From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Add the helper rpc_cancel_tasks(), which uses a caller-defined selection
function to define a set of in-flight RPC calls to cancel. This is
mainly intended for pNFS drivers which are subject to a layout recall,
and which may therefore want to cancel all pending I/O using that layout
in order to redrive it after the layout recall has been satisfied.
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
include/linux/sunrpc/sched.h | 5 +++++
net/sunrpc/clnt.c | 37 ++++++++++++++++++++++++++++++++++++
net/sunrpc/sched.c | 11 +++++++++++
3 files changed, 53 insertions(+)
diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index 647247040ef9..cdcf0fe56a6f 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -210,11 +210,16 @@ struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req);
void rpc_put_task(struct rpc_task *);
void rpc_put_task_async(struct rpc_task *);
bool rpc_task_set_rpc_status(struct rpc_task *task, int rpc_status);
+void rpc_task_try_cancel(struct rpc_task *task, int error);
void rpc_signal_task(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 *);
void rpc_killall_tasks(struct rpc_clnt *);
+unsigned long rpc_cancel_tasks(struct rpc_clnt *clnt, int error,
+ bool (*fnmatch)(const struct rpc_task *,
+ const void *),
+ const void *data);
void rpc_execute(struct rpc_task *);
void rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
void rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 77a44118c0da..3bee30cf8a7d 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -873,6 +873,43 @@ void rpc_killall_tasks(struct rpc_clnt *clnt)
}
EXPORT_SYMBOL_GPL(rpc_killall_tasks);
+/**
+ * rpc_cancel_tasks - try to cancel a set of RPC tasks
+ * @clnt: Pointer to RPC client
+ * @error: RPC task error value to set
+ * @fnmatch: Pointer to selector function
+ * @data: User data
+ *
+ * Uses @fnmatch to define a set of RPC tasks that are to be cancelled.
+ * The argument @error must be a negative error value.
+ */
+unsigned long rpc_cancel_tasks(struct rpc_clnt *clnt, int error,
+ bool (*fnmatch)(const struct rpc_task *,
+ const void *),
+ const void *data)
+{
+ struct rpc_task *task;
+ unsigned long count = 0;
+
+ if (list_empty(&clnt->cl_tasks))
+ return 0;
+ /*
+ * Spin lock all_tasks to prevent changes...
+ */
+ spin_lock(&clnt->cl_lock);
+ list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
+ if (!RPC_IS_ACTIVATED(task))
+ continue;
+ if (!fnmatch(task, data))
+ continue;
+ rpc_task_try_cancel(task, error);
+ count++;
+ }
+ spin_unlock(&clnt->cl_lock);
+ return count;
+}
+EXPORT_SYMBOL_GPL(rpc_cancel_tasks);
+
/*
* Properly shut down an RPC client, terminating all outstanding
* requests.
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index f388bfaf6ff0..de912e02371b 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -872,6 +872,17 @@ void rpc_signal_task(struct rpc_task *task)
rpc_wake_up_queued_task(queue, task);
}
+void rpc_task_try_cancel(struct rpc_task *task, int error)
+{
+ struct rpc_wait_queue *queue;
+
+ if (!rpc_task_set_rpc_status(task, error))
+ return;
+ queue = READ_ONCE(task->tk_waitqueue);
+ if (queue)
+ rpc_wake_up_queued_task(queue, task);
+}
+
void rpc_exit(struct rpc_task *task, int status)
{
task->tk_status = status;
--
2.37.3
