diff options
Diffstat (limited to 'block/qcow2.c')
| -rw-r--r-- | block/qcow2.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 1ad95ff..b878a6a 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1242,6 +1242,39 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options, return ret; } +static int validate_compression_type(BDRVQcow2State *s, Error **errp) +{ + switch (s->compression_type) { + case QCOW2_COMPRESSION_TYPE_ZLIB: + break; + + default: + error_setg(errp, "qcow2: unknown compression type: %u", + s->compression_type); + return -ENOTSUP; + } + + /* + * if the compression type differs from QCOW2_COMPRESSION_TYPE_ZLIB + * the incompatible feature flag must be set + */ + if (s->compression_type == QCOW2_COMPRESSION_TYPE_ZLIB) { + if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) { + error_setg(errp, "qcow2: Compression type incompatible feature " + "bit must not be set"); + return -EINVAL; + } + } else { + if (!(s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION)) { + error_setg(errp, "qcow2: Compression type incompatible feature " + "bit must be set"); + return -EINVAL; + } + } + + return 0; +} + /* Called with s->lock held. */ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) @@ -1357,6 +1390,23 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, s->compatible_features = header.compatible_features; s->autoclear_features = header.autoclear_features; + /* + * Handle compression type + * Older qcow2 images don't contain the compression type header. + * Distinguish them by the header length and use + * the only valid (default) compression type in that case + */ + if (header.header_length > offsetof(QCowHeader, compression_type)) { + s->compression_type = header.compression_type; + } else { + s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; + } + + ret = validate_compression_type(s, errp); + if (ret) { + goto fail; + } + if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) { void *feature_table = NULL; qcow2_read_extensions(bs, header.header_length, ext_end, @@ -2728,6 +2778,11 @@ int qcow2_update_header(BlockDriverState *bs) total_size = bs->total_sectors * BDRV_SECTOR_SIZE; refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); + ret = validate_compression_type(s, NULL); + if (ret) { + goto fail; + } + *header = (QCowHeader) { /* Version 2 fields */ .magic = cpu_to_be32(QCOW_MAGIC), @@ -2750,6 +2805,7 @@ int qcow2_update_header(BlockDriverState *bs) .autoclear_features = cpu_to_be64(s->autoclear_features), .refcount_order = cpu_to_be32(s->refcount_order), .header_length = cpu_to_be32(header_length), + .compression_type = s->compression_type, }; /* For older versions, write a shorter header */ @@ -2850,6 +2906,11 @@ int qcow2_update_header(BlockDriverState *bs) .name = "external data file", }, { + .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, + .bit = QCOW2_INCOMPAT_COMPRESSION_BITNR, + .name = "compression type", + }, + { .type = QCOW2_FEAT_TYPE_COMPATIBLE, .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, .name = "lazy refcounts", @@ -3287,6 +3348,7 @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp) uint64_t* refcount_table; Error *local_err = NULL; int ret; + uint8_t compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2); qcow2_opts = &create_options->u.qcow2; @@ -3404,6 +3466,27 @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp) } } + if (qcow2_opts->has_compression_type && + qcow2_opts->compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { + + ret = -EINVAL; + + if (version < 3) { + error_setg(errp, "Non-zlib compression type is only supported with " + "compatibility level 1.1 and above (use version=v3 or " + "greater)"); + goto out; + } + + switch (qcow2_opts->compression_type) { + default: + error_setg(errp, "Unknown compression type"); + goto out; + } + + compression_type = qcow2_opts->compression_type; + } + /* Create BlockBackend to write to the image */ blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, errp); @@ -3426,6 +3509,8 @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp) .refcount_table_offset = cpu_to_be64(cluster_size), .refcount_table_clusters = cpu_to_be32(1), .refcount_order = cpu_to_be32(refcount_order), + /* don't deal with endianness since compression_type is 1 byte long */ + .compression_type = compression_type, .header_length = cpu_to_be32(sizeof(*header)), }; @@ -3444,6 +3529,10 @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp) header->autoclear_features |= cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW); } + if (compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { + header->incompatible_features |= + cpu_to_be64(QCOW2_INCOMPAT_COMPRESSION); + } ret = blk_pwrite(blk, 0, header, cluster_size, 0); g_free(header); @@ -3629,6 +3718,7 @@ static int coroutine_fn qcow2_co_create_opts(BlockDriver *drv, { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT }, { BLOCK_OPT_COMPAT_LEVEL, "version" }, { BLOCK_OPT_DATA_FILE_RAW, "data-file-raw" }, + { BLOCK_OPT_COMPRESSION_TYPE, "compression-type" }, { NULL, NULL }, }; @@ -4925,6 +5015,7 @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs, .data_file = g_strdup(s->image_data_file), .has_data_file_raw = has_data_file(bs), .data_file_raw = data_file_is_raw(bs), + .compression_type = s->compression_type, }; } else { /* if this assertion fails, this probably means a new version was @@ -5330,6 +5421,22 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, "images"); return -EINVAL; } + } else if (!strcmp(desc->name, BLOCK_OPT_COMPRESSION_TYPE)) { + const char *ct_name = + qemu_opt_get(opts, BLOCK_OPT_COMPRESSION_TYPE); + int compression_type = + qapi_enum_parse(&Qcow2CompressionType_lookup, ct_name, -1, + NULL); + if (compression_type == -1) { + error_setg(errp, "Unknown compression type: %s", ct_name); + return -ENOTSUP; + } + + if (compression_type != s->compression_type) { + error_setg(errp, "Changing the compression type " + "is not supported"); + return -ENOTSUP; + } } else { /* if this point is reached, this probably means a new option was * added without having it covered here */ @@ -5596,6 +5703,12 @@ static QemuOptsList qcow2_create_opts = { .help = "Width of a reference count entry in bits", .def_value_str = "16" }, + { + .name = BLOCK_OPT_COMPRESSION_TYPE, + .type = QEMU_OPT_STRING, + .help = "Compression method used for image cluster compression", + .def_value_str = "zlib" + }, { /* end of list */ } } }; |