commit d5880c7a8620290a6c90ced7a0e8bd0ad9419601 upstream.

unlock_page() was missing in case of an already in-flight write against the
same page.
Signed-off-by: NVasily Averin <vvs@virtuozzo.com>
Fixes: ff17be08 ("fuse: writepage: skip already in flight")
Cc: <stable@vger.kernel.org> # v3.13
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>