md: use new helpers in md_do_sync()

Make code cleaner. and also use the action_name directly in kernel log:
 - "check" instead of "data-check"
 - "repair" instead of "requested-resync"
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240611132251.1967786-9-yukuai1@huaweicloud.com

drivers/md/md.c

@@ -8929,7 +8929,8 @@ void md_do_sync(struct md_thread *thread)
 	sector_t last_check;
 	int skipped = 0;
 	struct md_rdev *rdev;
-	char *desc, *action = NULL;
+	enum sync_action action;
+	const char *desc;
 	struct blk_plug plug;
 	int ret;
 
@@ -8960,21 +8961,9 @@ void md_do_sync(struct md_thread *thread)
 			goto skip;
 	}
 
-	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
-		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
-			desc = "data-check";
-			action = "check";
-		} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
-			desc = "requested-resync";
-			action = "repair";
-		} else
-			desc = "resync";
-	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
-		desc = "reshape";
-	else
-		desc = "recovery";
-
-	mddev->last_sync_action = action ?: desc;
+	action = md_sync_action(mddev);
+	desc = md_sync_action_name(action);
+	mddev->last_sync_action = desc;
 
 	/*
 	 * Before starting a resync we must have set curr_resync to

drivers/md/md.h

@@ -432,7 +432,7 @@ struct mddev {
 	 * when the sync thread is "frozen" (interrupted) or "idle" (stopped
 	 * or finished).  It is overwritten when a new sync operation is begun.
 	 */
-	char				*last_sync_action;
+	const char			*last_sync_action;
 	sector_t			curr_resync;	/* last block scheduled */
 	/* As resync requests can complete out of order, we cannot easily track
 	 * how much resync has been completed.  So we occasionally pause until