smb3: missing inode locks in punch hole

smb3: missing inode locks in punch hole

BugLink: https://bugs.launchpad.net/bugs/1991717
commit ba0803050d610d5072666be727bca5e03e55b242 upstream.

smb3 fallocate punch hole was not grabbing the inode or filemap_invalidate
locks so could have race with pagemap reinstantiating the page.

Cc: stable@vger.kernel.org
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>