1 files changed, 8 insertions, 5 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 8dc1c170f10f..4903b47c9780 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -25,7 +25,7 @@ static int join_transaction(struct btrfs_root *root)
                 init_waitqueue_head(&cur_trans->writer_wait);
                 init_waitqueue_head(&cur_trans->commit_wait);
                 cur_trans->in_commit = 0;
-                cur_trans->use_count = 0;
+                cur_trans->use_count = 1;
                 cur_trans->commit_done = 0;
         }
         cur_trans->num_writers++;
@@ -56,7 +56,7 @@ int btrfs_end_transaction(struct btrfs_trans_handle *trans,
         struct btrfs_transaction *cur_trans;
         mutex_lock(&root->fs_info->trans_mutex);
         cur_trans = root->fs_info->running_transaction;
-        WARN_ON(cur_trans->num_writers <= 1);
+        WARN_ON(cur_trans->num_writers < 1);
         if (waitqueue_active(&cur_trans->writer_wait))
                 wake_up(&cur_trans->writer_wait);
         cur_trans->num_writers--;
@@ -155,10 +155,13 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
         cur_trans = root->fs_info->running_transaction;
         root->fs_info->running_transaction = NULL;
-        mutex_unlock(&root->fs_info->trans_mutex);
 
-        memcpy(&snap_key, &root->root_key, sizeof(snap_key));
-        root->root_key.offset++;
+        if (root->node != root->commit_root) {
+                memcpy(&snap_key, &root->root_key, sizeof(snap_key));
+                root->root_key.offset++;
+        }
+
+        mutex_unlock(&root->fs_info->trans_mutex);
 
         if (btrfs_root_blocknr(&root->root_item) != root->node->b_blocknr) {
                 btrfs_set_root_blocknr(&root->root_item, root->node->b_blocknr);