storage/posix: Make rchecksum O_DIRECT friendly

Problem:
When posix-aio is enabled to perform aio fd is set with O_DIRECT
whenever possible in read, writev fops. Rchecksum does not take
this into account. If either offset/size/memory-buf passed to
pread in rchecksum fop is not aligned, pread fails with EINVAL.

Fix:
Before doing pread necessary O_DIRECT manipulation is done when
aio is enabled. Memory buffer passed to pread is now page-aligned.

Test:
1) Create replica volume with aio enabled.
2) dd if=/dev/urandom of=a bs=1M count=1
3) kill one of the bricks in the replica pair
4) dd if=/dev/urandom of=a bs=1M count=1
5) bring back the brick. Self-heal succeeds after the change.

The test above checks both rchecksum, writev fops that were
changed in this patch.

Change-Id: I186099a2854d4864c5b48086ab7bc5f1a7b27313
BUG: 866459
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/4134
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

0 files changed, 0 insertions, 0 deletions