Re: [PATCH 33/44] found_iovec_segment(): just return address

[Jeff Layton <jlayton@kernel.org>]

Subject line should read "first_iovec_segment" 

On Wed, 2022-06-22 at 05:15 +0100, Al Viro wrote:
> ... and calculate the offset in the caller
> 
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---
>  lib/iov_iter.c | 22 +++++++---------------
>  1 file changed, 7 insertions(+), 15 deletions(-)
> 
> diff --git a/lib/iov_iter.c b/lib/iov_iter.c
> index fca66ecce7a0..f455b8ee0d76 100644
> --- a/lib/iov_iter.c
> +++ b/lib/iov_iter.c
> @@ -1306,33 +1306,23 @@ static ssize_t iter_xarray_get_pages(struct iov_iter *i,
>  	return min_t(size_t, nr * PAGE_SIZE - offset, maxsize);
>  }
>  
> -static unsigned long found_ubuf_segment(unsigned long addr, size_t *start)
> -{
> -	*start = addr % PAGE_SIZE;
> -	return addr & PAGE_MASK;
> -}
> -
>  /* must be done on non-empty ITER_UBUF or ITER_IOVEC one */
>  static unsigned long first_iovec_segment(const struct iov_iter *i,
> -					 size_t *size, size_t *start)
> +					 size_t *size)
>  {
>  	size_t skip;
>  	long k;
>  
> -	if (iter_is_ubuf(i)) {
> -		unsigned long addr = (unsigned long)i->ubuf + i->iov_offset;
> -		return found_ubuf_segment(addr, start);
> -	}
> +	if (iter_is_ubuf(i))
> +		return (unsigned long)i->ubuf + i->iov_offset;
>  
>  	for (k = 0, skip = i->iov_offset; k < i->nr_segs; k++, skip = 0) {
> -		unsigned long addr = (unsigned long)i->iov[k].iov_base + skip;
>  		size_t len = i->iov[k].iov_len - skip;
> -
>  		if (unlikely(!len))
>  			continue;
>  		if (*size > len)
>  			*size = len;
> -		return found_ubuf_segment(addr, start);
> +		return (unsigned long)i->iov[k].iov_base + skip;
>  	}
>  	BUG(); // if it had been empty, we wouldn't get called
>  }
> @@ -1375,7 +1365,9 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i,
>  		if (i->nofault)
>  			gup_flags |= FOLL_NOFAULT;
>  
> -		addr = first_iovec_segment(i, &maxsize, start);
> +		addr = first_iovec_segment(i, &maxsize);
> +		*start = addr % PAGE_SIZE;
> +		addr &= PAGE_MASK;
>  		n = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE);
>  		if (n > maxpages)
>  			n = maxpages;

Reviewed-by: Jeff Layton <jlayton@kernel.org>