[PATCH -next v2 04/28] md: add new helpers to suspend/resume and lock/unlock array

From: Yu Kuai
Date: Sun Aug 27 2023 - 22:06:16 EST


From: Yu Kuai <yukuai3@xxxxxxxxxx>

The new helpers suspend the array first and then lock the array,

Prepare to refactor from:

mddev_lock/trylock/lock_nointr
mddev_suspend
...
mddev_resuem
mddev_lock

With:

mddev_suspend_and_lock/trylock/lock_nointr
...
mddev_unlock_and_resume

After all the use cases is refactored, mddev_suspend/resume() will be
removed.

And mddev_suspend_and_lock() will also replace mddev_lock() for the case
that the array will be reconfigured, in order to synchronize with io to
prevent problems in many corner cases.

Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
drivers/md/md.h | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)

diff --git a/drivers/md/md.h b/drivers/md/md.h
index 1103e6b08ad9..07496179084a 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -858,6 +858,42 @@ static inline void mddev_check_write_zeroes(struct mddev *mddev, struct bio *bio
mddev->queue->limits.max_write_zeroes_sectors = 0;
}

+static inline int mddev_suspend_and_lock(struct mddev *mddev)
+{
+ int ret;
+
+ __mddev_suspend(mddev);
+ ret = mddev_lock(mddev);
+ if (ret)
+ __mddev_resume(mddev);
+
+ return ret;
+}
+
+static inline void mddev_suspend_and_lock_nointr(struct mddev *mddev)
+{
+ __mddev_suspend(mddev);
+ mutex_lock(&mddev->reconfig_mutex);
+}
+
+static inline int mddev_suspend_and_trylock(struct mddev *mddev)
+{
+ int ret;
+
+ __mddev_suspend(mddev);
+ ret = mutex_trylock(&mddev->reconfig_mutex);
+ if (ret)
+ __mddev_resume(mddev);
+
+ return ret;
+}
+
+static inline void mddev_unlock_and_resume(struct mddev *mddev)
+{
+ mddev_unlock(mddev);
+ __mddev_resume(mddev);
+}
+
struct mdu_array_info_s;
struct mdu_disk_info_s;

--
2.39.2