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author | Eric Blake <eblake@redhat.com> | 2020-10-27 00:05:55 -0500 |
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committer | Eric Blake <eblake@redhat.com> | 2020-10-30 15:22:00 -0500 |
commit | dbc7b01492371e4a54b92d2b6d968f9b863cc794 (patch) | |
tree | 24812091f95b86d03192a23bec70e21d9a5b74eb /tests | |
parent | 71719cd57fc02ddfd91a4a3ca3f469bfb4d221bc (diff) | |
download | qemu-dbc7b01492371e4a54b92d2b6d968f9b863cc794.zip qemu-dbc7b01492371e4a54b92d2b6d968f9b863cc794.tar.gz qemu-dbc7b01492371e4a54b92d2b6d968f9b863cc794.tar.bz2 |
nbd: Add 'qemu-nbd -A' to expose allocation depth
Allow the server to expose an additional metacontext to be requested
by savvy clients. qemu-nbd adds a new option -A to expose the
qemu:allocation-depth metacontext through NBD_CMD_BLOCK_STATUS; this
can also be set via QMP when using block-export-add.
qemu as client is hacked into viewing the key aspects of this new
context by abusing the already-experimental x-dirty-bitmap option to
collapse all depths greater than 2, which results in a tri-state value
visible in the output of 'qemu-img map --output=json' (yes, that means
x-dirty-bitmap is now a bit of a misnomer, but I didn't feel like
renaming it as it would introduce a needless break of back-compat,
even though we make no compat guarantees with x- members):
unallocated (depth 0) => "zero":false, "data":true
local (depth 1) => "zero":false, "data":false
backing (depth 2+) => "zero":true, "data":true
libnbd as client is probably a nicer way to get at the information
without having to decipher such hacks in qemu as client. ;)
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20201027050556.269064-11-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Diffstat (limited to 'tests')
-rwxr-xr-x | tests/qemu-iotests/309 | 77 | ||||
-rw-r--r-- | tests/qemu-iotests/309.out | 22 | ||||
-rw-r--r-- | tests/qemu-iotests/group | 1 |
3 files changed, 100 insertions, 0 deletions
diff --git a/tests/qemu-iotests/309 b/tests/qemu-iotests/309 new file mode 100755 index 0000000..fb61157 --- /dev/null +++ b/tests/qemu-iotests/309 @@ -0,0 +1,77 @@ +#!/usr/bin/env bash +# +# Test qemu-nbd -A +# +# Copyright (C) 2018-2020 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 +# 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/>. +# + +seq="$(basename $0)" +echo "QA output created by $seq" + +status=1 # failure is the default! + +_cleanup() +{ + _cleanup_test_img + nbd_server_stop +} +trap "_cleanup; exit \$status" 0 1 2 3 15 + +# get standard environment, filters and checks +. ./common.rc +. ./common.filter +. ./common.nbd + +_supported_fmt qcow2 +_supported_proto file +_supported_os Linux +_require_command QEMU_NBD + +echo +echo "=== Initial image setup ===" +echo + +TEST_IMG="$TEST_IMG.base" _make_test_img 4M +$QEMU_IO -c 'w 0 2M' -f $IMGFMT "$TEST_IMG.base" | _filter_qemu_io +_make_test_img -b "$TEST_IMG.base" -F $IMGFMT 4M +$QEMU_IO -c 'w 1M 2M' -f $IMGFMT "$TEST_IMG" | _filter_qemu_io + +echo +echo "=== Check allocation over NBD ===" +echo + +$QEMU_IMG map --output=json -f qcow2 "$TEST_IMG" +IMG="driver=nbd,server.type=unix,server.path=$nbd_unix_socket" +nbd_server_start_unix_socket -r -f qcow2 -A "$TEST_IMG" +# Normal -f raw NBD block status loses access to allocation information +$QEMU_IMG map --output=json --image-opts \ + "$IMG" | _filter_qemu_img_map +# But when we use -A, coupled with x-dirty-bitmap in the client for feeding +# 2-bit block status from an alternative NBD metadata context (note that +# the client code for x-dirty-bitmap intentionally collapses all depths +# beyond 2 into a single value), we can determine: +# unallocated (depth 0) => "zero":false, "data":true +# local (depth 1) => "zero":false, "data":false +# backing (depth 2+) => "zero":true, "data":true +$QEMU_IMG map --output=json --image-opts \ + "$IMG,x-dirty-bitmap=qemu:allocation-depth" | _filter_qemu_img_map +# More accurate results can be obtained by other NBD clients such as +# libnbd, but this test works without such external dependencies. + +# success, all done +echo '*** done' +rm -f $seq.full +status=0 diff --git a/tests/qemu-iotests/309.out b/tests/qemu-iotests/309.out new file mode 100644 index 0000000..db75bb6 --- /dev/null +++ b/tests/qemu-iotests/309.out @@ -0,0 +1,22 @@ +QA output created by 309 + +=== Initial image setup === + +Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=4194304 +wrote 2097152/2097152 bytes at offset 0 +2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4194304 backing_file=TEST_DIR/t.IMGFMT.base backing_fmt=IMGFMT +wrote 2097152/2097152 bytes at offset 1048576 +2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) + +=== Check allocation over NBD === + +[{ "start": 0, "length": 1048576, "depth": 1, "zero": false, "data": true, "offset": 327680}, +{ "start": 1048576, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": 327680}, +{ "start": 3145728, "length": 1048576, "depth": 1, "zero": true, "data": false}] +[{ "start": 0, "length": 3145728, "depth": 0, "zero": false, "data": true, "offset": OFFSET}, +{ "start": 3145728, "length": 1048576, "depth": 0, "zero": true, "data": false, "offset": OFFSET}] +[{ "start": 0, "length": 1048576, "depth": 0, "zero": true, "data": true, "offset": OFFSET}, +{ "start": 1048576, "length": 2097152, "depth": 0, "zero": false, "data": false}, +{ "start": 3145728, "length": 1048576, "depth": 0, "zero": false, "data": true, "offset": OFFSET}] +*** done diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group index 3432989..2960dff 100644 --- a/tests/qemu-iotests/group +++ b/tests/qemu-iotests/group @@ -315,3 +315,4 @@ 304 rw quick 305 rw quick 307 rw quick export +309 rw auto quick |