md: don't update recovery_cp when curr_resync is ACTIVE

mainline inclusion
from mainline-v6.3-rc1
commit 1d1f25bf
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6JN1I
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1d1f25bfda432a6b61bd0205d426226bbbd73504

--------------------------------

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: eac58d08 ("md: Use enum for overloaded magic numbers used by mddev->curr_resync")
Cc: stable@vger.kernel.org # 6.0+
Signed-off-by: NHou Tao <houtao1@huawei.com>
Reviewed-by: NLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: NSong Liu <song@kernel.org>
Signed-off-by: NYu Kuai <yukuai3@huawei.com>
Reviewed-by: NHou Tao <houtao1@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>

drivers/md/md.c

@@ -9035,7 +9035,7 @@ 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) {