/* * linux/net/sunrpc/sched.c * * Scheduling for synchronous and asynchronous RPC requests. * * Copyright (C) 1996 Olaf Kirch, <okir@monad.swb.de> * * TCP NFS related read + write fixes * (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie> */ #include <linux/module.h> #include <linux/sched.h> #include <linux/interrupt.h> #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> #include <linux/sunrpc/clnt.h> #include <linux/sunrpc/xprt.h> #ifdef RPC_DEBUG #define RPCDBG_FACILITY RPCDBG_SCHED #define RPC_TASK_MAGIC_ID 0xf00baa static int rpc_task_id; #endif /* * RPC slabs and memory pools */ #define RPC_BUFFER_MAXSIZE (2048) #define RPC_BUFFER_POOLSIZE (8) #define RPC_TASK_POOLSIZE (8) static kmem_cache_t *rpc_task_slabp __read_mostly; static kmem_cache_t *rpc_buffer_slabp __read_mostly; static mempool_t *rpc_task_mempool __read_mostly; static mempool_t *rpc_buffer_mempool __read_mostly; static void __rpc_default_timer(struct rpc_task *task); static void rpciod_killall(void); static void rpc_async_schedule(void *); /* * RPC tasks that create another task (e.g. for contacting the portmapper) * will wait on this queue for their child's completion */ static RPC_WAITQ(childq, "childq"); /* * RPC tasks sit here while waiting for conditions to improve. */ static RPC_WAITQ(delay_queue, "delayq"); /* * All RPC tasks are linked into this list */ static LIST_HEAD(all_tasks); /* * rpciod-related stuff */ static DEFINE_MUTEX(rpciod_mutex); static unsigned int rpciod_users; struct workqueue_struct *rpciod_workqueue; /* * Spinlock for other critical sections of code. */ static DEFINE_SPINLOCK(rpc_sched_lock); /* * Disable the timer for a given RPC task. Should be called with * queue->lock and bh_disabled in order to avoid races within * rpc_run_timer(). */ static inline void __rpc_disable_timer(struct rpc_task *task) { dprintk("RPC: %4d disabling timer\n", task->tk_pid); task->tk_timeout_fn = NULL; task->tk_timeout = 0; } /* * Run a timeout function. * We use the callback in order to allow __rpc_wake_up_task() * and friends to disable the timer synchronously on SMP systems * without calling del_timer_sync(). The latter could cause a * deadlock if called while we're holding spinlocks... */ static void rpc_run_timer(struct rpc_task *task) { void (*callback)(struct rpc_task *); callback = task->tk_timeout_fn; task->tk_timeout_fn = NULL; if (callback && RPC_IS_QUEUED(task)) { dprintk("RPC: %4d running timer\n", task->tk_pid); callback(task); } smp_mb__before_clear_bit(); clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate); smp_mb__after_clear_bit(); } /* * Set up a timer for the current task. */ static inline void __rpc_add_timer(struct rpc_task *task, rpc_action timer) { if (!task->tk_timeout) return; dprintk("RPC: %4d 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: %4d deleting timer\n", task->tk_pid); } } /* * Add new request to a priority queue. */ static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, struct rpc_task *task) { struct list_head *q; struct rpc_task *t; INIT_LIST_HEAD(&task->u.tk_wait.links); q = &queue->tasks[task->tk_priority]; if (unlikely(task->tk_priority > queue->maxpriority)) q = &queue->tasks[queue->maxpriority]; list_for_each_entry(t, q, u.tk_wait.list) { if (t->tk_cookie == task->tk_cookie) { list_add_tail(&task->u.tk_wait.list, &t->u.tk_wait.links); return; } } list_add_tail(&task->u.tk_wait.list, q); } /* * Add new request to wait queue. * * Swapper tasks always get inserted at the head of the queue. * This should avoid many nasty memory deadlocks and hopefully * improve overall performance. * Everyone else gets appended to the queue to ensure proper FIFO behavior. */ static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task) { BUG_ON (RPC_IS_QUEUED(task)); if (RPC_IS_PRIORITY(queue)) __rpc_add_wait_queue_priority(queue, task); else if (RPC_IS_SWAPPER(task)) list_add(&task->u.tk_wait.list, &queue->tasks[0]); else list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]); task->u.tk_wait.rpc_waitq = queue; queue->qlen++; rpc_set_queued(task); dprintk("RPC: %4d added to queue %p \"%s\"\n", task->tk_pid, queue, rpc_qname(queue)); } /* * Remove request from a priority queue. */ static void __rpc_remove_wait_queue_priority(struct rpc_task *task) { struct rpc_task *t; if (!list_empty(&task->u.tk_wait.links)) { t = list_entry(task->u.tk_wait.links.next, struct rpc_task, u.tk_wait.list); 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); } /* * Remove request from queue. * Note: must be called with spin lock held. */ static void __rpc_remove_wait_queue(struct rpc_task *task) { struct rpc_wait_queue *queue; queue = task->u.tk_wait.rpc_waitq; if (RPC_IS_PRIORITY(queue)) __rpc_remove_wait_queue_priority(task); else list_del(&task->u.tk_wait.list); queue->qlen--; dprintk("RPC: %4d removed from queue %p \"%s\"\n", task->tk_pid, queue, rpc_qname(queue)); } static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority) { queue->priority = priority; queue->count = 1 << (priority * 2); } static inline void rpc_set_waitqueue_cookie(struct rpc_wait_queue *queue, unsigned long cookie) { queue->cookie = cookie; queue->nr = RPC_BATCH_COUNT; } static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue) { rpc_set_waitqueue_priority(queue, queue->maxpriority); rpc_set_waitqueue_cookie(queue, 0); } static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, int maxprio) { int i; spin_lock_init(&queue->lock); for (i = 0; i < ARRAY_SIZE(queue->tasks); i++) INIT_LIST_HEAD(&queue->tasks[i]); queue->maxpriority = maxprio; rpc_reset_waitqueue_priority(queue); #ifdef RPC_DEBUG queue->name = qname; #endif } void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname) { __rpc_init_priority_wait_queue(queue, qname, RPC_PRIORITY_HIGH); } void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname) { __rpc_init_priority_wait_queue(queue, qname, 0); } EXPORT_SYMBOL(rpc_init_wait_queue); static int rpc_wait_bit_interruptible(void *word) { if (signal_pending(current)) return -ERESTARTSYS; schedule(); return 0; } /* * Mark an RPC call as having completed by clearing the 'active' bit */ static inline void rpc_mark_complete_task(struct rpc_task *task) { rpc_clear_active(task); wake_up_bit(&task->tk_runstate, RPC_TASK_ACTIVE); } /* * Allow callers to wait for completion of an RPC call */ int __rpc_wait_for_completion_task(struct rpc_task *task, int (*action)(void *)) { if (action == NULL) action = rpc_wait_bit_interruptible; return wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE, action, TASK_INTERRUPTIBLE); } EXPORT_SYMBOL(__rpc_wait_for_completion_task); /* * Make an RPC task runnable. * * Note: If the task is ASYNC, this must be called with * the spinlock held to protect the wait queue operation. */ static void rpc_make_runnable(struct rpc_task *task) { int do_ret; BUG_ON(task->tk_timeout_fn); do_ret = rpc_test_and_set_running(task); rpc_clear_queued(task); if (do_ret) return; if (RPC_IS_ASYNC(task)) { int status; INIT_WORK(&task->u.tk_work, rpc_async_schedule, (void *)task); status = queue_work(task->tk_workqueue, &task->u.tk_work); if (status < 0) { printk(KERN_WARNING "RPC: failed to add task to queue: error: %d!\n", status); task->tk_status = status; return; } } else wake_up_bit(&task->tk_runstate, RPC_TASK_QUEUED); } /* * Place a newly initialized task on the workqueue. */ static inline void rpc_schedule_run(struct rpc_task *task) { rpc_set_active(task); rpc_make_runnable(task); } /* * Prepare for sleeping on a wait queue. * By always appending tasks to the list we ensure FIFO behavior. * NB: An RPC task will only receive interrupt-driven events as long * 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) { dprintk("RPC: %4d sleep_on(queue \"%s\" time %ld)\n", task->tk_pid, rpc_qname(q), jiffies); if (!RPC_IS_ASYNC(task) && !RPC_IS_ACTIVATED(task)) { printk(KERN_ERR "RPC: Inactive synchronous task put to sleep!\n"); return; } /* Mark the task as being activated if so needed */ rpc_set_active(task); __rpc_add_wait_queue(q, task); BUG_ON(task->tk_callback != NULL); task->tk_callback = action; __rpc_add_timer(task, timer); } void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task, rpc_action action, rpc_action timer) { /* * Protect the queue operations. */ spin_lock_bh(&q->lock); __rpc_sleep_on(q, task, action, timer); spin_unlock_bh(&q->lock); } /** * __rpc_do_wake_up_task - wake up a single rpc_task * @task: task to be woken up * * Caller must hold queue->lock, and have cleared the task queued flag. */ static void __rpc_do_wake_up_task(struct rpc_task *task) { dprintk("RPC: %4d __rpc_wake_up_task (now %ld)\n", task->tk_pid, jiffies); #ifdef RPC_DEBUG BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID); #endif /* Has the task been executed yet? If not, we cannot wake it up! */ if (!RPC_IS_ACTIVATED(task)) { printk(KERN_ERR "RPC: Inactive task (%p) being woken up!\n", task); return; } __rpc_disable_timer(task); __rpc_remove_wait_queue(task); rpc_make_runnable(task); dprintk("RPC: __rpc_wake_up_task done\n"); } /* * Wake up the specified task */ static void __rpc_wake_up_task(struct rpc_task *task) { if (rpc_start_wakeup(task)) { if (RPC_IS_QUEUED(task)) __rpc_do_wake_up_task(task); rpc_finish_wakeup(task); } } /* * Default timeout handler if none specified by user */ static void __rpc_default_timer(struct rpc_task *task) { dprintk("RPC: %d timeout (default timer)\n", task->tk_pid); task->tk_status = -ETIMEDOUT; rpc_wake_up_task(task); } /* * Wake up the specified task */ void rpc_wake_up_task(struct rpc_task *task) { if (rpc_start_wakeup(task)) { if (RPC_IS_QUEUED(task)) { struct rpc_wait_queue *queue = task->u.tk_wait.rpc_waitq; spin_lock_bh(&queue->lock); __rpc_do_wake_up_task(task); spin_unlock_bh(&queue->lock); } rpc_finish_wakeup(task); } } /* * Wake up the next task on a priority queue. */ static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queue) { struct list_head *q; struct rpc_task *task; /* * Service a batch of tasks from a single cookie. */ q = &queue->tasks[queue->priority]; if (!list_empty(q)) { task = list_entry(q->next, struct rpc_task, u.tk_wait.list); if (queue->cookie == task->tk_cookie) { if (--queue->nr) goto out; list_move_tail(&task->u.tk_wait.list, q); } /* * Check if we need to switch queues. */ if (--queue->count) goto new_cookie; } /* * Service the next queue. */ do { if (q == &queue->tasks[0]) q = &queue->tasks[queue->maxpriority]; else q = q - 1; if (!list_empty(q)) { task = list_entry(q->next, struct rpc_task, u.tk_wait.list); goto new_queue; } } while (q != &queue->tasks[queue->priority]); rpc_reset_waitqueue_priority(queue); return NULL; new_queue: rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0])); new_cookie: rpc_set_waitqueue_cookie(queue, task->tk_cookie); out: __rpc_wake_up_task(task); return task; } /* * Wake up the next task on the wait queue. */ struct rpc_task * rpc_wake_up_next(struct rpc_wait_queue *queue) { struct rpc_task *task = NULL; dprintk("RPC: wake_up_next(%p \"%s\")\n", queue, rpc_qname(queue)); 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(task); } spin_unlock_bh(&queue->lock); return task; } /** * rpc_wake_up - wake up all rpc_tasks * @queue: rpc_wait_queue on which the tasks are sleeping * * Grabs queue->lock */ void rpc_wake_up(struct rpc_wait_queue *queue) { struct rpc_task *task, *next; struct list_head *head; spin_lock_bh(&queue->lock); head = &queue->tasks[queue->maxpriority]; for (;;) { list_for_each_entry_safe(task, next, head, u.tk_wait.list) __rpc_wake_up_task(task); if (head == &queue->tasks[0]) break; head--; } spin_unlock_bh(&queue->lock); } /** * rpc_wake_up_status - wake up all rpc_tasks and set their status value. * @queue: rpc_wait_queue on which the tasks are sleeping * @status: status value to set * * Grabs queue->lock */ void rpc_wake_up_status(struct rpc_wait_queue *queue, int status) { struct rpc_task *task, *next; struct list_head *head; spin_lock_bh(&queue->lock); head = &queue->tasks[queue->maxpriority]; for (;;) { list_for_each_entry_safe(task, next, head, u.tk_wait.list) { task->tk_status = status; __rpc_wake_up_task(task); } if (head == &queue->tasks[0]) break; head--; } spin_unlock_bh(&queue->lock); } /* * Run a task at a later time */ static void __rpc_atrun(struct rpc_task *); void rpc_delay(struct rpc_task *task, unsigned long delay) { task->tk_timeout = delay; rpc_sleep_on(&delay_queue, task, NULL, __rpc_atrun); } static void __rpc_atrun(struct rpc_task *task) { task->tk_status = 0; rpc_wake_up_task(task); } /* * Helper to call task->tk_ops->rpc_call_prepare */ static void rpc_prepare_task(struct rpc_task *task) { task->tk_ops->rpc_call_prepare(task, task->tk_calldata); } /* * Helper that calls task->tk_ops->rpc_call_done if it exists */ void rpc_exit_task(struct rpc_task *task) { task->tk_action = NULL; if (task->tk_ops->rpc_call_done != NULL) { task->tk_ops->rpc_call_done(task, task->tk_calldata); if (task->tk_action != NULL) { WARN_ON(RPC_ASSASSINATED(task)); /* Always release the RPC slot and buffer memory */ xprt_release(task); } } } EXPORT_SYMBOL(rpc_exit_task); /* * This is the RPC `scheduler' (or rather, the finite state machine). */ static int __rpc_execute(struct rpc_task *task) { int status = 0; dprintk("RPC: %4d rpc_execute flgs %x\n", task->tk_pid, task->tk_flags); 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 */ 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 */ save_callback=task->tk_callback; task->tk_callback=NULL; lock_kernel(); save_callback(task); unlock_kernel(); } /* * Perform the next FSM step. * tk_action may be NULL when the task has been killed * by someone else. */ if (!RPC_IS_QUEUED(task)) { if (task->tk_action == NULL) break; lock_kernel(); task->tk_action(task); unlock_kernel(); } /* * Lockless check for whether task is sleeping or not. */ 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 0; if (rpc_test_and_set_running(task)) return 0; continue; } /* sync task: sleep here */ dprintk("RPC: %4d sync task going to sleep\n", task->tk_pid); /* Note: Caller should be using rpc_clnt_sigmask() */ status = out_of_line_wait_on_bit(&task->tk_runstate, RPC_TASK_QUEUED, rpc_wait_bit_interruptible, TASK_INTERRUPTIBLE); if (status == -ERESTARTSYS) { /* * When a sync task receives a signal, it exits with * -ERESTARTSYS. In order to catch any callbacks that * clean up after sleeping on some queue, we don't * break the loop here, but go around once more. */ dprintk("RPC: %4d got signal\n", task->tk_pid); task->tk_flags |= RPC_TASK_KILLED; rpc_exit(task, -ERESTARTSYS); rpc_wake_up_task(task); } rpc_set_running(task); dprintk("RPC: %4d sync task resuming\n", task->tk_pid); } dprintk("RPC: %4d, return %d, status %d\n", task->tk_pid, status, task->tk_status); /* Wake up anyone who is waiting for task completion */ rpc_mark_complete_task(task); /* Release all resources associated with the task */ rpc_release_task(task); return status; } /* * User-visible entry point to the scheduler. * * This may be called recursively if e.g. an async NFS task updates * the attributes and finds that dirty pages must be flushed. * NOTE: Upon exit of this function the task is guaranteed to be * released. In particular note that tk_release() will have * been called, so your task memory may have been freed. */ int rpc_execute(struct rpc_task *task) { rpc_set_active(task); rpc_set_running(task); return __rpc_execute(task); } static void rpc_async_schedule(void *arg) { __rpc_execute((struct rpc_task *)arg); } /** * rpc_malloc - allocate an RPC buffer * @task: RPC task that will use this buffer * @size: requested byte size * * We try to ensure that some NFS reads and writes can always proceed * by using a mempool when allocating 'small' buffers. * In order to avoid memory starvation triggering more writebacks of * NFS requests, we use GFP_NOFS rather than GFP_KERNEL. */ void * rpc_malloc(struct rpc_task *task, size_t size) { struct rpc_rqst *req = task->tk_rqstp; gfp_t gfp; if (task->tk_flags & RPC_TASK_SWAPPER) gfp = GFP_ATOMIC; else gfp = GFP_NOFS; if (size > RPC_BUFFER_MAXSIZE) { req->rq_buffer = kmalloc(size, gfp); if (req->rq_buffer) req->rq_bufsize = size; } else { req->rq_buffer = mempool_alloc(rpc_buffer_mempool, gfp); if (req->rq_buffer) req->rq_bufsize = RPC_BUFFER_MAXSIZE; } return req->rq_buffer; } /** * rpc_free - free buffer allocated via rpc_malloc * @task: RPC task with a buffer to be freed * */ void rpc_free(struct rpc_task *task) { struct rpc_rqst *req = task->tk_rqstp; if (req->rq_buffer) { if (req->rq_bufsize == RPC_BUFFER_MAXSIZE) mempool_free(req->rq_buffer, rpc_buffer_mempool); else kfree(req->rq_buffer); req->rq_buffer = NULL; req->rq_bufsize = 0; } } /* * Creation and deletion of RPC task structures */ void rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata) { memset(task, 0, sizeof(*task)); init_timer(&task->tk_timer); task->tk_timer.data = (unsigned long) task; task->tk_timer.function = (void (*)(unsigned long)) rpc_run_timer; atomic_set(&task->tk_count, 1); task->tk_client = clnt; task->tk_flags = flags; task->tk_ops = tk_ops; if (tk_ops->rpc_call_prepare != NULL) task->tk_action = rpc_prepare_task; task->tk_calldata = calldata; /* Initialize retry counters */ task->tk_garb_retry = 2; task->tk_cred_retry = 2; task->tk_priority = RPC_PRIORITY_NORMAL; task->tk_cookie = (unsigned long)current; /* Initialize workqueue for async tasks */ task->tk_workqueue = rpciod_workqueue; if (clnt) { atomic_inc(&clnt->cl_users); if (clnt->cl_softrtry) task->tk_flags |= RPC_TASK_SOFT; if (!clnt->cl_intr) task->tk_flags |= RPC_TASK_NOINTR; } #ifdef RPC_DEBUG task->tk_magic = RPC_TASK_MAGIC_ID; task->tk_pid = rpc_task_id++; #endif /* Add to global list of all tasks */ spin_lock(&rpc_sched_lock); list_add_tail(&task->tk_task, &all_tasks); spin_unlock(&rpc_sched_lock); BUG_ON(task->tk_ops == NULL); /* starting timestamp */ task->tk_start = jiffies; dprintk("RPC: %4d new task procpid %d\n", task->tk_pid, current->pid); } static struct rpc_task * rpc_alloc_task(void) { return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS); } static void rpc_free_task(struct rpc_task *task) { dprintk("RPC: %4d freeing task\n", task->tk_pid); mempool_free(task, rpc_task_mempool); } /* * Create a new task for the specified client. We have to * clean up after an allocation failure, as the client may * have specified "oneshot". */ struct rpc_task *rpc_new_task(struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata) { struct rpc_task *task; task = rpc_alloc_task(); if (!task) goto cleanup; rpc_init_task(task, clnt, flags, tk_ops, calldata); dprintk("RPC: %4d allocated task\n", task->tk_pid); task->tk_flags |= RPC_TASK_DYNAMIC; out: return task; cleanup: /* Check whether to release the client */ if (clnt) { printk("rpc_new_task: failed, users=%d, oneshot=%d\n", atomic_read(&clnt->cl_users), clnt->cl_oneshot); atomic_inc(&clnt->cl_users); /* pretend we were used ... */ rpc_release_client(clnt); } goto out; } void rpc_release_task(struct rpc_task *task) { const struct rpc_call_ops *tk_ops = task->tk_ops; void *calldata = task->tk_calldata; #ifdef RPC_DEBUG BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID); #endif if (!atomic_dec_and_test(&task->tk_count)) return; dprintk("RPC: %4d release task\n", task->tk_pid); /* Remove from global task list */ spin_lock(&rpc_sched_lock); list_del(&task->tk_task); spin_unlock(&rpc_sched_lock); BUG_ON (RPC_IS_QUEUED(task)); /* Synchronously delete any running timer */ rpc_delete_timer(task); /* Release resources */ if (task->tk_rqstp) xprt_release(task); if (task->tk_msg.rpc_cred) rpcauth_unbindcred(task); if (task->tk_client) { rpc_release_client(task->tk_client); task->tk_client = NULL; } #ifdef RPC_DEBUG task->tk_magic = 0; #endif if (task->tk_flags & RPC_TASK_DYNAMIC) rpc_free_task(task); if (tk_ops->rpc_release) tk_ops->rpc_release(calldata); } /** * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it * @clnt: pointer to RPC client * @flags: RPC flags * @ops: RPC call ops * @data: user call data */ struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *ops, void *data) { struct rpc_task *task; task = rpc_new_task(clnt, flags, ops, data); if (task == NULL) { if (ops->rpc_release != NULL) ops->rpc_release(data); return ERR_PTR(-ENOMEM); } atomic_inc(&task->tk_count); rpc_execute(task); return task; } EXPORT_SYMBOL(rpc_run_task); /** * rpc_find_parent - find the parent of a child task. * @child: child task * @parent: parent task * * Checks that the parent task is still sleeping on the * queue 'childq'. If so returns a pointer to the parent. * Upon failure returns NULL. * * Caller must hold childq.lock */ static inline struct rpc_task *rpc_find_parent(struct rpc_task *child, struct rpc_task *parent) { struct rpc_task *task; struct list_head *le; task_for_each(task, le, &childq.tasks[0]) if (task == parent) return parent; return NULL; } static void rpc_child_exit(struct rpc_task *child, void *calldata) { struct rpc_task *parent; spin_lock_bh(&childq.lock); if ((parent = rpc_find_parent(child, calldata)) != NULL) { parent->tk_status = child->tk_status; __rpc_wake_up_task(parent); } spin_unlock_bh(&childq.lock); } static const struct rpc_call_ops rpc_child_ops = { .rpc_call_done = rpc_child_exit, }; /* * Note: rpc_new_task releases the client after a failure. */ struct rpc_task * rpc_new_child(struct rpc_clnt *clnt, struct rpc_task *parent) { struct rpc_task *task; task = rpc_new_task(clnt, RPC_TASK_ASYNC | RPC_TASK_CHILD, &rpc_child_ops, parent); if (!task) goto fail; return task; fail: parent->tk_status = -ENOMEM; return NULL; } void rpc_run_child(struct rpc_task *task, struct rpc_task *child, rpc_action func) { spin_lock_bh(&childq.lock); /* N.B. Is it possible for the child to have already finished? */ __rpc_sleep_on(&childq, task, func, NULL); rpc_schedule_run(child); spin_unlock_bh(&childq.lock); } /* * Kill all tasks for the given client. * XXX: kill their descendants as well? */ void rpc_killall_tasks(struct rpc_clnt *clnt) { struct rpc_task *rovr; struct list_head *le; dprintk("RPC: killing all tasks for client %p\n", clnt); /* * Spin lock all_tasks to prevent changes... */ spin_lock(&rpc_sched_lock); alltask_for_each(rovr, le, &all_tasks) { if (! RPC_IS_ACTIVATED(rovr)) continue; if (!clnt || rovr->tk_client == clnt) { rovr->tk_flags |= RPC_TASK_KILLED; rpc_exit(rovr, -EIO); rpc_wake_up_task(rovr); } } spin_unlock(&rpc_sched_lock); } static DECLARE_MUTEX_LOCKED(rpciod_running); static void rpciod_killall(void) { unsigned long flags; while (!list_empty(&all_tasks)) { clear_thread_flag(TIF_SIGPENDING); rpc_killall_tasks(NULL); flush_workqueue(rpciod_workqueue); if (!list_empty(&all_tasks)) { dprintk("rpciod_killall: waiting for tasks to exit\n"); yield(); } } spin_lock_irqsave(¤t->sighand->siglock, flags); recalc_sigpending(); spin_unlock_irqrestore(¤t->sighand->siglock, flags); } /* * Start up the rpciod process if it's not already running. */ int rpciod_up(void) { struct workqueue_struct *wq; int error = 0; mutex_lock(&rpciod_mutex); dprintk("rpciod_up: users %d\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, %d users??\n", rpciod_users); /* * Create the rpciod thread and wait for it to start. */ error = -ENOMEM; wq = create_workqueue("rpciod"); if (wq == NULL) { printk(KERN_WARNING "rpciod_up: create workqueue failed, error=%d\n", error); rpciod_users--; goto out; } rpciod_workqueue = wq; error = 0; out: mutex_unlock(&rpciod_mutex); return error; } void rpciod_down(void) { mutex_lock(&rpciod_mutex); dprintk("rpciod_down sema %d\n", rpciod_users); if (rpciod_users) { if (--rpciod_users) goto out; } else printk(KERN_WARNING "rpciod_down: no users??\n"); if (!rpciod_workqueue) { dprintk("rpciod_down: Nothing to do!\n"); goto out; } rpciod_killall(); destroy_workqueue(rpciod_workqueue); rpciod_workqueue = NULL; out: mutex_unlock(&rpciod_mutex); } #ifdef RPC_DEBUG void rpc_show_tasks(void) { struct list_head *le; struct rpc_task *t; spin_lock(&rpc_sched_lock); if (list_empty(&all_tasks)) { spin_unlock(&rpc_sched_lock); return; } printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout " "-rpcwait -action- ---ops--\n"); alltask_for_each(t, le, &all_tasks) { const char *rpc_waitq = "none"; if (RPC_IS_QUEUED(t)) rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq); printk("%05d %04d %04x %06d %8p %6d %8p %08ld %8s %8p %8p\n", t->tk_pid, (t->tk_msg.rpc_proc ? t->tk_msg.rpc_proc->p_proc : -1), t->tk_flags, t->tk_status, t->tk_client, (t->tk_client ? t->tk_client->cl_prog : 0), t->tk_rqstp, t->tk_timeout, rpc_waitq, t->tk_action, t->tk_ops); } spin_unlock(&rpc_sched_lock); } #endif void rpc_destroy_mempool(void) { if (rpc_buffer_mempool) mempool_destroy(rpc_buffer_mempool); if (rpc_task_mempool) mempool_destroy(rpc_task_mempool); if (rpc_task_slabp && kmem_cache_destroy(rpc_task_slabp)) printk(KERN_INFO "rpc_task: not all structures were freed\n"); if (rpc_buffer_slabp && kmem_cache_destroy(rpc_buffer_slabp)) printk(KERN_INFO "rpc_buffers: not all structures were freed\n"); } int rpc_init_mempool(void) { rpc_task_slabp = kmem_cache_create("rpc_tasks", sizeof(struct rpc_task), 0, SLAB_HWCACHE_ALIGN, NULL, NULL); if (!rpc_task_slabp) goto err_nomem; rpc_buffer_slabp = kmem_cache_create("rpc_buffers", RPC_BUFFER_MAXSIZE, 0, SLAB_HWCACHE_ALIGN, NULL, NULL); if (!rpc_buffer_slabp) goto err_nomem; rpc_task_mempool = mempool_create_slab_pool(RPC_TASK_POOLSIZE, rpc_task_slabp); if (!rpc_task_mempool) goto err_nomem; rpc_buffer_mempool = mempool_create_slab_pool(RPC_BUFFER_POOLSIZE, rpc_buffer_slabp); if (!rpc_buffer_mempool) goto err_nomem; return 0; err_nomem: rpc_destroy_mempool(); return -ENOMEM; }