reiserfs: allow exposing privroot w/ xattrs enabled

This patch adds an -oexpose_privroot option to allow access to the privroot.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/reiserfs/dir.c b/fs/reiserfs/dir.c
index 45ee3d3..6d2668f 100644
--- a/fs/reiserfs/dir.c
+++ b/fs/reiserfs/dir.c
@@ -44,13 +44,11 @@
 static inline bool is_privroot_deh(struct dentry *dir,
 				   struct reiserfs_de_head *deh)
 {
-	int ret = 0;
-#ifdef CONFIG_REISERFS_FS_XATTR
 	struct dentry *privroot = REISERFS_SB(dir->d_sb)->priv_root;
-	ret = (dir == dir->d_parent && privroot->d_inode &&
-	       deh->deh_objectid == INODE_PKEY(privroot->d_inode)->k_objectid);
-#endif
-	return ret;
+	if (reiserfs_expose_privroot(dir->d_sb))
+		return 0;
+	return (dir == dir->d_parent && privroot->d_inode &&
+	        deh->deh_objectid == INODE_PKEY(privroot->d_inode)->k_objectid);
 }
 
 int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index 3567fb9..9dbdcfb 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -898,6 +898,7 @@
 		{"conv",.setmask = 1 << REISERFS_CONVERT},
 		{"attrs",.setmask = 1 << REISERFS_ATTRS},
 		{"noattrs",.clrmask = 1 << REISERFS_ATTRS},
+		{"expose_privroot", .setmask = 1 << REISERFS_EXPOSE_PRIVROOT},
 #ifdef CONFIG_REISERFS_FS_XATTR
 		{"user_xattr",.setmask = 1 << REISERFS_XATTRS_USER},
 		{"nouser_xattr",.clrmask = 1 << REISERFS_XATTRS_USER},
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 8e7deb0..f3d47d8 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -981,7 +981,8 @@
 				strlen(PRIVROOT_NAME));
 	if (!IS_ERR(dentry)) {
 		REISERFS_SB(s)->priv_root = dentry;
-		s->s_root->d_op = &xattr_lookup_poison_ops;
+		if (!reiserfs_expose_privroot(s))
+			s->s_root->d_op = &xattr_lookup_poison_ops;
 		if (dentry->d_inode)
 			dentry->d_inode->i_flags |= S_PRIVATE;
 	} else