[bug report] UBI: Fastmap: Do not add vol if it already exists

[Sheng Yong]

Hi Dan,

On 10/26/2016 4:46 AM, Dan Carpenter wrote:
> Hello shengyong,
> 
> The patch e96a8a3bb671: "UBI: Fastmap: Do not add vol if it already
> exists" from May 26, 2015, leads to the following static checker
> warning:
> 
> 	drivers/mtd/ubi/fastmap.c:712 ubi_attach_fastmap()
> 	warn: PTR_ERR(av) is never (-22)
> 
> drivers/mtd/ubi/fastmap.c
>    703  
>    704                  av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
>    705                               be32_to_cpu(fmvhdr->used_ebs),
>    706                               be32_to_cpu(fmvhdr->data_pad),
>    707                               fmvhdr->vol_type,
>    708                               be32_to_cpu(fmvhdr->last_eb_bytes));
>    709  
>    710                  if (!av)
>    711                          goto fail_bad;
>    712                  if (PTR_ERR(av) == -EINVAL) {
> 
> av is either -EEXIST or -ENOMEM.  It's never -EINVAL.
The commit e96a8a3bb671 ("UBI: Fastmap: Do not add vol if it already exists")
adds a "return ERR_PTR(-EINVAL);" to add_vol(). So I think av could be -EINVAL.
You mean add_vol should return -EEXIST instead of -EINVAL?

thanks,
Sheng
> 
>    713                          ubi_err(ubi, "volume (ID %i) already exists",
>    714                                  fmvhdr->vol_id);
>    715                          goto fail_bad;
>    716                  }
>    717  
> 
> regards,
> dan carpenter
> 
> .
>