Alexey Lyashkov have troubles with accessing this jira and asked my to create this issue. Here is problem description from him:
RHEL6.5 have a backported a upstream commit 91dd8c114499e9818f2d5919ef0b9eee61810220, which broke a lustre extent handing on OFD. But Intel have a copy-paste unfixed code and use with RHEL 6.5 and up code. It's looks wrong as it have don't fixed a fiemap vs walk race while fiemap used in lustre code now (lustre commit - 144b5a65c16f1bca81ae76010528a592c821308b)
it may produce an predictable results with memory corruption.
attached patch backport a new api from kernel upstream already supported in lustre.
Bug
Major