Re: [PATCH v2 5/5] flow: Introduce flow_epoll_set() to centralize epoll operations

[Laurent Vivier <lvivier@redhat.com>]

On 1/9/26 00:33, David Gibson wrote:
> On Thu, Jan 08, 2026 at 03:01:19PM +0100, Laurent Vivier wrote:
>> Currently, each flow type (TCP, TCP_SPLICE, PING, UDP) has its own
>> code to add or modify file descriptors in epoll. This leads to
>> duplicated boilerplate code across icmp.c, tcp.c, tcp_splice.c, and
>> udp_flow.c, each setting up epoll_ref unions and calling epoll_ctl()
>> with flow-type-specific details.
>>
>> Introduce flow_epoll_set() in flow.c to handle epoll operations for
>> all flow types in a unified way. The function takes an explicit epoll
>> type parameter, allowing it to handle not only flow socket types but
>> also the TCP timer (EPOLL_TYPE_TCP_TIMER).
>>
>> This will be needed to migrate queue pair from an epollfd to another.
>>
>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> 
> I'm not totally convinced if folding in TCP timers with the socket fds
> makes sense.  I think there's still room for improving consistency of

I agree. And as we don't need to manage the EPOLL_CTL_MOD for it anymore, the case is 
simpler. Moreover, if we don't manage it in the function we can remove the epoll_type from 
the parameters as we can rely on the flow type.

Thanks,
Laurent

> the epoll lifecycle (removing the in_epoll flag equivalent).  But both
> of those can be looked at later.  So,
> 
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> 
>> ---
>>   flow.c       | 33 ++++++++++++++++++++
>>   flow.h       |  3 ++
>>   icmp.c       | 11 +++----
>>   tcp.c        | 64 ++++++++++++++++++++------------------
>>   tcp_splice.c | 86 +++++++++++++++++++++++++---------------------------
>>   udp_flow.c   | 12 +++-----
>>   6 files changed, 119 insertions(+), 90 deletions(-)
>>
>> diff --git a/flow.c b/flow.c
>> index 4f53486586cd..73d24f9d3765 100644
>> --- a/flow.c
>> +++ b/flow.c
>> @@ -20,6 +20,7 @@
>>   #include "flow.h"
>>   #include "flow_table.h"
>>   #include "repair.h"
>> +#include "epoll_ctl.h"
>>   
>>   const char *flow_state_str[] = {
>>   	[FLOW_STATE_FREE]	= "FREE",
>> @@ -390,6 +391,38 @@ void flow_epollid_clear(struct flow_common *f)
>>   	f->epollid = EPOLLFD_ID_INVALID;
>>   }
>>   
>> +/**
>> + * flow_epoll_set() - Add or modify epoll registration for a flow socket
>> + * @command:	epoll_ctl() command: EPOLL_CTL_ADD or EPOLL_CTL_MOD
>> + * @type:	epoll type
>> + * @f:		Flow to register socket for
>> + * @events:	epoll events to watch for
>> + * @fd:		File descriptor to register
>> + * @sidei:	Side index of the flow
>> + *
>> + * Return: 0 on success, -1 on error (from epoll_ctl())
>> + */
>> +int flow_epoll_set(int command, enum epoll_type type,
>> +		   const struct flow_common *f, uint32_t events, int fd,
>> +		   unsigned int sidei)
>> +{
>> +	struct epoll_event ev;
>> +	union epoll_ref ref;
>> +
>> +	ref.type = type;
>> +	ref.fd = fd;
>> +
>> +	if (type == EPOLL_TYPE_TCP_TIMER)
>> +		ref.flow = flow_idx(f);
>> +	else
>> +		ref.flowside = flow_sidx(f, sidei);
>> +
>> +	ev.events = events;
>> +	ev.data.u64 = ref.u64;
>> +
>> +	return epoll_ctl(flow_epollfd(f), command, fd, &ev);
>> +}
>> +
>>   /**
>>    * flow_epollid_register() - Initialize the epoll id -> fd mapping
>>    * @epollid:	epoll id to associate to
>> diff --git a/flow.h b/flow.h
>> index b43b0b1dd7f2..bd5c6d90322b 100644
>> --- a/flow.h
>> +++ b/flow.h
>> @@ -265,6 +265,9 @@ bool flow_in_epoll(const struct flow_common *f);
>>   int flow_epollfd(const struct flow_common *f);
>>   void flow_epollid_set(struct flow_common *f, int epollid);
>>   void flow_epollid_clear(struct flow_common *f);
>> +int flow_epoll_set(int command, enum epoll_type type,
>> +		   const struct flow_common *f, uint32_t events, int fd,
>> +		   unsigned int sidei);
>>   void flow_epollid_register(int epollid, int epollfd);
>>   void flow_defer_handler(const struct ctx *c, const struct timespec *now);
>>   int flow_migrate_source_early(struct ctx *c, const struct migrate_stage *stage,
>> diff --git a/icmp.c b/icmp.c
>> index 9564c4963f7b..b6bb36d80715 100644
>> --- a/icmp.c
>> +++ b/icmp.c
>> @@ -177,7 +177,6 @@ static struct icmp_ping_flow *icmp_ping_new(const struct ctx *c,
>>   	union flow *flow = flow_alloc();
>>   	struct icmp_ping_flow *pingf;
>>   	const struct flowside *tgt;
>> -	union epoll_ref ref;
>>   
>>   	if (!flow)
>>   		return NULL;
>> @@ -211,13 +210,11 @@ static struct icmp_ping_flow *icmp_ping_new(const struct ctx *c,
>>   		goto cancel;
>>   
>>   	flow_epollid_set(&pingf->f, EPOLLFD_ID_DEFAULT);
>> -
>> -	ref.type = EPOLL_TYPE_PING;
>> -	ref.flowside = FLOW_SIDX(flow, TGTSIDE);
>> -	ref.fd = pingf->sock;
>> -
>> -	if (epoll_add(flow_epollfd(&pingf->f), EPOLLIN, ref) < 0) {
>> +	if (flow_epoll_set(EPOLL_CTL_ADD, EPOLL_TYPE_PING, &pingf->f,
>> +			   EPOLLIN, pingf->sock,
>> +			   TGTSIDE) < 0) {
>>   		close(pingf->sock);
>> +		flow_epollid_clear(&pingf->f);
>>   		goto cancel;
>>   	}
>>   
>> diff --git a/tcp.c b/tcp.c
>> index 5141cdc7e839..d8cc11b377de 100644
>> --- a/tcp.c
>> +++ b/tcp.c
>> @@ -523,34 +523,44 @@ static uint32_t tcp_conn_epoll_events(uint8_t events, uint8_t conn_flags)
>>   
>>   /**
>>    * tcp_epoll_ctl() - Add/modify/delete epoll state from connection events
>> - * @c:		Execution context
>>    * @conn:	Connection pointer
>>    *
>>    * Return: 0 on success, negative error code on failure (not on deletion)
>>    */
>> -static int tcp_epoll_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
>> +static int tcp_epoll_ctl(struct tcp_tap_conn *conn)
>>   {
>> -	int m = flow_in_epoll(&conn->f) ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
>> -	union epoll_ref ref = { .type = EPOLL_TYPE_TCP, .fd = conn->sock,
>> -		                .flowside = FLOW_SIDX(conn, !TAPSIDE(conn)), };
>> -	struct epoll_event ev = { .data.u64 = ref.u64 };
>> -	int epollfd = flow_in_epoll(&conn->f) ? flow_epollfd(&conn->f)
>> -					      : c->epollfd;
>> +	uint32_t events;
>> +	int m;
>>   
>>   	if (conn->events == CLOSED) {
>> -		if (flow_in_epoll(&conn->f))
>> +		if (flow_in_epoll(&conn->f)) {
>> +			int epollfd = flow_epollfd(&conn->f);
>> +
>>   			epoll_del(epollfd, conn->sock);
>> -		if (conn->timer != -1)
>> -			epoll_del(epollfd, conn->timer);
>> +			if (conn->timer != -1)
>> +				epoll_del(epollfd, conn->timer);
>> +		}
>> +
>>   		return 0;
>>   	}
>>   
>> -	ev.events = tcp_conn_epoll_events(conn->events, conn->flags);
>> +	events = tcp_conn_epoll_events(conn->events, conn->flags);
>>   
>> -	if (epoll_ctl(epollfd, m, conn->sock, &ev))
>> -		return -errno;
>> +	if (flow_in_epoll(&conn->f)) {
>> +		m = EPOLL_CTL_MOD;
>> +	} else {
>> +		flow_epollid_set(&conn->f, EPOLLFD_ID_DEFAULT);
>> +		m = EPOLL_CTL_ADD;
>> +	}
>> +
>> +	if (flow_epoll_set(m, EPOLL_TYPE_TCP, &conn->f, events, conn->sock,
>> +			   !TAPSIDE(conn)) < 0) {
>> +		int ret = -errno;
>>   
>> -	flow_epollid_set(&conn->f, EPOLLFD_ID_DEFAULT);
>> +		if (m == EPOLL_CTL_ADD)
>> +			flow_epollid_clear(&conn->f);
>> +		return ret;
>> +	}
>>   
>>   	return 0;
>>   }
>> @@ -569,11 +579,6 @@ static void tcp_timer_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
>>   		return;
>>   
>>   	if (conn->timer == -1) {
>> -		union epoll_ref ref = { .type = EPOLL_TYPE_TCP_TIMER,
>> -					.flow = FLOW_IDX(conn) };
>> -		struct epoll_event ev = { .data.u64 = ref.u64,
>> -					  .events = EPOLLIN | EPOLLET };
>> -		int epollfd = flow_epollfd(&conn->f);
>>   		int fd;
>>   
>>   		fd = timerfd_create(CLOCK_MONOTONIC, 0);
>> @@ -581,18 +586,17 @@ static void tcp_timer_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
>>   			flow_dbg_perror(conn, "failed to get timer");
>>   			if (fd > -1)
>>   				close(fd);
>> -			conn->timer = -1;
>>   			return;
>>   		}
>> -		conn->timer = fd;
>> -		ref.fd = conn->timer;
>>   
>> -		if (epoll_ctl(epollfd, EPOLL_CTL_ADD, conn->timer, &ev)) {
>> +		if (flow_epoll_set(EPOLL_CTL_ADD, EPOLL_TYPE_TCP_TIMER,
>> +				   &conn->f, EPOLLIN | EPOLLET, fd, 0) < 0) {
>>   			flow_dbg_perror(conn, "failed to add timer");
>> -			close(conn->timer);
>> -			conn->timer = -1;
>> +			close(fd);
>>   			return;
>>   		}
>> +
>> +		conn->timer = fd;
>>   	}
>>   
>>   	if (conn->flags & ACK_TO_TAP_DUE) {
>> @@ -669,7 +673,7 @@ void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn,
>>   	}
>>   
>>   	if (flag == STALLED || flag == ~STALLED)
>> -		tcp_epoll_ctl(c, conn);
>> +		tcp_epoll_ctl(conn);
>>   
>>   	if (flag == ACK_FROM_TAP_DUE || flag == ACK_TO_TAP_DUE		  ||
>>   	    (flag == ~ACK_FROM_TAP_DUE && (conn->flags & ACK_TO_TAP_DUE)) ||
>> @@ -726,7 +730,7 @@ void conn_event_do(const struct ctx *c, struct tcp_tap_conn *conn,
>>   	} else {
>>   		if (event == CLOSED)
>>   			flow_hash_remove(c, TAP_SIDX(conn));
>> -		tcp_epoll_ctl(c, conn);
>> +		tcp_epoll_ctl(conn);
>>   	}
>>   
>>   	if (CONN_HAS(conn, SOCK_FIN_SENT | TAP_FIN_ACKED))
>> @@ -1742,7 +1746,7 @@ static void tcp_conn_from_tap(const struct ctx *c, sa_family_t af,
>>   		conn_event(c, conn, TAP_SYN_ACK_SENT);
>>   	}
>>   
>> -	tcp_epoll_ctl(c, conn);
>> +	tcp_epoll_ctl(conn);
>>   
>>   	if (c->mode == MODE_VU) { /* To rebind to same oport after migration */
>>   		socklen_t sl = sizeof(sa);
>> @@ -3984,7 +3988,7 @@ int tcp_flow_migrate_target_ext(struct ctx *c, struct tcp_tap_conn *conn, int fd
>>   	tcp_send_flag(c, conn, ACK);
>>   	tcp_data_from_sock(c, conn);
>>   
>> -	if ((rc = tcp_epoll_ctl(c, conn))) {
>> +	if ((rc = tcp_epoll_ctl(conn))) {
>>   		flow_dbg(conn,
>>   			 "Failed to subscribe to epoll for migrated socket: %s",
>>   			 strerror_(-rc));
>> diff --git a/tcp_splice.c b/tcp_splice.c
>> index bf4ff466de07..26e9845c39ee 100644
>> --- a/tcp_splice.c
>> +++ b/tcp_splice.c
>> @@ -135,37 +135,35 @@ static uint32_t tcp_splice_conn_epoll_events(uint16_t events, unsigned sidei)
>>   
>>   /**
>>    * tcp_splice_epoll_ctl() - Add/modify/delete epoll state from connection events
>> - * @c:		Execution context
>>    * @conn:	Connection pointer
>>    *
>>    * Return: 0 on success, negative error code on failure (not on deletion)
>>    */
>> -static int tcp_splice_epoll_ctl(const struct ctx *c,
>> -				struct tcp_splice_conn *conn)
>> +static int tcp_splice_epoll_ctl(struct tcp_splice_conn *conn)
>>   {
>> -	int epollfd = flow_in_epoll(&conn->f) ? flow_epollfd(&conn->f)
>> -					      : c->epollfd;
>> -	int m = flow_in_epoll(&conn->f) ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
>> -	const union epoll_ref ref[SIDES] = {
>> -		{ .type = EPOLL_TYPE_TCP_SPLICE, .fd = conn->s[0],
>> -		  .flowside = FLOW_SIDX(conn, 0) },
>> -		{ .type = EPOLL_TYPE_TCP_SPLICE, .fd = conn->s[1],
>> -		  .flowside = FLOW_SIDX(conn, 1) }
>> -	};
>> -	struct epoll_event ev[SIDES] = { { .data.u64 = ref[0].u64 },
>> -					 { .data.u64 = ref[1].u64 } };
>> -
>> -	ev[0].events = tcp_splice_conn_epoll_events(conn->events, 0);
>> -	ev[1].events = tcp_splice_conn_epoll_events(conn->events, 1);
>> -
>> -
>> -	if (epoll_ctl(epollfd, m, conn->s[0], &ev[0]) ||
>> -	    epoll_ctl(epollfd, m, conn->s[1], &ev[1])) {
>> +	uint32_t events[2];
>> +	int m;
>> +
>> +	if (flow_in_epoll(&conn->f)) {
>> +		m = EPOLL_CTL_MOD;
>> +	} else {
>> +		flow_epollid_set(&conn->f, EPOLLFD_ID_DEFAULT);
>> +		m = EPOLL_CTL_ADD;
>> +	}
>> +
>> +	events[0] = tcp_splice_conn_epoll_events(conn->events, 0);
>> +	events[1] = tcp_splice_conn_epoll_events(conn->events, 1);
>> +
>> +	if (flow_epoll_set(m, EPOLL_TYPE_TCP_SPLICE, &conn->f, events[0],
>> +			   conn->s[0], 0) ||
>> +	    flow_epoll_set(m, EPOLL_TYPE_TCP_SPLICE, &conn->f, events[1],
>> +			   conn->s[1], 1)) {
>>   		int ret = -errno;
>>   		flow_perror(conn, "ERROR on epoll_ctl()");
>> +		if (m == EPOLL_CTL_ADD)
>> +			flow_epollid_clear(&conn->f);
>>   		return ret;
>>   	}
>> -	flow_epollid_set(&conn->f, EPOLLFD_ID_DEFAULT);
>>   
>>   	return 0;
>>   }
>> @@ -205,7 +203,7 @@ static void conn_flag_do(struct tcp_splice_conn *conn,
>>   	}
>>   }
>>   
>> -#define conn_flag(c, conn, flag)					\
>> +#define conn_flag(conn, flag)					\
>>   	do {								\
>>   		flow_trace(conn, "flag at %s:%i", __func__, __LINE__);	\
>>   		conn_flag_do(conn, flag);				\
>> @@ -213,12 +211,10 @@ static void conn_flag_do(struct tcp_splice_conn *conn,
>>   
>>   /**
>>    * conn_event_do() - Set and log connection events, update epoll state
>> - * @c:		Execution context
>>    * @conn:	Connection pointer
>>    * @event:	Connection event
>>    */
>> -static void conn_event_do(const struct ctx *c, struct tcp_splice_conn *conn,
>> -			  unsigned long event)
>> +static void conn_event_do(struct tcp_splice_conn *conn, unsigned long event)
>>   {
>>   	if (event & (event - 1)) {
>>   		int flag_index = fls(~event);
>> @@ -240,14 +236,14 @@ static void conn_event_do(const struct ctx *c, struct tcp_splice_conn *conn,
>>   			flow_dbg(conn, "%s", tcp_splice_event_str[flag_index]);
>>   	}
>>   
>> -	if (tcp_splice_epoll_ctl(c, conn))
>> -		conn_flag(c, conn, CLOSING);
>> +	if (tcp_splice_epoll_ctl(conn))
>> +		conn_flag(conn, CLOSING);
>>   }
>>   
>> -#define conn_event(c, conn, event)					\
>> +#define conn_event(conn, event)					\
>>   	do {								\
>>   		flow_trace(conn, "event at %s:%i",__func__, __LINE__);	\
>> -		conn_event_do(c, conn, event);				\
>> +		conn_event_do(conn, event);				\
>>   	} while (0)
>>   
>>   
>> @@ -315,7 +311,7 @@ static int tcp_splice_connect_finish(const struct ctx *c,
>>   			if (pipe2(conn->pipe[sidei], O_NONBLOCK | O_CLOEXEC)) {
>>   				flow_perror(conn, "cannot create %d->%d pipe",
>>   					    sidei, !sidei);
>> -				conn_flag(c, conn, CLOSING);
>> +				conn_flag(conn, CLOSING);
>>   				return -EIO;
>>   			}
>>   
>> @@ -329,7 +325,7 @@ static int tcp_splice_connect_finish(const struct ctx *c,
>>   	}
>>   
>>   	if (!(conn->events & SPLICE_ESTABLISHED))
>> -		conn_event(c, conn, SPLICE_ESTABLISHED);
>> +		conn_event(conn, SPLICE_ESTABLISHED);
>>   
>>   	return 0;
>>   }
>> @@ -376,7 +372,7 @@ static int tcp_splice_connect(const struct ctx *c, struct tcp_splice_conn *conn)
>>   
>>   	pif_sockaddr(c, &sa, tgtpif, &tgt->eaddr, tgt->eport);
>>   
>> -	conn_event(c, conn, SPLICE_CONNECT);
>> +	conn_event(conn, SPLICE_CONNECT);
>>   
>>   	if (connect(conn->s[1], &sa.sa, socklen_inany(&sa))) {
>>   		if (errno != EINPROGRESS) {
>> @@ -385,7 +381,7 @@ static int tcp_splice_connect(const struct ctx *c, struct tcp_splice_conn *conn)
>>   			return -errno;
>>   		}
>>   	} else {
>> -		conn_event(c, conn, SPLICE_ESTABLISHED);
>> +		conn_event(conn, SPLICE_ESTABLISHED);
>>   		return tcp_splice_connect_finish(c, conn);
>>   	}
>>   
>> @@ -445,7 +441,7 @@ void tcp_splice_conn_from_sock(const struct ctx *c, union flow *flow, int s0)
>>   		flow_trace(conn, "failed to set TCP_QUICKACK on %i", s0);
>>   
>>   	if (tcp_splice_connect(c, conn))
>> -		conn_flag(c, conn, CLOSING);
>> +		conn_flag(conn, CLOSING);
>>   
>>   	FLOW_ACTIVATE(conn);
>>   }
>> @@ -494,14 +490,14 @@ void tcp_splice_sock_handler(struct ctx *c, union epoll_ref ref,
>>   
>>   	if (events & EPOLLOUT) {
>>   		fromsidei = !evsidei;
>> -		conn_event(c, conn, ~OUT_WAIT(evsidei));
>> +		conn_event(conn, ~OUT_WAIT(evsidei));
>>   	} else {
>>   		fromsidei = evsidei;
>>   	}
>>   
>>   	if (events & EPOLLRDHUP)
>>   		/* For side 0 this is fake, but implied */
>> -		conn_event(c, conn, FIN_RCVD(evsidei));
>> +		conn_event(conn, FIN_RCVD(evsidei));
>>   
>>   swap:
>>   	eof = 0;
>> @@ -536,7 +532,7 @@ retry:
>>   				more = SPLICE_F_MORE;
>>   
>>   			if (conn->flags & lowat_set_flag)
>> -				conn_flag(c, conn, lowat_act_flag);
>> +				conn_flag(conn, lowat_act_flag);
>>   		}
>>   
>>   		do
>> @@ -568,8 +564,8 @@ retry:
>>   						   "Setting SO_RCVLOWAT %i: %s",
>>   						   lowat, strerror_(errno));
>>   				} else {
>> -					conn_flag(c, conn, lowat_set_flag);
>> -					conn_flag(c, conn, lowat_act_flag);
>> +					conn_flag(conn, lowat_set_flag);
>> +					conn_flag(conn, lowat_act_flag);
>>   				}
>>   			}
>>   
>> @@ -583,7 +579,7 @@ retry:
>>   			if (conn->read[fromsidei] == conn->written[fromsidei])
>>   				break;
>>   
>> -			conn_event(c, conn, OUT_WAIT(!fromsidei));
>> +			conn_event(conn, OUT_WAIT(!fromsidei));
>>   			break;
>>   		}
>>   
>> @@ -605,7 +601,7 @@ retry:
>>   			if ((conn->events & FIN_RCVD(sidei)) &&
>>   			    !(conn->events & FIN_SENT(!sidei))) {
>>   				shutdown(conn->s[!sidei], SHUT_WR);
>> -				conn_event(c, conn, FIN_SENT(!sidei));
>> +				conn_event(conn, FIN_SENT(!sidei));
>>   			}
>>   		}
>>   	}
>> @@ -626,7 +622,7 @@ retry:
>>   	return;
>>   
>>   close:
>> -	conn_flag(c, conn, CLOSING);
>> +	conn_flag(conn, CLOSING);
>>   }
>>   
>>   /**
>> @@ -762,10 +758,10 @@ void tcp_splice_timer(struct tcp_splice_conn *conn)
>>   				flow_trace(conn, "can't set SO_RCVLOWAT on %d",
>>   					   conn->s[sidei]);
>>   			}
>> -			conn_flag(c, conn, ~RCVLOWAT_SET(sidei));
>> +			conn_flag(conn, ~RCVLOWAT_SET(sidei));
>>   		}
>>   	}
>>   
>>   	flow_foreach_sidei(sidei)
>> -		conn_flag(c, conn, ~RCVLOWAT_ACT(sidei));
>> +		conn_flag(conn, ~RCVLOWAT_ACT(sidei));
>>   }
>> diff --git a/udp_flow.c b/udp_flow.c
>> index c4cf35c2c89d..b016a8095ec6 100644
>> --- a/udp_flow.c
>> +++ b/udp_flow.c
>> @@ -74,7 +74,6 @@ static int udp_flow_sock(const struct ctx *c,
>>   {
>>   	const struct flowside *side = &uflow->f.side[sidei];
>>   	uint8_t pif = uflow->f.pif[sidei];
>> -	union epoll_ref ref;
>>   	int rc;
>>   	int s;
>>   
>> @@ -84,14 +83,11 @@ static int udp_flow_sock(const struct ctx *c,
>>   		return s;
>>   	}
>>   
>> -	ref.type = EPOLL_TYPE_UDP;
>> -	ref.flowside = FLOW_SIDX(uflow, sidei);
>> -	ref.fd = s;
>> -
>>   	flow_epollid_set(&uflow->f, EPOLLFD_ID_DEFAULT);
>> -
>> -	rc = epoll_add(flow_epollfd(&uflow->f), EPOLLIN, ref);
>> -	if (rc < 0) {
>> +	if (flow_epoll_set(EPOLL_CTL_ADD, EPOLL_TYPE_UDP, &uflow->f,
>> +			   EPOLLIN, s, sidei) < 0) {
>> +		rc = -errno;
>> +		flow_epollid_clear(&uflow->f);
>>   		close(s);
>>   		return rc;
>>   	}
>> -- 
>> 2.52.0
>>
>