btrfs: move btrfs_defrag_root() to defrag.{c,h}

The btrfs_defrag_root() function does not really belong in the
transaction.{c,h} module and as we have a defrag.{c,h} nowadays,
move it to there instead. This also allows to stop exporting
btrfs_defrag_leaves(), so we can make it static.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ rename info to fs_info for consistency ]
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/defrag.c

@@ -343,8 +343,8 @@ int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
  * better reflect disk order
  */
 
-int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
-			struct btrfs_root *root)
+static int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
+			       struct btrfs_root *root)
 {
 	struct btrfs_path *path = NULL;
 	struct btrfs_key key;
@@ -460,6 +460,45 @@ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
+/*
+ * Defrag a given btree.  Every leaf in the btree is read and defragmented.
+ */
+int btrfs_defrag_root(struct btrfs_root *root)
+{
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	int ret;
+
+	if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state))
+		return 0;
+
+	while (1) {
+		struct btrfs_trans_handle *trans;
+
+		trans = btrfs_start_transaction(root, 0);
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
+			break;
+		}
+
+		ret = btrfs_defrag_leaves(trans, root);
+
+		btrfs_end_transaction(trans);
+		btrfs_btree_balance_dirty(fs_info);
+		cond_resched();
+
+		if (btrfs_fs_closing(fs_info) || ret != -EAGAIN)
+			break;
+
+		if (btrfs_defrag_cancelled(fs_info)) {
+			btrfs_debug(fs_info, "defrag_root cancelled");
+			ret = -EAGAIN;
+			break;
+		}
+	}
+	clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state);
+	return ret;
+}
+
 /*
  * Defrag specific helper to get an extent map.
  *

fs/btrfs/defrag.h

@@ -12,7 +12,7 @@ int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
 			   struct btrfs_inode *inode, u32 extent_thresh);
 int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info);
 void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info);
-int btrfs_defrag_leaves(struct btrfs_trans_handle *trans, struct btrfs_root *root);
+int btrfs_defrag_root(struct btrfs_root *root);
 
 static inline int btrfs_defrag_cancelled(struct btrfs_fs_info *fs_info)
 {

fs/btrfs/transaction.c

@@ -1564,45 +1564,6 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans)
 	return 0;
 }
 
-/*
- * defrag a given btree.
- * Every leaf in the btree is read and defragged.
- */
-int btrfs_defrag_root(struct btrfs_root *root)
-{
-	struct btrfs_fs_info *info = root->fs_info;
-	struct btrfs_trans_handle *trans;
-	int ret;
-
-	if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state))
-		return 0;
-
-	while (1) {
-		trans = btrfs_start_transaction(root, 0);
-		if (IS_ERR(trans)) {
-			ret = PTR_ERR(trans);
-			break;
-		}
-
-		ret = btrfs_defrag_leaves(trans, root);
-
-		btrfs_end_transaction(trans);
-		btrfs_btree_balance_dirty(info);
-		cond_resched();
-
-		if (btrfs_fs_closing(info) || ret != -EAGAIN)
-			break;
-
-		if (btrfs_defrag_cancelled(info)) {
-			btrfs_debug(info, "defrag_root cancelled");
-			ret = -EAGAIN;
-			break;
-		}
-	}
-	clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state);
-	return ret;
-}
-
 /*
  * Do all special snapshot related qgroup dirty hack.
  *

fs/btrfs/transaction.h

@@ -246,7 +246,6 @@ struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
 
 void btrfs_add_dead_root(struct btrfs_root *root);
-int btrfs_defrag_root(struct btrfs_root *root);
 void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info);
 int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info);
 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);