md: avoid endless recovery loop when waiting for fail device to complete.

If a device fails in a way that causes pending request to take a while
to complete, md will not be able to immediately remove it from the
array in remove_and_add_spares.
It will then incorrectly look like a spare device and md will try to
recover it even though it is failed.
This leads to a recovery process starting and instantly aborting over
and over again.

We should check if the device is faulty before considering it to be a
spare.  This will avoid trying to start a recovery that cannot
proceed.

This bug was introduced in 2.6.26 so that patch is suitable for any
kernel since then.

Cc: stable@kernel.org
Reported-by: Jim Paradis <james.paradis@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 4332fc2f25d4a2260b575f66229514bad10a2fa4..91e31e260b4afff9a51589351e08ec9c6f63da95 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7088,6 +7088,7 @@ static int remove_and_add_spares(mddev_t *mddev)
                list_for_each_entry(rdev, &mddev->disks, same_set) {
                        if (rdev->raid_disk >= 0 &&
                            !test_bit(In_sync, &rdev->flags) &&
+                           !test_bit(Faulty, &rdev->flags) &&
                            !test_bit(Blocked, &rdev->flags))
                                spares++;
                        if (rdev->raid_disk < 0