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

Calum Mackay
2019-08-03T01:27:55Z

On 02/08/2019 3:20 am, john.hubbard@gmail.com wrote:
> From: John Hubbard <jhubbard@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@hammerspace.com>
> Cc: Anna Schumaker <anna.schumaker@netapp.com>
> Cc: linux-nfs@vger.kernel.org
> Signed-off-by: John Hubbard <jhubbard@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,
>