To elaborate a bit: what that function does (well, tries to do - it has serious limitations, which is why there is only one caller remaining and that one is used only when nothing else can access the filesystem anymore) is "kill given dentry, along with all its children, all their children, etc."
I sincerely doubt that you will be able to come up with any word describing such action in any real-world context that would not come with very nasty associations.
I feel like there could have been better names possible... d_recursive_kill perhaps? I'm certainly not an expert in this system but I find it challenging to believe that "genocide" was the only word that is adequately descriptive of the functionality.
In fact, I'd argue it's not that descriptive, given that genocide involves targeting some group of people based on some trait, like race, culture, disability, etc. - based on the description "kill given dentry, along with all its children, all their children, etc." that doesn't seem to fit...
perhaps I'm overthinking.
