2019-06-26 19:50:39

by David Wysochanski

Subject: [PATCH] SUNRPC: Fix possible autodisconnect during connect due to stale last_used

When a connection is successful ensure last_used is updated before calling
xprt_schedule_autodisconnect inside xprt_unlock_connect. This avoids a
possible xprt_autoclose firing immediately after connect sequence due to
an old value of last_used given to mod_timer in xprt_schedule_autodisconnect.

Signed-off-by: Dave Wysochanski <[email protected]>
---
net/sunrpc/xprt.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index f6c82b1..fceaede 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -800,6 +800,7 @@ void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie)
goto out;
xprt->snd_task =NULL;
xprt->ops->release_xprt(xprt, NULL);
+ xprt->last_used = jiffies;
xprt_schedule_autodisconnect(xprt);
out:
spin_unlock_bh(&xprt->transport_lock);
--
1.8.3.1

2019-06-26 20:12:40

by Trond Myklebust

Subject: Re: [PATCH] SUNRPC: Fix possible autodisconnect during connect due to stale last_used

On Wed, 2019-06-26 at 15:50 -0400, Dave Wysochanski wrote:
> When a connection is successful ensure last_used is updated before
> calling
> xprt_schedule_autodisconnect inside xprt_unlock_connect. This avoids
> a
> possible xprt_autoclose firing immediately after connect sequence due
> to
> an old value of last_used given to mod_timer in
> xprt_schedule_autodisconnect.
>
> Signed-off-by: Dave Wysochanski <[email protected]>
> ---
> net/sunrpc/xprt.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
> index f6c82b1..fceaede 100644
> --- a/net/sunrpc/xprt.c
> +++ b/net/sunrpc/xprt.c
> @@ -800,6 +800,7 @@ void xprt_unlock_connect(struct rpc_xprt *xprt,
> void *cookie)
> goto out;
> xprt->snd_task =NULL;
> xprt->ops->release_xprt(xprt, NULL);
> + xprt->last_used = jiffies;
> xprt_schedule_autodisconnect(xprt);
> out:
> spin_unlock_bh(&xprt->transport_lock);

Let's just move that line into xprt_schedule_autodisconnect(), since in
practice this means all callers are doing the same thing.

--
Trond Myklebust
Linux NFS client maintainer, Hammerspace
[email protected]

2019-06-26 20:14:45

by David Wysochanski

Subject: Re: [PATCH] SUNRPC: Fix possible autodisconnect during connect due to stale last_used

On Wed, 2019-06-26 at 20:11 +0000, Trond Myklebust wrote:
> On Wed, 2019-06-26 at 15:50 -0400, Dave Wysochanski wrote:
> > When a connection is successful ensure last_used is updated before
> > calling
> > xprt_schedule_autodisconnect inside xprt_unlock_connect. This
> > avoids
> > a
> > possible xprt_autoclose firing immediately after connect sequence
> > due
> > to
> > an old value of last_used given to mod_timer in
> > xprt_schedule_autodisconnect.
> >
> > Signed-off-by: Dave Wysochanski <[email protected]>
> > ---
> > net/sunrpc/xprt.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
> > index f6c82b1..fceaede 100644
> > --- a/net/sunrpc/xprt.c
> > +++ b/net/sunrpc/xprt.c
> > @@ -800,6 +800,7 @@ void xprt_unlock_connect(struct rpc_xprt *xprt,
> > void *cookie)
> > goto out;
> > xprt->snd_task =NULL;
> > xprt->ops->release_xprt(xprt, NULL);
> > + xprt->last_used = jiffies;
> > xprt_schedule_autodisconnect(xprt);
> > out:
> > spin_unlock_bh(&xprt->transport_lock);
>
> Let's just move that line into xprt_schedule_autodisconnect(), since
> in
> practice this means all callers are doing the same thing.
>
>

Will do and resubmit - thanks!

2019-06-26 20:31:17

by David Wysochanski

Subject: [PATCH] SUNRPC: Fix possible autodisconnect during connect due to old last_used

Ensure last_used is updated before calling mod_timer inside
xprt_schedule_autodisconnect. This avoids a possible xprt_autoclose
firing immediately after a successful connect when xprt_unlock_connect
calls xprt_schedule_autodisconnect with an old value of last_used.

Signed-off-by: Dave Wysochanski <[email protected]>
---
net/sunrpc/xprt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index f6c82b1..871b904 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -750,6 +750,7 @@ void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie)
xprt_schedule_autodisconnect(struct rpc_xprt *xprt)
__must_hold(&xprt->transport_lock)
{
+ xprt->last_used = jiffies;
if (RB_EMPTY_ROOT(&xprt->recv_queue) && xprt_has_timer(xprt))
mod_timer(&xprt->timer, xprt->last_used + xprt->idle_timeout);
}
@@ -1774,7 +1775,6 @@ void xprt_release(struct rpc_task *task)
xprt->ops->release_xprt(xprt, task);
if (xprt->ops->release_request)
xprt->ops->release_request(task);
- xprt->last_used = jiffies;
xprt_schedule_autodisconnect(xprt);
spin_unlock_bh(&xprt->transport_lock);
if (req->rq_buffer)
--
1.8.3.1