On Wed, Sep 12, 2018 at 10:45:45AM -0400, Josef Bacik wrote: > While testing my backport I noticed there was a panic if I ran > generic/416 generic/417 generic/418 all in a row. This just happened to > uncover a race where we had outstanding IO after we destroy all of our > workqueues, and then we'd go to queue the endio work on those free'd > workqueues. This is because we aren't waiting for the caching threads > to be done before freeing everything up, so to fix this make sure we > wait on any outstanding caching that's being done before we free up the > block group, so we're sure to be done with all IO by the time we get to > btrfs_stop_all_workers(). This fixes the panic I was seeing > consistently in testing. Can you please attach the stacktrace(s)? I think I've seen similar error once or twice but not able to reproduce.
