Re: [PATCH v2 3/4] reftable/stack: move list lock to `struct reftable_stack`

[Patrick Steinhardt <ps@pks.im>]

On Mon, Aug 24, 2026 at 11:31:01AM +0200, Karthik Nayak wrote:
> diff --git a/reftable/stack.c b/reftable/stack.c
> index 703548417c..c3d4deff29 100644
> --- a/reftable/stack.c
> +++ b/reftable/stack.c
> @@ -628,10 +630,16 @@ int reftable_stack_reload(struct reftable_stack *st)
>  }
>  
>  struct reftable_addition {
> -	struct reftable_flock tables_list_lock;
>  	struct reftable_stack *stack;
>  	struct reftable_write_options opts;
>  
> +	/*
> +	 * While the list lock is acquired on the stack, we need to distinguish
> +	 * which 'reftable_addition' is responsible for the lock. This avoids
> +	 * clearing the lock of another 'reftable_addition'.
> +	 */
> +	unsigned int locked : 1;
> +
>  	char **new_tables;
>  	size_t new_tables_len, new_tables_cap;
>  	uint64_t next_update_index;

This feels somewhat fragile, as tracking state via a bit is very easy to
get wrong. I would have preferred a solution where we didn't have to
have this field and instead a more direct proxy. But there's not that
many spots where we have to do this, so this may be okay-ish.

Other than that this series looks good to me, thanks!

Patrick