[ 3.5.yuz extended stable ] Patch "libceph: prevent the race of incoming work during" has been added to staging queue

[Herton Ronaldo Krzesinski]

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

    libceph: prevent the race of incoming work during

to the linux-3.5.y-queue branch of the 3.5.yuz extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

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

For more information about the 3.5.yuz tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From 980a69d5c4950d96c659b372bae3905406f2b5a6 Mon Sep 17 00:00:00 2001
From: Guanjun He <gjhe at suse.com>
Date: Sun, 8 Jul 2012 19:50:33 -0700
Subject: [PATCH 47/78] libceph: prevent the race of incoming work during
 teardown

commit a2a3258417eb6a1799cf893350771428875a8287 upstream.

Add an atomic variable 'stopping' as flag in struct ceph_messenger,
set this flag to 1 in function ceph_destroy_client(), and add the condition code
in function ceph_data_ready() to test the flag value, if true(1), just return.

Signed-off-by: Guanjun He <gjhe at suse.com>
Reviewed-by: Sage Weil <sage at inktank.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 include/linux/ceph/messenger.h |    1 +
 net/ceph/ceph_common.c         |    2 ++
 net/ceph/messenger.c           |    5 +++++
 3 files changed, 8 insertions(+)

diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index ec22abd..de39cda 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -50,6 +50,7 @@ struct ceph_messenger {
 	struct ceph_entity_inst inst;    /* my name+address */
 	struct ceph_entity_addr my_enc_addr;

+	atomic_t stopping;
 	bool nocrc;

 	/*
diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index 58b09ef..3b45e01 100644
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -495,6 +495,8 @@ void ceph_destroy_client(struct ceph_client *client)
 {
 	dout("destroy_client %p\n", client);

+	atomic_set(&client->msgr.stopping, 1);
+
 	/* unmount */
 	ceph_osdc_stop(&client->osdc);

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 16814d1..63e1252 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -254,6 +254,9 @@ static void con_sock_state_closed(struct ceph_connection *con)
 static void ceph_sock_data_ready(struct sock *sk, int count_unused)
 {
 	struct ceph_connection *con = sk->sk_user_data;
+	if (atomic_read(&con->msgr->stopping)) {
+		return;
+	}

 	if (sk->sk_state != TCP_CLOSE_WAIT) {
 		dout("%s on %p state = %lu, queueing work\n", __func__,
@@ -2413,6 +2416,8 @@ void ceph_messenger_init(struct ceph_messenger *msgr,
 	encode_my_addr(msgr);
 	msgr->nocrc = nocrc;

+	atomic_set(&msgr->stopping, 0);
+
 	dout("%s %p\n", __func__, msgr);
 }
 EXPORT_SYMBOL(ceph_messenger_init);
--
1.7.9.5