md/raid10: resize bitmap when required during reshape.

If a reshape changes the size of the array, then we can now
update the bitmap to suit - so do so.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 8fe3aa469987ce98d932e6c2469b0778ace9c4a2..ae2a5a4c6bc587ec483268c47aa5fefda2c2aa81 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3786,8 +3786,6 @@ static int raid10_check_reshape(struct mddev *mddev)
                        /* not factor of array size */
                        return -EINVAL;
 
-       if (mddev->bitmap)
-               return -EBUSY;
        if (!enough(conf, -1))
                return -EINVAL;
 
@@ -3882,6 +3880,7 @@ static int raid10_start_reshape(struct mddev *mddev)
        struct r10conf *conf = mddev->private;
        struct md_rdev *rdev;
        int spares = 0;
+       int ret;
 
        if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
                return -EBUSY;
@@ -3943,6 +3942,14 @@ static int raid10_start_reshape(struct mddev *mddev)
                conf->reshape_progress = 0;
        spin_unlock_irq(&conf->device_lock);
 
+       if (mddev->delta_disks && mddev->bitmap) {
+               ret = bitmap_resize(mddev->bitmap,
+                                   raid10_size(mddev, 0,
+                                               conf->geo.raid_disks),
+                                   0, 0);
+               if (ret)
+                       goto abort;
+       }
        if (mddev->delta_disks > 0) {
                rdev_for_each(rdev, mddev)
                        if (rdev->raid_disk < 0 &&
@@ -3982,22 +3989,26 @@ static int raid10_start_reshape(struct mddev *mddev)
        mddev->sync_thread = md_register_thread(md_do_sync, mddev,
                                                "reshape");
        if (!mddev->sync_thread) {
-               mddev->recovery = 0;
-               spin_lock_irq(&conf->device_lock);
-               conf->geo = conf->prev;
-               mddev->raid_disks = conf->geo.raid_disks;
-               rdev_for_each(rdev, mddev)
-                       rdev->new_data_offset = rdev->data_offset;
-               smp_wmb();
-               conf->reshape_progress = MaxSector;
-               mddev->reshape_position = MaxSector;
-               spin_unlock_irq(&conf->device_lock);
-               return -EAGAIN;
+               ret = -EAGAIN;
+               goto abort;
        }
        conf->reshape_checkpoint = jiffies;
        md_wakeup_thread(mddev->sync_thread);
        md_new_event(mddev);
        return 0;
+
+abort:
+       mddev->recovery = 0;
+       spin_lock_irq(&conf->device_lock);
+       conf->geo = conf->prev;
+       mddev->raid_disks = conf->geo.raid_disks;
+       rdev_for_each(rdev, mddev)
+               rdev->new_data_offset = rdev->data_offset;
+       smp_wmb();
+       conf->reshape_progress = MaxSector;
+       mddev->reshape_position = MaxSector;
+       spin_unlock_irq(&conf->device_lock);
+       return ret;
 }
 
 /* Calculate the last device-address that could contain