reiserfs: shrink superblock if no xattrs

This makes in-core superblock fit into one cacheline here.

Before:
    struct dentry *            xattr_root;           /*   124     4 */
    /* --- cacheline 1 boundary (128 bytes) --- */
    struct rw_semaphore        xattr_dir_sem;        /*   128    12 */
    int                        j_errno;              /*   140     4 */
    }; /* size: 144, cachelines: 2 */
       /* sum members: 142, holes: 1, sum holes: 2 */
       /* last cacheline: 16 bytes */

After:
    int                        j_errno;              /*   124     4 */
    /* --- cacheline 1 boundary (128 bytes) --- */
    }; /* size: 128, cachelines: 1 */
       /* sum members: 126, holes: 1, sum holes: 2 */

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index 7054aae..5c58b41 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -433,12 +433,13 @@
 static void reiserfs_kill_sb(struct super_block *s)
 {
 	if (REISERFS_SB(s)) {
+#ifdef CONFIG_REISERFS_FS_XATTR
 		if (REISERFS_SB(s)->xattr_root) {
 			d_invalidate(REISERFS_SB(s)->xattr_root);
 			dput(REISERFS_SB(s)->xattr_root);
 			REISERFS_SB(s)->xattr_root = NULL;
 		}
-
+#endif
 		if (REISERFS_SB(s)->priv_root) {
 			d_invalidate(REISERFS_SB(s)->priv_root);
 			dput(REISERFS_SB(s)->priv_root);
@@ -1562,9 +1563,10 @@
 	REISERFS_SB(s)->s_alloc_options.preallocmin = 0;
 	/* Preallocate by 16 blocks (17-1) at once */
 	REISERFS_SB(s)->s_alloc_options.preallocsize = 17;
+#ifdef CONFIG_REISERFS_FS_XATTR
 	/* Initialize the rwsem for xattr dir */
 	init_rwsem(&REISERFS_SB(s)->xattr_dir_sem);
-
+#endif
 	/* setup default block allocator options */
 	reiserfs_init_alloc_options(s);