reiserfs: get rid of resierfs_sync_super

This patch stops reiserfs using the VFS 'write_super()' method along with the
s_dirt flag, because they are on their way out.

The whole "superblock write-out" VFS infrastructure is served by the
'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and
writes out all dirty superblock using the '->write_super()' call-back.  But the
problem with this thread is that it wastes power by waking up the system every
5 seconds, even if there are no diry superblocks, or there are no client
file-systems which would need this (e.g., btrfs does not use
'->write_super()'). So we want to kill it completely and thus, we need to make
file-systems to stop using the '->write_super()' VFS service, and then remove
it together with the kernel thread.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/reiserfs/reiserfs.h b/fs/reiserfs/reiserfs.h
index 5c70055..33215f5 100644
--- a/fs/reiserfs/reiserfs.h
+++ b/fs/reiserfs/reiserfs.h
@@ -480,6 +480,11 @@
 	struct dentry *priv_root;	/* root of /.reiserfs_priv */
 	struct dentry *xattr_root;	/* root of /.reiserfs_priv/xattrs */
 	int j_errno;
+
+	int work_queued;              /* non-zero delayed work is queued */
+	struct delayed_work old_work; /* old transactions flush delayed work */
+	spinlock_t old_work_lock;     /* protects old_work and work_queued */
+
 #ifdef CONFIG_QUOTA
 	char *s_qf_names[MAXQUOTAS];
 	int s_jquota_fmt;
@@ -2487,6 +2492,7 @@
 int reiserfs_allocate_list_bitmaps(struct super_block *s,
 				   struct reiserfs_list_bitmap *, unsigned int);
 
+void reiserfs_schedule_old_flush(struct super_block *s);
 void add_save_link(struct reiserfs_transaction_handle *th,
 		   struct inode *inode, int truncate);
 int remove_save_link(struct inode *inode, int truncate);