md: don't update curr_resync_completed without also updating reshape_position.

In order for the metadata to always be consistent, we mustn't updated
curr_resync_completed without also updating reshape_position.

The reshape code updates both at the same time.  However since
commit 97e4f42d62badb0f9fbc27c013e89bc1336a03bc
the common md_do_sync will sometimes update curr_resync_completed
but is not in a position to update reshape_position.
So if MD_RECOVERY_RESHAPE is set (indicating that a reshape is
happening, so reshape_position might change), don't update
curr_resync_completed in md_do_sync, leave it to the per-personality
reshape code.

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

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 384e4f0..9544565 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6362,12 +6362,13 @@ void md_do_sync(mddev_t *mddev)
 
                skipped = 0;
 
-               if ((mddev->curr_resync > mddev->curr_resync_completed &&
-                    (mddev->curr_resync - mddev->curr_resync_completed)
-                   > (max_sectors >> 4)) ||
-                   (j - mddev->curr_resync_completed)*2
-                   >= mddev->resync_max - mddev->curr_resync_completed
-                       ) {
+               if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
+                   ((mddev->curr_resync > mddev->curr_resync_completed &&
+                     (mddev->curr_resync - mddev->curr_resync_completed)
+                     > (max_sectors >> 4)) ||
+                    (j - mddev->curr_resync_completed)*2
+                    >= mddev->resync_max - mddev->curr_resync_completed
+                           )) {
                        /* time to update curr_resync_completed */
                        blk_unplug(mddev->queue);
                        wait_event(mddev->recovery_wait,