Re: [PATCH] 2.5.30 IDE 113

["Petr Vandrovec" <VANDROVE@vc.cvut.cz>]

On  6 Aug 02 at 11:02, Marcin Dalecki wrote:
> diff -durNp -X /tmp/diff.hDAz3d linux-2.5.30/drivers/ide/ide-taskfile.c linux/drivers/ide/ide-taskfile.c
> --- linux-2.5.30/drivers/ide/ide-taskfile.c 2002-08-06 01:18:47.000000000 +0200
> +++ linux/drivers/ide/ide-taskfile.c    2002-08-04 02:24:49.000000000 +0200
> @@ -188,41 +188,26 @@ static ide_startstop_t special_intr(stru
>  
>  int ide_raw_taskfile(struct ata_device *drive, struct ata_taskfile *ar, char *buf)
>  {
> -   struct request *rq;
> -   unsigned long flags;
> +   struct request *rq = &drive->srequest;
>     struct ata_channel *ch = drive->channel;
>     request_queue_t *q = &drive->queue;
> -   struct list_head *queue_head = &q->queue_head;
>     DECLARE_COMPLETION(wait);
> -   struct request req;
>  
>  #ifdef CONFIG_BLK_DEV_PDC4030
>     if (ch->chipset == ide_pdc4030 && buf)
>         return -ENOSYS;  /* special drive cmds not supported */
>  #endif
>  
> -   memset(&req, 0, sizeof(req));
> -   rq = &req;
> -   
> -   rq->flags = REQ_SPECIAL;
> +   memset(rq, 0, sizeof(*rq));
> +

Hi Marcin,
  what synchronizes these accesses to make sure that you do not have
two ide_raw_taskfile requests on the flight, both using same 
drive->srequest? It looks to me like that nothing, so you can overwrite 
request's contents while somebody else already uses this buffer.
                                                     Petr Vandrovec
                                                     vandrove@vc.cvut.cz