Btrfs: hold trans_mutex when using btrfs_record_root_in_trans

btrfs_record_root_in_trans needs the trans_mutex held to make sure two
callers don't race to setup the root in a given transaction.  This adds
it to all the places that were missing it.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index cd86bff..0a5d796 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5658,7 +5658,9 @@
 			prev_block = block_start;
 		}
 
+		mutex_lock(&extent_root->fs_info->trans_mutex);
 		btrfs_record_root_in_trans(found_root);
+		mutex_unlock(&extent_root->fs_info->trans_mutex);
 		if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
 			/*
 			 * try to update data extent references while
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 919172de..4112d53 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -688,7 +688,9 @@
 		num_bytes -= btrfs_root_used(&dirty->root->root_item);
 		bytes_used = btrfs_root_used(&root->root_item);
 		if (num_bytes) {
+			mutex_lock(&root->fs_info->trans_mutex);
 			btrfs_record_root_in_trans(root);
+			mutex_unlock(&root->fs_info->trans_mutex);
 			btrfs_set_root_used(&root->root_item,
 					    bytes_used - num_bytes);
 		}
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 2079429..9c462fb 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2832,7 +2832,9 @@
 		BUG_ON(!wc.replay_dest);
 
 		wc.replay_dest->log_root = log;
+		mutex_lock(&fs_info->trans_mutex);
 		btrfs_record_root_in_trans(wc.replay_dest);
+		mutex_unlock(&fs_info->trans_mutex);
 		ret = walk_log_tree(trans, log, &wc);
 		BUG_ON(ret);