On Thu, Mar 28, 2024 at 03:33:13PM +0900, Damien Le Moal wrote: > Ha. OK. I did not see that one. But that means that the plug kfree() can then > block the caller. Given that the last ref drop may happen from BIO completion > context (when the last write to a zone making the zone full complete), I do not > think we can use this function... Ah, damn. So yes, we probably still need the rcu head. We can kill the gendisk pointer, though. Or just stick with the existing version and don't bother with the micro-optimization, at which point the mempool might actually be the simpler implementation?