From nobody Tue Nov 19 19:51:42 2024 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4XtFW23kFQz5fNBk; Tue, 19 Nov 2024 19:51:42 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R10" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4XtFW22Vyhz4ccd; Tue, 19 Nov 2024 19:51:42 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1732045902; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=RT0SAu5idvzmOuUHGoAtlJDyAIfmI2JF0kwKeM0o9Bw=; b=rCvc0+q5P0kjbvxQbeY5ioSb5G9xWOihSFFuUTNfORgOz9Fp67RcEAfK37YLb7YHwTbn0q SggmP+GTTya9ZyJ/3x8YrMxVCoy0Wc+sqElhbll/CcLduyaWDzGr/qWAMfTtJR2b9x74kT IbV0NOPk2Be81lC/3coCYOawu9em2dpOLLJilpDwXSUaMnAYT+zh12oB7g7oUmpfMYq7Mq ydtLY7gFHrj1u6FoW80p52Gnyle3Bdx7zyZ7ScxgVL/P51rcpWhqryFm7BElXyba0UItAH 60a9DlwKtem94frKWTUVDSrENLAFPlcU5ebUulV3EviSSqH1iaEAoxf/Dxj+XA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1732045902; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=RT0SAu5idvzmOuUHGoAtlJDyAIfmI2JF0kwKeM0o9Bw=; b=OQqoJd1noDhTc4IKWWGFESHnMcOzZMnfYkS2PjaqQa4Qxw3Ot4PqnQBwdyo7JO2MWnOUw3 7hl7ue+tutkS53z4+eAyhFQpyY/nKRWjtudeRXcyYNpCktTYX2UVGAZFY8OLpssnZI+RaX TZ04KvT2JfI5XpghXTElt/jWGDl9vNedAnQPOMp5tSVcc5RjNUjtTvmihtMNlb2GDCyDHx OqoT9XdATZprxYdeLzM1e4IJHY/8Fm5scYj+RpqX+nyQ1vw45htxxq7r/EW+uE3coq0WKD ISxMhKFjpGHbrMlpWhWkrNSch1iQgh1EMc0jJ0yYgmELDabeYXK9Y1tsel8/dQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1732045902; a=rsa-sha256; cv=none; b=naLl2KNVNQkluT95omRnKi1xBJqmmHeNA7+HUc1DtV061M6WUX4VirugLSc4nLCGTCH4Ix Rf9XT/c2HlgImruhABiKd+tP1hAkjHsSuOHW0d9fyG47s1V52Zknf4RJPJ+PeULjI81k+g AABD1y/q/j4q27BJZpOg9YZRket/V48e9mr6eUkg82rRRsVYpQP+EwFRiyZbx+HxGZzBZf 8Sc7Jpv8K+7Y+whX30VPFpBObVwMRuag6k/peEi/CK9Y2J1nLGOUHC1xY8QK4ZIOyTf7VO NlBBX05a7+/NNuQK5z+cX0KWcLSpgpNZr90NGqvdlnCA9s6B2NlBsnF+S9o92g== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4XtFW226FWzNk8; Tue, 19 Nov 2024 19:51:42 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 4AJJpgV6035614; Tue, 19 Nov 2024 19:51:42 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 4AJJpgmB035611; Tue, 19 Nov 2024 19:51:42 GMT (envelope-from git) Date: Tue, 19 Nov 2024 19:51:42 GMT Message-Id: <202411191951.4AJJpgmB035611@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Kyle Evans Subject: git: bc1dfc316a2b - main - daemon: stop rebuilding the kqueue every restart of the child List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kevans X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: bc1dfc316a2bba97773a14b96f5e976a52524be4 Auto-Submitted: auto-generated The branch main has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=bc1dfc316a2bba97773a14b96f5e976a52524be4 commit bc1dfc316a2bba97773a14b96f5e976a52524be4 Author: Kyle Evans AuthorDate: 2024-11-19 19:51:27 +0000 Commit: Kyle Evans CommitDate: 2024-11-19 19:51:27 +0000 daemon: stop rebuilding the kqueue every restart of the child We populate the kqueue with all of four kevents: three signal handlers and one for read of the child pipe. Every time we start the child, we rebuild this kqueue from scratch for the child and tear it down before we exit and check if we need to restart the child. As a consequence, we effectively drop any of the signals we're interested in between restarts. Push the kqueue out into the daemon state to avoid losing any signal events in the process, and reimplement the restart timer in terms of kqueue timers. The pipe read event will be automatically deleted upon last close, which leaves us with only the signal events that really get retained between restarts of the child. PR: 277959 Reviewed by: des, markj Differential Revision: https://reviews.freebsd.org/D47004 --- usr.sbin/daemon/daemon.c | 121 +++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 101 insertions(+), 20 deletions(-) diff --git a/usr.sbin/daemon/daemon.c b/usr.sbin/daemon/daemon.c index a21346086dd1..efba87de19d4 100644 --- a/usr.sbin/daemon/daemon.c +++ b/usr.sbin/daemon/daemon.c @@ -86,6 +86,7 @@ struct daemon_state { int pipe_rd; int pipe_wr; int keep_cur_workdir; + int kqueue_fd; int restart_delay; int stdmask; int syslog_priority; @@ -113,6 +114,7 @@ static void daemon_terminate(struct daemon_state *); static void daemon_exec(struct daemon_state *); static bool daemon_is_child_dead(struct daemon_state *); static void daemon_set_child_pipe(struct daemon_state *); +static int daemon_setup_kqueue(void); static int pidfile_truncate(struct pidfh *); @@ -344,6 +346,8 @@ main(int argc, char *argv[]) /* Write out parent pidfile if needed. */ pidfile_write(state.parent_pidfh); + state.kqueue_fd = daemon_setup_kqueue(); + do { state.mode = MODE_SUPERVISE; daemon_eventloop(&state); @@ -408,27 +412,13 @@ daemon_eventloop(struct daemon_state *state) state->pipe_rd = pipe_fd[0]; state->pipe_wr = pipe_fd[1]; - kq = kqueuex(KQUEUE_CLOEXEC); + kq = state->kqueue_fd; EV_SET(&event, state->pipe_rd, EVFILT_READ, EV_ADD|EV_CLEAR, 0, 0, NULL); if (kevent(kq, &event, 1, NULL, 0, NULL) == -1) { err(EXIT_FAILURE, "failed to register kevent"); } - EV_SET(&event, SIGHUP, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL); - if (kevent(kq, &event, 1, NULL, 0, NULL) == -1) { - err(EXIT_FAILURE, "failed to register kevent"); - } - - EV_SET(&event, SIGTERM, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL); - if (kevent(kq, &event, 1, NULL, 0, NULL) == -1) { - err(EXIT_FAILURE, "failed to register kevent"); - } - - EV_SET(&event, SIGCHLD, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL); - if (kevent(kq, &event, 1, NULL, 0, NULL) == -1) { - err(EXIT_FAILURE, "failed to register kevent"); - } memset(&event, 0, sizeof(struct kevent)); /* Spawn a child to exec the command. */ @@ -521,11 +511,12 @@ daemon_eventloop(struct daemon_state *state) } continue; default: + assert(0 && "Unexpected kevent filter type"); continue; } } - close(kq); + /* EVFILT_READ kqueue filter goes away here. */ close(state->pipe_rd); state->pipe_rd = -1; @@ -539,19 +530,76 @@ daemon_eventloop(struct daemon_state *state) } } +/* + * Note that daemon_sleep() should not be called with anything but the signal + * events in the kqueue without further consideration. + */ static void daemon_sleep(struct daemon_state *state) { - struct timespec ts = { state->restart_delay, 0 }; + struct kevent event = { 0 }; + int ret; + + assert(state->pipe_rd == -1); + assert(state->pipe_wr == -1); if (!state->restart_enabled) { return; } - while (nanosleep(&ts, &ts) == -1) { - if (errno != EINTR) { - err(1, "nanosleep"); + + EV_SET(&event, 0, EVFILT_TIMER, EV_ADD|EV_ONESHOT, NOTE_SECONDS, + state->restart_delay, NULL); + if (kevent(state->kqueue_fd, &event, 1, NULL, 0, NULL) == -1) { + err(1, "failed to register timer"); + } + + for (;;) { + ret = kevent(state->kqueue_fd, NULL, 0, &event, 1, NULL); + if (ret == -1) { + if (errno != EINTR) { + err(1, "kevent"); + } + + continue; + } + + /* + * Any other events being raised are indicative of a problem + * that we need to investigate. Most likely being that + * something was not cleaned up from the eventloop. + */ + assert(event.filter == EVFILT_TIMER || + event.filter == EVFILT_SIGNAL); + + if (event.filter == EVFILT_TIMER) { + /* Break's over, back to work. */ + break; + } + + /* Process any pending signals. */ + switch (event.ident) { + case SIGTERM: + /* + * We could disarm the timer, but we'll be terminating + * promptly anyways. + */ + state->restart_enabled = false; + return; + case SIGHUP: + if (state->log_reopen && state->output_fd >= 0) { + reopen_log(state); + } + + break; + case SIGCHLD: + default: + /* Discard */ + break; } } + + /* SIGTERM should've returned immediately. */ + assert(state->restart_enabled); } static void @@ -745,6 +793,7 @@ daemon_state_init(struct daemon_state *state) .pipe_rd = -1, .pipe_wr = -1, .keep_cur_workdir = 1, + .kqueue_fd = -1, .restart_delay = 1, .stdmask = STDOUT_FILENO | STDERR_FILENO, .syslog_enabled = false, @@ -765,6 +814,9 @@ daemon_terminate(struct daemon_state *state) { assert(state != NULL); + if (state->kqueue_fd >= 0) { + close(state->kqueue_fd); + } if (state->output_fd >= 0) { close(state->output_fd); } @@ -835,6 +887,35 @@ daemon_set_child_pipe(struct daemon_state *state) close(state->pipe_rd); } +static int +daemon_setup_kqueue(void) +{ + int kq; + struct kevent event = { 0 }; + + kq = kqueuex(KQUEUE_CLOEXEC); + if (kq == -1) { + err(EXIT_FAILURE, "kqueue"); + } + + EV_SET(&event, SIGHUP, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL); + if (kevent(kq, &event, 1, NULL, 0, NULL) == -1) { + err(EXIT_FAILURE, "failed to register kevent"); + } + + EV_SET(&event, SIGTERM, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL); + if (kevent(kq, &event, 1, NULL, 0, NULL) == -1) { + err(EXIT_FAILURE, "failed to register kevent"); + } + + EV_SET(&event, SIGCHLD, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL); + if (kevent(kq, &event, 1, NULL, 0, NULL) == -1) { + err(EXIT_FAILURE, "failed to register kevent"); + } + + return (kq); +} + static int pidfile_truncate(struct pidfh *pfh) {