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: syzbot+0fecc032fa134afd49df@xxxxxxxxxxxxxxxxxxxxxxxxx Link: https://lore.kernel.org/linux-btrfs/0000000000004e7f980619f91835@xxxxxxxxxx/ Fixes: 81f7eb00ff5b ("btrfs: destroy qgroup extent records on transaction abort") CC: stable@xxxxxxxxxxxxxxx # 6.1+ Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx> Reviewed-by: Qu Wenruo <wqu@xxxxxxxx> Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index a91a8056758a..242ada7e47b4 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -4538,18 +4538,10 @@ 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;
