We've already improved discards to operate efficiently on the tail
of an unaligned qcow2 image; it's time to make a similar improvement
to write zeroes. The special case is only valid at the tail
cluster of a file, where we must recognize that any sectors beyond
the image end would implicitly read as zero, and therefore should
not penalize our logic for widening a partial cluster into writing
the whole cluster as zero.
However, note that for now, the special case of end-of-file is only
recognized if there is no backing file, or if the backing file has
the same length; that's because when the backing file is shorter
than the active layer, we don't have code in place to recognize
that reads of a sector unallocated at the top and beyond the backing
end-of-file are implicitly zero. It's not much of a real loss,
because most people don't use images that aren't cluster-aligned,
or where the active layer is a different size than the backing
layer (especially where the difference falls within a single cluster).
Update test 154 to cover the new scenarios, using two images of
intentionally differing length.
While at it, fix the test to gracefully skip when run as
./check -qcow2 -o compat=0.10 154
since the older format lacks zero clusters already required earlier
in the test.
Signed-off-by: Eric Blake <ebl...@redhat.com>
Reviewed-by: Max Reitz <mre...@redhat.com>
---
v13: fix typo that left pattern verification failure in test
v12: fix testsuite problems, document shortcoming of differing
v11: reserved for blkdebug half of v10
size of backing file
v10: rebase to better reporting of preallocated zero clusters
v9: new patch
---
block/qcow2.c | 7 ++
tests/qemu-iotests/154 | 160 ++++++++++++++++++++++++++++++++++++++++++++-
tests/qemu-iotests/154.out | 128 ++++++++++++++++++++++++++++++++++++
3 files changed, 293 insertions(+), 2 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index dded5a0..3478bb6 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2451,6 +2451,10 @@ static bool is_zero_sectors(BlockDriverState *bs,
int64_t start,
BlockDriverState *file;
int64_t res;
+ if (start + count > bs->total_sectors) {
+ count = bs->total_sectors - start;
+ }
+
if (!count) {
return true;
}
@@ -2469,6 +2473,9 @@ static coroutine_fn int
qcow2_co_pwrite_zeroes(BlockDriverState *bs,
uint32_t tail = (offset + count) % s->cluster_size;
trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, count);
+ if (offset + count == bs->total_sectors * BDRV_SECTOR_SIZE) {
+ tail = 0;
+ }
if (head || tail) {
int64_t cl_start = (offset - head) >> BDRV_SECTOR_BITS;
diff --git a/tests/qemu-iotests/154 b/tests/qemu-iotests/154
index 7ca7219..dd8a426 100755
--- a/tests/qemu-iotests/154
+++ b/tests/qemu-iotests/154
@@ -2,7 +2,7 @@
#
# qcow2 specific bdrv_pwrite_zeroes tests with backing files (complements 034)
#
-# Copyright (C) 2016 Red Hat, Inc.
+# Copyright (C) 2016-2017 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 +42,10 @@ _supported_proto file
_supported_os Linux
CLUSTER_SIZE=4k
-size=128M
+size=$((128 * 1024 * 1024))
+
+# This test requires zero clusters, added in v3 images
+_unsupported_imgopts compat=0.10
echo
echo == backing file contains zeros ==
@@ -299,6 +302,159 @@ $QEMU_IO -c "read -P 0 75k 1k" "$TEST_IMG" |
_filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+echo
+echo == unaligned image tail cluster, no allocation needed ==
+
+# With no backing file, write to all or part of unallocated partial cluster
+# will mark the cluster as zero, but does not allocate.
+# Re-create the image each time to get back to unallocated clusters.
+
+# Write at the front: sector-wise, the request is: 128m... | 00 -- -- --
+_make_test_img $((size + 2048))
+$QEMU_IO -c "write -z $size 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Write at the back: sector-wise, the request is: 128m... | -- -- -- 00
+_make_test_img $((size + 2048))
+$QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Write at middle: sector-wise, the request is: 128m... | -- 00 00 --
+_make_test_img $((size + 2048))
+$QEMU_IO -c "write -z $((size + 512)) 1024" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Write entire cluster: sector-wise, the request is: 128m... | 00 00 00 00
+_make_test_img $((size + 2048))
+$QEMU_IO -c "write -z $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Repeat with backing file holding unallocated cluster.
+# TODO: Note that this forces an allocation, because we aren't yet able to
+# quickly detect that reads beyond EOF of the backing file are always zero
+CLUSTER_SIZE=2048 TEST_IMG="$TEST_IMG.base" _make_test_img $((size + 1024))
+
+# Write at the front: sector-wise, the request is:
+# backing: 128m... | -- --
+# active: 128m... | 00 -- -- --
+_make_test_img -b "$TEST_IMG.base" $((size + 2048))
+$QEMU_IO -c "write -z $size 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Write at the back: sector-wise, the request is:
+# backing: 128m... | -- --
+# active: 128m... | -- -- -- 00
+_make_test_img -b "$TEST_IMG.base" $((size + 2048))
+$QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Write at middle: sector-wise, the request is:
+# backing: 128m... | -- --
+# active: 128m... | -- 00 00 --
+_make_test_img -b "$TEST_IMG.base" $((size + 2048))
+$QEMU_IO -c "write -z $((size + 512)) 1024" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Write entire cluster: sector-wise, the request is:
+# backing: 128m... | -- --
+# active: 128m... | 00 00 00 00
+_make_test_img -b "$TEST_IMG.base" $((size + 2048))
+$QEMU_IO -c "write -z $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Repeat with backing file holding zero'd cluster
+# TODO: Note that this forces an allocation, because we aren't yet able to
+# quickly detect that reads beyond EOF of the backing file are always zero
+$QEMU_IO -c "write -z $size 512" "$TEST_IMG.base" | _filter_qemu_io
+
+# Write at the front: sector-wise, the request is:
+# backing: 128m... | 00 00
+# active: 128m... | 00 -- -- --
+_make_test_img -b "$TEST_IMG.base" $((size + 2048))
+$QEMU_IO -c "write -z $size 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Write at the back: sector-wise, the request is:
+# backing: 128m... | 00 00
+# active: 128m... | -- -- -- 00
+_make_test_img -b "$TEST_IMG.base" $((size + 2048))
+$QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Write at middle: sector-wise, the request is:
+# backing: 128m... | 00 00
+# active: 128m... | -- 00 00 --
+_make_test_img -b "$TEST_IMG.base" $((size + 2048))
+$QEMU_IO -c "write -z $((size + 512)) 1024" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Write entire cluster: sector-wise, the request is:
+# backing: 128m... | 00 00
+# active: 128m... | 00 00 00 00
+_make_test_img -b "$TEST_IMG.base" $((size + 2048))
+$QEMU_IO -c "write -z $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# A preallocated cluster maintains its allocation, whether it stays as
+# data due to a partial write:
+# Convert 128m... | XX XX => ... | XX 00
+_make_test_img $((size + 1024))
+$QEMU_IO -c "write -P 1 $((size)) 1024" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "write -z $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 1 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 0 $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 1024" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# or because it is the entire cluster and can use the zero flag:
+# Convert 128m... | XX XX => ... | 00 00
+$QEMU_IO -c "write -z $((size)) 1024" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "alloc $size 1024" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 0 $size 1024" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+echo
+echo == unaligned image tail cluster, allocation required ==
+
+# Write beyond backing file must COW
+# Backing file: 128m... | XX --
+# Active layer: 128m... | -- -- 00 --
+CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $((size + 1024))
+_make_test_img -b "$TEST_IMG.base" $((size + 2048))
+$QEMU_IO -c "write -P 1 $((size)) 512" "$TEST_IMG.base" | _filter_qemu_io
+$QEMU_IO -c "write -z $((size + 1024)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 1 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 0 $((size + 512)) 1536" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+# Writes at boundaries of (partial) cluster must not lose mid-cluster data
+# Backing file: 128m: ... | -- XX
+# Active layer: 128m: ... | 00 -- -- 00
+CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $((size + 1024))
+_make_test_img -b "$TEST_IMG.base" $((size + 2048))
+$QEMU_IO -c "write -P 1 $((size + 512)) 512" "$TEST_IMG.base" | _filter_qemu_io
+$QEMU_IO -c "write -z $((size)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 0 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 1 $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 0 $((size + 1024)) 1024" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 0 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 1 $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read -P 0 $((size + 1024)) 1024" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
+
# success, all done
echo "*** done"
rm -f $seq.full
diff --git a/tests/qemu-iotests/154.out b/tests/qemu-iotests/154.out
index d3b68e7..d8485ee 100644
--- a/tests/qemu-iotests/154.out
+++ b/tests/qemu-iotests/154.out
@@ -282,4 +282,132 @@ read 1024/1024 bytes at offset 76800
{ "start": 69632, "length": 4096, "depth": 0, "zero": true, "data": false},
{ "start": 73728, "length": 4096, "depth": 0, "zero": false, "data": true,
"offset": OFFSET},
{ "start": 77824, "length": 134139904, "depth": 1, "zero": true, "data":
false}]
+
+== unaligned image tail cluster, no allocation needed ==
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
+wrote 512/512 bytes at offset 134217728
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134219776, "depth": 0, "zero": true, "data": false}]
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
+wrote 512/512 bytes at offset 134219264
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134219776, "depth": 0, "zero": true, "data": false}]
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
+wrote 1024/1024 bytes at offset 134218240
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134219776, "depth": 0, "zero": true, "data": false}]
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
+wrote 2048/2048 bytes at offset 134217728
+2 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134219776, "depth": 0, "zero": true, "data": false}]
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=134218752
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
backing_file=TEST_DIR/t.IMGFMT.base
+wrote 512/512 bytes at offset 134217728
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134217728, "depth": 1, "zero": true, "data": false},
+{ "start": 134217728, "length": 2048, "depth": 0, "zero": false, "data": true,
"offset": OFFSET}]
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
backing_file=TEST_DIR/t.IMGFMT.base
+wrote 512/512 bytes at offset 134219264
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134217728, "depth": 1, "zero": true, "data": false},
+{ "start": 134217728, "length": 2048, "depth": 0, "zero": false, "data": true,
"offset": OFFSET}]
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
backing_file=TEST_DIR/t.IMGFMT.base
+wrote 1024/1024 bytes at offset 134218240
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134217728, "depth": 1, "zero": true, "data": false},
+{ "start": 134217728, "length": 2048, "depth": 0, "zero": false, "data": true,
"offset": OFFSET}]
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
backing_file=TEST_DIR/t.IMGFMT.base
+wrote 2048/2048 bytes at offset 134217728
+2 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134217728, "depth": 1, "zero": true, "data": false},
+{ "start": 134217728, "length": 2048, "depth": 0, "zero": true, "data": false}]
+wrote 512/512 bytes at offset 134217728
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
backing_file=TEST_DIR/t.IMGFMT.base
+wrote 512/512 bytes at offset 134217728
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134217728, "depth": 1, "zero": true, "data": false},
+{ "start": 134217728, "length": 2048, "depth": 0, "zero": false, "data": true,
"offset": OFFSET}]
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
backing_file=TEST_DIR/t.IMGFMT.base
+wrote 512/512 bytes at offset 134219264
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134217728, "depth": 1, "zero": true, "data": false},
+{ "start": 134217728, "length": 2048, "depth": 0, "zero": false, "data": true,
"offset": OFFSET}]
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
backing_file=TEST_DIR/t.IMGFMT.base
+wrote 1024/1024 bytes at offset 134218240
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134217728, "depth": 1, "zero": true, "data": false},
+{ "start": 134217728, "length": 2048, "depth": 0, "zero": false, "data": true,
"offset": OFFSET}]
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
backing_file=TEST_DIR/t.IMGFMT.base
+wrote 2048/2048 bytes at offset 134217728
+2 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+2048/2048 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134217728, "depth": 1, "zero": true, "data": false},
+{ "start": 134217728, "length": 2048, "depth": 0, "zero": true, "data": false}]
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134218752
+wrote 1024/1024 bytes at offset 134217728
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 512/512 bytes at offset 134218240
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 134217728
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 134218240
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+1024/1024 bytes allocated at offset 128 MiB
+[{ "start": 0, "length": 134217728, "depth": 0, "zero": true, "data": false},
+{ "start": 134217728, "length": 1024, "depth": 0, "zero": false, "data": true,
"offset": OFFSET}]
+wrote 1024/1024 bytes at offset 134217728
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+1024/1024 bytes allocated at offset 128 MiB
+read 1024/1024 bytes at offset 134217728
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+[{ "start": 0, "length": 134217728, "depth": 0, "zero": true, "data": false},
+{ "start": 134217728, "length": 1024, "depth": 0, "zero": true, "data": false,
"offset": OFFSET}]
+
+== unaligned image tail cluster, allocation required ==
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=134218752
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
backing_file=TEST_DIR/t.IMGFMT.base
+wrote 512/512 bytes at offset 134217728
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 512/512 bytes at offset 134218752
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 134217728
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 1536/1536 bytes at offset 134218240
+1.500 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+[{ "start": 0, "length": 134217728, "depth": 1, "zero": true, "data": false},
+{ "start": 134217728, "length": 2048, "depth": 0, "zero": false, "data": true,
"offset": OFFSET}]
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=134218752
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134219776
backing_file=TEST_DIR/t.IMGFMT.base
+wrote 512/512 bytes at offset 134218240
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 512/512 bytes at offset 134217728
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 134217728
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 134218240
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 1024/1024 bytes at offset 134218752
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 512/512 bytes at offset 134219264
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 134217728
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 134218240
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 1024/1024 bytes at offset 134218752
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+[{ "start": 0, "length": 134217728, "depth": 1, "zero": true, "data": false},
+{ "start": 134217728, "length": 2048, "depth": 0, "zero": false, "data": true,
"offset": OFFSET}]
*** done
--
2.9.3
