On Wed, Jun 17, 2020 at 07:49:33AM +0800, Qu Wenruo wrote: > >>> Can we handle stat->dev not having a device set? Or will this blow up > >>> in other ways? Thanks, > >> > >> We can handle it without any problem, just users get confused. > >> > >> As a common practice, we use different bdev as a namespace for different > >> subvolumes. > >> Without a valid bdev, some user space tools may not be able to > >> distinguish inodes in different subvolumes. > >> > > > > Alright that's fine then. But I feel like stat is one of those things > > that'll flood the console, can we put this somewhere else that's going > > to be hit less? Thanks, > > Unfortunately, stat() is the only user of btrfs_root::anon_dev. > > While fortunately, the logical is pretty simple, even without the safe > net we can understand the lifespan pretty well. > > I'm fine to drop this patch if you're concerned about the possible > warning flood, as the benefit is really not that much. It could be a developer-only warning but if there's a root with a bad anon_dev, a simple 'ls -l' would flood the log for sure.
