+ fprintf(stderr, Name ": failed to add %s as spare for %s\n",
+ devname, chosen->sys_name);
+ }
+ sysfs_free(chosen);
+ }
+ return rv;
+}
+
+static int partition_try_spare(char *devname, int *dfdp, struct dev_policy *pol,
+ struct supertype *st, int verbose)
+{
+ /* we know that at least one partition virtual-metadata is
+ * allowed to incorporate spares like this device. We need to
+ * find a suitable device to copy partition information from.
+ *
+ * Getting a list of all disk (not partition) devices is
+ * slightly non-trivial. We could look at /sys/block, but
+ * that is theoretically due to be removed. Maybe best to use
+ * /dev/disk/by-path/?* and ignore names ending '-partNN' as
+ * we depend on this directory of 'path' info. But that fails
+ * to find loop devices and probably others. Maybe don't
+ * worry about that, they aren't the real target.
+ *
+ * So: check things in /dev/disk/by-path to see if they are in
+ * a compatible domain, then load the partition table and see
+ * if it is OK for the new device, and choose the largest
+ * partition table that fits.
+ */
+ DIR *dir;
+ struct dirent *de;
+ char *chosen = NULL;
+ unsigned long long chosen_size = 0;
+ struct supertype *chosen_st = NULL;
+ int fd;
+
+ dir = opendir("/dev/disk/by-path");
+ if (!dir)
+ return 1;
+ while ((de = readdir(dir)) != NULL) {
+ char *ep;
+ struct dev_policy *pol2 = NULL;
+ struct domainlist *domlist = NULL;
+ int fd = -1;
+ struct mdinfo info;
+ struct supertype *st2 = NULL;
+ char *devname = NULL;
+ unsigned long long devsectors;
+
+ if (de->d_ino == 0 ||
+ de->d_name[0] == '.' ||
+ (de->d_type != DT_LNK && de->d_type != DT_UNKNOWN))
+ goto next;
+
+ ep = de->d_name + strlen(de->d_name);
+ while (ep > de->d_name &&
+ isdigit(ep[-1]))
+ ep--;
+ if (ep > de->d_name + 5 &&
+ strncmp(ep-5, "-part", 5) == 0)
+ /* This is a partition - skip it */
+ goto next;
+
+ pol2 = path_policy(de->d_name, type_disk);
+
+ domain_merge(&domlist, pol2, st ? st->ss->name : NULL);
+ if (domain_test(domlist, pol, st ? st->ss->name : NULL) != 1)
+ /* new device is incompatible with this device. */
+ goto next;
+
+ domain_free(domlist);
+ domlist = NULL;
+
+ if (asprintf(&devname, "/dev/disk/by-path/%s", de->d_name) != 1) {
+ devname = NULL;
+ goto next;
+ }
+ fd = open(devname, O_RDONLY);
+ if (fd < 0)
+ goto next;
+ if (get_dev_size(fd, devname, &devsectors) == 0)
+ goto next;
+ devsectors >>= 9;
+
+ if (st)
+ st2 = dup_super(st);
+ else
+ st2 = guess_super_type(fd, guess_partitions);
+ if (st2 == NULL ||
+ st2->ss->load_super(st2, fd, NULL) < 0)
+ goto next;
+
+ if (!st) {
+ /* Check domain policy again, this time referring to metadata */
+ domain_merge(&domlist, pol2, st2->ss->name);
+ if (domain_test(domlist, pol, st2->ss->name) != 1)
+ /* Incompatible devices for this metadata type */
+ goto next;
+ if (!policy_action_allows(pol, st2->ss->name, act_spare))
+ /* Some partition types allow sparing, but not
+ * this one.
+ */
+ goto next;
+ }
+
+ st2->ss->getinfo_super(st2, &info, NULL);
+ if (info.component_size > devsectors)
+ /* This partitioning doesn't fit in the device */
+ goto next;
+
+ /* This is an acceptable device to copy partition
+ * metadata from. We could just stop here, but I
+ * think I want to keep looking incase a larger
+ * metadata which makes better use of the device can
+ * be found.
+ */
+ if (chosen == NULL ||
+ chosen_size < info.component_size) {
+ chosen_size = info.component_size;
+ free(chosen);
+ chosen = devname;
+ devname = NULL;
+ if (chosen_st) {
+ chosen_st->ss->free_super(chosen_st);
+ free(chosen_st);
+ }
+ chosen_st = st2;
+ st2 = NULL;
+ }
+
+ next:
+ free(devname);
+ domain_free(domlist);
+ dev_policy_free(pol2);
+ if (st2)
+ st2->ss->free_super(st2);
+ free(st2);
+
+ if (fd >= 0)
+ close(fd);
+ }
+
+ if (!chosen)
+ return 1;
+
+ /* 'chosen' is the best device we can find. Let's write its
+ * metadata to devname dfd is read-only so don't use that
+ */
+ fd = open(devname, O_RDWR);
+ if (fd >= 0) {
+ chosen_st->ss->store_super(chosen_st, fd);
+ close(fd);
+ }
+ free(chosen);
+ chosen_st->ss->free_super(chosen_st);
+ free(chosen_st);
+ return 0;
+}
+
+static int is_bare(int dfd)
+{
+ unsigned long long size = 0;
+ char bufpad[4096 + 4096];
+ char *buf = (char*)(((long)bufpad + 4096) & ~4095);
+
+ if (lseek(dfd, 0, SEEK_SET) != 0 ||
+ read(dfd, buf, 4096) != 4096)
+ return 0;
+
+ if (buf[0] != '\0' && buf[0] != '\x5a' && buf[0] != '\xff')
+ return 0;
+ if (memcmp(buf, buf+1, 4095) != 0)
+ return 0;
+
+ /* OK, first 4K appear blank, try the end. */
+ get_dev_size(dfd, NULL, &size);
+ if (lseek(dfd, size-4096, SEEK_SET) < 0 ||
+ read(dfd, buf, 4096) != 4096)
+ return 0;
+
+ if (buf[0] != '\0' && buf[0] != '\x5a' && buf[0] != '\xff')
+ return 0;
+ if (memcmp(buf, buf+1, 4095) != 0)
+ return 0;
+
+ return 1;
+}
+
+/* adding a spare to a regular array is quite different from adding one to
+ * a set-of-partitions virtual array.
+ * This function determines which is worth trying and tries as appropriate.
+ * Arrays are given priority over partitions.
+ */
+static int try_spare(char *devname, int *dfdp, struct dev_policy *pol,
+ struct map_ent *target,
+ struct supertype *st, int verbose)
+{
+ int i;
+ int rv;
+ int arrays_ok = 0;
+ int partitions_ok = 0;
+ int dfd = *dfdp;
+ int bare;
+
+ /* Can only add a spare if device has at least one domain */
+ if (pol_find(pol, pol_domain) == NULL)
+ return 1;
+ /* And only if some action allows spares */
+ if (!policy_action_allows(pol, st?st->ss->name:NULL, act_spare))
+ return 1;
+
+ /* Now check if the device is bare.
+ * bare devices can always be added as a spare
+ * non-bare devices can only be added if spare-same-slot is permitted,
+ * and this device is replacing a previous device - in which case 'target'
+ * will be set.
+ */
+ if (!is_bare(dfd)) {
+ /* Must have a target and allow same_slot */
+ /* Later - may allow force_spare without target */
+ if (!target ||
+ !policy_action_allows(pol, st?st->ss->name:NULL,
+ act_spare_same_slot)) {
+ if (verbose > 1)
+ fprintf(stderr, Name ": %s is not bare, so not "
+ "considering as a spare\n",
+ devname);
+ return 1;