Re: [PATCH v2] octeontx2-af: use seq_file for rsrc_alloc debugfs

[Ratheesh Kannoth]

On 2026-09-08 at 07:24:35, Heyang Tan (thy15333007817@xxxxxxx) wrote:
> The rsrc_alloc debugfs reader writes rows directly to userspace without
> respecting the caller's read count. It also uses the current row length as
> the userspace stride, which can corrupt output when rows have different
> widths.
>
> Use seq_file to handle userspace buffer sizes, offsets, and partial reads,
> and write output columns directly to the seq_file buffer.
>
> Fixes: 23205e6d06d4 ("octeontx2-af: Dump current resource provisioning status")
> Signed-off-by: Heyang Tan <thy15333007817@xxxxxxx>
> ---
> Changes in v2:
> - Write columns directly to the seq_file buffer as suggested by Ratheesh.
Thank you!

> +static int rvu_dbg_rsrc_attach_status(struct seq_file *filp, void *unused)
>  {
> -	int index, off = 0, flag = 0, len = 0, i = 0;
> -	struct rvu *rvu = filp->private_data;
> -	int bytes_not_copied = 0;
> +	int index, pf, vf, pcifunc;
> +	struct rvu *rvu = filp->private;
Reverse xmas tree?
>  	struct rvu_block block;
> -	int pf, vf, pcifunc;
> -	int buf_size = 2048;
>  	int lf_str_size;
>  	char *lfs;
> -	char *buf;
> -
> -	/* don't allow partial reads */
> -	if (*ppos != 0)
> -		return 0;
> -
> -	buf = kzalloc(buf_size, GFP_KERNEL);
> -	if (!buf)
> -		return -ENOMEM;
>
> -	/* Get the maximum width of a column */
>  	lf_str_size = get_max_column_width(rvu);
> +	if (lf_str_size < 0)
> +		return lf_str_size;
>
>  	lfs = kzalloc(lf_str_size, GFP_KERNEL);
Do we need this ? can we pass seqfile as well to get_lf_str_list() ?
may be rename the function to suit its functionality ?

> -	if (!lfs) {
> -		kfree(buf);
> +	if (!lfs)
>  		return -ENOMEM;
> -	}
> -	off +=	scnprintf(&buf[off], buf_size - 1 - off, "%-*s", lf_str_size,
> -			  "pcifunc");