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: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Rafael J. Wysocki 2007-10-18 03:04:44 -07:00 committed by Linus Torvalds
parent 2776365370
commit 232b143280
4 changed files with 14 additions and 1 deletions

View file

@ -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;

View file

@ -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;

View file

@ -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;

View file

@ -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();