From f2a371c5e74dd5685ab47effa4ac7b23b1fdaae5 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Mon, 9 Jan 2012 00:46:41 +1100
Subject: md: notify the 'degraded' sysfs attribute on failure.

We currently only 'notify' changes to the 'degraded' attribute
when it decreases, not when it increases.

Notifying on failure is a little awkward as it happen in
interrupt context.
So instead, notify when we remove the failed device from the array,
which is very soon afterwards.

Reported-and-tested-by: Mikhail Balabin <mbalabin@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 1c1c562..33aa06f 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7383,6 +7383,7 @@ static int remove_and_add_spares(struct mddev *mddev)
 {
 	struct md_rdev *rdev;
 	int spares = 0;
+	int removed = 0;
 
 	mddev->curr_resync_completed = 0;
 
@@ -7396,8 +7397,13 @@ static int remove_and_add_spares(struct mddev *mddev)
 				    mddev, rdev) == 0) {
 				sysfs_unlink_rdev(mddev, rdev);
 				rdev->raid_disk = -1;
+				removed++;
 			}
 		}
+	if (removed)
+		sysfs_notify(&mddev->kobj, NULL,
+			     "degraded");
+
 
 	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		if (rdev->raid_disk >= 0 &&
-- 
cgit v0.10.2


From 307729c8bc5b5a41361af8af95906eee7552acb1 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Mon, 9 Jan 2012 01:41:51 +1100
Subject: md/raid1: perform bad-block tests for WriteMostly devices too.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

We normally try to avoid reading from write-mostly devices, but when
we do we really have to check for bad blocks and be sure not to
try reading them.

With the current code, best_good_sectors might not get set and that
causes zero-length read requests to be send down which is very
confusing.

This bug was introduced in commit d2eb35acfdccbe2 and so the patch
is suitable for 3.1.x and 3.2.x

Reported-and-tested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reported-and-tested-by: Art -kwaak- van Breemen <ard@telegraafnet.nl>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel.org

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index cc24f0c..a368db2 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -531,8 +531,17 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
 		if (test_bit(WriteMostly, &rdev->flags)) {
 			/* Don't balance among write-mostly, just
 			 * use the first as a last resort */
-			if (best_disk < 0)
+			if (best_disk < 0) {
+				if (is_badblock(rdev, this_sector, sectors,
+						&first_bad, &bad_sectors)) {
+					if (first_bad < this_sector)
+						/* Cannot use this */
+						continue;
+					best_good_sectors = first_bad - this_sector;
+				} else
+					best_good_sectors = sectors;
 				best_disk = disk;
+			}
 			continue;
 		}
 		/* This is a reasonable device to use.  It might
-- 
cgit v0.10.2