From: Ingo Molnar Date: Wed, 20 Apr 2005 07:40:53 GMT Subject: enforcing DB immutability Message-ID: <20050420074053.GA22436@elte.hu> In-Reply-To: * Linus Torvalds wrote: > On Wed, 13 Apr 2005, Ingo Molnar wrote: > > > > well, the 'owned by another user' solution is valid though, and doesnt > > have this particular problem. (We've got a secure multiuser OS, so can > > as well use it to protect the DB against corruption.) > > So now you need root to set up new repositories? No thanks. yeah, it's a bit awkward to protect uncompressed repositories - but it will need some sort of kernel enforcement. (if userspace finds out the DB contains uncompressed blobs, it _will_ try to use them.) (perhaps having an in-kernel GIT-alike versioned filesystem will help - but that brings up the same 'I have to be root' issues. The FS will enforce the true immutability of objects.) perhaps having a new 'immutable hardlink' feature in the Linux VFS would help? I.e. a hardlink that can only be readonly followed, and can be removed, but cannot be chmod-ed to a writeable hardlink. That i think would be a large enough barrier for editors/build-tools not to play the tricks they already do that makes 'readonly' files virtually meaningless. Ingo