diff mbox series

[1/1] SUNRPC release the transport of a relocated task with an assigned transport

Message ID 20220420182121.87341-1-olga.kornievskaia@gmail.com (mailing list archive)
State New
Headers show
Series [1/1] SUNRPC release the transport of a relocated task with an assigned transport | expand

Commit Message

Olga Kornievskaia April 20, 2022, 6:21 p.m. UTC
From: Olga Kornievskaia <kolga@netapp.com>

A relocated task must release its previous transport.

Fixes: 82ee41b85cef1 ("SUNRPC don't resend a task on an offlined transport")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 net/sunrpc/clnt.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Trond Myklebust April 20, 2022, 6:41 p.m. UTC | #1
On Wed, 2022-04-20 at 14:21 -0400, Olga Kornievskaia wrote:
> From: Olga Kornievskaia <kolga@netapp.com>
> 
> A relocated task must release its previous transport.
> 
> Fixes: 82ee41b85cef1 ("SUNRPC don't resend a task on an offlined
> transport")
> Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
> ---
>  net/sunrpc/clnt.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
> index af0174d7ce5a..95de454a858b 100644
> --- a/net/sunrpc/clnt.c
> +++ b/net/sunrpc/clnt.c
> @@ -1067,8 +1067,10 @@ void rpc_task_set_transport(struct rpc_task
> *task, struct rpc_clnt *clnt)
>  {
>         if (task->tk_xprt &&
>                         !(test_bit(XPRT_OFFLINE, &task->tk_xprt-
> >state) &&
> -                        (task->tk_flags & RPC_TASK_MOVEABLE)))
> +                       (task->tk_flags & RPC_TASK_MOVEABLE))) {
> +                       xprt_release_write(task->tk_xprt, task);
>                 return;
> +       }
>         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
>                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
>         else


I don't think this patch is correct. It is changing the case where
we're not changing the value of task->tk_xprt, which was never a
problem before commit 82ee41b85cef.

What needs to change is the case where task->tk_xprt is set, but we're
going to change its value anyway because of the tests for XPRT_OFFLINE
and RPC_TASK_MOVEABLE.
In that case we need to call xprt_release(), followed by xprt_put().
Otherwise we're leaking slots, locks and references to the old task-
>tk_xprt.
Olga Kornievskaia April 20, 2022, 8:24 p.m. UTC | #2
On Wed, Apr 20, 2022 at 2:41 PM Trond Myklebust <trondmy@hammerspace.com> wrote:
>
> On Wed, 2022-04-20 at 14:21 -0400, Olga Kornievskaia wrote:
> > From: Olga Kornievskaia <kolga@netapp.com>
> >
> > A relocated task must release its previous transport.
> >
> > Fixes: 82ee41b85cef1 ("SUNRPC don't resend a task on an offlined
> > transport")
> > Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
> > ---
> >  net/sunrpc/clnt.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
> > index af0174d7ce5a..95de454a858b 100644
> > --- a/net/sunrpc/clnt.c
> > +++ b/net/sunrpc/clnt.c
> > @@ -1067,8 +1067,10 @@ void rpc_task_set_transport(struct rpc_task
> > *task, struct rpc_clnt *clnt)
> >  {
> >         if (task->tk_xprt &&
> >                         !(test_bit(XPRT_OFFLINE, &task->tk_xprt-
> > >state) &&
> > -                        (task->tk_flags & RPC_TASK_MOVEABLE)))
> > +                       (task->tk_flags & RPC_TASK_MOVEABLE))) {
> > +                       xprt_release_write(task->tk_xprt, task);
> >                 return;
> > +       }
> >         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
> >                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
> >         else
>
>
> I don't think this patch is correct. It is changing the case where
> we're not changing the value of task->tk_xprt, which was never a
> problem before commit 82ee41b85cef.
>
> What needs to change is the case where task->tk_xprt is set, but we're
> going to change its value anyway because of the tests for XPRT_OFFLINE
> and RPC_TASK_MOVEABLE.
> In that case we need to call xprt_release(), followed by xprt_put().
> Otherwise we're leaking slots, locks and references to the old task-
> >tk_xprt.

Thank you Trond. It is indeed incorrect. I've sent v2.
>
> --
> Trond Myklebust
> Linux NFS client maintainer, Hammerspace
> trond.myklebust@hammerspace.com
>
>
diff mbox series

Patch

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index af0174d7ce5a..95de454a858b 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1067,8 +1067,10 @@  void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
 {
 	if (task->tk_xprt &&
 			!(test_bit(XPRT_OFFLINE, &task->tk_xprt->state) &&
-                        (task->tk_flags & RPC_TASK_MOVEABLE)))
+			(task->tk_flags & RPC_TASK_MOVEABLE))) {
+			xprt_release_write(task->tk_xprt, task);
 		return;
+	}
 	if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
 		task->tk_xprt = rpc_task_get_first_xprt(clnt);
 	else