On 20/05/2025 20:49, John Stoffel wrote: >>>>>> "Kent" == Kent Overstreet <kent.overstreet@xxxxxxxxx> writes: >> On Tue, May 20, 2025 at 04:03:27PM +0200, Amir Goldstein wrote: >>> On Tue, May 20, 2025 at 2:43 PM Kent Overstreet >>> <kent.overstreet@xxxxxxxxx> wrote: >>>> On Tue, May 20, 2025 at 02:40:07PM +0200, Amir Goldstein wrote: >>>>> On Tue, May 20, 2025 at 2:25 PM Kent Overstreet >>>>> <kent.overstreet@xxxxxxxxx> wrote: >>>>>> On Tue, May 20, 2025 at 10:05:14AM +0200, Amir Goldstein wrote: >>>>>>> On Tue, May 20, 2025 at 7:16 AM Kent Overstreet >>>>>>> <kent.overstreet@xxxxxxxxx> wrote: >>>>>>>> This series allows overlayfs and casefolding to safely be used on the >>>>>>>> same filesystem by providing exclusion to ensure that overlayfs never >>>>>>>> has to deal with casefolded directories. >>>>>>>> >>>>>>>> Currently, overlayfs can't be used _at all_ if a filesystem even >>>>>>>> supports casefolding, which is really nasty for users. >>>>>>>> >>>>>>>> Components: >>>>>>>> >>>>>>>> - filesystem has to track, for each directory, "does any _descendent_ >>>>>>>> have casefolding enabled" >>>>>>>> >>>>>>>> - new inode flag to pass this to VFS layer >>>>>>>> >>>>>>>> - new dcache methods for providing refs for overlayfs, and filesystem >>>>>>>> methods for safely clearing this flag >>>>>>>> >>>>>>>> - new superblock flag for indicating to overlayfs & dcache "filesystem >>>>>>>> supports casefolding, it's safe to use provided new dcache methods are >>>>>>>> used" >>>>>>>> >>>>>>> I don't think that this is really needed. >>>>>>> >>>>>>> Too bad you did not ask before going through the trouble of this implementation. >>>>>>> >>>>>>> I think it is enough for overlayfs to know the THIS directory has no >>>>>>> casefolding. >>>>>> overlayfs works on trees, not directories... >>>>> I know how overlayfs works... >>>>> >>>>> I've explained why I don't think that sanitizing the entire tree is needed >>>>> for creating overlayfs over a filesystem that may enable casefolding >>>>> on some of its directories. >>>> So, you want to move error checking from mount time, where we _just_ >>>> did a massive API rework so that we can return errors in a way that >>>> users will actually see them - to open/lookup, where all we have are a >>>> small fixed set of error codes? >>> That's one way of putting it. >>> >>> Please explain the use case. >>> >>> When is overlayfs created over a subtree that is only partially case folded? >>> Is that really so common that a mount time error justifies all the vfs >>> infrastructure involved? >> Amir, you've got two widely used filesystem features that conflict and >> can't be used on the same filesystem. > Wait, what? How many people use casefolding, on a per-directory > basis? It's stupid. Unix/Linux has used case-sensitive filesystems > for years. Yes, linux supports other OSes which did do casefolding, > but yikes... per-directory support is just insane. It should be > per-filesystem only at BEST. > >> That's _broken_. > So? what about my cross mounting of VMS filesystems with "foo.txt;3" > version control so I can go back to previous versions? Why can't I do > that from my Linux systems that's mounting that VMS image? > > Just because it's done doesn't mean it's not dumb. > >> Users hate partitioning just for separate /boot and /home, having to >> partition for different applications is horrible. And since overlay >> fs is used under the hood by docker, and casefolding is used under >> the hood for running Windows applications, this isn't something >> people can predict in advance. > Sure I can, I don't run windows applications to screw casefolding. > :-) > > And I personally LIKE having a seperate /boot and /home, because it > gives isolation. The world is not just single user laptops with > everything all on one disk or spread across a couple of disks using > LVM or RAID or all of the above. > > I also don't see any updates for the XFS tests, or any other > filesystem tests, that actually checks and confirms this decidedly > obtuse and dumb to implement idea. > > > John > Hi there, would you partition different subdirs of your /home? So there is .local/share/containers where users put their container-stuff (at least podman does). Then there is .wine where case-folding-craziness lives. And then there is the mess that is Steam, which does all kinds of containery case-foldy stuff. As much as I would like to keep these things apart, it is not feasible. Not for me as a "power user", and certainly far out of reach for average Joe user. Just my 2 ct, greets /Malte
