quorum: Forbid adding children in blkverify mode

The blkverify mode of Quorum only works when the number of children is
exactly two, so any attempt to add a new one must return an error.

quorum_del_child() on the other hand doesn't need any additional check
because decreasing the number of children would make it go under the
vote threshold.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Alberto Garcia 2018-10-18 11:59:03 +03:00 committed by Kevin Wolf
parent 82c4c85978
commit 808b27d464

View File

@ -992,6 +992,11 @@ static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs,
char indexstr[32];
int ret;
if (s->is_blkverify) {
error_setg(errp, "Cannot add a child to a quorum in blkverify mode");
return;
}
assert(s->num_children <= INT_MAX / sizeof(BdrvChild *));
if (s->num_children == INT_MAX / sizeof(BdrvChild *) ||
s->next_child_index == UINT_MAX) {
@ -1046,6 +1051,9 @@ static void quorum_del_child(BlockDriverState *bs, BdrvChild *child,
return;
}
/* We know now that num_children > threshold, so blkverify must be false */
assert(!s->is_blkverify);
bdrv_drained_begin(bs);
/* We can safely remove this child now */