From ed6473ddc704a2005b9900ca08e236ebb2d8540a Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 26 Apr 2017 11:55:27 -0400 Subject: NFSv4: Fix callback server shutdown We want to use kthread_stop() in order to ensure the threads are shut down before we tear down the nfs_callback_info in nfs_callback_down. Tested-and-reviewed-by: Kinglong Mee Reported-by: Kinglong Mee Fixes: bb6aeba736ba9 ("NFSv4.x: Switch to using svc_set_num_threads()...") Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields --- net/sunrpc/svc.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'net/sunrpc') diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index 98dc33ae738b..bc0f5a0ecbdc 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -795,6 +795,44 @@ svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) } EXPORT_SYMBOL_GPL(svc_set_num_threads); +/* destroy old threads */ +static int +svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) +{ + struct task_struct *task; + unsigned int state = serv->sv_nrthreads-1; + + /* destroy old threads */ + do { + task = choose_victim(serv, pool, &state); + if (task == NULL) + break; + kthread_stop(task); + nrservs++; + } while (nrservs < 0); + return 0; +} + +int +svc_set_num_threads_sync(struct svc_serv *serv, struct svc_pool *pool, int nrservs) +{ + if (pool == NULL) { + /* The -1 assumes caller has done a svc_get() */ + nrservs -= (serv->sv_nrthreads-1); + } else { + spin_lock_bh(&pool->sp_lock); + nrservs -= pool->sp_nrthreads; + spin_unlock_bh(&pool->sp_lock); + } + + if (nrservs > 0) + return svc_start_kthreads(serv, pool, nrservs); + if (nrservs < 0) + return svc_stop_kthreads(serv, pool, nrservs); + return 0; +} +EXPORT_SYMBOL_GPL(svc_set_num_threads_sync); + /* * Called from a server thread as it's exiting. Caller must hold the "service * mutex" for the service. -- cgit v1.2.3