[PATCH] md: don't update recovery_cp when curr_resync is ACTIVE

[Hou Tao <houtao@xxxxxxxxxxxxxxx>]

From: Hou Tao <houtao1@xxxxxxxxxx>

Don't update recovery_cp when curr_resync is MD_RESYNC_ACTIVE, otherwise
md may skip the resync of the first 3 sectors if the resync procedure is
interrupted before the first calling of ->sync_request() as shown below:

md_do_sync thread          control thread
  // setup resync
  mddev->recovery_cp = 0
  j = 0
  mddev->curr_resync = MD_RESYNC_ACTIVE

                             // e.g., set array as idle
                             set_bit(MD_RECOVERY_INTR, &&mddev_recovery)
  // resync loop
  // check INTR before calling sync_request
  !test_bit(MD_RECOVERY_INTR, &mddev->recovery

  // resync interrupted
  // update recovery_cp from 0 to 3
  // the resync of three 3 sectors will be skipped
  mddev->recovery_cp = 3

Fixes: eac58d08d493 ("md: Use enum for overloaded magic numbers used by mddev->curr_resync")
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
 drivers/md/md.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 775f1dde190a..16de0ae65447 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -9028,7 +9028,7 @@ void md_do_sync(struct md_thread *thread)
 	mddev->pers->sync_request(mddev, max_sectors, &skipped);
 
 	if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
-	    mddev->curr_resync >= MD_RESYNC_ACTIVE) {
+	    mddev->curr_resync > MD_RESYNC_ACTIVE) {
 		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
 			if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
 				if (mddev->curr_resync >= mddev->recovery_cp) {
-- 
2.29.2