Populate post_op_attr with updated attributes after commit.

Ported from: 75eae985f14c0236beabf0fa3727469f289ec8f4

Signed-off-by: Srikrishan Malik <srimalik@in.ibm.com>
Signed-off-by: Frank Filz <ffilz@us.ibm.com>
Need content lock in write mode for open/close

Ported from: 6a850a0baeaebe5c354393197f8f2beac2571d19

Signed-off-by: Venkateswararao Jujjuri "<jvrao@linux.vnet.ibm.com>
Signed-off-by: Rong zeng <rongzeng@us.ibm.com>
Signed-off-by: Frank S. Filz <ffilz@us.ibm.com>
Remove wcc pre-attrs form Write and Commit Replies

Given that Ganesha need to make multiple calls to underlying filesystem
to perform write and then to get attributes, there is no way we can provide
accurate/atomic wcc pre-attrs. Because of this, the attr times on the client
side are not matching, resulting in invalidating client's cache. Removing
wcc pre-attrs in the Write and Commit replies, allows client to accurately
follow close-to-open semantics and keep the client cache sane.

Ported from: cc3af75fa4e8bd1668f0a967f6e7fb0a03261b20

Signed-off-by: Venkateswararao Jujjuri "<jvrao@linux.vnet.ibm.com>
Signed-off-by: Frank S. Filz <ffilz@us.ibm.com>
Update porting doc to indicate what I have completed

Signed-off-by: Frank S. Filz <ffilz@us.ibm.com>