[PATCH md-6.10 4/9] md: factor out helper to start reshape from action_store()

[Yu Kuai <yukuai1@xxxxxxxxxxxxxxx>]

From: Yu Kuai <yukuai3@xxxxxxxxxx>

There are no functional changes, just to make code cleaner and prepare
for following refactor.

Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
 drivers/md/md.c | 67 +++++++++++++++++++++++++++++++------------------
 drivers/md/md.h |  2 +-
 2 files changed, 43 insertions(+), 26 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 48ec35342d1b..7600da89d909 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4914,7 +4914,7 @@ enum sync_action md_sync_action(struct mddev *mddev)
 	return ACTION_IDLE;
 }
 
-enum sync_action md_sync_action_by_name(char *page)
+enum sync_action md_sync_action_by_name(const char *page)
 {
 	enum sync_action action;
 
@@ -5055,6 +5055,45 @@ static void frozen_sync_thread(struct mddev *mddev)
 	mutex_unlock(&mddev->sync_mutex);
 }
 
+static int mddev_start_reshape(struct mddev *mddev)
+{
+	int ret;
+
+	if (mddev->pers->start_reshape == NULL)
+		return -EINVAL;
+
+	ret = mddev_lock(mddev);
+	if (ret)
+		return ret;
+
+	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
+		mddev_unlock(mddev);
+		return -EBUSY;
+	}
+
+	if (mddev->reshape_position == MaxSector ||
+	    mddev->pers->check_reshape == NULL ||
+	    mddev->pers->check_reshape(mddev)) {
+		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+		ret = mddev->pers->start_reshape(mddev);
+		if (ret) {
+			mddev_unlock(mddev);
+			return ret;
+		}
+	} else {
+		/*
+		 * If reshape is still in progress, and md_check_recovery() can
+		 * continue to reshape, don't restart reshape because data can
+		 * be corrupted for raid456.
+		 */
+		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+	}
+
+	mddev_unlock(mddev);
+	sysfs_notify_dirent_safe(mddev->sysfs_degraded);
+	return 0;
+}
+
 static ssize_t
 action_store(struct mddev *mddev, const char *page, size_t len)
 {
@@ -5074,32 +5113,10 @@ action_store(struct mddev *mddev, const char *page, size_t len)
 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
 	} else if (cmd_match(page, "reshape")) {
-		int err;
-		if (mddev->pers->start_reshape == NULL)
-			return -EINVAL;
-		err = mddev_lock(mddev);
-		if (!err) {
-			if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
-				err =  -EBUSY;
-			} else if (mddev->reshape_position == MaxSector ||
-				   mddev->pers->check_reshape == NULL ||
-				   mddev->pers->check_reshape(mddev)) {
-				clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
-				err = mddev->pers->start_reshape(mddev);
-			} else {
-				/*
-				 * If reshape is still in progress, and
-				 * md_check_recovery() can continue to reshape,
-				 * don't restart reshape because data can be
-				 * corrupted for raid456.
-				 */
-				clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
-			}
-			mddev_unlock(mddev);
-		}
+		int err = mddev_start_reshape(mddev);
+
 		if (err)
 			return err;
-		sysfs_notify_dirent_safe(mddev->sysfs_degraded);
 	} else {
 		if (cmd_match(page, "check"))
 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 72ca7a796df5..cf54870e89db 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -865,7 +865,7 @@ extern void md_wakeup_thread(struct md_thread __rcu *thread);
 extern void md_check_recovery(struct mddev *mddev);
 extern void md_reap_sync_thread(struct mddev *mddev);
 extern enum sync_action md_sync_action(struct mddev *mddev);
-extern enum sync_action md_sync_action_by_name(char *page);
+extern enum sync_action md_sync_action_by_name(const char *page);
 extern char *md_sync_action_name(enum sync_action action);
 extern bool md_write_start(struct mddev *mddev, struct bio *bi);
 extern void md_write_inc(struct mddev *mddev, struct bio *bi);
-- 
2.39.2