Adding upstream version 4.2.upstream/4.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1275 insertions, 0 deletions

diff --git a/Monitor.c b/Monitor.c
new file mode 100644
index 0000000..30c031a
--- /dev/null
+++ b/Monitor.c
@@ -0,0 +1,1275 @@
+/*
+ * mdadm - manage Linux "md" devices aka RAID arrays.
+ *
+ * Copyright (C) 2001-2009 Neil Brown <neilb@suse.de>
+ *
+ *
+ *    This program is free software; you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation; either version 2 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program; if not, write to the Free Software
+ *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *    Author: Neil Brown
+ *    Email: <neilb@suse.de>
+ */
+
+#include	"mdadm.h"
+#include	"md_p.h"
+#include	"md_u.h"
+#include	<sys/wait.h>
+#include	<signal.h>
+#include	<limits.h>
+#include	<syslog.h>
+#ifndef NO_LIBUDEV
+#include	<libudev.h>
+#endif
+
+struct state {
+	char *devname;
+	char devnm[32];	/* to sync with mdstat info */
+	unsigned int utime;
+	int err;
+	char *spare_group;
+	int active, working, failed, spare, raid;
+	int from_config;
+	int from_auto;
+	int expected_spares;
+	int devstate[MAX_DISKS];
+	dev_t devid[MAX_DISKS];
+	int percent;
+	char parent_devnm[32]; /* For subarray, devnm of parent.
+				* For others, ""
+				*/
+	struct supertype *metadata;
+	struct state *subarray;/* for a container it is a link to first subarray
+				* for a subarray it is a link to next subarray
+				* in the same container */
+	struct state *parent;  /* for a subarray it is a link to its container
+				*/
+	struct state *next;
+};
+
+struct alert_info {
+	char *mailaddr;
+	char *mailfrom;
+	char *alert_cmd;
+	int dosyslog;
+};
+static int make_daemon(char *pidfile);
+static int check_one_sharer(int scan);
+static void write_autorebuild_pid(void);
+static void alert(char *event, char *dev, char *disc, struct alert_info *info);
+static int check_array(struct state *st, struct mdstat_ent *mdstat,
+		       int test, struct alert_info *info,
+		       int increments, char *prefer);
+static int add_new_arrays(struct mdstat_ent *mdstat, struct state **statelist,
+			  int test, struct alert_info *info);
+static void try_spare_migration(struct state *statelist, struct alert_info *info);
+static void link_containers_with_subarrays(struct state *list);
+#ifndef NO_LIBUDEV
+static int check_udev_activity(void);
+#endif
+
+int Monitor(struct mddev_dev *devlist,
+	    char *mailaddr, char *alert_cmd,
+	    struct context *c,
+	    int daemonise, int oneshot,
+	    int dosyslog, char *pidfile, int increments,
+	    int share)
+{
+	/*
+	 * Every few seconds, scan every md device looking for changes
+	 * When a change is found, log it, possibly run the alert command,
+	 * and possibly send Email
+	 *
+	 * For each array, we record:
+	 *   Update time
+	 *   active/working/failed/spare drives
+	 *   State of each device.
+	 *   %rebuilt if rebuilding
+	 *
+	 * If the update time changes, check out all the data again
+	 * It is possible that we cannot get the state of each device
+	 * due to bugs in the md kernel module.
+	 * We also read /proc/mdstat to get rebuild percent,
+	 * and to get state on all active devices incase of kernel bug.
+	 *
+	 * Events are:
+	 *    Fail
+	 *	An active device had Faulty set or Active/Sync removed
+	 *    FailSpare
+	 *      A spare device had Faulty set
+	 *    SpareActive
+	 *      An active device had a reverse transition
+	 *    RebuildStarted
+	 *      percent went from -1 to +ve
+	 *    RebuildNN
+	 *      percent went from below to not-below NN%
+	 *    DeviceDisappeared
+	 *      Couldn't access a device which was previously visible
+	 *
+	 * if we detect an array with active<raid and spare==0
+	 * we look at other arrays that have same spare-group
+	 * If we find one with active==raid and spare>0,
+	 *  and if we can get_disk_info and find a name
+	 *  Then we hot-remove and hot-add to the other array
+	 *
+	 * If devlist is NULL, then we can monitor everything because --scan
+	 * was given.  We get an initial list from config file and add anything
+	 * that appears in /proc/mdstat
+	 */
+
+	struct state *statelist = NULL;
+	struct state *st2;
+	int finished = 0;
+	struct mdstat_ent *mdstat = NULL;
+	char *mailfrom;
+	struct alert_info info;
+	struct mddev_ident *mdlist;
+	int delay_for_event = c->delay;
+
+	if (!mailaddr) {
+		mailaddr = conf_get_mailaddr();
+		if (mailaddr && ! c->scan)
+			pr_err("Monitor using email address \"%s\" from config file\n",
+			       mailaddr);
+	}
+	mailfrom = conf_get_mailfrom();
+
+	if (!alert_cmd) {
+		alert_cmd = conf_get_program();
+		if (alert_cmd && !c->scan)
+			pr_err("Monitor using program \"%s\" from config file\n",
+			       alert_cmd);
+	}
+	if (c->scan && !mailaddr && !alert_cmd && !dosyslog) {
+		pr_err("No mail address or alert command - not monitoring.\n");
+		return 1;
+	}
+	info.alert_cmd = alert_cmd;
+	info.mailaddr = mailaddr;
+	info.mailfrom = mailfrom;
+	info.dosyslog = dosyslog;
+
+	if (share){
+		if (check_one_sharer(c->scan))
+			return 1;
+	}
+
+	if (daemonise) {
+		int rv = make_daemon(pidfile);
+		if (rv >= 0)
+			return rv;
+	}
+
+	if (share)
+		write_autorebuild_pid();
+
+	if (devlist == NULL) {
+		mdlist = conf_get_ident(NULL);
+		for (; mdlist; mdlist = mdlist->next) {
+			struct state *st;
+
+			if (mdlist->devname == NULL)
+				continue;
+			if (strcasecmp(mdlist->devname, "<ignore>") == 0)
+				continue;
+			st = xcalloc(1, sizeof *st);
+			if (mdlist->devname[0] == '/')
+				st->devname = xstrdup(mdlist->devname);
+			else {
+				st->devname = xmalloc(8+strlen(mdlist->devname)+1);
+				strcpy(strcpy(st->devname, "/dev/md/"),
+				       mdlist->devname);
+			}
+			st->next = statelist;
+			st->devnm[0] = 0;
+			st->percent = RESYNC_UNKNOWN;
+			st->from_config = 1;
+			st->expected_spares = mdlist->spare_disks;
+			if (mdlist->spare_group)
+				st->spare_group = xstrdup(mdlist->spare_group);
+			statelist = st;
+		}
+	} else {
+		struct mddev_dev *dv;
+
+		for (dv = devlist; dv; dv = dv->next) {
+			struct state *st = xcalloc(1, sizeof *st);
+			mdlist = conf_get_ident(dv->devname);
+			st->devname = xstrdup(dv->devname);
+			st->next = statelist;
+			st->devnm[0] = 0;
+			st->percent = RESYNC_UNKNOWN;
+			st->expected_spares = -1;
+			if (mdlist) {
+				st->expected_spares = mdlist->spare_disks;
+				if (mdlist->spare_group)
+					st->spare_group = xstrdup(mdlist->spare_group);
+			}
+			statelist = st;
+		}
+	}
+
+	while (!finished) {
+		int new_found = 0;
+		struct state *st, **stp;
+		int anydegraded = 0;
+		int anyredundant = 0;
+
+		if (mdstat)
+			free_mdstat(mdstat);
+		mdstat = mdstat_read(oneshot ? 0 : 1, 0);
+
+		for (st = statelist; st; st = st->next) {
+			if (check_array(st, mdstat, c->test, &info,
+					increments, c->prefer))
+				anydegraded = 1;
+			/* for external arrays, metadata is filled for
+			 * containers only
+			 */
+			if (st->metadata && st->metadata->ss->external)
+				continue;
+			if (st->err == 0 && !anyredundant)
+				anyredundant = 1;
+		}
+
+		/* now check if there are any new devices found in mdstat */
+		if (c->scan)
+			new_found = add_new_arrays(mdstat, &statelist, c->test,
+						   &info);
+
+		/* If an array has active < raid && spare == 0 && spare_group != NULL
+		 * Look for another array with spare > 0 and active == raid and same spare_group
+		 * if found, choose a device and hotremove/hotadd
+		 */
+		if (share && anydegraded)
+			try_spare_migration(statelist, &info);
+		if (!new_found) {
+			if (oneshot)
+				break;
+			else if (!anyredundant) {
+				pr_err("No array with redundancy detected, stopping\n");
+				break;
+			}
+			else {
+#ifndef NO_LIBUDEV
+				/*
+				 * Wait for udevd to finish new devices
+				 * processing.
+				 */
+				if (mdstat_wait(delay_for_event) &&
+				    check_udev_activity())
+					pr_err("Error while waiting for UDEV to complete new devices processing\n");
+#else
+				int wait_result = mdstat_wait(delay_for_event);
+				/*
+				 * Give chance to process new device
+				 */
+				if (wait_result != 0) {
+					if (c->delay > 5)
+						delay_for_event = 5;
+				} else
+					delay_for_event = c->delay;
+#endif
+				mdstat_close();
+			}
+		}
+		c->test = 0;
+
+		for (stp = &statelist; (st = *stp) != NULL; ) {
+			if (st->from_auto && st->err > 5) {
+				*stp = st->next;
+				free(st->devname);
+				free(st->spare_group);
+				free(st);
+			} else
+				stp = &st->next;
+		}
+	}
+	for (st2 = statelist; st2; st2 = statelist) {
+		statelist = st2->next;
+		free(st2);
+	}
+
+	if (pidfile)
+		unlink(pidfile);
+	return 0;
+}
+
+static int make_daemon(char *pidfile)
+{
+	/* Return:
+	 * -1 in the forked daemon
+	 *  0 in the parent
+	 *  1 on error
+	 * so a none-negative becomes the exit code.
+	 */
+	int pid = fork();
+	if (pid > 0) {
+		if (!pidfile)
+			printf("%d\n", pid);
+		else {
+			FILE *pid_file = NULL;
+			int fd = open(pidfile, O_WRONLY | O_CREAT | O_TRUNC,
+				      0644);
+			if (fd >= 0)
+				pid_file = fdopen(fd, "w");
+			if (!pid_file)
+				perror("cannot create pid file");
+			else {
+				fprintf(pid_file,"%d\n", pid);
+				fclose(pid_file);
+			}
+		}
+		return 0;
+	}
+	if (pid < 0) {
+		perror("daemonise");
+		return 1;
+	}
+	manage_fork_fds(0);
+	setsid();
+	return -1;
+}
+
+static int check_one_sharer(int scan)
+{
+	int pid;
+	FILE *comm_fp;
+	FILE *fp;
+	char comm_path[PATH_MAX];
+	char path[PATH_MAX];
+	char comm[20];
+
+	sprintf(path, "%s/autorebuild.pid", MDMON_DIR);
+	fp = fopen(path, "r");
+	if (fp) {
+		if (fscanf(fp, "%d", &pid) != 1)
+			pid = -1;
+		snprintf(comm_path, sizeof(comm_path),
+			 "/proc/%d/comm", pid);
+		comm_fp = fopen(comm_path, "r");
+		if (comm_fp) {
+			if (fscanf(comm_fp, "%19s", comm) &&
+			    strncmp(basename(comm), Name, strlen(Name)) == 0) {
+				if (scan) {
+					pr_err("Only one autorebuild process allowed in scan mode, aborting\n");
+					fclose(comm_fp);
+					fclose(fp);
+					return 1;
+				} else {
+					pr_err("Warning: One autorebuild process already running.\n");
+				}
+			}
+			fclose(comm_fp);
+		}
+		fclose(fp);
+	}
+	return 0;
+}
+
+static void write_autorebuild_pid()
+{
+	char path[PATH_MAX];
+	int pid;
+	FILE *fp = NULL;
+	sprintf(path, "%s/autorebuild.pid", MDMON_DIR);
+
+	if (mkdir(MDMON_DIR, 0700) < 0 && errno != EEXIST) {
+		pr_err("Can't create autorebuild.pid file\n");
+	} else {
+		int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0700);
+
+		if (fd >= 0)
+			fp = fdopen(fd, "w");
+
+		if (!fp)
+			pr_err("Can't create autorebuild.pid file\n");
+		else {
+			pid = getpid();
+			fprintf(fp, "%d\n", pid);
+			fclose(fp);
+		}
+	}
+}
+
+static void alert(char *event, char *dev, char *disc, struct alert_info *info)
+{
+	int priority;
+
+	if (!info->alert_cmd && !info->mailaddr && !info->dosyslog) {
+		time_t now = time(0);
+
+		printf("%1.15s: %s on %s %s\n", ctime(&now) + 4,
+		       event, dev, disc?disc:"unknown device");
+	}
+	if (info->alert_cmd) {
+		int pid = fork();
+		switch(pid) {
+		default:
+			waitpid(pid, NULL, 0);
+			break;
+		case -1:
+			break;
+		case 0:
+			execl(info->alert_cmd, info->alert_cmd,
+			      event, dev, disc, NULL);
+			exit(2);
+		}
+	}
+	if (info->mailaddr && (strncmp(event, "Fail", 4) == 0 ||
+			       strncmp(event, "Test", 4) == 0 ||
+			       strncmp(event, "Spares", 6) == 0 ||
+			       strncmp(event, "Degrade", 7) == 0)) {
+		FILE *mp = popen(Sendmail, "w");
+		if (mp) {
+			FILE *mdstat;
+			char hname[256];
+			gethostname(hname, sizeof(hname));
+			signal(SIGPIPE, SIG_IGN);
+			if (info->mailfrom)
+				fprintf(mp, "From: %s\n", info->mailfrom);
+			else
+				fprintf(mp, "From: %s monitoring <root>\n",
+					Name);
+			fprintf(mp, "To: %s\n", info->mailaddr);
+			fprintf(mp, "Subject: %s event on %s:%s\n\n",
+				event, dev, hname);
+
+			fprintf(mp,
+				"This is an automatically generated mail message from %s\n", Name);
+			fprintf(mp, "running on %s\n\n", hname);
+
+			fprintf(mp,
+				"A %s event had been detected on md device %s.\n\n", event, dev);
+
+			if (disc && disc[0] != ' ')
+				fprintf(mp,
+					"It could be related to component device %s.\n\n", disc);
+			if (disc && disc[0] == ' ')
+				fprintf(mp, "Extra information:%s.\n\n", disc);
+
+			fprintf(mp, "Faithfully yours, etc.\n");
+
+			mdstat = fopen("/proc/mdstat", "r");
+			if (mdstat) {
+				char buf[8192];
+				int n;
+				fprintf(mp,
+					"\nP.S. The /proc/mdstat file currently contains the following:\n\n");
+				while ((n = fread(buf, 1, sizeof(buf),
+						  mdstat)) > 0)
+					n = fwrite(buf, 1, n, mp);
+				fclose(mdstat);
+			}
+			pclose(mp);
+		}
+	}
+
+	/* log the event to syslog maybe */
+	if (info->dosyslog) {
+		/* Log at a different severity depending on the event.
+		 *
+		 * These are the critical events:  */
+		if (strncmp(event, "Fail", 4) == 0 ||
+		    strncmp(event, "Degrade", 7) == 0 ||
+		    strncmp(event, "DeviceDisappeared", 17) == 0)
+			priority = LOG_CRIT;
+		/* Good to know about, but are not failures: */
+		else if (strncmp(event, "Rebuild", 7) == 0 ||
+			 strncmp(event, "MoveSpare", 9) == 0 ||
+			 strncmp(event, "Spares", 6) != 0)
+			priority = LOG_WARNING;
+		/* Everything else: */
+		else
+			priority = LOG_INFO;
+
+		if (disc && disc[0] != ' ')
+			syslog(priority,
+			       "%s event detected on md device %s, component device %s", event, dev, disc);
+		else if (disc)
+			syslog(priority,
+			       "%s event detected on md device %s: %s",
+			       event, dev, disc);
+		else
+			syslog(priority,
+			       "%s event detected on md device %s",
+			       event, dev);
+	}
+}
+
+static int check_array(struct state *st, struct mdstat_ent *mdstat,
+		       int test, struct alert_info *ainfo,
+		       int increments, char *prefer)
+{
+	/* Update the state 'st' to reflect any changes shown in mdstat,
+	 * or found by directly examining the array, and return
+	 * '1' if the array is degraded, or '0' if it is optimal (or dead).
+	 */
+	struct { int state, major, minor; } info[MAX_DISKS];
+	struct mdinfo *sra = NULL;
+	mdu_array_info_t array;
+	struct mdstat_ent *mse = NULL, *mse2;
+	char *dev = st->devname;
+	int fd;
+	int i;
+	int remaining_disks;
+	int last_disk;
+	int new_array = 0;
+	int retval;
+	int is_container = 0;
+	unsigned long redundancy_only_flags = 0;
+
+	if (test)
+		alert("TestMessage", dev, NULL, ainfo);
+
+	retval = 0;
+
+	fd = open(dev, O_RDONLY);
+	if (fd < 0)
+		goto disappeared;
+
+	if (st->devnm[0] == 0)
+		strcpy(st->devnm, fd2devnm(fd));
+
+	for (mse2 = mdstat; mse2; mse2 = mse2->next)
+		if (strcmp(mse2->devnm, st->devnm) == 0) {
+			mse2->devnm[0] = 0; /* flag it as "used" */
+			mse = mse2;
+		}
+
+	if (!mse) {
+		/* duplicated array in statelist
+		 * or re-created after reading mdstat
+		 */
+		st->err++;
+		goto out;
+	}
+
+	if (mse->level == NULL)
+		is_container = 1;
+
+	if (!is_container && !md_array_active(fd))
+		goto disappeared;
+
+	fcntl(fd, F_SETFD, FD_CLOEXEC);
+	if (md_get_array_info(fd, &array) < 0)
+		goto disappeared;
+
+	if (!is_container && map_name(pers, mse->level) > 0)
+		redundancy_only_flags |= GET_MISMATCH;
+
+	sra = sysfs_read(-1, st->devnm, GET_LEVEL | GET_DISKS | GET_DEVS |
+			GET_STATE | redundancy_only_flags);
+
+	if (!sra)
+		goto disappeared;
+
+	/* It's much easier to list what array levels can't
+	 * have a device disappear than all of them that can
+	 */
+	if (sra->array.level == 0 || sra->array.level == -1) {
+		if (!st->err && !st->from_config)
+			alert("DeviceDisappeared", dev, " Wrong-Level", ainfo);
+		st->err++;
+		goto out;
+	}
+
+	/* this array is in /proc/mdstat */
+	if (array.utime == 0)
+		/* external arrays don't update utime, so
+		 * just make sure it is always different. */
+		array.utime = st->utime + 1;;
+
+	if (st->err) {
+		/* New array appeared where previously had an error */
+		st->err = 0;
+		st->percent = RESYNC_NONE;
+		new_array = 1;
+		if (!is_container)
+			alert("NewArray", st->devname, NULL, ainfo);
+	}
+
+	if (st->utime == array.utime && st->failed == sra->array.failed_disks &&
+	    st->working == sra->array.working_disks &&
+	    st->spare == sra->array.spare_disks &&
+	    (mse == NULL || (mse->percent == st->percent))) {
+		if ((st->active < st->raid) && st->spare == 0)
+			retval = 1;
+		goto out;
+	}
+	if (st->utime == 0 && /* new array */
+	    mse->pattern && strchr(mse->pattern, '_') /* degraded */)
+		alert("DegradedArray", dev, NULL, ainfo);
+
+	if (st->utime == 0 && /* new array */ st->expected_spares > 0 &&
+	    sra->array.spare_disks < st->expected_spares)
+		alert("SparesMissing", dev, NULL, ainfo);
+	if (st->percent < 0 && st->percent != RESYNC_UNKNOWN &&
+	    mse->percent >= 0)
+		alert("RebuildStarted", dev, NULL, ainfo);
+	if (st->percent >= 0 && mse->percent >= 0 &&
+	    (mse->percent / increments) > (st->percent / increments)) {
+		char percentalert[18];
+		/*
+		 * "RebuildNN" (10 chars) or "RebuildStarted" (15 chars)
+		 */
+
+		if((mse->percent / increments) == 0)
+			snprintf(percentalert, sizeof(percentalert),
+				 "RebuildStarted");
+		else
+			snprintf(percentalert, sizeof(percentalert),
+				 "Rebuild%02d", mse->percent);
+
+		alert(percentalert, dev, NULL, ainfo);
+	}
+
+	if (mse->percent == RESYNC_NONE && st->percent >= 0) {
+		/* Rebuild/sync/whatever just finished.
+		 * If there is a number in /mismatch_cnt,
+		 * we should report that.
+		 */
+		if (sra && sra->mismatch_cnt > 0) {
+			char cnt[80];
+			snprintf(cnt, sizeof(cnt),
+				 " mismatches found: %d (on raid level %d)",
+				 sra->mismatch_cnt, sra->array.level);
+			alert("RebuildFinished", dev, cnt, ainfo);
+		} else
+			alert("RebuildFinished", dev, NULL, ainfo);
+	}
+	st->percent = mse->percent;
+
+	remaining_disks = sra->array.nr_disks;
+	for (i = 0; i < MAX_DISKS && remaining_disks > 0; i++) {
+		mdu_disk_info_t disc;
+		disc.number = i;
+		if (md_get_disk_info(fd, &disc) >= 0) {
+			info[i].state = disc.state;
+			info[i].major = disc.major;
+			info[i].minor = disc.minor;
+			if (disc.major || disc.minor)
+				remaining_disks --;
+		} else
+			info[i].major = info[i].minor = 0;
+	}
+	last_disk = i;
+
+	if (mse->metadata_version &&
+	    strncmp(mse->metadata_version, "external:", 9) == 0 &&
+	    is_subarray(mse->metadata_version+9)) {
+		char *sl;
+		strcpy(st->parent_devnm, mse->metadata_version + 10);
+		sl = strchr(st->parent_devnm, '/');
+		if (sl)
+			*sl = 0;
+	} else
+		st->parent_devnm[0] = 0;
+	if (st->metadata == NULL && st->parent_devnm[0] == 0)
+		st->metadata = super_by_fd(fd, NULL);
+
+	for (i = 0; i < MAX_DISKS; i++) {
+		mdu_disk_info_t disc = {0, 0, 0, 0, 0};
+		int newstate = 0;
+		int change;
+		char *dv = NULL;
+		disc.number = i;
+		if (i < last_disk && (info[i].major || info[i].minor)) {
+			newstate = info[i].state;
+			dv = map_dev_preferred(info[i].major, info[i].minor, 1,
+					       prefer);
+			disc.state = newstate;
+			disc.major = info[i].major;
+			disc.minor = info[i].minor;
+		} else
+			newstate = (1 << MD_DISK_REMOVED);
+
+		if (dv == NULL && st->devid[i])
+			dv = map_dev_preferred(major(st->devid[i]),
+					       minor(st->devid[i]), 1, prefer);
+		change = newstate ^ st->devstate[i];
+		if (st->utime && change && !st->err && !new_array) {
+			if ((st->devstate[i]&change) & (1 << MD_DISK_SYNC))
+				alert("Fail", dev, dv, ainfo);
+			else if ((newstate & (1 << MD_DISK_FAULTY)) &&
+				 (disc.major || disc.minor) &&
+				 st->devid[i] == makedev(disc.major,
+							 disc.minor))
+				alert("FailSpare", dev, dv, ainfo);
+			else if ((newstate&change) & (1 << MD_DISK_SYNC))
+				alert("SpareActive", dev, dv, ainfo);
+		}
+		st->devstate[i] = newstate;
+		st->devid[i] = makedev(disc.major, disc.minor);
+	}
+	st->active = sra->array.active_disks;
+	st->working = sra->array.working_disks;
+	st->spare = sra->array.spare_disks;
+	st->failed = sra->array.failed_disks;
+	st->utime = array.utime;
+	st->raid = sra->array.raid_disks;
+	st->err = 0;
+	if ((st->active < st->raid) && st->spare == 0)
+		retval = 1;
+
+ out:
+	if (sra)
+		sysfs_free(sra);
+	if (fd >= 0)
+		close(fd);
+	return retval;
+
+ disappeared:
+	if (!st->err && !is_container)
+		alert("DeviceDisappeared", dev, NULL, ainfo);
+	st->err++;
+	goto out;
+}
+
+static int add_new_arrays(struct mdstat_ent *mdstat, struct state **statelist,
+			  int test, struct alert_info *info)
+{
+	struct mdstat_ent *mse;
+	int new_found = 0;
+	char *name;
+
+	for (mse = mdstat; mse; mse = mse->next)
+		if (mse->devnm[0] && (!mse->level || /* retrieve containers */
+				      (strcmp(mse->level, "raid0") != 0 &&
+				       strcmp(mse->level, "linear") != 0))) {
+			struct state *st = xcalloc(1, sizeof *st);
+			mdu_array_info_t array;
+			int fd;
+
+			name = get_md_name(mse->devnm);
+			if (!name) {
+				free(st);
+				continue;
+			}
+
+			st->devname = xstrdup(name);
+			if ((fd = open(st->devname, O_RDONLY)) < 0 ||
+			    md_get_array_info(fd, &array) < 0) {
+				/* no such array */
+				if (fd >= 0)
+					close(fd);
+				put_md_name(st->devname);
+				free(st->devname);
+				if (st->metadata) {
+					st->metadata->ss->free_super(st->metadata);
+					free(st->metadata);
+				}
+				free(st);
+				continue;
+			}
+			close(fd);
+			st->next = *statelist;
+			st->err = 1;
+			st->from_auto = 1;
+			strcpy(st->devnm, mse->devnm);
+			st->percent = RESYNC_UNKNOWN;
+			st->expected_spares = -1;
+			if (mse->metadata_version &&
+			    strncmp(mse->metadata_version,
+				    "external:", 9) == 0 &&
+			    is_subarray(mse->metadata_version+9)) {
+				char *sl;
+				strcpy(st->parent_devnm,
+					mse->metadata_version+10);
+				sl = strchr(st->parent_devnm, '/');
+				*sl = 0;
+			} else
+				st->parent_devnm[0] = 0;
+			*statelist = st;
+			if (test)
+				alert("TestMessage", st->devname, NULL, info);
+			new_found = 1;
+		}
+	return new_found;
+}
+
+static int get_required_spare_criteria(struct state *st,
+				       struct spare_criteria *sc)
+{
+	int fd;
+
+	if (!st->metadata || !st->metadata->ss->get_spare_criteria) {
+		sc->min_size = 0;
+		sc->sector_size = 0;
+		return 0;
+	}
+
+	fd = open(st->devname, O_RDONLY);
+	if (fd < 0)
+		return 1;
+	if (st->metadata->ss->external)
+		st->metadata->ss->load_container(st->metadata, fd, st->devname);
+	else
+		st->metadata->ss->load_super(st->metadata, fd, st->devname);
+	close(fd);
+	if (!st->metadata->sb)
+		return 1;
+
+	st->metadata->ss->get_spare_criteria(st->metadata, sc);
+	st->metadata->ss->free_super(st->metadata);
+
+	return 0;
+}
+
+static int check_donor(struct state *from, struct state *to)
+{
+	struct state *sub;
+
+	if (from == to)
+		return 0;
+	if (from->parent)
+		/* Cannot move from a member */
+		return 0;
+	if (from->err)
+		return 0;
+	for (sub = from->subarray; sub; sub = sub->subarray)
+		/* If source array has degraded subarrays, don't
+		 * remove anything
+		 */
+		if (sub->active < sub->raid)
+			return 0;
+	if (from->metadata->ss->external == 0)
+		if (from->active < from->raid)
+			return 0;
+	if (from->spare <= 0)
+		return 0;
+	return 1;
+}
+
+static dev_t choose_spare(struct state *from, struct state *to,
+			  struct domainlist *domlist, struct spare_criteria *sc)
+{
+	int d;
+	dev_t dev = 0;
+
+	for (d = from->raid; !dev && d < MAX_DISKS; d++) {
+		if (from->devid[d] > 0 && from->devstate[d] == 0) {
+			struct dev_policy *pol;
+			unsigned long long dev_size;
+			unsigned int dev_sector_size;
+
+			if (to->metadata->ss->external &&
+			    test_partition_from_id(from->devid[d]))
+				continue;
+
+			if (sc->min_size &&
+			    dev_size_from_id(from->devid[d], &dev_size) &&
+			    dev_size < sc->min_size)
+				continue;
+
+			if (sc->sector_size &&
+			    dev_sector_size_from_id(from->devid[d],
+						    &dev_sector_size) &&
+			    sc->sector_size != dev_sector_size)
+				continue;
+
+			pol = devid_policy(from->devid[d]);
+			if (from->spare_group)
+				pol_add(&pol, pol_domain,
+					from->spare_group, NULL);
+			if (domain_test(domlist, pol,
+					to->metadata->ss->name) == 1)
+			    dev = from->devid[d];
+			dev_policy_free(pol);
+		}
+	}
+	return dev;
+}
+
+static dev_t container_choose_spare(struct state *from, struct state *to,
+				    struct domainlist *domlist,
+				    struct spare_criteria *sc, int active)
+{
+	/* This is similar to choose_spare, but we cannot trust devstate,
+	 * so we need to read the metadata instead
+	 */
+	struct mdinfo *list;
+	struct supertype *st = from->metadata;
+	int fd = open(from->devname, O_RDONLY);
+	int err;
+	dev_t dev = 0;
+
+	if (fd < 0)
+		return 0;
+	if (!st->ss->getinfo_super_disks) {
+		close(fd);
+		return 0;
+	}
+
+	err = st->ss->load_container(st, fd, NULL);
+	close(fd);
+	if (err)
+		return 0;
+
+	if (from == to) {
+		/* We must check if number of active disks has not increased
+		 * since ioctl in main loop. mdmon may have added spare
+		 * to subarray. If so we do not need to look for more spares
+		 * so return non zero value */
+		int active_cnt = 0;
+		struct mdinfo *dp;
+		list = st->ss->getinfo_super_disks(st);
+		if (!list) {
+			st->ss->free_super(st);
+			return 1;
+		}
+		dp = list->devs;
+		while (dp) {
+			if (dp->disk.state & (1 << MD_DISK_SYNC) &&
+			    !(dp->disk.state & (1 << MD_DISK_FAULTY)))
+				active_cnt++;
+			dp = dp->next;
+		}
+		sysfs_free(list);
+		if (active < active_cnt) {
+			/* Spare just activated.*/
+			st->ss->free_super(st);
+			return 1;
+		}
+	}
+
+	/* We only need one spare so full list not needed */
+	list = container_choose_spares(st, sc, domlist, from->spare_group,
+				       to->metadata->ss->name, 1);
+	if (list) {
+		struct mdinfo *disks = list->devs;
+		if (disks)
+			dev = makedev(disks->disk.major, disks->disk.minor);
+		sysfs_free(list);
+	}
+	st->ss->free_super(st);
+	return dev;
+}
+
+static void try_spare_migration(struct state *statelist, struct alert_info *info)
+{
+	struct state *from;
+	struct state *st;
+	struct spare_criteria sc;
+
+	link_containers_with_subarrays(statelist);
+	for (st = statelist; st; st = st->next)
+		if (st->active < st->raid && st->spare == 0 && !st->err) {
+			struct domainlist *domlist = NULL;
+			int d;
+			struct state *to = st;
+
+			if (to->parent_devnm[0] && !to->parent)
+				/* subarray monitored without parent container
+				 * we can't move spares here */
+				continue;
+
+			if (to->parent)
+				/* member of a container */
+				to = to->parent;
+
+			if (get_required_spare_criteria(to, &sc))
+				continue;
+			if (to->metadata->ss->external) {
+				/* We must make sure there is
+				 * no suitable spare in container already.
+				 * If there is we don't add more */
+				dev_t devid = container_choose_spare(
+					to, to, NULL, &sc, st->active);
+				if (devid > 0)
+					continue;
+			}
+			for (d = 0; d < MAX_DISKS; d++)
+				if (to->devid[d])
+					domainlist_add_dev(&domlist,
+							   to->devid[d],
+							   to->metadata->ss->name);
+			if (to->spare_group)
+				domain_add(&domlist, to->spare_group);
+			/*
+			 * No spare migration if the destination
+			 * has no domain. Skip this array.
+			 */
+			if (!domlist)
+				continue;
+			for (from=statelist ; from ; from=from->next) {
+				dev_t devid;
+				if (!check_donor(from, to))
+					continue;
+				if (from->metadata->ss->external)
+					devid = container_choose_spare(
+						from, to, domlist, &sc, 0);
+				else
+					devid = choose_spare(from, to, domlist,
+							     &sc);
+				if (devid > 0 &&
+				    move_spare(from->devname, to->devname,
+					       devid)) {
+					alert("MoveSpare", to->devname,
+					      from->devname, info);
+					break;
+				}
+			}
+			domain_free(domlist);
+		}
+}
+
+/* search the statelist to connect external
+ * metadata subarrays with their containers
+ * We always completely rebuild the tree from scratch as
+ * that is safest considering the possibility of entries
+ * disappearing or changing.
+ */
+static void link_containers_with_subarrays(struct state *list)
+{
+	struct state *st;
+	struct state *cont;
+	for (st = list; st; st = st->next) {
+		st->parent = NULL;
+		st->subarray = NULL;
+	}
+	for (st = list; st; st = st->next)
+		if (st->parent_devnm[0])
+			for (cont = list; cont; cont = cont->next)
+				if (!cont->err && cont->parent_devnm[0] == 0 &&
+				    strcmp(cont->devnm, st->parent_devnm) == 0) {
+					st->parent = cont;
+					st->subarray = cont->subarray;
+					cont->subarray = st;
+					break;
+				}
+}
+
+#ifndef NO_LIBUDEV
+/* function: check_udev_activity
+ * Description: Function waits for udev to finish
+ * events processing.
+ * Returns:
+ *		1 - detected error while opening udev
+ *		2 - timeout
+ *		0 - successfull completion
+ */
+static int check_udev_activity(void)
+{
+	struct udev *udev = NULL;
+	struct udev_queue *udev_queue = NULL;
+	int timeout_cnt = 30;
+	int rc = 0;
+
+	/*
+	 * In rare cases systemd may not have udevm,
+	 * in such cases just exit with rc 0
+	 */
+	if (!use_udev())
+		goto out;
+
+	udev = udev_new();
+	if (!udev) {
+		rc = 1;
+		goto out;
+	}
+
+	udev_queue = udev_queue_new(udev);
+	if (!udev_queue) {
+		rc = 1;
+		goto out;
+	}
+
+	if (udev_queue_get_queue_is_empty(udev_queue))
+		goto out;
+
+	while (!udev_queue_get_queue_is_empty(udev_queue)) {
+		sleep(1);
+
+		if (timeout_cnt)
+			timeout_cnt--;
+		else {
+			rc = 2;
+			goto out;
+		}
+	}
+
+out:
+	if (udev_queue)
+		udev_queue_unref(udev_queue);
+	if (udev)
+		udev_unref(udev);
+	return rc;
+}
+#endif
+
+/* Not really Monitor but ... */
+int Wait(char *dev)
+{
+	char devnm[32];
+	dev_t rdev;
+	char *tmp;
+	int rv = 1;
+	int frozen_remaining = 3;
+
+	if (!stat_is_blkdev(dev, &rdev))
+		return 2;
+
+	tmp = devid2devnm(rdev);
+	if (!tmp) {
+		pr_err("Cannot get md device name.\n");
+		return 2;
+	}
+
+	strcpy(devnm, tmp);
+
+	while(1) {
+		struct mdstat_ent *ms = mdstat_read(1, 0);
+		struct mdstat_ent *e;
+
+		for (e = ms; e; e = e->next)
+			if (strcmp(e->devnm, devnm) == 0)
+				break;
+
+		if (e && e->percent == RESYNC_NONE) {
+			/* We could be in the brief pause before something
+			 * starts. /proc/mdstat doesn't show that, but
+			 * sync_action does.
+			 */
+			struct mdinfo mdi;
+			char buf[21];
+
+			if (sysfs_init(&mdi, -1, devnm))
+				return 2;
+			if (sysfs_get_str(&mdi, NULL, "sync_action",
+					  buf, 20) > 0 &&
+			    strcmp(buf,"idle\n") != 0) {
+				e->percent = RESYNC_UNKNOWN;
+				if (strcmp(buf, "frozen\n") == 0) {
+					if (frozen_remaining == 0)
+						e->percent = RESYNC_NONE;
+					else
+						frozen_remaining -= 1;
+				}
+			}
+		}
+		if (!e || e->percent == RESYNC_NONE) {
+			if (e && e->metadata_version &&
+			    strncmp(e->metadata_version, "external:", 9) == 0) {
+				if (is_subarray(&e->metadata_version[9]))
+					ping_monitor(&e->metadata_version[9]);
+				else
+					ping_monitor(devnm);
+			}
+			free_mdstat(ms);
+			return rv;
+		}
+		free_mdstat(ms);
+		rv = 0;
+		mdstat_wait(5);
+	}
+}
+
+/* The state "broken" is used only for RAID0/LINEAR - it's the same as
+ * "clean", but used in case the array has one or more members missing.
+ */
+static char *clean_states[] = {
+	"clear", "inactive", "readonly", "read-auto", "clean", "broken", NULL };
+
+int WaitClean(char *dev, int verbose)
+{
+	int fd;
+	struct mdinfo *mdi;
+	int rv = 1;
+	char devnm[32];
+
+	if (!stat_is_blkdev(dev, NULL))
+		return 2;
+	fd = open(dev, O_RDONLY);
+	if (fd < 0) {
+		if (verbose)
+			pr_err("Couldn't open %s: %s\n", dev, strerror(errno));
+		return 1;
+	}
+
+	strcpy(devnm, fd2devnm(fd));
+	mdi = sysfs_read(fd, devnm, GET_VERSION|GET_LEVEL|GET_SAFEMODE);
+	if (!mdi) {
+		if (verbose)
+			pr_err("Failed to read sysfs attributes for %s\n", dev);
+		close(fd);
+		return 0;
+	}
+
+	switch(mdi->array.level) {
+	case LEVEL_LINEAR:
+	case LEVEL_MULTIPATH:
+	case 0:
+		/* safemode delay is irrelevant for these levels */
+		rv = 0;
+	}
+
+	/* for internal metadata the kernel handles the final clean
+	 * transition, containers can never be dirty
+	 */
+	if (!is_subarray(mdi->text_version))
+		rv = 0;
+
+	/* safemode disabled ? */
+	if (mdi->safe_mode_delay == 0)
+		rv = 0;
+
+	if (rv) {
+		int state_fd = sysfs_open(fd2devnm(fd), NULL, "array_state");
+		char buf[20];
+		int delay = 5000;
+
+		/* minimize the safe_mode_delay and prepare to wait up to 5s
+		 * for writes to quiesce
+		 */
+		sysfs_set_safemode(mdi, 1);
+
+		/* wait for array_state to be clean */
+		while (1) {
+			rv = read(state_fd, buf, sizeof(buf));
+			if (rv < 0)
+				break;
+			if (sysfs_match_word(buf, clean_states) <
+			    (int)ARRAY_SIZE(clean_states) - 1)
+				break;
+			rv = sysfs_wait(state_fd, &delay);
+			if (rv < 0 && errno != EINTR)
+				break;
+			lseek(state_fd, 0, SEEK_SET);
+		}
+		if (rv < 0)
+			rv = 1;
+		else if (ping_monitor(mdi->text_version) == 0) {
+			/* we need to ping to close the window between array
+			 * state transitioning to clean and the metadata being
+			 * marked clean
+			 */
+			rv = 0;
+		} else {
+			rv = 1;
+			pr_err("Error connecting monitor with %s\n", dev);
+		}
+		if (rv && verbose)
+			pr_err("Error waiting for %s to be clean\n", dev);
+
+		/* restore the original safe_mode_delay */
+		sysfs_set_safemode(mdi, mdi->safe_mode_delay);
+		close(state_fd);
+	}
+
+	sysfs_free(mdi);
+	close(fd);
+
+	return rv;
+}