cifs: don't instantiate new dentries in readdir for inodes that need to be revalidated immediately

commit 757c4f6260febff982276818bb946df89c1105aa upstream.

David reported that commit c2b93e06 (cifs: only set ops for inodes in
I_NEW state) caused a regression with mfsymlinks. Prior to that patch,
if a mfsymlink dentry was instantiated at readdir time, the inode would
get a new set of ops when it was revalidated. After that patch, this
did not occur.

This patch addresses this by simply skipping instantiating dentries in
the readdir codepath when we know that they will need to be immediately
revalidated. The next attempt to use that dentry will cause a new lookup
to occur (which is basically what we want to happen anyway).

Change-Id: Icb32a3cad7a111d57eeade873bba66f205cfa11e
Cc: "Stefan (metze) Metzmacher" <metze@samba.org>
Cc: Sachin Prabhu <sprabhu@redhat.com>
Reported-and-Tested-by: David McBride <dwm37@cam.ac.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
[bwh: Backported to 3.2: need to return NULL]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ncpfs: fix rmdir returns Device or resource busy

commit 698b8223631472bf982ed570b0812faa61955683 upstream.

1d2ef5901483004d74947bbf78d5146c24038fe7 caused a regression in ncpfs such that
directories could no longer be removed.  This was because ncp_rmdir checked
to see if a dentry could be unhashed before allowing it to be removed. Since
1d2ef5901483004d74947bbf78d5146c24038fe7 introduced a change that incremented
dentry->d_count causing it to always be greater than 1 unhash would always
fail.  Thus causing the error path in ncp_rmdir to always be taken.  Removing
this error path is safe as unhashing is still accomplished by calls to dput
from vfs_rmdir.

Change-Id: Iea5c58d4c14b56b9a950207c54f42c122700f53d
Signed-off-by: Dave Chiluk <chiluk@canonical.com>
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>