md: export helpers to stop sync_thread

[ Upstream commit 7a2347e284d7ec2f0759be4db60fa7ca937284fc ]

Add new helpers:

  void md_idle_sync_thread(struct mddev *mddev);
  void md_frozen_sync_thread(struct mddev *mddev);
  void md_unfrozen_sync_thread(struct mddev *mddev);

The helpers will be used in dm-raid in later patches to fix regressions
and prevent calling md_reap_sync_thread() directly.

Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240305072306.2562024-3-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 007fd071b44ed745bf429578a5b89cc6bd9cf67a..740541f6cad9825b908a06308f38b5f1c9abc471 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4945,6 +4945,35 @@ static void stop_sync_thread(struct mddev *mddev, bool locked, bool check_seq)
                mddev_lock_nointr(mddev);
 }
 
+void md_idle_sync_thread(struct mddev *mddev)
+{
+       lockdep_assert_held(&mddev->reconfig_mutex);
+
+       clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+       stop_sync_thread(mddev, true, true);
+}
+EXPORT_SYMBOL_GPL(md_idle_sync_thread);
+
+void md_frozen_sync_thread(struct mddev *mddev)
+{
+       lockdep_assert_held(&mddev->reconfig_mutex);
+
+       set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+       stop_sync_thread(mddev, true, false);
+}
+EXPORT_SYMBOL_GPL(md_frozen_sync_thread);
+
+void md_unfrozen_sync_thread(struct mddev *mddev)
+{
+       lockdep_assert_held(&mddev->reconfig_mutex);
+
+       clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+       set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+       md_wakeup_thread(mddev->thread);
+       sysfs_notify_dirent_safe(mddev->sysfs_action);
+}
+EXPORT_SYMBOL_GPL(md_unfrozen_sync_thread);
+
 static void idle_sync_thread(struct mddev *mddev)
 {
        mutex_lock(&mddev->sync_mutex);

diff --git a/drivers/md/md.h b/drivers/md/md.h
index 27d187ca6258a097fef570bccd65110a5a488edf..0d06d640aa06dcf80072dd0adaa33a61cc4c376c 100644 (file)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -782,6 +782,9 @@ extern void md_rdev_clear(struct md_rdev *rdev);
 extern void md_handle_request(struct mddev *mddev, struct bio *bio);
 extern int mddev_suspend(struct mddev *mddev, bool interruptible);
 extern void mddev_resume(struct mddev *mddev);
+extern void md_idle_sync_thread(struct mddev *mddev);
+extern void md_frozen_sync_thread(struct mddev *mddev);
+extern void md_unfrozen_sync_thread(struct mddev *mddev);
 
 extern void md_reload_sb(struct mddev *mddev, int raid_disk);
 extern void md_update_sb(struct mddev *mddev, int force);