ext4: force block allocation on quota_off

Perform full sync procedure so that any delayed allocation blocks are
allocated so quota will be consistent.
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/super.c

@@ -1118,6 +1118,7 @@ static int ext4_mark_dquot_dirty(struct dquot *dquot);
 static int ext4_write_info(struct super_block *sb, int type);
 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 				char *path);
+static int ext4_quota_off(struct super_block *sb, int type);
 static int ext4_quota_on_mount(struct super_block *sb, int type);
 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 			       size_t len, loff_t off);
@@ -1139,7 +1140,7 @@ static const struct dquot_operations ext4_quota_operations = {
 
 static const struct quotactl_ops ext4_qctl_operations = {
 	.quota_on	= ext4_quota_on,
-	.quota_off	= dquot_quota_off,
+	.quota_off	= ext4_quota_off,
 	.quota_sync	= dquot_quota_sync,
 	.get_info	= dquot_get_dqinfo,
 	.set_info	= dquot_set_dqinfo,
@@ -4098,6 +4099,18 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 	return err;
 }
 
+static int ext4_quota_off(struct super_block *sb, int type)
+{
+	/* Force all delayed allocation blocks to be allocated */
+	if (test_opt(sb, DELALLOC)) {
+		down_read(&sb->s_umount);
+		sync_filesystem(sb);
+		up_read(&sb->s_umount);
+	}
+
+	return dquot_quota_off(sb, type);
+}
+
 /* Read data from quotafile - avoid pagecache and such because we cannot afford
  * acquiring the locks... As quota files are never truncated and quota code
  * itself serializes the operations (and noone else should touch the files)