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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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|
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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; |
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uint32_t backing_file_size; |
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uint32_t cluster_bits; |
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uint64_t size; /* in bytes */
|
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uint32_t crypt_method; |
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uint32_t l1_size; /* XXX: save number of clusters instead ? */
|
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uint64_t l1_table_offset; |
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uint64_t refcount_table_offset; |
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uint32_t refcount_table_clusters; |
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uint32_t nb_snapshots; |
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uint64_t snapshots_offset; |
78 |
} 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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|
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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; |
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|
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typedef struct BDRVQcowState { |
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BlockDriverState *hd; |
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int cluster_bits;
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int cluster_size;
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int cluster_sectors;
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int l2_bits;
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int l2_size;
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int l1_size;
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int l1_vm_state_index;
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int csize_shift;
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int csize_mask;
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uint64_t cluster_offset_mask; |
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uint64_t l1_table_offset; |
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uint64_t *l1_table; |
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uint64_t *l2_cache; |
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uint64_t l2_cache_offsets[L2_CACHE_SIZE]; |
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uint32_t l2_cache_counts[L2_CACHE_SIZE]; |
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uint8_t *cluster_cache; |
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; |
136 |
uint32_t refcount_table_size; |
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uint64_t refcount_block_cache_offset; |
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uint16_t *refcount_block_cache; |
139 |
int64_t free_cluster_index; |
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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; |
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AES_KEY aes_encrypt_key; |
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AES_KEY aes_decrypt_key; |
146 |
|
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int64_t highest_alloc; /* highest cluester allocated (in clusters) */
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int64_t nc_free; /* num of free clusters below highest_alloc */
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|
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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; |
154 |
} BDRVQcowState; |
155 |
|
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static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset); |
157 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
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uint8_t *buf, int nb_sectors);
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static int qcow_read_snapshots(BlockDriverState *bs); |
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static void qcow_free_snapshots(BlockDriverState *bs); |
161 |
static int refcount_init(BlockDriverState *bs); |
162 |
static void refcount_close(BlockDriverState *bs); |
163 |
static int get_refcount(BlockDriverState *bs, int64_t cluster_index); |
164 |
static int update_cluster_refcount(BlockDriverState *bs, |
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int64_t cluster_index, |
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int addend);
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static void update_refcount(BlockDriverState *bs, |
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int64_t offset, int64_t length, |
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int addend);
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static int64_t alloc_clusters(BlockDriverState *bs, int64_t size);
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static int64_t alloc_bytes(BlockDriverState *bs, int size); |
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static void free_clusters(BlockDriverState *bs, |
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int64_t offset, int64_t size); |
174 |
#ifdef DEBUG_ALLOC
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static void check_refcounts(BlockDriverState *bs); |
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#endif
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static void scan_refcount(BlockDriverState *bs, int64_t *high, int64_t *free); |
178 |
|
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|
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static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
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{ |
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const QCowHeader *cow_header = (const void *)buf; |
183 |
|
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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) |
187 |
return 100; |
188 |
else
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return 0; |
190 |
} |
191 |
|
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static int qcow_open(BlockDriverState *bs, const char *filename, int flags) |
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{ |
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BDRVQcowState *s = bs->opaque; |
195 |
int len, i, shift, ret;
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QCowHeader header; |
197 |
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/* Performance is terrible right now with cache=writethrough due mainly
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* to reference count updates. If the user does not explicitly specify
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* a caching type, force to writeback caching.
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*/
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if ((flags & BDRV_O_CACHE_DEF)) {
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flags |= BDRV_O_CACHE_WB; |
204 |
flags &= ~BDRV_O_CACHE_DEF; |
205 |
} |
206 |
ret = bdrv_file_open(&s->hd, filename, flags); |
207 |
if (ret < 0) |
208 |
return ret;
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if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) |
210 |
goto fail;
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be32_to_cpus(&header.magic); |
212 |
be32_to_cpus(&header.version); |
213 |
be64_to_cpus(&header.backing_file_offset); |
214 |
be32_to_cpus(&header.backing_file_size); |
215 |
be64_to_cpus(&header.size); |
216 |
be32_to_cpus(&header.cluster_bits); |
217 |
be32_to_cpus(&header.crypt_method); |
218 |
be64_to_cpus(&header.l1_table_offset); |
219 |
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); |
224 |
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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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231 |
if (header.crypt_method > QCOW_CRYPT_AES)
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goto fail;
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s->crypt_method_header = header.crypt_method; |
234 |
if (s->crypt_method_header)
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bs->encrypted = 1;
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s->cluster_bits = header.cluster_bits; |
237 |
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 */ |
240 |
s->l2_size = 1 << s->l2_bits;
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bs->total_sectors = header.size / 512;
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s->csize_shift = (62 - (s->cluster_bits - 8)); |
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s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
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s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
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s->refcount_table_offset = header.refcount_table_offset; |
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s->refcount_table_size = |
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header.refcount_table_clusters << (s->cluster_bits - 3);
|
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|
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s->snapshots_offset = header.snapshots_offset; |
250 |
s->nb_snapshots = header.nb_snapshots; |
251 |
|
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/* read the level 1 table */
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s->l1_size = header.l1_size; |
254 |
shift = s->cluster_bits + s->l2_bits; |
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s->l1_vm_state_index = (header.size + (1LL << shift) - 1) >> shift; |
256 |
/* the L1 table must contain at least enough entries to put
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257 |
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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260 |
s->l1_table_offset = header.l1_table_offset; |
261 |
s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
|
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if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != |
263 |
s->l1_size * sizeof(uint64_t))
|
264 |
goto fail;
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265 |
for(i = 0;i < s->l1_size; i++) { |
266 |
be64_to_cpus(&s->l1_table[i]); |
267 |
} |
268 |
/* alloc L2 cache */
|
269 |
s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
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270 |
s->cluster_cache = qemu_malloc(s->cluster_size); |
271 |
/* one more sector for decompressed data alignment */
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272 |
s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size |
273 |
+ 512);
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274 |
s->cluster_cache_offset = -1;
|
275 |
|
276 |
if (refcount_init(bs) < 0) |
277 |
goto fail;
|
278 |
|
279 |
scan_refcount(bs, &s->highest_alloc, &s->nc_free); |
280 |
|
281 |
/* read the backing file name */
|
282 |
if (header.backing_file_offset != 0) { |
283 |
len = header.backing_file_size; |
284 |
if (len > 1023) |
285 |
len = 1023;
|
286 |
if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len)
|
287 |
goto fail;
|
288 |
bs->backing_file[len] = '\0';
|
289 |
} |
290 |
if (qcow_read_snapshots(bs) < 0) |
291 |
goto fail;
|
292 |
|
293 |
#ifdef DEBUG_ALLOC
|
294 |
check_refcounts(bs); |
295 |
#endif
|
296 |
return 0; |
297 |
|
298 |
fail:
|
299 |
qcow_free_snapshots(bs); |
300 |
refcount_close(bs); |
301 |
qemu_free(s->l1_table); |
302 |
qemu_free(s->l2_cache); |
303 |
qemu_free(s->cluster_cache); |
304 |
qemu_free(s->cluster_data); |
305 |
bdrv_delete(s->hd); |
306 |
return -1; |
307 |
} |
308 |
|
309 |
static int qcow_set_key(BlockDriverState *bs, const char *key) |
310 |
{ |
311 |
BDRVQcowState *s = bs->opaque; |
312 |
uint8_t keybuf[16];
|
313 |
int len, i;
|
314 |
|
315 |
memset(keybuf, 0, 16); |
316 |
len = strlen(key); |
317 |
if (len > 16) |
318 |
len = 16;
|
319 |
/* XXX: we could compress the chars to 7 bits to increase
|
320 |
entropy */
|
321 |
for(i = 0;i < len;i++) { |
322 |
keybuf[i] = key[i]; |
323 |
} |
324 |
s->crypt_method = s->crypt_method_header; |
325 |
|
326 |
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
327 |
return -1; |
328 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
329 |
return -1; |
330 |
#if 0
|
331 |
/* test */
|
332 |
{
|
333 |
uint8_t in[16];
|
334 |
uint8_t out[16];
|
335 |
uint8_t tmp[16];
|
336 |
for(i=0;i<16;i++)
|
337 |
in[i] = i;
|
338 |
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
339 |
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
340 |
for(i = 0; i < 16; i++)
|
341 |
printf(" %02x", tmp[i]);
|
342 |
printf("\n");
|
343 |
for(i = 0; i < 16; i++)
|
344 |
printf(" %02x", out[i]);
|
345 |
printf("\n");
|
346 |
}
|
347 |
#endif
|
348 |
return 0; |
349 |
} |
350 |
|
351 |
/* The crypt function is compatible with the linux cryptoloop
|
352 |
algorithm for < 4 GB images. NOTE: out_buf == in_buf is
|
353 |
supported */
|
354 |
static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
355 |
uint8_t *out_buf, const uint8_t *in_buf,
|
356 |
int nb_sectors, int enc, |
357 |
const AES_KEY *key)
|
358 |
{ |
359 |
union {
|
360 |
uint64_t ll[2];
|
361 |
uint8_t b[16];
|
362 |
} ivec; |
363 |
int i;
|
364 |
|
365 |
for(i = 0; i < nb_sectors; i++) { |
366 |
ivec.ll[0] = cpu_to_le64(sector_num);
|
367 |
ivec.ll[1] = 0; |
368 |
AES_cbc_encrypt(in_buf, out_buf, 512, key,
|
369 |
ivec.b, enc); |
370 |
sector_num++; |
371 |
in_buf += 512;
|
372 |
out_buf += 512;
|
373 |
} |
374 |
} |
375 |
|
376 |
static int copy_sectors(BlockDriverState *bs, uint64_t start_sect, |
377 |
uint64_t cluster_offset, int n_start, int n_end) |
378 |
{ |
379 |
BDRVQcowState *s = bs->opaque; |
380 |
int n, ret;
|
381 |
|
382 |
n = n_end - n_start; |
383 |
if (n <= 0) |
384 |
return 0; |
385 |
ret = qcow_read(bs, start_sect + n_start, s->cluster_data, n); |
386 |
if (ret < 0) |
387 |
return ret;
|
388 |
if (s->crypt_method) {
|
389 |
encrypt_sectors(s, start_sect + n_start, |
390 |
s->cluster_data, |
391 |
s->cluster_data, n, 1,
|
392 |
&s->aes_encrypt_key); |
393 |
} |
394 |
ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start,
|
395 |
s->cluster_data, n); |
396 |
if (ret < 0) |
397 |
return ret;
|
398 |
return 0; |
399 |
} |
400 |
|
401 |
static void l2_cache_reset(BlockDriverState *bs) |
402 |
{ |
403 |
BDRVQcowState *s = bs->opaque; |
404 |
|
405 |
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
406 |
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
407 |
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
408 |
} |
409 |
|
410 |
static inline int l2_cache_new_entry(BlockDriverState *bs) |
411 |
{ |
412 |
BDRVQcowState *s = bs->opaque; |
413 |
uint32_t min_count; |
414 |
int min_index, i;
|
415 |
|
416 |
/* find a new entry in the least used one */
|
417 |
min_index = 0;
|
418 |
min_count = 0xffffffff;
|
419 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
420 |
if (s->l2_cache_counts[i] < min_count) {
|
421 |
min_count = s->l2_cache_counts[i]; |
422 |
min_index = i; |
423 |
} |
424 |
} |
425 |
return min_index;
|
426 |
} |
427 |
|
428 |
static int64_t align_offset(int64_t offset, int n) |
429 |
{ |
430 |
offset = (offset + n - 1) & ~(n - 1); |
431 |
return offset;
|
432 |
} |
433 |
|
434 |
static int grow_l1_table(BlockDriverState *bs, int min_size) |
435 |
{ |
436 |
BDRVQcowState *s = bs->opaque; |
437 |
int new_l1_size, new_l1_size2, ret, i;
|
438 |
uint64_t *new_l1_table; |
439 |
uint64_t new_l1_table_offset; |
440 |
uint8_t data[12];
|
441 |
|
442 |
new_l1_size = s->l1_size; |
443 |
if (min_size <= new_l1_size)
|
444 |
return 0; |
445 |
while (min_size > new_l1_size) {
|
446 |
new_l1_size = (new_l1_size * 3 + 1) / 2; |
447 |
} |
448 |
#ifdef DEBUG_ALLOC2
|
449 |
printf("grow l1_table from %d to %d\n", s->l1_size, new_l1_size);
|
450 |
#endif
|
451 |
|
452 |
new_l1_size2 = sizeof(uint64_t) * new_l1_size;
|
453 |
new_l1_table = qemu_mallocz(new_l1_size2); |
454 |
memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
|
455 |
|
456 |
/* write new table (align to cluster) */
|
457 |
new_l1_table_offset = alloc_clusters(bs, new_l1_size2); |
458 |
|
459 |
for(i = 0; i < s->l1_size; i++) |
460 |
new_l1_table[i] = cpu_to_be64(new_l1_table[i]); |
461 |
ret = bdrv_pwrite(s->hd, new_l1_table_offset, new_l1_table, new_l1_size2); |
462 |
if (ret != new_l1_size2)
|
463 |
goto fail;
|
464 |
for(i = 0; i < s->l1_size; i++) |
465 |
new_l1_table[i] = be64_to_cpu(new_l1_table[i]); |
466 |
|
467 |
/* set new table */
|
468 |
cpu_to_be32w((uint32_t*)data, new_l1_size); |
469 |
cpu_to_be64w((uint64_t*)(data + 4), new_l1_table_offset);
|
470 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_size), data,
|
471 |
sizeof(data)) != sizeof(data)) |
472 |
goto fail;
|
473 |
qemu_free(s->l1_table); |
474 |
free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t));
|
475 |
s->l1_table_offset = new_l1_table_offset; |
476 |
s->l1_table = new_l1_table; |
477 |
s->l1_size = new_l1_size; |
478 |
return 0; |
479 |
fail:
|
480 |
qemu_free(s->l1_table); |
481 |
return -EIO;
|
482 |
} |
483 |
|
484 |
/*
|
485 |
* seek_l2_table
|
486 |
*
|
487 |
* seek l2_offset in the l2_cache table
|
488 |
* if not found, return NULL,
|
489 |
* if found,
|
490 |
* increments the l2 cache hit count of the entry,
|
491 |
* if counter overflow, divide by two all counters
|
492 |
* return the pointer to the l2 cache entry
|
493 |
*
|
494 |
*/
|
495 |
|
496 |
static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset)
|
497 |
{ |
498 |
int i, j;
|
499 |
|
500 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
501 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
502 |
/* increment the hit count */
|
503 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
504 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
505 |
s->l2_cache_counts[j] >>= 1;
|
506 |
} |
507 |
} |
508 |
return s->l2_cache + (i << s->l2_bits);
|
509 |
} |
510 |
} |
511 |
return NULL; |
512 |
} |
513 |
|
514 |
/*
|
515 |
* l2_load
|
516 |
*
|
517 |
* Loads a L2 table into memory. If the table is in the cache, the cache
|
518 |
* is used; otherwise the L2 table is loaded from the image file.
|
519 |
*
|
520 |
* Returns a pointer to the L2 table on success, or NULL if the read from
|
521 |
* the image file failed.
|
522 |
*/
|
523 |
|
524 |
static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset)
|
525 |
{ |
526 |
BDRVQcowState *s = bs->opaque; |
527 |
int min_index;
|
528 |
uint64_t *l2_table; |
529 |
|
530 |
/* seek if the table for the given offset is in the cache */
|
531 |
|
532 |
l2_table = seek_l2_table(s, l2_offset); |
533 |
if (l2_table != NULL) |
534 |
return l2_table;
|
535 |
|
536 |
/* not found: load a new entry in the least used one */
|
537 |
|
538 |
min_index = l2_cache_new_entry(bs); |
539 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
540 |
if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
541 |
s->l2_size * sizeof(uint64_t))
|
542 |
return NULL; |
543 |
s->l2_cache_offsets[min_index] = l2_offset; |
544 |
s->l2_cache_counts[min_index] = 1;
|
545 |
|
546 |
return l2_table;
|
547 |
} |
548 |
|
549 |
/*
|
550 |
* l2_allocate
|
551 |
*
|
552 |
* Allocate a new l2 entry in the file. If l1_index points to an already
|
553 |
* used entry in the L2 table (i.e. we are doing a copy on write for the L2
|
554 |
* table) copy the contents of the old L2 table into the newly allocated one.
|
555 |
* Otherwise the new table is initialized with zeros.
|
556 |
*
|
557 |
*/
|
558 |
|
559 |
static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index) |
560 |
{ |
561 |
BDRVQcowState *s = bs->opaque; |
562 |
int min_index;
|
563 |
uint64_t old_l2_offset, tmp; |
564 |
uint64_t *l2_table, l2_offset; |
565 |
|
566 |
old_l2_offset = s->l1_table[l1_index]; |
567 |
|
568 |
/* allocate a new l2 entry */
|
569 |
|
570 |
l2_offset = alloc_clusters(bs, s->l2_size * sizeof(uint64_t));
|
571 |
|
572 |
/* update the L1 entry */
|
573 |
|
574 |
s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; |
575 |
|
576 |
tmp = cpu_to_be64(l2_offset | QCOW_OFLAG_COPIED); |
577 |
if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), |
578 |
&tmp, sizeof(tmp)) != sizeof(tmp)) |
579 |
return NULL; |
580 |
|
581 |
/* allocate a new entry in the l2 cache */
|
582 |
|
583 |
min_index = l2_cache_new_entry(bs); |
584 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
585 |
|
586 |
if (old_l2_offset == 0) { |
587 |
/* if there was no old l2 table, clear the new table */
|
588 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
589 |
} else {
|
590 |
/* if there was an old l2 table, read it from the disk */
|
591 |
if (bdrv_pread(s->hd, old_l2_offset,
|
592 |
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
593 |
s->l2_size * sizeof(uint64_t))
|
594 |
return NULL; |
595 |
} |
596 |
/* write the l2 table to the file */
|
597 |
if (bdrv_pwrite(s->hd, l2_offset,
|
598 |
l2_table, s->l2_size * sizeof(uint64_t)) !=
|
599 |
s->l2_size * sizeof(uint64_t))
|
600 |
return NULL; |
601 |
|
602 |
/* update the l2 cache entry */
|
603 |
|
604 |
s->l2_cache_offsets[min_index] = l2_offset; |
605 |
s->l2_cache_counts[min_index] = 1;
|
606 |
|
607 |
return l2_table;
|
608 |
} |
609 |
|
610 |
static int size_to_clusters(BDRVQcowState *s, int64_t size) |
611 |
{ |
612 |
return (size + (s->cluster_size - 1)) >> s->cluster_bits; |
613 |
} |
614 |
|
615 |
static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, |
616 |
uint64_t *l2_table, uint64_t start, uint64_t mask) |
617 |
{ |
618 |
int i;
|
619 |
uint64_t offset = be64_to_cpu(l2_table[0]) & ~mask;
|
620 |
|
621 |
if (!offset)
|
622 |
return 0; |
623 |
|
624 |
for (i = start; i < start + nb_clusters; i++)
|
625 |
if (offset + i * cluster_size != (be64_to_cpu(l2_table[i]) & ~mask))
|
626 |
break;
|
627 |
|
628 |
return (i - start);
|
629 |
} |
630 |
|
631 |
static int count_contiguous_free_clusters(uint64_t nb_clusters, uint64_t *l2_table) |
632 |
{ |
633 |
int i = 0; |
634 |
|
635 |
while(nb_clusters-- && l2_table[i] == 0) |
636 |
i++; |
637 |
|
638 |
return i;
|
639 |
} |
640 |
|
641 |
/*
|
642 |
* get_cluster_offset
|
643 |
*
|
644 |
* For a given offset of the disk image, return cluster offset in
|
645 |
* qcow2 file.
|
646 |
*
|
647 |
* on entry, *num is the number of contiguous clusters we'd like to
|
648 |
* access following offset.
|
649 |
*
|
650 |
* on exit, *num is the number of contiguous clusters we can read.
|
651 |
*
|
652 |
* Return 1, if the offset is found
|
653 |
* Return 0, otherwise.
|
654 |
*
|
655 |
*/
|
656 |
|
657 |
static uint64_t get_cluster_offset(BlockDriverState *bs,
|
658 |
uint64_t offset, int *num)
|
659 |
{ |
660 |
BDRVQcowState *s = bs->opaque; |
661 |
int l1_index, l2_index;
|
662 |
uint64_t l2_offset, *l2_table, cluster_offset; |
663 |
int l1_bits, c;
|
664 |
int index_in_cluster, nb_available, nb_needed, nb_clusters;
|
665 |
|
666 |
index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1); |
667 |
nb_needed = *num + index_in_cluster; |
668 |
|
669 |
l1_bits = s->l2_bits + s->cluster_bits; |
670 |
|
671 |
/* compute how many bytes there are between the offset and
|
672 |
* the end of the l1 entry
|
673 |
*/
|
674 |
|
675 |
nb_available = (1 << l1_bits) - (offset & ((1 << l1_bits) - 1)); |
676 |
|
677 |
/* compute the number of available sectors */
|
678 |
|
679 |
nb_available = (nb_available >> 9) + index_in_cluster;
|
680 |
|
681 |
cluster_offset = 0;
|
682 |
|
683 |
/* seek the the l2 offset in the l1 table */
|
684 |
|
685 |
l1_index = offset >> l1_bits; |
686 |
if (l1_index >= s->l1_size)
|
687 |
goto out;
|
688 |
|
689 |
l2_offset = s->l1_table[l1_index]; |
690 |
|
691 |
/* seek the l2 table of the given l2 offset */
|
692 |
|
693 |
if (!l2_offset)
|
694 |
goto out;
|
695 |
|
696 |
/* load the l2 table in memory */
|
697 |
|
698 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
699 |
l2_table = l2_load(bs, l2_offset); |
700 |
if (l2_table == NULL) |
701 |
return 0; |
702 |
|
703 |
/* find the cluster offset for the given disk offset */
|
704 |
|
705 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
706 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
707 |
nb_clusters = size_to_clusters(s, nb_needed << 9);
|
708 |
|
709 |
if (!cluster_offset) {
|
710 |
/* how many empty clusters ? */
|
711 |
c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]); |
712 |
} else {
|
713 |
/* how many allocated clusters ? */
|
714 |
c = count_contiguous_clusters(nb_clusters, s->cluster_size, |
715 |
&l2_table[l2_index], 0, QCOW_OFLAG_COPIED);
|
716 |
} |
717 |
|
718 |
nb_available = (c * s->cluster_sectors); |
719 |
out:
|
720 |
if (nb_available > nb_needed)
|
721 |
nb_available = nb_needed; |
722 |
|
723 |
*num = nb_available - index_in_cluster; |
724 |
|
725 |
return cluster_offset & ~QCOW_OFLAG_COPIED;
|
726 |
} |
727 |
|
728 |
/*
|
729 |
* free_any_clusters
|
730 |
*
|
731 |
* free clusters according to its type: compressed or not
|
732 |
*
|
733 |
*/
|
734 |
|
735 |
static void free_any_clusters(BlockDriverState *bs, |
736 |
uint64_t cluster_offset, int nb_clusters)
|
737 |
{ |
738 |
BDRVQcowState *s = bs->opaque; |
739 |
|
740 |
/* free the cluster */
|
741 |
|
742 |
if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
743 |
int nb_csectors;
|
744 |
nb_csectors = ((cluster_offset >> s->csize_shift) & |
745 |
s->csize_mask) + 1;
|
746 |
free_clusters(bs, (cluster_offset & s->cluster_offset_mask) & ~511,
|
747 |
nb_csectors * 512);
|
748 |
return;
|
749 |
} |
750 |
|
751 |
free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits); |
752 |
|
753 |
return;
|
754 |
} |
755 |
|
756 |
/*
|
757 |
* get_cluster_table
|
758 |
*
|
759 |
* for a given disk offset, load (and allocate if needed)
|
760 |
* the l2 table.
|
761 |
*
|
762 |
* the l2 table offset in the qcow2 file and the cluster index
|
763 |
* in the l2 table are given to the caller.
|
764 |
*
|
765 |
*/
|
766 |
|
767 |
static int get_cluster_table(BlockDriverState *bs, uint64_t offset, |
768 |
uint64_t **new_l2_table, |
769 |
uint64_t *new_l2_offset, |
770 |
int *new_l2_index)
|
771 |
{ |
772 |
BDRVQcowState *s = bs->opaque; |
773 |
int l1_index, l2_index, ret;
|
774 |
uint64_t l2_offset, *l2_table; |
775 |
|
776 |
/* seek the the l2 offset in the l1 table */
|
777 |
|
778 |
l1_index = offset >> (s->l2_bits + s->cluster_bits); |
779 |
if (l1_index >= s->l1_size) {
|
780 |
ret = grow_l1_table(bs, l1_index + 1);
|
781 |
if (ret < 0) |
782 |
return 0; |
783 |
} |
784 |
l2_offset = s->l1_table[l1_index]; |
785 |
|
786 |
/* seek the l2 table of the given l2 offset */
|
787 |
|
788 |
if (l2_offset & QCOW_OFLAG_COPIED) {
|
789 |
/* load the l2 table in memory */
|
790 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
791 |
l2_table = l2_load(bs, l2_offset); |
792 |
if (l2_table == NULL) |
793 |
return 0; |
794 |
} else {
|
795 |
if (l2_offset)
|
796 |
free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t));
|
797 |
l2_table = l2_allocate(bs, l1_index); |
798 |
if (l2_table == NULL) |
799 |
return 0; |
800 |
l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED; |
801 |
} |
802 |
|
803 |
/* find the cluster offset for the given disk offset */
|
804 |
|
805 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
806 |
|
807 |
*new_l2_table = l2_table; |
808 |
*new_l2_offset = l2_offset; |
809 |
*new_l2_index = l2_index; |
810 |
|
811 |
return 1; |
812 |
} |
813 |
|
814 |
/*
|
815 |
* alloc_compressed_cluster_offset
|
816 |
*
|
817 |
* For a given offset of the disk image, return cluster offset in
|
818 |
* qcow2 file.
|
819 |
*
|
820 |
* If the offset is not found, allocate a new compressed cluster.
|
821 |
*
|
822 |
* Return the cluster offset if successful,
|
823 |
* Return 0, otherwise.
|
824 |
*
|
825 |
*/
|
826 |
|
827 |
static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs,
|
828 |
uint64_t offset, |
829 |
int compressed_size)
|
830 |
{ |
831 |
BDRVQcowState *s = bs->opaque; |
832 |
int l2_index, ret;
|
833 |
uint64_t l2_offset, *l2_table, cluster_offset; |
834 |
int nb_csectors;
|
835 |
|
836 |
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
837 |
if (ret == 0) |
838 |
return 0; |
839 |
|
840 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
841 |
if (cluster_offset & QCOW_OFLAG_COPIED)
|
842 |
return cluster_offset & ~QCOW_OFLAG_COPIED;
|
843 |
|
844 |
if (cluster_offset)
|
845 |
free_any_clusters(bs, cluster_offset, 1);
|
846 |
|
847 |
cluster_offset = alloc_bytes(bs, compressed_size); |
848 |
nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) - |
849 |
(cluster_offset >> 9);
|
850 |
|
851 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
852 |
((uint64_t)nb_csectors << s->csize_shift); |
853 |
|
854 |
/* update L2 table */
|
855 |
|
856 |
/* compressed clusters never have the copied flag */
|
857 |
|
858 |
l2_table[l2_index] = cpu_to_be64(cluster_offset); |
859 |
if (bdrv_pwrite(s->hd,
|
860 |
l2_offset + l2_index * sizeof(uint64_t),
|
861 |
l2_table + l2_index, |
862 |
sizeof(uint64_t)) != sizeof(uint64_t)) |
863 |
return 0; |
864 |
|
865 |
return cluster_offset;
|
866 |
} |
867 |
|
868 |
typedef struct QCowL2Meta |
869 |
{ |
870 |
uint64_t offset; |
871 |
int n_start;
|
872 |
int nb_available;
|
873 |
int nb_clusters;
|
874 |
} QCowL2Meta; |
875 |
|
876 |
static int alloc_cluster_link_l2(BlockDriverState *bs, uint64_t cluster_offset, |
877 |
QCowL2Meta *m) |
878 |
{ |
879 |
BDRVQcowState *s = bs->opaque; |
880 |
int i, j = 0, l2_index, ret; |
881 |
uint64_t *old_cluster, start_sect, l2_offset, *l2_table; |
882 |
|
883 |
if (m->nb_clusters == 0) |
884 |
return 0; |
885 |
|
886 |
old_cluster = qemu_malloc(m->nb_clusters * sizeof(uint64_t));
|
887 |
|
888 |
/* copy content of unmodified sectors */
|
889 |
start_sect = (m->offset & ~(s->cluster_size - 1)) >> 9; |
890 |
if (m->n_start) {
|
891 |
ret = copy_sectors(bs, start_sect, cluster_offset, 0, m->n_start);
|
892 |
if (ret < 0) |
893 |
goto err;
|
894 |
} |
895 |
|
896 |
if (m->nb_available & (s->cluster_sectors - 1)) { |
897 |
uint64_t end = m->nb_available & ~(uint64_t)(s->cluster_sectors - 1);
|
898 |
ret = copy_sectors(bs, start_sect + end, cluster_offset + (end << 9),
|
899 |
m->nb_available - end, s->cluster_sectors); |
900 |
if (ret < 0) |
901 |
goto err;
|
902 |
} |
903 |
|
904 |
ret = -EIO; |
905 |
/* update L2 table */
|
906 |
if (!get_cluster_table(bs, m->offset, &l2_table, &l2_offset, &l2_index))
|
907 |
goto err;
|
908 |
|
909 |
for (i = 0; i < m->nb_clusters; i++) { |
910 |
if(l2_table[l2_index + i] != 0) |
911 |
old_cluster[j++] = l2_table[l2_index + i]; |
912 |
|
913 |
l2_table[l2_index + i] = cpu_to_be64((cluster_offset + |
914 |
(i << s->cluster_bits)) | QCOW_OFLAG_COPIED); |
915 |
} |
916 |
|
917 |
if (bdrv_pwrite(s->hd, l2_offset + l2_index * sizeof(uint64_t), |
918 |
l2_table + l2_index, m->nb_clusters * sizeof(uint64_t)) !=
|
919 |
m->nb_clusters * sizeof(uint64_t))
|
920 |
goto err;
|
921 |
|
922 |
for (i = 0; i < j; i++) |
923 |
free_any_clusters(bs, old_cluster[i], 1);
|
924 |
|
925 |
ret = 0;
|
926 |
err:
|
927 |
qemu_free(old_cluster); |
928 |
return ret;
|
929 |
} |
930 |
|
931 |
/*
|
932 |
* alloc_cluster_offset
|
933 |
*
|
934 |
* For a given offset of the disk image, return cluster offset in
|
935 |
* qcow2 file.
|
936 |
*
|
937 |
* If the offset is not found, allocate a new cluster.
|
938 |
*
|
939 |
* Return the cluster offset if successful,
|
940 |
* Return 0, otherwise.
|
941 |
*
|
942 |
*/
|
943 |
|
944 |
static uint64_t alloc_cluster_offset(BlockDriverState *bs,
|
945 |
uint64_t offset, |
946 |
int n_start, int n_end, |
947 |
int *num, QCowL2Meta *m)
|
948 |
{ |
949 |
BDRVQcowState *s = bs->opaque; |
950 |
int l2_index, ret;
|
951 |
uint64_t l2_offset, *l2_table, cluster_offset; |
952 |
int nb_clusters, i = 0; |
953 |
|
954 |
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
955 |
if (ret == 0) |
956 |
return 0; |
957 |
|
958 |
nb_clusters = size_to_clusters(s, n_end << 9);
|
959 |
|
960 |
nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); |
961 |
|
962 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
963 |
|
964 |
/* We keep all QCOW_OFLAG_COPIED clusters */
|
965 |
|
966 |
if (cluster_offset & QCOW_OFLAG_COPIED) {
|
967 |
nb_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size, |
968 |
&l2_table[l2_index], 0, 0); |
969 |
|
970 |
cluster_offset &= ~QCOW_OFLAG_COPIED; |
971 |
m->nb_clusters = 0;
|
972 |
|
973 |
goto out;
|
974 |
} |
975 |
|
976 |
/* for the moment, multiple compressed clusters are not managed */
|
977 |
|
978 |
if (cluster_offset & QCOW_OFLAG_COMPRESSED)
|
979 |
nb_clusters = 1;
|
980 |
|
981 |
/* how many available clusters ? */
|
982 |
|
983 |
while (i < nb_clusters) {
|
984 |
i += count_contiguous_clusters(nb_clusters - i, s->cluster_size, |
985 |
&l2_table[l2_index], i, 0);
|
986 |
|
987 |
if(be64_to_cpu(l2_table[l2_index + i]))
|
988 |
break;
|
989 |
|
990 |
i += count_contiguous_free_clusters(nb_clusters - i, |
991 |
&l2_table[l2_index + i]); |
992 |
|
993 |
cluster_offset = be64_to_cpu(l2_table[l2_index + i]); |
994 |
|
995 |
if ((cluster_offset & QCOW_OFLAG_COPIED) ||
|
996 |
(cluster_offset & QCOW_OFLAG_COMPRESSED)) |
997 |
break;
|
998 |
} |
999 |
nb_clusters = i; |
1000 |
|
1001 |
/* allocate a new cluster */
|
1002 |
|
1003 |
cluster_offset = alloc_clusters(bs, nb_clusters * s->cluster_size); |
1004 |
|
1005 |
/* save info needed for meta data update */
|
1006 |
m->offset = offset; |
1007 |
m->n_start = n_start; |
1008 |
m->nb_clusters = nb_clusters; |
1009 |
|
1010 |
out:
|
1011 |
m->nb_available = MIN(nb_clusters << (s->cluster_bits - 9), n_end);
|
1012 |
|
1013 |
*num = m->nb_available - n_start; |
1014 |
|
1015 |
return cluster_offset;
|
1016 |
} |
1017 |
|
1018 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
1019 |
int nb_sectors, int *pnum) |
1020 |
{ |
1021 |
uint64_t cluster_offset; |
1022 |
|
1023 |
*pnum = nb_sectors; |
1024 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, pnum);
|
1025 |
|
1026 |
return (cluster_offset != 0); |
1027 |
} |
1028 |
|
1029 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
1030 |
const uint8_t *buf, int buf_size) |
1031 |
{ |
1032 |
z_stream strm1, *strm = &strm1; |
1033 |
int ret, out_len;
|
1034 |
|
1035 |
memset(strm, 0, sizeof(*strm)); |
1036 |
|
1037 |
strm->next_in = (uint8_t *)buf; |
1038 |
strm->avail_in = buf_size; |
1039 |
strm->next_out = out_buf; |
1040 |
strm->avail_out = out_buf_size; |
1041 |
|
1042 |
ret = inflateInit2(strm, -12);
|
1043 |
if (ret != Z_OK)
|
1044 |
return -1; |
1045 |
ret = inflate(strm, Z_FINISH); |
1046 |
out_len = strm->next_out - out_buf; |
1047 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
1048 |
out_len != out_buf_size) { |
1049 |
inflateEnd(strm); |
1050 |
return -1; |
1051 |
} |
1052 |
inflateEnd(strm); |
1053 |
return 0; |
1054 |
} |
1055 |
|
1056 |
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) |
1057 |
{ |
1058 |
int ret, csize, nb_csectors, sector_offset;
|
1059 |
uint64_t coffset; |
1060 |
|
1061 |
coffset = cluster_offset & s->cluster_offset_mask; |
1062 |
if (s->cluster_cache_offset != coffset) {
|
1063 |
nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
|
1064 |
sector_offset = coffset & 511;
|
1065 |
csize = nb_csectors * 512 - sector_offset;
|
1066 |
ret = bdrv_read(s->hd, coffset >> 9, s->cluster_data, nb_csectors);
|
1067 |
if (ret < 0) { |
1068 |
return -1; |
1069 |
} |
1070 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
1071 |
s->cluster_data + sector_offset, csize) < 0) {
|
1072 |
return -1; |
1073 |
} |
1074 |
s->cluster_cache_offset = coffset; |
1075 |
} |
1076 |
return 0; |
1077 |
} |
1078 |
|
1079 |
/* handle reading after the end of the backing file */
|
1080 |
static int backing_read1(BlockDriverState *bs, |
1081 |
int64_t sector_num, uint8_t *buf, int nb_sectors)
|
1082 |
{ |
1083 |
int n1;
|
1084 |
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
1085 |
return nb_sectors;
|
1086 |
if (sector_num >= bs->total_sectors)
|
1087 |
n1 = 0;
|
1088 |
else
|
1089 |
n1 = bs->total_sectors - sector_num; |
1090 |
memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1)); |
1091 |
return n1;
|
1092 |
} |
1093 |
|
1094 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
1095 |
uint8_t *buf, int nb_sectors)
|
1096 |
{ |
1097 |
BDRVQcowState *s = bs->opaque; |
1098 |
int ret, index_in_cluster, n, n1;
|
1099 |
uint64_t cluster_offset; |
1100 |
|
1101 |
while (nb_sectors > 0) { |
1102 |
n = nb_sectors; |
1103 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, &n);
|
1104 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
1105 |
if (!cluster_offset) {
|
1106 |
if (bs->backing_hd) {
|
1107 |
/* read from the base image */
|
1108 |
n1 = backing_read1(bs->backing_hd, sector_num, buf, n); |
1109 |
if (n1 > 0) { |
1110 |
ret = bdrv_read(bs->backing_hd, sector_num, buf, n1); |
1111 |
if (ret < 0) |
1112 |
return -1; |
1113 |
} |
1114 |
} else {
|
1115 |
memset(buf, 0, 512 * n); |
1116 |
} |
1117 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1118 |
if (decompress_cluster(s, cluster_offset) < 0) |
1119 |
return -1; |
1120 |
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); |
1121 |
} else {
|
1122 |
ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
1123 |
if (ret != n * 512) |
1124 |
return -1; |
1125 |
if (s->crypt_method) {
|
1126 |
encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
1127 |
&s->aes_decrypt_key); |
1128 |
} |
1129 |
} |
1130 |
nb_sectors -= n; |
1131 |
sector_num += n; |
1132 |
buf += n * 512;
|
1133 |
} |
1134 |
return 0; |
1135 |
} |
1136 |
|
1137 |
static int qcow_write(BlockDriverState *bs, int64_t sector_num, |
1138 |
const uint8_t *buf, int nb_sectors) |
1139 |
{ |
1140 |
BDRVQcowState *s = bs->opaque; |
1141 |
int ret, index_in_cluster, n;
|
1142 |
uint64_t cluster_offset; |
1143 |
int n_end;
|
1144 |
QCowL2Meta l2meta; |
1145 |
|
1146 |
while (nb_sectors > 0) { |
1147 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
1148 |
n_end = index_in_cluster + nb_sectors; |
1149 |
if (s->crypt_method &&
|
1150 |
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) |
1151 |
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
1152 |
cluster_offset = alloc_cluster_offset(bs, sector_num << 9,
|
1153 |
index_in_cluster, |
1154 |
n_end, &n, &l2meta); |
1155 |
if (!cluster_offset)
|
1156 |
return -1; |
1157 |
if (s->crypt_method) {
|
1158 |
encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1,
|
1159 |
&s->aes_encrypt_key); |
1160 |
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512,
|
1161 |
s->cluster_data, n * 512);
|
1162 |
} else {
|
1163 |
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
1164 |
} |
1165 |
if (ret != n * 512 || alloc_cluster_link_l2(bs, cluster_offset, &l2meta) < 0) { |
1166 |
free_any_clusters(bs, cluster_offset, l2meta.nb_clusters); |
1167 |
return -1; |
1168 |
} |
1169 |
nb_sectors -= n; |
1170 |
sector_num += n; |
1171 |
buf += n * 512;
|
1172 |
} |
1173 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
1174 |
return 0; |
1175 |
} |
1176 |
|
1177 |
typedef struct QCowAIOCB { |
1178 |
BlockDriverAIOCB common; |
1179 |
int64_t sector_num; |
1180 |
uint8_t *buf; |
1181 |
int nb_sectors;
|
1182 |
int n;
|
1183 |
uint64_t cluster_offset; |
1184 |
uint8_t *cluster_data; |
1185 |
BlockDriverAIOCB *hd_aiocb; |
1186 |
QEMUBH *bh; |
1187 |
QCowL2Meta l2meta; |
1188 |
} QCowAIOCB; |
1189 |
|
1190 |
static void qcow_aio_read_cb(void *opaque, int ret); |
1191 |
static void qcow_aio_read_bh(void *opaque) |
1192 |
{ |
1193 |
QCowAIOCB *acb = opaque; |
1194 |
qemu_bh_delete(acb->bh); |
1195 |
acb->bh = NULL;
|
1196 |
qcow_aio_read_cb(opaque, 0);
|
1197 |
} |
1198 |
|
1199 |
static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb) |
1200 |
{ |
1201 |
if (acb->bh)
|
1202 |
return -EIO;
|
1203 |
|
1204 |
acb->bh = qemu_bh_new(cb, acb); |
1205 |
if (!acb->bh)
|
1206 |
return -EIO;
|
1207 |
|
1208 |
qemu_bh_schedule(acb->bh); |
1209 |
|
1210 |
return 0; |
1211 |
} |
1212 |
|
1213 |
static void qcow_aio_read_cb(void *opaque, int ret) |
1214 |
{ |
1215 |
QCowAIOCB *acb = opaque; |
1216 |
BlockDriverState *bs = acb->common.bs; |
1217 |
BDRVQcowState *s = bs->opaque; |
1218 |
int index_in_cluster, n1;
|
1219 |
|
1220 |
acb->hd_aiocb = NULL;
|
1221 |
if (ret < 0) { |
1222 |
fail:
|
1223 |
acb->common.cb(acb->common.opaque, ret); |
1224 |
qemu_aio_release(acb); |
1225 |
return;
|
1226 |
} |
1227 |
|
1228 |
/* post process the read buffer */
|
1229 |
if (!acb->cluster_offset) {
|
1230 |
/* nothing to do */
|
1231 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1232 |
/* nothing to do */
|
1233 |
} else {
|
1234 |
if (s->crypt_method) {
|
1235 |
encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, |
1236 |
acb->n, 0,
|
1237 |
&s->aes_decrypt_key); |
1238 |
} |
1239 |
} |
1240 |
|
1241 |
acb->nb_sectors -= acb->n; |
1242 |
acb->sector_num += acb->n; |
1243 |
acb->buf += acb->n * 512;
|
1244 |
|
1245 |
if (acb->nb_sectors == 0) { |
1246 |
/* request completed */
|
1247 |
acb->common.cb(acb->common.opaque, 0);
|
1248 |
qemu_aio_release(acb); |
1249 |
return;
|
1250 |
} |
1251 |
|
1252 |
/* prepare next AIO request */
|
1253 |
acb->n = acb->nb_sectors; |
1254 |
acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, &acb->n);
|
1255 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
1256 |
|
1257 |
if (!acb->cluster_offset) {
|
1258 |
if (bs->backing_hd) {
|
1259 |
/* read from the base image */
|
1260 |
n1 = backing_read1(bs->backing_hd, acb->sector_num, |
1261 |
acb->buf, acb->n); |
1262 |
if (n1 > 0) { |
1263 |
acb->hd_aiocb = bdrv_aio_read(bs->backing_hd, acb->sector_num, |
1264 |
acb->buf, acb->n, qcow_aio_read_cb, acb); |
1265 |
if (acb->hd_aiocb == NULL) |
1266 |
goto fail;
|
1267 |
} else {
|
1268 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
1269 |
if (ret < 0) |
1270 |
goto fail;
|
1271 |
} |
1272 |
} else {
|
1273 |
/* Note: in this case, no need to wait */
|
1274 |
memset(acb->buf, 0, 512 * acb->n); |
1275 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
1276 |
if (ret < 0) |
1277 |
goto fail;
|
1278 |
} |
1279 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
1280 |
/* add AIO support for compressed blocks ? */
|
1281 |
if (decompress_cluster(s, acb->cluster_offset) < 0) |
1282 |
goto fail;
|
1283 |
memcpy(acb->buf, |
1284 |
s->cluster_cache + index_in_cluster * 512, 512 * acb->n); |
1285 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
1286 |
if (ret < 0) |
1287 |
goto fail;
|
1288 |
} else {
|
1289 |
if ((acb->cluster_offset & 511) != 0) { |
1290 |
ret = -EIO; |
1291 |
goto fail;
|
1292 |
} |
1293 |
acb->hd_aiocb = bdrv_aio_read(s->hd, |
1294 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
1295 |
acb->buf, acb->n, qcow_aio_read_cb, acb); |
1296 |
if (acb->hd_aiocb == NULL) |
1297 |
goto fail;
|
1298 |
} |
1299 |
} |
1300 |
|
1301 |
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
|
1302 |
int64_t sector_num, uint8_t *buf, int nb_sectors,
|
1303 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1304 |
{ |
1305 |
QCowAIOCB *acb; |
1306 |
|
1307 |
acb = qemu_aio_get(bs, cb, opaque); |
1308 |
if (!acb)
|
1309 |
return NULL; |
1310 |
acb->hd_aiocb = NULL;
|
1311 |
acb->sector_num = sector_num; |
1312 |
acb->buf = buf; |
1313 |
acb->nb_sectors = nb_sectors; |
1314 |
acb->n = 0;
|
1315 |
acb->cluster_offset = 0;
|
1316 |
acb->l2meta.nb_clusters = 0;
|
1317 |
return acb;
|
1318 |
} |
1319 |
|
1320 |
static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs,
|
1321 |
int64_t sector_num, uint8_t *buf, int nb_sectors,
|
1322 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1323 |
{ |
1324 |
QCowAIOCB *acb; |
1325 |
|
1326 |
acb = qcow_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque); |
1327 |
if (!acb)
|
1328 |
return NULL; |
1329 |
|
1330 |
qcow_aio_read_cb(acb, 0);
|
1331 |
return &acb->common;
|
1332 |
} |
1333 |
|
1334 |
static void qcow_aio_write_cb(void *opaque, int ret) |
1335 |
{ |
1336 |
QCowAIOCB *acb = opaque; |
1337 |
BlockDriverState *bs = acb->common.bs; |
1338 |
BDRVQcowState *s = bs->opaque; |
1339 |
int index_in_cluster;
|
1340 |
const uint8_t *src_buf;
|
1341 |
int n_end;
|
1342 |
|
1343 |
acb->hd_aiocb = NULL;
|
1344 |
|
1345 |
if (ret < 0) { |
1346 |
fail:
|
1347 |
acb->common.cb(acb->common.opaque, ret); |
1348 |
qemu_aio_release(acb); |
1349 |
return;
|
1350 |
} |
1351 |
|
1352 |
if (alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta) < 0) { |
1353 |
free_any_clusters(bs, acb->cluster_offset, acb->l2meta.nb_clusters); |
1354 |
goto fail;
|
1355 |
} |
1356 |
|
1357 |
acb->nb_sectors -= acb->n; |
1358 |
acb->sector_num += acb->n; |
1359 |
acb->buf += acb->n * 512;
|
1360 |
|
1361 |
if (acb->nb_sectors == 0) { |
1362 |
/* request completed */
|
1363 |
acb->common.cb(acb->common.opaque, 0);
|
1364 |
qemu_aio_release(acb); |
1365 |
return;
|
1366 |
} |
1367 |
|
1368 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
1369 |
n_end = index_in_cluster + acb->nb_sectors; |
1370 |
if (s->crypt_method &&
|
1371 |
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) |
1372 |
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
1373 |
|
1374 |
acb->cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9,
|
1375 |
index_in_cluster, |
1376 |
n_end, &acb->n, &acb->l2meta); |
1377 |
if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) { |
1378 |
ret = -EIO; |
1379 |
goto fail;
|
1380 |
} |
1381 |
if (s->crypt_method) {
|
1382 |
if (!acb->cluster_data) {
|
1383 |
acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * |
1384 |
s->cluster_size); |
1385 |
} |
1386 |
encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, |
1387 |
acb->n, 1, &s->aes_encrypt_key);
|
1388 |
src_buf = acb->cluster_data; |
1389 |
} else {
|
1390 |
src_buf = acb->buf; |
1391 |
} |
1392 |
acb->hd_aiocb = bdrv_aio_write(s->hd, |
1393 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
1394 |
src_buf, acb->n, |
1395 |
qcow_aio_write_cb, acb); |
1396 |
if (acb->hd_aiocb == NULL) |
1397 |
goto fail;
|
1398 |
} |
1399 |
|
1400 |
static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs,
|
1401 |
int64_t sector_num, const uint8_t *buf, int nb_sectors, |
1402 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1403 |
{ |
1404 |
BDRVQcowState *s = bs->opaque; |
1405 |
QCowAIOCB *acb; |
1406 |
|
1407 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
1408 |
|
1409 |
acb = qcow_aio_setup(bs, sector_num, (uint8_t*)buf, nb_sectors, cb, opaque); |
1410 |
if (!acb)
|
1411 |
return NULL; |
1412 |
|
1413 |
qcow_aio_write_cb(acb, 0);
|
1414 |
return &acb->common;
|
1415 |
} |
1416 |
|
1417 |
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) |
1418 |
{ |
1419 |
QCowAIOCB *acb = (QCowAIOCB *)blockacb; |
1420 |
if (acb->hd_aiocb)
|
1421 |
bdrv_aio_cancel(acb->hd_aiocb); |
1422 |
qemu_aio_release(acb); |
1423 |
} |
1424 |
|
1425 |
static void qcow_close(BlockDriverState *bs) |
1426 |
{ |
1427 |
BDRVQcowState *s = bs->opaque; |
1428 |
qemu_free(s->l1_table); |
1429 |
qemu_free(s->l2_cache); |
1430 |
qemu_free(s->cluster_cache); |
1431 |
qemu_free(s->cluster_data); |
1432 |
refcount_close(bs); |
1433 |
bdrv_delete(s->hd); |
1434 |
} |
1435 |
|
1436 |
/* XXX: use std qcow open function ? */
|
1437 |
typedef struct QCowCreateState { |
1438 |
int cluster_size;
|
1439 |
int cluster_bits;
|
1440 |
uint16_t *refcount_block; |
1441 |
uint64_t *refcount_table; |
1442 |
int64_t l1_table_offset; |
1443 |
int64_t refcount_table_offset; |
1444 |
int64_t refcount_block_offset; |
1445 |
} QCowCreateState; |
1446 |
|
1447 |
static void create_refcount_update(QCowCreateState *s, |
1448 |
int64_t offset, int64_t size) |
1449 |
{ |
1450 |
int refcount;
|
1451 |
int64_t start, last, cluster_offset; |
1452 |
uint16_t *p; |
1453 |
|
1454 |
start = offset & ~(s->cluster_size - 1);
|
1455 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
1456 |
for(cluster_offset = start; cluster_offset <= last;
|
1457 |
cluster_offset += s->cluster_size) { |
1458 |
p = &s->refcount_block[cluster_offset >> s->cluster_bits]; |
1459 |
refcount = be16_to_cpu(*p); |
1460 |
refcount++; |
1461 |
*p = cpu_to_be16(refcount); |
1462 |
} |
1463 |
} |
1464 |
|
1465 |
static int qcow_create(const char *filename, int64_t total_size, |
1466 |
const char *backing_file, int flags) |
1467 |
{ |
1468 |
int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
|
1469 |
QCowHeader header; |
1470 |
uint64_t tmp, offset; |
1471 |
QCowCreateState s1, *s = &s1; |
1472 |
|
1473 |
memset(s, 0, sizeof(*s)); |
1474 |
|
1475 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
1476 |
if (fd < 0) |
1477 |
return -1; |
1478 |
memset(&header, 0, sizeof(header)); |
1479 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
1480 |
header.version = cpu_to_be32(QCOW_VERSION); |
1481 |
header.size = cpu_to_be64(total_size * 512);
|
1482 |
header_size = sizeof(header);
|
1483 |
backing_filename_len = 0;
|
1484 |
if (backing_file) {
|
1485 |
header.backing_file_offset = cpu_to_be64(header_size); |
1486 |
backing_filename_len = strlen(backing_file); |
1487 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
1488 |
header_size += backing_filename_len; |
1489 |
} |
1490 |
s->cluster_bits = 12; /* 4 KB clusters */ |
1491 |
s->cluster_size = 1 << s->cluster_bits;
|
1492 |
header.cluster_bits = cpu_to_be32(s->cluster_bits); |
1493 |
header_size = (header_size + 7) & ~7; |
1494 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
1495 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
1496 |
} else {
|
1497 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
1498 |
} |
1499 |
l2_bits = s->cluster_bits - 3;
|
1500 |
shift = s->cluster_bits + l2_bits; |
1501 |
l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift); |
1502 |
offset = align_offset(header_size, s->cluster_size); |
1503 |
s->l1_table_offset = offset; |
1504 |
header.l1_table_offset = cpu_to_be64(s->l1_table_offset); |
1505 |
header.l1_size = cpu_to_be32(l1_size); |
1506 |
offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
|
1507 |
|
1508 |
s->refcount_table = qemu_mallocz(s->cluster_size); |
1509 |
s->refcount_block = qemu_mallocz(s->cluster_size); |
1510 |
|
1511 |
s->refcount_table_offset = offset; |
1512 |
header.refcount_table_offset = cpu_to_be64(offset); |
1513 |
header.refcount_table_clusters = cpu_to_be32(1);
|
1514 |
offset += s->cluster_size; |
1515 |
|
1516 |
s->refcount_table[0] = cpu_to_be64(offset);
|
1517 |
s->refcount_block_offset = offset; |
1518 |
offset += s->cluster_size; |
1519 |
|
1520 |
/* update refcounts */
|
1521 |
create_refcount_update(s, 0, header_size);
|
1522 |
create_refcount_update(s, s->l1_table_offset, l1_size * sizeof(uint64_t));
|
1523 |
create_refcount_update(s, s->refcount_table_offset, s->cluster_size); |
1524 |
create_refcount_update(s, s->refcount_block_offset, s->cluster_size); |
1525 |
|
1526 |
/* write all the data */
|
1527 |
write(fd, &header, sizeof(header));
|
1528 |
if (backing_file) {
|
1529 |
write(fd, backing_file, backing_filename_len); |
1530 |
} |
1531 |
lseek(fd, s->l1_table_offset, SEEK_SET); |
1532 |
tmp = 0;
|
1533 |
for(i = 0;i < l1_size; i++) { |
1534 |
write(fd, &tmp, sizeof(tmp));
|
1535 |
} |
1536 |
lseek(fd, s->refcount_table_offset, SEEK_SET); |
1537 |
write(fd, s->refcount_table, s->cluster_size); |
1538 |
|
1539 |
lseek(fd, s->refcount_block_offset, SEEK_SET); |
1540 |
write(fd, s->refcount_block, s->cluster_size); |
1541 |
|
1542 |
qemu_free(s->refcount_table); |
1543 |
qemu_free(s->refcount_block); |
1544 |
close(fd); |
1545 |
return 0; |
1546 |
} |
1547 |
|
1548 |
static int qcow_make_empty(BlockDriverState *bs) |
1549 |
{ |
1550 |
#if 0
|
1551 |
/* XXX: not correct */
|
1552 |
BDRVQcowState *s = bs->opaque;
|
1553 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
1554 |
int ret;
|
1555 |
|
1556 |
memset(s->l1_table, 0, l1_length);
|
1557 |
if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
1558 |
return -1;
|
1559 |
ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length);
|
1560 |
if (ret < 0)
|
1561 |
return ret;
|
1562 |
|
1563 |
l2_cache_reset(bs);
|
1564 |
#endif
|
1565 |
return 0; |
1566 |
} |
1567 |
|
1568 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
1569 |
tables to avoid losing bytes in alignment */
|
1570 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
1571 |
const uint8_t *buf, int nb_sectors) |
1572 |
{ |
1573 |
BDRVQcowState *s = bs->opaque; |
1574 |
z_stream strm; |
1575 |
int ret, out_len;
|
1576 |
uint8_t *out_buf; |
1577 |
uint64_t cluster_offset; |
1578 |
|
1579 |
if (nb_sectors == 0) { |
1580 |
/* align end of file to a sector boundary to ease reading with
|
1581 |
sector based I/Os */
|
1582 |
cluster_offset = bdrv_getlength(s->hd); |
1583 |
cluster_offset = (cluster_offset + 511) & ~511; |
1584 |
bdrv_truncate(s->hd, cluster_offset); |
1585 |
return 0; |
1586 |
} |
1587 |
|
1588 |
if (nb_sectors != s->cluster_sectors)
|
1589 |
return -EINVAL;
|
1590 |
|
1591 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
1592 |
|
1593 |
/* best compression, small window, no zlib header */
|
1594 |
memset(&strm, 0, sizeof(strm)); |
1595 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
1596 |
Z_DEFLATED, -12,
|
1597 |
9, Z_DEFAULT_STRATEGY);
|
1598 |
if (ret != 0) { |
1599 |
qemu_free(out_buf); |
1600 |
return -1; |
1601 |
} |
1602 |
|
1603 |
strm.avail_in = s->cluster_size; |
1604 |
strm.next_in = (uint8_t *)buf; |
1605 |
strm.avail_out = s->cluster_size; |
1606 |
strm.next_out = out_buf; |
1607 |
|
1608 |
ret = deflate(&strm, Z_FINISH); |
1609 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
1610 |
qemu_free(out_buf); |
1611 |
deflateEnd(&strm); |
1612 |
return -1; |
1613 |
} |
1614 |
out_len = strm.next_out - out_buf; |
1615 |
|
1616 |
deflateEnd(&strm); |
1617 |
|
1618 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
1619 |
/* could not compress: write normal cluster */
|
1620 |
qcow_write(bs, sector_num, buf, s->cluster_sectors); |
1621 |
} else {
|
1622 |
cluster_offset = alloc_compressed_cluster_offset(bs, sector_num << 9,
|
1623 |
out_len); |
1624 |
if (!cluster_offset)
|
1625 |
return -1; |
1626 |
cluster_offset &= s->cluster_offset_mask; |
1627 |
if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
|
1628 |
qemu_free(out_buf); |
1629 |
return -1; |
1630 |
} |
1631 |
} |
1632 |
|
1633 |
qemu_free(out_buf); |
1634 |
return 0; |
1635 |
} |
1636 |
|
1637 |
static void qcow_flush(BlockDriverState *bs) |
1638 |
{ |
1639 |
BDRVQcowState *s = bs->opaque; |
1640 |
bdrv_flush(s->hd); |
1641 |
} |
1642 |
|
1643 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
1644 |
{ |
1645 |
BDRVQcowState *s = bs->opaque; |
1646 |
bdi->cluster_size = s->cluster_size; |
1647 |
bdi->vm_state_offset = (int64_t)s->l1_vm_state_index << |
1648 |
(s->cluster_bits + s->l2_bits); |
1649 |
bdi->highest_alloc = s->highest_alloc << s->cluster_bits; |
1650 |
bdi->num_free_bytes = s->nc_free << s->cluster_bits; |
1651 |
return 0; |
1652 |
} |
1653 |
|
1654 |
/*********************************************************/
|
1655 |
/* snapshot support */
|
1656 |
|
1657 |
/* update the refcounts of snapshots and the copied flag */
|
1658 |
static int update_snapshot_refcount(BlockDriverState *bs, |
1659 |
int64_t l1_table_offset, |
1660 |
int l1_size,
|
1661 |
int addend)
|
1662 |
{ |
1663 |
BDRVQcowState *s = bs->opaque; |
1664 |
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; |
1665 |
int64_t old_offset, old_l2_offset; |
1666 |
int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount;
|
1667 |
|
1668 |
l2_cache_reset(bs); |
1669 |
|
1670 |
l2_table = NULL;
|
1671 |
l1_table = NULL;
|
1672 |
l1_size2 = l1_size * sizeof(uint64_t);
|
1673 |
l1_allocated = 0;
|
1674 |
if (l1_table_offset != s->l1_table_offset) {
|
1675 |
l1_table = qemu_malloc(l1_size2); |
1676 |
l1_allocated = 1;
|
1677 |
if (bdrv_pread(s->hd, l1_table_offset,
|
1678 |
l1_table, l1_size2) != l1_size2) |
1679 |
goto fail;
|
1680 |
for(i = 0;i < l1_size; i++) |
1681 |
be64_to_cpus(&l1_table[i]); |
1682 |
} else {
|
1683 |
assert(l1_size == s->l1_size); |
1684 |
l1_table = s->l1_table; |
1685 |
l1_allocated = 0;
|
1686 |
} |
1687 |
|
1688 |
l2_size = s->l2_size * sizeof(uint64_t);
|
1689 |
l2_table = qemu_malloc(l2_size); |
1690 |
l1_modified = 0;
|
1691 |
for(i = 0; i < l1_size; i++) { |
1692 |
l2_offset = l1_table[i]; |
1693 |
if (l2_offset) {
|
1694 |
old_l2_offset = l2_offset; |
1695 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
1696 |
l2_modified = 0;
|
1697 |
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
|
1698 |
goto fail;
|
1699 |
for(j = 0; j < s->l2_size; j++) { |
1700 |
offset = be64_to_cpu(l2_table[j]); |
1701 |
if (offset != 0) { |
1702 |
old_offset = offset; |
1703 |
offset &= ~QCOW_OFLAG_COPIED; |
1704 |
if (offset & QCOW_OFLAG_COMPRESSED) {
|
1705 |
nb_csectors = ((offset >> s->csize_shift) & |
1706 |
s->csize_mask) + 1;
|
1707 |
if (addend != 0) |
1708 |
update_refcount(bs, (offset & s->cluster_offset_mask) & ~511,
|
1709 |
nb_csectors * 512, addend);
|
1710 |
/* compressed clusters are never modified */
|
1711 |
refcount = 2;
|
1712 |
} else {
|
1713 |
if (addend != 0) { |
1714 |
refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend); |
1715 |
} else {
|
1716 |
refcount = get_refcount(bs, offset >> s->cluster_bits); |
1717 |
} |
1718 |
} |
1719 |
|
1720 |
if (refcount == 1) { |
1721 |
offset |= QCOW_OFLAG_COPIED; |
1722 |
} |
1723 |
if (offset != old_offset) {
|
1724 |
l2_table[j] = cpu_to_be64(offset); |
1725 |
l2_modified = 1;
|
1726 |
} |
1727 |
} |
1728 |
} |
1729 |
if (l2_modified) {
|
1730 |
if (bdrv_pwrite(s->hd,
|
1731 |
l2_offset, l2_table, l2_size) != l2_size) |
1732 |
goto fail;
|
1733 |
} |
1734 |
|
1735 |
if (addend != 0) { |
1736 |
refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); |
1737 |
} else {
|
1738 |
refcount = get_refcount(bs, l2_offset >> s->cluster_bits); |
1739 |
} |
1740 |
if (refcount == 1) { |
1741 |
l2_offset |= QCOW_OFLAG_COPIED; |
1742 |
} |
1743 |
if (l2_offset != old_l2_offset) {
|
1744 |
l1_table[i] = l2_offset; |
1745 |
l1_modified = 1;
|
1746 |
} |
1747 |
} |
1748 |
} |
1749 |
if (l1_modified) {
|
1750 |
for(i = 0; i < l1_size; i++) |
1751 |
cpu_to_be64s(&l1_table[i]); |
1752 |
if (bdrv_pwrite(s->hd, l1_table_offset, l1_table,
|
1753 |
l1_size2) != l1_size2) |
1754 |
goto fail;
|
1755 |
for(i = 0; i < l1_size; i++) |
1756 |
be64_to_cpus(&l1_table[i]); |
1757 |
} |
1758 |
if (l1_allocated)
|
1759 |
qemu_free(l1_table); |
1760 |
qemu_free(l2_table); |
1761 |
return 0; |
1762 |
fail:
|
1763 |
if (l1_allocated)
|
1764 |
qemu_free(l1_table); |
1765 |
qemu_free(l2_table); |
1766 |
return -EIO;
|
1767 |
} |
1768 |
|
1769 |
static void qcow_free_snapshots(BlockDriverState *bs) |
1770 |
{ |
1771 |
BDRVQcowState *s = bs->opaque; |
1772 |
int i;
|
1773 |
|
1774 |
for(i = 0; i < s->nb_snapshots; i++) { |
1775 |
qemu_free(s->snapshots[i].name); |
1776 |
qemu_free(s->snapshots[i].id_str); |
1777 |
} |
1778 |
qemu_free(s->snapshots); |
1779 |
s->snapshots = NULL;
|
1780 |
s->nb_snapshots = 0;
|
1781 |
} |
1782 |
|
1783 |
static int qcow_read_snapshots(BlockDriverState *bs) |
1784 |
{ |
1785 |
BDRVQcowState *s = bs->opaque; |
1786 |
QCowSnapshotHeader h; |
1787 |
QCowSnapshot *sn; |
1788 |
int i, id_str_size, name_size;
|
1789 |
int64_t offset; |
1790 |
uint32_t extra_data_size; |
1791 |
|
1792 |
if (!s->nb_snapshots) {
|
1793 |
s->snapshots = NULL;
|
1794 |
s->snapshots_size = 0;
|
1795 |
return 0; |
1796 |
} |
1797 |
|
1798 |
offset = s->snapshots_offset; |
1799 |
s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot));
|
1800 |
for(i = 0; i < s->nb_snapshots; i++) { |
1801 |
offset = align_offset(offset, 8);
|
1802 |
if (bdrv_pread(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
1803 |
goto fail;
|
1804 |
offset += sizeof(h);
|
1805 |
sn = s->snapshots + i; |
1806 |
sn->l1_table_offset = be64_to_cpu(h.l1_table_offset); |
1807 |
sn->l1_size = be32_to_cpu(h.l1_size); |
1808 |
sn->vm_state_size = be32_to_cpu(h.vm_state_size); |
1809 |
sn->date_sec = be32_to_cpu(h.date_sec); |
1810 |
sn->date_nsec = be32_to_cpu(h.date_nsec); |
1811 |
sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec); |
1812 |
extra_data_size = be32_to_cpu(h.extra_data_size); |
1813 |
|
1814 |
id_str_size = be16_to_cpu(h.id_str_size); |
1815 |
name_size = be16_to_cpu(h.name_size); |
1816 |
|
1817 |
offset += extra_data_size; |
1818 |
|
1819 |
sn->id_str = qemu_malloc(id_str_size + 1);
|
1820 |
if (bdrv_pread(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
1821 |
goto fail;
|
1822 |
offset += id_str_size; |
1823 |
sn->id_str[id_str_size] = '\0';
|
1824 |
|
1825 |
sn->name = qemu_malloc(name_size + 1);
|
1826 |
if (bdrv_pread(s->hd, offset, sn->name, name_size) != name_size)
|
1827 |
goto fail;
|
1828 |
offset += name_size; |
1829 |
sn->name[name_size] = '\0';
|
1830 |
} |
1831 |
s->snapshots_size = offset - s->snapshots_offset; |
1832 |
return 0; |
1833 |
fail:
|
1834 |
qcow_free_snapshots(bs); |
1835 |
return -1; |
1836 |
} |
1837 |
|
1838 |
/* add at the end of the file a new list of snapshots */
|
1839 |
static int qcow_write_snapshots(BlockDriverState *bs) |
1840 |
{ |
1841 |
BDRVQcowState *s = bs->opaque; |
1842 |
QCowSnapshot *sn; |
1843 |
QCowSnapshotHeader h; |
1844 |
int i, name_size, id_str_size, snapshots_size;
|
1845 |
uint64_t data64; |
1846 |
uint32_t data32; |
1847 |
int64_t offset, snapshots_offset; |
1848 |
|
1849 |
/* compute the size of the snapshots */
|
1850 |
offset = 0;
|
1851 |
for(i = 0; i < s->nb_snapshots; i++) { |
1852 |
sn = s->snapshots + i; |
1853 |
offset = align_offset(offset, 8);
|
1854 |
offset += sizeof(h);
|
1855 |
offset += strlen(sn->id_str); |
1856 |
offset += strlen(sn->name); |
1857 |
} |
1858 |
snapshots_size = offset; |
1859 |
|
1860 |
snapshots_offset = alloc_clusters(bs, snapshots_size); |
1861 |
offset = snapshots_offset; |
1862 |
|
1863 |
for(i = 0; i < s->nb_snapshots; i++) { |
1864 |
sn = s->snapshots + i; |
1865 |
memset(&h, 0, sizeof(h)); |
1866 |
h.l1_table_offset = cpu_to_be64(sn->l1_table_offset); |
1867 |
h.l1_size = cpu_to_be32(sn->l1_size); |
1868 |
h.vm_state_size = cpu_to_be32(sn->vm_state_size); |
1869 |
h.date_sec = cpu_to_be32(sn->date_sec); |
1870 |
h.date_nsec = cpu_to_be32(sn->date_nsec); |
1871 |
h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec); |
1872 |
|
1873 |
id_str_size = strlen(sn->id_str); |
1874 |
name_size = strlen(sn->name); |
1875 |
h.id_str_size = cpu_to_be16(id_str_size); |
1876 |
h.name_size = cpu_to_be16(name_size); |
1877 |
offset = align_offset(offset, 8);
|
1878 |
if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
1879 |
goto fail;
|
1880 |
offset += sizeof(h);
|
1881 |
if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
1882 |
goto fail;
|
1883 |
offset += id_str_size; |
1884 |
if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size)
|
1885 |
goto fail;
|
1886 |
offset += name_size; |
1887 |
} |
1888 |
|
1889 |
/* update the various header fields */
|
1890 |
data64 = cpu_to_be64(snapshots_offset); |
1891 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset),
|
1892 |
&data64, sizeof(data64)) != sizeof(data64)) |
1893 |
goto fail;
|
1894 |
data32 = cpu_to_be32(s->nb_snapshots); |
1895 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots),
|
1896 |
&data32, sizeof(data32)) != sizeof(data32)) |
1897 |
goto fail;
|
1898 |
|
1899 |
/* free the old snapshot table */
|
1900 |
free_clusters(bs, s->snapshots_offset, s->snapshots_size); |
1901 |
s->snapshots_offset = snapshots_offset; |
1902 |
s->snapshots_size = snapshots_size; |
1903 |
return 0; |
1904 |
fail:
|
1905 |
return -1; |
1906 |
} |
1907 |
|
1908 |
static void find_new_snapshot_id(BlockDriverState *bs, |
1909 |
char *id_str, int id_str_size) |
1910 |
{ |
1911 |
BDRVQcowState *s = bs->opaque; |
1912 |
QCowSnapshot *sn; |
1913 |
int i, id, id_max = 0; |
1914 |
|
1915 |
for(i = 0; i < s->nb_snapshots; i++) { |
1916 |
sn = s->snapshots + i; |
1917 |
id = strtoul(sn->id_str, NULL, 10); |
1918 |
if (id > id_max)
|
1919 |
id_max = id; |
1920 |
} |
1921 |
snprintf(id_str, id_str_size, "%d", id_max + 1); |
1922 |
} |
1923 |
|
1924 |
static int find_snapshot_by_id(BlockDriverState *bs, const char *id_str) |
1925 |
{ |
1926 |
BDRVQcowState *s = bs->opaque; |
1927 |
int i;
|
1928 |
|
1929 |
for(i = 0; i < s->nb_snapshots; i++) { |
1930 |
if (!strcmp(s->snapshots[i].id_str, id_str))
|
1931 |
return i;
|
1932 |
} |
1933 |
return -1; |
1934 |
} |
1935 |
|
1936 |
static int find_snapshot_by_id_or_name(BlockDriverState *bs, const char *name) |
1937 |
{ |
1938 |
BDRVQcowState *s = bs->opaque; |
1939 |
int i, ret;
|
1940 |
|
1941 |
ret = find_snapshot_by_id(bs, name); |
1942 |
if (ret >= 0) |
1943 |
return ret;
|
1944 |
for(i = 0; i < s->nb_snapshots; i++) { |
1945 |
if (!strcmp(s->snapshots[i].name, name))
|
1946 |
return i;
|
1947 |
} |
1948 |
return -1; |
1949 |
} |
1950 |
|
1951 |
/* if no id is provided, a new one is constructed */
|
1952 |
static int qcow_snapshot_create(BlockDriverState *bs, |
1953 |
QEMUSnapshotInfo *sn_info) |
1954 |
{ |
1955 |
BDRVQcowState *s = bs->opaque; |
1956 |
QCowSnapshot *snapshots1, sn1, *sn = &sn1; |
1957 |
int i, ret;
|
1958 |
uint64_t *l1_table = NULL;
|
1959 |
|
1960 |
memset(sn, 0, sizeof(*sn)); |
1961 |
|
1962 |
if (sn_info->id_str[0] == '\0') { |
1963 |
/* compute a new id */
|
1964 |
find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
|
1965 |
} |
1966 |
|
1967 |
/* check that the ID is unique */
|
1968 |
if (find_snapshot_by_id(bs, sn_info->id_str) >= 0) |
1969 |
return -ENOENT;
|
1970 |
|
1971 |
sn->id_str = qemu_strdup(sn_info->id_str); |
1972 |
if (!sn->id_str)
|
1973 |
goto fail;
|
1974 |
sn->name = qemu_strdup(sn_info->name); |
1975 |
if (!sn->name)
|
1976 |
goto fail;
|
1977 |
sn->vm_state_size = sn_info->vm_state_size; |
1978 |
sn->date_sec = sn_info->date_sec; |
1979 |
sn->date_nsec = sn_info->date_nsec; |
1980 |
sn->vm_clock_nsec = sn_info->vm_clock_nsec; |
1981 |
|
1982 |
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
|
1983 |
if (ret < 0) |
1984 |
goto fail;
|
1985 |
|
1986 |
/* create the L1 table of the snapshot */
|
1987 |
sn->l1_table_offset = alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
|
1988 |
sn->l1_size = s->l1_size; |
1989 |
|
1990 |
l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
|
1991 |
for(i = 0; i < s->l1_size; i++) { |
1992 |
l1_table[i] = cpu_to_be64(s->l1_table[i]); |
1993 |
} |
1994 |
if (bdrv_pwrite(s->hd, sn->l1_table_offset,
|
1995 |
l1_table, s->l1_size * sizeof(uint64_t)) !=
|
1996 |
(s->l1_size * sizeof(uint64_t)))
|
1997 |
goto fail;
|
1998 |
qemu_free(l1_table); |
1999 |
l1_table = NULL;
|
2000 |
|
2001 |
snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot)); |
2002 |
if (s->snapshots) {
|
2003 |
memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot));
|
2004 |
qemu_free(s->snapshots); |
2005 |
} |
2006 |
s->snapshots = snapshots1; |
2007 |
s->snapshots[s->nb_snapshots++] = *sn; |
2008 |
|
2009 |
if (qcow_write_snapshots(bs) < 0) |
2010 |
goto fail;
|
2011 |
#ifdef DEBUG_ALLOC
|
2012 |
check_refcounts(bs); |
2013 |
#endif
|
2014 |
return 0; |
2015 |
fail:
|
2016 |
qemu_free(sn->name); |
2017 |
qemu_free(l1_table); |
2018 |
return -1; |
2019 |
} |
2020 |
|
2021 |
/* copy the snapshot 'snapshot_name' into the current disk image */
|
2022 |
static int qcow_snapshot_goto(BlockDriverState *bs, |
2023 |
const char *snapshot_id) |
2024 |
{ |
2025 |
BDRVQcowState *s = bs->opaque; |
2026 |
QCowSnapshot *sn; |
2027 |
int i, snapshot_index, l1_size2;
|
2028 |
|
2029 |
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
2030 |
if (snapshot_index < 0) |
2031 |
return -ENOENT;
|
2032 |
sn = &s->snapshots[snapshot_index]; |
2033 |
|
2034 |
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1) < 0) |
2035 |
goto fail;
|
2036 |
|
2037 |
if (grow_l1_table(bs, sn->l1_size) < 0) |
2038 |
goto fail;
|
2039 |
|
2040 |
s->l1_size = sn->l1_size; |
2041 |
l1_size2 = s->l1_size * sizeof(uint64_t);
|
2042 |
/* copy the snapshot l1 table to the current l1 table */
|
2043 |
if (bdrv_pread(s->hd, sn->l1_table_offset,
|
2044 |
s->l1_table, l1_size2) != l1_size2) |
2045 |
goto fail;
|
2046 |
if (bdrv_pwrite(s->hd, s->l1_table_offset,
|
2047 |
s->l1_table, l1_size2) != l1_size2) |
2048 |
goto fail;
|
2049 |
for(i = 0;i < s->l1_size; i++) { |
2050 |
be64_to_cpus(&s->l1_table[i]); |
2051 |
} |
2052 |
|
2053 |
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1) < 0) |
2054 |
goto fail;
|
2055 |
|
2056 |
#ifdef DEBUG_ALLOC
|
2057 |
check_refcounts(bs); |
2058 |
#endif
|
2059 |
return 0; |
2060 |
fail:
|
2061 |
return -EIO;
|
2062 |
} |
2063 |
|
2064 |
static int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) |
2065 |
{ |
2066 |
BDRVQcowState *s = bs->opaque; |
2067 |
QCowSnapshot *sn; |
2068 |
int snapshot_index, ret;
|
2069 |
|
2070 |
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
2071 |
if (snapshot_index < 0) |
2072 |
return -ENOENT;
|
2073 |
sn = &s->snapshots[snapshot_index]; |
2074 |
|
2075 |
ret = update_snapshot_refcount(bs, sn->l1_table_offset, sn->l1_size, -1);
|
2076 |
if (ret < 0) |
2077 |
return ret;
|
2078 |
/* must update the copied flag on the current cluster offsets */
|
2079 |
ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0);
|
2080 |
if (ret < 0) |
2081 |
return ret;
|
2082 |
free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t));
|
2083 |
|
2084 |
qemu_free(sn->id_str); |
2085 |
qemu_free(sn->name); |
2086 |
memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn)); |
2087 |
s->nb_snapshots--; |
2088 |
ret = qcow_write_snapshots(bs); |
2089 |
if (ret < 0) { |
2090 |
/* XXX: restore snapshot if error ? */
|
2091 |
return ret;
|
2092 |
} |
2093 |
#ifdef DEBUG_ALLOC
|
2094 |
check_refcounts(bs); |
2095 |
#endif
|
2096 |
return 0; |
2097 |
} |
2098 |
|
2099 |
static int qcow_snapshot_list(BlockDriverState *bs, |
2100 |
QEMUSnapshotInfo **psn_tab) |
2101 |
{ |
2102 |
BDRVQcowState *s = bs->opaque; |
2103 |
QEMUSnapshotInfo *sn_tab, *sn_info; |
2104 |
QCowSnapshot *sn; |
2105 |
int i;
|
2106 |
|
2107 |
sn_tab = qemu_mallocz(s->nb_snapshots * sizeof(QEMUSnapshotInfo));
|
2108 |
for(i = 0; i < s->nb_snapshots; i++) { |
2109 |
sn_info = sn_tab + i; |
2110 |
sn = s->snapshots + i; |
2111 |
pstrcpy(sn_info->id_str, sizeof(sn_info->id_str),
|
2112 |
sn->id_str); |
2113 |
pstrcpy(sn_info->name, sizeof(sn_info->name),
|
2114 |
sn->name); |
2115 |
sn_info->vm_state_size = sn->vm_state_size; |
2116 |
sn_info->date_sec = sn->date_sec; |
2117 |
sn_info->date_nsec = sn->date_nsec; |
2118 |
sn_info->vm_clock_nsec = sn->vm_clock_nsec; |
2119 |
} |
2120 |
*psn_tab = sn_tab; |
2121 |
return s->nb_snapshots;
|
2122 |
} |
2123 |
|
2124 |
/*********************************************************/
|
2125 |
/* refcount handling */
|
2126 |
|
2127 |
static int refcount_init(BlockDriverState *bs) |
2128 |
{ |
2129 |
BDRVQcowState *s = bs->opaque; |
2130 |
int ret, refcount_table_size2, i;
|
2131 |
|
2132 |
s->refcount_block_cache = qemu_malloc(s->cluster_size); |
2133 |
refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t);
|
2134 |
s->refcount_table = qemu_malloc(refcount_table_size2); |
2135 |
if (s->refcount_table_size > 0) { |
2136 |
ret = bdrv_pread(s->hd, s->refcount_table_offset, |
2137 |
s->refcount_table, refcount_table_size2); |
2138 |
if (ret != refcount_table_size2)
|
2139 |
goto fail;
|
2140 |
for(i = 0; i < s->refcount_table_size; i++) |
2141 |
be64_to_cpus(&s->refcount_table[i]); |
2142 |
} |
2143 |
return 0; |
2144 |
fail:
|
2145 |
return -ENOMEM;
|
2146 |
} |
2147 |
|
2148 |
static void refcount_close(BlockDriverState *bs) |
2149 |
{ |
2150 |
BDRVQcowState *s = bs->opaque; |
2151 |
qemu_free(s->refcount_block_cache); |
2152 |
qemu_free(s->refcount_table); |
2153 |
} |
2154 |
|
2155 |
|
2156 |
static int load_refcount_block(BlockDriverState *bs, |
2157 |
int64_t refcount_block_offset) |
2158 |
{ |
2159 |
BDRVQcowState *s = bs->opaque; |
2160 |
int ret;
|
2161 |
ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache, |
2162 |
s->cluster_size); |
2163 |
if (ret != s->cluster_size)
|
2164 |
return -EIO;
|
2165 |
s->refcount_block_cache_offset = refcount_block_offset; |
2166 |
return 0; |
2167 |
} |
2168 |
|
2169 |
static void scan_refcount(BlockDriverState *bs, int64_t *high, int64_t *free) |
2170 |
{ |
2171 |
BDRVQcowState *s = bs->opaque; |
2172 |
int64_t refcnt_index, cluster_index, cluster_end, h = 0, f = 0; |
2173 |
int64_t tail = 0; /* do not count last consecutive free entries */ |
2174 |
|
2175 |
for (refcnt_index=0; refcnt_index < s->refcount_table_size; refcnt_index++){ |
2176 |
if (s->refcount_table[refcnt_index] == 0) { |
2177 |
f += 1 << (s->cluster_bits - REFCOUNT_SHIFT);
|
2178 |
tail += 1 << (s->cluster_bits - REFCOUNT_SHIFT);
|
2179 |
continue;
|
2180 |
} |
2181 |
cluster_index = refcnt_index << (s->cluster_bits - REFCOUNT_SHIFT); |
2182 |
cluster_end = (refcnt_index + 1) << (s->cluster_bits - REFCOUNT_SHIFT);
|
2183 |
for ( ; cluster_index < cluster_end; cluster_index++) {
|
2184 |
if (get_refcount(bs, cluster_index) == 0) { |
2185 |
f++; |
2186 |
tail++; |
2187 |
} |
2188 |
else {
|
2189 |
h = cluster_index; |
2190 |
tail = 0;
|
2191 |
} |
2192 |
} |
2193 |
} |
2194 |
|
2195 |
f -= tail; |
2196 |
if (free)
|
2197 |
*free = f; |
2198 |
if (high)
|
2199 |
*high = (h+1);
|
2200 |
} |
2201 |
|
2202 |
static int get_refcount(BlockDriverState *bs, int64_t cluster_index) |
2203 |
{ |
2204 |
BDRVQcowState *s = bs->opaque; |
2205 |
int refcount_table_index, block_index;
|
2206 |
int64_t refcount_block_offset; |
2207 |
|
2208 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
2209 |
if (refcount_table_index >= s->refcount_table_size)
|
2210 |
return 0; |
2211 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
2212 |
if (!refcount_block_offset)
|
2213 |
return 0; |
2214 |
if (refcount_block_offset != s->refcount_block_cache_offset) {
|
2215 |
/* better than nothing: return allocated if read error */
|
2216 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
2217 |
return 1; |
2218 |
} |
2219 |
block_index = cluster_index & |
2220 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
2221 |
return be16_to_cpu(s->refcount_block_cache[block_index]);
|
2222 |
} |
2223 |
|
2224 |
/* return < 0 if error */
|
2225 |
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
|
2226 |
{ |
2227 |
BDRVQcowState *s = bs->opaque; |
2228 |
int i, nb_clusters;
|
2229 |
|
2230 |
nb_clusters = size_to_clusters(s, size); |
2231 |
retry:
|
2232 |
for(i = 0; i < nb_clusters; i++) { |
2233 |
int64_t i = s->free_cluster_index++; |
2234 |
if (get_refcount(bs, i) != 0) |
2235 |
goto retry;
|
2236 |
} |
2237 |
#ifdef DEBUG_ALLOC2
|
2238 |
printf("alloc_clusters: size=%lld -> %lld\n",
|
2239 |
size, |
2240 |
(s->free_cluster_index - nb_clusters) << s->cluster_bits); |
2241 |
#endif
|
2242 |
|
2243 |
if (s->highest_alloc < s->free_cluster_index) {
|
2244 |
s->nc_free += (s->free_cluster_index - s->highest_alloc); |
2245 |
s->highest_alloc = s->free_cluster_index; |
2246 |
} |
2247 |
|
2248 |
return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
|
2249 |
} |
2250 |
|
2251 |
static int64_t alloc_clusters(BlockDriverState *bs, int64_t size)
|
2252 |
{ |
2253 |
int64_t offset; |
2254 |
|
2255 |
offset = alloc_clusters_noref(bs, size); |
2256 |
update_refcount(bs, offset, size, 1);
|
2257 |
return offset;
|
2258 |
} |
2259 |
|
2260 |
/* only used to allocate compressed sectors. We try to allocate
|
2261 |
contiguous sectors. size must be <= cluster_size */
|
2262 |
static int64_t alloc_bytes(BlockDriverState *bs, int size) |
2263 |
{ |
2264 |
BDRVQcowState *s = bs->opaque; |
2265 |
int64_t offset, cluster_offset; |
2266 |
int free_in_cluster;
|
2267 |
|
2268 |
assert(size > 0 && size <= s->cluster_size);
|
2269 |
if (s->free_byte_offset == 0) { |
2270 |
s->free_byte_offset = alloc_clusters(bs, s->cluster_size); |
2271 |
} |
2272 |
redo:
|
2273 |
free_in_cluster = s->cluster_size - |
2274 |
(s->free_byte_offset & (s->cluster_size - 1));
|
2275 |
if (size <= free_in_cluster) {
|
2276 |
/* enough space in current cluster */
|
2277 |
offset = s->free_byte_offset; |
2278 |
s->free_byte_offset += size; |
2279 |
free_in_cluster -= size; |
2280 |
if (free_in_cluster == 0) |
2281 |
s->free_byte_offset = 0;
|
2282 |
if ((offset & (s->cluster_size - 1)) != 0) |
2283 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
2284 |
} else {
|
2285 |
offset = alloc_clusters(bs, s->cluster_size); |
2286 |
cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1);
|
2287 |
if ((cluster_offset + s->cluster_size) == offset) {
|
2288 |
/* we are lucky: contiguous data */
|
2289 |
offset = s->free_byte_offset; |
2290 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
2291 |
s->free_byte_offset += size; |
2292 |
} else {
|
2293 |
s->free_byte_offset = offset; |
2294 |
goto redo;
|
2295 |
} |
2296 |
} |
2297 |
return offset;
|
2298 |
} |
2299 |
|
2300 |
static void free_clusters(BlockDriverState *bs, |
2301 |
int64_t offset, int64_t size) |
2302 |
{ |
2303 |
update_refcount(bs, offset, size, -1);
|
2304 |
} |
2305 |
|
2306 |
static int grow_refcount_table(BlockDriverState *bs, int min_size) |
2307 |
{ |
2308 |
BDRVQcowState *s = bs->opaque; |
2309 |
int new_table_size, new_table_size2, refcount_table_clusters, i, ret;
|
2310 |
uint64_t *new_table; |
2311 |
int64_t table_offset; |
2312 |
uint8_t data[12];
|
2313 |
int old_table_size;
|
2314 |
int64_t old_table_offset; |
2315 |
|
2316 |
if (min_size <= s->refcount_table_size)
|
2317 |
return 0; |
2318 |
/* compute new table size */
|
2319 |
refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
|
2320 |
for(;;) {
|
2321 |
if (refcount_table_clusters == 0) { |
2322 |
refcount_table_clusters = 1;
|
2323 |
} else {
|
2324 |
refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; |
2325 |
} |
2326 |
new_table_size = refcount_table_clusters << (s->cluster_bits - 3);
|
2327 |
if (min_size <= new_table_size)
|
2328 |
break;
|
2329 |
} |
2330 |
#ifdef DEBUG_ALLOC2
|
2331 |
printf("grow_refcount_table from %d to %d\n",
|
2332 |
s->refcount_table_size, |
2333 |
new_table_size); |
2334 |
#endif
|
2335 |
new_table_size2 = new_table_size * sizeof(uint64_t);
|
2336 |
new_table = qemu_mallocz(new_table_size2); |
2337 |
memcpy(new_table, s->refcount_table, |
2338 |
s->refcount_table_size * sizeof(uint64_t));
|
2339 |
for(i = 0; i < s->refcount_table_size; i++) |
2340 |
cpu_to_be64s(&new_table[i]); |
2341 |
/* Note: we cannot update the refcount now to avoid recursion */
|
2342 |
table_offset = alloc_clusters_noref(bs, new_table_size2); |
2343 |
ret = bdrv_pwrite(s->hd, table_offset, new_table, new_table_size2); |
2344 |
if (ret != new_table_size2)
|
2345 |
goto fail;
|
2346 |
for(i = 0; i < s->refcount_table_size; i++) |
2347 |
be64_to_cpus(&new_table[i]); |
2348 |
|
2349 |
cpu_to_be64w((uint64_t*)data, table_offset); |
2350 |
cpu_to_be32w((uint32_t*)(data + 8), refcount_table_clusters);
|
2351 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset),
|
2352 |
data, sizeof(data)) != sizeof(data)) |
2353 |
goto fail;
|
2354 |
qemu_free(s->refcount_table); |
2355 |
old_table_offset = s->refcount_table_offset; |
2356 |
old_table_size = s->refcount_table_size; |
2357 |
s->refcount_table = new_table; |
2358 |
s->refcount_table_size = new_table_size; |
2359 |
s->refcount_table_offset = table_offset; |
2360 |
|
2361 |
update_refcount(bs, table_offset, new_table_size2, 1);
|
2362 |
free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t));
|
2363 |
return 0; |
2364 |
fail:
|
2365 |
free_clusters(bs, table_offset, new_table_size2); |
2366 |
qemu_free(new_table); |
2367 |
return -EIO;
|
2368 |
} |
2369 |
|
2370 |
/* addend must be 1 or -1 */
|
2371 |
/* XXX: cache several refcount block clusters ? */
|
2372 |
static int update_cluster_refcount(BlockDriverState *bs, |
2373 |
int64_t cluster_index, |
2374 |
int addend)
|
2375 |
{ |
2376 |
BDRVQcowState *s = bs->opaque; |
2377 |
int64_t offset, refcount_block_offset; |
2378 |
int ret, refcount_table_index, block_index, refcount;
|
2379 |
uint64_t data64; |
2380 |
|
2381 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
2382 |
if (refcount_table_index >= s->refcount_table_size) {
|
2383 |
if (addend < 0) |
2384 |
return -EINVAL;
|
2385 |
ret = grow_refcount_table(bs, refcount_table_index + 1);
|
2386 |
if (ret < 0) |
2387 |
return ret;
|
2388 |
} |
2389 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
2390 |
if (!refcount_block_offset) {
|
2391 |
if (addend < 0) |
2392 |
return -EINVAL;
|
2393 |
/* create a new refcount block */
|
2394 |
/* Note: we cannot update the refcount now to avoid recursion */
|
2395 |
offset = alloc_clusters_noref(bs, s->cluster_size); |
2396 |
memset(s->refcount_block_cache, 0, s->cluster_size);
|
2397 |
ret = bdrv_pwrite(s->hd, offset, s->refcount_block_cache, s->cluster_size); |
2398 |
if (ret != s->cluster_size)
|
2399 |
return -EINVAL;
|
2400 |
s->refcount_table[refcount_table_index] = offset; |
2401 |
data64 = cpu_to_be64(offset); |
2402 |
ret = bdrv_pwrite(s->hd, s->refcount_table_offset + |
2403 |
refcount_table_index * sizeof(uint64_t),
|
2404 |
&data64, sizeof(data64));
|
2405 |
if (ret != sizeof(data64)) |
2406 |
return -EINVAL;
|
2407 |
|
2408 |
refcount_block_offset = offset; |
2409 |
s->refcount_block_cache_offset = offset; |
2410 |
update_refcount(bs, offset, s->cluster_size, 1);
|
2411 |
} else {
|
2412 |
if (refcount_block_offset != s->refcount_block_cache_offset) {
|
2413 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
2414 |
return -EIO;
|
2415 |
} |
2416 |
} |
2417 |
/* we can update the count and save it */
|
2418 |
block_index = cluster_index & |
2419 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
2420 |
refcount = be16_to_cpu(s->refcount_block_cache[block_index]); |
2421 |
|
2422 |
if (refcount == 1 && addend == -1) |
2423 |
s->nc_free += 1;
|
2424 |
else if (refcount == 0 && addend == 1) |
2425 |
s->nc_free -= 1;
|
2426 |
|
2427 |
refcount += addend; |
2428 |
if (refcount < 0 || refcount > 0xffff) |
2429 |
return -EINVAL;
|
2430 |
if (refcount == 0 && cluster_index < s->free_cluster_index) { |
2431 |
s->free_cluster_index = cluster_index; |
2432 |
} |
2433 |
s->refcount_block_cache[block_index] = cpu_to_be16(refcount); |
2434 |
if (bdrv_pwrite(s->hd,
|
2435 |
refcount_block_offset + (block_index << REFCOUNT_SHIFT), |
2436 |
&s->refcount_block_cache[block_index], 2) != 2) |
2437 |
return -EIO;
|
2438 |
return refcount;
|
2439 |
} |
2440 |
|
2441 |
static void update_refcount(BlockDriverState *bs, |
2442 |
int64_t offset, int64_t length, |
2443 |
int addend)
|
2444 |
{ |
2445 |
BDRVQcowState *s = bs->opaque; |
2446 |
int64_t start, last, cluster_offset; |
2447 |
|
2448 |
#ifdef DEBUG_ALLOC2
|
2449 |
printf("update_refcount: offset=%lld size=%lld addend=%d\n",
|
2450 |
offset, length, addend); |
2451 |
#endif
|
2452 |
if (length <= 0) |
2453 |
return;
|
2454 |
start = offset & ~(s->cluster_size - 1);
|
2455 |
last = (offset + length - 1) & ~(s->cluster_size - 1); |
2456 |
for(cluster_offset = start; cluster_offset <= last;
|
2457 |
cluster_offset += s->cluster_size) { |
2458 |
update_cluster_refcount(bs, cluster_offset >> s->cluster_bits, addend); |
2459 |
} |
2460 |
} |
2461 |
|
2462 |
#ifdef DEBUG_ALLOC
|
2463 |
static void inc_refcounts(BlockDriverState *bs, |
2464 |
uint16_t *refcount_table, |
2465 |
int refcount_table_size,
|
2466 |
int64_t offset, int64_t size) |
2467 |
{ |
2468 |
BDRVQcowState *s = bs->opaque; |
2469 |
int64_t start, last, cluster_offset; |
2470 |
int k;
|
2471 |
|
2472 |
if (size <= 0) |
2473 |
return;
|
2474 |
|
2475 |
start = offset & ~(s->cluster_size - 1);
|
2476 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
2477 |
for(cluster_offset = start; cluster_offset <= last;
|
2478 |
cluster_offset += s->cluster_size) { |
2479 |
k = cluster_offset >> s->cluster_bits; |
2480 |
if (k < 0 || k >= refcount_table_size) { |
2481 |
printf("ERROR: invalid cluster offset=0x%llx\n", cluster_offset);
|
2482 |
} else {
|
2483 |
if (++refcount_table[k] == 0) { |
2484 |
printf("ERROR: overflow cluster offset=0x%llx\n", cluster_offset);
|
2485 |
} |
2486 |
} |
2487 |
} |
2488 |
} |
2489 |
|
2490 |
static int check_refcounts_l1(BlockDriverState *bs, |
2491 |
uint16_t *refcount_table, |
2492 |
int refcount_table_size,
|
2493 |
int64_t l1_table_offset, int l1_size,
|
2494 |
int check_copied)
|
2495 |
{ |
2496 |
BDRVQcowState *s = bs->opaque; |
2497 |
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2; |
2498 |
int l2_size, i, j, nb_csectors, refcount;
|
2499 |
|
2500 |
l2_table = NULL;
|
2501 |
l1_size2 = l1_size * sizeof(uint64_t);
|
2502 |
|
2503 |
inc_refcounts(bs, refcount_table, refcount_table_size, |
2504 |
l1_table_offset, l1_size2); |
2505 |
|
2506 |
l1_table = qemu_malloc(l1_size2); |
2507 |
if (bdrv_pread(s->hd, l1_table_offset,
|
2508 |
l1_table, l1_size2) != l1_size2) |
2509 |
goto fail;
|
2510 |
for(i = 0;i < l1_size; i++) |
2511 |
be64_to_cpus(&l1_table[i]); |
2512 |
|
2513 |
l2_size = s->l2_size * sizeof(uint64_t);
|
2514 |
l2_table = qemu_malloc(l2_size); |
2515 |
for(i = 0; i < l1_size; i++) { |
2516 |
l2_offset = l1_table[i]; |
2517 |
if (l2_offset) {
|
2518 |
if (check_copied) {
|
2519 |
refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits); |
2520 |
if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { |
2521 |
printf("ERROR OFLAG_COPIED: l2_offset=%llx refcount=%d\n",
|
2522 |
l2_offset, refcount); |
2523 |
} |
2524 |
} |
2525 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
2526 |
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
|
2527 |
goto fail;
|
2528 |
for(j = 0; j < s->l2_size; j++) { |
2529 |
offset = be64_to_cpu(l2_table[j]); |
2530 |
if (offset != 0) { |
2531 |
if (offset & QCOW_OFLAG_COMPRESSED) {
|
2532 |
if (offset & QCOW_OFLAG_COPIED) {
|
2533 |
printf("ERROR: cluster %lld: copied flag must never be set for compressed clusters\n",
|
2534 |
offset >> s->cluster_bits); |
2535 |
offset &= ~QCOW_OFLAG_COPIED; |
2536 |
} |
2537 |
nb_csectors = ((offset >> s->csize_shift) & |
2538 |
s->csize_mask) + 1;
|
2539 |
offset &= s->cluster_offset_mask; |
2540 |
inc_refcounts(bs, refcount_table, |
2541 |
refcount_table_size, |
2542 |
offset & ~511, nb_csectors * 512); |
2543 |
} else {
|
2544 |
if (check_copied) {
|
2545 |
refcount = get_refcount(bs, (offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits); |
2546 |
if ((refcount == 1) != ((offset & QCOW_OFLAG_COPIED) != 0)) { |
2547 |
printf("ERROR OFLAG_COPIED: offset=%llx refcount=%d\n",
|
2548 |
offset, refcount); |
2549 |
} |
2550 |
} |
2551 |
offset &= ~QCOW_OFLAG_COPIED; |
2552 |
inc_refcounts(bs, refcount_table, |
2553 |
refcount_table_size, |
2554 |
offset, s->cluster_size); |
2555 |
} |
2556 |
} |
2557 |
} |
2558 |
inc_refcounts(bs, refcount_table, |
2559 |
refcount_table_size, |
2560 |
l2_offset, |
2561 |
s->cluster_size); |
2562 |
} |
2563 |
} |
2564 |
qemu_free(l1_table); |
2565 |
qemu_free(l2_table); |
2566 |
return 0; |
2567 |
fail:
|
2568 |
printf("ERROR: I/O error in check_refcounts_l1\n");
|
2569 |
qemu_free(l1_table); |
2570 |
qemu_free(l2_table); |
2571 |
return -EIO;
|
2572 |
} |
2573 |
|
2574 |
static void check_refcounts(BlockDriverState *bs) |
2575 |
{ |
2576 |
BDRVQcowState *s = bs->opaque; |
2577 |
int64_t size; |
2578 |
int nb_clusters, refcount1, refcount2, i;
|
2579 |
QCowSnapshot *sn; |
2580 |
uint16_t *refcount_table; |
2581 |
|
2582 |
size = bdrv_getlength(s->hd); |
2583 |
nb_clusters = size_to_clusters(s, size); |
2584 |
refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t));
|
2585 |
|
2586 |
/* header */
|
2587 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2588 |
0, s->cluster_size);
|
2589 |
|
2590 |
check_refcounts_l1(bs, refcount_table, nb_clusters, |
2591 |
s->l1_table_offset, s->l1_size, 1);
|
2592 |
|
2593 |
/* snapshots */
|
2594 |
for(i = 0; i < s->nb_snapshots; i++) { |
2595 |
sn = s->snapshots + i; |
2596 |
check_refcounts_l1(bs, refcount_table, nb_clusters, |
2597 |
sn->l1_table_offset, sn->l1_size, 0);
|
2598 |
} |
2599 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2600 |
s->snapshots_offset, s->snapshots_size); |
2601 |
|
2602 |
/* refcount data */
|
2603 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2604 |
s->refcount_table_offset, |
2605 |
s->refcount_table_size * sizeof(uint64_t));
|
2606 |
for(i = 0; i < s->refcount_table_size; i++) { |
2607 |
int64_t offset; |
2608 |
offset = s->refcount_table[i]; |
2609 |
if (offset != 0) { |
2610 |
inc_refcounts(bs, refcount_table, nb_clusters, |
2611 |
offset, s->cluster_size); |
2612 |
} |
2613 |
} |
2614 |
|
2615 |
/* compare ref counts */
|
2616 |
for(i = 0; i < nb_clusters; i++) { |
2617 |
refcount1 = get_refcount(bs, i); |
2618 |
refcount2 = refcount_table[i]; |
2619 |
if (refcount1 != refcount2)
|
2620 |
printf("ERROR cluster %d refcount=%d reference=%d\n",
|
2621 |
i, refcount1, refcount2); |
2622 |
} |
2623 |
|
2624 |
qemu_free(refcount_table); |
2625 |
} |
2626 |
|
2627 |
#if 0
|
2628 |
static void dump_refcounts(BlockDriverState *bs)
|
2629 |
{
|
2630 |
BDRVQcowState *s = bs->opaque;
|
2631 |
int64_t nb_clusters, k, k1, size;
|
2632 |
int refcount;
|
2633 |
|
2634 |
size = bdrv_getlength(s->hd);
|
2635 |
nb_clusters = size_to_clusters(s, size);
|
2636 |
for(k = 0; k < nb_clusters;) {
|
2637 |
k1 = k;
|
2638 |
refcount = get_refcount(bs, k);
|
2639 |
k++;
|
2640 |
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
2641 |
k++;
|
2642 |
printf("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1);
|
2643 |
}
|
2644 |
}
|
2645 |
#endif
|
2646 |
#endif
|
2647 |
|
2648 |
BlockDriver bdrv_qcow2 = { |
2649 |
"qcow2",
|
2650 |
sizeof(BDRVQcowState),
|
2651 |
qcow_probe, |
2652 |
qcow_open, |
2653 |
NULL,
|
2654 |
NULL,
|
2655 |
qcow_close, |
2656 |
qcow_create, |
2657 |
qcow_flush, |
2658 |
qcow_is_allocated, |
2659 |
qcow_set_key, |
2660 |
qcow_make_empty, |
2661 |
|
2662 |
.bdrv_aio_read = qcow_aio_read, |
2663 |
.bdrv_aio_write = qcow_aio_write, |
2664 |
.bdrv_aio_cancel = qcow_aio_cancel, |
2665 |
.aiocb_size = sizeof(QCowAIOCB),
|
2666 |
.bdrv_write_compressed = qcow_write_compressed, |
2667 |
|
2668 |
.bdrv_snapshot_create = qcow_snapshot_create, |
2669 |
.bdrv_snapshot_goto = qcow_snapshot_goto, |
2670 |
.bdrv_snapshot_delete = qcow_snapshot_delete, |
2671 |
.bdrv_snapshot_list = qcow_snapshot_list, |
2672 |
.bdrv_get_info = qcow_get_info, |
2673 |
}; |