* [PATCH v6 0/4] qcow2: Implement zstd cluster compression method
@ 2020-03-12 9:22 Denis Plotnikov
2020-03-12 9:22 ` [PATCH v6 1/4] qcow2: introduce compression type feature Denis Plotnikov
` (3 more replies)
0 siblings, 4 replies; 9+ messages in thread
From: Denis Plotnikov @ 2020-03-12 9:22 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, vsementsov, berto, qemu-block, armbru, mreitz, den
v6:
* "block/qcow2-threads: fix qcow2_decompress" is removed from the series
since it has been accepted by Max already
* add compile time checking for Qcow2Header to be a multiple of 8 [Max, Alberto]
* report error on qcow2 amending when the compression type is actually chnged [Max]
* remove the extra space and the extra new line [Max]
* re-arrange acks and signed-off-s [Vladimir]
v5:
* replace -ENOTSUP with abort in qcow2_co_decompress [Vladimir]
* set cluster size for all test cases in the beginning of the 287 test
v4:
* the series is rebased on top of 01 "block/qcow2-threads: fix qcow2_decompress"
* 01 is just a no-change resend to avoid extra dependencies. Still, it may be merged in separate
v3:
* remove redundant max compression type value check [Vladimir, Eric]
(the switch below checks everything)
* prevent compression type changing on "qemu-img amend" [Vladimir]
* remove zstd config setting, since it has been added already by
"migration" patches [Vladimir]
* change the compression type error message [Vladimir]
* fix alignment and 80-chars exceeding [Vladimir]
v2:
* rework compression type setting [Vladimir]
* squash iotest changes to the compression type introduction patch [Vladimir, Eric]
* fix zstd availability checking in zstd iotest [Vladimir]
* remove unnecessry casting [Eric]
* remove rudundant checks [Eric]
* fix compressed cluster layout in qcow2 spec [Vladimir]
* fix wording [Eric, Vladimir]
* fix compression type filtering in iotests [Eric]
v1:
the initial series
Denis Plotnikov (4):
qcow2: introduce compression type feature
qcow2: rework the cluster compression routine
qcow2: add zstd cluster compression
iotests: 287: add qcow2 compression type test
docs/interop/qcow2.txt | 20 ++++
configure | 2 +-
qapi/block-core.json | 23 +++-
block/qcow2.h | 20 +++-
include/block/block_int.h | 1 +
block/qcow2-threads.c | 195 +++++++++++++++++++++++++++++--
block/qcow2.c | 132 +++++++++++++++++++++
tests/qemu-iotests/031.out | 14 +--
tests/qemu-iotests/036.out | 4 +-
tests/qemu-iotests/049.out | 102 ++++++++--------
tests/qemu-iotests/060.out | 1 +
tests/qemu-iotests/061.out | 34 +++---
tests/qemu-iotests/065 | 28 +++--
tests/qemu-iotests/080 | 2 +-
tests/qemu-iotests/144.out | 4 +-
tests/qemu-iotests/182.out | 2 +-
tests/qemu-iotests/242.out | 5 +
tests/qemu-iotests/255.out | 8 +-
tests/qemu-iotests/287 | 128 ++++++++++++++++++++
tests/qemu-iotests/287.out | 43 +++++++
tests/qemu-iotests/common.filter | 3 +-
tests/qemu-iotests/group | 1 +
22 files changed, 664 insertions(+), 108 deletions(-)
create mode 100755 tests/qemu-iotests/287
create mode 100644 tests/qemu-iotests/287.out
--
2.17.0
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v6 1/4] qcow2: introduce compression type feature
2020-03-12 9:22 [PATCH v6 0/4] qcow2: Implement zstd cluster compression method Denis Plotnikov
@ 2020-03-12 9:22 ` Denis Plotnikov
2020-03-13 21:40 ` Eric Blake
2020-03-12 9:22 ` [PATCH v6 2/4] qcow2: rework the cluster compression routine Denis Plotnikov
` (2 subsequent siblings)
3 siblings, 1 reply; 9+ messages in thread
From: Denis Plotnikov @ 2020-03-12 9:22 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, vsementsov, berto, qemu-block, armbru, mreitz, den
The patch adds some preparation parts for incompatible compression type
feature to qcow2 allowing the use different compression methods for
image clusters (de)compressing.
It is implied that the compression type is set on the image creation and
can be changed only later by image conversion, thus compression type
defines the only compression algorithm used for the image, and thus,
for all image clusters.
The goal of the feature is to add support of other compression methods
to qcow2. For example, ZSTD which is more effective on compression than ZLIB.
The default compression is ZLIB. Images created with ZLIB compression type
are backward compatible with older qemu versions.
Adding of the compression type breaks a number of tests because now the
compression type is reported on image creation and there are some changes
in the qcow2 header in size and offsets.
The tests are fixed in the following ways:
* filter out compression_type for all the tests
* fix header size, feature table size and backing file offset
affected tests: 031, 036, 061, 080
header_size +=8: 1 byte compression type
7 bytes padding
feature_table += 48: incompatible feture compression type
backing_file_offset += 56 (8 + 48 -> header_change + fature_table_change)
* add "compression type" for test output matching when it isn't filtered
affected tests: 049, 060, 061, 065, 144, 182, 242, 255
Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
qapi/block-core.json | 22 +++++-
block/qcow2.h | 20 ++++-
include/block/block_int.h | 1 +
block/qcow2.c | 121 +++++++++++++++++++++++++++++++
tests/qemu-iotests/031.out | 14 ++--
tests/qemu-iotests/036.out | 4 +-
tests/qemu-iotests/049.out | 102 +++++++++++++-------------
tests/qemu-iotests/060.out | 1 +
tests/qemu-iotests/061.out | 34 +++++----
tests/qemu-iotests/065 | 28 ++++---
tests/qemu-iotests/080 | 2 +-
tests/qemu-iotests/144.out | 4 +-
tests/qemu-iotests/182.out | 2 +-
tests/qemu-iotests/242.out | 5 ++
tests/qemu-iotests/255.out | 8 +-
tests/qemu-iotests/common.filter | 3 +-
16 files changed, 275 insertions(+), 96 deletions(-)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 85e27bb61f..a306484973 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -78,6 +78,8 @@
#
# @bitmaps: A list of qcow2 bitmap details (since 4.0)
#
+# @compression-type: the image cluster compression method (since 5.0)
+#
# Since: 1.7
##
{ 'struct': 'ImageInfoSpecificQCow2',
@@ -89,7 +91,8 @@
'*corrupt': 'bool',
'refcount-bits': 'int',
'*encrypt': 'ImageInfoSpecificQCow2Encryption',
- '*bitmaps': ['Qcow2BitmapInfo']
+ '*bitmaps': ['Qcow2BitmapInfo'],
+ 'compression-type': 'Qcow2CompressionType'
} }
##
@@ -4392,6 +4395,18 @@
'data': [ 'v2', 'v3' ] }
+##
+# @Qcow2CompressionType:
+#
+# Compression type used in qcow2 image file
+#
+# @zlib: zlib compression, see <http://zlib.net/>
+#
+# Since: 5.0
+##
+{ 'enum': 'Qcow2CompressionType',
+ 'data': [ 'zlib' ] }
+
##
# @BlockdevCreateOptionsQcow2:
#
@@ -4415,6 +4430,8 @@
# allowed values: off, falloc, full, metadata)
# @lazy-refcounts: True if refcounts may be updated lazily (default: off)
# @refcount-bits: Width of reference counts in bits (default: 16)
+# @compression-type: The image cluster compression method
+# (default: zlib, since 5.0)
#
# Since: 2.12
##
@@ -4430,7 +4447,8 @@
'*cluster-size': 'size',
'*preallocation': 'PreallocMode',
'*lazy-refcounts': 'bool',
- '*refcount-bits': 'int' } }
+ '*refcount-bits': 'int',
+ '*compression-type':'Qcow2CompressionType' } }
##
# @BlockdevCreateOptionsQed:
diff --git a/block/qcow2.h b/block/qcow2.h
index 0942126232..e434cff9ff 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -146,8 +146,16 @@ typedef struct QCowHeader {
uint32_t refcount_order;
uint32_t header_length;
+
+ /* Additional fields */
+ uint8_t compression_type;
+
+ /* header must be a multiple of 8 */
+ uint8_t padding[7];
} QEMU_PACKED QCowHeader;
+QEMU_BUILD_BUG_ON(sizeof(QCowHeader) % 8 != 0);
+
typedef struct QEMU_PACKED QCowSnapshotHeader {
/* header is 8 byte aligned */
uint64_t l1_table_offset;
@@ -216,13 +224,16 @@ enum {
QCOW2_INCOMPAT_DIRTY_BITNR = 0,
QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
QCOW2_INCOMPAT_DATA_FILE_BITNR = 2,
+ QCOW2_INCOMPAT_COMPRESSION_BITNR = 3,
QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
QCOW2_INCOMPAT_DATA_FILE = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
+ QCOW2_INCOMPAT_COMPRESSION = 1 << QCOW2_INCOMPAT_COMPRESSION_BITNR,
QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY
| QCOW2_INCOMPAT_CORRUPT
- | QCOW2_INCOMPAT_DATA_FILE,
+ | QCOW2_INCOMPAT_DATA_FILE
+ | QCOW2_INCOMPAT_COMPRESSION,
};
/* Compatible feature bits */
@@ -369,6 +380,13 @@ typedef struct BDRVQcow2State {
bool metadata_preallocation_checked;
bool metadata_preallocation;
+ /*
+ * Compression type used for the image. Default: 0 - ZLIB
+ * The image compression type is set on image creation.
+ * The only way to change the compression type is to convert the image
+ * with the desired compression type set
+ */
+ Qcow2CompressionType compression_type;
} BDRVQcow2State;
typedef struct Qcow2COWRegion {
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 6f9fd5e20e..2c6bb9dc99 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -57,6 +57,7 @@
#define BLOCK_OPT_REFCOUNT_BITS "refcount_bits"
#define BLOCK_OPT_DATA_FILE "data_file"
#define BLOCK_OPT_DATA_FILE_RAW "data_file_raw"
+#define BLOCK_OPT_COMPRESSION_TYPE "compression_type"
#define BLOCK_PROBE_BUF_SIZE 512
diff --git a/block/qcow2.c b/block/qcow2.c
index 3c754f616b..21231adb63 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1242,6 +1242,48 @@ 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;
+}
+
+static int qcow2_compression_type_from_format(const char *ct)
+{
+ if (g_str_equal(ct, "zlib")) {
+ return QCOW2_COMPRESSION_TYPE_ZLIB;
+ } else {
+ return -EINVAL;
+ }
+}
+
/* Called with s->lock held. */
static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
int flags, Error **errp)
@@ -1357,6 +1399,23 @@ 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,
@@ -2720,6 +2779,11 @@ 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),
@@ -2742,6 +2806,7 @@ 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 */
@@ -2834,6 +2899,11 @@ int qcow2_update_header(BlockDriverState *bs)
.bit = QCOW2_INCOMPAT_DATA_FILE_BITNR,
.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,
@@ -3262,6 +3332,7 @@ 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;
@@ -3379,6 +3450,27 @@ 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(bdrv_get_aio_context(bs),
BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL);
@@ -3401,6 +3493,8 @@ 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 endians since compression_type is 1 byte long */
+ .compression_type = compression_type,
.header_length = cpu_to_be32(sizeof(*header)),
};
@@ -3419,6 +3513,10 @@ 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);
@@ -3602,6 +3700,7 @@ static int coroutine_fn qcow2_co_create_opts(const char *filename, QemuOpts *opt
{ 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 },
};
@@ -4859,6 +4958,7 @@ 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
@@ -5248,6 +5348,21 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
"images");
return -EINVAL;
}
+ } else if (!strcmp(desc->name, BLOCK_OPT_COMPRESSION_TYPE)) {
+ int compression_type =
+ qcow2_compression_type_from_format(
+ qemu_opt_get(opts, BLOCK_OPT_COMPRESSION_TYPE));
+
+ if (compression_type == -EINVAL) {
+ error_setg(errp, "Unknown compression type");
+ 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 */
@@ -5516,6 +5631,12 @@ 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 clusters compression",
+ .def_value_str = "zlib"
+ },
{ /* end of list */ }
}
};
diff --git a/tests/qemu-iotests/031.out b/tests/qemu-iotests/031.out
index d535e407bc..ed51afe9ce 100644
--- a/tests/qemu-iotests/031.out
+++ b/tests/qemu-iotests/031.out
@@ -113,11 +113,11 @@ incompatible_features []
compatible_features []
autoclear_features []
refcount_order 4
-header_length 104
+header_length 112
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
Header extension:
@@ -146,11 +146,11 @@ incompatible_features []
compatible_features []
autoclear_features []
refcount_order 4
-header_length 104
+header_length 112
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
Header extension:
@@ -164,7 +164,7 @@ No errors were found on the image.
magic 0x514649fb
version 3
-backing_file_offset 0x178
+backing_file_offset 0x1b0
backing_file_size 0x17
cluster_bits 16
size 67108864
@@ -179,7 +179,7 @@ incompatible_features []
compatible_features []
autoclear_features []
refcount_order 4
-header_length 104
+header_length 112
Header extension:
magic 0xe2792aca
@@ -188,7 +188,7 @@ data 'host_device'
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
Header extension:
diff --git a/tests/qemu-iotests/036.out b/tests/qemu-iotests/036.out
index 0b52b934e1..fb509f6357 100644
--- a/tests/qemu-iotests/036.out
+++ b/tests/qemu-iotests/036.out
@@ -26,7 +26,7 @@ compatible_features []
autoclear_features [63]
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
@@ -38,7 +38,7 @@ compatible_features []
autoclear_features []
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
*** done
diff --git a/tests/qemu-iotests/049.out b/tests/qemu-iotests/049.out
index affa55b341..a5cfba1756 100644
--- a/tests/qemu-iotests/049.out
+++ b/tests/qemu-iotests/049.out
@@ -4,90 +4,90 @@ QA output created by 049
== 1. Traditional size parameter ==
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1024
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1024b
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1k
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1K
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1048576 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1048576 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1073741824 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1073741824 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1T
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1099511627776 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1099511627776 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1024.0
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1024.0b
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1.5k
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1.5K
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1.5M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1572864 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1572864 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1.5G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1610612736 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1610612736 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 TEST_DIR/t.qcow2 1.5T
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1649267441664 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1649267441664 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
== 2. Specifying size via -o ==
qemu-img create -f qcow2 -o size=1024 TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1024b TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1k TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1K TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1M TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1048576 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1048576 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1G TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1073741824 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1073741824 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1T TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1099511627776 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1099511627776 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1024.0 TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1024.0b TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1.5k TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1.5K TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1.5M TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1572864 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1572864 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1.5G TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1610612736 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1610612736 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o size=1.5T TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1649267441664 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1649267441664 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
== 3. Invalid sizes ==
@@ -129,84 +129,84 @@ qemu-img: TEST_DIR/t.qcow2: The image size must be specified only once
== Check correct interpretation of suffixes for cluster size ==
qemu-img create -f qcow2 -o cluster_size=1024 TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o cluster_size=1024b TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o cluster_size=1k TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o cluster_size=1K TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o cluster_size=1M TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1048576 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1048576 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o cluster_size=1024.0 TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o cluster_size=1024.0b TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=1024 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o cluster_size=0.5k TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=512 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=512 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o cluster_size=0.5K TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=512 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=512 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o cluster_size=0.5M TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=524288 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=524288 lazy_refcounts=off refcount_bits=16 compression_type=zlib
== Check compat level option ==
qemu-img create -f qcow2 -o compat=0.10 TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=0.10 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=0.10 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o compat=1.1 TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=1.1 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=1.1 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o compat=0.42 TEST_DIR/t.qcow2 64M
qemu-img: TEST_DIR/t.qcow2: Invalid parameter '0.42'
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=0.42 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=0.42 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o compat=foobar TEST_DIR/t.qcow2 64M
qemu-img: TEST_DIR/t.qcow2: Invalid parameter 'foobar'
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=foobar cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=foobar cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
== Check preallocation option ==
qemu-img create -f qcow2 -o preallocation=off TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=65536 preallocation=off lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=65536 preallocation=off lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o preallocation=metadata TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=65536 preallocation=metadata lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=65536 preallocation=metadata lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o preallocation=1234 TEST_DIR/t.qcow2 64M
qemu-img: TEST_DIR/t.qcow2: Invalid parameter '1234'
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=65536 preallocation=1234 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=65536 preallocation=1234 lazy_refcounts=off refcount_bits=16 compression_type=zlib
== Check encryption option ==
qemu-img create -f qcow2 -o encryption=off TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 --object secret,id=sec0,data=123456 -o encryption=on,encrypt.key-secret=sec0 TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=on encrypt.key-secret=sec0 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=on encrypt.key-secret=sec0 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
== Check lazy_refcounts option (only with v3) ==
qemu-img create -f qcow2 -o compat=1.1,lazy_refcounts=off TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=1.1 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=1.1 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o compat=1.1,lazy_refcounts=on TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=1.1 cluster_size=65536 lazy_refcounts=on refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=1.1 cluster_size=65536 lazy_refcounts=on refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o compat=0.10,lazy_refcounts=off TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=0.10 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=0.10 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
qemu-img create -f qcow2 -o compat=0.10,lazy_refcounts=on TEST_DIR/t.qcow2 64M
qemu-img: TEST_DIR/t.qcow2: Lazy refcounts only supported with compatibility level 1.1 and above (use version=v3 or greater)
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=0.10 cluster_size=65536 lazy_refcounts=on refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=0.10 cluster_size=65536 lazy_refcounts=on refcount_bits=16 compression_type=zlib
*** done
diff --git a/tests/qemu-iotests/060.out b/tests/qemu-iotests/060.out
index d27692a33c..3e47f537e8 100644
--- a/tests/qemu-iotests/060.out
+++ b/tests/qemu-iotests/060.out
@@ -17,6 +17,7 @@ virtual size: 64 MiB (67108864 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
refcount bits: 16
corrupt: true
diff --git a/tests/qemu-iotests/061.out b/tests/qemu-iotests/061.out
index 8b3091a412..c913f02ad6 100644
--- a/tests/qemu-iotests/061.out
+++ b/tests/qemu-iotests/061.out
@@ -22,11 +22,11 @@ incompatible_features []
compatible_features [0]
autoclear_features []
refcount_order 4
-header_length 104
+header_length 112
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
magic 0x514649fb
@@ -80,11 +80,11 @@ incompatible_features []
compatible_features [0]
autoclear_features []
refcount_order 4
-header_length 104
+header_length 112
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
magic 0x514649fb
@@ -136,11 +136,11 @@ incompatible_features [0]
compatible_features [0]
autoclear_features []
refcount_order 4
-header_length 104
+header_length 112
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
ERROR cluster 5 refcount=0 reference=1
@@ -191,11 +191,11 @@ incompatible_features []
compatible_features [42]
autoclear_features [42]
refcount_order 4
-header_length 104
+header_length 112
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
magic 0x514649fb
@@ -260,11 +260,11 @@ incompatible_features []
compatible_features [0]
autoclear_features []
refcount_order 4
-header_length 104
+header_length 112
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
read 65536/65536 bytes at offset 44040192
@@ -294,11 +294,11 @@ incompatible_features [0]
compatible_features [0]
autoclear_features []
refcount_order 4
-header_length 104
+header_length 112
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
ERROR cluster 5 refcount=0 reference=1
@@ -323,11 +323,11 @@ incompatible_features []
compatible_features []
autoclear_features []
refcount_order 4
-header_length 104
+header_length 112
Header extension:
magic 0x6803f857
-length 192
+length 240
data <binary>
read 131072/131072 bytes at offset 0
@@ -491,6 +491,7 @@ virtual size: 64 MiB (67108864 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
refcount bits: 16
data file: TEST_DIR/t.IMGFMT.data
@@ -511,6 +512,7 @@ virtual size: 64 MiB (67108864 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
refcount bits: 16
data file: foo
@@ -524,6 +526,7 @@ virtual size: 64 MiB (67108864 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
refcount bits: 16
data file raw: false
@@ -538,6 +541,7 @@ virtual size: 64 MiB (67108864 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
refcount bits: 16
data file: TEST_DIR/t.IMGFMT.data
@@ -550,6 +554,7 @@ virtual size: 64 MiB (67108864 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
refcount bits: 16
data file: TEST_DIR/t.IMGFMT.data
@@ -563,6 +568,7 @@ virtual size: 64 MiB (67108864 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
refcount bits: 16
data file: TEST_DIR/t.IMGFMT.data
diff --git a/tests/qemu-iotests/065 b/tests/qemu-iotests/065
index 6426474271..18dc488c7a 100755
--- a/tests/qemu-iotests/065
+++ b/tests/qemu-iotests/065
@@ -88,24 +88,30 @@ class TestQMP(TestImageInfoSpecific):
class TestQCow2(TestQemuImgInfo):
'''Testing a qcow2 version 2 image'''
img_options = 'compat=0.10'
- json_compare = { 'compat': '0.10', 'refcount-bits': 16 }
- human_compare = [ 'compat: 0.10', 'refcount bits: 16' ]
+ json_compare = { 'compat': '0.10', 'refcount-bits': 16,
+ 'compression-type': 'zlib' }
+ human_compare = [ 'compat: 0.10', 'compression type: zlib',
+ 'refcount bits: 16' ]
class TestQCow3NotLazy(TestQemuImgInfo):
'''Testing a qcow2 version 3 image with lazy refcounts disabled'''
img_options = 'compat=1.1,lazy_refcounts=off'
json_compare = { 'compat': '1.1', 'lazy-refcounts': False,
- 'refcount-bits': 16, 'corrupt': False }
- human_compare = [ 'compat: 1.1', 'lazy refcounts: false',
- 'refcount bits: 16', 'corrupt: false' ]
+ 'refcount-bits': 16, 'corrupt': False,
+ 'compression-type': 'zlib' }
+ human_compare = [ 'compat: 1.1', 'compression type: zlib',
+ 'lazy refcounts: false', 'refcount bits: 16',
+ 'corrupt: false' ]
class TestQCow3Lazy(TestQemuImgInfo):
'''Testing a qcow2 version 3 image with lazy refcounts enabled'''
img_options = 'compat=1.1,lazy_refcounts=on'
json_compare = { 'compat': '1.1', 'lazy-refcounts': True,
- 'refcount-bits': 16, 'corrupt': False }
- human_compare = [ 'compat: 1.1', 'lazy refcounts: true',
- 'refcount bits: 16', 'corrupt: false' ]
+ 'refcount-bits': 16, 'corrupt': False,
+ 'compression-type': 'zlib' }
+ human_compare = [ 'compat: 1.1', 'compression type: zlib',
+ 'lazy refcounts: true', 'refcount bits: 16',
+ 'corrupt: false' ]
class TestQCow3NotLazyQMP(TestQMP):
'''Testing a qcow2 version 3 image with lazy refcounts disabled, opening
@@ -113,7 +119,8 @@ class TestQCow3NotLazyQMP(TestQMP):
img_options = 'compat=1.1,lazy_refcounts=off'
qemu_options = 'lazy-refcounts=on'
compare = { 'compat': '1.1', 'lazy-refcounts': False,
- 'refcount-bits': 16, 'corrupt': False }
+ 'refcount-bits': 16, 'corrupt': False,
+ 'compression-type': 'zlib' }
class TestQCow3LazyQMP(TestQMP):
@@ -122,7 +129,8 @@ class TestQCow3LazyQMP(TestQMP):
img_options = 'compat=1.1,lazy_refcounts=on'
qemu_options = 'lazy-refcounts=off'
compare = { 'compat': '1.1', 'lazy-refcounts': True,
- 'refcount-bits': 16, 'corrupt': False }
+ 'refcount-bits': 16, 'corrupt': False,
+ 'compression-type': 'zlib' }
TestImageInfoSpecific = None
TestQemuImgInfo = None
diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080
index a3d13c414e..7588c63b6c 100755
--- a/tests/qemu-iotests/080
+++ b/tests/qemu-iotests/080
@@ -45,7 +45,7 @@ _supported_os Linux
# - This is generally a test for compat=1.1 images
_unsupported_imgopts 'refcount_bits=1[^0-9]' data_file 'compat=0.10'
-header_size=104
+header_size=112
offset_backing_file_offset=8
offset_backing_file_size=16
diff --git a/tests/qemu-iotests/144.out b/tests/qemu-iotests/144.out
index c7aa2e4820..885a8874a5 100644
--- a/tests/qemu-iotests/144.out
+++ b/tests/qemu-iotests/144.out
@@ -9,7 +9,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=536870912
{ 'execute': 'qmp_capabilities' }
{"return": {}}
{ 'execute': 'blockdev-snapshot-sync', 'arguments': { 'device': 'virtio0', 'snapshot-file':'TEST_DIR/tmp.IMGFMT', 'format': 'IMGFMT' } }
-Formatting 'TEST_DIR/tmp.qcow2', fmt=qcow2 size=536870912 backing_file=TEST_DIR/t.qcow2 backing_fmt=qcow2 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/tmp.qcow2', fmt=qcow2 size=536870912 backing_file=TEST_DIR/t.qcow2 backing_fmt=qcow2 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
{"return": {}}
=== Performing block-commit on active layer ===
@@ -31,6 +31,6 @@ Formatting 'TEST_DIR/tmp.qcow2', fmt=qcow2 size=536870912 backing_file=TEST_DIR/
=== Performing Live Snapshot 2 ===
{ 'execute': 'blockdev-snapshot-sync', 'arguments': { 'device': 'virtio0', 'snapshot-file':'TEST_DIR/tmp2.IMGFMT', 'format': 'IMGFMT' } }
-Formatting 'TEST_DIR/tmp2.qcow2', fmt=qcow2 size=536870912 backing_file=TEST_DIR/t.qcow2 backing_fmt=qcow2 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/tmp2.qcow2', fmt=qcow2 size=536870912 backing_file=TEST_DIR/t.qcow2 backing_fmt=qcow2 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
{"return": {}}
*** done
diff --git a/tests/qemu-iotests/182.out b/tests/qemu-iotests/182.out
index a8eea166c3..ae43654d32 100644
--- a/tests/qemu-iotests/182.out
+++ b/tests/qemu-iotests/182.out
@@ -13,7 +13,7 @@ Is another process using the image [TEST_DIR/t.qcow2]?
{'execute': 'blockdev-add', 'arguments': { 'node-name': 'node0', 'driver': 'file', 'filename': 'TEST_DIR/t.IMGFMT', 'locking': 'on' } }
{"return": {}}
{'execute': 'blockdev-snapshot-sync', 'arguments': { 'node-name': 'node0', 'snapshot-file': 'TEST_DIR/t.IMGFMT.overlay', 'snapshot-node-name': 'node1' } }
-Formatting 'TEST_DIR/t.qcow2.overlay', fmt=qcow2 size=197120 backing_file=TEST_DIR/t.qcow2 backing_fmt=file cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/t.qcow2.overlay', fmt=qcow2 size=197120 backing_file=TEST_DIR/t.qcow2 backing_fmt=file cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
{"return": {}}
{'execute': 'blockdev-add', 'arguments': { 'node-name': 'node1', 'driver': 'file', 'filename': 'TEST_DIR/t.IMGFMT', 'locking': 'on' } }
{"return": {}}
diff --git a/tests/qemu-iotests/242.out b/tests/qemu-iotests/242.out
index 7ac8404d11..091b9126ce 100644
--- a/tests/qemu-iotests/242.out
+++ b/tests/qemu-iotests/242.out
@@ -12,6 +12,7 @@ virtual size: 1 MiB (1048576 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
refcount bits: 16
corrupt: false
@@ -32,6 +33,7 @@ virtual size: 1 MiB (1048576 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
bitmaps:
[0]:
@@ -64,6 +66,7 @@ virtual size: 1 MiB (1048576 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
bitmaps:
[0]:
@@ -104,6 +107,7 @@ virtual size: 1 MiB (1048576 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
bitmaps:
[0]:
@@ -153,6 +157,7 @@ virtual size: 1 MiB (1048576 bytes)
cluster_size: 65536
Format specific information:
compat: 1.1
+ compression type: zlib
lazy refcounts: false
bitmaps:
[0]:
diff --git a/tests/qemu-iotests/255.out b/tests/qemu-iotests/255.out
index 348909fdef..a3c99fd62e 100644
--- a/tests/qemu-iotests/255.out
+++ b/tests/qemu-iotests/255.out
@@ -3,9 +3,9 @@ Finishing a commit job with background reads
=== Create backing chain and start VM ===
-Formatting 'TEST_DIR/PID-t.qcow2.mid', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/PID-t.qcow2.mid', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
-Formatting 'TEST_DIR/PID-t.qcow2', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/PID-t.qcow2', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
=== Start background read requests ===
@@ -23,9 +23,9 @@ Closing the VM while a job is being cancelled
=== Create images and start VM ===
-Formatting 'TEST_DIR/PID-src.qcow2', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/PID-src.qcow2', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
-Formatting 'TEST_DIR/PID-dst.qcow2', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/PID-dst.qcow2', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
wrote 1048576/1048576 bytes at offset 0
1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
diff --git a/tests/qemu-iotests/common.filter b/tests/qemu-iotests/common.filter
index 3f8ee3e5f7..279e0bbb0d 100644
--- a/tests/qemu-iotests/common.filter
+++ b/tests/qemu-iotests/common.filter
@@ -152,7 +152,8 @@ _filter_img_create()
-e "s# refcount_bits=[0-9]\\+##g" \
-e "s# key-secret=[a-zA-Z0-9]\\+##g" \
-e "s# iter-time=[0-9]\\+##g" \
- -e "s# force_size=\\(on\\|off\\)##g"
+ -e "s# force_size=\\(on\\|off\\)##g" \
+ -e "s# compression_type=[a-zA-Z0-9]\\+##g"
}
_filter_img_info()
--
2.17.0
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v6 2/4] qcow2: rework the cluster compression routine
2020-03-12 9:22 [PATCH v6 0/4] qcow2: Implement zstd cluster compression method Denis Plotnikov
2020-03-12 9:22 ` [PATCH v6 1/4] qcow2: introduce compression type feature Denis Plotnikov
@ 2020-03-12 9:22 ` Denis Plotnikov
2020-03-12 9:22 ` [PATCH v6 3/4] qcow2: add zstd cluster compression Denis Plotnikov
2020-03-12 9:22 ` [PATCH v6 4/4] iotests: 287: add qcow2 compression type test Denis Plotnikov
3 siblings, 0 replies; 9+ messages in thread
From: Denis Plotnikov @ 2020-03-12 9:22 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, vsementsov, berto, qemu-block, armbru, mreitz, den
The patch enables processing the image compression type defined
for the image and chooses an appropriate method for image clusters
(de)compression.
Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
block/qcow2-threads.c | 71 ++++++++++++++++++++++++++++++++++++-------
1 file changed, 60 insertions(+), 11 deletions(-)
diff --git a/block/qcow2-threads.c b/block/qcow2-threads.c
index a68126f291..7dbaf53489 100644
--- a/block/qcow2-threads.c
+++ b/block/qcow2-threads.c
@@ -74,7 +74,9 @@ typedef struct Qcow2CompressData {
} Qcow2CompressData;
/*
- * qcow2_compress()
+ * qcow2_zlib_compress()
+ *
+ * Compress @src_size bytes of data using zlib compression method
*
* @dest - destination buffer, @dest_size bytes
* @src - source buffer, @src_size bytes
@@ -83,8 +85,8 @@ typedef struct Qcow2CompressData {
* -ENOMEM destination buffer is not enough to store compressed data
* -EIO on any other error
*/
-static ssize_t qcow2_compress(void *dest, size_t dest_size,
- const void *src, size_t src_size)
+static ssize_t qcow2_zlib_compress(void *dest, size_t dest_size,
+ const void *src, size_t src_size)
{
ssize_t ret;
z_stream strm;
@@ -119,10 +121,10 @@ static ssize_t qcow2_compress(void *dest, size_t dest_size,
}
/*
- * qcow2_decompress()
+ * qcow2_zlib_decompress()
*
* Decompress some data (not more than @src_size bytes) to produce exactly
- * @dest_size bytes.
+ * @dest_size bytes using zlib compression method
*
* @dest - destination buffer, @dest_size bytes
* @src - source buffer, @src_size bytes
@@ -130,8 +132,8 @@ static ssize_t qcow2_compress(void *dest, size_t dest_size,
* Returns: 0 on success
* -EIO on fail
*/
-static ssize_t qcow2_decompress(void *dest, size_t dest_size,
- const void *src, size_t src_size)
+static ssize_t qcow2_zlib_decompress(void *dest, size_t dest_size,
+ const void *src, size_t src_size)
{
int ret;
z_stream strm;
@@ -191,20 +193,67 @@ qcow2_co_do_compress(BlockDriverState *bs, void *dest, size_t dest_size,
return arg.ret;
}
+/*
+ * qcow2_co_compress()
+ *
+ * Compress @src_size bytes of data using the compression
+ * method defined by the image compression type
+ *
+ * @dest - destination buffer, @dest_size bytes
+ * @src - source buffer, @src_size bytes
+ *
+ * Returns: compressed size on success
+ * a negative error code on failure
+ */
ssize_t coroutine_fn
qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
const void *src, size_t src_size)
{
- return qcow2_co_do_compress(bs, dest, dest_size, src, src_size,
- qcow2_compress);
+ BDRVQcow2State *s = bs->opaque;
+ Qcow2CompressFunc fn;
+
+ switch (s->compression_type) {
+ case QCOW2_COMPRESSION_TYPE_ZLIB:
+ fn = qcow2_zlib_compress;
+ break;
+
+ default:
+ abort();
+ }
+
+ return qcow2_co_do_compress(bs, dest, dest_size, src, src_size, fn);
}
+/*
+ * qcow2_co_decompress()
+ *
+ * Decompress some data (not more than @src_size bytes) to produce exactly
+ * @dest_size bytes using the compression method defined by the image
+ * compression type
+ *
+ * @dest - destination buffer, @dest_size bytes
+ * @src - source buffer, @src_size bytes
+ *
+ * Returns: 0 on success
+ * a negative error code on failure
+ */
ssize_t coroutine_fn
qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
const void *src, size_t src_size)
{
- return qcow2_co_do_compress(bs, dest, dest_size, src, src_size,
- qcow2_decompress);
+ BDRVQcow2State *s = bs->opaque;
+ Qcow2CompressFunc fn;
+
+ switch (s->compression_type) {
+ case QCOW2_COMPRESSION_TYPE_ZLIB:
+ fn = qcow2_zlib_decompress;
+ break;
+
+ default:
+ abort();
+ }
+
+ return qcow2_co_do_compress(bs, dest, dest_size, src, src_size, fn);
}
--
2.17.0
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v6 3/4] qcow2: add zstd cluster compression
2020-03-12 9:22 [PATCH v6 0/4] qcow2: Implement zstd cluster compression method Denis Plotnikov
2020-03-12 9:22 ` [PATCH v6 1/4] qcow2: introduce compression type feature Denis Plotnikov
2020-03-12 9:22 ` [PATCH v6 2/4] qcow2: rework the cluster compression routine Denis Plotnikov
@ 2020-03-12 9:22 ` Denis Plotnikov
2020-03-16 14:01 ` Eric Blake
2020-03-12 9:22 ` [PATCH v6 4/4] iotests: 287: add qcow2 compression type test Denis Plotnikov
3 siblings, 1 reply; 9+ messages in thread
From: Denis Plotnikov @ 2020-03-12 9:22 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, vsementsov, berto, qemu-block, armbru, mreitz, den
zstd significantly reduces cluster compression time.
It provides better compression performance maintaining
the same level of the compression ratio in comparison with
zlib, which, at the moment, is the only compression
method available.
The performance test results:
Test compresses and decompresses qemu qcow2 image with just
installed rhel-7.6 guest.
Image cluster size: 64K. Image on disk size: 2.2G
The test was conducted with brd disk to reduce the influence
of disk subsystem to the test results.
The results is given in seconds.
compress cmd:
time ./qemu-img convert -O qcow2 -c -o compression_type=[zlib|zstd]
src.img [zlib|zstd]_compressed.img
decompress cmd
time ./qemu-img convert -O qcow2
[zlib|zstd]_compressed.img uncompressed.img
compression decompression
zlib zstd zlib zstd
------------------------------------------------------------
real 65.5 16.3 (-75 %) 1.9 1.6 (-16 %)
user 65.0 15.8 5.3 2.5
sys 3.3 0.2 2.0 2.0
Both ZLIB and ZSTD gave the same compression ratio: 1.57
compressed image size in both cases: 1.4G
Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
QAPI part:
Acked-by: Markus Armbruster <armbru@redhat.com>
---
docs/interop/qcow2.txt | 20 +++++++
configure | 2 +-
qapi/block-core.json | 3 +-
block/qcow2-threads.c | 124 +++++++++++++++++++++++++++++++++++++++++
block/qcow2.c | 11 ++++
5 files changed, 158 insertions(+), 2 deletions(-)
diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt
index 5597e24474..9048114445 100644
--- a/docs/interop/qcow2.txt
+++ b/docs/interop/qcow2.txt
@@ -208,6 +208,7 @@ version 2.
Available compression type values:
0: zlib <https://www.zlib.net/>
+ 1: zstd <http://github.com/facebook/zstd>
=== Header padding ===
@@ -575,11 +576,30 @@ Compressed Clusters Descriptor (x = 62 - (cluster_bits - 8)):
Another compressed cluster may map to the tail of the final
sector used by this compressed cluster.
+ The layout of the compressed data depends on the compression
+ type used for the image (see compressed cluster layout).
+
If a cluster is unallocated, read requests shall read the data from the backing
file (except if bit 0 in the Standard Cluster Descriptor is set). If there is
no backing file or the backing file is smaller than the image, they shall read
zeros for all parts that are not covered by the backing file.
+=== Compressed Cluster Layout ===
+
+The compressed cluster data has a layout depending on the compression
+type used for the image, as follows:
+
+Compressed data layout for the available compression types:
+data_space_lenght - data chunk length available to store a compressed cluster.
+(for more details see "Compressed Clusters Descriptor")
+x = data_space_length - 1
+
+ 0: (default) zlib <http://zlib.net/>:
+ Byte 0 - x: the compressed data content
+ all the space provided used for compressed data
+ 1: zstd <http://github.com/facebook/zstd>:
+ Byte 0 - 3: the length of compressed data in bytes
+ 4 - x: the compressed data content
== Snapshots ==
diff --git a/configure b/configure
index caa65f5883..b2a0aa241a 100755
--- a/configure
+++ b/configure
@@ -1835,7 +1835,7 @@ disabled with --disable-FEATURE, default is enabled if available:
lzfse support of lzfse compression library
(for reading lzfse-compressed dmg images)
zstd support for zstd compression library
- (for migration compression)
+ (for migration compression and qcow2 cluster compression)
seccomp seccomp support
coroutine-pool coroutine freelist (better performance)
glusterfs GlusterFS backend
diff --git a/qapi/block-core.json b/qapi/block-core.json
index a306484973..8953451818 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -4401,11 +4401,12 @@
# Compression type used in qcow2 image file
#
# @zlib: zlib compression, see <http://zlib.net/>
+# @zstd: zstd compression, see <http://github.com/facebook/zstd>
#
# Since: 5.0
##
{ 'enum': 'Qcow2CompressionType',
- 'data': [ 'zlib' ] }
+ 'data': [ 'zlib', { 'name': 'zstd', 'if': 'defined(CONFIG_ZSTD)' } ] }
##
# @BlockdevCreateOptionsQcow2:
diff --git a/block/qcow2-threads.c b/block/qcow2-threads.c
index 7dbaf53489..b2d1c6d395 100644
--- a/block/qcow2-threads.c
+++ b/block/qcow2-threads.c
@@ -28,6 +28,11 @@
#define ZLIB_CONST
#include <zlib.h>
+#ifdef CONFIG_ZSTD
+#include <zstd.h>
+#include <zstd_errors.h>
+#endif
+
#include "qcow2.h"
#include "block/thread-pool.h"
#include "crypto.h"
@@ -166,6 +171,115 @@ static ssize_t qcow2_zlib_decompress(void *dest, size_t dest_size,
return ret;
}
+#ifdef CONFIG_ZSTD
+
+/* The buffer size to store compressed chunk length */
+#define ZSTD_LEN_BUF 4
+
+/*
+ * qcow2_zstd_compress()
+ *
+ * Compress @src_size bytes of data using zstd compression method
+ *
+ * @dest - destination buffer, @dest_size bytes
+ * @src - source buffer, @src_size bytes
+ *
+ * Returns: compressed size on success
+ * -ENOMEM destination buffer is not enough to store compressed data
+ * -EIO on any other error
+ */
+static ssize_t qcow2_zstd_compress(void *dest, size_t dest_size,
+ const void *src, size_t src_size)
+{
+ size_t ret;
+
+ /*
+ * steal ZSTD_LEN_BUF bytes in the very beginning of the buffer
+ * to store compressed chunk size
+ */
+ char *d_buf = ((char *) dest) + ZSTD_LEN_BUF;
+
+ /*
+ * sanity check that we can store the compressed data length,
+ * and there is some space left for the compressor buffer
+ */
+ if (dest_size <= ZSTD_LEN_BUF) {
+ return -ENOMEM;
+ }
+
+ dest_size -= ZSTD_LEN_BUF;
+
+ ret = ZSTD_compress(d_buf, dest_size, src, src_size, 5);
+
+ if (ZSTD_isError(ret)) {
+ if (ZSTD_getErrorCode(ret) == ZSTD_error_dstSize_tooSmall) {
+ return -ENOMEM;
+ } else {
+ return -EIO;
+ }
+ }
+
+ /*
+ * paranoid sanity check that we can store
+ * the compressed size in the first 4 bytes
+ */
+ if (ret > UINT32_MAX) {
+ return -ENOMEM;
+ }
+
+ /* store the compressed chunk size in the very beginning of the buffer */
+ stl_be_p(dest, ret);
+
+ return ret + ZSTD_LEN_BUF;
+}
+
+/*
+ * qcow2_zstd_decompress()
+ *
+ * Decompress some data (not more than @src_size bytes) to produce exactly
+ * @dest_size bytes using zstd compression method
+ *
+ * @dest - destination buffer, @dest_size bytes
+ * @src - source buffer, @src_size bytes
+ *
+ * Returns: 0 on success
+ * -EIO on any error
+ */
+static ssize_t qcow2_zstd_decompress(void *dest, size_t dest_size,
+ const void *src, size_t src_size)
+{
+ /*
+ * zstd decompress wants to know the exact length of the data.
+ * For that purpose, on compression, the length is stored in
+ * the very beginning of the compressed buffer
+ */
+ size_t s_size;
+ const char *s_buf = ((const char *) src) + ZSTD_LEN_BUF;
+
+ /*
+ * sanity check that we can read 4 byte the content length and
+ * and there is some content to decompress
+ */
+ if (src_size <= ZSTD_LEN_BUF) {
+ return -EIO;
+ }
+
+ s_size = ldl_be_p(src);
+
+ /* sanity check that the buffer is big enough to read the content from */
+ if (src_size - ZSTD_LEN_BUF < s_size) {
+ return -EIO;
+ }
+
+ if (ZSTD_isError(
+ ZSTD_decompress(dest, dest_size, s_buf, s_size))) {
+ return -EIO;
+ }
+
+ return 0;
+}
+#endif
+
static int qcow2_compress_pool_func(void *opaque)
{
Qcow2CompressData *data = opaque;
@@ -217,6 +331,11 @@ qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
fn = qcow2_zlib_compress;
break;
+#ifdef CONFIG_ZSTD
+ case QCOW2_COMPRESSION_TYPE_ZSTD:
+ fn = qcow2_zstd_compress;
+ break;
+#endif
default:
abort();
}
@@ -249,6 +368,11 @@ qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
fn = qcow2_zlib_decompress;
break;
+#ifdef CONFIG_ZSTD
+ case QCOW2_COMPRESSION_TYPE_ZSTD:
+ fn = qcow2_zstd_decompress;
+ break;
+#endif
default:
abort();
}
diff --git a/block/qcow2.c b/block/qcow2.c
index 21231adb63..53f65502f1 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1246,6 +1246,9 @@ static int validate_compression_type(BDRVQcow2State *s, Error **errp)
{
switch (s->compression_type) {
case QCOW2_COMPRESSION_TYPE_ZLIB:
+#ifdef CONFIG_ZSTD
+ case QCOW2_COMPRESSION_TYPE_ZSTD:
+#endif
break;
default:
@@ -1279,6 +1282,10 @@ static int qcow2_compression_type_from_format(const char *ct)
{
if (g_str_equal(ct, "zlib")) {
return QCOW2_COMPRESSION_TYPE_ZLIB;
+#ifdef CONFIG_ZSTD
+ } else if (g_str_equal(ct, "zstd")) {
+ return QCOW2_COMPRESSION_TYPE_ZSTD;
+#endif
} else {
return -EINVAL;
}
@@ -3463,6 +3470,10 @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
}
switch (qcow2_opts->compression_type) {
+#ifdef CONFIG_ZSTD
+ case QCOW2_COMPRESSION_TYPE_ZSTD:
+ break;
+#endif
default:
error_setg(errp, "Unknown compression type");
goto out;
--
2.17.0
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v6 4/4] iotests: 287: add qcow2 compression type test
2020-03-12 9:22 [PATCH v6 0/4] qcow2: Implement zstd cluster compression method Denis Plotnikov
` (2 preceding siblings ...)
2020-03-12 9:22 ` [PATCH v6 3/4] qcow2: add zstd cluster compression Denis Plotnikov
@ 2020-03-12 9:22 ` Denis Plotnikov
3 siblings, 0 replies; 9+ messages in thread
From: Denis Plotnikov @ 2020-03-12 9:22 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, vsementsov, berto, qemu-block, armbru, mreitz, den
The test checks fulfilling qcow2 requiriements for the compression
type feature and zstd compression type operability.
Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
tests/qemu-iotests/287 | 128 +++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/287.out | 43 +++++++++++++
tests/qemu-iotests/group | 1 +
3 files changed, 172 insertions(+)
create mode 100755 tests/qemu-iotests/287
create mode 100644 tests/qemu-iotests/287.out
diff --git a/tests/qemu-iotests/287 b/tests/qemu-iotests/287
new file mode 100755
index 0000000000..49d15b3d43
--- /dev/null
+++ b/tests/qemu-iotests/287
@@ -0,0 +1,128 @@
+#!/usr/bin/env bash
+#
+# Test case for an image using zstd compression
+#
+# Copyright (c) 2020 Virtuozzo International GmbH
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+# creator
+owner=dplotnikov@virtuozzo.com
+
+seq="$(basename $0)"
+echo "QA output created by $seq"
+
+status=1 # failure is the default!
+
+_cleanup()
+{
+ _cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# standard environment
+. ./common.rc
+. ./common.filter
+
+# This tests qocw2-specific low-level functionality
+_supported_fmt qcow2
+_supported_proto file
+_supported_os Linux
+
+# for all the cases
+CLUSTER_SIZE=65536
+
+# Check if we can run this test.
+
+IMGOPTS='compression_type=zstd' _make_test_img 64M | grep "Invalid parameter 'zstd'" 2>&1 1>/dev/null
+
+ZSTD_SUPPORTED=$?
+
+if (($ZSTD_SUPPORTED==0)); then
+ _notrun "ZSTD is disabled"
+fi
+
+# Test: when compression is zlib the incompatible bit is unset
+echo
+echo "=== Testing compression type incompatible bit setting for zlib ==="
+echo
+
+IMGOPTS='compression_type=zlib' _make_test_img 64M
+$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
+
+# Test: when compression differs from zlib the incompatible bit is set
+echo
+echo "=== Testing compression type incompatible bit setting for zstd ==="
+echo
+
+IMGOPTS='compression_type=zstd' _make_test_img 64M
+$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
+
+# Test: an image can't be openned if compression type is zlib and
+# incompatible feature compression type is set
+echo
+echo "=== Testing zlib with incompatible bit set ==="
+echo
+
+IMGOPTS='compression_type=zlib' _make_test_img 64M
+$PYTHON qcow2.py "$TEST_IMG" set-feature-bit incompatible 3
+# to make sure the bit was actually set
+$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
+$QEMU_IMG info "$TEST_IMG" 2>1 1>/dev/null
+if (($?==0)); then
+ echo "Error: The image openned successfully. The image must not be openned"
+fi
+
+# Test: an image can't be openned if compression type is NOT zlib and
+# incompatible feature compression type is UNSET
+echo
+echo "=== Testing zstd with incompatible bit unset ==="
+echo
+
+IMGOPTS='compression_type=zstd' _make_test_img 64M
+$PYTHON qcow2.py "$TEST_IMG" set-header incompatible_features 0
+# to make sure the bit was actually unset
+$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
+$QEMU_IMG info "$TEST_IMG" 2>1 1>/dev/null
+if (($?==0)); then
+ echo "Error: The image openned successfully. The image must not be openned"
+fi
+# Test: check compression type values
+echo
+echo "=== Testing compression type values ==="
+echo
+# zlib=0
+IMGOPTS='compression_type=zlib' _make_test_img 64M
+od -j104 -N1 -An -vtu1 "$TEST_IMG"
+
+# zstd=1
+IMGOPTS='compression_type=zstd' _make_test_img 64M
+od -j104 -N1 -An -vtu1 "$TEST_IMG"
+
+# Test: using zstd compression, write to and read from an image
+echo
+echo "=== Testing reading and writing with zstd ==="
+echo
+
+IMGOPTS='compression_type=zstd' _make_test_img 64M
+$QEMU_IO -c "write -c -P 0xAC 65536 64k " "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 0xAC 65536 65536 " "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -v 131070 8 " "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -v 65534 8" "$TEST_IMG" | _filter_qemu_io
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/287.out b/tests/qemu-iotests/287.out
new file mode 100644
index 0000000000..8e51c3078d
--- /dev/null
+++ b/tests/qemu-iotests/287.out
@@ -0,0 +1,43 @@
+QA output created by 287
+
+=== Testing compression type incompatible bit setting for zlib ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+incompatible_features []
+
+=== Testing compression type incompatible bit setting for zstd ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+incompatible_features [3]
+
+=== Testing zlib with incompatible bit set ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+incompatible_features [3]
+
+=== Testing zstd with incompatible bit unset ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+incompatible_features []
+
+=== Testing compression type values ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+ 0
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+ 1
+
+=== Testing reading and writing with zstd ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+wrote 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+0001fffe: ac ac 00 00 00 00 00 00 ........
+read 8/8 bytes at offset 131070
+8 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+0000fffe: 00 00 ac ac ac ac ac ac ........
+read 8/8 bytes at offset 65534
+8 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 0317667695..5edbadef40 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -293,3 +293,4 @@
283 auto quick
284 rw
286 rw quick
+287 auto quick
--
2.17.0
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v6 1/4] qcow2: introduce compression type feature
2020-03-12 9:22 ` [PATCH v6 1/4] qcow2: introduce compression type feature Denis Plotnikov
@ 2020-03-13 21:40 ` Eric Blake
2020-03-16 8:13 ` Denis Plotnikov
0 siblings, 1 reply; 9+ messages in thread
From: Eric Blake @ 2020-03-13 21:40 UTC (permalink / raw)
To: Denis Plotnikov, qemu-devel
Cc: kwolf, vsementsov, qemu-block, armbru, mreitz, den
On 3/12/20 4:22 AM, Denis Plotnikov wrote:
> The patch adds some preparation parts for incompatible compression type
> feature to qcow2 allowing the use different compression methods for
> image clusters (de)compressing.
>
> It is implied that the compression type is set on the image creation and
> can be changed only later by image conversion, thus compression type
> defines the only compression algorithm used for the image, and thus,
> for all image clusters.
>
> The goal of the feature is to add support of other compression methods
> to qcow2. For example, ZSTD which is more effective on compression than ZLIB.
>
> The default compression is ZLIB. Images created with ZLIB compression type
> are backward compatible with older qemu versions.
>
> Adding of the compression type breaks a number of tests because now the
> compression type is reported on image creation and there are some changes
> in the qcow2 header in size and offsets.
>
> The tests are fixed in the following ways:
> * filter out compression_type for all the tests
Presumably this filter is optional, and we will not use it on the
specific new tests that prove zstd compression works - but that should
be later in the series, so for this patch it is okay.
> * fix header size, feature table size and backing file offset
> affected tests: 031, 036, 061, 080
> header_size +=8: 1 byte compression type
> 7 bytes padding
> feature_table += 48: incompatible feture compression type
feature
> backing_file_offset += 56 (8 + 48 -> header_change + fature_table_change)
feature
(interesting that you have two different changed spellings ;)
> * add "compression type" for test output matching when it isn't filtered
> affected tests: 049, 060, 061, 065, 144, 182, 242, 255
Or maybe the comment above should be changed to "many tests" rather than
"all the tests".
>
> Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
> qapi/block-core.json | 22 +++++-
> block/qcow2.h | 20 ++++-
> include/block/block_int.h | 1 +
> block/qcow2.c | 121 +++++++++++++++++++++++++++++++
> tests/qemu-iotests/031.out | 14 ++--
> tests/qemu-iotests/036.out | 4 +-
> tests/qemu-iotests/049.out | 102 +++++++++++++-------------
> tests/qemu-iotests/060.out | 1 +
> tests/qemu-iotests/061.out | 34 +++++----
> tests/qemu-iotests/065 | 28 ++++---
> tests/qemu-iotests/080 | 2 +-
> tests/qemu-iotests/144.out | 4 +-
> tests/qemu-iotests/182.out | 2 +-
> tests/qemu-iotests/242.out | 5 ++
> tests/qemu-iotests/255.out | 8 +-
> tests/qemu-iotests/common.filter | 3 +-
> 16 files changed, 275 insertions(+), 96 deletions(-)
>
> +++ b/block/qcow2.h
> @@ -146,8 +146,16 @@ typedef struct QCowHeader {
>
> uint32_t refcount_order;
> uint32_t header_length;
> +
> + /* Additional fields */
> + uint8_t compression_type;
> +
> + /* header must be a multiple of 8 */
> + uint8_t padding[7];
Why two spaces after uint8_t (twice)?
> @@ -369,6 +380,13 @@ typedef struct BDRVQcow2State {
>
> bool metadata_preallocation_checked;
> bool metadata_preallocation;
> + /*
> + * Compression type used for the image. Default: 0 - ZLIB
> + * The image compression type is set on image creation.
> + * The only way to change the compression type is to convert the image
> + * with the desired compression type set
Missing trailing '.'. Maybe someday we can get 'qemu-img amend' to also
adjust the compression type in-place; if that's something we think we
might do, then this could be better worded as "For now, the only way to
change...".
> +++ b/block/qcow2.c
> @@ -1242,6 +1242,48 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options,
> return ret;
> }
>
> +static int validate_compression_type(BDRVQcow2State *s, Error **errp)
> +
> +static int qcow2_compression_type_from_format(const char *ct)
> +{
> + if (g_str_equal(ct, "zlib")) {
> + return QCOW2_COMPRESSION_TYPE_ZLIB;
> + } else {
> + return -EINVAL;
> + }
Why are you open-coding this?
qapi_enum_parse(&Qcow2CompressionType_lookup, ct, -1, errp)
should do what you use this for, and automatically updates itself when
you add zstd to the qapi enum later.
> @@ -3401,6 +3493,8 @@ 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 endians since compression_type is 1 byte long */
endianness
> + .compression_type = compression_type,
> .header_length = cpu_to_be32(sizeof(*header)),
> };
>
> @@ -5516,6 +5631,12 @@ 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 clusters compression",
s/clusters/cluster/
Overall, getting closer. I assume this would go through Max's tree, if
he has time to include it before soft freeze...
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v6 1/4] qcow2: introduce compression type feature
2020-03-13 21:40 ` Eric Blake
@ 2020-03-16 8:13 ` Denis Plotnikov
0 siblings, 0 replies; 9+ messages in thread
From: Denis Plotnikov @ 2020-03-16 8:13 UTC (permalink / raw)
To: Eric Blake, qemu-devel; +Cc: kwolf, vsementsov, qemu-block, armbru, mreitz, den
Thanks for the comments.
I'll make the fixes accordingly and re-sent the series shortly.
Denis
On 14.03.2020 00:40, Eric Blake wrote:
> On 3/12/20 4:22 AM, Denis Plotnikov wrote:
>> The patch adds some preparation parts for incompatible compression type
>> feature to qcow2 allowing the use different compression methods for
>> image clusters (de)compressing.
>>
>> It is implied that the compression type is set on the image creation and
>> can be changed only later by image conversion, thus compression type
>> defines the only compression algorithm used for the image, and thus,
>> for all image clusters.
>>
>> The goal of the feature is to add support of other compression methods
>> to qcow2. For example, ZSTD which is more effective on compression
>> than ZLIB.
>>
>> The default compression is ZLIB. Images created with ZLIB compression
>> type
>> are backward compatible with older qemu versions.
>>
>> Adding of the compression type breaks a number of tests because now the
>> compression type is reported on image creation and there are some
>> changes
>> in the qcow2 header in size and offsets.
>>
>> The tests are fixed in the following ways:
>> * filter out compression_type for all the tests
>
> Presumably this filter is optional, and we will not use it on the
> specific new tests that prove zstd compression works - but that should
> be later in the series, so for this patch it is okay.
>
>> * fix header size, feature table size and backing file offset
>> affected tests: 031, 036, 061, 080
>> header_size +=8: 1 byte compression type
>> 7 bytes padding
>> feature_table += 48: incompatible feture compression type
>
> feature
>
>> backing_file_offset += 56 (8 + 48 -> header_change +
>> fature_table_change)
>
> feature
>
> (interesting that you have two different changed spellings ;)
>
>> * add "compression type" for test output matching when it isn't
>> filtered
>> affected tests: 049, 060, 061, 065, 144, 182, 242, 255
>
> Or maybe the comment above should be changed to "many tests" rather
> than "all the tests".
>
>>
>> Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
>> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> ---
>> qapi/block-core.json | 22 +++++-
>> block/qcow2.h | 20 ++++-
>> include/block/block_int.h | 1 +
>> block/qcow2.c | 121 +++++++++++++++++++++++++++++++
>> tests/qemu-iotests/031.out | 14 ++--
>> tests/qemu-iotests/036.out | 4 +-
>> tests/qemu-iotests/049.out | 102 +++++++++++++-------------
>> tests/qemu-iotests/060.out | 1 +
>> tests/qemu-iotests/061.out | 34 +++++----
>> tests/qemu-iotests/065 | 28 ++++---
>> tests/qemu-iotests/080 | 2 +-
>> tests/qemu-iotests/144.out | 4 +-
>> tests/qemu-iotests/182.out | 2 +-
>> tests/qemu-iotests/242.out | 5 ++
>> tests/qemu-iotests/255.out | 8 +-
>> tests/qemu-iotests/common.filter | 3 +-
>> 16 files changed, 275 insertions(+), 96 deletions(-)
>>
>
>> +++ b/block/qcow2.h
>> @@ -146,8 +146,16 @@ typedef struct QCowHeader {
>> uint32_t refcount_order;
>> uint32_t header_length;
>> +
>> + /* Additional fields */
>> + uint8_t compression_type;
>> +
>> + /* header must be a multiple of 8 */
>> + uint8_t padding[7];
>
> Why two spaces after uint8_t (twice)?
>
>
>> @@ -369,6 +380,13 @@ typedef struct BDRVQcow2State {
>> bool metadata_preallocation_checked;
>> bool metadata_preallocation;
>> + /*
>> + * Compression type used for the image. Default: 0 - ZLIB
>> + * The image compression type is set on image creation.
>> + * The only way to change the compression type is to convert the
>> image
>> + * with the desired compression type set
>
> Missing trailing '.'. Maybe someday we can get 'qemu-img amend' to
> also adjust the compression type in-place; if that's something we
> think we might do, then this could be better worded as "For now, the
> only way to change...".
>
>> +++ b/block/qcow2.c
>> @@ -1242,6 +1242,48 @@ static int
>> qcow2_update_options(BlockDriverState *bs, QDict *options,
>> return ret;
>> }
>> +static int validate_compression_type(BDRVQcow2State *s, Error **errp)
>
>> +
>> +static int qcow2_compression_type_from_format(const char *ct)
>> +{
>> + if (g_str_equal(ct, "zlib")) {
>> + return QCOW2_COMPRESSION_TYPE_ZLIB;
>> + } else {
>> + return -EINVAL;
>> + }
>
> Why are you open-coding this?
>
> qapi_enum_parse(&Qcow2CompressionType_lookup, ct, -1, errp)
>
> should do what you use this for, and automatically updates itself when
> you add zstd to the qapi enum later.
>
>
>> @@ -3401,6 +3493,8 @@ 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 endians since compression_type is 1 byte
>> long */
>
> endianness
>
>> + .compression_type = compression_type,
>> .header_length = cpu_to_be32(sizeof(*header)),
>> };
>> @@ -5516,6 +5631,12 @@ 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 clusters
>> compression",
>
> s/clusters/cluster/
>
> Overall, getting closer. I assume this would go through Max's tree, if
> he has time to include it before soft freeze...
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v6 3/4] qcow2: add zstd cluster compression
2020-03-12 9:22 ` [PATCH v6 3/4] qcow2: add zstd cluster compression Denis Plotnikov
@ 2020-03-16 14:01 ` Eric Blake
2020-03-16 15:57 ` Denis Plotnikov
0 siblings, 1 reply; 9+ messages in thread
From: Eric Blake @ 2020-03-16 14:01 UTC (permalink / raw)
To: Denis Plotnikov, qemu-devel
Cc: kwolf, vsementsov, berto, qemu-block, armbru, mreitz, den
On 3/12/20 4:22 AM, Denis Plotnikov wrote:
> zstd significantly reduces cluster compression time.
> It provides better compression performance maintaining
> the same level of the compression ratio in comparison with
> zlib, which, at the moment, is the only compression
> method available.
>
> +++ b/docs/interop/qcow2.txt
> @@ -208,6 +208,7 @@ version 2.
>
> Available compression type values:
> 0: zlib <https://www.zlib.net/>
> + 1: zstd <http://github.com/facebook/zstd>
>
>
> === Header padding ===
> @@ -575,11 +576,30 @@ Compressed Clusters Descriptor (x = 62 - (cluster_bits - 8)):
> Another compressed cluster may map to the tail of the final
> sector used by this compressed cluster.
>
> + The layout of the compressed data depends on the compression
> + type used for the image (see compressed cluster layout).
> +
> If a cluster is unallocated, read requests shall read the data from the backing
> file (except if bit 0 in the Standard Cluster Descriptor is set). If there is
> no backing file or the backing file is smaller than the image, they shall read
> zeros for all parts that are not covered by the backing file.
>
> +=== Compressed Cluster Layout ===
> +
> +The compressed cluster data has a layout depending on the compression
> +type used for the image, as follows:
> +
> +Compressed data layout for the available compression types:
> +data_space_lenght - data chunk length available to store a compressed cluster.
length
> +(for more details see "Compressed Clusters Descriptor")
> +x = data_space_length - 1
If I understand correctly, data_space_length is really an upper bounds
on the length available, because it is computed by rounding UP to the
next 512-byte boundary (that is, the L2 descriptor lists the number of
additional sectors used in storing the compressed data). Which really
means that we have the following, where + is cluster boundaries, S and E
are the start and end of the compressed data, and D is the offset
determined by data_space_length:
+-------+-------+------+
S============E...D
> +
> + 0: (default) zlib <http://zlib.net/>:
> + Byte 0 - x: the compressed data content
> + all the space provided used for compressed data
For zlib, we have byte 0-E are compressed data, and bytes (E+1)-D (if
any) are ignored. There is no way to tell how many bytes between E and
D exist, because zlib doesn't care (the compression stream itself
ensures that decompression stops when input reaches E because the output
reached a cluster boundary at that point).
> + 1: zstd <http://github.com/facebook/zstd>:
> + Byte 0 - 3: the length of compressed data in bytes
> + 4 - x: the compressed data content
Whereas for zstd, the decompression MUST know the actual location of E,
rather than passing in the slop between E and D; bytes 0-3 give us that
information.
But your description is not very accurate: if 'x' is point E, then it
is NOT data_space_length - 1, but rather data_space_length - slop, where
slop can be up to 511 bytes (the number of bytes from (E+1) to D). And
if 'x' is point E, then the real layout for zlib is:
byte 0 - E: the compressed data content
byte E+1 - x: ignored slop (E is implied solely by the compressed data)
and for zstd is:
byte 0 - 3: the length of the compressed data
byte 4 - E: the compressed data (E computed from byte 0-3)
byte E+1 - x: ignored
I'm not sure what the best way is to document this.
> +++ b/block/qcow2-threads.c
> +static ssize_t qcow2_zstd_compress(void *dest, size_t dest_size,
> + const void *src, size_t src_size)
> +{
> + size_t ret;
> +
> + /*
> + * steal ZSTD_LEN_BUF bytes in the very beginning of the buffer
> + * to store compressed chunk size
> + */
> + char *d_buf = ((char *) dest) + ZSTD_LEN_BUF;
> +
> + /*
> + * sanity check that we can store the compressed data length,
> + * and there is some space left for the compressor buffer
> + */
> + if (dest_size <= ZSTD_LEN_BUF) {
> + return -ENOMEM;
> + }
> +
> + dest_size -= ZSTD_LEN_BUF;
> +
> + ret = ZSTD_compress(d_buf, dest_size, src, src_size, 5);
Where does the magic number 5 come from?
> +
> + if (ZSTD_isError(ret)) {
> + if (ZSTD_getErrorCode(ret) == ZSTD_error_dstSize_tooSmall) {
> + return -ENOMEM;
> + } else {
> + return -EIO;
> + }
> + }
> +
> + /*
> + * paranoid sanity check that we can store
> + * the compressed size in the first 4 bytes
> + */
> + if (ret > UINT32_MAX) {
> + return -ENOMEM;
> + }
The if is awkward. I'd prefer to change this to:
/*
* Our largest cluster is 2M, and we insist that compression
* actually compressed things.
*/
assert(ret < UINT32_MAX);
or even tighten to assert(ret <= dest_size)
> +
> + /* store the compressed chunk size in the very beginning of the buffer */
> + stl_be_p(dest, ret);
> +
> + return ret + ZSTD_LEN_BUF;
> +}
> +
> +/*
> + * qcow2_zstd_decompress()
> + *
> + * Decompress some data (not more than @src_size bytes) to produce exactly
> + * @dest_size bytes using zstd compression method
> + *
> + * @dest - destination buffer, @dest_size bytes
> + * @src - source buffer, @src_size bytes
> + *
> + * Returns: 0 on success
> + * -EIO on any error
> + */
> +static ssize_t qcow2_zstd_decompress(void *dest, size_t dest_size,
> + const void *src, size_t src_size)
> +{
> + /*
> + * zstd decompress wants to know the exact length of the data.
> + * For that purpose, on compression, the length is stored in
> + * the very beginning of the compressed buffer
> + */
> + size_t s_size;
> + const char *s_buf = ((const char *) src) + ZSTD_LEN_BUF;
> +
> + /*
> + * sanity check that we can read 4 byte the content length and
> + * and there is some content to decompress
> + */
> + if (src_size <= ZSTD_LEN_BUF) {
> + return -EIO;
> + }
> +
> + s_size = ldl_be_p(src);
> +
> + /* sanity check that the buffer is big enough to read the content from */
> + if (src_size - ZSTD_LEN_BUF < s_size) {
> + return -EIO;
> + }
> +
> + if (ZSTD_isError(
> + ZSTD_decompress(dest, dest_size, s_buf, s_size))) {
You are correct that ZSTD_decompress() is picky that it must be given
the exact size of the compressed buffer it is decompressing. But the
ZSTD manual mentions that if an exact size is not known in advance, that
the streaming API can be used instead:
https://facebook.github.io/zstd/zstd_manual.html#Chapter9
In other words, would it be possible to NOT have to prepend four bytes
of exact size information, by instead setting up decompression via the
streaming API where the input is (usually) oversized, but the output
buffer limited to exactly one cluster is sufficient to consume the exact
compressed data and ignore the slop, just as we do in zlib?
The rest of this patch looks okay.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v6 3/4] qcow2: add zstd cluster compression
2020-03-16 14:01 ` Eric Blake
@ 2020-03-16 15:57 ` Denis Plotnikov
0 siblings, 0 replies; 9+ messages in thread
From: Denis Plotnikov @ 2020-03-16 15:57 UTC (permalink / raw)
To: Eric Blake, qemu-devel
Cc: kwolf, vsementsov, berto, qemu-block, armbru, mreitz, den
On 16.03.2020 17:01, Eric Blake wrote:
> On 3/12/20 4:22 AM, Denis Plotnikov wrote:
>> zstd significantly reduces cluster compression time.
>> It provides better compression performance maintaining
>> the same level of the compression ratio in comparison with
>> zlib, which, at the moment, is the only compression
>> method available.
>>
>
>> +++ b/docs/interop/qcow2.txt
>> @@ -208,6 +208,7 @@ version 2.
>> Available compression type values:
>> 0: zlib <https://www.zlib.net/>
>> + 1: zstd <http://github.com/facebook/zstd>
>> === Header padding ===
>> @@ -575,11 +576,30 @@ Compressed Clusters Descriptor (x = 62 -
>> (cluster_bits - 8)):
>> Another compressed cluster may map to the tail
>> of the final
>> sector used by this compressed cluster.
>> + The layout of the compressed data depends on
>> the compression
>> + type used for the image (see compressed cluster
>> layout).
>> +
>> If a cluster is unallocated, read requests shall read the data from
>> the backing
>> file (except if bit 0 in the Standard Cluster Descriptor is set).
>> If there is
>> no backing file or the backing file is smaller than the image, they
>> shall read
>> zeros for all parts that are not covered by the backing file.
>> +=== Compressed Cluster Layout ===
>> +
>> +The compressed cluster data has a layout depending on the compression
>> +type used for the image, as follows:
>> +
>> +Compressed data layout for the available compression types:
>> +data_space_lenght - data chunk length available to store a
>> compressed cluster.
>
> length
>
>> +(for more details see "Compressed Clusters Descriptor")
>> +x = data_space_length - 1
>
> If I understand correctly, data_space_length is really an upper bounds
> on the length available, because it is computed by rounding UP to the
> next 512-byte boundary (that is, the L2 descriptor lists the number of
> additional sectors used in storing the compressed data). Which really
> means that we have the following, where + is cluster boundaries, S and
> E are the start and end of the compressed data, and D is the offset
> determined by data_space_length:
>
> +-------+-------+------+
> S============E...D
>
>> +
>> + 0: (default) zlib <http://zlib.net/>:
>> + Byte 0 - x: the compressed data content
>> + all the space provided used for
>> compressed data
>
> For zlib, we have byte 0-E are compressed data, and bytes (E+1)-D (if
> any) are ignored. There is no way to tell how many bytes between E
> and D exist, because zlib doesn't care (the compression stream itself
> ensures that decompression stops when input reaches E because the
> output reached a cluster boundary at that point).
>
>> + 1: zstd <http://github.com/facebook/zstd>:
>> + Byte 0 - 3: the length of compressed data in bytes
>> + 4 - x: the compressed data content
>
> Whereas for zstd, the decompression MUST know the actual location of
> E, rather than passing in the slop between E and D; bytes 0-3 give us
> that information.
>
> But your description is not very accurate: if 'x' is point E, then it
> is NOT data_space_length - 1, but rather data_space_length - slop,
> where slop can be up to 511 bytes (the number of bytes from (E+1) to
> D). And if 'x' is point E, then the real layout for zlib is:
>
> byte 0 - E: the compressed data content
> byte E+1 - x: ignored slop (E is implied solely by the compressed data)
>
> and for zstd is:
>
> byte 0 - 3: the length of the compressed data
> byte 4 - E: the compressed data (E computed from byte 0-3)
> byte E+1 - x: ignored
>
> I'm not sure what the best way is to document this.
>
>> +++ b/block/qcow2-threads.c
>
>> +static ssize_t qcow2_zstd_compress(void *dest, size_t dest_size,
>> + const void *src, size_t src_size)
>> +{
>> + size_t ret;
>> +
>> + /*
>> + * steal ZSTD_LEN_BUF bytes in the very beginning of the buffer
>> + * to store compressed chunk size
>> + */
>> + char *d_buf = ((char *) dest) + ZSTD_LEN_BUF;
>> +
>> + /*
>> + * sanity check that we can store the compressed data length,
>> + * and there is some space left for the compressor buffer
>> + */
>> + if (dest_size <= ZSTD_LEN_BUF) {
>> + return -ENOMEM;
>> + }
>> +
>> + dest_size -= ZSTD_LEN_BUF;
>> +
>> + ret = ZSTD_compress(d_buf, dest_size, src, src_size, 5);
>
> Where does the magic number 5 come from?
I did some tests to get the same compression ratio as zlib but do it
faster than zlib.
ZLIB also used hardcoded "compression ratio". Changing of the
compression ratios in both compression types is something that can be
changed with later patches.
>
>
>> +
>> + if (ZSTD_isError(ret)) {
>> + if (ZSTD_getErrorCode(ret) == ZSTD_error_dstSize_tooSmall) {
>> + return -ENOMEM;
>> + } else {
>> + return -EIO;
>> + }
>> + }
>> +
>> + /*
>> + * paranoid sanity check that we can store
>> + * the compressed size in the first 4 bytes
>> + */
>> + if (ret > UINT32_MAX) {
>> + return -ENOMEM;
>> + }
>
> The if is awkward. I'd prefer to change this to:
>
> /*
> * Our largest cluster is 2M, and we insist that compression
> * actually compressed things.
> */
> assert(ret < UINT32_MAX);
>
> or even tighten to assert(ret <= dest_size)
>
>> +
>> + /* store the compressed chunk size in the very beginning of the
>> buffer */
>> + stl_be_p(dest, ret);
>> +
>> + return ret + ZSTD_LEN_BUF;
>> +}
>> +
>> +/*
>> + * qcow2_zstd_decompress()
>> + *
>> + * Decompress some data (not more than @src_size bytes) to produce
>> exactly
>> + * @dest_size bytes using zstd compression method
>> + *
>> + * @dest - destination buffer, @dest_size bytes
>> + * @src - source buffer, @src_size bytes
>> + *
>> + * Returns: 0 on success
>> + * -EIO on any error
>> + */
>> +static ssize_t qcow2_zstd_decompress(void *dest, size_t dest_size,
>> + const void *src, size_t src_size)
>> +{
>> + /*
>> + * zstd decompress wants to know the exact length of the data.
>> + * For that purpose, on compression, the length is stored in
>> + * the very beginning of the compressed buffer
>> + */
>> + size_t s_size;
>> + const char *s_buf = ((const char *) src) + ZSTD_LEN_BUF;
>> +
>> + /*
>> + * sanity check that we can read 4 byte the content length and
>> + * and there is some content to decompress
>> + */
>> + if (src_size <= ZSTD_LEN_BUF) {
>> + return -EIO;
>> + }
>> +
>> + s_size = ldl_be_p(src);
>> +
>> + /* sanity check that the buffer is big enough to read the
>> content from */
>> + if (src_size - ZSTD_LEN_BUF < s_size) {
>> + return -EIO;
>> + }
>> +
>> + if (ZSTD_isError(
>> + ZSTD_decompress(dest, dest_size, s_buf, s_size))) {
>
> You are correct that ZSTD_decompress() is picky that it must be given
> the exact size of the compressed buffer it is decompressing. But the
> ZSTD manual mentions that if an exact size is not known in advance,
> that the streaming API can be used instead:
>
> https://facebook.github.io/zstd/zstd_manual.html#Chapter9
To be honest, I didn't find where they mentioned that explicitly. Could
you please point where exactly?
But I found the following:
Calling ZSTD_compressStream2() with ZSTD_e_end instructs to finish a frame.
It will perform a flush and write frame epilogue.
The epilogue is required for decoders to consider a frame completed.
flush operation is the same, and follows same rules as calling ZSTD_compressStream2() with ZSTD_e_flush.
You must continue calling ZSTD_compressStream2() with ZSTD_e_end until it returns 0, at which point you are free to
start a new frame
I think in the epilogue they store the same information that I did and potentially (I didn't check) some more to finish the frame.
So we didn't win any space. Additionally, using streaming API will make the code more complex.
So I decided to stick with more simple version.
>
> In other words, would it be possible to NOT have to prepend four bytes
> of exact size information, by instead setting up decompression via the
> streaming API where the input is (usually) oversized, but the output
> buffer limited to exactly one cluster is sufficient to consume the
> exact compressed data and ignore the slop, just as we do in zlib?
>
> The rest of this patch looks okay.
>
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2020-03-16 17:20 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-12 9:22 [PATCH v6 0/4] qcow2: Implement zstd cluster compression method Denis Plotnikov
2020-03-12 9:22 ` [PATCH v6 1/4] qcow2: introduce compression type feature Denis Plotnikov
2020-03-13 21:40 ` Eric Blake
2020-03-16 8:13 ` Denis Plotnikov
2020-03-12 9:22 ` [PATCH v6 2/4] qcow2: rework the cluster compression routine Denis Plotnikov
2020-03-12 9:22 ` [PATCH v6 3/4] qcow2: add zstd cluster compression Denis Plotnikov
2020-03-16 14:01 ` Eric Blake
2020-03-16 15:57 ` Denis Plotnikov
2020-03-12 9:22 ` [PATCH v6 4/4] iotests: 287: add qcow2 compression type test Denis Plotnikov
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