[CentOS] ext3_free_blocks_sb: bit already cleared for block

In an attempt to confirm this bug, I set up a system under KVM and
started three loops to generate filesystem activity. I ran bonnie++ as
two different users in separate directories under /var/tmp, and an
additional loop copying /usr to a directory under /var/tmp and then
removing it. The /var filesystem became corrupt relatively quickly.

I'm now nearly certain that there is a severe filesystem corruption bug
in 2.6.18-128.1.6.el5. Please, if you are running this kernel, reboot
your systems into single user mode and check your filesystems with "fsck
-f". Your filesystems may appear clean despite corruption. My test
system exhibited this behavior. Even though the corruption should have
been obvious (files could not be deleted), the FS was marked clean.

Just to be clear, this corruption appears on the HOST, not inside the KVM virtual machine?

Glenn

No, the host is Fedora 10. The KVM guest is CentOS 5.3 running kernel
2.6.18-128.1.6.el5. The filesystem activity caused corruption on the
filesystem being stressed (barely).

I've also seen corruption on a CentOS 5.3 install running on a physical
machine.

One of my friends is now attempting to reproduce the corruption on Red
Hat's release of the same package, and I'm trying to reproduce the
corruption on 2.6.18-128. I suggest that anyone using that kernel check
their filesystems and report any corruption that they find.