From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:32801) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UF4Xp-0004BU-Jm for qemu-devel@nongnu.org; Mon, 11 Mar 2013 11:21:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UF4Xn-0006zM-Q0 for qemu-devel@nongnu.org; Mon, 11 Mar 2013 11:21:45 -0400 Received: from mail-pb0-f41.google.com ([209.85.160.41]:35604) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UF4Xn-0006zF-JH for qemu-devel@nongnu.org; Mon, 11 Mar 2013 11:21:43 -0400 Received: by mail-pb0-f41.google.com with SMTP id um15so3875842pbc.0 for ; Mon, 11 Mar 2013 08:21:42 -0700 (PDT) Date: Tue, 12 Mar 2013 00:21:41 +0900 Message-ID: From: MORITA Kazutaka In-Reply-To: <20130311143905.GB7611@stefanha-thinkpad.redhat.com> References: <1362992462-1864-1-git-send-email-morita.kazutaka@lab.ntt.co.jp> <20130311143905.GB7611@stefanha-thinkpad.redhat.com> MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Subject: Re: [Qemu-devel] [PATCH] sheepdog: set io_flush handler in do_co_req List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: kwolf@redhat.com, qemu-devel@nongnu.org, MORITA Kazutaka At Mon, 11 Mar 2013 15:39:05 +0100, Stefan Hajnoczi wrote: > > On Mon, Mar 11, 2013 at 06:01:02PM +0900, MORITA Kazutaka wrote: > > If an io_flush handler is not set, qemu_aio_wait doesn't invoke > > callbacks. > > > > Signed-off-by: MORITA Kazutaka > > --- > > block/sheepdog.c | 11 +++++++++-- > > 1 file changed, 9 insertions(+), 2 deletions(-) > > > > diff --git a/block/sheepdog.c b/block/sheepdog.c > > index e4ec32d..cb0eeed 100644 > > --- a/block/sheepdog.c > > +++ b/block/sheepdog.c > > @@ -501,6 +501,13 @@ static void restart_co_req(void *opaque) > > qemu_coroutine_enter(co, NULL); > > } > > > > +static int have_co_req(void *opaque) > > +{ > > + /* this handler is set only when there is a pending request, so > > + * always returns 1. */ > > + return 1; > > +} > > + > > typedef struct SheepdogReqCo { > > int sockfd; > > SheepdogReq *hdr; > > @@ -523,14 +530,14 @@ static coroutine_fn void do_co_req(void *opaque) > > unsigned int *rlen = srco->rlen; > > > > co = qemu_coroutine_self(); > > - qemu_aio_set_fd_handler(sockfd, NULL, restart_co_req, NULL, co); > > + qemu_aio_set_fd_handler(sockfd, NULL, restart_co_req, have_co_req, co); > > > > ret = send_co_req(sockfd, hdr, data, wlen); > > Which tree is this patch against? block/sheepdog.c:do_co_req() has a > socket_set_block(sockfd) call before this line. Sorry, I have another patch in my local tree that needed to be sent before this one. I'll send v2 including the missing patch. > > Is there a guarantee that only one coroutine executes do_co_req() at a > time? Otherwise the first coroutine that finishes the function sets > io_flush to NULL even though there's still another request processing. Yes - the sockfd is opened just before calling do_req() and is closed just after returning the function, so the sheepdog driver cannot call multiple do_co_req() at a time against the same socket descriptor. Thanks, Kazutaka