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|
/*
* Shared Memory Communications over RDMA (SMC-R) and RoCE
*
* Socket Closing - normal and abnormal
*
* Copyright IBM Corp. 2016
*
* Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
*/
#include <linux/workqueue.h>
#include <net/sock.h>
#include "smc.h"
#include "smc_tx.h"
#include "smc_cdc.h"
#include "smc_close.h"
#define SMC_CLOSE_WAIT_TX_PENDS_TIME (5 * HZ)
static void smc_close_cleanup_listen(struct sock *parent)
{
struct sock *sk;
/* Close non-accepted connections */
while ((sk = smc_accept_dequeue(parent, NULL)))
smc_close_non_accepted(sk);
}
static void smc_close_wait_tx_pends(struct smc_sock *smc)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
struct sock *sk = &smc->sk;
signed long timeout;
timeout = SMC_CLOSE_WAIT_TX_PENDS_TIME;
add_wait_queue(sk_sleep(sk), &wait);
while (!signal_pending(current) && timeout) {
int rc;
rc = sk_wait_event(sk, &timeout,
!smc_cdc_tx_has_pending(&smc->conn),
&wait);
if (rc)
break;
}
remove_wait_queue(sk_sleep(sk), &wait);
}
/* wait for sndbuf data being transmitted */
static void smc_close_stream_wait(struct smc_sock *smc, long timeout)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
struct sock *sk = &smc->sk;
if (!timeout)
return;
if (!smc_tx_prepared_sends(&smc->conn))
return;
smc->wait_close_tx_prepared = 1;
add_wait_queue(sk_sleep(sk), &wait);
while (!signal_pending(current) && timeout) {
int rc;
rc = sk_wait_event(sk, &timeout,
!smc_tx_prepared_sends(&smc->conn) ||
(sk->sk_err == ECONNABORTED) ||
(sk->sk_err == ECONNRESET),
&wait);
if (rc)
break;
}
remove_wait_queue(sk_sleep(sk), &wait);
smc->wait_close_tx_prepared = 0;
}
void smc_close_wake_tx_prepared(struct smc_sock *smc)
{
if (smc->wait_close_tx_prepared)
/* wake up socket closing */
smc->sk.sk_state_change(&smc->sk);
}
static int smc_close_wr(struct smc_connection *conn)
{
conn->local_tx_ctrl.conn_state_flags.peer_done_writing = 1;
return smc_cdc_get_slot_and_msg_send(conn);
}
static int smc_close_final(struct smc_connection *conn)
{
if (atomic_read(&conn->bytes_to_rcv))
conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
else
conn->local_tx_ctrl.conn_state_flags.peer_conn_closed = 1;
return smc_cdc_get_slot_and_msg_send(conn);
}
static int smc_close_abort(struct smc_connection *conn)
{
conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
return smc_cdc_get_slot_and_msg_send(conn);
}
/* terminate smc socket abnormally - active abort
* RDMA communication no longer possible
*/
void smc_close_active_abort(struct smc_sock *smc)
{
struct smc_cdc_conn_state_flags *txflags =
&smc->conn.local_tx_ctrl.conn_state_flags;
bh_lock_sock(&smc->sk);
smc->sk.sk_err = ECONNABORTED;
if (smc->clcsock && smc->clcsock->sk) {
smc->clcsock->sk->sk_err = ECONNABORTED;
smc->clcsock->sk->sk_state_change(smc->clcsock->sk);
}
switch (smc->sk.sk_state) {
case SMC_INIT:
smc->sk.sk_state = SMC_PEERABORTWAIT;
break;
case SMC_APPCLOSEWAIT1:
case SMC_APPCLOSEWAIT2:
txflags->peer_conn_abort = 1;
sock_release(smc->clcsock);
if (!smc_cdc_rxed_any_close(&smc->conn))
smc->sk.sk_state = SMC_PEERABORTWAIT;
else
smc->sk.sk_state = SMC_CLOSED;
break;
case SMC_PEERCLOSEWAIT1:
case SMC_PEERCLOSEWAIT2:
if (!txflags->peer_conn_closed) {
smc->sk.sk_state = SMC_PEERABORTWAIT;
txflags->peer_conn_abort = 1;
sock_release(smc->clcsock);
} else {
smc->sk.sk_state = SMC_CLOSED;
}
break;
case SMC_PROCESSABORT:
case SMC_APPFINCLOSEWAIT:
if (!txflags->peer_conn_closed) {
txflags->peer_conn_abort = 1;
sock_release(smc->clcsock);
}
smc->sk.sk_state = SMC_CLOSED;
break;
case SMC_PEERFINCLOSEWAIT:
case SMC_PEERABORTWAIT:
case SMC_CLOSED:
break;
}
sock_set_flag(&smc->sk, SOCK_DEAD);
bh_unlock_sock(&smc->sk);
smc->sk.sk_state_change(&smc->sk);
}
int smc_close_active(struct smc_sock *smc)
{
struct smc_cdc_conn_state_flags *txflags =
&smc->conn.local_tx_ctrl.conn_state_flags;
long timeout = SMC_MAX_STREAM_WAIT_TIMEOUT;
struct smc_connection *conn = &smc->conn;
struct sock *sk = &smc->sk;
int old_state;
int rc = 0;
if (sock_flag(sk, SOCK_LINGER) &&
!(current->flags & PF_EXITING))
timeout = sk->sk_lingertime;
again:
old_state = sk->sk_state;
switch (old_state) {
case SMC_INIT:
sk->sk_state = SMC_CLOSED;
if (smc->smc_listen_work.func)
flush_work(&smc->smc_listen_work);
sock_put(sk);
break;
case SMC_LISTEN:
sk->sk_state = SMC_CLOSED;
sk->sk_state_change(sk); /* wake up accept */
if (smc->clcsock && smc->clcsock->sk) {
rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
/* wake up kernel_accept of smc_tcp_listen_worker */
smc->clcsock->sk->sk_data_ready(smc->clcsock->sk);
}
release_sock(sk);
smc_close_cleanup_listen(sk);
flush_work(&smc->tcp_listen_work);
lock_sock(sk);
break;
case SMC_ACTIVE:
smc_close_stream_wait(smc, timeout);
release_sock(sk);
cancel_work_sync(&conn->tx_work);
lock_sock(sk);
if (sk->sk_state == SMC_ACTIVE) {
/* send close request */
rc = smc_close_final(conn);
sk->sk_state = SMC_PEERCLOSEWAIT1;
} else {
/* peer event has changed the state */
goto again;
}
break;
case SMC_APPFINCLOSEWAIT:
/* socket already shutdown wr or both (active close) */
if (txflags->peer_done_writing &&
!txflags->peer_conn_closed) {
/* just shutdown wr done, send close request */
rc = smc_close_final(conn);
}
sk->sk_state = SMC_CLOSED;
smc_close_wait_tx_pends(smc);
break;
case SMC_APPCLOSEWAIT1:
case SMC_APPCLOSEWAIT2:
if (!smc_cdc_rxed_any_close(conn))
smc_close_stream_wait(smc, timeout);
release_sock(sk);
cancel_work_sync(&conn->tx_work);
lock_sock(sk);
if (sk->sk_err != ECONNABORTED) {
/* confirm close from peer */
rc = smc_close_final(conn);
if (rc)
break;
}
if (smc_cdc_rxed_any_close(conn))
/* peer has closed the socket already */
sk->sk_state = SMC_CLOSED;
else
/* peer has just issued a shutdown write */
sk->sk_state = SMC_PEERFINCLOSEWAIT;
smc_close_wait_tx_pends(smc);
break;
case SMC_PEERCLOSEWAIT1:
case SMC_PEERCLOSEWAIT2:
case SMC_PEERFINCLOSEWAIT:
/* peer sending PeerConnectionClosed will cause transition */
break;
case SMC_PROCESSABORT:
cancel_work_sync(&conn->tx_work);
smc_close_abort(conn);
sk->sk_state = SMC_CLOSED;
smc_close_wait_tx_pends(smc);
break;
case SMC_PEERABORTWAIT:
case SMC_CLOSED:
/* nothing to do, add tracing in future patch */
break;
}
if (old_state != sk->sk_state)
sk->sk_state_change(&smc->sk);
return rc;
}
static void smc_close_passive_abort_received(struct smc_sock *smc)
{
struct smc_cdc_conn_state_flags *txflags =
&smc->conn.local_tx_ctrl.conn_state_flags;
struct sock *sk = &smc->sk;
switch (sk->sk_state) {
case SMC_ACTIVE:
case SMC_APPFINCLOSEWAIT:
case SMC_APPCLOSEWAIT1:
case SMC_APPCLOSEWAIT2:
smc_close_abort(&smc->conn);
sk->sk_state = SMC_PROCESSABORT;
break;
case SMC_PEERCLOSEWAIT1:
case SMC_PEERCLOSEWAIT2:
if (txflags->peer_done_writing &&
!txflags->peer_conn_closed) {
/* just shutdown, but not yet closed locally */
smc_close_abort(&smc->conn);
sk->sk_state = SMC_PROCESSABORT;
} else {
sk->sk_state = SMC_CLOSED;
}
break;
case SMC_PEERFINCLOSEWAIT:
case SMC_PEERABORTWAIT:
sk->sk_state = SMC_CLOSED;
break;
case SMC_INIT:
case SMC_PROCESSABORT:
/* nothing to do, add tracing in future patch */
break;
}
}
/* Some kind of closing has been received: peer_conn_closed, peer_conn_abort,
* or peer_done_writing.
* Called under tasklet context.
*/
void smc_close_passive_received(struct smc_sock *smc)
{
struct smc_cdc_conn_state_flags *rxflags =
&smc->conn.local_rx_ctrl.conn_state_flags;
struct sock *sk = &smc->sk;
int old_state;
sk->sk_shutdown |= RCV_SHUTDOWN;
if (smc->clcsock && smc->clcsock->sk)
smc->clcsock->sk->sk_shutdown |= RCV_SHUTDOWN;
sock_set_flag(&smc->sk, SOCK_DONE);
old_state = sk->sk_state;
if (rxflags->peer_conn_abort) {
smc_close_passive_abort_received(smc);
goto wakeup;
}
switch (sk->sk_state) {
case SMC_INIT:
if (atomic_read(&smc->conn.bytes_to_rcv) ||
(rxflags->peer_done_writing &&
!rxflags->peer_conn_closed))
sk->sk_state = SMC_APPCLOSEWAIT1;
else
sk->sk_state = SMC_CLOSED;
break;
case SMC_ACTIVE:
sk->sk_state = SMC_APPCLOSEWAIT1;
break;
case SMC_PEERCLOSEWAIT1:
if (rxflags->peer_done_writing)
sk->sk_state = SMC_PEERCLOSEWAIT2;
/* fall through to check for closing */
case SMC_PEERCLOSEWAIT2:
case SMC_PEERFINCLOSEWAIT:
if (!smc_cdc_rxed_any_close(&smc->conn))
break;
if (sock_flag(sk, SOCK_DEAD) &&
(sk->sk_shutdown == SHUTDOWN_MASK)) {
/* smc_release has already been called locally */
sk->sk_state = SMC_CLOSED;
} else {
/* just shutdown, but not yet closed locally */
sk->sk_state = SMC_APPFINCLOSEWAIT;
}
break;
case SMC_APPCLOSEWAIT1:
case SMC_APPCLOSEWAIT2:
case SMC_APPFINCLOSEWAIT:
case SMC_PEERABORTWAIT:
case SMC_PROCESSABORT:
case SMC_CLOSED:
/* nothing to do, add tracing in future patch */
break;
}
wakeup:
if (old_state != sk->sk_state)
sk->sk_state_change(sk);
sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
if ((sk->sk_state == SMC_CLOSED) &&
(sock_flag(sk, SOCK_DEAD) || (old_state == SMC_INIT))) {
smc_conn_free(&smc->conn);
schedule_delayed_work(&smc->sock_put_work,
SMC_CLOSE_SOCK_PUT_DELAY);
}
}
void smc_close_sock_put_work(struct work_struct *work)
{
struct smc_sock *smc = container_of(to_delayed_work(work),
struct smc_sock,
sock_put_work);
sock_put(&smc->sk);
}
int smc_close_shutdown_write(struct smc_sock *smc)
{
struct smc_connection *conn = &smc->conn;
long timeout = SMC_MAX_STREAM_WAIT_TIMEOUT;
struct sock *sk = &smc->sk;
int old_state;
int rc = 0;
if (sock_flag(sk, SOCK_LINGER))
timeout = sk->sk_lingertime;
again:
old_state = sk->sk_state;
switch (old_state) {
case SMC_ACTIVE:
smc_close_stream_wait(smc, timeout);
release_sock(sk);
cancel_work_sync(&conn->tx_work);
lock_sock(sk);
/* send close wr request */
rc = smc_close_wr(conn);
if (sk->sk_state == SMC_ACTIVE)
sk->sk_state = SMC_PEERCLOSEWAIT1;
else
goto again;
break;
case SMC_APPCLOSEWAIT1:
/* passive close */
if (!smc_cdc_rxed_any_close(conn))
smc_close_stream_wait(smc, timeout);
release_sock(sk);
cancel_work_sync(&conn->tx_work);
lock_sock(sk);
/* confirm close from peer */
rc = smc_close_wr(conn);
sk->sk_state = SMC_APPCLOSEWAIT2;
break;
case SMC_APPCLOSEWAIT2:
case SMC_PEERFINCLOSEWAIT:
case SMC_PEERCLOSEWAIT1:
case SMC_PEERCLOSEWAIT2:
case SMC_APPFINCLOSEWAIT:
case SMC_PROCESSABORT:
case SMC_PEERABORTWAIT:
/* nothing to do, add tracing in future patch */
break;
}
if (old_state != sk->sk_state)
sk->sk_state_change(&smc->sk);
return rc;
}
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