Launch mdmon via systemctl to avoid it ending up in the wrong cgroup

Resolves bz879327

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>

mdadm-3.2.6-Add-support-for-launching-mdmon-via-systemctl-instea.patch

@@ -0,0 +1,160 @@
+From df9a354667f1a8b2994cf73a4d396766bc565a91 Mon Sep 17 00:00:00 2001
+From: Jes Sorensen <Jes.Sorensen@redhat.com>
+Date: Thu, 17 Jan 2013 18:06:43 +0100
+Subject: [PATCH 1/1] Add support for launching mdmon via systemctl instead of
+ fork/exec
+
+To launch mdmon via systemctl, a new command line argument is added to
+mdadm '--systemctl'. Alternatively it is possible to set the
+environment variable MDMON_SYSTEMCTL.
+
+This allows for having mdmon launched via systemctl which avoids
+problems with it getting killed by systemd due to it ending up in the
+parent's cgroup (udev).
+
+Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
+---
+ ReadMe.c |  2 ++
+ mdadm.c  |  4 ++++
+ mdadm.h  |  2 ++
+ mdmon.c  |  4 +++-
+ util.c   | 41 ++++++++++++++++++++++++++++++-----------
+ 6 files changed, 47 insertions(+), 12 deletions(-)
+
+diff --git a/ReadMe.c b/ReadMe.c
+index 0aa8cbd..69b8597 100644
+--- a/ReadMe.c
++++ b/ReadMe.c
+@@ -95,6 +95,7 @@ struct option long_options[] = {
+     {"update-subarray", 1, 0, UpdateSubarray},
+     {"udev-rules", 2, 0, UdevRules},
+     {"offroot", 0, 0, OffRootOpt},
++    {"systemctl", 0, 0, SystemctlOpt},
+ 
+     /* synonyms */
+     {"monitor",   0, 0, 'F'},
+@@ -261,6 +262,7 @@ char OptionHelp[] =
+ "                       application was launched from initrd/initramfs and\n"
+ "                       should not be shutdown by systemd as part of the\n"
+ "                       regular shutdown process.\n"
++"  --systemctl        : Use systemctl to launch mdmon rather than exec/fork\n"
+ ;
+ /*
+ "\n"
+diff --git a/mdadm.c b/mdadm.c
+index 11016e7..4c8d382 100644
+--- a/mdadm.c
++++ b/mdadm.c
+@@ -176,6 +176,10 @@ int main(int argc, char *argv[])
+ 				prefer = NULL;
+ 			continue;
+ 
++		case SystemctlOpt:
++			__mdmon_systemctl = 1;
++			continue;
++
+ 		case ':':
+ 		case '?':
+ 			fputs(Usage, stderr);
+diff --git a/mdadm.h b/mdadm.h
+index f1352e3..54874cb 100644
+--- a/mdadm.h
++++ b/mdadm.h
+@@ -337,6 +337,7 @@ enum special_options {
+ 	Continue,
+ 	OffRootOpt,
+ 	Prefer,
++	SystemctlOpt,
+ };
+ 
+ /* structures read from config file */
+@@ -1485,3 +1486,4 @@ char *xstrdup(const char *str);
+ #define MAX_DISKS	4096
+ 
+ extern int __offroot;
++extern int __mdmon_systemctl;
+diff --git a/mdmon.c b/mdmon.c
+index 5d5ae94..7459ae2 100644
+--- a/mdmon.c
++++ b/mdmon.c
+@@ -188,7 +188,9 @@ static void try_kill_monitor(pid_t pid, char *devname, int sock)
+ 	 * might be "@dmon"
+ 	 */
+ 	if (n < 0 || !(strstr(buf, "mdmon") ||
+-		       strstr(buf, "@dmon")))
++		       strstr(buf, "@dmon") ||
++		       strstr(buf, "/usr/sbin/mdmon") ||
++		       strstr(buf, "@usr/sbin/mdmon")))
+ 		return;
+ 
+ 	kill(pid, SIGTERM);
+diff --git a/util.c b/util.c
+index 6c10365..8202748 100644
+--- a/util.c
++++ b/util.c
+@@ -33,6 +33,7 @@
+ #include	<signal.h>
+ 
+ int __offroot;
++int __mdmon_systemctl = 1;
+ 
+ /*
+  * following taken from linux/blkpg.h because they aren't
+@@ -1651,6 +1652,9 @@ int start_mdmon(int devnum)
+ 	if (check_env("MDADM_NO_MDMON"))
+ 		return 0;
+ 
++	if (check_env("MDMON_SYSTEMCTL"))
++		__mdmon_systemctl = 1;
++
+ 	len = readlink("/proc/self/exe", pathbuf, sizeof(pathbuf)-1);
+ 	if (len > 0) {
+ 		char *sl;
+@@ -1651,18 +1655,33 @@ int start_mdmon(int devnum)
+ 			else
+ 				skipped = 0;
+ 
+-		for (i=0; paths[i]; i++)
+-			if (paths[i][0]) {
+-				if (__offroot) {
+-					execl(paths[i], "mdmon", "--offroot",
+-					      devnum2devname(devnum),
+-					      NULL);
+-				} else {
+-					execl(paths[i], "mdmon",
+-					      devnum2devname(devnum),
+-					      NULL);
+-				}
++		if (__mdmon_systemctl) {
++			if (__offroot) {
++				snprintf(pathbuf, 40, "mdmon-offroot@%s.service",
++					 devnum2devname(devnum));
++				execl("/usr/bin/systemctl", "systemctl",
++				      "start", pathbuf, NULL);
++			} else {
++				snprintf(pathbuf, 30, "mdmon@%s.service",
++					 devnum2devname(devnum));
++				execl("/usr/bin/systemctl", "systemctl",
++				      "start", pathbuf, NULL);
+ 			}
++		} else {
++			for (i = 0; paths[i]; i++)
++				if (paths[i][0]) {
++					if (__offroot) {
++						execl(paths[i], "mdmon",
++						      "--offroot",
++						      devnum2devname(devnum),
++						      NULL);
++					} else {
++						execl(paths[i], "mdmon",
++						      devnum2devname(devnum),
++						      NULL);
++					}
++				}
++		}
+ 		exit(1);
+ 	case -1: fprintf(stderr, Name ": cannot run mdmon. "
+ 			 "Array remains readonly\n");
+-- 
+1.7.11.7
+

mdadm-3.2.6-cgroup.patch

@@ -1,38 +0,0 @@
-diff -up mdadm-3.2.6/util.c.cgroup mdadm-3.2.6/util.c
---- mdadm-3.2.6/mdmon.c.cgroup	2012-11-15 16:48:03.327035349 -0500
-+++ mdadm-3.2.6/mdmon.c	2012-11-15 17:07:16.628751041 -0500
-@@ -386,6 +386,25 @@
- 	return mdmon(devname, devnum, do_fork(), takeover);
- }
- 
-+int set_cgroup(char *group)
-+{
-+	char pid[8];
-+	char pathbuf[PATH_MAX];
-+	int tasks_fd, n;
-+
-+	snprintf(pathbuf, PATH_MAX, "/sys/fs/cgroup/%s/tasks", group);
-+	tasks_fd = open(pathbuf, O_WRONLY);
-+	if (tasks_fd >= 0) {
-+		snprintf(pid, sizeof(pid), "%d", getpid());
-+		n = write(tasks_fd, pid, strlen(pid));
-+		close(tasks_fd);
-+		if (n != (int)strlen(pid)) {
-+			return -1;
-+		}
-+	}
-+	return 0;
-+}
-+
- static int mdmon(char *devname, int devnum, int must_fork, int takeover)
- {
- 	int mdfd;
-@@ -438,6 +457,8 @@
- 	} else
- 		pfd[0] = pfd[1] = -1;
- 
-+	set_cgroup("systemd");
-+
- 	container = calloc(1, sizeof(*container));
- 	container->devnum = devnum;
- 	container->devname = devname;

mdadm.spec

@@ -1,7 +1,7 @@
 Summary:     The mdadm program controls Linux md devices (software RAID arrays)
 Name:        mdadm
 Version:     3.2.6
-Release:     11%{?dist}
+Release:     12%{?dist}
 Source:      http://www.kernel.org/pub/linux/utils/raid/mdadm/mdadm-%{version}.tar.xz
 Source1:     mdmonitor.init
 Source2:     raid-check
@@ -9,15 +9,17 @@ Source3:     mdadm.rules
 Source4:     mdadm-raid-check-sysconfig
 Source5:     mdadm-cron
 Source6:     mdmonitor.service
-Source8:     mdadm.conf
+Source7:     mdmon-offroot@.service
-Source9:     mdadm_event.conf
+Source8:     mdmon@.service
-Patch0:      mdadm-3.2.6-cgroup.patch
+Source9:     mdadm.conf
+Source10:    mdadm_event.conf
 Patch1:	     mdadm-3.2.6-Create.c-check-if-freesize-is-equal-0.patch
 Patch2:	     mdadm-3.2.6-imsm-Forbid-spanning-between-multiple-controllers.patch
+Patch96:     mdadm-3.2.6-Add-support-for-launching-mdmon-via-systemctl-instea.patch
 # Fedora customization patches
 Patch97:     mdadm-3.2.6-udev.patch
 Patch98:     mdadm-2.5.2-static.patch
-# Fedora 15, 16, 17 - only
+# Fedora 16, 17 - only
 Patch99:     mdadm-3.2.4-map-dir.patch
 URL:         http://www.kernel.org/pub/linux/utils/raid/mdadm/
 License:     GPLv2+
@@ -26,18 +28,15 @@ BuildRoot:   %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 Obsoletes:   mdctl,raidtools
 %if "%{fedora}" >= "18"
 Obsoletes:   mdadm-sysvinit
-%endif
+Conflicts:   dracut < 024-23
-BuildRequires: systemd-units binutils-devel
-%if "%{fedora}" <= "17"
-Requires(post): systemd-units systemd-sysv chkconfig coreutils
-%else
 Requires(post): systemd-units chkconfig coreutils
-%endif
+%else
-Requires(preun): systemd-units
+Requires(post): systemd-units systemd-sysv chkconfig coreutils
-Requires(postun): systemd-units coreutils
-%if "%{fedora}" <= "17"
 Requires: udev initscripts
 %endif
+BuildRequires: systemd-units binutils-devel
+Requires(preun): systemd-units
+Requires(postun): systemd-units coreutils
 %if "%{fedora}" >= "17"
 Requires: libreport-filesystem
 Conflicts: dracut < 009-14
@@ -66,9 +65,9 @@ is not used as the system init process.
 
 %prep
 %setup -q
-# Only apply cgroups workaround on F18 and higher
+# Use systemctl to launch mdmon on F18 and higher
 %if "%{fedora}" >= "18"
-%patch0 -p1 -b .cgroup
+%patch96 -p1 -b .sysctl
 %endif
 
 %patch1 -p1 -b .raidsize
@@ -77,7 +76,7 @@ is not used as the system init process.
 # Fedora customization patches
 %patch97 -p1 -b .udev
 %patch98 -p1 -b .static
-# Fedora 15, 16, 17 - only
+# Fedora 16, 17 - only
 %if "%{fedora}" <= "17"
 %patch99 -p1 -b .map-dir
 %endif
@@ -100,17 +99,19 @@ mkdir -p -m 700 %{buildroot}/var/run/mdadm
 # systemd
 mkdir -p %{buildroot}%{_unitdir}
 install -m644 %{SOURCE6} %{buildroot}%{_unitdir}
+install -m644 %{SOURCE7} %{buildroot}%{_unitdir}
+install -m644 %{SOURCE8} %{buildroot}%{_unitdir}
 
 # tmpfile
 mkdir -p %{buildroot}%{_prefix}/lib/tmpfiles.d
-install -m 0644 %{SOURCE8} %{buildroot}%{_prefix}/lib/tmpfiles.d/%{name}.conf
+install -m 0644 %{SOURCE9} %{buildroot}%{_prefix}/lib/tmpfiles.d/%{name}.conf
 mkdir -p %{buildroot}%{_localstatedir}/run/
 install -d -m 0710 %{buildroot}%{_localstatedir}/run/%{name}/
 
 # abrt
 %if "%{fedora}" >= "17"
 mkdir -p %{buildroot}/etc/libreport/events.d
-install -m644 %{SOURCE9} %{buildroot}/etc/libreport/events.d
+install -m644 %{SOURCE10} %{buildroot}/etc/libreport/events.d
 %endif
 
 %clean
@@ -144,6 +145,8 @@ rm -rf %{buildroot}
 /sbin/*
 %{_sbindir}/raid-check
 %{_unitdir}/mdmonitor.service
+%{_unitdir}/mdmon-offroot@.service
+%{_unitdir}/mdmon@.service
 %{_mandir}/man*/md*
 %config(noreplace) %{_sysconfdir}/cron.d/*
 %config(noreplace) %{_sysconfdir}/sysconfig/*
@@ -159,6 +162,12 @@ rm -rf %{buildroot}
 %endif
 
 %changelog
+* Mon Jan 21 2013 Jes Sorensen <Jes.Sorensen@redhat.com> - 3.2.6-12
+- Launch mdmon via systemctl to avoid it ending up in the wrong cgroup
+  and getting killed in the boot process when switching from the
+  initrd to the real root.
+- Resolves bz879327
+
 * Tue Jan 8 2013 Jes Sorensen <Jes.Sorensen@redhat.com> - 3.2.6-11
 - Move code to leave udev cgroup into mdmon and excute it after we
   work, to make sure it actually does the right thing.