Commit ae67bd38 authored by Trond Myklebust's avatar Trond Myklebust Committed by Anna Schumaker
Browse files

SUNRPC: Fix up task signalling 



The RPC_TASK_KILLED flag should really not be set from another context
because it can clobber data in the struct task when task->tk_flags is
changed non-atomically.
Let's therefore swap out RPC_TASK_KILLED with an atomic flag, and add
a function to set that flag and safely wake up the task.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 085b7755

fs/lockd/clntproc.c

+2 −2
Original line number Diff line number Diff line
@@ -715,7 +715,7 @@ static void nlmclnt_unlock_callback(struct rpc_task *task, void *data) 
	struct nlm_rqst	*req = data;

	u32 status = ntohl(req->a_res.status);



	if (RPC_ASSASSINATED(task))

	if (RPC_SIGNALLED(task))

		goto die;



	if (task->tk_status < 0) {
@@ -783,7 +783,7 @@ static void nlmclnt_cancel_callback(struct rpc_task *task, void *data) 
	struct nlm_rqst	*req = data;

	u32 status = ntohl(req->a_res.status);



	if (RPC_ASSASSINATED(task))

	if (RPC_SIGNALLED(task))

		goto die;



	if (task->tk_status < 0) {

fs/nfsd/nfs4callback.c

+2 −2
Original line number Diff line number Diff line
@@ -1032,7 +1032,7 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback 
		 * the submission code will error out, so we don't need to

		 * handle that case here.

		 */

		if (task->tk_flags & RPC_TASK_KILLED)

		if (RPC_SIGNALLED(task))

			goto need_restart;



		return true;
@@ -1081,7 +1081,7 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback 
	dprintk("%s: freed slot, new seqid=%d\n", __func__,

		clp->cl_cb_session->se_cb_seq_nr);



	if (task->tk_flags & RPC_TASK_KILLED)

	if (RPC_SIGNALLED(task))

		goto need_restart;

out:

	return ret;

include/linux/sunrpc/sched.h

+4 −2
Original line number Diff line number Diff line
@@ -125,7 +125,6 @@ struct rpc_task_setup { 
#define RPC_CALL_MAJORSEEN	0x0020		/* major timeout seen */

#define RPC_TASK_ROOTCREDS	0x0040		/* force root creds */

#define RPC_TASK_DYNAMIC	0x0080		/* task was kmalloc'ed */

#define RPC_TASK_KILLED		0x0100		/* task was killed */

#define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */

#define RPC_TASK_SOFTCONN	0x0400		/* Fail if can't connect */

#define RPC_TASK_SENT		0x0800		/* message was sent */
@@ -135,7 +134,6 @@ struct rpc_task_setup { 


#define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)

#define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)

#define RPC_ASSASSINATED(t)	((t)->tk_flags & RPC_TASK_KILLED)

#define RPC_IS_SOFT(t)		((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))

#define RPC_IS_SOFTCONN(t)	((t)->tk_flags & RPC_TASK_SOFTCONN)

#define RPC_WAS_SENT(t)		((t)->tk_flags & RPC_TASK_SENT)
@@ -146,6 +144,7 @@ struct rpc_task_setup { 
#define RPC_TASK_NEED_XMIT	3

#define RPC_TASK_NEED_RECV	4

#define RPC_TASK_MSG_PIN_WAIT	5

#define RPC_TASK_SIGNALLED	6



#define RPC_IS_RUNNING(t)	test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)

#define rpc_set_running(t)	set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
@@ -169,6 +168,8 @@ struct rpc_task_setup { 


#define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)



#define RPC_SIGNALLED(t)	test_bit(RPC_TASK_SIGNALLED, &(t)->tk_runstate)



/*

 * Task priorities.

 * Note: if you change these, you must also change
@@ -217,6 +218,7 @@ struct rpc_task *rpc_run_task(const struct rpc_task_setup *); 
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 *);

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 *);

include/trace/events/sunrpc.h

+3 −3
Original line number Diff line number Diff line
@@ -82,7 +82,6 @@ TRACE_DEFINE_ENUM(RPC_TASK_SWAPPER); 
TRACE_DEFINE_ENUM(RPC_CALL_MAJORSEEN);

TRACE_DEFINE_ENUM(RPC_TASK_ROOTCREDS);

TRACE_DEFINE_ENUM(RPC_TASK_DYNAMIC);

TRACE_DEFINE_ENUM(RPC_TASK_KILLED);

TRACE_DEFINE_ENUM(RPC_TASK_SOFT);

TRACE_DEFINE_ENUM(RPC_TASK_SOFTCONN);

TRACE_DEFINE_ENUM(RPC_TASK_SENT);
@@ -97,7 +96,6 @@ TRACE_DEFINE_ENUM(RPC_TASK_NO_RETRANS_TIMEOUT); 
		{ RPC_CALL_MAJORSEEN, "MAJORSEEN" },			\

		{ RPC_TASK_ROOTCREDS, "ROOTCREDS" },			\

		{ RPC_TASK_DYNAMIC, "DYNAMIC" },			\

		{ RPC_TASK_KILLED, "KILLED" },				\

		{ RPC_TASK_SOFT, "SOFT" },				\

		{ RPC_TASK_SOFTCONN, "SOFTCONN" },			\

		{ RPC_TASK_SENT, "SENT" },				\
@@ -111,6 +109,7 @@ TRACE_DEFINE_ENUM(RPC_TASK_ACTIVE); 
TRACE_DEFINE_ENUM(RPC_TASK_NEED_XMIT);

TRACE_DEFINE_ENUM(RPC_TASK_NEED_RECV);

TRACE_DEFINE_ENUM(RPC_TASK_MSG_PIN_WAIT);

TRACE_DEFINE_ENUM(RPC_TASK_SIGNALLED);



#define rpc_show_runstate(flags)					\

	__print_flags(flags, "|",					\
@@ -119,7 +118,8 @@ TRACE_DEFINE_ENUM(RPC_TASK_MSG_PIN_WAIT); 
		{ (1UL << RPC_TASK_ACTIVE), "ACTIVE" },			\

		{ (1UL << RPC_TASK_NEED_XMIT), "NEED_XMIT" },		\

		{ (1UL << RPC_TASK_NEED_RECV), "NEED_RECV" },		\

		{ (1UL << RPC_TASK_MSG_PIN_WAIT), "MSG_PIN_WAIT" })

		{ (1UL << RPC_TASK_MSG_PIN_WAIT), "MSG_PIN_WAIT" },	\

		{ (1UL << RPC_TASK_SIGNALLED), "SIGNALLED" })



DECLARE_EVENT_CLASS(rpc_task_running,

net/sunrpc/clnt.c

+2 −12
Original line number Diff line number Diff line
@@ -827,14 +827,8 @@ void rpc_killall_tasks(struct rpc_clnt *clnt) 
	 * Spin lock all_tasks to prevent changes...

	 */

	spin_lock(&clnt->cl_lock);

	list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {

		if (!RPC_IS_ACTIVATED(rovr))

			continue;

		if (!(rovr->tk_flags & RPC_TASK_KILLED)) {

			rovr->tk_flags |= RPC_TASK_KILLED;

			rpc_exit(rovr, -EIO);

		}

	}

	list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)

		rpc_signal_task(rovr);

	spin_unlock(&clnt->cl_lock);

}

EXPORT_SYMBOL_GPL(rpc_killall_tasks);
@@ -1477,8 +1471,6 @@ EXPORT_SYMBOL_GPL(rpc_force_rebind); 
int

rpc_restart_call_prepare(struct rpc_task *task)

{

	if (RPC_ASSASSINATED(task))

		return 0;

	task->tk_action = call_start;

	task->tk_status = 0;

	if (task->tk_ops->rpc_call_prepare != NULL)
@@ -1494,8 +1486,6 @@ EXPORT_SYMBOL_GPL(rpc_restart_call_prepare); 
int

rpc_restart_call(struct rpc_task *task)

{

	if (RPC_ASSASSINATED(task))

		return 0;

	task->tk_action = call_start;

	task->tk_status = 0;

	return 1;

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