+ 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, unsigned long long min_size)
+{
+ int d;
+ dev_t dev = 0;
+
+ for (d = from->raid; !dev && d < MaxDisks; d++) {
+ if (from->devid[d] > 0 &&
+ from->devstate[d] == 0) {
+ struct dev_policy *pol;
+ unsigned long long dev_size;
+
+ if (to->metadata->ss->external &&
+ test_partition_from_id(from->devid[d]))
+ continue;
+
+ if (min_size &&
+ dev_size_from_id(from->devid[d], &dev_size) &&
+ dev_size < min_size)
+ continue;
+
+ pol = devnum_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,
+ unsigned long long min_size, 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, min_size, 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;