From: Yu Kuai <yukuai3@xxxxxxxxxx>
There are no functional changes for now, prepare to fix a deadlock for
dm-raid456.
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
drivers/md/dm-raid.c | 18 ++++++++++++++++++
drivers/md/md.h | 1 +
2 files changed, 19 insertions(+)
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 766a0334460e..002dcac20403 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3803,6 +3803,23 @@ static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs));
}
+static void raid_presuspend(struct dm_target *ti)
+{
+ struct raid_set *rs = ti->private;
+ struct mddev *mddev = &rs->md;
+
+ if (!reshape_interrupted(mddev))
+ return;
+
+ /*
+ * For raid456, if reshape is interrupted, IO across reshape position
+ * will never make progress, while caller will wait for IO to be done.
+ * Inform raid456 to handle those IO to prevent deadlock.
+ */
+ if (mddev->pers && mddev->pers->prepare_suspend)
+ mddev->pers->prepare_suspend(mddev);
+}
+
static void raid_postsuspend(struct dm_target *ti)
{
struct raid_set *rs = ti->private;
@@ -4087,6 +4104,7 @@ static struct target_type raid_target = {
.message = raid_message,
.iterate_devices = raid_iterate_devices,
.io_hints = raid_io_hints,
+ .presuspend = raid_presuspend,
.postsuspend = raid_postsuspend,
.preresume = raid_preresume,
.resume = raid_resume,
diff --git a/drivers/md/md.h b/drivers/md/md.h
index b961c1b4ead7..23080727e75b 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -648,6 +648,7 @@ struct md_personality
int (*start_reshape) (struct mddev *mddev);
void (*finish_reshape) (struct mddev *mddev);
void (*update_reshape_pos) (struct mddev *mddev);
+ void (*prepare_suspend) (struct mddev *mddev);
/* quiesce suspends or resumes internal processing.
* 1 - stop new actions and wait for action io to complete
* 0 - return to normal behaviour
--
2.39.2
