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
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
the epoll lifecycle (removing the in_epoll flag equivalent). But both
of those can be looked at later. So,
Reviewed-by: David Gibson
--- 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
-- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson