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Diffstat (limited to 'block/qcow2.c')
-rw-r--r--block/qcow2.c113
1 files changed, 113 insertions, 0 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index 1ad95ff048..b878a6a474 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 */ }
}
};
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-20 10:02:05 +0000