When caching the mtime of the spool directory and system crontab files,

stash a struct timespec, not just a time_t.  Fixes a bug where cron
could skip re-reading the spool after two consecutive changes.

5 files changed, 30 insertions, 20 deletions

diff --git a/usr.sbin/cron/atrun.c b/usr.sbin/cron/atrun.c
index 95f6fbe70ba..78798b960ff 100644
--- a/usr.sbin/cron/atrun.c
+++ b/usr.sbin/cron/atrun.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: atrun.c,v 1.42 2015/11/17 22:31:44 millert Exp $	*/
+/*	$OpenBSD: atrun.c,v 1.43 2016/01/11 14:23:50 millert Exp $	*/
 
 /*
  * Copyright (c) 2002-2003 Todd C. Miller <Todd.Miller@courtesan.com>
@@ -23,6 +23,7 @@
 #include <sys/types.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
+#include <sys/time.h>
 #include <sys/wait.h>
 
 #include <bitstring.h>		/* for structs.h */
@@ -91,7 +92,7 @@ scan_atjobs(at_db **db, struct timespec *ts)
 		close(dfd);
 		return (0);
 	}
-	if (old_db != NULL && old_db->mtime == sb.st_mtime) {
+	if (old_db != NULL && timespeccmp(&old_db->mtime, &sb.st_mtim, ==)) {
 		close(dfd);
 		return (0);
 	}
@@ -106,7 +107,7 @@ scan_atjobs(at_db **db, struct timespec *ts)
 		closedir(atdir);
 		return (0);
 	}
-	new_db->mtime = sb.st_mtime;	/* stash at dir mtime */
+	new_db->mtime = sb.st_mtim;	/* stash at dir mtime */
 	TAILQ_INIT(&new_db->jobs);
 
 	pending = 0;
diff --git a/usr.sbin/cron/cron.c b/usr.sbin/cron/cron.c
index ab36fdaefa9..57262e8d296 100644
--- a/usr.sbin/cron/cron.c
+++ b/usr.sbin/cron/cron.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cron.c,v 1.73 2015/11/15 23:24:24 millert Exp $	*/
+/*	$OpenBSD: cron.c,v 1.74 2016/01/11 14:23:50 millert Exp $	*/
 
 /* Copyright 1988,1990,1993,1994 by Paul Vixie
  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
@@ -20,6 +20,7 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
+#include <sys/time.h>
 #include <sys/un.h>
 #include <sys/wait.h>
 
@@ -373,7 +374,7 @@ cron_sleep(time_t target, sigset_t *mask)
 				(void) read(fd, &poke, 1);
 				close(fd);
 				if (poke & RELOAD_CRON) {
-					database->mtime = 0;
+					timespecclear(&database->mtime);
 					load_database(&database);
 				}
 				if (poke & RELOAD_AT) {
@@ -383,7 +384,7 @@ cron_sleep(time_t target, sigset_t *mask)
 					 * jobs immediately.
 					 */
 					clock_gettime(CLOCK_REALTIME, &t2);
-					at_database->mtime = 0;
+					timespecclear(&at_database->mtime);
 					if (scan_atjobs(&at_database, &t2))
 						atrun(at_database,
 						    batch_maxload, t2.tv_sec);
diff --git a/usr.sbin/cron/crontab.c b/usr.sbin/cron/crontab.c
index ce26afc493a..d22aae2538d 100644
--- a/usr.sbin/cron/crontab.c
+++ b/usr.sbin/cron/crontab.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: crontab.c,v 1.91 2015/11/17 21:56:57 millert Exp $	*/
+/*	$OpenBSD: crontab.c,v 1.92 2016/01/11 14:23:50 millert Exp $	*/
 
 /* Copyright 1988,1990,1993,1994 by Paul Vixie
  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
@@ -19,6 +19,7 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/time.h>
 #include <sys/wait.h>
 
 #include <bitstring.h>		/* for structs.h */
diff --git a/usr.sbin/cron/database.c b/usr.sbin/cron/database.c
index 7be6df68f9c..6fe1a0d2ee3 100644
--- a/usr.sbin/cron/database.c
+++ b/usr.sbin/cron/database.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: database.c,v 1.33 2015/11/14 13:09:14 millert Exp $	*/
+/*	$OpenBSD: database.c,v 1.34 2016/01/11 14:23:50 millert Exp $	*/
 
 /* Copyright 1988,1990,1993,1994 by Paul Vixie
  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
@@ -19,6 +19,7 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/time.h>
 
 #include <bitstring.h>		/* for structs.h */
 #include <dirent.h>
@@ -47,6 +48,7 @@ load_database(cron_db **db)
 {
 	struct stat statbuf, syscron_stat;
 	cron_db *new_db, *old_db = *db;
+	struct timespec mtime;
 	struct dirent *dp;
 	DIR *dir;
 	user *u;
@@ -63,15 +65,20 @@ load_database(cron_db **db)
 	/* track system crontab file
 	 */
 	if (stat(_PATH_SYS_CRONTAB, &syscron_stat) < 0)
-		syscron_stat.st_mtime = 0;
+		timespecclear(&syscron_stat.st_mtim);
+
+	/* hash mtime of system crontab file and crontab dir
+	 */
+	mtime.tv_sec =
+	    HASH(statbuf.st_mtim.tv_sec, syscron_stat.st_mtim.tv_sec);
+	mtime.tv_nsec =
+	    HASH(statbuf.st_mtim.tv_nsec, syscron_stat.st_mtim.tv_nsec);
 
 	/* if spooldir's mtime has not changed, we don't need to fiddle with
 	 * the database.
 	 */
-	if (old_db != NULL &&
-	    old_db->mtime == HASH(statbuf.st_mtime, syscron_stat.st_mtime)) {
+	if (old_db != NULL && timespeccmp(&mtime, &old_db->mtime, ==))
 		return;
-	}
 
 	/* something's different.  make a new database, moving unchanged
 	 * elements from the old database, reloading elements that have
@@ -80,10 +87,10 @@ load_database(cron_db **db)
 	 */
 	if ((new_db = malloc(sizeof(*new_db))) == NULL)
 		return;
-	new_db->mtime = HASH(statbuf.st_mtime, syscron_stat.st_mtime);
+	new_db->mtime = mtime;
 	TAILQ_INIT(&new_db->users);
 
-	if (syscron_stat.st_mtime) {
+	if (timespecisset(&syscron_stat.st_mtim)) {
 		process_crontab(AT_FDCWD, "*system*", _PATH_SYS_CRONTAB,
 				&syscron_stat, new_db, old_db);
 	}
@@ -212,7 +219,7 @@ process_crontab(int dfd, const char *uname, const char *fname,
 		/* if crontab has not changed since we last read it
 		 * in, then we can just use our existing entry.
 		 */
-		if (u->mtime == statbuf->st_mtime) {
+		if (timespeccmp(&u->mtime, &statbuf->st_mtim, ==)) {
 			TAILQ_REMOVE(&old_db->users, u, entries);
 			TAILQ_INSERT_TAIL(&new_db->users, u, entries);
 			goto next_crontab;
@@ -231,7 +238,7 @@ process_crontab(int dfd, const char *uname, const char *fname,
 	}
 	u = load_user(crontab_fd, pw, fname);
 	if (u != NULL) {
-		u->mtime = statbuf->st_mtime;
+		u->mtime = statbuf->st_mtim;
 		TAILQ_INSERT_TAIL(&new_db->users, u, entries);
 	}
 
diff --git a/usr.sbin/cron/structs.h b/usr.sbin/cron/structs.h
index e9e73816b00..af0d75c3b55 100644
--- a/usr.sbin/cron/structs.h
+++ b/usr.sbin/cron/structs.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: structs.h,v 1.7 2015/11/09 01:12:27 millert Exp $	*/
+/*	$OpenBSD: structs.h,v 1.8 2016/01/11 14:23:50 millert Exp $	*/
 
 /*
  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
@@ -50,13 +50,13 @@ typedef	struct _entry {
 typedef	struct _user {
 	TAILQ_ENTRY(_user) entries;	/* links */
 	char		*name;
-	time_t		mtime;		/* last modtime of crontab */
+	struct timespec	mtime;		/* last modtime of crontab */
 	SLIST_HEAD(crontab_list, _entry) crontab;	/* this person's crontab */
 } user;
 
 typedef	struct _cron_db {
 	TAILQ_HEAD(user_list, _user) users;
-	time_t		mtime;		/* last modtime on spooldir */
+	struct timespec	mtime;		/* last modtime on spooldir */
 } cron_db;
 
 typedef struct _atjob {
@@ -69,5 +69,5 @@ typedef struct _atjob {
 
 typedef struct _at_db {
 	TAILQ_HEAD(atjob_list, _atjob) jobs;
-	time_t		mtime;		/* last modtime on spooldir */
+	struct timespec	mtime;		/* last modtime on spooldir */
 } at_db;