Re: [PATCH 08/10] xfs: add a xlog_write_space_left helper

["Darrick J. Wong" <djwong@kernel.org>]

On Thu, Oct 30, 2025 at 03:49:18PM +0100, Christoph Hellwig wrote:
> Various places check how much space is left in the current iclog,
> add a helper for that.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks ok,
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/xfs/xfs_log.c | 22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> index 2b1744af8a67..7c751665bc44 100644
> --- a/fs/xfs/xfs_log.c
> +++ b/fs/xfs/xfs_log.c
> @@ -1878,13 +1878,18 @@ xlog_print_trans(
>  	}
>  }
>  
> +static inline uint32_t xlog_write_space_left(struct xlog_write_data *data)
> +{
> +	return data->iclog->ic_size - data->log_offset;
> +}
> +
>  static inline void
>  xlog_write_iovec(
>  	struct xlog_write_data	*data,
>  	void			*buf,
>  	uint32_t		buf_len)
>  {
> -	ASSERT(data->log_offset < data->iclog->ic_log->l_iclog_size);
> +	ASSERT(xlog_write_space_left(data) > 0);
>  	ASSERT(data->log_offset % sizeof(int32_t) == 0);
>  	ASSERT(buf_len % sizeof(int32_t) == 0);
>  
> @@ -1906,7 +1911,7 @@ xlog_write_full(
>  {
>  	int			index;
>  
> -	ASSERT(data->log_offset + data->bytes_left <= data->iclog->ic_size ||
> +	ASSERT(data->bytes_left <= xlog_write_space_left(data) ||
>  		data->iclog->ic_state == XLOG_STATE_WANT_SYNC);
>  
>  	/*
> @@ -1978,7 +1983,7 @@ xlog_write_partial(
>  		 * Hence if there isn't space for region data after the
>  		 * opheader, then we need to start afresh with a new iclog.
>  		 */
> -		if (data->iclog->ic_size - data->log_offset <=
> +		if (xlog_write_space_left(data) <=
>  					sizeof(struct xlog_op_header)) {
>  			error = xlog_write_get_more_iclog_space(data);
>  			if (error)
> @@ -1986,8 +1991,7 @@ xlog_write_partial(
>  		}
>  
>  		ophdr = reg->i_addr;
> -		rlen = min_t(uint32_t, reg->i_len,
> -			data->iclog->ic_size - data->log_offset);
> +		rlen = min_t(uint32_t, reg->i_len, xlog_write_space_left(data));
>  
>  		ophdr->oh_tid = cpu_to_be32(data->ticket->t_tid);
>  		ophdr->oh_len = cpu_to_be32(rlen - sizeof(struct xlog_op_header));
> @@ -2052,13 +2056,13 @@ xlog_write_partial(
>  			 */
>  			reg_offset += rlen;
>  			rlen = reg->i_len - reg_offset;
> -			if (rlen <= data->iclog->ic_size - data->log_offset)
> +			if (rlen <= xlog_write_space_left(data))
>  				ophdr->oh_flags |= XLOG_END_TRANS;
>  			else
>  				ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
>  
>  			rlen = min_t(uint32_t, rlen,
> -				data->iclog->ic_size - data->log_offset);
> +					xlog_write_space_left(data));
>  			ophdr->oh_len = cpu_to_be32(rlen);
>  
>  			xlog_write_iovec(data, reg->i_addr + reg_offset, rlen);
> @@ -2135,7 +2139,7 @@ xlog_write(
>  	if (error)
>  		return error;
>  
> -	ASSERT(data.log_offset <= data.iclog->ic_size - 1);
> +	ASSERT(xlog_write_space_left(&data) > 0);
>  
>  	/*
>  	 * If we have a context pointer, pass it the first iclog we are
> @@ -2151,7 +2155,7 @@ xlog_write(
>  		 * the partial copy loop which can handle this case.
>  		 */
>  		if (lv->lv_niovecs &&
> -		    lv->lv_bytes > data.iclog->ic_size - data.log_offset) {
> +		    lv->lv_bytes > xlog_write_space_left(&data)) {
>  			error = xlog_write_partial(lv, &data);
>  			if (error) {
>  				/*
> -- 
> 2.47.3
> 
>