Hello, Jan. On Mon, Jun 24, 2019 at 10:21:30AM +0200, Jan Kara wrote: > OK, now I understand. Just one more question: So effectively, you are using > wbc->no_wbc_acct to pass information from btrfs code to btrfs code telling > it whether IO should or should not be accounted with wbc_account_io().
Yes. > Wouldn't it make more sense to just pass this information internally > within btrfs? Granted, if this mechanism gets more widespread use by other > filesystems, then probably using wbc flag makes more sense. But I'm not > sure if this isn't a premature generalization... The btrfs async issuers end up using generic writeback path and uses the generic wbc owner mechanisms so that ios are attached to the right cgroup too. So, I kinda prefer to provide a generic mechanism from wbc side. That said, the names are a bit misleading and I think it'd be better to rename them to something more explicit, e.g. sth along the line of wbc_update_cgroup_owner() and wbc->no_cgroup_owner. What do you think? Thanks. -- tejun
