xfs: start periodic workers later

Start the periodic sync workers only after we have finished xfs_mountfs
and thus fully set up the filesystem structures.  Without this we can
call into xfs_qm_sync before the quotainfo strucute is set up if the
mount takes unusually long, and probably hit other incomplete states
as well.

Also clean up the xfs_fs_fill_super error path by using consistent
label names, and removing an impossible to reach case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Arkadiusz Miskiewicz <arekm@maven.pl>
Reviewed-by: Alex Elder <aelder@sgi.com>

fs/xfs/linux-2.6/xfs_super.c

@@ -1412,37 +1412,35 @@ xfs_fs_fill_super(
 	sb->s_time_gran = 1;
 	set_posix_acl_flag(sb);
 
-	error = xfs_syncd_init(mp);
-	if (error)
-		goto out_filestream_unmount;
-
 	xfs_inode_shrinker_register(mp);
 
 	error = xfs_mountfs(mp);
 	if (error)
-		goto out_syncd_stop;
+		goto out_filestream_unmount;
+
+	error = xfs_syncd_init(mp);
+	if (error)
+		goto out_unmount;
 
 	root = igrab(VFS_I(mp->m_rootip));
 	if (!root) {
 		error = ENOENT;
-		goto fail_unmount;
+		goto out_syncd_stop;
 	}
 	if (is_bad_inode(root)) {
 		error = EINVAL;
-		goto fail_vnrele;
+		goto out_syncd_stop;
 	}
 	sb->s_root = d_alloc_root(root);
 	if (!sb->s_root) {
 		error = ENOMEM;
-		goto fail_vnrele;
+		goto out_iput;
 	}
 
 	return 0;
 
- out_syncd_stop:
-	xfs_inode_shrinker_unregister(mp);
-	xfs_syncd_stop(mp);
  out_filestream_unmount:
+	xfs_inode_shrinker_unregister(mp);
 	xfs_filestream_unmount(mp);
  out_free_sb:
 	xfs_freesb(mp);
@@ -1456,17 +1454,12 @@ xfs_fs_fill_super(
  out:
 	return -error;
 
- fail_vnrele:
-	if (sb->s_root) {
-		dput(sb->s_root);
-		sb->s_root = NULL;
-	} else {
-		iput(root);
-	}
-
- fail_unmount:
-	xfs_inode_shrinker_unregister(mp);
+ out_iput:
+	iput(root);
+ out_syncd_stop:
 	xfs_syncd_stop(mp);
+ out_unmount:
+	xfs_inode_shrinker_unregister(mp);
 
 	/*
 	 * Blow away any referenced inode in the filestreams cache.