Messages in this thread | | | Subject | Re: [PATCH 3/5] blktrace: refcount the request_queue during ioctl | From | Bart Van Assche <> | Date | Wed, 15 Apr 2020 20:43:32 -0700 |
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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.
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