From c83e45e9b001591633188a480a896c935d3c9625 Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Tue, 22 Jun 2021 18:47:51 +0200 Subject: [PATCH] MEDIUM: queue: simplify again the process_srv_queue() API This basically undoes the API changes that were performed by commit 0274286dd ("BUG/MAJOR: server: fix deadlock when changing maxconn via agent-check") to address the deadlock issue: since process_srv_queue() doesn't use the server lock anymore, it doesn't need the "server_locked" argument, so let's get rid of it before it gets used again. --- include/haproxy/queue.h | 2 +- include/haproxy/stream.h | 2 +- src/backend.c | 8 ++++---- src/cli.c | 2 +- src/queue.c | 5 ++--- src/server.c | 5 +---- src/stream.c | 4 ++-- 7 files changed, 12 insertions(+), 16 deletions(-) diff --git a/include/haproxy/queue.h b/include/haproxy/queue.h index 58a0b091c..101a4ca5f 100644 --- a/include/haproxy/queue.h +++ b/include/haproxy/queue.h @@ -34,7 +34,7 @@ extern struct pool_head *pool_head_pendconn; struct pendconn *pendconn_add(struct stream *strm); int pendconn_dequeue(struct stream *strm); -void process_srv_queue(struct server *s, int server_locked); +void process_srv_queue(struct server *s); unsigned int srv_dynamic_maxconn(const struct server *s); int pendconn_redistribute(struct server *s); int pendconn_grab_from_px(struct server *s); diff --git a/include/haproxy/stream.h b/include/haproxy/stream.h index d313d2c42..9a7ffa1d2 100644 --- a/include/haproxy/stream.h +++ b/include/haproxy/stream.h @@ -339,7 +339,7 @@ static inline void stream_choose_redispatch(struct stream *s) ((s->be->lbprm.algo & BE_LB_KIND) == BE_LB_KIND_RR)))) { sess_change_server(s, NULL); if (may_dequeue_tasks(objt_server(s->target), s->be)) - process_srv_queue(objt_server(s->target), 0); + process_srv_queue(objt_server(s->target)); s->flags &= ~(SF_DIRECT | SF_ASSIGNED | SF_ADDR_SET); si->state = SI_ST_REQ; diff --git a/src/backend.c b/src/backend.c index f6f3ef037..2041c430e 100644 --- a/src/backend.c +++ b/src/backend.c @@ -819,7 +819,7 @@ out_ok: sess_change_server(s, srv); } else { if (may_dequeue_tasks(conn_slot, s->be)) - process_srv_queue(conn_slot, 0); + process_srv_queue(conn_slot); } } @@ -1831,7 +1831,7 @@ int srv_redispatch_connect(struct stream *s) /* release other streams waiting for this server */ if (may_dequeue_tasks(srv, s->be)) - process_srv_queue(srv, 0); + process_srv_queue(srv); return 1; } /* if we get here, it's because we got SRV_STATUS_OK, which also @@ -1907,7 +1907,7 @@ void back_try_conn_req(struct stream *s) /* release other streams waiting for this server */ sess_change_server(s, NULL); if (may_dequeue_tasks(srv, s->be)) - process_srv_queue(srv, 0); + process_srv_queue(srv); /* Failed and not retryable. */ si_shutr(si); @@ -2235,7 +2235,7 @@ void back_handle_st_cer(struct stream *s) _HA_ATOMIC_INC(&s->be->be_counters.failed_conns); sess_change_server(s, NULL); if (may_dequeue_tasks(objt_server(s->target), s->be)) - process_srv_queue(objt_server(s->target), 0); + process_srv_queue(objt_server(s->target)); /* shutw is enough so stop a connecting socket */ si_shutw(si); diff --git a/src/cli.c b/src/cli.c index 00990dc47..bc561cf2c 100644 --- a/src/cli.c +++ b/src/cli.c @@ -2565,7 +2565,7 @@ int pcli_wait_for_response(struct stream *s, struct channel *rep, int an_bit) HA_ATOMIC_DEC(&__objt_server(s->target)->cur_sess); } if (may_dequeue_tasks(__objt_server(s->target), be)) - process_srv_queue(__objt_server(s->target), 0); + process_srv_queue(__objt_server(s->target)); } s->target = NULL; diff --git a/src/queue.c b/src/queue.c index 78a4b5211..618825eaa 100644 --- a/src/queue.c +++ b/src/queue.c @@ -331,10 +331,9 @@ static struct pendconn *pendconn_process_next_strm(struct server *srv, struct pr } /* Manages a server's connection queue. This function will try to dequeue as - * many pending streams as possible, and wake them up. must - * only be set if the caller already hold the server lock. + * many pending streams as possible, and wake them up. */ -void process_srv_queue(struct server *s, int server_locked) +void process_srv_queue(struct server *s) { struct proxy *p = s->proxy; int done = 0; diff --git a/src/server.c b/src/server.c index 0a128a2f1..2b3cc82be 100644 --- a/src/server.c +++ b/src/server.c @@ -1818,11 +1818,8 @@ const char *server_parse_maxconn_change_request(struct server *sv, sv->maxconn = v; } - /* server_parse_maxconn_change_request requires the server lock held. - * Specify it to process_srv_queue to prevent a deadlock. - */ if (may_dequeue_tasks(sv, sv->proxy)) - process_srv_queue(sv, 1); + process_srv_queue(sv); return NULL; } diff --git a/src/stream.c b/src/stream.c index b8da93564..c9c01fce2 100644 --- a/src/stream.c +++ b/src/stream.c @@ -623,7 +623,7 @@ static void stream_free(struct stream *s) _HA_ATOMIC_DEC(&__objt_server(s->target)->cur_sess); } if (may_dequeue_tasks(objt_server(s->target), s->be)) - process_srv_queue(objt_server(s->target), 0); + process_srv_queue(objt_server(s->target)); } if (unlikely(s->srv_conn)) { @@ -1815,7 +1815,7 @@ struct task *process_stream(struct task *t, void *context, unsigned int state) } sess_change_server(s, NULL); if (may_dequeue_tasks(srv, s->be)) - process_srv_queue(srv, 0); + process_srv_queue(srv); } }