diff options
Diffstat (limited to 'block/qcow2.c')
| -rw-r--r-- | block/qcow2.c | 252 |
1 files changed, 229 insertions, 23 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 70d3141dd1..ad46c03c2f 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -54,6 +54,7 @@ typedef struct { } QCowExtension; #define QCOW2_EXT_MAGIC_END 0 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA +#define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) { @@ -61,7 +62,7 @@ static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) if (buf_size >= sizeof(QCowHeader) && be32_to_cpu(cow_header->magic) == QCOW_MAGIC && - be32_to_cpu(cow_header->version) >= QCOW_VERSION) + be32_to_cpu(cow_header->version) >= 2) return 100; else return 0; @@ -76,7 +77,7 @@ static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) * return 0 upon success, non-0 otherwise */ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, - uint64_t end_offset) + uint64_t end_offset, void **p_feature_table) { BDRVQcowState *s = bs->opaque; QCowExtension ext; @@ -134,6 +135,18 @@ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, #endif break; + case QCOW2_EXT_MAGIC_FEATURE_TABLE: + if (p_feature_table != NULL) { + void* feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); + ret = bdrv_pread(bs->file, offset , feature_table, ext.len); + if (ret < 0) { + return ret; + } + + *p_feature_table = feature_table; + } + break; + default: /* unknown magic - save it in case we need to rewrite the header */ { @@ -169,6 +182,37 @@ static void cleanup_unknown_header_ext(BlockDriverState *bs) } } +static void report_unsupported(BlockDriverState *bs, const char *fmt, ...) +{ + char msg[64]; + va_list ap; + + va_start(ap, fmt); + vsnprintf(msg, sizeof(msg), fmt, ap); + va_end(ap); + + qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, + bs->device_name, "qcow2", msg); +} + +static void report_unsupported_feature(BlockDriverState *bs, + Qcow2Feature *table, uint64_t mask) +{ + while (table && table->name[0] != '\0') { + if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { + if (mask & (1 << table->bit)) { + report_unsupported(bs, "%.46s",table->name); + mask &= ~(1 << table->bit); + } + } + table++; + } + + if (mask) { + report_unsupported(bs, "Unknown incompatible feature: %" PRIx64, mask); + } +} + static int qcow2_open(BlockDriverState *bs, int flags) { BDRVQcowState *s = bs->opaque; @@ -199,14 +243,73 @@ static int qcow2_open(BlockDriverState *bs, int flags) ret = -EINVAL; goto fail; } - if (header.version != QCOW_VERSION) { - char version[64]; - snprintf(version, sizeof(version), "QCOW version %d", header.version); - qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, - bs->device_name, "qcow2", version); + if (header.version < 2 || header.version > 3) { + report_unsupported(bs, "QCOW version %d", header.version); + ret = -ENOTSUP; + goto fail; + } + + s->qcow_version = header.version; + + /* Initialise version 3 header fields */ + if (header.version == 2) { + header.incompatible_features = 0; + header.compatible_features = 0; + header.autoclear_features = 0; + header.refcount_order = 4; + header.header_length = 72; + } else { + be64_to_cpus(&header.incompatible_features); + be64_to_cpus(&header.compatible_features); + be64_to_cpus(&header.autoclear_features); + be32_to_cpus(&header.refcount_order); + be32_to_cpus(&header.header_length); + } + + if (header.header_length > sizeof(header)) { + s->unknown_header_fields_size = header.header_length - sizeof(header); + s->unknown_header_fields = g_malloc(s->unknown_header_fields_size); + ret = bdrv_pread(bs->file, sizeof(header), s->unknown_header_fields, + s->unknown_header_fields_size); + if (ret < 0) { + goto fail; + } + } + + if (header.backing_file_offset) { + ext_end = header.backing_file_offset; + } else { + ext_end = 1 << header.cluster_bits; + } + + /* Handle feature bits */ + s->incompatible_features = header.incompatible_features; + s->compatible_features = header.compatible_features; + s->autoclear_features = header.autoclear_features; + + if (s->incompatible_features != 0) { + void *feature_table = NULL; + qcow2_read_extensions(bs, header.header_length, ext_end, + &feature_table); + report_unsupported_feature(bs, feature_table, + s->incompatible_features); + ret = -ENOTSUP; + goto fail; + } + + if (!bs->read_only && s->autoclear_features != 0) { + s->autoclear_features = 0; + qcow2_update_header(bs); + } + + /* Check support for various header values */ + if (header.refcount_order != 4) { + report_unsupported(bs, "%d bit reference counts", + 1 << header.refcount_order); ret = -ENOTSUP; goto fail; } + if (header.cluster_bits < MIN_CLUSTER_BITS || header.cluster_bits > MAX_CLUSTER_BITS) { ret = -EINVAL; @@ -280,12 +383,7 @@ static int qcow2_open(BlockDriverState *bs, int flags) QLIST_INIT(&s->cluster_allocs); /* read qcow2 extensions */ - if (header.backing_file_offset) { - ext_end = header.backing_file_offset; - } else { - ext_end = s->cluster_size; - } - if (qcow2_read_extensions(bs, sizeof(header), ext_end)) { + if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL)) { ret = -EINVAL; goto fail; } @@ -321,6 +419,7 @@ static int qcow2_open(BlockDriverState *bs, int flags) return ret; fail: + g_free(s->unknown_header_fields); cleanup_unknown_header_ext(bs); qcow2_free_snapshots(bs); qcow2_refcount_close(bs); @@ -449,7 +548,8 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, qemu_iovec_copy(&hd_qiov, qiov, bytes_done, cur_nr_sectors * 512); - if (!cluster_offset) { + switch (ret) { + case QCOW2_CLUSTER_UNALLOCATED: if (bs->backing_hd) { /* read from the base image */ @@ -469,7 +569,17 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, /* Note: in this case, no need to wait */ qemu_iovec_memset(&hd_qiov, 0, 512 * cur_nr_sectors); } - } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { + break; + + case QCOW2_CLUSTER_ZERO: + if (s->qcow_version < 3) { + ret = -EIO; + goto fail; + } + qemu_iovec_memset(&hd_qiov, 0, 512 * cur_nr_sectors); + break; + + case QCOW2_CLUSTER_COMPRESSED: /* add AIO support for compressed blocks ? */ ret = qcow2_decompress_cluster(bs, cluster_offset); if (ret < 0) { @@ -479,7 +589,9 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, qemu_iovec_from_buffer(&hd_qiov, s->cluster_cache + index_in_cluster * 512, 512 * cur_nr_sectors); - } else { + break; + + case QCOW2_CLUSTER_NORMAL: if ((cluster_offset & 511) != 0) { ret = -EIO; goto fail; @@ -520,6 +632,12 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, qemu_iovec_from_buffer(&hd_qiov, cluster_data, 512 * cur_nr_sectors); } + break; + + default: + g_assert_not_reached(); + ret = -EIO; + goto fail; } remaining_sectors -= cur_nr_sectors; @@ -671,7 +789,9 @@ static void qcow2_close(BlockDriverState *bs) qcow2_cache_destroy(bs, s->l2_table_cache); qcow2_cache_destroy(bs, s->refcount_block_cache); + g_free(s->unknown_header_fields); cleanup_unknown_header_ext(bs); + g_free(s->cluster_cache); qemu_vfree(s->cluster_data); qcow2_refcount_close(bs); @@ -745,10 +865,10 @@ int qcow2_update_header(BlockDriverState *bs) int ret; uint64_t total_size; uint32_t refcount_table_clusters; + size_t header_length; Qcow2UnknownHeaderExtension *uext; buf = qemu_blockalign(bs, buflen); - memset(buf, 0, s->cluster_size); /* Header structure */ header = (QCowHeader*) buf; @@ -758,12 +878,14 @@ int qcow2_update_header(BlockDriverState *bs) goto fail; } + header_length = sizeof(*header) + s->unknown_header_fields_size; total_size = bs->total_sectors * BDRV_SECTOR_SIZE; refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); *header = (QCowHeader) { + /* Version 2 fields */ .magic = cpu_to_be32(QCOW_MAGIC), - .version = cpu_to_be32(QCOW_VERSION), + .version = cpu_to_be32(s->qcow_version), .backing_file_offset = 0, .backing_file_size = 0, .cluster_bits = cpu_to_be32(s->cluster_bits), @@ -775,10 +897,42 @@ int qcow2_update_header(BlockDriverState *bs) .refcount_table_clusters = cpu_to_be32(refcount_table_clusters), .nb_snapshots = cpu_to_be32(s->nb_snapshots), .snapshots_offset = cpu_to_be64(s->snapshots_offset), + + /* Version 3 fields */ + .incompatible_features = cpu_to_be64(s->incompatible_features), + .compatible_features = cpu_to_be64(s->compatible_features), + .autoclear_features = cpu_to_be64(s->autoclear_features), + .refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT), + .header_length = cpu_to_be32(header_length), }; - buf += sizeof(*header); - buflen -= sizeof(*header); + /* For older versions, write a shorter header */ + switch (s->qcow_version) { + case 2: + ret = offsetof(QCowHeader, incompatible_features); + break; + case 3: + ret = sizeof(*header); + break; + default: + return -EINVAL; + } + + buf += ret; + buflen -= ret; + memset(buf, 0, buflen); + + /* Preserve any unknown field in the header */ + if (s->unknown_header_fields_size) { + if (buflen < s->unknown_header_fields_size) { + ret = -ENOSPC; + goto fail; + } + + memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); + buf += s->unknown_header_fields_size; + buflen -= s->unknown_header_fields_size; + } /* Backing file format header extension */ if (*bs->backing_format) { @@ -793,6 +947,19 @@ int qcow2_update_header(BlockDriverState *bs) buflen -= ret; } + /* Feature table */ + Qcow2Feature features[] = { + /* no feature defined yet */ + }; + + ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, + features, sizeof(features), buflen); + if (ret < 0) { + goto fail; + } + buf += ret; + buflen -= ret; + /* Keep unknown header extensions */ QLIST_FOREACH(uext, &s->unknown_header_ext, next) { ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); @@ -910,7 +1077,7 @@ static int preallocate(BlockDriverState *bs) static int qcow2_create2(const char *filename, int64_t total_size, const char *backing_file, const char *backing_format, int flags, size_t cluster_size, int prealloc, - QEMUOptionParameter *options) + QEMUOptionParameter *options, int version) { /* Calculate cluster_bits */ int cluster_bits; @@ -954,13 +1121,15 @@ static int qcow2_create2(const char *filename, int64_t total_size, /* Write the header */ memset(&header, 0, sizeof(header)); header.magic = cpu_to_be32(QCOW_MAGIC); - header.version = cpu_to_be32(QCOW_VERSION); + header.version = cpu_to_be32(version); header.cluster_bits = cpu_to_be32(cluster_bits); header.size = cpu_to_be64(0); header.l1_table_offset = cpu_to_be64(0); header.l1_size = cpu_to_be32(0); header.refcount_table_offset = cpu_to_be64(cluster_size); header.refcount_table_clusters = cpu_to_be32(1); + header.refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT); + header.header_length = cpu_to_be32(sizeof(header)); if (flags & BLOCK_FLAG_ENCRYPT) { header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); @@ -1042,6 +1211,7 @@ static int qcow2_create(const char *filename, QEMUOptionParameter *options) int flags = 0; size_t cluster_size = DEFAULT_CLUSTER_SIZE; int prealloc = 0; + int version = 2; /* Read out options */ while (options && options->name) { @@ -1067,6 +1237,16 @@ static int qcow2_create(const char *filename, QEMUOptionParameter *options) options->value.s); return -EINVAL; } + } else if (!strcmp(options->name, BLOCK_OPT_COMPAT_LEVEL)) { + if (!options->value.s || !strcmp(options->value.s, "0.10")) { + version = 2; + } else if (!strcmp(options->value.s, "1.1")) { + version = 3; + } else { + fprintf(stderr, "Invalid compatibility level: '%s'\n", + options->value.s); + return -EINVAL; + } } options++; } @@ -1078,7 +1258,7 @@ static int qcow2_create(const char *filename, QEMUOptionParameter *options) } return qcow2_create2(filename, sectors, backing_file, backing_fmt, flags, - cluster_size, prealloc, options); + cluster_size, prealloc, options, version); } static int qcow2_make_empty(BlockDriverState *bs) @@ -1101,6 +1281,26 @@ static int qcow2_make_empty(BlockDriverState *bs) return 0; } +static coroutine_fn int qcow2_co_write_zeroes(BlockDriverState *bs, + int64_t sector_num, int nb_sectors) +{ + int ret; + BDRVQcowState *s = bs->opaque; + + /* Emulate misaligned zero writes */ + if (sector_num % s->cluster_sectors || nb_sectors % s->cluster_sectors) { + return -ENOTSUP; + } + + /* Whatever is left can use real zero clusters */ + qemu_co_mutex_lock(&s->lock); + ret = qcow2_zero_clusters(bs, sector_num << BDRV_SECTOR_BITS, + nb_sectors); + qemu_co_mutex_unlock(&s->lock); + + return ret; +} + static coroutine_fn int qcow2_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) { @@ -1330,6 +1530,11 @@ static QEMUOptionParameter qcow2_create_options[] = { .help = "Virtual disk size" }, { + .name = BLOCK_OPT_COMPAT_LEVEL, + .type = OPT_STRING, + .help = "Compatibility level (0.10 or 1.1)" + }, + { .name = BLOCK_OPT_BACKING_FILE, .type = OPT_STRING, .help = "File name of a base image" @@ -1373,6 +1578,7 @@ static BlockDriver bdrv_qcow2 = { .bdrv_co_writev = qcow2_co_writev, .bdrv_co_flush_to_os = qcow2_co_flush_to_os, + .bdrv_co_write_zeroes = qcow2_co_write_zeroes, .bdrv_co_discard = qcow2_co_discard, .bdrv_truncate = qcow2_truncate, .bdrv_write_compressed = qcow2_write_compressed, |