On Mon, Jul 20 2015 at 12:50pm -0400, Thanos Makatos <thanos.makatos@xxxxxxxxx> wrote: > I'm working on a back-ported dm-cache version for kernel 2.6.32-431.29.2 > (the CentOS 6 patched one) and I'm trying to solve a corruption bug > apparently introduced during the back-port. I can consistently reproduce it > by simply mounting an ext4 file-system that contains some data and running > stat(1) against a specific directory. stat(1) fails with "Input/output > error" and dmesg says:"EXT4-fs error (device dm-8): ext4_lookup: deleted > inode referenced: 29". The file-system is mounted with options > "data=writeback,ro,nodiscard,inode_readahead_blks=1" in order to minimise > noise. Upstream backports to RHEL6 are tricky because it doesn't have upstream's latest block changes. Care must be taken during the backport. I could easily see someone less aware of the pitfalls producing a buggy kernel that cause corruption like you've reported. The last dm-cache backport to RHEL6 was kernel-2.6.32-528.el6. That backport sync'd dm-cache changes through upstream Linux 3.19. I'm not going to put any time to this report. Your best bet is to rebase to the >= 528.el6 kernel and go from there (this translates to the forthcoming RHEL6.7 kernel as the first publicly available release with the changes in question). Mike -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
