linux-kernel - Re: [PATCH 08/11] cifs: Remove call to filemap_check_wb

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Message-ID: <7d1499fadf42052711e39f0d8c7656f4d3a4bc9d.camel@redhat.com>
Date:   Mon, 09 Jan 2023 09:42:36 -0500
From:   Jeff Layton <jlayton@...hat.com>
To:     "Matthew Wilcox (Oracle)" <willy@...radead.org>
Cc:     linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, Christoph Hellwig <hch@....de>
Subject: Re: [PATCH 08/11] cifs: Remove call to filemap_check_wb_err()

On Mon, 2023-01-09 at 05:18 +0000, Matthew Wilcox (Oracle) wrote:
> filemap_write_and_wait() now calls filemap_check_wb_err(), so we cannot
> glean any additional information by calling it ourselves.  It may also
> be misleading as it will pick up on any errors since the beginning of
> time which may well be since before this program opened the file.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
> ---
>  fs/cifs/file.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index 22dfc1f8b4f1..7e7ee26cf77d 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -3042,14 +3042,12 @@ int cifs_flush(struct file *file, fl_owner_t id)
>  	int rc = 0;
>  
>  	if (file->f_mode & FMODE_WRITE)
> -		rc = filemap_write_and_wait(inode->i_mapping);
> +		rc = filemap_write_and_wait(file->f_mapping);

If we're calling ->flush, then the file is being closed. Should this
just be?
		rc = file_write_and_wait(file);

It's not like we need to worry about corrupting ->f_wb_err at that
point.

>  
>  	cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file rc);
> -	if (rc) {
> -		/* get more nuanced writeback errors */
> -		rc = filemap_check_wb_err(file->f_mapping, 0);
> +	if (rc)
>  		trace_cifs_flush_err(inode->i_ino, rc);
> -	}
> +
>  	return rc;
>  }
>  

-- 
Jeff Layton <jlayton@...hat.com>