From: Liu Bo <bo.li.liu@oracle.com>
Date: Mon, 4 Mar 2013 16:25:41 +0000 (+0000)
Subject: Btrfs: avoid deadlock on transaction waiting list
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=66b6135b7cf741f6f44ba938b27583ea3b83bd12;p=linux.git

Btrfs: avoid deadlock on transaction waiting list

Only let one trans handle to wait for other handles, otherwise we
will get ABBA issues.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
---

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index d8fce6fe9cf83..fedede1fe178b 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1457,6 +1457,13 @@ static void cleanup_transaction(struct btrfs_trans_handle *trans,
 	btrfs_abort_transaction(trans, root, err);
 
 	spin_lock(&root->fs_info->trans_lock);
+
+	if (list_empty(&cur_trans->list)) {
+		spin_unlock(&root->fs_info->trans_lock);
+		btrfs_end_transaction(trans, root);
+		return;
+	}
+
 	list_del_init(&cur_trans->list);
 	if (cur_trans == root->fs_info->running_transaction) {
 		root->fs_info->trans_no_join = 1;