From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753318AbbJZHuK (ORCPT ); Mon, 26 Oct 2015 03:50:10 -0400 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:37032 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752844AbbJZHuI (ORCPT ); Mon, 26 Oct 2015 03:50:08 -0400 Date: Mon, 26 Oct 2015 08:50:03 +0100 From: Markus Pargmann To: Oleg Nesterov Cc: Andrew Morton , nbd-general@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH -mm 3/3] nbd: don't abuse irqsave/irqrestore while taking nbd->tasks_lock Message-ID: <20151026075003.GG16521@pengutronix.de> References: <20151025152625.GA1385@redhat.com> <20151025152641.GA1405@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="tvOENZuN7d6HfOWU" Content-Disposition: inline In-Reply-To: <20151025152641.GA1405@redhat.com> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 08:49:32 up 36 days, 21:11, 161 users, load average: 0.63, 0.73, 0.90 User-Agent: Mutt/1.5.24 (2015-08-30) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: mpa@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --tvOENZuN7d6HfOWU Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Oct 25, 2015 at 04:26:41PM +0100, Oleg Nesterov wrote: > Both nbd_thread_recv() and nbd_thread_send() are might_sleep() and > called with irqs enabled(), irqsave/irqrestore make no sense and imo > look confusing. Thanks, applied. Regards, Markus >=20 > Signed-off-by: Oleg Nesterov > --- > drivers/block/nbd.c | 22 ++++++++++------------ > 1 files changed, 10 insertions(+), 12 deletions(-) >=20 > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c > index 0ffd73c..fd79405 100644 > --- a/drivers/block/nbd.c > +++ b/drivers/block/nbd.c > @@ -406,23 +406,22 @@ static int nbd_thread_recv(struct nbd_device *nbd) > { > struct request *req; > int ret; > - unsigned long flags; > =20 > BUG_ON(nbd->magic !=3D NBD_MAGIC); > =20 > sk_set_memalloc(nbd->sock->sk); > =20 > - spin_lock_irqsave(&nbd->tasks_lock, flags); > + spin_lock_irq(&nbd->tasks_lock); > nbd->task_recv =3D current; > - spin_unlock_irqrestore(&nbd->tasks_lock, flags); > + spin_unlock_irq(&nbd->tasks_lock); > =20 > ret =3D device_create_file(disk_to_dev(nbd->disk), &pid_attr); > if (ret) { > dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); > =20 > - spin_lock_irqsave(&nbd->tasks_lock, flags); > + spin_lock_irq(&nbd->tasks_lock); > nbd->task_recv =3D NULL; > - spin_unlock_irqrestore(&nbd->tasks_lock, flags); > + spin_unlock_irq(&nbd->tasks_lock); > =20 > return ret; > } > @@ -439,9 +438,9 @@ static int nbd_thread_recv(struct nbd_device *nbd) > =20 > device_remove_file(disk_to_dev(nbd->disk), &pid_attr); > =20 > - spin_lock_irqsave(&nbd->tasks_lock, flags); > + spin_lock_irq(&nbd->tasks_lock); > nbd->task_recv =3D NULL; > - spin_unlock_irqrestore(&nbd->tasks_lock, flags); > + spin_unlock_irq(&nbd->tasks_lock); > =20 > if (signal_pending(current)) { > dev_warn(nbd_to_dev(nbd), "pid %d, %s, got signal", > @@ -543,11 +542,10 @@ static int nbd_thread_send(void *data) > { > struct nbd_device *nbd =3D data; > struct request *req; > - unsigned long flags; > =20 > - spin_lock_irqsave(&nbd->tasks_lock, flags); > + spin_lock_irq(&nbd->tasks_lock); > nbd->task_send =3D current; > - spin_unlock_irqrestore(&nbd->tasks_lock, flags); > + spin_unlock_irq(&nbd->tasks_lock); > =20 > set_user_nice(current, MIN_NICE); > while (!kthread_should_stop() || !list_empty(&nbd->waiting_queue)) { > @@ -581,9 +579,9 @@ static int nbd_thread_send(void *data) > nbd_handle_req(nbd, req); > } > =20 > - spin_lock_irqsave(&nbd->tasks_lock, flags); > + spin_lock_irq(&nbd->tasks_lock); > nbd->task_send =3D NULL; > - spin_unlock_irqrestore(&nbd->tasks_lock, flags); > + spin_unlock_irq(&nbd->tasks_lock); > =20 > return 0; > } > --=20 > 1.5.5.1 >=20 >=20 --=20 Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | --tvOENZuN7d6HfOWU Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJWLdsrAAoJEEpcgKtcEGQQ1gwQAI7jJvdNIxrMjFgfQFlNUFgd TOTmz9AVwr5uX9Vuh7oDRT+Zc06Lywi85NAKKJlNvoffFuT5nsTczm2WuobmhbLF DwqmyGSXevV2zcvWo6GjKAadqV0VKU7TxtjsALXAsmibyH6k+3JS0ScJtn49wMNH Lg1jklbSjTQ1glp1dAJjG2TQka1Q8xROK7S2Vr7eiM82EOPcWFXr0wE9YDFRi7Oh MEmeYmvo0pRmNEAIiCn4pWnjn0PnRmKgs30vEH6j/SwnlhvffUDQzY+Q/L/5c6bm BGwuvD6W4j+wrk6sePWzEd9lASYrjY6zAbGikutDYd7QJkDNEUGRG9/P9aF3qqz1 /5zv56Anz4nMM+LFHBEotM7gMDzQJtq+WF2DvV6q7bI296zfYeeHE9u0UYW00Tmj 7QdVbOnZKnKYALRpZq5xIJPG4rFiT6c5R8owQen3PAdsYx3kqsXv2cjC0HHXWDhA AUhtBFrNUljF3CxplDttal4z8jpQATqxdNkvpexMOfMKIao6Yb574YU0eJBBNGOc zrWMUEdf5JRNyiUNwKKAwWHyfVLBRMx59jIUZv1V+3rCyLFAJt4LrDvLW6uLBFtN ffT4sobPbEs4q9a7CljCtxF6uMpZPMucQXs9MGMndnc367Wy+5NVa8cC0+g6103t 2kknHYMvS5P3imwNo2+h =H4NV -----END PGP SIGNATURE----- --tvOENZuN7d6HfOWU--