X-Git-Url: http://git.ipfire.org/?p=thirdparty%2Fmdadm.git;a=blobdiff_plain;f=super-intel.c;h=609aaf51a04dcf28fb595ce82a9c522b0031999f;hp=0e3ed89416a85157e022555647c7c0953f0d8725;hb=1e5c69836d4d0b6dcaef8fc187e6bf2841eb57f6;hpb=f796af5d5ea603085ce6bcf3c171b89a1f84f37a

diff --git a/super-intel.c b/super-intel.c
index 0e3ed894..609aaf51 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -619,7 +619,6 @@ static __u32 imsm_reserved_sectors(struct intel_super *super, struct dl *dl)
 	return rv;
 }
 
-#ifndef MDASSEMBLE
 static int is_spare(struct imsm_disk *disk)
 {
 	return (disk->status & SPARE_DISK) == SPARE_DISK;
@@ -635,6 +634,9 @@ static int is_failed(struct imsm_disk *disk)
 	return (disk->status & FAILED_DISK) == FAILED_DISK;
 }
 
+#ifndef MDASSEMBLE
+static __u64 blocks_per_migr_unit(struct imsm_dev *dev);
+
 static void print_imsm_dev(struct imsm_dev *dev, char *uuid, int disk_idx)
 {
 	__u64 sz;
@@ -669,27 +671,32 @@ static void print_imsm_dev(struct imsm_dev *dev, char *uuid, int disk_idx)
 	printf("     Chunk Size : %u KiB\n",
 		__le16_to_cpu(map->blocks_per_strip) / 2);
 	printf("       Reserved : %d\n", __le32_to_cpu(dev->reserved_blocks));
-	printf("  Migrate State : %s", dev->vol.migr_state ? "migrating" : "idle\n");
+	printf("  Migrate State : ");
 	if (dev->vol.migr_state) {
 		if (migr_type(dev) == MIGR_INIT)
-			printf(": initializing\n");
+			printf("initialize\n");
 		else if (migr_type(dev) == MIGR_REBUILD)
-			printf(": rebuilding\n");
+			printf("rebuild\n");
 		else if (migr_type(dev) == MIGR_VERIFY)
-			printf(": check\n");
+			printf("check\n");
 		else if (migr_type(dev) == MIGR_GEN_MIGR)
-			printf(": general migration\n");
+			printf("general migration\n");
 		else if (migr_type(dev) == MIGR_STATE_CHANGE)
-			printf(": state change\n");
+			printf("state change\n");
 		else if (migr_type(dev) == MIGR_REPAIR)
-			printf(": repair\n");
+			printf("repair\n");
 		else
-			printf(": <unknown:%d>\n", migr_type(dev));
-	}
+			printf("<unknown:%d>\n", migr_type(dev));
+	} else
+		printf("idle\n");
 	printf("      Map State : %s", map_state_str[map->map_state]);
 	if (dev->vol.migr_state) {
 		struct imsm_map *map = get_imsm_map(dev, 1);
+
 		printf(" <-- %s", map_state_str[map->map_state]);
+		printf("\n     Checkpoint : %u (%llu)",
+		       __le32_to_cpu(dev->vol.curr_migr_unit),
+		       blocks_per_migr_unit(dev));
 	}
 	printf("\n");
 	printf("    Dirty State : %s\n", dev->vol.dirty ? "dirty" : "clean");
@@ -1215,6 +1222,179 @@ get_imsm_numerical_version(struct imsm_super *mpb, int *m, int *p)
 }
 #endif
 
+static __u32 migr_strip_blocks_resync(struct imsm_dev *dev)
+{
+	/* migr_strip_size when repairing or initializing parity */
+	struct imsm_map *map = get_imsm_map(dev, 0);
+	__u32 chunk = __le32_to_cpu(map->blocks_per_strip);
+
+	switch (get_imsm_raid_level(map)) {
+	case 5:
+	case 10:
+		return chunk;
+	default:
+		return 128*1024 >> 9;
+	}
+}
+
+static __u32 migr_strip_blocks_rebuild(struct imsm_dev *dev)
+{
+	/* migr_strip_size when rebuilding a degraded disk, no idea why
+	 * this is different than migr_strip_size_resync(), but it's good
+	 * to be compatible
+	 */
+	struct imsm_map *map = get_imsm_map(dev, 1);
+	__u32 chunk = __le32_to_cpu(map->blocks_per_strip);
+
+	switch (get_imsm_raid_level(map)) {
+	case 1:
+	case 10:
+		if (map->num_members % map->num_domains == 0)
+			return 128*1024 >> 9;
+		else
+			return chunk;
+	case 5:
+		return max((__u32) 64*1024 >> 9, chunk);
+	default:
+		return 128*1024 >> 9;
+	}
+}
+
+static __u32 num_stripes_per_unit_resync(struct imsm_dev *dev)
+{
+	struct imsm_map *lo = get_imsm_map(dev, 0);
+	struct imsm_map *hi = get_imsm_map(dev, 1);
+	__u32 lo_chunk = __le32_to_cpu(lo->blocks_per_strip);
+	__u32 hi_chunk = __le32_to_cpu(hi->blocks_per_strip);
+
+	return max((__u32) 1, hi_chunk / lo_chunk);
+}
+
+static __u32 num_stripes_per_unit_rebuild(struct imsm_dev *dev)
+{
+	struct imsm_map *lo = get_imsm_map(dev, 0);
+	int level = get_imsm_raid_level(lo);
+
+	if (level == 1 || level == 10) {
+		struct imsm_map *hi = get_imsm_map(dev, 1);
+
+		return hi->num_domains;
+	} else
+		return num_stripes_per_unit_resync(dev);
+}
+
+static __u8 imsm_num_data_members(struct imsm_dev *dev)
+{
+	/* named 'imsm_' because raid0, raid1 and raid10
+	 * counter-intuitively have the same number of data disks
+	 */
+	struct imsm_map *map = get_imsm_map(dev, 0);
+
+	switch (get_imsm_raid_level(map)) {
+	case 0:
+	case 1:
+	case 10:
+		return map->num_members;
+	case 5:
+		return map->num_members - 1;
+	default:
+		dprintf("%s: unsupported raid level\n", __func__);
+		return 0;
+	}
+}
+
+static __u32 parity_segment_depth(struct imsm_dev *dev)
+{
+	struct imsm_map *map = get_imsm_map(dev, 0);
+	__u32 chunk =  __le32_to_cpu(map->blocks_per_strip);
+
+	switch(get_imsm_raid_level(map)) {
+	case 1:
+	case 10:
+		return chunk * map->num_domains;
+	case 5:
+		return chunk * map->num_members;
+	default:
+		return chunk;
+	}
+}
+
+static __u32 map_migr_block(struct imsm_dev *dev, __u32 block)
+{
+	struct imsm_map *map = get_imsm_map(dev, 1);
+	__u32 chunk = __le32_to_cpu(map->blocks_per_strip);
+	__u32 strip = block / chunk;
+
+	switch (get_imsm_raid_level(map)) {
+	case 1:
+	case 10: {
+		__u32 vol_strip = (strip * map->num_domains) + 1;
+		__u32 vol_stripe = vol_strip / map->num_members;
+
+		return vol_stripe * chunk + block % chunk;
+	} case 5: {
+		__u32 stripe = strip / (map->num_members - 1);
+
+		return stripe * chunk + block % chunk;
+	}
+	default:
+		return 0;
+	}
+}
+
+static __u64 blocks_per_migr_unit(struct imsm_dev *dev)
+{
+	/* calculate the conversion factor between per member 'blocks'
+	 * (md/{resync,rebuild}_start) and imsm migration units, return
+	 * 0 for the 'not migrating' and 'unsupported migration' cases
+	 */
+	if (!dev->vol.migr_state)
+		return 0;
+
+	switch (migr_type(dev)) {
+	case MIGR_VERIFY:
+	case MIGR_REPAIR:
+	case MIGR_INIT: {
+		struct imsm_map *map = get_imsm_map(dev, 0);
+		__u32 stripes_per_unit;
+		__u32 blocks_per_unit;
+		__u32 parity_depth;
+		__u32 migr_chunk;
+		__u32 block_map;
+		__u32 block_rel;
+		__u32 segment;
+		__u32 stripe;
+		__u8  disks;
+
+		/* yes, this is really the translation of migr_units to
+		 * per-member blocks in the 'resync' case
+		 */
+		stripes_per_unit = num_stripes_per_unit_resync(dev);
+		migr_chunk = migr_strip_blocks_resync(dev);
+		disks = imsm_num_data_members(dev);
+		blocks_per_unit = stripes_per_unit * migr_chunk * disks;
+		stripe = __le32_to_cpu(map->blocks_per_strip) * disks;
+		segment = blocks_per_unit / stripe;
+		block_rel = blocks_per_unit - segment * stripe;
+		parity_depth = parity_segment_depth(dev);
+		block_map = map_migr_block(dev, block_rel);
+		return block_map + parity_depth * segment;
+	}
+	case MIGR_REBUILD: {
+		__u32 stripes_per_unit;
+		__u32 migr_chunk;
+
+		stripes_per_unit = num_stripes_per_unit_rebuild(dev);
+		migr_chunk = migr_strip_blocks_rebuild(dev);
+		return migr_chunk * stripes_per_unit;
+	}
+	case MIGR_GEN_MIGR:
+	case MIGR_STATE_CHANGE:
+	default:
+		return 0;
+	}
+}
+
 static int imsm_level_to_layout(int level)
 {
 	switch (level) {
@@ -1264,13 +1444,34 @@ static void getinfo_super_imsm_volume(struct supertype *st, struct mdinfo *info)
 	info->component_size	  = __le32_to_cpu(map->blocks_per_member);
 	memset(info->uuid, 0, sizeof(info->uuid));
 
-	if (map->map_state == IMSM_T_STATE_UNINITIALIZED || dev->vol.dirty)
+	if (map->map_state == IMSM_T_STATE_UNINITIALIZED || dev->vol.dirty) {
 		info->resync_start = 0;
-	else if (dev->vol.migr_state)
-		/* FIXME add curr_migr_unit to resync_start conversion */
-		info->resync_start = 0;
-	else
-		info->resync_start = ~0ULL;
+	} else if (dev->vol.migr_state) {
+		switch (migr_type(dev)) {
+		case MIGR_REPAIR:
+		case MIGR_INIT: {
+			__u64 blocks_per_unit = blocks_per_migr_unit(dev);
+			__u64 units = __le32_to_cpu(dev->vol.curr_migr_unit);
+
+			info->resync_start = blocks_per_unit * units;
+			break;
+		}
+		case MIGR_VERIFY:
+			/* we could emulate the checkpointing of
+			 * 'sync_action=check' migrations, but for now
+			 * we just immediately complete them
+			 */
+		case MIGR_REBUILD:
+			/* this is handled by container_content_imsm() */
+		case MIGR_GEN_MIGR:
+		case MIGR_STATE_CHANGE:
+			/* FIXME handle other migrations */
+		default:
+			/* we are not dirty, so... */
+			info->resync_start = MaxSector;
+		}
+	} else
+		info->resync_start = MaxSector;
 
 	strncpy(info->name, (char *) dev->volume, MAX_RAID_SERIAL_LEN);
 	info->name[MAX_RAID_SERIAL_LEN] = 0;
@@ -1378,8 +1579,6 @@ static int update_super_imsm(struct supertype *st, struct mdinfo *info,
 			     char *update, char *devname, int verbose,
 			     int uuid_set, char *homehost)
 {
-	/* FIXME */
-
 	/* For 'assemble' and 'force' we need to return non-zero if any
 	 * change was made.  For others, the return value is ignored.
 	 * Update options are:
@@ -1395,26 +1594,55 @@ static int update_super_imsm(struct supertype *st, struct mdinfo *info,
 	 *		linear only
 	 *  resync: mark as dirty so a resync will happen.
 	 *  name:  update the name - preserving the homehost
+	 *  uuid:  Change the uuid of the array to match watch is given
 	 *
 	 * Following are not relevant for this imsm:
 	 *  sparc2.2 : update from old dodgey metadata
 	 *  super-minor: change the preferred_minor number
 	 *  summaries:  update redundant counters.
-	 *  uuid:  Change the uuid of the array to match watch is given
 	 *  homehost:  update the recorded homehost
 	 *  _reshape_progress: record new reshape_progress position.
 	 */
-	int rv = 0;
-	//struct intel_super *super = st->sb;
-	//struct imsm_super *mpb = super->mpb;
+	int rv = 1;
+	struct intel_super *super = st->sb;
+	struct imsm_super *mpb;
 
-	if (strcmp(update, "grow") == 0) {
-	}
-	if (strcmp(update, "resync") == 0) {
-		/* dev->vol.dirty = 1; */
-	}
+	/* we can only update container info */
+	if (!super || super->current_vol >= 0 || !super->anchor)
+		return 1;
+
+	mpb = super->anchor;
 
-	/* IMSM has no concept of UUID or homehost */
+	if (strcmp(update, "uuid") == 0 && uuid_set && !info->update_private)
+		fprintf(stderr,
+			Name ": '--uuid' not supported for imsm metadata\n");
+	else if (strcmp(update, "uuid") == 0 && uuid_set && info->update_private) {
+		mpb->orig_family_num = *((__u32 *) info->update_private);
+		rv = 0;
+	} else if (strcmp(update, "uuid") == 0) {
+		__u32 *new_family = malloc(sizeof(*new_family));
+
+		/* update orig_family_number with the incoming random
+		 * data, report the new effective uuid, and store the
+		 * new orig_family_num for future updates.
+		 */
+		if (new_family) {
+			memcpy(&mpb->orig_family_num, info->uuid, sizeof(__u32));
+			uuid_from_super_imsm(st, info->uuid);
+			*new_family = mpb->orig_family_num;
+			info->update_private = new_family;
+			rv = 0;
+		}
+	} else if (strcmp(update, "assemble") == 0)
+		rv = 0;
+	else
+		fprintf(stderr,
+			Name ": '--update=%s' not supported for imsm metadata\n",
+			update);
+
+	/* successful update? recompute checksum */
+	if (rv == 0)
+		mpb->check_sum = __le32_to_cpu(__gen_imsm_checksum(mpb));
 
 	return rv;
 }
@@ -1539,6 +1767,7 @@ static int compare_super_imsm(struct supertype *st, struct supertype *tst)
 		first->anchor->num_raid_devs = sec->anchor->num_raid_devs;
 		first->anchor->orig_family_num = sec->anchor->orig_family_num;
 		first->anchor->family_num = sec->anchor->family_num;
+		memcpy(first->anchor->sig, sec->anchor->sig, MAX_SIGNATURE_LENGTH);
 		for (i = 0; i < sec->anchor->num_raid_devs; i++)
 			imsm_copy_dev(get_imsm_dev(first, i), get_imsm_dev(sec, i));
 	}
@@ -1652,6 +1881,7 @@ static void serialcpy(__u8 *dest, __u8 *src)
 	strncpy((char *) dest, (char *) src, MAX_RAID_SERIAL_LEN);
 }
 
+#ifndef MDASSEMBLE
 static struct dl *serial_to_dl(__u8 *serial, struct intel_super *super)
 {
 	struct dl *dl;
@@ -1662,6 +1892,7 @@ static struct dl *serial_to_dl(__u8 *serial, struct intel_super *super)
 
 	return dl;
 }
+#endif
 
 static struct imsm_disk *
 __serial_to_disk(__u8 *serial, struct imsm_super *mpb, int *idx)
@@ -2399,7 +2630,7 @@ imsm_thunderdome(struct intel_super **super_list, int len)
 			struct intel_disk *idisk;
 
 			idisk = disk_list_get(dl->serial, disk_list);
-			if (is_spare(&idisk->disk) &&
+			if (idisk && is_spare(&idisk->disk) &&
 			    !is_failed(&idisk->disk) && !is_configured(&idisk->disk))
 				dl->index = -1;
 			else {
@@ -2819,24 +3050,33 @@ static int init_super_imsm(struct supertype *st, mdu_array_info_t *info,
 	size_t mpb_size;
 	char *version;
 
-	if (!info) {
-		st->sb = NULL;
-		return 0;
-	}
 	if (st->sb)
-		return init_super_imsm_volume(st, info, size, name, homehost,
-					      uuid);
+		return init_super_imsm_volume(st, info, size, name, homehost, uuid);
+
+	if (info)
+		mpb_size = disks_to_mpb_size(info->nr_disks);
+	else
+		mpb_size = 512;
 
 	super = alloc_super(1);
-	if (!super)
-		return 0;
-	mpb_size = disks_to_mpb_size(info->nr_disks);
-	if (posix_memalign(&super->buf, 512, mpb_size) != 0) {
+	if (super && posix_memalign(&super->buf, 512, mpb_size) != 0) {
 		free(super);
+		super = NULL;
+	}
+	if (!super) {
+		fprintf(stderr, Name
+			": %s could not allocate superblock\n", __func__);
 		return 0;
 	}
+	memset(super->buf, 0, mpb_size);
 	mpb = super->buf;
-	memset(mpb, 0, mpb_size); 
+	mpb->mpb_size = __cpu_to_le32(mpb_size);
+	st->sb = super;
+
+	if (info == NULL) {
+		/* zeroing superblock */
+		return 0;
+	}
 
 	mpb->attributes = MPB_ATTRIB_CHECKSUM_VERIFY;
 
@@ -2844,9 +3084,7 @@ static int init_super_imsm(struct supertype *st, mdu_array_info_t *info,
 	strcpy(version, MPB_SIGNATURE);
 	version += strlen(MPB_SIGNATURE);
 	strcpy(version, MPB_VERSION_RAID0);
-	mpb->mpb_size = mpb_size;
 
-	st->sb = super;
 	return 1;
 }
 
@@ -3188,24 +3426,19 @@ static int write_init_super_imsm(struct supertype *st)
 }
 #endif
 
-static int store_zero_imsm(struct supertype *st, int fd)
+static int store_super_imsm(struct supertype *st, int fd)
 {
-	unsigned long long dsize;
-	void *buf;
-
-	get_dev_size(fd, NULL, &dsize);
-
-	/* first block is stored on second to last sector of the disk */
-	if (lseek64(fd, dsize - (512 * 2), SEEK_SET) < 0)
-		return 1;
+	struct intel_super *super = st->sb;
+	struct imsm_super *mpb = super ? super->anchor : NULL;
 
-	if (posix_memalign(&buf, 512, 512) != 0)
+	if (!mpb)
 		return 1;
 
-	memset(buf, 0, 512);
-	if (write(fd, buf, 512) != 512)
-		return 1;
-	return 0;
+#ifndef MDASSEMBLE
+	return store_imsm_mpb(fd, mpb);
+#else
+	return 1;
+#endif
 }
 
 static int imsm_bbm_log_size(struct imsm_super *mpb)
@@ -3302,7 +3535,7 @@ static unsigned long long merge_extents(struct intel_super *super, int sum_exten
 	unsigned long reserve;
 
 	if (!e)
-		return ~0ULL; /* error */
+		return 0;
 
 	/* coalesce and sort all extents. also, check to see if we need to
 	 * reserve space between member arrays
@@ -3345,17 +3578,23 @@ static unsigned long long merge_extents(struct intel_super *super, int sum_exten
 	} while (e[i-1].size);
 	free(e);
 
+	if (maxsize == 0)
+		return 0;
+
+	/* FIXME assumes volume at offset 0 is the first volume in a
+	 * container
+	 */
 	if (start_extent > 0)
 		reserve = IMSM_RESERVED_SECTORS; /* gap between raid regions */
 	else
 		reserve = 0;
 
 	if (maxsize < reserve)
-		return ~0ULL;
+		return 0;
 
 	super->create_offset = ~((__u32) 0);
 	if (start + reserve > super->create_offset)
-		return ~0ULL; /* start overflows create_offset */
+		return 0; /* start overflows create_offset */
 	super->create_offset = start + reserve;
 
 	return maxsize - reserve;
@@ -3384,6 +3623,34 @@ static int is_raid_level_supported(const struct imsm_orom *orom, int level, int
 }
 
 #define pr_vrb(fmt, arg...) (void) (verbose && fprintf(stderr, Name fmt, ##arg))
+static int
+validate_geometry_imsm_orom(struct intel_super *super, int level, int layout,
+			    int raiddisks, int chunk, int verbose)
+{
+	if (!is_raid_level_supported(super->orom, level, raiddisks)) {
+		pr_vrb(": platform does not support raid%d with %d disk%s\n",
+			level, raiddisks, raiddisks > 1 ? "s" : "");
+		return 0;
+	}
+	if (super->orom && level != 1 &&
+	    !imsm_orom_has_chunk(super->orom, chunk)) {
+		pr_vrb(": platform does not support a chunk size of: %d\n", chunk);
+		return 0;
+	}
+	if (layout != imsm_level_to_layout(level)) {
+		if (level == 5)
+			pr_vrb(": imsm raid 5 only supports the left-asymmetric layout\n");
+		else if (level == 10)
+			pr_vrb(": imsm raid 10 only supports the n2 layout\n");
+		else
+			pr_vrb(": imsm unknown layout %#x for this raid level %d\n",
+				layout, level);
+		return 0;
+	}
+
+	return 1;
+}
+
 /* validate_geometry_imsm_volume - lifted from validate_geometry_ddf_bvd 
  * FIX ME add ahci details
  */
@@ -3406,26 +3673,8 @@ static int validate_geometry_imsm_volume(struct supertype *st, int level,
 	if (!super)
 		return 0;
 
-	if (!is_raid_level_supported(super->orom, level, raiddisks)) {
-		pr_vrb(": platform does not support raid%d with %d disk%s\n",
-			level, raiddisks, raiddisks > 1 ? "s" : "");
-		return 0;
-	}
-	if (super->orom && level != 1 &&
-	    !imsm_orom_has_chunk(super->orom, chunk)) {
-		pr_vrb(": platform does not support a chunk size of: %d\n", chunk);
-		return 0;
-	}
-	if (layout != imsm_level_to_layout(level)) {
-		if (level == 5)
-			pr_vrb(": imsm raid 5 only supports the left-asymmetric layout\n");
-		else if (level == 10)
-			pr_vrb(": imsm raid 10 only supports the n2 layout\n");
-		else
-			pr_vrb(": imsm unknown layout %#x for this raid level %d\n",
-				layout, level);
+	if (!validate_geometry_imsm_orom(super, level, layout, raiddisks, chunk, verbose))
 		return 0;
-	}
 
 	if (!dev) {
 		/* General test:  make sure there is space for
@@ -3433,7 +3682,7 @@ static int validate_geometry_imsm_volume(struct supertype *st, int level,
 		 * offset
 		 */
 		unsigned long long minsize = size;
-		unsigned long long start_offset = ~0ULL;
+		unsigned long long start_offset = MaxSector;
 		int dcnt = 0;
 		if (minsize == 0)
 			minsize = MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS;
@@ -3449,7 +3698,7 @@ static int validate_geometry_imsm_volume(struct supertype *st, int level,
 				esize = e[i].start - pos;
 				if (esize >= minsize)
 					found = 1;
-				if (found && start_offset == ~0ULL) {
+				if (found && start_offset == MaxSector) {
 					start_offset = pos;
 					break;
 				} else if (found && pos != start_offset) {
@@ -3538,15 +3787,11 @@ static int validate_geometry_imsm_volume(struct supertype *st, int level,
 			i += dl->extent_cnt;
 
 	maxsize = merge_extents(super, i);
-	if (maxsize < size) {
+	if (maxsize < size || maxsize == 0) {
 		if (verbose)
 			fprintf(stderr, Name ": not enough space after merge (%llu < %llu)\n",
 				maxsize, size);
 		return 0;
-	} else if (maxsize == ~0ULL) {
-		if (verbose)
-			fprintf(stderr, Name ": failed to merge %d extents\n", i);
-		return 0;
 	}
 
 	*freesize = maxsize;
@@ -3603,7 +3848,8 @@ static int reserve_space(struct supertype *st, int raiddisks,
 
 	if (cnt < raiddisks ||
 	    (super->orom && used && used != raiddisks) ||
-	    maxsize < minsize) {
+	    maxsize < minsize ||
+	    maxsize == 0) {
 		fprintf(stderr, Name ": not enough devices with space to create array.\n");
 		return 0; /* No enough free spaces large enough */
 	}
@@ -3655,6 +3901,10 @@ static int validate_geometry_imsm(struct supertype *st, int level, int layout,
 			 * created.  add_to_super and getinfo_super
 			 * detect when autolayout is in progress.
 			 */
+			if (!validate_geometry_imsm_orom(st->sb, level, layout,
+							 raiddisks, chunk,
+							 verbose))
+				return 0;
 			return reserve_space(st, raiddisks, size, chunk, freesize);
 		}
 		return 1;
@@ -3673,8 +3923,11 @@ static int validate_geometry_imsm(struct supertype *st, int level, int layout,
 		case 1:
 		case 10:
 		case 5:
-			break;
+			return 0;
 		default:
+			if (verbose)
+				fprintf(stderr, Name
+					": IMSM only supports levels 0,1,5,10\n");
 			return 1;
 		}
 
@@ -3729,6 +3982,46 @@ static int validate_geometry_imsm(struct supertype *st, int level, int layout,
 }
 #endif /* MDASSEMBLE */
 
+static int is_rebuilding(struct imsm_dev *dev)
+{
+	struct imsm_map *migr_map;
+
+	if (!dev->vol.migr_state)
+		return 0;
+
+	if (migr_type(dev) != MIGR_REBUILD)
+		return 0;
+
+	migr_map = get_imsm_map(dev, 1);
+
+	if (migr_map->map_state == IMSM_T_STATE_DEGRADED)
+		return 1;
+	else
+		return 0;
+}
+
+static void update_recovery_start(struct imsm_dev *dev, struct mdinfo *array)
+{
+	struct mdinfo *rebuild = NULL;
+	struct mdinfo *d;
+	__u32 units;
+
+	if (!is_rebuilding(dev))
+		return;
+
+	/* Find the rebuild target, but punt on the dual rebuild case */
+	for (d = array->devs; d; d = d->next)
+		if (d->recovery_start == 0) {
+			if (rebuild)
+				return;
+			rebuild = d;
+		}
+
+	units = __le32_to_cpu(dev->vol.curr_migr_unit);
+	rebuild->recovery_start = units * blocks_per_migr_unit(dev);
+}
+
+
 static struct mdinfo *container_content_imsm(struct supertype *st)
 {
 	/* Given a container loaded by load_super_imsm_all,
@@ -3776,6 +4069,7 @@ static struct mdinfo *container_content_imsm(struct supertype *st)
 		super->current_vol = i;
 		getinfo_super_imsm_volume(st, this);
 		for (slot = 0 ; slot <  map->num_members; slot++) {
+			unsigned long long recovery_start;
 			struct mdinfo *info_d;
 			struct dl *d;
 			int idx;
@@ -3789,33 +4083,41 @@ static struct mdinfo *container_content_imsm(struct supertype *st)
 				if (d->index == idx)
                                         break;
 
+			recovery_start = MaxSector;
 			if (d == NULL)
 				skip = 1;
 			if (d && is_failed(&d->disk))
 				skip = 1;
 			if (ord & IMSM_ORD_REBUILD)
-				skip = 1;
+				recovery_start = 0;
 
 			/* 
 			 * if we skip some disks the array will be assmebled degraded;
-			 * reset resync start to avoid a dirty-degraded situation
+			 * reset resync start to avoid a dirty-degraded
+			 * situation when performing the intial sync
 			 *
 			 * FIXME handle dirty degraded
 			 */
-			if (skip && !dev->vol.dirty)
-				this->resync_start = ~0ULL;
+			if ((skip || recovery_start == 0) && !dev->vol.dirty)
+				this->resync_start = MaxSector;
 			if (skip)
 				continue;
 
-			info_d = malloc(sizeof(*info_d));
+			info_d = calloc(1, sizeof(*info_d));
 			if (!info_d) {
 				fprintf(stderr, Name ": failed to allocate disk"
 					" for volume %.16s\n", dev->volume);
+				info_d = this->devs;
+				while (info_d) {
+					struct mdinfo *d = info_d->next;
+
+					free(info_d);
+					info_d = d;
+				}
 				free(this);
 				this = rest;
 				break;
 			}
-			memset(info_d, 0, sizeof(*info_d));
 			info_d->next = this->devs;
 			this->devs = info_d;
 
@@ -3823,8 +4125,10 @@ static struct mdinfo *container_content_imsm(struct supertype *st)
 			info_d->disk.major = d->major;
 			info_d->disk.minor = d->minor;
 			info_d->disk.raid_disk = slot;
+			info_d->recovery_start = recovery_start;
 
-			this->array.working_disks++;
+			if (info_d->recovery_start == MaxSector)
+				this->array.working_disks++;
 
 			info_d->events = __le32_to_cpu(mpb->generation_num);
 			info_d->data_offset = __le32_to_cpu(map->pba_of_lba0);
@@ -3832,6 +4136,8 @@ static struct mdinfo *container_content_imsm(struct supertype *st)
 			if (d->devname)
 				strcpy(info_d->name, d->devname);
 		}
+		/* now that the disk list is up-to-date fixup recovery_start */
+		update_recovery_start(dev, this);
 		rest = this;
 	}
 
@@ -3974,24 +4280,6 @@ static int is_resyncing(struct imsm_dev *dev)
 		return 0;
 }
 
-static int is_rebuilding(struct imsm_dev *dev)
-{
-	struct imsm_map *migr_map;
-
-	if (!dev->vol.migr_state)
-		return 0;
-
-	if (migr_type(dev) != MIGR_REBUILD)
-		return 0;
-
-	migr_map = get_imsm_map(dev, 1);
-
-	if (migr_map->map_state == IMSM_T_STATE_DEGRADED)
-		return 1;
-	else
-		return 0;
-}
-
 /* return true if we recorded new information */
 static int mark_failure(struct imsm_dev *dev, struct imsm_disk *disk, int idx)
 {
@@ -4042,6 +4330,7 @@ static int imsm_set_array_state(struct active_array *a, int consistent)
 	struct imsm_map *map = get_imsm_map(dev, 0);
 	int failed = imsm_count_failed(super, dev);
 	__u8 map_state = imsm_check_degraded(super, dev, failed);
+	__u32 blocks_per_unit;
 
 	/* before we activate this array handle any missing disks */
 	if (consistent == 2 && super->missing) {
@@ -4053,14 +4342,14 @@ static int imsm_set_array_state(struct active_array *a, int consistent)
 			mark_missing(dev, &dl->disk, dl->index);
 		super->updates_pending++;
 	}
-		
+
 	if (consistent == 2 &&
-	    (!is_resync_complete(a) ||
+	    (!is_resync_complete(&a->info) ||
 	     map_state != IMSM_T_STATE_NORMAL ||
 	     dev->vol.migr_state))
 		consistent = 0;
 
-	if (is_resync_complete(a)) {
+	if (is_resync_complete(&a->info)) {
 		/* complete intialization / resync,
 		 * recovery and interrupted recovery is completed in
 		 * ->set_disk
@@ -4072,7 +4361,7 @@ static int imsm_set_array_state(struct active_array *a, int consistent)
 		}
 	} else if (!is_resyncing(dev) && !failed) {
 		/* mark the start of the init process if nothing is failed */
-		dprintf("imsm: mark resync start (%llu)\n", a->resync_start);
+		dprintf("imsm: mark resync start\n");
 		if (map->map_state == IMSM_T_STATE_UNINITIALIZED)
 			migrate(dev, IMSM_T_STATE_NORMAL, MIGR_INIT);
 		else
@@ -4080,12 +4369,32 @@ static int imsm_set_array_state(struct active_array *a, int consistent)
 		super->updates_pending++;
 	}
 
-	 /* FIXME check if we can update curr_migr_unit from resync_start */
+	/* check if we can update curr_migr_unit from resync_start, recovery_start */
+	blocks_per_unit = blocks_per_migr_unit(dev);
+	if (blocks_per_unit && failed <= 1) {
+		__u32 units32;
+		__u64 units;
+
+		if (migr_type(dev) == MIGR_REBUILD)
+			units = min_recovery_start(&a->info) / blocks_per_unit;
+		else
+			units = a->info.resync_start / blocks_per_unit;
+		units32 = units;
+
+		/* check that we did not overflow 32-bits, and that
+		 * curr_migr_unit needs updating
+		 */
+		if (units32 == units &&
+		    __le32_to_cpu(dev->vol.curr_migr_unit) != units32) {
+			dprintf("imsm: mark checkpoint (%u)\n", units32);
+			dev->vol.curr_migr_unit = __cpu_to_le32(units32);
+			super->updates_pending++;
+		}
+	}
 
 	/* mark dirty / clean */
 	if (dev->vol.dirty != !consistent) {
-		dprintf("imsm: mark '%s' (%llu)\n",
-			consistent ? "clean" : "dirty", a->resync_start);
+		dprintf("imsm: mark '%s'\n", consistent ? "clean" : "dirty");
 		if (consistent)
 			dev->vol.dirty = 0;
 		else
@@ -4402,6 +4711,7 @@ static struct mdinfo *imsm_activate_spare(struct active_array *a,
 		di->disk.major = dl->major;
 		di->disk.minor = dl->minor;
 		di->disk.state = 0;
+		di->recovery_start = 0;
 		di->data_offset = __le32_to_cpu(map->pba_of_lba0);
 		di->component_size = a->info.component_size;
 		di->container_member = inst;
@@ -4914,7 +5224,7 @@ struct superswitch super_imsm = {
 
 	.load_super	= load_super_imsm,
 	.init_super	= init_super_imsm,
-	.store_super	= store_zero_imsm,
+	.store_super	= store_super_imsm,
 	.free_super	= free_super_imsm,
 	.match_metadata_desc = match_metadata_desc_imsm,
 	.container_content = container_content_imsm,