libglusterfs: Implement API that provides page-aligned iobufs

        Backport of: http://review.gluster.org/14672

One of the consumers of a page aligned buffer would be posix's
readv fop on O_DIRECT fds. Today the way it works is by getting
a page-aligned buffer through calloc, pread()ing into this buffer
and then copying its contents into a newly created iobuf's ptr.
This results in an extra memcpy() which can be avoided if we could
implement an api that would return an iobuf whose ptr is
page-aligned. That way the iobuf->ptr can be directly passed to
sys_pread() as a parameter by posix translator.

Change-Id: Ie44c300dc773fef8e1669d609987d47dbd340ac2
BUG: 1351024
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: http://review.gluster.org/14826
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Zhou Zhengping <johnzzpcrystal@gmail.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>

0 files changed, 0 insertions, 0 deletions