[LU-30] improve & cleanup ldlm_handle_enqueue

Wed, 13 Feb 2019 06:55:25 +0000

current ldlm_handle_enqueue0 is a huge function, it's so big and too complex to read, I would like to cleanup it for some reasons:

just cleanup code and make it easier to understand
for MDT stack (non-replay request), the lock created in ldlm_handle_enqueue0 is not really necessary, mdt_intent_policy() will always create it's own lock and replace it (if we need to return a lock), we probably can't just ignore overhead of the redundant lock although it's never granted, especially for the case of many clients are accessing a shared directory at the same time.
- overhead of add/remove items to/from namespace::ns_rs_hash
- overhead of add/remove items to/from lustre-handle hash
- overhead of add/remove items to/from exp_lock_hash
- destroying lock need to content on ldlm_resource:lr_lock
- overhead of all kinds of counters
- overhead of memory allocate/free
some small bugs, i.e: bug 24324, which has been fixed, but I think there are some other small issues.

Whamcloud Community JIRA