From 4c97f2d89392d8abc46e57141b49993bb1ea91a9 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Mon, 1 May 2006 12:15:47 -0700
Subject: [PATCH] --- yaml --- r: 26389 b: refs/heads/master c:
 62de608da0b0ab17d81a233b50d1e952b9816f69 h: refs/heads/master i:   26387:
 77d39bae450ea025af2d86ba154fc4d741686b47 v: v3

---
 [refs]                   |  2 +-
 trunk/drivers/md/raid1.c | 16 +++++++++++-----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index 7e725c592ecc..ec8a6ad00894 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: bea2771871ed1084c9a85ed0c86340f188505702
+refs/heads/master: 62de608da0b0ab17d81a233b50d1e952b9816f69
diff --git a/trunk/drivers/md/raid1.c b/trunk/drivers/md/raid1.c
index 532d04077301..b8c13c897ccb 100644
--- a/trunk/drivers/md/raid1.c
+++ b/trunk/drivers/md/raid1.c
@@ -753,18 +753,24 @@ static int make_request(request_queue_t *q, struct bio * bio)
 	const int rw = bio_data_dir(bio);
 	int do_barriers;
 
-	if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
-		bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
-		return 0;
-	}
-
 	/*
 	 * 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.
+	 * We test barriers_work *after* md_write_start as md_write_start
+	 * may cause the first superblock write, and that will check out
+	 * if barriers work.
 	 */
+
 	md_write_start(mddev, bio); /* wait on superblock update early */
 
+	if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
+		if (rw == WRITE)
+			md_write_end(mddev);
+		bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
+		return 0;
+	}
+
 	wait_barrier(conf);
 
 	disk_stat_inc(mddev->gendisk, ios[rw]);