[PATCH 4/9] btrfs: use assertion helpers for spinning readers

[David Sterba <dsterba@xxxxxxxx>]

Use the helpers where open coded. On non-debug builds, the warnings will
not trigger and extent_buffer::spining_readers become unused and can be
moved to the appropriate section, saving a few bytes.

Signed-off-by: David Sterba <dsterba@xxxxxxxx>
---
 fs/btrfs/extent_io.c |  2 +-
 fs/btrfs/extent_io.h |  2 +-
 fs/btrfs/locking.c   | 12 +++++-------
 3 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 11a95919bb3e..30363cb97625 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4672,7 +4672,6 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
 	atomic_set(&eb->read_locks, 0);
 	atomic_set(&eb->blocking_readers, 0);
 	atomic_set(&eb->blocking_writers, 0);
-	atomic_set(&eb->spinning_readers, 0);
 	eb->lock_nested = 0;
 	init_waitqueue_head(&eb->write_lock_wq);
 	init_waitqueue_head(&eb->read_lock_wq);
@@ -4692,6 +4691,7 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
 
 #ifdef CONFIG_BTRFS_DEBUG
 	atomic_set(&eb->spinning_writers, 0);
+	atomic_set(&eb->spinning_readers, 0);
 #endif
 
 	return eb;
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index c5eb261c1ea9..e49310d2caf4 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -151,7 +151,6 @@ struct extent_buffer {
 	atomic_t read_locks;
 	atomic_t blocking_writers;
 	atomic_t blocking_readers;
-	atomic_t spinning_readers;
 	short lock_nested;
 	/* >= 0 if eb belongs to a log tree, -1 otherwise */
 	short log_index;
@@ -171,6 +170,7 @@ struct extent_buffer {
 	struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
 #ifdef CONFIG_BTRFS_DEBUG
 	atomic_t spinning_writers;
+	atomic_t spinning_readers;
 	struct list_head leak_list;
 #endif
 };
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 2dd3ae524aa3..ce9dc985ce05 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -62,8 +62,7 @@ void btrfs_set_lock_blocking_read(struct extent_buffer *eb)
 		return;
 	btrfs_assert_tree_read_locked(eb);
 	atomic_inc(&eb->blocking_readers);
-	WARN_ON(atomic_read(&eb->spinning_readers) == 0);
-	atomic_dec(&eb->spinning_readers);
+	btrfs_assert_spinning_readers_put(eb);
 	read_unlock(&eb->lock);
 }
 
@@ -150,7 +149,7 @@ void btrfs_tree_read_lock(struct extent_buffer *eb)
 		goto again;
 	}
 	atomic_inc(&eb->read_locks);
-	atomic_inc(&eb->spinning_readers);
+	btrfs_assert_spinning_readers_get(eb);
 }
 
 /*
@@ -169,7 +168,7 @@ int btrfs_tree_read_lock_atomic(struct extent_buffer *eb)
 		return 0;
 	}
 	atomic_inc(&eb->read_locks);
-	atomic_inc(&eb->spinning_readers);
+	btrfs_assert_spinning_readers_get(eb);
 	return 1;
 }
 
@@ -190,7 +189,7 @@ int btrfs_try_tree_read_lock(struct extent_buffer *eb)
 		return 0;
 	}
 	atomic_inc(&eb->read_locks);
-	atomic_inc(&eb->spinning_readers);
+	btrfs_assert_spinning_readers_get(eb);
 	return 1;
 }
 
@@ -232,8 +231,7 @@ void btrfs_tree_read_unlock(struct extent_buffer *eb)
 		return;
 	}
 	btrfs_assert_tree_read_locked(eb);
-	WARN_ON(atomic_read(&eb->spinning_readers) == 0);
-	atomic_dec(&eb->spinning_readers);
+	btrfs_assert_spinning_readers_put(eb);
 	atomic_dec(&eb->read_locks);
 	read_unlock(&eb->lock);
 }
-- 
2.20.1