diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/quorum.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/block/quorum.c b/block/quorum.c index 1b2b56f8a0..73dd45b6ff 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); + 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); + 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, |