Description of problem: If device_write function is called via dlm-control, file->private_data will be NULL. See ctl_device_open() in user.c. Through proc->flags is read.
Proposed upstream patch: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=254ae43ab8d7877c980fca3636624e0777a70fa4
Created attachment 314042 [details] Upstream patch for this issue
in -77.
Verified that upstream patch 254ae43ab8d7877c980fca3636624e0777a70fa4 is implemented as commit 2636c514d9a35c7bf9d39f40c9c57849df90895d in mrt-rt-2.6.24.7-81
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2008-0857.html