Re: [PATCH 1/1] client: prevent the race of incoming work during teardown

[Guanjun He <heguanbo@gmail.com>]

	Reproduce the patch against the latest source repo.

	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@suse.com>
---
 include/linux/ceph/messenger.h |    1 +
 net/ceph/ceph_common.c         |    2 ++
 net/ceph/messenger.c           |    5 +++++
 3 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index 2521a95..2586f34 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -53,6 +53,7 @@ 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 ba4323b..478f3a4 100644
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -501,6 +501,8 @@ 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 b332c3d..11ea62e 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -156,6 +156,9 @@ EXPORT_SYMBOL(ceph_msgr_flush);
 static void ceph_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("ceph_data_ready on %p state = %lu, queueing work\n",
@@ -2285,6 +2288,8 @@ struct ceph_messenger *ceph_messenger_create(struct ceph_entity_addr *myaddr,
 	get_random_bytes(&msgr->inst.addr.nonce, sizeof(msgr->inst.addr.nonce));
 	encode_my_addr(msgr);
 
+	atomic_set(&msgr->stopping, 0);
+
 	dout("messenger_create %p\n", msgr);
 	return msgr;
 }
-- 
1.7.3.4