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: I5126e20ca1d6aeb71d4d66d14de277729fc8e89f
BUG: 866459
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/156
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Vijay Bellur <vbellur@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/1880

0 files changed, 0 insertions, 0 deletions