Re: [dm-devel] [PATCH 1/6] dm-stripe: drop kstriped

[Mike Snitzer <snitzer redhat com>]

On Sun, Dec 12 2010 at  2:10pm -0500,
Tejun Heo <tj kernel org> wrote:

> kstriped only serves sc->kstriped_ws which runs dm_table_event().
> This doesn't need to be executed from an ordered workqueue w/ rescuer.
> Drop kstriped and use the system_wq instead.

What might look unnecessary at first glance is a bit more nuanced than
we'd both like...

I'm concerned about switching to using the global system_wq and calling
flush_scheduled_work() when resuming a DM table (calls a DM target's
->dtr() via dm_table_destroy in drivers/md/dm-ioctl.c:do_resume).

This introduces potential for a DM table swap performing a storm of
additional unrelated works.

Definitely needs further review.

Mike