diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2023-10-11 09:20:55 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-10-13 16:49:32 -0700 |
| commit | 419ce133ab928ab5efd7b50b2ef36ddfd4eadbd2 (patch) | |
| tree | 8d934593e6eaf8f7ded2c7c32e8bd0db8effccd9 /include/net/sock.h | |
| parent | 242e34500a32631f85c2b4eb6cb42a368a39e54f (diff) | |
tcp: allow again tcp_disconnect() when threads are waiting
As reported by Tom, .NET and applications build on top of it rely
on connect(AF_UNSPEC) to async cancel pending I/O operations on TCP
socket.
The blamed commit below caused a regression, as such cancellation
can now fail.
As suggested by Eric, this change addresses the problem explicitly
causing blocking I/O operation to terminate immediately (with an error)
when a concurrent disconnect() is executed.
Instead of tracking the number of threads blocked on a given socket,
track the number of disconnect() issued on such socket. If such counter
changes after a blocking operation releasing and re-acquiring the socket
lock, error out the current operation.
Fixes: 4faeee0cf8a5 ("tcp: deny tcp_disconnect() when threads are waiting")
Reported-by: Tom Deseyn <tdeseyn@redhat.com>
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1886305
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/f3b95e47e3dbed840960548aebaa8d954372db41.1697008693.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/net/sock.h')
| -rw-r--r-- | include/net/sock.h | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index b770261fbdaf..92f7ea62a915 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -336,7 +336,7 @@ struct sk_filter; * @sk_cgrp_data: cgroup data for this cgroup * @sk_memcg: this socket's memory cgroup association * @sk_write_pending: a write to stream socket waits to start - * @sk_wait_pending: number of threads blocked on this socket + * @sk_disconnects: number of disconnect operations performed on this sock * @sk_state_change: callback to indicate change in the state of the sock * @sk_data_ready: callback to indicate there is data to be processed * @sk_write_space: callback to indicate there is bf sending space available @@ -429,7 +429,7 @@ struct sock { unsigned int sk_napi_id; #endif int sk_rcvbuf; - int sk_wait_pending; + int sk_disconnects; struct sk_filter __rcu *sk_filter; union { @@ -1189,8 +1189,7 @@ static inline void sock_rps_reset_rxhash(struct sock *sk) } #define sk_wait_event(__sk, __timeo, __condition, __wait) \ - ({ int __rc; \ - __sk->sk_wait_pending++; \ + ({ int __rc, __dis = __sk->sk_disconnects; \ release_sock(__sk); \ __rc = __condition; \ if (!__rc) { \ @@ -1200,8 +1199,7 @@ static inline void sock_rps_reset_rxhash(struct sock *sk) } \ sched_annotate_sleep(); \ lock_sock(__sk); \ - __sk->sk_wait_pending--; \ - __rc = __condition; \ + __rc = __dis == __sk->sk_disconnects ? __condition : -EPIPE; \ __rc; \ }) |