[PATCH] md: allow a linear array to have drives added while active

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index a296edd7e1c3..2ce750d4be02 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -817,8 +817,8 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 
                 if (desc->state & (1<<MD_DISK_FAULTY))
                         set_bit(Faulty, &rdev->flags);
-                else if (desc->state & (1<<MD_DISK_SYNC) &&
-                         desc->raid_disk < mddev->raid_disks) {
+                else if (desc->state & (1<<MD_DISK_SYNC) /* &&
+                            desc->raid_disk < mddev->raid_disks */) {
                         set_bit(In_sync, &rdev->flags);
                         rdev->raid_disk = desc->raid_disk;
                 }
@@ -3359,6 +3359,17 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
 
                 rdev->raid_disk = -1;
                 err = bind_rdev_to_array(rdev, mddev);
+                if (!err && !mddev->pers->hot_remove_disk) {
+                        /* If there is hot_add_disk but no hot_remove_disk
+                         * then added disks for geometry changes,
+                         * and should be added immediately.
+                         */
+                        super_types[mddev->major_version].
+                                validate_super(mddev, rdev);
+                        err = mddev->pers->hot_add_disk(mddev, rdev);
+                        if (err)
+                                unbind_rdev_from_array(rdev);
+                }
                 if (err)
                         export_rdev(rdev);