From: Ursula Braun <ubraun@linux.ibm.com>
Date: Fri, 12 Apr 2019 12:57:23 +0200
Subject: net/smc: nonblocking connect rework
Git-commit: 50717a37db032ce783f50685a73bb2ac68471a5a
Patch-mainline: v5.2-rc1
References: bsc#1134607 bsc#1134618 LTC#177518 LTC#177520
For nonblocking sockets move the kernel_connect() from the connect
worker into the initial smc_connect part to return kernel_connect()
errors other than -EINPROGRESS to user space.
Reviewed-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
net/smc/af_smc.c | 76 ++++++++++++++++++++++++++++++-------------------------
net/smc/smc.h | 11 ++-----
2 files changed, 46 insertions(+), 41 deletions(-)
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -134,11 +134,9 @@ static int smc_release(struct socket *so
smc = smc_sk(sk);
/* cleanup for a dangling non-blocking connect */
- if (smc->connect_info && sk->sk_state == SMC_INIT)
+ if (smc->connect_nonblock && sk->sk_state == SMC_INIT)
tcp_abort(smc->clcsock->sk, ECONNABORTED);
flush_work(&smc->connect_work);
- kfree(smc->connect_info);
- smc->connect_info = NULL;
if (sk->sk_state == SMC_LISTEN)
/* smc_close_non_accepted() is called and acquires
@@ -460,6 +458,7 @@ static int smc_connect_fallback(struct s
smc_switch_to_fallback(smc);
smc->fallback_rsn = reason_code;
smc_copy_sock_settings_to_clc(smc);
+ smc->connect_nonblock = 0;
if (smc->sk.sk_state == SMC_INIT)
smc->sk.sk_state = SMC_ACTIVE;
return 0;
@@ -499,6 +498,7 @@ static int smc_connect_abort(struct smc_
mutex_unlock(&smc_client_lgr_pending);
smc_conn_free(&smc->conn);
+ smc->connect_nonblock = 0;
return reason_code;
}
@@ -641,6 +641,7 @@ static int smc_connect_rdma(struct smc_s
mutex_unlock(&smc_client_lgr_pending);
smc_copy_sock_settings_to_clc(smc);
+ smc->connect_nonblock = 0;
if (smc->sk.sk_state == SMC_INIT)
smc->sk.sk_state = SMC_ACTIVE;
@@ -679,6 +680,7 @@ static int smc_connect_ism(struct smc_so
mutex_unlock(&smc_server_lgr_pending);
smc_copy_sock_settings_to_clc(smc);
+ smc->connect_nonblock = 0;
if (smc->sk.sk_state == SMC_INIT)
smc->sk.sk_state = SMC_ACTIVE;
@@ -764,17 +766,30 @@ static void smc_connect_work(struct work
{
struct smc_sock *smc = container_of(work, struct smc_sock,
connect_work);
- int rc;
+ long timeo = smc->sk.sk_sndtimeo;
+ int rc = 0;
- lock_sock(&smc->sk);
- rc = kernel_connect(smc->clcsock, &smc->connect_info->addr,
- smc->connect_info->alen, smc->connect_info->flags);
+ if (!timeo)
+ timeo = MAX_SCHEDULE_TIMEOUT;
+ lock_sock(smc->clcsock->sk);
if (smc->clcsock->sk->sk_err) {
smc->sk.sk_err = smc->clcsock->sk->sk_err;
- goto out;
+ } else if ((1 << smc->clcsock->sk->sk_state) &
+ (TCPF_SYN_SENT | TCP_SYN_RECV)) {
+ rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
+ if ((rc == -EPIPE) &&
+ ((1 << smc->clcsock->sk->sk_state) &
+ (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
+ rc = 0;
}
- if (rc < 0) {
- smc->sk.sk_err = -rc;
+ release_sock(smc->clcsock->sk);
+ lock_sock(&smc->sk);
+ if (rc != 0 || smc->sk.sk_err) {
+ smc->sk.sk_state = SMC_CLOSED;
+ if (rc == -EPIPE || rc == -EAGAIN)
+ smc->sk.sk_err = EPIPE;
+ else if (signal_pending(current))
+ smc->sk.sk_err = -sock_intr_errno(timeo);
goto out;
}
@@ -791,8 +806,6 @@ out:
smc->sk.sk_write_space(&smc->sk);
}
}
- kfree(smc->connect_info);
- smc->connect_info = NULL;
release_sock(&smc->sk);
}
@@ -825,26 +838,18 @@ static int smc_connect(struct socket *so
smc_copy_sock_settings_to_clc(smc);
tcp_sk(smc->clcsock->sk)->syn_smc = 1;
+ if (smc->connect_nonblock) {
+ rc = -EALREADY;
+ goto out;
+ }
+ rc = kernel_connect(smc->clcsock, addr, alen, flags);
+ if (rc && rc != -EINPROGRESS)
+ goto out;
if (flags & O_NONBLOCK) {
- if (smc->connect_info) {
- rc = -EALREADY;
- goto out;
- }
- smc->connect_info = kzalloc(alen + 2 * sizeof(int), GFP_KERNEL);
- if (!smc->connect_info) {
- rc = -ENOMEM;
- goto out;
- }
- smc->connect_info->alen = alen;
- smc->connect_info->flags = flags ^ O_NONBLOCK;
- memcpy(&smc->connect_info->addr, addr, alen);
- schedule_work(&smc->connect_work);
+ if (schedule_work(&smc->connect_work))
+ smc->connect_nonblock = 1;
rc = -EINPROGRESS;
} else {
- rc = kernel_connect(smc->clcsock, addr, alen, flags);
- if (rc)
- goto out;
-
rc = __smc_connect(smc);
if (rc < 0)
goto out;
@@ -1591,8 +1596,8 @@ static unsigned int smc_poll(struct file
poll_table *wait)
{
struct sock *sk = sock->sk;
- unsigned int mask = 0;
struct smc_sock *smc;
+ unsigned int mask = 0;
if (!sk)
return POLLNVAL;
@@ -1602,8 +1607,6 @@ static unsigned int smc_poll(struct file
/* delegate to CLC child sock */
mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
sk->sk_err = smc->clcsock->sk->sk_err;
- if (sk->sk_err)
- mask |= POLLERR;
} else {
if (sk->sk_state != SMC_CLOSED)
sock_poll_wait(file, sk_sleep(sk), wait);
@@ -1614,9 +1617,14 @@ static unsigned int smc_poll(struct file
mask |= POLLHUP;
if (sk->sk_state == SMC_LISTEN) {
/* woken up by sk_data_ready in smc_listen_work() */
- mask = smc_accept_poll(sk);
+ mask |= smc_accept_poll(sk);
+ } else if (smc->use_fallback) { /* as result of connect_work()*/
+ mask |= smc->clcsock->ops->poll(file, smc->clcsock,
+ wait);
+ sk->sk_err = smc->clcsock->sk->sk_err;
} else {
- if (atomic_read(&smc->conn.sndbuf_space) ||
+ if ((sk->sk_state != SMC_INIT &&
+ atomic_read(&smc->conn.sndbuf_space)) ||
sk->sk_shutdown & SEND_SHUTDOWN) {
mask |= POLLOUT | POLLWRNORM;
} else {
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -189,18 +189,11 @@ struct smc_connection {
u64 peer_token; /* SMC-D token of peer */
};
-struct smc_connect_info {
- int flags;
- int alen;
- struct sockaddr addr;
-};
-
struct smc_sock { /* smc sock container */
struct sock sk;
struct socket *clcsock; /* internal tcp socket */
struct smc_connection conn; /* smc connection */
struct smc_sock *listen_smc; /* listen parent */
- struct smc_connect_info *connect_info; /* connect address & flags */
struct work_struct connect_work; /* handle non-blocking connect*/
struct work_struct tcp_listen_work;/* handle tcp socket accepts */
struct work_struct smc_listen_work;/* prepare new accept socket */
@@ -218,6 +211,10 @@ struct smc_sock { /* smc sock contain
* started, waiting for unsent
* data to be sent
*/
+ u8 connect_nonblock : 1;
+ /* non-blocking connect in
+ * flight
+ */
struct mutex clcsock_release_lock;
/* protects clcsock of a listen
* socket