Hi, On Fri, 27 May 2011 08:28:28 +0200, dexen deVries wrote: > Hi, > > > recently I was searching for a way to discard all changes after a certain > point in time -- that is, to rollback filesystem state to a particular > checkpoint. I couldn't find a way, is there any? > > If not, I'd like to request such functionality. Preferrably selectable at > mount time, via an argument to mount (or the `rootflags' kernel parameter). > > Something along the lines `rollbackto=<checkpoint-number>'. > > The desired effect is to set the indicated checkpoint as the latest one, so all > subsequent changes to filesystem are discarded. > > > What are your thoughts on that? The feature is indeed one of todo items, and I just have been considering the topic for upcoming LinuxCon Japan. At present, I made a patchset which can revert only one fully deleted regular file without duplicating data blocks. (This work derives your post titled "It is not possible to restore file from a mounted snapshot using a hardlink" and the successive reflink topic.) The challenge in the rollback (or revert) feature is to handle lifetime of each disk block, which is maintained for garbage collection. (a disk address table, which we call DAT file, preserves this metadata). The mount-time whole checkpoint reversion, that is to say rollback, seems rather difficult than this. In my estimation, it would take too long time to rewrite whole DAT file. But, yes, I think this feature is one of priorities, and have plan to take time for it. Thanks, Ryusuke Konishi > Regards, > -- > dexen deVries > > ``One can't proceed from the informal to the formal by formal means.'' > -- > To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
