root / block / qcow2.c @ 0bfcd599
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/*
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* Block driver for the QCOW version 2 format
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*
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* Copyright (c) 2004-2006 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu-common.h" |
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#include "block_int.h" |
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#include "module.h" |
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#include <zlib.h> |
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#include "aes.h" |
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#include "block/qcow2.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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|
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typedef struct { |
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uint32_t magic; |
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uint32_t len; |
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} QCowExtension; |
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#define QCOW_EXT_MAGIC_END 0 |
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#define QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA |
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|
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static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
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{ |
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const QCowHeader *cow_header = (const void *)buf; |
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|
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if (buf_size >= sizeof(QCowHeader) && |
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be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
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be32_to_cpu(cow_header->version) == QCOW_VERSION) |
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return 100; |
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else
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return 0; |
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} |
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|
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|
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/*
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* read qcow2 extension and fill bs
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* start reading from start_offset
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* finish reading upon magic of value 0 or when end_offset reached
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* unknown magic is skipped (future extension this version knows nothing about)
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* return 0 upon success, non-0 otherwise
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*/
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static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset, |
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uint64_t end_offset) |
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{ |
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QCowExtension ext; |
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uint64_t offset; |
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|
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#ifdef DEBUG_EXT
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printf("qcow_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
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#endif
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offset = start_offset; |
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while (offset < end_offset) {
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#ifdef DEBUG_EXT
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/* Sanity check */
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if (offset > s->cluster_size)
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printf("qcow_handle_extension: suspicious offset %lu\n", offset);
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printf("attemting to read extended header in offset %lu\n", offset);
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#endif
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if (bdrv_pread(bs->file, offset, &ext, sizeof(ext)) != sizeof(ext)) { |
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fprintf(stderr, "qcow_handle_extension: ERROR: "
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"pread fail from offset %" PRIu64 "\n", |
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offset); |
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return 1; |
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} |
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be32_to_cpus(&ext.magic); |
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be32_to_cpus(&ext.len); |
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offset += sizeof(ext);
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#ifdef DEBUG_EXT
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printf("ext.magic = 0x%x\n", ext.magic);
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#endif
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switch (ext.magic) {
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case QCOW_EXT_MAGIC_END:
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return 0; |
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|
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case QCOW_EXT_MAGIC_BACKING_FORMAT:
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if (ext.len >= sizeof(bs->backing_format)) { |
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fprintf(stderr, "ERROR: ext_backing_format: len=%u too large"
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" (>=%zu)\n",
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ext.len, sizeof(bs->backing_format));
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return 2; |
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} |
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if (bdrv_pread(bs->file, offset , bs->backing_format,
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ext.len) != ext.len) |
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return 3; |
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bs->backing_format[ext.len] = '\0';
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#ifdef DEBUG_EXT
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printf("Qcow2: Got format extension %s\n", bs->backing_format);
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#endif
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offset = ((offset + ext.len + 7) & ~7); |
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break;
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|
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default:
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/* unknown magic -- just skip it */
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offset = ((offset + ext.len + 7) & ~7); |
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break;
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} |
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} |
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return 0; |
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} |
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|
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static int qcow_open(BlockDriverState *bs, int flags) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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int len, i;
|
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QCowHeader header; |
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uint64_t ext_end; |
145 |
|
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if (bdrv_pread(bs->file, 0, &header, sizeof(header)) != sizeof(header)) |
147 |
goto fail;
|
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be32_to_cpus(&header.magic); |
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be32_to_cpus(&header.version); |
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be64_to_cpus(&header.backing_file_offset); |
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be32_to_cpus(&header.backing_file_size); |
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be64_to_cpus(&header.size); |
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be32_to_cpus(&header.cluster_bits); |
154 |
be32_to_cpus(&header.crypt_method); |
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be64_to_cpus(&header.l1_table_offset); |
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be32_to_cpus(&header.l1_size); |
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be64_to_cpus(&header.refcount_table_offset); |
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be32_to_cpus(&header.refcount_table_clusters); |
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be64_to_cpus(&header.snapshots_offset); |
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be32_to_cpus(&header.nb_snapshots); |
161 |
|
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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.cluster_bits < MIN_CLUSTER_BITS ||
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header.cluster_bits > MAX_CLUSTER_BITS) |
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goto fail;
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if (header.crypt_method > QCOW_CRYPT_AES)
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goto fail;
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s->crypt_method_header = header.crypt_method; |
170 |
if (s->crypt_method_header)
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bs->encrypted = 1;
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s->cluster_bits = header.cluster_bits; |
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s->cluster_size = 1 << s->cluster_bits;
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s->cluster_sectors = 1 << (s->cluster_bits - 9); |
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s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ |
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s->l2_size = 1 << s->l2_bits;
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bs->total_sectors = header.size / 512;
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s->csize_shift = (62 - (s->cluster_bits - 8)); |
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s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
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s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
181 |
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; |
186 |
s->nb_snapshots = header.nb_snapshots; |
187 |
|
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/* read the level 1 table */
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s->l1_size = header.l1_size; |
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s->l1_vm_state_index = size_to_l1(s, header.size); |
191 |
/* the L1 table must contain at least enough entries to put
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header.size bytes */
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if (s->l1_size < s->l1_vm_state_index)
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goto fail;
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s->l1_table_offset = header.l1_table_offset; |
196 |
if (s->l1_size > 0) { |
197 |
s->l1_table = qemu_mallocz( |
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align_offset(s->l1_size * sizeof(uint64_t), 512)); |
199 |
if (bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != |
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s->l1_size * sizeof(uint64_t))
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goto fail;
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for(i = 0;i < s->l1_size; i++) { |
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be64_to_cpus(&s->l1_table[i]); |
204 |
} |
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} |
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/* alloc L2 cache */
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s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
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s->cluster_cache = qemu_malloc(s->cluster_size); |
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/* one more sector for decompressed data alignment */
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s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size |
211 |
+ 512);
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s->cluster_cache_offset = -1;
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|
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if (qcow2_refcount_init(bs) < 0) |
215 |
goto fail;
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216 |
|
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QLIST_INIT(&s->cluster_allocs); |
218 |
|
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/* read qcow2 extensions */
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if (header.backing_file_offset)
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ext_end = header.backing_file_offset; |
222 |
else
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ext_end = s->cluster_size; |
224 |
if (qcow_read_extensions(bs, sizeof(header), ext_end)) |
225 |
goto fail;
|
226 |
|
227 |
/* read the backing file name */
|
228 |
if (header.backing_file_offset != 0) { |
229 |
len = header.backing_file_size; |
230 |
if (len > 1023) |
231 |
len = 1023;
|
232 |
if (bdrv_pread(bs->file, header.backing_file_offset, bs->backing_file, len) != len)
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goto fail;
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bs->backing_file[len] = '\0';
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} |
236 |
if (qcow2_read_snapshots(bs) < 0) |
237 |
goto fail;
|
238 |
|
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#ifdef DEBUG_ALLOC
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qcow2_check_refcounts(bs); |
241 |
#endif
|
242 |
return 0; |
243 |
|
244 |
fail:
|
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qcow2_free_snapshots(bs); |
246 |
qcow2_refcount_close(bs); |
247 |
qemu_free(s->l1_table); |
248 |
qemu_free(s->l2_cache); |
249 |
qemu_free(s->cluster_cache); |
250 |
qemu_free(s->cluster_data); |
251 |
return -1; |
252 |
} |
253 |
|
254 |
static int qcow_set_key(BlockDriverState *bs, const char *key) |
255 |
{ |
256 |
BDRVQcowState *s = bs->opaque; |
257 |
uint8_t keybuf[16];
|
258 |
int len, i;
|
259 |
|
260 |
memset(keybuf, 0, 16); |
261 |
len = strlen(key); |
262 |
if (len > 16) |
263 |
len = 16;
|
264 |
/* XXX: we could compress the chars to 7 bits to increase
|
265 |
entropy */
|
266 |
for(i = 0;i < len;i++) { |
267 |
keybuf[i] = key[i]; |
268 |
} |
269 |
s->crypt_method = s->crypt_method_header; |
270 |
|
271 |
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
272 |
return -1; |
273 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
274 |
return -1; |
275 |
#if 0
|
276 |
/* test */
|
277 |
{
|
278 |
uint8_t in[16];
|
279 |
uint8_t out[16];
|
280 |
uint8_t tmp[16];
|
281 |
for(i=0;i<16;i++)
|
282 |
in[i] = i;
|
283 |
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
284 |
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
285 |
for(i = 0; i < 16; i++)
|
286 |
printf(" %02x", tmp[i]);
|
287 |
printf("\n");
|
288 |
for(i = 0; i < 16; i++)
|
289 |
printf(" %02x", out[i]);
|
290 |
printf("\n");
|
291 |
}
|
292 |
#endif
|
293 |
return 0; |
294 |
} |
295 |
|
296 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
297 |
int nb_sectors, int *pnum) |
298 |
{ |
299 |
uint64_t cluster_offset; |
300 |
|
301 |
*pnum = nb_sectors; |
302 |
cluster_offset = qcow2_get_cluster_offset(bs, sector_num << 9, pnum);
|
303 |
|
304 |
return (cluster_offset != 0); |
305 |
} |
306 |
|
307 |
/* handle reading after the end of the backing file */
|
308 |
int qcow2_backing_read1(BlockDriverState *bs,
|
309 |
int64_t sector_num, uint8_t *buf, int nb_sectors)
|
310 |
{ |
311 |
int n1;
|
312 |
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
313 |
return nb_sectors;
|
314 |
if (sector_num >= bs->total_sectors)
|
315 |
n1 = 0;
|
316 |
else
|
317 |
n1 = bs->total_sectors - sector_num; |
318 |
memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1)); |
319 |
return n1;
|
320 |
} |
321 |
|
322 |
typedef struct QCowAIOCB { |
323 |
BlockDriverAIOCB common; |
324 |
int64_t sector_num; |
325 |
QEMUIOVector *qiov; |
326 |
uint8_t *buf; |
327 |
void *orig_buf;
|
328 |
int remaining_sectors;
|
329 |
int cur_nr_sectors; /* number of sectors in current iteration */ |
330 |
uint64_t cluster_offset; |
331 |
uint8_t *cluster_data; |
332 |
BlockDriverAIOCB *hd_aiocb; |
333 |
struct iovec hd_iov;
|
334 |
QEMUIOVector hd_qiov; |
335 |
QEMUBH *bh; |
336 |
QCowL2Meta l2meta; |
337 |
QLIST_ENTRY(QCowAIOCB) next_depend; |
338 |
} QCowAIOCB; |
339 |
|
340 |
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) |
341 |
{ |
342 |
QCowAIOCB *acb = container_of(blockacb, QCowAIOCB, common); |
343 |
if (acb->hd_aiocb)
|
344 |
bdrv_aio_cancel(acb->hd_aiocb); |
345 |
qemu_aio_release(acb); |
346 |
} |
347 |
|
348 |
static AIOPool qcow_aio_pool = {
|
349 |
.aiocb_size = sizeof(QCowAIOCB),
|
350 |
.cancel = qcow_aio_cancel, |
351 |
}; |
352 |
|
353 |
static void qcow_aio_read_cb(void *opaque, int ret); |
354 |
static void qcow_aio_read_bh(void *opaque) |
355 |
{ |
356 |
QCowAIOCB *acb = opaque; |
357 |
qemu_bh_delete(acb->bh); |
358 |
acb->bh = NULL;
|
359 |
qcow_aio_read_cb(opaque, 0);
|
360 |
} |
361 |
|
362 |
static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb) |
363 |
{ |
364 |
if (acb->bh)
|
365 |
return -EIO;
|
366 |
|
367 |
acb->bh = qemu_bh_new(cb, acb); |
368 |
if (!acb->bh)
|
369 |
return -EIO;
|
370 |
|
371 |
qemu_bh_schedule(acb->bh); |
372 |
|
373 |
return 0; |
374 |
} |
375 |
|
376 |
static void qcow_aio_read_cb(void *opaque, int ret) |
377 |
{ |
378 |
QCowAIOCB *acb = opaque; |
379 |
BlockDriverState *bs = acb->common.bs; |
380 |
BDRVQcowState *s = bs->opaque; |
381 |
int index_in_cluster, n1;
|
382 |
|
383 |
acb->hd_aiocb = NULL;
|
384 |
if (ret < 0) |
385 |
goto done;
|
386 |
|
387 |
/* post process the read buffer */
|
388 |
if (!acb->cluster_offset) {
|
389 |
/* nothing to do */
|
390 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
391 |
/* nothing to do */
|
392 |
} else {
|
393 |
if (s->crypt_method) {
|
394 |
qcow2_encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, |
395 |
acb->cur_nr_sectors, 0,
|
396 |
&s->aes_decrypt_key); |
397 |
} |
398 |
} |
399 |
|
400 |
acb->remaining_sectors -= acb->cur_nr_sectors; |
401 |
acb->sector_num += acb->cur_nr_sectors; |
402 |
acb->buf += acb->cur_nr_sectors * 512;
|
403 |
|
404 |
if (acb->remaining_sectors == 0) { |
405 |
/* request completed */
|
406 |
ret = 0;
|
407 |
goto done;
|
408 |
} |
409 |
|
410 |
/* prepare next AIO request */
|
411 |
acb->cur_nr_sectors = acb->remaining_sectors; |
412 |
acb->cluster_offset = qcow2_get_cluster_offset(bs, acb->sector_num << 9,
|
413 |
&acb->cur_nr_sectors); |
414 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
415 |
|
416 |
if (!acb->cluster_offset) {
|
417 |
if (bs->backing_hd) {
|
418 |
/* read from the base image */
|
419 |
n1 = qcow2_backing_read1(bs->backing_hd, acb->sector_num, |
420 |
acb->buf, acb->cur_nr_sectors); |
421 |
if (n1 > 0) { |
422 |
acb->hd_iov.iov_base = (void *)acb->buf;
|
423 |
acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
|
424 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
425 |
BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); |
426 |
acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num, |
427 |
&acb->hd_qiov, acb->cur_nr_sectors, |
428 |
qcow_aio_read_cb, acb); |
429 |
if (acb->hd_aiocb == NULL) |
430 |
goto done;
|
431 |
} else {
|
432 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
433 |
if (ret < 0) |
434 |
goto done;
|
435 |
} |
436 |
} else {
|
437 |
/* Note: in this case, no need to wait */
|
438 |
memset(acb->buf, 0, 512 * acb->cur_nr_sectors); |
439 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
440 |
if (ret < 0) |
441 |
goto done;
|
442 |
} |
443 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
444 |
/* add AIO support for compressed blocks ? */
|
445 |
if (qcow2_decompress_cluster(bs, acb->cluster_offset) < 0) |
446 |
goto done;
|
447 |
memcpy(acb->buf, s->cluster_cache + index_in_cluster * 512,
|
448 |
512 * acb->cur_nr_sectors);
|
449 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
450 |
if (ret < 0) |
451 |
goto done;
|
452 |
} else {
|
453 |
if ((acb->cluster_offset & 511) != 0) { |
454 |
ret = -EIO; |
455 |
goto done;
|
456 |
} |
457 |
|
458 |
acb->hd_iov.iov_base = (void *)acb->buf;
|
459 |
acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
|
460 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
461 |
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); |
462 |
acb->hd_aiocb = bdrv_aio_readv(bs->file, |
463 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
464 |
&acb->hd_qiov, acb->cur_nr_sectors, |
465 |
qcow_aio_read_cb, acb); |
466 |
if (acb->hd_aiocb == NULL) { |
467 |
ret = -EIO; |
468 |
goto done;
|
469 |
} |
470 |
} |
471 |
|
472 |
return;
|
473 |
done:
|
474 |
if (acb->qiov->niov > 1) { |
475 |
qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size); |
476 |
qemu_vfree(acb->orig_buf); |
477 |
} |
478 |
acb->common.cb(acb->common.opaque, ret); |
479 |
qemu_aio_release(acb); |
480 |
} |
481 |
|
482 |
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
|
483 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
484 |
BlockDriverCompletionFunc *cb, void *opaque, int is_write) |
485 |
{ |
486 |
QCowAIOCB *acb; |
487 |
|
488 |
acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque); |
489 |
if (!acb)
|
490 |
return NULL; |
491 |
acb->hd_aiocb = NULL;
|
492 |
acb->sector_num = sector_num; |
493 |
acb->qiov = qiov; |
494 |
if (qiov->niov > 1) { |
495 |
acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size); |
496 |
if (is_write)
|
497 |
qemu_iovec_to_buffer(qiov, acb->buf); |
498 |
} else {
|
499 |
acb->buf = (uint8_t *)qiov->iov->iov_base; |
500 |
} |
501 |
acb->remaining_sectors = nb_sectors; |
502 |
acb->cur_nr_sectors = 0;
|
503 |
acb->cluster_offset = 0;
|
504 |
acb->l2meta.nb_clusters = 0;
|
505 |
QLIST_INIT(&acb->l2meta.dependent_requests); |
506 |
return acb;
|
507 |
} |
508 |
|
509 |
static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
|
510 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
511 |
BlockDriverCompletionFunc *cb, void *opaque)
|
512 |
{ |
513 |
QCowAIOCB *acb; |
514 |
|
515 |
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
|
516 |
if (!acb)
|
517 |
return NULL; |
518 |
|
519 |
qcow_aio_read_cb(acb, 0);
|
520 |
return &acb->common;
|
521 |
} |
522 |
|
523 |
static void qcow_aio_write_cb(void *opaque, int ret); |
524 |
|
525 |
static void run_dependent_requests(QCowL2Meta *m) |
526 |
{ |
527 |
QCowAIOCB *req; |
528 |
QCowAIOCB *next; |
529 |
|
530 |
/* Take the request off the list of running requests */
|
531 |
if (m->nb_clusters != 0) { |
532 |
QLIST_REMOVE(m, next_in_flight); |
533 |
} |
534 |
|
535 |
/* Restart all dependent requests */
|
536 |
QLIST_FOREACH_SAFE(req, &m->dependent_requests, next_depend, next) { |
537 |
qcow_aio_write_cb(req, 0);
|
538 |
} |
539 |
|
540 |
/* Empty the list for the next part of the request */
|
541 |
QLIST_INIT(&m->dependent_requests); |
542 |
} |
543 |
|
544 |
static void qcow_aio_write_cb(void *opaque, int ret) |
545 |
{ |
546 |
QCowAIOCB *acb = opaque; |
547 |
BlockDriverState *bs = acb->common.bs; |
548 |
BDRVQcowState *s = bs->opaque; |
549 |
int index_in_cluster;
|
550 |
const uint8_t *src_buf;
|
551 |
int n_end;
|
552 |
|
553 |
acb->hd_aiocb = NULL;
|
554 |
|
555 |
if (ret >= 0) { |
556 |
ret = qcow2_alloc_cluster_link_l2(bs, &acb->l2meta); |
557 |
} |
558 |
|
559 |
run_dependent_requests(&acb->l2meta); |
560 |
|
561 |
if (ret < 0) |
562 |
goto done;
|
563 |
|
564 |
acb->remaining_sectors -= acb->cur_nr_sectors; |
565 |
acb->sector_num += acb->cur_nr_sectors; |
566 |
acb->buf += acb->cur_nr_sectors * 512;
|
567 |
|
568 |
if (acb->remaining_sectors == 0) { |
569 |
/* request completed */
|
570 |
ret = 0;
|
571 |
goto done;
|
572 |
} |
573 |
|
574 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
575 |
n_end = index_in_cluster + acb->remaining_sectors; |
576 |
if (s->crypt_method &&
|
577 |
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) |
578 |
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
579 |
|
580 |
ret = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9,
|
581 |
index_in_cluster, n_end, &acb->cur_nr_sectors, &acb->l2meta); |
582 |
if (ret < 0) { |
583 |
goto done;
|
584 |
} |
585 |
|
586 |
acb->cluster_offset = acb->l2meta.cluster_offset; |
587 |
|
588 |
/* Need to wait for another request? If so, we are done for now. */
|
589 |
if (acb->l2meta.nb_clusters == 0 && acb->l2meta.depends_on != NULL) { |
590 |
QLIST_INSERT_HEAD(&acb->l2meta.depends_on->dependent_requests, |
591 |
acb, next_depend); |
592 |
return;
|
593 |
} |
594 |
|
595 |
assert((acb->cluster_offset & 511) == 0); |
596 |
|
597 |
if (s->crypt_method) {
|
598 |
if (!acb->cluster_data) {
|
599 |
acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * |
600 |
s->cluster_size); |
601 |
} |
602 |
qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, |
603 |
acb->cur_nr_sectors, 1, &s->aes_encrypt_key);
|
604 |
src_buf = acb->cluster_data; |
605 |
} else {
|
606 |
src_buf = acb->buf; |
607 |
} |
608 |
acb->hd_iov.iov_base = (void *)src_buf;
|
609 |
acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
|
610 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
611 |
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); |
612 |
acb->hd_aiocb = bdrv_aio_writev(bs->file, |
613 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
614 |
&acb->hd_qiov, acb->cur_nr_sectors, |
615 |
qcow_aio_write_cb, acb); |
616 |
if (acb->hd_aiocb == NULL) { |
617 |
ret = -EIO; |
618 |
goto fail;
|
619 |
} |
620 |
|
621 |
return;
|
622 |
|
623 |
fail:
|
624 |
if (acb->l2meta.nb_clusters != 0) { |
625 |
QLIST_REMOVE(&acb->l2meta, next_in_flight); |
626 |
} |
627 |
done:
|
628 |
if (acb->qiov->niov > 1) |
629 |
qemu_vfree(acb->orig_buf); |
630 |
acb->common.cb(acb->common.opaque, ret); |
631 |
qemu_aio_release(acb); |
632 |
} |
633 |
|
634 |
static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
|
635 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
636 |
BlockDriverCompletionFunc *cb, void *opaque)
|
637 |
{ |
638 |
BDRVQcowState *s = bs->opaque; |
639 |
QCowAIOCB *acb; |
640 |
|
641 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
642 |
|
643 |
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
|
644 |
if (!acb)
|
645 |
return NULL; |
646 |
|
647 |
qcow_aio_write_cb(acb, 0);
|
648 |
return &acb->common;
|
649 |
} |
650 |
|
651 |
static void qcow_close(BlockDriverState *bs) |
652 |
{ |
653 |
BDRVQcowState *s = bs->opaque; |
654 |
qemu_free(s->l1_table); |
655 |
qemu_free(s->l2_cache); |
656 |
qemu_free(s->cluster_cache); |
657 |
qemu_free(s->cluster_data); |
658 |
qcow2_refcount_close(bs); |
659 |
} |
660 |
|
661 |
/*
|
662 |
* Updates the variable length parts of the qcow2 header, i.e. the backing file
|
663 |
* name and all extensions. qcow2 was not designed to allow such changes, so if
|
664 |
* we run out of space (we can only use the first cluster) this function may
|
665 |
* fail.
|
666 |
*
|
667 |
* Returns 0 on success, -errno in error cases.
|
668 |
*/
|
669 |
static int qcow2_update_ext_header(BlockDriverState *bs, |
670 |
const char *backing_file, const char *backing_fmt) |
671 |
{ |
672 |
size_t backing_file_len = 0;
|
673 |
size_t backing_fmt_len = 0;
|
674 |
BDRVQcowState *s = bs->opaque; |
675 |
QCowExtension ext_backing_fmt = {0, 0}; |
676 |
int ret;
|
677 |
|
678 |
/* Backing file format doesn't make sense without a backing file */
|
679 |
if (backing_fmt && !backing_file) {
|
680 |
return -EINVAL;
|
681 |
} |
682 |
|
683 |
/* Prepare the backing file format extension if needed */
|
684 |
if (backing_fmt) {
|
685 |
ext_backing_fmt.len = cpu_to_be32(strlen(backing_fmt)); |
686 |
ext_backing_fmt.magic = cpu_to_be32(QCOW_EXT_MAGIC_BACKING_FORMAT); |
687 |
backing_fmt_len = ((sizeof(ext_backing_fmt)
|
688 |
+ strlen(backing_fmt) + 7) & ~7); |
689 |
} |
690 |
|
691 |
/* Check if we can fit the new header into the first cluster */
|
692 |
if (backing_file) {
|
693 |
backing_file_len = strlen(backing_file); |
694 |
} |
695 |
|
696 |
size_t header_size = sizeof(QCowHeader) + backing_file_len
|
697 |
+ backing_fmt_len; |
698 |
|
699 |
if (header_size > s->cluster_size) {
|
700 |
return -ENOSPC;
|
701 |
} |
702 |
|
703 |
/* Rewrite backing file name and qcow2 extensions */
|
704 |
size_t ext_size = header_size - sizeof(QCowHeader);
|
705 |
uint8_t buf[ext_size]; |
706 |
size_t offset = 0;
|
707 |
size_t backing_file_offset = 0;
|
708 |
|
709 |
if (backing_file) {
|
710 |
if (backing_fmt) {
|
711 |
int padding = backing_fmt_len -
|
712 |
(sizeof(ext_backing_fmt) + strlen(backing_fmt));
|
713 |
|
714 |
memcpy(buf + offset, &ext_backing_fmt, sizeof(ext_backing_fmt));
|
715 |
offset += sizeof(ext_backing_fmt);
|
716 |
|
717 |
memcpy(buf + offset, backing_fmt, strlen(backing_fmt)); |
718 |
offset += strlen(backing_fmt); |
719 |
|
720 |
memset(buf + offset, 0, padding);
|
721 |
offset += padding; |
722 |
} |
723 |
|
724 |
memcpy(buf + offset, backing_file, backing_file_len); |
725 |
backing_file_offset = sizeof(QCowHeader) + offset;
|
726 |
} |
727 |
|
728 |
ret = bdrv_pwrite(bs->file, sizeof(QCowHeader), buf, ext_size);
|
729 |
if (ret < 0) { |
730 |
goto fail;
|
731 |
} |
732 |
|
733 |
/* Update header fields */
|
734 |
uint64_t be_backing_file_offset = cpu_to_be64(backing_file_offset); |
735 |
uint32_t be_backing_file_size = cpu_to_be32(backing_file_len); |
736 |
|
737 |
ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, backing_file_offset), |
738 |
&be_backing_file_offset, sizeof(uint64_t));
|
739 |
if (ret < 0) { |
740 |
goto fail;
|
741 |
} |
742 |
|
743 |
ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, backing_file_size), |
744 |
&be_backing_file_size, sizeof(uint32_t));
|
745 |
if (ret < 0) { |
746 |
goto fail;
|
747 |
} |
748 |
|
749 |
ret = 0;
|
750 |
fail:
|
751 |
return ret;
|
752 |
} |
753 |
|
754 |
static int qcow2_change_backing_file(BlockDriverState *bs, |
755 |
const char *backing_file, const char *backing_fmt) |
756 |
{ |
757 |
return qcow2_update_ext_header(bs, backing_file, backing_fmt);
|
758 |
} |
759 |
|
760 |
static int get_bits_from_size(size_t size) |
761 |
{ |
762 |
int res = 0; |
763 |
|
764 |
if (size == 0) { |
765 |
return -1; |
766 |
} |
767 |
|
768 |
while (size != 1) { |
769 |
/* Not a power of two */
|
770 |
if (size & 1) { |
771 |
return -1; |
772 |
} |
773 |
|
774 |
size >>= 1;
|
775 |
res++; |
776 |
} |
777 |
|
778 |
return res;
|
779 |
} |
780 |
|
781 |
|
782 |
static int preallocate(BlockDriverState *bs) |
783 |
{ |
784 |
uint64_t nb_sectors; |
785 |
uint64_t offset; |
786 |
int num;
|
787 |
int ret;
|
788 |
QCowL2Meta meta; |
789 |
|
790 |
nb_sectors = bdrv_getlength(bs) >> 9;
|
791 |
offset = 0;
|
792 |
QLIST_INIT(&meta.dependent_requests); |
793 |
meta.cluster_offset = 0;
|
794 |
|
795 |
while (nb_sectors) {
|
796 |
num = MIN(nb_sectors, INT_MAX >> 9);
|
797 |
ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta);
|
798 |
|
799 |
if (ret < 0) { |
800 |
return -1; |
801 |
} |
802 |
|
803 |
if (qcow2_alloc_cluster_link_l2(bs, &meta) < 0) { |
804 |
qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters); |
805 |
return -1; |
806 |
} |
807 |
|
808 |
/* There are no dependent requests, but we need to remove our request
|
809 |
* from the list of in-flight requests */
|
810 |
run_dependent_requests(&meta); |
811 |
|
812 |
/* TODO Preallocate data if requested */
|
813 |
|
814 |
nb_sectors -= num; |
815 |
offset += num << 9;
|
816 |
} |
817 |
|
818 |
/*
|
819 |
* It is expected that the image file is large enough to actually contain
|
820 |
* all of the allocated clusters (otherwise we get failing reads after
|
821 |
* EOF). Extend the image to the last allocated sector.
|
822 |
*/
|
823 |
if (meta.cluster_offset != 0) { |
824 |
uint8_t buf[512];
|
825 |
memset(buf, 0, 512); |
826 |
bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1); |
827 |
} |
828 |
|
829 |
return 0; |
830 |
} |
831 |
|
832 |
static int qcow_create2(const char *filename, int64_t total_size, |
833 |
const char *backing_file, const char *backing_format, |
834 |
int flags, size_t cluster_size, int prealloc) |
835 |
{ |
836 |
|
837 |
int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
|
838 |
int ref_clusters, reftable_clusters, backing_format_len = 0; |
839 |
int rounded_ext_bf_len = 0; |
840 |
QCowHeader header; |
841 |
uint64_t tmp, offset; |
842 |
uint64_t old_ref_clusters; |
843 |
QCowCreateState s1, *s = &s1; |
844 |
QCowExtension ext_bf = {0, 0}; |
845 |
int ret;
|
846 |
|
847 |
memset(s, 0, sizeof(*s)); |
848 |
|
849 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
850 |
if (fd < 0) |
851 |
return -errno;
|
852 |
memset(&header, 0, sizeof(header)); |
853 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
854 |
header.version = cpu_to_be32(QCOW_VERSION); |
855 |
header.size = cpu_to_be64(total_size * 512);
|
856 |
header_size = sizeof(header);
|
857 |
backing_filename_len = 0;
|
858 |
if (backing_file) {
|
859 |
if (backing_format) {
|
860 |
ext_bf.magic = QCOW_EXT_MAGIC_BACKING_FORMAT; |
861 |
backing_format_len = strlen(backing_format); |
862 |
ext_bf.len = backing_format_len; |
863 |
rounded_ext_bf_len = (sizeof(ext_bf) + ext_bf.len + 7) & ~7; |
864 |
header_size += rounded_ext_bf_len; |
865 |
} |
866 |
header.backing_file_offset = cpu_to_be64(header_size); |
867 |
backing_filename_len = strlen(backing_file); |
868 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
869 |
header_size += backing_filename_len; |
870 |
} |
871 |
|
872 |
/* Cluster size */
|
873 |
s->cluster_bits = get_bits_from_size(cluster_size); |
874 |
if (s->cluster_bits < MIN_CLUSTER_BITS ||
|
875 |
s->cluster_bits > MAX_CLUSTER_BITS) |
876 |
{ |
877 |
fprintf(stderr, "Cluster size must be a power of two between "
|
878 |
"%d and %dk\n",
|
879 |
1 << MIN_CLUSTER_BITS,
|
880 |
1 << (MAX_CLUSTER_BITS - 10)); |
881 |
return -EINVAL;
|
882 |
} |
883 |
s->cluster_size = 1 << s->cluster_bits;
|
884 |
|
885 |
header.cluster_bits = cpu_to_be32(s->cluster_bits); |
886 |
header_size = (header_size + 7) & ~7; |
887 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
888 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
889 |
} else {
|
890 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
891 |
} |
892 |
l2_bits = s->cluster_bits - 3;
|
893 |
shift = s->cluster_bits + l2_bits; |
894 |
l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift); |
895 |
offset = align_offset(header_size, s->cluster_size); |
896 |
s->l1_table_offset = offset; |
897 |
header.l1_table_offset = cpu_to_be64(s->l1_table_offset); |
898 |
header.l1_size = cpu_to_be32(l1_size); |
899 |
offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
|
900 |
|
901 |
/* count how many refcount blocks needed */
|
902 |
|
903 |
#define NUM_CLUSTERS(bytes) \
|
904 |
(((bytes) + (s->cluster_size) - 1) / (s->cluster_size))
|
905 |
|
906 |
ref_clusters = NUM_CLUSTERS(NUM_CLUSTERS(offset) * sizeof(uint16_t));
|
907 |
|
908 |
do {
|
909 |
uint64_t image_clusters; |
910 |
old_ref_clusters = ref_clusters; |
911 |
|
912 |
/* Number of clusters used for the refcount table */
|
913 |
reftable_clusters = NUM_CLUSTERS(ref_clusters * sizeof(uint64_t));
|
914 |
|
915 |
/* Number of clusters that the whole image will have */
|
916 |
image_clusters = NUM_CLUSTERS(offset) + ref_clusters |
917 |
+ reftable_clusters; |
918 |
|
919 |
/* Number of refcount blocks needed for the image */
|
920 |
ref_clusters = NUM_CLUSTERS(image_clusters * sizeof(uint16_t));
|
921 |
|
922 |
} while (ref_clusters != old_ref_clusters);
|
923 |
|
924 |
s->refcount_table = qemu_mallocz(reftable_clusters * s->cluster_size); |
925 |
|
926 |
s->refcount_table_offset = offset; |
927 |
header.refcount_table_offset = cpu_to_be64(offset); |
928 |
header.refcount_table_clusters = cpu_to_be32(reftable_clusters); |
929 |
offset += (reftable_clusters * s->cluster_size); |
930 |
s->refcount_block_offset = offset; |
931 |
|
932 |
for (i=0; i < ref_clusters; i++) { |
933 |
s->refcount_table[i] = cpu_to_be64(offset); |
934 |
offset += s->cluster_size; |
935 |
} |
936 |
|
937 |
s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size); |
938 |
|
939 |
/* update refcounts */
|
940 |
qcow2_create_refcount_update(s, 0, header_size);
|
941 |
qcow2_create_refcount_update(s, s->l1_table_offset, |
942 |
l1_size * sizeof(uint64_t));
|
943 |
qcow2_create_refcount_update(s, s->refcount_table_offset, |
944 |
reftable_clusters * s->cluster_size); |
945 |
qcow2_create_refcount_update(s, s->refcount_block_offset, |
946 |
ref_clusters * s->cluster_size); |
947 |
|
948 |
/* write all the data */
|
949 |
ret = qemu_write_full(fd, &header, sizeof(header));
|
950 |
if (ret != sizeof(header)) { |
951 |
ret = -errno; |
952 |
goto exit;
|
953 |
} |
954 |
if (backing_file) {
|
955 |
if (backing_format_len) {
|
956 |
char zero[16]; |
957 |
int padding = rounded_ext_bf_len - (ext_bf.len + sizeof(ext_bf)); |
958 |
|
959 |
memset(zero, 0, sizeof(zero)); |
960 |
cpu_to_be32s(&ext_bf.magic); |
961 |
cpu_to_be32s(&ext_bf.len); |
962 |
ret = qemu_write_full(fd, &ext_bf, sizeof(ext_bf));
|
963 |
if (ret != sizeof(ext_bf)) { |
964 |
ret = -errno; |
965 |
goto exit;
|
966 |
} |
967 |
ret = qemu_write_full(fd, backing_format, backing_format_len); |
968 |
if (ret != backing_format_len) {
|
969 |
ret = -errno; |
970 |
goto exit;
|
971 |
} |
972 |
if (padding > 0) { |
973 |
ret = qemu_write_full(fd, zero, padding); |
974 |
if (ret != padding) {
|
975 |
ret = -errno; |
976 |
goto exit;
|
977 |
} |
978 |
} |
979 |
} |
980 |
ret = qemu_write_full(fd, backing_file, backing_filename_len); |
981 |
if (ret != backing_filename_len) {
|
982 |
ret = -errno; |
983 |
goto exit;
|
984 |
} |
985 |
} |
986 |
lseek(fd, s->l1_table_offset, SEEK_SET); |
987 |
tmp = 0;
|
988 |
for(i = 0;i < l1_size; i++) { |
989 |
ret = qemu_write_full(fd, &tmp, sizeof(tmp));
|
990 |
if (ret != sizeof(tmp)) { |
991 |
ret = -errno; |
992 |
goto exit;
|
993 |
} |
994 |
} |
995 |
lseek(fd, s->refcount_table_offset, SEEK_SET); |
996 |
ret = qemu_write_full(fd, s->refcount_table, |
997 |
reftable_clusters * s->cluster_size); |
998 |
if (ret != reftable_clusters * s->cluster_size) {
|
999 |
ret = -errno; |
1000 |
goto exit;
|
1001 |
} |
1002 |
|
1003 |
lseek(fd, s->refcount_block_offset, SEEK_SET); |
1004 |
ret = qemu_write_full(fd, s->refcount_block, |
1005 |
ref_clusters * s->cluster_size); |
1006 |
if (ret != ref_clusters * s->cluster_size) {
|
1007 |
ret = -errno; |
1008 |
goto exit;
|
1009 |
} |
1010 |
|
1011 |
ret = 0;
|
1012 |
exit:
|
1013 |
qemu_free(s->refcount_table); |
1014 |
qemu_free(s->refcount_block); |
1015 |
close(fd); |
1016 |
|
1017 |
/* Preallocate metadata */
|
1018 |
if (ret == 0 && prealloc) { |
1019 |
BlockDriverState *bs; |
1020 |
BlockDriver *drv = bdrv_find_format("qcow2");
|
1021 |
bs = bdrv_new("");
|
1022 |
bdrv_open(bs, filename, BDRV_O_CACHE_WB | BDRV_O_RDWR, drv); |
1023 |
preallocate(bs); |
1024 |
bdrv_close(bs); |
1025 |
} |
1026 |
|
1027 |
return ret;
|
1028 |
} |
1029 |
|
1030 |
static int qcow_create(const char *filename, QEMUOptionParameter *options) |
1031 |
{ |
1032 |
const char *backing_file = NULL; |
1033 |
const char *backing_fmt = NULL; |
1034 |
uint64_t sectors = 0;
|
1035 |
int flags = 0; |
1036 |
size_t cluster_size = 65536;
|
1037 |
int prealloc = 0; |
1038 |
|
1039 |
/* Read out options */
|
1040 |
while (options && options->name) {
|
1041 |
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
1042 |
sectors = options->value.n / 512;
|
1043 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { |
1044 |
backing_file = options->value.s; |
1045 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { |
1046 |
backing_fmt = options->value.s; |
1047 |
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { |
1048 |
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
1049 |
} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { |
1050 |
if (options->value.n) {
|
1051 |
cluster_size = options->value.n; |
1052 |
} |
1053 |
} else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) { |
1054 |
if (!options->value.s || !strcmp(options->value.s, "off")) { |
1055 |
prealloc = 0;
|
1056 |
} else if (!strcmp(options->value.s, "metadata")) { |
1057 |
prealloc = 1;
|
1058 |
} else {
|
1059 |
fprintf(stderr, "Invalid preallocation mode: '%s'\n",
|
1060 |
options->value.s); |
1061 |
return -EINVAL;
|
1062 |
} |
1063 |
} |
1064 |
options++; |
1065 |
} |
1066 |
|
1067 |
if (backing_file && prealloc) {
|
1068 |
fprintf(stderr, "Backing file and preallocation cannot be used at "
|
1069 |
"the same time\n");
|
1070 |
return -EINVAL;
|
1071 |
} |
1072 |
|
1073 |
return qcow_create2(filename, sectors, backing_file, backing_fmt, flags,
|
1074 |
cluster_size, prealloc); |
1075 |
} |
1076 |
|
1077 |
static int qcow_make_empty(BlockDriverState *bs) |
1078 |
{ |
1079 |
#if 0
|
1080 |
/* XXX: not correct */
|
1081 |
BDRVQcowState *s = bs->opaque;
|
1082 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
1083 |
int ret;
|
1084 |
|
1085 |
memset(s->l1_table, 0, l1_length);
|
1086 |
if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
1087 |
return -1;
|
1088 |
ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
|
1089 |
if (ret < 0)
|
1090 |
return ret;
|
1091 |
|
1092 |
l2_cache_reset(bs);
|
1093 |
#endif
|
1094 |
return 0; |
1095 |
} |
1096 |
|
1097 |
static int qcow2_truncate(BlockDriverState *bs, int64_t offset) |
1098 |
{ |
1099 |
BDRVQcowState *s = bs->opaque; |
1100 |
int ret, new_l1_size;
|
1101 |
|
1102 |
if (offset & 511) { |
1103 |
return -EINVAL;
|
1104 |
} |
1105 |
|
1106 |
/* cannot proceed if image has snapshots */
|
1107 |
if (s->nb_snapshots) {
|
1108 |
return -ENOTSUP;
|
1109 |
} |
1110 |
|
1111 |
/* shrinking is currently not supported */
|
1112 |
if (offset < bs->total_sectors * 512) { |
1113 |
return -ENOTSUP;
|
1114 |
} |
1115 |
|
1116 |
new_l1_size = size_to_l1(s, offset); |
1117 |
ret = qcow2_grow_l1_table(bs, new_l1_size); |
1118 |
if (ret < 0) { |
1119 |
return ret;
|
1120 |
} |
1121 |
|
1122 |
/* write updated header.size */
|
1123 |
offset = cpu_to_be64(offset); |
1124 |
ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, size), |
1125 |
&offset, sizeof(uint64_t));
|
1126 |
if (ret < 0) { |
1127 |
return ret;
|
1128 |
} |
1129 |
|
1130 |
s->l1_vm_state_index = new_l1_size; |
1131 |
return 0; |
1132 |
} |
1133 |
|
1134 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
1135 |
tables to avoid losing bytes in alignment */
|
1136 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
1137 |
const uint8_t *buf, int nb_sectors) |
1138 |
{ |
1139 |
BDRVQcowState *s = bs->opaque; |
1140 |
z_stream strm; |
1141 |
int ret, out_len;
|
1142 |
uint8_t *out_buf; |
1143 |
uint64_t cluster_offset; |
1144 |
|
1145 |
if (nb_sectors == 0) { |
1146 |
/* align end of file to a sector boundary to ease reading with
|
1147 |
sector based I/Os */
|
1148 |
cluster_offset = bdrv_getlength(bs->file); |
1149 |
cluster_offset = (cluster_offset + 511) & ~511; |
1150 |
bdrv_truncate(bs->file, cluster_offset); |
1151 |
return 0; |
1152 |
} |
1153 |
|
1154 |
if (nb_sectors != s->cluster_sectors)
|
1155 |
return -EINVAL;
|
1156 |
|
1157 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
1158 |
|
1159 |
/* best compression, small window, no zlib header */
|
1160 |
memset(&strm, 0, sizeof(strm)); |
1161 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
1162 |
Z_DEFLATED, -12,
|
1163 |
9, Z_DEFAULT_STRATEGY);
|
1164 |
if (ret != 0) { |
1165 |
qemu_free(out_buf); |
1166 |
return -1; |
1167 |
} |
1168 |
|
1169 |
strm.avail_in = s->cluster_size; |
1170 |
strm.next_in = (uint8_t *)buf; |
1171 |
strm.avail_out = s->cluster_size; |
1172 |
strm.next_out = out_buf; |
1173 |
|
1174 |
ret = deflate(&strm, Z_FINISH); |
1175 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
1176 |
qemu_free(out_buf); |
1177 |
deflateEnd(&strm); |
1178 |
return -1; |
1179 |
} |
1180 |
out_len = strm.next_out - out_buf; |
1181 |
|
1182 |
deflateEnd(&strm); |
1183 |
|
1184 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
1185 |
/* could not compress: write normal cluster */
|
1186 |
bdrv_write(bs, sector_num, buf, s->cluster_sectors); |
1187 |
} else {
|
1188 |
cluster_offset = qcow2_alloc_compressed_cluster_offset(bs, |
1189 |
sector_num << 9, out_len);
|
1190 |
if (!cluster_offset)
|
1191 |
return -1; |
1192 |
cluster_offset &= s->cluster_offset_mask; |
1193 |
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); |
1194 |
if (bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len) != out_len) {
|
1195 |
qemu_free(out_buf); |
1196 |
return -1; |
1197 |
} |
1198 |
} |
1199 |
|
1200 |
qemu_free(out_buf); |
1201 |
return 0; |
1202 |
} |
1203 |
|
1204 |
static void qcow_flush(BlockDriverState *bs) |
1205 |
{ |
1206 |
bdrv_flush(bs->file); |
1207 |
} |
1208 |
|
1209 |
static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs,
|
1210 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1211 |
{ |
1212 |
return bdrv_aio_flush(bs->file, cb, opaque);
|
1213 |
} |
1214 |
|
1215 |
static int64_t qcow_vm_state_offset(BDRVQcowState *s)
|
1216 |
{ |
1217 |
return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
|
1218 |
} |
1219 |
|
1220 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
1221 |
{ |
1222 |
BDRVQcowState *s = bs->opaque; |
1223 |
bdi->cluster_size = s->cluster_size; |
1224 |
bdi->vm_state_offset = qcow_vm_state_offset(s); |
1225 |
return 0; |
1226 |
} |
1227 |
|
1228 |
|
1229 |
static int qcow_check(BlockDriverState *bs) |
1230 |
{ |
1231 |
return qcow2_check_refcounts(bs);
|
1232 |
} |
1233 |
|
1234 |
#if 0
|
1235 |
static void dump_refcounts(BlockDriverState *bs)
|
1236 |
{
|
1237 |
BDRVQcowState *s = bs->opaque;
|
1238 |
int64_t nb_clusters, k, k1, size;
|
1239 |
int refcount;
|
1240 |
|
1241 |
size = bdrv_getlength(bs->file);
|
1242 |
nb_clusters = size_to_clusters(s, size);
|
1243 |
for(k = 0; k < nb_clusters;) {
|
1244 |
k1 = k;
|
1245 |
refcount = get_refcount(bs, k);
|
1246 |
k++;
|
1247 |
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
1248 |
k++;
|
1249 |
printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount,
|
1250 |
k - k1);
|
1251 |
}
|
1252 |
}
|
1253 |
#endif
|
1254 |
|
1255 |
static int qcow_save_vmstate(BlockDriverState *bs, const uint8_t *buf, |
1256 |
int64_t pos, int size)
|
1257 |
{ |
1258 |
BDRVQcowState *s = bs->opaque; |
1259 |
int growable = bs->growable;
|
1260 |
int ret;
|
1261 |
|
1262 |
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); |
1263 |
bs->growable = 1;
|
1264 |
ret = bdrv_pwrite(bs, qcow_vm_state_offset(s) + pos, buf, size); |
1265 |
bs->growable = growable; |
1266 |
|
1267 |
return ret;
|
1268 |
} |
1269 |
|
1270 |
static int qcow_load_vmstate(BlockDriverState *bs, uint8_t *buf, |
1271 |
int64_t pos, int size)
|
1272 |
{ |
1273 |
BDRVQcowState *s = bs->opaque; |
1274 |
int growable = bs->growable;
|
1275 |
int ret;
|
1276 |
|
1277 |
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); |
1278 |
bs->growable = 1;
|
1279 |
ret = bdrv_pread(bs, qcow_vm_state_offset(s) + pos, buf, size); |
1280 |
bs->growable = growable; |
1281 |
|
1282 |
return ret;
|
1283 |
} |
1284 |
|
1285 |
static QEMUOptionParameter qcow_create_options[] = {
|
1286 |
{ |
1287 |
.name = BLOCK_OPT_SIZE, |
1288 |
.type = OPT_SIZE, |
1289 |
.help = "Virtual disk size"
|
1290 |
}, |
1291 |
{ |
1292 |
.name = BLOCK_OPT_BACKING_FILE, |
1293 |
.type = OPT_STRING, |
1294 |
.help = "File name of a base image"
|
1295 |
}, |
1296 |
{ |
1297 |
.name = BLOCK_OPT_BACKING_FMT, |
1298 |
.type = OPT_STRING, |
1299 |
.help = "Image format of the base image"
|
1300 |
}, |
1301 |
{ |
1302 |
.name = BLOCK_OPT_ENCRYPT, |
1303 |
.type = OPT_FLAG, |
1304 |
.help = "Encrypt the image"
|
1305 |
}, |
1306 |
{ |
1307 |
.name = BLOCK_OPT_CLUSTER_SIZE, |
1308 |
.type = OPT_SIZE, |
1309 |
.help = "qcow2 cluster size"
|
1310 |
}, |
1311 |
{ |
1312 |
.name = BLOCK_OPT_PREALLOC, |
1313 |
.type = OPT_STRING, |
1314 |
.help = "Preallocation mode (allowed values: off, metadata)"
|
1315 |
}, |
1316 |
{ NULL }
|
1317 |
}; |
1318 |
|
1319 |
static BlockDriver bdrv_qcow2 = {
|
1320 |
.format_name = "qcow2",
|
1321 |
.instance_size = sizeof(BDRVQcowState),
|
1322 |
.bdrv_probe = qcow_probe, |
1323 |
.bdrv_open = qcow_open, |
1324 |
.bdrv_close = qcow_close, |
1325 |
.bdrv_create = qcow_create, |
1326 |
.bdrv_flush = qcow_flush, |
1327 |
.bdrv_is_allocated = qcow_is_allocated, |
1328 |
.bdrv_set_key = qcow_set_key, |
1329 |
.bdrv_make_empty = qcow_make_empty, |
1330 |
|
1331 |
.bdrv_aio_readv = qcow_aio_readv, |
1332 |
.bdrv_aio_writev = qcow_aio_writev, |
1333 |
.bdrv_aio_flush = qcow_aio_flush, |
1334 |
|
1335 |
.bdrv_truncate = qcow2_truncate, |
1336 |
.bdrv_write_compressed = qcow_write_compressed, |
1337 |
|
1338 |
.bdrv_snapshot_create = qcow2_snapshot_create, |
1339 |
.bdrv_snapshot_goto = qcow2_snapshot_goto, |
1340 |
.bdrv_snapshot_delete = qcow2_snapshot_delete, |
1341 |
.bdrv_snapshot_list = qcow2_snapshot_list, |
1342 |
.bdrv_get_info = qcow_get_info, |
1343 |
|
1344 |
.bdrv_save_vmstate = qcow_save_vmstate, |
1345 |
.bdrv_load_vmstate = qcow_load_vmstate, |
1346 |
|
1347 |
.bdrv_change_backing_file = qcow2_change_backing_file, |
1348 |
|
1349 |
.create_options = qcow_create_options, |
1350 |
.bdrv_check = qcow_check, |
1351 |
}; |
1352 |
|
1353 |
static void bdrv_qcow2_init(void) |
1354 |
{ |
1355 |
bdrv_register(&bdrv_qcow2); |
1356 |
} |
1357 |
|
1358 |
block_init(bdrv_qcow2_init); |