diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 14ddc40..6eb3421 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -243,11 +243,27 @@ struct proto smc_proto6 = {
};
EXPORT_SYMBOL_GPL(smc_proto6);
+static void smc_fback_restore_callbacks(struct smc_sock *smc)
+{
+ struct sock *clcsk = smc->clcsock->sk;
+
+ write_lock_bh(&clcsk->sk_callback_lock);
+ clcsk->sk_user_data = NULL;
+
+ smc_clcsock_restore_cb(&clcsk->sk_state_change, &smc->clcsk_state_change);
+ smc_clcsock_restore_cb(&clcsk->sk_data_ready, &smc->clcsk_data_ready);
+ smc_clcsock_restore_cb(&clcsk->sk_write_space, &smc->clcsk_write_space);
+ smc_clcsock_restore_cb(&clcsk->sk_error_report, &smc->clcsk_error_report);
+
+ write_unlock_bh(&clcsk->sk_callback_lock);
+}
+
static void smc_restore_fallback_changes(struct smc_sock *smc)
{
if (smc->clcsock->file) { /* non-accepted sockets have no file yet */
smc->clcsock->file->private_data = smc->sk.sk_socket;
smc->clcsock->file = NULL;
+ smc_fback_restore_callbacks(smc);
}
}
@@ -373,6 +389,7 @@ static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
sk->sk_prot->hash(sk);
sk_refcnt_debug_inc(sk);
mutex_init(&smc->clcsock_release_lock);
+ smc_init_saved_callbacks(smc);
return sk;
}
@@ -744,47 +761,73 @@ static void smc_fback_forward_wakeup(struct smc_sock *smc, struct sock *clcsk,
static void smc_fback_state_change(struct sock *clcsk)
{
- struct smc_sock *smc =
- smc_clcsock_user_data(clcsk);
+ struct smc_sock *smc;
- if (!smc)
- return;
- smc_fback_forward_wakeup(smc, clcsk, smc->clcsk_state_change);
+ read_lock_bh(&clcsk->sk_callback_lock);
+ smc = smc_clcsock_user_data(clcsk);
+ if (smc)
+ smc_fback_forward_wakeup(smc, clcsk,
+ smc->clcsk_state_change);
+ read_unlock_bh(&clcsk->sk_callback_lock);
}
static void smc_fback_data_ready(struct sock *clcsk)
{
- struct smc_sock *smc =
- smc_clcsock_user_data(clcsk);
+ struct smc_sock *smc;
- if (!smc)
- return;
- smc_fback_forward_wakeup(smc, clcsk, smc->clcsk_data_ready);
+ read_lock_bh(&clcsk->sk_callback_lock);
+ smc = smc_clcsock_user_data(clcsk);
+ if (smc)
+ smc_fback_forward_wakeup(smc, clcsk,
+ smc->clcsk_data_ready);
+ read_unlock_bh(&clcsk->sk_callback_lock);
}
static void smc_fback_write_space(struct sock *clcsk)
{
- struct smc_sock *smc =
- smc_clcsock_user_data(clcsk);
+ struct smc_sock *smc;
- if (!smc)
- return;
- smc_fback_forward_wakeup(smc, clcsk, smc->clcsk_write_space);
+ read_lock_bh(&clcsk->sk_callback_lock);
+ smc = smc_clcsock_user_data(clcsk);
+ if (smc)
+ smc_fback_forward_wakeup(smc, clcsk,
+ smc->clcsk_write_space);
+ read_unlock_bh(&clcsk->sk_callback_lock);
}
static void smc_fback_error_report(struct sock *clcsk)
{
- struct smc_sock *smc =
- smc_clcsock_user_data(clcsk);
+ struct smc_sock *smc;
- if (!smc)
- return;
- smc_fback_forward_wakeup(smc, clcsk, smc->clcsk_error_report);
+ read_lock_bh(&clcsk->sk_callback_lock);
+ smc = smc_clcsock_user_data(clcsk);
+ if (smc)
+ smc_fback_forward_wakeup(smc, clcsk,
+ smc->clcsk_error_report);
+ read_unlock_bh(&clcsk->sk_callback_lock);
+}
+
+static void smc_fback_replace_callbacks(struct smc_sock *smc)
+{
+ struct sock *clcsk = smc->clcsock->sk;
+
+ write_lock_bh(&clcsk->sk_callback_lock);
+ clcsk->sk_user_data = (void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
+
+ smc_clcsock_replace_cb(&clcsk->sk_state_change, smc_fback_state_change,
+ &smc->clcsk_state_change);
+ smc_clcsock_replace_cb(&clcsk->sk_data_ready, smc_fback_data_ready,
+ &smc->clcsk_data_ready);
+ smc_clcsock_replace_cb(&clcsk->sk_write_space, smc_fback_write_space,
+ &smc->clcsk_write_space);
+ smc_clcsock_replace_cb(&clcsk->sk_error_report, smc_fback_error_report,
+ &smc->clcsk_error_report);
+
+ write_unlock_bh(&clcsk->sk_callback_lock);
}
static int smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
{
- struct sock *clcsk;
int rc = 0;
mutex_lock(&smc->clcsock_release_lock);
@@ -792,10 +835,7 @@ static int smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
rc = -EBADF;
goto out;
}
- clcsk = smc->clcsock->sk;
- if (smc->use_fallback)
- goto out;
smc->use_fallback = true;
smc->fallback_rsn = reason_code;
smc_stat_fallback(smc);
@@ -810,18 +850,7 @@ static int smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
* in smc sk->sk_wq and they should be woken up
* as clcsock's wait queue is woken up.
*/
- smc->clcsk_state_change = clcsk->sk_state_change;
- smc->clcsk_data_ready = clcsk->sk_data_ready;
- smc->clcsk_write_space = clcsk->sk_write_space;
- smc->clcsk_error_report = clcsk->sk_error_report;
-
- clcsk->sk_state_change = smc_fback_state_change;
- clcsk->sk_data_ready = smc_fback_data_ready;
- clcsk->sk_write_space = smc_fback_write_space;
- clcsk->sk_error_report = smc_fback_error_report;
-
- smc->clcsock->sk->sk_user_data =
- (void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
+ smc_fback_replace_callbacks(smc);
}
out:
mutex_unlock(&smc->clcsock_release_lock);
@@ -1594,6 +1623,19 @@ static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
* function; switch it back to the original sk_data_ready function
*/
new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
+
+ /* if new clcsock has also inherited the fallback-specific callback
+ * functions, switch them back to the original ones.
+ */
+ if (lsmc->use_fallback) {
+ if (lsmc->clcsk_state_change)
+ new_clcsock->sk->sk_state_change = lsmc->clcsk_state_change;
+ if (lsmc->clcsk_write_space)
+ new_clcsock->sk->sk_write_space = lsmc->clcsk_write_space;
+ if (lsmc->clcsk_error_report)
+ new_clcsock->sk->sk_error_report = lsmc->clcsk_error_report;
+ }
+
(*new_smc)->clcsock = new_clcsock;
out:
return rc;
@@ -2353,17 +2395,20 @@ static void smc_tcp_listen_work(struct work_struct *work)
static void smc_clcsock_data_ready(struct sock *listen_clcsock)
{
- struct smc_sock *lsmc =
- smc_clcsock_user_data(listen_clcsock);
+ struct smc_sock *lsmc;
+ read_lock_bh(&listen_clcsock->sk_callback_lock);
+ lsmc = smc_clcsock_user_data(listen_clcsock);
if (!lsmc)
- return;
+ goto out;
lsmc->clcsk_data_ready(listen_clcsock);
if (lsmc->sk.sk_state == SMC_LISTEN) {
sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
if (!queue_work(smc_tcp_ls_wq, &lsmc->tcp_listen_work))
sock_put(&lsmc->sk);
}
+out:
+ read_unlock_bh(&listen_clcsock->sk_callback_lock);
}
static int smc_listen(struct socket *sock, int backlog)
@@ -2395,10 +2440,12 @@ static int smc_listen(struct socket *sock, int backlog)
/* save original sk_data_ready function and establish
* smc-specific sk_data_ready function
*/
- smc->clcsk_data_ready = smc->clcsock->sk->sk_data_ready;
- smc->clcsock->sk->sk_data_ready = smc_clcsock_data_ready;
+ write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
smc->clcsock->sk->sk_user_data =
(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
+ smc_clcsock_replace_cb(&smc->clcsock->sk->sk_data_ready,
+ smc_clcsock_data_ready, &smc->clcsk_data_ready);
+ write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
/* save original ops */
smc->ori_af_ops = inet_csk(smc->clcsock->sk)->icsk_af_ops;
@@ -2413,7 +2460,11 @@ static int smc_listen(struct socket *sock, int backlog)
rc = kernel_listen(smc->clcsock, backlog);
if (rc) {
- smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
+ write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
+ smc_clcsock_restore_cb(&smc->clcsock->sk->sk_data_ready,
+ &smc->clcsk_data_ready);
+ smc->clcsock->sk->sk_user_data = NULL;
+ write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
goto out;
}
sk->sk_max_ack_backlog = backlog;
diff --git a/net/smc/smc.h b/net/smc/smc.h
index ea06205..5ed765e 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -288,12 +288,41 @@ static inline struct smc_sock *smc_sk(const struct sock *sk)
return (struct smc_sock *)sk;
}
+static inline void smc_init_saved_callbacks(struct smc_sock *smc)
+{
+ smc->clcsk_state_change = NULL;
+ smc->clcsk_data_ready = NULL;
+ smc->clcsk_write_space = NULL;
+ smc->clcsk_error_report = NULL;
+}
+
static inline struct smc_sock *smc_clcsock_user_data(const struct sock *clcsk)
{
return (struct smc_sock *)
((uintptr_t)clcsk->sk_user_data & ~SK_USER_DATA_NOCOPY);
}
+/* save target_cb in saved_cb, and replace target_cb with new_cb */
+static inline void smc_clcsock_replace_cb(void (**target_cb)(struct sock *),
+ void (*new_cb)(struct sock *),
+ void (**saved_cb)(struct sock *))
+{
+ /* only save once */
+ if (!*saved_cb)
+ *saved_cb = *target_cb;
+ *target_cb = new_cb;
+}
+
+/* restore target_cb to saved_cb, and reset saved_cb to NULL */
+static inline void smc_clcsock_restore_cb(void (**target_cb)(struct sock *),
+ void (**saved_cb)(struct sock *))
+{
+ if (!*saved_cb)
+ return;
+ *target_cb = *saved_cb;
+ *saved_cb = NULL;
+}
+
extern struct workqueue_struct *smc_hs_wq; /* wq for handshake work */
extern struct workqueue_struct *smc_close_wq; /* wq for close work */
diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c
index 676cb23..31db743 100644
--- a/net/smc/smc_close.c
+++ b/net/smc/smc_close.c
@@ -214,8 +214,11 @@ int smc_close_active(struct smc_sock *smc)
sk->sk_state = SMC_CLOSED;
sk->sk_state_change(sk); /* wake up accept */
if (smc->clcsock && smc->clcsock->sk) {
- smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
+ write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
+ smc_clcsock_restore_cb(&smc->clcsock->sk->sk_data_ready,
+ &smc->clcsk_data_ready);
smc->clcsock->sk->sk_user_data = NULL;
+ write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
}
smc_close_cleanup_listen(sk);