From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51978) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eHoxp-0002yP-Kj for qemu-devel@nongnu.org; Thu, 23 Nov 2017 05:42:38 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eHoxj-0006Md-VU for qemu-devel@nongnu.org; Thu, 23 Nov 2017 05:42:37 -0500 References: <1511364808-30171-1-git-send-email-deepa.srinivasan@oracle.com> <20171122170607.GA8217@stefanha-x1.localdomain> <20171122180426.GC10954@localhost.localdomain> <20171123102325.GA26022@stefanha-x1.localdomain> From: Paolo Bonzini Message-ID: <2735b9a3-7f03-d82b-fe88-b189f1989abf@redhat.com> Date: Thu, 23 Nov 2017 11:42:15 +0100 MIME-Version: 1.0 In-Reply-To: <20171123102325.GA26022@stefanha-x1.localdomain> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] block: Fix qemu crash when using scsi-block List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi , Kevin Wolf Cc: Deepa Srinivasan , mreitz@redhat.com, qemu-block@nongnu.org, qemu-devel@nongnu.org, mark.kanda@oracle.com, Konrad Rzeszutek Wilk On 23/11/2017 11:23, Stefan Hajnoczi wrote: > You are right. I audited the blk_aio_preadv() callers and they all kee= p > qiov around until the request is complete. >=20 > Actually this makes sense because even in the simple non-coroutine case > with aio=3Dthreads the qiov hasn't necessarily been read yet when the > function returns. The aio_worker() function executes later and only > then is qiov handed to the host kernel. >=20 > So this is a one-off bug in blk_aio_ioctl() callers. Only in blk_aio_ioctl, not in the callers. Paolo