Monitor: policy based spare migration.

Rather than only migrating between arrays with the same spare_group,
we now migrate based on domains set in the policy.

In order for spare_group to continue to work, we treat it as a domain
of the destination array, and a domain of any device we might remove
from a source array.

Signed-off-by: NeilBrown <neilb@suse.de>

3 files changed, 73 insertions, 31 deletions

diff --git a/Monitor.c b/Monitor.c
index 38dad640..ba6735c4 100644
--- a/Monitor.c
+++ b/Monitor.c
@@ -681,15 +681,16 @@ static int add_new_arrays(struct mdstat_ent *mdstat, struct state *statelist,
 	return new_found;
 }
 
-static int move_spare(struct state *st2, struct state *st,
+static int move_spare(struct state *from, struct state *to,
+		      struct domainlist *domlist,
 		      struct alert_info *info)
 {
 	struct mddev_dev devlist;
 	char devname[20];
 
 	/* try to remove and add */
-	int fd1 = open(st->devname, O_RDONLY);
-	int fd2 = open(st2->devname, O_RDONLY);
+	int fd1 = open(to->devname, O_RDONLY);
+	int fd2 = open(from->devname, O_RDONLY);
 	int dev = -1;
 	int d;
 	if (fd1 < 0 || fd2 < 0) {
@@ -697,11 +698,14 @@ static int move_spare(struct state *st2, struct state *st,
 		if (fd2>=0) close(fd2);
 		return 0;
 	}
-	for (d=st2->raid; d < MaxDisks; d++) {
-		if (st2->devid[d] > 0 &&
-		    st2->devstate[d] == 0) {
-			dev = st2->devid[d];
-			break;
+	for (d = from->raid; dev < 0 && d < MaxDisks; d++) {
+		if (from->devid[d] > 0 &&
+		    from->devstate[d] == 0) {
+			struct dev_policy *pol = devnum_policy(from->devid[d]);
+			pol_add(&pol, pol_domain, from->spare_group, NULL);
+			if (domain_test(domlist, pol, to->metadata->ss->name))
+			    dev = from->devid[d];
+			dev_policy_free(pol);
 		}
 	}
 	if (dev < 0) {
@@ -718,22 +722,23 @@ static int move_spare(struct state *st2, struct state *st,
 	sprintf(devname, "%d:%d", major(dev), minor(dev));
 
 	devlist.disposition = 'r';
-	if (Manage_subdevs(st2->devname, fd2, &devlist, -1, 0) == 0) {
+	if (Manage_subdevs(from->devname, fd2, &devlist, -1, 0) == 0) {
 		devlist.disposition = 'a';
-		if (Manage_subdevs(st->devname, fd1, &devlist, -1, 0) == 0) {
-			alert("MoveSpare", st->devname, st2->devname, info);
+		if (Manage_subdevs(to->devname, fd1, &devlist, -1, 0) == 0) {
+			alert("MoveSpare", to->devname, from->devname, info);
 			close(fd1);
 			close(fd2);
 			return 1;
 		}
-		else Manage_subdevs(st2->devname, fd2, &devlist, -1, 0);
+		else Manage_subdevs(from->devname, fd2, &devlist, -1, 0);
 	}
 	close(fd1);
 	close(fd2);
 	return 0;
 }
 
-static int check_donor(struct state *from, struct state *to)
+static int check_donor(struct state *from, struct state *to,
+		       struct domainlist *domlist)
 {
 	if (from == to)
 		return 0;
@@ -741,24 +746,35 @@ static int check_donor(struct state *from, struct state *to)
 		return 0;
 	if (from->spare <= 0)
 		return 0;
-	if (!from->spare_group || !to->spare_group)
+	if (domlist == NULL)
 		return 0;
-	return (strcmp(from->spare_group, to->spare_group) == 0);
+	return 1;
 }
 
 static void try_spare_migration(struct state *statelist, struct alert_info *info)
 {
-	struct state *st;
+	struct state *from, *to;
 
 	link_containers_with_subarrays(statelist);
-	for (st = statelist; st; st=st->next)
-		if (st->active < st->raid &&
-		    st->spare == 0) {
-			struct state *st2;
-			for (st2=statelist ; st2 ; st2=st2->next)
-				if (check_donor(st2, st)
-				    && move_spare(st2, st, info))
+	for (to = statelist; to; to = to->next)
+		if (to->active < to->raid &&
+		    to->spare == 0) {
+			struct domainlist *domlist = NULL;
+			int d;
+
+			for (d = 0; d < MaxDisks; 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);
+
+			for (from=statelist ; from ; from=from->next)
+				if (check_donor(from, to, domlist)
+				    && move_spare(from, to, domlist, info))
 						break;
+			domain_free(domlist);
 		}
 }
 
diff --git a/mdadm.h b/mdadm.h
index 3b0cad18..83152f7d 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -811,7 +811,8 @@ extern struct dev_policy *disk_policy(struct mdinfo *disk);
 extern struct dev_policy *devnum_policy(int dev);
 extern void dev_policy_free(struct dev_policy *p);
 
-extern void pol_new(struct dev_policy **pol, char *name, char *val, char *metadata);
+//extern void pol_new(struct dev_policy **pol, char *name, char *val, char *metadata);
+extern void pol_add(struct dev_policy **pol, char *name, char *val, char *metadata);
 extern struct dev_policy *pol_find(struct dev_policy *pol, char *name);
 
 enum policy_action {
@@ -839,9 +840,12 @@ extern int domain_test(struct domainlist *dom, struct dev_policy *pol,
 		       const char *metadata);
 extern struct domainlist *domain_from_array(struct mdinfo *mdi,
 					    const char *metadata);
+extern void domainlist_add_dev(struct domainlist **dom, int devnum,
+			       const char *metadata);
 extern void domain_free(struct domainlist *dl);
 extern void domain_merge(struct domainlist **domp, struct dev_policy *pol,
 			 const char *metadata);
+void domain_add(struct domainlist **domp, char *domain);
 
 extern void policy_save_path(char *id_path, struct map_ent *array);
 extern int policy_check_path(struct mdinfo *disk, struct map_ent *array);
diff --git a/policy.c b/policy.c
index cc126949..ad5850bd 100644
--- a/policy.c
+++ b/policy.c
@@ -40,7 +40,7 @@
  * particularly from a set of policy rules in mdadm.conf
  */
 
-void pol_new(struct dev_policy **pol, char *name, char *val, char *metadata)
+static void pol_new(struct dev_policy **pol, char *name, char *val, char *metadata)
 {
 	struct dev_policy *n = malloc(sizeof(*n));
 	const char *real_metadata = NULL;
@@ -365,6 +365,16 @@ struct dev_policy *path_policy(char *path, char *type)
 	return pol;
 }
 
+void pol_add(struct dev_policy **pol,
+		    char *name, char *val,
+		    char *metadata)
+{
+	pol_new(pol, name, val, metadata);
+	pol_sort(pol);
+	pol_dedup(*pol);
+}
+
+
 /*
  * disk_policy() gathers policy information for the
  * disk described in the given mdinfo (disk.{major,minor}).
@@ -600,7 +610,7 @@ void domain_merge(struct domainlist **domp, struct dev_policy *pollist,
 	struct dev_policy *pol;
 	pollist = pol_find(pollist, pol_domain);
 	pol_for_each(pol, pollist, metadata)
-		domp = domain_merge_one(domp, pol->value);
+		domain_merge_one(domp, pol->value);
 }
 
 int domain_test(struct domainlist *dom, struct dev_policy *pol,
@@ -625,19 +635,31 @@ int domain_test(struct domainlist *dom, struct dev_policy *pol,
 	return found_any;
 }
 
+void domainlist_add_dev(struct domainlist **dom, int devnum, const char *metadata)
+{
+	struct dev_policy *pol = devnum_policy(devnum);
+	domain_merge(dom, pol, metadata);
+	dev_policy_free(pol);
+}
+
 struct domainlist *domain_from_array(struct mdinfo *mdi, const char *metadata)
 {
 	struct domainlist *domlist = NULL;
 
-	for (mdi = mdi->devs ; mdi ; mdi = mdi->next) {
-		struct dev_policy *pol = disk_policy(mdi);
+	for (mdi = mdi->devs ; mdi ; mdi = mdi->next)
+		domainlist_add_dev(&domlist, makedev(mdi->disk.major,
+						     mdi->disk.minor),
+				   metadata);
 
-		domain_merge(&domlist, pol, metadata);
-		dev_policy_free(pol);
-	}
 	return domlist;
 }
 
+void domain_add(struct domainlist **domp, char *domain)
+{
+	domain_merge_one(domp, domain);
+}
+
+
 void domain_free(struct domainlist *dl)
 {
 	while (dl) {