diff options
| author | Alexander Aring <aahringo@redhat.com> | 2025-04-29 16:29:11 -0400 |
|---|---|---|
| committer | David Teigland <teigland@redhat.com> | 2025-04-30 09:26:34 -0500 |
| commit | 55612ddb62fc12437a7ff2f27b51a8981bc187a4 (patch) | |
| tree | 3b6c81cb86f7a88b049188dca0f97094307e7073 | |
| parent | 8a856fdede1669cbaeadeea87fc5b2ac071cee1b (diff) | |
dlm: use SHUT_RDWR for SCTP shutdown
Currently SCTP shutdown() call gets stuck because there is no incoming
EOF indicator on its socket. On the peer side the EOF indicator as
recvmsg() returns 0 will be triggered as mechanism to flush the socket
queue on the receive side. In SCTP recvmsg() function sctp_recvmsg() we
can see that only if sk_shutdown has the bit RCV_SHUTDOWN set SCTP will
recvmsg() will return EOF. The RCV_SHUTDOWN bit will only be set when
shutdown with SHUT_RD is called. We use now SHUT_RDWR to also get a EOF
indicator from recvmsg() call on the shutdown() initiator.
SCTP does not support half closed sockets and the semantic of SHUT_WR is
different here, it seems that calling SHUT_WR on sctp sockets keeps the
socket open to have the possibility to do some specific SCTP operations on
it that we don't do here.
There exists still a difference in the limitations of TCP vs SCTP in
case if we are required to have a half closed socket functionality. This
was tried to archieve with DLM protocol changes in the past and
hopefully we really don't require half closed socket functionality.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Tested-by: Heming zhao <heming.zhao@suse.com>
Reviewed-by: Heming zhao <heming.zhao@suse.com>
Signed-off-by: David Teigland <teigland@redhat.com>
| -rw-r--r-- | fs/dlm/lowcomms.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index 50c42b368c83..e4373bce1bc2 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -160,6 +160,7 @@ struct dlm_proto_ops { bool try_new_addr; const char *name; int proto; + int how; void (*sockopts)(struct socket *sock); int (*bind)(struct socket *sock); @@ -810,7 +811,7 @@ static void shutdown_connection(struct connection *con, bool and_other) return; } - ret = kernel_sock_shutdown(con->sock, SHUT_WR); + ret = kernel_sock_shutdown(con->sock, dlm_proto_ops->how); up_read(&con->sock_lock); if (ret) { log_print("Connection %p failed to shutdown: %d will force close", @@ -1858,6 +1859,7 @@ static int dlm_tcp_listen_bind(struct socket *sock) static const struct dlm_proto_ops dlm_tcp_ops = { .name = "TCP", .proto = IPPROTO_TCP, + .how = SHUT_WR, .sockopts = dlm_tcp_sockopts, .bind = dlm_tcp_bind, .listen_validate = dlm_tcp_listen_validate, @@ -1896,6 +1898,7 @@ static void dlm_sctp_sockopts(struct socket *sock) static const struct dlm_proto_ops dlm_sctp_ops = { .name = "SCTP", .proto = IPPROTO_SCTP, + .how = SHUT_RDWR, .try_new_addr = true, .sockopts = dlm_sctp_sockopts, .bind = dlm_sctp_bind, |