From 382279336f428c80f344edfc30d53797e3e76146 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Tue, 26 Oct 2010 12:52:53 -0400 Subject: [PATCH] Btrfs: set trans to null in reserve_metadata_bytes if we commit the transaction btrfs_commit_transaction will free our trans, but because we pass trans to shrink_delalloc we could possibly have a use after free situation. So instead if we commit the transaction, set trans to null and set committed to true so we don't keep trying to commit a transaction. This fixes a panic I could reproduce at will. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/extent-tree.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 180a50146ddf..e2dfd4ab3b9b 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3157,6 +3157,7 @@ static int reserve_metadata_bytes(struct btrfs_trans_handle *trans, int retries = 0; int ret = 0; bool reserved = false; + bool committed = false; again: ret = -ENOSPC; @@ -3249,17 +3250,19 @@ again: goto out; ret = -EAGAIN; - if (trans) + if (trans || committed) goto out; - ret = -ENOSPC; trans = btrfs_join_transaction(root, 1); if (IS_ERR(trans)) goto out; ret = btrfs_commit_transaction(trans, root); - if (!ret) + if (!ret) { + trans = NULL; + committed = true; goto again; + } out: if (reserved) { -- 2.20.1