Created attachment 883027 [details] emerge --info After upgrading to kernel 6.7.0, if I try to upgrade grub.cfg with the usual grub-mkconfig -o /boot/grub/grub.cfg I get the error message /usr/sbin/grub-probe: error: cannot find a device for / (is /dev mounted?). "/dev" is indeed mounted: devtmpfs on /dev type devtmpfs (rw,nosuid,noexec,relatime,size=10240k,nr_inodes=8218697,mode=755) Before upgrading to 6.7.0, everything worked fine, and it still works if I boot with older kernels. The main difference I found is that, with gentoo admin livecd, the filesystem is "udev" instead of "devtmpfs", and udev leaves a trace in dmesg; with my current setup, I see no udev occurrencies in dmesg. The issue is present both with vanilla-sources and gentoo-sources, versions 6.7.0 and 6.7.1; in order to avoid configuration issues, I tested also with kernel defconfig -- adding as builtin just the support for nvme and btrfs, my machines storage and filesystem. I don't use systemd; I don't use initramfs. Some extra info: emerge -pqv grub systemd-utils [ebuild R ] sys-boot/grub-2.12-r1 USE="fonts nls themes truetype -device-mapper -doc -efiemu -libzfs -mount -sdl (-test) -verify-sig" GRUB_PLATFORMS="efi-64 pc -coreboot -efi-32 -emu -ieee1275 (-loongson) -multiboot -qemu (-qemu-mips) -uboot -xen -xen-32 -xen-pvh" [ebuild R ] sys-apps/systemd-utils-254.8 USE="acl kmod (split-usr) tmpfiles udev -boot -kernel-install -secureboot (-selinux) -sysusers -test -ukify" ABI_X86="(64) -32 (-x32)" PYTHON_SINGLE_TARGET="python3_11 -python3_10 -python3_12"
Same here! Confirmed that just by booting into kernel 6.6.12-gentoo, grub finds the / device again. And then back in current 6.7.1-gentoo-r1, again not. No idea why...
... BTW I do use systemd but also no initramfs here.
I think the bug is known upstream: https://bugzilla.kernel.org/show_bug.cgi?id=218353
Created attachment 884274 [details, diff] Working fix (https://github.com/kdave/btrfs-devel/commit/b80f3ec6592c69f88ebc74a4e16676af161e2759) There is a working fix now in https://bugzilla.kernel.org/show_bug.cgi?id=218353 by David Sterba - I attach it.
Also confirming here. Happened when I migrated from 6.6.y to 6.7.y. Root filesystem is btrfs, no initramfs in use. I'm using this patch successfully: https://patchwork.kernel.org/project/linux-btrfs/patch/8dd1990114aabb775d4631969f1beabeadaac5b7.1707132247.git.anand.jain@oracle.com/ This is the latest patch discussed in the aforementioned kernel bugreport as of today: https://bugzilla.kernel.org/show_bug.cgi?id=218353
Should be resolved in linux 6.7.12.
