libteam: set netlink event socket as non-blocking
diff mbox series

Message ID 20190528080245.29690-1-bgalvani@redhat.com
State New
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Series
  • libteam: set netlink event socket as non-blocking
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Commit Message

Beniamino Galvani May 28, 2019, 8:02 a.m. UTC
In some situations it was observed that recvmsg() blocks even if
epoll_wait() reports the netlink socket as ready:

 select(15, [3 9 10 14], [], [], NULL)   = 1 (in [9])
 epoll_wait(9, [{EPOLLIN, {u32=8, u64=8}}], 2, -1) = 1
 recvmsg(8,                                  ### blocked

(9 is the epoll fd, 8 the nl_cli event socket).

Probably this is caused by a bug in kernel, however it seems more
robust anyway to set the socket as non-blocking to avoid problems like
this.

Signed-off-by: Beniamino Galvani <bgalvani@redhat.com>
---
 libteam/libteam.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Jiri Pirko May 28, 2019, 12:36 p.m. UTC | #1
Tue, May 28, 2019 at 10:02:45AM CEST, bgalvani@redhat.com wrote:
>In some situations it was observed that recvmsg() blocks even if
>epoll_wait() reports the netlink socket as ready:
>
> select(15, [3 9 10 14], [], [], NULL)   = 1 (in [9])
> epoll_wait(9, [{EPOLLIN, {u32=8, u64=8}}], 2, -1) = 1
> recvmsg(8,                                  ### blocked
>
>(9 is the epoll fd, 8 the nl_cli event socket).
>
>Probably this is caused by a bug in kernel, however it seems more
>robust anyway to set the socket as non-blocking to avoid problems like
>this.
>
>Signed-off-by: Beniamino Galvani <bgalvani@redhat.com>

applied, thanks.

Patch
diff mbox series

diff --git a/libteam/libteam.c b/libteam/libteam.c
index 0065a7f..9c9c93a 100644
--- a/libteam/libteam.c
+++ b/libteam/libteam.c
@@ -638,6 +638,7 @@  int team_init(struct team_handle *th, uint32_t ifindex)
 	nl_socket_modify_cb(th->nl_cli.sock_event, NL_CB_VALID,
 			    NL_CB_CUSTOM, cli_event_handler, th);
 	nl_cli_connect(th->nl_cli.sock_event, NETLINK_ROUTE);
+	nl_socket_set_nonblocking(th->nl_cli.sock_event);
 
 	env = getenv("TEAM_EVENT_BUFSIZE");
 	if (env) {