LU-5502 ofd: add a high level description of the OFD layer

Add a high-level description of the OFD module to
lustre/ofd/ofd_dev.c.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: Id46a2d24ff2e2834e80e9d0f378ef2b515268bb3
Reviewed-on: http://review.whamcloud.com/11576
Tested-by: Jenkins
Reviewed-by: Ned Bass <bass6@llnl.gov>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
LU-1279 kernel: Fix concurrent module loading deadlocks

Concurrently starting multiple OSTs on a single OSS frequently
triggers 30s deadlocks on module_mutex.  This RHEL 6 kernel bug
applies to any module that results in additional request_module()
calls in its init callback.  In Lustre, at least ptlrpc and libcfs are
affected.  (RHEL 7 should have enough fixes in this area, but testing
needs to be done.)  This patch adds a fix adapted from a number of
upstream commits to the RHEL 6 kernel patch series.

Change-Id: Ibdd384fd7622a0b4fcbf4cb5fdb864de87fcc25e
Signed-off-by: Li Wei <wei.g.li@intel.com>
Reviewed-on: http://review.whamcloud.com/11229
Tested-by: Jenkins
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
LU-2675 lustre: remove linux/lprocfs_status.h

Remove lustre/include/linux/lprocfs_status.h. Include linux/statfs.h
where needed.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I4f5965fee6b82187a0f5f548843a2643b1438bc1
Reviewed-on: http://review.whamcloud.com/11489
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Emoly Liu <emoly.liu@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
LU-2675 lustre: remove linux/lustre_acl.h

Remove lustre/include/linux/lustre_acl.h. Include linux/xattr.h where
needed.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I1faec3acb8ff0b578a2f962a4601a44f17d65c41
Reviewed-on: http://review.whamcloud.com/11490
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: frank zago <fzago@cray.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>