2009-12-21

Bad, bad Linux kernel!

Ever since Linux kernel 2.6.31 was released, my AMD Geode LX800-based FIC ION 603 can no longer boot; I get a fatal kernel crash near the end of the initramfs loading phase. At the crux of the issue seems to be a recently added kernel feature for caching filesystem ACL. I don't even use the ACL feature on my hosts, but there you go; it still crashes the kernel. Sigh.

Having filed a bug on Launchpad and reported the issue upstream failed to produce a fix - despite the sustained involvement of two members of the Ubuntu kernel team members to help me narrow down the cause of this fatal kernel crash.

Mentioning the issue to OLPC kernel developer Andres Salomon, he commented how he finds the new ACL caching code in the ext2/ext3/ext4 filesystem drivers downright creepy, but added that he currently lacks the time to further investigate the issue.

I'm thus wondering if anyone else is experiencing this issue and might possibly have a fix to propose?

Alternately, help towards debugging and fixing this issue is extremely welcome, as this bug will seriously affect users upgrading from older Debian and Ubuntu releases based on pre-2.6.31 kernels, when Debian/Squeeze and Ubuntu/Lucid are published in spring.

PS: yes, the issue still exists in kernel 2.6.32 also.