Here is another opportunity for all the sites with RedHat TAM's. -Connie Sieh ---------- Forwarded message ---------- Date: Fri, 23 Apr 2010 15:08:13 -0400 From: Marc Dionne <[log in to unmask]> Reply-To: [log in to unmask] To: [log in to unmask] Subject: [OpenAFS-announce] OpenAFS on Red Had Enterprise Linux 6 Red Hat has recently announced the availability of a beta version of its next Red Hat Enterprise Linux release (RHEL6). While OpenAFS is functional with this release, it generates a large volume of messages in the system log when used with a disk cache. Background The 2.6.32 kernel in RHEL6 enables IMA (Integrity Management Architecture). This feature uses counters to verify and require that certain operations on files be "balanced", and produces warnings in the syslog if they are not. OpenAFS uses dentry_open() to open disk cache files, and in 2.6.32 this function does not increment any IMA counters. Every caller is expected to also call ima_counts_get() to properly increment the counters and balance with the decrement that happens automatically in fput(). Unfortunately, ima_counts_get() is available only for GPL modules, which leaves non GPL modules with no way to use the dentry_open/fput combination correctly. As cache files are opened and closed repeatedly in OpenAFS, this generates a very large number of warnings in the system log. Fixes Kernel developers have acknowledged that this API is problematic, and it has been reworked in 2.6.33 and later, notably with these commits: 0552f879: Untangling ima mess, part 1: alloc_file() b65a9cfc: Untangling ima mess, part 2: deal with counters 1429b3ec: Untangling ima mess, part 3: kill dead code in ima These commits have not yet been backported to 2.6.32 and earlier stable kernels. If you have a support contract with Red Hat and care about running OpenAFS with RHEL 6, we encourage you to open a case through your support channel and inquire about getting these changes backported to RHEL 6. Thanks, Marc _______________________________________________ OpenAFS-announce mailing list [log in to unmask] https://lists.openafs.org/mailman/listinfo/openafs-announce