On 2020-04-15 18:12, Luis Chamberlain wrote: > On Wed, Apr 15, 2020 at 07:18:22AM -0700, Bart Van Assche wrote: >> blk_get_queue() prevents concurrent freeing of struct request_queue but >> does not prevent concurrent blk_cleanup_queue() calls. > > Wouldn't concurrent blk_cleanup_queue() calls be a bug? If so should > I make it clear that it would be or simply prevent it? I think calling blk_cleanup_queue() while the queue refcount > 0 is well established behavior. At least the SCSI core triggers that behavior since a very long time. I prefer not to change that behavior. Regarding patch 3/5: how about dropping that patch? If the queue refcount can drop to zero while blk_trace_ioctl() is in progress I think that should be fixed in the block_device_operations.open callback instead of in blk_trace_ioctl(). Thanks, Bart.
