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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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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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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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* 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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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)) |
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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); |
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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; |
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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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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 |
} |
205 |
} |
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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;
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238 |
|
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#ifdef DEBUG_ALLOC
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qcow2_check_refcounts(bs); |
241 |
#endif
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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
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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 |
int ret;
|
301 |
|
302 |
*pnum = nb_sectors; |
303 |
/* FIXME We can get errors here, but the bdrv_is_allocated interface can't
|
304 |
* pass them on today */
|
305 |
ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
|
306 |
if (ret < 0) { |
307 |
*pnum = 0;
|
308 |
} |
309 |
|
310 |
return (cluster_offset != 0); |
311 |
} |
312 |
|
313 |
/* handle reading after the end of the backing file */
|
314 |
int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
|
315 |
int64_t sector_num, int nb_sectors)
|
316 |
{ |
317 |
int n1;
|
318 |
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
319 |
return nb_sectors;
|
320 |
if (sector_num >= bs->total_sectors)
|
321 |
n1 = 0;
|
322 |
else
|
323 |
n1 = bs->total_sectors - sector_num; |
324 |
|
325 |
qemu_iovec_memset(qiov, 0, 512 * (nb_sectors - n1)); |
326 |
|
327 |
return n1;
|
328 |
} |
329 |
|
330 |
typedef struct QCowAIOCB { |
331 |
BlockDriverAIOCB common; |
332 |
int64_t sector_num; |
333 |
QEMUIOVector *qiov; |
334 |
int remaining_sectors;
|
335 |
int cur_nr_sectors; /* number of sectors in current iteration */ |
336 |
uint64_t bytes_done; |
337 |
uint64_t cluster_offset; |
338 |
uint8_t *cluster_data; |
339 |
BlockDriverAIOCB *hd_aiocb; |
340 |
QEMUIOVector hd_qiov; |
341 |
QEMUBH *bh; |
342 |
QCowL2Meta l2meta; |
343 |
QLIST_ENTRY(QCowAIOCB) next_depend; |
344 |
} QCowAIOCB; |
345 |
|
346 |
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) |
347 |
{ |
348 |
QCowAIOCB *acb = container_of(blockacb, QCowAIOCB, common); |
349 |
if (acb->hd_aiocb)
|
350 |
bdrv_aio_cancel(acb->hd_aiocb); |
351 |
qemu_aio_release(acb); |
352 |
} |
353 |
|
354 |
static AIOPool qcow_aio_pool = {
|
355 |
.aiocb_size = sizeof(QCowAIOCB),
|
356 |
.cancel = qcow_aio_cancel, |
357 |
}; |
358 |
|
359 |
static void qcow_aio_read_cb(void *opaque, int ret); |
360 |
static void qcow_aio_read_bh(void *opaque) |
361 |
{ |
362 |
QCowAIOCB *acb = opaque; |
363 |
qemu_bh_delete(acb->bh); |
364 |
acb->bh = NULL;
|
365 |
qcow_aio_read_cb(opaque, 0);
|
366 |
} |
367 |
|
368 |
static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb) |
369 |
{ |
370 |
if (acb->bh)
|
371 |
return -EIO;
|
372 |
|
373 |
acb->bh = qemu_bh_new(cb, acb); |
374 |
if (!acb->bh)
|
375 |
return -EIO;
|
376 |
|
377 |
qemu_bh_schedule(acb->bh); |
378 |
|
379 |
return 0; |
380 |
} |
381 |
|
382 |
static void qcow_aio_read_cb(void *opaque, int ret) |
383 |
{ |
384 |
QCowAIOCB *acb = opaque; |
385 |
BlockDriverState *bs = acb->common.bs; |
386 |
BDRVQcowState *s = bs->opaque; |
387 |
int index_in_cluster, n1;
|
388 |
|
389 |
acb->hd_aiocb = NULL;
|
390 |
if (ret < 0) |
391 |
goto done;
|
392 |
|
393 |
/* post process the read buffer */
|
394 |
if (!acb->cluster_offset) {
|
395 |
/* nothing to do */
|
396 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
397 |
/* nothing to do */
|
398 |
} else {
|
399 |
if (s->crypt_method) {
|
400 |
qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data, |
401 |
acb->cluster_data, acb->cur_nr_sectors, 0, &s->aes_decrypt_key);
|
402 |
qemu_iovec_reset(&acb->hd_qiov); |
403 |
qemu_iovec_copy(&acb->hd_qiov, acb->qiov, acb->bytes_done, |
404 |
acb->cur_nr_sectors * 512);
|
405 |
qemu_iovec_from_buffer(&acb->hd_qiov, acb->cluster_data, |
406 |
512 * acb->cur_nr_sectors);
|
407 |
} |
408 |
} |
409 |
|
410 |
acb->remaining_sectors -= acb->cur_nr_sectors; |
411 |
acb->sector_num += acb->cur_nr_sectors; |
412 |
acb->bytes_done += acb->cur_nr_sectors * 512;
|
413 |
|
414 |
if (acb->remaining_sectors == 0) { |
415 |
/* request completed */
|
416 |
ret = 0;
|
417 |
goto done;
|
418 |
} |
419 |
|
420 |
/* prepare next AIO request */
|
421 |
acb->cur_nr_sectors = acb->remaining_sectors; |
422 |
if (s->crypt_method) {
|
423 |
acb->cur_nr_sectors = MIN(acb->cur_nr_sectors, |
424 |
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); |
425 |
} |
426 |
|
427 |
ret = qcow2_get_cluster_offset(bs, acb->sector_num << 9,
|
428 |
&acb->cur_nr_sectors, &acb->cluster_offset); |
429 |
if (ret < 0) { |
430 |
goto done;
|
431 |
} |
432 |
|
433 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
434 |
|
435 |
qemu_iovec_reset(&acb->hd_qiov); |
436 |
qemu_iovec_copy(&acb->hd_qiov, acb->qiov, acb->bytes_done, |
437 |
acb->cur_nr_sectors * 512);
|
438 |
|
439 |
if (!acb->cluster_offset) {
|
440 |
|
441 |
if (bs->backing_hd) {
|
442 |
/* read from the base image */
|
443 |
n1 = qcow2_backing_read1(bs->backing_hd, &acb->hd_qiov, |
444 |
acb->sector_num, acb->cur_nr_sectors); |
445 |
if (n1 > 0) { |
446 |
BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); |
447 |
acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num, |
448 |
&acb->hd_qiov, acb->cur_nr_sectors, |
449 |
qcow_aio_read_cb, acb); |
450 |
if (acb->hd_aiocb == NULL) |
451 |
goto done;
|
452 |
} else {
|
453 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
454 |
if (ret < 0) |
455 |
goto done;
|
456 |
} |
457 |
} else {
|
458 |
/* Note: in this case, no need to wait */
|
459 |
qemu_iovec_memset(&acb->hd_qiov, 0, 512 * acb->cur_nr_sectors); |
460 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
461 |
if (ret < 0) |
462 |
goto done;
|
463 |
} |
464 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
465 |
/* add AIO support for compressed blocks ? */
|
466 |
if (qcow2_decompress_cluster(bs, acb->cluster_offset) < 0) |
467 |
goto done;
|
468 |
|
469 |
qemu_iovec_from_buffer(&acb->hd_qiov, |
470 |
s->cluster_cache + index_in_cluster * 512,
|
471 |
512 * acb->cur_nr_sectors);
|
472 |
|
473 |
ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
474 |
if (ret < 0) |
475 |
goto done;
|
476 |
} else {
|
477 |
if ((acb->cluster_offset & 511) != 0) { |
478 |
ret = -EIO; |
479 |
goto done;
|
480 |
} |
481 |
|
482 |
if (s->crypt_method) {
|
483 |
/*
|
484 |
* For encrypted images, read everything into a temporary
|
485 |
* contiguous buffer on which the AES functions can work.
|
486 |
*/
|
487 |
if (!acb->cluster_data) {
|
488 |
acb->cluster_data = |
489 |
qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
490 |
} |
491 |
|
492 |
assert(acb->cur_nr_sectors <= |
493 |
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); |
494 |
qemu_iovec_reset(&acb->hd_qiov); |
495 |
qemu_iovec_add(&acb->hd_qiov, acb->cluster_data, |
496 |
512 * acb->cur_nr_sectors);
|
497 |
} |
498 |
|
499 |
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); |
500 |
acb->hd_aiocb = bdrv_aio_readv(bs->file, |
501 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
502 |
&acb->hd_qiov, acb->cur_nr_sectors, |
503 |
qcow_aio_read_cb, acb); |
504 |
if (acb->hd_aiocb == NULL) { |
505 |
ret = -EIO; |
506 |
goto done;
|
507 |
} |
508 |
} |
509 |
|
510 |
return;
|
511 |
done:
|
512 |
acb->common.cb(acb->common.opaque, ret); |
513 |
qemu_iovec_destroy(&acb->hd_qiov); |
514 |
qemu_aio_release(acb); |
515 |
} |
516 |
|
517 |
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
|
518 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
519 |
BlockDriverCompletionFunc *cb, void *opaque, int is_write) |
520 |
{ |
521 |
QCowAIOCB *acb; |
522 |
|
523 |
acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque); |
524 |
if (!acb)
|
525 |
return NULL; |
526 |
acb->hd_aiocb = NULL;
|
527 |
acb->sector_num = sector_num; |
528 |
acb->qiov = qiov; |
529 |
|
530 |
qemu_iovec_init(&acb->hd_qiov, qiov->niov); |
531 |
|
532 |
acb->bytes_done = 0;
|
533 |
acb->remaining_sectors = nb_sectors; |
534 |
acb->cur_nr_sectors = 0;
|
535 |
acb->cluster_offset = 0;
|
536 |
acb->l2meta.nb_clusters = 0;
|
537 |
QLIST_INIT(&acb->l2meta.dependent_requests); |
538 |
return acb;
|
539 |
} |
540 |
|
541 |
static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
|
542 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
543 |
BlockDriverCompletionFunc *cb, void *opaque)
|
544 |
{ |
545 |
QCowAIOCB *acb; |
546 |
|
547 |
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
|
548 |
if (!acb)
|
549 |
return NULL; |
550 |
|
551 |
qcow_aio_read_cb(acb, 0);
|
552 |
return &acb->common;
|
553 |
} |
554 |
|
555 |
static void qcow_aio_write_cb(void *opaque, int ret); |
556 |
|
557 |
static void run_dependent_requests(QCowL2Meta *m) |
558 |
{ |
559 |
QCowAIOCB *req; |
560 |
QCowAIOCB *next; |
561 |
|
562 |
/* Take the request off the list of running requests */
|
563 |
if (m->nb_clusters != 0) { |
564 |
QLIST_REMOVE(m, next_in_flight); |
565 |
} |
566 |
|
567 |
/* Restart all dependent requests */
|
568 |
QLIST_FOREACH_SAFE(req, &m->dependent_requests, next_depend, next) { |
569 |
qcow_aio_write_cb(req, 0);
|
570 |
} |
571 |
|
572 |
/* Empty the list for the next part of the request */
|
573 |
QLIST_INIT(&m->dependent_requests); |
574 |
} |
575 |
|
576 |
static void qcow_aio_write_cb(void *opaque, int ret) |
577 |
{ |
578 |
QCowAIOCB *acb = opaque; |
579 |
BlockDriverState *bs = acb->common.bs; |
580 |
BDRVQcowState *s = bs->opaque; |
581 |
int index_in_cluster;
|
582 |
int n_end;
|
583 |
|
584 |
acb->hd_aiocb = NULL;
|
585 |
|
586 |
if (ret >= 0) { |
587 |
ret = qcow2_alloc_cluster_link_l2(bs, &acb->l2meta); |
588 |
} |
589 |
|
590 |
run_dependent_requests(&acb->l2meta); |
591 |
|
592 |
if (ret < 0) |
593 |
goto done;
|
594 |
|
595 |
acb->remaining_sectors -= acb->cur_nr_sectors; |
596 |
acb->sector_num += acb->cur_nr_sectors; |
597 |
acb->bytes_done += acb->cur_nr_sectors * 512;
|
598 |
|
599 |
if (acb->remaining_sectors == 0) { |
600 |
/* request completed */
|
601 |
ret = 0;
|
602 |
goto done;
|
603 |
} |
604 |
|
605 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
606 |
n_end = index_in_cluster + acb->remaining_sectors; |
607 |
if (s->crypt_method &&
|
608 |
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) |
609 |
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
610 |
|
611 |
ret = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9,
|
612 |
index_in_cluster, n_end, &acb->cur_nr_sectors, &acb->l2meta); |
613 |
if (ret < 0) { |
614 |
goto done;
|
615 |
} |
616 |
|
617 |
acb->cluster_offset = acb->l2meta.cluster_offset; |
618 |
|
619 |
/* Need to wait for another request? If so, we are done for now. */
|
620 |
if (acb->l2meta.nb_clusters == 0 && acb->l2meta.depends_on != NULL) { |
621 |
QLIST_INSERT_HEAD(&acb->l2meta.depends_on->dependent_requests, |
622 |
acb, next_depend); |
623 |
return;
|
624 |
} |
625 |
|
626 |
assert((acb->cluster_offset & 511) == 0); |
627 |
|
628 |
qemu_iovec_reset(&acb->hd_qiov); |
629 |
qemu_iovec_copy(&acb->hd_qiov, acb->qiov, acb->bytes_done, |
630 |
acb->cur_nr_sectors * 512);
|
631 |
|
632 |
if (s->crypt_method) {
|
633 |
if (!acb->cluster_data) {
|
634 |
acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * |
635 |
s->cluster_size); |
636 |
} |
637 |
|
638 |
assert(acb->hd_qiov.size <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
639 |
qemu_iovec_to_buffer(&acb->hd_qiov, acb->cluster_data); |
640 |
|
641 |
qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data, |
642 |
acb->cluster_data, acb->cur_nr_sectors, 1, &s->aes_encrypt_key);
|
643 |
|
644 |
qemu_iovec_reset(&acb->hd_qiov); |
645 |
qemu_iovec_add(&acb->hd_qiov, acb->cluster_data, |
646 |
acb->cur_nr_sectors * 512);
|
647 |
} |
648 |
|
649 |
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); |
650 |
acb->hd_aiocb = bdrv_aio_writev(bs->file, |
651 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
652 |
&acb->hd_qiov, acb->cur_nr_sectors, |
653 |
qcow_aio_write_cb, acb); |
654 |
if (acb->hd_aiocb == NULL) { |
655 |
ret = -EIO; |
656 |
goto fail;
|
657 |
} |
658 |
|
659 |
return;
|
660 |
|
661 |
fail:
|
662 |
if (acb->l2meta.nb_clusters != 0) { |
663 |
QLIST_REMOVE(&acb->l2meta, next_in_flight); |
664 |
} |
665 |
done:
|
666 |
acb->common.cb(acb->common.opaque, ret); |
667 |
qemu_iovec_destroy(&acb->hd_qiov); |
668 |
qemu_aio_release(acb); |
669 |
} |
670 |
|
671 |
static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
|
672 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
673 |
BlockDriverCompletionFunc *cb, void *opaque)
|
674 |
{ |
675 |
BDRVQcowState *s = bs->opaque; |
676 |
QCowAIOCB *acb; |
677 |
|
678 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
679 |
|
680 |
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
|
681 |
if (!acb)
|
682 |
return NULL; |
683 |
|
684 |
qcow_aio_write_cb(acb, 0);
|
685 |
return &acb->common;
|
686 |
} |
687 |
|
688 |
static void qcow_close(BlockDriverState *bs) |
689 |
{ |
690 |
BDRVQcowState *s = bs->opaque; |
691 |
qemu_free(s->l1_table); |
692 |
qemu_free(s->l2_cache); |
693 |
qemu_free(s->cluster_cache); |
694 |
qemu_free(s->cluster_data); |
695 |
qcow2_refcount_close(bs); |
696 |
} |
697 |
|
698 |
/*
|
699 |
* Updates the variable length parts of the qcow2 header, i.e. the backing file
|
700 |
* name and all extensions. qcow2 was not designed to allow such changes, so if
|
701 |
* we run out of space (we can only use the first cluster) this function may
|
702 |
* fail.
|
703 |
*
|
704 |
* Returns 0 on success, -errno in error cases.
|
705 |
*/
|
706 |
static int qcow2_update_ext_header(BlockDriverState *bs, |
707 |
const char *backing_file, const char *backing_fmt) |
708 |
{ |
709 |
size_t backing_file_len = 0;
|
710 |
size_t backing_fmt_len = 0;
|
711 |
BDRVQcowState *s = bs->opaque; |
712 |
QCowExtension ext_backing_fmt = {0, 0}; |
713 |
int ret;
|
714 |
|
715 |
/* Backing file format doesn't make sense without a backing file */
|
716 |
if (backing_fmt && !backing_file) {
|
717 |
return -EINVAL;
|
718 |
} |
719 |
|
720 |
/* Prepare the backing file format extension if needed */
|
721 |
if (backing_fmt) {
|
722 |
ext_backing_fmt.len = cpu_to_be32(strlen(backing_fmt)); |
723 |
ext_backing_fmt.magic = cpu_to_be32(QCOW_EXT_MAGIC_BACKING_FORMAT); |
724 |
backing_fmt_len = ((sizeof(ext_backing_fmt)
|
725 |
+ strlen(backing_fmt) + 7) & ~7); |
726 |
} |
727 |
|
728 |
/* Check if we can fit the new header into the first cluster */
|
729 |
if (backing_file) {
|
730 |
backing_file_len = strlen(backing_file); |
731 |
} |
732 |
|
733 |
size_t header_size = sizeof(QCowHeader) + backing_file_len
|
734 |
+ backing_fmt_len; |
735 |
|
736 |
if (header_size > s->cluster_size) {
|
737 |
return -ENOSPC;
|
738 |
} |
739 |
|
740 |
/* Rewrite backing file name and qcow2 extensions */
|
741 |
size_t ext_size = header_size - sizeof(QCowHeader);
|
742 |
uint8_t buf[ext_size]; |
743 |
size_t offset = 0;
|
744 |
size_t backing_file_offset = 0;
|
745 |
|
746 |
if (backing_file) {
|
747 |
if (backing_fmt) {
|
748 |
int padding = backing_fmt_len -
|
749 |
(sizeof(ext_backing_fmt) + strlen(backing_fmt));
|
750 |
|
751 |
memcpy(buf + offset, &ext_backing_fmt, sizeof(ext_backing_fmt));
|
752 |
offset += sizeof(ext_backing_fmt);
|
753 |
|
754 |
memcpy(buf + offset, backing_fmt, strlen(backing_fmt)); |
755 |
offset += strlen(backing_fmt); |
756 |
|
757 |
memset(buf + offset, 0, padding);
|
758 |
offset += padding; |
759 |
} |
760 |
|
761 |
memcpy(buf + offset, backing_file, backing_file_len); |
762 |
backing_file_offset = sizeof(QCowHeader) + offset;
|
763 |
} |
764 |
|
765 |
ret = bdrv_pwrite_sync(bs->file, sizeof(QCowHeader), buf, ext_size);
|
766 |
if (ret < 0) { |
767 |
goto fail;
|
768 |
} |
769 |
|
770 |
/* Update header fields */
|
771 |
uint64_t be_backing_file_offset = cpu_to_be64(backing_file_offset); |
772 |
uint32_t be_backing_file_size = cpu_to_be32(backing_file_len); |
773 |
|
774 |
ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_offset), |
775 |
&be_backing_file_offset, sizeof(uint64_t));
|
776 |
if (ret < 0) { |
777 |
goto fail;
|
778 |
} |
779 |
|
780 |
ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_size), |
781 |
&be_backing_file_size, sizeof(uint32_t));
|
782 |
if (ret < 0) { |
783 |
goto fail;
|
784 |
} |
785 |
|
786 |
ret = 0;
|
787 |
fail:
|
788 |
return ret;
|
789 |
} |
790 |
|
791 |
static int qcow2_change_backing_file(BlockDriverState *bs, |
792 |
const char *backing_file, const char *backing_fmt) |
793 |
{ |
794 |
return qcow2_update_ext_header(bs, backing_file, backing_fmt);
|
795 |
} |
796 |
|
797 |
static int get_bits_from_size(size_t size) |
798 |
{ |
799 |
int res = 0; |
800 |
|
801 |
if (size == 0) { |
802 |
return -1; |
803 |
} |
804 |
|
805 |
while (size != 1) { |
806 |
/* Not a power of two */
|
807 |
if (size & 1) { |
808 |
return -1; |
809 |
} |
810 |
|
811 |
size >>= 1;
|
812 |
res++; |
813 |
} |
814 |
|
815 |
return res;
|
816 |
} |
817 |
|
818 |
|
819 |
static int preallocate(BlockDriverState *bs) |
820 |
{ |
821 |
uint64_t nb_sectors; |
822 |
uint64_t offset; |
823 |
int num;
|
824 |
int ret;
|
825 |
QCowL2Meta meta; |
826 |
|
827 |
nb_sectors = bdrv_getlength(bs) >> 9;
|
828 |
offset = 0;
|
829 |
QLIST_INIT(&meta.dependent_requests); |
830 |
meta.cluster_offset = 0;
|
831 |
|
832 |
while (nb_sectors) {
|
833 |
num = MIN(nb_sectors, INT_MAX >> 9);
|
834 |
ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta);
|
835 |
if (ret < 0) { |
836 |
return ret;
|
837 |
} |
838 |
|
839 |
ret = qcow2_alloc_cluster_link_l2(bs, &meta); |
840 |
if (ret < 0) { |
841 |
qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters); |
842 |
return ret;
|
843 |
} |
844 |
|
845 |
/* There are no dependent requests, but we need to remove our request
|
846 |
* from the list of in-flight requests */
|
847 |
run_dependent_requests(&meta); |
848 |
|
849 |
/* TODO Preallocate data if requested */
|
850 |
|
851 |
nb_sectors -= num; |
852 |
offset += num << 9;
|
853 |
} |
854 |
|
855 |
/*
|
856 |
* It is expected that the image file is large enough to actually contain
|
857 |
* all of the allocated clusters (otherwise we get failing reads after
|
858 |
* EOF). Extend the image to the last allocated sector.
|
859 |
*/
|
860 |
if (meta.cluster_offset != 0) { |
861 |
uint8_t buf[512];
|
862 |
memset(buf, 0, 512); |
863 |
ret = bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1); |
864 |
if (ret < 0) { |
865 |
return ret;
|
866 |
} |
867 |
} |
868 |
|
869 |
return 0; |
870 |
} |
871 |
|
872 |
static int qcow_create2(const char *filename, int64_t total_size, |
873 |
const char *backing_file, const char *backing_format, |
874 |
int flags, size_t cluster_size, int prealloc) |
875 |
{ |
876 |
|
877 |
int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
|
878 |
int ref_clusters, reftable_clusters, backing_format_len = 0; |
879 |
int rounded_ext_bf_len = 0; |
880 |
QCowHeader header; |
881 |
uint64_t tmp, offset; |
882 |
uint64_t old_ref_clusters; |
883 |
QCowCreateState s1, *s = &s1; |
884 |
QCowExtension ext_bf = {0, 0}; |
885 |
int ret;
|
886 |
|
887 |
memset(s, 0, sizeof(*s)); |
888 |
|
889 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
890 |
if (fd < 0) |
891 |
return -errno;
|
892 |
memset(&header, 0, sizeof(header)); |
893 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
894 |
header.version = cpu_to_be32(QCOW_VERSION); |
895 |
header.size = cpu_to_be64(total_size * 512);
|
896 |
header_size = sizeof(header);
|
897 |
backing_filename_len = 0;
|
898 |
if (backing_file) {
|
899 |
if (backing_format) {
|
900 |
ext_bf.magic = QCOW_EXT_MAGIC_BACKING_FORMAT; |
901 |
backing_format_len = strlen(backing_format); |
902 |
ext_bf.len = backing_format_len; |
903 |
rounded_ext_bf_len = (sizeof(ext_bf) + ext_bf.len + 7) & ~7; |
904 |
header_size += rounded_ext_bf_len; |
905 |
} |
906 |
header.backing_file_offset = cpu_to_be64(header_size); |
907 |
backing_filename_len = strlen(backing_file); |
908 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
909 |
header_size += backing_filename_len; |
910 |
} |
911 |
|
912 |
/* Cluster size */
|
913 |
s->cluster_bits = get_bits_from_size(cluster_size); |
914 |
if (s->cluster_bits < MIN_CLUSTER_BITS ||
|
915 |
s->cluster_bits > MAX_CLUSTER_BITS) |
916 |
{ |
917 |
fprintf(stderr, "Cluster size must be a power of two between "
|
918 |
"%d and %dk\n",
|
919 |
1 << MIN_CLUSTER_BITS,
|
920 |
1 << (MAX_CLUSTER_BITS - 10)); |
921 |
return -EINVAL;
|
922 |
} |
923 |
s->cluster_size = 1 << s->cluster_bits;
|
924 |
|
925 |
header.cluster_bits = cpu_to_be32(s->cluster_bits); |
926 |
header_size = (header_size + 7) & ~7; |
927 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
928 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
929 |
} else {
|
930 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
931 |
} |
932 |
l2_bits = s->cluster_bits - 3;
|
933 |
shift = s->cluster_bits + l2_bits; |
934 |
l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift); |
935 |
offset = align_offset(header_size, s->cluster_size); |
936 |
s->l1_table_offset = offset; |
937 |
header.l1_table_offset = cpu_to_be64(s->l1_table_offset); |
938 |
header.l1_size = cpu_to_be32(l1_size); |
939 |
offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
|
940 |
|
941 |
/* count how many refcount blocks needed */
|
942 |
|
943 |
#define NUM_CLUSTERS(bytes) \
|
944 |
(((bytes) + (s->cluster_size) - 1) / (s->cluster_size))
|
945 |
|
946 |
ref_clusters = NUM_CLUSTERS(NUM_CLUSTERS(offset) * sizeof(uint16_t));
|
947 |
|
948 |
do {
|
949 |
uint64_t image_clusters; |
950 |
old_ref_clusters = ref_clusters; |
951 |
|
952 |
/* Number of clusters used for the refcount table */
|
953 |
reftable_clusters = NUM_CLUSTERS(ref_clusters * sizeof(uint64_t));
|
954 |
|
955 |
/* Number of clusters that the whole image will have */
|
956 |
image_clusters = NUM_CLUSTERS(offset) + ref_clusters |
957 |
+ reftable_clusters; |
958 |
|
959 |
/* Number of refcount blocks needed for the image */
|
960 |
ref_clusters = NUM_CLUSTERS(image_clusters * sizeof(uint16_t));
|
961 |
|
962 |
} while (ref_clusters != old_ref_clusters);
|
963 |
|
964 |
s->refcount_table = qemu_mallocz(reftable_clusters * s->cluster_size); |
965 |
|
966 |
s->refcount_table_offset = offset; |
967 |
header.refcount_table_offset = cpu_to_be64(offset); |
968 |
header.refcount_table_clusters = cpu_to_be32(reftable_clusters); |
969 |
offset += (reftable_clusters * s->cluster_size); |
970 |
s->refcount_block_offset = offset; |
971 |
|
972 |
for (i=0; i < ref_clusters; i++) { |
973 |
s->refcount_table[i] = cpu_to_be64(offset); |
974 |
offset += s->cluster_size; |
975 |
} |
976 |
|
977 |
s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size); |
978 |
|
979 |
/* update refcounts */
|
980 |
qcow2_create_refcount_update(s, 0, header_size);
|
981 |
qcow2_create_refcount_update(s, s->l1_table_offset, |
982 |
l1_size * sizeof(uint64_t));
|
983 |
qcow2_create_refcount_update(s, s->refcount_table_offset, |
984 |
reftable_clusters * s->cluster_size); |
985 |
qcow2_create_refcount_update(s, s->refcount_block_offset, |
986 |
ref_clusters * s->cluster_size); |
987 |
|
988 |
/* write all the data */
|
989 |
ret = qemu_write_full(fd, &header, sizeof(header));
|
990 |
if (ret != sizeof(header)) { |
991 |
ret = -errno; |
992 |
goto exit;
|
993 |
} |
994 |
if (backing_file) {
|
995 |
if (backing_format_len) {
|
996 |
char zero[16]; |
997 |
int padding = rounded_ext_bf_len - (ext_bf.len + sizeof(ext_bf)); |
998 |
|
999 |
memset(zero, 0, sizeof(zero)); |
1000 |
cpu_to_be32s(&ext_bf.magic); |
1001 |
cpu_to_be32s(&ext_bf.len); |
1002 |
ret = qemu_write_full(fd, &ext_bf, sizeof(ext_bf));
|
1003 |
if (ret != sizeof(ext_bf)) { |
1004 |
ret = -errno; |
1005 |
goto exit;
|
1006 |
} |
1007 |
ret = qemu_write_full(fd, backing_format, backing_format_len); |
1008 |
if (ret != backing_format_len) {
|
1009 |
ret = -errno; |
1010 |
goto exit;
|
1011 |
} |
1012 |
if (padding > 0) { |
1013 |
ret = qemu_write_full(fd, zero, padding); |
1014 |
if (ret != padding) {
|
1015 |
ret = -errno; |
1016 |
goto exit;
|
1017 |
} |
1018 |
} |
1019 |
} |
1020 |
ret = qemu_write_full(fd, backing_file, backing_filename_len); |
1021 |
if (ret != backing_filename_len) {
|
1022 |
ret = -errno; |
1023 |
goto exit;
|
1024 |
} |
1025 |
} |
1026 |
lseek(fd, s->l1_table_offset, SEEK_SET); |
1027 |
tmp = 0;
|
1028 |
for(i = 0;i < l1_size; i++) { |
1029 |
ret = qemu_write_full(fd, &tmp, sizeof(tmp));
|
1030 |
if (ret != sizeof(tmp)) { |
1031 |
ret = -errno; |
1032 |
goto exit;
|
1033 |
} |
1034 |
} |
1035 |
lseek(fd, s->refcount_table_offset, SEEK_SET); |
1036 |
ret = qemu_write_full(fd, s->refcount_table, |
1037 |
reftable_clusters * s->cluster_size); |
1038 |
if (ret != reftable_clusters * s->cluster_size) {
|
1039 |
ret = -errno; |
1040 |
goto exit;
|
1041 |
} |
1042 |
|
1043 |
lseek(fd, s->refcount_block_offset, SEEK_SET); |
1044 |
ret = qemu_write_full(fd, s->refcount_block, |
1045 |
ref_clusters * s->cluster_size); |
1046 |
if (ret != ref_clusters * s->cluster_size) {
|
1047 |
ret = -errno; |
1048 |
goto exit;
|
1049 |
} |
1050 |
|
1051 |
ret = 0;
|
1052 |
exit:
|
1053 |
qemu_free(s->refcount_table); |
1054 |
qemu_free(s->refcount_block); |
1055 |
close(fd); |
1056 |
|
1057 |
/* Preallocate metadata */
|
1058 |
if (ret == 0 && prealloc) { |
1059 |
BlockDriverState *bs; |
1060 |
BlockDriver *drv = bdrv_find_format("qcow2");
|
1061 |
bs = bdrv_new("");
|
1062 |
bdrv_open(bs, filename, BDRV_O_CACHE_WB | BDRV_O_RDWR, drv); |
1063 |
ret = preallocate(bs); |
1064 |
bdrv_close(bs); |
1065 |
} |
1066 |
|
1067 |
return ret;
|
1068 |
} |
1069 |
|
1070 |
static int qcow_create(const char *filename, QEMUOptionParameter *options) |
1071 |
{ |
1072 |
const char *backing_file = NULL; |
1073 |
const char *backing_fmt = NULL; |
1074 |
uint64_t sectors = 0;
|
1075 |
int flags = 0; |
1076 |
size_t cluster_size = 65536;
|
1077 |
int prealloc = 0; |
1078 |
|
1079 |
/* Read out options */
|
1080 |
while (options && options->name) {
|
1081 |
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
1082 |
sectors = options->value.n / 512;
|
1083 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { |
1084 |
backing_file = options->value.s; |
1085 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { |
1086 |
backing_fmt = options->value.s; |
1087 |
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { |
1088 |
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
1089 |
} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { |
1090 |
if (options->value.n) {
|
1091 |
cluster_size = options->value.n; |
1092 |
} |
1093 |
} else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) { |
1094 |
if (!options->value.s || !strcmp(options->value.s, "off")) { |
1095 |
prealloc = 0;
|
1096 |
} else if (!strcmp(options->value.s, "metadata")) { |
1097 |
prealloc = 1;
|
1098 |
} else {
|
1099 |
fprintf(stderr, "Invalid preallocation mode: '%s'\n",
|
1100 |
options->value.s); |
1101 |
return -EINVAL;
|
1102 |
} |
1103 |
} |
1104 |
options++; |
1105 |
} |
1106 |
|
1107 |
if (backing_file && prealloc) {
|
1108 |
fprintf(stderr, "Backing file and preallocation cannot be used at "
|
1109 |
"the same time\n");
|
1110 |
return -EINVAL;
|
1111 |
} |
1112 |
|
1113 |
return qcow_create2(filename, sectors, backing_file, backing_fmt, flags,
|
1114 |
cluster_size, prealloc); |
1115 |
} |
1116 |
|
1117 |
static int qcow_make_empty(BlockDriverState *bs) |
1118 |
{ |
1119 |
#if 0
|
1120 |
/* XXX: not correct */
|
1121 |
BDRVQcowState *s = bs->opaque;
|
1122 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
1123 |
int ret;
|
1124 |
|
1125 |
memset(s->l1_table, 0, l1_length);
|
1126 |
if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
1127 |
return -1;
|
1128 |
ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
|
1129 |
if (ret < 0)
|
1130 |
return ret;
|
1131 |
|
1132 |
l2_cache_reset(bs);
|
1133 |
#endif
|
1134 |
return 0; |
1135 |
} |
1136 |
|
1137 |
static int qcow2_truncate(BlockDriverState *bs, int64_t offset) |
1138 |
{ |
1139 |
BDRVQcowState *s = bs->opaque; |
1140 |
int ret, new_l1_size;
|
1141 |
|
1142 |
if (offset & 511) { |
1143 |
return -EINVAL;
|
1144 |
} |
1145 |
|
1146 |
/* cannot proceed if image has snapshots */
|
1147 |
if (s->nb_snapshots) {
|
1148 |
return -ENOTSUP;
|
1149 |
} |
1150 |
|
1151 |
/* shrinking is currently not supported */
|
1152 |
if (offset < bs->total_sectors * 512) { |
1153 |
return -ENOTSUP;
|
1154 |
} |
1155 |
|
1156 |
new_l1_size = size_to_l1(s, offset); |
1157 |
ret = qcow2_grow_l1_table(bs, new_l1_size, true);
|
1158 |
if (ret < 0) { |
1159 |
return ret;
|
1160 |
} |
1161 |
|
1162 |
/* write updated header.size */
|
1163 |
offset = cpu_to_be64(offset); |
1164 |
ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size), |
1165 |
&offset, sizeof(uint64_t));
|
1166 |
if (ret < 0) { |
1167 |
return ret;
|
1168 |
} |
1169 |
|
1170 |
s->l1_vm_state_index = new_l1_size; |
1171 |
return 0; |
1172 |
} |
1173 |
|
1174 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
1175 |
tables to avoid losing bytes in alignment */
|
1176 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
1177 |
const uint8_t *buf, int nb_sectors) |
1178 |
{ |
1179 |
BDRVQcowState *s = bs->opaque; |
1180 |
z_stream strm; |
1181 |
int ret, out_len;
|
1182 |
uint8_t *out_buf; |
1183 |
uint64_t cluster_offset; |
1184 |
|
1185 |
if (nb_sectors == 0) { |
1186 |
/* align end of file to a sector boundary to ease reading with
|
1187 |
sector based I/Os */
|
1188 |
cluster_offset = bdrv_getlength(bs->file); |
1189 |
cluster_offset = (cluster_offset + 511) & ~511; |
1190 |
bdrv_truncate(bs->file, cluster_offset); |
1191 |
return 0; |
1192 |
} |
1193 |
|
1194 |
if (nb_sectors != s->cluster_sectors)
|
1195 |
return -EINVAL;
|
1196 |
|
1197 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
1198 |
|
1199 |
/* best compression, small window, no zlib header */
|
1200 |
memset(&strm, 0, sizeof(strm)); |
1201 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
1202 |
Z_DEFLATED, -12,
|
1203 |
9, Z_DEFAULT_STRATEGY);
|
1204 |
if (ret != 0) { |
1205 |
qemu_free(out_buf); |
1206 |
return -1; |
1207 |
} |
1208 |
|
1209 |
strm.avail_in = s->cluster_size; |
1210 |
strm.next_in = (uint8_t *)buf; |
1211 |
strm.avail_out = s->cluster_size; |
1212 |
strm.next_out = out_buf; |
1213 |
|
1214 |
ret = deflate(&strm, Z_FINISH); |
1215 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
1216 |
qemu_free(out_buf); |
1217 |
deflateEnd(&strm); |
1218 |
return -1; |
1219 |
} |
1220 |
out_len = strm.next_out - out_buf; |
1221 |
|
1222 |
deflateEnd(&strm); |
1223 |
|
1224 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
1225 |
/* could not compress: write normal cluster */
|
1226 |
bdrv_write(bs, sector_num, buf, s->cluster_sectors); |
1227 |
} else {
|
1228 |
cluster_offset = qcow2_alloc_compressed_cluster_offset(bs, |
1229 |
sector_num << 9, out_len);
|
1230 |
if (!cluster_offset)
|
1231 |
return -1; |
1232 |
cluster_offset &= s->cluster_offset_mask; |
1233 |
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); |
1234 |
if (bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len) != out_len) {
|
1235 |
qemu_free(out_buf); |
1236 |
return -1; |
1237 |
} |
1238 |
} |
1239 |
|
1240 |
qemu_free(out_buf); |
1241 |
return 0; |
1242 |
} |
1243 |
|
1244 |
static void qcow_flush(BlockDriverState *bs) |
1245 |
{ |
1246 |
bdrv_flush(bs->file); |
1247 |
} |
1248 |
|
1249 |
static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs,
|
1250 |
BlockDriverCompletionFunc *cb, void *opaque)
|
1251 |
{ |
1252 |
return bdrv_aio_flush(bs->file, cb, opaque);
|
1253 |
} |
1254 |
|
1255 |
static int64_t qcow_vm_state_offset(BDRVQcowState *s)
|
1256 |
{ |
1257 |
return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
|
1258 |
} |
1259 |
|
1260 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
1261 |
{ |
1262 |
BDRVQcowState *s = bs->opaque; |
1263 |
bdi->cluster_size = s->cluster_size; |
1264 |
bdi->vm_state_offset = qcow_vm_state_offset(s); |
1265 |
return 0; |
1266 |
} |
1267 |
|
1268 |
|
1269 |
static int qcow_check(BlockDriverState *bs, BdrvCheckResult *result) |
1270 |
{ |
1271 |
return qcow2_check_refcounts(bs, result);
|
1272 |
} |
1273 |
|
1274 |
#if 0
|
1275 |
static void dump_refcounts(BlockDriverState *bs)
|
1276 |
{
|
1277 |
BDRVQcowState *s = bs->opaque;
|
1278 |
int64_t nb_clusters, k, k1, size;
|
1279 |
int refcount;
|
1280 |
|
1281 |
size = bdrv_getlength(bs->file);
|
1282 |
nb_clusters = size_to_clusters(s, size);
|
1283 |
for(k = 0; k < nb_clusters;) {
|
1284 |
k1 = k;
|
1285 |
refcount = get_refcount(bs, k);
|
1286 |
k++;
|
1287 |
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
1288 |
k++;
|
1289 |
printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount,
|
1290 |
k - k1);
|
1291 |
}
|
1292 |
}
|
1293 |
#endif
|
1294 |
|
1295 |
static int qcow_save_vmstate(BlockDriverState *bs, const uint8_t *buf, |
1296 |
int64_t pos, int size)
|
1297 |
{ |
1298 |
BDRVQcowState *s = bs->opaque; |
1299 |
int growable = bs->growable;
|
1300 |
int ret;
|
1301 |
|
1302 |
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); |
1303 |
bs->growable = 1;
|
1304 |
ret = bdrv_pwrite(bs, qcow_vm_state_offset(s) + pos, buf, size); |
1305 |
bs->growable = growable; |
1306 |
|
1307 |
return ret;
|
1308 |
} |
1309 |
|
1310 |
static int qcow_load_vmstate(BlockDriverState *bs, uint8_t *buf, |
1311 |
int64_t pos, int size)
|
1312 |
{ |
1313 |
BDRVQcowState *s = bs->opaque; |
1314 |
int growable = bs->growable;
|
1315 |
int ret;
|
1316 |
|
1317 |
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); |
1318 |
bs->growable = 1;
|
1319 |
ret = bdrv_pread(bs, qcow_vm_state_offset(s) + pos, buf, size); |
1320 |
bs->growable = growable; |
1321 |
|
1322 |
return ret;
|
1323 |
} |
1324 |
|
1325 |
static QEMUOptionParameter qcow_create_options[] = {
|
1326 |
{ |
1327 |
.name = BLOCK_OPT_SIZE, |
1328 |
.type = OPT_SIZE, |
1329 |
.help = "Virtual disk size"
|
1330 |
}, |
1331 |
{ |
1332 |
.name = BLOCK_OPT_BACKING_FILE, |
1333 |
.type = OPT_STRING, |
1334 |
.help = "File name of a base image"
|
1335 |
}, |
1336 |
{ |
1337 |
.name = BLOCK_OPT_BACKING_FMT, |
1338 |
.type = OPT_STRING, |
1339 |
.help = "Image format of the base image"
|
1340 |
}, |
1341 |
{ |
1342 |
.name = BLOCK_OPT_ENCRYPT, |
1343 |
.type = OPT_FLAG, |
1344 |
.help = "Encrypt the image"
|
1345 |
}, |
1346 |
{ |
1347 |
.name = BLOCK_OPT_CLUSTER_SIZE, |
1348 |
.type = OPT_SIZE, |
1349 |
.help = "qcow2 cluster size"
|
1350 |
}, |
1351 |
{ |
1352 |
.name = BLOCK_OPT_PREALLOC, |
1353 |
.type = OPT_STRING, |
1354 |
.help = "Preallocation mode (allowed values: off, metadata)"
|
1355 |
}, |
1356 |
{ NULL }
|
1357 |
}; |
1358 |
|
1359 |
static BlockDriver bdrv_qcow2 = {
|
1360 |
.format_name = "qcow2",
|
1361 |
.instance_size = sizeof(BDRVQcowState),
|
1362 |
.bdrv_probe = qcow_probe, |
1363 |
.bdrv_open = qcow_open, |
1364 |
.bdrv_close = qcow_close, |
1365 |
.bdrv_create = qcow_create, |
1366 |
.bdrv_flush = qcow_flush, |
1367 |
.bdrv_is_allocated = qcow_is_allocated, |
1368 |
.bdrv_set_key = qcow_set_key, |
1369 |
.bdrv_make_empty = qcow_make_empty, |
1370 |
|
1371 |
.bdrv_aio_readv = qcow_aio_readv, |
1372 |
.bdrv_aio_writev = qcow_aio_writev, |
1373 |
.bdrv_aio_flush = qcow_aio_flush, |
1374 |
|
1375 |
.bdrv_truncate = qcow2_truncate, |
1376 |
.bdrv_write_compressed = qcow_write_compressed, |
1377 |
|
1378 |
.bdrv_snapshot_create = qcow2_snapshot_create, |
1379 |
.bdrv_snapshot_goto = qcow2_snapshot_goto, |
1380 |
.bdrv_snapshot_delete = qcow2_snapshot_delete, |
1381 |
.bdrv_snapshot_list = qcow2_snapshot_list, |
1382 |
.bdrv_get_info = qcow_get_info, |
1383 |
|
1384 |
.bdrv_save_vmstate = qcow_save_vmstate, |
1385 |
.bdrv_load_vmstate = qcow_load_vmstate, |
1386 |
|
1387 |
.bdrv_change_backing_file = qcow2_change_backing_file, |
1388 |
|
1389 |
.create_options = qcow_create_options, |
1390 |
.bdrv_check = qcow_check, |
1391 |
}; |
1392 |
|
1393 |
static void bdrv_qcow2_init(void) |
1394 |
{ |
1395 |
bdrv_register(&bdrv_qcow2); |
1396 |
} |
1397 |
|
1398 |
block_init(bdrv_qcow2_init); |