On Thu, Nov 28, 2013 at 08:23:13PM +0100, Goffredo Baroncelli wrote: > Definetely you are right. In fact this is true also for other tools like > tar: they complaint if you remove/move/rename a file during the copy. We > can work to increase the robustness of the process, to avoid strange > behaviour when a subvolume is removed/moved/renamed. > > Anyway I am more afraid that we can't mix recursive and readonly snapshot.
Agreed, this would eg. need to toggle RO/RW status when needed, but this does not sound very clean. > Implementing the atomic recursive snapshot in the kernel, is out of my > possibility; anyway basically this means that the filesystem is frozen > until all the snapshot are done, which requires a finite time. In case > of a high number of subvolumes this could be a problem. High number of subvolumes to snapshot atomically will always be problematic and a lazy userspace-based recursive snapshot might be actually better regarding the impact on the rest of the system, but without guaranteed atomicity. But, I don't want to kill the whole idea just because there's some scenario that's possible but hard to handle. david -- 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
