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>

1 files changed, 24 insertions, 13 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 8fe3aa469987..ae2a5a4c6bc5 100644
--- 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