On Fri, Feb 24, 2017 at 04:43:29PM +0100, Peter Zijlstra wrote: > There's a number of options here: > > - I'm not completely insane, and these patches can be made to work. > > - We decide usage-counts are useful and try and support them in refcount_t; > this has the down-side that people can more easily write bad code (by doing > from 0 increments that should not have happened). > > - We decide usage-counts need their own type (urgh, more...). > > - None of the above, we keep i_count as is and let people hunt and convert > actual refcounts.
The last one; if some object has non-trivial lifetime rules, don't try to shoehorn it into refcount_t. VFS-side the same goes for struct dentry (non-trivial lifetime and locking rules) struct mount (per-CPU fun, barriers, etc.) struct super_block (non-trivial lifecycle and lifetime rules) I'm not sure if struct file is a good match, BTW - net/unix/garbage.c would be one place in need of a careful looking into if we went for it.
