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 nbd-server-add.
qemu as client can be hacked into viewing this new context by using the now-misnamed x-dirty-bitmap option when creating an NBD blockdev; although it is worth noting the decoding of how such context information will appear in 'qemu-img map --output=json': NBD_STATE_DEPTH_UNALLOC => "zero":false, "data":true NBD_STATE_DEPTH_LOCAL => "zero":false, "data":false NBD_STATE_DEPTH_BACKING => "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 <ebl...@redhat.com> --- docs/tools/qemu-nbd.rst | 6 ++++ qapi/block-core.json | 7 ++-- include/block/nbd.h | 7 ++-- blockdev-nbd.c | 3 +- nbd/server.c | 8 +++-- qemu-nbd.c | 16 ++++++--- tests/qemu-iotests/309 | 73 ++++++++++++++++++++++++++++++++++++++ tests/qemu-iotests/309.out | 22 ++++++++++++ tests/qemu-iotests/group | 1 + 9 files changed, 129 insertions(+), 14 deletions(-) create mode 100755 tests/qemu-iotests/309 create mode 100644 tests/qemu-iotests/309.out diff --git a/docs/tools/qemu-nbd.rst b/docs/tools/qemu-nbd.rst index 667861cb22e9..0e545a97cfa3 100644 --- a/docs/tools/qemu-nbd.rst +++ b/docs/tools/qemu-nbd.rst @@ -72,6 +72,12 @@ driver options if ``--image-opts`` is specified. Export the disk as read-only. +.. option:: -A, --allocation-depth + + Expose allocation depth information via the + ``qemu:allocation-depth`` context accessible through + NBD_OPT_SET_META_CONTEXT. + .. option:: -B, --bitmap=NAME If *filename* has a qcow2 persistent bitmap *NAME*, expose diff --git a/qapi/block-core.json b/qapi/block-core.json index b3ec30a83cd7..84f7a7a34dc1 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -3874,9 +3874,12 @@ # # @tls-creds: TLS credentials ID # -# @x-dirty-bitmap: A "qemu:dirty-bitmap:NAME" string to query in place of +# @x-dirty-bitmap: A metacontext name such as "qemu:dirty-bitmap:NAME" or +# "qemu:allocation-depth" to query in place of the # traditional "base:allocation" block status (see -# NBD_OPT_LIST_META_CONTEXT in the NBD protocol) (since 3.0) +# NBD_OPT_LIST_META_CONTEXT in the NBD protocol; and +# yes, naming this option x-context would have made +# more sense) (since 3.0) # # @reconnect-delay: On an unexpected disconnect, the nbd client tries to # connect again until succeeding or encountering a serious diff --git a/include/block/nbd.h b/include/block/nbd.h index 71a2623f7842..f660e0274ce3 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -336,9 +336,10 @@ typedef struct NBDClient NBDClient; NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, uint64_t size, const char *name, const char *desc, - const char *bitmap, bool readonly, bool shared, - void (*close)(NBDExport *), bool writethrough, - BlockBackend *on_eject_blk, Error **errp); + bool alloc_depth, const char *bitmap, bool readonly, + bool shared, void (*close)(NBDExport *), + bool writethrough, BlockBackend *on_eject_blk, + Error **errp); void nbd_export_close(NBDExport *exp); void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp); void nbd_export_get(NBDExport *exp); diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 1a95d89f0096..562ea3751b85 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -203,7 +203,8 @@ void qmp_nbd_server_add(BlockExportNbd *arg, Error **errp) arg->writable = false; } - exp = nbd_export_new(bs, 0, len, arg->name, arg->description, arg->bitmap, + exp = nbd_export_new(bs, 0, len, arg->name, arg->description, + arg->alloc, arg->bitmap, !arg->writable, !arg->writable, NULL, false, on_eject_blk, errp); if (!exp) { diff --git a/nbd/server.c b/nbd/server.c index 02d5fb375b24..f5e0e115b703 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1450,9 +1450,10 @@ static void nbd_eject_notifier(Notifier *n, void *data) NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, uint64_t size, const char *name, const char *desc, - const char *bitmap, bool readonly, bool shared, - void (*close)(NBDExport *), bool writethrough, - BlockBackend *on_eject_blk, Error **errp) + bool alloc_depth, const char *bitmap, bool readonly, + bool shared, void (*close)(NBDExport *), + bool writethrough, BlockBackend *on_eject_blk, + Error **errp) { AioContext *ctx; BlockBackend *blk; @@ -1545,6 +1546,7 @@ NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, assert(strlen(exp->export_bitmap_context) < NBD_MAX_STRING_SIZE); } + exp->alloc_context = alloc_depth; exp->close = close; exp->ctx = ctx; blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp); diff --git a/qemu-nbd.c b/qemu-nbd.c index e39d3b23c121..5aeef60b0a5a 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -100,6 +100,7 @@ static void usage(const char *name) "\n" "Exposing part of the image:\n" " -o, --offset=OFFSET offset into the image\n" +" -A, --allocation-depth expose the allocation depth\n" " -B, --bitmap=NAME expose a persistent dirty bitmap\n" "\n" "General purpose options:\n" @@ -527,7 +528,7 @@ int main(int argc, char **argv) int64_t fd_size; QemuOpts *sn_opts = NULL; const char *sn_id_or_name = NULL; - const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:B:L"; + const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:AB:L"; struct option lopt[] = { { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, 'V' }, @@ -536,6 +537,7 @@ int main(int argc, char **argv) { "socket", required_argument, NULL, 'k' }, { "offset", required_argument, NULL, 'o' }, { "read-only", no_argument, NULL, 'r' }, + { "allocation-depth", no_argument, NULL, 'A' }, { "bitmap", required_argument, NULL, 'B' }, { "connect", required_argument, NULL, 'c' }, { "disconnect", no_argument, NULL, 'd' }, @@ -577,6 +579,7 @@ int main(int argc, char **argv) QDict *options = NULL; const char *export_name = NULL; /* defaults to "" later for server mode */ const char *export_description = NULL; + bool alloc_depth = false; const char *bitmap = NULL; const char *tlscredsid = NULL; bool imageOpts = false; @@ -700,6 +703,9 @@ int main(int argc, char **argv) readonly = true; flags &= ~BDRV_O_RDWR; break; + case 'A': + alloc_depth = true; + break; case 'B': bitmap = optarg; break; @@ -797,8 +803,8 @@ int main(int argc, char **argv) exit(EXIT_FAILURE); } if (export_name || export_description || dev_offset || - device || disconnect || fmt || sn_id_or_name || bitmap || - seen_aio || seen_discard || seen_cache) { + device || disconnect || fmt || sn_id_or_name || alloc_depth || + bitmap || seen_aio || seen_discard || seen_cache) { error_report("List mode is incompatible with per-device settings"); exit(EXIT_FAILURE); } @@ -1069,8 +1075,8 @@ int main(int argc, char **argv) fd_size -= dev_offset; export = nbd_export_new(bs, dev_offset, fd_size, export_name, - export_description, bitmap, readonly, shared > 1, - nbd_export_closed, writethrough, NULL, + export_description, alloc_depth, bitmap, readonly, + shared > 1, nbd_export_closed, writethrough, NULL, &error_fatal); if (device) { diff --git a/tests/qemu-iotests/309 b/tests/qemu-iotests/309 new file mode 100755 index 000000000000..fda3be9abbd2 --- /dev/null +++ b/tests/qemu-iotests/309 @@ -0,0 +1,73 @@ +#!/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 + +# Normal -f raw NBD block status loses access to allocation information +$QEMU_IMG map --output=json -f qcow2 "$TEST_IMG" +IMG="driver=nbd,server.type=unix,server.path=$nbd_unix_socket" +nbd_server_start_unix_socket -r -f qcow2 -A "$TEST_IMG" +$QEMU_IMG map --output=json --image-opts \ + "$IMG" | _filter_qemu_img_map +# But since we used -A, and use x-dirty-bitmap as a hack for reading bitmaps, +# we can reconstruct it, by abusing block status to report: +# NBD_STATE_DEPTH_UNALLOC => "zero":false, "data":true +# NBD_STATE_DEPTH_LOCAL => "zero":false, "data":false +# NBD_STATE_DEPTH_BACKING => "zero":true, "data":true +$QEMU_IMG map --output=json --image-opts \ + "$IMG,x-dirty-bitmap=qemu:allocation-depth" | _filter_qemu_img_map + +# 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 000000000000..db75bb6b0df9 --- /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 ff59cfd2d4c4..57182e4b3169 100644 --- a/tests/qemu-iotests/group +++ b/tests/qemu-iotests/group @@ -314,3 +314,4 @@ 303 rw quick 304 rw quick 305 rw quick +309 rw auto quick -- 2.28.0