[NFS-Ganesha-Devel] Hitting a crash in mdcache_lru_cleanup_push.

Hello Daniel/Frank, While debugging a crash from 2.7.1 Ganesha, I see a potential race between the two paths below: Thread 1 (waiting for the qlock to insert to LRU) nfs4_mds_putfh -> mdcache_create_handle -> mdcache_locate_host -> mdcache_new_entry -> mdcache_lru_insert -> lru_insert_entry Thread 2 (unlink the same object) - since the object is already in mdcache at this point, I believe other threads will get it. fsal_remove -> mdcache_unlink -> _mdc_unreachable -> _mdcache_kill_entry -> mdcache_lru_cleanup_push The second thread will find the lru something like this: $5 = {q = {next = 0x0, prev = 0x0}, qid = LRU_ENTRY_NONE, refcnt = 2, flags = 0, lane = 12, cf = 0} So, the below code will end up crashing: if (!(lru->qid == LRU_ENTRY_CLEANUP)) { struct lru_q *q; /* out with the old queue */ q = lru_queue_of(entry); <<-- q will be NULL because qid == LRU_ENTRY_NONE Should Thread 2 just ignore if q is NULL and let Thread1's operation to free the entry later? Also, please let me know if there is any recent fixes in this area. Thanks, Pradeep