[PATCH] fs/ceph: use release_pages() directly

[PATCH] fs/ceph: use release_pages() directly

[john.hubbard]

From: John Hubbard <jhubbard@nvidia.com>

release_pages() has been available to modules since Oct, 2010,
when commit 0be8557bcd34 ("fuse: use release_pages()") added
EXPORT_SYMBOL(release_pages). However, this ceph code was still
using a workaround.

Remove the workaround, and call release_pages() directly.

Cc: Jeff Layton <jlayton@kernel.org>
Cc: Sage Weil <sage@redhat.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: ceph-devel@vger.kernel.org
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---

Hi,

I noticed this while I trying to understand mlock.c's use of
pagevec_release(). So I was looking around for examples, and stumbled
across this, which seems worth cleaning up.

thanks,
John Hubbard
NVIDIA

 fs/ceph/addr.c | 19 +------------------
 1 file changed, 1 insertion(+), 18 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index e078cc55b989..22ed45d143be 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -679,23 +679,6 @@ static int ceph_writepage(struct page *page, struct writeback_control *wbc)
 	return err;
 }
 
-/*
- * lame release_pages helper.  release_pages() isn't exported to
- * modules.
- */
-static void ceph_release_pages(struct page **pages, int num)
-{
-	struct pagevec pvec;
-	int i;
-
-	pagevec_init(&pvec);
-	for (i = 0; i < num; i++) {
-		if (pagevec_add(&pvec, pages[i]) == 0)
-			pagevec_release(&pvec);
-	}
-	pagevec_release(&pvec);
-}
-
 /*
  * async writeback completion handler.
  *
@@ -769,7 +752,7 @@ static void writepages_finish(struct ceph_osd_request *req)
 		dout("writepages_finish %p wrote %llu bytes cleaned %d pages\n",
 		     inode, osd_data->length, rc >= 0 ? num_pages : 0);
 
-		ceph_release_pages(osd_data->pages, num_pages);
+		release_pages(osd_data->pages, num_pages);
 	}
 
 	ceph_put_wrbuffer_cap_refs(ci, total_pages, snapc);
-- 
2.22.0

Re: [PATCH] fs/ceph: use release_pages() directly

[Jeff Layton]

On Thu, 2019-08-08 at 20:56 -0700, john.hubbard@gmail.com wrote:
> From: John Hubbard <jhubbard@nvidia.com>
> 
> release_pages() has been available to modules since Oct, 2010,
> when commit 0be8557bcd34 ("fuse: use release_pages()") added
> EXPORT_SYMBOL(release_pages). However, this ceph code was still
> using a workaround.
> 
> Remove the workaround, and call release_pages() directly.
> 
> Cc: Jeff Layton <jlayton@kernel.org>
> Cc: Sage Weil <sage@redhat.com>
> Cc: Ilya Dryomov <idryomov@gmail.com>
> Cc: ceph-devel@vger.kernel.org
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> ---
> 
> Hi,
> 
> I noticed this while I trying to understand mlock.c's use of
> pagevec_release(). So I was looking around for examples, and stumbled
> across this, which seems worth cleaning up.
> 
> thanks,
> John Hubbard
> NVIDIA
> 
>  fs/ceph/addr.c | 19 +------------------
>  1 file changed, 1 insertion(+), 18 deletions(-)
> 
> diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
> index e078cc55b989..22ed45d143be 100644
> --- a/fs/ceph/addr.c
> +++ b/fs/ceph/addr.c
> @@ -679,23 +679,6 @@ static int ceph_writepage(struct page *page, struct writeback_control *wbc)
>  	return err;
>  }
>  
> -/*
> - * lame release_pages helper.  release_pages() isn't exported to
> - * modules.
> - */
> -static void ceph_release_pages(struct page **pages, int num)
> -{
> -	struct pagevec pvec;
> -	int i;
> -
> -	pagevec_init(&pvec);
> -	for (i = 0; i < num; i++) {
> -		if (pagevec_add(&pvec, pages[i]) == 0)
> -			pagevec_release(&pvec);
> -	}
> -	pagevec_release(&pvec);
> -}
> -
>  /*
>   * async writeback completion handler.
>   *
> @@ -769,7 +752,7 @@ static void writepages_finish(struct ceph_osd_request *req)
>  		dout("writepages_finish %p wrote %llu bytes cleaned %d pages\n",
>  		     inode, osd_data->length, rc >= 0 ? num_pages : 0);
>  
> -		ceph_release_pages(osd_data->pages, num_pages);
> +		release_pages(osd_data->pages, num_pages);
>  	}
>  
>  	ceph_put_wrbuffer_cap_refs(ci, total_pages, snapc);

Thanks John. Running tests on it now, and will probably push to our
testing branch later today. It should make v5.4.

-- 
Jeff Layton <jlayton@kernel.org>