On Wed, Sep 06, 2023 at 09:53:27PM -0400, Steven Rostedt wrote: > On Thu, 7 Sep 2023 08:54:38 +1000 > Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > > And let's not forget: removing a filesystem from the kernel is not > > removing end user support for extracting data from old filesystems. > > We have VMs for that - we can run pretty much any kernel ever built > > inside a VM, so users that need to extract data from a really old > > filesystem we no longer support in a modern kernel can simply boot > > up an old distro that did support it and extract the data that way. > > Of course there's the case of trying to recreate a OS that can run on a > very old kernel. Just building an old kernel is difficult today because > today's compilers will refuse to build them (I've hit issues in bisections > because of that!) > > You could argue that you could just install an old OS into the VM, but that > too requires access to that old OS. Well, yes - why would anyone even bother trying to build an ancient kernel when all they need to do is download an iso and point the VM at it? > Anyway, what about just having read-only be the minimum for supporting a > file system? We can say "sorry, due to no one maintaining this file system, > we will no longer allow write access." But I'm guessing that just > supporting reading an old file system is much easier than modifying one > (wasn't that what we did with NTFS for the longest time?) "Read only" doesn't mean the filesytsem implementation is in any way secure, robust or trustworthy - the kernel is still parsing untrusted data in ring 0 using unmaintained, bit-rotted, untested code.... -Dave. -- Dave Chinner david@xxxxxxxxxxxxx
