Re: [PATCH 3/9] iomap: Use kzalloc to allocate iomap_page

[Darrick J. Wong]

On Mon, Aug 24, 2020 at 03:55:04PM +0100, Matthew Wilcox (Oracle) wrote:
> We can skip most of the initialisation, although spinlocks still
> need explicit initialisation as architectures may use a non-zero
> value to indicate unlocked.  The comment is no longer useful as
> attach_page_private() handles the refcount now.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>

Looks good to me,
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

--D

> ---
>  fs/iomap/buffered-io.c | 10 +---------
>  1 file changed, 1 insertion(+), 9 deletions(-)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 13d5cdab8dcd..639d54a4177e 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -49,16 +49,8 @@ iomap_page_create(struct inode *inode, struct page *page)
>  	if (iop || i_blocks_per_page(inode, page) <= 1)
>  		return iop;
>  
> -	iop = kmalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL);
> -	atomic_set(&iop->read_count, 0);
> -	atomic_set(&iop->write_count, 0);
> +	iop = kzalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL);
>  	spin_lock_init(&iop->uptodate_lock);
> -	bitmap_zero(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);
> -
> -	/*
> -	 * migrate_page_move_mapping() assumes that pages with private data have
> -	 * their count elevated by 1.
> -	 */
>  	attach_page_private(page, iop);
>  	return iop;
>  }
> -- 
> 2.28.0
>