Factor out code into md_should_do_recovery()

In md_check_recovery(), use new helper to make code cleaner.

Link: https://lore.kernel.org/linux-raid/[e-mail]
Signed-off-by: Wu Guanghao <[e-mail]>
Reviewed-by: Yu Kuai <[e-mail]>
Signed-off-by: Yu Kuai <[e-mail]>

drivers/md/md.c

···
 	md_reap_sync_thread(mddev);
 }
 
+static bool md_should_do_recovery(struct mddev *mddev)
+{
+	/*
+	 * As long as one of the following flags is set,
+	 * recovery needs to do or cleanup.
+	 */
+	if (test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
+	    test_bit(MD_RECOVERY_DONE, &mddev->recovery))
+		return true;
+
+	/*
+	 * If no flags are set and it is in read-only status,
+	 * there is nothing to do.
+	 */
+	if (!md_is_rdwr(mddev))
+		return false;
+
+	/*
+	 * MD_SB_CHANGE_PENDING indicates that the array is switching from clean to
+	 * active, and no action is needed for now.
+	 * All other MD_SB_* flags require to update the superblock.
+	 */
+	if (mddev->sb_flags & ~ (1<<MD_SB_CHANGE_PENDING))
+		return true;
+
+	/*
+	 * If the array is not using external metadata and there has been no data
+	 * written for some time, then the array's status needs to be set to
+	 * in_sync.
+	 */
+	if (mddev->external == 0 && mddev->safemode == 1)
+		return true;
+
+	/*
+	 * When the system is about to restart or the process receives an signal,
+	 * the array needs to be synchronized as soon as possible.
+	 * Once the data synchronization is completed, need to change the array
+	 * status to in_sync.
+	 */
+	if (mddev->safemode == 2 && !mddev->in_sync &&
+	    mddev->resync_offset == MaxSector)
+		return true;
+
+	return false;
+}
+
 /*
  * This routine is regularly called by all per-raid-array threads to
  * deal with generic issues like resync and super-block update.
···
 		flush_signals(current);
 	}
 
-	if (!md_is_rdwr(mddev) &&
-	    !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) &&
-	    !test_bit(MD_RECOVERY_DONE, &mddev->recovery))
-		return;
-	if ( ! (
-		(mddev->sb_flags & ~ (1<<MD_SB_CHANGE_PENDING)) ||
-		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
-		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
-		(mddev->external == 0 && mddev->safemode == 1) ||
-		(mddev->safemode == 2
-		 && !mddev->in_sync && mddev->resync_offset == MaxSector)
-		))
+	if (!md_should_do_recovery(mddev))
 		return;
 
 	if (mddev_trylock(mddev)) {