ntfs: remove unnecessary PG_uptodate check from ntfs_readpage

ntfs: remove unnecessary PG_uptodate check from ntfs_readpage

[Pekka J Enberg]

From: Pekka Enberg <penberg@cs.helsinki.fi>

The check is not needed because SetPageUptodate is called for locked pages
and callers of ->readpage either explicitly check for PageUptodate or pass
newly allocated pages (see read_cache_pages and page_cache_read).

Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
---

 fs/ntfs/aops.c |    8 --------
 1 file changed, 8 deletions(-)

Index: 2.6/fs/ntfs/aops.c
===================================================================
--- 2.6.orig/fs/ntfs/aops.c
+++ 2.6/fs/ntfs/aops.c
@@ -410,14 +410,6 @@ static int ntfs_readpage(struct file *fi
 
 retry_readpage:
 	BUG_ON(!PageLocked(page));
-	/*
-	 * This can potentially happen because we clear PageUptodate() during
-	 * ntfs_writepage() of MstProtected() attributes.
-	 */
-	if (PageUptodate(page)) {
-		unlock_page(page);
-		return 0;
-	}
 	vi = page->mapping->host;
 	ni = NTFS_I(vi);
 	/*

Re: ntfs: remove unnecessary PG_uptodate check from ntfs_readpage

[Anton Altaparmakov]

Please do not apply this patch or you will see metadata corruption on 
NTFS.

Pekka, given there is a comment saying why this check is necessary, I 
really do not understand how you can claim that it is not...

Best regards,

	Anton

On Tue, 25 Jul 2006, Pekka J Enberg wrote:

> From: Pekka Enberg <penberg@cs.helsinki.fi>
> 
> The check is not needed because SetPageUptodate is called for locked pages
> and callers of ->readpage either explicitly check for PageUptodate or pass
> newly allocated pages (see read_cache_pages and page_cache_read).
> 
> Cc: Andrew Morton <akpm@osdl.org>
> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
> ---
> 
>  fs/ntfs/aops.c |    8 --------
>  1 file changed, 8 deletions(-)
> 
> Index: 2.6/fs/ntfs/aops.c
> ===================================================================
> --- 2.6.orig/fs/ntfs/aops.c
> +++ 2.6/fs/ntfs/aops.c
> @@ -410,14 +410,6 @@ static int ntfs_readpage(struct file *fi
>  
>  retry_readpage:
>  	BUG_ON(!PageLocked(page));
> -	/*
> -	 * This can potentially happen because we clear PageUptodate() during
> -	 * ntfs_writepage() of MstProtected() attributes.
> -	 */
> -	if (PageUptodate(page)) {
> -		unlock_page(page);
> -		return 0;
> -	}
>  	vi = page->mapping->host;
>  	ni = NTFS_I(vi);
>  	/*
> 

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer, http://www.linux-ntfs.org/

Re: ntfs: remove unnecessary PG_uptodate check from ntfs_readpage

[Pekka J Enberg]

On Tue, 25 Jul 2006, Anton Altaparmakov wrote:
> Please do not apply this patch or you will see metadata corruption on 
> NTFS.
> 
> Pekka, given there is a comment saying why this check is necessary, I 
> really do not understand how you can claim that it is not...

Sorry Anton, that's just me being confused, I guess... I don't see you 
dropping page lock in ntfs_writepage so how does that happen then? Thanks.

					Pekka