[PATCH net-next 2/4] smc: make smc_rx_wait_data() generic

Ursula Braun
2018-05-03T16:12:37Z

Turn smc_rx_wait_data into a generic function that can be used at various
instances to wait on traffic to complete with varying criteria.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com><
---
net/smc/af_smc.c | 2 +-
net/smc/smc_rx.c | 21 +++++++++++----------
net/smc/smc_rx.h | 8 +++++++-
3 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 823ea3371575..747fdf1a2d6f 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1092,7 +1092,7 @@ static int smc_accept(struct socket *sock, struct socket *new_sock,
release_sock(clcsk);
} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
lock_sock(nsk);
- smc_rx_wait_data(smc_sk(nsk), &timeo);
+ smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
release_sock(nsk);
}
}
diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c
index def33fb29ac9..7b64bee656e8 100644
--- a/net/smc/smc_rx.c
+++ b/net/smc/smc_rx.c
@@ -22,11 +22,10 @@
#include "smc_tx.h" /* smc_tx_consumer_update() */
#include "smc_rx.h"

-/* callback implementation for sk.sk_data_ready()
- * to wakeup rcvbuf consumers that blocked with smc_rx_wait_data().
+/* callback implementation to wakeup consumers blocked with smc_rx_wait().
* indirectly called by smc_cdc_msg_recv_action().
*/
-static void smc_rx_data_ready(struct sock *sk)
+static void smc_rx_wake_up(struct sock *sk)
{
struct socket_wq *wq;

@@ -47,25 +46,27 @@ static void smc_rx_data_ready(struct sock *sk)
/* blocks rcvbuf consumer until >=len bytes available or timeout or interrupted
* @smc smc socket
* @timeo pointer to max seconds to wait, pointer to value 0 for no timeout
+ * @fcrit add'l criterion to evaluate as function pointer
* Returns:
* 1 if at least 1 byte available in rcvbuf or if socket error/shutdown.
* 0 otherwise (nothing in rcvbuf nor timeout, e.g. interrupted).
*/
-int smc_rx_wait_data(struct smc_sock *smc, long *timeo)
+int smc_rx_wait(struct smc_sock *smc, long *timeo,
+ int (*fcrit)(struct smc_connection *conn))
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
struct smc_connection *conn = &smc->conn;
struct sock *sk = &smc->sk;
int rc;

- if (atomic_read(&conn->bytes_to_rcv))
+ if (fcrit(conn))
return 1;
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
add_wait_queue(sk_sleep(sk), &wait);
rc = sk_wait_event(sk, timeo,
sk->sk_err ||
sk->sk_shutdown & RCV_SHUTDOWN ||
- atomic_read(&conn->bytes_to_rcv) ||
+ fcrit(conn) ||
smc_cdc_rxed_any_close_or_senddone(conn),
&wait);
remove_wait_queue(sk_sleep(sk), &wait);
@@ -146,14 +147,14 @@ int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, size_t len,
return -EAGAIN;
}

- if (!atomic_read(&conn->bytes_to_rcv)) {
- smc_rx_wait_data(smc, &timeo);
+ if (!smc_rx_data_available(conn)) {
+ smc_rx_wait(smc, &timeo, smc_rx_data_available);
continue;
}

copy:
/* initialize variables for 1st iteration of subsequent loop */
- /* could be just 1 byte, even after smc_rx_wait_data above */
+ /* could be just 1 byte, even after waiting on data above */
readable = atomic_read(&conn->bytes_to_rcv);
/* not more than what user space asked for */
copylen = min_t(size_t, read_remaining, readable);
@@ -213,5 +214,5 @@ int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, size_t len,
/* Initialize receive properties on connection establishment. NB: not __init! */
void smc_rx_init(struct smc_sock *smc)
{
- smc->sk.sk_data_ready = smc_rx_data_ready;
+ smc->sk.sk_data_ready = smc_rx_wake_up;
}
diff --git a/net/smc/smc_rx.h b/net/smc/smc_rx.h
index 0b75a6b470e6..8f9f00997641 100644
--- a/net/smc/smc_rx.h
+++ b/net/smc/smc_rx.h
@@ -20,6 +20,12 @@
void smc_rx_init(struct smc_sock *smc);
int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, size_t len,
int flags);
-int smc_rx_wait_data(struct smc_sock *smc, long *timeo);
+int smc_rx_wait(struct smc_sock *smc, long *timeo,
+ int (*fcrit)(struct smc_connection *conn));
+static inline int smc_rx_data_available(struct smc_connection *conn)
+{
+ return atomic_read(&conn->bytes_to_rcv);
+}
+

#endif /* SMC_RX_H */
--
2.13.5