Zbigniew Jędrzejewski-Szmek [off-list ref] writes:
I've added 'v4' to the other two patches in this series like to this
one, despite them beeing new. I hope that this is proper form.
Yeah, we usually say [PATCH v4 1/3] to mean that this is the fourth
incarnation of the whole series (it is an instruction to reviewers to
discard anything labeled without v$N and $N smaller than 4, and read only
the ones marked with "v4") and it often happens that the earlier round did
not have three patches, so that is perfectly fine.