Use ADD_NEW_DISK to hot-add to non-version-0 arrays

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>

Manage.c

@@ -169,8 +169,8 @@ int Manage_subdevs(char *devname, int fd,
 	struct stat stb;
 	int j;
 	int tfd;
-	int save_errno;
+	struct supertype *st;
-	static char buf[4096];
+	void *dsuper = NULL;
 
 	if (ioctl(fd, GET_ARRAY_INFO, &array)) {
 		fprintf(stderr, Name ": cannot get array info for %s\n",
@@ -203,26 +203,54 @@ int Manage_subdevs(char *devname, int fd,
 				return 1;
 			}
 			close(tfd);
-			if (ioctl(fd, HOT_ADD_DISK, (unsigned long)stb.st_rdev)==0) {
+			if (array.major_version == 0) {
-				fprintf(stderr, Name ": hot added %s\n",
+				if (ioctl(fd, HOT_ADD_DISK,
-					dv->devname);
+					  (unsigned long)stb.st_rdev)==0) {
-				continue;
+					fprintf(stderr, Name ": hot added %s\n",
-			}
+						dv->devname);
-			save_errno = errno;
+					continue;
-			if (read(fd, buf, sizeof(buf)) > 0) {
+				}
-				/* array is active, so don't try to add.
+
-				 * i.e. something is wrong 
-				 */
 				fprintf(stderr, Name ": hot add failed for %s: %s\n",
-					dv->devname, strerror(save_errno));
+					dv->devname, strerror(errno));
 				return 1;
 			}
-			/* try ADD_NEW_DISK.
+
-			 * we might be creating, we might be assembling,
+			/* need to find a sample superblock to copy, and
-			 * it is hard to tell.
+			 * a spare slot to use 
-			 * set up number/raid_disk/state just
-			 * in case
 			 */
+			st = super_by_version(array.major_version,
+					      array.minor_version);
+			if (!st) {
+				fprintf(stderr, Name ": unsupport array - version %d.%d\n",
+					array.major_version, array.minor_version);
+				return 1;
+			}
+			for (j=0; j<array.active_disks+array.spare_disks+ array.failed_disks; j++) {
+				char *dev;
+				int dfd;
+				disc.number = j;
+				if (ioctl(fd, GET_DISK_INFO, &disc))
+					continue;
+				if (disc.major==0 && disc.minor==0)
+					continue;
+				if ((disc.state & 4)==0) continue; /* sync */
+				/* Looks like a good device to try */
+				dev = map_dev(disc.major, disc.minor);
+				if (!dev) continue;
+				dfd = open(dev, O_RDONLY);
+				if (dfd < 0) continue;
+				if (st->ss->load_super(st, dfd, &dsuper, NULL)) {
+					close(dfd);
+					continue;
+				}
+				close(dfd);
+				break;
+			}
+			if (!dsuper) {
+				fprintf(stderr, Name ": cannot find valid superblock in this array - HELP\n");
+				return 1;
+			}
 			for (j=0; j<array.nr_disks; j++) {
 				disc.number = j;
 				if (ioctl(fd, GET_DISK_INFO, &disc))
@@ -232,11 +260,12 @@ int Manage_subdevs(char *devname, int fd,
 				if (disc.state & 8) /* removed */
 					break;
 			}
-			disc.number =j;
-			disc.raid_disk = j;
-			disc.state = 0;
 			disc.major = major(stb.st_rdev);
 			disc.minor = minor(stb.st_rdev);
+			disc.number =j;
+			disc.state = 0;
+			if (st->ss->write_init_super(st, dsuper, &disc, dv->devname))
+				return 1;
 			if (ioctl(fd,ADD_NEW_DISK, &disc)) {
 				fprintf(stderr, Name ": add new device failed for %s: %s\n",
 					dv->devname, strerror(errno));

super1.c

@@ -459,10 +459,13 @@ static int store_super1(int fd, void *sbv)
 	return 0;
 }
 
+static int load_super1(struct supertype *st, int fd, void **sbp, char *devname);
+
 static int write_init_super1(struct supertype *st, void *sbv, mdu_disk_info_t *dinfo, char *devname)
 {
 	struct mdp_superblock_1 *sb = sbv;
-	int fd = open(devname, O_RDWR, O_EXCL);
+	struct mdp_superblock_1 *refsb = NULL;
+	int fd = open(devname, O_RDWR | O_EXCL);
 	int rv;
 
 	long size;
@@ -476,11 +479,22 @@ static int write_init_super1(struct supertype *st, void *sbv, mdu_disk_info_t *d
 	}
 
 	sb->dev_number = __cpu_to_le32(dinfo->number);
+
 	*(__u32*)(sb->device_uuid) = random();
 	*(__u32*)(sb->device_uuid+4) = random();
 	*(__u32*)(sb->device_uuid+8) = random();
 	*(__u32*)(sb->device_uuid+12) = random();
+	sb->events = 0;
 
+	if (load_super1(st, fd, (void**)&refsb, NULL)==0) {
+		memcpy(sb->device_uuid, refsb->device_uuid, 16);
+		if (memcmp(sb->set_uuid, refsb->set_uuid, 16)==0) {
+			/* same array, so preserve events and dev_number */
+			sb->events = refsb->events;
+			sb->dev_number = refsb->dev_number;
+		}
+		free(refsb);
+	}
     
 	if (ioctl(fd, BLKGETSIZE, &size)) {
 		close(fd);