[PATCH -next 28/29] md/raid5: Revert "md/raid5: fix a deadlock in the case that reshape is interrupted"

[Yu Kuai]

From: Yu Kuai <yukuai3@xxxxxxxxxx>

This reverts commit 868bba54a3bcbfc34314e963d5a7e66717f39d4e.

Because the old apis mddev_suspend() and mddev_resume() is removed, and
the deadlock is not possible anymore.

Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
 drivers/md/md.c    |  1 -
 drivers/md/raid5.c | 44 +-------------------------------------------
 2 files changed, 1 insertion(+), 44 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 3f4537876cc2..f480f225781a 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -9165,7 +9165,6 @@ void md_do_sync(struct md_thread *thread)
 	spin_unlock(&mddev->lock);
 
 	wake_up(&resync_wait);
-	wake_up(&mddev->sb_wait);
 	md_wakeup_thread(mddev->thread);
 	return;
 }
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 4709b7ad0317..8a3045e4d43f 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5953,19 +5953,6 @@ static int add_all_stripe_bios(struct r5conf *conf,
 	return ret;
 }
 
-static bool reshape_inprogress(struct mddev *mddev)
-{
-	return test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
-	       test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
-	       !test_bit(MD_RECOVERY_DONE, &mddev->recovery) &&
-	       !test_bit(MD_RECOVERY_INTR, &mddev->recovery);
-}
-
-static bool reshape_disabled(struct mddev *mddev)
-{
-	return is_md_suspended(mddev) || !md_is_rdwr(mddev);
-}
-
 static enum stripe_result make_stripe_request(struct mddev *mddev,
 		struct r5conf *conf, struct stripe_request_ctx *ctx,
 		sector_t logical_sector, struct bio *bi)
@@ -5997,8 +5984,7 @@ static enum stripe_result make_stripe_request(struct mddev *mddev,
 			if (ahead_of_reshape(mddev, logical_sector,
 					     conf->reshape_safe)) {
 				spin_unlock_irq(&conf->device_lock);
-				ret = STRIPE_SCHEDULE_AND_RETRY;
-				goto out;
+				return STRIPE_SCHEDULE_AND_RETRY;
 			}
 		}
 		spin_unlock_irq(&conf->device_lock);
@@ -6077,15 +6063,6 @@ static enum stripe_result make_stripe_request(struct mddev *mddev,
 
 out_release:
 	raid5_release_stripe(sh);
-out:
-	if (ret == STRIPE_SCHEDULE_AND_RETRY && !reshape_inprogress(mddev) &&
-	    reshape_disabled(mddev)) {
-		bi->bi_status = BLK_STS_IOERR;
-		ret = STRIPE_FAIL;
-		pr_err("md/raid456:%s: io failed across reshape position while reshape can't make progress.\n",
-		       mdname(mddev));
-	}
-
 	return ret;
 }
 
@@ -9026,22 +9003,6 @@ static int raid5_start(struct mddev *mddev)
 	return r5l_start(conf->log);
 }
 
-static void raid5_prepare_suspend(struct mddev *mddev)
-{
-	struct r5conf *conf = mddev->private;
-
-	wait_event(mddev->sb_wait, !reshape_inprogress(mddev) ||
-				    percpu_ref_is_zero(&mddev->active_io));
-	if (percpu_ref_is_zero(&mddev->active_io))
-		return;
-
-	/*
-	 * Reshape is not in progress, and array is suspended, io that is
-	 * waiting for reshpape can never be done.
-	 */
-	wake_up(&conf->wait_for_overlap);
-}
-
 static struct md_personality raid6_personality =
 {
 	.name		= "raid6",
@@ -9062,7 +9023,6 @@ static struct md_personality raid6_personality =
 	.check_reshape	= raid6_check_reshape,
 	.start_reshape  = raid5_start_reshape,
 	.finish_reshape = raid5_finish_reshape,
-	.prepare_suspend = raid5_prepare_suspend,
 	.quiesce	= raid5_quiesce,
 	.takeover	= raid6_takeover,
 	.change_consistency_policy = raid5_change_consistency_policy,
@@ -9087,7 +9047,6 @@ static struct md_personality raid5_personality =
 	.check_reshape	= raid5_check_reshape,
 	.start_reshape  = raid5_start_reshape,
 	.finish_reshape = raid5_finish_reshape,
-	.prepare_suspend = raid5_prepare_suspend,
 	.quiesce	= raid5_quiesce,
 	.takeover	= raid5_takeover,
 	.change_consistency_policy = raid5_change_consistency_policy,
@@ -9113,7 +9072,6 @@ static struct md_personality raid4_personality =
 	.check_reshape	= raid5_check_reshape,
 	.start_reshape  = raid5_start_reshape,
 	.finish_reshape = raid5_finish_reshape,
-	.prepare_suspend = raid5_prepare_suspend,
 	.quiesce	= raid5_quiesce,
 	.takeover	= raid4_takeover,
 	.change_consistency_policy = raid5_change_consistency_policy,
-- 
2.39.2