From ec28e02ca5f2a4287c19c585f8be2d9b3ba123ea Mon Sep 17 00:00:00 2001 From: Stanislav Kinsbursky Date: Wed, 21 Nov 2012 18:07:38 +0300 Subject: [PATCH] nfsd4: remove state lock from nfs4_state_shutdown Protection of __nfs4_state_shutdown() with nfs4_lock_state() looks redundant. This function is called by the last NFSd thread on it's exit and state lock protects actually two functions (del_recall_lru is protected by recall_lock): 1) nfsd4_client_tracking_exit 2) __nfs4_state_shutdown_net "nfsd4_client_tracking_exit" doesn't require state lock protection, because it's state can be modified only by tracker callbacks. Here a re they: 1) create: is called only from nfsd4_proc_compound. 2) remove: is called from either nfsd4_proc_compound or nfs4_laundromat. 3) check: is called only from nfsd4_proc_compound. 4) grace_done; called only from nfs4_laundromat. nfsd4_proc_compound is called onll by NFSd kthread, which is exiting right now. nfs4_laundromat is called by laundry_wq. But laundromat_work was canceled already. "__nfs4_state_shutdown_net" also doesn't require state lock protection, because all NFSd kthreads are dead, and no race can happen with NFSd start, because "nfsd_up" flag is still set. Moreover, all Nfsd shutdown is protected with global nfsd_mutex. Signed-off-by: Stanislav Kinsbursky Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 41d2aed8ed06..ffec73cdfaca 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4930,9 +4930,7 @@ nfs4_state_shutdown(void) cancel_delayed_work_sync(&nn->laundromat_work); destroy_workqueue(laundry_wq); locks_end_grace(&nn->nfsd4_manager); - nfs4_lock_state(); __nfs4_state_shutdown(net); - nfs4_unlock_state(); nfsd4_destroy_callback_queue(); } -- 2.20.1