Re: What trigge fsync of file on last close of the open inode?

[Zach Brown <zach.brown@oracle.com>]

Steve French wrote:
> Dave Kleikamp wrote:
>>> Someone had reported a problem with a writepages call coming in on
>>> with no open files (so presumably the file was closed, with dirty
>>> pages not written).

So is the problem that you're getting a cifs_writepages() call after
cifs_close() returns?

fwiw, 9 out of 10 brains would be less confused if cifs_close() was
called cifs_release().

> May be a case in which filemap_fdatawrite returns before the write(s) is
> sent to the vfs and write races with close (although cifs will defer a
> file close if a write is pending on that handle)?

Are writes to mmap()ed regions involved at all?  They lead to pages
being dirtied at unmapping and eventually hitting ->writepage,
potentially after ->flush and ->release have been called.

I imagine you could force writeback of dirty pages in ->release so that
you don't wait for writeback to come around and hit them.  Heck, it
might be doing this already.  I didn't look very hard :).

- z