On Fri, May 26, 2017 at 08:45:08PM +0000, Sargun Dhillon wrote: > This patch introduces a new mount option - qgroup_auto_cleanup. > The purpose of this mount option is to cause btrfs to automatically > delete qgroups on subvolume deletion. This only cleans up the > associated level-0 qgroup, and not qgroups that are above it. > > Since this behaviour is API-breaking, as people may already have scripts > that do this cleanup on subvolume destruction, this feature, at least > for now, must be opt-in.
I'd rather make the auto-cleaning default and I don't remember why this wasn't actually done back then. I don't like mount options for fine grained tuning of a filesystem, IMO it's almost always the bad interface for that. But people propose various mout options because it's easy to implement and test (known interface, existing tools). Ok for testing and first draft but as it's an interface that's supposed to be forever, it's good to take time to think it through. >From the API-breaking point you wrote above, sounds like switching auto-cleaning on by default is not a good option. The mount option is somehow persistent, ie. stored in a config file and applied on mount. I was thinking about a sysfs tunable, this would require a post-mount action, less comfort. Another option is to add a new property for the filesystem. That would need some more preparatory work though but I'd prefer this approach. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
