On Wed, Jul 19, 2023 at 05:42:55PM -0400, Josef Bacik wrote: > More investigation, what's happening is dmsetup suspend is stuck because it's > waiting for outstanding io to finish, so these other IO's are stuck in the > deffered list for the linear mapping. I'm still getting to why the outstanding > IO's aren't going, I'll figure that out in the morning, but seems like this may > not be a btrfs problem. Thanks, I tried to bisect it based on my earlier observation that 6.5-rc2 wasn't affect, but at that point could not reproduce the hang any more. Overall the conditions seems very non-deterministic and might depend on the state and thus latency of the SSD or something like that. Instead of seen a bunch of unmount failures and then busy devices which clear up with another re-run..
