On Wed, 2023-11-08 at 17:07 +0100, Johannes Berg wrote: > > From the backtrace in the removal logic, it seems that something waits > > for a debugfs file to be closed. > > Yes, debugfs remove waits for it to no longer have active users, but > that cannot succeed because the users are blocked on acquiring the > mutex. > > > Maybe the logic attempting to get the > > mutex in debugfs can check if file is waiting to be deleted, > > combined with a try-mutex-lock logic, and bail out that way? > > I don't know if there's a way to check that, but I'm also not sure how > you'd even implement that? Is it likely that we have lock contention for debugfs operations? If it is relatively unlikely, then maybe just doing a mutex_trylock() and immediately failing the operation with -EAGAIN could be a solution? Obviously userspace would need some retry logic, but that is simple and it could solve the delete problem. Benjamin
