Commit f8423909 authored by Trond Myklebust's avatar Trond Myklebust Committed by Anna Schumaker
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SUNRPC: Add a helper to allow pNFS drivers to selectively cancel RPC calls 



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: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 39494194

include/linux/sunrpc/sched.h

+5 −0
Original line number Diff line number Diff line
@@ -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 *);

net/sunrpc/clnt.c

+37 −0
Original line number Diff line number Diff line
@@ -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.

net/sunrpc/sched.c

+11 −0
Original line number Diff line number Diff line
@@ -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;