SUNRPC: One more clean up for rpc_create_client_dir()
[safe/jmp/linux-2.6] / net / sunrpc / sched.c
index 35acdc3..8f459ab 100644 (file)
@@ -16,7 +16,6 @@
 #include <linux/slab.h>
 #include <linux/mempool.h>
 #include <linux/smp.h>
-#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 #include <linux/mutex.h>
 
@@ -40,6 +39,7 @@ static mempool_t      *rpc_buffer_mempool __read_mostly;
 
 static void                    rpc_async_schedule(struct work_struct *);
 static void                     rpc_release_task(struct rpc_task *task);
+static void __rpc_queue_timer_fn(unsigned long ptr);
 
 /*
  * RPC tasks sit here while waiting for conditions to improve.
@@ -56,29 +56,30 @@ struct workqueue_struct *rpciod_workqueue;
  * queue->lock and bh_disabled in order to avoid races within
  * rpc_run_timer().
  */
-static inline void
-__rpc_disable_timer(struct rpc_task *task)
+static void
+__rpc_disable_timer(struct rpc_wait_queue *queue, struct rpc_task *task)
 {
+       if (task->tk_timeout == 0)
+               return;
        dprintk("RPC: %5u disabling timer\n", task->tk_pid);
-       task->tk_timeout_fn = NULL;
        task->tk_timeout = 0;
+       list_del(&task->u.tk_wait.timer_list);
+       if (list_empty(&queue->timer_list.list))
+               del_timer(&queue->timer_list.timer);
 }
 
-/*
- * Default timeout handler if none specified by user
- */
 static void
-__rpc_default_timer(struct rpc_task *task)
+rpc_set_queue_timer(struct rpc_wait_queue *queue, unsigned long expires)
 {
-       dprintk("RPC: %5u timeout (default timer)\n", task->tk_pid);
-       task->tk_status = -ETIMEDOUT;
+       queue->timer_list.expires = expires;
+       mod_timer(&queue->timer_list.timer, expires);
 }
 
 /*
  * Set up a timer for the current task.
  */
-static inline void
-__rpc_add_timer(struct rpc_task *task, rpc_action timer)
+static void
+__rpc_add_timer(struct rpc_wait_queue *queue, struct rpc_task *task)
 {
        if (!task->tk_timeout)
                return;
@@ -86,27 +87,10 @@ __rpc_add_timer(struct rpc_task *task, rpc_action timer)
        dprintk("RPC: %5u setting alarm for %lu ms\n",
                        task->tk_pid, task->tk_timeout * 1000 / HZ);
 
-       if (timer)
-               task->tk_timeout_fn = timer;
-       else
-               task->tk_timeout_fn = __rpc_default_timer;
-       set_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
-       mod_timer(&task->tk_timer, jiffies + task->tk_timeout);
-}
-
-/*
- * Delete any timer for the current task. Because we use del_timer_sync(),
- * this function should never be called while holding queue->lock.
- */
-static void
-rpc_delete_timer(struct rpc_task *task)
-{
-       if (RPC_IS_QUEUED(task))
-               return;
-       if (test_and_clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate)) {
-               del_singleshot_timer_sync(&task->tk_timer);
-               dprintk("RPC: %5u deleting timer\n", task->tk_pid);
-       }
+       task->u.tk_wait.expires = jiffies + task->tk_timeout;
+       if (list_empty(&queue->timer_list.list) || time_before(task->u.tk_wait.expires, queue->timer_list.expires))
+               rpc_set_queue_timer(queue, task->u.tk_wait.expires);
+       list_add(&task->u.tk_wait.timer_list, &queue->timer_list.list);
 }
 
 /*
@@ -168,7 +152,6 @@ static void __rpc_remove_wait_queue_priority(struct rpc_task *task)
                list_move(&t->u.tk_wait.list, &task->u.tk_wait.list);
                list_splice_init(&task->u.tk_wait.links, &t->u.tk_wait.links);
        }
-       list_del(&task->u.tk_wait.list);
 }
 
 /*
@@ -177,10 +160,10 @@ static void __rpc_remove_wait_queue_priority(struct rpc_task *task)
  */
 static void __rpc_remove_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task)
 {
+       __rpc_disable_timer(queue, task);
        if (RPC_IS_PRIORITY(queue))
                __rpc_remove_wait_queue_priority(task);
-       else
-               list_del(&task->u.tk_wait.list);
+       list_del(&task->u.tk_wait.list);
        queue->qlen--;
        dprintk("RPC: %5u removed from queue %p \"%s\"\n",
                        task->tk_pid, queue, rpc_qname(queue));
@@ -213,6 +196,9 @@ static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const c
                INIT_LIST_HEAD(&queue->tasks[i]);
        queue->maxpriority = nr_queues - 1;
        rpc_reset_waitqueue_priority(queue);
+       queue->qlen = 0;
+       setup_timer(&queue->timer_list.timer, __rpc_queue_timer_fn, (unsigned long)queue);
+       INIT_LIST_HEAD(&queue->timer_list.list);
 #ifdef RPC_DEBUG
        queue->name = qname;
 #endif
@@ -229,6 +215,12 @@ void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname)
 }
 EXPORT_SYMBOL_GPL(rpc_init_wait_queue);
 
+void rpc_destroy_wait_queue(struct rpc_wait_queue *queue)
+{
+       del_timer_sync(&queue->timer_list.timer);
+}
+EXPORT_SYMBOL_GPL(rpc_destroy_wait_queue);
+
 static int rpc_wait_bit_killable(void *word)
 {
        if (fatal_signal_pending(current))
@@ -297,15 +289,9 @@ EXPORT_SYMBOL_GPL(__rpc_wait_for_completion_task);
  */
 static void rpc_make_runnable(struct rpc_task *task)
 {
-       BUG_ON(task->tk_timeout_fn);
        rpc_clear_queued(task);
        if (rpc_test_and_set_running(task))
                return;
-       /* We might have raced */
-       if (RPC_IS_QUEUED(task)) {
-               rpc_clear_running(task);
-               return;
-       }
        if (RPC_IS_ASYNC(task)) {
                int status;
 
@@ -327,7 +313,7 @@ static void rpc_make_runnable(struct rpc_task *task)
  * as it's on a wait queue.
  */
 static void __rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
-                       rpc_action action, rpc_action timer)
+                       rpc_action action)
 {
        dprintk("RPC: %5u sleep_on(queue \"%s\" time %lu)\n",
                        task->tk_pid, rpc_qname(q), jiffies);
@@ -341,11 +327,11 @@ static void __rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
 
        BUG_ON(task->tk_callback != NULL);
        task->tk_callback = action;
-       __rpc_add_timer(task, timer);
+       __rpc_add_timer(q, task);
 }
 
 void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
-                               rpc_action action, rpc_action timer)
+                               rpc_action action)
 {
        /* Mark the task as being activated if so needed */
        rpc_set_active(task);
@@ -354,7 +340,7 @@ void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
         * Protect the queue operations.
         */
        spin_lock_bh(&q->lock);
-       __rpc_sleep_on(q, task, action, timer);
+       __rpc_sleep_on(q, task, action);
        spin_unlock_bh(&q->lock);
 }
 EXPORT_SYMBOL_GPL(rpc_sleep_on);
@@ -380,7 +366,6 @@ static void __rpc_do_wake_up_task(struct rpc_wait_queue *queue, struct rpc_task
                return;
        }
 
-       __rpc_disable_timer(task);
        __rpc_remove_wait_queue(queue, task);
 
        rpc_make_runnable(task);
@@ -393,12 +378,8 @@ static void __rpc_do_wake_up_task(struct rpc_wait_queue *queue, struct rpc_task
  */
 static void rpc_wake_up_task_queue_locked(struct rpc_wait_queue *queue, struct rpc_task *task)
 {
-       if (!RPC_IS_QUEUED(task) || task->tk_waitqueue != queue)
-               return;
-       if (rpc_start_wakeup(task)) {
-                       __rpc_do_wake_up_task(queue, task);
-               rpc_finish_wakeup(task);
-       }
+       if (RPC_IS_QUEUED(task) && task->tk_waitqueue == queue)
+               __rpc_do_wake_up_task(queue, task);
 }
 
 /*
@@ -406,11 +387,9 @@ static void rpc_wake_up_task_queue_locked(struct rpc_wait_queue *queue, struct r
  */
 void rpc_wake_up_queued_task(struct rpc_wait_queue *queue, struct rpc_task *task)
 {
-       rcu_read_lock_bh();
-       spin_lock(&queue->lock);
+       spin_lock_bh(&queue->lock);
        rpc_wake_up_task_queue_locked(queue, task);
-       spin_unlock(&queue->lock);
-       rcu_read_unlock_bh();
+       spin_unlock_bh(&queue->lock);
 }
 EXPORT_SYMBOL_GPL(rpc_wake_up_queued_task);
 
@@ -483,16 +462,14 @@ struct rpc_task * rpc_wake_up_next(struct rpc_wait_queue *queue)
 
        dprintk("RPC:       wake_up_next(%p \"%s\")\n",
                        queue, rpc_qname(queue));
-       rcu_read_lock_bh();
-       spin_lock(&queue->lock);
+       spin_lock_bh(&queue->lock);
        if (RPC_IS_PRIORITY(queue))
                task = __rpc_wake_up_next_priority(queue);
        else {
                task_for_first(task, &queue->tasks[0])
                        rpc_wake_up_task_queue_locked(queue, task);
        }
-       spin_unlock(&queue->lock);
-       rcu_read_unlock_bh();
+       spin_unlock_bh(&queue->lock);
 
        return task;
 }
@@ -509,8 +486,7 @@ void rpc_wake_up(struct rpc_wait_queue *queue)
        struct rpc_task *task, *next;
        struct list_head *head;
 
-       rcu_read_lock_bh();
-       spin_lock(&queue->lock);
+       spin_lock_bh(&queue->lock);
        head = &queue->tasks[queue->maxpriority];
        for (;;) {
                list_for_each_entry_safe(task, next, head, u.tk_wait.list)
@@ -519,8 +495,7 @@ void rpc_wake_up(struct rpc_wait_queue *queue)
                        break;
                head--;
        }
-       spin_unlock(&queue->lock);
-       rcu_read_unlock_bh();
+       spin_unlock_bh(&queue->lock);
 }
 EXPORT_SYMBOL_GPL(rpc_wake_up);
 
@@ -536,8 +511,7 @@ void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
        struct rpc_task *task, *next;
        struct list_head *head;
 
-       rcu_read_lock_bh();
-       spin_lock(&queue->lock);
+       spin_lock_bh(&queue->lock);
        head = &queue->tasks[queue->maxpriority];
        for (;;) {
                list_for_each_entry_safe(task, next, head, u.tk_wait.list) {
@@ -548,38 +522,37 @@ void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
                        break;
                head--;
        }
-       spin_unlock(&queue->lock);
-       rcu_read_unlock_bh();
+       spin_unlock_bh(&queue->lock);
 }
 EXPORT_SYMBOL_GPL(rpc_wake_up_status);
 
-/*
- * Run a timeout function.
- */
-static void rpc_run_timer(unsigned long ptr)
+static void __rpc_queue_timer_fn(unsigned long ptr)
 {
-       struct rpc_task *task = (struct rpc_task *)ptr;
-       void (*callback)(struct rpc_task *);
-
-       if (RPC_IS_QUEUED(task)) {
-               struct rpc_wait_queue *queue = task->tk_waitqueue;
-               callback = task->tk_timeout_fn;
-
-               dprintk("RPC: %5u running timer\n", task->tk_pid);
-               if (callback != NULL)
-                       callback(task);
-               /* Note: we're already in a bh-safe context */
-               spin_lock(&queue->lock);
-               rpc_wake_up_task_queue_locked(queue, task);
-               spin_unlock(&queue->lock);
+       struct rpc_wait_queue *queue = (struct rpc_wait_queue *)ptr;
+       struct rpc_task *task, *n;
+       unsigned long expires, now, timeo;
+
+       spin_lock(&queue->lock);
+       expires = now = jiffies;
+       list_for_each_entry_safe(task, n, &queue->timer_list.list, u.tk_wait.timer_list) {
+               timeo = task->u.tk_wait.expires;
+               if (time_after_eq(now, timeo)) {
+                       dprintk("RPC: %5u timeout\n", task->tk_pid);
+                       task->tk_status = -ETIMEDOUT;
+                       rpc_wake_up_task_queue_locked(queue, task);
+                       continue;
+               }
+               if (expires == now || time_after(expires, timeo))
+                       expires = timeo;
        }
-       smp_mb__before_clear_bit();
-       clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
-       smp_mb__after_clear_bit();
+       if (!list_empty(&queue->timer_list.list))
+               rpc_set_queue_timer(queue, expires);
+       spin_unlock(&queue->lock);
 }
 
 static void __rpc_atrun(struct rpc_task *task)
 {
+       task->tk_status = 0;
 }
 
 /*
@@ -588,18 +561,16 @@ static void __rpc_atrun(struct rpc_task *task)
 void rpc_delay(struct rpc_task *task, unsigned long delay)
 {
        task->tk_timeout = delay;
-       rpc_sleep_on(&delay_queue, task, NULL, __rpc_atrun);
+       rpc_sleep_on(&delay_queue, task, __rpc_atrun);
 }
 EXPORT_SYMBOL_GPL(rpc_delay);
 
 /*
  * Helper to call task->tk_ops->rpc_call_prepare
  */
-static void rpc_prepare_task(struct rpc_task *task)
+void rpc_prepare_task(struct rpc_task *task)
 {
-       lock_kernel();
        task->tk_ops->rpc_call_prepare(task, task->tk_calldata);
-       unlock_kernel();
 }
 
 /*
@@ -609,9 +580,7 @@ void rpc_exit_task(struct rpc_task *task)
 {
        task->tk_action = NULL;
        if (task->tk_ops->rpc_call_done != NULL) {
-               lock_kernel();
                task->tk_ops->rpc_call_done(task, task->tk_calldata);
-               unlock_kernel();
                if (task->tk_action != NULL) {
                        WARN_ON(RPC_ASSASSINATED(task));
                        /* Always release the RPC slot and buffer memory */
@@ -623,11 +592,8 @@ EXPORT_SYMBOL_GPL(rpc_exit_task);
 
 void rpc_release_calldata(const struct rpc_call_ops *ops, void *calldata)
 {
-       if (ops->rpc_release != NULL) {
-               lock_kernel();
+       if (ops->rpc_release != NULL)
                ops->rpc_release(calldata);
-               unlock_kernel();
-       }
 }
 
 /*
@@ -635,7 +601,9 @@ void rpc_release_calldata(const struct rpc_call_ops *ops, void *calldata)
  */
 static void __rpc_execute(struct rpc_task *task)
 {
-       int             status = 0;
+       struct rpc_wait_queue *queue;
+       int task_is_async = RPC_IS_ASYNC(task);
+       int status = 0;
 
        dprintk("RPC: %5u __rpc_execute flags=0x%x\n",
                        task->tk_pid, task->tk_flags);
@@ -643,27 +611,19 @@ static void __rpc_execute(struct rpc_task *task)
        BUG_ON(RPC_IS_QUEUED(task));
 
        for (;;) {
-               /*
-                * Garbage collection of pending timers...
-                */
-               rpc_delete_timer(task);
 
                /*
                 * Execute any pending callback.
                 */
-               if (RPC_DO_CALLBACK(task)) {
-                       /* Define a callback save pointer */
+               if (task->tk_callback) {
                        void (*save_callback)(struct rpc_task *);
 
                        /*
-                        * If a callback exists, save it, reset it,
-                        * call it.
-                        * The save is needed to stop from resetting
-                        * another callback set within the callback handler
-                        * - Dave
+                        * We set tk_callback to NULL before calling it,
+                        * in case it sets the tk_callback field itself:
                         */
-                       save_callback=task->tk_callback;
-                       task->tk_callback=NULL;
+                       save_callback = task->tk_callback;
+                       task->tk_callback = NULL;
                        save_callback(task);
                }
 
@@ -683,15 +643,25 @@ static void __rpc_execute(struct rpc_task *task)
                 */
                if (!RPC_IS_QUEUED(task))
                        continue;
-               rpc_clear_running(task);
-               if (RPC_IS_ASYNC(task)) {
-                       /* Careful! we may have raced... */
-                       if (RPC_IS_QUEUED(task))
-                               return;
-                       if (rpc_test_and_set_running(task))
-                               return;
+               /*
+                * The queue->lock protects against races with
+                * rpc_make_runnable().
+                *
+                * Note that once we clear RPC_TASK_RUNNING on an asynchronous
+                * rpc_task, rpc_make_runnable() can assign it to a
+                * different workqueue. We therefore cannot assume that the
+                * rpc_task pointer may still be dereferenced.
+                */
+               queue = task->tk_waitqueue;
+               spin_lock_bh(&queue->lock);
+               if (!RPC_IS_QUEUED(task)) {
+                       spin_unlock_bh(&queue->lock);
                        continue;
                }
+               rpc_clear_running(task);
+               spin_unlock_bh(&queue->lock);
+               if (task_is_async)
+                       return;
 
                /* sync task: sleep here */
                dprintk("RPC: %5u sync task going to sleep\n", task->tk_pid);
@@ -815,7 +785,6 @@ EXPORT_SYMBOL_GPL(rpc_free);
 static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *task_setup_data)
 {
        memset(task, 0, sizeof(*task));
-       setup_timer(&task->tk_timer, rpc_run_timer, (unsigned long)task);
        atomic_set(&task->tk_count, 1);
        task->tk_flags  = task_setup_data->flags;
        task->tk_ops = task_setup_data->callback_ops;
@@ -843,12 +812,11 @@ static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *ta
                task->tk_action = rpc_prepare_task;
 
        if (task_setup_data->rpc_message != NULL) {
-               memcpy(&task->tk_msg, task_setup_data->rpc_message, sizeof(task->tk_msg));
+               task->tk_msg.rpc_proc = task_setup_data->rpc_message->rpc_proc;
+               task->tk_msg.rpc_argp = task_setup_data->rpc_message->rpc_argp;
+               task->tk_msg.rpc_resp = task_setup_data->rpc_message->rpc_resp;
                /* Bind the user cred */
-               if (task->tk_msg.rpc_cred != NULL)
-                       rpcauth_holdcred(task);
-               else
-                       rpcauth_bindcred(task);
+               rpcauth_bindcred(task, task_setup_data->rpc_message->rpc_cred, task_setup_data->flags);
                if (task->tk_action == NULL)
                        rpc_call_start(task);
        }
@@ -866,13 +834,6 @@ rpc_alloc_task(void)
        return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS);
 }
 
-static void rpc_free_task_rcu(struct rcu_head *rcu)
-{
-       struct rpc_task *task = container_of(rcu, struct rpc_task, u.tk_rcu);
-       dprintk("RPC: %5u freeing task\n", task->tk_pid);
-       mempool_free(task, rpc_task_mempool);
-}
-
 /*
  * Create a new task for the specified client.
  */
@@ -901,8 +862,10 @@ static void rpc_free_task(struct rpc_task *task)
        const struct rpc_call_ops *tk_ops = task->tk_ops;
        void *calldata = task->tk_calldata;
 
-       if (task->tk_flags & RPC_TASK_DYNAMIC)
-               call_rcu_bh(&task->u.tk_rcu, rpc_free_task_rcu);
+       if (task->tk_flags & RPC_TASK_DYNAMIC) {
+               dprintk("RPC: %5u freeing task\n", task->tk_pid);
+               mempool_free(task, rpc_task_mempool);
+       }
        rpc_release_calldata(tk_ops, calldata);
 }
 
@@ -948,9 +911,6 @@ static void rpc_release_task(struct rpc_task *task)
        }
        BUG_ON (RPC_IS_QUEUED(task));
 
-       /* Synchronously delete any running timer */
-       rpc_delete_timer(task);
-
 #ifdef RPC_DEBUG
        task->tk_magic = 0;
 #endif
@@ -1040,11 +1000,20 @@ rpc_destroy_mempool(void)
                kmem_cache_destroy(rpc_task_slabp);
        if (rpc_buffer_slabp)
                kmem_cache_destroy(rpc_buffer_slabp);
+       rpc_destroy_wait_queue(&delay_queue);
 }
 
 int
 rpc_init_mempool(void)
 {
+       /*
+        * The following is not strictly a mempool initialisation,
+        * but there is no harm in doing it here
+        */
+       rpc_init_wait_queue(&delay_queue, "delayq");
+       if (!rpciod_start())
+               goto err_nomem;
+
        rpc_task_slabp = kmem_cache_create("rpc_tasks",
                                             sizeof(struct rpc_task),
                                             0, SLAB_HWCACHE_ALIGN,
@@ -1065,13 +1034,6 @@ rpc_init_mempool(void)
                                                      rpc_buffer_slabp);
        if (!rpc_buffer_mempool)
                goto err_nomem;
-       if (!rpciod_start())
-               goto err_nomem;
-       /*
-        * The following is not strictly a mempool initialisation,
-        * but there is no harm in doing it here
-        */
-       rpc_init_wait_queue(&delay_queue, "delayq");
        return 0;
 err_nomem:
        rpc_destroy_mempool();