Re: [PATCH] block: fix blk_get_backing_dev_info() crash, use bdev->bd_queue

[Christoph Hellwig]

On Fri, Jan 06, 2017 at 11:23:30AM +0100, Jan Kara wrote:
> So what I think needs to be done is that we make backing_dev_info
> independently allocated structure with different lifetime rules to gendisk
> or request_queue - definitely I want it to live as long as block device
> inode exists. However it needs more thought what the exact lifetime rules
> will be.

Yes, moving the backing dev out (or keeping the request_queue memoery alive)
is something we need to do.  And we need to look into the other half
of the backing_dev life time isssues - we need to make sure the name
and sysfs resources are released as soon as the devices goes away so that
we aren't going to run into reuse races.