search for: zbtrfs_txn_commit_phase_started

caching_thread()s do all their work under read access to extent_commit_sem. They give up on this read access only when need_resched() tells them, or when they exit. As a result, somebody that wants a WRITE access to this sem, might wait for a long time. Especially this is problematic in cache_block_group(), which can be called on critical paths like find_free_extent() and in commit path via