1 files changed, 5 insertions, 0 deletions

diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 94876709217f..94f5bde2b58d 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -23,7 +23,12 @@
 
 struct btrfs_transaction {
         u64 transid;
+        /*
+         * total writers in this transaction, it must be zero before the
+         * transaction can end
+         */
         unsigned long num_writers;
+
         unsigned long num_joined;
         int in_commit;
         int use_count;