diff options
| -rw-r--r-- | block/qcow2.c | 146 | ||||
| -rw-r--r-- | block/qcow2.h | 17 | ||||
| -rw-r--r-- | block_int.h | 1 |
3 files changed, 149 insertions, 15 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 4c82adc96f..3e1482fa7e 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -61,7 +61,7 @@ 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; @@ -169,6 +169,19 @@ 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 int qcow2_open(BlockDriverState *bs, int flags) { BDRVQcowState *s = bs->opaque; @@ -199,14 +212,64 @@ 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; + } + } + + /* 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) { + report_unsupported(bs, "incompatible features mask %" PRIx64, + header.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; @@ -285,7 +348,7 @@ static int qcow2_open(BlockDriverState *bs, int flags) } 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)) { ret = -EINVAL; goto fail; } @@ -321,6 +384,7 @@ 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); @@ -682,7 +746,9 @@ 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); @@ -756,10 +822,10 @@ 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; @@ -769,12 +835,14 @@ 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), @@ -786,10 +854,42 @@ 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) { @@ -921,7 +1021,7 @@ 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; @@ -965,13 +1065,15 @@ 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); @@ -1053,6 +1155,7 @@ 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) { @@ -1078,6 +1181,16 @@ 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++; } @@ -1089,7 +1202,7 @@ 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) @@ -1341,6 +1454,11 @@ 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" diff --git a/block/qcow2.h b/block/qcow2.h index 291309a9e7..2dc8ca26fb 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -33,7 +33,6 @@ //#define DEBUG_EXT #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) -#define QCOW_VERSION 2 #define QCOW_CRYPT_NONE 0 #define QCOW_CRYPT_AES 1 @@ -71,6 +70,14 @@ typedef struct QCowHeader { uint32_t refcount_table_clusters; uint32_t nb_snapshots; uint64_t snapshots_offset; + + /* The following fields are only valid for version >= 3 */ + uint64_t incompatible_features; + uint64_t compatible_features; + uint64_t autoclear_features; + + uint32_t refcount_order; + uint32_t header_length; } QCowHeader; typedef struct QCowSnapshot { @@ -135,6 +142,14 @@ typedef struct BDRVQcowState { QCowSnapshot *snapshots; int flags; + int qcow_version; + + uint64_t incompatible_features; + uint64_t compatible_features; + uint64_t autoclear_features; + + size_t unknown_header_fields_size; + void* unknown_header_fields; QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext; } BDRVQcowState; diff --git a/block_int.h b/block_int.h index 0e5a032e77..0acb49f100 100644 --- a/block_int.h +++ b/block_int.h @@ -50,6 +50,7 @@ #define BLOCK_OPT_TABLE_SIZE "table_size" #define BLOCK_OPT_PREALLOC "preallocation" #define BLOCK_OPT_SUBFMT "subformat" +#define BLOCK_OPT_COMPAT_LEVEL "compat" typedef struct BdrvTrackedRequest BdrvTrackedRequest; 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