Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422860AbXBILAh (ORCPT ); Fri, 9 Feb 2007 06:00:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422998AbXBILAh (ORCPT ); Fri, 9 Feb 2007 06:00:37 -0500 Received: from e5.ny.us.ibm.com ([32.97.182.145]:49718 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422860AbXBILAf (ORCPT ); Fri, 9 Feb 2007 06:00:35 -0500 Date: Fri, 9 Feb 2007 16:35:55 +0530 From: Suparna Bhattacharya To: Jiri Kosina Cc: Andrew Morton , "Ananiev, Leonid I" , linux-kernel@vger.kernel.org, linux-aio , Zach Brown , Chris Mason , Badari Pulavarty , Jan Kara Subject: Re: [PATCH] aio: fix kernel bug when page is temporally busy Message-ID: <20070209110555.GA11232@in.ibm.com> Reply-To: suparna@in.ibm.com References: <20070209021444.2213deb6.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1747 Lines: 53 On Fri, Feb 09, 2007 at 11:40:27AM +0100, Jiri Kosina wrote: > On Fri, 9 Feb 2007, Andrew Morton wrote: > > > > @@ -1204,7 +1204,7 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, > > > do_generic_file_read(filp,ppos,&desc,file_read_actor); > > > retval += desc.written; > > > if (desc.error) { > > > - retval = retval ?: desc.error; > > > + retval = desc.error; > > > break; > > > } > > Nope. On error the read() syscall must return the number of bytes which > > were successfully read. > > You are right. > > In current mainline this even is not a problem, because noone seems to be > setting the error values to EIOCBRETRY. But it still stinks a bit, as > there are tests for EIOCBRETRY. We'd want retries to act only on the remaining bytes which haven't been transferred as yet, so even in the EIOCBRETRY case the right thing to do is to return the number of bytes that were successfully read without blocking. The high level AIO code (see aio_rw_vect_rety) has the ability to handle this. So this is still correct. Is there a real bug that you are seeing here ? Regards Suparna > > -- > Jiri Kosina > > -- > To unsubscribe, send a message with 'unsubscribe linux-aio' in > the body to majordomo@kvack.org. For more info on Linux AIO, > see: http://www.kvack.org/aio/ > Don't email: aart@kvack.org -- Suparna Bhattacharya (suparna@in.ibm.com) Linux Technology Center IBM Software Lab, India - 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/