Commit 0f1b6212 authored by Filipe Manana's avatar Filipe Manana Committed by Ma Wupeng
Browse files

btrfs: fix leak of qgroup extent records after transaction abort 

stable inclusion
from stable-v6.6.34
commit 44bc51c08d6459a608c6d445ddee86044948251d
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAD6H2

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=44bc51c08d6459a608c6d445ddee86044948251d



--------------------------------

commit fb33eb2ef0d88e75564983ef057b44c5b7e4fded upstream.

Qgroup extent records are created when delayed ref heads are created and
then released after accounting extents at btrfs_qgroup_account_extents(),
called during the transaction commit path.

If a transaction is aborted we free the qgroup records by calling
btrfs_qgroup_destroy_extent_records() at btrfs_destroy_delayed_refs(),
unless we don't have delayed references. We are incorrectly assuming
that no delayed references means we don't have qgroup extents records.

We can currently have no delayed references because we ran them all
during a transaction commit and the transaction was aborted after that
due to some error in the commit path.

So fix this by ensuring we btrfs_qgroup_destroy_extent_records() at
btrfs_destroy_delayed_refs() even if we don't have any delayed references.

Reported-by: default avatar <syzbot+0fecc032fa134afd49df@syzkaller.appspotmail.com>
Link: https://lore.kernel.org/linux-btrfs/0000000000004e7f980619f91835@google.com/


Fixes: 81f7eb00 ("btrfs: destroy qgroup extent records on transaction abort")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarWang Hai <wanghai38@huawei.com>
parent 243b51b4

fs/btrfs/disk-io.c

+1 −9
Original line number Diff line number Diff line
@@ -4594,18 +4594,10 @@ static void btrfs_destroy_delayed_refs(struct btrfs_transaction *trans, 
				       struct btrfs_fs_info *fs_info)

{

	struct rb_node *node;

	struct btrfs_delayed_ref_root *delayed_refs;

	struct btrfs_delayed_ref_root *delayed_refs = &trans->delayed_refs;

	struct btrfs_delayed_ref_node *ref;



	delayed_refs = &trans->delayed_refs;



	spin_lock(&delayed_refs->lock);

	if (atomic_read(&delayed_refs->num_entries) == 0) {

		spin_unlock(&delayed_refs->lock);

		btrfs_debug(fs_info, "delayed_refs has NO entry");

		return;

	}



	while ((node = rb_first_cached(&delayed_refs->href_root)) != NULL) {

		struct btrfs_delayed_ref_head *head;

		struct rb_node *n;