Prepare llbitmap before RAID5 reshape starts, checkpoint the bitmap
before advancing reshape_position, and finish the llbitmap geometry
update when reshape completes.

Signed-off-by: Yu Kuai <yukuai@fnnas.com>
---
 drivers/md/raid5.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 178283aa91a4..476f6fc5a97c 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -6378,6 +6378,13 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *sk
 			   || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
 		if (atomic_read(&conf->reshape_stripes) != 0)
 			return 0;
+		if (md_bitmap_enabled(mddev, false) &&
+		    mddev->bitmap_ops->reshape_mark &&
+		    conf->reshape_safe != conf->reshape_progress) {
+			mddev->bitmap_ops->reshape_mark(mddev, conf->reshape_safe,
+						       conf->reshape_progress);
+			mddev->bitmap_ops->unplug(mddev, true);
+		}
 		mddev->reshape_position = conf->reshape_progress;
 		mddev->curr_resync_completed = sector_nr;
 		if (!mddev->reshape_backwards)
@@ -6487,6 +6494,13 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *sk
 			   || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
 		if (atomic_read(&conf->reshape_stripes) != 0)
 			goto ret;
+		if (md_bitmap_enabled(mddev, false) &&
+		    mddev->bitmap_ops->reshape_mark &&
+		    conf->reshape_safe != conf->reshape_progress) {
+			mddev->bitmap_ops->reshape_mark(mddev, conf->reshape_safe,
+						       conf->reshape_progress);
+			mddev->bitmap_ops->unplug(mddev, true);
+		}
 		mddev->reshape_position = conf->reshape_progress;
 		mddev->curr_resync_completed = sector_nr;
 		if (!mddev->reshape_backwards)
@@ -8524,6 +8538,12 @@ static int raid5_start_reshape(struct mddev *mddev)
 			mdname(mddev));
 		return -EINVAL;
 	}
+	if (md_bitmap_enabled(mddev, false) &&
+	    mddev->bitmap_id == ID_LLBITMAP) {
+		i = mddev->bitmap_ops->resize(mddev, mddev->dev_sectors, 0);
+		if (i)
+			return i;
+	}
 
 	atomic_set(&conf->reshape_stripes, 0);
 	spin_lock_irq(&conf->device_lock);
@@ -8608,10 +8628,19 @@ static int raid5_start_reshape(struct mddev *mddev)
  */
 static void end_reshape(struct r5conf *conf)
 {
+	struct mddev *mddev = conf->mddev;
 
 	if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
 		struct md_rdev *rdev;
 
+		if (md_bitmap_enabled(mddev, false) &&
+		    mddev->bitmap_ops->reshape_mark &&
+		    conf->reshape_safe != conf->reshape_progress) {
+			mddev->bitmap_ops->reshape_mark(mddev, conf->reshape_safe,
+						       conf->reshape_progress);
+			mddev->bitmap_ops->unplug(mddev, true);
+		}
+
 		spin_lock_irq(&conf->device_lock);
 		conf->previous_raid_disks = conf->raid_disks;
 		md_finish_reshape(conf->mddev);
@@ -8638,8 +8667,16 @@ static void raid5_finish_reshape(struct mddev *mddev)
 {
 	struct r5conf *conf = mddev->private;
 	struct md_rdev *rdev;
+	bool llbitmap = mddev->bitmap_id == ID_LLBITMAP &&
+		md_bitmap_enabled(mddev, false);
 
 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
+		if (llbitmap && mddev->bitmap_ops->reshape_finish)
+			mddev->bitmap_ops->reshape_finish(mddev);
+		if (llbitmap) {
+			mddev->resync_offset = 0;
+			mddev->resync_max_sectors = mddev->dev_sectors;
+		}
 
 		if (mddev->delta_disks <= 0) {
 			int d;
-- 
2.51.0