From mboxrd@z Thu Jan 1 00:00:00 1970 From: unixmania at gmail.com Date: Sun, 21 Jul 2019 21:24:25 -0300 Subject: [Buildroot] [PATCH v2] package/dcron: fix startup error due to missing directories Message-ID: <20190722002425.6783-1-unixmania@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net From: Carlos Santos crond uses the /var/spool/cron/{crontabs,cronstamps} directories to store the per-user crontabs and timestamps for jobs, respectively. On systems with busybox or sysv init /var/spool is by default a link to /tmp (see package/skeleton-init-sysv/skeleton/). So if those directories are created at installation time they actually are under /tmp/spool and vanish at run time when a tmpfs is mounted at /tmp. In this case crond issues error messages that can't be seen. The error is hidden because we use start-stop-daemon to run crond in foreground mode to create a pid file and move crond to background. In this mode crond does not use syslog and all error messages are lost because start-stop-daemon redirects strderr to /dev/null. Getting a presistent storage for /var/spool would require customisations of the directory layout, which can not be done in a generic way, as each one will need to adapt to their own constraints. Fix these problem by means of the following changes: - Add configs for the crontabs and cronstamps paths. They can be used to move the directories to persistent filesystems, if necessary. - Change the init script and systemd unit to ensure that the directories are created before starting crond. - Start crond in daemon mode in the init script and use "pidof crond" to create the required pid file. Fixes: https://bugs.busybox.net/show_bug.cgi?id=12011 Signed-off-by: Carlos Santos --- Changes v1->v2: - Remove (partially), since the fix is now complete --- package/dcron/Config.in | 16 ++++++++++++++++ package/dcron/S90dcron | 8 +++++++- package/dcron/dcron.mk | 11 +++++++++-- package/dcron/dcron.service | 3 ++- 4 files changed, 34 insertions(+), 4 deletions(-) diff --git a/package/dcron/Config.in b/package/dcron/Config.in index d7f66bdb7d..1203c42dec 100644 --- a/package/dcron/Config.in +++ b/package/dcron/Config.in @@ -21,3 +21,19 @@ config BR2_PACKAGE_DCRON with sgid bit enabled. http://www.jimpryor.net/linux/dcron.html + +if BR2_PACKAGE_DCRON + +config BR2_PACKAGE_DCRON_CRONTABS_DIR + string "crontabs directory" + default "/var/spool/cron/crontabs" + help + Directory of per-user crontabs + +config BR2_PACKAGE_DCRON_CRONSTAMPS_DIR + string "cronstamps directory" + default "/var/spool/cron/cronstamps" + help + Directory of timestamps for @freq and FREQ=... jobs + +endif diff --git a/package/dcron/S90dcron b/package/dcron/S90dcron index de21d2ca13..4527277623 100644 --- a/package/dcron/S90dcron +++ b/package/dcron/S90dcron @@ -1,9 +1,15 @@ #!/bin/sh +CRONTABS_DIR=%%CRONTABS_DIR%% +CRONSTAMPS_DIR=%%CRONSTAMPS_DIR%% + case "$1" in start) printf "Starting cron ... " - start-stop-daemon -S -q -m -b -p /var/run/dcron.pid --exec /usr/sbin/crond -- -f + mkdir -p "$CRONTABS_DIR" "$CRONSTAMPS_DIR" + start-stop-daemon -S -q -p /var/run/dcron.pid -x /usr/sbin/crond \ + -- -c "$CRONTABS_DIR" -t "$CRONSTAMPS_DIR" + pidof crond > /var/run/dcron.pid || rm -f /var/run/dcron.pid echo "done." ;; stop) diff --git a/package/dcron/dcron.mk b/package/dcron/dcron.mk index 2ee0709af5..453e3acb54 100644 --- a/package/dcron/dcron.mk +++ b/package/dcron/dcron.mk @@ -19,18 +19,25 @@ define DCRON_INSTALL_TARGET_CMDS $(INSTALL) -D -m0644 $(@D)/extra/root.crontab $(TARGET_DIR)/etc/cron.d/system # Busybox provides run-parts, so there is no need to use nor install provided run-cron $(SED) 's#/usr/sbin/run-cron#/bin/run-parts#g' $(TARGET_DIR)/etc/cron.d/system - $(INSTALL) -d -m0755 $(TARGET_DIR)/var/spool/cron/crontabs \ - $(TARGET_DIR)/etc/cron.daily $(TARGET_DIR)/etc/cron.hourly \ + $(INSTALL) -d -m750 $(TARGET_DIR)/etc/cron.daily $(TARGET_DIR)/etc/cron.hourly \ $(TARGET_DIR)/etc/cron.monthly $(TARGET_DIR)/etc/cron.weekly endef define DCRON_INSTALL_INIT_SYSV $(INSTALL) -D -m 0755 package/dcron/S90dcron $(TARGET_DIR)/etc/init.d/S90dcron + $(SED) 's#%%CRONTABS_DIR%%#$(BR2_PACKAGE_DCRON_CRONTABS_DIR)#' \ + $(TARGET_DIR)/etc/init.d/S90dcron + $(SED) 's#%%CRONSTAMPS_DIR%%#$(BR2_PACKAGE_DCRON_CRONSTAMPS_DIR)#' \ + $(TARGET_DIR)/etc/init.d/S90dcron endef define DCRON_INSTALL_INIT_SYSTEMD $(INSTALL) -D -m 644 package/dcron/dcron.service \ $(TARGET_DIR)/usr/lib/systemd/system/dcron.service + $(SED) 's#%%CRONTABS_DIR%%#$(BR2_PACKAGE_DCRON_CRONTABS_DIR)#' \ + $(TARGET_DIR)/usr/lib/systemd/system/dcron.service + $(SED) 's#%%CRONSTAMPS_DIR%%#$(BR2_PACKAGE_DCRON_CRONSTAMPS_DIR)#' \ + $(TARGET_DIR)/usr/lib/systemd/system/dcron.service mkdir -p $(TARGET_DIR)/etc/systemd/system/multi-user.target.wants ln -sf ../../../../usr/lib/systemd/system/dcron.service \ $(TARGET_DIR)/etc/systemd/system/multi-user.target.wants/dcron.service diff --git a/package/dcron/dcron.service b/package/dcron/dcron.service index 924ed72205..abce25ba4f 100644 --- a/package/dcron/dcron.service +++ b/package/dcron/dcron.service @@ -3,7 +3,8 @@ Description=Task scheduler daemon After=syslog.target [Service] -ExecStart=/usr/sbin/crond -S +ExecStartPre=mkdir -p %%CRONTABS_DIR%% %%CRONSTAMPS_DIR%% +ExecStart=/usr/sbin/crond -c %%CRONTABS_DIR%% -t %%CRONSTAMPS_DIR%% Type=forking [Install] -- 2.18.1