From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pali =?utf-8?q?Roh=C3=A1r?= Subject: Re: [PATCH 1/3] PM suspend/hibernate: Call notifier after freezing processes Date: Thu, 9 Apr 2015 08:36:57 +0200 Message-ID: <201504090836.57365@pali> References: <1428254419-7334-1-git-send-email-pali.rohar@gmail.com> <1428254419-7334-2-git-send-email-pali.rohar@gmail.com> <1530775.n2Kjx1bffW@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2566388.gOmNIJrIqI"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1530775.n2Kjx1bffW@vostro.rjw.lan> Sender: linux-raid-owner@vger.kernel.org To: "Rafael J. Wysocki" Cc: Alasdair Kergon , Mike Snitzer , Neil Brown , Len Brown , Pavel Machek , dm-devel@redhat.com, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org List-Id: linux-raid.ids --nextPart2566388.gOmNIJrIqI Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable On Thursday 09 April 2015 02:28:41 Rafael J. Wysocki wrote: > On Sunday, April 05, 2015 07:20:17 PM Pali Roh=C3=A1r wrote: > > To prevent race conditions on userspace processes with I/O > > some taks must be called after processes are freezed. This > > patch adds new events which are delivered by > > pm_notifier_call_chain() after freezing processes when > > doing suspend or hibernate action. > >=20 > > Signed-off-by: Pali Roh=C3=A1r >=20 > Please don't add more notifiers. Just call whatever you need > directly from where you need to call that. >=20 > If that is device-related, try to use device PM > suspend/hibernate callbacks instead. >=20 Hi! It is not possible to use any exiting pm notifiers! This is=20 reason why I added new ones. As I wrote wiping dm crypt keys must=20 be done *after* userspace processes are freezed to prevent race=20 conditions... > > --- > >=20 > > include/linux/suspend.h | 2 ++ > > kernel/power/hibernate.c | 2 ++ > > kernel/power/suspend.c | 4 +++- > > 3 files changed, 7 insertions(+), 1 deletion(-) > >=20 > > diff --git a/include/linux/suspend.h > > b/include/linux/suspend.h index 5efe743..bc743c8 100644 > > --- a/include/linux/suspend.h > > +++ b/include/linux/suspend.h > > @@ -368,6 +368,8 @@ static inline bool > > hibernation_available(void) { return false; } > >=20 > > #define PM_POST_SUSPEND 0x0004 /* Suspend finished */ > > #define PM_RESTORE_PREPARE 0x0005 /* Going to restore a > > saved image */ #define PM_POST_RESTORE 0x0006 /* > > Restore > > failed */ > >=20 > > +#define PM_HIBERNATION_AFTER_FREEZE 0x0007 /* After > > hibernation freeze */ +#define > > PM_SUSPEND_AFTER_FREEZE 0x0008 /* After suspend freeze */ > >=20 > > extern struct mutex pm_mutex; > >=20 > > diff --git a/kernel/power/hibernate.c > > b/kernel/power/hibernate.c index 2329daa..184f7ee 100644 > > --- a/kernel/power/hibernate.c > > +++ b/kernel/power/hibernate.c > > @@ -671,6 +671,8 @@ int hibernate(void) > >=20 > > if (error) > > =09 > > goto Exit; > >=20 > > + pm_notifier_call_chain(PM_HIBERNATION_AFTER_FREEZE); > > + > >=20 > > lock_device_hotplug(); > > /* Allocate memory management structures */ > > error =3D create_basic_memory_bitmaps(); > >=20 > > diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c > > index b7d6b3a..1776938 100644 > > --- a/kernel/power/suspend.c > > +++ b/kernel/power/suspend.c > > @@ -268,8 +268,10 @@ static int > > suspend_prepare(suspend_state_t state) > >=20 > > trace_suspend_resume(TPS("freeze_processes"), 0, true); > > error =3D suspend_freeze_processes(); > > trace_suspend_resume(TPS("freeze_processes"), 0, false); > >=20 > > - if (!error) > > + if (!error) { > > + pm_notifier_call_chain(PM_SUSPEND_AFTER_FREEZE); > >=20 > > return 0; > >=20 > > + } > >=20 > > suspend_stats.failed_freeze++; > > dpm_save_failed_step(SUSPEND_FREEZE); =2D-=20 Pali Roh=C3=A1r pali.rohar@gmail.com --nextPart2566388.gOmNIJrIqI Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iEYEABECAAYFAlUmHgkACgkQi/DJPQPkQ1KqBQCgsCMPDSjapvieT2WGen4RFz1c FZ0AoLar16geldAQXYKF7cbDoVv1l2bf =QehT -----END PGP SIGNATURE----- --nextPart2566388.gOmNIJrIqI--