Commits
Trond Myklebust committed e231c6879cf
NFS: Fix a race between mmap() and O_DIRECT
When locking the file in order to do O_DIRECT on it, we must unmap
any mmapped ranges on the pagecache so that we can flush out the
dirty data.
Fixes: a5864c999de67 ("NFS: Do not serialise O_DIRECT reads and writes")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v4.8+