commit 58a2ddaedbf74b8a209426128c130cc9f0dbd11b
author David Sterba <dsterba@suse.com> Fri Aug 24 16:13:41 2018 +0200
committer David Sterba <dsterba@suse.com> Mon Apr 29 19:02:21 2019 +0200
tree 963b3c5e936dfab65624b44d062ddc615ff201a3
parent afd495a8264fb25cef49834b5c3559b8aaa612ee

btrfs: add assertion helpers for extent buffer read lock counters

The read_locks are a simple counter to track locking balance and used to
assert tree locks.  Add helpers to make it conditionally work only in
DEBUG builds.  Will be used in followup patches.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/locking.c

diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 47bcd28..d3bb198 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -12,8 +12,6 @@
 #include "extent_io.h"
 #include "locking.h"
 
-static void btrfs_assert_tree_read_locked(struct extent_buffer *eb);
-
 #ifdef CONFIG_BTRFS_DEBUG
 static void btrfs_assert_spinning_writers_get(struct extent_buffer *eb)
 {
@@ -43,12 +41,30 @@ static void btrfs_assert_spinning_readers_put(struct extent_buffer *eb)
 	atomic_dec(&eb->spinning_readers);
 }
 
+static void btrfs_assert_tree_read_locks_get(struct extent_buffer *eb)
+{
+	atomic_inc(&eb->read_locks);
+}
+
+static void btrfs_assert_tree_read_locks_put(struct extent_buffer *eb)
+{
+	atomic_dec(&eb->read_locks);
+}
+
+static void btrfs_assert_tree_read_locked(struct extent_buffer *eb)
+{
+	BUG_ON(!atomic_read(&eb->read_locks));
+}
+
 #else
 static void btrfs_assert_spinning_writers_get(struct extent_buffer *eb) { }
 static void btrfs_assert_spinning_writers_put(struct extent_buffer *eb) { }
 static void btrfs_assert_no_spinning_writers(struct extent_buffer *eb) { }
 static void btrfs_assert_spinning_readers_put(struct extent_buffer *eb) { }
 static void btrfs_assert_spinning_readers_get(struct extent_buffer *eb) { }
+static void btrfs_assert_tree_read_locked(struct extent_buffer *eb) { }
+static void btrfs_assert_tree_read_locks_get(struct extent_buffer *eb) { }
+static void btrfs_assert_tree_read_locks_put(struct extent_buffer *eb) { }
 #endif
 
 void btrfs_set_lock_blocking_read(struct extent_buffer *eb)
@@ -309,8 +325,3 @@ void btrfs_assert_tree_locked(struct extent_buffer *eb)
 {
 	BUG_ON(!atomic_read(&eb->write_locks));
 }
-
-static void btrfs_assert_tree_read_locked(struct extent_buffer *eb)
-{
-	BUG_ON(!atomic_read(&eb->read_locks));
-}