ufs: don't flush page immediately for DIRSYNC directories

ufs: don't flush page immediately for DIRSYNC directories

Patch series "remove most callers of write_one_page", v4.

This series removes most users of the write_one_page API.  These helpers
internally call ->writepage which we are gradually removing from the
kernel.

This patch (of 3):

We do not need to writeout modified directory blocks immediately when
modifying them while the page is locked.  It is enough to do the flush
somewhat later which has the added benefit that inode times can be flushed
as well.  It also allows us to stop depending on write_one_page()
function.

Ported from an ext2 patch by Jan Kara.

Link: https://lkml.kernel.org/r/20230307143125.27778-1-hch@lst.de
Link: https://lkml.kernel.org/r/20230307143125.27778-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Jan Kara via Ocfs2-devel <ocfs2-devel@oss.oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>