Re: [Outreachy kernel] [PATCH v4] staging: unisys: visorhba: Convert module from IDR to XArray

[Matthew Wilcox <willy@infradead.org>]

On Tue, Apr 27, 2021 at 03:25:22PM +0200, Fabio M. De Francesco wrote:
> +++ b/drivers/staging/unisys/include/iochannel.h
> @@ -474,8 +474,8 @@ struct uiscmdrsp_scsitaskmgmt {
>  	enum task_mgmt_types tasktype;
>  	struct uisscsi_dest vdest;
>  	u64 handle;
> -	u64 notify_handle;
> -	u64 notifyresult_handle;
> +	u32 notify_handle;
> +	u32 notifyresult_handle;
>  	char result;
>  
>  #define TASK_MGMT_FAILED 0

I'm scared of this change.  Read the top of the file:

 * Everything needed for IOPart-GuestPart communication is define in
 * this file. Note: Everything is OS-independent because this file is
 * used by Windows, Linux and possible EFI drivers.

I don't know that you can make any changes to this file.

> +static void setup_scsitaskmgmt_handles(struct xarray *xa, struct uiscmdrsp *cmdrsp,
>  				       wait_queue_head_t *event, int *result)
>  {
> -	/* specify the event that has to be triggered when this */
> -	/* cmd is complete */
> -	cmdrsp->scsitaskmgmt.notify_handle =
> -		simple_idr_get(idrtable, event, lock);
> -	cmdrsp->scsitaskmgmt.notifyresult_handle =
> -		simple_idr_get(idrtable, result, lock);
> +	int ret;
> +	u32 *id;
> +
> +	/* specify the event that has to be triggered when this cmd is complete */
> +	id = &cmdrsp->scsitaskmgmt.notify_handle;
> +	ret = xa_alloc_irq(xa, id, event, XA_LIMIT(1, INT_MAX), GFP_KERNEL);

You're still not handling the error here.