@@ -616,6 +616,7 @@ Command description:
required size: 524288
fully allocated size: 1074069504
+ bitmaps size: 0
The ``required size`` is the file size of the new image. It may be smaller
than the virtual disk size if the image format supports compact representation.
@@ -625,6 +626,12 @@ Command description:
occupy with the exception of internal snapshots, dirty bitmaps, vmstate data,
and other advanced image format features.
+ The ``bitmaps size`` is the additional size required in order to
+ copy bitmaps from a source image in addition to the guest-visible
+ data; the line is omitted if either source or destination lacks
+ bitmap support, or 0 if bitmaps are supported but there is nothing
+ to copy.
+
.. option:: snapshot [--object OBJECTDEF] [--image-opts] [-U] [-q] [-l | -a SNAPSHOT | -c SNAPSHOT | -d SNAPSHOT] FILENAME
List, apply, create or delete snapshots in image *FILENAME*.
@@ -636,18 +636,24 @@
# efficiently so file size may be smaller than virtual disk size.
#
# The values are upper bounds that are guaranteed to fit the new image file.
-# Subsequent modification, such as internal snapshot or bitmap creation, may
-# require additional space and is not covered here.
+# Subsequent modification, such as internal snapshot or further bitmap
+# creation, may require additional space and is not covered here.
#
-# @required: Size required for a new image file, in bytes.
+# @required: Size required for a new image file, in bytes, when copying just
+# allocated guest-visible contents.
#
# @fully-allocated: Image file size, in bytes, once data has been written
-# to all sectors.
+# to all sectors, when copying just guest-visible contents.
+#
+# @bitmaps: Additional size required if all the top-level bitmap metadata
+# in the source image were to be copied to the destination,
+# present only when source and destination both support
+# persistent bitmaps. (since 5.1)
#
# Since: 2.10
##
{ 'struct': 'BlockMeasureInfo',
- 'data': {'required': 'int', 'fully-allocated': 'int'} }
+ 'data': {'required': 'int', 'fully-allocated': 'int', '*bitmaps': 'int'} }
##
# @query-block:
@@ -783,6 +783,8 @@ int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
const char *name,
Error **errp);
bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs);
+uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
+ uint32_t cluster_size);
ssize_t coroutine_fn
qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
@@ -552,7 +552,7 @@ static BlockMeasureInfo *block_crypto_measure(QemuOpts *opts,
* Unallocated blocks are still encrypted so allocation status makes no
* difference to the file size.
*/
- info = g_new(BlockMeasureInfo, 1);
+ info = g_new0(BlockMeasureInfo, 1);
info->fully_allocated = luks_payload_size + size;
info->required = luks_payload_size + size;
return info;
@@ -1755,3 +1755,39 @@ bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs)
return s->qcow_version >= 3;
}
+
+/*
+ * Compute the space required for bitmaps in @bs.
+ *
+ * The computation is based as if copying to a new image with the
+ * given @cluster_size, which may differ from the cluster size in @bs.
+ */
+uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
+ uint32_t cluster_size)
+{
+ uint64_t bitmaps_size = 0;
+ BdrvDirtyBitmap *bm;
+ size_t bitmap_dir_size = 0;
+
+ FOR_EACH_DIRTY_BITMAP(bs, bm) {
+ if (bdrv_dirty_bitmap_get_persistence(bm)) {
+ const char *name = bdrv_dirty_bitmap_name(bm);
+ uint32_t granularity = bdrv_dirty_bitmap_granularity(bm);
+ uint64_t bmbytes =
+ get_bitmap_bytes_needed(bdrv_dirty_bitmap_size(bm),
+ granularity);
+ uint64_t bmclusters = DIV_ROUND_UP(bmbytes, cluster_size);
+
+ /* Assume the entire bitmap is allocated */
+ bitmaps_size += bmclusters * cluster_size;
+ /* Also reserve space for the bitmap table entries */
+ bitmaps_size += ROUND_UP(bmclusters * sizeof(uint64_t),
+ cluster_size);
+ /* And space for contribution to bitmap directory size */
+ bitmap_dir_size += calc_dir_entry_size(strlen(name), 0);
+ }
+ }
+ bitmaps_size += ROUND_UP(bitmap_dir_size, cluster_size);
+
+ return bitmaps_size;
+}
@@ -4953,16 +4953,24 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
required = virtual_size;
}
- info = g_new(BlockMeasureInfo, 1);
+ info = g_new0(BlockMeasureInfo, 1);
info->fully_allocated =
qcow2_calc_prealloc_size(virtual_size, cluster_size,
ctz32(refcount_bits)) + luks_payload_size;
- /* Remove data clusters that are not required. This overestimates the
+ /*
+ * Remove data clusters that are not required. This overestimates the
* required size because metadata needed for the fully allocated file is
- * still counted.
+ * still counted. Show bitmaps only if both source and destination
+ * would support them.
*/
info->required = info->fully_allocated - virtual_size + required;
+ info->has_bitmaps = version >= 3 && in_bs &&
+ bdrv_supports_persistent_dirty_bitmap(in_bs);
+ if (info->has_bitmaps) {
+ info->bitmaps = qcow2_get_persistent_dirty_bitmap_size(in_bs,
+ cluster_size);
+ }
return info;
err:
@@ -359,7 +359,7 @@ static BlockMeasureInfo *raw_measure(QemuOpts *opts, BlockDriverState *in_bs,
BDRV_SECTOR_SIZE);
}
- info = g_new(BlockMeasureInfo, 1);
+ info = g_new0(BlockMeasureInfo, 1);
info->required = required;
/* Unallocated sectors count towards the file size in raw images */
@@ -5302,6 +5302,9 @@ static int img_measure(int argc, char **argv)
if (output_format == OFORMAT_HUMAN) {
printf("required size: %" PRIu64 "\n", info->required);
printf("fully allocated size: %" PRIu64 "\n", info->fully_allocated);
+ if (info->has_bitmaps) {
+ printf("bitmaps size: %" PRIu64 "\n", info->bitmaps);
+ }
} else {
dump_json_block_measure_info(info);
}
@@ -37,6 +37,7 @@ qemu-img: The image size is too large (try using a larger cluster size)
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=0
required size: 196608
fully allocated size: 196608
+bitmaps size: 0
converted image file size in bytes: 196608
@@ -45,6 +46,7 @@ converted image file size in bytes: 196608
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
required size: 393216
fully allocated size: 1074135040
+bitmaps size: 0
wrote 512/512 bytes at offset 512
512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 65536/65536 bytes at offset 65536
@@ -53,6 +55,7 @@ wrote 64512/64512 bytes at offset 134217728
63 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
required size: 589824
fully allocated size: 1074135040
+bitmaps size: 0
converted image file size in bytes: 524288
@@ -60,6 +63,7 @@ converted image file size in bytes: 524288
required size: 524288
fully allocated size: 1074135040
+bitmaps size: 0
converted image file size in bytes: 458752
@@ -67,16 +71,19 @@ converted image file size in bytes: 458752
required size: 1074135040
fully allocated size: 1074135040
+bitmaps size: 0
== qcow2 input image and LUKS encryption ==
required size: 2686976
fully allocated size: 1076232192
+bitmaps size: 0
== qcow2 input image and preallocation (human) ==
required size: 1074135040
fully allocated size: 1074135040
+bitmaps size: 0
converted image file size in bytes: 1074135040
@@ -87,6 +94,7 @@ wrote 8388608/8388608 bytes at offset 0
8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
required size: 8716288
fully allocated size: 8716288
+bitmaps size: 0
converted image file size in bytes: 8716288
@@ -173,6 +181,7 @@ qemu-img: The image size is too large (try using a larger cluster size)
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=0
{
+ "bitmaps": 0,
"required": 196608,
"fully-allocated": 196608
}
@@ -183,6 +192,7 @@ converted image file size in bytes: 196608
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
{
+ "bitmaps": 0,
"required": 393216,
"fully-allocated": 1074135040
}
@@ -193,6 +203,7 @@ wrote 65536/65536 bytes at offset 65536
wrote 64512/64512 bytes at offset 134217728
63 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
{
+ "bitmaps": 0,
"required": 589824,
"fully-allocated": 1074135040
}
@@ -202,6 +213,7 @@ converted image file size in bytes: 524288
== qcow2 input image with internal snapshot (json) ==
{
+ "bitmaps": 0,
"required": 524288,
"fully-allocated": 1074135040
}
@@ -211,6 +223,7 @@ converted image file size in bytes: 458752
== qcow2 input image and a backing file (json) ==
{
+ "bitmaps": 0,
"required": 1074135040,
"fully-allocated": 1074135040
}
@@ -218,6 +231,7 @@ converted image file size in bytes: 458752
== qcow2 input image and LUKS encryption ==
{
+ "bitmaps": 0,
"required": 2686976,
"fully-allocated": 1076232192
}
@@ -225,6 +239,7 @@ converted image file size in bytes: 458752
== qcow2 input image and preallocation (json) ==
{
+ "bitmaps": 0,
"required": 1074135040,
"fully-allocated": 1074135040
}
@@ -237,6 +252,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=8388608
wrote 8388608/8388608 bytes at offset 0
8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
{
+ "bitmaps": 0,
"required": 8716288,
"fully-allocated": 8716288
}
@@ -2,7 +2,7 @@
#
# qemu-img measure sub-command tests on huge qcow2 files
#
-# Copyright (C) 2017 Red Hat, Inc.
+# Copyright (C) 2017-2020 Red Hat, Inc.
#
# 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
@@ -42,7 +42,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
_supported_fmt qcow2
_supported_proto file
-echo "== Huge file =="
+echo "== Huge file without bitmaps =="
echo
_make_test_img -o 'cluster_size=2M' 2T
@@ -51,6 +51,49 @@ $QEMU_IMG measure -O raw -f qcow2 "$TEST_IMG"
$QEMU_IMG measure -O qcow2 -o cluster_size=64k -f qcow2 "$TEST_IMG"
$QEMU_IMG measure -O qcow2 -o cluster_size=2M -f qcow2 "$TEST_IMG"
+echo
+echo "== Huge file with bitmaps =="
+echo
+
+$QEMU_IMG bitmap --add --granularity 512 -f qcow2 "$TEST_IMG" b1
+$QEMU_IMG bitmap --add -g 2M -f qcow2 "$TEST_IMG" b2
+
+# No bitmap without a source
+$QEMU_IMG measure -O qcow2 --size 10M
+# No bitmap output, since raw does not support it
+$QEMU_IMG measure -O raw -f qcow2 "$TEST_IMG"
+# No bitmap output, since no bitmaps on raw source. Munge required size, as
+# some filesystems store the qcow2 file with less sparseness than others
+$QEMU_IMG measure -O qcow2 -f raw "$TEST_IMG" |
+ sed '/^required size:/ s/[0-9]\+/SIZE/'
+# No bitmap output, since v2 does not support it
+$QEMU_IMG measure -O qcow2 -o compat=0.10 -f qcow2 "$TEST_IMG"
+
+# Compute expected output: bitmap clusters + bitmap tables + bitmaps directory
+echo
+val2T=$((2*1024*1024*1024*1024))
+cluster=$((64*1024))
+b1clusters=$(( (val2T/512/8 + cluster - 1) / cluster ))
+b2clusters=$(( (val2T/2/1024/1024/8 + cluster - 1) / cluster ))
+echo expected bitmap $((b1clusters * cluster +
+ (b1clusters * 8 + cluster - 1) / cluster * cluster +
+ b2clusters * cluster +
+ (b2clusters * 8 + cluster - 1) / cluster * cluster +
+ cluster))
+$QEMU_IMG measure -O qcow2 -o cluster_size=64k -f qcow2 "$TEST_IMG"
+
+# Compute expected output: bitmap clusters + bitmap tables + bitmaps directory
+echo
+cluster=$((2*1024*1024))
+b1clusters=$(( (val2T/512/8 + cluster - 1) / cluster ))
+b2clusters=$(( (val2T/2/1024/1024/8 + cluster - 1) / cluster ))
+echo expected bitmap $((b1clusters * cluster +
+ (b1clusters * 8 + cluster - 1) / cluster * cluster +
+ b2clusters * cluster +
+ (b2clusters * 8 + cluster - 1) / cluster * cluster +
+ cluster))
+$QEMU_IMG measure --output=json -O qcow2 -o cluster_size=2M -f qcow2 "$TEST_IMG"
+
# success, all done
echo "*** done"
rm -f $seq.full
@@ -1,11 +1,36 @@
QA output created by 190
-== Huge file ==
+== Huge file without bitmaps ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=2199023255552
required size: 2199023255552
fully allocated size: 2199023255552
required size: 335806464
fully allocated size: 2199359062016
+bitmaps size: 0
required size: 18874368
fully allocated size: 2199042129920
+bitmaps size: 0
+
+== Huge file with bitmaps ==
+
+required size: 327680
+fully allocated size: 10813440
+required size: 2199023255552
+fully allocated size: 2199023255552
+required size: SIZE
+fully allocated size: 17170432
+required size: 335806464
+fully allocated size: 2199359062016
+
+expected bitmap 537198592
+required size: 335806464
+fully allocated size: 2199359062016
+bitmaps size: 537198592
+
+expected bitmap 545259520
+{
+ "bitmaps": 545259520,
+ "required": 18874368,
+ "fully-allocated": 2199042129920
+}
*** done