On Wed, Feb 12, 2020 at 08:38:33PM +0000, Al Viro wrote: > On Wed, Feb 12, 2020 at 12:35:04PM -0800, Linus Torvalds wrote: > > On Wed, Feb 12, 2020 at 12:03 PM Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > > > > > > What's to prevent racing with fs shutdown while you are doing the second part? > > > > I was thinking that only the proc_flush_task() code would do this. > > > > And that holds a ref to the vfsmount through upid->ns. > > > > So I wasn't suggesting doing this in general - just splitting up the > > implementation of d_invalidate() so that proc_flush_task_mnt() could > > delay the complex part to after having traversed the RCU-protected > > list. > > > > But hey - I missed this part of the problem originally, so maybe I'm > > just missing something else this time. Wouldn't be the first time. > > Wait, I thought the whole point of that had been to allow multiple > procfs instances for the same userns? Confused... s/userns/pidns/, sorry
