On Thu, Jun 26, 2025 at 3:37 PM Kent Overstreet <kent.overstreet@xxxxxxxxx> wrote: > > On Sun, Jun 22, 2025 at 09:20:24AM +0200, Amir Goldstein wrote: > > On Mon, Jun 16, 2025 at 10:06 AM Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > > > > > On Sun, Jun 15, 2025 at 9:20 PM Kent Overstreet > > > <kent.overstreet@xxxxxxxxx> wrote: > > > > > > > > On Mon, Jun 02, 2025 at 07:17:02PM +0200, Amir Goldstein wrote: > > > > > Case folding is often applied to subtrees and not on an entire > > > > > filesystem. > > > > > > > > > > Disallowing layers from filesystems that support case folding is over > > > > > limiting. > > > > > > > > > > Replace the rule that case-folding capable are not allowed as layers > > > > > with a rule that case folded directories are not allowed in a merged > > > > > directory stack. > > > > > > > > > > Should case folding be enabled on an underlying directory while > > > > > overlayfs is mounted the outcome is generally undefined. > > > > > > > > > > Specifically in ovl_lookup(), we check the base underlying directory > > > > > and fail with -ESTALE and write a warning to kmsg if an underlying > > > > > directory case folding is enabled. > > > > > > > > > > Suggested-by: Kent Overstreet <kent.overstreet@xxxxxxxxx> > > > > > Link: https://lore.kernel.org/linux-fsdevel/20250520051600.1903319-1-kent.overstreet@xxxxxxxxx/ > > > > > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> > > > > > --- > > > > > > > > > > Miklos, > > > > > > > > > > This is my solution to Kent's request to allow overlayfs mount on > > > > > bcachefs subtrees that do not have casefolding enabled, while other > > > > > subtrees do have casefolding enabled. > > > > > > > > > > I have written a test to cover the change of behavior [1]. > > > > > This test does not run on old kernel's where the mount always fails > > > > > with casefold capable layers. > > > > > > > > > > Let me know what you think. > > > > > > > > > > Kent, > > > > > > > > > > I have tested this on ext4. > > > > > Please test on bcachefs. > > > > > > > > Where are we at with getting this in? I've got users who keep asking, so > > > > hoping we can get it backported to 6.15 > > > > > > I'm planning to queue this for 6.17, but hoping to get an ACK from Miklos first. > > > > > > > Hi Christian, > > > > I would like to let this change soak in next for 6.17. > > I can push to overlayfs-next, but since you have some changes on vfs.file, > > I wanted to consult with you first. > > > > The changes are independent so they could go through different trees, > > but I don't like that so much, so I propose a few options. > > > > 1. make vfs.file a stable branch, so I can base overlayfs-next on it > > 2. rename to vfs.backing_file and make stable > > 3. take this single ovl patch via your tree, as I don't currently have > > any other ovl patches queued to 6.17 > > I've got more users hitting the casefolding + overlayfs issue. > > If we made the new behaviour bcachefs only, would that make it work for > you to get it into 6.16 + 6.15 backport? Sorry, overlayfs is not going to special case bcachefs. The patch is queued for 6.17 in Christian's tree and is still waiting for an ACK from Miklos. > > Otherwise I'm going to have to get my own workaround out... Not sure which workaround that is, but if it's in bcachefs then it's up to you. Thanks, Amir.
