On Tue, Feb 18, 2014 at 01:11:26PM +0100, Beno??t Canet wrote:
> From: Beno??t Canet <ben...@irqsave.net>
>
> Example of command line:
>
> -drive if=virtio,driver=quorum,\
> children.0.file.filename=1.raw,\
> children.0.node-name=1.raw,\
> children.0.driver=raw,\
> children.1.file.filename=2.raw,\
> children.1.node-name=2.raw,\
> children.1.driver=raw,\
> children.2.file.filename=3.raw,\
> children.2.node-name=3.raw,\
> children.2.driver=raw,\
> vote-threshold=2
>
> blkverify=on with vote-threshold=2 and two files can be passed to
> emulate blkverify.
>
> Signed-off-by: Benoit Canet <ben...@irqsave.net>
> ---
> block/quorum.c | 161
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> monitor.c | 3 ++
> qapi-schema.json | 21 +++++++-
> 3 files changed, 184 insertions(+), 1 deletion(-)
>
> diff --git a/block/quorum.c b/block/quorum.c
> index 40832c0..18721ba 100644
> --- a/block/quorum.c
> +++ b/block/quorum.c
> @@ -20,6 +20,9 @@
>
> #define HASH_LENGTH 32
>
> +#define QUORUM_OPT_VOTE_THRESHOLD "vote-threshold"
> +#define QUORUM_OPT_BLKVERIFY "blkverify"
> +
> /* This union holds a vote hash value */
> typedef union QuorumVoteValue {
> char h[HASH_LENGTH]; /* SHA-256 hash */
> @@ -672,12 +675,170 @@ static bool
> quorum_recurse_is_first_non_filter(BlockDriverState *bs,
> return false;
> }
>
> +static int quorum_valid_threshold(int threshold, int num_children, Error
> **errp)
> +{
> +
> + if (threshold < 1) {
> + error_set(errp, QERR_INVALID_PARAMETER_VALUE,
> + "vote-threshold", "value >= 1");
> + return -ERANGE;
> + }
> +
> + if (threshold > num_children) {
> + error_setg(errp, "threshold may not exceed children count");
> + return -ERANGE;
> + }
> +
> + return 0;
> +}
> +
> +static QemuOptsList quorum_runtime_opts = {
> + .name = "quorum",
> + .head = QTAILQ_HEAD_INITIALIZER(quorum_runtime_opts.head),
> + .desc = {
> + {
> + .name = QUORUM_OPT_VOTE_THRESHOLD,
> + .type = QEMU_OPT_NUMBER,
> + .help = "The number of vote needed for reaching quorum",
> + },
> + {
> + .name = QUORUM_OPT_BLKVERIFY,
> + .type = QEMU_OPT_BOOL,
> + .help = "Trigger block verify mode if set",
> + },
> + { /* end of list */ }
> + },
> +};
> +
> +static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
> + Error **errp)
> +{
> + BDRVQuorumState *s = bs->opaque;
> + Error *local_err = NULL;
> + QemuOpts *opts;
> + bool *opened;
> + QDict *sub = NULL;
> + QList *list = NULL;
> + const QListEntry *lentry;
> + const QDictEntry *dentry;
> + int i;
> + int ret = 0;
> +
> + qdict_flatten(options);
> + qdict_extract_subqdict(options, &sub, "children.");
> + qdict_array_split(sub, &list);
> +
> + /* count how many different children are present and validate
> + * qdict_size(sub) address the open by reference case
> + */
> + s->num_children = !qlist_size(list) ? qdict_size(sub) : qlist_size(list);
> + if (s->num_children < 2) {
> + error_setg(&local_err,
> + "Number of provided children must be greater than 1");
> + ret = -EINVAL;
> + goto exit;
> + }
> +
> + opts = qemu_opts_create(&quorum_runtime_opts, NULL, 0, &error_abort);
> + qemu_opts_absorb_qdict(opts, options, &local_err);
> + if (error_is_set(&local_err)) {
> + ret = -EINVAL;
> + goto exit;
> + }
> +
> + s->threshold = qemu_opt_get_number(opts, QUORUM_OPT_VOTE_THRESHOLD, 0);
> +
> + /* and validate it against s->num_children */
> + ret = quorum_valid_threshold(s->threshold, s->num_children, &local_err);
> + if (ret < 0) {
> + goto exit;
> + }
> +
> + /* is the driver in blkverify mode */
> + if (qemu_opt_get_bool(opts, QUORUM_OPT_BLKVERIFY, false) &&
> + s->num_children == 2 && s->threshold == 2) {
> + s->is_blkverify = true;
> + } else if (qemu_opt_get_bool(opts, QUORUM_OPT_BLKVERIFY, false)) {
> + fprintf(stderr, "blkverify mode is set by setting blkverify=on "
> + "and using two files with vote_threshold=2\n");
> + }
> +
> + /* allocate the children BlockDriverState array */
> + s->bs = g_new0(BlockDriverState *, s->num_children);
> + opened = g_new0(bool, s->num_children);
> +
> + /* Open by file name or options dict (command line or QMP) */
> + if (s->num_children == qlist_size(list)) {
> + for (i = 0, lentry = qlist_first(list); lentry;
> + lentry = qlist_next(lentry), i++) {
> + QDict *d = qobject_to_qdict(lentry->value);
> + QINCREF(d);
> + ret = bdrv_open(&s->bs[i], NULL, NULL, d, flags, NULL,
> &local_err);
Shouldn't this bdrv_open call be?
ret = bdrv_open(s->bs[i], NULL, d, flags, NULL, &local_err);
> + if (ret < 0) {
> + goto close_exit;
> + }
> + opened[i] = true;
> + }
> + /* Open by QMP references */
> + } else {
> + for (i = 0, dentry = qdict_first(sub); dentry;
> + dentry = qdict_next(sub, dentry), i++) {
> + QString *string = qobject_to_qstring(dentry->value);
> + ret = bdrv_open(&s->bs[i], NULL, qstring_get_str(string), NULL,
> + flags, NULL, &local_err);
This other bdrv_open() call seems to be not right as well, I think it should be:
ret = bdrv_open(s->bs[i], qstring_get_str(string), NULL,
flags, NULL, &local_err);
> + if (ret < 0) {
> + goto close_exit;
> + }
> + opened[i] = true;
> + }
> + }
> +
> + g_free(opened);
> + goto exit;
> +
> +close_exit:
> + /* cleanup on error */
> + for (i = 0; i < s->num_children; i++) {
> + if (!opened[i]) {
> + continue;
> + }
> + bdrv_unref(s->bs[i]);
> + }
> + g_free(s->bs);
> + g_free(opened);
> +exit:
> + /* propagate error */
> + if (error_is_set(&local_err)) {
> + error_propagate(errp, local_err);
> + }
> + QDECREF(list);
> + QDECREF(sub);
> + return ret;
> +}
> +
> +static void quorum_close(BlockDriverState *bs)
> +{
> + BDRVQuorumState *s = bs->opaque;
> + int i;
> +
> + for (i = 0; i < s->num_children; i++) {
> + bdrv_unref(s->bs[i]);
> + }
> +
> + g_free(s->bs);
> +}
> +
> static BlockDriver bdrv_quorum = {
> .format_name = "quorum",
> .protocol_name = "quorum",
>
> .instance_size = sizeof(BDRVQuorumState),
>
> + .bdrv_file_open = quorum_open,
> + .bdrv_close = quorum_close,
> +
> + .authorizations = { true, true },
> +
> .bdrv_co_flush_to_disk = quorum_co_flush,
>
> .bdrv_getlength = quorum_getlength,
> diff --git a/monitor.c b/monitor.c
> index 81ffa0f..ed5bb98 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -639,6 +639,9 @@ static void monitor_protocol_event_init(void)
> monitor_protocol_event_throttle(QEVENT_RTC_CHANGE, 1000);
> monitor_protocol_event_throttle(QEVENT_BALLOON_CHANGE, 1000);
> monitor_protocol_event_throttle(QEVENT_WATCHDOG, 1000);
> + /* limit the rate of quorum events to avoid hammering the management */
> + monitor_protocol_event_throttle(QEVENT_QUORUM_REPORT_BAD, 1000);
> + monitor_protocol_event_throttle(QEVENT_QUORUM_FAILURE, 1000);
> }
>
> /**
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 7cfb5e5..990d0c5 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -4352,6 +4352,24 @@
> 'raw': 'BlockdevRef' } }
>
> ##
> +# @BlockdevOptionsQuorum
> +#
> +# Driver specific block device options for Quorum
> +#
> +# @blkverify: #optional true if the driver must print content mismatch
> +#
> +# @children: the children block device to use
> +#
> +# @vote_threshold: the vote limit under which a read will fail
> +#
> +# Since: 2.0
> +##
> +{ 'type': 'BlockdevOptionsQuorum',
> + 'data': { '*blkverify': 'bool',
> + 'children': [ 'BlockdevRef' ],
> + 'vote-threshold': 'int' } }
> +
> +##
> # @BlockdevOptions
> #
> # Options for creating a block device.
> @@ -4390,7 +4408,8 @@
> 'vdi': 'BlockdevOptionsGenericFormat',
> 'vhdx': 'BlockdevOptionsGenericFormat',
> 'vmdk': 'BlockdevOptionsGenericCOWFormat',
> - 'vpc': 'BlockdevOptionsGenericFormat'
> + 'vpc': 'BlockdevOptionsGenericFormat',
> + 'quorum': 'BlockdevOptionsQuorum'
> } }
>
> ##
> --
> 1.8.3.2
>
>
--
Leandro Dorileo
