md: remove test for duplicate device when setting slot number.

When setting the slot number on a device in an active array we
currently check that the number is not already in use.
We then call into the personality's hot_add_disk function
which performs the same test and returns the same error.

Thus the common test is not needed.

As we will shortly be changing some personalities to allow duplicates
in some cases (to support hot-replace), the common test will become
inconvenient.

So remove the common test.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 004d8e5b2a57e84e8db86cb77f2bb173f626dab2..d51c688d9c94f73be5305eb512fbaf026e24de8c 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2697,7 +2697,6 @@ slot_store(struct md_rdev *rdev, const char *buf, size_t len)
                set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
                md_wakeup_thread(rdev->mddev->thread);
        } else if (rdev->mddev->pers) {
-               struct md_rdev *rdev2;
                /* Activating a spare .. or possibly reactivating
                 * if we ever get bitmaps working here.
                 */
@@ -2711,10 +2710,6 @@ slot_store(struct md_rdev *rdev, const char *buf, size_t len)
                if (rdev->mddev->pers->hot_add_disk == NULL)
                        return -EINVAL;
 
-               list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
-                       if (rdev2->raid_disk == slot)
-                               return -EEXIST;
-
                if (slot >= rdev->mddev->raid_disks &&
                    slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
                        return -ENOSPC;