Commit 232b1432 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
Browse files

freezer: do not sync filesystems from freeze_processes 



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: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 27763653

kernel/power/disk.c

+4 −0
Original line number Diff line number Diff line
@@ -313,6 +313,10 @@ int hibernate(void) 
	if (error)

		goto Exit;



	printk("Syncing filesystems ... ");

	sys_sync();

	printk("done.\n");



	error = prepare_processes();

	if (error)

		goto Finish;

kernel/power/main.c

+6 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/resume-trace.h>

#include <linux/freezer.h>

#include <linux/vmstat.h>

#include <linux/syscalls.h>



#include "power.h"
@@ -230,9 +231,14 @@ static int enter_state(suspend_state_t state) 


	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;

kernel/power/process.c

+0 −1
Original line number Diff line number Diff line
@@ -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;

kernel/power/user.c

+4 −0
Original line number Diff line number Diff line
@@ -153,6 +153,10 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, 
		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();

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