On 6/30/25 5:42 PM, Keith Busch wrote:
On Mon, Jun 30, 2025 at 03:39:18PM -0700, Bart Van Assche wrote:
On 6/27/25 12:17 AM, Christoph Hellwig wrote:
Well, if there are queued never completed bios the freeze will obviously
fail. I don't see how this freeze is special vs other freezes or other
attributes that freeze.
Hi Christoph,
Do you perhaps want me to remove the freeze/unfreeze calls from all
sysfs store callbacks from which it is safe to remove these callbacks?
But don't the remaining attributes that are not safe remain susceptible
to this deadlock?
For the remaining sysfs attributes the deadlock can be solved by
letting the blk_mq_freeze_queue() call by the sysfs store methods time
out if that call takes too long or by making that call interruptible by
signals like Ctrl-C. I think its better to let functions like
queue_requests_store() fail if an attempt to freeze a request
queue takes longer than it should rather than to trigger a kernel
deadlock.
Bart.
