b=6514

b=6514
r=adilger,green
originally by nikita

Severity   : major
Frequency  : rare (only unsupported configurations with a node running as an
             OST and a client)
Bugzilla   : 6514, 5137
Description: Mounting a Lustre file system on a node running as an OST could
             lead to deadlocks
Details    : OSTs now allocate memory needed to write out data at
             startup, instead of when needed, to avoid having to
             allocate memory in possibly low memory situations.
             Specifically, if the file system is mounted on on OST,
             memory pressure could force it to try to write out data,
             which it needed to allocate memory to do.  Due to the low
             memory, it would be unable to do so and the node would
             become unresponsive.