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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 <zlib.h> |
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#include "aes.h" |
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#include <assert.h> |
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|
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/*
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Differences with QCOW:
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- Support for multiple incremental snapshots.
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- Memory management by reference counts.
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- Clusters which have a reference count of one have the bit
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QCOW_OFLAG_COPIED to optimize write performance.
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- Size of compressed clusters is stored in sectors to reduce bit usage
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in the cluster offsets.
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- Support for storing additional data (such as the VM state) in the
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snapshots.
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- If a backing store is used, the cluster size is not constrained
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(could be backported to QCOW).
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- L2 tables have always a size of one cluster.
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*/
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|
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//#define DEBUG_ALLOC
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//#define DEBUG_ALLOC2
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#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) |
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#define QCOW_VERSION 2 |
51 |
|
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#define QCOW_CRYPT_NONE 0 |
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#define QCOW_CRYPT_AES 1 |
54 |
|
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#define QCOW_MAX_CRYPT_CLUSTERS 32 |
56 |
|
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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) |
61 |
|
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#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */ |
63 |
|
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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; |
68 |
uint32_t backing_file_size; |
69 |
uint32_t cluster_bits; |
70 |
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; |
79 |
|
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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; |
83 |
|
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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; |
87 |
|
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uint32_t date_sec; |
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uint32_t date_nsec; |
90 |
|
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uint64_t vm_clock_nsec; |
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uint32_t vm_state_size; |
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uint32_t extra_data_size; /* for extension */
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/* extra data follows */
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/* id_str follows */
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/* name follows */
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} QCowSnapshotHeader; |
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|
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#define L2_CACHE_SIZE 16 |
101 |
|
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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; |
112 |
|
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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; |
125 |
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]; |
130 |
uint8_t *cluster_cache; |
131 |
uint8_t *cluster_data; |
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uint64_t cluster_cache_offset; |
133 |
|
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uint64_t *refcount_table; |
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uint64_t refcount_table_offset; |
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uint32_t refcount_table_size; |
137 |
uint64_t refcount_block_cache_offset; |
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uint16_t *refcount_block_cache; |
139 |
int64_t free_cluster_index; |
140 |
int64_t free_byte_offset; |
141 |
|
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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; |
144 |
AES_KEY aes_encrypt_key; |
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AES_KEY aes_decrypt_key; |
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uint64_t snapshots_offset; |
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int snapshots_size;
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int nb_snapshots;
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QCowSnapshot *snapshots; |
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} BDRVQcowState; |
151 |
|
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static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset); |
153 |
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); |
156 |
static void qcow_free_snapshots(BlockDriverState *bs); |
157 |
static int refcount_init(BlockDriverState *bs); |
158 |
static void refcount_close(BlockDriverState *bs); |
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static int get_refcount(BlockDriverState *bs, int64_t cluster_index); |
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static int update_cluster_refcount(BlockDriverState *bs, |
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int64_t cluster_index, |
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int addend);
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static void update_refcount(BlockDriverState *bs, |
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int64_t offset, int64_t length, |
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int addend);
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static int64_t alloc_clusters(BlockDriverState *bs, int64_t size);
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static int64_t alloc_bytes(BlockDriverState *bs, int size); |
168 |
static void free_clusters(BlockDriverState *bs, |
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int64_t offset, int64_t size); |
170 |
#ifdef DEBUG_ALLOC
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static void check_refcounts(BlockDriverState *bs); |
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#endif
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static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
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{ |
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const QCowHeader *cow_header = (const void *)buf; |
177 |
|
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if (buf_size >= sizeof(QCowHeader) && |
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be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
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be32_to_cpu(cow_header->version) == QCOW_VERSION) |
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return 100; |
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else
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return 0; |
184 |
} |
185 |
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static int qcow_open(BlockDriverState *bs, const char *filename, int flags) |
187 |
{ |
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BDRVQcowState *s = bs->opaque; |
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int len, i, shift, ret;
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QCowHeader header; |
191 |
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ret = bdrv_file_open(&s->hd, filename, flags); |
193 |
if (ret < 0) |
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return ret;
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if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) |
196 |
goto fail;
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be32_to_cpus(&header.magic); |
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be32_to_cpus(&header.version); |
199 |
be64_to_cpus(&header.backing_file_offset); |
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be32_to_cpus(&header.backing_file_size); |
201 |
be64_to_cpus(&header.size); |
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be32_to_cpus(&header.cluster_bits); |
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be32_to_cpus(&header.crypt_method); |
204 |
be64_to_cpus(&header.l1_table_offset); |
205 |
be32_to_cpus(&header.l1_size); |
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be64_to_cpus(&header.refcount_table_offset); |
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be32_to_cpus(&header.refcount_table_clusters); |
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be64_to_cpus(&header.snapshots_offset); |
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be32_to_cpus(&header.nb_snapshots); |
210 |
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if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION)
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goto fail;
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if (header.size <= 1 || |
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header.cluster_bits < 9 ||
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header.cluster_bits > 16)
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goto fail;
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if (header.crypt_method > QCOW_CRYPT_AES)
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goto fail;
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s->crypt_method_header = header.crypt_method; |
220 |
if (s->crypt_method_header)
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bs->encrypted = 1;
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s->cluster_bits = header.cluster_bits; |
223 |
s->cluster_size = 1 << s->cluster_bits;
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s->cluster_sectors = 1 << (s->cluster_bits - 9); |
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s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ |
226 |
s->l2_size = 1 << s->l2_bits;
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bs->total_sectors = header.size / 512;
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s->csize_shift = (62 - (s->cluster_bits - 8)); |
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s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
230 |
s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
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s->refcount_table_offset = header.refcount_table_offset; |
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s->refcount_table_size = |
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header.refcount_table_clusters << (s->cluster_bits - 3);
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|
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s->snapshots_offset = header.snapshots_offset; |
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s->nb_snapshots = header.nb_snapshots; |
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|
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/* read the level 1 table */
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s->l1_size = header.l1_size; |
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shift = s->cluster_bits + s->l2_bits; |
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s->l1_vm_state_index = (header.size + (1LL << shift) - 1) >> shift; |
242 |
/* the L1 table must contain at least enough entries to put
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header.size bytes */
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if (s->l1_size < s->l1_vm_state_index)
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goto fail;
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s->l1_table_offset = header.l1_table_offset; |
247 |
s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
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if (!s->l1_table)
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goto fail;
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if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != |
251 |
s->l1_size * sizeof(uint64_t))
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goto fail;
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for(i = 0;i < s->l1_size; i++) { |
254 |
be64_to_cpus(&s->l1_table[i]); |
255 |
} |
256 |
/* alloc L2 cache */
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s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
|
258 |
if (!s->l2_cache)
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goto fail;
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260 |
s->cluster_cache = qemu_malloc(s->cluster_size); |
261 |
if (!s->cluster_cache)
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262 |
goto fail;
|
263 |
/* one more sector for decompressed data alignment */
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264 |
s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size |
265 |
+ 512);
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266 |
if (!s->cluster_data)
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267 |
goto fail;
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268 |
s->cluster_cache_offset = -1;
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269 |
|
270 |
if (refcount_init(bs) < 0) |
271 |
goto fail;
|
272 |
|
273 |
/* read the backing file name */
|
274 |
if (header.backing_file_offset != 0) { |
275 |
len = header.backing_file_size; |
276 |
if (len > 1023) |
277 |
len = 1023;
|
278 |
if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len)
|
279 |
goto fail;
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280 |
bs->backing_file[len] = '\0';
|
281 |
} |
282 |
if (qcow_read_snapshots(bs) < 0) |
283 |
goto fail;
|
284 |
|
285 |
#ifdef DEBUG_ALLOC
|
286 |
check_refcounts(bs); |
287 |
#endif
|
288 |
return 0; |
289 |
|
290 |
fail:
|
291 |
qcow_free_snapshots(bs); |
292 |
refcount_close(bs); |
293 |
qemu_free(s->l1_table); |
294 |
qemu_free(s->l2_cache); |
295 |
qemu_free(s->cluster_cache); |
296 |
qemu_free(s->cluster_data); |
297 |
bdrv_delete(s->hd); |
298 |
return -1; |
299 |
} |
300 |
|
301 |
static int qcow_set_key(BlockDriverState *bs, const char *key) |
302 |
{ |
303 |
BDRVQcowState *s = bs->opaque; |
304 |
uint8_t keybuf[16];
|
305 |
int len, i;
|
306 |
|
307 |
memset(keybuf, 0, 16); |
308 |
len = strlen(key); |
309 |
if (len > 16) |
310 |
len = 16;
|
311 |
/* XXX: we could compress the chars to 7 bits to increase
|
312 |
entropy */
|
313 |
for(i = 0;i < len;i++) { |
314 |
keybuf[i] = key[i]; |
315 |
} |
316 |
s->crypt_method = s->crypt_method_header; |
317 |
|
318 |
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
319 |
return -1; |
320 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
321 |
return -1; |
322 |
#if 0
|
323 |
/* test */
|
324 |
{
|
325 |
uint8_t in[16];
|
326 |
uint8_t out[16];
|
327 |
uint8_t tmp[16];
|
328 |
for(i=0;i<16;i++)
|
329 |
in[i] = i;
|
330 |
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
331 |
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
332 |
for(i = 0; i < 16; i++)
|
333 |
printf(" %02x", tmp[i]);
|
334 |
printf("\n");
|
335 |
for(i = 0; i < 16; i++)
|
336 |
printf(" %02x", out[i]);
|
337 |
printf("\n");
|
338 |
}
|
339 |
#endif
|
340 |
return 0; |
341 |
} |
342 |
|
343 |
/* The crypt function is compatible with the linux cryptoloop
|
344 |
algorithm for < 4 GB images. NOTE: out_buf == in_buf is
|
345 |
supported */
|
346 |
static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
347 |
uint8_t *out_buf, const uint8_t *in_buf,
|
348 |
int nb_sectors, int enc, |
349 |
const AES_KEY *key)
|
350 |
{ |
351 |
union {
|
352 |
uint64_t ll[2];
|
353 |
uint8_t b[16];
|
354 |
} ivec; |
355 |
int i;
|
356 |
|
357 |
for(i = 0; i < nb_sectors; i++) { |
358 |
ivec.ll[0] = cpu_to_le64(sector_num);
|
359 |
ivec.ll[1] = 0; |
360 |
AES_cbc_encrypt(in_buf, out_buf, 512, key,
|
361 |
ivec.b, enc); |
362 |
sector_num++; |
363 |
in_buf += 512;
|
364 |
out_buf += 512;
|
365 |
} |
366 |
} |
367 |
|
368 |
static int copy_sectors(BlockDriverState *bs, uint64_t start_sect, |
369 |
uint64_t cluster_offset, int n_start, int n_end) |
370 |
{ |
371 |
BDRVQcowState *s = bs->opaque; |
372 |
int n, ret;
|
373 |
|
374 |
n = n_end - n_start; |
375 |
if (n <= 0) |
376 |
return 0; |
377 |
ret = qcow_read(bs, start_sect + n_start, s->cluster_data, n); |
378 |
if (ret < 0) |
379 |
return ret;
|
380 |
if (s->crypt_method) {
|
381 |
encrypt_sectors(s, start_sect + n_start, |
382 |
s->cluster_data, |
383 |
s->cluster_data, n, 1,
|
384 |
&s->aes_encrypt_key); |
385 |
} |
386 |
ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start,
|
387 |
s->cluster_data, n); |
388 |
if (ret < 0) |
389 |
return ret;
|
390 |
return 0; |
391 |
} |
392 |
|
393 |
static void l2_cache_reset(BlockDriverState *bs) |
394 |
{ |
395 |
BDRVQcowState *s = bs->opaque; |
396 |
|
397 |
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
398 |
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
399 |
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
400 |
} |
401 |
|
402 |
static inline int l2_cache_new_entry(BlockDriverState *bs) |
403 |
{ |
404 |
BDRVQcowState *s = bs->opaque; |
405 |
uint32_t min_count; |
406 |
int min_index, i;
|
407 |
|
408 |
/* find a new entry in the least used one */
|
409 |
min_index = 0;
|
410 |
min_count = 0xffffffff;
|
411 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
412 |
if (s->l2_cache_counts[i] < min_count) {
|
413 |
min_count = s->l2_cache_counts[i]; |
414 |
min_index = i; |
415 |
} |
416 |
} |
417 |
return min_index;
|
418 |
} |
419 |
|
420 |
static int64_t align_offset(int64_t offset, int n) |
421 |
{ |
422 |
offset = (offset + n - 1) & ~(n - 1); |
423 |
return offset;
|
424 |
} |
425 |
|
426 |
static int grow_l1_table(BlockDriverState *bs, int min_size) |
427 |
{ |
428 |
BDRVQcowState *s = bs->opaque; |
429 |
int new_l1_size, new_l1_size2, ret, i;
|
430 |
uint64_t *new_l1_table; |
431 |
uint64_t new_l1_table_offset; |
432 |
uint64_t data64; |
433 |
uint32_t data32; |
434 |
|
435 |
new_l1_size = s->l1_size; |
436 |
if (min_size <= new_l1_size)
|
437 |
return 0; |
438 |
while (min_size > new_l1_size) {
|
439 |
new_l1_size = (new_l1_size * 3 + 1) / 2; |
440 |
} |
441 |
#ifdef DEBUG_ALLOC2
|
442 |
printf("grow l1_table from %d to %d\n", s->l1_size, new_l1_size);
|
443 |
#endif
|
444 |
|
445 |
new_l1_size2 = sizeof(uint64_t) * new_l1_size;
|
446 |
new_l1_table = qemu_mallocz(new_l1_size2); |
447 |
if (!new_l1_table)
|
448 |
return -ENOMEM;
|
449 |
memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
|
450 |
|
451 |
/* write new table (align to cluster) */
|
452 |
new_l1_table_offset = alloc_clusters(bs, new_l1_size2); |
453 |
|
454 |
for(i = 0; i < s->l1_size; i++) |
455 |
new_l1_table[i] = cpu_to_be64(new_l1_table[i]); |
456 |
ret = bdrv_pwrite(s->hd, new_l1_table_offset, new_l1_table, new_l1_size2); |
457 |
if (ret != new_l1_size2)
|
458 |
goto fail;
|
459 |
for(i = 0; i < s->l1_size; i++) |
460 |
new_l1_table[i] = be64_to_cpu(new_l1_table[i]); |
461 |
|
462 |
/* set new table */
|
463 |
data64 = cpu_to_be64(new_l1_table_offset); |
464 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_table_offset),
|
465 |
&data64, sizeof(data64)) != sizeof(data64)) |
466 |
goto fail;
|
467 |
data32 = cpu_to_be32(new_l1_size); |
468 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_size),
|
469 |
&data32, sizeof(data32)) != sizeof(data32)) |
470 |
goto fail;
|
471 |
qemu_free(s->l1_table); |
472 |
free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t));
|
473 |
s->l1_table_offset = new_l1_table_offset; |
474 |
s->l1_table = new_l1_table; |
475 |
s->l1_size = new_l1_size; |
476 |
return 0; |
477 |
fail:
|
478 |
qemu_free(s->l1_table); |
479 |
return -EIO;
|
480 |
} |
481 |
|
482 |
/*
|
483 |
* seek_l2_table
|
484 |
*
|
485 |
* seek l2_offset in the l2_cache table
|
486 |
* if not found, return NULL,
|
487 |
* if found,
|
488 |
* increments the l2 cache hit count of the entry,
|
489 |
* if counter overflow, divide by two all counters
|
490 |
* return the pointer to the l2 cache entry
|
491 |
*
|
492 |
*/
|
493 |
|
494 |
static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset)
|
495 |
{ |
496 |
int i, j;
|
497 |
|
498 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
499 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
500 |
/* increment the hit count */
|
501 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
502 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
503 |
s->l2_cache_counts[j] >>= 1;
|
504 |
} |
505 |
} |
506 |
return s->l2_cache + (i << s->l2_bits);
|
507 |
} |
508 |
} |
509 |
return NULL; |
510 |
} |
511 |
|
512 |
/*
|
513 |
* l2_load
|
514 |
*
|
515 |
* Loads a L2 table into memory. If the table is in the cache, the cache
|
516 |
* is used; otherwise the L2 table is loaded from the image file.
|
517 |
*
|
518 |
* Returns a pointer to the L2 table on success, or NULL if the read from
|
519 |
* the image file failed.
|
520 |
*/
|
521 |
|
522 |
static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset)
|
523 |
{ |
524 |
BDRVQcowState *s = bs->opaque; |
525 |
int min_index;
|
526 |
uint64_t *l2_table; |
527 |
|
528 |
/* seek if the table for the given offset is in the cache */
|
529 |
|
530 |
l2_table = seek_l2_table(s, l2_offset); |
531 |
if (l2_table != NULL) |
532 |
return l2_table;
|
533 |
|
534 |
/* not found: load a new entry in the least used one */
|
535 |
|
536 |
min_index = l2_cache_new_entry(bs); |
537 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
538 |
if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
539 |
s->l2_size * sizeof(uint64_t))
|
540 |
return NULL; |
541 |
s->l2_cache_offsets[min_index] = l2_offset; |
542 |
s->l2_cache_counts[min_index] = 1;
|
543 |
|
544 |
return l2_table;
|
545 |
} |
546 |
|
547 |
/*
|
548 |
* l2_allocate
|
549 |
*
|
550 |
* Allocate a new l2 entry in the file. If l1_index points to an already
|
551 |
* used entry in the L2 table (i.e. we are doing a copy on write for the L2
|
552 |
* table) copy the contents of the old L2 table into the newly allocated one.
|
553 |
* Otherwise the new table is initialized with zeros.
|
554 |
*
|
555 |
*/
|
556 |
|
557 |
static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index) |
558 |
{ |
559 |
BDRVQcowState *s = bs->opaque; |
560 |
int min_index;
|
561 |
uint64_t old_l2_offset, tmp; |
562 |
uint64_t *l2_table, l2_offset; |
563 |
|
564 |
old_l2_offset = s->l1_table[l1_index]; |
565 |
|
566 |
/* allocate a new l2 entry */
|
567 |
|
568 |
l2_offset = alloc_clusters(bs, s->l2_size * sizeof(uint64_t));
|
569 |
|
570 |
/* update the L1 entry */
|
571 |
|
572 |
s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; |
573 |
|
574 |
tmp = cpu_to_be64(l2_offset | QCOW_OFLAG_COPIED); |
575 |
if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), |
576 |
&tmp, sizeof(tmp)) != sizeof(tmp)) |
577 |
return NULL; |
578 |
|
579 |
/* allocate a new entry in the l2 cache */
|
580 |
|
581 |
min_index = l2_cache_new_entry(bs); |
582 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
583 |
|
584 |
if (old_l2_offset == 0) { |
585 |
/* if there was no old l2 table, clear the new table */
|
586 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
587 |
} else {
|
588 |
/* if there was an old l2 table, read it from the disk */
|
589 |
if (bdrv_pread(s->hd, old_l2_offset,
|
590 |
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
591 |
s->l2_size * sizeof(uint64_t))
|
592 |
return NULL; |
593 |
} |
594 |
/* write the l2 table to the file */
|
595 |
if (bdrv_pwrite(s->hd, l2_offset,
|
596 |
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
597 |
s->l2_size * sizeof(uint64_t))
|
598 |
return NULL; |
599 |
|
600 |
/* update the l2 cache entry */
|
601 |
|
602 |
s->l2_cache_offsets[min_index] = l2_offset; |
603 |
s->l2_cache_counts[min_index] = 1;
|
604 |
|
605 |
return l2_table;
|
606 |
} |
607 |
|
608 |
/*
|
609 |
* get_cluster_offset
|
610 |
*
|
611 |
* For a given offset of the disk image, return cluster offset in
|
612 |
* qcow2 file.
|
613 |
*
|
614 |
* on entry, *num is the number of contiguous clusters we'd like to
|
615 |
* access following offset.
|
616 |
*
|
617 |
* on exit, *num is the number of contiguous clusters we can read.
|
618 |
*
|
619 |
* Return 1, if the offset is found
|
620 |
* Return 0, otherwise.
|
621 |
*
|
622 |
*/
|
623 |
|
624 |
static uint64_t get_cluster_offset(BlockDriverState *bs,
|
625 |
uint64_t offset, int *num)
|
626 |
{ |
627 |
BDRVQcowState *s = bs->opaque; |
628 |
int l1_index, l2_index;
|
629 |
uint64_t l2_offset, *l2_table, cluster_offset, next; |
630 |
int l1_bits;
|
631 |
int index_in_cluster, nb_available, nb_needed;
|
632 |
|
633 |
index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1); |
634 |
nb_needed = *num + index_in_cluster; |
635 |
|
636 |
l1_bits = s->l2_bits + s->cluster_bits; |
637 |
|
638 |
/* compute how many bytes there are between the offset and
|
639 |
* and the end of the l1 entry
|
640 |
*/
|
641 |
|
642 |
nb_available = (1 << l1_bits) - (offset & ((1 << l1_bits) - 1)); |
643 |
|
644 |
/* compute the number of available sectors */
|
645 |
|
646 |
nb_available = (nb_available >> 9) + index_in_cluster;
|
647 |
|
648 |
cluster_offset = 0;
|
649 |
|
650 |
/* seek the the l2 offset in the l1 table */
|
651 |
|
652 |
l1_index = offset >> l1_bits; |
653 |
if (l1_index >= s->l1_size)
|
654 |
goto out;
|
655 |
|
656 |
l2_offset = s->l1_table[l1_index]; |
657 |
|
658 |
/* seek the l2 table of the given l2 offset */
|
659 |
|
660 |
if (!l2_offset)
|
661 |
goto out;
|
662 |
|
663 |
/* load the l2 table in memory */
|
664 |
|
665 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
666 |
l2_table = l2_load(bs, l2_offset); |
667 |
if (l2_table == NULL) |
668 |
return 0; |
669 |
|
670 |
/* find the cluster offset for the given disk offset */
|
671 |
|
672 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
673 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
674 |
nb_available = s->cluster_sectors; |
675 |
l2_index++; |
676 |
|
677 |
if (!cluster_offset) {
|
678 |
|
679 |
/* how many empty clusters ? */
|
680 |
|
681 |
while (nb_available < nb_needed && !l2_table[l2_index]) {
|
682 |
l2_index++; |
683 |
nb_available += s->cluster_sectors; |
684 |
} |
685 |
} else {
|
686 |
|
687 |
/* how many allocated clusters ? */
|
688 |
|
689 |
cluster_offset &= ~QCOW_OFLAG_COPIED; |
690 |
while (nb_available < nb_needed) {
|
691 |
next = be64_to_cpu(l2_table[l2_index]) & ~QCOW_OFLAG_COPIED; |
692 |
if (next != cluster_offset + (nb_available << 9)) |
693 |
break;
|
694 |
l2_index++; |
695 |
nb_available += s->cluster_sectors; |
696 |
} |
697 |
} |
698 |
|
699 |
out:
|
700 |
if (nb_available > nb_needed)
|
701 |
nb_available = nb_needed; |
702 |
|
703 |
*num = nb_available - index_in_cluster; |
704 |
|
705 |
return cluster_offset;
|
706 |
} |
707 |
|
708 |
/*
|
709 |
* free_any_clusters
|
710 |
*
|
711 |
* free clusters according to its type: compressed or not
|
712 |
*
|
713 |
*/
|
714 |
|
715 |
static void free_any_clusters(BlockDriverState *bs, |
716 |
uint64_t cluster_offset, int nb_clusters)
|
717 |
{ |
718 |
BDRVQcowState *s = bs->opaque; |
719 |
|
720 |
/* free the cluster */
|
721 |
|
722 |
if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
723 |
int nb_csectors;
|
724 |
nb_csectors = ((cluster_offset >> s->csize_shift) & |
725 |
s->csize_mask) + 1;
|
726 |
free_clusters(bs, (cluster_offset & s->cluster_offset_mask) & ~511,
|
727 |
nb_csectors * 512);
|
728 |
return;
|
729 |
} |
730 |
|
731 |
free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits); |
732 |
|
733 |
return;
|
734 |
} |
735 |
|
736 |
/*
|
737 |
* get_cluster_table
|
738 |
*
|
739 |
* for a given disk offset, load (and allocate if needed)
|
740 |
* the l2 table.
|
741 |
*
|
742 |
* the l2 table offset in the qcow2 file and the cluster index
|
743 |
* in the l2 table are given to the caller.
|
744 |
*
|
745 |
*/
|
746 |
|
747 |
static int get_cluster_table(BlockDriverState *bs, uint64_t offset, |
748 |
uint64_t **new_l2_table, |
749 |
uint64_t *new_l2_offset, |
750 |
int *new_l2_index)
|
751 |
{ |
752 |
BDRVQcowState *s = bs->opaque; |
753 |
int l1_index, l2_index, ret;
|
754 |
uint64_t l2_offset, *l2_table; |
755 |
|
756 |
/* seek the the l2 offset in the l1 table */
|
757 |
|
758 |
l1_index = offset >> (s->l2_bits + s->cluster_bits); |
759 |
if (l1_index >= s->l1_size) {
|
760 |
ret = grow_l1_table(bs, l1_index + 1);
|
761 |
if (ret < 0) |
762 |
return 0; |
763 |
} |
764 |
l2_offset = s->l1_table[l1_index]; |
765 |
|
766 |
/* seek the l2 table of the given l2 offset */
|
767 |
|
768 |
if (l2_offset & QCOW_OFLAG_COPIED) {
|
769 |
/* load the l2 table in memory */
|
770 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
771 |
l2_table = l2_load(bs, l2_offset); |
772 |
if (l2_table == NULL) |
773 |
return 0; |
774 |
} else {
|
775 |
if (l2_offset)
|
776 |
free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t));
|
777 |
l2_table = l2_allocate(bs, l1_index); |
778 |
if (l2_table == NULL) |
779 |
return 0; |
780 |
l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED; |
781 |
} |
782 |
|
783 |
/* find the cluster offset for the given disk offset */
|
784 |
|
785 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
786 |
|
787 |
*new_l2_table = l2_table; |
788 |
*new_l2_offset = l2_offset; |
789 |
*new_l2_index = l2_index; |
790 |
|
791 |
return 1; |
792 |
} |
793 |
|
794 |
/*
|
795 |
* alloc_compressed_cluster_offset
|
796 |
*
|
797 |
* For a given offset of the disk image, return cluster offset in
|
798 |
* qcow2 file.
|
799 |
*
|
800 |
* If the offset is not found, allocate a new compressed cluster.
|
801 |
*
|
802 |
* Return the cluster offset if successful,
|
803 |
* Return 0, otherwise.
|
804 |
*
|
805 |
*/
|
806 |
|
807 |
static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs,
|
808 |
uint64_t offset, |
809 |
int compressed_size)
|
810 |
{ |
811 |
BDRVQcowState *s = bs->opaque; |
812 |
int l2_index, ret;
|
813 |
uint64_t l2_offset, *l2_table, cluster_offset; |
814 |
int nb_csectors;
|
815 |
|
816 |
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
817 |
if (ret == 0) |
818 |
return 0; |
819 |
|
820 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
821 |
if (cluster_offset & QCOW_OFLAG_COPIED)
|
822 |
return cluster_offset & ~QCOW_OFLAG_COPIED;
|
823 |
|
824 |
if (cluster_offset)
|
825 |
free_any_clusters(bs, cluster_offset, 1);
|
826 |
|
827 |
cluster_offset = alloc_bytes(bs, compressed_size); |
828 |
nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) - |
829 |
(cluster_offset >> 9);
|
830 |
|
831 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
832 |
((uint64_t)nb_csectors << s->csize_shift); |
833 |
|
834 |
/* update L2 table */
|
835 |
|
836 |
/* compressed clusters never have the copied flag */
|
837 |
|
838 |
l2_table[l2_index] = cpu_to_be64(cluster_offset); |
839 |
if (bdrv_pwrite(s->hd,
|
840 |
l2_offset + l2_index * sizeof(uint64_t),
|
841 |
l2_table + l2_index, |
842 |
sizeof(uint64_t)) != sizeof(uint64_t)) |
843 |
return 0; |
844 |
|
845 |
return cluster_offset;
|
846 |
} |
847 |
|
848 |
/*
|
849 |
* alloc_cluster_offset
|
850 |
*
|
851 |
* For a given offset of the disk image, return cluster offset in
|
852 |
* qcow2 file.
|
853 |
*
|
854 |
* If the offset is not found, allocate a new cluster.
|
855 |
*
|
856 |
* Return the cluster offset if successful,
|
857 |
* Return 0, otherwise.
|
858 |
*
|
859 |
*/
|
860 |
|
861 |
static uint64_t alloc_cluster_offset(BlockDriverState *bs,
|
862 |
uint64_t offset, |
863 |
int n_start, int n_end, |
864 |
int *num)
|
865 |
{ |
866 |
BDRVQcowState *s = bs->opaque; |
867 |
int l2_index, ret;
|
868 |
uint64_t l2_offset, *l2_table, cluster_offset; |
869 |
int nb_available, nb_clusters, i, j;
|
870 |
uint64_t start_sect, current; |
871 |
|
872 |
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
873 |
if (ret == 0) |
874 |
return 0; |
875 |
|
876 |
nb_clusters = ((n_end << 9) + s->cluster_size - 1) >> |
877 |
s->cluster_bits; |
878 |
if (nb_clusters > s->l2_size - l2_index)
|
879 |
nb_clusters = s->l2_size - l2_index; |
880 |
|
881 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
882 |
|
883 |
/* We keep all QCOW_OFLAG_COPIED clusters */
|
884 |
|
885 |
if (cluster_offset & QCOW_OFLAG_COPIED) {
|
886 |
|
887 |
for (i = 1; i < nb_clusters; i++) { |
888 |
current = be64_to_cpu(l2_table[l2_index + i]); |
889 |
if (cluster_offset + (i << s->cluster_bits) != current)
|
890 |
break;
|
891 |
} |
892 |
nb_clusters = i; |
893 |
|
894 |
nb_available = nb_clusters << (s->cluster_bits - 9);
|
895 |
if (nb_available > n_end)
|
896 |
nb_available = n_end; |
897 |
|
898 |
cluster_offset &= ~QCOW_OFLAG_COPIED; |
899 |
|
900 |
goto out;
|
901 |
} |
902 |
|
903 |
/* for the moment, multiple compressed clusters are not managed */
|
904 |
|
905 |
if (cluster_offset & QCOW_OFLAG_COMPRESSED)
|
906 |
nb_clusters = 1;
|
907 |
|
908 |
/* how many available clusters ? */
|
909 |
|
910 |
i = 0;
|
911 |
while (i < nb_clusters) {
|
912 |
|
913 |
i++; |
914 |
|
915 |
if (!cluster_offset) {
|
916 |
|
917 |
/* how many free clusters ? */
|
918 |
|
919 |
while (i < nb_clusters) {
|
920 |
cluster_offset = l2_table[l2_index + i]; |
921 |
if (cluster_offset != 0) |
922 |
break;
|
923 |
i++; |
924 |
} |
925 |
|
926 |
if ((cluster_offset & QCOW_OFLAG_COPIED) ||
|
927 |
(cluster_offset & QCOW_OFLAG_COMPRESSED)) |
928 |
break;
|
929 |
|
930 |
} else {
|
931 |
|
932 |
/* how many contiguous clusters ? */
|
933 |
|
934 |
j = 1;
|
935 |
current = 0;
|
936 |
while (i < nb_clusters) {
|
937 |
current = be64_to_cpu(l2_table[l2_index + i]); |
938 |
if (cluster_offset + (j << s->cluster_bits) != current)
|
939 |
break;
|
940 |
|
941 |
i++; |
942 |
j++; |
943 |
} |
944 |
|
945 |
free_any_clusters(bs, cluster_offset, j); |
946 |
if (current)
|
947 |
break;
|
948 |
cluster_offset = current; |
949 |
} |
950 |
} |
951 |
nb_clusters = i; |
952 |
|
953 |
/* allocate a new cluster */
|
954 |
|
955 |
cluster_offset = alloc_clusters(bs, nb_clusters * s->cluster_size); |
956 |
|
957 |
/* we must initialize the cluster content which won't be
|
958 |
written */
|
959 |
|
960 |
nb_available = nb_clusters << (s->cluster_bits - 9);
|
961 |
if (nb_available > n_end)
|
962 |
nb_available = n_end; |
963 |
|
964 |
/* copy content of unmodified sectors */
|
965 |
|
966 |
start_sect = (offset & ~(s->cluster_size - 1)) >> 9; |
967 |
if (n_start) {
|
968 |
ret = copy_sectors(bs, start_sect, cluster_offset, 0, n_start);
|
969 |
if (ret < 0) |
970 |
return 0; |
971 |
} |
972 |
|
973 |
if (nb_available & (s->cluster_sectors - 1)) { |
974 |
uint64_t end = nb_available & ~(uint64_t)(s->cluster_sectors - 1);
|
975 |
ret = copy_sectors(bs, start_sect + end, |
976 |
cluster_offset + (end << 9),
|
977 |
nb_available - end, |
978 |
s->cluster_sectors); |
979 |
if (ret < 0) |
980 |
return 0; |
981 |
} |
982 |
|
983 |
/* update L2 table */
|
984 |
|
985 |
for (i = 0; i < nb_clusters; i++) |
986 |
l2_table[l2_index + i] = cpu_to_be64((cluster_offset + |
987 |
(i << s->cluster_bits)) | |
988 |
QCOW_OFLAG_COPIED); |
989 |
|
990 |
if (bdrv_pwrite(s->hd,
|
991 |
l2_offset + l2_index * sizeof(uint64_t),
|
992 |
l2_table + l2_index, |
993 |
nb_clusters * sizeof(uint64_t)) !=
|
994 |
nb_clusters * sizeof(uint64_t))
|
995 |
return 0; |
996 |
|
997 |
out:
|
998 |
*num = nb_available - n_start; |
999 |
|
1000 |
return cluster_offset;
|
1001 |
} |
1002 |
|
1003 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
1004 |
int nb_sectors, int *pnum) |
1005 |
{ |
1006 |
uint64_t cluster_offset; |
1007 |
|
1008 |
*pnum = nb_sectors; |
1009 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, pnum);
|
1010 |
|
1011 |
return (cluster_offset != 0); |
1012 |
} |
1013 |
|
1014 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
1015 |
const uint8_t *buf, int buf_size) |
1016 |
{ |
1017 |
z_stream strm1, *strm = &strm1; |
1018 |
int ret, out_len;
|
1019 |
|
1020 |
memset(strm, 0, sizeof(*strm)); |
1021 |
|
1022 |
strm->next_in = (uint8_t *)buf; |
1023 |
strm->avail_in = buf_size; |
1024 |
strm->next_out = out_buf; |
1025 |
strm->avail_out = out_buf_size; |
1026 |
|
1027 |
ret = inflateInit2(strm, -12);
|
1028 |
if (ret != Z_OK)
|
1029 |
return -1; |
1030 |
ret = inflate(strm, Z_FINISH); |
1031 |
out_len = strm->next_out - out_buf; |
1032 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
1033 |
out_len != out_buf_size) { |
1034 |
inflateEnd(strm); |
1035 |
return -1; |
1036 |
} |
1037 |
inflateEnd(strm); |
1038 |
return 0; |
1039 |
} |
1040 |
|
1041 |
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) |
1042 |
{ |
1043 |
int ret, csize, nb_csectors, sector_offset;
|
1044 |
uint64_t coffset; |
1045 |
|
1046 |
coffset = cluster_offset & s->cluster_offset_mask; |
1047 |
if (s->cluster_cache_offset != coffset) {
|
1048 |
nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
|
1049 |
sector_offset = coffset & 511;
|
1050 |
csize = nb_csectors * 512 - sector_offset;
|
1051 |
ret = bdrv_read(s->hd, coffset >> 9, s->cluster_data, nb_csectors);
|
1052 |
if (ret < 0) { |
1053 |
return -1; |
1054 |
} |
1055 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
1056 |
s->cluster_data + sector_offset, csize) < 0) {
|
1057 |
return -1; |
1058 |
} |
1059 |
s->cluster_cache_offset = coffset; |
1060 |
} |
1061 |
return 0; |
1062 |
} |
1063 |
|
1064 |
/* handle reading after the end of the backing file */
|
1065 |
static int backing_read1(BlockDriverState *bs, |
1066 |
int64_t sector_num, uint8_t *buf, int nb_sectors)
|
1067 |
{ |
1068 |
int n1;
|
1069 |
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
1070 |
return nb_sectors;
|
1071 |
if (sector_num >= bs->total_sectors)
|
1072 |
n1 = 0;
|
1073 |
else
|
1074 |
n1 = bs->total_sectors - sector_num; |
1075 |
memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1)); |
1076 |
return n1;
|
1077 |
} |
1078 |
|
1079 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
1080 |
uint8_t *buf, int nb_sectors)
|
1081 |
{ |
1082 |
BDRVQcowState *s = bs->opaque; |
1083 |
int ret, index_in_cluster, n, n1;
|
1084 |
uint64_t cluster_offset; |
1085 |
|
1086 |
while (nb_sectors > 0) { |
1087 |
n = nb_sectors; |
1088 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, &n);
|
1089 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
1090 |
if (!cluster_offset) {
|
1091 |
if (bs->backing_hd) {
|
1092 |
/* read from the base image */
|
1093 |
n1 = backing_read1(bs->backing_hd, sector_num, buf, n); |
1094 |
if (n1 > 0) { |
1095 |
ret = bdrv_read(bs->backing_hd, sector_num, buf, n1); |
1096 |
if (ret < 0) |
1097 |
return -1; |
1098 |
} |
1099 |
} else {
|
1100 |
memset(buf, 0, 512 * n); |
1101 |
} |
1102 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1103 |
if (decompress_cluster(s, cluster_offset) < 0) |
1104 |
return -1; |
1105 |
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); |
1106 |
} else {
|
1107 |
ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
1108 |
if (ret != n * 512) |
1109 |
return -1; |
1110 |
if (s->crypt_method) {
|
1111 |
encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
1112 |
&s->aes_decrypt_key); |
1113 |
} |
1114 |
} |
1115 |
nb_sectors -= n; |
1116 |
sector_num += n; |
1117 |
buf += n * 512;
|
1118 |
} |
1119 |
return 0; |
1120 |
} |
1121 |
|
1122 |
static int qcow_write(BlockDriverState *bs, int64_t sector_num, |
1123 |
const uint8_t *buf, int nb_sectors) |
1124 |
{ |
1125 |
BDRVQcowState *s = bs->opaque; |
1126 |
int ret, index_in_cluster, n;
|
1127 |
uint64_t cluster_offset; |
1128 |
int n_end;
|
1129 |
|
1130 |
while (nb_sectors > 0) { |
1131 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
1132 |
n_end = index_in_cluster + nb_sectors; |
1133 |
if (s->crypt_method &&
|
1134 |
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) |
1135 |
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
1136 |
cluster_offset = alloc_cluster_offset(bs, sector_num << 9,
|
1137 |
index_in_cluster, |
1138 |
n_end, &n); |
1139 |
if (!cluster_offset)
|
1140 |
return -1; |
1141 |
if (s->crypt_method) {
|
1142 |
encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1,
|
1143 |
&s->aes_encrypt_key); |
1144 |
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512,
|
1145 |
s->cluster_data, n * 512);
|
1146 |
} else {
|
1147 |
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
1148 |
} |
1149 |
if (ret != n * 512) |
1150 |
return -1; |
1151 |
nb_sectors -= n; |
1152 |
sector_num += n; |
1153 |
buf += n * 512;
|
1154 |
} |
1155 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
1156 |
return 0; |
1157 |
} |
1158 |
|
1159 |
typedef struct QCowAIOCB { |
1160 |
BlockDriverAIOCB common; |
1161 |
int64_t sector_num; |
1162 |
uint8_t *buf; |
1163 |
int nb_sectors;
|
1164 |
int n;
|
1165 |
uint64_t cluster_offset; |
1166 |
uint8_t *cluster_data; |
1167 |
BlockDriverAIOCB *hd_aiocb; |
1168 |
} QCowAIOCB; |
1169 |
|
1170 |
static void qcow_aio_read_cb(void *opaque, int ret) |
1171 |
{ |
1172 |
QCowAIOCB *acb = opaque; |
1173 |
BlockDriverState *bs = acb->common.bs; |
1174 |
BDRVQcowState *s = bs->opaque; |
1175 |
int index_in_cluster, n1;
|
1176 |
|
1177 |
acb->hd_aiocb = NULL;
|
1178 |
if (ret < 0) { |
1179 |
fail:
|
1180 |
acb->common.cb(acb->common.opaque, ret); |
1181 |
qemu_aio_release(acb); |
1182 |
return;
|
1183 |
} |
1184 |
|
1185 |
redo:
|
1186 |
/* post process the read buffer */
|
1187 |
if (!acb->cluster_offset) {
|
1188 |
/* nothing to do */
|
1189 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1190 |
/* nothing to do */
|
1191 |
} else {
|
1192 |
if (s->crypt_method) {
|
1193 |
encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, |
1194 |
acb->n, 0,
|
1195 |
&s->aes_decrypt_key); |
1196 |
} |
1197 |
} |
1198 |
|
1199 |
acb->nb_sectors -= acb->n; |
1200 |
acb->sector_num += acb->n; |
1201 |
acb->buf += acb->n * 512;
|
1202 |
|
1203 |
if (acb->nb_sectors == 0) { |
1204 |
/* request completed */
|
1205 |
acb->common.cb(acb->common.opaque, 0);
|
1206 |
qemu_aio_release(acb); |
1207 |
return;
|
1208 |
} |
1209 |
|
1210 |
/* prepare next AIO request */
|
1211 |
acb->n = acb->nb_sectors; |
1212 |
acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, &acb->n);
|
1213 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
1214 |
|
1215 |
if (!acb->cluster_offset) {
|
1216 |
if (bs->backing_hd) {
|
1217 |
/* read from the base image */
|
1218 |
n1 = backing_read1(bs->backing_hd, acb->sector_num, |
1219 |
acb->buf, acb->n); |
1220 |
if (n1 > 0) { |
1221 |
acb->hd_aiocb = bdrv_aio_read(bs->backing_hd, acb->sector_num, |
1222 |
acb->buf, acb->n, qcow_aio_read_cb, acb); |
1223 |
if (acb->hd_aiocb == NULL) |
1224 |
goto fail;
|
1225 |
} else {
|
1226 |
goto redo;
|
1227 |
} |
1228 |
} else {
|
1229 |
/* Note: in this case, no need to wait */
|
1230 |
memset(acb->buf, 0, 512 * acb->n); |
1231 |
goto redo;
|
1232 |
} |
1233 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1234 |
/* add AIO support for compressed blocks ? */
|
1235 |
if (decompress_cluster(s, acb->cluster_offset) < 0) |
1236 |
goto fail;
|
1237 |
memcpy(acb->buf, |
1238 |
s->cluster_cache + index_in_cluster * 512, 512 * acb->n); |
1239 |
goto redo;
|
1240 |
} else {
|
1241 |
if ((acb->cluster_offset & 511) != 0) { |
1242 |
ret = -EIO; |
1243 |
goto fail;
|
1244 |
} |
1245 |
acb->hd_aiocb = bdrv_aio_read(s->hd, |
1246 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
1247 |
acb->buf, acb->n, qcow_aio_read_cb, acb); |
1248 |
if (acb->hd_aiocb == NULL) |
1249 |
goto fail;
|
1250 |
} |
1251 |
} |
1252 |
|
1253 |
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
|
1254 |
int64_t sector_num, uint8_t *buf, int nb_sectors,
|
1255 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1256 |
{ |
1257 |
QCowAIOCB *acb; |
1258 |
|
1259 |
acb = qemu_aio_get(bs, cb, opaque); |
1260 |
if (!acb)
|
1261 |
return NULL; |
1262 |
acb->hd_aiocb = NULL;
|
1263 |
acb->sector_num = sector_num; |
1264 |
acb->buf = buf; |
1265 |
acb->nb_sectors = nb_sectors; |
1266 |
acb->n = 0;
|
1267 |
acb->cluster_offset = 0;
|
1268 |
return acb;
|
1269 |
} |
1270 |
|
1271 |
static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs,
|
1272 |
int64_t sector_num, uint8_t *buf, int nb_sectors,
|
1273 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1274 |
{ |
1275 |
QCowAIOCB *acb; |
1276 |
|
1277 |
acb = qcow_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque); |
1278 |
if (!acb)
|
1279 |
return NULL; |
1280 |
|
1281 |
qcow_aio_read_cb(acb, 0);
|
1282 |
return &acb->common;
|
1283 |
} |
1284 |
|
1285 |
static void qcow_aio_write_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;
|
1291 |
uint64_t cluster_offset; |
1292 |
const uint8_t *src_buf;
|
1293 |
int n_end;
|
1294 |
|
1295 |
acb->hd_aiocb = NULL;
|
1296 |
|
1297 |
if (ret < 0) { |
1298 |
fail:
|
1299 |
acb->common.cb(acb->common.opaque, ret); |
1300 |
qemu_aio_release(acb); |
1301 |
return;
|
1302 |
} |
1303 |
|
1304 |
acb->nb_sectors -= acb->n; |
1305 |
acb->sector_num += acb->n; |
1306 |
acb->buf += acb->n * 512;
|
1307 |
|
1308 |
if (acb->nb_sectors == 0) { |
1309 |
/* request completed */
|
1310 |
acb->common.cb(acb->common.opaque, 0);
|
1311 |
qemu_aio_release(acb); |
1312 |
return;
|
1313 |
} |
1314 |
|
1315 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
1316 |
n_end = index_in_cluster + acb->nb_sectors; |
1317 |
if (s->crypt_method &&
|
1318 |
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) |
1319 |
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
1320 |
|
1321 |
cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9,
|
1322 |
index_in_cluster, |
1323 |
n_end, &acb->n); |
1324 |
if (!cluster_offset || (cluster_offset & 511) != 0) { |
1325 |
ret = -EIO; |
1326 |
goto fail;
|
1327 |
} |
1328 |
if (s->crypt_method) {
|
1329 |
if (!acb->cluster_data) {
|
1330 |
acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * |
1331 |
s->cluster_size); |
1332 |
if (!acb->cluster_data) {
|
1333 |
ret = -ENOMEM; |
1334 |
goto fail;
|
1335 |
} |
1336 |
} |
1337 |
encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, |
1338 |
acb->n, 1, &s->aes_encrypt_key);
|
1339 |
src_buf = acb->cluster_data; |
1340 |
} else {
|
1341 |
src_buf = acb->buf; |
1342 |
} |
1343 |
acb->hd_aiocb = bdrv_aio_write(s->hd, |
1344 |
(cluster_offset >> 9) + index_in_cluster,
|
1345 |
src_buf, acb->n, |
1346 |
qcow_aio_write_cb, acb); |
1347 |
if (acb->hd_aiocb == NULL) |
1348 |
goto fail;
|
1349 |
} |
1350 |
|
1351 |
static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs,
|
1352 |
int64_t sector_num, const uint8_t *buf, int nb_sectors, |
1353 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1354 |
{ |
1355 |
BDRVQcowState *s = bs->opaque; |
1356 |
QCowAIOCB *acb; |
1357 |
|
1358 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
1359 |
|
1360 |
acb = qcow_aio_setup(bs, sector_num, (uint8_t*)buf, nb_sectors, cb, opaque); |
1361 |
if (!acb)
|
1362 |
return NULL; |
1363 |
|
1364 |
qcow_aio_write_cb(acb, 0);
|
1365 |
return &acb->common;
|
1366 |
} |
1367 |
|
1368 |
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) |
1369 |
{ |
1370 |
QCowAIOCB *acb = (QCowAIOCB *)blockacb; |
1371 |
if (acb->hd_aiocb)
|
1372 |
bdrv_aio_cancel(acb->hd_aiocb); |
1373 |
qemu_aio_release(acb); |
1374 |
} |
1375 |
|
1376 |
static void qcow_close(BlockDriverState *bs) |
1377 |
{ |
1378 |
BDRVQcowState *s = bs->opaque; |
1379 |
qemu_free(s->l1_table); |
1380 |
qemu_free(s->l2_cache); |
1381 |
qemu_free(s->cluster_cache); |
1382 |
qemu_free(s->cluster_data); |
1383 |
refcount_close(bs); |
1384 |
bdrv_delete(s->hd); |
1385 |
} |
1386 |
|
1387 |
/* XXX: use std qcow open function ? */
|
1388 |
typedef struct QCowCreateState { |
1389 |
int cluster_size;
|
1390 |
int cluster_bits;
|
1391 |
uint16_t *refcount_block; |
1392 |
uint64_t *refcount_table; |
1393 |
int64_t l1_table_offset; |
1394 |
int64_t refcount_table_offset; |
1395 |
int64_t refcount_block_offset; |
1396 |
} QCowCreateState; |
1397 |
|
1398 |
static void create_refcount_update(QCowCreateState *s, |
1399 |
int64_t offset, int64_t size) |
1400 |
{ |
1401 |
int refcount;
|
1402 |
int64_t start, last, cluster_offset; |
1403 |
uint16_t *p; |
1404 |
|
1405 |
start = offset & ~(s->cluster_size - 1);
|
1406 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
1407 |
for(cluster_offset = start; cluster_offset <= last;
|
1408 |
cluster_offset += s->cluster_size) { |
1409 |
p = &s->refcount_block[cluster_offset >> s->cluster_bits]; |
1410 |
refcount = be16_to_cpu(*p); |
1411 |
refcount++; |
1412 |
*p = cpu_to_be16(refcount); |
1413 |
} |
1414 |
} |
1415 |
|
1416 |
static int qcow_create(const char *filename, int64_t total_size, |
1417 |
const char *backing_file, int flags) |
1418 |
{ |
1419 |
int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
|
1420 |
QCowHeader header; |
1421 |
uint64_t tmp, offset; |
1422 |
QCowCreateState s1, *s = &s1; |
1423 |
|
1424 |
memset(s, 0, sizeof(*s)); |
1425 |
|
1426 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
1427 |
if (fd < 0) |
1428 |
return -1; |
1429 |
memset(&header, 0, sizeof(header)); |
1430 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
1431 |
header.version = cpu_to_be32(QCOW_VERSION); |
1432 |
header.size = cpu_to_be64(total_size * 512);
|
1433 |
header_size = sizeof(header);
|
1434 |
backing_filename_len = 0;
|
1435 |
if (backing_file) {
|
1436 |
header.backing_file_offset = cpu_to_be64(header_size); |
1437 |
backing_filename_len = strlen(backing_file); |
1438 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
1439 |
header_size += backing_filename_len; |
1440 |
} |
1441 |
s->cluster_bits = 12; /* 4 KB clusters */ |
1442 |
s->cluster_size = 1 << s->cluster_bits;
|
1443 |
header.cluster_bits = cpu_to_be32(s->cluster_bits); |
1444 |
header_size = (header_size + 7) & ~7; |
1445 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
1446 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
1447 |
} else {
|
1448 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
1449 |
} |
1450 |
l2_bits = s->cluster_bits - 3;
|
1451 |
shift = s->cluster_bits + l2_bits; |
1452 |
l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift); |
1453 |
offset = align_offset(header_size, s->cluster_size); |
1454 |
s->l1_table_offset = offset; |
1455 |
header.l1_table_offset = cpu_to_be64(s->l1_table_offset); |
1456 |
header.l1_size = cpu_to_be32(l1_size); |
1457 |
offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
|
1458 |
|
1459 |
s->refcount_table = qemu_mallocz(s->cluster_size); |
1460 |
if (!s->refcount_table)
|
1461 |
goto fail;
|
1462 |
s->refcount_block = qemu_mallocz(s->cluster_size); |
1463 |
if (!s->refcount_block)
|
1464 |
goto fail;
|
1465 |
|
1466 |
s->refcount_table_offset = offset; |
1467 |
header.refcount_table_offset = cpu_to_be64(offset); |
1468 |
header.refcount_table_clusters = cpu_to_be32(1);
|
1469 |
offset += s->cluster_size; |
1470 |
|
1471 |
s->refcount_table[0] = cpu_to_be64(offset);
|
1472 |
s->refcount_block_offset = offset; |
1473 |
offset += s->cluster_size; |
1474 |
|
1475 |
/* update refcounts */
|
1476 |
create_refcount_update(s, 0, header_size);
|
1477 |
create_refcount_update(s, s->l1_table_offset, l1_size * sizeof(uint64_t));
|
1478 |
create_refcount_update(s, s->refcount_table_offset, s->cluster_size); |
1479 |
create_refcount_update(s, s->refcount_block_offset, s->cluster_size); |
1480 |
|
1481 |
/* write all the data */
|
1482 |
write(fd, &header, sizeof(header));
|
1483 |
if (backing_file) {
|
1484 |
write(fd, backing_file, backing_filename_len); |
1485 |
} |
1486 |
lseek(fd, s->l1_table_offset, SEEK_SET); |
1487 |
tmp = 0;
|
1488 |
for(i = 0;i < l1_size; i++) { |
1489 |
write(fd, &tmp, sizeof(tmp));
|
1490 |
} |
1491 |
lseek(fd, s->refcount_table_offset, SEEK_SET); |
1492 |
write(fd, s->refcount_table, s->cluster_size); |
1493 |
|
1494 |
lseek(fd, s->refcount_block_offset, SEEK_SET); |
1495 |
write(fd, s->refcount_block, s->cluster_size); |
1496 |
|
1497 |
qemu_free(s->refcount_table); |
1498 |
qemu_free(s->refcount_block); |
1499 |
close(fd); |
1500 |
return 0; |
1501 |
fail:
|
1502 |
qemu_free(s->refcount_table); |
1503 |
qemu_free(s->refcount_block); |
1504 |
close(fd); |
1505 |
return -ENOMEM;
|
1506 |
} |
1507 |
|
1508 |
static int qcow_make_empty(BlockDriverState *bs) |
1509 |
{ |
1510 |
#if 0
|
1511 |
/* XXX: not correct */
|
1512 |
BDRVQcowState *s = bs->opaque;
|
1513 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
1514 |
int ret;
|
1515 |
|
1516 |
memset(s->l1_table, 0, l1_length);
|
1517 |
if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
1518 |
return -1;
|
1519 |
ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length);
|
1520 |
if (ret < 0)
|
1521 |
return ret;
|
1522 |
|
1523 |
l2_cache_reset(bs);
|
1524 |
#endif
|
1525 |
return 0; |
1526 |
} |
1527 |
|
1528 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
1529 |
tables to avoid losing bytes in alignment */
|
1530 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
1531 |
const uint8_t *buf, int nb_sectors) |
1532 |
{ |
1533 |
BDRVQcowState *s = bs->opaque; |
1534 |
z_stream strm; |
1535 |
int ret, out_len;
|
1536 |
uint8_t *out_buf; |
1537 |
uint64_t cluster_offset; |
1538 |
|
1539 |
if (nb_sectors == 0) { |
1540 |
/* align end of file to a sector boundary to ease reading with
|
1541 |
sector based I/Os */
|
1542 |
cluster_offset = bdrv_getlength(s->hd); |
1543 |
cluster_offset = (cluster_offset + 511) & ~511; |
1544 |
bdrv_truncate(s->hd, cluster_offset); |
1545 |
return 0; |
1546 |
} |
1547 |
|
1548 |
if (nb_sectors != s->cluster_sectors)
|
1549 |
return -EINVAL;
|
1550 |
|
1551 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
1552 |
if (!out_buf)
|
1553 |
return -ENOMEM;
|
1554 |
|
1555 |
/* best compression, small window, no zlib header */
|
1556 |
memset(&strm, 0, sizeof(strm)); |
1557 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
1558 |
Z_DEFLATED, -12,
|
1559 |
9, Z_DEFAULT_STRATEGY);
|
1560 |
if (ret != 0) { |
1561 |
qemu_free(out_buf); |
1562 |
return -1; |
1563 |
} |
1564 |
|
1565 |
strm.avail_in = s->cluster_size; |
1566 |
strm.next_in = (uint8_t *)buf; |
1567 |
strm.avail_out = s->cluster_size; |
1568 |
strm.next_out = out_buf; |
1569 |
|
1570 |
ret = deflate(&strm, Z_FINISH); |
1571 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
1572 |
qemu_free(out_buf); |
1573 |
deflateEnd(&strm); |
1574 |
return -1; |
1575 |
} |
1576 |
out_len = strm.next_out - out_buf; |
1577 |
|
1578 |
deflateEnd(&strm); |
1579 |
|
1580 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
1581 |
/* could not compress: write normal cluster */
|
1582 |
qcow_write(bs, sector_num, buf, s->cluster_sectors); |
1583 |
} else {
|
1584 |
cluster_offset = alloc_compressed_cluster_offset(bs, sector_num << 9,
|
1585 |
out_len); |
1586 |
if (!cluster_offset)
|
1587 |
return -1; |
1588 |
cluster_offset &= s->cluster_offset_mask; |
1589 |
if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
|
1590 |
qemu_free(out_buf); |
1591 |
return -1; |
1592 |
} |
1593 |
} |
1594 |
|
1595 |
qemu_free(out_buf); |
1596 |
return 0; |
1597 |
} |
1598 |
|
1599 |
static void qcow_flush(BlockDriverState *bs) |
1600 |
{ |
1601 |
BDRVQcowState *s = bs->opaque; |
1602 |
bdrv_flush(s->hd); |
1603 |
} |
1604 |
|
1605 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
1606 |
{ |
1607 |
BDRVQcowState *s = bs->opaque; |
1608 |
bdi->cluster_size = s->cluster_size; |
1609 |
bdi->vm_state_offset = (int64_t)s->l1_vm_state_index << |
1610 |
(s->cluster_bits + s->l2_bits); |
1611 |
return 0; |
1612 |
} |
1613 |
|
1614 |
/*********************************************************/
|
1615 |
/* snapshot support */
|
1616 |
|
1617 |
/* update the refcounts of snapshots and the copied flag */
|
1618 |
static int update_snapshot_refcount(BlockDriverState *bs, |
1619 |
int64_t l1_table_offset, |
1620 |
int l1_size,
|
1621 |
int addend)
|
1622 |
{ |
1623 |
BDRVQcowState *s = bs->opaque; |
1624 |
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; |
1625 |
int64_t old_offset, old_l2_offset; |
1626 |
int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount;
|
1627 |
|
1628 |
l2_cache_reset(bs); |
1629 |
|
1630 |
l2_table = NULL;
|
1631 |
l1_table = NULL;
|
1632 |
l1_size2 = l1_size * sizeof(uint64_t);
|
1633 |
l1_allocated = 0;
|
1634 |
if (l1_table_offset != s->l1_table_offset) {
|
1635 |
l1_table = qemu_malloc(l1_size2); |
1636 |
if (!l1_table)
|
1637 |
goto fail;
|
1638 |
l1_allocated = 1;
|
1639 |
if (bdrv_pread(s->hd, l1_table_offset,
|
1640 |
l1_table, l1_size2) != l1_size2) |
1641 |
goto fail;
|
1642 |
for(i = 0;i < l1_size; i++) |
1643 |
be64_to_cpus(&l1_table[i]); |
1644 |
} else {
|
1645 |
assert(l1_size == s->l1_size); |
1646 |
l1_table = s->l1_table; |
1647 |
l1_allocated = 0;
|
1648 |
} |
1649 |
|
1650 |
l2_size = s->l2_size * sizeof(uint64_t);
|
1651 |
l2_table = qemu_malloc(l2_size); |
1652 |
if (!l2_table)
|
1653 |
goto fail;
|
1654 |
l1_modified = 0;
|
1655 |
for(i = 0; i < l1_size; i++) { |
1656 |
l2_offset = l1_table[i]; |
1657 |
if (l2_offset) {
|
1658 |
old_l2_offset = l2_offset; |
1659 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
1660 |
l2_modified = 0;
|
1661 |
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
|
1662 |
goto fail;
|
1663 |
for(j = 0; j < s->l2_size; j++) { |
1664 |
offset = be64_to_cpu(l2_table[j]); |
1665 |
if (offset != 0) { |
1666 |
old_offset = offset; |
1667 |
offset &= ~QCOW_OFLAG_COPIED; |
1668 |
if (offset & QCOW_OFLAG_COMPRESSED) {
|
1669 |
nb_csectors = ((offset >> s->csize_shift) & |
1670 |
s->csize_mask) + 1;
|
1671 |
if (addend != 0) |
1672 |
update_refcount(bs, (offset & s->cluster_offset_mask) & ~511,
|
1673 |
nb_csectors * 512, addend);
|
1674 |
/* compressed clusters are never modified */
|
1675 |
refcount = 2;
|
1676 |
} else {
|
1677 |
if (addend != 0) { |
1678 |
refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend); |
1679 |
} else {
|
1680 |
refcount = get_refcount(bs, offset >> s->cluster_bits); |
1681 |
} |
1682 |
} |
1683 |
|
1684 |
if (refcount == 1) { |
1685 |
offset |= QCOW_OFLAG_COPIED; |
1686 |
} |
1687 |
if (offset != old_offset) {
|
1688 |
l2_table[j] = cpu_to_be64(offset); |
1689 |
l2_modified = 1;
|
1690 |
} |
1691 |
} |
1692 |
} |
1693 |
if (l2_modified) {
|
1694 |
if (bdrv_pwrite(s->hd,
|
1695 |
l2_offset, l2_table, l2_size) != l2_size) |
1696 |
goto fail;
|
1697 |
} |
1698 |
|
1699 |
if (addend != 0) { |
1700 |
refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); |
1701 |
} else {
|
1702 |
refcount = get_refcount(bs, l2_offset >> s->cluster_bits); |
1703 |
} |
1704 |
if (refcount == 1) { |
1705 |
l2_offset |= QCOW_OFLAG_COPIED; |
1706 |
} |
1707 |
if (l2_offset != old_l2_offset) {
|
1708 |
l1_table[i] = l2_offset; |
1709 |
l1_modified = 1;
|
1710 |
} |
1711 |
} |
1712 |
} |
1713 |
if (l1_modified) {
|
1714 |
for(i = 0; i < l1_size; i++) |
1715 |
cpu_to_be64s(&l1_table[i]); |
1716 |
if (bdrv_pwrite(s->hd, l1_table_offset, l1_table,
|
1717 |
l1_size2) != l1_size2) |
1718 |
goto fail;
|
1719 |
for(i = 0; i < l1_size; i++) |
1720 |
be64_to_cpus(&l1_table[i]); |
1721 |
} |
1722 |
if (l1_allocated)
|
1723 |
qemu_free(l1_table); |
1724 |
qemu_free(l2_table); |
1725 |
return 0; |
1726 |
fail:
|
1727 |
if (l1_allocated)
|
1728 |
qemu_free(l1_table); |
1729 |
qemu_free(l2_table); |
1730 |
return -EIO;
|
1731 |
} |
1732 |
|
1733 |
static void qcow_free_snapshots(BlockDriverState *bs) |
1734 |
{ |
1735 |
BDRVQcowState *s = bs->opaque; |
1736 |
int i;
|
1737 |
|
1738 |
for(i = 0; i < s->nb_snapshots; i++) { |
1739 |
qemu_free(s->snapshots[i].name); |
1740 |
qemu_free(s->snapshots[i].id_str); |
1741 |
} |
1742 |
qemu_free(s->snapshots); |
1743 |
s->snapshots = NULL;
|
1744 |
s->nb_snapshots = 0;
|
1745 |
} |
1746 |
|
1747 |
static int qcow_read_snapshots(BlockDriverState *bs) |
1748 |
{ |
1749 |
BDRVQcowState *s = bs->opaque; |
1750 |
QCowSnapshotHeader h; |
1751 |
QCowSnapshot *sn; |
1752 |
int i, id_str_size, name_size;
|
1753 |
int64_t offset; |
1754 |
uint32_t extra_data_size; |
1755 |
|
1756 |
offset = s->snapshots_offset; |
1757 |
s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot));
|
1758 |
if (!s->snapshots)
|
1759 |
goto fail;
|
1760 |
for(i = 0; i < s->nb_snapshots; i++) { |
1761 |
offset = align_offset(offset, 8);
|
1762 |
if (bdrv_pread(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
1763 |
goto fail;
|
1764 |
offset += sizeof(h);
|
1765 |
sn = s->snapshots + i; |
1766 |
sn->l1_table_offset = be64_to_cpu(h.l1_table_offset); |
1767 |
sn->l1_size = be32_to_cpu(h.l1_size); |
1768 |
sn->vm_state_size = be32_to_cpu(h.vm_state_size); |
1769 |
sn->date_sec = be32_to_cpu(h.date_sec); |
1770 |
sn->date_nsec = be32_to_cpu(h.date_nsec); |
1771 |
sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec); |
1772 |
extra_data_size = be32_to_cpu(h.extra_data_size); |
1773 |
|
1774 |
id_str_size = be16_to_cpu(h.id_str_size); |
1775 |
name_size = be16_to_cpu(h.name_size); |
1776 |
|
1777 |
offset += extra_data_size; |
1778 |
|
1779 |
sn->id_str = qemu_malloc(id_str_size + 1);
|
1780 |
if (!sn->id_str)
|
1781 |
goto fail;
|
1782 |
if (bdrv_pread(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
1783 |
goto fail;
|
1784 |
offset += id_str_size; |
1785 |
sn->id_str[id_str_size] = '\0';
|
1786 |
|
1787 |
sn->name = qemu_malloc(name_size + 1);
|
1788 |
if (!sn->name)
|
1789 |
goto fail;
|
1790 |
if (bdrv_pread(s->hd, offset, sn->name, name_size) != name_size)
|
1791 |
goto fail;
|
1792 |
offset += name_size; |
1793 |
sn->name[name_size] = '\0';
|
1794 |
} |
1795 |
s->snapshots_size = offset - s->snapshots_offset; |
1796 |
return 0; |
1797 |
fail:
|
1798 |
qcow_free_snapshots(bs); |
1799 |
return -1; |
1800 |
} |
1801 |
|
1802 |
/* add at the end of the file a new list of snapshots */
|
1803 |
static int qcow_write_snapshots(BlockDriverState *bs) |
1804 |
{ |
1805 |
BDRVQcowState *s = bs->opaque; |
1806 |
QCowSnapshot *sn; |
1807 |
QCowSnapshotHeader h; |
1808 |
int i, name_size, id_str_size, snapshots_size;
|
1809 |
uint64_t data64; |
1810 |
uint32_t data32; |
1811 |
int64_t offset, snapshots_offset; |
1812 |
|
1813 |
/* compute the size of the snapshots */
|
1814 |
offset = 0;
|
1815 |
for(i = 0; i < s->nb_snapshots; i++) { |
1816 |
sn = s->snapshots + i; |
1817 |
offset = align_offset(offset, 8);
|
1818 |
offset += sizeof(h);
|
1819 |
offset += strlen(sn->id_str); |
1820 |
offset += strlen(sn->name); |
1821 |
} |
1822 |
snapshots_size = offset; |
1823 |
|
1824 |
snapshots_offset = alloc_clusters(bs, snapshots_size); |
1825 |
offset = snapshots_offset; |
1826 |
|
1827 |
for(i = 0; i < s->nb_snapshots; i++) { |
1828 |
sn = s->snapshots + i; |
1829 |
memset(&h, 0, sizeof(h)); |
1830 |
h.l1_table_offset = cpu_to_be64(sn->l1_table_offset); |
1831 |
h.l1_size = cpu_to_be32(sn->l1_size); |
1832 |
h.vm_state_size = cpu_to_be32(sn->vm_state_size); |
1833 |
h.date_sec = cpu_to_be32(sn->date_sec); |
1834 |
h.date_nsec = cpu_to_be32(sn->date_nsec); |
1835 |
h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec); |
1836 |
|
1837 |
id_str_size = strlen(sn->id_str); |
1838 |
name_size = strlen(sn->name); |
1839 |
h.id_str_size = cpu_to_be16(id_str_size); |
1840 |
h.name_size = cpu_to_be16(name_size); |
1841 |
offset = align_offset(offset, 8);
|
1842 |
if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
1843 |
goto fail;
|
1844 |
offset += sizeof(h);
|
1845 |
if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
1846 |
goto fail;
|
1847 |
offset += id_str_size; |
1848 |
if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size)
|
1849 |
goto fail;
|
1850 |
offset += name_size; |
1851 |
} |
1852 |
|
1853 |
/* update the various header fields */
|
1854 |
data64 = cpu_to_be64(snapshots_offset); |
1855 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset),
|
1856 |
&data64, sizeof(data64)) != sizeof(data64)) |
1857 |
goto fail;
|
1858 |
data32 = cpu_to_be32(s->nb_snapshots); |
1859 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots),
|
1860 |
&data32, sizeof(data32)) != sizeof(data32)) |
1861 |
goto fail;
|
1862 |
|
1863 |
/* free the old snapshot table */
|
1864 |
free_clusters(bs, s->snapshots_offset, s->snapshots_size); |
1865 |
s->snapshots_offset = snapshots_offset; |
1866 |
s->snapshots_size = snapshots_size; |
1867 |
return 0; |
1868 |
fail:
|
1869 |
return -1; |
1870 |
} |
1871 |
|
1872 |
static void find_new_snapshot_id(BlockDriverState *bs, |
1873 |
char *id_str, int id_str_size) |
1874 |
{ |
1875 |
BDRVQcowState *s = bs->opaque; |
1876 |
QCowSnapshot *sn; |
1877 |
int i, id, id_max = 0; |
1878 |
|
1879 |
for(i = 0; i < s->nb_snapshots; i++) { |
1880 |
sn = s->snapshots + i; |
1881 |
id = strtoul(sn->id_str, NULL, 10); |
1882 |
if (id > id_max)
|
1883 |
id_max = id; |
1884 |
} |
1885 |
snprintf(id_str, id_str_size, "%d", id_max + 1); |
1886 |
} |
1887 |
|
1888 |
static int find_snapshot_by_id(BlockDriverState *bs, const char *id_str) |
1889 |
{ |
1890 |
BDRVQcowState *s = bs->opaque; |
1891 |
int i;
|
1892 |
|
1893 |
for(i = 0; i < s->nb_snapshots; i++) { |
1894 |
if (!strcmp(s->snapshots[i].id_str, id_str))
|
1895 |
return i;
|
1896 |
} |
1897 |
return -1; |
1898 |
} |
1899 |
|
1900 |
static int find_snapshot_by_id_or_name(BlockDriverState *bs, const char *name) |
1901 |
{ |
1902 |
BDRVQcowState *s = bs->opaque; |
1903 |
int i, ret;
|
1904 |
|
1905 |
ret = find_snapshot_by_id(bs, name); |
1906 |
if (ret >= 0) |
1907 |
return ret;
|
1908 |
for(i = 0; i < s->nb_snapshots; i++) { |
1909 |
if (!strcmp(s->snapshots[i].name, name))
|
1910 |
return i;
|
1911 |
} |
1912 |
return -1; |
1913 |
} |
1914 |
|
1915 |
/* if no id is provided, a new one is constructed */
|
1916 |
static int qcow_snapshot_create(BlockDriverState *bs, |
1917 |
QEMUSnapshotInfo *sn_info) |
1918 |
{ |
1919 |
BDRVQcowState *s = bs->opaque; |
1920 |
QCowSnapshot *snapshots1, sn1, *sn = &sn1; |
1921 |
int i, ret;
|
1922 |
uint64_t *l1_table = NULL;
|
1923 |
|
1924 |
memset(sn, 0, sizeof(*sn)); |
1925 |
|
1926 |
if (sn_info->id_str[0] == '\0') { |
1927 |
/* compute a new id */
|
1928 |
find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
|
1929 |
} |
1930 |
|
1931 |
/* check that the ID is unique */
|
1932 |
if (find_snapshot_by_id(bs, sn_info->id_str) >= 0) |
1933 |
return -ENOENT;
|
1934 |
|
1935 |
sn->id_str = qemu_strdup(sn_info->id_str); |
1936 |
if (!sn->id_str)
|
1937 |
goto fail;
|
1938 |
sn->name = qemu_strdup(sn_info->name); |
1939 |
if (!sn->name)
|
1940 |
goto fail;
|
1941 |
sn->vm_state_size = sn_info->vm_state_size; |
1942 |
sn->date_sec = sn_info->date_sec; |
1943 |
sn->date_nsec = sn_info->date_nsec; |
1944 |
sn->vm_clock_nsec = sn_info->vm_clock_nsec; |
1945 |
|
1946 |
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
|
1947 |
if (ret < 0) |
1948 |
goto fail;
|
1949 |
|
1950 |
/* create the L1 table of the snapshot */
|
1951 |
sn->l1_table_offset = alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
|
1952 |
sn->l1_size = s->l1_size; |
1953 |
|
1954 |
l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
|
1955 |
if (!l1_table)
|
1956 |
goto fail;
|
1957 |
for(i = 0; i < s->l1_size; i++) { |
1958 |
l1_table[i] = cpu_to_be64(s->l1_table[i]); |
1959 |
} |
1960 |
if (bdrv_pwrite(s->hd, sn->l1_table_offset,
|
1961 |
l1_table, s->l1_size * sizeof(uint64_t)) !=
|
1962 |
(s->l1_size * sizeof(uint64_t)))
|
1963 |
goto fail;
|
1964 |
qemu_free(l1_table); |
1965 |
l1_table = NULL;
|
1966 |
|
1967 |
snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot)); |
1968 |
if (!snapshots1)
|
1969 |
goto fail;
|
1970 |
memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot));
|
1971 |
s->snapshots = snapshots1; |
1972 |
s->snapshots[s->nb_snapshots++] = *sn; |
1973 |
|
1974 |
if (qcow_write_snapshots(bs) < 0) |
1975 |
goto fail;
|
1976 |
#ifdef DEBUG_ALLOC
|
1977 |
check_refcounts(bs); |
1978 |
#endif
|
1979 |
return 0; |
1980 |
fail:
|
1981 |
qemu_free(sn->name); |
1982 |
qemu_free(l1_table); |
1983 |
return -1; |
1984 |
} |
1985 |
|
1986 |
/* copy the snapshot 'snapshot_name' into the current disk image */
|
1987 |
static int qcow_snapshot_goto(BlockDriverState *bs, |
1988 |
const char *snapshot_id) |
1989 |
{ |
1990 |
BDRVQcowState *s = bs->opaque; |
1991 |
QCowSnapshot *sn; |
1992 |
int i, snapshot_index, l1_size2;
|
1993 |
|
1994 |
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
1995 |
if (snapshot_index < 0) |
1996 |
return -ENOENT;
|
1997 |
sn = &s->snapshots[snapshot_index]; |
1998 |
|
1999 |
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1) < 0) |
2000 |
goto fail;
|
2001 |
|
2002 |
if (grow_l1_table(bs, sn->l1_size) < 0) |
2003 |
goto fail;
|
2004 |
|
2005 |
s->l1_size = sn->l1_size; |
2006 |
l1_size2 = s->l1_size * sizeof(uint64_t);
|
2007 |
/* copy the snapshot l1 table to the current l1 table */
|
2008 |
if (bdrv_pread(s->hd, sn->l1_table_offset,
|
2009 |
s->l1_table, l1_size2) != l1_size2) |
2010 |
goto fail;
|
2011 |
if (bdrv_pwrite(s->hd, s->l1_table_offset,
|
2012 |
s->l1_table, l1_size2) != l1_size2) |
2013 |
goto fail;
|
2014 |
for(i = 0;i < s->l1_size; i++) { |
2015 |
be64_to_cpus(&s->l1_table[i]); |
2016 |
} |
2017 |
|
2018 |
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1) < 0) |
2019 |
goto fail;
|
2020 |
|
2021 |
#ifdef DEBUG_ALLOC
|
2022 |
check_refcounts(bs); |
2023 |
#endif
|
2024 |
return 0; |
2025 |
fail:
|
2026 |
return -EIO;
|
2027 |
} |
2028 |
|
2029 |
static int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) |
2030 |
{ |
2031 |
BDRVQcowState *s = bs->opaque; |
2032 |
QCowSnapshot *sn; |
2033 |
int snapshot_index, ret;
|
2034 |
|
2035 |
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
2036 |
if (snapshot_index < 0) |
2037 |
return -ENOENT;
|
2038 |
sn = &s->snapshots[snapshot_index]; |
2039 |
|
2040 |
ret = update_snapshot_refcount(bs, sn->l1_table_offset, sn->l1_size, -1);
|
2041 |
if (ret < 0) |
2042 |
return ret;
|
2043 |
/* must update the copied flag on the current cluster offsets */
|
2044 |
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0);
|
2045 |
if (ret < 0) |
2046 |
return ret;
|
2047 |
free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t));
|
2048 |
|
2049 |
qemu_free(sn->id_str); |
2050 |
qemu_free(sn->name); |
2051 |
memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn)); |
2052 |
s->nb_snapshots--; |
2053 |
ret = qcow_write_snapshots(bs); |
2054 |
if (ret < 0) { |
2055 |
/* XXX: restore snapshot if error ? */
|
2056 |
return ret;
|
2057 |
} |
2058 |
#ifdef DEBUG_ALLOC
|
2059 |
check_refcounts(bs); |
2060 |
#endif
|
2061 |
return 0; |
2062 |
} |
2063 |
|
2064 |
static int qcow_snapshot_list(BlockDriverState *bs, |
2065 |
QEMUSnapshotInfo **psn_tab) |
2066 |
{ |
2067 |
BDRVQcowState *s = bs->opaque; |
2068 |
QEMUSnapshotInfo *sn_tab, *sn_info; |
2069 |
QCowSnapshot *sn; |
2070 |
int i;
|
2071 |
|
2072 |
sn_tab = qemu_mallocz(s->nb_snapshots * sizeof(QEMUSnapshotInfo));
|
2073 |
if (!sn_tab)
|
2074 |
goto fail;
|
2075 |
for(i = 0; i < s->nb_snapshots; i++) { |
2076 |
sn_info = sn_tab + i; |
2077 |
sn = s->snapshots + i; |
2078 |
pstrcpy(sn_info->id_str, sizeof(sn_info->id_str),
|
2079 |
sn->id_str); |
2080 |
pstrcpy(sn_info->name, sizeof(sn_info->name),
|
2081 |
sn->name); |
2082 |
sn_info->vm_state_size = sn->vm_state_size; |
2083 |
sn_info->date_sec = sn->date_sec; |
2084 |
sn_info->date_nsec = sn->date_nsec; |
2085 |
sn_info->vm_clock_nsec = sn->vm_clock_nsec; |
2086 |
} |
2087 |
*psn_tab = sn_tab; |
2088 |
return s->nb_snapshots;
|
2089 |
fail:
|
2090 |
qemu_free(sn_tab); |
2091 |
*psn_tab = NULL;
|
2092 |
return -ENOMEM;
|
2093 |
} |
2094 |
|
2095 |
/*********************************************************/
|
2096 |
/* refcount handling */
|
2097 |
|
2098 |
static int refcount_init(BlockDriverState *bs) |
2099 |
{ |
2100 |
BDRVQcowState *s = bs->opaque; |
2101 |
int ret, refcount_table_size2, i;
|
2102 |
|
2103 |
s->refcount_block_cache = qemu_malloc(s->cluster_size); |
2104 |
if (!s->refcount_block_cache)
|
2105 |
goto fail;
|
2106 |
refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t);
|
2107 |
s->refcount_table = qemu_malloc(refcount_table_size2); |
2108 |
if (!s->refcount_table)
|
2109 |
goto fail;
|
2110 |
if (s->refcount_table_size > 0) { |
2111 |
ret = bdrv_pread(s->hd, s->refcount_table_offset, |
2112 |
s->refcount_table, refcount_table_size2); |
2113 |
if (ret != refcount_table_size2)
|
2114 |
goto fail;
|
2115 |
for(i = 0; i < s->refcount_table_size; i++) |
2116 |
be64_to_cpus(&s->refcount_table[i]); |
2117 |
} |
2118 |
return 0; |
2119 |
fail:
|
2120 |
return -ENOMEM;
|
2121 |
} |
2122 |
|
2123 |
static void refcount_close(BlockDriverState *bs) |
2124 |
{ |
2125 |
BDRVQcowState *s = bs->opaque; |
2126 |
qemu_free(s->refcount_block_cache); |
2127 |
qemu_free(s->refcount_table); |
2128 |
} |
2129 |
|
2130 |
|
2131 |
static int load_refcount_block(BlockDriverState *bs, |
2132 |
int64_t refcount_block_offset) |
2133 |
{ |
2134 |
BDRVQcowState *s = bs->opaque; |
2135 |
int ret;
|
2136 |
ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache, |
2137 |
s->cluster_size); |
2138 |
if (ret != s->cluster_size)
|
2139 |
return -EIO;
|
2140 |
s->refcount_block_cache_offset = refcount_block_offset; |
2141 |
return 0; |
2142 |
} |
2143 |
|
2144 |
static int get_refcount(BlockDriverState *bs, int64_t cluster_index) |
2145 |
{ |
2146 |
BDRVQcowState *s = bs->opaque; |
2147 |
int refcount_table_index, block_index;
|
2148 |
int64_t refcount_block_offset; |
2149 |
|
2150 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
2151 |
if (refcount_table_index >= s->refcount_table_size)
|
2152 |
return 0; |
2153 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
2154 |
if (!refcount_block_offset)
|
2155 |
return 0; |
2156 |
if (refcount_block_offset != s->refcount_block_cache_offset) {
|
2157 |
/* better than nothing: return allocated if read error */
|
2158 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
2159 |
return 1; |
2160 |
} |
2161 |
block_index = cluster_index & |
2162 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
2163 |
return be16_to_cpu(s->refcount_block_cache[block_index]);
|
2164 |
} |
2165 |
|
2166 |
/* return < 0 if error */
|
2167 |
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
|
2168 |
{ |
2169 |
BDRVQcowState *s = bs->opaque; |
2170 |
int i, nb_clusters;
|
2171 |
|
2172 |
nb_clusters = (size + s->cluster_size - 1) >> s->cluster_bits;
|
2173 |
for(;;) {
|
2174 |
if (get_refcount(bs, s->free_cluster_index) == 0) { |
2175 |
s->free_cluster_index++; |
2176 |
for(i = 1; i < nb_clusters; i++) { |
2177 |
if (get_refcount(bs, s->free_cluster_index) != 0) |
2178 |
goto not_found;
|
2179 |
s->free_cluster_index++; |
2180 |
} |
2181 |
#ifdef DEBUG_ALLOC2
|
2182 |
printf("alloc_clusters: size=%lld -> %lld\n",
|
2183 |
size, |
2184 |
(s->free_cluster_index - nb_clusters) << s->cluster_bits); |
2185 |
#endif
|
2186 |
return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
|
2187 |
} else {
|
2188 |
not_found:
|
2189 |
s->free_cluster_index++; |
2190 |
} |
2191 |
} |
2192 |
} |
2193 |
|
2194 |
static int64_t alloc_clusters(BlockDriverState *bs, int64_t size)
|
2195 |
{ |
2196 |
int64_t offset; |
2197 |
|
2198 |
offset = alloc_clusters_noref(bs, size); |
2199 |
update_refcount(bs, offset, size, 1);
|
2200 |
return offset;
|
2201 |
} |
2202 |
|
2203 |
/* only used to allocate compressed sectors. We try to allocate
|
2204 |
contiguous sectors. size must be <= cluster_size */
|
2205 |
static int64_t alloc_bytes(BlockDriverState *bs, int size) |
2206 |
{ |
2207 |
BDRVQcowState *s = bs->opaque; |
2208 |
int64_t offset, cluster_offset; |
2209 |
int free_in_cluster;
|
2210 |
|
2211 |
assert(size > 0 && size <= s->cluster_size);
|
2212 |
if (s->free_byte_offset == 0) { |
2213 |
s->free_byte_offset = alloc_clusters(bs, s->cluster_size); |
2214 |
} |
2215 |
redo:
|
2216 |
free_in_cluster = s->cluster_size - |
2217 |
(s->free_byte_offset & (s->cluster_size - 1));
|
2218 |
if (size <= free_in_cluster) {
|
2219 |
/* enough space in current cluster */
|
2220 |
offset = s->free_byte_offset; |
2221 |
s->free_byte_offset += size; |
2222 |
free_in_cluster -= size; |
2223 |
if (free_in_cluster == 0) |
2224 |
s->free_byte_offset = 0;
|
2225 |
if ((offset & (s->cluster_size - 1)) != 0) |
2226 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
2227 |
} else {
|
2228 |
offset = alloc_clusters(bs, s->cluster_size); |
2229 |
cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1);
|
2230 |
if ((cluster_offset + s->cluster_size) == offset) {
|
2231 |
/* we are lucky: contiguous data */
|
2232 |
offset = s->free_byte_offset; |
2233 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
2234 |
s->free_byte_offset += size; |
2235 |
} else {
|
2236 |
s->free_byte_offset = offset; |
2237 |
goto redo;
|
2238 |
} |
2239 |
} |
2240 |
return offset;
|
2241 |
} |
2242 |
|
2243 |
static void free_clusters(BlockDriverState *bs, |
2244 |
int64_t offset, int64_t size) |
2245 |
{ |
2246 |
update_refcount(bs, offset, size, -1);
|
2247 |
} |
2248 |
|
2249 |
static int grow_refcount_table(BlockDriverState *bs, int min_size) |
2250 |
{ |
2251 |
BDRVQcowState *s = bs->opaque; |
2252 |
int new_table_size, new_table_size2, refcount_table_clusters, i, ret;
|
2253 |
uint64_t *new_table; |
2254 |
int64_t table_offset; |
2255 |
uint64_t data64; |
2256 |
uint32_t data32; |
2257 |
int old_table_size;
|
2258 |
int64_t old_table_offset; |
2259 |
|
2260 |
if (min_size <= s->refcount_table_size)
|
2261 |
return 0; |
2262 |
/* compute new table size */
|
2263 |
refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
|
2264 |
for(;;) {
|
2265 |
if (refcount_table_clusters == 0) { |
2266 |
refcount_table_clusters = 1;
|
2267 |
} else {
|
2268 |
refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; |
2269 |
} |
2270 |
new_table_size = refcount_table_clusters << (s->cluster_bits - 3);
|
2271 |
if (min_size <= new_table_size)
|
2272 |
break;
|
2273 |
} |
2274 |
#ifdef DEBUG_ALLOC2
|
2275 |
printf("grow_refcount_table from %d to %d\n",
|
2276 |
s->refcount_table_size, |
2277 |
new_table_size); |
2278 |
#endif
|
2279 |
new_table_size2 = new_table_size * sizeof(uint64_t);
|
2280 |
new_table = qemu_mallocz(new_table_size2); |
2281 |
if (!new_table)
|
2282 |
return -ENOMEM;
|
2283 |
memcpy(new_table, s->refcount_table, |
2284 |
s->refcount_table_size * sizeof(uint64_t));
|
2285 |
for(i = 0; i < s->refcount_table_size; i++) |
2286 |
cpu_to_be64s(&new_table[i]); |
2287 |
/* Note: we cannot update the refcount now to avoid recursion */
|
2288 |
table_offset = alloc_clusters_noref(bs, new_table_size2); |
2289 |
ret = bdrv_pwrite(s->hd, table_offset, new_table, new_table_size2); |
2290 |
if (ret != new_table_size2)
|
2291 |
goto fail;
|
2292 |
for(i = 0; i < s->refcount_table_size; i++) |
2293 |
be64_to_cpus(&new_table[i]); |
2294 |
|
2295 |
data64 = cpu_to_be64(table_offset); |
2296 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset),
|
2297 |
&data64, sizeof(data64)) != sizeof(data64)) |
2298 |
goto fail;
|
2299 |
data32 = cpu_to_be32(refcount_table_clusters); |
2300 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_clusters),
|
2301 |
&data32, sizeof(data32)) != sizeof(data32)) |
2302 |
goto fail;
|
2303 |
qemu_free(s->refcount_table); |
2304 |
old_table_offset = s->refcount_table_offset; |
2305 |
old_table_size = s->refcount_table_size; |
2306 |
s->refcount_table = new_table; |
2307 |
s->refcount_table_size = new_table_size; |
2308 |
s->refcount_table_offset = table_offset; |
2309 |
|
2310 |
update_refcount(bs, table_offset, new_table_size2, 1);
|
2311 |
free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t));
|
2312 |
return 0; |
2313 |
fail:
|
2314 |
free_clusters(bs, table_offset, new_table_size2); |
2315 |
qemu_free(new_table); |
2316 |
return -EIO;
|
2317 |
} |
2318 |
|
2319 |
/* addend must be 1 or -1 */
|
2320 |
/* XXX: cache several refcount block clusters ? */
|
2321 |
static int update_cluster_refcount(BlockDriverState *bs, |
2322 |
int64_t cluster_index, |
2323 |
int addend)
|
2324 |
{ |
2325 |
BDRVQcowState *s = bs->opaque; |
2326 |
int64_t offset, refcount_block_offset; |
2327 |
int ret, refcount_table_index, block_index, refcount;
|
2328 |
uint64_t data64; |
2329 |
|
2330 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
2331 |
if (refcount_table_index >= s->refcount_table_size) {
|
2332 |
if (addend < 0) |
2333 |
return -EINVAL;
|
2334 |
ret = grow_refcount_table(bs, refcount_table_index + 1);
|
2335 |
if (ret < 0) |
2336 |
return ret;
|
2337 |
} |
2338 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
2339 |
if (!refcount_block_offset) {
|
2340 |
if (addend < 0) |
2341 |
return -EINVAL;
|
2342 |
/* create a new refcount block */
|
2343 |
/* Note: we cannot update the refcount now to avoid recursion */
|
2344 |
offset = alloc_clusters_noref(bs, s->cluster_size); |
2345 |
memset(s->refcount_block_cache, 0, s->cluster_size);
|
2346 |
ret = bdrv_pwrite(s->hd, offset, s->refcount_block_cache, s->cluster_size); |
2347 |
if (ret != s->cluster_size)
|
2348 |
return -EINVAL;
|
2349 |
s->refcount_table[refcount_table_index] = offset; |
2350 |
data64 = cpu_to_be64(offset); |
2351 |
ret = bdrv_pwrite(s->hd, s->refcount_table_offset + |
2352 |
refcount_table_index * sizeof(uint64_t),
|
2353 |
&data64, sizeof(data64));
|
2354 |
if (ret != sizeof(data64)) |
2355 |
return -EINVAL;
|
2356 |
|
2357 |
refcount_block_offset = offset; |
2358 |
s->refcount_block_cache_offset = offset; |
2359 |
update_refcount(bs, offset, s->cluster_size, 1);
|
2360 |
} else {
|
2361 |
if (refcount_block_offset != s->refcount_block_cache_offset) {
|
2362 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
2363 |
return -EIO;
|
2364 |
} |
2365 |
} |
2366 |
/* we can update the count and save it */
|
2367 |
block_index = cluster_index & |
2368 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
2369 |
refcount = be16_to_cpu(s->refcount_block_cache[block_index]); |
2370 |
refcount += addend; |
2371 |
if (refcount < 0 || refcount > 0xffff) |
2372 |
return -EINVAL;
|
2373 |
if (refcount == 0 && cluster_index < s->free_cluster_index) { |
2374 |
s->free_cluster_index = cluster_index; |
2375 |
} |
2376 |
s->refcount_block_cache[block_index] = cpu_to_be16(refcount); |
2377 |
if (bdrv_pwrite(s->hd,
|
2378 |
refcount_block_offset + (block_index << REFCOUNT_SHIFT), |
2379 |
&s->refcount_block_cache[block_index], 2) != 2) |
2380 |
return -EIO;
|
2381 |
return refcount;
|
2382 |
} |
2383 |
|
2384 |
static void update_refcount(BlockDriverState *bs, |
2385 |
int64_t offset, int64_t length, |
2386 |
int addend)
|
2387 |
{ |
2388 |
BDRVQcowState *s = bs->opaque; |
2389 |
int64_t start, last, cluster_offset; |
2390 |
|
2391 |
#ifdef DEBUG_ALLOC2
|
2392 |
printf("update_refcount: offset=%lld size=%lld addend=%d\n",
|
2393 |
offset, length, addend); |
2394 |
#endif
|
2395 |
if (length <= 0) |
2396 |
return;
|
2397 |
start = offset & ~(s->cluster_size - 1);
|
2398 |
last = (offset + length - 1) & ~(s->cluster_size - 1); |
2399 |
for(cluster_offset = start; cluster_offset <= last;
|
2400 |
cluster_offset += s->cluster_size) { |
2401 |
update_cluster_refcount(bs, cluster_offset >> s->cluster_bits, addend); |
2402 |
} |
2403 |
} |
2404 |
|
2405 |
#ifdef DEBUG_ALLOC
|
2406 |
static void inc_refcounts(BlockDriverState *bs, |
2407 |
uint16_t *refcount_table, |
2408 |
int refcount_table_size,
|
2409 |
int64_t offset, int64_t size) |
2410 |
{ |
2411 |
BDRVQcowState *s = bs->opaque; |
2412 |
int64_t start, last, cluster_offset; |
2413 |
int k;
|
2414 |
|
2415 |
if (size <= 0) |
2416 |
return;
|
2417 |
|
2418 |
start = offset & ~(s->cluster_size - 1);
|
2419 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
2420 |
for(cluster_offset = start; cluster_offset <= last;
|
2421 |
cluster_offset += s->cluster_size) { |
2422 |
k = cluster_offset >> s->cluster_bits; |
2423 |
if (k < 0 || k >= refcount_table_size) { |
2424 |
printf("ERROR: invalid cluster offset=0x%llx\n", cluster_offset);
|
2425 |
} else {
|
2426 |
if (++refcount_table[k] == 0) { |
2427 |
printf("ERROR: overflow cluster offset=0x%llx\n", cluster_offset);
|
2428 |
} |
2429 |
} |
2430 |
} |
2431 |
} |
2432 |
|
2433 |
static int check_refcounts_l1(BlockDriverState *bs, |
2434 |
uint16_t *refcount_table, |
2435 |
int refcount_table_size,
|
2436 |
int64_t l1_table_offset, int l1_size,
|
2437 |
int check_copied)
|
2438 |
{ |
2439 |
BDRVQcowState *s = bs->opaque; |
2440 |
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2; |
2441 |
int l2_size, i, j, nb_csectors, refcount;
|
2442 |
|
2443 |
l2_table = NULL;
|
2444 |
l1_size2 = l1_size * sizeof(uint64_t);
|
2445 |
|
2446 |
inc_refcounts(bs, refcount_table, refcount_table_size, |
2447 |
l1_table_offset, l1_size2); |
2448 |
|
2449 |
l1_table = qemu_malloc(l1_size2); |
2450 |
if (!l1_table)
|
2451 |
goto fail;
|
2452 |
if (bdrv_pread(s->hd, l1_table_offset,
|
2453 |
l1_table, l1_size2) != l1_size2) |
2454 |
goto fail;
|
2455 |
for(i = 0;i < l1_size; i++) |
2456 |
be64_to_cpus(&l1_table[i]); |
2457 |
|
2458 |
l2_size = s->l2_size * sizeof(uint64_t);
|
2459 |
l2_table = qemu_malloc(l2_size); |
2460 |
if (!l2_table)
|
2461 |
goto fail;
|
2462 |
for(i = 0; i < l1_size; i++) { |
2463 |
l2_offset = l1_table[i]; |
2464 |
if (l2_offset) {
|
2465 |
if (check_copied) {
|
2466 |
refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits); |
2467 |
if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { |
2468 |
printf("ERROR OFLAG_COPIED: l2_offset=%llx refcount=%d\n",
|
2469 |
l2_offset, refcount); |
2470 |
} |
2471 |
} |
2472 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
2473 |
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
|
2474 |
goto fail;
|
2475 |
for(j = 0; j < s->l2_size; j++) { |
2476 |
offset = be64_to_cpu(l2_table[j]); |
2477 |
if (offset != 0) { |
2478 |
if (offset & QCOW_OFLAG_COMPRESSED) {
|
2479 |
if (offset & QCOW_OFLAG_COPIED) {
|
2480 |
printf("ERROR: cluster %lld: copied flag must never be set for compressed clusters\n",
|
2481 |
offset >> s->cluster_bits); |
2482 |
offset &= ~QCOW_OFLAG_COPIED; |
2483 |
} |
2484 |
nb_csectors = ((offset >> s->csize_shift) & |
2485 |
s->csize_mask) + 1;
|
2486 |
offset &= s->cluster_offset_mask; |
2487 |
inc_refcounts(bs, refcount_table, |
2488 |
refcount_table_size, |
2489 |
offset & ~511, nb_csectors * 512); |
2490 |
} else {
|
2491 |
if (check_copied) {
|
2492 |
refcount = get_refcount(bs, (offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits); |
2493 |
if ((refcount == 1) != ((offset & QCOW_OFLAG_COPIED) != 0)) { |
2494 |
printf("ERROR OFLAG_COPIED: offset=%llx refcount=%d\n",
|
2495 |
offset, refcount); |
2496 |
} |
2497 |
} |
2498 |
offset &= ~QCOW_OFLAG_COPIED; |
2499 |
inc_refcounts(bs, refcount_table, |
2500 |
refcount_table_size, |
2501 |
offset, s->cluster_size); |
2502 |
} |
2503 |
} |
2504 |
} |
2505 |
inc_refcounts(bs, refcount_table, |
2506 |
refcount_table_size, |
2507 |
l2_offset, |
2508 |
s->cluster_size); |
2509 |
} |
2510 |
} |
2511 |
qemu_free(l1_table); |
2512 |
qemu_free(l2_table); |
2513 |
return 0; |
2514 |
fail:
|
2515 |
printf("ERROR: I/O error in check_refcounts_l1\n");
|
2516 |
qemu_free(l1_table); |
2517 |
qemu_free(l2_table); |
2518 |
return -EIO;
|
2519 |
} |
2520 |
|
2521 |
static void check_refcounts(BlockDriverState *bs) |
2522 |
{ |
2523 |
BDRVQcowState *s = bs->opaque; |
2524 |
int64_t size; |
2525 |
int nb_clusters, refcount1, refcount2, i;
|
2526 |
QCowSnapshot *sn; |
2527 |
uint16_t *refcount_table; |
2528 |
|
2529 |
size = bdrv_getlength(s->hd); |
2530 |
nb_clusters = (size + s->cluster_size - 1) >> s->cluster_bits;
|
2531 |
refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t));
|
2532 |
|
2533 |
/* header */
|
2534 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2535 |
0, s->cluster_size);
|
2536 |
|
2537 |
check_refcounts_l1(bs, refcount_table, nb_clusters, |
2538 |
s->l1_table_offset, s->l1_size, 1);
|
2539 |
|
2540 |
/* snapshots */
|
2541 |
for(i = 0; i < s->nb_snapshots; i++) { |
2542 |
sn = s->snapshots + i; |
2543 |
check_refcounts_l1(bs, refcount_table, nb_clusters, |
2544 |
sn->l1_table_offset, sn->l1_size, 0);
|
2545 |
} |
2546 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2547 |
s->snapshots_offset, s->snapshots_size); |
2548 |
|
2549 |
/* refcount data */
|
2550 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2551 |
s->refcount_table_offset, |
2552 |
s->refcount_table_size * sizeof(uint64_t));
|
2553 |
for(i = 0; i < s->refcount_table_size; i++) { |
2554 |
int64_t offset; |
2555 |
offset = s->refcount_table[i]; |
2556 |
if (offset != 0) { |
2557 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2558 |
offset, s->cluster_size); |
2559 |
} |
2560 |
} |
2561 |
|
2562 |
/* compare ref counts */
|
2563 |
for(i = 0; i < nb_clusters; i++) { |
2564 |
refcount1 = get_refcount(bs, i); |
2565 |
refcount2 = refcount_table[i]; |
2566 |
if (refcount1 != refcount2)
|
2567 |
printf("ERROR cluster %d refcount=%d reference=%d\n",
|
2568 |
i, refcount1, refcount2); |
2569 |
} |
2570 |
|
2571 |
qemu_free(refcount_table); |
2572 |
} |
2573 |
|
2574 |
#if 0
|
2575 |
static void dump_refcounts(BlockDriverState *bs)
|
2576 |
{
|
2577 |
BDRVQcowState *s = bs->opaque;
|
2578 |
int64_t nb_clusters, k, k1, size;
|
2579 |
int refcount;
|
2580 |
|
2581 |
size = bdrv_getlength(s->hd);
|
2582 |
nb_clusters = (size + s->cluster_size - 1) >> s->cluster_bits;
|
2583 |
for(k = 0; k < nb_clusters;) {
|
2584 |
k1 = k;
|
2585 |
refcount = get_refcount(bs, k);
|
2586 |
k++;
|
2587 |
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
2588 |
k++;
|
2589 |
printf("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1);
|
2590 |
}
|
2591 |
}
|
2592 |
#endif
|
2593 |
#endif
|
2594 |
|
2595 |
BlockDriver bdrv_qcow2 = { |
2596 |
"qcow2",
|
2597 |
sizeof(BDRVQcowState),
|
2598 |
qcow_probe, |
2599 |
qcow_open, |
2600 |
NULL,
|
2601 |
NULL,
|
2602 |
qcow_close, |
2603 |
qcow_create, |
2604 |
qcow_flush, |
2605 |
qcow_is_allocated, |
2606 |
qcow_set_key, |
2607 |
qcow_make_empty, |
2608 |
|
2609 |
.bdrv_aio_read = qcow_aio_read, |
2610 |
.bdrv_aio_write = qcow_aio_write, |
2611 |
.bdrv_aio_cancel = qcow_aio_cancel, |
2612 |
.aiocb_size = sizeof(QCowAIOCB),
|
2613 |
.bdrv_write_compressed = qcow_write_compressed, |
2614 |
|
2615 |
.bdrv_snapshot_create = qcow_snapshot_create, |
2616 |
.bdrv_snapshot_goto = qcow_snapshot_goto, |
2617 |
.bdrv_snapshot_delete = qcow_snapshot_delete, |
2618 |
.bdrv_snapshot_list = qcow_snapshot_list, |
2619 |
.bdrv_get_info = qcow_get_info, |
2620 |
}; |