[PATCH] btrfs: remove warnings superseded by refcount_t usage

[David Sterba <dsterba@suse.com>]

There are several WARN_ON calls that catch incrorrect reference counter
updates, but this is what the refcount_t does already:

* refcount_inc from 0 will warn
* refcount_dec_and_test from 0 will warn

Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/delayed-ref.h | 1 -
 fs/btrfs/extent_map.c  | 2 +-
 fs/btrfs/transaction.c | 1 -
 fs/btrfs/volumes.c     | 1 -
 4 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index ea1aecb6a50d..16ee92c541bf 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -210,7 +210,6 @@ btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op)
 
 static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref)
 {
-	WARN_ON(refcount_read(&ref->refs) == 0);
 	if (refcount_dec_and_test(&ref->refs)) {
 		WARN_ON(ref->in_tree);
 		switch (ref->type) {
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 6648d55e5339..6808ad4ed3c9 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -72,7 +72,7 @@ void free_extent_map(struct extent_map *em)
 {
 	if (!em)
 		return;
-	WARN_ON(refcount_read(&em->refs) == 0);
+
 	if (refcount_dec_and_test(&em->refs)) {
 		WARN_ON(extent_map_in_tree(em));
 		WARN_ON(!list_empty(&em->list));
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 4485eae41e88..f6b68099b767 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -41,7 +41,6 @@ static const unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = {
 
 void btrfs_put_transaction(struct btrfs_transaction *transaction)
 {
-	WARN_ON(refcount_read(&transaction->use_count) == 0);
 	if (refcount_dec_and_test(&transaction->use_count)) {
 		BUG_ON(!list_empty(&transaction->list));
 		WARN_ON(!RB_EMPTY_ROOT(&transaction->delayed_refs.href_root));
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e034ad9e23b4..f64d26b4f278 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5330,7 +5330,6 @@ static struct btrfs_bio *alloc_btrfs_bio(int total_stripes, int real_stripes)
 
 void btrfs_get_bbio(struct btrfs_bio *bbio)
 {
-	WARN_ON(!refcount_read(&bbio->refs));
 	refcount_inc(&bbio->refs);
 }
 
-- 
2.17.0