The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 72c9925f87c8b74f36f8e75a4cd93d964538d3ca Mon Sep 17 00:00:00 2001
From: Filipe Manana <fdmanana@xxxxxxxx>
Date: Thu, 4 Feb 2021 14:35:44 +0000
Subject: [PATCH] btrfs: fix extent buffer leak on failure to copy root
At btrfs_copy_root(), if the call to btrfs_inc_ref() fails we end up
returning without unlocking and releasing our reference on the extent
buffer named "cow" we previously allocated with btrfs_alloc_tree_block().
So fix that by unlocking the extent buffer and dropping our reference on
it before returning.
Fixes: be20aa9dbadc8c ("Btrfs: Add mount option to turn off data cow")
CC: stable@xxxxxxxxxxxxxxx # 4.4+
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 95d9bae764ab..d56730a67885 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -222,6 +222,8 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
else
ret = btrfs_inc_ref(trans, root, cow, 0);
if (ret) {
+ btrfs_tree_unlock(cow);
+ free_extent_buffer(cow);
btrfs_abort_transaction(trans, ret);
return ret;
}
