diff options
Diffstat (limited to 'net/sunrpc')
| -rw-r--r-- | net/sunrpc/clnt.c | 7 | ||||
| -rw-r--r-- | net/sunrpc/sched.c | 30 | ||||
| -rw-r--r-- | net/sunrpc/xprt.c | 12 |
3 files changed, 35 insertions, 14 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 822f020fa7f4..507b5e84fbdb 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -555,7 +555,7 @@ EXPORT_SYMBOL_GPL(rpc_clone_client); * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth * * @clnt: RPC client whose parameters are copied - * @auth: security flavor for new client + * @flavor: security flavor for new client * * Returns a fresh RPC client or an ERR_PTR. */ @@ -610,11 +610,6 @@ EXPORT_SYMBOL_GPL(rpc_killall_tasks); */ void rpc_shutdown_client(struct rpc_clnt *clnt) { - /* - * To avoid deadlock, never call rpc_shutdown_client from a - * workqueue context! - */ - WARN_ON_ONCE(current->flags & PF_WQ_WORKER); might_sleep(); dprintk_rcu("RPC: shutting down %s client for %s\n", diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index d17a704aaf5f..bfa31714581f 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -934,16 +934,35 @@ struct rpc_task *rpc_new_task(const struct rpc_task_setup *setup_data) return task; } +/* + * rpc_free_task - release rpc task and perform cleanups + * + * Note that we free up the rpc_task _after_ rpc_release_calldata() + * in order to work around a workqueue dependency issue. + * + * Tejun Heo states: + * "Workqueue currently considers two work items to be the same if they're + * on the same address and won't execute them concurrently - ie. it + * makes a work item which is queued again while being executed wait + * for the previous execution to complete. + * + * If a work function frees the work item, and then waits for an event + * which should be performed by another work item and *that* work item + * recycles the freed work item, it can create a false dependency loop. + * There really is no reliable way to detect this short of verifying + * every memory free." + * + */ static void rpc_free_task(struct rpc_task *task) { - const struct rpc_call_ops *tk_ops = task->tk_ops; - void *calldata = task->tk_calldata; + unsigned short tk_flags = task->tk_flags; + + rpc_release_calldata(task->tk_ops, task->tk_calldata); - if (task->tk_flags & RPC_TASK_DYNAMIC) { + if (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); } static void rpc_async_release(struct work_struct *work) @@ -953,8 +972,7 @@ static void rpc_async_release(struct work_struct *work) static void rpc_release_resources_task(struct rpc_task *task) { - if (task->tk_rqstp) - xprt_release(task); + xprt_release(task); if (task->tk_msg.rpc_cred) { put_rpccred(task->tk_msg.rpc_cred); task->tk_msg.rpc_cred = NULL; diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index bd462a532acf..33811db8788a 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -1136,10 +1136,18 @@ static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) void xprt_release(struct rpc_task *task) { struct rpc_xprt *xprt; - struct rpc_rqst *req; + struct rpc_rqst *req = task->tk_rqstp; - if (!(req = task->tk_rqstp)) + if (req == NULL) { + if (task->tk_client) { + rcu_read_lock(); + xprt = rcu_dereference(task->tk_client->cl_xprt); + if (xprt->snd_task == task) + xprt_release_write(xprt, task); + rcu_read_unlock(); + } return; + } xprt = req->rq_xprt; if (task->tk_ops->rpc_count_stats != NULL) |