[PATCH 11/11] md: avoid conflicts in nr_pending operations

[tada keisuke]

This patch depends on patch 10.

Change nr_pending from atomic mode to percpu mode.

Signed-off-by: Keisuke TADA <keisuke1.tada@xxxxxxxxxx>
Signed-off-by: Toshifumi OHTAKE <toshifumi.ootake@xxxxxxxxxx>
---
 drivers/md/md.c     | 5 +++--
 drivers/md/raid1.c  | 6 ++++++
 drivers/md/raid10.c | 6 ++++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 1c7b774dbb48..7cbf199bd168 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3742,7 +3742,6 @@ int md_rdev_init(struct md_rdev *rdev)
 	ret = percpu_ref_init(&rdev->nr_pending, percpu_wakeup_handle_req_pending,
 		PERCPU_REF_ALLOW_REINIT, GFP_KERNEL);
 	WARN_ON(ret);
-	percpu_ref_switch_to_atomic_sync(&rdev->nr_pending);
 	nr_pending_dec(rdev);
 	atomic_set(&rdev->read_errors, 0);
 	atomic_set(&rdev->corrected_errors, 0);
@@ -9266,7 +9265,7 @@ static bool rdev_removeable(struct md_rdev *rdev)
 		return false;
 
 	/* There are still inflight io, don't remove this rdev. */
-	if (nr_pending_is_not_zero(rdev))
+	if (nr_pending_is_atomic_mode(rdev) && nr_pending_is_not_zero(rdev))
 		return false;
 
 	/*
@@ -9364,6 +9363,8 @@ static int remove_and_add_spares(struct mddev *mddev,
 			rdev->raid_disk = -1;
 			removed++;
 		}
+		if (mddev->pers->level != 1 && mddev->pers->level != 10)
+			percpu_ref_switch_to_percpu(&rdev->nr_pending);
 	}
 
 	if (removed && mddev->kobj.sd)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 146eda6c4961..dd721b9c19b9 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2006,6 +2006,7 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
 			conf->mirrors[conf->raid_disks + number].rdev = NULL;
 			unfreeze_array(conf);
 		}
+		percpu_ref_switch_to_percpu(&rdev->nr_pending);
 
 		clear_bit(WantReplacement, &rdev->flags);
 		err = md_integrity_register(mddev);
@@ -3298,6 +3299,11 @@ static int raid1_run(struct mddev *mddev)
 static void raid1_free(struct mddev *mddev, void *priv)
 {
 	struct r1conf *conf = priv;
+	struct md_rdev *rdev;
+
+	rdev_for_each(rdev, mddev) {
+		percpu_ref_switch_to_percpu(&rdev->nr_pending);
+	}
 
 	mempool_exit(&conf->r1bio_pool);
 	kfree(conf->mirrors);
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index eebbf9185deb..e285481464b9 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2180,6 +2180,7 @@ static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
 		clear_bit(Replacement, &p->replacement->flags);
 		WRITE_ONCE(p->replacement, NULL);
 	}
+	percpu_ref_switch_to_percpu(&rdev->nr_pending);
 
 	clear_bit(WantReplacement, &rdev->flags);
 	err = md_integrity_register(mddev);
@@ -4172,6 +4173,11 @@ static int raid10_run(struct mddev *mddev)
 
 static void raid10_free(struct mddev *mddev, void *priv)
 {
+	struct md_rdev *rdev;
+
+	rdev_for_each(rdev, mddev) {
+		percpu_ref_switch_to_percpu(&rdev->nr_pending);
+	}
 	raid10_free_conf(priv);
 }
 
-- 
2.34.1