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/*
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* Block driver for the QCOW version 2 format
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*
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* Copyright (c) 2004-2006 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu-common.h" |
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#include "block_int.h" |
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#include "module.h" |
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#include <zlib.h> |
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#include "aes.h" |
29 |
|
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/*
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Differences with QCOW:
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- Support for multiple incremental snapshots.
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- Memory management by reference counts.
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- Clusters which have a reference count of one have the bit
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QCOW_OFLAG_COPIED to optimize write performance.
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- Size of compressed clusters is stored in sectors to reduce bit usage
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in the cluster offsets.
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- Support for storing additional data (such as the VM state) in the
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snapshots.
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- If a backing store is used, the cluster size is not constrained
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(could be backported to QCOW).
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- L2 tables have always a size of one cluster.
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*/
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|
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//#define DEBUG_ALLOC
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//#define DEBUG_ALLOC2
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//#define DEBUG_EXT
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|
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#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) |
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#define QCOW_VERSION 2 |
52 |
|
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#define QCOW_CRYPT_NONE 0 |
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#define QCOW_CRYPT_AES 1 |
55 |
|
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#define QCOW_MAX_CRYPT_CLUSTERS 32 |
57 |
|
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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) |
62 |
|
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#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */ |
64 |
|
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#define MIN_CLUSTER_BITS 9 |
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#define MAX_CLUSTER_BITS 16 |
67 |
|
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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; |
83 |
|
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|
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typedef struct { |
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uint32_t magic; |
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uint32_t len; |
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} QCowExtension; |
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#define QCOW_EXT_MAGIC_END 0 |
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#define QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA |
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|
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|
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typedef struct __attribute__((packed)) QCowSnapshotHeader { |
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/* header is 8 byte aligned */
|
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uint64_t l1_table_offset; |
96 |
|
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uint32_t l1_size; |
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uint16_t id_str_size; |
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uint16_t name_size; |
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|
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uint32_t date_sec; |
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uint32_t date_nsec; |
103 |
|
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uint64_t vm_clock_nsec; |
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|
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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; |
125 |
|
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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; |
138 |
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; |
145 |
uint64_t cluster_cache_offset; |
146 |
|
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uint64_t *refcount_table; |
148 |
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; |
153 |
int64_t free_byte_offset; |
154 |
|
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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; |
157 |
AES_KEY aes_encrypt_key; |
158 |
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; |
164 |
|
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static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset); |
166 |
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); |
170 |
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 int 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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static int check_refcounts(BlockDriverState *bs); |
184 |
|
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static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
186 |
{ |
187 |
const QCowHeader *cow_header = (const void *)buf; |
188 |
|
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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; |
193 |
else
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return 0; |
195 |
} |
196 |
|
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|
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/*
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* read qcow2 extension and fill bs
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* start reading from start_offset
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* finish reading upon magic of value 0 or when end_offset reached
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* unknown magic is skipped (future extension this version knows nothing about)
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* return 0 upon success, non-0 otherwise
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*/
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static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset, |
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uint64_t end_offset) |
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{ |
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BDRVQcowState *s = bs->opaque; |
209 |
QCowExtension ext; |
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uint64_t offset; |
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#ifdef DEBUG_EXT
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printf("qcow_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
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#endif
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offset = start_offset; |
216 |
while (offset < end_offset) {
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|
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#ifdef DEBUG_EXT
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/* Sanity check */
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if (offset > s->cluster_size)
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printf("qcow_handle_extension: suspicious offset %lu\n", offset);
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printf("attemting to read extended header in offset %lu\n", offset);
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#endif
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if (bdrv_pread(s->hd, offset, &ext, sizeof(ext)) != sizeof(ext)) { |
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fprintf(stderr, "qcow_handle_extension: ERROR: pread fail from offset %llu\n",
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(unsigned long long)offset); |
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return 1; |
230 |
} |
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be32_to_cpus(&ext.magic); |
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be32_to_cpus(&ext.len); |
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offset += sizeof(ext);
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#ifdef DEBUG_EXT
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printf("ext.magic = 0x%x\n", ext.magic);
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#endif
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switch (ext.magic) {
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case QCOW_EXT_MAGIC_END:
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return 0; |
240 |
|
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case QCOW_EXT_MAGIC_BACKING_FORMAT:
|
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if (ext.len >= sizeof(bs->backing_format)) { |
243 |
fprintf(stderr, "ERROR: ext_backing_format: len=%u too large"
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" (>=%zu)\n",
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ext.len, sizeof(bs->backing_format));
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return 2; |
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} |
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if (bdrv_pread(s->hd, offset , bs->backing_format,
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ext.len) != ext.len) |
250 |
return 3; |
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bs->backing_format[ext.len] = '\0';
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#ifdef DEBUG_EXT
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printf("Qcow2: Got format extension %s\n", bs->backing_format);
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#endif
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offset += ((ext.len + 7) & ~7); |
256 |
break;
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257 |
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default:
|
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/* unknown magic -- just skip it */
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offset += ((ext.len + 7) & ~7); |
261 |
break;
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} |
263 |
} |
264 |
|
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return 0; |
266 |
} |
267 |
|
268 |
|
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static int qcow_open(BlockDriverState *bs, const char *filename, int flags) |
270 |
{ |
271 |
BDRVQcowState *s = bs->opaque; |
272 |
int len, i, shift, ret;
|
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QCowHeader header; |
274 |
uint64_t ext_end; |
275 |
|
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/* Performance is terrible right now with cache=writethrough due mainly
|
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* to reference count updates. If the user does not explicitly specify
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278 |
* a caching type, force to writeback caching.
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*/
|
280 |
if ((flags & BDRV_O_CACHE_DEF)) {
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281 |
flags |= BDRV_O_CACHE_WB; |
282 |
flags &= ~BDRV_O_CACHE_DEF; |
283 |
} |
284 |
ret = bdrv_file_open(&s->hd, filename, flags); |
285 |
if (ret < 0) |
286 |
return ret;
|
287 |
if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) |
288 |
goto fail;
|
289 |
be32_to_cpus(&header.magic); |
290 |
be32_to_cpus(&header.version); |
291 |
be64_to_cpus(&header.backing_file_offset); |
292 |
be32_to_cpus(&header.backing_file_size); |
293 |
be64_to_cpus(&header.size); |
294 |
be32_to_cpus(&header.cluster_bits); |
295 |
be32_to_cpus(&header.crypt_method); |
296 |
be64_to_cpus(&header.l1_table_offset); |
297 |
be32_to_cpus(&header.l1_size); |
298 |
be64_to_cpus(&header.refcount_table_offset); |
299 |
be32_to_cpus(&header.refcount_table_clusters); |
300 |
be64_to_cpus(&header.snapshots_offset); |
301 |
be32_to_cpus(&header.nb_snapshots); |
302 |
|
303 |
if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION)
|
304 |
goto fail;
|
305 |
if (header.size <= 1 || |
306 |
header.cluster_bits < MIN_CLUSTER_BITS || |
307 |
header.cluster_bits > MAX_CLUSTER_BITS) |
308 |
goto fail;
|
309 |
if (header.crypt_method > QCOW_CRYPT_AES)
|
310 |
goto fail;
|
311 |
s->crypt_method_header = header.crypt_method; |
312 |
if (s->crypt_method_header)
|
313 |
bs->encrypted = 1;
|
314 |
s->cluster_bits = header.cluster_bits; |
315 |
s->cluster_size = 1 << s->cluster_bits;
|
316 |
s->cluster_sectors = 1 << (s->cluster_bits - 9); |
317 |
s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ |
318 |
s->l2_size = 1 << s->l2_bits;
|
319 |
bs->total_sectors = header.size / 512;
|
320 |
s->csize_shift = (62 - (s->cluster_bits - 8)); |
321 |
s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
322 |
s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
323 |
s->refcount_table_offset = header.refcount_table_offset; |
324 |
s->refcount_table_size = |
325 |
header.refcount_table_clusters << (s->cluster_bits - 3);
|
326 |
|
327 |
s->snapshots_offset = header.snapshots_offset; |
328 |
s->nb_snapshots = header.nb_snapshots; |
329 |
|
330 |
/* read the level 1 table */
|
331 |
s->l1_size = header.l1_size; |
332 |
shift = s->cluster_bits + s->l2_bits; |
333 |
s->l1_vm_state_index = (header.size + (1LL << shift) - 1) >> shift; |
334 |
/* the L1 table must contain at least enough entries to put
|
335 |
header.size bytes */
|
336 |
if (s->l1_size < s->l1_vm_state_index)
|
337 |
goto fail;
|
338 |
s->l1_table_offset = header.l1_table_offset; |
339 |
s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
|
340 |
if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != |
341 |
s->l1_size * sizeof(uint64_t))
|
342 |
goto fail;
|
343 |
for(i = 0;i < s->l1_size; i++) { |
344 |
be64_to_cpus(&s->l1_table[i]); |
345 |
} |
346 |
/* alloc L2 cache */
|
347 |
s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
|
348 |
s->cluster_cache = qemu_malloc(s->cluster_size); |
349 |
/* one more sector for decompressed data alignment */
|
350 |
s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size |
351 |
+ 512);
|
352 |
s->cluster_cache_offset = -1;
|
353 |
|
354 |
if (refcount_init(bs) < 0) |
355 |
goto fail;
|
356 |
|
357 |
/* read qcow2 extensions */
|
358 |
if (header.backing_file_offset)
|
359 |
ext_end = header.backing_file_offset; |
360 |
else
|
361 |
ext_end = s->cluster_size; |
362 |
if (qcow_read_extensions(bs, sizeof(header), ext_end)) |
363 |
goto fail;
|
364 |
|
365 |
/* read the backing file name */
|
366 |
if (header.backing_file_offset != 0) { |
367 |
len = header.backing_file_size; |
368 |
if (len > 1023) |
369 |
len = 1023;
|
370 |
if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len)
|
371 |
goto fail;
|
372 |
bs->backing_file[len] = '\0';
|
373 |
} |
374 |
if (qcow_read_snapshots(bs) < 0) |
375 |
goto fail;
|
376 |
|
377 |
#ifdef DEBUG_ALLOC
|
378 |
check_refcounts(bs); |
379 |
#endif
|
380 |
return 0; |
381 |
|
382 |
fail:
|
383 |
qcow_free_snapshots(bs); |
384 |
refcount_close(bs); |
385 |
qemu_free(s->l1_table); |
386 |
qemu_free(s->l2_cache); |
387 |
qemu_free(s->cluster_cache); |
388 |
qemu_free(s->cluster_data); |
389 |
bdrv_delete(s->hd); |
390 |
return -1; |
391 |
} |
392 |
|
393 |
static int qcow_set_key(BlockDriverState *bs, const char *key) |
394 |
{ |
395 |
BDRVQcowState *s = bs->opaque; |
396 |
uint8_t keybuf[16];
|
397 |
int len, i;
|
398 |
|
399 |
memset(keybuf, 0, 16); |
400 |
len = strlen(key); |
401 |
if (len > 16) |
402 |
len = 16;
|
403 |
/* XXX: we could compress the chars to 7 bits to increase
|
404 |
entropy */
|
405 |
for(i = 0;i < len;i++) { |
406 |
keybuf[i] = key[i]; |
407 |
} |
408 |
s->crypt_method = s->crypt_method_header; |
409 |
|
410 |
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
411 |
return -1; |
412 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
413 |
return -1; |
414 |
#if 0
|
415 |
/* test */
|
416 |
{
|
417 |
uint8_t in[16];
|
418 |
uint8_t out[16];
|
419 |
uint8_t tmp[16];
|
420 |
for(i=0;i<16;i++)
|
421 |
in[i] = i;
|
422 |
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
423 |
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
424 |
for(i = 0; i < 16; i++)
|
425 |
printf(" %02x", tmp[i]);
|
426 |
printf("\n");
|
427 |
for(i = 0; i < 16; i++)
|
428 |
printf(" %02x", out[i]);
|
429 |
printf("\n");
|
430 |
}
|
431 |
#endif
|
432 |
return 0; |
433 |
} |
434 |
|
435 |
/* The crypt function is compatible with the linux cryptoloop
|
436 |
algorithm for < 4 GB images. NOTE: out_buf == in_buf is
|
437 |
supported */
|
438 |
static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
439 |
uint8_t *out_buf, const uint8_t *in_buf,
|
440 |
int nb_sectors, int enc, |
441 |
const AES_KEY *key)
|
442 |
{ |
443 |
union {
|
444 |
uint64_t ll[2];
|
445 |
uint8_t b[16];
|
446 |
} ivec; |
447 |
int i;
|
448 |
|
449 |
for(i = 0; i < nb_sectors; i++) { |
450 |
ivec.ll[0] = cpu_to_le64(sector_num);
|
451 |
ivec.ll[1] = 0; |
452 |
AES_cbc_encrypt(in_buf, out_buf, 512, key,
|
453 |
ivec.b, enc); |
454 |
sector_num++; |
455 |
in_buf += 512;
|
456 |
out_buf += 512;
|
457 |
} |
458 |
} |
459 |
|
460 |
static int copy_sectors(BlockDriverState *bs, uint64_t start_sect, |
461 |
uint64_t cluster_offset, int n_start, int n_end) |
462 |
{ |
463 |
BDRVQcowState *s = bs->opaque; |
464 |
int n, ret;
|
465 |
|
466 |
n = n_end - n_start; |
467 |
if (n <= 0) |
468 |
return 0; |
469 |
ret = qcow_read(bs, start_sect + n_start, s->cluster_data, n); |
470 |
if (ret < 0) |
471 |
return ret;
|
472 |
if (s->crypt_method) {
|
473 |
encrypt_sectors(s, start_sect + n_start, |
474 |
s->cluster_data, |
475 |
s->cluster_data, n, 1,
|
476 |
&s->aes_encrypt_key); |
477 |
} |
478 |
ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start,
|
479 |
s->cluster_data, n); |
480 |
if (ret < 0) |
481 |
return ret;
|
482 |
return 0; |
483 |
} |
484 |
|
485 |
static void l2_cache_reset(BlockDriverState *bs) |
486 |
{ |
487 |
BDRVQcowState *s = bs->opaque; |
488 |
|
489 |
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
490 |
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
491 |
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
492 |
} |
493 |
|
494 |
static inline int l2_cache_new_entry(BlockDriverState *bs) |
495 |
{ |
496 |
BDRVQcowState *s = bs->opaque; |
497 |
uint32_t min_count; |
498 |
int min_index, i;
|
499 |
|
500 |
/* find a new entry in the least used one */
|
501 |
min_index = 0;
|
502 |
min_count = 0xffffffff;
|
503 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
504 |
if (s->l2_cache_counts[i] < min_count) {
|
505 |
min_count = s->l2_cache_counts[i]; |
506 |
min_index = i; |
507 |
} |
508 |
} |
509 |
return min_index;
|
510 |
} |
511 |
|
512 |
static int64_t align_offset(int64_t offset, int n) |
513 |
{ |
514 |
offset = (offset + n - 1) & ~(n - 1); |
515 |
return offset;
|
516 |
} |
517 |
|
518 |
static int grow_l1_table(BlockDriverState *bs, int min_size) |
519 |
{ |
520 |
BDRVQcowState *s = bs->opaque; |
521 |
int new_l1_size, new_l1_size2, ret, i;
|
522 |
uint64_t *new_l1_table; |
523 |
uint64_t new_l1_table_offset; |
524 |
uint8_t data[12];
|
525 |
|
526 |
new_l1_size = s->l1_size; |
527 |
if (min_size <= new_l1_size)
|
528 |
return 0; |
529 |
while (min_size > new_l1_size) {
|
530 |
new_l1_size = (new_l1_size * 3 + 1) / 2; |
531 |
} |
532 |
#ifdef DEBUG_ALLOC2
|
533 |
printf("grow l1_table from %d to %d\n", s->l1_size, new_l1_size);
|
534 |
#endif
|
535 |
|
536 |
new_l1_size2 = sizeof(uint64_t) * new_l1_size;
|
537 |
new_l1_table = qemu_mallocz(new_l1_size2); |
538 |
memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
|
539 |
|
540 |
/* write new table (align to cluster) */
|
541 |
new_l1_table_offset = alloc_clusters(bs, new_l1_size2); |
542 |
|
543 |
for(i = 0; i < s->l1_size; i++) |
544 |
new_l1_table[i] = cpu_to_be64(new_l1_table[i]); |
545 |
ret = bdrv_pwrite(s->hd, new_l1_table_offset, new_l1_table, new_l1_size2); |
546 |
if (ret != new_l1_size2)
|
547 |
goto fail;
|
548 |
for(i = 0; i < s->l1_size; i++) |
549 |
new_l1_table[i] = be64_to_cpu(new_l1_table[i]); |
550 |
|
551 |
/* set new table */
|
552 |
cpu_to_be32w((uint32_t*)data, new_l1_size); |
553 |
cpu_to_be64w((uint64_t*)(data + 4), new_l1_table_offset);
|
554 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_size), data,
|
555 |
sizeof(data)) != sizeof(data)) |
556 |
goto fail;
|
557 |
qemu_free(s->l1_table); |
558 |
free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t));
|
559 |
s->l1_table_offset = new_l1_table_offset; |
560 |
s->l1_table = new_l1_table; |
561 |
s->l1_size = new_l1_size; |
562 |
return 0; |
563 |
fail:
|
564 |
qemu_free(s->l1_table); |
565 |
return -EIO;
|
566 |
} |
567 |
|
568 |
/*
|
569 |
* seek_l2_table
|
570 |
*
|
571 |
* seek l2_offset in the l2_cache table
|
572 |
* if not found, return NULL,
|
573 |
* if found,
|
574 |
* increments the l2 cache hit count of the entry,
|
575 |
* if counter overflow, divide by two all counters
|
576 |
* return the pointer to the l2 cache entry
|
577 |
*
|
578 |
*/
|
579 |
|
580 |
static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset)
|
581 |
{ |
582 |
int i, j;
|
583 |
|
584 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
585 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
586 |
/* increment the hit count */
|
587 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
588 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
589 |
s->l2_cache_counts[j] >>= 1;
|
590 |
} |
591 |
} |
592 |
return s->l2_cache + (i << s->l2_bits);
|
593 |
} |
594 |
} |
595 |
return NULL; |
596 |
} |
597 |
|
598 |
/*
|
599 |
* l2_load
|
600 |
*
|
601 |
* Loads a L2 table into memory. If the table is in the cache, the cache
|
602 |
* is used; otherwise the L2 table is loaded from the image file.
|
603 |
*
|
604 |
* Returns a pointer to the L2 table on success, or NULL if the read from
|
605 |
* the image file failed.
|
606 |
*/
|
607 |
|
608 |
static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset)
|
609 |
{ |
610 |
BDRVQcowState *s = bs->opaque; |
611 |
int min_index;
|
612 |
uint64_t *l2_table; |
613 |
|
614 |
/* seek if the table for the given offset is in the cache */
|
615 |
|
616 |
l2_table = seek_l2_table(s, l2_offset); |
617 |
if (l2_table != NULL) |
618 |
return l2_table;
|
619 |
|
620 |
/* not found: load a new entry in the least used one */
|
621 |
|
622 |
min_index = l2_cache_new_entry(bs); |
623 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
624 |
if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
625 |
s->l2_size * sizeof(uint64_t))
|
626 |
return NULL; |
627 |
s->l2_cache_offsets[min_index] = l2_offset; |
628 |
s->l2_cache_counts[min_index] = 1;
|
629 |
|
630 |
return l2_table;
|
631 |
} |
632 |
|
633 |
/*
|
634 |
* l2_allocate
|
635 |
*
|
636 |
* Allocate a new l2 entry in the file. If l1_index points to an already
|
637 |
* used entry in the L2 table (i.e. we are doing a copy on write for the L2
|
638 |
* table) copy the contents of the old L2 table into the newly allocated one.
|
639 |
* Otherwise the new table is initialized with zeros.
|
640 |
*
|
641 |
*/
|
642 |
|
643 |
static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index) |
644 |
{ |
645 |
BDRVQcowState *s = bs->opaque; |
646 |
int min_index;
|
647 |
uint64_t old_l2_offset, tmp; |
648 |
uint64_t *l2_table, l2_offset; |
649 |
|
650 |
old_l2_offset = s->l1_table[l1_index]; |
651 |
|
652 |
/* allocate a new l2 entry */
|
653 |
|
654 |
l2_offset = alloc_clusters(bs, s->l2_size * sizeof(uint64_t));
|
655 |
|
656 |
/* update the L1 entry */
|
657 |
|
658 |
s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; |
659 |
|
660 |
tmp = cpu_to_be64(l2_offset | QCOW_OFLAG_COPIED); |
661 |
if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), |
662 |
&tmp, sizeof(tmp)) != sizeof(tmp)) |
663 |
return NULL; |
664 |
|
665 |
/* allocate a new entry in the l2 cache */
|
666 |
|
667 |
min_index = l2_cache_new_entry(bs); |
668 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
669 |
|
670 |
if (old_l2_offset == 0) { |
671 |
/* if there was no old l2 table, clear the new table */
|
672 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
673 |
} else {
|
674 |
/* if there was an old l2 table, read it from the disk */
|
675 |
if (bdrv_pread(s->hd, old_l2_offset,
|
676 |
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
677 |
s->l2_size * sizeof(uint64_t))
|
678 |
return NULL; |
679 |
} |
680 |
/* write the l2 table to the file */
|
681 |
if (bdrv_pwrite(s->hd, l2_offset,
|
682 |
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
683 |
s->l2_size * sizeof(uint64_t))
|
684 |
return NULL; |
685 |
|
686 |
/* update the l2 cache entry */
|
687 |
|
688 |
s->l2_cache_offsets[min_index] = l2_offset; |
689 |
s->l2_cache_counts[min_index] = 1;
|
690 |
|
691 |
return l2_table;
|
692 |
} |
693 |
|
694 |
static int size_to_clusters(BDRVQcowState *s, int64_t size) |
695 |
{ |
696 |
return (size + (s->cluster_size - 1)) >> s->cluster_bits; |
697 |
} |
698 |
|
699 |
static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, |
700 |
uint64_t *l2_table, uint64_t start, uint64_t mask) |
701 |
{ |
702 |
int i;
|
703 |
uint64_t offset = be64_to_cpu(l2_table[0]) & ~mask;
|
704 |
|
705 |
if (!offset)
|
706 |
return 0; |
707 |
|
708 |
for (i = start; i < start + nb_clusters; i++)
|
709 |
if (offset + i * cluster_size != (be64_to_cpu(l2_table[i]) & ~mask))
|
710 |
break;
|
711 |
|
712 |
return (i - start);
|
713 |
} |
714 |
|
715 |
static int count_contiguous_free_clusters(uint64_t nb_clusters, uint64_t *l2_table) |
716 |
{ |
717 |
int i = 0; |
718 |
|
719 |
while(nb_clusters-- && l2_table[i] == 0) |
720 |
i++; |
721 |
|
722 |
return i;
|
723 |
} |
724 |
|
725 |
/*
|
726 |
* get_cluster_offset
|
727 |
*
|
728 |
* For a given offset of the disk image, return cluster offset in
|
729 |
* qcow2 file.
|
730 |
*
|
731 |
* on entry, *num is the number of contiguous clusters we'd like to
|
732 |
* access following offset.
|
733 |
*
|
734 |
* on exit, *num is the number of contiguous clusters we can read.
|
735 |
*
|
736 |
* Return 1, if the offset is found
|
737 |
* Return 0, otherwise.
|
738 |
*
|
739 |
*/
|
740 |
|
741 |
static uint64_t get_cluster_offset(BlockDriverState *bs,
|
742 |
uint64_t offset, int *num)
|
743 |
{ |
744 |
BDRVQcowState *s = bs->opaque; |
745 |
int l1_index, l2_index;
|
746 |
uint64_t l2_offset, *l2_table, cluster_offset; |
747 |
int l1_bits, c;
|
748 |
int index_in_cluster, nb_available, nb_needed, nb_clusters;
|
749 |
|
750 |
index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1); |
751 |
nb_needed = *num + index_in_cluster; |
752 |
|
753 |
l1_bits = s->l2_bits + s->cluster_bits; |
754 |
|
755 |
/* compute how many bytes there are between the offset and
|
756 |
* the end of the l1 entry
|
757 |
*/
|
758 |
|
759 |
nb_available = (1 << l1_bits) - (offset & ((1 << l1_bits) - 1)); |
760 |
|
761 |
/* compute the number of available sectors */
|
762 |
|
763 |
nb_available = (nb_available >> 9) + index_in_cluster;
|
764 |
|
765 |
if (nb_needed > nb_available) {
|
766 |
nb_needed = nb_available; |
767 |
} |
768 |
|
769 |
cluster_offset = 0;
|
770 |
|
771 |
/* seek the the l2 offset in the l1 table */
|
772 |
|
773 |
l1_index = offset >> l1_bits; |
774 |
if (l1_index >= s->l1_size)
|
775 |
goto out;
|
776 |
|
777 |
l2_offset = s->l1_table[l1_index]; |
778 |
|
779 |
/* seek the l2 table of the given l2 offset */
|
780 |
|
781 |
if (!l2_offset)
|
782 |
goto out;
|
783 |
|
784 |
/* load the l2 table in memory */
|
785 |
|
786 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
787 |
l2_table = l2_load(bs, l2_offset); |
788 |
if (l2_table == NULL) |
789 |
return 0; |
790 |
|
791 |
/* find the cluster offset for the given disk offset */
|
792 |
|
793 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
794 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
795 |
nb_clusters = size_to_clusters(s, nb_needed << 9);
|
796 |
|
797 |
if (!cluster_offset) {
|
798 |
/* how many empty clusters ? */
|
799 |
c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]); |
800 |
} else {
|
801 |
/* how many allocated clusters ? */
|
802 |
c = count_contiguous_clusters(nb_clusters, s->cluster_size, |
803 |
&l2_table[l2_index], 0, QCOW_OFLAG_COPIED);
|
804 |
} |
805 |
|
806 |
nb_available = (c * s->cluster_sectors); |
807 |
out:
|
808 |
if (nb_available > nb_needed)
|
809 |
nb_available = nb_needed; |
810 |
|
811 |
*num = nb_available - index_in_cluster; |
812 |
|
813 |
return cluster_offset & ~QCOW_OFLAG_COPIED;
|
814 |
} |
815 |
|
816 |
/*
|
817 |
* free_any_clusters
|
818 |
*
|
819 |
* free clusters according to its type: compressed or not
|
820 |
*
|
821 |
*/
|
822 |
|
823 |
static void free_any_clusters(BlockDriverState *bs, |
824 |
uint64_t cluster_offset, int nb_clusters)
|
825 |
{ |
826 |
BDRVQcowState *s = bs->opaque; |
827 |
|
828 |
/* free the cluster */
|
829 |
|
830 |
if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
831 |
int nb_csectors;
|
832 |
nb_csectors = ((cluster_offset >> s->csize_shift) & |
833 |
s->csize_mask) + 1;
|
834 |
free_clusters(bs, (cluster_offset & s->cluster_offset_mask) & ~511,
|
835 |
nb_csectors * 512);
|
836 |
return;
|
837 |
} |
838 |
|
839 |
free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits); |
840 |
|
841 |
return;
|
842 |
} |
843 |
|
844 |
/*
|
845 |
* get_cluster_table
|
846 |
*
|
847 |
* for a given disk offset, load (and allocate if needed)
|
848 |
* the l2 table.
|
849 |
*
|
850 |
* the l2 table offset in the qcow2 file and the cluster index
|
851 |
* in the l2 table are given to the caller.
|
852 |
*
|
853 |
*/
|
854 |
|
855 |
static int get_cluster_table(BlockDriverState *bs, uint64_t offset, |
856 |
uint64_t **new_l2_table, |
857 |
uint64_t *new_l2_offset, |
858 |
int *new_l2_index)
|
859 |
{ |
860 |
BDRVQcowState *s = bs->opaque; |
861 |
int l1_index, l2_index, ret;
|
862 |
uint64_t l2_offset, *l2_table; |
863 |
|
864 |
/* seek the the l2 offset in the l1 table */
|
865 |
|
866 |
l1_index = offset >> (s->l2_bits + s->cluster_bits); |
867 |
if (l1_index >= s->l1_size) {
|
868 |
ret = grow_l1_table(bs, l1_index + 1);
|
869 |
if (ret < 0) |
870 |
return 0; |
871 |
} |
872 |
l2_offset = s->l1_table[l1_index]; |
873 |
|
874 |
/* seek the l2 table of the given l2 offset */
|
875 |
|
876 |
if (l2_offset & QCOW_OFLAG_COPIED) {
|
877 |
/* load the l2 table in memory */
|
878 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
879 |
l2_table = l2_load(bs, l2_offset); |
880 |
if (l2_table == NULL) |
881 |
return 0; |
882 |
} else {
|
883 |
if (l2_offset)
|
884 |
free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t));
|
885 |
l2_table = l2_allocate(bs, l1_index); |
886 |
if (l2_table == NULL) |
887 |
return 0; |
888 |
l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED; |
889 |
} |
890 |
|
891 |
/* find the cluster offset for the given disk offset */
|
892 |
|
893 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
894 |
|
895 |
*new_l2_table = l2_table; |
896 |
*new_l2_offset = l2_offset; |
897 |
*new_l2_index = l2_index; |
898 |
|
899 |
return 1; |
900 |
} |
901 |
|
902 |
/*
|
903 |
* alloc_compressed_cluster_offset
|
904 |
*
|
905 |
* For a given offset of the disk image, return cluster offset in
|
906 |
* qcow2 file.
|
907 |
*
|
908 |
* If the offset is not found, allocate a new compressed cluster.
|
909 |
*
|
910 |
* Return the cluster offset if successful,
|
911 |
* Return 0, otherwise.
|
912 |
*
|
913 |
*/
|
914 |
|
915 |
static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs,
|
916 |
uint64_t offset, |
917 |
int compressed_size)
|
918 |
{ |
919 |
BDRVQcowState *s = bs->opaque; |
920 |
int l2_index, ret;
|
921 |
uint64_t l2_offset, *l2_table, cluster_offset; |
922 |
int nb_csectors;
|
923 |
|
924 |
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
925 |
if (ret == 0) |
926 |
return 0; |
927 |
|
928 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
929 |
if (cluster_offset & QCOW_OFLAG_COPIED)
|
930 |
return cluster_offset & ~QCOW_OFLAG_COPIED;
|
931 |
|
932 |
if (cluster_offset)
|
933 |
free_any_clusters(bs, cluster_offset, 1);
|
934 |
|
935 |
cluster_offset = alloc_bytes(bs, compressed_size); |
936 |
nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) - |
937 |
(cluster_offset >> 9);
|
938 |
|
939 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
940 |
((uint64_t)nb_csectors << s->csize_shift); |
941 |
|
942 |
/* update L2 table */
|
943 |
|
944 |
/* compressed clusters never have the copied flag */
|
945 |
|
946 |
l2_table[l2_index] = cpu_to_be64(cluster_offset); |
947 |
if (bdrv_pwrite(s->hd,
|
948 |
l2_offset + l2_index * sizeof(uint64_t),
|
949 |
l2_table + l2_index, |
950 |
sizeof(uint64_t)) != sizeof(uint64_t)) |
951 |
return 0; |
952 |
|
953 |
return cluster_offset;
|
954 |
} |
955 |
|
956 |
typedef struct QCowL2Meta |
957 |
{ |
958 |
uint64_t offset; |
959 |
int n_start;
|
960 |
int nb_available;
|
961 |
int nb_clusters;
|
962 |
} QCowL2Meta; |
963 |
|
964 |
static int alloc_cluster_link_l2(BlockDriverState *bs, uint64_t cluster_offset, |
965 |
QCowL2Meta *m) |
966 |
{ |
967 |
BDRVQcowState *s = bs->opaque; |
968 |
int i, j = 0, l2_index, ret; |
969 |
uint64_t *old_cluster, start_sect, l2_offset, *l2_table; |
970 |
|
971 |
if (m->nb_clusters == 0) |
972 |
return 0; |
973 |
|
974 |
old_cluster = qemu_malloc(m->nb_clusters * sizeof(uint64_t));
|
975 |
|
976 |
/* copy content of unmodified sectors */
|
977 |
start_sect = (m->offset & ~(s->cluster_size - 1)) >> 9; |
978 |
if (m->n_start) {
|
979 |
ret = copy_sectors(bs, start_sect, cluster_offset, 0, m->n_start);
|
980 |
if (ret < 0) |
981 |
goto err;
|
982 |
} |
983 |
|
984 |
if (m->nb_available & (s->cluster_sectors - 1)) { |
985 |
uint64_t end = m->nb_available & ~(uint64_t)(s->cluster_sectors - 1);
|
986 |
ret = copy_sectors(bs, start_sect + end, cluster_offset + (end << 9),
|
987 |
m->nb_available - end, s->cluster_sectors); |
988 |
if (ret < 0) |
989 |
goto err;
|
990 |
} |
991 |
|
992 |
ret = -EIO; |
993 |
/* update L2 table */
|
994 |
if (!get_cluster_table(bs, m->offset, &l2_table, &l2_offset, &l2_index))
|
995 |
goto err;
|
996 |
|
997 |
for (i = 0; i < m->nb_clusters; i++) { |
998 |
/* if two concurrent writes happen to the same unallocated cluster
|
999 |
* each write allocates separate cluster and writes data concurrently.
|
1000 |
* The first one to complete updates l2 table with pointer to its
|
1001 |
* cluster the second one has to do RMW (which is done above by
|
1002 |
* copy_sectors()), update l2 table with its cluster pointer and free
|
1003 |
* old cluster. This is what this loop does */
|
1004 |
if(l2_table[l2_index + i] != 0) |
1005 |
old_cluster[j++] = l2_table[l2_index + i]; |
1006 |
|
1007 |
l2_table[l2_index + i] = cpu_to_be64((cluster_offset + |
1008 |
(i << s->cluster_bits)) | QCOW_OFLAG_COPIED); |
1009 |
} |
1010 |
|
1011 |
if (bdrv_pwrite(s->hd, l2_offset + l2_index * sizeof(uint64_t), |
1012 |
l2_table + l2_index, m->nb_clusters * sizeof(uint64_t)) !=
|
1013 |
m->nb_clusters * sizeof(uint64_t))
|
1014 |
goto err;
|
1015 |
|
1016 |
for (i = 0; i < j; i++) |
1017 |
free_any_clusters(bs, be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED, |
1018 |
1);
|
1019 |
|
1020 |
ret = 0;
|
1021 |
err:
|
1022 |
qemu_free(old_cluster); |
1023 |
return ret;
|
1024 |
} |
1025 |
|
1026 |
/*
|
1027 |
* alloc_cluster_offset
|
1028 |
*
|
1029 |
* For a given offset of the disk image, return cluster offset in
|
1030 |
* qcow2 file.
|
1031 |
*
|
1032 |
* If the offset is not found, allocate a new cluster.
|
1033 |
*
|
1034 |
* Return the cluster offset if successful,
|
1035 |
* Return 0, otherwise.
|
1036 |
*
|
1037 |
*/
|
1038 |
|
1039 |
static uint64_t alloc_cluster_offset(BlockDriverState *bs,
|
1040 |
uint64_t offset, |
1041 |
int n_start, int n_end, |
1042 |
int *num, QCowL2Meta *m)
|
1043 |
{ |
1044 |
BDRVQcowState *s = bs->opaque; |
1045 |
int l2_index, ret;
|
1046 |
uint64_t l2_offset, *l2_table, cluster_offset; |
1047 |
int nb_clusters, i = 0; |
1048 |
|
1049 |
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
1050 |
if (ret == 0) |
1051 |
return 0; |
1052 |
|
1053 |
nb_clusters = size_to_clusters(s, n_end << 9);
|
1054 |
|
1055 |
nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); |
1056 |
|
1057 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
1058 |
|
1059 |
/* We keep all QCOW_OFLAG_COPIED clusters */
|
1060 |
|
1061 |
if (cluster_offset & QCOW_OFLAG_COPIED) {
|
1062 |
nb_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size, |
1063 |
&l2_table[l2_index], 0, 0); |
1064 |
|
1065 |
cluster_offset &= ~QCOW_OFLAG_COPIED; |
1066 |
m->nb_clusters = 0;
|
1067 |
|
1068 |
goto out;
|
1069 |
} |
1070 |
|
1071 |
/* for the moment, multiple compressed clusters are not managed */
|
1072 |
|
1073 |
if (cluster_offset & QCOW_OFLAG_COMPRESSED)
|
1074 |
nb_clusters = 1;
|
1075 |
|
1076 |
/* how many available clusters ? */
|
1077 |
|
1078 |
while (i < nb_clusters) {
|
1079 |
i += count_contiguous_clusters(nb_clusters - i, s->cluster_size, |
1080 |
&l2_table[l2_index], i, 0);
|
1081 |
|
1082 |
if(be64_to_cpu(l2_table[l2_index + i]))
|
1083 |
break;
|
1084 |
|
1085 |
i += count_contiguous_free_clusters(nb_clusters - i, |
1086 |
&l2_table[l2_index + i]); |
1087 |
|
1088 |
cluster_offset = be64_to_cpu(l2_table[l2_index + i]); |
1089 |
|
1090 |
if ((cluster_offset & QCOW_OFLAG_COPIED) ||
|
1091 |
(cluster_offset & QCOW_OFLAG_COMPRESSED)) |
1092 |
break;
|
1093 |
} |
1094 |
nb_clusters = i; |
1095 |
|
1096 |
/* allocate a new cluster */
|
1097 |
|
1098 |
cluster_offset = alloc_clusters(bs, nb_clusters * s->cluster_size); |
1099 |
|
1100 |
/* save info needed for meta data update */
|
1101 |
m->offset = offset; |
1102 |
m->n_start = n_start; |
1103 |
m->nb_clusters = nb_clusters; |
1104 |
|
1105 |
out:
|
1106 |
m->nb_available = MIN(nb_clusters << (s->cluster_bits - 9), n_end);
|
1107 |
|
1108 |
*num = m->nb_available - n_start; |
1109 |
|
1110 |
return cluster_offset;
|
1111 |
} |
1112 |
|
1113 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
1114 |
int nb_sectors, int *pnum) |
1115 |
{ |
1116 |
uint64_t cluster_offset; |
1117 |
|
1118 |
*pnum = nb_sectors; |
1119 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, pnum);
|
1120 |
|
1121 |
return (cluster_offset != 0); |
1122 |
} |
1123 |
|
1124 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
1125 |
const uint8_t *buf, int buf_size) |
1126 |
{ |
1127 |
z_stream strm1, *strm = &strm1; |
1128 |
int ret, out_len;
|
1129 |
|
1130 |
memset(strm, 0, sizeof(*strm)); |
1131 |
|
1132 |
strm->next_in = (uint8_t *)buf; |
1133 |
strm->avail_in = buf_size; |
1134 |
strm->next_out = out_buf; |
1135 |
strm->avail_out = out_buf_size; |
1136 |
|
1137 |
ret = inflateInit2(strm, -12);
|
1138 |
if (ret != Z_OK)
|
1139 |
return -1; |
1140 |
ret = inflate(strm, Z_FINISH); |
1141 |
out_len = strm->next_out - out_buf; |
1142 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
1143 |
out_len != out_buf_size) { |
1144 |
inflateEnd(strm); |
1145 |
return -1; |
1146 |
} |
1147 |
inflateEnd(strm); |
1148 |
return 0; |
1149 |
} |
1150 |
|
1151 |
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) |
1152 |
{ |
1153 |
int ret, csize, nb_csectors, sector_offset;
|
1154 |
uint64_t coffset; |
1155 |
|
1156 |
coffset = cluster_offset & s->cluster_offset_mask; |
1157 |
if (s->cluster_cache_offset != coffset) {
|
1158 |
nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
|
1159 |
sector_offset = coffset & 511;
|
1160 |
csize = nb_csectors * 512 - sector_offset;
|
1161 |
ret = bdrv_read(s->hd, coffset >> 9, s->cluster_data, nb_csectors);
|
1162 |
if (ret < 0) { |
1163 |
return -1; |
1164 |
} |
1165 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
1166 |
s->cluster_data + sector_offset, csize) < 0) {
|
1167 |
return -1; |
1168 |
} |
1169 |
s->cluster_cache_offset = coffset; |
1170 |
} |
1171 |
return 0; |
1172 |
} |
1173 |
|
1174 |
/* handle reading after the end of the backing file */
|
1175 |
static int backing_read1(BlockDriverState *bs, |
1176 |
int64_t sector_num, uint8_t *buf, int nb_sectors)
|
1177 |
{ |
1178 |
int n1;
|
1179 |
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
1180 |
return nb_sectors;
|
1181 |
if (sector_num >= bs->total_sectors)
|
1182 |
n1 = 0;
|
1183 |
else
|
1184 |
n1 = bs->total_sectors - sector_num; |
1185 |
memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1)); |
1186 |
return n1;
|
1187 |
} |
1188 |
|
1189 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
1190 |
uint8_t *buf, int nb_sectors)
|
1191 |
{ |
1192 |
BDRVQcowState *s = bs->opaque; |
1193 |
int ret, index_in_cluster, n, n1;
|
1194 |
uint64_t cluster_offset; |
1195 |
|
1196 |
while (nb_sectors > 0) { |
1197 |
n = nb_sectors; |
1198 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, &n);
|
1199 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
1200 |
if (!cluster_offset) {
|
1201 |
if (bs->backing_hd) {
|
1202 |
/* read from the base image */
|
1203 |
n1 = backing_read1(bs->backing_hd, sector_num, buf, n); |
1204 |
if (n1 > 0) { |
1205 |
ret = bdrv_read(bs->backing_hd, sector_num, buf, n1); |
1206 |
if (ret < 0) |
1207 |
return -1; |
1208 |
} |
1209 |
} else {
|
1210 |
memset(buf, 0, 512 * n); |
1211 |
} |
1212 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1213 |
if (decompress_cluster(s, cluster_offset) < 0) |
1214 |
return -1; |
1215 |
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); |
1216 |
} else {
|
1217 |
ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
1218 |
if (ret != n * 512) |
1219 |
return -1; |
1220 |
if (s->crypt_method) {
|
1221 |
encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
1222 |
&s->aes_decrypt_key); |
1223 |
} |
1224 |
} |
1225 |
nb_sectors -= n; |
1226 |
sector_num += n; |
1227 |
buf += n * 512;
|
1228 |
} |
1229 |
return 0; |
1230 |
} |
1231 |
|
1232 |
typedef struct QCowAIOCB { |
1233 |
BlockDriverAIOCB common; |
1234 |
int64_t sector_num; |
1235 |
QEMUIOVector *qiov; |
1236 |
uint8_t *buf; |
1237 |
void *orig_buf;
|
1238 |
int nb_sectors;
|
1239 |
int n;
|
1240 |
uint64_t cluster_offset; |
1241 |
uint8_t *cluster_data; |
1242 |
BlockDriverAIOCB *hd_aiocb; |
1243 |
struct iovec hd_iov;
|
1244 |
QEMUIOVector hd_qiov; |
1245 |
QEMUBH *bh; |
1246 |
QCowL2Meta l2meta; |
1247 |
} QCowAIOCB; |
1248 |
|
1249 |
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) |
1250 |
{ |
1251 |
QCowAIOCB *acb = (QCowAIOCB *)blockacb; |
1252 |
if (acb->hd_aiocb)
|
1253 |
bdrv_aio_cancel(acb->hd_aiocb); |
1254 |
qemu_aio_release(acb); |
1255 |
} |
1256 |
|
1257 |
static AIOPool qcow_aio_pool = {
|
1258 |
.aiocb_size = sizeof(QCowAIOCB),
|
1259 |
.cancel = qcow_aio_cancel, |
1260 |
}; |
1261 |
|
1262 |
static void qcow_aio_read_cb(void *opaque, int ret); |
1263 |
static void qcow_aio_read_bh(void *opaque) |
1264 |
{ |
1265 |
QCowAIOCB *acb = opaque; |
1266 |
qemu_bh_delete(acb->bh); |
1267 |
acb->bh = NULL;
|
1268 |
qcow_aio_read_cb(opaque, 0);
|
1269 |
} |
1270 |
|
1271 |
static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb) |
1272 |
{ |
1273 |
if (acb->bh)
|
1274 |
return -EIO;
|
1275 |
|
1276 |
acb->bh = qemu_bh_new(cb, acb); |
1277 |
if (!acb->bh)
|
1278 |
return -EIO;
|
1279 |
|
1280 |
qemu_bh_schedule(acb->bh); |
1281 |
|
1282 |
return 0; |
1283 |
} |
1284 |
|
1285 |
static void qcow_aio_read_cb(void *opaque, int ret) |
1286 |
{ |
1287 |
QCowAIOCB *acb = opaque; |
1288 |
BlockDriverState *bs = acb->common.bs; |
1289 |
BDRVQcowState *s = bs->opaque; |
1290 |
int index_in_cluster, n1;
|
1291 |
|
1292 |
acb->hd_aiocb = NULL;
|
1293 |
if (ret < 0) |
1294 |
goto done;
|
1295 |
|
1296 |
/* post process the read buffer */
|
1297 |
if (!acb->cluster_offset) {
|
1298 |
/* nothing to do */
|
1299 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1300 |
/* nothing to do */
|
1301 |
} else {
|
1302 |
if (s->crypt_method) {
|
1303 |
encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, |
1304 |
acb->n, 0,
|
1305 |
&s->aes_decrypt_key); |
1306 |
} |
1307 |
} |
1308 |
|
1309 |
acb->nb_sectors -= acb->n; |
1310 |
acb->sector_num += acb->n; |
1311 |
acb->buf += acb->n * 512;
|
1312 |
|
1313 |
if (acb->nb_sectors == 0) { |
1314 |
/* request completed */
|
1315 |
ret = 0;
|
1316 |
goto done;
|
1317 |
} |
1318 |
|
1319 |
/* prepare next AIO request */
|
1320 |
acb->n = acb->nb_sectors; |
1321 |
acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, &acb->n);
|
1322 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
1323 |
|
1324 |
if (!acb->cluster_offset) {
|
1325 |
if (bs->backing_hd) {
|
1326 |
/* read from the base image */
|
1327 |
n1 = backing_read1(bs->backing_hd, acb->sector_num, |
1328 |
acb->buf, acb->n); |
1329 |
if (n1 > 0) { |
1330 |
acb->hd_iov.iov_base = (void *)acb->buf;
|
1331 |
acb->hd_iov.iov_len = acb->n * 512;
|
1332 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
1333 |
acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num, |
1334 |
&acb->hd_qiov, acb->n, |
1335 |
qcow_aio_read_cb, acb); |
1336 |
if (acb->hd_aiocb == NULL) |
1337 |
goto done;
|
1338 |
} else {
|
1339 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
1340 |
if (ret < 0) |
1341 |
goto done;
|
1342 |
} |
1343 |
} else {
|
1344 |
/* Note: in this case, no need to wait */
|
1345 |
memset(acb->buf, 0, 512 * acb->n); |
1346 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
1347 |
if (ret < 0) |
1348 |
goto done;
|
1349 |
} |
1350 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1351 |
/* add AIO support for compressed blocks ? */
|
1352 |
if (decompress_cluster(s, acb->cluster_offset) < 0) |
1353 |
goto done;
|
1354 |
memcpy(acb->buf, |
1355 |
s->cluster_cache + index_in_cluster * 512, 512 * acb->n); |
1356 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
1357 |
if (ret < 0) |
1358 |
goto done;
|
1359 |
} else {
|
1360 |
if ((acb->cluster_offset & 511) != 0) { |
1361 |
ret = -EIO; |
1362 |
goto done;
|
1363 |
} |
1364 |
|
1365 |
acb->hd_iov.iov_base = (void *)acb->buf;
|
1366 |
acb->hd_iov.iov_len = acb->n * 512;
|
1367 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
1368 |
acb->hd_aiocb = bdrv_aio_readv(s->hd, |
1369 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
1370 |
&acb->hd_qiov, acb->n, qcow_aio_read_cb, acb); |
1371 |
if (acb->hd_aiocb == NULL) |
1372 |
goto done;
|
1373 |
} |
1374 |
|
1375 |
return;
|
1376 |
done:
|
1377 |
if (acb->qiov->niov > 1) { |
1378 |
qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size); |
1379 |
qemu_vfree(acb->orig_buf); |
1380 |
} |
1381 |
acb->common.cb(acb->common.opaque, ret); |
1382 |
qemu_aio_release(acb); |
1383 |
} |
1384 |
|
1385 |
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
|
1386 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
1387 |
BlockDriverCompletionFunc *cb, void *opaque, int is_write) |
1388 |
{ |
1389 |
QCowAIOCB *acb; |
1390 |
|
1391 |
acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque); |
1392 |
if (!acb)
|
1393 |
return NULL; |
1394 |
acb->hd_aiocb = NULL;
|
1395 |
acb->sector_num = sector_num; |
1396 |
acb->qiov = qiov; |
1397 |
if (qiov->niov > 1) { |
1398 |
acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size); |
1399 |
if (is_write)
|
1400 |
qemu_iovec_to_buffer(qiov, acb->buf); |
1401 |
} else {
|
1402 |
acb->buf = (uint8_t *)qiov->iov->iov_base; |
1403 |
} |
1404 |
acb->nb_sectors = nb_sectors; |
1405 |
acb->n = 0;
|
1406 |
acb->cluster_offset = 0;
|
1407 |
acb->l2meta.nb_clusters = 0;
|
1408 |
return acb;
|
1409 |
} |
1410 |
|
1411 |
static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
|
1412 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
1413 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1414 |
{ |
1415 |
QCowAIOCB *acb; |
1416 |
|
1417 |
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
|
1418 |
if (!acb)
|
1419 |
return NULL; |
1420 |
|
1421 |
qcow_aio_read_cb(acb, 0);
|
1422 |
return &acb->common;
|
1423 |
} |
1424 |
|
1425 |
static void qcow_aio_write_cb(void *opaque, int ret) |
1426 |
{ |
1427 |
QCowAIOCB *acb = opaque; |
1428 |
BlockDriverState *bs = acb->common.bs; |
1429 |
BDRVQcowState *s = bs->opaque; |
1430 |
int index_in_cluster;
|
1431 |
const uint8_t *src_buf;
|
1432 |
int n_end;
|
1433 |
|
1434 |
acb->hd_aiocb = NULL;
|
1435 |
|
1436 |
if (ret < 0) |
1437 |
goto done;
|
1438 |
|
1439 |
if (alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta) < 0) { |
1440 |
free_any_clusters(bs, acb->cluster_offset, acb->l2meta.nb_clusters); |
1441 |
goto done;
|
1442 |
} |
1443 |
|
1444 |
acb->nb_sectors -= acb->n; |
1445 |
acb->sector_num += acb->n; |
1446 |
acb->buf += acb->n * 512;
|
1447 |
|
1448 |
if (acb->nb_sectors == 0) { |
1449 |
/* request completed */
|
1450 |
ret = 0;
|
1451 |
goto done;
|
1452 |
} |
1453 |
|
1454 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
1455 |
n_end = index_in_cluster + acb->nb_sectors; |
1456 |
if (s->crypt_method &&
|
1457 |
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) |
1458 |
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
1459 |
|
1460 |
acb->cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9,
|
1461 |
index_in_cluster, |
1462 |
n_end, &acb->n, &acb->l2meta); |
1463 |
if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) { |
1464 |
ret = -EIO; |
1465 |
goto done;
|
1466 |
} |
1467 |
if (s->crypt_method) {
|
1468 |
if (!acb->cluster_data) {
|
1469 |
acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * |
1470 |
s->cluster_size); |
1471 |
} |
1472 |
encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, |
1473 |
acb->n, 1, &s->aes_encrypt_key);
|
1474 |
src_buf = acb->cluster_data; |
1475 |
} else {
|
1476 |
src_buf = acb->buf; |
1477 |
} |
1478 |
acb->hd_iov.iov_base = (void *)src_buf;
|
1479 |
acb->hd_iov.iov_len = acb->n * 512;
|
1480 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
1481 |
acb->hd_aiocb = bdrv_aio_writev(s->hd, |
1482 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
1483 |
&acb->hd_qiov, acb->n, |
1484 |
qcow_aio_write_cb, acb); |
1485 |
if (acb->hd_aiocb == NULL) |
1486 |
goto done;
|
1487 |
|
1488 |
return;
|
1489 |
|
1490 |
done:
|
1491 |
if (acb->qiov->niov > 1) |
1492 |
qemu_vfree(acb->orig_buf); |
1493 |
acb->common.cb(acb->common.opaque, ret); |
1494 |
qemu_aio_release(acb); |
1495 |
} |
1496 |
|
1497 |
static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
|
1498 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
1499 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1500 |
{ |
1501 |
BDRVQcowState *s = bs->opaque; |
1502 |
QCowAIOCB *acb; |
1503 |
|
1504 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
1505 |
|
1506 |
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
|
1507 |
if (!acb)
|
1508 |
return NULL; |
1509 |
|
1510 |
qcow_aio_write_cb(acb, 0);
|
1511 |
return &acb->common;
|
1512 |
} |
1513 |
|
1514 |
static void qcow_close(BlockDriverState *bs) |
1515 |
{ |
1516 |
BDRVQcowState *s = bs->opaque; |
1517 |
qemu_free(s->l1_table); |
1518 |
qemu_free(s->l2_cache); |
1519 |
qemu_free(s->cluster_cache); |
1520 |
qemu_free(s->cluster_data); |
1521 |
refcount_close(bs); |
1522 |
bdrv_delete(s->hd); |
1523 |
} |
1524 |
|
1525 |
/* XXX: use std qcow open function ? */
|
1526 |
typedef struct QCowCreateState { |
1527 |
int cluster_size;
|
1528 |
int cluster_bits;
|
1529 |
uint16_t *refcount_block; |
1530 |
uint64_t *refcount_table; |
1531 |
int64_t l1_table_offset; |
1532 |
int64_t refcount_table_offset; |
1533 |
int64_t refcount_block_offset; |
1534 |
} QCowCreateState; |
1535 |
|
1536 |
static void create_refcount_update(QCowCreateState *s, |
1537 |
int64_t offset, int64_t size) |
1538 |
{ |
1539 |
int refcount;
|
1540 |
int64_t start, last, cluster_offset; |
1541 |
uint16_t *p; |
1542 |
|
1543 |
start = offset & ~(s->cluster_size - 1);
|
1544 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
1545 |
for(cluster_offset = start; cluster_offset <= last;
|
1546 |
cluster_offset += s->cluster_size) { |
1547 |
p = &s->refcount_block[cluster_offset >> s->cluster_bits]; |
1548 |
refcount = be16_to_cpu(*p); |
1549 |
refcount++; |
1550 |
*p = cpu_to_be16(refcount); |
1551 |
} |
1552 |
} |
1553 |
|
1554 |
static int get_bits_from_size(size_t size) |
1555 |
{ |
1556 |
int res = 0; |
1557 |
|
1558 |
if (size == 0) { |
1559 |
return -1; |
1560 |
} |
1561 |
|
1562 |
while (size != 1) { |
1563 |
/* Not a power of two */
|
1564 |
if (size & 1) { |
1565 |
return -1; |
1566 |
} |
1567 |
|
1568 |
size >>= 1;
|
1569 |
res++; |
1570 |
} |
1571 |
|
1572 |
return res;
|
1573 |
} |
1574 |
|
1575 |
static int qcow_create2(const char *filename, int64_t total_size, |
1576 |
const char *backing_file, const char *backing_format, |
1577 |
int flags, size_t cluster_size)
|
1578 |
{ |
1579 |
|
1580 |
int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
|
1581 |
int ref_clusters, backing_format_len = 0; |
1582 |
QCowHeader header; |
1583 |
uint64_t tmp, offset; |
1584 |
QCowCreateState s1, *s = &s1; |
1585 |
QCowExtension ext_bf = {0, 0}; |
1586 |
|
1587 |
|
1588 |
memset(s, 0, sizeof(*s)); |
1589 |
|
1590 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
1591 |
if (fd < 0) |
1592 |
return -1; |
1593 |
memset(&header, 0, sizeof(header)); |
1594 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
1595 |
header.version = cpu_to_be32(QCOW_VERSION); |
1596 |
header.size = cpu_to_be64(total_size * 512);
|
1597 |
header_size = sizeof(header);
|
1598 |
backing_filename_len = 0;
|
1599 |
if (backing_file) {
|
1600 |
if (backing_format) {
|
1601 |
ext_bf.magic = QCOW_EXT_MAGIC_BACKING_FORMAT; |
1602 |
backing_format_len = strlen(backing_format); |
1603 |
ext_bf.len = (backing_format_len + 7) & ~7; |
1604 |
header_size += ((sizeof(ext_bf) + ext_bf.len + 7) & ~7); |
1605 |
} |
1606 |
header.backing_file_offset = cpu_to_be64(header_size); |
1607 |
backing_filename_len = strlen(backing_file); |
1608 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
1609 |
header_size += backing_filename_len; |
1610 |
} |
1611 |
|
1612 |
/* Cluster size */
|
1613 |
s->cluster_bits = get_bits_from_size(cluster_size); |
1614 |
if (s->cluster_bits < MIN_CLUSTER_BITS ||
|
1615 |
s->cluster_bits > MAX_CLUSTER_BITS) |
1616 |
{ |
1617 |
fprintf(stderr, "Cluster size must be a power of two between "
|
1618 |
"%d and %dk\n",
|
1619 |
1 << MIN_CLUSTER_BITS,
|
1620 |
1 << (MAX_CLUSTER_BITS - 10)); |
1621 |
return -EINVAL;
|
1622 |
} |
1623 |
s->cluster_size = 1 << s->cluster_bits;
|
1624 |
|
1625 |
header.cluster_bits = cpu_to_be32(s->cluster_bits); |
1626 |
header_size = (header_size + 7) & ~7; |
1627 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
1628 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
1629 |
} else {
|
1630 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
1631 |
} |
1632 |
l2_bits = s->cluster_bits - 3;
|
1633 |
shift = s->cluster_bits + l2_bits; |
1634 |
l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift); |
1635 |
offset = align_offset(header_size, s->cluster_size); |
1636 |
s->l1_table_offset = offset; |
1637 |
header.l1_table_offset = cpu_to_be64(s->l1_table_offset); |
1638 |
header.l1_size = cpu_to_be32(l1_size); |
1639 |
offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
|
1640 |
|
1641 |
s->refcount_table = qemu_mallocz(s->cluster_size); |
1642 |
|
1643 |
s->refcount_table_offset = offset; |
1644 |
header.refcount_table_offset = cpu_to_be64(offset); |
1645 |
header.refcount_table_clusters = cpu_to_be32(1);
|
1646 |
offset += s->cluster_size; |
1647 |
s->refcount_block_offset = offset; |
1648 |
|
1649 |
/* count how many refcount blocks needed */
|
1650 |
tmp = offset >> s->cluster_bits; |
1651 |
ref_clusters = (tmp >> (s->cluster_bits - REFCOUNT_SHIFT)) + 1;
|
1652 |
for (i=0; i < ref_clusters; i++) { |
1653 |
s->refcount_table[i] = cpu_to_be64(offset); |
1654 |
offset += s->cluster_size; |
1655 |
} |
1656 |
|
1657 |
s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size); |
1658 |
|
1659 |
/* update refcounts */
|
1660 |
create_refcount_update(s, 0, header_size);
|
1661 |
create_refcount_update(s, s->l1_table_offset, l1_size * sizeof(uint64_t));
|
1662 |
create_refcount_update(s, s->refcount_table_offset, s->cluster_size); |
1663 |
create_refcount_update(s, s->refcount_block_offset, ref_clusters * s->cluster_size); |
1664 |
|
1665 |
/* write all the data */
|
1666 |
write(fd, &header, sizeof(header));
|
1667 |
if (backing_file) {
|
1668 |
if (backing_format_len) {
|
1669 |
char zero[16]; |
1670 |
int d = ext_bf.len - backing_format_len;
|
1671 |
|
1672 |
memset(zero, 0, sizeof(zero)); |
1673 |
cpu_to_be32s(&ext_bf.magic); |
1674 |
cpu_to_be32s(&ext_bf.len); |
1675 |
write(fd, &ext_bf, sizeof(ext_bf));
|
1676 |
write(fd, backing_format, backing_format_len); |
1677 |
if (d>0) { |
1678 |
write(fd, zero, d); |
1679 |
} |
1680 |
} |
1681 |
write(fd, backing_file, backing_filename_len); |
1682 |
} |
1683 |
lseek(fd, s->l1_table_offset, SEEK_SET); |
1684 |
tmp = 0;
|
1685 |
for(i = 0;i < l1_size; i++) { |
1686 |
write(fd, &tmp, sizeof(tmp));
|
1687 |
} |
1688 |
lseek(fd, s->refcount_table_offset, SEEK_SET); |
1689 |
write(fd, s->refcount_table, s->cluster_size); |
1690 |
|
1691 |
lseek(fd, s->refcount_block_offset, SEEK_SET); |
1692 |
write(fd, s->refcount_block, ref_clusters * s->cluster_size); |
1693 |
|
1694 |
qemu_free(s->refcount_table); |
1695 |
qemu_free(s->refcount_block); |
1696 |
close(fd); |
1697 |
return 0; |
1698 |
} |
1699 |
|
1700 |
static int qcow_create(const char *filename, QEMUOptionParameter *options) |
1701 |
{ |
1702 |
const char *backing_file = NULL; |
1703 |
const char *backing_fmt = NULL; |
1704 |
uint64_t sectors = 0;
|
1705 |
int flags = 0; |
1706 |
size_t cluster_size = 65536;
|
1707 |
|
1708 |
/* Read out options */
|
1709 |
while (options && options->name) {
|
1710 |
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
1711 |
sectors = options->value.n / 512;
|
1712 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { |
1713 |
backing_file = options->value.s; |
1714 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { |
1715 |
backing_fmt = options->value.s; |
1716 |
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { |
1717 |
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
1718 |
} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { |
1719 |
if (options->value.n) {
|
1720 |
cluster_size = options->value.n; |
1721 |
} |
1722 |
} |
1723 |
options++; |
1724 |
} |
1725 |
|
1726 |
return qcow_create2(filename, sectors, backing_file, backing_fmt, flags,
|
1727 |
cluster_size); |
1728 |
} |
1729 |
|
1730 |
static int qcow_make_empty(BlockDriverState *bs) |
1731 |
{ |
1732 |
#if 0
|
1733 |
/* XXX: not correct */
|
1734 |
BDRVQcowState *s = bs->opaque;
|
1735 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
1736 |
int ret;
|
1737 |
|
1738 |
memset(s->l1_table, 0, l1_length);
|
1739 |
if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
1740 |
return -1;
|
1741 |
ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length);
|
1742 |
if (ret < 0)
|
1743 |
return ret;
|
1744 |
|
1745 |
l2_cache_reset(bs);
|
1746 |
#endif
|
1747 |
return 0; |
1748 |
} |
1749 |
|
1750 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
1751 |
tables to avoid losing bytes in alignment */
|
1752 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
1753 |
const uint8_t *buf, int nb_sectors) |
1754 |
{ |
1755 |
BDRVQcowState *s = bs->opaque; |
1756 |
z_stream strm; |
1757 |
int ret, out_len;
|
1758 |
uint8_t *out_buf; |
1759 |
uint64_t cluster_offset; |
1760 |
|
1761 |
if (nb_sectors == 0) { |
1762 |
/* align end of file to a sector boundary to ease reading with
|
1763 |
sector based I/Os */
|
1764 |
cluster_offset = bdrv_getlength(s->hd); |
1765 |
cluster_offset = (cluster_offset + 511) & ~511; |
1766 |
bdrv_truncate(s->hd, cluster_offset); |
1767 |
return 0; |
1768 |
} |
1769 |
|
1770 |
if (nb_sectors != s->cluster_sectors)
|
1771 |
return -EINVAL;
|
1772 |
|
1773 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
1774 |
|
1775 |
/* best compression, small window, no zlib header */
|
1776 |
memset(&strm, 0, sizeof(strm)); |
1777 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
1778 |
Z_DEFLATED, -12,
|
1779 |
9, Z_DEFAULT_STRATEGY);
|
1780 |
if (ret != 0) { |
1781 |
qemu_free(out_buf); |
1782 |
return -1; |
1783 |
} |
1784 |
|
1785 |
strm.avail_in = s->cluster_size; |
1786 |
strm.next_in = (uint8_t *)buf; |
1787 |
strm.avail_out = s->cluster_size; |
1788 |
strm.next_out = out_buf; |
1789 |
|
1790 |
ret = deflate(&strm, Z_FINISH); |
1791 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
1792 |
qemu_free(out_buf); |
1793 |
deflateEnd(&strm); |
1794 |
return -1; |
1795 |
} |
1796 |
out_len = strm.next_out - out_buf; |
1797 |
|
1798 |
deflateEnd(&strm); |
1799 |
|
1800 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
1801 |
/* could not compress: write normal cluster */
|
1802 |
bdrv_write(bs, sector_num, buf, s->cluster_sectors); |
1803 |
} else {
|
1804 |
cluster_offset = alloc_compressed_cluster_offset(bs, sector_num << 9,
|
1805 |
out_len); |
1806 |
if (!cluster_offset)
|
1807 |
return -1; |
1808 |
cluster_offset &= s->cluster_offset_mask; |
1809 |
if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
|
1810 |
qemu_free(out_buf); |
1811 |
return -1; |
1812 |
} |
1813 |
} |
1814 |
|
1815 |
qemu_free(out_buf); |
1816 |
return 0; |
1817 |
} |
1818 |
|
1819 |
static void qcow_flush(BlockDriverState *bs) |
1820 |
{ |
1821 |
BDRVQcowState *s = bs->opaque; |
1822 |
bdrv_flush(s->hd); |
1823 |
} |
1824 |
|
1825 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
1826 |
{ |
1827 |
BDRVQcowState *s = bs->opaque; |
1828 |
bdi->cluster_size = s->cluster_size; |
1829 |
bdi->vm_state_offset = (int64_t)s->l1_vm_state_index << |
1830 |
(s->cluster_bits + s->l2_bits); |
1831 |
return 0; |
1832 |
} |
1833 |
|
1834 |
/*********************************************************/
|
1835 |
/* snapshot support */
|
1836 |
|
1837 |
/* update the refcounts of snapshots and the copied flag */
|
1838 |
static int update_snapshot_refcount(BlockDriverState *bs, |
1839 |
int64_t l1_table_offset, |
1840 |
int l1_size,
|
1841 |
int addend)
|
1842 |
{ |
1843 |
BDRVQcowState *s = bs->opaque; |
1844 |
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; |
1845 |
int64_t old_offset, old_l2_offset; |
1846 |
int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount;
|
1847 |
|
1848 |
l2_cache_reset(bs); |
1849 |
|
1850 |
l2_table = NULL;
|
1851 |
l1_table = NULL;
|
1852 |
l1_size2 = l1_size * sizeof(uint64_t);
|
1853 |
l1_allocated = 0;
|
1854 |
if (l1_table_offset != s->l1_table_offset) {
|
1855 |
l1_table = qemu_malloc(l1_size2); |
1856 |
l1_allocated = 1;
|
1857 |
if (bdrv_pread(s->hd, l1_table_offset,
|
1858 |
l1_table, l1_size2) != l1_size2) |
1859 |
goto fail;
|
1860 |
for(i = 0;i < l1_size; i++) |
1861 |
be64_to_cpus(&l1_table[i]); |
1862 |
} else {
|
1863 |
assert(l1_size == s->l1_size); |
1864 |
l1_table = s->l1_table; |
1865 |
l1_allocated = 0;
|
1866 |
} |
1867 |
|
1868 |
l2_size = s->l2_size * sizeof(uint64_t);
|
1869 |
l2_table = qemu_malloc(l2_size); |
1870 |
l1_modified = 0;
|
1871 |
for(i = 0; i < l1_size; i++) { |
1872 |
l2_offset = l1_table[i]; |
1873 |
if (l2_offset) {
|
1874 |
old_l2_offset = l2_offset; |
1875 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
1876 |
l2_modified = 0;
|
1877 |
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
|
1878 |
goto fail;
|
1879 |
for(j = 0; j < s->l2_size; j++) { |
1880 |
offset = be64_to_cpu(l2_table[j]); |
1881 |
if (offset != 0) { |
1882 |
old_offset = offset; |
1883 |
offset &= ~QCOW_OFLAG_COPIED; |
1884 |
if (offset & QCOW_OFLAG_COMPRESSED) {
|
1885 |
nb_csectors = ((offset >> s->csize_shift) & |
1886 |
s->csize_mask) + 1;
|
1887 |
if (addend != 0) |
1888 |
update_refcount(bs, (offset & s->cluster_offset_mask) & ~511,
|
1889 |
nb_csectors * 512, addend);
|
1890 |
/* compressed clusters are never modified */
|
1891 |
refcount = 2;
|
1892 |
} else {
|
1893 |
if (addend != 0) { |
1894 |
refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend); |
1895 |
} else {
|
1896 |
refcount = get_refcount(bs, offset >> s->cluster_bits); |
1897 |
} |
1898 |
} |
1899 |
|
1900 |
if (refcount == 1) { |
1901 |
offset |= QCOW_OFLAG_COPIED; |
1902 |
} |
1903 |
if (offset != old_offset) {
|
1904 |
l2_table[j] = cpu_to_be64(offset); |
1905 |
l2_modified = 1;
|
1906 |
} |
1907 |
} |
1908 |
} |
1909 |
if (l2_modified) {
|
1910 |
if (bdrv_pwrite(s->hd,
|
1911 |
l2_offset, l2_table, l2_size) != l2_size) |
1912 |
goto fail;
|
1913 |
} |
1914 |
|
1915 |
if (addend != 0) { |
1916 |
refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); |
1917 |
} else {
|
1918 |
refcount = get_refcount(bs, l2_offset >> s->cluster_bits); |
1919 |
} |
1920 |
if (refcount == 1) { |
1921 |
l2_offset |= QCOW_OFLAG_COPIED; |
1922 |
} |
1923 |
if (l2_offset != old_l2_offset) {
|
1924 |
l1_table[i] = l2_offset; |
1925 |
l1_modified = 1;
|
1926 |
} |
1927 |
} |
1928 |
} |
1929 |
if (l1_modified) {
|
1930 |
for(i = 0; i < l1_size; i++) |
1931 |
cpu_to_be64s(&l1_table[i]); |
1932 |
if (bdrv_pwrite(s->hd, l1_table_offset, l1_table,
|
1933 |
l1_size2) != l1_size2) |
1934 |
goto fail;
|
1935 |
for(i = 0; i < l1_size; i++) |
1936 |
be64_to_cpus(&l1_table[i]); |
1937 |
} |
1938 |
if (l1_allocated)
|
1939 |
qemu_free(l1_table); |
1940 |
qemu_free(l2_table); |
1941 |
return 0; |
1942 |
fail:
|
1943 |
if (l1_allocated)
|
1944 |
qemu_free(l1_table); |
1945 |
qemu_free(l2_table); |
1946 |
return -EIO;
|
1947 |
} |
1948 |
|
1949 |
static void qcow_free_snapshots(BlockDriverState *bs) |
1950 |
{ |
1951 |
BDRVQcowState *s = bs->opaque; |
1952 |
int i;
|
1953 |
|
1954 |
for(i = 0; i < s->nb_snapshots; i++) { |
1955 |
qemu_free(s->snapshots[i].name); |
1956 |
qemu_free(s->snapshots[i].id_str); |
1957 |
} |
1958 |
qemu_free(s->snapshots); |
1959 |
s->snapshots = NULL;
|
1960 |
s->nb_snapshots = 0;
|
1961 |
} |
1962 |
|
1963 |
static int qcow_read_snapshots(BlockDriverState *bs) |
1964 |
{ |
1965 |
BDRVQcowState *s = bs->opaque; |
1966 |
QCowSnapshotHeader h; |
1967 |
QCowSnapshot *sn; |
1968 |
int i, id_str_size, name_size;
|
1969 |
int64_t offset; |
1970 |
uint32_t extra_data_size; |
1971 |
|
1972 |
if (!s->nb_snapshots) {
|
1973 |
s->snapshots = NULL;
|
1974 |
s->snapshots_size = 0;
|
1975 |
return 0; |
1976 |
} |
1977 |
|
1978 |
offset = s->snapshots_offset; |
1979 |
s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot));
|
1980 |
for(i = 0; i < s->nb_snapshots; i++) { |
1981 |
offset = align_offset(offset, 8);
|
1982 |
if (bdrv_pread(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
1983 |
goto fail;
|
1984 |
offset += sizeof(h);
|
1985 |
sn = s->snapshots + i; |
1986 |
sn->l1_table_offset = be64_to_cpu(h.l1_table_offset); |
1987 |
sn->l1_size = be32_to_cpu(h.l1_size); |
1988 |
sn->vm_state_size = be32_to_cpu(h.vm_state_size); |
1989 |
sn->date_sec = be32_to_cpu(h.date_sec); |
1990 |
sn->date_nsec = be32_to_cpu(h.date_nsec); |
1991 |
sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec); |
1992 |
extra_data_size = be32_to_cpu(h.extra_data_size); |
1993 |
|
1994 |
id_str_size = be16_to_cpu(h.id_str_size); |
1995 |
name_size = be16_to_cpu(h.name_size); |
1996 |
|
1997 |
offset += extra_data_size; |
1998 |
|
1999 |
sn->id_str = qemu_malloc(id_str_size + 1);
|
2000 |
if (bdrv_pread(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
2001 |
goto fail;
|
2002 |
offset += id_str_size; |
2003 |
sn->id_str[id_str_size] = '\0';
|
2004 |
|
2005 |
sn->name = qemu_malloc(name_size + 1);
|
2006 |
if (bdrv_pread(s->hd, offset, sn->name, name_size) != name_size)
|
2007 |
goto fail;
|
2008 |
offset += name_size; |
2009 |
sn->name[name_size] = '\0';
|
2010 |
} |
2011 |
s->snapshots_size = offset - s->snapshots_offset; |
2012 |
return 0; |
2013 |
fail:
|
2014 |
qcow_free_snapshots(bs); |
2015 |
return -1; |
2016 |
} |
2017 |
|
2018 |
/* add at the end of the file a new list of snapshots */
|
2019 |
static int qcow_write_snapshots(BlockDriverState *bs) |
2020 |
{ |
2021 |
BDRVQcowState *s = bs->opaque; |
2022 |
QCowSnapshot *sn; |
2023 |
QCowSnapshotHeader h; |
2024 |
int i, name_size, id_str_size, snapshots_size;
|
2025 |
uint64_t data64; |
2026 |
uint32_t data32; |
2027 |
int64_t offset, snapshots_offset; |
2028 |
|
2029 |
/* compute the size of the snapshots */
|
2030 |
offset = 0;
|
2031 |
for(i = 0; i < s->nb_snapshots; i++) { |
2032 |
sn = s->snapshots + i; |
2033 |
offset = align_offset(offset, 8);
|
2034 |
offset += sizeof(h);
|
2035 |
offset += strlen(sn->id_str); |
2036 |
offset += strlen(sn->name); |
2037 |
} |
2038 |
snapshots_size = offset; |
2039 |
|
2040 |
snapshots_offset = alloc_clusters(bs, snapshots_size); |
2041 |
offset = snapshots_offset; |
2042 |
|
2043 |
for(i = 0; i < s->nb_snapshots; i++) { |
2044 |
sn = s->snapshots + i; |
2045 |
memset(&h, 0, sizeof(h)); |
2046 |
h.l1_table_offset = cpu_to_be64(sn->l1_table_offset); |
2047 |
h.l1_size = cpu_to_be32(sn->l1_size); |
2048 |
h.vm_state_size = cpu_to_be32(sn->vm_state_size); |
2049 |
h.date_sec = cpu_to_be32(sn->date_sec); |
2050 |
h.date_nsec = cpu_to_be32(sn->date_nsec); |
2051 |
h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec); |
2052 |
|
2053 |
id_str_size = strlen(sn->id_str); |
2054 |
name_size = strlen(sn->name); |
2055 |
h.id_str_size = cpu_to_be16(id_str_size); |
2056 |
h.name_size = cpu_to_be16(name_size); |
2057 |
offset = align_offset(offset, 8);
|
2058 |
if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
2059 |
goto fail;
|
2060 |
offset += sizeof(h);
|
2061 |
if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
2062 |
goto fail;
|
2063 |
offset += id_str_size; |
2064 |
if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size)
|
2065 |
goto fail;
|
2066 |
offset += name_size; |
2067 |
} |
2068 |
|
2069 |
/* update the various header fields */
|
2070 |
data64 = cpu_to_be64(snapshots_offset); |
2071 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset),
|
2072 |
&data64, sizeof(data64)) != sizeof(data64)) |
2073 |
goto fail;
|
2074 |
data32 = cpu_to_be32(s->nb_snapshots); |
2075 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots),
|
2076 |
&data32, sizeof(data32)) != sizeof(data32)) |
2077 |
goto fail;
|
2078 |
|
2079 |
/* free the old snapshot table */
|
2080 |
free_clusters(bs, s->snapshots_offset, s->snapshots_size); |
2081 |
s->snapshots_offset = snapshots_offset; |
2082 |
s->snapshots_size = snapshots_size; |
2083 |
return 0; |
2084 |
fail:
|
2085 |
return -1; |
2086 |
} |
2087 |
|
2088 |
static void find_new_snapshot_id(BlockDriverState *bs, |
2089 |
char *id_str, int id_str_size) |
2090 |
{ |
2091 |
BDRVQcowState *s = bs->opaque; |
2092 |
QCowSnapshot *sn; |
2093 |
int i, id, id_max = 0; |
2094 |
|
2095 |
for(i = 0; i < s->nb_snapshots; i++) { |
2096 |
sn = s->snapshots + i; |
2097 |
id = strtoul(sn->id_str, NULL, 10); |
2098 |
if (id > id_max)
|
2099 |
id_max = id; |
2100 |
} |
2101 |
snprintf(id_str, id_str_size, "%d", id_max + 1); |
2102 |
} |
2103 |
|
2104 |
static int find_snapshot_by_id(BlockDriverState *bs, const char *id_str) |
2105 |
{ |
2106 |
BDRVQcowState *s = bs->opaque; |
2107 |
int i;
|
2108 |
|
2109 |
for(i = 0; i < s->nb_snapshots; i++) { |
2110 |
if (!strcmp(s->snapshots[i].id_str, id_str))
|
2111 |
return i;
|
2112 |
} |
2113 |
return -1; |
2114 |
} |
2115 |
|
2116 |
static int find_snapshot_by_id_or_name(BlockDriverState *bs, const char *name) |
2117 |
{ |
2118 |
BDRVQcowState *s = bs->opaque; |
2119 |
int i, ret;
|
2120 |
|
2121 |
ret = find_snapshot_by_id(bs, name); |
2122 |
if (ret >= 0) |
2123 |
return ret;
|
2124 |
for(i = 0; i < s->nb_snapshots; i++) { |
2125 |
if (!strcmp(s->snapshots[i].name, name))
|
2126 |
return i;
|
2127 |
} |
2128 |
return -1; |
2129 |
} |
2130 |
|
2131 |
/* if no id is provided, a new one is constructed */
|
2132 |
static int qcow_snapshot_create(BlockDriverState *bs, |
2133 |
QEMUSnapshotInfo *sn_info) |
2134 |
{ |
2135 |
BDRVQcowState *s = bs->opaque; |
2136 |
QCowSnapshot *snapshots1, sn1, *sn = &sn1; |
2137 |
int i, ret;
|
2138 |
uint64_t *l1_table = NULL;
|
2139 |
|
2140 |
memset(sn, 0, sizeof(*sn)); |
2141 |
|
2142 |
if (sn_info->id_str[0] == '\0') { |
2143 |
/* compute a new id */
|
2144 |
find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
|
2145 |
} |
2146 |
|
2147 |
/* check that the ID is unique */
|
2148 |
if (find_snapshot_by_id(bs, sn_info->id_str) >= 0) |
2149 |
return -ENOENT;
|
2150 |
|
2151 |
sn->id_str = qemu_strdup(sn_info->id_str); |
2152 |
if (!sn->id_str)
|
2153 |
goto fail;
|
2154 |
sn->name = qemu_strdup(sn_info->name); |
2155 |
if (!sn->name)
|
2156 |
goto fail;
|
2157 |
sn->vm_state_size = sn_info->vm_state_size; |
2158 |
sn->date_sec = sn_info->date_sec; |
2159 |
sn->date_nsec = sn_info->date_nsec; |
2160 |
sn->vm_clock_nsec = sn_info->vm_clock_nsec; |
2161 |
|
2162 |
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
|
2163 |
if (ret < 0) |
2164 |
goto fail;
|
2165 |
|
2166 |
/* create the L1 table of the snapshot */
|
2167 |
sn->l1_table_offset = alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
|
2168 |
sn->l1_size = s->l1_size; |
2169 |
|
2170 |
l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
|
2171 |
for(i = 0; i < s->l1_size; i++) { |
2172 |
l1_table[i] = cpu_to_be64(s->l1_table[i]); |
2173 |
} |
2174 |
if (bdrv_pwrite(s->hd, sn->l1_table_offset,
|
2175 |
l1_table, s->l1_size * sizeof(uint64_t)) !=
|
2176 |
(s->l1_size * sizeof(uint64_t)))
|
2177 |
goto fail;
|
2178 |
qemu_free(l1_table); |
2179 |
l1_table = NULL;
|
2180 |
|
2181 |
snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot)); |
2182 |
if (s->snapshots) {
|
2183 |
memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot));
|
2184 |
qemu_free(s->snapshots); |
2185 |
} |
2186 |
s->snapshots = snapshots1; |
2187 |
s->snapshots[s->nb_snapshots++] = *sn; |
2188 |
|
2189 |
if (qcow_write_snapshots(bs) < 0) |
2190 |
goto fail;
|
2191 |
#ifdef DEBUG_ALLOC
|
2192 |
check_refcounts(bs); |
2193 |
#endif
|
2194 |
return 0; |
2195 |
fail:
|
2196 |
qemu_free(sn->name); |
2197 |
qemu_free(l1_table); |
2198 |
return -1; |
2199 |
} |
2200 |
|
2201 |
/* copy the snapshot 'snapshot_name' into the current disk image */
|
2202 |
static int qcow_snapshot_goto(BlockDriverState *bs, |
2203 |
const char *snapshot_id) |
2204 |
{ |
2205 |
BDRVQcowState *s = bs->opaque; |
2206 |
QCowSnapshot *sn; |
2207 |
int i, snapshot_index, l1_size2;
|
2208 |
|
2209 |
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
2210 |
if (snapshot_index < 0) |
2211 |
return -ENOENT;
|
2212 |
sn = &s->snapshots[snapshot_index]; |
2213 |
|
2214 |
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1) < 0) |
2215 |
goto fail;
|
2216 |
|
2217 |
if (grow_l1_table(bs, sn->l1_size) < 0) |
2218 |
goto fail;
|
2219 |
|
2220 |
s->l1_size = sn->l1_size; |
2221 |
l1_size2 = s->l1_size * sizeof(uint64_t);
|
2222 |
/* copy the snapshot l1 table to the current l1 table */
|
2223 |
if (bdrv_pread(s->hd, sn->l1_table_offset,
|
2224 |
s->l1_table, l1_size2) != l1_size2) |
2225 |
goto fail;
|
2226 |
if (bdrv_pwrite(s->hd, s->l1_table_offset,
|
2227 |
s->l1_table, l1_size2) != l1_size2) |
2228 |
goto fail;
|
2229 |
for(i = 0;i < s->l1_size; i++) { |
2230 |
be64_to_cpus(&s->l1_table[i]); |
2231 |
} |
2232 |
|
2233 |
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1) < 0) |
2234 |
goto fail;
|
2235 |
|
2236 |
#ifdef DEBUG_ALLOC
|
2237 |
check_refcounts(bs); |
2238 |
#endif
|
2239 |
return 0; |
2240 |
fail:
|
2241 |
return -EIO;
|
2242 |
} |
2243 |
|
2244 |
static int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) |
2245 |
{ |
2246 |
BDRVQcowState *s = bs->opaque; |
2247 |
QCowSnapshot *sn; |
2248 |
int snapshot_index, ret;
|
2249 |
|
2250 |
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
2251 |
if (snapshot_index < 0) |
2252 |
return -ENOENT;
|
2253 |
sn = &s->snapshots[snapshot_index]; |
2254 |
|
2255 |
ret = update_snapshot_refcount(bs, sn->l1_table_offset, sn->l1_size, -1);
|
2256 |
if (ret < 0) |
2257 |
return ret;
|
2258 |
/* must update the copied flag on the current cluster offsets */
|
2259 |
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0);
|
2260 |
if (ret < 0) |
2261 |
return ret;
|
2262 |
free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t));
|
2263 |
|
2264 |
qemu_free(sn->id_str); |
2265 |
qemu_free(sn->name); |
2266 |
memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn)); |
2267 |
s->nb_snapshots--; |
2268 |
ret = qcow_write_snapshots(bs); |
2269 |
if (ret < 0) { |
2270 |
/* XXX: restore snapshot if error ? */
|
2271 |
return ret;
|
2272 |
} |
2273 |
#ifdef DEBUG_ALLOC
|
2274 |
check_refcounts(bs); |
2275 |
#endif
|
2276 |
return 0; |
2277 |
} |
2278 |
|
2279 |
static int qcow_snapshot_list(BlockDriverState *bs, |
2280 |
QEMUSnapshotInfo **psn_tab) |
2281 |
{ |
2282 |
BDRVQcowState *s = bs->opaque; |
2283 |
QEMUSnapshotInfo *sn_tab, *sn_info; |
2284 |
QCowSnapshot *sn; |
2285 |
int i;
|
2286 |
|
2287 |
if (!s->nb_snapshots) {
|
2288 |
*psn_tab = NULL;
|
2289 |
return s->nb_snapshots;
|
2290 |
} |
2291 |
|
2292 |
sn_tab = qemu_mallocz(s->nb_snapshots * sizeof(QEMUSnapshotInfo));
|
2293 |
for(i = 0; i < s->nb_snapshots; i++) { |
2294 |
sn_info = sn_tab + i; |
2295 |
sn = s->snapshots + i; |
2296 |
pstrcpy(sn_info->id_str, sizeof(sn_info->id_str),
|
2297 |
sn->id_str); |
2298 |
pstrcpy(sn_info->name, sizeof(sn_info->name),
|
2299 |
sn->name); |
2300 |
sn_info->vm_state_size = sn->vm_state_size; |
2301 |
sn_info->date_sec = sn->date_sec; |
2302 |
sn_info->date_nsec = sn->date_nsec; |
2303 |
sn_info->vm_clock_nsec = sn->vm_clock_nsec; |
2304 |
} |
2305 |
*psn_tab = sn_tab; |
2306 |
return s->nb_snapshots;
|
2307 |
} |
2308 |
|
2309 |
/*********************************************************/
|
2310 |
/* refcount handling */
|
2311 |
|
2312 |
static int refcount_init(BlockDriverState *bs) |
2313 |
{ |
2314 |
BDRVQcowState *s = bs->opaque; |
2315 |
int ret, refcount_table_size2, i;
|
2316 |
|
2317 |
s->refcount_block_cache = qemu_malloc(s->cluster_size); |
2318 |
refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t);
|
2319 |
s->refcount_table = qemu_malloc(refcount_table_size2); |
2320 |
if (s->refcount_table_size > 0) { |
2321 |
ret = bdrv_pread(s->hd, s->refcount_table_offset, |
2322 |
s->refcount_table, refcount_table_size2); |
2323 |
if (ret != refcount_table_size2)
|
2324 |
goto fail;
|
2325 |
for(i = 0; i < s->refcount_table_size; i++) |
2326 |
be64_to_cpus(&s->refcount_table[i]); |
2327 |
} |
2328 |
return 0; |
2329 |
fail:
|
2330 |
return -ENOMEM;
|
2331 |
} |
2332 |
|
2333 |
static void refcount_close(BlockDriverState *bs) |
2334 |
{ |
2335 |
BDRVQcowState *s = bs->opaque; |
2336 |
qemu_free(s->refcount_block_cache); |
2337 |
qemu_free(s->refcount_table); |
2338 |
} |
2339 |
|
2340 |
|
2341 |
static int load_refcount_block(BlockDriverState *bs, |
2342 |
int64_t refcount_block_offset) |
2343 |
{ |
2344 |
BDRVQcowState *s = bs->opaque; |
2345 |
int ret;
|
2346 |
ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache, |
2347 |
s->cluster_size); |
2348 |
if (ret != s->cluster_size)
|
2349 |
return -EIO;
|
2350 |
s->refcount_block_cache_offset = refcount_block_offset; |
2351 |
return 0; |
2352 |
} |
2353 |
|
2354 |
static int get_refcount(BlockDriverState *bs, int64_t cluster_index) |
2355 |
{ |
2356 |
BDRVQcowState *s = bs->opaque; |
2357 |
int refcount_table_index, block_index;
|
2358 |
int64_t refcount_block_offset; |
2359 |
|
2360 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
2361 |
if (refcount_table_index >= s->refcount_table_size)
|
2362 |
return 0; |
2363 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
2364 |
if (!refcount_block_offset)
|
2365 |
return 0; |
2366 |
if (refcount_block_offset != s->refcount_block_cache_offset) {
|
2367 |
/* better than nothing: return allocated if read error */
|
2368 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
2369 |
return 1; |
2370 |
} |
2371 |
block_index = cluster_index & |
2372 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
2373 |
return be16_to_cpu(s->refcount_block_cache[block_index]);
|
2374 |
} |
2375 |
|
2376 |
/* return < 0 if error */
|
2377 |
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
|
2378 |
{ |
2379 |
BDRVQcowState *s = bs->opaque; |
2380 |
int i, nb_clusters;
|
2381 |
|
2382 |
nb_clusters = size_to_clusters(s, size); |
2383 |
retry:
|
2384 |
for(i = 0; i < nb_clusters; i++) { |
2385 |
int64_t i = s->free_cluster_index++; |
2386 |
if (get_refcount(bs, i) != 0) |
2387 |
goto retry;
|
2388 |
} |
2389 |
#ifdef DEBUG_ALLOC2
|
2390 |
printf("alloc_clusters: size=%lld -> %lld\n",
|
2391 |
size, |
2392 |
(s->free_cluster_index - nb_clusters) << s->cluster_bits); |
2393 |
#endif
|
2394 |
return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
|
2395 |
} |
2396 |
|
2397 |
static int64_t alloc_clusters(BlockDriverState *bs, int64_t size)
|
2398 |
{ |
2399 |
int64_t offset; |
2400 |
|
2401 |
offset = alloc_clusters_noref(bs, size); |
2402 |
update_refcount(bs, offset, size, 1);
|
2403 |
return offset;
|
2404 |
} |
2405 |
|
2406 |
/* only used to allocate compressed sectors. We try to allocate
|
2407 |
contiguous sectors. size must be <= cluster_size */
|
2408 |
static int64_t alloc_bytes(BlockDriverState *bs, int size) |
2409 |
{ |
2410 |
BDRVQcowState *s = bs->opaque; |
2411 |
int64_t offset, cluster_offset; |
2412 |
int free_in_cluster;
|
2413 |
|
2414 |
assert(size > 0 && size <= s->cluster_size);
|
2415 |
if (s->free_byte_offset == 0) { |
2416 |
s->free_byte_offset = alloc_clusters(bs, s->cluster_size); |
2417 |
} |
2418 |
redo:
|
2419 |
free_in_cluster = s->cluster_size - |
2420 |
(s->free_byte_offset & (s->cluster_size - 1));
|
2421 |
if (size <= free_in_cluster) {
|
2422 |
/* enough space in current cluster */
|
2423 |
offset = s->free_byte_offset; |
2424 |
s->free_byte_offset += size; |
2425 |
free_in_cluster -= size; |
2426 |
if (free_in_cluster == 0) |
2427 |
s->free_byte_offset = 0;
|
2428 |
if ((offset & (s->cluster_size - 1)) != 0) |
2429 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
2430 |
} else {
|
2431 |
offset = alloc_clusters(bs, s->cluster_size); |
2432 |
cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1);
|
2433 |
if ((cluster_offset + s->cluster_size) == offset) {
|
2434 |
/* we are lucky: contiguous data */
|
2435 |
offset = s->free_byte_offset; |
2436 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
2437 |
s->free_byte_offset += size; |
2438 |
} else {
|
2439 |
s->free_byte_offset = offset; |
2440 |
goto redo;
|
2441 |
} |
2442 |
} |
2443 |
return offset;
|
2444 |
} |
2445 |
|
2446 |
static void free_clusters(BlockDriverState *bs, |
2447 |
int64_t offset, int64_t size) |
2448 |
{ |
2449 |
update_refcount(bs, offset, size, -1);
|
2450 |
} |
2451 |
|
2452 |
static int grow_refcount_table(BlockDriverState *bs, int min_size) |
2453 |
{ |
2454 |
BDRVQcowState *s = bs->opaque; |
2455 |
int new_table_size, new_table_size2, refcount_table_clusters, i, ret;
|
2456 |
uint64_t *new_table; |
2457 |
int64_t table_offset; |
2458 |
uint8_t data[12];
|
2459 |
int old_table_size;
|
2460 |
int64_t old_table_offset; |
2461 |
|
2462 |
if (min_size <= s->refcount_table_size)
|
2463 |
return 0; |
2464 |
/* compute new table size */
|
2465 |
refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
|
2466 |
for(;;) {
|
2467 |
if (refcount_table_clusters == 0) { |
2468 |
refcount_table_clusters = 1;
|
2469 |
} else {
|
2470 |
refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; |
2471 |
} |
2472 |
new_table_size = refcount_table_clusters << (s->cluster_bits - 3);
|
2473 |
if (min_size <= new_table_size)
|
2474 |
break;
|
2475 |
} |
2476 |
#ifdef DEBUG_ALLOC2
|
2477 |
printf("grow_refcount_table from %d to %d\n",
|
2478 |
s->refcount_table_size, |
2479 |
new_table_size); |
2480 |
#endif
|
2481 |
new_table_size2 = new_table_size * sizeof(uint64_t);
|
2482 |
new_table = qemu_mallocz(new_table_size2); |
2483 |
memcpy(new_table, s->refcount_table, |
2484 |
s->refcount_table_size * sizeof(uint64_t));
|
2485 |
for(i = 0; i < s->refcount_table_size; i++) |
2486 |
cpu_to_be64s(&new_table[i]); |
2487 |
/* Note: we cannot update the refcount now to avoid recursion */
|
2488 |
table_offset = alloc_clusters_noref(bs, new_table_size2); |
2489 |
ret = bdrv_pwrite(s->hd, table_offset, new_table, new_table_size2); |
2490 |
if (ret != new_table_size2)
|
2491 |
goto fail;
|
2492 |
for(i = 0; i < s->refcount_table_size; i++) |
2493 |
be64_to_cpus(&new_table[i]); |
2494 |
|
2495 |
cpu_to_be64w((uint64_t*)data, table_offset); |
2496 |
cpu_to_be32w((uint32_t*)(data + 8), refcount_table_clusters);
|
2497 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset),
|
2498 |
data, sizeof(data)) != sizeof(data)) |
2499 |
goto fail;
|
2500 |
qemu_free(s->refcount_table); |
2501 |
old_table_offset = s->refcount_table_offset; |
2502 |
old_table_size = s->refcount_table_size; |
2503 |
s->refcount_table = new_table; |
2504 |
s->refcount_table_size = new_table_size; |
2505 |
s->refcount_table_offset = table_offset; |
2506 |
|
2507 |
update_refcount(bs, table_offset, new_table_size2, 1);
|
2508 |
free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t));
|
2509 |
return 0; |
2510 |
fail:
|
2511 |
free_clusters(bs, table_offset, new_table_size2); |
2512 |
qemu_free(new_table); |
2513 |
return -EIO;
|
2514 |
} |
2515 |
|
2516 |
|
2517 |
static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
|
2518 |
{ |
2519 |
BDRVQcowState *s = bs->opaque; |
2520 |
int64_t offset, refcount_block_offset; |
2521 |
int ret, refcount_table_index;
|
2522 |
uint64_t data64; |
2523 |
|
2524 |
/* Find L1 index and grow refcount table if needed */
|
2525 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
2526 |
if (refcount_table_index >= s->refcount_table_size) {
|
2527 |
ret = grow_refcount_table(bs, refcount_table_index + 1);
|
2528 |
if (ret < 0) |
2529 |
return ret;
|
2530 |
} |
2531 |
|
2532 |
/* Load or allocate the refcount block */
|
2533 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
2534 |
if (!refcount_block_offset) {
|
2535 |
/* create a new refcount block */
|
2536 |
/* Note: we cannot update the refcount now to avoid recursion */
|
2537 |
offset = alloc_clusters_noref(bs, s->cluster_size); |
2538 |
memset(s->refcount_block_cache, 0, s->cluster_size);
|
2539 |
ret = bdrv_pwrite(s->hd, offset, s->refcount_block_cache, s->cluster_size); |
2540 |
if (ret != s->cluster_size)
|
2541 |
return -EINVAL;
|
2542 |
s->refcount_table[refcount_table_index] = offset; |
2543 |
data64 = cpu_to_be64(offset); |
2544 |
ret = bdrv_pwrite(s->hd, s->refcount_table_offset + |
2545 |
refcount_table_index * sizeof(uint64_t),
|
2546 |
&data64, sizeof(data64));
|
2547 |
if (ret != sizeof(data64)) |
2548 |
return -EINVAL;
|
2549 |
|
2550 |
refcount_block_offset = offset; |
2551 |
s->refcount_block_cache_offset = offset; |
2552 |
update_refcount(bs, offset, s->cluster_size, 1);
|
2553 |
} else {
|
2554 |
if (refcount_block_offset != s->refcount_block_cache_offset) {
|
2555 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
2556 |
return -EIO;
|
2557 |
} |
2558 |
} |
2559 |
|
2560 |
return refcount_block_offset;
|
2561 |
} |
2562 |
|
2563 |
/* addend must be 1 or -1 */
|
2564 |
static int update_cluster_refcount(BlockDriverState *bs, |
2565 |
int64_t cluster_index, |
2566 |
int addend)
|
2567 |
{ |
2568 |
BDRVQcowState *s = bs->opaque; |
2569 |
int ret;
|
2570 |
|
2571 |
ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend);
|
2572 |
if (ret < 0) { |
2573 |
return ret;
|
2574 |
} |
2575 |
|
2576 |
return get_refcount(bs, cluster_index);
|
2577 |
} |
2578 |
|
2579 |
/* XXX: cache several refcount block clusters ? */
|
2580 |
static int update_refcount(BlockDriverState *bs, |
2581 |
int64_t offset, int64_t length, |
2582 |
int addend)
|
2583 |
{ |
2584 |
BDRVQcowState *s = bs->opaque; |
2585 |
int64_t start, last, cluster_offset; |
2586 |
int64_t refcount_block_offset = 0;
|
2587 |
int64_t table_index = -1, old_table_index;
|
2588 |
int first_index = -1, last_index = -1; |
2589 |
|
2590 |
#ifdef DEBUG_ALLOC2
|
2591 |
printf("update_refcount: offset=%lld size=%lld addend=%d\n",
|
2592 |
offset, length, addend); |
2593 |
#endif
|
2594 |
if (length <= 0) |
2595 |
return -EINVAL;
|
2596 |
start = offset & ~(s->cluster_size - 1);
|
2597 |
last = (offset + length - 1) & ~(s->cluster_size - 1); |
2598 |
for(cluster_offset = start; cluster_offset <= last;
|
2599 |
cluster_offset += s->cluster_size) |
2600 |
{ |
2601 |
int block_index, refcount;
|
2602 |
int64_t cluster_index = cluster_offset >> s->cluster_bits; |
2603 |
|
2604 |
/* Only write refcount block to disk when we are done with it */
|
2605 |
old_table_index = table_index; |
2606 |
table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
2607 |
if ((old_table_index >= 0) && (table_index != old_table_index)) { |
2608 |
size_t size = (last_index - first_index + 1) << REFCOUNT_SHIFT;
|
2609 |
if (bdrv_pwrite(s->hd,
|
2610 |
refcount_block_offset + (first_index << REFCOUNT_SHIFT), |
2611 |
&s->refcount_block_cache[first_index], size) != size) |
2612 |
{ |
2613 |
return -EIO;
|
2614 |
} |
2615 |
|
2616 |
first_index = -1;
|
2617 |
last_index = -1;
|
2618 |
} |
2619 |
|
2620 |
/* Load the refcount block and allocate it if needed */
|
2621 |
refcount_block_offset = alloc_refcount_block(bs, cluster_index); |
2622 |
if (refcount_block_offset < 0) { |
2623 |
return refcount_block_offset;
|
2624 |
} |
2625 |
|
2626 |
/* we can update the count and save it */
|
2627 |
block_index = cluster_index & |
2628 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
2629 |
if (first_index == -1 || block_index < first_index) { |
2630 |
first_index = block_index; |
2631 |
} |
2632 |
if (block_index > last_index) {
|
2633 |
last_index = block_index; |
2634 |
} |
2635 |
|
2636 |
refcount = be16_to_cpu(s->refcount_block_cache[block_index]); |
2637 |
refcount += addend; |
2638 |
if (refcount < 0 || refcount > 0xffff) |
2639 |
return -EINVAL;
|
2640 |
if (refcount == 0 && cluster_index < s->free_cluster_index) { |
2641 |
s->free_cluster_index = cluster_index; |
2642 |
} |
2643 |
s->refcount_block_cache[block_index] = cpu_to_be16(refcount); |
2644 |
} |
2645 |
|
2646 |
/* Write last changed block to disk */
|
2647 |
if (refcount_block_offset != 0) { |
2648 |
size_t size = (last_index - first_index + 1) << REFCOUNT_SHIFT;
|
2649 |
if (bdrv_pwrite(s->hd,
|
2650 |
refcount_block_offset + (first_index << REFCOUNT_SHIFT), |
2651 |
&s->refcount_block_cache[first_index], size) != size) |
2652 |
{ |
2653 |
return -EIO;
|
2654 |
} |
2655 |
} |
2656 |
|
2657 |
return 0; |
2658 |
} |
2659 |
|
2660 |
/*
|
2661 |
* Increases the refcount for a range of clusters in a given refcount table.
|
2662 |
* This is used to construct a temporary refcount table out of L1 and L2 tables
|
2663 |
* which can be compared the the refcount table saved in the image.
|
2664 |
*
|
2665 |
* Returns the number of errors in the image that were found
|
2666 |
*/
|
2667 |
static int inc_refcounts(BlockDriverState *bs, |
2668 |
uint16_t *refcount_table, |
2669 |
int refcount_table_size,
|
2670 |
int64_t offset, int64_t size) |
2671 |
{ |
2672 |
BDRVQcowState *s = bs->opaque; |
2673 |
int64_t start, last, cluster_offset; |
2674 |
int k;
|
2675 |
int errors = 0; |
2676 |
|
2677 |
if (size <= 0) |
2678 |
return 0; |
2679 |
|
2680 |
start = offset & ~(s->cluster_size - 1);
|
2681 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
2682 |
for(cluster_offset = start; cluster_offset <= last;
|
2683 |
cluster_offset += s->cluster_size) { |
2684 |
k = cluster_offset >> s->cluster_bits; |
2685 |
if (k < 0 || k >= refcount_table_size) { |
2686 |
fprintf(stderr, "ERROR: invalid cluster offset=0x%" PRIx64 "\n", |
2687 |
cluster_offset); |
2688 |
errors++; |
2689 |
} else {
|
2690 |
if (++refcount_table[k] == 0) { |
2691 |
fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64
|
2692 |
"\n", cluster_offset);
|
2693 |
errors++; |
2694 |
} |
2695 |
} |
2696 |
} |
2697 |
|
2698 |
return errors;
|
2699 |
} |
2700 |
|
2701 |
/*
|
2702 |
* Increases the refcount in the given refcount table for the all clusters
|
2703 |
* referenced in the L2 table. While doing so, performs some checks on L2
|
2704 |
* entries.
|
2705 |
*
|
2706 |
* Returns the number of errors found by the checks or -errno if an internal
|
2707 |
* error occurred.
|
2708 |
*/
|
2709 |
static int check_refcounts_l2(BlockDriverState *bs, |
2710 |
uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset,
|
2711 |
int check_copied)
|
2712 |
{ |
2713 |
BDRVQcowState *s = bs->opaque; |
2714 |
uint64_t *l2_table, offset; |
2715 |
int i, l2_size, nb_csectors, refcount;
|
2716 |
int errors = 0; |
2717 |
|
2718 |
/* Read L2 table from disk */
|
2719 |
l2_size = s->l2_size * sizeof(uint64_t);
|
2720 |
l2_table = qemu_malloc(l2_size); |
2721 |
|
2722 |
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
|
2723 |
goto fail;
|
2724 |
|
2725 |
/* Do the actual checks */
|
2726 |
for(i = 0; i < s->l2_size; i++) { |
2727 |
offset = be64_to_cpu(l2_table[i]); |
2728 |
if (offset != 0) { |
2729 |
if (offset & QCOW_OFLAG_COMPRESSED) {
|
2730 |
/* Compressed clusters don't have QCOW_OFLAG_COPIED */
|
2731 |
if (offset & QCOW_OFLAG_COPIED) {
|
2732 |
fprintf(stderr, "ERROR: cluster %" PRId64 ": " |
2733 |
"copied flag must never be set for compressed "
|
2734 |
"clusters\n", offset >> s->cluster_bits);
|
2735 |
offset &= ~QCOW_OFLAG_COPIED; |
2736 |
errors++; |
2737 |
} |
2738 |
|
2739 |
/* Mark cluster as used */
|
2740 |
nb_csectors = ((offset >> s->csize_shift) & |
2741 |
s->csize_mask) + 1;
|
2742 |
offset &= s->cluster_offset_mask; |
2743 |
errors += inc_refcounts(bs, refcount_table, |
2744 |
refcount_table_size, |
2745 |
offset & ~511, nb_csectors * 512); |
2746 |
} else {
|
2747 |
/* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
|
2748 |
if (check_copied) {
|
2749 |
uint64_t entry = offset; |
2750 |
offset &= ~QCOW_OFLAG_COPIED; |
2751 |
refcount = get_refcount(bs, offset >> s->cluster_bits); |
2752 |
if ((refcount == 1) != ((entry & QCOW_OFLAG_COPIED) != 0)) { |
2753 |
fprintf(stderr, "ERROR OFLAG_COPIED: offset=%"
|
2754 |
PRIx64 " refcount=%d\n", entry, refcount);
|
2755 |
errors++; |
2756 |
} |
2757 |
} |
2758 |
|
2759 |
/* Mark cluster as used */
|
2760 |
offset &= ~QCOW_OFLAG_COPIED; |
2761 |
errors += inc_refcounts(bs, refcount_table, |
2762 |
refcount_table_size, |
2763 |
offset, s->cluster_size); |
2764 |
|
2765 |
/* Correct offsets are cluster aligned */
|
2766 |
if (offset & (s->cluster_size - 1)) { |
2767 |
fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " |
2768 |
"properly aligned; L2 entry corrupted.\n", offset);
|
2769 |
errors++; |
2770 |
} |
2771 |
} |
2772 |
} |
2773 |
} |
2774 |
|
2775 |
qemu_free(l2_table); |
2776 |
return errors;
|
2777 |
|
2778 |
fail:
|
2779 |
fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
|
2780 |
qemu_free(l2_table); |
2781 |
return -EIO;
|
2782 |
} |
2783 |
|
2784 |
/*
|
2785 |
* Increases the refcount for the L1 table, its L2 tables and all referenced
|
2786 |
* clusters in the given refcount table. While doing so, performs some checks
|
2787 |
* on L1 and L2 entries.
|
2788 |
*
|
2789 |
* Returns the number of errors found by the checks or -errno if an internal
|
2790 |
* error occurred.
|
2791 |
*/
|
2792 |
static int check_refcounts_l1(BlockDriverState *bs, |
2793 |
uint16_t *refcount_table, |
2794 |
int refcount_table_size,
|
2795 |
int64_t l1_table_offset, int l1_size,
|
2796 |
int check_copied)
|
2797 |
{ |
2798 |
BDRVQcowState *s = bs->opaque; |
2799 |
uint64_t *l1_table, l2_offset, l1_size2; |
2800 |
int i, refcount, ret;
|
2801 |
int errors = 0; |
2802 |
|
2803 |
l1_size2 = l1_size * sizeof(uint64_t);
|
2804 |
|
2805 |
/* Mark L1 table as used */
|
2806 |
errors += inc_refcounts(bs, refcount_table, refcount_table_size, |
2807 |
l1_table_offset, l1_size2); |
2808 |
|
2809 |
/* Read L1 table entries from disk */
|
2810 |
l1_table = qemu_malloc(l1_size2); |
2811 |
if (bdrv_pread(s->hd, l1_table_offset,
|
2812 |
l1_table, l1_size2) != l1_size2) |
2813 |
goto fail;
|
2814 |
for(i = 0;i < l1_size; i++) |
2815 |
be64_to_cpus(&l1_table[i]); |
2816 |
|
2817 |
/* Do the actual checks */
|
2818 |
for(i = 0; i < l1_size; i++) { |
2819 |
l2_offset = l1_table[i]; |
2820 |
if (l2_offset) {
|
2821 |
/* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
|
2822 |
if (check_copied) {
|
2823 |
refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) |
2824 |
>> s->cluster_bits); |
2825 |
if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { |
2826 |
fprintf(stderr, "ERROR OFLAG_COPIED: l2_offset=%" PRIx64
|
2827 |
" refcount=%d\n", l2_offset, refcount);
|
2828 |
errors++; |
2829 |
} |
2830 |
} |
2831 |
|
2832 |
/* Mark L2 table as used */
|
2833 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
2834 |
errors += inc_refcounts(bs, refcount_table, |
2835 |
refcount_table_size, |
2836 |
l2_offset, |
2837 |
s->cluster_size); |
2838 |
|
2839 |
/* L2 tables are cluster aligned */
|
2840 |
if (l2_offset & (s->cluster_size - 1)) { |
2841 |
fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " |
2842 |
"cluster aligned; L1 entry corrupted\n", l2_offset);
|
2843 |
errors++; |
2844 |
} |
2845 |
|
2846 |
/* Process and check L2 entries */
|
2847 |
ret = check_refcounts_l2(bs, refcount_table, refcount_table_size, |
2848 |
l2_offset, check_copied); |
2849 |
if (ret < 0) { |
2850 |
goto fail;
|
2851 |
} |
2852 |
errors += ret; |
2853 |
} |
2854 |
} |
2855 |
qemu_free(l1_table); |
2856 |
return errors;
|
2857 |
|
2858 |
fail:
|
2859 |
fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
|
2860 |
qemu_free(l1_table); |
2861 |
return -EIO;
|
2862 |
} |
2863 |
|
2864 |
/*
|
2865 |
* Checks an image for refcount consistency.
|
2866 |
*
|
2867 |
* Returns 0 if no errors are found, the number of errors in case the image is
|
2868 |
* detected as corrupted, and -errno when an internal error occured.
|
2869 |
*/
|
2870 |
static int check_refcounts(BlockDriverState *bs) |
2871 |
{ |
2872 |
BDRVQcowState *s = bs->opaque; |
2873 |
int64_t size; |
2874 |
int nb_clusters, refcount1, refcount2, i;
|
2875 |
QCowSnapshot *sn; |
2876 |
uint16_t *refcount_table; |
2877 |
int ret, errors = 0; |
2878 |
|
2879 |
size = bdrv_getlength(s->hd); |
2880 |
nb_clusters = size_to_clusters(s, size); |
2881 |
refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t));
|
2882 |
|
2883 |
/* header */
|
2884 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
2885 |
0, s->cluster_size);
|
2886 |
|
2887 |
/* current L1 table */
|
2888 |
ret = check_refcounts_l1(bs, refcount_table, nb_clusters, |
2889 |
s->l1_table_offset, s->l1_size, 1);
|
2890 |
if (ret < 0) { |
2891 |
return ret;
|
2892 |
} |
2893 |
errors += ret; |
2894 |
|
2895 |
/* snapshots */
|
2896 |
for(i = 0; i < s->nb_snapshots; i++) { |
2897 |
sn = s->snapshots + i; |
2898 |
check_refcounts_l1(bs, refcount_table, nb_clusters, |
2899 |
sn->l1_table_offset, sn->l1_size, 0);
|
2900 |
} |
2901 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
2902 |
s->snapshots_offset, s->snapshots_size); |
2903 |
|
2904 |
/* refcount data */
|
2905 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
2906 |
s->refcount_table_offset, |
2907 |
s->refcount_table_size * sizeof(uint64_t));
|
2908 |
for(i = 0; i < s->refcount_table_size; i++) { |
2909 |
int64_t offset; |
2910 |
offset = s->refcount_table[i]; |
2911 |
if (offset != 0) { |
2912 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
2913 |
offset, s->cluster_size); |
2914 |
} |
2915 |
} |
2916 |
|
2917 |
/* compare ref counts */
|
2918 |
for(i = 0; i < nb_clusters; i++) { |
2919 |
refcount1 = get_refcount(bs, i); |
2920 |
refcount2 = refcount_table[i]; |
2921 |
if (refcount1 != refcount2) {
|
2922 |
fprintf(stderr, "ERROR cluster %d refcount=%d reference=%d\n",
|
2923 |
i, refcount1, refcount2); |
2924 |
errors++; |
2925 |
} |
2926 |
} |
2927 |
|
2928 |
qemu_free(refcount_table); |
2929 |
|
2930 |
return errors;
|
2931 |
} |
2932 |
|
2933 |
static int qcow_check(BlockDriverState *bs) |
2934 |
{ |
2935 |
return check_refcounts(bs);
|
2936 |
} |
2937 |
|
2938 |
#if 0
|
2939 |
static void dump_refcounts(BlockDriverState *bs)
|
2940 |
{
|
2941 |
BDRVQcowState *s = bs->opaque;
|
2942 |
int64_t nb_clusters, k, k1, size;
|
2943 |
int refcount;
|
2944 |
|
2945 |
size = bdrv_getlength(s->hd);
|
2946 |
nb_clusters = size_to_clusters(s, size);
|
2947 |
for(k = 0; k < nb_clusters;) {
|
2948 |
k1 = k;
|
2949 |
refcount = get_refcount(bs, k);
|
2950 |
k++;
|
2951 |
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
2952 |
k++;
|
2953 |
printf("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1);
|
2954 |
}
|
2955 |
}
|
2956 |
#endif
|
2957 |
|
2958 |
static int qcow_put_buffer(BlockDriverState *bs, const uint8_t *buf, |
2959 |
int64_t pos, int size)
|
2960 |
{ |
2961 |
int growable = bs->growable;
|
2962 |
|
2963 |
bs->growable = 1;
|
2964 |
bdrv_pwrite(bs, pos, buf, size); |
2965 |
bs->growable = growable; |
2966 |
|
2967 |
return size;
|
2968 |
} |
2969 |
|
2970 |
static int qcow_get_buffer(BlockDriverState *bs, uint8_t *buf, |
2971 |
int64_t pos, int size)
|
2972 |
{ |
2973 |
int growable = bs->growable;
|
2974 |
int ret;
|
2975 |
|
2976 |
bs->growable = 1;
|
2977 |
ret = bdrv_pread(bs, pos, buf, size); |
2978 |
bs->growable = growable; |
2979 |
|
2980 |
return ret;
|
2981 |
} |
2982 |
|
2983 |
static QEMUOptionParameter qcow_create_options[] = {
|
2984 |
{ |
2985 |
.name = BLOCK_OPT_SIZE, |
2986 |
.type = OPT_SIZE, |
2987 |
.help = "Virtual disk size"
|
2988 |
}, |
2989 |
{ |
2990 |
.name = BLOCK_OPT_BACKING_FILE, |
2991 |
.type = OPT_STRING, |
2992 |
.help = "File name of a base image"
|
2993 |
}, |
2994 |
{ |
2995 |
.name = BLOCK_OPT_BACKING_FMT, |
2996 |
.type = OPT_STRING, |
2997 |
.help = "Image format of the base image"
|
2998 |
}, |
2999 |
{ |
3000 |
.name = BLOCK_OPT_ENCRYPT, |
3001 |
.type = OPT_FLAG, |
3002 |
.help = "Encrypt the image"
|
3003 |
}, |
3004 |
{ |
3005 |
.name = BLOCK_OPT_CLUSTER_SIZE, |
3006 |
.type = OPT_SIZE, |
3007 |
.help = "qcow2 cluster size"
|
3008 |
}, |
3009 |
{ NULL }
|
3010 |
}; |
3011 |
|
3012 |
static BlockDriver bdrv_qcow2 = {
|
3013 |
.format_name = "qcow2",
|
3014 |
.instance_size = sizeof(BDRVQcowState),
|
3015 |
.bdrv_probe = qcow_probe, |
3016 |
.bdrv_open = qcow_open, |
3017 |
.bdrv_close = qcow_close, |
3018 |
.bdrv_create = qcow_create, |
3019 |
.bdrv_flush = qcow_flush, |
3020 |
.bdrv_is_allocated = qcow_is_allocated, |
3021 |
.bdrv_set_key = qcow_set_key, |
3022 |
.bdrv_make_empty = qcow_make_empty, |
3023 |
|
3024 |
.bdrv_aio_readv = qcow_aio_readv, |
3025 |
.bdrv_aio_writev = qcow_aio_writev, |
3026 |
.bdrv_write_compressed = qcow_write_compressed, |
3027 |
|
3028 |
.bdrv_snapshot_create = qcow_snapshot_create, |
3029 |
.bdrv_snapshot_goto = qcow_snapshot_goto, |
3030 |
.bdrv_snapshot_delete = qcow_snapshot_delete, |
3031 |
.bdrv_snapshot_list = qcow_snapshot_list, |
3032 |
.bdrv_get_info = qcow_get_info, |
3033 |
|
3034 |
.bdrv_put_buffer = qcow_put_buffer, |
3035 |
.bdrv_get_buffer = qcow_get_buffer, |
3036 |
|
3037 |
.create_options = qcow_create_options, |
3038 |
.bdrv_check = qcow_check, |
3039 |
}; |
3040 |
|
3041 |
static void bdrv_qcow2_init(void) |
3042 |
{ |
3043 |
bdrv_register(&bdrv_qcow2); |
3044 |
} |
3045 |
|
3046 |
block_init(bdrv_qcow2_init); |