Re: [for-4.16 PATCH v6 2/4] block: properly protect the 'queue' kobj in blk_unregister_queue

2018-01-13 Thread Ming Lei
On Fri, Jan 12, 2018 at 11:03:52AM -0500, Mike Snitzer wrote: > The original commit e9a823fb34a8b (block: fix warning when I/O elevator > is changed as request_queue is being removed) is pretty conflated. > "conflated" because the resource being protected by q->sysfs_lock isn't > the queue_flags

[for-4.16 PATCH v6 2/4] block: properly protect the 'queue' kobj in blk_unregister_queue

2018-01-12 Thread Mike Snitzer
The original commit e9a823fb34a8b (block: fix warning when I/O elevator is changed as request_queue is being removed) is pretty conflated. "conflated" because the resource being protected by q->sysfs_lock isn't the queue_flags (it is the 'queue' kobj). q->sysfs_lock serializes __elevator_change()