[thirdparty/mdadm.git] / mdmon.c


/*
 * md array manager.
 * When md arrays have user-space managed metadata, this is the program
 * that does the managing.
 *
 * Given one argument: the name of the array (e.g. /dev/md0) that is
 * the container.
 * We fork off a helper that runs high priority and mlocked.  It responds to
 * device failures and other events that might stop writeout, or that are
 * trivial to deal with.
 * The main thread then watches for new arrays being created in the container
 * and starts monitoring them too ... along with a few other tasks.
 *
 * The main thread communicates with the priority thread by writing over
 * a pipe.
 * Separate programs can communicate with the main thread via Unix-domain
 * socket.
 * The two threads share address space and open file table.
 *
 */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include	<unistd.h>
#include	<stdlib.h>
#include	<sys/types.h>
#include	<sys/stat.h>
#include	<sys/socket.h>
#include	<sys/un.h>
#include	<sys/mman.h>
#include	<sys/syscall.h>
#include	<sys/wait.h>
#include	<stdio.h>
#include	<errno.h>
#include	<string.h>
#include	<fcntl.h>
#include	<signal.h>
#include	<dirent.h>

#include	<sched.h>

#include	"mdadm.h"
#include	"mdmon.h"

struct active_array *discard_this;
struct active_array *pending_discard;

int mon_tid, mgr_tid;

int sigterm;

int run_child(void *v)
{
	struct supertype *c = v;

	do_monitor(c);
	return 0;
}

int clone_monitor(struct supertype *container)
{
	static char stack[4096];

	mon_tid = clone(run_child, stack+4096-64,
		   CLONE_FS|CLONE_FILES|CLONE_VM|CLONE_SIGHAND|CLONE_THREAD,
		   container);

	mgr_tid = syscall(SYS_gettid);

	return mon_tid;
}

static struct superswitch *find_metadata_methods(char *vers)
{
	if (strcmp(vers, "ddf") == 0)
		return &super_ddf;
	if (strcmp(vers, "imsm") == 0)
		return &super_imsm;
	return NULL;
}


int make_pidfile(char *devname, int o_excl)
{
	char path[100];
	char pid[10];
	int fd;
	int n;

	if (sigterm)
		return -1;

	sprintf(path, "/var/run/mdadm/%s.pid", devname);

	fd = open(path, O_RDWR|O_CREAT|o_excl, 0600);
	if (fd < 0)
		return -errno;
	sprintf(pid, "%d\n", getpid());
	n = write(fd, pid, strlen(pid));
	close(fd);
	if (n < 0)
		return -errno;
	return 0;
}

int is_container_member(struct mdstat_ent *mdstat, char *container)
{
	if (mdstat->metadata_version == NULL ||
	    strncmp(mdstat->metadata_version, "external:", 9) != 0 ||
	    !is_subarray(mdstat->metadata_version+9) ||
	    strncmp(mdstat->metadata_version+10, container, strlen(container)) != 0 ||
	    mdstat->metadata_version[10+strlen(container)] != '/')
		return 0;

	return 1;
}

void remove_pidfile(char *devname);
static void try_kill_monitor(char *devname)
{
	char buf[100];
	int fd;
	pid_t pid;
	struct mdstat_ent *mdstat;

	sprintf(buf, "/var/run/mdadm/%s.pid", devname);
	fd = open(buf, O_RDONLY);
	if (fd < 0)
		return;

	if (read(fd, buf, sizeof(buf)) < 0) {
		close(fd);
		return;
	}

	close(fd);
	pid = strtoul(buf, NULL, 10);

	/* kill this process if it is mdmon */
	sprintf(buf, "/proc/%lu/cmdline", (unsigned long) pid);
	fd = open(buf, O_RDONLY);
	if (fd < 0)
		return;

	if (read(fd, buf, sizeof(buf)) < 0) {
		close(fd);
		return;
	}

	if (!strstr(buf, "mdmon"))
		return;

	kill(pid, SIGTERM);

	mdstat = mdstat_read(0, 0);
	for ( ; mdstat; mdstat = mdstat->next)
		if (is_container_member(mdstat, devname)) {
			sprintf(buf, "/dev/%s", mdstat->dev);
			WaitClean(buf);
		}
	free_mdstat(mdstat);
	remove_pidfile(devname);
}

void remove_pidfile(char *devname)
{
	char buf[100];

	if (sigterm)
		return;

	sprintf(buf, "/var/run/mdadm/%s.pid", devname);
	unlink(buf);
	sprintf(buf, "/var/run/mdadm/%s.sock", devname);
	unlink(buf);
}

int make_control_sock(char *devname)
{
	char path[100];
	int sfd;
	long fl;
	struct sockaddr_un addr;

	if (sigterm)
		return -1;

	sprintf(path, "/var/run/mdadm/%s.sock", devname);
	unlink(path);
	sfd = socket(PF_LOCAL, SOCK_STREAM, 0);
	if (sfd < 0)
		return -1;

	addr.sun_family = PF_LOCAL;
	strcpy(addr.sun_path, path);
	if (bind(sfd, &addr, sizeof(addr)) < 0) {
		close(sfd);
		return -1;
	}
	listen(sfd, 10);
	fl = fcntl(sfd, F_GETFL, 0);
	fl |= O_NONBLOCK;
	fcntl(sfd, F_SETFL, fl);
	return sfd;
}

int socket_hup_requested;
static void hup(int sig)
{
	socket_hup_requested = 1;
}

static void term(int sig)
{
	sigterm = 1;
}

static void wake_me(int sig)
{

}

/* if we are debugging and starting mdmon by hand then don't fork */
static int do_fork(void)
{
	#ifdef DEBUG
	if (env_no_mdmon())
		return 0;
	#endif

	return 1;
}

void usage(void)
{
	fprintf(stderr, "Usage: mdmon [--switch-root dir] /device/name/for/container\n");
	exit(2);
}

int main(int argc, char *argv[])
{
	int mdfd;
	struct mdinfo *mdi, *di;
	struct supertype *container;
	sigset_t set;
	struct sigaction act;
	int pfd[2];
	int status;
	int ignore;
	char *container_name = NULL;
	char *switchroot = NULL;

	switch (argc) {
	case 2:
		container_name = argv[1];
		break;
	case 4:
		if (strcmp(argv[1], "--switch-root") != 0) {
			fprintf(stderr, "mdmon: unknown argument %s\n", argv[1]);
			usage();
		}
		switchroot = argv[2];
		container_name = argv[3];
		break;
	default:
		usage();
	}

	mdfd = open(container_name, O_RDWR);
	if (mdfd < 0) {
		fprintf(stderr, "mdmon: %s: %s\n", container_name,
			strerror(errno));
		exit(1);
	}
	if (md_get_version(mdfd) < 0) {
		fprintf(stderr, "mdmon: %s: Not an md device\n",
			container_name);
		exit(1);
	}

	/* Fork, and have the child tell us when they are ready */
	if (do_fork()) {
		if (pipe(pfd) != 0) {
			fprintf(stderr, "mdmon: failed to create pipe\n");
			exit(1);
		}
		switch(fork()) {
		case -1:
			fprintf(stderr, "mdmon: failed to fork: %s\n",
				strerror(errno));
			exit(1);
		case 0: /* child */
			close(pfd[0]);
			break;
		default: /* parent */
			close(pfd[1]);
			if (read(pfd[0], &status, sizeof(status)) != sizeof(status)) {
				wait(&status);
				status = WEXITSTATUS(status);
			}
			exit(status);
		}
	} else
		pfd[0] = pfd[1] = -1;

	container = malloc(sizeof(*container));
	container->devnum = fd2devnum(mdfd);
	container->devname = devnum2devname(container->devnum);
	container->device_name = container_name;
	container->arrays = NULL;

	if (!container->devname) {
		fprintf(stderr, "mdmon: failed to allocate container name string\n");
		exit(3);
	}

	mdi = sysfs_read(mdfd, container->devnum,
			 GET_VERSION|GET_LEVEL|GET_DEVS);

	if (!mdi) {
		fprintf(stderr, "mdmon: failed to load sysfs info for %s\n",
			container->devname);
		exit(3);
	}
	if (mdi->array.level != UnSet) {
		fprintf(stderr, "mdmon: %s is not a container - cannot monitor\n",
			container_name);
		exit(3);
	}
	if (mdi->array.major_version != -1 ||
	    mdi->array.minor_version != -2) {
		fprintf(stderr, "mdmon: %s does not use external metadata - cannot monitor\n",
			container_name);
		exit(3);
	}

	container->ss = find_metadata_methods(mdi->text_version);
	if (container->ss == NULL) {
		fprintf(stderr, "mdmon: %s uses unknown metadata: %s\n",
			container_name, mdi->text_version);
		exit(3);
	}

	container->devs = NULL;
	for (di = mdi->devs; di; di = di->next) {
		struct mdinfo *cd = malloc(sizeof(*cd));
		*cd = *di;
		cd->next = container->devs;
		container->devs = cd;
	}
	sysfs_free(mdi);

	/* SIGUSR is sent between parent and child.  So both block it
	 * and enable it only with pselect.
	 */
	sigemptyset(&set);
	sigaddset(&set, SIGUSR1);
	sigaddset(&set, SIGHUP);
	sigaddset(&set, SIGALRM);
	sigaddset(&set, SIGTERM);
	sigprocmask(SIG_BLOCK, &set, NULL);
	act.sa_handler = wake_me;
	act.sa_flags = 0;
	sigaction(SIGUSR1, &act, NULL);
	sigaction(SIGALRM, &act, NULL);
	act.sa_handler = hup;
	sigaction(SIGHUP, &act, NULL);
	act.sa_handler = term;
	sigaction(SIGTERM, &act, NULL);
	act.sa_handler = SIG_IGN;
	sigaction(SIGPIPE, &act, NULL);

	if (switchroot) {
		/* we assume we assume that /sys /proc /dev are available in
		 * the new root (see nash:setuproot)
		 *
		 * kill any monitors in the current namespace and change
		 * to the new one
		 */
		try_kill_monitor(container->devname);
		if (chroot(switchroot) != 0) {
			fprintf(stderr, "mdmon: failed to chroot to '%s': %s\n",
				switchroot, strerror(errno));
			exit(4);
		}
	}

	/* If this fails, we hope it already exists 
	 * pid file lives in /var/run/mdadm/mdXX.pid
	 */
	mkdir("/var", 0600);
	mkdir("/var/run", 0600);
	mkdir("/var/run/mdadm", 0600);
	ignore = chdir("/");
	if (make_pidfile(container->devname, O_EXCL) < 0) {
		if (ping_monitor(container->devname) == 0) {
			fprintf(stderr, "mdmon: %s already managed\n",
				container->devname);
			exit(3);
		} else {
			int err;

			/* cleanup the old monitor, this one is taking over */
			try_kill_monitor(container->devname);
			err = make_pidfile(container->devname, 0);
			if (err < 0) {
				fprintf(stderr, "mdmon: %s Cannot create pidfile\n",
					container->devname);
				if (err == -EROFS) {
					/* FIXME implement a mechanism to
					 * prevent duplicate monitor instances
					 */
					fprintf(stderr,
						"mdmon: continuing on read-only file system\n");
				} else
					exit(3);
			}
		}
	}
	container->sock = make_control_sock(container->devname);

	if (container->ss->load_super(container, mdfd, container_name)) {
		fprintf(stderr, "mdmon: Cannot load metadata for %s\n",
			container_name);
		exit(3);
	}

	/* Ok, this is close enough.  We can say goodbye to our parent now.
	 */
	status = 0;
	if (write(pfd[1], &status, sizeof(status)) < 0)
		fprintf(stderr, "mdmon: failed to notify our parent: %d\n",
			getppid());
	close(pfd[1]);

	setsid();
	close(0);
	open("/dev/null", O_RDWR);
	close(1);
	ignore = dup(0);
#ifndef DEBUG
	close(2);
	ignore = dup(0);
#endif

	mlockall(MCL_FUTURE);

	if (clone_monitor(container) < 0) {
		fprintf(stderr, "mdmon: failed to start monitor process: %s\n",
			strerror(errno));
		exit(2);
	}

	do_manager(container);

	exit(0);
}
Commit	Line	Data
549e9569 NB	1
	2	/*
	3	* md array manager.
	4	* When md arrays have user-space managed metadata, this is the program
	5	* that does the managing.
	6	*
	7	* Given one argument: the name of the array (e.g. /dev/md0) that is
	8	* the container.
	9	* We fork off a helper that runs high priority and mlocked. It responds to
	10	* device failures and other events that might stop writeout, or that are
	11	* trivial to deal with.
	12	* The main thread then watches for new arrays being created in the container
	13	* and starts monitoring them too ... along with a few other tasks.
	14	*
	15	* The main thread communicates with the priority thread by writing over
	16	* a pipe.
	17	* Separate programs can communicate with the main thread via Unix-domain
	18	* socket.
	19	* The two threads share address space and open file table.
	20	*
	21	*/
	22
	23	#ifndef _GNU_SOURCE
	24	#define _GNU_SOURCE
	25	#endif
	26
	27	#include <unistd.h>
	28	#include <stdlib.h>
4d43913c	29	#include <sys/types.h>
549e9569 NB	30	#include <sys/stat.h>
	31	#include <sys/socket.h>
	32	#include <sys/un.h>
	33	#include <sys/mman.h>
4d43913c	34	#include <sys/syscall.h>
9fe32043	35	#include <sys/wait.h>
549e9569 NB	36	#include <stdio.h>
	37	#include <errno.h>
	38	#include <string.h>
	39	#include <fcntl.h>
b109d928	40	#include <signal.h>
13047e4c	41	#include <dirent.h>
549e9569 NB	42
	43	#include <sched.h>
	44
	45	#include "mdadm.h"
	46	#include "mdmon.h"
	47
549e9569 NB	48	struct active_array *discard_this;
549e9569 NB	49	struct active_array *pending_discard;
4d43913c NB	50
4d43913c NB	51	int mon_tid, mgr_tid;
549e9569	52
6144ed44 DW	53	int sigterm;
6144ed44 DW	54
549e9569 NB	55	int run_child(void *v)
	56	{
	57	struct supertype *c = v;
1ed3f387	58
549e9569 NB	59	do_monitor(c);
	60	return 0;
	61	}
	62
	63	int clone_monitor(struct supertype *container)
	64	{
549e9569	65	static char stack[4096];
549e9569	66
2cc98f9e	67	mon_tid = clone(run_child, stack+4096-64,
549e9569 NB	68	CLONE_FS\|CLONE_FILES\|CLONE_VM\|CLONE_SIGHAND\|CLONE_THREAD,
549e9569 NB	69	container);
3e70c845	70
4d43913c	71	mgr_tid = syscall(SYS_gettid);
2cc98f9e DW	72
2cc98f9e DW	73	return mon_tid;
549e9569 NB	74	}
	75
	76	static struct superswitch find_metadata_methods(char vers)
	77	{
	78	if (strcmp(vers, "ddf") == 0)
	79	return &super_ddf;
5b65005f DW	80	if (strcmp(vers, "imsm") == 0)
5b65005f DW	81	return &super_imsm;
549e9569 NB	82	return NULL;
	83	}
	84
	85
295646b3	86	int make_pidfile(char *devname, int o_excl)
549e9569 NB	87	{
	88	char path[100];
	89	char pid[10];
	90	int fd;
3d2c4fc7 DW	91	int n;
3d2c4fc7 DW	92
6144ed44 DW	93	if (sigterm)
	94	return -1;
	95
549e9569 NB	96	sprintf(path, "/var/run/mdadm/%s.pid", devname);
549e9569 NB	97
b109d928	98	fd = open(path, O_RDWR\|O_CREAT\|o_excl, 0600);
549e9569	99	if (fd < 0)
295646b3	100	return -errno;
549e9569	101	sprintf(pid, "%d\n", getpid());
3d2c4fc7	102	n = write(fd, pid, strlen(pid));
549e9569	103	close(fd);
3d2c4fc7 DW	104	if (n < 0)
3d2c4fc7 DW	105	return -errno;
549e9569 NB	106	return 0;
	107	}
	108
883a6142 DW	109	int is_container_member(struct mdstat_ent mdstat, char container)
	110	{
	111	if (mdstat->metadata_version == NULL \|\|
	112	strncmp(mdstat->metadata_version, "external:", 9) != 0 \|\|
	113	!is_subarray(mdstat->metadata_version+9) \|\|
	114	strncmp(mdstat->metadata_version+10, container, strlen(container)) != 0 \|\|
	115	mdstat->metadata_version[10+strlen(container)] != '/')
	116	return 0;
	117
	118	return 1;
	119	}
	120
	121	void remove_pidfile(char *devname);
b109d928 DW	122	static void try_kill_monitor(char *devname)
	123	{
	124	char buf[100];
	125	int fd;
	126	pid_t pid;
883a6142	127	struct mdstat_ent *mdstat;
b109d928 DW	128
	129	sprintf(buf, "/var/run/mdadm/%s.pid", devname);
	130	fd = open(buf, O_RDONLY);
	131	if (fd < 0)
	132	return;
	133
	134	if (read(fd, buf, sizeof(buf)) < 0) {
	135	close(fd);
	136	return;
	137	}
	138
	139	close(fd);
	140	pid = strtoul(buf, NULL, 10);
	141
	142	/* kill this process if it is mdmon */
	143	sprintf(buf, "/proc/%lu/cmdline", (unsigned long) pid);
	144	fd = open(buf, O_RDONLY);
	145	if (fd < 0)
	146	return;
	147
	148	if (read(fd, buf, sizeof(buf)) < 0) {
	149	close(fd);
	150	return;
	151	}
	152
883a6142 DW	153	if (!strstr(buf, "mdmon"))
	154	return;
	155
	156	kill(pid, SIGTERM);
	157
	158	mdstat = mdstat_read(0, 0);
	159	for ( ; mdstat; mdstat = mdstat->next)
	160	if (is_container_member(mdstat, devname)) {
	161	sprintf(buf, "/dev/%s", mdstat->dev);
	162	WaitClean(buf);
	163	}
	164	free_mdstat(mdstat);
	165	remove_pidfile(devname);
b109d928 DW	166	}
b109d928 DW	167
e0d6609f NB	168	void remove_pidfile(char *devname)
	169	{
	170	char buf[100];
	171
6144ed44 DW	172	if (sigterm)
	173	return;
	174
e0d6609f NB	175	sprintf(buf, "/var/run/mdadm/%s.pid", devname);
e0d6609f NB	176	unlink(buf);
57752795 N	177	sprintf(buf, "/var/run/mdadm/%s.sock", devname);
57752795 N	178	unlink(buf);
e0d6609f NB	179	}
e0d6609f NB	180
295646b3	181	int make_control_sock(char *devname)
549e9569 NB	182	{
	183	char path[100];
	184	int sfd;
	185	long fl;
	186	struct sockaddr_un addr;
	187
6144ed44 DW	188	if (sigterm)
	189	return -1;
	190
549e9569 NB	191	sprintf(path, "/var/run/mdadm/%s.sock", devname);
	192	unlink(path);
	193	sfd = socket(PF_LOCAL, SOCK_STREAM, 0);
	194	if (sfd < 0)
	195	return -1;
	196
	197	addr.sun_family = PF_LOCAL;
	198	strcpy(addr.sun_path, path);
	199	if (bind(sfd, &addr, sizeof(addr)) < 0) {
	200	close(sfd);
	201	return -1;
	202	}
	203	listen(sfd, 10);
	204	fl = fcntl(sfd, F_GETFL, 0);
	205	fl \|= O_NONBLOCK;
	206	fcntl(sfd, F_SETFL, fl);
	207	return sfd;
	208	}
	209
295646b3 DW	210	int socket_hup_requested;
	211	static void hup(int sig)
	212	{
	213	socket_hup_requested = 1;
	214	}
	215
6144ed44 DW	216	static void term(int sig)
	217	{
	218	sigterm = 1;
	219	}
	220
4d43913c NB	221	static void wake_me(int sig)
	222	{
	223
	224	}
	225
16ddab0d DW	226	/* if we are debugging and starting mdmon by hand then don't fork */
	227	static int do_fork(void)
	228	{
	229	#ifdef DEBUG
	230	if (env_no_mdmon())
	231	return 0;
	232	#endif
	233
	234	return 1;
	235	}
	236
13047e4c DW	237	void usage(void)
	238	{
	239	fprintf(stderr, "Usage: mdmon [--switch-root dir] /device/name/for/container\n");
	240	exit(2);
	241	}
16ddab0d	242
549e9569 NB	243	int main(int argc, char *argv[])
	244	{
	245	int mdfd;
549e9569 NB	246	struct mdinfo mdi, di;
549e9569 NB	247	struct supertype *container;
4d43913c	248	sigset_t set;
bfa44e2e	249	struct sigaction act;
9fe32043 N	250	int pfd[2];
9fe32043 N	251	int status;
3d2c4fc7	252	int ignore;
13047e4c DW	253	char *container_name = NULL;
	254	char *switchroot = NULL;
	255
	256	switch (argc) {
	257	case 2:
	258	container_name = argv[1];
	259	break;
	260	case 4:
	261	if (strcmp(argv[1], "--switch-root") != 0) {
	262	fprintf(stderr, "mdmon: unknown argument %s\n", argv[1]);
	263	usage();
	264	}
	265	switchroot = argv[2];
	266	container_name = argv[3];
	267	break;
	268	default:
	269	usage();
549e9569	270	}
13047e4c DW	271
13047e4c DW	272	mdfd = open(container_name, O_RDWR);
549e9569	273	if (mdfd < 0) {
13047e4c	274	fprintf(stderr, "mdmon: %s: %s\n", container_name,
549e9569 NB	275	strerror(errno));
	276	exit(1);
	277	}
	278	if (md_get_version(mdfd) < 0) {
13047e4c DW	279	fprintf(stderr, "mdmon: %s: Not an md device\n",
13047e4c DW	280	container_name);
549e9569 NB	281	exit(1);
	282	}
	283
9fe32043	284	/* Fork, and have the child tell us when they are ready */
16ddab0d	285	if (do_fork()) {
3d2c4fc7 DW	286	if (pipe(pfd) != 0) {
	287	fprintf(stderr, "mdmon: failed to create pipe\n");
	288	exit(1);
	289	}
16ddab0d DW	290	switch(fork()) {
	291	case -1:
	292	fprintf(stderr, "mdmon: failed to fork: %s\n",
	293	strerror(errno));
	294	exit(1);
	295	case 0: /* child */
	296	close(pfd[0]);
	297	break;
	298	default: /* parent */
	299	close(pfd[1]);
	300	if (read(pfd[0], &status, sizeof(status)) != sizeof(status)) {
	301	wait(&status);
	302	status = WEXITSTATUS(status);
	303	}
	304	exit(status);
9fe32043	305	}
16ddab0d DW	306	} else
16ddab0d DW	307	pfd[0] = pfd[1] = -1;
549e9569 NB	308
549e9569 NB	309	container = malloc(sizeof(*container));
549e9569 NB	310	container->devnum = fd2devnum(mdfd);
549e9569 NB	311	container->devname = devnum2devname(container->devnum);
13047e4c DW	312	container->device_name = container_name;
	313	container->arrays = NULL;
	314
	315	if (!container->devname) {
	316	fprintf(stderr, "mdmon: failed to allocate container name string\n");
	317	exit(3);
	318	}
	319
	320	mdi = sysfs_read(mdfd, container->devnum,
	321	GET_VERSION\|GET_LEVEL\|GET_DEVS);
	322
	323	if (!mdi) {
	324	fprintf(stderr, "mdmon: failed to load sysfs info for %s\n",
	325	container->devname);
	326	exit(3);
	327	}
	328	if (mdi->array.level != UnSet) {
	329	fprintf(stderr, "mdmon: %s is not a container - cannot monitor\n",
	330	container_name);
	331	exit(3);
	332	}
	333	if (mdi->array.major_version != -1 \|\|
	334	mdi->array.minor_version != -2) {
	335	fprintf(stderr, "mdmon: %s does not use external metadata - cannot monitor\n",
	336	container_name);
	337	exit(3);
	338	}
	339
	340	container->ss = find_metadata_methods(mdi->text_version);
	341	if (container->ss == NULL) {
	342	fprintf(stderr, "mdmon: %s uses unknown metadata: %s\n",
	343	container_name, mdi->text_version);
	344	exit(3);
	345	}
	346
	347	container->devs = NULL;
	348	for (di = mdi->devs; di; di = di->next) {
	349	struct mdinfo cd = malloc(sizeof(cd));
	350	cd = di;
	351	cd->next = container->devs;
	352	container->devs = cd;
	353	}
	354	sysfs_free(mdi);
549e9569	355
883a6142 DW	356	/* SIGUSR is sent between parent and child. So both block it
	357	* and enable it only with pselect.
	358	*/
	359	sigemptyset(&set);
	360	sigaddset(&set, SIGUSR1);
	361	sigaddset(&set, SIGHUP);
	362	sigaddset(&set, SIGALRM);
	363	sigaddset(&set, SIGTERM);
	364	sigprocmask(SIG_BLOCK, &set, NULL);
	365	act.sa_handler = wake_me;
	366	act.sa_flags = 0;
	367	sigaction(SIGUSR1, &act, NULL);
	368	sigaction(SIGALRM, &act, NULL);
	369	act.sa_handler = hup;
	370	sigaction(SIGHUP, &act, NULL);
	371	act.sa_handler = term;
	372	sigaction(SIGTERM, &act, NULL);
	373	act.sa_handler = SIG_IGN;
	374	sigaction(SIGPIPE, &act, NULL);
	375
13047e4c DW	376	if (switchroot) {
	377	/* we assume we assume that /sys /proc /dev are available in
	378	* the new root (see nash:setuproot)
	379	*
	380	* kill any monitors in the current namespace and change
	381	* to the new one
	382	*/
	383	try_kill_monitor(container->devname);
	384	if (chroot(switchroot) != 0) {
	385	fprintf(stderr, "mdmon: failed to chroot to '%s': %s\n",
	386	switchroot, strerror(errno));
	387	exit(4);
	388	}
	389	}
	390
	391	/* If this fails, we hope it already exists
	392	* pid file lives in /var/run/mdadm/mdXX.pid
	393	*/
	394	mkdir("/var", 0600);
	395	mkdir("/var/run", 0600);
549e9569	396	mkdir("/var/run/mdadm", 0600);
13047e4c	397	ignore = chdir("/");
b109d928 DW	398	if (make_pidfile(container->devname, O_EXCL) < 0) {
	399	if (ping_monitor(container->devname) == 0) {
	400	fprintf(stderr, "mdmon: %s already managed\n",
	401	container->devname);
	402	exit(3);
	403	} else {
295646b3 DW	404	int err;
295646b3 DW	405
b109d928 DW	406	/* cleanup the old monitor, this one is taking over */
b109d928 DW	407	try_kill_monitor(container->devname);
295646b3 DW	408	err = make_pidfile(container->devname, 0);
295646b3 DW	409	if (err < 0) {
b109d928 DW	410	fprintf(stderr, "mdmon: %s Cannot create pidfile\n",
b109d928 DW	411	container->devname);
295646b3 DW	412	if (err == -EROFS) {
	413	/* FIXME implement a mechanism to
	414	* prevent duplicate monitor instances
	415	*/
	416	fprintf(stderr,
	417	"mdmon: continuing on read-only file system\n");
	418	} else
	419	exit(3);
b109d928 DW	420	}
b109d928 DW	421	}
549e9569	422	}
549e9569	423	container->sock = make_control_sock(container->devname);
549e9569	424
13047e4c	425	if (container->ss->load_super(container, mdfd, container_name)) {
549e9569	426	fprintf(stderr, "mdmon: Cannot load metadata for %s\n",
13047e4c	427	container_name);
549e9569 NB	428	exit(3);
549e9569 NB	429	}
549e9569	430
9fe32043 N	431	/* Ok, this is close enough. We can say goodbye to our parent now.
	432	*/
	433	status = 0;
3d2c4fc7 DW	434	if (write(pfd[1], &status, sizeof(status)) < 0)
	435	fprintf(stderr, "mdmon: failed to notify our parent: %d\n",
	436	getppid());
9fe32043 N	437	close(pfd[1]);
9fe32043 N	438
9fe32043 N	439	setsid();
	440	close(0);
	441	open("/dev/null", O_RDWR);
	442	close(1);
3d2c4fc7	443	ignore = dup(0);
9fe32043 N	444	#ifndef DEBUG
9fe32043 N	445	close(2);
3d2c4fc7	446	ignore = dup(0);
9fe32043 N	447	#endif
9fe32043 N	448
549e9569 NB	449	mlockall(MCL_FUTURE);
549e9569 NB	450
3e70c845	451	if (clone_monitor(container) < 0) {
295646b3	452	fprintf(stderr, "mdmon: failed to start monitor process: %s\n",
549e9569 NB	453	strerror(errno));
	454	exit(2);
	455	}
	456
	457	do_manager(container);
	458
	459	exit(0);
	460	}