The patch titled
freezer: do not sync filesystems from freeze_processes
has been added to the -mm tree. Its filename is
freezer-do-not-sync-filesystems-from-freeze_processes.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: freezer: do not sync filesystems from freeze_processes
From: Rafael J. Wysocki <rjw@xxxxxxx>
The syncing of filesystems from within the freezer is generally not needed.
Also, if there's an ext3 filesystem loopback-mounted from a FUSE one, the
syncing results in writes to it and deadlocks. Similarly, it will deadlock if
FUSE implements sync.
Change freeze_processes() so that it doesn't execute sys_sync() and make the
suspend and hibernation code path sync filesystems independently of the
freezer.
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
Acked-by: Pavel Machek <pavel@xxxxxx>
Cc: Nigel Cunningham <nigel@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/power/disk.c | 4 ++++
kernel/power/main.c | 6 ++++++
kernel/power/process.c | 1 -
kernel/power/user.c | 4 ++++
4 files changed, 14 insertions(+), 1 deletion(-)
diff -puN kernel/power/disk.c~freezer-do-not-sync-filesystems-from-freeze_processes kernel/power/disk.c
--- a/kernel/power/disk.c~freezer-do-not-sync-filesystems-from-freeze_processes
+++ a/kernel/power/disk.c
@@ -312,6 +312,10 @@ int hibernate(void)
if (error)
goto Exit;
+ printk("Syncing filesystems ... ");
+ sys_sync();
+ printk("done.\n");
+
error = prepare_processes();
if (error)
goto Finish;
diff -puN kernel/power/main.c~freezer-do-not-sync-filesystems-from-freeze_processes kernel/power/main.c
--- a/kernel/power/main.c~freezer-do-not-sync-filesystems-from-freeze_processes
+++ a/kernel/power/main.c
@@ -20,6 +20,7 @@
#include <linux/resume-trace.h>
#include <linux/freezer.h>
#include <linux/vmstat.h>
+#include <linux/syscalls.h>
#include "power.h"
@@ -228,9 +229,14 @@ static int enter_state(suspend_state_t s
if (!valid_state(state))
return -ENODEV;
+
if (!mutex_trylock(&pm_mutex))
return -EBUSY;
+ printk("Syncing filesystems ... ");
+ sys_sync();
+ printk("done.\n");
+
pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
if ((error = suspend_prepare()))
goto Unlock;
diff -puN kernel/power/process.c~freezer-do-not-sync-filesystems-from-freeze_processes kernel/power/process.c
--- a/kernel/power/process.c~freezer-do-not-sync-filesystems-from-freeze_processes
+++ a/kernel/power/process.c
@@ -191,7 +191,6 @@ int freeze_processes(void)
if (error)
return error;
- sys_sync();
error = try_to_freeze_tasks(FREEZER_KERNEL_THREADS);
if (error)
return error;
diff -puN kernel/power/user.c~freezer-do-not-sync-filesystems-from-freeze_processes kernel/power/user.c
--- a/kernel/power/user.c~freezer-do-not-sync-filesystems-from-freeze_processes
+++ a/kernel/power/user.c
@@ -153,6 +153,10 @@ static int snapshot_ioctl(struct inode *
mutex_lock(&pm_mutex);
error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
if (!error) {
+ printk("Syncing filesystems ... ");
+ sys_sync();
+ printk("done.\n");
+
error = freeze_processes();
if (error)
thaw_processes();
_
Patches currently in -mm which might be from rjw@xxxxxxx are
git-acpi.patch
pm-move-definition-of-struct-pm_ops-to-suspendh.patch
pm-rename-struct-pm_ops-and-related-things.patch
pm-rework-struct-platform_suspend_ops.patch
pm-fix-compilation-of-suspend-code-if-config_pm-is-unset.patch
pm-make-suspend_ops-static.patch
pm-rework-struct-hibernation_ops.patch
pm-rename-hibernation_ops-to-platform_hibernation_ops.patch
freezer-document-relationship-with-memory-shrinking.patch
freezer-do-not-sync-filesystems-from-freeze_processes.patch
freezer-prevent-new-tasks-from-inheriting-tif_freeze-set.patch
freezer-introduce-freezer-firendly-waiting-macros.patch
freezer-do-not-send-signals-to-kernel-threads.patch
shrink_slab-handle-bad-shrinkers.patch
-
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