cifs: FS-Cache page management

Takes care of invalidation and release of FS-Cache marked pages and also
invalidation of the FsCache page flag when the inode is removed.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

diff --cc fs/cifs/cache.c
Simple merge

diff --cc fs/cifs/file.c
Simple merge

diff --cc fs/cifs/fscache.c
Simple merge

diff --cc fs/cifs/fscache.h
Simple merge