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>

1 files changed, 4 insertions, 0 deletions

diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 9348d95a4fb8..555c0f0b2f7e 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -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;