diff options
| -rw-r--r-- | net/sunrpc/sched.c | 49 |
1 files changed, 21 insertions, 28 deletions
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index d95fe4e40eb4..f6eed4d4e5dd 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -58,7 +58,7 @@ static DECLARE_WAIT_QUEUE_HEAD(client_kill_wait); * rpciod-related stuff */ static DEFINE_MUTEX(rpciod_mutex); -static unsigned int rpciod_users; +static atomic_t rpciod_users = ATOMIC_INIT(0); struct workqueue_struct *rpciod_workqueue; /* @@ -1047,28 +1047,27 @@ rpciod_up(void) struct workqueue_struct *wq; int error = 0; + if (atomic_inc_not_zero(&rpciod_users)) + return 0; + mutex_lock(&rpciod_mutex); - dprintk("RPC: rpciod_up: users %u\n", rpciod_users); - rpciod_users++; - if (rpciod_workqueue) - goto out; - /* - * If there's no pid, we should be the first user. - */ - if (rpciod_users > 1) - printk(KERN_WARNING "rpciod_up: no workqueue, %u users??\n", rpciod_users); + + /* Guard against races with rpciod_down() */ + if (rpciod_workqueue != NULL) + goto out_ok; /* * Create the rpciod thread and wait for it to start. */ + dprintk("RPC: creating workqueue rpciod\n"); error = -ENOMEM; wq = create_workqueue("rpciod"); - if (wq == NULL) { - printk(KERN_WARNING "rpciod_up: create workqueue failed, error=%d\n", error); - rpciod_users--; + if (wq == NULL) goto out; - } + rpciod_workqueue = wq; error = 0; +out_ok: + atomic_inc(&rpciod_users); out: mutex_unlock(&rpciod_mutex); return error; @@ -1077,23 +1076,17 @@ out: void rpciod_down(void) { + if (!atomic_dec_and_test(&rpciod_users)) + return; + mutex_lock(&rpciod_mutex); - dprintk("RPC: rpciod_down sema %u\n", rpciod_users); - if (rpciod_users) { - if (--rpciod_users) - goto out; - } else - printk(KERN_WARNING "rpciod_down: no users??\n"); + dprintk("RPC: destroying workqueue rpciod\n"); - if (!rpciod_workqueue) { - dprintk("RPC: rpciod_down: Nothing to do!\n"); - goto out; + if (atomic_read(&rpciod_users) == 0 && rpciod_workqueue != NULL) { + rpciod_killall(); + destroy_workqueue(rpciod_workqueue); + rpciod_workqueue = NULL; } - rpciod_killall(); - - destroy_workqueue(rpciod_workqueue); - rpciod_workqueue = NULL; - out: mutex_unlock(&rpciod_mutex); } |