*
* We group bitmap updates into batches. Each batch has a number.
* We may write out several batches at once, but that isn't very important.
- * conf->bm_write is the number of the last batch successfully written.
- * conf->bm_flush is the number of the last batch that was closed to
+ * conf->seq_write is the number of the last batch successfully written.
+ * conf->seq_flush is the number of the last batch that was closed to
* new additions.
* When we discover that we will need to write to any block in a stripe
* (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
- * the number of the batch it will be in. This is bm_flush+1.
+ * the number of the batch it will be in. This is seq_flush+1.
* When we are ready to do a write, if that batch hasn't been written yet,
* we plug the array and queue the stripe for later.
* When an unplug happens, we increment bm_flush, thus closing the current
static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt)
{
- bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 16);
+ bio->bi_phys_segments = raid5_bi_phys_segments(bio) | (cnt << 16);
}
/* Find first data disk in a raid6 stripe */
BUG_ON(!list_empty(&sh->lru));
BUG_ON(atomic_read(&conf->active_stripes)==0);
if (test_bit(STRIPE_HANDLE, &sh->state)) {
- if (test_bit(STRIPE_DELAYED, &sh->state)) {
+ if (test_bit(STRIPE_DELAYED, &sh->state) &&
+ !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
list_add_tail(&sh->lru, &conf->delayed_list);
- plugger_set_plug(&conf->plug);
- } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
- sh->bm_seq - conf->seq_write > 0) {
+ else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
+ sh->bm_seq - conf->seq_write > 0)
list_add_tail(&sh->lru, &conf->bitmap_list);
- plugger_set_plug(&conf->plug);
- } else {
+ else {
+ clear_bit(STRIPE_DELAYED, &sh->state);
clear_bit(STRIPE_BIT_DELAY, &sh->state);
list_add_tail(&sh->lru, &conf->handle_list);
}
return 0;
}
-static void unplug_slaves(mddev_t *mddev);
-
static struct stripe_head *
get_active_stripe(raid5_conf_t *conf, sector_t sector,
int previous, int noblock, int noquiesce)
< (conf->max_nr_stripes *3/4)
|| !conf->inactive_blocked),
conf->device_lock,
- md_raid5_unplug_device(conf)
- );
+ );
conf->inactive_blocked = 0;
} else
init_stripe(sh, sector, previous);
int rw;
struct bio *bi;
mdk_rdev_t *rdev;
- if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
- rw = WRITE;
- else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
+ if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
+ if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
+ rw = WRITE_FUA;
+ else
+ rw = WRITE;
+ } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
rw = READ;
else
continue;
bi = &sh->dev[i].req;
bi->bi_rw = rw;
- if (rw == WRITE)
+ if (rw & WRITE)
bi->bi_end_io = raid5_end_write_request;
else
bi->bi_end_io = raid5_end_read_request;
bi->bi_io_vec[0].bv_offset = 0;
bi->bi_size = STRIPE_SIZE;
bi->bi_next = NULL;
- if (rw == WRITE &&
+ if ((rw & WRITE) &&
test_bit(R5_ReWrite, &sh->dev[i].flags))
atomic_add(STRIPE_SECTORS,
&rdev->corrected_errors);
generic_make_request(bi);
} else {
- if (rw == WRITE)
+ if (rw & WRITE)
set_bit(STRIPE_DEGRADED, &sh->state);
pr_debug("skip op %ld on disc %d for sector %llu\n",
bi->bi_rw, i, (unsigned long long)sh->sector);
init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
bio_for_each_segment(bvl, bio, i) {
- int len = bio_iovec_idx(bio, i)->bv_len;
+ int len = bvl->bv_len;
int clen;
int b_offset = 0;
clen = len;
if (clen > 0) {
- b_offset += bio_iovec_idx(bio, i)->bv_offset;
- bio_page = bio_iovec_idx(bio, i)->bv_page;
+ b_offset += bvl->bv_offset;
+ bio_page = bvl->bv_page;
if (frombio)
tx = async_memcpy(page, bio_page, page_offset,
b_offset, clen, &submit);
while (wbi && wbi->bi_sector <
dev->sector + STRIPE_SECTORS) {
+ if (wbi->bi_rw & REQ_FUA)
+ set_bit(R5_WantFUA, &dev->flags);
tx = async_copy_data(1, wbi, dev->page,
dev->sector, tx);
wbi = r5_next_bio(wbi, dev->sector);
int pd_idx = sh->pd_idx;
int qd_idx = sh->qd_idx;
int i;
+ bool fua = false;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
+ for (i = disks; i--; )
+ fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
+
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
- if (dev->written || i == pd_idx || i == qd_idx)
+ if (dev->written || i == pd_idx || i == qd_idx) {
set_bit(R5_UPTODATE, &dev->flags);
+ if (fua)
+ set_bit(R5_WantFUA, &dev->flags);
+ }
}
if (sh->reconstruct_state == reconstruct_state_drain_run)
wait_event_lock_irq(conf->wait_for_stripe,
!list_empty(&conf->inactive_list),
conf->device_lock,
- unplug_slaves(conf->mddev)
- );
+ );
osh = get_free_stripe(conf);
spin_unlock_irq(&conf->device_lock);
atomic_set(&nsh->count, 1);
raid5_conf_t *conf = mddev->private;
pr_debug("raid456: error called\n");
- if (!test_bit(Faulty, &rdev->flags)) {
- set_bit(MD_CHANGE_DEVS, &mddev->flags);
- if (test_and_clear_bit(In_sync, &rdev->flags)) {
- unsigned long flags;
- spin_lock_irqsave(&conf->device_lock, flags);
- mddev->degraded++;
- spin_unlock_irqrestore(&conf->device_lock, flags);
- /*
- * if recovery was running, make sure it aborts.
- */
- set_bit(MD_RECOVERY_INTR, &mddev->recovery);
- }
- set_bit(Faulty, &rdev->flags);
- printk(KERN_ALERT
- "md/raid:%s: Disk failure on %s, disabling device.\n"
- KERN_ALERT
- "md/raid:%s: Operation continuing on %d devices.\n",
- mdname(mddev),
- bdevname(rdev->bdev, b),
- mdname(mddev),
- conf->raid_disks - mddev->degraded);
+ if (test_and_clear_bit(In_sync, &rdev->flags)) {
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ mddev->degraded++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ /*
+ * if recovery was running, make sure it aborts.
+ */
+ set_bit(MD_RECOVERY_INTR, &mddev->recovery);
}
+ set_bit(Faulty, &rdev->flags);
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ printk(KERN_ALERT
+ "md/raid:%s: Disk failure on %s, disabling device.\n"
+ "md/raid:%s: Operation continuing on %d devices.\n",
+ mdname(mddev),
+ bdevname(rdev->bdev, b),
+ mdname(mddev),
+ conf->raid_disks - mddev->degraded);
}
/*
/* Not in-sync */;
else if (test_bit(In_sync, &rdev->flags))
set_bit(R5_Insync, &dev->flags);
- else {
+ else if (!test_bit(Faulty, &rdev->flags)) {
/* could be in-sync depending on recovery/reshape status */
if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
set_bit(R5_Insync, &dev->flags);
/* check if the array has lost two devices and, if so, some requests might
* need to be failed
*/
- if (s.failed > 1 && s.to_read+s.to_write+s.written)
- handle_failed_stripe(conf, sh, &s, disks, &return_bi);
- if (s.failed > 1 && s.syncing) {
- md_done_sync(conf->mddev, STRIPE_SECTORS,0);
- clear_bit(STRIPE_SYNCING, &sh->state);
- s.syncing = 0;
+ if (s.failed > 1) {
+ sh->check_state = 0;
+ sh->reconstruct_state = 0;
+ if (s.to_read+s.to_write+s.written)
+ handle_failed_stripe(conf, sh, &s, disks, &return_bi);
+ if (s.syncing) {
+ md_done_sync(conf->mddev, STRIPE_SECTORS,0);
+ clear_bit(STRIPE_SYNCING, &sh->state);
+ s.syncing = 0;
+ }
}
/* might be able to return some write requests if the parity block
if (dec_preread_active) {
/* We delay this until after ops_run_io so that if make_request
- * is waiting on a barrier, it won't continue until the writes
+ * is waiting on a flush, it won't continue until the writes
* have actually been submitted.
*/
atomic_dec(&conf->preread_active_stripes);
/* Not in-sync */;
else if (test_bit(In_sync, &rdev->flags))
set_bit(R5_Insync, &dev->flags);
- else {
+ else if (!test_bit(Faulty, &rdev->flags)) {
/* in sync if before recovery_offset */
if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
set_bit(R5_Insync, &dev->flags);
/* check if the array has lost >2 devices and, if so, some requests
* might need to be failed
*/
- if (s.failed > 2 && s.to_read+s.to_write+s.written)
- handle_failed_stripe(conf, sh, &s, disks, &return_bi);
- if (s.failed > 2 && s.syncing) {
- md_done_sync(conf->mddev, STRIPE_SECTORS,0);
- clear_bit(STRIPE_SYNCING, &sh->state);
- s.syncing = 0;
+ if (s.failed > 2) {
+ sh->check_state = 0;
+ sh->reconstruct_state = 0;
+ if (s.to_read+s.to_write+s.written)
+ handle_failed_stripe(conf, sh, &s, disks, &return_bi);
+ if (s.syncing) {
+ md_done_sync(conf->mddev, STRIPE_SECTORS,0);
+ clear_bit(STRIPE_SYNCING, &sh->state);
+ s.syncing = 0;
+ }
}
/*
if (dec_preread_active) {
/* We delay this until after ops_run_io so that if make_request
- * is waiting on a barrier, it won't continue until the writes
+ * is waiting on a flush, it won't continue until the writes
* have actually been submitted.
*/
atomic_dec(&conf->preread_active_stripes);
atomic_inc(&conf->preread_active_stripes);
list_add_tail(&sh->lru, &conf->hold_list);
}
- } else
- plugger_set_plug(&conf->plug);
+ }
}
static void activate_bit_delay(raid5_conf_t *conf)
}
}
-static void unplug_slaves(mddev_t *mddev)
-{
- raid5_conf_t *conf = mddev->private;
- int i;
- int devs = max(conf->raid_disks, conf->previous_raid_disks);
-
- rcu_read_lock();
- for (i = 0; i < devs; i++) {
- mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
- if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
- struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
-
- atomic_inc(&rdev->nr_pending);
- rcu_read_unlock();
-
- blk_unplug(r_queue);
-
- rdev_dec_pending(rdev, mddev);
- rcu_read_lock();
- }
- }
- rcu_read_unlock();
-}
-
-void md_raid5_unplug_device(raid5_conf_t *conf)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&conf->device_lock, flags);
-
- if (plugger_remove_plug(&conf->plug)) {
- conf->seq_flush++;
- raid5_activate_delayed(conf);
- }
- md_wakeup_thread(conf->mddev->thread);
-
- spin_unlock_irqrestore(&conf->device_lock, flags);
-
- unplug_slaves(conf->mddev);
-}
-EXPORT_SYMBOL_GPL(md_raid5_unplug_device);
-
-static void raid5_unplug(struct plug_handle *plug)
-{
- raid5_conf_t *conf = container_of(plug, raid5_conf_t, plug);
- md_raid5_unplug_device(conf);
-}
-
-static void raid5_unplug_queue(struct request_queue *q)
-{
- mddev_t *mddev = q->queuedata;
- md_raid5_unplug_device(mddev->private);
-}
-
int md_raid5_congested(mddev_t *mddev, int bits)
{
raid5_conf_t *conf = mddev->private;
return 0;
}
/*
- * use bio_clone to make a copy of the bio
+ * use bio_clone_mddev to make a copy of the bio
*/
- align_bi = bio_clone(raid_bio, GFP_NOIO);
+ align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev);
if (!align_bi)
return 0;
/*
raid_bio->bi_next = (void*)rdev;
align_bi->bi_bdev = rdev->bdev;
align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
- align_bi->bi_sector += rdev->data_offset;
if (!bio_fits_rdev(align_bi)) {
/* too big in some way */
return 0;
}
+ /* No reshape active, so we can trust rdev->data_offset */
+ align_bi->bi_sector += rdev->data_offset;
+
spin_lock_irq(&conf->device_lock);
wait_event_lock_irq(conf->wait_for_stripe,
conf->quiesce == 0,
struct stripe_head *sh;
const int rw = bio_data_dir(bi);
int remaining;
+ int plugged;
- if (unlikely(bi->bi_rw & REQ_HARDBARRIER)) {
- /* Drain all pending writes. We only really need
- * to ensure they have been submitted, but this is
- * easier.
- */
- mddev->pers->quiesce(mddev, 1);
- mddev->pers->quiesce(mddev, 0);
- md_barrier_request(mddev, bi);
+ if (unlikely(bi->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bi);
return 0;
}
bi->bi_next = NULL;
bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
+ plugged = mddev_check_plugged(mddev);
for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
DEFINE_WAIT(w);
int disks, data_disks;
/* spinlock is needed as reshape_progress may be
* 64bit on a 32bit platform, and so it might be
* possible to see a half-updated value
- * Ofcourse reshape_progress could change after
+ * Of course reshape_progress could change after
* the lock is dropped, so once we get a reference
* to the stripe that we think it is, we will have
* to check again.
* add failed due to overlap. Flush everything
* and wait a while
*/
- md_raid5_unplug_device(conf);
+ md_wakeup_thread(mddev->thread);
release_stripe(sh);
schedule();
goto retry;
finish_wait(&conf->wait_for_overlap, &w);
set_bit(STRIPE_HANDLE, &sh->state);
clear_bit(STRIPE_DELAYED, &sh->state);
- if (mddev->barrier &&
+ if ((bi->bi_rw & REQ_SYNC) &&
!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
atomic_inc(&conf->preread_active_stripes);
release_stripe(sh);
}
}
+ if (!plugged)
+ md_wakeup_thread(mddev->thread);
+
spin_lock_irq(&conf->device_lock);
remaining = raid5_dec_bi_phys_segments(bi);
spin_unlock_irq(&conf->device_lock);
bio_endio(bi, 0);
}
- if (mddev->barrier) {
- /* We need to wait for the stripes to all be handled.
- * So: wait for preread_active_stripes to drop to 0.
- */
- wait_event(mddev->thread->wqueue,
- atomic_read(&conf->preread_active_stripes) == 0);
- }
return 0;
}
wait_event(conf->wait_for_overlap,
atomic_read(&conf->reshape_stripes)==0);
mddev->reshape_position = conf->reshape_progress;
- mddev->curr_resync_completed = mddev->curr_resync;
+ mddev->curr_resync_completed = sector_nr;
conf->reshape_checkpoint = jiffies;
set_bit(MD_CHANGE_DEVS, &mddev->flags);
md_wakeup_thread(mddev->thread);
wait_event(conf->wait_for_overlap,
atomic_read(&conf->reshape_stripes) == 0);
mddev->reshape_position = conf->reshape_progress;
- mddev->curr_resync_completed = mddev->curr_resync + reshape_sectors;
+ mddev->curr_resync_completed = sector_nr;
conf->reshape_checkpoint = jiffies;
set_bit(MD_CHANGE_DEVS, &mddev->flags);
md_wakeup_thread(mddev->thread);
raid5_conf_t *conf = mddev->private;
struct stripe_head *sh;
sector_t max_sector = mddev->dev_sectors;
- int sync_blocks;
+ sector_t sync_blocks;
int still_degraded = 0;
int i;
if (sector_nr >= max_sector) {
/* just being told to finish up .. nothing much to do */
- unplug_slaves(mddev);
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
end_reshape(conf);
struct stripe_head *sh;
raid5_conf_t *conf = mddev->private;
int handled;
+ struct blk_plug plug;
pr_debug("+++ raid5d active\n");
md_check_recovery(mddev);
+ blk_start_plug(&plug);
handled = 0;
spin_lock_irq(&conf->device_lock);
while (1) {
struct bio *bio;
- if (conf->seq_flush != conf->seq_write) {
- int seq = conf->seq_flush;
+ if (atomic_read(&mddev->plug_cnt) == 0 &&
+ !list_empty(&conf->bitmap_list)) {
+ /* Now is a good time to flush some bitmap updates */
+ conf->seq_flush++;
spin_unlock_irq(&conf->device_lock);
bitmap_unplug(mddev->bitmap);
spin_lock_irq(&conf->device_lock);
- conf->seq_write = seq;
+ conf->seq_write = conf->seq_flush;
activate_bit_delay(conf);
}
+ if (atomic_read(&mddev->plug_cnt) == 0)
+ raid5_activate_delayed(conf);
while ((bio = remove_bio_from_retry(conf))) {
int ok;
spin_unlock_irq(&conf->device_lock);
async_tx_issue_pending_all();
- unplug_slaves(mddev);
+ blk_finish_plug(&plug);
pr_debug("--- raid5d inactive\n");
}
printk(KERN_INFO "md/raid:%s: device %s operational as raid"
" disk %d\n",
mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
- } else
+ } else if (rdev->saved_raid_disk != raid_disk)
/* Cannot rely on bitmap to complete recovery */
conf->fullsync = 1;
}
mdname(mddev));
md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
- plugger_init(&conf->plug, raid5_unplug);
- mddev->plug = &conf->plug;
if (mddev->queue) {
int chunk_size;
/* read-ahead size must cover two whole stripes, which
mddev->queue->backing_dev_info.congested_data = mddev;
mddev->queue->backing_dev_info.congested_fn = raid5_congested;
- mddev->queue->queue_lock = &conf->device_lock;
- mddev->queue->unplug_fn = raid5_unplug_queue;
chunk_size = mddev->chunk_sectors << 9;
blk_queue_io_min(mddev->queue, chunk_size);
return 0;
abort:
- md_unregister_thread(mddev->thread);
- mddev->thread = NULL;
+ md_unregister_thread(&mddev->thread);
if (conf) {
print_raid5_conf(conf);
free_conf(conf);
{
raid5_conf_t *conf = mddev->private;
- md_unregister_thread(mddev->thread);
- mddev->thread = NULL;
+ md_unregister_thread(&mddev->thread);
if (mddev->queue)
mddev->queue->backing_dev_info.congested_fn = NULL;
- plugger_flush(&conf->plug); /* the unplug fn references 'conf'*/
free_conf(conf);
mddev->private = NULL;
mddev->to_remove = &raid5_attrs_group;
&& !test_bit(Faulty, &tmp->rdev->flags)
&& !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
count++;
- sysfs_notify_dirent(tmp->rdev->sysfs_state);
+ sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
}
}
spin_lock_irqsave(&conf->device_lock, flags);
return -EINVAL;
set_capacity(mddev->gendisk, mddev->array_sectors);
revalidate_disk(mddev->gendisk);
- if (sectors > mddev->dev_sectors && mddev->recovery_cp == MaxSector) {
+ if (sectors > mddev->dev_sectors &&
+ mddev->recovery_cp > mddev->dev_sectors) {
mddev->recovery_cp = mddev->dev_sectors;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
}
raid5_conf_t *conf = mddev->private;
mdk_rdev_t *rdev;
int spares = 0;
- int added_devices = 0;
unsigned long flags;
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
return -ENOSPC;
list_for_each_entry(rdev, &mddev->disks, same_set)
- if (rdev->raid_disk < 0 &&
- !test_bit(Faulty, &rdev->flags))
+ if (!test_bit(In_sync, &rdev->flags)
+ && !test_bit(Faulty, &rdev->flags))
spares++;
if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
* to correctly record the "partially reconstructed" state of
* such devices during the reshape and confusion could result.
*/
- if (mddev->delta_disks >= 0)
- list_for_each_entry(rdev, &mddev->disks, same_set)
- if (rdev->raid_disk < 0 &&
- !test_bit(Faulty, &rdev->flags)) {
- if (raid5_add_disk(mddev, rdev) == 0) {
- char nm[20];
- if (rdev->raid_disk >= conf->previous_raid_disks) {
- set_bit(In_sync, &rdev->flags);
- added_devices++;
- } else
- rdev->recovery_offset = 0;
- sprintf(nm, "rd%d", rdev->raid_disk);
- if (sysfs_create_link(&mddev->kobj,
- &rdev->kobj, nm))
- /* Failure here is OK */;
- } else
- break;
- }
+ if (mddev->delta_disks >= 0) {
+ int added_devices = 0;
+ list_for_each_entry(rdev, &mddev->disks, same_set)
+ if (rdev->raid_disk < 0 &&
+ !test_bit(Faulty, &rdev->flags)) {
+ if (raid5_add_disk(mddev, rdev) == 0) {
+ char nm[20];
+ if (rdev->raid_disk
+ >= conf->previous_raid_disks) {
+ set_bit(In_sync, &rdev->flags);
+ added_devices++;
+ } else
+ rdev->recovery_offset = 0;
+ sprintf(nm, "rd%d", rdev->raid_disk);
+ if (sysfs_create_link(&mddev->kobj,
+ &rdev->kobj, nm))
+ /* Failure here is OK */;
+ }
+ } else if (rdev->raid_disk >= conf->previous_raid_disks
+ && !test_bit(Faulty, &rdev->flags)) {
+ /* This is a spare that was manually added */
+ set_bit(In_sync, &rdev->flags);
+ added_devices++;
+ }
- /* When a reshape changes the number of devices, ->degraded
- * is measured against the larger of the pre and post number of
- * devices.*/
- if (mddev->delta_disks > 0) {
+ /* When a reshape changes the number of devices,
+ * ->degraded is measured against the larger of the
+ * pre and post number of devices.
+ */
spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded += (conf->raid_disks - conf->previous_raid_disks)
- added_devices;
static void *raid45_takeover_raid0(mddev_t *mddev, int level)
{
struct raid0_private_data *raid0_priv = mddev->private;
+ sector_t sectors;
/* for raid0 takeover only one zone is supported */
if (raid0_priv->nr_strip_zones > 1) {
return ERR_PTR(-EINVAL);
}
+ sectors = raid0_priv->strip_zone[0].zone_end;
+ sector_div(sectors, raid0_priv->strip_zone[0].nb_dev);
+ mddev->dev_sectors = sectors;
mddev->new_level = level;
mddev->new_layout = ALGORITHM_PARITY_N;
mddev->new_chunk_sectors = mddev->chunk_sectors;