@@ -633,18 +633,23 @@
# 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
+# 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 for bitmap metadata not directly used
+# for guest contents, when that metadata can be copied in addition
+# to guest contents. (since 5.1)
#
# Since: 2.10
##
{ 'struct': 'BlockMeasureInfo',
- 'data': {'required': 'int', 'fully-allocated': 'int'} }
+ 'data': {'required': 'int', 'fully-allocated': 'int', '*bitmaps': 'int'} }
##
# @query-block:
@@ -535,7 +535,7 @@ 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;
@@ -4657,6 +4657,7 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
PreallocMode prealloc;
bool has_backing_file;
bool has_luks;
+ uint64_t bitmaps_size = 0; /* size occupied by bitmaps in in_bs */
/* Parse image creation options */
cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err);
@@ -4732,6 +4733,8 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
/* Account for input image */
if (in_bs) {
+ BdrvDirtyBitmap *bm;
+ size_t bitmap_overhead = 0;
int64_t ssize = bdrv_getlength(in_bs);
if (ssize < 0) {
error_setg_errno(&local_err, -ssize,
@@ -4739,6 +4742,28 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
goto err;
}
+ FOR_EACH_DIRTY_BITMAP(in_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 bmbits = DIV_ROUND_UP(bdrv_dirty_bitmap_size(bm),
+ granularity);
+ uint64_t bmclusters = DIV_ROUND_UP(DIV_ROUND_UP(bmbits,
+ CHAR_BIT),
+ 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);
+ /* Guess at contribution to bitmap directory size */
+ bitmap_overhead += ROUND_UP(strlen(name) + 24,
+ sizeof(uint64_t));
+ }
+ }
+ bitmaps_size += ROUND_UP(bitmap_overhead, cluster_size);
+
virtual_size = ROUND_UP(ssize, cluster_size);
if (has_backing_file) {
@@ -4785,7 +4810,7 @@ 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;
@@ -4795,6 +4820,8 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
* still counted.
*/
info->required = info->fully_allocated - virtual_size + required;
+ info->has_bitmaps = !!bitmaps_size;
+ info->bitmaps = bitmaps_size;
return info;
err:
@@ -346,7 +346,7 @@ 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 */
@@ -5084,6 +5084,9 @@ 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);
}
@@ -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 +42,19 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
_supported_fmt qcow2
_supported_proto file
-echo "== Huge file =="
+do_run_qemu()
+{
+ echo Testing: "$@"
+ $QEMU -nographic -qmp stdio -serial none "$@"
+ echo
+}
+
+run_qemu()
+{
+ do_run_qemu "$@" 2>&1 | _filter_testdir | _filter_qmp
+}
+
+echo "== Huge file without bitmaps =="
echo
_make_test_img -o 'cluster_size=2M' 2T
@@ -51,6 +63,40 @@ $QEMU_IMG measure -O raw -f qcow2 "$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
+
+run_qemu -blockdev \
+ driver=qcow2,node-name=n,file.driver=file,file.filename="$TEST_IMG" <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "transaction",
+ "arguments": {
+ "actions": [
+ { "type": "block-dirty-bitmap-add",
+ "data": {
+ "node": "n",
+ "name": "b1",
+ "persistent": true,
+ "granularity": 512
+ } },
+ { "type": "block-dirty-bitmap-add",
+ "data": {
+ "node": "n",
+ "name": "b2",
+ "persistent": true,
+ "granularity": 2097152
+ } }
+ ]
+ }
+}
+{ "execute": "quit" }
+EOF
+
+$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"
+
# success, all done
echo "*** done"
rm -f $seq.full
@@ -1,5 +1,5 @@
QA output created by 190
-== Huge file ==
+== Huge file without bitmaps ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=2199023255552
required size: 2199023255552
@@ -8,4 +8,22 @@ required size: 335806464
fully allocated size: 2199359062016
required size: 18874368
fully allocated size: 2199042129920
+
+== Huge file with bitmaps ==
+
+Testing: -blockdev driver=qcow2,node-name=n,file.driver=file,file.filename=TEST_DIR/t.qcow2
+QMP_VERSION
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}}
+
+required size: 2199023255552
+fully allocated size: 2199023255552
+required size: 335806464
+fully allocated size: 2199359062016
+bitmaps size: 537198592
+required size: 18874368
+fully allocated size: 2199042129920
+bitmaps size: 545259520
*** done
It's useful to know how much space can be occupied by qcow2 persistent bitmaps, even though such metadata is unrelated to the guest-visible data. Report this value as an additional field. Update iotest 190 to cover it. The addition of a new field demonstrates why we should always zero-initialize qapi C structs; while the qcow2 driver still fully populates all fields, the raw and crypto drivers had to be tweaked. See also: https://bugzilla.redhat.com/1779904 Reported-by: Nir Soffer <nsoffer@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> --- In v2: - fix uninit memory [patchew] - add BZ number [Nir] - add iotest coverage qapi/block-core.json | 15 ++++++++---- block/crypto.c | 2 +- block/qcow2.c | 29 +++++++++++++++++++++- block/raw-format.c | 2 +- qemu-img.c | 3 +++ tests/qemu-iotests/190 | 50 ++++++++++++++++++++++++++++++++++++-- tests/qemu-iotests/190.out | 20 ++++++++++++++- 7 files changed, 110 insertions(+), 11 deletions(-)