On Thu, Jan 26, 2017 at 9:45 AM, Jan Kara <[email protected]> wrote:
> Hello,
>
> this patch series attempts to solve the problems with the life time of a
> backing_dev_info structure. Currently it lives inside request_queue structure
> and thus it gets destroyed as soon as request queue goes away. However
> the block device inode still stays around and thus inode_to_bdi() call on
> that inode (e.g. from flusher worker) may happen after request queue has been
> destroyed resulting in oops.
>
> This patch set tries to solve these problems by making backing_dev_info
> independent structure referenced from block device inode. That makes sure
> inode_to_bdi() cannot ever oops. The patches are lightly tested for now
> (they boot, basic tests with adding & removing loop devices seem to do what
> I'd expect them to do ;). If someone is able to reproduce crashes on bdi
> when device goes away, please test these patches.

This survives a several runs of the libnvdimm unit tests which stress
del_gendisk() and blk_cleanup_queue(). I'll keep testing since the
failure was intermittent, but this is looking good.

> I'd also appreciate if people had a look whether the approach I took looks
> sensible.

Looks sensible, just the kref comment.

I also don't see a need to try to tag on the bdi device name reuse
into this series. I'm wondering if we can handle that separately with
device_rename(bdi->dev, ...) when we know scsi is done with the old
bdi but it has not finished being deleted
--
To unsubscribe from this list: send the line "unsubscribe linux-block" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to