Revert "net: simplify sock_poll_wait"

This reverts commit dd979b4df8.

This broke tcp_poll for SMC fallback: An AF_SMC socket establishes an
internal TCP socket for the initial handshake with the remote peer.
Whenever the SMC connection can not be established this TCP socket is
used as a fallback. All socket operations on the SMC socket are then
forwarded to the TCP socket. In case of poll, the file->private_data
pointer references the SMC socket because the TCP socket has no file
assigned. This causes tcp_poll to wait on the wrong socket.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Karsten Graul 2018-10-23 13:40:39 +02:00 committed by David S. Miller
parent 6b7a02f708
commit 89ab066d42
13 changed files with 22 additions and 16 deletions

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@ -1071,7 +1071,7 @@ __poll_t af_alg_poll(struct file *file, struct socket *sock,
struct af_alg_ctx *ctx = ask->private;
__poll_t mask;
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
mask = 0;
if (!ctx->more || ctx->used)

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@ -2059,14 +2059,20 @@ static inline bool skwq_has_sleeper(struct socket_wq *wq)
/**
* sock_poll_wait - place memory barrier behind the poll_wait call.
* @filp: file
* @sock: socket to wait on
* @p: poll_table
*
* See the comments in the wq_has_sleeper function.
*
* Do not derive sock from filp->private_data here. An SMC socket establishes
* an internal TCP socket that is used in the fallback case. All socket
* operations on the SMC socket are then forwarded to the TCP socket. In case of
* poll, the filp->private_data pointer references the SMC socket because the
* TCP socket has no file assigned.
*/
static inline void sock_poll_wait(struct file *filp, poll_table *p)
static inline void sock_poll_wait(struct file *filp, struct socket *sock,
poll_table *p)
{
struct socket *sock = filp->private_data;
if (!poll_does_not_wait(p)) {
poll_wait(filp, &sock->wq->wait, p);
/* We need to be sure we are in sync with the

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@ -653,7 +653,7 @@ __poll_t vcc_poll(struct file *file, struct socket *sock, poll_table *wait)
struct atm_vcc *vcc;
__poll_t mask;
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
mask = 0;
vcc = ATM_SD(sock);

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@ -941,7 +941,7 @@ static __poll_t caif_poll(struct file *file,
__poll_t mask;
struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
mask = 0;
/* exceptional events? */

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@ -837,7 +837,7 @@ __poll_t datagram_poll(struct file *file, struct socket *sock,
struct sock *sk = sock->sk;
__poll_t mask;
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
mask = 0;
/* exceptional events? */

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@ -325,7 +325,7 @@ __poll_t dccp_poll(struct file *file, struct socket *sock,
__poll_t mask;
struct sock *sk = sock->sk;
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
if (sk->sk_state == DCCP_LISTEN)
return inet_csk_listen_poll(sk);

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@ -507,7 +507,7 @@ __poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
const struct tcp_sock *tp = tcp_sk(sk);
int state;
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
state = inet_sk_state_load(sk);
if (state == TCP_LISTEN)

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@ -1504,7 +1504,7 @@ __poll_t iucv_sock_poll(struct file *file, struct socket *sock,
struct sock *sk = sock->sk;
__poll_t mask = 0;
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
if (sk->sk_state == IUCV_LISTEN)
return iucv_accept_poll(sk);

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@ -556,7 +556,7 @@ static __poll_t llcp_sock_poll(struct file *file, struct socket *sock,
pr_debug("%p\n", sk);
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
if (sk->sk_state == LLCP_LISTEN)
return llcp_accept_poll(sk);

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@ -756,7 +756,7 @@ static __poll_t rxrpc_poll(struct file *file, struct socket *sock,
struct rxrpc_sock *rx = rxrpc_sk(sk);
__poll_t mask;
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
mask = 0;
/* the socket is readable if there are any messages waiting on the Rx

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@ -1543,7 +1543,7 @@ static __poll_t smc_poll(struct file *file, struct socket *sock,
mask |= EPOLLERR;
} else {
if (sk->sk_state != SMC_CLOSED)
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
if (sk->sk_err)
mask |= EPOLLERR;
if ((sk->sk_shutdown == SHUTDOWN_MASK) ||

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@ -717,7 +717,7 @@ static __poll_t tipc_poll(struct file *file, struct socket *sock,
struct tipc_sock *tsk = tipc_sk(sk);
__poll_t revents = 0;
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
if (sk->sk_shutdown & RCV_SHUTDOWN)
revents |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM;

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@ -2642,7 +2642,7 @@ static __poll_t unix_poll(struct file *file, struct socket *sock, poll_table *wa
struct sock *sk = sock->sk;
__poll_t mask;
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
mask = 0;
/* exceptional events? */
@ -2679,7 +2679,7 @@ static __poll_t unix_dgram_poll(struct file *file, struct socket *sock,
unsigned int writable;
__poll_t mask;
sock_poll_wait(file, wait);
sock_poll_wait(file, sock, wait);
mask = 0;
/* exceptional events? */