On 6/13/07, Chris Mason <chris.mason@xxxxxxxxxx> wrote:
On Wed, Jun 13, 2007 at 12:14:40PM -0400, Albert Cahalan wrote: > On 6/13/07, Chris Mason <chris.mason@xxxxxxxxxx> wrote: > >On Wed, Jun 13, 2007 at 01:45:28AM -0400, Albert Cahalan wrote:
> >> * secure delete via destruction of per-file or per-block random crypto > >keys > > > >I'd rather keep secure delete as a userland problem (or a layered FS > >problem). When you take backups and other copies of the file into > >account, it's a bigger problem than btrfs wants to tackle right now. > > It can't be a userland problem if you allow disk blocks to move. > Volume resizing, logging/journalling, etc. -- they combine to make > the userland solution essentially impossible. (one could wipe the > whole partition, or maybe fill ALL space on the volume) Right about here is where I would insert a long story about ecryptfs, or encryption solutions that happen all in userland. At any rate, it is outside the scope of v1.0, even though I definitely agree it is an important problem for some people.
I'm sure you do have a nice long story, and I'm sure it seems correct, but there is something not quite right about the add-on hacks. BTW, I'm suggesting that this be about deletion, not protection of data you wish to keep. It covers more than just file bodies. It covers inode data, block allocations, etc.
> >> * atomic creation of copy-on-write directory trees > > > >Do you mean something more fine grained than the current snapshotting > >system? > > I believe so. Example: I have a linux-2.6 directory. It's not > a mount point or anything special like that. I want to copy > it to a new directory called wip, without actually copying > all the blocks. To all the normal POSIX API stuff, this copy > should look like the result of "cp -a", not hard links. This would be a snapshot, which has to be done on a subvolume right now. It is not as nice as being able to pick a random directory, but I've only been able to get this far by limiting the feature scope significantly. What I did do was make subvolumes very cheap...just make a bunch of them.
Can a regular user create and use a subvolume? If not, then this doesn't work. (if so, then I have other concerns...) - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
