From: "Pali Rohár" <pali.rohar@gmail.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Alasdair Kergon <agk@redhat.com>,
Mike Snitzer <snitzer@redhat.com>, Neil Brown <neilb@suse.de>,
Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
dm-devel@redhat.com, linux-raid@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Subject: Re: [PATCH 1/3] PM suspend/hibernate: Call notifier after freezing processes
Date: Thu, 9 Apr 2015 08:36:57 +0200 [thread overview]
Message-ID: <201504090836.57365@pali> (raw)
In-Reply-To: <1530775.n2Kjx1bffW@vostro.rjw.lan>
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On Thursday 09 April 2015 02:28:41 Rafael J. Wysocki wrote:
> On Sunday, April 05, 2015 07:20:17 PM Pali Rohár 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.
> >
> > Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
>
> Please don't add more notifiers. Just call whatever you need
> directly from where you need to call that.
>
> If that is device-related, try to use device PM
> suspend/hibernate callbacks instead.
>
Hi! It is not possible to use any exiting pm notifiers! This is
reason why I added new ones. As I wrote wiping dm crypt keys must
be done *after* userspace processes are freezed to prevent race
conditions...
> > ---
> >
> > include/linux/suspend.h | 2 ++
> > kernel/power/hibernate.c | 2 ++
> > kernel/power/suspend.c | 4 +++-
> > 3 files changed, 7 insertions(+), 1 deletion(-)
> >
> > 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; }
> >
> > #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 */
> >
> > +#define PM_HIBERNATION_AFTER_FREEZE 0x0007 /* After
> > hibernation freeze */ +#define
> > PM_SUSPEND_AFTER_FREEZE 0x0008 /* After suspend freeze */
> >
> > extern struct mutex pm_mutex;
> >
> > 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)
> >
> > if (error)
> >
> > goto Exit;
> >
> > + pm_notifier_call_chain(PM_HIBERNATION_AFTER_FREEZE);
> > +
> >
> > lock_device_hotplug();
> > /* Allocate memory management structures */
> > error = create_basic_memory_bitmaps();
> >
> > 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)
> >
> > trace_suspend_resume(TPS("freeze_processes"), 0, true);
> > error = suspend_freeze_processes();
> > trace_suspend_resume(TPS("freeze_processes"), 0, false);
> >
> > - if (!error)
> > + if (!error) {
> > + pm_notifier_call_chain(PM_SUSPEND_AFTER_FREEZE);
> >
> > return 0;
> >
> > + }
> >
> > suspend_stats.failed_freeze++;
> > dpm_save_failed_step(SUSPEND_FREEZE);
--
Pali Rohár
pali.rohar@gmail.com
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next prev parent reply other threads:[~2015-04-09 6:37 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-05 17:20 [PATCH 0/3] dm-crypt: Adds support for wiping key when doing suspend/hibernation Pali Rohár
2015-04-05 17:20 ` [PATCH 1/3] PM suspend/hibernate: Call notifier after freezing processes Pali Rohár
2015-04-09 0:28 ` Rafael J. Wysocki
2015-04-09 6:36 ` Pali Rohár [this message]
2015-04-09 17:13 ` Rafael J. Wysocki
2015-04-09 16:55 ` Pali Rohár
2015-04-05 17:20 ` [PATCH 2/3] dm: Export function dm_suspend_md() Pali Rohár
2015-04-05 17:20 ` [PATCH 3/3] dm-crypt: Adds support for wiping key when doing suspend/hibernation Pali Rohár
2015-04-07 13:55 ` [dm-devel] " Alasdair G Kergon
2015-04-06 13:00 ` [PATCH 0/3] " Mike Snitzer
2015-04-06 13:25 ` Pavel Machek
2015-04-06 20:51 ` Mike Snitzer
2015-04-06 21:13 ` Why wipe crypto keys during suspend (was Re: [PATCH 0/3] dm-crypt: Adds support for wiping key when doing suspend/hibernation) Pavel Machek
2015-04-06 13:29 ` [PATCH 0/3] dm-crypt: Adds support for wiping key when doing suspend/hibernation Pali Rohár
2015-04-06 18:17 ` Pavel Machek
2015-04-06 21:27 ` Pali Rohár
2015-04-09 13:12 ` Mike Snitzer
2015-04-09 13:28 ` Pali Rohár
2015-04-09 14:08 ` Mike Snitzer
2015-04-09 14:16 ` Pali Rohár
2015-04-09 14:26 ` Mike Snitzer
2015-04-09 14:38 ` Pali Rohár
2015-04-14 6:50 ` Pavel Machek
2015-04-23 17:02 ` Pali Rohár
[not found] ` <mgnv2g$if5$2@ger.gmane.org>
2015-04-17 7:52 ` Mike Snitzer
2015-04-17 8:52 ` [dm-devel] " Ondrej Kozina
2015-04-17 15:53 ` Alex Elsayed
2015-04-14 6:41 ` Pavel Machek
2015-06-21 11:20 ` [PATCH v2 " Pali Rohár
2015-06-21 11:20 ` [PATCH v2 1/3] PM suspend/hibernate: Call notifier after freezing processes Pali Rohár
2015-07-16 1:02 ` Rafael J. Wysocki
2015-07-16 7:33 ` Pali Rohár
2015-07-17 23:27 ` Rafael J. Wysocki
2015-07-20 7:32 ` Pali Rohár
2015-07-20 21:46 ` Rafael J. Wysocki
2015-07-21 22:08 ` NeilBrown
2015-07-21 23:00 ` Rafael J. Wysocki
2015-07-21 23:03 ` Rafael J. Wysocki
2016-12-27 14:29 ` Pali Rohár
2015-06-21 11:20 ` [PATCH v2 2/3] dm: Export function dm_suspend_md() Pali Rohár
2015-07-17 14:04 ` Mike Snitzer
2015-07-17 14:22 ` Pali Rohár
2015-07-17 15:22 ` Mike Snitzer
2015-07-17 15:30 ` Mike Snitzer
2015-07-17 17:13 ` Pali Rohár
2015-07-17 17:31 ` Mike Snitzer
2015-06-21 11:20 ` [PATCH v2 3/3] dm-crypt: Adds support for wiping key when doing suspend/hibernation Pali Rohár
2015-07-28 14:44 ` Pavel Machek
2015-07-28 14:48 ` Pali Rohár
2015-07-07 7:59 ` [PATCH v2 0/3] " Pali Rohár
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