diff --git a/Makefile b/Makefile
index 43dfd296..8001f46a 100644
--- a/Makefile
+++ b/Makefile
@@ -182,6 +182,7 @@ objects = \
 	kernel-shared/free-space-tree.o	\
 	kernel-shared/inode-item.o	\
 	kernel-shared/inode.o	\
+	kernel-shared/locking.o	\
 	kernel-shared/messages.o	\
 	kernel-shared/print-tree.o	\
 	kernel-shared/root-tree.o	\
diff --git a/include/kerncompat.h b/include/kerncompat.h
index 68007915..28e9f443 100644
--- a/include/kerncompat.h
+++ b/include/kerncompat.h
@@ -615,6 +615,10 @@ do {									\
 #define smp_mb__before_atomic() do {} while (0)
 #define smp_mb() do {} while (0)
 
+struct percpu_counter {
+	int count;
+};
+
 typedef struct refcount_struct {
 	int refs;
 } refcount_t;
diff --git a/kernel-shared/locking.c b/kernel-shared/locking.c
new file mode 100644
index 00000000..c4138e68
--- /dev/null
+++ b/kernel-shared/locking.c
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2008 Oracle.  All rights reserved.
+ */
+
+#include "ctree.h"
+#include "locking.h"
+
+struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root)
+{
+	return root->node;
+}
+
+struct extent_buffer *btrfs_try_read_lock_root_node(struct btrfs_root *root)
+{
+	return root->node;
+}
+
+struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
+{
+	return root->node;
+}
diff --git a/kernel-shared/locking.h b/kernel-shared/locking.h
new file mode 100644
index 00000000..02c302e4
--- /dev/null
+++ b/kernel-shared/locking.h
@@ -0,0 +1,258 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2008 Oracle.  All rights reserved.
+ */
+
+#ifndef BTRFS_LOCKING_H
+#define BTRFS_LOCKING_H
+
+#include "kerncompat.h"
+
+#define BTRFS_WRITE_LOCK 1
+#define BTRFS_READ_LOCK 2
+
+struct btrfs_root;
+
+/*
+ * We are limited in number of subclasses by MAX_LOCKDEP_SUBCLASSES, which at
+ * the time of this patch is 8, which is how many we use.  Keep this in mind if
+ * you decide you want to add another subclass.
+ */
+enum btrfs_lock_nesting {
+	BTRFS_NESTING_NORMAL,
+
+	/*
+	 * When we COW a block we are holding the lock on the original block,
+	 * and since our lockdep maps are rootid+level, this confuses lockdep
+	 * when we lock the newly allocated COW'd block.  Handle this by having
+	 * a subclass for COW'ed blocks so that lockdep doesn't complain.
+	 */
+	BTRFS_NESTING_COW,
+
+	/*
+	 * Oftentimes we need to lock adjacent nodes on the same level while
+	 * still holding the lock on the original node we searched to, such as
+	 * for searching forward or for split/balance.
+	 *
+	 * Because of this we need to indicate to lockdep that this is
+	 * acceptable by having a different subclass for each of these
+	 * operations.
+	 */
+	BTRFS_NESTING_LEFT,
+	BTRFS_NESTING_RIGHT,
+
+	/*
+	 * When splitting we will be holding a lock on the left/right node when
+	 * we need to cow that node, thus we need a new set of subclasses for
+	 * these two operations.
+	 */
+	BTRFS_NESTING_LEFT_COW,
+	BTRFS_NESTING_RIGHT_COW,
+
+	/*
+	 * When splitting we may push nodes to the left or right, but still use
+	 * the subsequent nodes in our path, keeping our locks on those adjacent
+	 * blocks.  Thus when we go to allocate a new split block we've already
+	 * used up all of our available subclasses, so this subclass exists to
+	 * handle this case where we need to allocate a new split block.
+	 */
+	BTRFS_NESTING_SPLIT,
+
+	/*
+	 * When promoting a new block to a root we need to have a special
+	 * subclass so we don't confuse lockdep, as it will appear that we are
+	 * locking a higher level node before a lower level one.  Copying also
+	 * has this problem as it appears we're locking the same block again
+	 * when we make a snapshot of an existing root.
+	 */
+	BTRFS_NESTING_NEW_ROOT,
+
+	/*
+	 * We are limited to MAX_LOCKDEP_SUBLCLASSES number of subclasses, so
+	 * add this in here and add a static_assert to keep us from going over
+	 * the limit.  As of this writing we're limited to 8, and we're
+	 * definitely using 8, hence this check to keep us from messing up in
+	 * the future.
+	 */
+	BTRFS_NESTING_MAX,
+};
+
+enum btrfs_lockdep_trans_states {
+	BTRFS_LOCKDEP_TRANS_COMMIT_START,
+	BTRFS_LOCKDEP_TRANS_UNBLOCKED,
+	BTRFS_LOCKDEP_TRANS_SUPER_COMMITTED,
+	BTRFS_LOCKDEP_TRANS_COMPLETED,
+};
+
+/*
+ * Lockdep annotation for wait events.
+ *
+ * @owner:  The struct where the lockdep map is defined
+ * @lock:   The lockdep map corresponding to a wait event
+ *
+ * This macro is used to annotate a wait event. In this case a thread acquires
+ * the lockdep map as writer (exclusive lock) because it has to block until all
+ * the threads that hold the lock as readers signal the condition for the wait
+ * event and release their locks.
+ */
+#define btrfs_might_wait_for_event(owner, lock)					\
+	do {									\
+		rwsem_acquire(&owner->lock##_map, 0, 0, _THIS_IP_);		\
+		rwsem_release(&owner->lock##_map, _THIS_IP_);			\
+	} while (0)
+
+/*
+ * Protection for the resource/condition of a wait event.
+ *
+ * @owner:  The struct where the lockdep map is defined
+ * @lock:   The lockdep map corresponding to a wait event
+ *
+ * Many threads can modify the condition for the wait event at the same time
+ * and signal the threads that block on the wait event. The threads that modify
+ * the condition and do the signaling acquire the lock as readers (shared
+ * lock).
+ */
+#define btrfs_lockdep_acquire(owner, lock)					\
+	rwsem_acquire_read(&owner->lock##_map, 0, 0, _THIS_IP_)
+
+/*
+ * Used after signaling the condition for a wait event to release the lockdep
+ * map held by a reader thread.
+ */
+#define btrfs_lockdep_release(owner, lock)					\
+	rwsem_release(&owner->lock##_map, _THIS_IP_)
+
+/*
+ * Macros for the transaction states wait events, similar to the generic wait
+ * event macros.
+ */
+#define btrfs_might_wait_for_state(owner, i)					\
+	do {									\
+		rwsem_acquire(&owner->btrfs_state_change_map[i], 0, 0, _THIS_IP_); \
+		rwsem_release(&owner->btrfs_state_change_map[i], _THIS_IP_);	\
+	} while (0)
+
+#define btrfs_trans_state_lockdep_acquire(owner, i)				\
+	rwsem_acquire_read(&owner->btrfs_state_change_map[i], 0, 0, _THIS_IP_)
+
+#define btrfs_trans_state_lockdep_release(owner, i)				\
+	rwsem_release(&owner->btrfs_state_change_map[i], _THIS_IP_)
+
+/* Initialization of the lockdep map */
+#define btrfs_lockdep_init_map(owner, lock)					\
+	do {									\
+		static struct lock_class_key lock##_key;			\
+		lockdep_init_map(&owner->lock##_map, #lock, &lock##_key, 0);	\
+	} while (0)
+
+/* Initialization of the transaction states lockdep maps. */
+#define btrfs_state_lockdep_init_map(owner, lock, state)			\
+	do {									\
+		static struct lock_class_key lock##_key;			\
+		lockdep_init_map(&owner->btrfs_state_change_map[state], #lock,	\
+				 &lock##_key, 0);				\
+	} while (0)
+
+struct btrfs_path;
+
+static inline void __btrfs_tree_lock(struct extent_buffer *eb, enum btrfs_lock_nesting nest)
+{
+}
+
+static inline void btrfs_tree_lock(struct extent_buffer *eb)
+{
+}
+
+static inline void btrfs_tree_unlock(struct extent_buffer *eb)
+{
+}
+
+static inline void __btrfs_tree_read_lock(struct extent_buffer *eb, enum btrfs_lock_nesting nest)
+{
+}
+
+static inline void btrfs_tree_read_lock(struct extent_buffer *eb)
+{
+}
+
+static inline void btrfs_tree_read_unlock(struct extent_buffer *eb)
+{
+}
+
+static inline int btrfs_try_tree_read_lock(struct extent_buffer *eb)
+{
+	return 1;
+}
+
+static inline int btrfs_try_tree_write_lock(struct extent_buffer *eb)
+{
+	return 1;
+}
+
+static inline void btrfs_assert_tree_write_locked(struct extent_buffer *eb) { }
+
+static inline void btrfs_unlock_up_safe(struct btrfs_path *path, int level)
+{
+}
+
+struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root);
+struct extent_buffer *btrfs_try_read_lock_root_node(struct btrfs_root *root);
+struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root);
+
+static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw)
+{
+	if (rw == BTRFS_WRITE_LOCK)
+		btrfs_tree_unlock(eb);
+	else if (rw == BTRFS_READ_LOCK)
+		btrfs_tree_read_unlock(eb);
+	else
+		BUG();
+}
+
+struct btrfs_drew_lock {
+	atomic_t readers;
+	struct percpu_counter writers;
+	wait_queue_head_t pending_writers;
+	wait_queue_head_t pending_readers;
+};
+
+static inline int btrfs_drew_lock_init(struct btrfs_drew_lock *lock)
+{
+	return 0;
+}
+
+static inline void btrfs_drew_lock_destroy(struct btrfs_drew_lock *lock)
+{
+}
+
+static inline void btrfs_drew_write_lock(struct btrfs_drew_lock *lock)
+{
+}
+
+static inline bool btrfs_drew_try_write_lock(struct btrfs_drew_lock *lock)
+{
+	return true;
+}
+
+static inline void btrfs_drew_write_unlock(struct btrfs_drew_lock *lock)
+{
+}
+
+static inline void btrfs_drew_read_lock(struct btrfs_drew_lock *lock)
+{
+}
+
+static inline void btrfs_drew_read_unlock(struct btrfs_drew_lock *lock)
+{
+}
+
+static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
+					struct extent_buffer *eb, int level)
+{
+}
+static inline void btrfs_maybe_reset_lockdep_class(struct btrfs_root *root,
+						   struct extent_buffer *eb)
+{
+}
+
+#endif
