libglusterfs: Implement API that provides page-aligned iobufs

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: I385139bc6ee309fc501034b3af8f7814fab8cd65
BUG: 1343838
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: http://review.gluster.org/14672
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Zhou Zhengping <johnzzpcrystal@gmail.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>

0 files changed, 0 insertions, 0 deletions