Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

---
 drivers/md/dm-raid1.c          |   53 ++++++++++++++++++++---------------------
 drivers/md/dm-region-hash.c    |    6 ----
 include/linux/dm-region-hash.h |    3 --
 3 files changed, 29 insertions(+), 33 deletions(-)

Index: linux-2.6.31-rc3-devel/drivers/md/dm-raid1.c
===================================================================
--- linux-2.6.31-rc3-devel.orig/drivers/md/dm-raid1.c	2009-07-20 20:48:45.000000000 +0200
+++ linux-2.6.31-rc3-devel/drivers/md/dm-raid1.c	2009-07-20 20:52:26.000000000 +0200
@@ -532,7 +532,6 @@ static void write_callback(unsigned long
 	unsigned i, ret = 0;
 	struct bio *bio = (struct bio *) context;
 	struct mirror_set *ms;
-	int uptodate = 0;
 	unsigned long flags;
 
 	ms = bio_get_m(bio)->ms;
@@ -544,33 +543,23 @@ static void write_callback(unsigned long
 	 * This way we handle both writes to SYNC and NOSYNC
 	 * regions with the same code.
 	 */
-	if (likely(!error))
-		goto out;
+	if (likely(!error)) {
+		bio_endio(bio, ret);
+		return;
+	}
 
 	for (i = 0; i < ms->nr_mirrors; i++)
 		if (test_bit(i, &error))
 			fail_mirror(ms->mirror + i, DM_RAID1_WRITE_ERROR);
-		else
-			uptodate = 1;
 
-	if (unlikely(!uptodate)) {
-		DMERR("All replicated volumes dead, failing I/O");
-		/* None of the writes succeeded, fail the I/O. */
-		ret = -EIO;
-	} else if (errors_handled(ms)) {
-		/*
-		 * Need to raise event.  Since raising
-		 * events can block, we need to do it in
-		 * the main thread.
-		 */
-		spin_lock_irqsave(&ms->lock, flags);
-		bio_list_add(&ms->failures, bio);
-		spin_unlock_irqrestore(&ms->lock, flags);
-		wakeup_mirrord(ms);
-		return;
-	}
-out:
-	bio_endio(bio, ret);
+	/*
+	 * In either case we must mark the region as NOSYNC.
+	 * That would block, so do it in the thread.
+	 */
+	spin_lock_irqsave(&ms->lock, flags);
+	bio_list_add(&ms->failures, bio);
+	spin_unlock_irqrestore(&ms->lock, flags);
+	wakeup_mirrord(ms);
 }
 
 static void do_write(struct mirror_set *ms, struct bio *bio)
@@ -716,10 +705,22 @@ static void do_failures(struct mirror_se
 	while ((bio = bio_list_pop(failures))) {
 		if (!ms->log_failure) {
 			ms->in_sync = 0;
-			dm_rh_mark_nosync(ms->rh, bio, bio->bi_size, 0);
-		} else {
-			hold_bio(ms, bio);
+			dm_rh_mark_nosync(ms->rh, bio);
 		}
+		/*
+		 * If we are not using dmeventd, we must fail the I/O.
+		 * (the failed leg might come online again after reboot and
+		 * it would be replicated back to the good leg).
+		 *
+		 * If all the legs are dead, fail the I/O too.
+		 *
+		 * If some of the legs survived, hold the bio until dmeventd
+		 * does its job.
+		 */
+		if (!errors_handled(ms) || !get_valid_mirror(ms))
+			bio_endio(bio, -EIO);
+		else
+			hold_bio(ms, bio);
 	}
 }
 
Index: linux-2.6.31-rc3-devel/drivers/md/dm-region-hash.c
===================================================================
--- linux-2.6.31-rc3-devel.orig/drivers/md/dm-region-hash.c	2009-07-20 20:48:45.000000000 +0200
+++ linux-2.6.31-rc3-devel/drivers/md/dm-region-hash.c	2009-07-20 20:48:58.000000000 +0200
@@ -386,8 +386,6 @@ static void complete_resync_work(struct 
 /* dm_rh_mark_nosync
  * @ms
  * @bio
- * @done
- * @error
  *
  * The bio was written on some mirror(s) but failed on other mirror(s).
  * We can successfully endio the bio but should avoid the region being
@@ -395,8 +393,7 @@ static void complete_resync_work(struct 
  *
  * This function is _not_ safe in interrupt context!
  */
-void dm_rh_mark_nosync(struct dm_region_hash *rh,
-		       struct bio *bio, unsigned done, int error)
+void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio)
 {
 	unsigned long flags;
 	struct dm_dirty_log *log = rh->log;
@@ -428,7 +425,6 @@ void dm_rh_mark_nosync(struct dm_region_
 	BUG_ON(!list_empty(&reg->list));
 	spin_unlock_irqrestore(&rh->region_lock, flags);
 
-	bio_endio(bio, error);
 	if (recovering)
 		complete_resync_work(reg, 0);
 }
Index: linux-2.6.31-rc3-devel/include/linux/dm-region-hash.h
===================================================================
--- linux-2.6.31-rc3-devel.orig/include/linux/dm-region-hash.h	2009-07-20 20:48:45.000000000 +0200
+++ linux-2.6.31-rc3-devel/include/linux/dm-region-hash.h	2009-07-20 20:48:58.000000000 +0200
@@ -78,8 +78,7 @@ void dm_rh_dec(struct dm_region_hash *rh
 /* Delay bios on regions. */
 void dm_rh_delay(struct dm_region_hash *rh, struct bio *bio);
 
-void dm_rh_mark_nosync(struct dm_region_hash *rh,
-		       struct bio *bio, unsigned done, int error);
+void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio);
 
 /*
  * Region recovery control.