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From: Andrew Morton <akpm@linux-foundation.org>
To: Krishna Kumar <krkumar2@in.ibm.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: do_generic_file_read() never gets a NULL 'filp' argument
Date: Mon, 22 Sep 2008 01:33:38 -0700	[thread overview]
Message-ID: <20080922013338.8e1c10ff.akpm@linux-foundation.org> (raw)
In-Reply-To: <20080922061610.20158.86022.sendpatchset@localhost.localdomain>

On Mon, 22 Sep 2008 11:46:10 +0530 Krishna Kumar <krkumar2@in.ibm.com> wrote:

> From: Krishna Kumar <krkumar2@in.ibm.com>
> 
> The 'filp' argument to do_generic_file_read() is never NULL.
> 

How did you verify this?

NFS used to like passing NULL file*'s into VFS functions.  I don't
recall whether it affected do_generic_file_read().

>  mm/filemap.c |    3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff -ruNp 2.6.27-rc7-org/mm/filemap.c 2.6.27-rc7-new/mm/filemap.c
> --- 2.6.27-rc7-org/mm/filemap.c	2008-09-17 12:53:25.000000000 +0530
> +++ 2.6.27-rc7-new/mm/filemap.c	2008-09-17 12:53:59.000000000 +0530
> @@ -1186,8 +1186,7 @@ out:
>  	ra->prev_pos |= prev_offset;
>  
>  	*ppos = ((loff_t)index << PAGE_CACHE_SHIFT) + offset;
> -	if (filp)
> -		file_accessed(filp);
> +	file_accessed(filp);
>  }
>  
>  int file_read_actor(read_descriptor_t *desc, struct page *page,

  reply	other threads:[~2008-09-22  8:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-09-22  6:16 [PATCH] mm: do_generic_file_read() never gets a NULL 'filp' argument Krishna Kumar
2008-09-22  8:33 ` Andrew Morton [this message]
2008-09-22  8:39   ` Christoph Hellwig
2008-09-22 17:36     ` Andrew Morton
2008-09-23 11:00       ` KOSAKI Motohiro
2008-09-22  8:40   ` KOSAKI Motohiro

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