Merge branch 'for-linus' of git://neil.brown.name/md

* 'for-linus' of git://neil.brown.name/md: (39 commits)
  md/raid5: correctly update sync_completed when we reach max_resync
  md/raid5: add missing call to schedule() after prepare_to_wait()
  md/linear: use call_rcu to free obsolete 'conf' structures.
  md linear: Protecting mddev with rcu locks to avoid races
  md: Move check for bitmap presence to personality code.
  md: remove chunksize rounding from common code.
  md: raid0/linear: ensure device sizes are rounded to chunk size.
  md: move assignment of ->utime so that it never gets skipped.
  md: Push down reconstruction log message to personality code.
  md: merge reconfig and check_reshape methods.
  md: remove unnecessary arguments from ->reconfig method.
  md: raid5: check stripe cache is large enough in start_reshape
  md: raid0: chunk_sectors cleanups.
  md: fix some comments.
  md/raid5: Use is_power_of_2() in raid5_reconfig()/raid6_reconfig().
  md: convert conf->chunk_size and conf->prev_chunk to sectors.
  md: Convert mddev->new_chunk to sectors.
  md: Make mddev->chunk_size sector-based.
  md: raid0 :Enables chunk size other than powers of 2.
  md: prepare for non-power-of-two chunk sizes
  ...

16 files changed, 588 insertions, 663 deletions

diff --git a/drivers/md/faulty.c b/drivers/md/faulty.c
index 8695809b24b..87d88dbb667 100644
--- a/drivers/md/faulty.c
+++ b/drivers/md/faulty.c
@@ -255,14 +255,14 @@ static void status(struct seq_file *seq, mddev_t *mddev)
 }
 
 
-static int reconfig(mddev_t *mddev, int layout, int chunk_size)
+static int reshape(mddev_t *mddev)
 {
-	int mode = layout & ModeMask;
-	int count = layout >> ModeShift;
+	int mode = mddev->new_layout & ModeMask;
+	int count = mddev->new_layout >> ModeShift;
 	conf_t *conf = mddev->private;
 
-	if (chunk_size != -1)
-		return -EINVAL;
+	if (mddev->new_layout < 0)
+		return 0;
 
 	/* new layout */
 	if (mode == ClearFaults)
@@ -279,6 +279,7 @@ static int reconfig(mddev_t *mddev, int layout, int chunk_size)
 		atomic_set(&conf->counters[mode], count);
 	} else
 		return -EINVAL;
+	mddev->new_layout = -1;
 	mddev->layout = -1; /* makes sure further changes come through */
 	return 0;
 }
@@ -298,8 +299,12 @@ static int run(mddev_t *mddev)
 {
 	mdk_rdev_t *rdev;
 	int i;
+	conf_t *conf;
+
+	if (md_check_no_bitmap(mddev))
+		return -EINVAL;
 
-	conf_t *conf = kmalloc(sizeof(*conf), GFP_KERNEL);
+	conf = kmalloc(sizeof(*conf), GFP_KERNEL);
 	if (!conf)
 		return -ENOMEM;
 
@@ -315,7 +320,7 @@ static int run(mddev_t *mddev)
 	md_set_array_sectors(mddev, faulty_size(mddev, 0, 0));
 	mddev->private = conf;
 
-	reconfig(mddev, mddev->layout, -1);
+	reshape(mddev);
 
 	return 0;
 }
@@ -338,7 +343,7 @@ static struct mdk_personality faulty_personality =
 	.run		= run,
 	.stop		= stop,
 	.status		= status,
-	.reconfig	= reconfig,
+	.check_reshape	= reshape,
 	.size		= faulty_size,
 };
 
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index 64f1f3e046e..15c8b7b25a9 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -27,19 +27,27 @@
  */
 static inline dev_info_t *which_dev(mddev_t *mddev, sector_t sector)
 {
-	dev_info_t *hash;
-	linear_conf_t *conf = mddev_to_conf(mddev);
-	sector_t idx = sector >> conf->sector_shift;
+	int lo, mid, hi;
+	linear_conf_t *conf;
+
+	lo = 0;
+	hi = mddev->raid_disks - 1;
+	conf = rcu_dereference(mddev->private);
 
 	/*
-	 * sector_div(a,b) returns the remainer and sets a to a/b
+	 * Binary Search
 	 */
-	(void)sector_div(idx, conf->spacing);
-	hash = conf->hash_table[idx];
 
-	while (sector >= hash->num_sectors + hash->start_sector)
-		hash++;
-	return hash;
+	while (hi > lo) {
+
+		mid = (hi + lo) / 2;
+		if (sector < conf->disks[mid].end_sector)
+			hi = mid;
+		else
+			lo = mid + 1;
+	}
+
+	return conf->disks + lo;
 }
 
 /**
@@ -59,8 +67,10 @@ static int linear_mergeable_bvec(struct request_queue *q,
 	unsigned long maxsectors, bio_sectors = bvm->bi_size >> 9;
 	sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
 
+	rcu_read_lock();
 	dev0 = which_dev(mddev, sector);
-	maxsectors = dev0->num_sectors - (sector - dev0->start_sector);
+	maxsectors = dev0->end_sector - sector;
+	rcu_read_unlock();
 
 	if (maxsectors < bio_sectors)
 		maxsectors = 0;
@@ -79,46 +89,57 @@ static int linear_mergeable_bvec(struct request_queue *q,
 static void linear_unplug(struct request_queue *q)
 {
 	mddev_t *mddev = q->queuedata;
-	linear_conf_t *conf = mddev_to_conf(mddev);
+	linear_conf_t *conf;
 	int i;
 
+	rcu_read_lock();
+	conf = rcu_dereference(mddev->private);
+
 	for (i=0; i < mddev->raid_disks; i++) {
 		struct request_queue *r_queue = bdev_get_queue(conf->disks[i].rdev->bdev);
 		blk_unplug(r_queue);
 	}
+	rcu_read_unlock();
 }
 
 static int linear_congested(void *data, int bits)
 {
 	mddev_t *mddev = data;
-	linear_conf_t *conf = mddev_to_conf(mddev);
+	linear_conf_t *conf;
 	int i, ret = 0;
 
+	rcu_read_lock();
+	conf = rcu_dereference(mddev->private);
+
 	for (i = 0; i < mddev->raid_disks && !ret ; i++) {
 		struct request_queue *q = bdev_get_queue(conf->disks[i].rdev->bdev);
 		ret |= bdi_congested(&q->backing_dev_info, bits);
 	}
+
+	rcu_read_unlock();
 	return ret;
 }
 
 static sector_t linear_size(mddev_t *mddev, sector_t sectors, int raid_disks)
 {
-	linear_conf_t *conf = mddev_to_conf(mddev);
+	linear_conf_t *conf;
+	sector_t array_sectors;
 
+	rcu_read_lock();
+	conf = rcu_dereference(mddev->private);
 	WARN_ONCE(sectors || raid_disks,
 		  "%s does not support generic reshape\n", __func__);
+	array_sectors = conf->array_sectors;
+	rcu_read_unlock();
 
-	return conf->array_sectors;
+	return array_sectors;
 }
 
 static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks)
 {
 	linear_conf_t *conf;
-	dev_info_t **table;
 	mdk_rdev_t *rdev;
-	int i, nb_zone, cnt;
-	sector_t min_sectors;
-	sector_t curr_sector;
+	int i, cnt;
 
 	conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(dev_info_t),
 			GFP_KERNEL);
@@ -131,6 +152,7 @@ static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks)
 	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		int j = rdev->raid_disk;
 		dev_info_t *disk = conf->disks + j;
+		sector_t sectors;
 
 		if (j < 0 || j >= raid_disks || disk->rdev) {
 			printk("linear: disk numbering problem. Aborting!\n");
@@ -138,6 +160,11 @@ static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks)
 		}
 
 		disk->rdev = rdev;
+		if (mddev->chunk_sectors) {
+			sectors = rdev->sectors;
+			sector_div(sectors, mddev->chunk_sectors);
+			rdev->sectors = sectors * mddev->chunk_sectors;
+		}
 
 		blk_queue_stack_limits(mddev->queue,
 				       rdev->bdev->bd_disk->queue);
@@ -149,102 +176,24 @@ static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks)
 		    queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9))
 			blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
 
-		disk->num_sectors = rdev->sectors;
 		conf->array_sectors += rdev->sectors;
-
 		cnt++;
+
 	}
 	if (cnt != raid_disks) {
 		printk("linear: not enough drives present. Aborting!\n");
 		goto out;
 	}
 
-	min_sectors = conf->array_sectors;
-	sector_div(min_sectors, PAGE_SIZE/sizeof(struct dev_info *));
-	if (min_sectors == 0)
-		min_sectors = 1;
-
-	/* min_sectors is the minimum spacing that will fit the hash
-	 * table in one PAGE.  This may be much smaller than needed.
-	 * We find the smallest non-terminal set of consecutive devices
-	 * that is larger than min_sectors and use the size of that as
-	 * the actual spacing
-	 */
-	conf->spacing = conf->array_sectors;
-	for (i=0; i < cnt-1 ; i++) {
-		sector_t tmp = 0;
-		int j;
-		for (j = i; j < cnt - 1 && tmp < min_sectors; j++)
-			tmp += conf->disks[j].num_sectors;
-		if (tmp >= min_sectors && tmp < conf->spacing)
-			conf->spacing = tmp;
-	}
-
-	/* spacing may be too large for sector_div to work with,
-	 * so we might need to pre-shift
-	 */
-	conf->sector_shift = 0;
-	if (sizeof(sector_t) > sizeof(u32)) {
-		sector_t space = conf->spacing;
-		while (space > (sector_t)(~(u32)0)) {
-			space >>= 1;
-			conf->sector_shift++;
-		}
-	}
 	/*
-	 * This code was restructured to work around a gcc-2.95.3 internal
-	 * compiler error.  Alter it with care.
+	 * Here we calculate the device offsets.
 	 */
-	{
-		sector_t sz;
-		unsigned round;
-		unsigned long base;
-
-		sz = conf->array_sectors >> conf->sector_shift;
-		sz += 1; /* force round-up */
-		base = conf->spacing >> conf->sector_shift;
-		round = sector_div(sz, base);
-		nb_zone = sz + (round ? 1 : 0);
-	}
-	BUG_ON(nb_zone > PAGE_SIZE / sizeof(struct dev_info *));
-
-	conf->hash_table = kmalloc (sizeof (struct dev_info *) * nb_zone,
-					GFP_KERNEL);
-	if (!conf->hash_table)
-		goto out;
+	conf->disks[0].end_sector = conf->disks[0].rdev->sectors;
 
-	/*
-	 * Here we generate the linear hash table
-	 * First calculate the device offsets.
-	 */
-	conf->disks[0].start_sector = 0;
 	for (i = 1; i < raid_disks; i++)
-		conf->disks[i].start_sector =
-			conf->disks[i-1].start_sector +
-			conf->disks[i-1].num_sectors;
-
-	table = conf->hash_table;
-	i = 0;
-	for (curr_sector = 0;
-	     curr_sector < conf->array_sectors;
-	     curr_sector += conf->spacing) {
-
-		while (i < raid_disks-1 &&
-		       curr_sector >= conf->disks[i+1].start_sector)
-			i++;
-
-		*table ++ = conf->disks + i;
-	}
-
-	if (conf->sector_shift) {
-		conf->spacing >>= conf->sector_shift;
-		/* round spacing up so that when we divide by it,
-		 * we err on the side of "too-low", which is safest.
-		 */
-		conf->spacing++;
-	}
-
-	BUG_ON(table - conf->hash_table > nb_zone);
+		conf->disks[i].end_sector =
+			conf->disks[i-1].end_sector +
+			conf->disks[i].rdev->sectors;
 
 	return conf;
 
@@ -257,6 +206,8 @@ static int linear_run (mddev_t *mddev)
 {
 	linear_conf_t *conf;
 
+	if (md_check_no_bitmap(mddev))
+		return -EINVAL;
 	mddev->queue->queue_lock = &mddev->queue->__queue_lock;
 	conf = linear_conf(mddev, mddev->raid_disks);
 
@@ -272,6 +223,12 @@ static int linear_run (mddev_t *mddev)
 	return 0;
 }
 
+static void free_conf(struct rcu_head *head)
+{
+	linear_conf_t *conf = container_of(head, linear_conf_t, rcu);
+	kfree(conf);
+}
+
 static int linear_add(mddev_t *mddev, mdk_rdev_t *rdev)
 {
 	/* Adding a drive to a linear array allows the array to grow.
@@ -282,7 +239,7 @@ static int linear_add(mddev_t *mddev, mdk_rdev_t *rdev)
 	 * The current one is never freed until the array is stopped.
 	 * This avoids races.
 	 */
-	linear_conf_t *newconf;
+	linear_conf_t *newconf, *oldconf;
 
 	if (rdev->saved_raid_disk != mddev->raid_disks)
 		return -EINVAL;
@@ -294,25 +251,29 @@ static int linear_add(mddev_t *mddev, mdk_rdev_t *rdev)
 	if (!newconf)
 		return -ENOMEM;
 
-	newconf->prev = mddev_to_conf(mddev);
-	mddev->private = newconf;
+	oldconf = rcu_dereference(mddev->private);
 	mddev->raid_disks++;
+	rcu_assign_pointer(mddev->private, newconf);
 	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
 	set_capacity(mddev->gendisk, mddev->array_sectors);
+	call_rcu(&oldconf->rcu, free_conf);
 	return 0;
 }
 
 static int linear_stop (mddev_t *mddev)
 {
-	linear_conf_t *conf = mddev_to_conf(mddev);
-  
+	linear_conf_t *conf = mddev->private;
+
+	/*
+	 * We do not require rcu protection here since
+	 * we hold reconfig_mutex for both linear_add and
+	 * linear_stop, so they cannot race.
+	 * We should make sure any old 'conf's are properly
+	 * freed though.
+	 */
+	rcu_barrier();
 	blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
-	do {
-		linear_conf_t *t = conf->prev;
-		kfree(conf->hash_table);
-		kfree(conf);
-		conf = t;
-	} while (conf);
+	kfree(conf);
 
 	return 0;
 }
@@ -322,6 +283,7 @@ static int linear_make_request (struct request_queue *q, struct bio *bio)
 	const int rw = bio_data_dir(bio);
 	mddev_t *mddev = q->queuedata;
 	dev_info_t *tmp_dev;
+	sector_t start_sector;
 	int cpu;
 
 	if (unlikely(bio_barrier(bio))) {
@@ -335,33 +297,36 @@ static int linear_make_request (struct request_queue *q, struct bio *bio)
 		      bio_sectors(bio));
 	part_stat_unlock();
 
+	rcu_read_lock();
 	tmp_dev = which_dev(mddev, bio->bi_sector);
-    
-	if (unlikely(bio->bi_sector >= (tmp_dev->num_sectors +
-					tmp_dev->start_sector)
-		     || (bio->bi_sector <
-			 tmp_dev->start_sector))) {
+	start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
+
+
+	if (unlikely(bio->bi_sector >= (tmp_dev->end_sector)
+		     || (bio->bi_sector < start_sector))) {
 		char b[BDEVNAME_SIZE];
 
 		printk("linear_make_request: Sector %llu out of bounds on "
 			"dev %s: %llu sectors, offset %llu\n",
 			(unsigned long long)bio->bi_sector,
 			bdevname(tmp_dev->rdev->bdev, b),
-			(unsigned long long)tmp_dev->num_sectors,
-			(unsigned long long)tmp_dev->start_sector);
+			(unsigned long long)tmp_dev->rdev->sectors,
+			(unsigned long long)start_sector);
+		rcu_read_unlock();
 		bio_io_error(bio);
 		return 0;
 	}
 	if (unlikely(bio->bi_sector + (bio->bi_size >> 9) >
-		     tmp_dev->start_sector + tmp_dev->num_sectors)) {
+		     tmp_dev->end_sector)) {
 		/* This bio crosses a device boundary, so we have to
 		 * split it.
 		 */
 		struct bio_pair *bp;
+		sector_t end_sector = tmp_dev->end_sector;
+
+		rcu_read_unlock();
 
-		bp = bio_split(bio,
-			       tmp_dev->start_sector + tmp_dev->num_sectors
-			       - bio->bi_sector);
+		bp = bio_split(bio, end_sector - bio->bi_sector);
 
 		if (linear_make_request(q, &bp->bio1))
 			generic_make_request(&bp->bio1);
@@ -372,8 +337,9 @@ static int linear_make_request (struct request_queue *q, struct bio *bio)
 	}
 		    
 	bio->bi_bdev = tmp_dev->rdev->bdev;
-	bio->bi_sector = bio->bi_sector - tmp_dev->start_sector
+	bio->bi_sector = bio->bi_sector - start_sector
 		+ tmp_dev->rdev->data_offset;
+	rcu_read_unlock();
 
 	return 1;
 }
@@ -381,7 +347,7 @@ static int linear_make_request (struct request_queue *q, struct bio *bio)
 static void linear_status (struct seq_file *seq, mddev_t *mddev)
 {
 
-	seq_printf(seq, " %dk rounding", mddev->chunk_size/1024);
+	seq_printf(seq, " %dk rounding", mddev->chunk_sectors / 2);
 }
 
 
diff --git a/drivers/md/linear.h b/drivers/md/linear.h
index bf8179587f9..0ce29b61605 100644
--- a/drivers/md/linear.h
+++ b/drivers/md/linear.h
@@ -3,27 +3,19 @@
 
 struct dev_info {
 	mdk_rdev_t	*rdev;
-	sector_t	num_sectors;
-	sector_t	start_sector;
+	sector_t	end_sector;
 };
 
 typedef struct dev_info dev_info_t;
 
 struct linear_private_data
 {
-	struct linear_private_data *prev;	/* earlier version */
-	dev_info_t		**hash_table;
-	sector_t		spacing;
 	sector_t		array_sectors;
-	int			sector_shift;	/* shift before dividing
-						 * by spacing
-						 */
 	dev_info_t		disks[0];
+	struct rcu_head		rcu;
 };
 
 
 typedef struct linear_private_data linear_conf_t;
 
-#define mddev_to_conf(mddev) ((linear_conf_t *) mddev->private)
-
 #endif
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 20f6ac33834..09be637d52c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -440,15 +440,6 @@ static inline sector_t calc_dev_sboffset(struct block_device *bdev)
 	return MD_NEW_SIZE_SECTORS(num_sectors);
 }
 
-static sector_t calc_num_sectors(mdk_rdev_t *rdev, unsigned chunk_size)
-{
-	sector_t num_sectors = rdev->sb_start;
-
-	if (chunk_size)
-		num_sectors &= ~((sector_t)chunk_size/512 - 1);
-	return num_sectors;
-}
-
 static int alloc_disk_sb(mdk_rdev_t * rdev)
 {
 	if (rdev->sb_page)
@@ -745,6 +736,24 @@ struct super_type  {
 };
 
 /*
+ * Check that the given mddev has no bitmap.
+ *
+ * This function is called from the run method of all personalities that do not
+ * support bitmaps. It prints an error message and returns non-zero if mddev
+ * has a bitmap. Otherwise, it returns 0.
+ *
+ */
+int md_check_no_bitmap(mddev_t *mddev)
+{
+	if (!mddev->bitmap_file && !mddev->bitmap_offset)
+		return 0;
+	printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
+		mdname(mddev), mddev->pers->name);
+	return 1;
+}
+EXPORT_SYMBOL(md_check_no_bitmap);
+
+/*
  * load_super for 0.90.0 
  */
 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
@@ -797,17 +806,6 @@ static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version
 	rdev->data_offset = 0;
 	rdev->sb_size = MD_SB_BYTES;
 
-	if (sb->state & (1<<MD_SB_BITMAP_PRESENT)) {
-		if (sb->level != 1 && sb->level != 4
-		    && sb->level != 5 && sb->level != 6
-		    && sb->level != 10) {
-			/* FIXME use a better test */
-			printk(KERN_WARNING
-			       "md: bitmaps not supported for this level.\n");
-			goto abort;
-		}
-	}
-
 	if (sb->level == LEVEL_MULTIPATH)
 		rdev->desc_nr = -1;
 	else
@@ -836,7 +834,7 @@ static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version
 		else 
 			ret = 0;
 	}
-	rdev->sectors = calc_num_sectors(rdev, sb->chunk_size);
+	rdev->sectors = rdev->sb_start;
 
 	if (rdev->sectors < sb->size * 2 && sb->level > 1)
 		/* "this cannot possibly happen" ... */
@@ -866,7 +864,7 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 		mddev->minor_version = sb->minor_version;
 		mddev->patch_version = sb->patch_version;
 		mddev->external = 0;
-		mddev->chunk_size = sb->chunk_size;
+		mddev->chunk_sectors = sb->chunk_size >> 9;
 		mddev->ctime = sb->ctime;
 		mddev->utime = sb->utime;
 		mddev->level = sb->level;
@@ -883,13 +881,13 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 			mddev->delta_disks = sb->delta_disks;
 			mddev->new_level = sb->new_level;
 			mddev->new_layout = sb->new_layout;
-			mddev->new_chunk = sb->new_chunk;
+			mddev->new_chunk_sectors = sb->new_chunk >> 9;
 		} else {
 			mddev->reshape_position = MaxSector;
 			mddev->delta_disks = 0;
 			mddev->new_level = mddev->level;
 			mddev->new_layout = mddev->layout;
-			mddev->new_chunk = mddev->chunk_size;
+			mddev->new_chunk_sectors = mddev->chunk_sectors;
 		}
 
 		if (sb->state & (1<<MD_SB_CLEAN))
@@ -1004,7 +1002,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 		sb->new_level = mddev->new_level;
 		sb->delta_disks = mddev->delta_disks;
 		sb->new_layout = mddev->new_layout;
-		sb->new_chunk = mddev->new_chunk;
+		sb->new_chunk = mddev->new_chunk_sectors << 9;
 	}
 	mddev->minor_version = sb->minor_version;
 	if (mddev->in_sync)
@@ -1018,7 +1016,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 		sb->recovery_cp = 0;
 
 	sb->layout = mddev->layout;
-	sb->chunk_size = mddev->chunk_size;
+	sb->chunk_size = mddev->chunk_sectors << 9;
 
 	if (mddev->bitmap && mddev->bitmap_file == NULL)
 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
@@ -1185,17 +1183,6 @@ static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
 		       bdevname(rdev->bdev,b));
 		return -EINVAL;
 	}
-	if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET)) {
-		if (sb->level != cpu_to_le32(1) &&
-		    sb->level != cpu_to_le32(4) &&
-		    sb->level != cpu_to_le32(5) &&
-		    sb->level != cpu_to_le32(6) &&
-		    sb->level != cpu_to_le32(10)) {
-			printk(KERN_WARNING
-			       "md: bitmaps not supported for this level.\n");
-			return -EINVAL;
-		}
-	}
 
 	rdev->preferred_minor = 0xffff;
 	rdev->data_offset = le64_to_cpu(sb->data_offset);
@@ -1248,9 +1235,6 @@ static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
 	if (rdev->sectors < le64_to_cpu(sb->data_size))
 		return -EINVAL;
 	rdev->sectors = le64_to_cpu(sb->data_size);
-	if (le32_to_cpu(sb->chunksize))
-		rdev->sectors &= ~((sector_t)le32_to_cpu(sb->chunksize) - 1);
-
 	if (le64_to_cpu(sb->size) > rdev->sectors)
 		return -EINVAL;
 	return ret;
@@ -1271,7 +1255,7 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 		mddev->major_version = 1;
 		mddev->patch_version = 0;
 		mddev->external = 0;
-		mddev->chunk_size = le32_to_cpu(sb->chunksize) << 9;
+		mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
 		mddev->level = le32_to_cpu(sb->level);
@@ -1297,13 +1281,13 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
 			mddev->new_level = le32_to_cpu(sb->new_level);
 			mddev->new_layout = le32_to_cpu(sb->new_layout);
-			mddev->new_chunk = le32_to_cpu(sb->new_chunk)<<9;
+			mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
 		} else {
 			mddev->reshape_position = MaxSector;
 			mddev->delta_disks = 0;
 			mddev->new_level = mddev->level;
 			mddev->new_layout = mddev->layout;
-			mddev->new_chunk = mddev->chunk_size;
+			mddev->new_chunk_sectors = mddev->chunk_sectors;
 		}
 
 	} else if (mddev->pers == NULL) {
@@ -1375,7 +1359,7 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 
 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
 	sb->size = cpu_to_le64(mddev->dev_sectors);
-	sb->chunksize = cpu_to_le32(mddev->chunk_size >> 9);
+	sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
 	sb->level = cpu_to_le32(mddev->level);
 	sb->layout = cpu_to_le32(mddev->layout);
 
@@ -1402,7 +1386,7 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 		sb->new_layout = cpu_to_le32(mddev->new_layout);
 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
 		sb->new_level = cpu_to_le32(mddev->new_level);
-		sb->new_chunk = cpu_to_le32(mddev->new_chunk>>9);
+		sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
 	}
 
 	max_dev = 0;
@@ -1897,6 +1881,7 @@ static void md_update_sb(mddev_t * mddev, int force_change)
 	int sync_req;
 	int nospares = 0;
 
+	mddev->utime = get_seconds();
 	if (mddev->external)
 		return;
 repeat:
@@ -1926,7 +1911,6 @@ repeat:
 		nospares = 0;
 
 	sync_req = mddev->in_sync;
-	mddev->utime = get_seconds();
 
 	/* If this is just a dirty<->clean transition, and the array is clean
 	 * and 'events' is odd, we can roll back to the previous clean state */
@@ -2597,15 +2581,6 @@ static void analyze_sbs(mddev_t * mddev)
 			clear_bit(In_sync, &rdev->flags);
 		}
 	}
-
-
-
-	if (mddev->recovery_cp != MaxSector &&
-	    mddev->level >= 1)
-		printk(KERN_ERR "md: %s: raid array is not clean"
-		       " -- starting background reconstruction\n",
-		       mdname(mddev));
-
 }
 
 static void md_safemode_timeout(unsigned long data);
@@ -2746,7 +2721,7 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
 	if (IS_ERR(priv)) {
 		mddev->new_level = mddev->level;
 		mddev->new_layout = mddev->layout;
-		mddev->new_chunk = mddev->chunk_size;
+		mddev->new_chunk_sectors = mddev->chunk_sectors;
 		mddev->raid_disks -= mddev->delta_disks;
 		mddev->delta_disks = 0;
 		module_put(pers->owner);
@@ -2764,7 +2739,7 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
 	mddev->level = mddev->new_level;
 	mddev->layout = mddev->new_layout;
-	mddev->chunk_size = mddev->new_chunk;
+	mddev->chunk_sectors = mddev->new_chunk_sectors;
 	mddev->delta_disks = 0;
 	pers->run(mddev);
 	mddev_resume(mddev);
@@ -2800,11 +2775,14 @@ layout_store(mddev_t *mddev, const char *buf, size_t len)
 
 	if (mddev->pers) {
 		int err;
-		if (mddev->pers->reconfig == NULL)
+		if (mddev->pers->check_reshape == NULL)
 			return -EBUSY;
-		err = mddev->pers->reconfig(mddev, n, -1);
-		if (err)
+		mddev->new_layout = n;
+		err = mddev->pers->check_reshape(mddev);
+		if (err) {
+			mddev->new_layout = mddev->layout;
 			return err;
+		}
 	} else {
 		mddev->new_layout = n;
 		if (mddev->reshape_position == MaxSector)
@@ -2857,10 +2835,11 @@ static ssize_t
 chunk_size_show(mddev_t *mddev, char *page)
 {
 	if (mddev->reshape_position != MaxSector &&
-	    mddev->chunk_size != mddev->new_chunk)
-		return sprintf(page, "%d (%d)\n", mddev->new_chunk,
-			       mddev->chunk_size);
-	return sprintf(page, "%d\n", mddev->chunk_size);
+	    mddev->chunk_sectors != mddev->new_chunk_sectors)
+		return sprintf(page, "%d (%d)\n",
+			       mddev->new_chunk_sectors << 9,
+			       mddev->chunk_sectors << 9);
+	return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
 }
 
 static ssize_t
@@ -2874,15 +2853,18 @@ chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
 
 	if (mddev->pers) {
 		int err;
-		if (mddev->pers->reconfig == NULL)
+		if (mddev->pers->check_reshape == NULL)
 			return -EBUSY;
-		err = mddev->pers->reconfig(mddev, -1, n);
-		if (err)
+		mddev->new_chunk_sectors = n >> 9;
+		err = mddev->pers->check_reshape(mddev);
+		if (err) {
+			mddev->new_chunk_sectors = mddev->chunk_sectors;
 			return err;
+		}
 	} else {
-		mddev->new_chunk = n;
+		mddev->new_chunk_sectors = n >> 9;
 		if (mddev->reshape_position == MaxSector)
-			mddev->chunk_size = n;
+			mddev->chunk_sectors = n >> 9;
 	}
 	return len;
 }
@@ -3527,8 +3509,9 @@ min_sync_store(mddev_t *mddev, const char *buf, size_t len)
 		return -EBUSY;
 
 	/* Must be a multiple of chunk_size */
-	if (mddev->chunk_size) {
-		if (min & (sector_t)((mddev->chunk_size>>9)-1))
+	if (mddev->chunk_sectors) {
+		sector_t temp = min;
+		if (sector_div(temp, mddev->chunk_sectors))
 			return -EINVAL;
 	}
 	mddev->resync_min = min;
@@ -3564,8 +3547,9 @@ max_sync_store(mddev_t *mddev, const char *buf, size_t len)
 			return -EBUSY;
 
 		/* Must be a multiple of chunk_size */
-		if (mddev->chunk_size) {
-			if (max & (sector_t)((mddev->chunk_size>>9)-1))
+		if (mddev->chunk_sectors) {
+			sector_t temp = max;
+			if (sector_div(temp, mddev->chunk_sectors))
 				return -EINVAL;
 		}
 		mddev->resync_max = max;
@@ -3656,7 +3640,7 @@ reshape_position_store(mddev_t *mddev, const char *buf, size_t len)
 	mddev->delta_disks = 0;
 	mddev->new_level = mddev->level;
 	mddev->new_layout = mddev->layout;
-	mddev->new_chunk = mddev->chunk_size;
+	mddev->new_chunk_sectors = mddev->chunk_sectors;
 	return len;
 }
 
@@ -3976,11 +3960,9 @@ static int start_dirty_degraded;
 static int do_md_run(mddev_t * mddev)
 {
 	int err;
-	int chunk_size;
 	mdk_rdev_t *rdev;
 	struct gendisk *disk;
 	struct mdk_personality *pers;
-	char b[BDEVNAME_SIZE];
 
 	if (list_empty(&mddev->disks))
 		/* cannot run an array with no devices.. */
@@ -3998,38 +3980,6 @@ static int do_md_run(mddev_t * mddev)
 		analyze_sbs(mddev);
 	}
 
-	chunk_size = mddev->chunk_size;
-
-	if (chunk_size) {
-		if (chunk_size > MAX_CHUNK_SIZE) {
-			printk(KERN_ERR "too big chunk_size: %d > %d\n",
-				chunk_size, MAX_CHUNK_SIZE);
-			return -EINVAL;
-		}
-		/*
-		 * chunk-size has to be a power of 2
-		 */
-		if ( (1 << ffz(~chunk_size)) != chunk_size) {
-			printk(KERN_ERR "chunk_size of %d not valid\n", chunk_size);
-			return -EINVAL;
-		}
-
-		/* devices must have minimum size of one chunk */
-		list_for_each_entry(rdev, &mddev->disks, same_set) {
-			if (test_bit(Faulty, &rdev->flags))
-				continue;
-			if (rdev->sectors < chunk_size / 512) {
-				printk(KERN_WARNING
-					"md: Dev %s smaller than chunk_size:"
-					" %llu < %d\n",
-					bdevname(rdev->bdev,b),
-					(unsigned long long)rdev->sectors,
-					chunk_size / 512);
-				return -EINVAL;
-			}
-		}
-	}
-
 	if (mddev->level != LEVEL_NONE)
 		request_module("md-level-%d", mddev->level);
 	else if (mddev->clevel[0])
@@ -4405,7 +4355,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
 		mddev->flags = 0;
 		mddev->ro = 0;
 		mddev->metadata_type[0] = 0;
-		mddev->chunk_size = 0;
+		mddev->chunk_sectors = 0;
 		mddev->ctime = mddev->utime = 0;
 		mddev->layout = 0;
 		mddev->max_disks = 0;
@@ -4413,7 +4363,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
 		mddev->delta_disks = 0;
 		mddev->new_level = LEVEL_NONE;
 		mddev->new_layout = 0;
-		mddev->new_chunk = 0;
+		mddev->new_chunk_sectors = 0;
 		mddev->curr_resync = 0;
 		mddev->resync_mismatches = 0;
 		mddev->suspend_lo = mddev->suspend_hi = 0;
@@ -4618,7 +4568,7 @@ static int get_array_info(mddev_t * mddev, void __user * arg)
 	info.spare_disks   = spare;
 
 	info.layout        = mddev->layout;
-	info.chunk_size    = mddev->chunk_size;
+	info.chunk_size    = mddev->chunk_sectors << 9;
 
 	if (copy_to_user(arg, &info, sizeof(info)))
 		return -EFAULT;
@@ -4843,7 +4793,7 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
 			rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
 		} else 
 			rdev->sb_start = calc_dev_sboffset(rdev->bdev);
-		rdev->sectors = calc_num_sectors(rdev, mddev->chunk_size);
+		rdev->sectors = rdev->sb_start;
 
 		err = bind_rdev_to_array(rdev, mddev);
 		if (err) {
@@ -4913,7 +4863,7 @@ static int hot_add_disk(mddev_t * mddev, dev_t dev)
 	else
 		rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
 
-	rdev->sectors = calc_num_sectors(rdev, mddev->chunk_size);
+	rdev->sectors = rdev->sb_start;
 
 	if (test_bit(Faulty, &rdev->flags)) {
 		printk(KERN_WARNING 
@@ -5062,7 +5012,7 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
 	mddev->external	     = 0;
 
 	mddev->layout        = info->layout;
-	mddev->chunk_size    = info->chunk_size;
+	mddev->chunk_sectors = info->chunk_size >> 9;
 
 	mddev->max_disks     = MD_SB_DISKS;
 
@@ -5081,7 +5031,7 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
 	get_random_bytes(mddev->uuid, 16);
 
 	mddev->new_level = mddev->level;
-	mddev->new_chunk = mddev->chunk_size;
+	mddev->new_chunk_sectors = mddev->chunk_sectors;
 	mddev->new_layout = mddev->layout;
 	mddev->delta_disks = 0;
 
@@ -5191,7 +5141,7 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
 	    mddev->level         != info->level         ||
 /*	    mddev->layout        != info->layout        || */
 	    !mddev->persistent	 != info->not_persistent||
-	    mddev->chunk_size    != info->chunk_size    ||
+	    mddev->chunk_sectors != info->chunk_size >> 9 ||
 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
 	    ((state^info->state) & 0xfffffe00)
 		)
@@ -5215,10 +5165,15 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
 		 * we