ext4: pass -ESHUTDOWN code to jbd2 layer

ext4: pass -ESHUTDOWN code to jbd2 layer

commit fb7c02445c497943e7296cd3deee04422b63acb8 upstream.

Previously the jbd2 layer assumed that a file system check would be
required after a journal abort.  In the case of the deliberate file
system shutdown, this should not be necessary.  Allow the jbd2 layer
to distinguish between these two cases by using the ESHUTDOWN errno.

Also add proper locking to __journal_abort_soft().

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>