On Thu, Jan 26, 2017 at 10:15:06PM -0800, Dan Williams wrote: > On Thu, Jan 26, 2017 at 9:45 AM, Jan Kara <jack@xxxxxxx> 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 What's the status of the device name issue? We're hitting it a lot here. It's really easy to reproduce with scsi_debug, script attached. I'd be happy to test out any patches.
Attachment:
stress_test_scsi_debug.sh
Description: Bourne shell script
