)
|
2230 |
goto fail;
|
2231 |
if (bdrv_pread(s->hd, l1_table_offset,
|
2232 |
l1_table, l1_size2) != l1_size2) |
2233 |
goto fail;
|
2234 |
for(i = 0;i < l1_size; i++) |
2235 |
be64_to_cpus(&l1_table[i]); |
2236 |
|
2237 |
l2_size = s->l2_size * sizeof(uint64_t);
|
2238 |
l2_table = qemu_malloc(l2_size); |
2239 |
if (!l2_table)
|
2240 |
goto fail;
|
2241 |
for(i = 0; i < l1_size; i++) { |
2242 |
l2_offset = l1_table[i]; |
2243 |
if (l2_offset) {
|
2244 |
if (check_copied) {
|
2245 |
refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits); |
2246 |
if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { |
2247 |
printf("ERROR OFLAG_COPIED: l2_offset=%llx refcount=%d\n",
|
2248 |
l2_offset, refcount); |
2249 |
} |
2250 |
} |
2251 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
2252 |
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
|
2253 |
goto fail;
|
2254 |
for(j = 0; j < s->l2_size; j++) { |
2255 |
offset = be64_to_cpu(l2_table[j]); |
2256 |
if (offset != 0) { |
2257 |
if (offset & QCOW_OFLAG_COMPRESSED) {
|
2258 |
if (offset & QCOW_OFLAG_COPIED) {
|
2259 |
printf("ERROR: cluster %lld: copied flag must never be set for compressed clusters\n",
|
2260 |
offset >> s->cluster_bits); |
2261 |
offset &= ~QCOW_OFLAG_COPIED; |
2262 |
} |
2263 |
nb_csectors = ((offset >> s->csize_shift) & |
2264 |
s->csize_mask) + 1;
|
2265 |
offset &= s->cluster_offset_mask; |
2266 |
inc_refcounts(bs, refcount_table, |
2267 |
refcount_table_size, |
2268 |
offset & ~511, nb_csectors * 512); |
2269 |
} else {
|
2270 |
if (check_copied) {
|
2271 |
refcount = get_refcount(bs, (offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits); |
2272 |
if ((refcount == 1) != ((offset & QCOW_OFLAG_COPIED) != 0)) { |
2273 |
printf("ERROR OFLAG_COPIED: offset=%llx refcount=%d\n",
|
2274 |
offset, refcount); |
2275 |
} |
2276 |
} |
2277 |
offset &= ~QCOW_OFLAG_COPIED; |
2278 |
inc_refcounts(bs, refcount_table, |
2279 |
refcount_table_size, |
2280 |
offset, s->cluster_size); |
2281 |
} |
2282 |
} |
2283 |
} |
2284 |
inc_refcounts(bs, refcount_table, |
2285 |
refcount_table_size, |
2286 |
l2_offset, |
2287 |
s->cluster_size); |
2288 |
} |
2289 |
} |
2290 |
qemu_free(l1_table); |
2291 |
qemu_free(l2_table); |
2292 |
return 0; |
2293 |
fail:
|
2294 |
printf("ERROR: I/O error in check_refcounts_l1\n");
|
2295 |
qemu_free(l1_table); |
2296 |
qemu_free(l2_table); |
2297 |
return -EIO;
|
2298 |
} |
2299 |
|
2300 |
static void check_refcounts(BlockDriverState *bs) |
2301 |
{ |
2302 |
BDRVQcowState *s = bs->opaque; |
2303 |
int64_t size; |
2304 |
int nb_clusters, refcount1, refcount2, i;
|
2305 |
QCowSnapshot *sn; |
2306 |
uint16_t *refcount_table; |
2307 |
|
2308 |
size = bdrv_getlength(s->hd); |
2309 |
nb_clusters = (size + s->cluster_size - 1) >> s->cluster_bits;
|
2310 |
refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t));
|
2311 |
|
2312 |
/* header */
|
2313 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2314 |
0, s->cluster_size);
|
2315 |
|
2316 |
check_refcounts_l1(bs, refcount_table, nb_clusters, |
2317 |
s->l1_table_offset, s->l1_size, 1);
|
2318 |
|
2319 |
/* snapshots */
|
2320 |
for(i = 0; i < s->nb_snapshots; i++) { |
2321 |
sn = s->snapshots + i; |
2322 |
check_refcounts_l1(bs, refcount_table, nb_clusters, |
2323 |
sn->l1_table_offset, sn->l1_size, 0);
|
2324 |
} |
2325 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2326 |
s->snapshots_offset, s->snapshots_size); |
2327 |
|
2328 |
/* refcount data */
|
2329 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2330 |
s->refcount_table_offset, |
2331 |
s->refcount_table_size * sizeof(uint64_t));
|
2332 |
for(i = 0; i < s->refcount_table_size; i++) { |
2333 |
int64_t offset; |
2334 |
offset = s->refcount_table[i]; |
2335 |
if (offset != 0) { |
2336 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2337 |
offset, s->cluster_size); |
2338 |
} |
2339 |
} |
2340 |
|
2341 |
/* compare ref counts */
|
2342 |
for(i = 0; i < nb_clusters; i++) { |
2343 |
refcount1 = get_refcount(bs, i); |
2344 |
refcount2 = refcount_table[i]; |
2345 |
if (refcount1 != refcount2)
|
2346 |
printf("ERROR cluster %d refcount=%d reference=%d\n",
|
2347 |
i, refcount1, refcount2); |
2348 |
} |
2349 |
|
2350 |
qemu_free(refcount_table); |
2351 |
} |
2352 |
|
2353 |
#if 0
|
2354 |
static void dump_refcounts(BlockDriverState *bs)
|
2355 |
{
|
2356 |
BDRVQcowState *s = bs->opaque;
|
2357 |
int64_t nb_clusters, k, k1, size;
|
2358 |
int refcount;
|
2359 |
|
2360 |
size = bdrv_getlength(s->hd);
|
2361 |
nb_clusters = (size + s->cluster_size - 1) >> s->cluster_bits;
|
2362 |
for(k = 0; k < nb_clusters;) {
|
2363 |
k1 = k;
|
2364 |
refcount = get_refcount(bs, k);
|
2365 |
k++;
|
2366 |
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
2367 |
k++;
|
2368 |
printf("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1);
|
2369 |
}
|
2370 |
}
|
2371 |
#endif
|
2372 |
#endif
|
2373 |
|
2374 |
BlockDriver bdrv_qcow2 = { |
2375 |
"qcow2",
|
2376 |
sizeof(BDRVQcowState),
|
2377 |
qcow_probe, |
2378 |
qcow_open, |
2379 |
NULL,
|
2380 |
NULL,
|
2381 |
qcow_close, |
2382 |
qcow_create, |
2383 |
qcow_flush, |
2384 |
qcow_is_allocated, |
2385 |
qcow_set_key, |
2386 |
qcow_make_empty, |
2387 |
|
2388 |
.bdrv_aio_read = qcow_aio_read, |
2389 |
.bdrv_aio_write = qcow_aio_write, |
2390 |
.bdrv_aio_cancel = qcow_aio_cancel, |
2391 |
.aiocb_size = sizeof(QCowAIOCB),
|
2392 |
.bdrv_write_compressed = qcow_write_compressed, |
2393 |
|
2394 |
.bdrv_snapshot_create = qcow_snapshot_create, |
2395 |
.bdrv_snapshot_goto = qcow_snapshot_goto, |
2396 |
.bdrv_snapshot_delete = qcow_snapshot_delete, |
2397 |
.bdrv_snapshot_list = qcow_snapshot_list, |
2398 |
.bdrv_get_info = qcow_get_info, |
2399 |
}; |