Signed-off-by: Wen Congyang <we...@cn.fujitsu.com> Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com> Signed-off-by: Gonglei <arei.gong...@huawei.com> --- block.c | 6 ++--- block/quorum.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++-- include/block/block.h | 3 +++ 3 files changed, 76 insertions(+), 5 deletions(-)
diff --git a/block.c b/block.c index 1b25e43..01f6d69 100644 --- a/block.c +++ b/block.c @@ -1079,9 +1079,9 @@ static int bdrv_fill_options(QDict **options, const char **pfilename, return 0; } -static BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, - BlockDriverState *child_bs, - const BdrvChildRole *child_role) +BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, + BlockDriverState *child_bs, + const BdrvChildRole *child_role) { BdrvChild *child = g_new(BdrvChild, 1); *child = (BdrvChild) { diff --git a/block/quorum.c b/block/quorum.c index 8fe53b4..111a57b 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -66,6 +66,9 @@ typedef struct QuorumVotes { typedef struct BDRVQuorumState { BlockDriverState **bs; /* children BlockDriverStates */ int num_children; /* children count */ + int max_children; /* The maximum children count, we need to reallocate + * bs if num_children grows larger than maximum. + */ int threshold; /* if less than threshold children reads gave the * same result a quorum error occurs. */ @@ -874,9 +877,9 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, ret = -EINVAL; goto exit; } - if (s->num_children < 2) { + if (s->num_children < 1) { error_setg(&local_err, - "Number of provided children must be greater than 1"); + "Number of provided children must be 1 or more"); ret = -EINVAL; goto exit; } @@ -925,6 +928,7 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, /* allocate the children BlockDriverState array */ s->bs = g_new0(BlockDriverState *, s->num_children); opened = g_new0(bool, s->num_children); + s->max_children = s->num_children; for (i = 0; i < s->num_children; i++) { char indexstr[32]; @@ -995,6 +999,67 @@ static void quorum_attach_aio_context(BlockDriverState *bs, } } +static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs, + Error **errp) +{ + BDRVQuorumState *s = bs->opaque; + + bdrv_drain(bs); + + if (s->num_children == s->max_children) { + if (s->max_children >= INT_MAX) { + error_setg(errp, "Too many children"); + return; + } + + s->bs = g_renew(BlockDriverState *, s->bs, s->max_children + 1); + s->bs[s->num_children] = NULL; + s->max_children++; + } + + bdrv_ref(child_bs); + bdrv_attach_child(bs, child_bs, &child_format); + s->bs[s->num_children++] = child_bs; +} + +static void quorum_del_child(BlockDriverState *bs, BlockDriverState *child_bs, + Error **errp) +{ + BDRVQuorumState *s = bs->opaque; + BdrvChild *child; + int i; + + for (i = 0; i < s->num_children; i++) { + if (s->bs[i] == child_bs) { + break; + } + } + + QLIST_FOREACH(child, &bs->children, next) { + if (child->bs == child_bs) { + break; + } + } + + /* we have checked it in bdrv_del_child() */ + assert(i < s->num_children && child); + + if (s->num_children <= s->threshold) { + error_setg(errp, + "The number of children cannot be lower than the vote threshold %d", + s->threshold); + return; + } + + bdrv_drain(bs); + /* We can safely remove this child now */ + memmove(&s->bs[i], &s->bs[i + 1], + (s->num_children - i - 1) * sizeof(void *)); + s->num_children--; + s->bs[s->num_children] = NULL; + bdrv_unref_child(bs, child); +} + static void quorum_refresh_filename(BlockDriverState *bs) { BDRVQuorumState *s = bs->opaque; @@ -1049,6 +1114,9 @@ static BlockDriver bdrv_quorum = { .bdrv_detach_aio_context = quorum_detach_aio_context, .bdrv_attach_aio_context = quorum_attach_aio_context, + .bdrv_add_child = quorum_add_child, + .bdrv_del_child = quorum_del_child, + .is_filter = true, .bdrv_recurse_is_first_non_filter = quorum_recurse_is_first_non_filter, }; diff --git a/include/block/block.h b/include/block/block.h index 665c56f..bd97399 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -514,6 +514,9 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs); void bdrv_ref(BlockDriverState *bs); void bdrv_unref(BlockDriverState *bs); void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child); +BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, + BlockDriverState *child_bs, + const BdrvChildRole *child_role); bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp); void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason); -- 2.4.3