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>

fs/reiserfs/dir.c

@@ -44,13 +44,11 @@ static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
 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,

fs/reiserfs/super.c

@@ -898,6 +898,7 @@ static int reiserfs_parse_options(struct super_block *s, char *options,	/* strin
 		{"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},

fs/reiserfs/xattr.c

@@ -981,7 +981,8 @@ int reiserfs_lookup_privroot(struct super_block *s)
 				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

include/linux/reiserfs_fs_sb.h

@@ -453,6 +453,7 @@ enum reiserfs_mount_options {
 	REISERFS_ATTRS,
 	REISERFS_XATTRS_USER,
 	REISERFS_POSIXACL,
+	REISERFS_EXPOSE_PRIVROOT,
 	REISERFS_BARRIER_NONE,
 	REISERFS_BARRIER_FLUSH,
 
@@ -490,6 +491,7 @@ enum reiserfs_mount_options {
 #define reiserfs_data_writeback(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_DATA_WRITEBACK))
 #define reiserfs_xattrs_user(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_XATTRS_USER))
 #define reiserfs_posixacl(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_POSIXACL))
+#define reiserfs_expose_privroot(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_EXPOSE_PRIVROOT))
 #define reiserfs_xattrs_optional(s) (reiserfs_xattrs_user(s) || reiserfs_posixacl(s))
 #define reiserfs_barrier_none(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_BARRIER_NONE))
 #define reiserfs_barrier_flush(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_BARRIER_FLUSH))