[PATCH] Btrfs: fix warning when creating snapshots

[Liu Bo <bo.li.liu@oracle.com>]

Creating snapshot passes extent_root to commit its transaction,
but it can lead to the warning of checking root for quota in
the __btrfs_end_transaction() when someone else is committing
the current transaction.  Since we've recorded the needed root
in trans_handle, just use it to get rid of the warning.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
---
 fs/btrfs/transaction.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index f11c2e0..5c10871 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -626,14 +626,14 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
 
 	btrfs_trans_release_metadata(trans, root);
 	trans->block_rsv = NULL;
-	/*
-	 * the same root has to be passed to start_transaction and
-	 * end_transaction. Subvolume quota depends on this.
-	 */
 	WARN_ON(trans->root != root);
 
 	if (trans->qgroup_reserved) {
-		btrfs_qgroup_free(root, trans->qgroup_reserved);
+		/*
+		 * the same root has to be passed here between start_transaction
+		 * and end_transaction. Subvolume quota depends on this.
+		 */
+		btrfs_qgroup_free(trans->root, trans->qgroup_reserved);
 		trans->qgroup_reserved = 0;
 	}
 
-- 
1.7.7.6