Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755614Ab2F1Wj7 (ORCPT ); Thu, 28 Jun 2012 18:39:59 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:42448 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751012Ab2F1Wj6 (ORCPT ); Thu, 28 Jun 2012 18:39:58 -0400 Date: Thu, 28 Jun 2012 15:39:56 -0700 From: Andrew Morton To: Junxiao Bi Cc: ocfs2-devel@oss.oracle.com, linux-aio@kvack.org, mfasheh@suse.com, linux-kernel@vger.kernel.org, joe.jin@oracle.com, stable@vger.kernel.org Subject: Re: [PATCH v4 1/2] aio: make kiocb->private NUll in init_sync_kiocb() Message-Id: <20120628153956.9b7405d9.akpm@linux-foundation.org> In-Reply-To: <1340788195-20623-2-git-send-email-junxiao.bi@oracle.com> References: <1340788195-20623-1-git-send-email-junxiao.bi@oracle.com> <1340788195-20623-2-git-send-email-junxiao.bi@oracle.com> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2327 Lines: 78 On Wed, 27 Jun 2012 17:09:54 +0800 Junxiao Bi wrote: > Ocfs2 uses kiocb.*private as a flag of unsigned long size. In > commit a11f7e6 ocfs2: serialize unaligned aio, the unaligned > io flag is involved in it to serialize the unaligned aio. As > *private is not initialized in init_sync_kiocb() of do_sync_write(), > this unaligned io flag may be unexpectly set in an aligned dio. > And this will cause OCFS2_I(inode)->ip_unaligned_aio decreased > to -1 in ocfs2_dio_end_io(), thus the following unaligned dio > will hang forever at ocfs2_aiodio_wait() in ocfs2_file_aio_write(). > > Signed-off-by: Junxiao Bi > Cc: stable@vger.kernel.org > Acked-by: Jeff Moyer > Acked-by: Joel Becker > --- > include/linux/aio.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/include/linux/aio.h b/include/linux/aio.h > index 2314ad8..b1a520e 100644 > --- a/include/linux/aio.h > +++ b/include/linux/aio.h > @@ -140,6 +140,7 @@ struct kiocb { > (x)->ki_dtor = NULL; \ > (x)->ki_obj.tsk = tsk; \ > (x)->ki_user_data = 0; \ > + (x)->private = NULL; \ > } while (0) > > #define AIO_RING_MAGIC 0xa10a10a1 hm, that code is rather cruddy. Pointless macromania. If we do this: static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) { struct task_struct *tsk = current; kiocb->ki_flags = 0; kiocb->ki_users = 1; kiocb->ki_key = KIOCB_SYNC_KEY; kiocb->ki_filp = filp; kiocb->ki_ctx = NULL; kiocb->ki_cancel = NULL; kiocb->ki_retry = NULL; kiocb->ki_dtor = NULL; kiocb->ki_obj.tsk = tsk; kiocb->ki_user_data = 0; } it is nicer and there is no impact on code size. If we do this: static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) { *kiocb = (struct kiocb) { .ki_users = 1, .ki_key = KIOCB_SYNC_KEY, .ki_filp = filp, .ki_obj.tsk = current, }; } then fs/read_write.o's .text is shrunk from 9857 bytes to 9714, which is rather a lot. But that's all rather irrelevant to your bugfix. -- 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/