libceph: prevent the race of incoming work during teardown

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>
Reviewed-by: Sage Weil <sage@inktank.com>

2 files changed, 7 insertions, 0 deletions

diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index 58b09efb528d..3b45e01fa8d1 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 16814d1f4774..63e1252d3af5 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);