Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index d9f2a4e..1c977e6 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -79,7 +79,7 @@
 	struct mutex mutex;
 
 	spinlock_t lock;
-	struct rb_root ref_tree;
+	struct rb_root_cached ref_tree;
 	/* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */
 	struct list_head ref_add_list;
 
@@ -103,17 +103,6 @@
 	int ref_mod;
 
 	/*
-	 * For qgroup reserved space freeing.
-	 *
-	 * ref_root and reserved will be recorded after
-	 * BTRFS_ADD_DELAYED_EXTENT is called.
-	 * And will be used to free reserved qgroup space at
-	 * run_delayed_refs() time.
-	 */
-	u64 qgroup_ref_root;
-	u64 qgroup_reserved;
-
-	/*
 	 * when a new extent is allocated, it is just reserved in memory
 	 * The actual extent isn't inserted into the extent allocation tree
 	 * until the delayed ref is processed.  must_insert_reserved is
@@ -148,7 +137,7 @@
 
 struct btrfs_delayed_ref_root {
 	/* head ref rbtree */
-	struct rb_root href_root;
+	struct rb_root_cached href_root;
 
 	/* dirty extent records */
 	struct rb_root dirty_extent_root;
@@ -187,6 +176,83 @@
 	u64 qgroup_to_skip;
 };
 
+enum btrfs_ref_type {
+	BTRFS_REF_NOT_SET,
+	BTRFS_REF_DATA,
+	BTRFS_REF_METADATA,
+	BTRFS_REF_LAST,
+};
+
+struct btrfs_data_ref {
+	/* For EXTENT_DATA_REF */
+
+	/* Root which refers to this data extent */
+	u64 ref_root;
+
+	/* Inode which refers to this data extent */
+	u64 ino;
+
+	/*
+	 * file_offset - extent_offset
+	 *
+	 * file_offset is the key.offset of the EXTENT_DATA key.
+	 * extent_offset is btrfs_file_extent_offset() of the EXTENT_DATA data.
+	 */
+	u64 offset;
+};
+
+struct btrfs_tree_ref {
+	/*
+	 * Level of this tree block
+	 *
+	 * Shared for skinny (TREE_BLOCK_REF) and normal tree ref.
+	 */
+	int level;
+
+	/*
+	 * Root which refers to this tree block.
+	 *
+	 * For TREE_BLOCK_REF (skinny metadata, either inline or keyed)
+	 */
+	u64 root;
+
+	/* For non-skinny metadata, no special member needed */
+};
+
+struct btrfs_ref {
+	enum btrfs_ref_type type;
+	int action;
+
+	/*
+	 * Whether this extent should go through qgroup record.
+	 *
+	 * Normally false, but for certain cases like delayed subtree scan,
+	 * setting this flag can hugely reduce qgroup overhead.
+	 */
+	bool skip_qgroup;
+
+	/*
+	 * Optional. For which root is this modification.
+	 * Mostly used for qgroup optimization.
+	 *
+	 * When unset, data/tree ref init code will populate it.
+	 * In certain cases, we're modifying reference for a different root.
+	 * E.g. COW fs tree blocks for balance.
+	 * In that case, tree_ref::root will be fs tree, but we're doing this
+	 * for reloc tree, then we should set @real_root to reloc tree.
+	 */
+	u64 real_root;
+	u64 bytenr;
+	u64 len;
+
+	/* Bytenr of the parent tree block */
+	u64 parent;
+	union {
+		struct btrfs_data_ref data_ref;
+		struct btrfs_tree_ref tree_ref;
+	};
+};
+
 extern struct kmem_cache *btrfs_delayed_ref_head_cachep;
 extern struct kmem_cache *btrfs_delayed_tree_ref_cachep;
 extern struct kmem_cache *btrfs_delayed_data_ref_cachep;
@@ -195,6 +261,38 @@
 int __init btrfs_delayed_ref_init(void);
 void __cold btrfs_delayed_ref_exit(void);
 
+static inline void btrfs_init_generic_ref(struct btrfs_ref *generic_ref,
+				int action, u64 bytenr, u64 len, u64 parent)
+{
+	generic_ref->action = action;
+	generic_ref->bytenr = bytenr;
+	generic_ref->len = len;
+	generic_ref->parent = parent;
+}
+
+static inline void btrfs_init_tree_ref(struct btrfs_ref *generic_ref,
+				int level, u64 root)
+{
+	/* If @real_root not set, use @root as fallback */
+	if (!generic_ref->real_root)
+		generic_ref->real_root = root;
+	generic_ref->tree_ref.level = level;
+	generic_ref->tree_ref.root = root;
+	generic_ref->type = BTRFS_REF_METADATA;
+}
+
+static inline void btrfs_init_data_ref(struct btrfs_ref *generic_ref,
+				u64 ref_root, u64 ino, u64 offset)
+{
+	/* If @real_root not set, use @root as fallback */
+	if (!generic_ref->real_root)
+		generic_ref->real_root = ref_root;
+	generic_ref->data_ref.ref_root = ref_root;
+	generic_ref->data_ref.ino = ino;
+	generic_ref->data_ref.offset = offset;
+	generic_ref->type = BTRFS_REF_DATA;
+}
+
 static inline struct btrfs_delayed_extent_op *
 btrfs_alloc_delayed_extent_op(void)
 {
@@ -235,17 +333,14 @@
 }
 
 int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
-			       u64 bytenr, u64 num_bytes, u64 parent,
-			       u64 ref_root, int level, int action,
+			       struct btrfs_ref *generic_ref,
 			       struct btrfs_delayed_extent_op *extent_op,
 			       int *old_ref_mod, int *new_ref_mod);
 int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
-			       u64 bytenr, u64 num_bytes,
-			       u64 parent, u64 ref_root,
-			       u64 owner, u64 offset, u64 reserved, int action,
-			       int *old_ref_mod, int *new_ref_mod);
-int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
-				struct btrfs_trans_handle *trans,
+			       struct btrfs_ref *generic_ref,
+			       u64 reserved, int *old_ref_mod,
+			       int *new_ref_mod);
+int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
 				u64 bytenr, u64 num_bytes,
 				struct btrfs_delayed_extent_op *extent_op);
 void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
@@ -255,19 +350,30 @@
 struct btrfs_delayed_ref_head *
 btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
 			    u64 bytenr);
-int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
+int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
 			   struct btrfs_delayed_ref_head *head);
 static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
 {
 	mutex_unlock(&head->mutex);
 }
+void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
+			   struct btrfs_delayed_ref_head *head);
 
-
-struct btrfs_delayed_ref_head *
-btrfs_select_ref_head(struct btrfs_trans_handle *trans);
+struct btrfs_delayed_ref_head *btrfs_select_ref_head(
+		struct btrfs_delayed_ref_root *delayed_refs);
 
 int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq);
 
+void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr);
+void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans);
+int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
+				  enum btrfs_reserve_flush_enum flush);
+void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
+				       struct btrfs_block_rsv *src,
+				       u64 num_bytes);
+int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans);
+bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info);
+
 /*
  * helper functions to cast a node into its container
  */