md: remove_and_add_spares() to activate specific rdev

remove_and_add_spares() checks for all devices to activate spare.
Change it to activate a specific device if a non-null rdev
argument is passed.

remove_and_add_spares() can be used to activate spares in
slot_store() as well.

For hot_remove_disk(), check if rdev->raid_disk == -1 before
calling remove_and_add_spares()

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 9798a99..e21a2fe 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2691,15 +2691,9 @@ slot_store(struct md_rdev *rdev, const char *buf, size_t len)
                        rdev->saved_raid_disk = -1;
                clear_bit(In_sync, &rdev->flags);
                clear_bit(Bitmap_sync, &rdev->flags);
-               err = rdev->mddev->pers->
-                       hot_add_disk(rdev->mddev, rdev);
-               if (err) {
-                       rdev->raid_disk = -1;
-                       return err;
-               } else
-                       sysfs_notify_dirent_safe(rdev->sysfs_state);
-               if (sysfs_link_rdev(rdev->mddev, rdev))
-                       /* failure here is OK */;
+               remove_and_add_spares(rdev->mddev, rdev);
+               if (rdev->raid_disk == -1)
+                       return -EBUSY;
                /* don't wakeup anyone, leave that to userspace. */
        } else {
                if (slot >= rdev->mddev->raid_disks &&
@@ -6004,12 +5998,16 @@ static int hot_remove_disk(struct mddev *mddev, dev_t dev)
        if (mddev_is_clustered(mddev))
                md_cluster_ops->metadata_update_start(mddev);
 
+       if (rdev->raid_disk < 0)
+               goto kick_rdev;
+
        clear_bit(Blocked, &rdev->flags);
        remove_and_add_spares(mddev, rdev);
 
        if (rdev->raid_disk >= 0)
                goto busy;
 
+kick_rdev:
        if (mddev_is_clustered(mddev))
                md_cluster_ops->remove_disk(mddev, rdev);
 
@@ -6024,6 +6022,7 @@ static int hot_remove_disk(struct mddev *mddev, dev_t dev)
 busy:
        if (mddev_is_clustered(mddev))
                md_cluster_ops->metadata_update_cancel(mddev);
+
        printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
                bdevname(rdev->bdev,b), mdname(mddev));
        return -EBUSY;
@@ -8018,10 +8017,12 @@ static int remove_and_add_spares(struct mddev *mddev,
        if (removed && mddev->kobj.sd)
                sysfs_notify(&mddev->kobj, NULL, "degraded");
 
-       if (this)
+       if (this && removed)
                goto no_add;
 
        rdev_for_each(rdev, mddev) {
+               if (this && this != rdev)
+                       continue;
                if (rdev->raid_disk >= 0 &&
                    !test_bit(In_sync, &rdev->flags) &&
                    !test_bit(Faulty, &rdev->flags))