Hi All, this is just a question. I'm not asserting an openafs bug.
Since SL6, we have we have been using "kABI tracking kmods" for installing the OpenAFS kernel module on clients. For full information on this mechanism, see http://people.redhat.com/jcm/el6/dup/docs/dup_book.pdf . In short, you only have to compile and install the module once, and it will be used with future kernels as long as it doesn't use parts of the ABI that changed. Trying this may have been stupid in the first place. If so, happy bashing :-) But in practice, it has worked perfectly for a long time. The modules built against the EL6 GA kernel (2.6.32-71.el6) work fine with every released kernel up to the latest EL6.2 kernels (2.6.32-220.23.1.el6), on both 32-bit and 64-bit systems. But with the EL6.3 update (2.6.32-279.el5), something changed that broke at least the interface to the 32-bit module. The symptoms are reads getting stuck at the very beginning, except for very small files. The reads can be interrupted, but the client can no longer be stopped cleanly. Using a module built against the 6.3 kernel with pre-6.3 ones has worse effects. BUGs, panics, spontaneous reboots. All this was only observed on 32-bit systems, and only if the cache is on ext4. I have a suspicion that it might be related to a change described here: http://joejulian.name/blog/glusterfs-bit-by-ext4-structure-change/ . Quote: << a patch against ext4 to "return 32/64-bit dir name hash according to usage type". Prior to that, ext2/3/4 would return a 32-bit hash value from telldir()/seekdir() [. . .] That patch was for kernel v3.3-rc2. To make things more fun, [. . .] merged in that patch in 2.6.32-268.el6 >> The direct link to the patch is http://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=commit;h=d1f5273e9adb40724a85272f248f210dc4ce919a . Does anyone familiar withe the openafs module's inner workings see whether that patch would have the effects described above, on 32-bit systems only? Thanks a lot in advance for any insights. Stephan -- Stephan Wiesand DESY - DV - Platanenallee 6 15732 Zeuthen, Germany _______________________________________________ OpenAFS-devel mailing list [email protected] https://lists.openafs.org/mailman/listinfo/openafs-devel
