[PATCH 31/34] nfs: convert put_page() to put_user_page*()

[Calum Mackay]

On 02/08/2019 3:20 am, john.hubbard at gmail.com wrote:
> From: John Hubbard <jhubbard at nvidia.com>
> 
> For pages that were retained via get_user_pages*(), release those pages
> via the new put_user_page*() routines, instead of via put_page() or
> release_pages().
> 
> This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
> ("mm: introduce put_user_page*(), placeholder versions").
> 
> Cc: Trond Myklebust <trond.myklebust at hammerspace.com>
> Cc: Anna Schumaker <anna.schumaker at netapp.com>
> Cc: linux-nfs at vger.kernel.org
> Signed-off-by: John Hubbard <jhubbard at nvidia.com>
> ---
>   fs/nfs/direct.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
> index 0cb442406168..b00b89dda3c5 100644
> --- a/fs/nfs/direct.c
> +++ b/fs/nfs/direct.c
> @@ -278,9 +278,7 @@ ssize_t nfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
>   
>   static void nfs_direct_release_pages(struct page **pages, unsigned int npages)
>   {
> -	unsigned int i;
> -	for (i = 0; i < npages; i++)
> -		put_page(pages[i]);
> +	put_user_pages(pages, npages);
>   }

Since it's static, and only called twice, might it be better to change 
its two callers [nfs_direct_{read,write}_schedule_iovec()] to call 
put_user_pages() directly, and remove nfs_direct_release_pages() entirely?

thanks,
calum.


>   
>   void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
>