Return NFS4ERR_ROFS for NFS v4 open for write on read-only export

Ported from 1.5 3c179ffba7d4c2318cc7540796229edf23ab724b

Signed-off-by: Frank S. Filz <ffilzlnx@mindspring.com>
Return NFS4ERR_NOENT instead of NFS4ERR_ACCESS on export client has no access to

If a client doesn't have any access to an EXPORT (is not listed in any
Access list for the EXPORT or covered by any wild card), we already
hide that export in READDIR. We should also return NFS4ERR_NOENT rather
than NFS4ERR_ACCESS to match.

Ported from 1.5 cee1437b2d0890f7da1a107991d6b86a37af57d5

Signed-off-by: Frank S. Filz <ffilzlnx@mindspring.com>
Make SECINFO not always return NFS4ERR_WRONGSEC

Signed-off-by: Frank S. Filz <ffilzlnx@mindspring.com>
Handle errors in PseudoFS READDIR and LOOKUP gracefully

If there is a problem with a junction, we should handle it gracefully,
not bomb out the whole READDIR, In this case, we skip the entry.

This could occur because the exported directory has been removed or
the attributes could not be fetched. There are permissions fixes that
will prevent the ACE4_READ_ATTR from blocking reading attributes
though ACE4_READ_ACL could still come into play if a client did a
READDIR asking for ACLs (which I don't expect will ever be done).

Also, return more sensible errors in other places.

Ported from 1.5 dd054f1d38dea6d82c5643af28569e27c226853e

Fixed up a some additional error handling.

Signed-off-by: Frank S. Filz <ffilzlnx@mindspring.com>
Make NFSv3 FSID unique/less collision prone
By performing xor on filesystem_id major and rotated minor numbers.
This allows client to mount one export on top of other even if the
major numbers of the exported filesystem is same.

Ported from 1.5 b78bb90a389beaaf5381397ece37c75748c92e1b

Signed-off-by: Venkateswararao Jujjuri "<jvrao@linux.vnet.ibm.com>
Signed-off-by: Frank S. Filz <ffilzlnx@mindspring.com>
Multilock tool: Fix for using it with AIX.
Signed-off-by: suhrud <supatank@in.ibm.com>
Update porting doc to reflect EXP work mostly completed and up to 1.5.0.rev13

Signed-off-by: Frank S. Filz <ffilzlnx@mindspring.com>