Date: Tue, 03 Sep 2019 14:07:26 -0000 From: Kyle Evans <kevans@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r346586 - in stable: 11/usr.sbin/cron/cron 11/usr.sbin/cron/crontab 12/usr.sbin/cron/cron 12/usr.sbin/cron/crontab Message-ID: <201904230229.x3N2T8bg025990@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: kevans Date: Tue Apr 23 02:29:08 2019 New Revision: 346586 URL: https://svnweb.freebsd.org/changeset/base/346586 Log: MFC r346427: cron(8): schedule interval jobs that loaded during execution Jobs using the @<second> syntax currently only get executed if they exist when cron is started. The simplest reproducer of this is: echo '@20 root echo "Hello!"' >> /etc/cron.d/myjob myjob will get loaded at the next second==0, but this echo job will not run until cron restarts. These jobs are normally handled in run_reboot_jobs(), which sets e->lastexit of INTERVAL jobs to the startup time so they run 'n' seconds later. Fix this by special-casing TargetTime > 0 in the database load. Preexisting jobs will be handled at startup during run_reboot_jobs as normal, but if we've reloaded a database during runtime we'll hit this case and set e->lastexit to the current time when we process it. They will then run every 'n' seconds from that point, and a full restart of cron is no longer required to make these jobs work. Modified: stable/12/usr.sbin/cron/cron/database.c stable/12/usr.sbin/cron/crontab/crontab.5 Directory Properties: stable/12/ (props changed) Changes in other areas also in this revision: Modified: stable/11/usr.sbin/cron/cron/database.c stable/11/usr.sbin/cron/crontab/crontab.5 Directory Properties: stable/11/ (props changed) Modified: stable/12/usr.sbin/cron/cron/database.c ============================================================================== --- stable/12/usr.sbin/cron/cron/database.c Mon Apr 22 21:28:43 2019 (r346585) +++ stable/12/usr.sbin/cron/cron/database.c Tue Apr 23 02:29:08 2019 (r346586) @@ -259,6 +259,8 @@ process_crontab(uname, fname, tabname, statbuf, new_db struct passwd *pw = NULL; int crontab_fd = OK - 1; user *u; + entry *e; + time_t now; if (strcmp(fname, SYS_NAME) && !(pw = getpwnam(uname))) { /* file doesn't have a user in passwd file. @@ -307,6 +309,21 @@ process_crontab(uname, fname, tabname, statbuf, new_db u = load_user(crontab_fd, pw, fname); if (u != NULL) { u->mtime = statbuf->st_mtime; + /* + * TargetTime == 0 when we're initially populating the database, + * and TargetTime > 0 any time after that (i.e. we're reloading + * cron.d/ files because they've been created/modified). In the + * latter case, we should check for any interval jobs and run + * them 'n' seconds from the time the job was loaded/reloaded. + * Otherwise, they will not be run until cron is restarted. + */ + if (TargetTime != 0) { + now = time(NULL); + for (e = u->crontab; e != NULL; e = e->next) { + if ((e->flags & INTERVAL) != 0) + e->lastexit = now; + } + } link_user(new_db, u); } Modified: stable/12/usr.sbin/cron/crontab/crontab.5 ============================================================================== --- stable/12/usr.sbin/cron/crontab/crontab.5 Mon Apr 22 21:28:43 2019 (r346585) +++ stable/12/usr.sbin/cron/crontab/crontab.5 Tue Apr 23 02:29:08 2019 (r346586) @@ -17,7 +17,7 @@ .\" .\" $FreeBSD$ .\" -.Dd April 15, 2019 +.Dd April 19, 2019 .Dt CRONTAB 5 .Os .Sh NAME @@ -245,12 +245,14 @@ string meaning The .Sq @ symbol followed by a numeric value has a special notion of running -a job that much seconds after completion of previous invocation of +a job that many seconds after completion of the previous invocation of the job. Unlike regular syntax, it guarantees not to overlap two or more -invocations of the same job. -The first run is scheduled specified amount of seconds after cron -has started. +invocations of the same job during normal cron execution. +Note, however, that overlap may occur if the job is running when the file +containing the job is modified and subsequently reloaded. +The first run is scheduled for the specified number of seconds after cron +is started or the crontab entry is reloaded. .Sh EXAMPLE CRON FILE .Bd -literal
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201904230229.x3N2T8bg025990>