This reverts commit b87c397091bac6a4a6dec4e45a7671fad4a11770.

There seems to be some performance regression with the patch and hence recommended to have it reverted.

Updates: #325
Change-Id: Id85d6203173a44fad6cf51d39b3e96f37afcec09

The current implementation of iobuf_pool has two problems:
- prealloc of 12.5MB memory, this limits the scale factor of the gluster
  processes due to RAM requirements
- lock contention, as the current implementation has one global
  iobuf_pool lock. Credits for debugging and addressing the same goes to
  Krutika Dhananjay <kdhananj@redhat.com>. Issue: #410

Hence changing the iobuf implementation to use per thread mem pool.
This may theoritically appear to cause perf dip as there is no preallocation.
But per thread mem pool will not have significant perf impact as the last
allocated memory is kept alive for subsequent allocs, for some time.
The worst case would be if iobufs requested are of random sizes each time.
The best case is, if we get iobuf request of the same size. From the perf
tests, this patch did not seem to cause any perf decrease.

Note that, with this patch, the rdma performance is going to degrade
drastically. In one of the previous patchsets we had fixes to not
degrade rdma perf, but rdma is not supported and also not tested [1].
Hence the decision was to not have code in rdma that is not tested
and not supported.

[1] https://lists.gluster.org/pipermail/gluster-users.old/2018-July/034400.html

Updates: #325
Change-Id: Ic2ef3bd498f9250dea25f25ba0c01fde19584b27
Signed-off-by: Poornima G <pgurusid@redhat.com>

libglusterfs devel package headers are referenced in code using
include semantics for a program, this while it works can be better
especially when dealing with out of tree xlator builds or in
general out of tree devel package usage.

Towards this, the following changes are done,
- moved all devel headers under a glusterfs directory
- Included these headers using system header notation <> in all
code outside of libglusterfs
- Included these headers using own program notation "" within
libglusterfs

This change although big, is just moving around the headers and
making it correct when including these headers from other sources.

This helps us correctly include libglusterfs includes without
namespace conflicts.

Change-Id: Id2a98854e671a7ee5d73be44da5ba1a74252423b
Updates: bz#1193929
Signed-off-by: ShyamsundarR <srangana@redhat.com>