md: report failure if a 'set faulty' request doesn't.

Sometimes a device will refuse to be set faulty.  e.g. RAID1 will
never let the last working device become faulty.

So check if "md_error()" did manage to set the faulty flag and fail
with EBUSY if it didn't.

Resolves-Debian-Bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=601198
Reported-by: Mike Hommey <mh+reportbug@glandium.org>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8e221a2..1cd9bfb 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2561,7 +2561,10 @@ state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
        int err = -EINVAL;
        if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
                md_error(rdev->mddev, rdev);
-               err = 0;
+               if (test_bit(Faulty, &rdev->flags))
+                       err = 0;
+               else
+                       err = -EBUSY;
        } else if (cmd_match(buf, "remove")) {
                if (rdev->raid_disk >= 0)
                        err = -EBUSY;
@@ -5983,6 +5986,8 @@ static int set_disk_faulty(mddev_t *mddev, dev_t dev)
                return -ENODEV;
 
        md_error(mddev, rdev);
+       if (!test_bit(Faulty, &rdev->flags))
+               return -EBUSY;
        return 0;
 }