Re: [PATCH v4] scsi: sd: Fix build warning in sd_revalidate_disk()

[Bart Van Assche <bvanassche@acm.org>]

On 8/8/25 11:28 AM, Abinash Singh wrote:
> A build warning was triggered due to excessive stack usage in
> sd_revalidate_disk():
 > [ ... ]

New versions of a patch should be posted as a new email thread instead
of a reply. Otherwise there is a significant chance that the new version
gets overlooked.

> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index 4a68b2ab2804..c7fbfb801b40 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -3696,10 +3696,10 @@ static int sd_revalidate_disk(struct gendisk *disk)
>   	struct scsi_disk *sdkp = scsi_disk(disk);
>   	struct scsi_device *sdp = sdkp->device;
>   	sector_t old_capacity = sdkp->capacity;
> -	struct queue_limits lim;
> -	unsigned char *buffer;
> +	struct queue_limits *lim = NULL;
> +	unsigned char *buffer = NULL;
>   	unsigned int dev_max;
> -	int err;
> +	int err = 0;
>   
>   	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
>   				      "sd_revalidate_disk\n"));
> @@ -3711,6 +3711,13 @@ static int sd_revalidate_disk(struct gendisk *disk)
>   	if (!scsi_device_online(sdp))
>   		goto out;
>   
> +	lim = kmalloc(sizeof(*lim), GFP_KERNEL);
> +	if (!lim) {
> +		sd_printk(KERN_WARNING, sdkp,
> +			"sd_revalidate_disk: Disk limit allocation failure.\n");
> +		goto out;
> +	}

Returning a negative value for some errors and zero in case of success
or in case of memory allocation failure is confusing.

Since none of the sd_revalidate_disk() callers care about the value
returned by this function, please change the return type of this
function into 'void'. Since that change is logically independent of 
allocating 'lim' dynamically, that change probably should be a patch on
its own.

Thanks,

Bart.