diff options
| -rw-r--r-- | fs/nfs/nfs4proc.c | 4 | ||||
| -rw-r--r-- | fs/nfs/unlink.c | 2 | ||||
| -rw-r--r-- | include/linux/sunrpc/sched.h | 1 | ||||
| -rw-r--r-- | kernel/sched.c | 1 | ||||
| -rw-r--r-- | net/sunrpc/sched.c | 75 |
5 files changed, 66 insertions, 17 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 1ff76acc7e9..d1ed67145cf 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4150,7 +4150,7 @@ static void nfs4_lock_release(void *calldata) task = nfs4_do_unlck(&data->fl, data->ctx, data->lsp, data->arg.lock_seqid); if (!IS_ERR(task)) - rpc_put_task(task); + rpc_put_task_async(task); dprintk("%s: cancelling lock!\n", __func__); } else nfs_free_seqid(data->arg.lock_seqid); @@ -5227,7 +5227,7 @@ static int nfs41_proc_async_sequence(struct nfs_client *clp, struct rpc_cred *cr if (IS_ERR(task)) ret = PTR_ERR(task); else - rpc_put_task(task); + rpc_put_task_async(task); dprintk("<-- %s status=%d\n", __func__, ret); return ret; } diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c index e313a51acdd..6481d537d69 100644 --- a/fs/nfs/unlink.c +++ b/fs/nfs/unlink.c @@ -180,7 +180,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n task_setup_data.rpc_client = NFS_CLIENT(dir); task = rpc_run_task(&task_setup_data); if (!IS_ERR(task)) - rpc_put_task(task); + rpc_put_task_async(task); return 1; } diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h index 88513fd8e20..d81db8012c6 100644 --- a/include/linux/sunrpc/sched.h +++ b/include/linux/sunrpc/sched.h @@ -212,6 +212,7 @@ struct rpc_task *rpc_run_task(const struct rpc_task_setup *); struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req, const struct rpc_call_ops *ops); void rpc_put_task(struct rpc_task *); +void rpc_put_task_async(struct rpc_task *); void rpc_exit_task(struct rpc_task *); void rpc_exit(struct rpc_task *, int); void rpc_release_calldata(const struct rpc_call_ops *, void *); diff --git a/kernel/sched.c b/kernel/sched.c index 18d38e4ec7b..42eab5a8437 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4213,6 +4213,7 @@ void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) { __wake_up_common(q, mode, 1, 0, key); } +EXPORT_SYMBOL_GPL(__wake_up_locked_key); /** * __wake_up_sync_key - wake up threads blocked on a waitqueue. diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index 243fc09b164..59e599498e3 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -252,23 +252,37 @@ static void rpc_set_active(struct rpc_task *task) /* * Mark an RPC call as having completed by clearing the 'active' bit + * and then waking up all tasks that were sleeping. */ -static void rpc_mark_complete_task(struct rpc_task *task) +static int rpc_complete_task(struct rpc_task *task) { - smp_mb__before_clear_bit(); + void *m = &task->tk_runstate; + wait_queue_head_t *wq = bit_waitqueue(m, RPC_TASK_ACTIVE); + struct wait_bit_key k = __WAIT_BIT_KEY_INITIALIZER(m, RPC_TASK_ACTIVE); + unsigned long flags; + int ret; + + spin_lock_irqsave(&wq->lock, flags); clear_bit(RPC_TASK_ACTIVE, &task->tk_runstate); - smp_mb__after_clear_bit(); - wake_up_bit(&task->tk_runstate, RPC_TASK_ACTIVE); + ret = atomic_dec_and_test(&task->tk_count); + if (waitqueue_active(wq)) + __wake_up_locked_key(wq, TASK_NORMAL, &k); + spin_unlock_irqrestore(&wq->lock, flags); + return ret; } /* * Allow callers to wait for completion of an RPC call + * + * Note the use of out_of_line_wait_on_bit() rather than wait_on_bit() + * to enforce taking of the wq->lock and hence avoid races with + * rpc_complete_task(). */ int __rpc_wait_for_completion_task(struct rpc_task *task, int (*action)(void *)) { if (action == NULL) action = rpc_wait_bit_killable; - return wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE, + return out_of_line_wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE, action, TASK_KILLABLE); } EXPORT_SYMBOL_GPL(__rpc_wait_for_completion_task); @@ -857,34 +871,67 @@ static void rpc_async_release(struct work_struct *work) rpc_free_task(container_of(work, struct rpc_task, u.tk_work)); } -void rpc_put_task(struct rpc_task *task) +static void rpc_release_resources_task(struct rpc_task *task) { - if (!atomic_dec_and_test(&task->tk_count)) - return; - /* Release resources */ if (task->tk_rqstp) xprt_release(task); if (task->tk_msg.rpc_cred) put_rpccred(task->tk_msg.rpc_cred); rpc_task_release_client(task); - if (task->tk_workqueue != NULL) { +} + +static void rpc_final_put_task(struct rpc_task *task, + struct workqueue_struct *q) +{ + if (q != NULL) { INIT_WORK(&task->u.tk_work, rpc_async_release); - queue_work(task->tk_workqueue, &task->u.tk_work); + queue_work(q, &task->u.tk_work); } else rpc_free_task(task); } + +static void rpc_do_put_task(struct rpc_task *task, struct workqueue_struct *q) +{ + if (atomic_dec_and_test(&task->tk_count)) { + rpc_release_resources_task(task); + rpc_final_put_task(task, q); + } +} + +void rpc_put_task(struct rpc_task *task) +{ + rpc_do_put_task(task, NULL); +} EXPORT_SYMBOL_GPL(rpc_put_task); +void rpc_put_task_async(struct rpc_task *task) +{ + rpc_do_put_task(task, task->tk_workqueue); +} +EXPORT_SYMBOL_GPL(rpc_put_task_async); + static void rpc_release_task(struct rpc_task *task) { dprintk("RPC: %5u release task\n", task->tk_pid); BUG_ON (RPC_IS_QUEUED(task)); - /* Wake up anyone who is waiting for task completion */ - rpc_mark_complete_task(task); + rpc_release_resources_task(task); - rpc_put_task(task); + /* + * Note: at this point we have been removed from rpc_clnt->cl_tasks, + * so it should be safe to use task->tk_count as a test for whether + * or not any other processes still hold references to our rpc_task. + */ + if (atomic_read(&task->tk_count) != 1 + !RPC_IS_ASYNC(task)) { + /* Wake up anyone who may be waiting for task completion */ + if (!rpc_complete_task(task)) + return; + } else { + if (!atomic_dec_and_test(&task->tk_count)) + return; + } + rpc_final_put_task(task, task->tk_workqueue); } int rpciod_up(void) |