Re: [PATCH] blkcg: add rcu lock to bio_clone_blkg_association()

[Jens Axboe]

On 12/21/18 7:54 AM, Dennis Zhou wrote:
> I cleaned up blkg_tryget_closest() to require rcu_read_lock() earlier.
> However, this was a subtle case too which clearly was too subtle for me.
> The idea was the src bio should be holding a ref to the blkg so rcu
> wasn't technically needed. If it doesn't hold a ref, it should be %NULL
> and the blkg->parent pointers are unused.
> 
> This adds the appropriate read lock in bio_clone_blkg_association().

Shall I just fold this with the previous? I staged it in a
later-in-merge-cycle branch, so that's not an issue to amend.

-- 
Jens Axboe