X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fmd%2Fraid10.c;h=1440935414e63825adfb5278d2aad8d0be6e1822;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=3c37be6423d75a1a576cd545d80c0d76e25a246e;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 3c37be642..144093541 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -18,7 +18,9 @@
  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "dm-bio-list.h"
 #include <linux/raid/raid10.h>
+#include <linux/raid/bitmap.h>
 
 /*
  * RAID10 provides a combination of RAID0 and RAID1 functionality.
@@ -47,17 +49,18 @@
 
 static void unplug_slaves(mddev_t *mddev);
 
-static void * r10bio_pool_alloc(unsigned int __nocast gfp_flags, void *data)
+static void allow_barrier(conf_t *conf);
+static void lower_barrier(conf_t *conf);
+
+static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
 {
 	conf_t *conf = data;
 	r10bio_t *r10_bio;
 	int size = offsetof(struct r10bio_s, devs[conf->copies]);
 
 	/* allocate a r10bio with room for raid_disks entries in the bios array */
-	r10_bio = kmalloc(size, gfp_flags);
-	if (r10_bio)
-		memset(r10_bio, 0, size);
-	else
+	r10_bio = kzalloc(size, gfp_flags);
+	if (!r10_bio)
 		unplug_slaves(conf->mddev);
 
 	return r10_bio;
@@ -81,7 +84,7 @@ static void r10bio_pool_free(void *r10_bio, void *data)
  * one for write (we recover only one drive per r10buf)
  *
  */
-static void * r10buf_pool_alloc(unsigned int __nocast gfp_flags, void *data)
+static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
 {
 	conf_t *conf = data;
 	struct page *page;
@@ -129,10 +132,10 @@ static void * r10buf_pool_alloc(unsigned int __nocast gfp_flags, void *data)
 
 out_free_pages:
 	for ( ; i > 0 ; i--)
-		__free_page(bio->bi_io_vec[i-1].bv_page);
+		safe_put_page(bio->bi_io_vec[i-1].bv_page);
 	while (j--)
 		for (i = 0; i < RESYNC_PAGES ; i++)
-			__free_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
+			safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
 	j = -1;
 out_free_bio:
 	while ( ++j < nalloc )
@@ -152,7 +155,7 @@ static void r10buf_pool_free(void *__r10_bio, void *data)
 		struct bio *bio = r10bio->devs[j].bio;
 		if (bio) {
 			for (i = 0; i < RESYNC_PAGES; i++) {
-				__free_page(bio->bi_io_vec[i].bv_page);
+				safe_put_page(bio->bi_io_vec[i].bv_page);
 				bio->bi_io_vec[i].bv_page = NULL;
 			}
 			bio_put(bio);
@@ -167,52 +170,33 @@ static void put_all_bios(conf_t *conf, r10bio_t *r10_bio)
 
 	for (i = 0; i < conf->copies; i++) {
 		struct bio **bio = & r10_bio->devs[i].bio;
-		if (*bio)
+		if (*bio && *bio != IO_BLOCKED)
 			bio_put(*bio);
 		*bio = NULL;
 	}
 }
 
-static inline void free_r10bio(r10bio_t *r10_bio)
+static void free_r10bio(r10bio_t *r10_bio)
 {
-	unsigned long flags;
-
 	conf_t *conf = mddev_to_conf(r10_bio->mddev);
 
 	/*
 	 * Wake up any possible resync thread that waits for the device
 	 * to go idle.
 	 */
-	spin_lock_irqsave(&conf->resync_lock, flags);
-	if (!--conf->nr_pending) {
-		wake_up(&conf->wait_idle);
-		wake_up(&conf->wait_resume);
-	}
-	spin_unlock_irqrestore(&conf->resync_lock, flags);
+	allow_barrier(conf);
 
 	put_all_bios(conf, r10_bio);
 	mempool_free(r10_bio, conf->r10bio_pool);
 }
 
-static inline void put_buf(r10bio_t *r10_bio)
+static void put_buf(r10bio_t *r10_bio)
 {
 	conf_t *conf = mddev_to_conf(r10_bio->mddev);
-	unsigned long flags;
 
 	mempool_free(r10_bio, conf->r10buf_pool);
 
-	spin_lock_irqsave(&conf->resync_lock, flags);
-	if (!conf->barrier)
-		BUG();
-	--conf->barrier;
-	wake_up(&conf->wait_resume);
-	wake_up(&conf->wait_idle);
-
-	if (!--conf->nr_pending) {
-		wake_up(&conf->wait_idle);
-		wake_up(&conf->wait_resume);
-	}
-	spin_unlock_irqrestore(&conf->resync_lock, flags);
+	lower_barrier(conf);
 }
 
 static void reschedule_retry(r10bio_t *r10_bio)
@@ -223,6 +207,7 @@ static void reschedule_retry(r10bio_t *r10_bio)
 
 	spin_lock_irqsave(&conf->device_lock, flags);
 	list_add(&r10_bio->retry_list, &conf->retry_list);
+	conf->nr_queued ++;
 	spin_unlock_irqrestore(&conf->device_lock, flags);
 
 	md_wakeup_thread(mddev->thread);
@@ -268,9 +253,9 @@ static int raid10_end_read_request(struct bio *bio, unsigned int bytes_done, int
 	/*
 	 * this branch is our 'one mirror IO has finished' event handler:
 	 */
-	if (!uptodate)
-		md_error(r10_bio->mddev, conf->mirrors[dev].rdev);
-	else
+	update_head_pos(slot, r10_bio);
+
+	if (uptodate) {
 		/*
 		 * Set R10BIO_Uptodate in our master bio, so that
 		 * we will return a good error code to the higher
@@ -281,15 +266,8 @@ static int raid10_end_read_request(struct bio *bio, unsigned int bytes_done, int
 		 * wait for the 'master' bio.
 		 */
 		set_bit(R10BIO_Uptodate, &r10_bio->state);
-
-	update_head_pos(slot, r10_bio);
-
-	/*
-	 * we have only one bio on the read side
-	 */
-	if (uptodate)
 		raid_end_bio_io(r10_bio);
-	else {
+	} else {
 		/*
 		 * oops, read error:
 		 */
@@ -322,9 +300,11 @@ static int raid10_end_write_request(struct bio *bio, unsigned int bytes_done, in
 	/*
 	 * this branch is our 'one mirror IO has finished' event handler:
 	 */
-	if (!uptodate)
+	if (!uptodate) {
 		md_error(r10_bio->mddev, conf->mirrors[dev].rdev);
-	else
+		/* an I/O failed, we can't clear the bitmap */
+		set_bit(R10BIO_Degraded, &r10_bio->state);
+	} else
 		/*
 		 * Set R10BIO_Uptodate in our master bio, so that
 		 * we will return a good error code for to the higher
@@ -344,6 +324,11 @@ static int raid10_end_write_request(struct bio *bio, unsigned int bytes_done, in
 	 * already.
 	 */
 	if (atomic_dec_and_test(&r10_bio->remaining)) {
+		/* clear the bitmap if all writes complete successfully */
+		bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
+				r10_bio->sectors,
+				!test_bit(R10BIO_Degraded, &r10_bio->state),
+				0);
 		md_write_end(r10_bio->mddev);
 		raid_end_bio_io(r10_bio);
 	}
@@ -496,13 +481,15 @@ static int read_balance(conf_t *conf, r10bio_t *r10_bio)
 	int disk, slot, nslot;
 	const int sectors = r10_bio->sectors;
 	sector_t new_distance, current_distance;
+	mdk_rdev_t *rdev;
 
 	raid10_find_phys(conf, r10_bio);
 	rcu_read_lock();
 	/*
 	 * Check if we can balance. We can balance on the whole
-	 * device if no resync is going on, or below the resync window.
-	 * We take the first readable disk when above the resync window.
+	 * device if no resync is going on (recovery is ok), or below
+	 * the resync window. We take the first readable disk when
+	 * above the resync window.
 	 */
 	if (conf->mddev->recovery_cp < MaxSector
 	    && (this_sector + sectors >= conf->next_resync)) {
@@ -510,8 +497,9 @@ static int read_balance(conf_t *conf, r10bio_t *r10_bio)
 		slot = 0;
 		disk = r10_bio->devs[slot].devnum;
 
-		while (!conf->mirrors[disk].rdev ||
-		       !conf->mirrors[disk].rdev->in_sync) {
+		while ((rdev = rcu_dereference(conf->mirrors[disk].rdev)) == NULL ||
+		       r10_bio->devs[slot].bio == IO_BLOCKED ||
+		       !test_bit(In_sync, &rdev->flags)) {
 			slot++;
 			if (slot == conf->copies) {
 				slot = 0;
@@ -527,8 +515,9 @@ static int read_balance(conf_t *conf, r10bio_t *r10_bio)
 	/* make sure the disk is operational */
 	slot = 0;
 	disk = r10_bio->devs[slot].devnum;
-	while (!conf->mirrors[disk].rdev ||
-	       !conf->mirrors[disk].rdev->in_sync) {
+	while ((rdev=rcu_dereference(conf->mirrors[disk].rdev)) == NULL ||
+	       r10_bio->devs[slot].bio == IO_BLOCKED ||
+	       !test_bit(In_sync, &rdev->flags)) {
 		slot ++;
 		if (slot == conf->copies) {
 			disk = -1;
@@ -538,7 +527,8 @@ static int read_balance(conf_t *conf, r10bio_t *r10_bio)
 	}
 
 
-	current_distance = abs(this_sector - conf->mirrors[disk].head_position);
+	current_distance = abs(r10_bio->devs[slot].addr -
+			       conf->mirrors[disk].head_position);
 
 	/* Find the disk whose head is closest */
 
@@ -546,11 +536,16 @@ static int read_balance(conf_t *conf, r10bio_t *r10_bio)
 		int ndisk = r10_bio->devs[nslot].devnum;
 
 
-		if (!conf->mirrors[ndisk].rdev ||
-		    !conf->mirrors[ndisk].rdev->in_sync)
+		if ((rdev=rcu_dereference(conf->mirrors[ndisk].rdev)) == NULL ||
+		    r10_bio->devs[nslot].bio == IO_BLOCKED ||
+		    !test_bit(In_sync, &rdev->flags))
 			continue;
 
-		if (!atomic_read(&conf->mirrors[ndisk].rdev->nr_pending)) {
+		/* This optimisation is debatable, and completely destroys
+		 * sequential read speed for 'far copies' arrays.  So only
+		 * keep it for 'near' arrays, and review those later.
+		 */
+		if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending)) {
 			disk = ndisk;
 			slot = nslot;
 			break;
@@ -568,8 +563,10 @@ rb_out:
 	r10_bio->read_slot = slot;
 /*	conf->next_seq_sect = this_sector + sectors;*/
 
-	if (disk >= 0 && conf->mirrors[disk].rdev)
+	if (disk >= 0 && (rdev=rcu_dereference(conf->mirrors[disk].rdev))!= NULL)
 		atomic_inc(&conf->mirrors[disk].rdev->nr_pending);
+	else
+		disk = -1;
 	rcu_read_unlock();
 
 	return disk;
@@ -582,8 +579,8 @@ static void unplug_slaves(mddev_t *mddev)
 
 	rcu_read_lock();
 	for (i=0; i<mddev->raid_disks; i++) {
-		mdk_rdev_t *rdev = conf->mirrors[i].rdev;
-		if (rdev && !rdev->faulty && atomic_read(&rdev->nr_pending)) {
+		mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+		if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
 			request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
 
 			atomic_inc(&rdev->nr_pending);
@@ -601,7 +598,10 @@ static void unplug_slaves(mddev_t *mddev)
 
 static void raid10_unplug(request_queue_t *q)
 {
+	mddev_t *mddev = q->queuedata;
+
 	unplug_slaves(q->queuedata);
+	md_wakeup_thread(mddev->thread);
 }
 
 static int raid10_issue_flush(request_queue_t *q, struct gendisk *disk,
@@ -613,8 +613,8 @@ static int raid10_issue_flush(request_queue_t *q, struct gendisk *disk,
 
 	rcu_read_lock();
 	for (i=0; i<mddev->raid_disks && ret == 0; i++) {
-		mdk_rdev_t *rdev = conf->mirrors[i].rdev;
-		if (rdev && !rdev->faulty) {
+		mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+		if (rdev && !test_bit(Faulty, &rdev->flags)) {
 			struct block_device *bdev = rdev->bdev;
 			request_queue_t *r_queue = bdev_get_queue(bdev);
 
@@ -634,27 +634,107 @@ static int raid10_issue_flush(request_queue_t *q, struct gendisk *disk,
 	return ret;
 }
 
-/*
- * Throttle resync depth, so that we can both get proper overlapping of
- * requests, but are still able to handle normal requests quickly.
+/* Barriers....
+ * Sometimes we need to suspend IO while we do something else,
+ * either some resync/recovery, or reconfigure the array.
+ * To do this we raise a 'barrier'.
+ * The 'barrier' is a counter that can be raised multiple times
+ * to count how many activities are happening which preclude
+ * normal IO.
+ * We can only raise the barrier if there is no pending IO.
+ * i.e. if nr_pending == 0.
+ * We choose only to raise the barrier if no-one is waiting for the
+ * barrier to go down.  This means that as soon as an IO request
+ * is ready, no other operations which require a barrier will start
+ * until the IO request has had a chance.
+ *
+ * So: regular IO calls 'wait_barrier'.  When that returns there
+ *    is no backgroup IO happening,  It must arrange to call
+ *    allow_barrier when it has finished its IO.
+ * backgroup IO calls must call raise_barrier.  Once that returns
+ *    there is no normal IO happeing.  It must arrange to call
+ *    lower_barrier when the particular background IO completes.
  */
 #define RESYNC_DEPTH 32
 
-static void device_barrier(conf_t *conf, sector_t sect)
+static void raise_barrier(conf_t *conf, int force)
 {
+	BUG_ON(force && !conf->barrier);
 	spin_lock_irq(&conf->resync_lock);
-	wait_event_lock_irq(conf->wait_idle, !waitqueue_active(&conf->wait_resume),
-			    conf->resync_lock, unplug_slaves(conf->mddev));
-
-	if (!conf->barrier++) {
-		wait_event_lock_irq(conf->wait_idle, !conf->nr_pending,
-				    conf->resync_lock, unplug_slaves(conf->mddev));
-		if (conf->nr_pending)
-			BUG();
+
+	/* Wait until no block IO is waiting (unless 'force') */
+	wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
+			    conf->resync_lock,
+			    raid10_unplug(conf->mddev->queue));
+
+	/* block any new IO from starting */
+	conf->barrier++;
+
+	/* No wait for all pending IO to complete */
+	wait_event_lock_irq(conf->wait_barrier,
+			    !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
+			    conf->resync_lock,
+			    raid10_unplug(conf->mddev->queue));
+
+	spin_unlock_irq(&conf->resync_lock);
+}
+
+static void lower_barrier(conf_t *conf)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&conf->resync_lock, flags);
+	conf->barrier--;
+	spin_unlock_irqrestore(&conf->resync_lock, flags);
+	wake_up(&conf->wait_barrier);
+}
+
+static void wait_barrier(conf_t *conf)
+{
+	spin_lock_irq(&conf->resync_lock);
+	if (conf->barrier) {
+		conf->nr_waiting++;
+		wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
+				    conf->resync_lock,
+				    raid10_unplug(conf->mddev->queue));
+		conf->nr_waiting--;
 	}
-	wait_event_lock_irq(conf->wait_resume, conf->barrier < RESYNC_DEPTH,
-			    conf->resync_lock, unplug_slaves(conf->mddev));
-	conf->next_resync = sect;
+	conf->nr_pending++;
+	spin_unlock_irq(&conf->resync_lock);
+}
+
+static void allow_barrier(conf_t *conf)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&conf->resync_lock, flags);
+	conf->nr_pending--;
+	spin_unlock_irqrestore(&conf->resync_lock, flags);
+	wake_up(&conf->wait_barrier);
+}
+
+static void freeze_array(conf_t *conf)
+{
+	/* stop syncio and normal IO and wait for everything to
+	 * go quiet.
+	 * We increment barrier and nr_waiting, and then
+	 * wait until barrier+nr_pending match nr_queued+2
+	 */
+	spin_lock_irq(&conf->resync_lock);
+	conf->barrier++;
+	conf->nr_waiting++;
+	wait_event_lock_irq(conf->wait_barrier,
+			    conf->barrier+conf->nr_pending == conf->nr_queued+2,
+			    conf->resync_lock,
+			    raid10_unplug(conf->mddev->queue));
+	spin_unlock_irq(&conf->resync_lock);
+}
+
+static void unfreeze_array(conf_t *conf)
+{
+	/* reverse the effect of the freeze */
+	spin_lock_irq(&conf->resync_lock);
+	conf->barrier--;
+	conf->nr_waiting--;
+	wake_up(&conf->wait_barrier);
 	spin_unlock_irq(&conf->resync_lock);
 }
 
@@ -667,6 +747,14 @@ static int make_request(request_queue_t *q, struct bio * bio)
 	struct bio *read_bio;
 	int i;
 	int chunk_sects = conf->chunk_mask + 1;
+	const int rw = bio_data_dir(bio);
+	struct bio_list bl;
+	unsigned long flags;
+
+	if (unlikely(bio_barrier(bio))) {
+		bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
+		return 0;
+	}
 
 	/* If this request crosses a chunk boundary, we need to
 	 * split it.  This will only happen for 1 PAGE (or less) requests.
@@ -700,23 +788,17 @@ static int make_request(request_queue_t *q, struct bio * bio)
 		return 0;
 	}
 
+	md_write_start(mddev, bio);
+
 	/*
 	 * Register the new request and wait if the reconstruction
 	 * thread has put up a bar for new requests.
 	 * Continue immediately if no resync is active currently.
 	 */
-	spin_lock_irq(&conf->resync_lock);
-	wait_event_lock_irq(conf->wait_resume, !conf->barrier, conf->resync_lock, );
-	conf->nr_pending++;
-	spin_unlock_irq(&conf->resync_lock);
+	wait_barrier(conf);
 
-	if (bio_data_dir(bio)==WRITE) {
-		disk_stat_inc(mddev->gendisk, writes);
-		disk_stat_add(mddev->gendisk, write_sectors, bio_sectors(bio));
-	} else {
-		disk_stat_inc(mddev->gendisk, reads);
-		disk_stat_add(mddev->gendisk, read_sectors, bio_sectors(bio));
-	}
+	disk_stat_inc(mddev->gendisk, ios[rw]);
+	disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
 
 	r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
 
@@ -725,8 +807,9 @@ static int make_request(request_queue_t *q, struct bio * bio)
 
 	r10_bio->mddev = mddev;
 	r10_bio->sector = bio->bi_sector;
+	r10_bio->state = 0;
 
-	if (bio_data_dir(bio) == READ) {
+	if (rw == READ) {
 		/*
 		 * read balancing logic:
 		 */
@@ -764,17 +847,21 @@ static int make_request(request_queue_t *q, struct bio * bio)
 	rcu_read_lock();
 	for (i = 0;  i < conf->copies; i++) {
 		int d = r10_bio->devs[i].devnum;
-		if (conf->mirrors[d].rdev &&
-		    !conf->mirrors[d].rdev->faulty) {
-			atomic_inc(&conf->mirrors[d].rdev->nr_pending);
+		mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev);
+		if (rdev &&
+		    !test_bit(Faulty, &rdev->flags)) {
+			atomic_inc(&rdev->nr_pending);
 			r10_bio->devs[i].bio = bio;
-		} else
+		} else {
 			r10_bio->devs[i].bio = NULL;
+			set_bit(R10BIO_Degraded, &r10_bio->state);
+		}
 	}
 	rcu_read_unlock();
 
-	atomic_set(&r10_bio->remaining, 1);
-	md_write_start(mddev);
+	atomic_set(&r10_bio->remaining, 0);
+
+	bio_list_init(&bl);
 	for (i = 0; i < conf->copies; i++) {
 		struct bio *mbio;
 		int d = r10_bio->devs[i].devnum;
@@ -792,13 +879,14 @@ static int make_request(request_queue_t *q, struct bio * bio)
 		mbio->bi_private = r10_bio;
 
 		atomic_inc(&r10_bio->remaining);
-		generic_make_request(mbio);
+		bio_list_add(&bl, mbio);
 	}
 
-	if (atomic_dec_and_test(&r10_bio->remaining)) {
-		md_write_end(mddev);
-		raid_end_bio_io(r10_bio);
-	}
+	bitmap_startwrite(mddev->bitmap, bio->bi_sector, r10_bio->sectors, 0);
+	spin_lock_irqsave(&conf->device_lock, flags);
+	bio_list_merge(&conf->pending_bio_list, &bl);
+	blk_plug_device(mddev->queue);
+	spin_unlock_irqrestore(&conf->device_lock, flags);
 
 	return 0;
 }
@@ -820,7 +908,7 @@ static void status(struct seq_file *seq, mddev_t *mddev)
 	for (i = 0; i < conf->raid_disks; i++)
 		seq_printf(seq, "%s",
 			      conf->mirrors[i].rdev &&
-			      conf->mirrors[i].rdev->in_sync ? "U" : "_");
+			      test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
 	seq_printf(seq, "]");
 }
 
@@ -835,7 +923,7 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev)
 	 * next level up know.
 	 * else mark the drive as failed
 	 */
-	if (rdev->in_sync
+	if (test_bit(In_sync, &rdev->flags)
 	    && conf->working_disks == 1)
 		/*
 		 * Don't fail the drive, just return an IO error.
@@ -845,7 +933,7 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev)
 		 * really dead" tests...
 		 */
 		return;
-	if (rdev->in_sync) {
+	if (test_bit(In_sync, &rdev->flags)) {
 		mddev->degraded++;
 		conf->working_disks--;
 		/*
@@ -853,8 +941,8 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev)
 		 */
 		set_bit(MD_RECOVERY_ERR, &mddev->recovery);
 	}
-	rdev->in_sync = 0;
-	rdev->faulty = 1;
+	clear_bit(In_sync, &rdev->flags);
+	set_bit(Faulty, &rdev->flags);
 	mddev->sb_dirty = 1;
 	printk(KERN_ALERT "raid10: Disk failure on %s, disabling device. \n"
 		"	Operation continuing on %d devices\n",
@@ -879,25 +967,42 @@ static void print_conf(conf_t *conf)
 		tmp = conf->mirrors + i;
 		if (tmp->rdev)
 			printk(" disk %d, wo:%d, o:%d, dev:%s\n",
-				i, !tmp->rdev->in_sync, !tmp->rdev->faulty,
+				i, !test_bit(In_sync, &tmp->rdev->flags),
+			        !test_bit(Faulty, &tmp->rdev->flags),
 				bdevname(tmp->rdev->bdev,b));
 	}
 }
 
 static void close_sync(conf_t *conf)
 {
-	spin_lock_irq(&conf->resync_lock);
-	wait_event_lock_irq(conf->wait_resume, !conf->barrier,
-			    conf->resync_lock, 	unplug_slaves(conf->mddev));
-	spin_unlock_irq(&conf->resync_lock);
-
-	if (conf->barrier) BUG();
-	if (waitqueue_active(&conf->wait_idle)) BUG();
+	wait_barrier(conf);
+	allow_barrier(conf);
 
 	mempool_destroy(conf->r10buf_pool);
 	conf->r10buf_pool = NULL;
 }
 
+/* check if there are enough drives for
+ * every block to appear on atleast one
+ */
+static int enough(conf_t *conf)
+{
+	int first = 0;
+
+	do {
+		int n = conf->copies;
+		int cnt = 0;
+		while (n--) {
+			if (conf->mirrors[first].rdev)
+				cnt++;
+			first = (first+1) % conf->raid_disks;
+		}
+		if (cnt == 0)
+			return 0;
+	} while (first != 0);
+	return 1;
+}
+
 static int raid10_spare_active(mddev_t *mddev)
 {
 	int i;
@@ -911,11 +1016,11 @@ static int raid10_spare_active(mddev_t *mddev)
 	for (i = 0; i < conf->raid_disks; i++) {
 		tmp = conf->mirrors + i;
 		if (tmp->rdev
-		    && !tmp->rdev->faulty
-		    && !tmp->rdev->in_sync) {
+		    && !test_bit(Faulty, &tmp->rdev->flags)
+		    && !test_bit(In_sync, &tmp->rdev->flags)) {
 			conf->working_disks++;
 			mddev->degraded--;
-			tmp->rdev->in_sync = 1;
+			set_bit(In_sync, &tmp->rdev->flags);
 		}
 	}
 
@@ -936,8 +1041,15 @@ static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 		 * very different from resync
 		 */
 		return 0;
+	if (!enough(conf))
+		return 0;
 
-	for (mirror=0; mirror < mddev->raid_disks; mirror++)
+	if (rdev->saved_raid_disk >= 0 &&
+	    conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
+		mirror = rdev->saved_raid_disk;
+	else
+		mirror = 0;
+	for ( ; mirror < mddev->raid_disks; mirror++)
 		if ( !(p=conf->mirrors+mirror)->rdev) {
 
 			blk_queue_stack_limits(mddev->queue,
@@ -953,7 +1065,9 @@ static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 			p->head_position = 0;
 			rdev->raid_disk = mirror;
 			found = 1;
-			p->rdev = rdev;
+			if (rdev->saved_raid_disk != mirror)
+				conf->fullsync = 1;
+			rcu_assign_pointer(p->rdev, rdev);
 			break;
 		}
 
@@ -971,7 +1085,7 @@ static int raid10_remove_disk(mddev_t *mddev, int number)
 	print_conf(conf);
 	rdev = p->rdev;
 	if (rdev) {
-		if (rdev->in_sync ||
+		if (test_bit(In_sync, &rdev->flags) ||
 		    atomic_read(&rdev->nr_pending)) {
 			err = -EBUSY;
 			goto abort;
@@ -993,7 +1107,6 @@ abort:
 
 static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
 {
-	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 	r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private);
 	conf_t *conf = mddev_to_conf(r10_bio->mddev);
 	int i,d;
@@ -1004,13 +1117,19 @@ static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
 	for (i=0; i<conf->copies; i++)
 		if (r10_bio->devs[i].bio == bio)
 			break;
-	if (i == conf->copies)
-		BUG();
+	BUG_ON(i == conf->copies);
 	update_head_pos(i, r10_bio);
 	d = r10_bio->devs[i].devnum;
-	if (!uptodate)
-		md_error(r10_bio->mddev,
-			 conf->mirrors[d].rdev);
+
+	if (test_bit(BIO_UPTODATE, &bio->bi_flags))
+		set_bit(R10BIO_Uptodate, &r10_bio->state);
+	else {
+		atomic_add(r10_bio->sectors,
+			   &conf->mirrors[d].rdev->corrected_errors);
+		if (!test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
+			md_error(r10_bio->mddev,
+				 conf->mirrors[d].rdev);
+	}
 
 	/* for reconstruct, we always reschedule after a read.
 	 * for resync, only after all reads
@@ -1098,23 +1217,32 @@ static void sync_request_write(mddev_t *mddev, r10bio_t *r10_bio)
 	fbio = r10_bio->devs[i].bio;
 
 	/* now find blocks with errors */
-	for (i=first+1 ; i < conf->copies ; i++) {
-		int vcnt, j, d;
+	for (i=0 ; i < conf->copies ; i++) {
+		int  j, d;
+		int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
 
-		if (!test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags))
-			continue;
-		/* We know that the bi_io_vec layout is the same for
-		 * both 'first' and 'i', so we just compare them.
-		 * All vec entries are PAGE_SIZE;
-		 */
 		tbio = r10_bio->devs[i].bio;
-		vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
-		for (j = 0; j < vcnt; j++)
-			if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
-				   page_address(tbio->bi_io_vec[j].bv_page),
-				   PAGE_SIZE))
-				break;
-		if (j == vcnt)
+
+		if (tbio->bi_end_io != end_sync_read)
+			continue;
+		if (i == first)
+			continue;
+		if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) {
+			/* We know that the bi_io_vec layout is the same for
+			 * both 'first' and 'i', so we just compare them.
+			 * All vec entries are PAGE_SIZE;
+			 */
+			for (j = 0; j < vcnt; j++)
+				if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
+					   page_address(tbio->bi_io_vec[j].bv_page),
+					   PAGE_SIZE))
+					break;
+			if (j == vcnt)
+				continue;
+			mddev->resync_mismatches += r10_bio->sectors;
+		}
+		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
+			/* Don't fix anything. */
 			continue;
 		/* Ok, we need to write this bio
 		 * First we need to fixup bv_offset, bv_len and
@@ -1193,7 +1321,10 @@ static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio)
 
 	atomic_inc(&conf->mirrors[d].rdev->nr_pending);
 	md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9);
-	generic_make_request(wbio);
+	if (test_bit(R10BIO_Uptodate, &r10_bio->state))
+		generic_make_request(wbio);
+	else
+		bio_endio(wbio, wbio->bi_size, -EIO);
 }
 
 
@@ -1216,15 +1347,35 @@ static void raid10d(mddev_t *mddev)
 	mdk_rdev_t *rdev;
 
 	md_check_recovery(mddev);
-	md_handle_safemode(mddev);
 
 	for (;;) {
 		char b[BDEVNAME_SIZE];
 		spin_lock_irqsave(&conf->device_lock, flags);
+
+		if (conf->pending_bio_list.head) {
+			bio = bio_list_get(&conf->pending_bio_list);
+			blk_remove_plug(mddev->queue);
+			spin_unlock_irqrestore(&conf->device_lock, flags);
+			/* flush any pending bitmap writes to disk before proceeding w/ I/O */
+			if (bitmap_unplug(mddev->bitmap) != 0)
+				printk("%s: bitmap file write failed!\n", mdname(mddev));
+
+			while (bio) { /* submit pending writes */
+				struct bio *next = bio->bi_next;
+				bio->bi_next = NULL;
+				generic_make_request(bio);
+				bio = next;
+			}
+			unplug = 1;
+
+			continue;
+		}
+
 		if (list_empty(head))
 			break;
 		r10_bio = list_entry(head->prev, r10bio_t, retry_list);
 		list_del(head->prev);
+		conf->nr_queued--;
 		spin_unlock_irqrestore(&conf->device_lock, flags);
 
 		mddev = r10_bio->mddev;
@@ -1237,8 +1388,112 @@ static void raid10d(mddev_t *mddev)
 			unplug = 1;
 		} else {
 			int mirror;
+			/* we got a read error. Maybe the drive is bad.  Maybe just
+			 * the block and we can fix it.
+			 * We freeze all other IO, and try reading the block from
+			 * other devices.  When we find one, we re-write
+			 * and check it that fixes the read error.
+			 * This is all done synchronously while the array is
+			 * frozen.
+			 */
+			int sect = 0; /* Offset from r10_bio->sector */
+			int sectors = r10_bio->sectors;
+			freeze_array(conf);
+			if (mddev->ro == 0) while(sectors) {
+				int s = sectors;
+				int sl = r10_bio->read_slot;
+				int success = 0;
+
+				if (s > (PAGE_SIZE>>9))
+					s = PAGE_SIZE >> 9;
+
+				rcu_read_lock();
+				do {
+					int d = r10_bio->devs[sl].devnum;
+					rdev = rcu_dereference(conf->mirrors[d].rdev);
+					if (rdev &&
+					    test_bit(In_sync, &rdev->flags)) {
+						atomic_inc(&rdev->nr_pending);
+						rcu_read_unlock();
+						success = sync_page_io(rdev->bdev,
+								       r10_bio->devs[sl].addr +
+								       sect + rdev->data_offset,
+								       s<<9,
+								       conf->tmppage, READ);
+						rdev_dec_pending(rdev, mddev);
+						rcu_read_lock();
+						if (success)
+							break;
+					}
+					sl++;
+					if (sl == conf->copies)
+						sl = 0;
+				} while (!success && sl != r10_bio->read_slot);
+				rcu_read_unlock();
+
+				if (success) {
+					int start = sl;
+					/* write it back and re-read */
+					rcu_read_lock();
+					while (sl != r10_bio->read_slot) {
+						int d;
+						if (sl==0)
+							sl = conf->copies;
+						sl--;
+						d = r10_bio->devs[sl].devnum;
+						rdev = rcu_dereference(conf->mirrors[d].rdev);
+						if (rdev &&
+						    test_bit(In_sync, &rdev->flags)) {
+							atomic_inc(&rdev->nr_pending);
+							rcu_read_unlock();
+							atomic_add(s, &rdev->corrected_errors);
+							if (sync_page_io(rdev->bdev,
+									 r10_bio->devs[sl].addr +
+									 sect + rdev->data_offset,
+									 s<<9, conf->tmppage, WRITE) == 0)
+								/* Well, this device is dead */
+								md_error(mddev, rdev);
+							rdev_dec_pending(rdev, mddev);
+							rcu_read_lock();
+						}
+					}
+					sl = start;
+					while (sl != r10_bio->read_slot) {
+						int d;
+						if (sl==0)
+							sl = conf->copies;
+						sl--;
+						d = r10_bio->devs[sl].devnum;
+						rdev = rcu_dereference(conf->mirrors[d].rdev);
+						if (rdev &&
+						    test_bit(In_sync, &rdev->flags)) {
+							atomic_inc(&rdev->nr_pending);
+							rcu_read_unlock();
+							if (sync_page_io(rdev->bdev,
+									 r10_bio->devs[sl].addr +
+									 sect + rdev->data_offset,
+									 s<<9, conf->tmppage, READ) == 0)
+								/* Well, this device is dead */
+								md_error(mddev, rdev);
+							rdev_dec_pending(rdev, mddev);
+							rcu_read_lock();
+						}
+					}
+					rcu_read_unlock();
+				} else {
+					/* Cannot read from anywhere -- bye bye array */
+					md_error(mddev, conf->mirrors[r10_bio->devs[r10_bio->read_slot].devnum].rdev);
+					break;
+				}
+				sectors -= s;
+				sect += s;
+			}
+
+			unfreeze_array(conf);
+
 			bio = r10_bio->devs[r10_bio->read_slot].bio;
-			r10_bio->devs[r10_bio->read_slot].bio = NULL;
+			r10_bio->devs[r10_bio->read_slot].bio =
+				mddev->ro ? IO_BLOCKED : NULL;
 			bio_put(bio);
 			mirror = read_balance(conf, r10_bio);
 			if (mirror == -1) {
@@ -1278,8 +1533,7 @@ static int init_resync(conf_t *conf)
 	int buffs;
 
 	buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
-	if (conf->r10buf_pool)
-		BUG();
+	BUG_ON(conf->r10buf_pool);
 	conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
 	if (!conf->r10buf_pool)
 		return -ENOMEM;
@@ -1319,7 +1573,7 @@ static int init_resync(conf_t *conf)
  *
  */
 
-static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
+static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
 {
 	conf_t *conf = mddev_to_conf(mddev);
 	r10bio_t *r10_bio;
@@ -1327,29 +1581,54 @@ static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
 	sector_t max_sector, nr_sectors;
 	int disk;
 	int i;
+	int max_sync;
+	int sync_blocks;
 
 	sector_t sectors_skipped = 0;
 	int chunks_skipped = 0;
 
 	if (!conf->r10buf_pool)
 		if (init_resync(conf))
-			return -ENOMEM;
+			return 0;
 
  skipped:
 	max_sector = mddev->size << 1;
 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
 		max_sector = mddev->resync_max_sectors;
 	if (sector_nr >= max_sector) {
+		/* If we aborted, we need to abort the
+		 * sync on the 'current' bitmap chucks (there can
+		 * be several when recovering multiple devices).
+		 * as we may have started syncing it but not finished.
+		 * We can find the current address in
+		 * mddev->curr_resync, but for recovery,
+		 * we need to convert that to several
+		 * virtual addresses.
+		 */
+		if (mddev->curr_resync < max_sector) { /* aborted */
+			if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
+				bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
+						&sync_blocks, 1);
+			else for (i=0; i<conf->raid_disks; i++) {
+				sector_t sect =
+					raid10_find_virt(conf, mddev->curr_resync, i);
+				bitmap_end_sync(mddev->bitmap, sect,
+						&sync_blocks, 1);
+			}
+		} else /* completed sync */
+			conf->fullsync = 0;
+
+		bitmap_close_sync(mddev->bitmap);
 		close_sync(conf);
+		*skipped = 1;
 		return sectors_skipped;
 	}
 	if (chunks_skipped >= conf->raid_disks) {
 		/* if there has been nothing to do on any drive,
 		 * then there is nothing to do at all..
 		 */
-		sector_t sec = max_sector - sector_nr;
-		md_done_sync(mddev, sec, 1);
-		return sec + sectors_skipped;
+		*skipped = 1;
+		return (max_sector - sector_nr) + sectors_skipped;
 	}
 
 	/* make sure whole request will fit in a chunk - if chunks
@@ -1362,9 +1641,8 @@ static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
 	 * If there is non-resync activity waiting for us then
 	 * put in a delay to throttle resync.
 	 */
-	if (!go_faster && waitqueue_active(&conf->wait_resume))
+	if (!go_faster && conf->nr_waiting)
 		msleep_interruptible(1000);
-	device_barrier(conf, sector_nr + RESYNC_SECTORS);
 
 	/* Again, very different code for resync and recovery.
 	 * Both must result in an r10bio with a list of bios that
@@ -1381,6 +1659,7 @@ static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
 	 * end_sync_write if we will want to write.
 	 */
 
+	max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
 	if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
 		/* recovery... the complicated one */
 		int i, j, k;
@@ -1388,15 +1667,30 @@ static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
 
 		for (i=0 ; i<conf->raid_disks; i++)
 			if (conf->mirrors[i].rdev &&
-			    !conf->mirrors[i].rdev->in_sync) {
+			    !test_bit(In_sync, &conf->mirrors[i].rdev->flags)) {
+				int still_degraded = 0;
 				/* want to reconstruct this device */
 				r10bio_t *rb2 = r10_bio;
+				sector_t sect = raid10_find_virt(conf, sector_nr, i);
+				int must_sync;
+				/* Unless we are doing a full sync, we only need
+				 * to recover the block if it is set in the bitmap
+				 */
+				must_sync = bitmap_start_sync(mddev->bitmap, sect,
+							      &sync_blocks, 1);
+				if (sync_blocks < max_sync)
+					max_sync = sync_blocks;
+				if (!must_sync &&
+				    !conf->fullsync) {
+					/* yep, skip the sync_blocks here, but don't assume
+					 * that there will never be anything to do here
+					 */
+					chunks_skipped = -1;
+					continue;
+				}
 
 				r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
-				spin_lock_irq(&conf->resync_lock);
-				conf->nr_pending++;
-				if (rb2) conf->barrier++;
-				spin_unlock_irq(&conf->resync_lock);
+				raise_barrier(conf, rb2 != NULL);
 				atomic_set(&r10_bio->remaining, 0);
 
 				r10_bio->master_bio = (struct bio*)rb2;
@@ -1404,12 +1698,27 @@ static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
 					atomic_inc(&rb2->remaining);
 				r10_bio->mddev = mddev;
 				set_bit(R10BIO_IsRecover, &r10_bio->state);
-				r10_bio->sector = raid10_find_virt(conf, sector_nr, i);
+				r10_bio->sector = sect;
+
 				raid10_find_phys(conf, r10_bio);
+				/* Need to check if this section will still be
+				 * degraded
+				 */
+				for (j=0; j<conf->copies;j++) {
+					int d = r10_bio->devs[j].devnum;
+					if (conf->mirrors[d].rdev == NULL ||
+					    test_bit(Faulty, &conf->mirrors[d].rdev->flags)) {
+						still_degraded = 1;
+						break;
+					}
+				}
+				must_sync = bitmap_start_sync(mddev->bitmap, sect,
+							      &sync_blocks, still_degraded);
+
 				for (j=0; j<conf->copies;j++) {
 					int d = r10_bio->devs[j].devnum;
 					if (conf->mirrors[d].rdev &&
-					    conf->mirrors[d].rdev->in_sync) {
+					    test_bit(In_sync, &conf->mirrors[d].rdev->flags)) {
 						/* This is where we read from */
 						bio = r10_bio->devs[0].bio;
 						bio->bi_next = biolist;
@@ -1444,7 +1753,13 @@ static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
 					}
 				}
 				if (j == conf->copies) {
-					BUG();
+					/* Cannot recover, so abort the recovery */
+					put_buf(r10_bio);
+					r10_bio = rb2;
+					if (!test_and_set_bit(MD_RECOVERY_ERR, &mddev->recovery))
+						printk(KERN_INFO "raid10: %s: insufficient working devices for recovery.\n",
+						       mdname(mddev));
+					break;
 				}
 			}
 		if (biolist == NULL) {
@@ -1459,14 +1774,22 @@ static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
 	} else {
 		/* resync. Schedule a read for every block at this virt offset */
 		int count = 0;
-		r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
 
-		spin_lock_irq(&conf->resync_lock);
-		conf->nr_pending++;
-		spin_unlock_irq(&conf->resync_lock);
+		if (!bitmap_start_sync(mddev->bitmap, sector_nr,
+				       &sync_blocks, mddev->degraded) &&
+		    !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
+			/* We can skip this block */
+			*skipped = 1;
+			return sync_blocks + sectors_skipped;
+		}
+		if (sync_blocks < max_sync)
+			max_sync = sync_blocks;
+		r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
 
 		r10_bio->mddev = mddev;
 		atomic_set(&r10_bio->remaining, 0);
+		raise_barrier(conf, 0);
+		conf->next_resync = sector_nr;
 
 		r10_bio->master_bio = NULL;
 		r10_bio->sector = sector_nr;
@@ -1479,7 +1802,7 @@ static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
 			bio = r10_bio->devs[i].bio;
 			bio->bi_end_io = NULL;
 			if (conf->mirrors[d].rdev == NULL ||
-			    conf->mirrors[d].rdev->faulty)
+			    test_bit(Faulty, &conf->mirrors[d].rdev->flags))
 				continue;
 			atomic_inc(&conf->mirrors[d].rdev->nr_pending);
 			atomic_inc(&r10_bio->remaining);
@@ -1519,6 +1842,8 @@ static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
 	}
 
 	nr_sectors = 0;
+	if (sector_nr + max_sync < max_sector)
+		max_sector = sector_nr + max_sync;
 	do {
 		struct page *page;
 		int len = PAGE_SIZE;
@@ -1563,17 +1888,22 @@ static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
 		}
 	}
 
+	if (sectors_skipped)
+		/* pretend they weren't skipped, it makes
+		 * no important difference in this case
+		 */
+		md_done_sync(mddev, sectors_skipped, 1);
+
 	return sectors_skipped + nr_sectors;
  giveup:
 	/* There is nowhere to write, so all non-sync
 	 * drives must be failed, so try the next chunk...
 	 */
 	{
-	int sec = max_sector - sector_nr;
+	sector_t sec = max_sector - sector_nr;
 	sectors_skipped += sec;
 	chunks_skipped ++;
 	sector_nr = max_sector;
-	md_done_sync(mddev, sec, 1);
 	goto skipped;
 	}
 }
@@ -1588,11 +1918,11 @@ static int run(mddev_t *mddev)
 	int nc, fc;
 	sector_t stride, size;
 
-	if (mddev->level != 10) {
-		printk(KERN_ERR "raid10: %s: raid level not set correctly... (%d)\n",
-		       mdname(mddev), mddev->level);
-		goto out;
+	if (mddev->chunk_size == 0) {
+		printk(KERN_ERR "md/raid10: non-zero chunk size required.\n");
+		return -EINVAL;
 	}
+
 	nc = mddev->layout & 255;
 	fc = (mddev->layout >> 8) & 255;
 	if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
@@ -1606,22 +1936,24 @@ static int run(mddev_t *mddev)
 	 * bookkeeping area. [whatever we allocate in run(),
 	 * should be freed in stop()]
 	 */
-	conf = kmalloc(sizeof(conf_t), GFP_KERNEL);
+	conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
 	mddev->private = conf;
 	if (!conf) {
 		printk(KERN_ERR "raid10: couldn't allocate memory for %s\n",
 			mdname(mddev));
 		goto out;
 	}
-	memset(conf, 0, sizeof(*conf));
-	conf->mirrors = kmalloc(sizeof(struct mirror_info)*mddev->raid_disks,
+	conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
 				 GFP_KERNEL);
 	if (!conf->mirrors) {
 		printk(KERN_ERR "raid10: couldn't allocate memory for %s\n",
 		       mdname(mddev));
 		goto out_free_conf;
 	}
-	memset(conf->mirrors, 0, sizeof(struct mirror_info)*mddev->raid_disks);
+
+	conf->tmppage = alloc_page(GFP_KERNEL);
+	if (!conf->tmppage)
+		goto out_free_conf;
 
 	conf->near_copies = nc;
 	conf->far_copies = fc;
@@ -1660,7 +1992,7 @@ static int run(mddev_t *mddev)
 			mddev->queue->max_sectors = (PAGE_SIZE>>9);
 
 		disk->head_position = 0;
-		if (!rdev->faulty && rdev->in_sync)
+		if (!test_bit(Faulty, &rdev->flags) && test_bit(In_sync, &rdev->flags))
 			conf->working_disks++;
 	}
 	conf->raid_disks = mddev->raid_disks;
@@ -1669,12 +2001,12 @@ static int run(mddev_t *mddev)
 	INIT_LIST_HEAD(&conf->retry_list);
 
 	spin_lock_init(&conf->resync_lock);
-	init_waitqueue_head(&conf->wait_idle);
-	init_waitqueue_head(&conf->wait_resume);
+	init_waitqueue_head(&conf->wait_barrier);
 
-	if (!conf->working_disks) {
-		printk(KERN_ERR "raid10: no operational mirrors for %s\n",
-			mdname(mddev));
+	/* need to check that every block has at least one working mirror */
+	if (!enough(conf)) {
+		printk(KERN_ERR "raid10: not enough operational mirrors for %s\n",
+		       mdname(mddev));
 		goto out_free_conf;
 	}
 
@@ -1718,7 +2050,7 @@ static int run(mddev_t *mddev)
 	 * maybe...
 	 */
 	{
-		int stripe = conf->raid_disks * mddev->chunk_size / PAGE_CACHE_SIZE;
+		int stripe = conf->raid_disks * mddev->chunk_size / PAGE_SIZE;
 		stripe /= conf->near_copies;
 		if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
 			mddev->queue->backing_dev_info.ra_pages = 2* stripe;
@@ -1731,8 +2063,8 @@ static int run(mddev_t *mddev)
 out_free_conf:
 	if (conf->r10bio_pool)
 		mempool_destroy(conf->r10bio_pool);
-	if (conf->mirrors)
-		kfree(conf->mirrors);
+	safe_put_page(conf->tmppage);
+	kfree(conf->mirrors);
 	kfree(conf);
 	mddev->private = NULL;
 out:
@@ -1748,17 +2080,37 @@ static int stop(mddev_t *mddev)
 	blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
 	if (conf->r10bio_pool)
 		mempool_destroy(conf->r10bio_pool);
-	if (conf->mirrors)
-		kfree(conf->mirrors);
+	kfree(conf->mirrors);
 	kfree(conf);
 	mddev->private = NULL;
 	return 0;
 }
 
+static void raid10_quiesce(mddev_t *mddev, int state)
+{
+	conf_t *conf = mddev_to_conf(mddev);
+
+	switch(state) {
+	case 1:
+		raise_barrier(conf, 0);
+		break;
+	case 0:
+		lower_barrier(conf);
+		break;
+	}
+	if (mddev->thread) {
+		if (mddev->bitmap)
+			mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ;
+		else
+			mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
+		md_wakeup_thread(mddev->thread);
+	}
+}
 
-static mdk_personality_t raid10_personality =
+static struct mdk_personality raid10_personality =
 {
 	.name		= "raid10",
+	.level		= 10,
 	.owner		= THIS_MODULE,
 	.make_request	= make_request,
 	.run		= run,
@@ -1769,19 +2121,22 @@ static mdk_personality_t raid10_personality =
 	.hot_remove_disk= raid10_remove_disk,
 	.spare_active	= raid10_spare_active,
 	.sync_request	= sync_request,
+	.quiesce	= raid10_quiesce,
 };
 
 static int __init raid_init(void)
 {
-	return register_md_personality(RAID10, &raid10_personality);
+	return register_md_personality(&raid10_personality);
 }
 
 static void raid_exit(void)
 {
-	unregister_md_personality(RAID10);
+	unregister_md_personality(&raid10_personality);
 }
 
 module_init(raid_init);
 module_exit(raid_exit);
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("md-personality-9"); /* RAID10 */
+MODULE_ALIAS("md-raid10");
+MODULE_ALIAS("md-level-10");