Re: [PATCH 0/5 v3] BDI lifetime fix

[Jens Axboe <axboe@kernel.dk>]

On 02/02/2017 07:56 AM, Jan Kara wrote:
> Hello,
> 
> this is the third version of the patch series that 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. I gave some basic testing to the patches in
> KVM and on a real machine, Dan was running them with libnvdimm test suite which
> was previously triggering the oops and things look good. So patches should be
> reasonably healthy.
> 
> Changes since v2:
> * Added Reviewed-by tags
> * Removed slab cache for backing_dev_info
> * Added patch to remove blkdev_get_backing_dev_info()
> 
> Changes since v1:
> * Use kref instead of atomic_t for refcount
> * Get rid of free_on_put flag

Added for 4.11, thanks Jan!

-- 
Jens Axboe