Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755290AbXABP0e (ORCPT ); Tue, 2 Jan 2007 10:26:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755308AbXABP0e (ORCPT ); Tue, 2 Jan 2007 10:26:34 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:36464 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755290AbXABP0d (ORCPT ); Tue, 2 Jan 2007 10:26:33 -0500 Date: Tue, 2 Jan 2007 10:26:32 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Oliver Neukum cc: gregkh@suse.de, , Subject: Re: error handling in sysfs, fill_read_buffer() In-Reply-To: <200701020850.28724.oliver@neukum.name> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1302 Lines: 37 On Tue, 2 Jan 2007, Oliver Neukum wrote: > Hi, > > if a driver returns an error in fill_read_buffer(), the buffer will be > marked as filled. Subsequent reads will return eof. But there is > no data because of an error, not because it has been read. > Not marking the buffer filled is the obvious fix. > > Regards > Oliver > > Signed-off-by: Oliver Neukum > -- > > --- a/fs/sysfs/file.c 2006-12-24 05:00:32.000000000 +0100 > +++ b/fs/sysfs/file.c 2007-01-01 15:03:14.000000000 +0100 > @@ -70,7 +70,8 @@ > * Allocate @buffer->page, if it hasn't been already, then call the > * kobject's show() method to fill the buffer with this attribute's > * data. > - * This is called only once, on the file's first read. > + * This is called only once, on the file's first read unless an error > + * is returned. > */ I don't think this matches what people expect of sysfs. If a show method fails then the assumption is that the file cannot be read at all, so there's no point in trying to call the method again. Alan Stern - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/