[3.16.y-ckt stable] Patch "SUNRPC: Don't wake tasks during connection abort" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    SUNRPC: Don't wake tasks during connection abort

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 0b37ceb86cb0ba09ed094143d314e3b4daf85aa9 Mon Sep 17 00:00:00 2001
From: Benjamin Coddington <bcodding at redhat.com>
Date: Tue, 23 Sep 2014 12:26:19 -0400
Subject: SUNRPC: Don't wake tasks during connection abort

commit a743419f420a64d442280845c0377a915b76644f upstream.

When aborting a connection to preserve source ports, don't wake the task in
xs_error_report.  This allows tasks with RPC_TASK_SOFTCONN to succeed if the
connection needs to be re-established since it preserves the task's status
instead of setting it to the status of the aborting kernel_connect().

This may also avoid a potential conflict on the socket's lock.

Signed-off-by: Benjamin Coddington <bcodding at redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust at primarydata.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 include/linux/sunrpc/xprt.h | 1 +
 net/sunrpc/xprtsock.c       | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index fcbfe8783243..cf391eef2e6d 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -357,6 +357,7 @@ int			xs_swapper(struct rpc_xprt *xprt, int enable);
 #define XPRT_CONNECTION_ABORT	(7)
 #define XPRT_CONNECTION_CLOSE	(8)
 #define XPRT_CONGESTED		(9)
+#define XPRT_CONNECTION_REUSE	(10)

 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 {
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index be8bbd5d65ec..ab52cefa8f39 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -842,6 +842,8 @@ static void xs_error_report(struct sock *sk)
 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
 			xprt, -err);
 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
+	if (test_bit(XPRT_CONNECTION_REUSE, &xprt->state))
+		goto out;
 	xprt_wake_pending_tasks(xprt, err);
  out:
 	read_unlock_bh(&sk->sk_callback_lock);
@@ -2241,7 +2243,9 @@ static void xs_tcp_setup_socket(struct work_struct *work)
 		abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
 				&xprt->state);
 		/* "close" the socket, preserving the local port */
+		set_bit(XPRT_CONNECTION_REUSE, &xprt->state);
 		xs_tcp_reuse_connection(transport);
+		clear_bit(XPRT_CONNECTION_REUSE, &xprt->state);

 		if (abort_and_exit)
 			goto out_eagain;
--
2.1.0