June 1, 2026 at 5:37 AM, "Borja Tarraso" <[email protected] mailto:[email protected]?to=%22Borja%20Tarraso%22%20%3Cborja.tarraso%40member.fsf.org%3E > wrote:
> > Hi, > > On canonical Debian GNU/Hurd 0.9, an apt-get install of around > 14 MB of packages onto the underlying ext2fs /var reproducibly > trips an ext2fs translator assertion within a minute or two and > wedges the rootfs. Perhaps try again with the "ext3/4fs" that just landed, and see if the bug is still there...just a thought. > Reproducer: > > 1. Boot a canonical Debian GNU/Hurd 0.9 image (gnumach > 2:1.8+git20260224-8, hurd 1:0.9.git20251029-7+b1). /var is > mounted via /hurd/tmpfs (size 256M) by default and masks the > underlying ext2fs /var on the rootfs. > > 2. Drop the tmpfs to expose the underlying /var: > > settrans -fg /var > > 3. apt-install a multi-package set, for example: > > apt-get install -y --no-install-recommends \ > xvfb emacs-lucid elpa-exwm elpa-xelb pulseaudio > > dpkg unpacks a few packages and then the kernel log emits: > > ext2fs: ../../ext2fs/pager.c:455: > file_pager_write_pages: Assertion 'blk' failed. > > The translator does not recover; subsequent writes to / > hang and the VM has to be reset. > > The same install runs to completion against the /hurd/tmpfs > overlay (nothing persists in that case, of course). The rootfs > is well under any size limit (5 GB qcow2 with around 3.6 GB > free per df before the install). Reading pager.c around line > 455 the failing condition looks like an indirect-block lookup > returning zero for a block the pager is about to write out, > which on the face of it reads like a metadata coherency issue > between the inode block map and the pager's view of the dirty > page; I am not an ext2fs maintainer, so that reading may be > wrong. > > I would appreciate: > > - Confirmation that this reproduces, or a pointer if it is > a known bug already in flight. > - Guidance on whether the root cause sits in ext2fs's pager, > in inode block-map maintenance under the apt-install > workload, or upstream of both. > - If a patch exists or is planned, which release it lands in. > > Happy to test patches in a qemu loop, run the workload against > a debug build of ext2fs with extra logging, or send the full > serial trace if any of that helps. > > Alternative filing channel if a tracker entry is preferred: > https://savannah.gnu.org/bugs/?group=hurd > > Thanks, > Borja Tarraso > [email protected] mailto:[email protected] >
